CN112178072B

CN112178072B - Overrunning clutch

Info

Publication number: CN112178072B
Application number: CN202011227178.1A
Authority: CN
Inventors: 许涛; 许水电; 李延福; 严春波; 陈志伟
Original assignee: Tranf Technology Xiamen Co ltd
Current assignee: Tranf Technology Xiamen Co ltd
Priority date: 2020-11-06
Filing date: 2020-11-06
Publication date: 2022-06-03
Anticipated expiration: 2040-11-06
Also published as: CN112178072A

Abstract

The overrunning clutch comprises an inner ring, an outer ring and a plurality of special-shaped rolling bodies arranged between the inner ring and the outer ring, wherein the surfaces of the special-shaped rolling bodies are provided with at least two sections of arc surfaces, and the two sections of arc surfaces have different circle centers, so that the special-shaped rolling bodies can be mutually abutted when rolling, and the surfaces of the special-shaped rolling bodies are respectively abutted against the outer wall of the inner ring and the inner wall of the outer ring. The non-concentric arc surfaces respectively realize the butt connection with other special-shaped rolling bodies and the inner ring and the outer ring when the inner ring rotates to drive the special-shaped rolling bodies to rotate, and then the overrunning clutch effect can be realized.

Description

Overrunning clutch

Technical Field

The invention relates to the technical field of clutches, in particular to an overrunning clutch.

Background

The overrunning clutch is a basic component which appears along with the development of mechatronics products, and is an important part for power transmission and separation functions between a prime mover and a working machine or between a driving shaft and a driven shaft in the machine. It is a device with self-clutch function by using speed change of driving and driven parts or change of rotation direction.

Overrunning clutches are generally classified into wedge type overrunning clutches, roller type overrunning clutches, and ratchet type overrunning clutches. The wedge overrunning clutch uses the special-shaped wedge to replace the roller as a wedge part and is a clutch with a friction pair consisting of the wedge, an inner raceway and an outer raceway. When the inner ring, the outer ring and the wedge blocks do not move relatively, the rotation directions are the same, the rotating speeds are equal, the torque can be transmitted, otherwise, the torque is transmitted in a relative sliding mode, and the sliding state without transmitting the torque is called overrunning. The wedge type overrunning clutch mainly comprises a basic type, a non-inner ring type and a type with a bearing. The connection mode of the chain wheel is divided into key connection, gear connection, belt wheel connection, chain wheel connection, bolt connection and the like. The roller type overrunning clutch is divided into an inner star wheel type and an outer star wheel type. In order to facilitate machining and ensure machining accuracy, an inner star wheel is widely used. The wedge type wedge has the advantages that the number of wedges can be arranged more, but a retainer is needed to position the wedges, and the retainer is easily influenced by eccentricity, so that the retainer is easily stressed and deformed to cause asynchrony until the bearing capacity is reduced to cause early damage.

The existing overrunning clutch has a complex structure, generally needs to realize the function of overrunning clutch by utilizing the matching of a spring or a retainer structure, and the service life of the existing overrunning clutch is easily influenced by the spring or the retainer.

Disclosure of Invention

In order to solve the technical problems that an overrunning clutch in the prior art is complex in structure and easy to influence the service life by a spring or a retainer, the invention provides the overrunning clutch which is used for solving the problems.

The overrunning clutch comprises an inner ring, an outer ring and a plurality of special-shaped rolling bodies arranged between the inner ring and the outer ring, wherein the surfaces of the special-shaped rolling bodies are provided with at least two sections of arc surfaces, and the two sections of arc surfaces have different circle centers, so that the special-shaped rolling bodies can be mutually abutted when rolling, and the two sections of arc surfaces are respectively abutted against the outer wall of the inner ring and the inner wall of the outer ring. The inner ring and the outer ring are mutually abutted or separated by utilizing different arc surfaces of the special-shaped rolling bodies, so that the meshing or overrunning state is realized.

Preferably, the profiled rolling elements comprise rollers. The roller can be obtained by cold-drawing process, and the processing process is relatively simple.

