TW201335503A - One-way clutch - Google Patents

Abstract

The present invention provides a one-way clutch characterized by delicacy, a greater tolerable torque, and excellent productivity. The one-way clutch 10 comprises an outer wheel 12, an inner wheel 20, and a cam holder 30. The cam holder 30 is composed of a pair of holder rings 32, 32. Stops 32a are integrally formed with the holder rings 32 to limit the rotation of cams 38 so that the number of parts can be reduced, the space in the circumferential direction of the holder 30 can be preserved, and additional cams 38 can be included.

Description

One-way clutch

The present invention relates to a centrifugal force split type unidirectional clutch.

The centrifugal force split type one-way clutch (hereinafter, simply referred to as "one-way clutch") includes an inner wheel, a cam cage attached to the inner wheel, a cam supported by the cam holder, and an outer wheel, and the inner wheel is The cam cage is rotated in the same direction. In the assembly of the one-way clutch, a plurality of cams that are biased by the torsion coil spring are pressed to be pressed against the outer circumferential surface of the inner wheel and the inner circumferential surface of the outer wheel. When the drive shaft connected to the inner wheel rotates in one direction, the inner wheel rotates relative to the outer wheel because the cam slides on the inner circumferential surface of the outer wheel. Moreover, once the drive shaft rotates at a high speed in the same direction, the centrifugal force will resist the biasing force of the cam located at a position offset from the center of the shaft of the shaft support cam to the biasing direction of the torsion coil spring, and act to exceed the elastic force of the torsion coil spring, due to The cam rotates to create a gap between the cam and the outer circumferential surface of the inner wheel and the inner circumferential surface of the outer wheel. Therefore, the cam does not rub against the outer circumferential surface of the inner wheel and the inner circumferential surface of the outer wheel, and the inner wheel performs relative to the outer wheel. Idle. At this time, the rotation of the cam is stopped by the stopper portion at a position where the cam can be kept in contact with the outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring. Further, since the cam is biased by the torsion coil spring, when the drive shaft becomes low speed or stopped, the state at the time of assembly is restored. On the other hand, once the drive shaft is intended to rotate in the opposite direction, the cam acts on the cam by friction with the inner peripheral surface of the outer wheel. The torque of the member in the same direction of the biasing direction, and the cam further presses the outer circumferential surface of the inner wheel and the inner circumferential surface of the outer wheel, so that the driving is driven by the friction between the cam and the outer circumferential surface of the inner wheel and the inner circumferential surface of the outer wheel The torque of the shaft is transmitted to the outer wheel through the inner wheel and the cam. Hereinafter, for convenience of explanation, the case where the torque is transmitted from the inner ring to the outer wheel is referred to as an "ON state", and the case where the inner wheel is idling with respect to the outer wheel is referred to as an "OFF state".

The use of such a centrifugal force separation type unidirectional clutch is roughly classified into two types. The first use is used in the following manner: the inner wheel is connected to the drive shaft, the outer wheel is connected to the driven shaft, and is turned on during normal operation, and torque is transmitted from the inner wheel to the outer wheel, and the other On the other hand, when the drive shaft connected to the inner wheel is reversely rotated, or the driven shaft connected to the outer wheel is in the over-speed state, the torque is not transmitted between the inner and outer wheels. Moreover, the second use is used in the following manner: the inner wheel is connected to the mechanical drive shaft, and the outer wheel is fixed so as not to be rotatable. In normal operation, the drive shaft can be rotated in the closed state. When the drive shaft is stopped, it is turned on to prevent the drive shaft from being reversed due to external force. As a specific example, the use example of a ski lift or a tilt conveyor is mentioned, for example.

The centrifugal force separation type unidirectional clutch is a closed state. When the drive shaft rotates at a high speed, a gap is generated between the cam and the outer surface of the outer wheel and the outer surface of the inner wheel by centrifugal force, thereby preventing friction between the cam, the outer wheel and the inner wheel. In addition, it has a larger allowable torque in the ON state (hereinafter, simply referred to as "permissible torque") as compared with other one-way clutches such as a roller free wheel. advantage.

As an example of such a centrifugal force separation type unidirectional clutch, the following are listed.

