WO2019235485A1

WO2019235485A1 - Buffer structure for armature, rotation transmitting device, and rotation braking device

Info

Publication number: WO2019235485A1
Application number: PCT/JP2019/022201
Authority: WO
Inventors: 齋藤　隆英; 佐藤　光司; 匡顕松木
Original assignee: Ntn株式会社
Priority date: 2018-06-08
Filing date: 2019-06-04
Publication date: 2019-12-12
Also published as: JP2019211057A

Abstract

In a rotation transmitting device which includes a buffer member (50) disposed between an armature (30) and an electromagnet (32), and in which the buffer member (50) includes a metal ring (51) having an annular surface (53), and a buffer rubber (52) bonded to the annular surface (53), the buffer rubber (52) is configured to include a high hardness rubber portion (63) and a low hardness rubber portion (64).

Description

Armature buffer structure, rotation transmission device, and rotation braking device

The present invention relates to an armature buffer structure, and a rotation transmission device and a rotation braking device that employ the armature buffer structure.

As a rotation transmission device used for switching between a state in which rotation is transmitted from an input shaft to an output shaft and a state in which transmission of the rotation is interrupted, for example, the one described in Patent Document 1 is known.

The rotation transmission device described in Patent Document 1 includes an outer ring, an inner member disposed inside the outer ring, and an electromagnetic clutch that switches between transmission and interruption of rotation between the outer ring and the inner member. The electromagnetic clutch includes an armature supported so as to be movable in the axial direction, a rotor disposed so as to face the armature in the axial direction, a spring member that urges the armature in a direction away from the rotor, and an armature that is energized to the rotor. And an electromagnet to be adsorbed.

In the rotation transmission device of Patent Document 1, when the energization to the electromagnet is interrupted, the armature is separated from the rotor by the force of the spring member, and the rotation is transmitted between the outer ring and the inner member. It becomes a joint state. On the other hand, when the electromagnet is energized, the armature is attracted to the rotor due to the attraction force of the electromagnet, and the rotation state between the outer ring and the inner member is cut off.

Here, when the armature is attracted to the rotor by energizing the electromagnet, a collision sound may be generated between the armature and the rotor, and this collision sound is particularly important in the field of automobiles that require high silence in recent years. It becomes a problem.

Therefore, in order to reduce the collision noise between the armature and the rotor, in the rotation transmission device of Patent Document 1, a buffer member is provided between the armature and the rotor to absorb an impact when the armature is attracted to the rotor. The buffer member is bonded to the annular surface of the metal ring so that the armature is supported so as to be movable in the axial direction and the armature is compressed in the axial direction between the armature and the metal ring as the armature approaches the rotor. With cushioning rubber.

By the way, as in Patent Document 1, when a buffer rubber is interposed between the armature and the rotor, the operation of the armature may become unstable. That is, when the electromagnet is energized, not only the force attracted to the rotor by the energization of the electromagnet but also the force in the direction away from the rotor by the buffer rubber and the spring member acts. The armature is attracted to the rotor when the force with which the armature is attracted to the rotor exceeds the force in the direction away from the rotor.

Here, the force with which the armature is attracted to the rotor by energizing the electromagnet changes according to the distance between the armature and the rotor, and increases as the armature approaches the rotor. This increase is gradual when the armature is relatively far from the rotor and abrupt when the armature is relatively close to the rotor. That is, the armature tends to accelerate greatly as it approaches the rotor.

For this reason, using a shock absorbing rubber with a small rubber compression load (ie, the force required to compress the shock absorbing rubber) cannot suppress the acceleration of the armature just before the armature is adsorbed to the rotor. The impact noise of the rotor cannot be reduced effectively. On the other hand, if a rubber cushion with a large rubber compression load is used, the force in the direction away from the rotor that the armature receives from the buffer rubber and the spring member during the period from when the armature starts moving toward the rotor to be attracted to the rotor, There is a possibility that the armature may temporarily exceed the force attracted to the rotor by energizing the electromagnet, the armature is not attracted to the rotor, and the operation of the armature may become unstable.

With respect to this problem, in the rotation transmission device of Patent Document 1, the method of increasing the force required to compress the shock absorbing rubber in the axial direction becomes gentle when the amount of axial compression of the shock absorbing rubber is small. A shock absorbing rubber having a compression load characteristic of becoming steep when the amount of compression in the axial direction is large is employed. In order to obtain such compressive load characteristics, a plurality of protrusions having different heights are formed on a buffer rubber made of a single rubber material, and the cross-sectional shape of these protrusions is changed according to the height of the protrusions. By adopting different shapes, the compression load characteristics as described above are obtained.

Japanese Patent Laying-Open No. 2015-140911

However, the method of increasing the force required to compress the shock absorbing rubber in the axial direction becomes gentle when the amount of compression of the shock absorbing rubber in the axial direction is small, and becomes steep when the amount of compressing rubber in the axial direction is large. As a method for obtaining the compression load characteristic, a plurality of protrusions having different heights are formed on a buffer rubber made of a single rubber material as in Patent Document 1, and the cross-sectional shape of the protrusions is defined as the height of the protrusions. It was found that there was a problem in terms of durability and ease of design of the shock absorbing rubber if it was designed individually according to each.

That is, as a method for obtaining the above compression load characteristics, when the cross-sectional shape of the protrusion is individually designed according to the height of the protrusion, a soft compression load characteristic at a stage where the compression amount of the shock absorbing rubber is small is obtained. For this reason, it is necessary to adopt a cross-sectional shape in which the tip of the protrusion is narrow and the protrusion having a high height. For this reason, it is difficult to ensure the durability of the high protrusion portion of the buffer rubber. In addition, when the cross-sectional shape of multiple protrusions with different heights is designed to be different for each protrusion height, the deformation behavior of the protrusion when the protrusion is compressively deformed is analyzed for each protrusion shape. This is necessary, and the labor required for designing the cross-sectional shape of the protrusion is large.

