One-way clutch with tapered roller

Abstract

The one-way clutch 200 includes an outer body 202 having an inner circumference and a conical inner surface 204, a shaft 206 having a cylindrical outer surface 208, a plurality of tapered rollers 210 arranged in a plurality of pockets 214 opening toward the shaft 206, and a plurality of springs 216 configured to axially bias the plurality of tapered rollers 210 toward the smaller diameter side of each tapered roller 210. Furthermore, as viewed from the large end side of the rollers 210, the counterclockwise rotation of the shaft 206 is prevented due to the property of the rollers 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 rollers 210 on the cylindrical outer surface of the shaft 206 and the biasing force from the springs 216.

Description

Technical Field

[0001] The present disclosure generally relates to the technical field of one-way clutches. In particular, the present disclosure relates to a one-way clutch assembly having tapered rollers.

Background Art

[0002] The description of the background art includes information that may be useful for understanding the present invention. The description of the background art does not admit that any of the information provided herein is prior art or information related to the presently claimed invention, or that any of the publications specifically or implicitly referenced is prior art.

[0003] One-way clutches are widely used in the automotive industry as torque transmission devices or backstop devices. One-way clutches are mainly used with the starter motor of an IC engine to turn the crank of the engine to start the engine. One-way clutches allow the transmission of torque and rotation from the starter motor to the engine, but prevent the driving of the starter motor once the engine is started.

[0004] Referring to FIG. 1, which is a cross-sectional view of a conventional one-way clutch 100, this one-way clutch 100 has an outer ring 102 having a plurality of pockets 104, each pocket having a cam surface 106. A plurality of cylindrical rollers 108 are disposed in each of the plurality of pockets 104 disposed between the outer surface of the shaft 112 and the respective cam surfaces 106. These rollers 108 are spring-loaded tangentially by an accordion spring 110. The cam surface causes a wedging action, preventing the rolling of the roller 108 in the biasing direction, thereby preventing the rotation of the shaft 112 in the corresponding direction. However, when the roller is pushed towards the spring, it allows the roller to roll, thereby enabling the rotation of the shaft 112 in the opposite direction.

[0005] Conventional one-way clutches include a cam surface with a complex shape for wedge action, which has the disadvantage of being difficult to manufacture. Furthermore, conventional one-way clutches are complex and difficult to assemble. They also require a significant amount of space to accommodate the accordion spring 110. Specifically, a spring locking configuration is required on the contour of the outer ring 102; omitting this would allow the space to be used to accommodate additional rollers, resulting in a higher load-bearing capacity for the bearing. Therefore, the conventional design, which requires one spring 110 for each roller 108, presents a packaging problem that limits the load-bearing capacity of the bearing within a given size.

[0006] Efforts have been made in the art to eliminate the need for a cam surface in a one-way clutch. For example, U.S. Patent No. 3,557,921 discloses a one-way clutch in which the inner and outer rings are formed in the shape of tapered roller bearings. Cylindrical rollers are positioned between the inner and outer rings, and these cylindrical rollers are appropriately inclined with respect to the generatrix of the surfaces of the inner and outer rings. In one direction of relative rotation of the races, the rollers act as wedges between the races to produce a clutch action.

[0007] Another patent document, U.S. Patent No. 5,653,320, describes a tapered roller one-way clutch for use with a vertical shaft having an outer surface, comprising a clutch housing having a bore extending through the housing and a vertical shaft rotatably inserted into the bore, wherein a plurality of roller pockets are formed on the inner surface of the bore, the roller pockets extending axially along the inner surface of the bore from near the top of the bore to near the bottom of the bore and arranged at equal intervals around the circumference of the bore, and each roller pocket further comprises a roller landing which tapers away from the axis of the bore and along the diameter of the bore, and the tapered roller has an outer surface The present invention discloses a tapered roller one-way clutch in which the rollers are rotatably held within each roller pocket by the outer surface of the shaft, the roller landing is inclined with respect to the axis of the bore to hold the tapered rollers at an angle that maximizes surface contact, allowing the outer roller surfaces to roll along the outer surface of the shaft, and the roller landing has an arc-shaped or helical shape from the roller shoulder to the inner cylindrical surface, allowing the tapered rollers to roll and move laterally when the vertical shaft is moved in the clutch direction and the tapered rollers restrain the vertical shaft between the roller landing and the outer shaft surface. [Overview of the project] [Problems that the invention aims to solve]

[0008] The referenced documents disclose different types of one-way clutches, including one-way clutches based on tapered rollers. However, conventional one-way clutches using tapered rollers have the problem that they can only be used in configurations where the corresponding shaft is vertically oriented.

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

[0010] The general objective of this disclosure is to provide a simple, improved, and cost-effective one-way clutch.

[0011] The purpose of this disclosure is to provide a one-way clutch that is easy to manufacture.

[0012] Another object of this disclosure is to provide an improved one-way clutch based on a tapered roller.

