One-way clutch with tapered rollers

Abstract

A one-way clutch 200 includes: an outer body 202 having an inner periphery and a conical inner surface 204; a shaft 206 having a cylindrical outer surface 208; a plurality of tapered rollers 210 disposed in a plurality of dimples 214 open toward the shaft 206; and a plurality of springs (216) configured to bias the plurality of tapered rollers (210) in the axial direction toward the smaller diameter side of the corresponding tapered rollers (210). Furthermore, when viewed from the larger end side of the roller 210, counterclockwise rotation of the shaft 206 is prevented due to the tendency of the roller 210 to move axially toward the narrower side of the conical inner surface 204 of the outer body 202 due to the rotation of the tapered roller 210 on the cylindrical outer surface of the shaft 206 and the biasing force from the spring 216.

Description

Technical Field

[0001] This disclosure generally relates to the technical field of one-way clutches. Specifically, this disclosure relates to a one-way clutch assembly having tapered rollers. Background Technology

[0002] The background description includes information that may be useful for understanding the invention. It is not acknowledged that any information provided herein is prior art or related to the currently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] One-way clutches are widely used in the automotive industry as torque transmission or stopping devices. They are primarily used with the starter motor of an internal combustion engine to turn the crankshaft and start the engine. A one-way clutch allows torque and rotation to be transmitted from the starter motor to the engine, but prevents the engine from driving the starter motor during startup.

[0004] refer to Figure 1 The diagram shows a cross-sectional view of a conventional one-way clutch 100 with an outer ring 102 having a plurality of recesses 104, each recess 104 having a cam surface 106. A plurality of cylindrical rollers 108 are disposed in each of the plurality of recesses 104, positioned between the outer surface of the shaft 112 and the corresponding cam surface 106. These rollers 108 are tangentially spring-loaded by an accordion spring 110. The cam surfaces are configured to induce a wedging action and prevent the rollers 108 from rolling in the bias direction, thereby preventing rotation of the shaft 112 in the corresponding direction, but allowing the rollers to roll when pushed toward the spring, thereby allowing rotation of the shaft 112 in the opposite direction.

[0005] A disadvantage of conventional one-way clutches is that they include cam surfaces with complex geometry for wedging, which are difficult to manufacture. Furthermore, conventional one-way clutches are complex and difficult to assemble. Additionally, a significant amount of space is required to accommodate the accordion spring 110. Specifically, a spring locking device is needed in the profile of the outer ring 102; if this spring locking device were eliminated, the outer ring 102 could be used to accommodate additional rollers, resulting in a higher bearing capacity. Therefore, the conventional design requiring one spring 110 for each roller 108 presents encapsulation problems, limiting the bearing's load capacity to a given bearing size.

[0006] Efforts have been made in this field to eliminate the need for cam surfaces in one-way clutches. For example, patent document US3557921 discloses a one-way clutch having an inner ring and an outer ring formed in the shape of tapered roller bearings. Cylindrical rollers are inserted between the inner and outer rings, the cylindrical rollers being appropriately inclined relative to the generating lines of the surfaces of the inner and outer rings. In one direction of relative rotation of the inner and outer rings, the rollers act as wedges between the inner and outer rings to achieve clutch actuation.

[0007] Another patent document, US5653320, discloses a tapered roller one-way clutch for use with a vertical shaft having an outer surface. The tapered roller one-way clutch includes a clutch housing having a bore extending through the housing, into which the vertical shaft is rotatably inserted. A plurality of roller recesses are formed on the inner surface of the bore, the roller recesses extending axially along the inner surface of the bore from near the top of the bore to near the bottom of the bore and being equally spaced around the circumference of the bore. Each roller recess also includes a roller platform, which gradually moves away from the axis of the bore. The tapered rollers, tapering to a diameter along the bore, are rotatably held in each roller recess by the outer surface of the shaft. The roller platform is inclined relative to the axis of the bore to allow the outer surface of the rollers to roll along the outer surface of the shaft and to hold the tapered rollers at an angle to maximize surface contact. The roller platform has an arcuate or helical shape from the roller shoulder to the cylindrical inner surface to allow the tapered rollers to roll forward and move laterally as the vertical shaft moves in the engagement direction, thereby engaging the tapered rollers with the vertical shaft between the roller platform and the outer surface of the shaft.

