POWER TRANSMISSION SYSTEM

Abstract

The present disclosure relates to a power transmission system 100 for mechanical implements, for transference of power from a power shaft 101 associated with a prime mover of the mechanical implement to an output shaft 102 of the mechanical implement arranged in a non-collinear manner with respect to the power shaft 101. A segmented pulley 103 is provided, composed of a first segment 104 configured for mounting onto the power shaft 101 or the output shaft 102 and a second segment 110 having radially disposed serrated elements 112, detachably mounted on the first segment 104 and adapted to engage with a flexible transmission member 113 for conveying motion from the power shaft 101 to the output shaft 102. The instant disclosure also pertains to a method for the assembly of the first segment 104 and the second segment 110 of the segmented pulley 103.

Specification

Description:FIELD OF THE DISCLOSURE

[0001] The present disclosure relates to the field of power transmission systems. More particularly, the disclosure pertains to a power transmission system for transfer of power from a prime mover to an output shaft of a mechanical implement.

BACKGROUND OF THE DISCLOSURE

[0002] A mechanical implement refers to a tool, device, or machine that is designed to perform a specific function or task through mechanical means. Typically, such mechanical implements include various mechanical components adapted to convert and transmit forces to perform work more efficiently than could be done manually. These mechanical components generally include a prime mover for generating power and a mechanism for conveying the power generated from the prime mover to an output shaft.

[0003] Conventionally, most mechanical implements include prime movers designed to generate power in the form of rotational motion. Commonly used prime movers such as internal combustion (IC) engines, electric motors, pneumatic motors, steam turbines, hydraulic turbines, wind turbines, etc., output the generated power by means of a rotation of a power shaft associated with the prime mover. The rotational motion of the power shaft is transferred to the output shaft of the mechanical implement to achieve the intended end effect. In cases of mechanical implements having the power shaft arranged parallel to the output shaft such that the power and output shafts are not collinear, the preferred technique for transference of power from the power shaft to the output shaft is to connect the power and the output shafts with a flexible looped element. The looped element is engaged with the power and the output shafts for continuously transmitting rotational motion from the axis of rotation of the power shaft to the axis of the output shaft for rotation of the output shaft.

[0004] Mechanical implements in consideration include automobiles, conveyor belts, machining apparatus such as lathes, mills, agricultural machinery, elevators, escalators, hoists, chain lifts, etc. Elevators, installed in high-rise buildings, are a type of mechanical implement that requires the transmission of motion from a power shaft associated with an electric motor to the output shaft of an elevator car. Typically, each of the shafts is configured with a pulley, such that a cable or a rope functioning as the looped element is coupled with the pulleys and a set of intermediary pulleys for transferring motion from the electric motor to the elevator car for lifting or lowering of the elevator car. Various industrial lifting machineries such as hoists function on a principally equivalent mechanism. Escalators, often provided in commercial facilities, implement a chain drive to continuously rotate an endless flight of stairs, which are rotated by a motor, where a chain, functioning as the looped element, connects a power shaft associated with the motor configured with a sprocket with the output shaft of the stairs provided with another sprocket.

[0005] In the specific context of automobiles, an automobile is configured with a prime mover for generating power and an arrangement for transmitting the power generated from the prime mover to the wheels of the automobile. For instance, automobiles may be energized by internal combustion (IC) engines as the prime movers. Alternatively, in a bid to combat pollution caused by vehicular emissions, the industry also manufactures automobiles where electric motors serve the purpose of the prime movers. Electrically powered automobiles implement mechanisms for the transference of motion produced by the prime mover to the wheels of the automobile. Some of the most commonly implemented power transmission systems for the transmission of power from the prime mover to the wheels, include belt drives and chain drives.

[0006] Belt drives and chain drives essentially involve a belt and a chain functioning as the looped element, mechanically engaged with a power shaft associated with the prime mover and an output shaft associated with the wheels of the automobile to convey the rotation of the power shaft to the output shaft. The power and output shafts are provided with structures capable of positively engaging with the belt or the chain to prevent occurrence of slippage between the belt or chain and the power and output shafts. In the case of belt drives, pulleys are disposed on the shafts, having a groove on an outer surface. The groove accommodates a cross-section of the belt for maximizing friction. In chain drives, sprockets are mounted on the shafts, such that the teeth of the sprockets insert into the roller pockets between rollers of the chain to acquire the positive mechanical engagement for transference of motion. Another type of belt drive employs a pulley having several ribs carved along the outer surface. A timing belt is configured with cavities to accommodate the ribs of the pulley for a mechanical coupling.

[0007] During the ordinary course of power transmission, the power transmission system bears a number of mechanical loads. Focusing specifically on the pulley or the sprocket, the ribs and the teeth undergo various types of loading including shear loading, impact loading, fatigue loading, angular loading, corrosion, etc., which lead to inevitable wear and tear of the pulley or the sprocket, eventually necessitating a replacement of the pulley or the sprocket.

[0008] Primarily considering belt drives, the pulleys are typically made of cast aluminium. To further augment the life of the pulley, coatings made of specialized materials are applied onto the cast aluminium pulleys. The application of these coatings serves to enhance the durability of the pulley against the mechanical loads generated during the operation of the mechanical implement. The specialized materials that improve the mechanical characteristics of the pulley include compounds such as Tungsten Carbide, Chromium Carbide, Cobalt-Chromium alloy, etc. Since these coatings contain rare earth elements, the process of procuring and coating cast aluminium pulleys is substantially expensive thereby increasing production costs. Consequently, the cost of replacement or repair of the pulley is also significantly increased for routine maintenance of the automobile.

[0009] Alternate power transmission solutions, other than chain drives having sprockets connected by a chain and belt drives having pulleys coupled by a belt, include rope drives. The rope drives, which are fundamentally equivalent to chain drives and belt drives, are composed of sheaves that are engaged with one another by a rope or a cable. The sheaves are structurally similar to pulleys and have a surface for seating of the rope or cable instead of the belt. None of the implementations utilized in the prior art suggest a composite mechanism separating the more stressed and worn and torn portion of the pulley, from the core structure of the pulley. None of the solutions of the prior art provide a composite structure aiding to reduce the production and maintenance costs of the power transmission system.