Preferably, the special-shaped rolling body surface comprises two arc surfaces, and the two arc surfaces have different circle centers. The arrangement ensures that the arc surface of the special-shaped rolling body is in an outward convex state, so that the rolling body is convenient to abut against the inner ring and the outer ring on one hand; on the other hand, different circle centers are arranged to form a segment difference protruding structure to play a role in limiting between the rolling bodies, and the clutch is prevented from losing efficacy due to autorotation when the rolling bodies are disengaged.

Preferably, the surface of the special-shaped rolling body is provided with a concave structure, so that the gravity center of the special-shaped rolling body is deviated to one side of the special-shaped rolling body. By means of the arrangement, the special-shaped rolling bodies can rotate towards the meshing direction under the action of centrifugal force when the outer ring rotates, so that the special-shaped rolling bodies and the inner ring and the outer ring are in butt joint.

Further preferably, the surface of the special-shaped rolling body is also provided with a protruding structure, and the height of the protruding structure is at least larger than the gap between the two special-shaped rolling bodies. The arrangement of the convex structure can prevent the phenomenon that the special-shaped rolling bodies are subjected to the reaction force of the inner ring and the outer ring to generate reverse rotation when being disengaged, so that the clutch fails.

Further preferably, the concave structures and the convex structures are arranged on the surface of the side of the special-shaped rolling body facing the outer ring. By means of the arrangement, the gravity center position of the special-shaped rolling body can be controlled, so that the special-shaped rolling body is tightly attached to the inner ring and the outer ring under the action of centrifugal force when the special-shaped rolling body works.

Further preferably, the surface of the special-shaped rolling body is provided with a first arc surface, a second arc surface, a third arc surface and a fourth arc surface, and the second arc surface, the third arc surface and the fourth arc surface have the same circle center. The four sections of arc surfaces are provided with two circle centers, so that the abnormal rolling bodies cannot be mutually abutted when rotating.

Further preferably, the first arc surface, the second arc surface, the third arc surface and the fourth arc surface have the same radius.

Preferably, the first arc surface is configured to abut against an outer wall of the inner ring, the third arc surface is configured to abut against an inner wall of the outer ring, and the second arc surface and the fourth arc surface are configured to abut against arc surfaces on adjacent special-shaped rolling bodies. The four arc surfaces are arranged to realize the mutual butt between different special-shaped rolling bodies and between the special-shaped rolling bodies and the inner ring and the outer ring.

Further preferably, the concave structure is located between the second arc surface and the third arc surface, and the convex structure is located between the third arc surface and the fourth arc surface. The concave structure and the convex structure are arranged between different arc surface sections, so that the arc surface can be divided into different butting intervals.

The overrunning clutch has the advantages that the plurality of special-shaped rolling bodies are arranged between the inner ring and the outer ring, the effect of overrunning clutch can be realized by synchronously realizing abutting engagement between the special-shaped rolling bodies and the inner ring and the outer ring by utilizing the arrangement of the plurality of sections of non-concentric arc surfaces on the special-shaped rolling bodies during autorotation, the phenomenon of idling of the special-shaped rolling bodies is further prevented by utilizing the concave or convex structures on the special-shaped rolling bodies, the structure of the overrunning clutch is simple, the effect of overrunning clutch can be realized without utilizing a retainer and a spring, the service life is longer than that of a common roller or wedge type overrunning clutch with the retainer and the spring, the special-shaped rolling bodies can be processed by a cold drawing process, and the processing process is also simpler.

Drawings

The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain the principles of the invention. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

FIG. 1 is an internal block diagram of an overrunning clutch according to one embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of a contoured rolling element of an overrunning clutch according to one embodiment of the present invention;

FIG. 3 is a schematic diagram of a self-locking state of an overrunning clutch according to one embodiment of the present invention;

FIG. 4 is a schematic diagram of an overrunning condition of an overrunning clutch according to one embodiment of the present invention.

