Cam and one-way cam clutch

Abstract

The object of the present invention is to provide a cam and a one-way cam clutch that achieves lightweighting and reduced manufacturing costs, and offers high design freedom and excellent responsiveness in the cam's center of gravity position. Specifically, the above-mentioned problems are solved by the following: on a cam (130) that contacts the inner ring (110) and outer ring (120) by applying torque in the meshing direction using an annular spring (160), a plurality of cam plates (131) having the same outer peripheral profile shape and arranged side by side in the rocking axis direction are integrally connected by a connecting pin (135) extending in the rocking axis direction; and the annular spring (160) is configured to be able to be installed between adjacent cam plates (131) and / or on the outside of the rocking axis direction of the plurality of cam plates (131). Furthermore, the above-mentioned problems are solved by configuring the cam (130) as an engaging member on the one-way cam clutch (100).

Description

Technical Field

[0001] The present invention relates to a cam and a one-way cam clutch using the cam as an engaging element, the cam being disposed in an annular space between an inner ring and an outer ring to transmit or cut off torque between the inner and outer rings. Background Technology

[0002] A one-way cam clutch is a structure in which a cam engages in one direction to transmit torque between the input and output shafts, and does not engage in other directions to allow idling. This characteristic can be used in many industrial machines.

[0003] A certain type of one-way cam clutch is configured to transmit and cut off torque from the driving side to the driven side by engaging and disengaging multiple cams (wedges) arranged in an annular space between the inner and outer rings according to the relative movement of the inner and outer rings.

[0004] As such a one-way cam clutch, one known configuration is to form a spring mounting groove extending in the circumferential direction on the inner ring side engagement surface or the outer ring side engagement surface of each of the plurality of cams, and to fit an annular spring into the spring mounting groove of each of the plurality of cams, thereby imparting torque in the engagement direction of the cams (see, for example, Patent Document 1).

[0005] Figure 11 This is a three-dimensional diagram representing an example of the configuration of an existing cam.

[0006] The cam 230 is configured such that a spring mounting groove 236 is formed on the outer ring side engagement surface 233, and the force of the annular spring is applied radially inward.

[0007] like Figure 12 As shown, the spring mounting groove 236 is formed by two straight grooves 237 and 23, and is configured such that the angle of the top 238, which is sandwiched between the bottom surfaces of each straight groove 237 and 237, is an obtuse angle. The top 238 of the spring mounting groove 236 is formed relative to the rocking shaft in a position biased towards the engagement direction of the cam 230, and the annular spring is always in contact with the top 238.

[0008] The spring mounting groove 236 is, for example, formed by using a disc milling cutter when cutting steel such as a round wire that has been machined into a specified outer peripheral contour shape to a specified thickness.

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 9-177840 Summary of the Invention

[0011] Furthermore, centrifugal force is utilized in one-way cam clutches to minimize energy loss. From this perspective, the design of the center of gravity position in the cross-section orthogonal to the cam shaft becomes an important factor, and the shape of each cam needs to be designed according to the required performance (application) of the one-way cam clutch.

[0012] However, since existing cams are composed of a single component, the design of the center of gravity position on the cross section in the orthogonal direction of the cam axis has to be done by changing the material, shape, size, etc. of the cam, which results in a significant limitation on the design of the center of gravity position.

[0013] Furthermore, in the aforementioned one-way cam clutch, the structure of using ring springs to restrict multiple cams requires machining spring mounting slots for each of the multiple cams, thus increasing the machining burden. Moreover, special machinery for slot machining must be used to machine the spring mounting slots, resulting in increased manufacturing costs.

[0014] The present invention is based on the above situation, and the technical problem to be solved is to provide a cam and a one-way cam clutch that can achieve lightweight and reduced manufacturing costs, and has a high degree of design freedom and excellent responsiveness in the cam center of gravity position.

[0015] The present invention relates to a cam disposed in an annular space between an inner ring and an outer ring, and configured to contact the inner and outer rings by applying torque in the meshing direction using an annular spring. The invention addresses the aforementioned problem by comprising: a plurality of cam plates having the same outer peripheral profile shape and arranged side-by-side in the rocking axis direction; and a connecting pin arranged to extend in the rocking axis direction and connect the plurality of cam plates to each other, wherein the annular spring is configured to be mounted between adjacent cam plates and / or on the outer side of the plurality of cam plates in the rocking axis direction.