[0010] To overcome the aforementioned drawbacks, there exists a need in the art to develop a more economically-producible power transmission system that eliminates the need for application of such coatings over the pulleys by conceptualizing a segmented pulley which is segmented into two parts. The more stressed and worn and torn portion of the segmented pulley, i.e., the part having the ribs, is attached, in a rigid but removable manner, on to body which is configured to be coupled onto the shaft. Therefore, in case the segmented pulley is rendered impaired due to an excessive damage or deformation of the ribs, specifically the part of the segmented pulley containing the ribs is replaced, thus significantly bringing down the maintenance cost.

OBJECTS OF THE DISCLOSURE

[0011] The principal object of the present disclosure is to overcome the disadvantages of the prior art.

[0012] One of the main objects of the present disclosure is to provide a power transmission system for mechanical implements having significantly reduced production and maintenance costs.

[0013] Another object of the present disclosure is to develop a power transmission system that is modular in nature thereby enabling selective replacement of the impaired portions to reduce production and maintenance cost.

[0014] Another object of the present disclosure is to conceive a power transmission system fabricated from a material having mechanical characteristics more resistive towards wear and tear, along with a base portion of the power transmission system constructed from a lighter material, thus reducing the production cost of the power transmission system as well as the overall mass of the power transmission system.

[0015] Another object of the present disclosure is to design the power transmission system in a manner to allow for the retrofitting of the power transmission system with an existing mechanical implement to reduce operational expenditure of the mechanical implement by reducing maintenance cost.

[0016] Yet another object of the instant disclosure is to configure the power transmission system to be adaptable for belt drives, chain drives, rope and cable drives.

[0017] The foregoing and other objects, features, and advantages of the present disclosure will become readily apparent upon further review of the following detailed description of the preferred embodiment as illustrated in the accompanying drawings.

SUMMARY OF THE DISCLOSURE

[0018] This summary is provided to introduce a selection of concepts in a simplified format that are further described in the detailed description of the disclosure. This summary is not intended to identify key or essential inventive concepts of the disclosure, nor is it intended for determining the scope of the disclosure.

[0019] The present disclosure relates to a power transmission system for mechanical implements, for transference of power from a power shaft associated with a prime mover of the mechanical implement to the output shaft of the mechanical implement arranged in a non-collinear manner with respect to the power shaft. The instant disclosure aims to design a segmented pulley adaptable for a belt drive, chain drive, rope drive-type power transmission system, such that the segmented pulley is rendered to be adaptable for various types of existing power transmission systems by incorporating a composite construction. The construction of the segmented pulley also enables a selecting replacement or repair in case of an impairment of the segmented pulley.

[0020] In accordance with an embodiment of the present disclosure, a segmented pulley adapted to be mounted on at least one of a power shaft and an output shaft of a power transmission system, the segmented pulley including a first segment including a planar base hub and a cylindrical seat extending orthogonally from a side of the planar base hub and coaxial relative to the planar base hub, and a second segment including an annular ring adapted to be removably secured onto an outer lateral face of the cylindrical seat, such that an outer lateral surface of the annular ring defines a multitude of serrated elements.

[0021] According to another embodiment of the present disclosure, the power transmission system for a mechanical implement, includes a power shaft connected to a prime mover, an output shaft configured to impart an intended end effect of the mechanical implement, such that the output shaft is positioned non-collinearly with respect to the power shaft. The power transmission system is further provided with a segmented pulley fastened on at least one of the power and the output shafts, such that the segmented pulley is composed of a first segment, having a planar base hub adapted to be coupled with at least one of the power and the output shafts, and a cylindrical seat protruding orthogonally on a side of the planar base hub in a coaxial manner, and a second segment, including an annular ring configured to be detachably secured onto an outward lateral face of the cylindrical seat, and a multitude of serrated elements uniformly incorporated along an outer lateral surface of the annular ring.

[0022] According to an embodiment of the present disclosure, a flexible transmission member that is looped around the segmented pulley for connecting the power and the output shafts for transmission of power from the prime mover to the output shaft to achieve the required end effect of the mechanical implement, such that the flexible transmission member is configured to mechanically engage with the serrated elements of the second segment to enable a transmission of power between the flexible transmission member and the segmented pulley. An inner region of the flexible transmission member is crafted with a series of protrusions to impart a pattern equivalent to the serrated elements formed over the outer lateral surface of the second segment to enable a mechanical engagement of the flexible transmission member with the second segment without slippage.

[0023] According to another embodiment of the present disclosure, the first segment includes a bore fabricated centrally through the planar base hub for enabling a passage of one of the the power shaft and the output shaft and several slots disposed radially around the bore to enable a positive mechanical engagement of the first segment with one of the the power shaft and the output shaft.

[0024] In accordance with yet another embodiment of the present disclosure, a method for the assembling of the first and the second segments of a segmented pulley, has been provided, which includes the steps of having a first segment with a cylindrical seat having an outer diameter d1, acquiring a second segment with an annular ring of an inner diameter d2, such that the inner diameter d2 of the annular ring is lesser than the outer diameter d1 of the cylindrical seat. Next, the second segment is heated to cause thermal expansion of the second segment. Thereafter, the first segment and the second segment are assembled by coaxially aligning the first and the second segments and sliding the annular ring of the second segment onto the cylindrical seat of the first segment. Finally, equalizing the temperatures of the assembled first and second segments with the ambient temperature for affixing the second segment over the first segment.

[0025] To further clarify the advantages and features of the method and system, a more particular description of the method and system will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawing. It is appreciated that these drawings depict only typical embodiments of the disclosure and are therefore not to be considered limiting its scope. The disclosure will be described and explained with additional specificity and detail with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description and appended claims are read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Figure 1 exemplarily illustrates an isometric view of a power transmission system according to an embodiment of the disclosure;
Figure 2 exemplarily illustrates a side view of the power transmission system;
Figure 3 exemplarily illustrates an isometric view of an assembled segmented pulley according to an embodiment of the disclosure;
Figure 4 exemplarily illustrates an exploded view of the segmented pulley shown in Figure 3;
Figure 5 exemplarily illustrates an isometric view of an alternative embodiment of the power transmission system;
Figure 6 exemplarily illustrates an isometric view of the segmented pulley installed over a rotating body of a mechanical implement;
Figure 7 exemplarily illustrates an exploded view of the segmented pulley shown in Figure 6;
Figure 8 exemplarily illustrates a top view of the segmented pulley shown in Figure 6; and
Figure 9 exemplarily illustrates a flow diagram depicting a method for assembling the segmented pulley.