Patent Document 1: Japanese Patent Laid-Open Publication No. SHO 49-13551

Patent Document 2: Japanese Patent Laid-Open Publication No. 9-151964

The unidirectional clutch disclosed in Patent Document 1 is provided with a cam holder that frictionally engages with the inner wheel on both sides of the cam, and is connected to the state in which the interposer is mounted between the cam and the cam holder. The bolts support the cams, and the cams are biased by the torsion coil springs in a direction to engage the inner and outer wheels. Further, the coil is fitted to the groove of the inner ring to prevent the cam holder from moving in the axial direction. The operation when the drive shaft connected to the inner wheel rotates is as described above. Further, when the drive shaft is rotated at a high speed in the closed state, the cam is rotated by the centrifugal force until it comes into contact with the pin stuck to the end of the torsion coil spring. That is, it becomes a pin to function as a stopper.

In the unidirectional clutch disclosed in Patent Document 2, a pin for synchronous rotation is protruded from the outer side of the cam holder as a synchronous rotating portion, and is engaged with a buckle fitted in a groove provided in the inner wheel. Position the pin for synchronous rotation. Once the drive shaft coupled to the inner wheel rotates, the torque in the same direction as the drive shaft is transmitted to the cam cage as the buckle contacts the pin for synchronous rotation. Further, the cam supported by the cam holder is biased in the direction of engagement with the inner and outer wheels by the torsion coil spring. The operation when the drive shaft connected to the inner wheel rotates is as described above. In addition, when the drive shaft is rotated at a high speed in the closed state, the cam is rotated by the centrifugal force until it is disposed at the end of the cam cage and is caught at the end of the torsion coil spring. The shafts are connected.

In the unidirectional clutches of Patent Documents 1 and 2, since the pin for stopping the rotation of the cam when the drive shaft is rotated at a high speed in the closed state or the stop shaft becomes a necessary number of the respective cams, the number of parts is increased. The manufacturing cost is increased, and there are also problems in terms of miniaturization, assembly, maintenance work hours, and weight. Further, since it is necessary to provide not only the shaft of the cam but also the hole for the pin or the stop shaft to the cam holder, it is necessary to perform drilling and chamfering work. In particular, since the chamfering operation of the dish can be performed only once, the processing cost and time will be incurred. Further, as in Patent Document 2, the pin for synchronous rotation and the cam holder are separately provided, which also causes an increase in the number of parts, which is a factor of the above problem.

Further, the allowable torque is increased as the total length of the cam in contact with the inner and outer wheels is longer. Therefore, the allowable torque can be increased by increasing the number of cams or increasing the width of the cam. However, if the width of the cam is simply increased, the size of the unidirectional clutch in the axial direction is increased. Further, even if the number of the cams is intentionally increased, the number of parts is increased, and the space of each part is required, which is not ensured. It is used to increase the space of the cam, so it is difficult to increase the allowable torque without increasing the size.

Here, the present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a one-way clutch that is compact and allows for large torque and good productivity.

The present invention solves the above problems by providing a unidirectional clutch having the following features: an outer wheel; an inner wheel having two parallel grooves on the outer peripheral surface; a buckle, embedded Mounted in the annular groove; the cam holder is arranged side by side on the outer circumferential surface of the inner wheel between the annular grooves, and is composed of a pair of retainer rings which are fixed by a plurality of pin intervals; a coil spring that is biased toward a cam of the cam holder and a direction in which the cam engages with the inner and outer wheels; a synchronous rotating portion disposed on the retainer ring, and the inner ring and the cam holder The rotation is synchronized and engaged with the buckle; and the stopper is integrally formed on the retainer ring to restrict the rotation of the cam.

Further, it is preferable that the synchronous rotating portion is formed integrally with the retainer ring, and it is preferable that the pin system also serves as a stopper.