[0016] Furthermore, the present invention is a one-way cam clutch comprising: an inner ring and an outer ring, configured to rotate relative to each other on the same axis; a plurality of engaging members disposed in the circumferential direction in an annular space between the inner ring and the outer ring; and an annular spring that applies force to the plurality of engaging members in the engagement direction relative to the inner ring and the outer ring. The problem can be solved by wherein each of the plurality of engaging members is constituted by the aforementioned cam, and the annular spring is mounted between adjacent cam plates of each of the plurality of engaging members and / or on the outer side of the rocking axis direction of the plurality of cam plates.

[0017] According to the cam described in this technical solution 1, since the position and size of the connecting pin connecting the adjacent cam plate can be adjusted, the center of gravity position of the cam in the orthogonal direction section of the rocking axis can be adjusted, thus improving the design freedom of the cam's center of gravity position and enabling flexible adaptation to the outer peripheral contour shape of the cam 130 corresponding to the required performance.

[0018] Furthermore, since the space where there is no cam plate can be used as the mounting part for the annular spring, there is no need to process the annular spring mounting groove during the manufacturing process of the cam. In addition, since each cam plate and pin hole can be made simultaneously by punching holes in the sheet metal, the processing burden can be reduced, productivity can be improved, and manufacturing costs can be reduced.

[0019] Furthermore, since the structure does not have any excess material (unnecessary parts) in the part supporting the annular spring, it is possible to achieve lightweight design.

[0020] According to the configuration described in this technical solution 2, since misalignment in the relative positional relationship (or orientation of the cam plates) of the multiple cam plates can be avoided, differences in the degree of meshing of the various cam plates can be avoided.

[0021] According to the configuration described in technical solution 3, since the connecting pin can also serve as a force-bearing part that bears the applied force from the annular spring, it is not necessary to provide a separate component constituting the force-bearing part in addition to the connecting component of the connecting cam plate, thus achieving weight reduction and cost reduction. Furthermore, since only simple hole machining is required on the cam plate, the machining burden can be reduced, which also improves productivity and reduces manufacturing costs.

[0022] According to the configuration described in technical solution 4, since the force from the annular spring can be applied appropriately in the engagement direction of the cam, the orientation of the cam can be stably maintained.

[0023] According to the configuration described in technical solution 5, since the force-adding unit support plate does not contact the inner and outer rings, friction loss can be reduced.

[0024] According to the one-way cam clutch described in technical solution 6, by using a cam with the above-described configuration as the engaging element, it is possible to achieve lightweighting and reduced manufacturing costs, as well as excellent responsiveness and the expected torque transmission performance. Attached Figure Description

[0025] Figure 1 This is a schematic cross-sectional view of a portion of the rotating shaft in an orthogonal direction, representing an example of a one-way cam clutch of the present invention.

[0026] Figure 2 yes Figure 1 The diagram shows a cross-sectional view of a one-way cam clutch along its axis of rotation.

[0027] Figure 3 It means Figure 1 The diagram shows a three-dimensional representation of the cam configuration in a one-way cam clutch.

[0028] Figure 4 yes Figure 3 The exploded perspective view of the cam shown.

[0029] Figure 5 yes Figure 3 The cam shown is viewed from the direction of the rocking axis.

[0030] Figure 6A It is a schematic representation. Figure 1 The cross-sectional view of the cam's state (attitude) during engagement of the one-way cam clutch is shown.

[0031] Figure 6B It is a schematic representation. Figure 1 The cross-sectional view of the state (attitude) of the cam during idling of the one-way cam clutch is shown.

[0032] Figure 7 This is a perspective view showing other configuration examples of the cam of the present invention.

[0033] Figure 8 yes Figure 7 The exploded perspective view of the cam shown.

[0034] Figure 9 yes Figure 7 The cam shown is shown as a cross-sectional view orthogonal to its rocking axis.

[0035] Figure 10 This is a perspective view showing further configuration examples of the cam of the present invention.

[0036] Figure 11 This is a three-dimensional diagram representing an example of the configuration of an existing cam.