[0027] Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the disclosure. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the disclosure so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0028] The following description includes the preferred best mode of one embodiment of the present disclosure. It will be clear from this description of the disclosure that the disclosure is not limited to these illustrated embodiments but that the disclosure also includes a variety of modifications and embodiments thereto. Therefore, the present description should be seen as illustrative and not limiting. While the disclosure is susceptible to various modifications and alternative constructions, it should be understood, that there is no intention to limit the disclosure to the specific form disclosed, but, on the contrary, the disclosure is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the disclosure as defined in the claims.

[0029] In any embodiment described herein, the open-ended terms "comprising," "comprises," and the like (which are synonymous with "including," "having" and "characterized by") may be replaced by the respective partially closed phrases "consisting essentially of," consists essentially of," and the like or the respective closed phrases "consisting of," "consists of, the like.

[0030] As used herein, the singular forms "a," "an," and "the" designate both the singular and the plural, unless expressly stated to designate the singular only.

[0031] The present disclosure relates to a power transmission system 100 for mechanical implements including automobiles, conveyor belts, machining apparatus such as lathes, mills, agricultural machinery, elevators, escalators, hoists, chain lifts, etc., where motion is required to be transmitted between a pair of non-collinear shafts, i.e., from a power shaft connected with a power shaft associated with a mechanical implement, to an output shaft of the mechanical implement, where the intended end effect of the mechanical implement is realized. Many mechanical implements, such as lifts, hoists, employ a multitude of intermediate shafts installed with pulleys, provided between the power shaft and the output shaft for achieving a desired mechanical advantage.

[0032] The prime mover, as mentioned in the present disclosure, refers to arrangements used for the conversion of potential energy into kinetic energy to provide actuation in the form of a rotation of a structure. Prime movers, thus, include, but are not limited to, internal combustion (IC) engines fueled by petrol, diesel or any other working fluid, electric motors energized by a battery pack storing electrical energy, tidal or wind turbines, and steam engines.

[0033] The output of the prime mover is delivered in a form of a rotational motion of the power shaft associated with the prime mover. Similarly, a shaft-like structure is incorporated with the output of the mechanical implement, referred to as the output shaft of the mechanical implement, for imparting the intended end effect, such as propulsion of automobiles, lifting motion of lifts and escalators, hoists, etc. The present disclosure relates to a power transmission system for a transference of motion from the power shaft and the output shaft.

[0034] The instant description includes one or more embodiments of the power transmission system 100 employing one or more intermediate shafts arranged in relation with the power shaft and the output shaft.

[0035] Figure 1 exemplarily illustrates an isometric view of a power transmission system 100 according to an embodiment of the disclosure. Figure 2 exemplarily illustrates a side view of the power transmission system 100. The power transmission system 100 primarily includes a power shaft 101 and an output shaft 102 and a means for mechanically connecting the power shaft 101 and the output shaft 102 to enable a transference of power from the power shaft 101 to the output shaft 102. In an embodiment according to the present disclosure, the power shaft 101 and the output shaft 102 are substantially cylindrical rigid elongated bodies. Both of the power shaft 101 and the output shaft 102 are configured with rigidly mounted segmented pulleys 103 to facilitate mechanical engagement between the power shaft 101 and the output shaft 102. The power transmission system 100 also includes a flexible transmission member 113 looped over both the segmented pulleys 103 for mechanically connecting the two segmented pulleys 103 with one another, and in turn the power shaft 101 and the output shaft 102 for transferring motion from the power shaft 101 to the output shaft 102.

[0036] The term "substantially cylindrical" as used in the present disclosure to describe the power shaft 101 and the output shaft 102, includes shafts having shapes deviating from a straight cylinder, including tapered shafts with at least one narrow end, splined shafts having multiple scores along the length, square shaft providing a non-slip fit without requiring scores along the surface of the shaft, and shafts crafted with other polygonal cross-sections.

[0037] The flexible transmission member 113 has an endless construction, i.e., the flexible transmission member 113 does not have any open ends and essentially forms a continuous loop. Additionally, the flexible structure of the flexible transmission member 113 enables it to be bent and twisted without breaking.

[0038] It will be appreciated that Figure 1 illustrates an exemplary embodiment of the power transmission system 100 where one of the segmented pulleys 103 is depicted to be of smaller dimensions compared to the other segmented pulley 103, to enable a specific mechanical advantage between the power shaft 101 and the output shaft 102. Other embodiments of the present disclosure may include segmented pulleys 103 of different dimensions based on the intended loading of the mechanical implement and the mechanical advantage to be applied for bearing the intended load. The segmented pulley 103 installed over the output shaft 102 maybe selected to have a diameter half that of the diameter of the segmented pulley 103 disposed with the power shaft 101 in order to achieve a mechanical advantage of two.

[0039] Figure 3 exemplarily illustrates an isometric view of an assembled segmented pulley 103 according to an embodiment of the disclosure. The segmented pulley 103 of the present disclosure follows a two-part design having a first segment 104 and a second segment 110 detachably assembled with one another to form the entirety of the segmented pulley 103.

[0040] Figure 4 exemplarily illustrates an exploded view of the segmented pulley 103 shown in Figure 3. The first segment 104 of the segmented pulley 103, installed over the output shaft 102, includes a planar base hub 105 adapted to be installed over either or both of the power shaft 101 and the output shaft 102. An opening, herein referred to as a bore 108, is disposed at a geometrical center of the planar base hub 105 through which an end of the the power shaft 101 or the output shaft 102 is inserted for installation of the first segment 104 onto the the power shaft 101 or the output shaft 102. In an embodiment, several slots 109 are formed in the planar base hub 105 in a radially symmetrical manner surrounding the bore 108. The bore 108 is centrally located and may be adapted to mate with a coupler sleeved rigidly onto the power shaft 101 or the output shaft 102 for the fastening of the the power shaft 101 or the output shaft 102 with the first segment 104. The bore 108 may be coupled to the power shaft 101 or the output shaft 102 in a manner to prevent a relative rotational motion between the the power shaft 101 or the output shaft 102 and the first segment 104.

[0041] In an embodiment of the present disclosure, the bore 108 and the slots 109 are through holes through the thickness of the planar base hub 105 to enable a complete passing of the the power shaft 101 or the output shaft 102 and the coupler through the bore 108 and the slots 109, respectively. In another embodiment of the instant disclosure, one or both of the bore 108 and the slots 109 are machined partially through the thickness of the planar base hub 105 for a partial insertion of the the power shaft 101 or the output shaft 102 and the coupler into the bore 108 and the slots 109, respectively.