Detailed Description

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as "top," "bottom," "left," "right," "up," "down," etc., is used with reference to the orientation of the figure(s) being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and logical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

Fig. 1 shows an internal structural view of an overrunning clutch according to an embodiment of the present invention. As shown in fig. 1, the overrunning clutch includes an inner race 1, an outer race 2, and a shaped rolling body 3. The inner ring 1 is used for being connected with a driving shaft, a through hole and a key groove which are connected with the driving shaft are formed in the inner ring 1, a plurality of special-shaped rolling bodies 3 are uniformly distributed between the inner ring 1 and the outer ring 2 along the circumferential direction, the special-shaped rolling bodies 3 can be arranged between the inner ring 1 and the outer ring 2 in a self-rotating mode, and the structures of the inner ring 1, the outer ring 2 and the special-shaped rolling bodies 3 of the overrunning clutch simplify the overall structure of the overrunning clutch, eliminate the arrangement of a retainer and a spring and achieve light weight of the overrunning clutch.

With continued reference to fig. 2, fig. 2 shows a schematic cross-sectional view of the special-shaped rolling element of the overrunning clutch according to a specific embodiment of the present invention, as shown in fig. 2, the special-shaped rolling element 3 is of a roller structure, and its cross section includes a first arc surface 31, a second arc surface 32, a third arc surface 33 and a fourth arc surface 34, preferably, the first arc surface 31, the second arc surface 32, the third arc surface 33 and the fourth arc surface 34 have the same radius, and their centers are all located inside the special-shaped rolling element 3, so that all the arc surfaces are of a convex structure, and are convenient to abut against each other or against the inner ring 1 or the outer ring 2, and the same radius setting can also facilitate processing and control of the self-locking angle. The second arc surface 32, the third arc surface 33 and the fourth arc surface 34 have the same circle center, the circle center of the first arc surface 31 is different from the circle centers of the second arc surface 32, the third arc surface 33 and the fourth arc surface 34, and the two circle centers are arranged so that at least two sections of arc surfaces of the special-shaped rolling body 3 can be respectively abutted against the inner ring 1 and the outer ring 2 during rotation to obtain the state of meshing transmission of the inner ring and the outer ring. It should also be appreciated that, besides the four-segment structure, the arc surface segments may be arranged as at least two segments of non-concentric arc surface segments according to different design requirements, such as the self-locking angle, and the radius may be adjusted accordingly according to different requirements, so as to achieve the technical effects of the present invention.

In a preferred embodiment, a concave structure 35 is arranged between the second arc surface 32 and the third arc surface 33, a convex structure 36 is arranged between the third arc surface 33 and the fourth arc surface 34, and the convex height of the convex structure 36 is larger than the gap between the two profiled rolling elements 3. The concave structures 35 and the convex structures 36 can further make the gravity center of the special-shaped rolling body 3 deviated to the convex side, so that the special-shaped rolling body can rotate under the action of centrifugal force when rotating or rotating along with the inner and outer rings, and the direction always faces to the direction meshed with the inner and outer rings under the action of the centrifugal force. In addition, the bulge structure 36 can also limit the autorotation of the special-shaped rolling body 3, the special-shaped rolling body 3 is meshed with the inner ring and the outer ring when the clutch is in a locked state, when the locked state is released, the special-shaped rolling body 3 is reversely bounced off by the reverse acting force of the inner ring and the outer ring at the moment of disengagement, so that the special-shaped rolling body reversely autorotates, at the moment, the bulge formed among the bulge structure 36, the first arc surface 31 and the second arc surface 32 due to different circle centers has a limiting effect on the special-shaped rolling body 3, the special-shaped rolling body cannot reversely rotate at a large angle, meanwhile, the special-shaped rolling body is reset under the action of centrifugal force according to the gravity center of the special-shaped rolling body 3 and is kept always in contact with the inner ring and the outer ring under the action of the centrifugal force, the clutch is prevented from being out of work, and the special-shaped rolling body 3 can be self-locked again under the action of the centrifugal force during subsequent use.

In a specific embodiment, the overrunning clutch further comprises an upper end cover and a lower end cover, and the upper end cover and the lower end cover are used for sealing the special-shaped rolling bodies 3 between the inner ring 1 and the outer ring 2 so as to prevent the special-shaped rolling bodies 3 from being separated from the inner ring and the outer ring in the operation process of the overrunning clutch and damage the overrunning clutch.