[0013] Another object of this disclosure is to provide a one-way clutch based on a tapered roller that can be used in any orientation of the corresponding shaft.

[0014] Another purpose of this disclosure is to solve the problem of spring packaging in conventional one-way clutches.

[0015] Another object of this disclosure is to provide a one-way clutch that optimizes load-bearing capacity for a given size of the one-way clutch. [Means for solving the problem]

[0016] This disclosure relates in general to the technical field of one-way clutches. In particular, this disclosure relates to one-way clutch assemblies based on tapered rollers (also referred to herein as tapered rollers).

[0017] In one embodiment, the one-way clutch of the present disclosure includes an outer body (hereinafter also simply referred to as the body) having an inner circumference with a conical inner surface, a shaft including an outer circumference having a cylindrical outer surface, and a plurality of tapered rollers (hereinafter also simply referred to as rollers, the two terms are used interchangeably) configured between the conical inner surface of the body and the cylindrical outer surface of the shaft. The one-way clutch further includes a single spring that axially biases the plurality of tapered rollers toward the smaller diameter side of each tapered roller (hereinafter also simply referred to as rollers). Rotation of the shaft in a counterclockwise direction when viewed from the large end side of the rollers is prevented by the wedge action of the tapered rollers caused by the biasing force from the spring.

[0018] In one embodiment, a plurality of rollers are supported by a single spring. The spring has a desired profile design comprising multiple spring elements, and each of the plurality of rollers is supported from its large end face by one spring element, biasing the roller toward its small end.

[0019] In one embodiment, the spring may be configured such that, when the shaft is rotated clockwise, the biasing force of the spring is overcome by the property of the roller, which moves axially toward the larger diameter side of the conical inner surface of the main body, as viewed from the large end side of the roller, thereby eliminating the wedge action of the roller and enabling the free rotation of the shaft.

[0020] In one embodiment, the body may include a plurality of pockets, and a plurality of rollers may be arranged within the plurality of pockets, with one tapered roller located in each of the plurality of pockets. Each pocket may have a contour including a conical inner surface to produce a wedge action for locking the corresponding roller in place.

[0021] In one embodiment, the inner circumference of the body may be a truncated periphery comprising multiple segments, each segment located within a corresponding pocket.

[0022] In one embodiment, the one-way clutch may further include a top plate for holding a plurality of tapered rollers in the pockets and a spring positioned adjacent to the rollers. The top plate may be fixed to the body by crimping. In one embodiment, the plurality of pockets may open towards the shaft to facilitate contact between the rollers and the shaft.

[0023] Various objectives, features, aspects and advantages of the subject matter of the present invention will become more apparent from the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings (where like numerals represent like components).

Advantages of the Invention

[0024] A general effect of the present disclosure is to provide a simple, improved, and cost-effective one-way clutch.

[0025] The present disclosure provides a one-way clutch that is easy to manufacture.

[0026] The present disclosure provides an improved one-way clutch based on tapered rollers.

[0027] The present disclosure provides a one-way clutch based on tapered rollers that can be used in any orientation of the corresponding shaft.

[0028] The present disclosure solves the spring packaging problem in conventional one-way clutches.

[0029] The present disclosure provides a one-way clutch that optimizes the load-bearing capacity for a given size of the one-way clutch.

[0030] The accompanying drawings are included to provide a further understanding of the present disclosure, are incorporated herein, and constitute a part hereof. The drawings illustrate exemplary embodiments of the present disclosure and, together with the specification, serve to explain the principles of the present disclosure.

Brief Description of the Drawings

[0031] [Figure 1] This is a cross-sectional view of a conventional one-way clutch. [Figure 2] This is an exemplary cross-sectional view of a one-way clutch along a plane perpendicular to the axis of the proposed one-way clutch, according to an embodiment of the present disclosure. [Figure 3] This is an exemplary side cross-sectional view of a one-way clutch along the diameter plane of a one-way clutch according to a first embodiment of a one-way clutch having a top plate and a spring having a plurality of spring elements. [Modes for carrying out the invention]

[0032] The following is a detailed description of embodiments of the present disclosure shown in the accompanying drawings. The embodiments are so detailed that they clearly convey the present disclosure. However, the degree of detail presented is not intended to limit the expected variations of the embodiments, but rather to cover all modifications, equivalents, and substitutions that fall within the spirit and scope of the present disclosure as defined by the accompanying claims.

[0033] The embodiments described herein generally relate to one-way clutches based on tapered rollers. In one embodiment, by using tapered rollers instead of the cylindrical rollers conventionally used in one-way clutches, the need to bias the rollers radially / tangentially is eliminated and replaced with axial biasing. The spring required for axial biasing is fixed between the top plate and the body of the one-way clutch and is less likely to come loose, thus providing greater reliability. In another embodiment, axial biasing can be provided by a spring element incorporated into a single spring positioned at one end of the roller between the roller and the top plate. In an alternative embodiment, the spring element may be incorporated into the top plate, which further improves reliability. Furthermore, in either case, the proposed modifications make the assembly process easier and less time-consuming.