[0042] In one embodiment of the present disclosure, a singular or a multitude of keyways are fabricated along an outer periphery of the bore 108 of the first segment 104 to allow a passage of one or several keys integrally located over a lateral surface of the the power shaft 101 or the output shaft 102. The passage of the keys through the keyways locks the first segment 104 onto the the power shaft 101 or the output shaft 102.

[0043] A cylindrical seat 106 is integrally formed onto a side 107 of the planar base hub 105 with the longitudinal axis of the cylindrical seat 106 being perpendicular to the plane of the planar base hub 105 and the longitudinal axis being coincident with the central axis of the planar base hub 105, thus the cylindrical seat 106 is disposed coaxially onto the planar base hub 105. The cylindrical seat 106 has an outer lateral face 401 which has a height w1 measured orthogonally from the side 107 of the planar base hub 105, on which the cylindrical seat 106 is integrated. An outer lateral face 401 of the cylindrical seat 106 is configured to enable a mounting of the second segment 110 on the cylindrical seat 106 in a detachable manner.

[0044] The second segment 110 is primarily composed of an annular ring 111, which is a cylindrical body having an inner lateral surface 402 and an outer lateral surface 301, where the inner lateral surface 402 is affixed onto the outer lateral face 401 of the cylindrical seat 106 of the planar base hub 105 in a removable manner. The width of the annular ring 111, more specifically, the width of the inner lateral surface 402 of the annular ring 111 is denoted by w2. In one embodiment of the present disclosure, the width w2 of the second segment 110 and the height w1 of the cylindrical seat 106 are selected to be equivalent to ensure a complete surface to surface contact between inner lateral surface 402 of the annular ring 111 and the outer lateral face 401 of the cylindrical seat 106 of the first segment 104.

[0045] In another embodiment of the power transmission system 100, where the mechanical load is comparatively low leading to a reduction in the requirement of traction between the outer lateral surface 301 of the annular ring 111 for the transfer of motion, the inner region 114 of the flexible transmission member 113 is selected to have a flat profile and consequently, the outer lateral surface 301 of the annular ring 111 as well is fabricated to have a flat profile for producing optimum static friction for conveying power.

[0046] The outer lateral surface 301 of the annular ring 111 is provided with a multitude of serrated elements 112 spaced in a radially symmetrical manner. The stated serrated elements 112 are rigid projections developed to mechanically engage with a flexible transmission member 113 looped over the annular ring 111. The flexible transmission member 113 is configured to mechanically engage with the serrated elements 112 of the annular ring 111 to enable a transmission of power between the flexible transmission member 113 and the segmented pulley 103. A series of protrusions 115 of the flexible transmission member 113 interlock with the serrated elements 112 to provide a positive mechanical contact between the flexible transmission member 113 and the segmented pulley 103.

[0047] In an exemplary implementation of the present disclosure illustrated in the Figure 1, the segmented pulley 103 of the present disclosure is installed on both the power shaft 101 and the output shaft 102 of the mechanical implement. The segmented pulley 103 incorporated over the power shaft 101 is structurally equivalent to the segmented pulley 103 coupled with the output shaft 102. The dimensions of the segmented pulleys 103 are selected as per a required mechanical advantage or gear ratio of the mechanical implement and accordingly the flexible transmission member 113 of characteristics compatible with the segmented pulleys 103 is looped over the segmented pulleys 103 to enable transmission of motion.

[0048] To configure the mechanical implement to be belt driven, the flexible transmission member 113 is selected to be a belt having several consecutively located hollow grooves formed between the protrusions 115 disposed along an inner region 114 of the belt. To facilitate the belt drive, the serrated elements 112 of the annular ring 111 are chosen to be protruding blunt ribs shaped to be complementary to the grooves, i.e., similar to the pattern crafted over the outer lateral surface 301 of the annular ring 111 for enabling a positive mechanical engagement between the flexible transmission member 113 and the segmented pulleys 103 and in-turn between the power shaft 101 and the output shaft 102. In another example of the instant application, the ribs on the outer surface of the annular ring 111 are selected to be hollow indents and the flexible transmission member 113 is provided with a series of raised ridges to insert into the hollow ribs for mechanical engagement/interlocking.

[0049] Another embodiment of the present disclosure is adapted for a type of belt-driven mechanical implement operating with a belt having a V-shaped cross-section. In this embodiment, for the flexible transmission member 113 having the V-shaped inner region 114, the annular ring 111 of the second segment 110 is constructed to have a V-shaped peripheral cross-section, i.e., the outer lateral surface 301 is fabricated with a V-shaped indentation continuing along the entire circumference of the annular ring 111 to accommodate the entire width of the flexible transmission member 113.

[0050] Alternatively, for a mechanical implement which is designed to have a chain drive, the serrated elements 112 of the second segment 110 are selected to be acutely-angled teeth which are configured to mesh with roller pockets of a chain selected to serve as the flexible transmission member 113. The chain is coiled around the segmented pulleys 103 of the power shaft 101 and the output shaft 102 to mechanically link the power shaft 101 and the output shaft 102 for transmission of motion.

[0051] In another alternative embodiment, the power transmission system 100 may be adapted for a rope driven implement by configuring the annular ring 111 to have a concave outer lateral surface 301 to conform to the cross-sectional curvature of a rope selected as the flexible transmission member 113. A multiplicity of shallow serrated elements 112 maybe formed along the concave outer lateral surface 301 to enhance friction between the annular ring 111 and the rope to prevent slippage between the annular ring 111 and the rope. In another example of the present disclosure, a cable is implemented as the flexible transmission member 113 to enable a cable driven transmission system.

[0052] An advantage of the structural configuration of the first segment 104, from an assembly stand point, is that the cylindrical seat 106 of the first segment 104 is flanked on one side 107 by the surface of the planar base hub 105. This design supports the flexible transmission member 113 on one side portion of the flexible transmission member 113, thus significantly reducing the probability of the slippage of the flexible transmission member 113 off the second segment 110 during the operation of the mechanical implement, specifically in the case where the segmented pulley 103 is adapted for a belt drive transmission system.