[0008] The cited references disclose different types of one-way clutches, including one-way clutches based on tapered rollers. However, a drawback of prior art one-way clutches using tapered rollers is that they can only be used in constructions where the corresponding shaft is vertically oriented.

[0009] Therefore, there is a need in the art to provide a simple, improved and cost-effective one-way clutch that eliminates the aforementioned limitations of known one-way clutches based on tapered rollers.

[0010] Purpose of the invention

[0011] The overall objective of this disclosure is to provide a simple, improved, and cost-effective one-way clutch.

[0012] One object of this disclosure is to provide a one-way clutch that is easy to manufacture.

[0013] Another object of this disclosure is to provide an improved one-way clutch based on tapered rollers.

[0014] Another object of this disclosure is to provide a one-way clutch based on tapered rollers that can be used in any orientation of the corresponding shaft.

[0015] Another objective of this disclosure is to provide a method for solving the problem of spring encapsulation in conventional one-way clutches.

[0016] Another object of this disclosure is to provide a one-way clutch that optimizes load-bearing capacity for a given size of one-way clutch. Summary of the Invention

[0017] This disclosure generally relates to the technical field of one-way clutches. In particular, the present invention relates to a one-way clutch assembly based on tapered rollers (also referred to herein as tapered rollers).

[0018] In one aspect, the disclosed one-way clutch includes: an outer body (hereinafter also simply referred to as the body) having an inner periphery with a conical inner surface; a shaft having an outer periphery with a cylindrical outer surface; and a plurality of tapered rollers (hereinafter also simply referred to as rollers, the two terms are used interchangeably below) disposed between the conical inner surface of the body and the cylindrical outer surface of the shaft. The one-way clutch also includes a single spring configured to bias the plurality of tapered rollers in the axial direction toward the smaller diameter side of the respective tapered rollers (hereinafter also simply referred to as rollers). When viewed from the larger end side of the rollers, rotation of the shaft in the counterclockwise direction is prevented due to the wedging action of the tapered rollers caused by the biasing force of the spring.

[0019] In one aspect, the plurality of rollers are supported by a single spring having a desired profile design comprising a plurality of spring elements such that each of the plurality of rollers is supported by a spring element from a large end face to bias the roller toward a small end.

[0020] In one aspect, the spring can be configured such that when the shaft rotates clockwise, when viewed from the larger end side of the roller, the biasing force of the spring is overcome by the tendency of the roller to move axially toward the larger diameter side of the conical inner surface of the body, thereby eliminating the wedging effect of the roller to allow the shaft to rotate freely.

[0021] In one embodiment, the body may include a plurality of recesses, and a plurality of rollers are located within the plurality of recesses, each of the plurality of recesses containing a tapered roller. Each recess may have a profile including a conical inner surface to create a wedging effect thereby locking the corresponding roller in place.

[0022] In one embodiment, the inner periphery of the body may be a truncated periphery comprising multiple segments, each segment located within a corresponding recess.

[0023] In one embodiment, the one-way clutch may further include a top plate for retaining a plurality of tapered rollers in recesses and for holding a spring positioned adjacent to the rollers. The top plate may be press-fitted to the body. In one embodiment, the plurality of recesses may face the shaft opening to facilitate contact between the rollers and the shaft.

[0024] Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments and the accompanying drawings, wherein the same reference numerals denote the same parts. Attached Figure Description

[0025] The accompanying drawings are included to provide a further understanding of this disclosure, and these drawings are incorporated in and form a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the disclosure.