In a specific embodiment, the operating principle of the overrunning clutch is as follows: the outer ring 2 rotates, the outer ring 2 rotates through relative motion with any one of the special-shaped rolling bodies 3 which is in contact with the outer ring 2 when rotating, so that the special-shaped rolling body 3 rotates towards one side of the gravity center of the special-shaped rolling body 3, one section of at least two sections of arc surfaces with different circle centers arranged on the special-shaped rolling body 3 is abutted against the outer wall of the inner ring 1, the other section of arc surface is abutted against the inner wall of the outer ring 2, meanwhile, the adjacent special-shaped rolling bodies 3 are also abutted against each other, and at the moment, the special-shaped rolling bodies 3 respectively form a self-locking angle alpha with the outer ring 2 and the inner ring 1₁And alpha₂At the same timeThe self-locking requirement is met: no matter how much acting force is applied to the special-shaped rolling bodies 3 in the direction, the self-locking angle alpha is always kept within a certain range (for example, less than 5 degrees), the clutch is self-locked, and the inner ring 1 and the outer ring 2 rotate simultaneously. When the rotating speeds of the inner ring and the outer ring are different (when the rotating speed of the inner ring is higher than that of the outer ring), the special-shaped rolling bodies 3 perform reverse rotation at the moment of relative action of the inner ring and the outer ring at different rotating speeds, so that one of at least two sections of arc surfaces with different circle centers is separated from the outer wall of the inner ring 1, the special-shaped rolling bodies 3 slide relative to the inner ring and the outer ring after being reset under the action of centrifugal force, the self-locking angle cannot be formed, the inner ring 1 and the outer ring 2 are relatively independent, and the clutch is in an overrunning state at the moment. In the process, the self-rotation angle of the special-shaped rolling body 3 is limited by the convex structure 36 and the convex formed between the first arc surface 31 and the second arc surface 32 due to different circle centers, so that the special-shaped rolling body 3 is prevented from idling to cause the inner ring 1 and the outer ring 2 to be incapable of being abutted and the clutch is prevented from failing.

Fig. 3 is a schematic diagram illustrating a self-locking state of the overrunning clutch according to an embodiment of the present invention, as shown in fig. 3, under a counter-clockwise rotation of the outer ring 2, one of the irregular rolling elements 3 contacting with the outer ring 2 rotates counterclockwise under a centrifugal force, at this time, the first arc surface 31 abuts against an outer wall of the inner ring 1, the third arc surface 33 abuts against an inner wall of the outer ring 2, and simultaneously, two adjacent irregular rolling elements 3 abut against each other synchronously through the second arc surface 32 and the fourth arc surface 24, at this time, a self-locking angle α formed by the inner ring 1 and the outer ring 2 at the irregular rolling elements 3 respectively is formed₂And alpha₁And meanwhile, the self-locking requirement is met, the clutch is in a self-locking state, and the inner ring and the outer ring synchronously rotate under the state.

Fig. 4 is a schematic diagram showing an overrunning state of the overrunning clutch according to an embodiment of the present invention, as shown in fig. 4, when the rotation speed of the outer ring 2 is lower than that of the inner ring 1, the rotation speed difference between the inner ring and the outer ring changes the opposite rolling elements 3 from the engaged state to the disengaged state, and then the special-shaped rolling elements 3 are reset under the action of centrifugal force and continue to maintain contact with the inner ring and the outer ring, at this time, the inner ring 1 and the special-shaped rolling elements 3 are in a sliding friction relationship, the special-shaped rolling elements 3 cannot form a self-locking angle with the inner ring and the outer ring, the rotation of the inner ring 1 cannot be transmitted to the outer ring 2, the outer ring 2 can also maintain a higher rotation speed, and the clutch is in the overrunning state. In the process, when rotating clockwise, the convex structure 36 between the third arc surface 33 and the fourth arc surface 34 will collide with the second arc surface 32 on the adjacent special-shaped rolling body, and the protrusion formed between the first arc surface 31 and the second arc surface 32 due to different circle centers will collide with the fourth arc surface on the adjacent special-shaped rolling body, so that the special-shaped rolling body 3 cannot idle, and the clutch failure caused by the fact that the overrunning clutch cannot be switched to the self-locking state again is avoided. The concave structure 35 between the second arc surface 32 and the third arc surface 33 makes the gravity center of the special-shaped rolling body 3 biased to one side of the convex structure 36, when the overrunning clutch needs to be locked again, the centrifugal force can provide acting force for counterclockwise rotation of the special-shaped rolling body 3, so that at least one special-shaped rolling body 3 can form a self-locking angle meeting the self-locking requirement with the inner ring 1 and the outer ring 2 again, and a locking state is formed.