[0053] In the preferred embodiment of the present disclosure, the first segment 104 is fabricated from a first material and the second segment 110 is made of a second material and the first material and the second material are specifically selected to be dissimilar. During the course of operation of the segmented pulley 103, the first segment 104 serves the purpose of mechanical locking onto the the power shaft 101 or the output shaft 102 and the second segment 110 particularly bears the torque generated by the prime mover of the mechanical implement, for conveying the force from the power shaft 101 to the output shaft 102. Therefore, the second segment 110, specifically the serrated elements 112, undergo greater magnitudes of mechanical loads and thus wear and tear at a higher rate in comparison with the first segment 104. The first material is selected to have a lower density and thus weight to ensure a reduction in the overall weight of the segmented pulley 103, and subsequently result in an improved efficiency of the mechanical implement. The second material is chosen with consideration for higher strength and hardness to render the segmented pulley 103 durable against mechanical loads generated during power transmission.

[0054] In one embodiment of the present disclosure, the first segment 104 is constructed from an alloy of aluminium by the process of die casting. Aluminum alloys have relatively lower density while being durable thus leading to a reduction in the weight and cost of the segmented pulley 103. The process of die casting ensures dimensionally accurate production of the first segment 104. In an embodiment of the present disclosure, the second segment 110 is fabricated from copper steel by the process of sintering. The resultant second segment 110 has higher density and a comparatively enhanced yield strength and hardness. The superior mechanical characteristic of the second segment 110 render it more resistant to the mechanical forces generated during the operation of the mechanical implement.

[0055] In the preferred embodiment of the present disclosure, the specific alloy of aluminium selected for manufacturing the first segment 104 is an ADC-12 grade aluminium alloy. ADC-12 is primarily composed of aluminum with significant amounts of silicon (approximately 11-13%) and smaller amounts of copper, nickel, and other elements.

[0056] The typical composition of ADC-12 includes:
1. Silicon (Si): 11-13%
2. Copper (Cu): 1.0-1.5%
3. Nickel (Ni): Up to 0.5%
4. Others: Small amounts of elements like magnesium, zinc, and iron.
5. Aluminum (Al): Balance amounts.

[0057] ADC-12 aluminium is a die-casting alloy known for its desirable fluidity, mechanical properties, and dimensional accuracy causing it to be widely used in automotive, industrial, and consumer electronic applications, offering a balance of strength, ductility, and corrosion resistance rendering it suitable for the first segment 104 to be manufactured from. Typical tensile strength of the aluminium alloy ranges from 220 to 300 MPa (32 to 44 ksi).

[0058] The first segment 104 of the segmented pulley 103 is preferably made by the process of die casting. Die casting is a manufacturing process used to produce metal parts with high precision, complexity, and excellent surface finishes. It involves injecting molten metal into a mold cavity under high pressure.

[0059] The construction of the segmented pulley 103 may also be using the process of insert molding or casting. Alternatively, the first segment 104 and the second segment 110 may be stacked using a laminate stacking process followed by riveting the first segment 104 and the second segment 110 to form the segmented pulley 103.

[0060] In another embodiment of the present disclosure, the first segment 104 is constructed from a lightweight durable material such as Magnesium alloys including AZ31, AZ91, AM60, WE43, and ZK60. In other exemplary implementations according to the disclosure, the material of the first segment 104 is selected to be a lighter material than the material used to form the second segment 110. In an embodiment according to the present disclosure, the specific alloy of copper steel selected for manufacturing the second segment 110 is an MPIF-FC208-50 grade alloy of steel and copper. MPIF FC-0208-50 is a designation for a specific type of sintered steel according to the standards of the Metal Powder Industries Federation (MPIF). This steel is used in powder metallurgy and has distinctive characteristics suited for a range of mechanical applications.

[0061] The typical composition of MPIF FC-0208-50 is:
1. Base Material: Iron (Fe) is the primary component.
2. Carbon (C): Approximately 0.8% carbon content, providing hardness and strength.
3. Copper (Cu): Up to 2%, enhancing strength and corrosion resistance.
4. Other Elements: Minor additions of elements like manganese, sulfur, or phosphorus to improve specific properties.

[0062] MPIF FC-0208-50 has a tensile strength typically around 50 ksi (345 MPa). The precise strength may vary depending on the sintering process and any subsequent heat treatment. The typical hardness range for MPIF FC-0208-50 is approximately 15-30 HRC (Rockwell Hardness C scale). The specific hardness varies based on factors such as sintering conditions, density, and any additional heat treatment processes applied to the material.

[0063] MPIF FC-0208-50 steel is a high-strength sintered steel displaying desirable wear resistance, machinability, and moderate corrosion resistance making it resistant to mechanical forces generated during power transmission of a mechanical implement. Mechanical properties of MPIF FC-0208-50 make it suitable for a wide range of applications, particularly in the automotive and industrial sectors. This alloy of steel is specifically suited for sintering due to its ability to achieve high density through sintering, thus enhancing mechanical properties and enabling a control over porosity levels to balance mechanical properties as per requirement. The controlled sintering process ensures high density and dimensional accuracy enabling a reliable manufacturing of the second segment 110 of the segmented pulley 103 of the present disclosure.

[0064] The second segment 110 of the segmented pulley 103 is preferably made with the process of sintering. Sintering is a manufacturing process used to produce solid materials from powders by heating them below their melting points until the particles adhere to each other. Sintering is widely used in powder metallurgy and ceramics to create components with high strength and controlled porosity.

[0065] In other embodiments of the present disclosure, the second material is selected from materials having higher hardness and resistance to wear and tear, including alloy steel, high speed steel, hardened steel, tool steel, titanium alloys such as grade 5, grade 9, tungsten alloys including tungsten carbide, tungsten heavy alloy, nickel alloys such as Inconel 718, etc.

[0066] Figure 6 exemplarily illustrates an isometric view of the segmented pulley 103 installed over a rotating body 601 of a mechanical implement. Figure 7 exemplarily illustrates an exploded view of the segmented pulley 103 shown in Figure 6. Figure 8 exemplarily illustrates a top view of the segmented pulley 103 shown in Figure 6, such that the rotating body 601 is adapted for the power transmission system 100 of the present disclosure. The segmented pulley 103 is rigidly coupled with a hub 602 of the rotating body 601 such that the hub 602 is developed to enable a linkage of the segmented pulley 103 with the rotating body 601 and as well as the coupling of the rotating body 601 with the mechanical implement, for a transfer of motion from the prime mover associated with the mechanical implement to the rotating body 601 for achieving an intended end effect.