According to the present invention, since the stopper for restricting the rotation of the cam when the drive shaft is rotated at a high speed in the closed state is integrally formed on the retainer ring, there is no need to be a pin that is not integrated with the retainer ring as is conventional. Or stop the shaft. Therefore, compared with the conventional one, the number of parts is reduced, and the manufacturing cost is small, and assembly or maintenance can be easily performed, and further, it contributes to weight reduction. Further, as a result, since it is not necessary to machine the pin for the cam holder or the hole for the stopper shaft, it is possible to reduce the number of processing steps, costs, and time. Further, by eliminating the need for a non-integral pin or a stop shaft, the distance between the cams can be shortened, and the number of cams can be increased. Therefore, it is possible to achieve an increase in the allowable torque in a size which is smaller than the axial direction which is conventionally known.

Further, if the inner wheel is synchronized with the rotation of the cam holder, and the synchronous rotating portion engaged with the buckle is integrally formed on the retainer ring, there is no need to It is known that the non-integral pin for synchronizing the rotation of the inner ring with the cam holder can achieve the same effect as described above. Further, if the pin is configured to also serve as a stopper, it is not necessary to provide a stopper having a portion where the pin is provided, so that the number of processing steps can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to Figs. However, the present invention is not limited to this embodiment.

The unidirectional clutch 10 according to the first embodiment of the present invention shown in Fig. 1 includes an outer ring 12, an inner ring 20, and a cam holder 30. In addition, in FIG. 1, the detailed illustration of the cam holder 30 is abbreviate|omitted. The inner ring 20 has a shaft hole 22, and a drive shaft (not shown) is inserted into the shaft hole 22 and fastened by a key. Further, of course, the drive shaft may be coupled to the inner ring 20 by a method other than key fastening. On the other hand, the outer ring 12 is connected to the driven shaft (not shown) or fixed so as not to be rotatable.

Figure 2 is a longitudinal sectional view taken along line 2-2 of Figure 1. A cam holder 30 is provided between the outer wheel 12 and the inner wheel 20. The cam holder 30 is constituted by the retainer rings 32 and 32 which are disposed side by side on the outer circumferential surface 24 between the two annular grooves 26 and 26 which are parallel to each other in the inner wheel 20, and the intervals are fixed by the pins 34. The pin 34 is attached to the retainer rings 32 and 32 at a plurality of positions by bolts 35 and 35 (three portions in FIG. 4), and is formed by fitting the retaining rings 28 and 28 to the inner ring 20. Since the annular grooves 26 and 26 can prevent the movement of the cam holder 30 in the axial direction, the cam holder 30 is attached so as not to be detached from the inner wheel 20. In addition, the cage ring 32 is not limited to iron and steel. For the material cutting machine, it is also possible to use a stamping processor. In addition, if the strength is satisfied, a resin such as engineering plastic or a non-ferrous material such as aluminum may be used.

Further, the cam holder 30 includes a cam 38 that is pivotally supported by the cage rings 32 and 32, and a torsion coil spring 39 that is biased in a direction in which the cam 38 is engaged with the inner wheel 20 and the outer wheel 12, and is assembled by The torsion coil spring 39 is biased such that the cam 38 is pressed against the outer peripheral surface 24 of the inner ring 20 and the inner peripheral surface 14 of the outer ring 12. Further, the support shaft 36 of the cam 38 penetrates the cam 38 as shown in FIG. 2, but may be integrally formed on the cam 38 as a trunnion. Further, the torsion coil spring 39 is formed as shown in Fig. 3(a), and is provided in such a manner that one spiral portion 39a is provided on one side of the cam, but it may be used as (b) The torsion coil spring 39c is shown as being provided in such a manner that two spiral portions 39d and 39d are provided on both side portions of the cam. Further, the use of the torsion coil spring 39 having the one-part spiral portion 39a as shown in (a) is preferable because the space between the retainer rings 32 and 32 can be secured. For example, the torsion coil spring 39 is engaged with the locking recess 32e (see FIG. 5) provided on the inner circumferential side of the retainer ring 32, and the other end 39b is engaged with the cam 38, and the cam 38 is engaged with the cam 38. The inner wheel 20 and the outer wheel 12 are biased in the direction of engagement. On the other hand, the torsion coil spring 39c is engaged with, for example, the end portions 39e and 39e of the retaining recess 32e (see FIG. 5) of the retainer ring 32, and the connecting portion 39f is engaged with the cam to the cam 38 and the inner portion. The direction in which the wheel 20 and the outer wheel 12 are engaged is biased.