[0026] Figure 1 A cross-sectional view of a conventional one-way clutch is shown.

[0027] Figure 2 An exemplary cross-sectional view of a proposed one-way clutch according to an embodiment of the present disclosure is shown along a plane perpendicular to the axis of the one-way clutch.

[0028] Figure 3 An exemplary side sectional view of a disclosed one-way clutch according to a first embodiment of the one-way clutch is shown along the diametrical plane of the one-way clutch, which has a top plate and a spring having a plurality of spring elements. Detailed Implementation

[0029] The following is a detailed description of embodiments of the present disclosure depicted in the accompanying drawings. These embodiments are so detailed that they clearly convey the present disclosure. However, the amount of detail provided is not intended to limit the contemplation of the embodiments; rather, it is intended to cover all modifications, equivalents, and alternatives that fall within the spirit and scope of the present disclosure as defined by the appended claims.

[0030] The embodiments explained herein generally relate to a one-way clutch based on tapered rollers. In one aspect, tapered rollers are used instead of the cylindrical rollers conventionally used in one-way clutches, eliminating the need for roller biasing in the radial / tangential direction, which is replaced by axial biasing. The springs required for axial biasing are more reliable because they are fixed between the top plate and the body of the one-way clutch and are not easily displaced from their position. In another aspect, axial biasing can be provided by spring elements built into a single spring positioned at one end of the roller between the roller and the top plate. In alternative embodiments, the spring elements can also be built into the top plate, which further improves reliability. Furthermore, in either case, the proposed changes make the assembly process easier and less time-consuming.

[0031] refer to Figure 2 The diagram shows an axial cross-sectional view perpendicular to the axis of the disclosed one-way clutch 200, which may include: an outer body 202 having an inner periphery; and a plurality of tapered rollers 210 (also referred to herein as rollers 210) disposed in a plurality of recesses 214, the recesses 214 being configured on the inner side of the outer body 202. Each recess 214 may include a conical inner surface 204 (also referred to herein as a conical surface 204), the outer conical surface of which may engage with the conical inner surface 204. Each recess 214 may be open on its inner side (hereinafter referred to as an inner opening) such that the rollers 210 may contact the cylindrical outer surface of a cylindrical shaft 206 (also referred to herein as shaft 206) disposed within the outer body 202. The shaft 206 includes a cylindrical outer surface 208.

[0032] In one embodiment, the size of the inner opening of the recess can be smaller than the diameter of the roller 210, for example, the diameter at the larger end of the roller 210. This prevents the tapered roller 210 from moving out of the recess without the shaft 206 in place.

[0033] In one embodiment, the one-way clutch 200 may further include a top plate 212 (see...) Figure 3 A plurality of tapered rollers 210 are axially constrained. Furthermore, a plurality of springs 216 are positioned between the top plate 212 and the rollers 210 to axially bias the rollers 210. The top plate 212 can be press-fitted to the outer body 202. In one embodiment, the function of the plurality of springs 216 can be combined in a single component placed between the outer body 202 and the top plate 212. In one embodiment, the tapered surface 204 and the rollers 210 can be configured such that the rollers 210 are biased axially by the springs 216 toward the smaller diameter side of the respective tapered roller 210. For example, the larger diameter side of the tapered surface 204 of the recess 214 can face the top plate 212.

[0034] In one embodiment, the plurality of springs 216 may be spring elements / fingers (also referred to herein as springs 216) constructed into a single formed plate / diaphragm spring, which may be positioned at one end of a roller between the roller 210 and the top plate 212, such that the formed spring element / finger 216 contacts the large-diameter side of the roller 210 to axially bias the respective roller 210.

[0035] Figure 3 A side sectional view of the one-way clutch 200 disclosed in the first and second embodiments is shown with respect to the spring and top plate, respectively.