[0067] An exemplary implementation of the power transmission system 100 relates to an automobile configured with an IC engine or an electric motor as the prime mover. The automobile essentially involves a prime mover for the generation of propulsive power and a mechanism for conveying the power generated from the prime mover to a set of wheels of the automobile. The power transmission system 100 implemented for the transmission of power from the prime mover to the wheels is generally herein referred to as the power transmission system 100. In the automobile, an IC engine or an electric motor is incorporated as the prime mover for generating power in the form of a rotational motion of the power shaft 101 of the prime mover. The generated motion is transferred to the output shaft 102 of the automobile, associated with a rotating body 601 associated with the automobile, for the propulsion of the automobile, which is the intended end effect of the automobile.

[0068] In the automotive example described herewith, the segmented pulley 103 is coupled with the rotating body 601, such that the rotating body 601 is in mechanical communication with the prime mover powering the automobile for receiving power from the prime mover. The rotating body 601 is a structure in communication with the wheel of the automobile for receiving rotational motion from the power shaft 101 for propulsion of the automobile. The centrally located hub 602 of the rotating body 601, installed over a spindle, functions as the output shaft 102 of the automobile. A flexible transmission member 113 is looped over the segmented pulley 103 installed over the output shaft 102 and the segmented pulley 103 is installed over the power shaft 101 associated with the prime mover. In another variation of the example, the segmented pulley 103 is mounted over only one of the power shaft 101 and the output shaft 102 and the other shaft is provided with a traditional pulley 501.

[0069] For a belt driven automobile, the flexible transmission member 113 is chosen to be a belt having a series of consecutively located hollow grooves formed on the inner region 114 of the belt. To enable the belt drive, the serrated elements 112 of the second segment 110 are chosen to be protruding blunt ribs shaped to be complementary to the grooves, i.e., similar to the pattern crafted over the outer lateral surface 301 of the second segment 110 for enabling a positive mechanical engagement between the flexible transmission member 113 and the segmented pulleys 103 and in-turn between the power shaft 101 and the output shaft 102.

[0070] Alternatively, for a chain-driven automobile, the serrated elements 112 of the second segment 110 are selected to be acutely-angled teeth which are configured to mesh with roller pockets of a chain selected to serve as the flexible transmission member 113. The chain is coiled around the segmented pulleys 103 of the power shaft 101 and the output shaft 102 to mechanically link the the power shaft 101 and the output shaft 102 for transmission of motion.

[0071] In an implementation of the power transmission system 100 in an automobile, the segmented pulley 103 is installed over both the power shaft 101 and the output shaft 102 of the automobile. In another alternative application of the power transmission system 100, as depicted in the Figure 5 exemplarily illustrating an isometric view of an alternative embodiment of the power transmission system 100, where only one of the power shaft 101 and the output shaft 102 of the power transmission system 100, i.e., the output shaft 102, is configured with the segmented pulley 103, such that the the power shaft 101 carries a traditional pulley 501. If the mechanical implement under consideration is chain driven, consequently having a sprocket coupled on one of the the power shaft 101 and the output shaft 102, then for the other of the power shaft 101 or the output shaft 102, the serrated elements 112 of the second segment 110 are embodied as teeth that are disposed on the annular ring 111 is selected and assembled with the first segment 104.

[0072] In another example of the present disclosure, the power shaft 101 is selected to be coupled to the segmented pulley 103 and the output shaft 102 is chosen to be coupled to a conventional pulley, such that the flexible transmission member 113 is selected from a type of belt, chain, rope, cable, etc., as per requirement and accordingly a second segment 110 of a compatible configuration is implemented.

[0073] Moreover, if the automobile is belt-driven, with a belt pulley coupled on one of the the power shaft 101 and the output shaft 102, then for the other of the power shaft 101 and the output shaft 102, a second segment 110 having ribs as serrated elements 112 provided on the annular ring 111 is selected and joined with the first segment 104.

[0074] The design of the segmented pulley 103 conceived herewith enables the retrofitting of the segmented pulley 103 in transmission systems of existing automobiles driven by belt or chain drives. The first segment 104 is conceived to be compatible with the power shaft 101 and the output shaft 102 of the automobiles and the second segment 110 maybe selected to have ribs formed on the annular ring 111 or teeth integrated on the annular ring 111 as the serrated elements 112 in accordance to maintain compatibility with the existing automobile in consideration.

[0075] Another advantageous consequence of the power transmission system 100 is that, an alteration of the gear ratio of an automobile is enabled with minimal disassembly of the power train of the automobile. To change the gear ratio of the power transmission system 100 of a belt-driven automobile the second segment 110 may be replaced with another second segment 110 having a different number of ribs. Accordingly, the flexible transmission member 113 is replaced to change the gear ratio between the power shaft 101 and the output shaft 102. Similarly, for a chain-driven automobile, the second segment 110 of the power transmission system 100 is replaced with another second segment 110 having a different number of teeth. Accordingly, the flexible transmission member 113 is replaced to change the gear ratio between the power shaft 101 and the output shaft 102.

[0076] The first segment 104 and the second segment 110 are assembled with one another in a removable manner to allow for a maintenance of the segmented pulley 103 by selective restoration or replacement of the first segment 104 and/or the second segment 110. For the power transmission system 100 to function in an intended manner, it is imperative for the first segment 104 and the second segment 110 to be coupled with one another in a manner to prevent a relative rotational motion between the first segment 104 and the second segment 110 while allowing a disassembly at the time of maintenance of the segmented pulley 103.

[0077] In the preferred embodiment of the present disclosure, the principle of thermal expansion and contraction is utilized to affix the second segment 110 onto the first segment 104 while allowing for disassembly as per requirement. The first segment 104 is manufactured with the outward face of the cylindrical seat 106 having a diameter d1 and the second segment 110 is fabricated with the inner lateral surface 402 of the annular ring 111 having a diameter d2. The dimensions d1 and d2 are selected such that, at an ambient temperature ta, and in absence of external mechanical loads acting on the first segment 104 and the second segment 110, the diameter d2 is less than the diameter d1, i.e., d2<d1. Thus, in such a condition, due to fouling, the second segment 110 is prevented from sliding over the cylindrical seat 106.