Compared with the traditional clutch in the prior art, the overrunning clutch is simpler, the function of the overrunning clutch can be realized without using a retainer and a spring, the self-locking and overrunning functions of the overrunning clutch are realized by means of linkage loading of a plurality of special-shaped rolling bodies, the structure is simpler, the stability is higher, the bearing performance is stronger, the service life is not influenced by the retainer and the spring, the special-shaped rolling bodies can be manufactured by adopting a cold drawing process, and the processing process is simpler.

It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present invention without departing from the spirit and scope of the invention. In this way, if these modifications and changes are within the scope of the claims of the present invention and their equivalents, the present invention is also intended to cover these modifications and changes. The word "comprising" does not exclude the presence of other elements or steps than those listed in a claim. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims shall not be construed as limiting the scope.

Claims

1. An overrunning clutch is characterized by comprising an inner ring, an outer ring and a plurality of special-shaped rolling bodies arranged between the inner ring and the outer ring, wherein the surface of each special-shaped rolling body is provided with at least two sections of arc surfaces, the two sections of arc surfaces are provided with different circle centers, so that the special-shaped rolling bodies can be mutually abutted when rolling, the surfaces of the special-shaped rolling bodies are respectively abutted against the outer wall of the inner ring and the inner wall of the outer ring, the outer ring is enabled to rotate towards one side of the gravity center of the special-shaped rolling bodies through the relative motion of the special-shaped rolling bodies contacting with any one of the outer ring when rotating, one section of the at least two sections of arc surfaces with different circle centers arranged on the special-shaped rolling bodies is abutted against the outer wall of the inner ring, the other section of arc surface is abutted against the inner wall of the outer ring, and the adjacent special-shaped rolling bodies are also mutually abutted, at this time, the special-shaped rolling bodies form a self-locking angle alpha with the outer ring and the inner ring respectively₁And alpha₂Meanwhile, the self-locking requirement is met; when the rotating speeds of the inner ring and the outer ring are different, the special-shaped rolling bodies perform reverse rotation at the moment of the relative action of the different rotating speeds of the inner ring and the outer ring, so that one section of at least two sections of arc surfaces with different centers of circles is separated from the outer wall of the inner ring, and after the special-shaped rolling bodies are reset under the action of centrifugal force, the special-shaped rolling bodies slide relative to the inner ring and the outer ring and cannot form the self-locking angle.

2. An overrunning clutch according to claim 1 wherein said profiled rolling elements comprise rollers.

3. The overrunning clutch of claim 1, wherein the contoured rolling body surface comprises two arcuate surfaces, and the two arcuate surfaces have different centers.

4. The overrunning clutch of claim 1, wherein the surface of the shaped rolling body is provided with a recess structure such that the center of gravity of the shaped rolling body is offset to one side of the shaped rolling body.

5. The overrunning clutch of claim 4, wherein said contoured rolling elements further have raised structures on their surfaces, said raised structures having a height at least greater than the gap between said contoured rolling elements.

6. An overrunning clutch according to claim 5, wherein said recesses and said protrusions are provided on a surface of said shaped rolling elements on a side facing said outer race.

7. The overrunning clutch according to claim 5, wherein the surface of the special-shaped rolling body is provided with a first arc surface, a second arc surface, a third arc surface and a fourth arc surface, and the second arc surface, the third arc surface and the fourth arc surface have the same circle center.

8. The overrunning clutch of claim 7, wherein the first arcuate surface, the second arcuate surface, the third arcuate surface and the fourth arcuate surface have the same radius.

9. The overrunning clutch according to claim 7, wherein the first arc surface is configured to abut against an outer wall of the inner ring, the third arc surface is configured to abut against an inner wall of the outer ring, and the second arc surface and the fourth arc surface are configured to abut against adjacent arc surfaces on the special-shaped rolling elements.

10. An overrunning clutch according to claim 7 wherein said recessed formation is located between said second arcuate surface and said third arcuate surface and said raised formation is located between said third arcuate surface and said fourth arcuate surface.