[0037] Figure 12 yes Figure 11 The cam shown is shown as a cross-sectional view orthogonal to its rocking axis.

[0038] Symbol Explanation

[0039] 100 - One-way cam clutch; 110 - Inner ring; 111 - Track surface; 120 - Outer ring; 121 - Track surface; 130, 230 - Cam; 131 - Cam plate; 132 - Inner ring side engagement surface; 133, 233 - Outer ring side engagement surface; 134 - Pin hole; 135 - Connecting pin; 236 - Spring mounting slot; 237 - Straight groove; 238 - Top; 140 - Force-applying unit support plate; 141 - Pin hole; 150 - Cam retainer; 160 - Ring spring. Detailed Implementation

[0040] like Figure 1 and Figure 2 As shown, the one-way cam clutch 100 of the present invention includes: an inner ring 110 and an outer ring 120, which are configured to rotate relative to each other on the same axis; a plurality of cams 130, which are arranged in the circumferential direction in the annular space between the track surface 111 of the inner ring 110 and the track surface 121 of the outer ring 120, serving as engaging members for transmitting and disengaging torque between the inner ring 110 and the outer ring 120; a cam retainer 150, which holds each of the plurality of cams 130 in a position arranged at predetermined intervals in the circumferential direction, and an annular spring 160, which applies force to each of the plurality of cams 130 in the engagement direction relative to the inner ring 110 and the outer ring 120.

[0041] Also Figure 3 and Figure 4 As shown, each of the plurality of cams 130 comprises the following components: two cam plates 131 arranged side by side in the direction of the rocking axis; and a connecting pin 135, which is configured to extend in the direction of the rocking axis to connect the two cam plates 131 to each other. By forming this configuration, the center of gravity position of the cam 130 in the orthogonal direction of the rocking axis can be adjusted by adjusting the position and size of the connecting pin 135. Therefore, the design freedom of the center of gravity position of the cam 130 can be improved, and the outer peripheral profile shape of the cam 130 can be flexibly adapted to the required performance.

[0042] In this embodiment, such as Figure 5 As shown, the position of the connecting pin 135 is set such that, relative to the normal H on the tangent point C of the outer ring side engagement surface 133 of the cam 130 and the track surface 121 of the outer ring 120, the center of gravity G of the cam 130 is formed at a position biased towards the engagement direction.

[0043] Each cam plate 131 has the same outer peripheral profile shape. Therefore, there is no difference in the degree of meshing between the cam plates 131, which reduces frictional losses. Furthermore, it enables increased productivity and reduced manufacturing costs.

[0044] like Figure 5As shown, the cam plate 131 has an inner ring side engagement surface 132 that abuts against the track surface 111 of the inner ring 110 and an outer ring side engagement surface 133 that abuts against the track surface 121 of the outer ring 120. The cross-sectional shape of the inner ring side engagement surface 132 is, for example, an arc shape, and the cross-sectional shape of the outer ring side engagement surface 133 is curved, which includes an arc-shaped portion with a radius of curvature smaller than that of the inner ring side engagement surface 132. Furthermore, in Figure 5 For convenience, parallel planes are used to represent the track surface 111 of the inner ring 110 and the track surface 121 of the outer ring 120.

[0045] A pin hole 134 extending through the thickness direction is formed on the cam plate 131. By pressing the connecting pin 135 into the pin hole 134, the two cam plates 131 can be fixed together.

[0046] This configuration avoids misalignment in the relative positional relationship (or orientation) of the two cam plates 131, thus preventing differences in the degree of meshing between the cam plates 131. Furthermore, since both the cam plates 131 and the pin holes 134 can be fabricated simultaneously by punching holes in the sheet metal, this reduces processing workload, improves productivity, and lowers manufacturing costs.

[0047] In this embodiment, the connecting pin 135 is, for example, a cylindrical connecting pin, and thus the pin hole 134 is configured to have a circular opening shape and a hole diameter with a uniform size in the thickness direction.

[0048] Furthermore, each cam 130 is configured such that an annular spring 160 can be installed between the two cam plates 131. That is, in the cam 130 of this embodiment, the space where there is no cam plate 131 can be used as a mounting part for the annular spring 160. Therefore, during the manufacturing process of the cam 130, it is not necessary to process the annular spring mounting groove, thereby reducing the processing burden and improving productivity, and reducing manufacturing costs.