[0078] The present disclosure also relates to a method 900 for the assembling of the two parts of the segmented pulley 103 by implementing the shrink fitting technique. Figure 9 exemplarily illustrates a flow diagram depicting the method 900 for assembling the segmented pulley 103. The method 900 involves having 901 a first segment 104 with a cylindrical seat 106 having an outer diameter d1 and acquiring 902 a second segment 110 with an annular ring 111 of an inner diameter d2, such that d2 is lesser than d1. The method 900 further includes heating 903 the second segment 110 to a temperature t1, such that the difference between the ambient temperature ta and the temperature t1 is Δti. This heating 903 causes the second segment 110 to thermally expand, with the diameter d2 of the annular ring 111 increasing to d2'. In an embodiment of the present disclosure, the second segment 110 is heated to a temperature t1 selected in the range of 600°C to 700°C.

[0079] The degree of the heating of the second segment 110, Δti is specifically determined to result in d2' being greater than d1, i.e., d2'>d1, and the difference Δd' between in d2' and d1 is greater than the difference Δd between d1 and d2 to enable an assembling 904 of the first segment 104 and the second segment 110 by a passage of the second segment 110 along the outward lateral face 401 of the cylindrical seat 106. In the described condition, such that the diameters of the cylindrical seat 106 and the annular ring 111 are thermally altered, the second segment 110 is sleeved around the cylindrical seat 106 in a coaxially aligned position.

[0080] Subsequently, the temperature of the second segment 110 is returned back to the ambient thermal conditions by equalizing 905 the temperature of the assembled first segment 104 and the second segment 110 with the ambient temperature ta. The equalizing 905 causes the second segment 110 to lose heat and contract, leading to the cylindrical seat 106 being circumferentially squeezed by the second segment 110 thus locking the positions of the first segment 104 and the second segment 110 with respect to one another to prevent any linear or rotational motion between the first segment 104 and the second segment 110.

[0081] In an embodiment of the stated method 900, the temperature of the assembled first segment 104 and the second segment 110 is gradually equalized under natural draught. Alternatively, in another embodiment of the disclosure, an external heat absorption means is implemented for a comparatively rapid equalization of temperature.

[0082] To ensure a positive fastening of the first segment 104 with the second segment 110, an ample magnitude of static friction is required to be developed between the outer lateral face 401 of the cylindrical seat 106 of the first segment 104 and the inner lateral surface 402 of the second segment 110. To produce a required static friction, in an embodiment of the power transmission system 100, a surface roughness in the range of 1.8 Ra to 3.2 Ra is imparted to the outer lateral face 401 of the cylindrical seat 106 of the first segment 104 and the inner lateral surface 402 of the second segment 110.

[0083] The two-part design of the segmented pulley 103 enables it to be selectively repaired or replaced in case of a damage is caused to either the first segment 104 of the second segment 110. The segmented pulley 103 is conveniently disassembled by leveraging the same principle thermal expansion used for the assembly of the first segment 104 with the second segment 110. For a removal of the second segment 110 from the cylindrical seat 106 of the first segment 104, heat is applied to the second segment 110, causing the diameter of the inner lateral surface 402 of the second segment 110 to be expanded due to thermal expansion, which enables a convenient sliding off of the second segment 110 from the cylindrical seat 106 of the first segment 104 thereby separating both the first segment 104 and the second segment 110. In case the second segment 110 is required to be replaced, another second segment 110 is installed over the cylindrical seat 106 of the first segment 104 by implementing the method 900. Alternatively, in an instance where the first segment 104 has been impaired, the repaired or new first segment 104 is mounted over another first segment 104.

[0084] The convenient disassembly allows for easy swapping of the first segment 104 and the second segment 110, which manifests into advantages apart from cost-effective maintenance, such as the power transmission system 100 is enabled to be changed from one type to another. For example, a belt driven power transmission system may be changed into a chain driven power transmission system 100, by swapping the second segments 110 configured with ribs, with the second segments 110 having teeth as the serrated elements 112 and replacing the belt as the flexible transmission member 113 with a chain. Similarly, a belt drive, a chain drive, a rope drive and a cable drive may be altered to any other of the drives as per requirement.

[0085] Moreover, in a chain-driven implementation, the gear ratio of the power transmission system 100 is capable of being changed by changing the second segment 110 of one or both of the segmented pulleys 103 of the power transmission system, with second segment 110 having a different number of serrated elements 112 in accordance with a need raised by the nature of load borne by the mechanical implement.

ADVANTAGES OF THE PRESENT DISCLOSURE

[0086] The power transmission system 100 presents a number of advantages over the prior art, which include the elimination of requirement for application of expensive coatings based on rare-earth elements, on the surface of cast aluminium pulleys in enhance their mechanical properties. The recyclability of the segmented pulley 103 is also improved since the absence of the aerospace-grade rare-earth elements based coatings simplify the process of recycling. Such coatings are often made of toxic compounds; therefore, the power transmission system 100 eliminates reliance on conventional transmission systems employing materials damaging for human health.

[0087] Another consequential advantage of the two-part construction of the segmented pulley 103, over the pulleys of the prior art, is a considerable reduction in the cost of manufacturing of the segmented pulley 103, since the segmented pulley 103 is partially fabricated from a relatively lighter material and particularly the portion of the segmented pulley 103 engaging with the belt is constructed from a material having a higher hardness and resistance to failure against mechanical loads. The proportion of the segmented pulley 103 manufactured from the costlier material is reduced leading to a decrease in the overall production cost of the segmented pulley 103. In comparison to traditionally-constructed pulley of a given set of dimensions, a segmented pulley 103 having matching dimensions results in a cost reduction of 61%. Thus, a considerable economic significance is observed.

[0088] Another benefit of the modular design of the power transmission system 100 may be noted from a production standpoint. Both, belt drive and chain drive systems may be produced at manufacturing facility, such that the less stressed portion of the segmented pulley 103 is physically equivalent for the belt drive, chain drive, rope drive and cable drive, thus optimizing the production line and bringing down the cost of manufacturing of the belt drive, chain drive, rope drive and cable drive transmission systems.

[0089] The composite structure of the segmented pulley 103 of the present disclosure allows for the execution of selective maintenance of the segmented pulley 103 in case of an impairment, thus reducing the maintenance cost.

[0090] The segmented design of the present segmented pulley 103 enables it to be retrofitted into power transmission arrangements of mechanical implements previously configured with conventional chain or belt drives.

[0091] The modular configuration of the segmented pulley 103 facilitates the conversion of a belt-driven implement such as an automobile, into a chain driven implement, and vice versa, as per the requirement of a user.

[0092] Consequently, the gear ratio of a transmission of a mechanical may also be altered, as required by the load bourn by the mechanical implement, with minimal disassembly of the existing power transmission system.