Next, as shown in FIG. 2, the buckles 28, 28 are attached in such a manner as to be in close contact with the annular groove 26 by their elasticity. Here, as shown in FIG. 4, at the buckle 28 The engaging portion 28a is provided with a synchronous rotating portion 32b that is integrally formed in the retainer ring 32 and bent in the direction of the annular groove 26 (see FIG. 2). Therefore, once the inner ring 20 rotates, the engaging portion of the retaining ring 28 The 28a contacts the synchronous rotating portion 32b, and transmits torque in the same direction as the inner ring 20 to the cam holder 30. Further, the synchronous rotating portion 32b is formed so as to be formed so as to protrude toward the annular groove 26 after the retainer ring 32 is formed as described above, but may be integrally formed from the integral portion of the retainer ring 32. It is formed in such a manner as to protrude toward the annular groove 26 . In addition, the engaging portion 28a of the synchronous rotating portion 32b and the buckle 28 is not limited to the notch portion in the case of the buckle 28, and the synchronous rotating portion 32b can be engaged with the buckle, depending on the shape of the buckle. Make changes. Further, in the case of the cam holder 30, the synchronous rotating portion 32b is provided on the inner peripheral side concave portion 32c provided on the inner peripheral side of the retainer ring 32 as shown in Fig. 5, and a pair of retainer rings 32, 32 are provided. At least one of them may be bent in the direction of the annular groove 26. As described above, by providing the inner peripheral side recessed portion 32c, it is possible to reduce the weight of the retainer ring 32. In addition, a plurality of inner circumferential side concave portions 32c and rotation synchronization portions 32b may be provided depending on the shape of the buckle.

Further, on the outer peripheral side of the retainer ring 32, the outer peripheral side recessed portion 32d is provided in the same number as the cam 38, and the outer peripheral side recessed portion 32d is provided with a projecting stopper portion 32a. The stopper portion 32a is formed by bending at least one of the pair of cage rings 32 and 32 in the direction of the cam 38. As described above, by providing the outer peripheral side concave portion 32d, it is possible to reduce the weight of the retainer ring 32. Further, the stopper portion 32a is formed integrally with the holder ring 32 as described above, and is processed so as to protrude toward the cam 38, but it is also possible to The first formed in the holder ring 32 is formed so as to protrude toward the cam 38.

As described above, the cam 38 is biased in the direction of engagement with the inner ring 20 and the outer ring 12 by the torsion coil spring 39. Therefore, the assembly is brought into the state of A of FIG. 5, that is, pressed against the inner circumferential surface 14 of the outer ring 12 and The state of the outer peripheral surface 24 of the inner wheel 20. Fig. 6 is a partial enlarged view showing the state of A of Fig. 5. The center of gravity G of the cam 38 is located away from the center of the support shaft 36, and the cam 38 is biased in the leftward direction by the torsion coil spring 39. When the drive shaft (not shown) is rotated to the left, the torque in the left rotation direction is also transmitted to the inner wheel 20 and the cam holder 30. Here, the cam 38 is designed to be slidable only in a single direction (right rotation direction) from the state of assembly, and further, since it is in contact with the inner circumferential surface 14 of the outer ring 12, by the outer wheel 12 The friction of the inner peripheral surface 14 is rotated in the right direction of rotation about the support shaft 36. Therefore, since the cam 38 slides on the inner peripheral surface 14 of the outer ring 12, it is in a closed state when the drive shaft is rotated to the left.

On the other hand, as shown by the arrow in Fig. 6, in the case where the drive shaft is rotated rightward, the cam 38 is in contact with the inner peripheral surface 14 of the outer ring 12, so that the support shaft is supported by friction with the inner peripheral surface 14 of the outer ring 12. 36 is centered to rotate in the left direction of rotation. Therefore, the cam 38 is further pressed against the inner circumferential surface 14 of the outer ring 12 and the outer circumferential surface 24 of the inner ring 20, and the rotation is impossible. Therefore, the drive shaft is rotated in the right state.