[0049] Furthermore, in this embodiment, the connecting pin 135 on the cam 130 is configured to contact the annular spring 160 to receive the applied force from the annular spring 160. Since the connecting pin 135 can also serve as a force-bearing part that receives the applied force from the annular spring 160, it is not necessary to provide a separate component constituting the force-bearing part in addition to the connecting component of the connecting cam plate 131, thus achieving weight reduction and cost reduction. In addition, since the configuration does not have any excess (unnecessary part) on the part supporting the annular spring 160, weight reduction can be achieved.

[0050] In the one-way cam clutch 100 of this embodiment, as a ring spring 160, for example, a ring-shaped clamp spring is used. With the plurality of cams 130 each arranged in the receiving portion of the cam holder 150, by installing the clamp spring from the outer ring side engagement surface 133 side of the cam 130, it can be configured to apply force to each of the plurality of cams 130 radially inward (see reference). Figure 6A By using clamps to restrain each of the multiple cams 130, all cams 130 are stably held and no unevenness in posture (tilt) is caused.

[0051] Moreover, in the aforementioned one-way cam clutch 100, such as Figure 6A As shown, while the inner ring side engagement surface 132 of the cam 130 is contacted by the force F1 from the annular spring 160 and comes into contact with the track surface 111 of the inner ring 110, the outer ring side engagement surface 133 of the cam 130 contacts the track surface 121 of the outer ring 120, in one direction of the outer ring 120 ( Figure 6A When the cam 130 rotates (in the counterclockwise direction), the inner ring side engagement surface 132 of the cam 130 engages with the track surface 111 of the inner ring 110 through friction, while the outer ring side engagement surface 133 of the cam 130 engages with the track surface 121 of the outer ring 120 through friction, thereby transmitting torque between the inner ring 110 and the outer ring 120.

[0052] On the other hand, such as Figure 6B As shown, in other directions of the outer ring 120 ( Figure 6B When the cam 130 rotates clockwise, it is subjected to a specified centrifugal force F2. Therefore, the cam 130 resists the rotational torque of the annular spring F1 and thus the cam 130 floats relative to the inner ring 110 due to the centrifugal force F2. Consequently, the inner ring side engagement surface 132 of the cam 130 and the track surface 111 of the inner ring 110 become non-contact, thereby cutting off the torque transmission between the inner ring 110 and the outer ring 120. Therefore, frictional wear on the inner ring side engagement surface 132 and the outer ring side engagement surface 133 of the cam 130 during high-speed idling can be prevented.

[0053] Figure 7 and Figure 8 This is a diagram showing other examples of cam configurations.

[0054] The cam 130 is configured to also include a force-applying unit support plate 140, which is configured to contact the annular spring to receive the applied force from the annular spring. Here, in Figure 7 and Figure 8 In the middle, to and Figures 3 to 5 The same components of the cam shown are labeled with the same symbols, and the descriptions are omitted.

[0055] A pin hole 141 extending through the thickness direction is formed on the force-adding unit support plate 140. By pressing the connecting pin 135 connecting the two cam plates 131, 131 into the pin hole 141, the force-adding unit support plate 140 and the two cam plates 131, 131 are integrally fixed.

[0056] like Figure 9 As shown, the force-applying unit support plate 140 has, for example, a planar shape in which a portion of a circular plate is cut off by two planes, the two planes intersecting at an obtuse angle and perpendicular to the circular plate, and forming a force-applying bearing portion that bears the force from the annular spring 160 through the top sandwiched between the two planes.

[0057] In this embodiment, the force-applying unit support plate 140 is disposed between the two cam plates 131, 131, and the annular spring is configured to be mounted between the two cam plates 131, 131. By providing the force-applying unit support plate 140, the force from the annular spring can be appropriately applied in the meshing direction of the cam 130.

[0058] Furthermore, the force-applying unit support plate 140 is located inside the outer periphery of the cam plate 131. As a result, since the force-applying unit support plate 140 does not contact the inner ring 110 and the outer ring 120, friction loss can be reduced.