[0034] Referring to Figure 2, an axial cross-sectional view perpendicular to the axis of the one-way clutch of the present disclosure, the one-way clutch 200 may include an outer body 202 having an inner circumference and a plurality of tapered rollers 210 (hereinafter also referred to as rollers 210) disposed within a plurality of pockets 214 configured inside the outer body 202. The pockets 214 may include a conical inner surface 204 (hereinafter also referred to as conical surface 204) that can engage with the outer conical surface of the tapered roller 210. The pockets 214 may open inward (hereinafter referred to as inner openings) so that the rollers 210 can contact the outer cylindrical surface of a cylindrical shaft 206 (hereinafter also referred to as shaft 206) disposed inside the outer body 202. The shaft 206 includes a cylindrical outer surface 208.

[0035] In one embodiment, the inner opening of the pocket may be smaller than the diameter of the roller 210, such as the diameter at the large end of the roller 210. This prevents the tapered roller 210 from coming out of the pocket when the shaft 206 is not in a fixed position.

[0036] In one embodiment, the one-way clutch 200 may further include a top plate 212 (see Figure 3) to axially hold a plurality of rollers 210. Furthermore, a plurality of springs 216 are positioned between the top plate 212 and the rollers 210 to bias the rollers 210 axially. The top plate 212 may be fixed to the outer body 202 by crimping. In one embodiment, the function of the plurality of springs 216 may be incorporated into a single component positioned between the outer body 202 and the top plate 212. In one embodiment, the conical surface 204 and the rollers 210 may be configured such that the rollers 210 are axially biased by the springs 216 toward the smaller diameter side of each tapered roller 210. For example, the larger diameter side of the conical surface 204 of the pocket 214 may be toward the top plate 212.

[0037] In one embodiment, the multiple springs 216 may be spring elements / fingers (also referred to herein as springs 216) incorporated into a single profile plate / diaphragm spring that can be positioned at one end of the roller between the roller 210 and the top plate 212, thereby causing the profile spring elements / fingers 216 to contact the larger diameter side of the roller 210 and bias each roller 210 in the axial direction.

[0038] Figure 3 is a side cross-sectional view relating to the spring and top plate of the one-way clutch 200 of the present invention, which has a first embodiment and a second embodiment, respectively.

[0039] In the first embodiment shown in Figure 3, the top plate 212 and the springs 216 are separate components, and the springs 216 are positioned between the rollers and the top plate 212 such that each spring 216 biases one of the rollers 210.

[0040] Accordingly, this disclosure provides a robust one-way clutch that overcomes the problems associated with conventional one-way clutches by replacing the spring that radially biases the roller with a spring that provides an inherently more stable axial bias. By using a spring that axially biases the roller, the space previously occupied by the spring in conventional designs becomes free, allowing for increased load-bearing capacity and a simplified structure. Furthermore, the absence of a cavity in the outer body for accommodating the spring makes the outer body more robust, which also helps to increase the load-bearing capacity of the clutch. Thus, the load-bearing capacity is increased for a given size of the clutch. Alternatively, the size of the clutch can be reduced for a given load-bearing capacity, making clutch packaging easier.

[0041] While the above discloses various embodiments of the present invention, other further embodiments of the present invention may be devised without departing from the basic scope of the invention. The scope of the present invention is determined by the scope of the following claims. The present invention is not limited to the embodiments, versions, or examples described herein. These are listed so that a person skilled in the art can construct and use the present invention in combination with information and knowledge available to a person skilled in the art.

Claims

1. An outer body (202) having an inner circumference with a conical inner surface (204), A shaft (206) having an outer circumference with a cylindrical outer surface (208), A plurality of tapered rollers (210) are formed between the conical inner surface (204) of the outer body (202) and the cylindrical outer surface (208) of the shaft (206), Multiple springs (216) are configured to bias each of the multiple tapered rollers (210) axially toward the smaller diameter side of each tapered roller (210). A one-way clutch (200) comprising, One-way clutch (200) prevents the rotation of the shaft (206) in a counterclockwise direction when viewed from the big end side of the tapered roller (210) due to the wedge action 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 finger of a single diaphragm spring.

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

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

5. The one-way clutch according to claim 1, wherein the plurality of pockets (214) have a profile surface including the conical inner surface for generating the wedge action.

6. The one-way clutch according to claim 4, wherein the inner circumference of the outer body (202) is a truncated periphery having a plurality of segments, each segment located in a corresponding pocket (214).

7. The one-way clutch (200) further comprises a top plate (212) for holding the plurality of tapered rollers (210) and the spring (216) within the pocket (214), wherein the top plate (212) is fixed to the outer body (202) by crimping, as described in claim 4.

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

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