Next, in the closed state and the drive shaft is rotated at a high speed, the cam 38 is in the state of B of Fig. 5 . A partial enlarged view of the state of B is shown in Fig. 7. Once the drive shaft rotates at a high speed, it becomes the centrifugal force in the F direction on the cam 38. Since the center of gravity G acts beyond the elastic force of the torsion coil spring 39, the cam 38 is rotated until it comes into contact with the stopper portion 32a. At this time, a gap is formed between the cam 38 and the outer peripheral surface 24 of the inner ring 20 and the inner peripheral surface 14 of the outer ring 12. Therefore, the cam 38 is not in contact with the outer peripheral surface 24 of the inner ring 20 and the inner peripheral surface 14 of the outer ring 12, so that heat generation of such friction can be prevented, and wear and grilling of the parts can be prevented. Further, by the torsion coil spring 39, the cam 38 is biased in the direction in which it engages with the inner ring 20 and the outer ring 12. Therefore, when the rotation of the drive shaft is at a low speed or stopped, the state shown in Fig. 6 is restored.

As shown in Fig. 8, when one end portion 39b of the torsion coil spring 39 (see Fig. 3(a)) is engaged with the stopper portion 32a, it is not necessary to provide the locking recess portion 32e (see Fig. 4), so that it can be suppressed. Processing hours and costs. Alternatively, it may be fixed by winding one end portion 39b of the torsion coil spring 39 around the stopper portion 32a or the like. Further, in the case where the torsion coil spring 39c (see FIG. 3(b)) is used, the end portions 39e, 39e may be engaged with the stopper portion 32a.

Further, as shown in FIG. 9, when the pin 34 is also used as the stopper portion 32a, it is not necessary to provide the stopper portion 32a having a portion of the pin 34, so that the processing time and cost can be suppressed. Further, the configuration in which the end portion of the torsion coil spring is engaged with the stopper portion 32a and the pin 34 also serve as the stopper portion 32a may be combined. In this case, the end portion of the torsion coil spring may be engaged with the pin 34.

Next, Fig. 10 is a front view (partial sectional view) of a cam holder 130 of a conventional one-way clutch as in Patent Document 2. The size of the cam holder 130 is the same as that of the cam holder 30 shown in FIG. The cam holder 130 is attached to the cage ring 132 and has a support shaft 136. The pin 134 to which the pin 135 is fixed and the synchronous rotating pin 131 which is a synchronous rotating portion that engages with the engaging portion of the buckle (not shown). The cam 138 is biased by a torsion coil spring 139 having two portions of spiral portions 139a and 139a (see FIG. 11), and the connecting portion of the torsion coil spring 139 is engaged with the cam 138, and the end portion 139b is engaged with the pin 134.

Next, Fig. 11 is a view in which the dimensions of the conventional cam holder 130 and the cam holders 30, 30a of the present invention are compared in the axial direction. Further, in the conventional cam holder 130, the head of the flat head bolt provided on the retainer ring 128 is embedded in the retainer ring 128, and on the other hand, the cam holder 30, 30a of the present invention is the head of the bolt 35. Located on the outer side of the cage rings 28, 28a, the dimensions of the cam holder 130 including the cage rings 128, 128 in the axial direction are compared with the dimensions of the cam holders 30, 30a including the heads of the bolts 35. . Here, (a) shows a conventional cam holder 130; (b) shows the same thickness of the cage ring as that of (a), the width and number of cams, and the case where a torsion coil spring 39 is used for the spiral portion; c) indicates the configuration of (b), the number of cams is increased by one, and the total length of the cam in contact with the outer circumferential surface of the inner wheel or the inner circumferential surface of the outer wheel becomes the same as (a); ) indicates the width and number of cams which are the same as (a), and compared with (a) making the cage ring thinner, and using a torsion coil spring 39 for the spiral portion; (e) indicating by (d) In the configuration, the number of cams is increased by one, and the total length of the cam connected to the outer peripheral surface of the inner ring or the inner peripheral surface of the outer ring is the same as (a).