[0059] While one embodiment of the present invention has been described in detail above, the present invention is limited to the above embodiment. Various design changes can be made without departing from the scope of the present invention as described herein.

[0060] For example, although in the above embodiment the annular spring is installed between the two cam plates, it can also be configured such that the connecting pin protrudes from the outer end face of the cam plate and the annular spring is installed on the outside of the rocking axis direction of the cam plate.

[0061] Furthermore, although it is configured to connect two cam plates using one connecting pin, it can also be configured to connect them using two or more connecting pins.

[0062] Furthermore, the number of cam plates is not limited to two; it can also be three or more. Figure 10 The diagram shows an example configuration of a cam with three cam plates. On this cam 130, the space between two adjacent cam plates 131, 131 can be used as a mounting portion for annular springs, thus allowing the mounting of two annular springs. Therefore, the cam 130 can be reliably supplied with a force suitable for the required function.

[0063] Furthermore, although the cross-sectional shape of the connecting pin and the opening shape of the pin hole are circular in the above embodiment, the cross-sectional shape of the connecting pin and the opening shape of the pin hole are not limited to circular. As long as they are easily manufactured, they can be polygonal, elliptical, oblong, etc. When the cross-sectional shape of the connecting pin and the opening shape of the pin hole are polygonal, the anti-rotation function of preventing the relative rotation of the two cam plates can be more reliably obtained. In addition, the connecting pin does not need to be a cylinder with a uniform outer diameter in the axial direction; it can also have parts with different outer diameters. Although the connecting pin is composed of a different component from the cam plate, it can also be integrally formed with one of the cam plates.

[0064] Furthermore, although in the above embodiment the annular spring is configured to apply force to each of the plurality of cams radially inward, it can also be configured to apply force to each of the plurality of cams radially outward. Moreover, the annular spring is not limited to a clamp spring, as long as it applies force to each of the plurality of cams relative to the inner and outer rings in the meshing direction.

[0065] Furthermore, although the cam is configured as a disengaged type in the above embodiments, it can also be configured as an engaging type in which the center of gravity of the cam is designed to engage by utilizing centrifugal force.

[0066] Furthermore, the one-way cam clutch of the present invention may also be configured to not have a retainer (cam retainer).

Claims

1. A cam, disposed in an annular space between an inner ring and an outer ring, and configured to contact the inner and outer rings by means of a torque applied in the meshing direction by a ring spring, characterized in that, It comprises: a plurality of cam plates having the same outer peripheral contour shape and arranged side by side in the direction of the rocking axis; and a connecting pin, which is configured to extend in the direction of the rocking axis and connect the plurality of cam plates to each other. The annular spring is configured to be installed between adjacent cam plates and on any one or both of the outer sides of the plurality of cam plates in the direction of their rocking axis. The position of the connecting pin is set such that, relative to the normal line on the tangent point between the outer ring side engagement surface of the cam and the track surface of the outer ring, the center of gravity of the cam is formed in a position biased towards the engagement direction or the engagement disengagement direction.

2. The cam according to claim 1, characterized in that, On each of the plurality of cam plates, a pin hole extending through the thickness direction is formed. The plurality of cam plates are integrally fixed by pressing the connecting pin into the pin hole.

3. The cam according to claim 1 or claim 2, characterized in that, The connecting pin is configured to contact the annular spring to receive the applied force from the annular spring.

4. The cam according to claim 1 or claim 2, characterized in that, The force-applying unit support plate is integrally fixed to the adjacent cam plate via the connecting pin. The force-applying unit support plate is configured to contact the annular spring to receive the applied force from the annular spring.

5. The cam according to claim 4, characterized in that, The force-adding unit support plate is located on the inner side of the outer periphery of the cam plate.

6. A one-way cam clutch comprising: an inner ring and an outer ring configured to rotate relative to each other on the same axis; a plurality of engaging members disposed circumferentially in an annular space between the inner ring and the outer ring; and an annular spring for applying force to the plurality of engaging members in an engagement direction relative to the inner ring and the outer ring, characterized in that, Each of the plurality of engaging components is constituted by a cam as described in claim 1, and the annular spring is installed between adjacent cam plates of each of the plurality of engaging components and on either or both of the outer sides of the rocking axis direction of the plurality of cam plates.

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