[0036] exist Figure 3 In the first embodiment shown, the top plate 212 and the spring 216 are separate parts, wherein the spring 216 is positioned between the roller and the top plate 212 such that each spring 216 biases one of the rollers 210.

[0037] Therefore, this disclosure provides a robust one-way clutch that replaces the spring that biases rollers in the radial direction with an axially biasing spring. The axially biasing spring is inherently more stable, thus overcoming the problems associated with conventional one-way clutches. The use of an axially biasing roller spring frees up space previously occupied by springs in conventional designs, enabling increased load-carrying capacity and simplified structure. Furthermore, the absence of cavities in the outer body for locating the spring makes the outer body more robust, which also contributes to increased clutch load-carrying capacity. Therefore, for a given clutch size, the load-carrying capacity is increased. Alternatively, for a given load-carrying capacity, the clutch size is reduced, making clutch encapsulation easier.

[0038] While various embodiments of the invention have been described above, other and further embodiments of the invention can be devised without departing from the basic scope of the invention. The scope of the invention is defined by the appended claims. The invention is not limited to the described embodiments, versions, or examples, which are intended to enable those skilled in the art to make and use the invention in combination with information and knowledge available to them.

[0039] Advantages of the present invention

[0040] The overall advantage of this disclosure is that it provides a simple, improved, and cost-effective solution for one-way clutches.

[0041] This disclosure provides a one-way clutch that is easy to manufacture.

[0042] This disclosure provides an improved one-way clutch based on tapered rollers.

[0043] This disclosure provides a one-way clutch based on tapered rollers, which can be used in any orientation of the corresponding shaft.

[0044] This disclosure provides a solution to the problem of encapsulating springs in conventional one-way clutches.

[0045] This disclosure provides a one-way clutch that optimizes load-bearing capacity for a given size of the one-way clutch.

Claims

1. A one-way clutch (200), the one-way clutch (200) comprising: An outer body (202) includes an inner periphery having a conical inner surface (204); Shaft (206), the shaft (206) includes an outer periphery having a cylindrical outer surface (208); A plurality of tapered rollers (210) are disposed between the conical inner surface (204) of the outer body (202) and the cylindrical outer surface (208) of the shaft (206); and Multiple springs (216) are configured to bias the multiple tapered rollers (210) toward the smaller diameter side of the respective tapered rollers (210) in the axial direction. When viewed from the larger end of the tapered roller (210), the rotation of the shaft (206) in the counterclockwise direction is prevented due to the wedging effect of the tapered roller (210) caused by the biasing force from the spring (216).

2. The one-way clutch according to claim 1, wherein, The spring (216) is configured as a single diaphragm spring finger.

3. The one-way clutch according to claim 1, wherein, The spring (216) is configured such that when the shaft (206) rotates clockwise, when viewed from the larger end side of the tapered roller (210), the biasing force of the spring (216) is overcome by the tendency of the tapered roller (210) to move axially toward the larger diameter side of the conical inner surface (204) of the outer body (202).

4. The one-way clutch according to claim 1, wherein, The outer body (202) includes a plurality of recesses (214), and a plurality of tapered rollers (210) are located within the plurality of recesses (214), with one tapered roller (210) in each of the plurality of recesses (214).

5. The one-way clutch according to claim 1, wherein, The plurality of recesses (214) include a shaped surface, the shaped surface including the conical inner surface to create a wedging effect.

6. The one-way clutch according to claim 4, wherein, The inner periphery of the outer body (202) is a truncated periphery comprising multiple segments, each segment being located within a corresponding recess (214).

7. The one-way clutch according to claim 4, wherein, The one-way clutch (200) also includes a top plate (212) for holding the plurality of tapered rollers (210) and the spring (216) within the recess (214), wherein the top plate (212) is press-fitted to the outer body (202).

8. The one-way clutch according to claim 4, wherein, The plurality of recesses (214) open toward the shaft (206) to facilitate contact between the tapered roller (210) and the shaft (206).

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