In the case of (b), the space corresponding to one spiral spiral portion 139a of (a) can be secured; in the case of (c), except for the case of (b) The size of each of the cams 38 in the axial direction is reduced, which is equivalent to the addition of one cam 38. Further, in the case of (d), in addition to the case of (b), a space equivalent to making the cage ring 28a thinner can be secured; in the case of (e), except for the case of (d), The size of the cams 38 in the axial direction is reduced, which is equivalent to the addition of one cam 38. Therefore, when the dimensions of the entire cam holder of FIGS. 11(a) to (e) in the axial direction are A, B, C, D, and E, A>B>C>D>E is obtained. Therefore, by adopting the configuration of the present invention, it is possible to achieve an increase in flexibility or an increase in torque as compared with the prior art, and further, if a thin-walled retainer ring 28a is used, it is possible to further improve the flexibility or allow torque. Increase.

As described above, according to the present invention, since the number of parts can be reduced, the space in the circumferential direction of the cam holder of the unidirectional clutch can be secured, and the cam can be added. Therefore, it is possible to provide compactness, allowable torque, and high productivity. The effect of a one-way clutch.

10‧‧‧One-way clutch

12‧‧‧ outer wheel

20‧‧‧ Inner wheel

24‧‧‧ outside the inner wheel

26‧‧‧ annular groove

28‧‧‧ buckle

28a‧‧‧Knuckle of the buckle

30‧‧‧Cam cage

32‧‧‧ cage ring

32a‧‧‧stop

32b‧‧‧Synchronous rotation

32c‧‧‧inside recess

32d‧‧‧peripheral recess

34‧‧ ‧ sales

38‧‧‧ cam

39‧‧‧Twisted coil spring

Fig. 1 is a front view showing a one-way clutch according to a first embodiment of the present invention.

Figure 2 is a longitudinal sectional view taken along line 2-2 of Figure 1.

Figure 3 is a front view of a torsion coil spring used in a one-way clutch.

Fig. 4 is a front view showing the state in which the cam holder of the inner wheel of the one-way clutch of the first embodiment of the present invention is attached.

Fig. 5 is a front view (partially sectional view) showing a cam holder of the unidirectional clutch according to the first embodiment of the present invention.

Figure 6 is an enlarged view of A of Figure 5.

Figure 7 is an enlarged view of B of Figure 5.

Fig. 8 is an enlarged view (partially sectional view) of a main portion of a cam holder of a unidirectional clutch according to a second embodiment of the present invention.

Fig. 9 is an enlarged view (partially sectional view) of a main portion of a cam holder of a unidirectional clutch according to a third embodiment of the present invention.

Figure 10 is a front view (partially cross-sectional view) of a conventional cam cage of a one-way clutch.

Figure 11 is a view for comparing the dimensions of the unidirectional clutch of the present invention with the axial direction of a conventional unidirectional clutch.

14‧‧‧The inner circumference of the outer wheel 12

24‧‧‧ outside the inner wheel

30‧‧‧Cam cage

32‧‧‧ cage ring

32a‧‧‧stop

32b‧‧‧Rotation Synchronization Department

32c‧‧‧inside recess

32d‧‧‧peripheral recess

32e‧‧‧Recessed recess

34‧‧ ‧ sales

35‧‧‧Bolts

36‧‧‧ Support shaft

38‧‧‧ cam

39‧‧‧Twisted coil spring

Claims (3)

A unidirectional clutch is characterized in that: an outer wheel; an inner wheel having two annular grooves on the outer peripheral surface; a buckle fitted to the annular groove; and a cam holder arranged side by side in the annular groove Between the outer circumferential surfaces of the inner wheel and the retainer ring formed by a plurality of pin intervals being fixed; the torsion coil spring, the cam supported by the cam holder, and the cam and the cam The inner wheel and the outer wheel are in a direction of engagement; the synchronous rotating portion is disposed on the retainer ring, and the inner wheel is synchronized with the rotation of the cam holder and engaged with the buckle; and the stop portion is integrated Formed on the above retainer ring to restrict the rotation of the cam. The one-way clutch of claim 1, wherein the synchronous rotating portion is integrally formed on the retainer ring. A unidirectional clutch according to claim 1 or 2, wherein the above-mentioned pin serves as the above-mentioned stopper.