[0093] Since, the power transmission system 100 describes a system for transmission of power, for example between a pair of shafts, i.e., the power shaft 101 and the output shaft 102, spindles, or similar structures for a transference of motion, any mechanical implement, fundamentally operating by a conveyance of motion from a prime mover to such structures, is capable of being installed with the power transmission system 100. Such mechanical implements include but are not limited to automobiles, lifts, escalators, lathes, mills, agricultural equipment, machining tools. Many mechanical implements, such as lifts, hoists, employ a multitude of intermediate shafts and pulleys on the intermediate shafts, between the power shaft 101 and the output shaft 102 for achieving a desired mechanical advantage. Any or all of the power shaft 101, the output shaft 102, and the intermediate shafts are provided with the segmented pulleys 103 to avail the advantages imparted by the power transmission system 100.

[0094] Although the field of the disclosure has been described herein with limited reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the disclosure, will become apparent to persons skilled in the art upon reference to the description of the disclosure. , Claims:1) A segmented pulley 103 adapted to be mounted on at least one of a power shaft 101 and an output shaft 102 of a power transmission system 100, the segmented pulley 103 comprising:

a first segment 104 including a planar base hub 105 and a cylindrical seat 106 extending orthogonally from a side 107 of the planar base hub 105 and coaxial relative to the planar base hub 105; and

a second segment 110 including an annular ring 111 adapted to be removably secured onto an outer lateral face 401 of the cylindrical seat 106, wherein an outer lateral surface 301 of the annular ring 111 defines a plurality of serrated elements 112.

2) The segmented pulley 103 as claimed in claim 1, wherein the serrated elements 112 are adapted to mechanically engage a flexible transmission member 113 of the power transmission system 100.

3) The segmented pulley 103 as claimed in claim 1, wherein an inner region 114 of the flexible transmission member 113 is defined as a series of protrusions 115 such that the protrusions 115 mesh without slippage with the serrated elements 112 upon mechanical engagement of the flexible transmission member 113 with the second segment 110.

4) A power transmission system 100 for a mechanical implement, the power transmission system 100 comprising:

a power shaft 101 and an output shaft 102 associated with the mechanical implement;

a segmented pulley 103 fastened on at least one of the power shaft 101 and the output shaft 102, the segmented pulley 103 comprising:

a first segment 104, having a planar base hub 105 adapted to be coupled with at least one of the power shaft 101 and the output shaft 102, and a cylindrical seat 106 protruding orthogonally on a side 107 of the planar base hub 105 in a coaxial manner;

a second segment 110, including an annular ring 111 configured to be detachably secured onto an outer lateral face 401 of the cylindrical seat 106, and a plurality of serrated elements 112 uniformly incorporated along an outer lateral surface 301 of the annular ring 111; and

a flexible transmission member 113 looped around the segmented pulley 103 for connecting the power shaft 101 and the output shaft 102 for transmission of power from the power shaft 101 to the output shaft 102.

5) The power transmission system 100 as claimed in claim 4, wherein the flexible transmission member 113 is configured to mechanically engage with the serrated elements 112 of the annular ring 111 to enable a transmission of power between the flexible transmission member 113 and the segmented pulley 103.

6) The power transmission system as claimed in claim 5, wherein an inner region 114 of the flexible transmission member 113 is crafted with a series of protrusions 115 to impart a pattern equivalent to the serrated elements 112 formed over the outer lateral surface 301 of the annular ring 111 to enable a mechanical engagement of the flexible transmission member 113 with the second segment 110 without slippage.

7) The power transmission system 100 as claimed in claim 4, wherein the first segment 104 further comprises a bore 108 fabricated centrally through the planar base hub 105 for enabling a passage of one of the power shaft 101 or the output shaft 102.

8) The power transmission system as claimed in claim 4, wherein a plurality of slots 109 is defined in the planar base hub 105 and the slots 109 are disposed radially around the bore 108 to enable a positive mechanical engagement of the first segment 104 with the power shaft 101 and/or the output shaft 102.

9) The power transmission system 100 as claimed in claim 4, wherein an inner diameter d2 of the annular ring 111 is lesser than the outer diameter d1 of the cylindrical seat 106.

10) The power transmission system 100 as claimed in claim 4, wherein a width w1 of the outer lateral face 401 of the cylindrical seat 106 and a width w2 of the inner lateral surface 402 of the annular ring 111 are selected to be equal.

11) The power transmission system 100 as claimed in claim 4, wherein the flexible transmission member 113 is selected from a belt having belt grooves, a V-shaped belt, a belt having a flat profile at the inner region 114, and a chain having roller pockets.

12) The power transmission system 100 as claimed in claim 4, wherein the serrated elements 112 of the second segment 110 and an inner region 114 of the flexible transmission member 113 are complementarily shaped such that the serrated elements 112 mesh with the inner region 114 of the flexible transmission member 113 upon mechanical engagement of the flexible transmission member 113 with the second segment 110.

13) The power transmission system 100 as claimed in claim 4, wherein the first segment 104 is constructed from a first material and the second segment 110 is made of a second material.

14) The power transmission system 100 as claimed in claim 13, wherein the density of the first material is lower than the density of the second material.

15) The power transmission system 100 as claimed in claim 13, wherein the hardness of the second material is greater than the hardness of the first material.

16) The power transmission system 100 as claimed in claim 4, wherein a width w1 of the outer lateral face 401 of the cylindrical seat 106 and a width w2 of the inner lateral surface 402 of the second segment 110 are selected to be equal.

17) A method 900 for assembling a segmented pulley 103, comprising steps:

i) having 901 a first segment 104 with a cylindrical seat 106 having an outer diameter d1;

ii) acquiring 902 a second segment 110 with an annular ring 111 of an inner diameter d2, wherein d2 is lesser than d1;

iii) heating 903 the second segment 110 to cause thermal expansion of the second segment 110;

iv) assembling 904 the first segment 104 and the second segment 110 by:

coaxially aligning the first segment 104 and the second segment 110, and

sliding the annular ring 111 of the heated second segment 110 onto an outer lateral face 401 of the cylindrical seat 106 of the first segment 104; and

v) equalizing 905 the temperature of the assembled first segment 104 and the second segment 110 with the ambient temperature ta.

18) The method 900 as claimed in claim 17, wherein the second segment 110 is heated to a temperature t1.

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