The problem to be solved by the present invention is to provide an armature buffer structure excellent in durability and design ease of a buffer member that absorbs an impact when the armature is adsorbed.

In order to solve the above-described problems, the present invention provides an armature buffer structure having the following configuration.
An armature supported so as to be movable in the axial direction;
An electromagnet disposed axially opposite the armature and attracting the armature axially by energization;
A buffer member disposed between the armature and the electromagnet;
In the buffer structure of the armature, the buffer member includes a metal ring having an annular surface and a buffer rubber bonded to the annular surface.
The armature buffer structure characterized in that the buffer rubber has a high hardness rubber portion and a low hardness rubber portion made of a rubber material having a lower hardness than the rubber material forming the high hardness rubber portion.

In this way, in the process in which the buffer rubber is compressed in the axial direction, the low-hardness rubber portion and the high-hardness rubber portion are provided so that the low-hardness rubber portion is compressed in preference to the high-hardness rubber portion. Compressive load in which the force required to compress the rubber in the axial direction becomes gentle when the amount of compression of the shock absorbing rubber is small and becomes steep when the amount of compression of the shock absorbing rubber is large Characteristics can be obtained. Therefore, the acceleration of the armature just before the armature is attracted to the rotor is effectively suppressed, and the collision noise between the armature and the rotor can be effectively reduced. In addition, in the process of compressing the buffer rubber in the axial direction, at a stage where the compression amount of the buffer rubber in the axial direction is small, a soft compression load characteristic is obtained by the low hardness rubber portion and the compression amount of the buffer rubber in the axial direction is large. At the stage, a hard compression load characteristic can be obtained by the high-hardness rubber part, so that it is not necessary to provide a protrusion with a cross-sectional shape with a narrow tip as in the case of forming the buffer rubber with a single rubber material. Excellent durability of shock absorbing rubber. Also, by adjusting the axial thickness of each of the low-hardness rubber part and the high-hardness rubber part, the compression load characteristics of the shock-absorbing rubber can be easily adjusted, so the cross-sectional shape of the shock-absorbing rubber can be easily designed. is there.

The low-hardness rubber portion and the high-hardness rubber portion are arranged on the annular surface at a circumferential interval, and the axial thickness of the low-hardness rubber portion is determined by the axial thickness of the high-hardness rubber portion. Can also be used.

In this way, since the axial thickness of the low-hardness rubber part is larger than the axial thickness of the high-hardness rubber part, first, in the process in which the buffer rubber is compressed in the axial direction, Compression is started in preference to the rubber part, and then the buffer rubber is further compressed in the axial direction, and the high-hardness rubber part starts compression. Therefore, it is possible to adjust the compression load characteristic of the buffer rubber by adjusting the axial thickness of the low hardness rubber portion and the axial thickness of the high hardness rubber portion, respectively.

The low-hardness rubber part and the high-hardness rubber part may be laminated in the axial direction.

In this way, since the low-hardness rubber portion and the high-hardness rubber portion are laminated in the axial direction, in the process in which the buffer rubber is compressed in the axial direction, first, the low-hardness rubber portion is more than the high-hardness rubber portion. After preferentially compressing and sufficiently compressing the low-hardness rubber part, the buffering action by the compression of the high-hardness rubber part becomes dominant. Therefore, it is possible to adjust the compression load characteristic of the buffer rubber by adjusting the axial thickness of the low hardness rubber portion and the axial thickness of the high hardness rubber portion, respectively.

As the laminated arrangement, it is possible to adopt an arrangement in which the low-hardness rubber portion is bonded to the annular surface and the high-hardness rubber portion is bonded to the surface of the low-hardness rubber portion. It is preferable to employ an arrangement in which the portion is bonded to the annular surface and the low hardness rubber portion is bonded to the surface of the high hardness rubber portion.

In this case, since the low hardness rubber portion becomes a buffer rubber configured to be supported by the high hardness rubber portion, the case where the high hardness rubber portion is configured to be supported by the low hardness rubber portion is adopted than when the buffer rubber is adopted. When the shock absorbing rubber is compressed in the axial direction, the way the shock absorbing rubber is deformed is stabilized.

When further providing a rotor disposed between the armature and the electromagnet and attracting the armature by energization of the electromagnet, the buffer member absorbs an impact when the armature is attracted to the rotor. It can be arranged between the armature and the rotor.

Further, a spring member that urges the armature in a direction away from the rotor can be further provided.

The metal ring is provided so as to be movable in the axial direction on one member of the armature and the rotor,
The buffer rubber may be provided so as to be compressed in the axial direction between the one member and the metal ring as the armature approaches the rotor.

The present invention also provides the following as a rotation transmission device using the armature cushioning structure described above.
The above armature buffer structure,
An outer ring rotatably supported;
An inner member supported to be rotatable relative to the outer ring;
An engagement member incorporated between the inner periphery of the outer ring and the outer periphery of the inner member;
It is movable between an engagement position for engaging the engagement element between the outer ring and the inner member and an engagement release position for releasing the engagement of the engagement element between the outer ring and the inner member. An engaging cage supported by
An operation conversion mechanism that converts the movement of the armature in the axial direction by energization of the electromagnet into the movement of the engagement holder moving from one of the engagement position and the engagement release position to the other. Rotation transmission device.

In this rotation transmission device, a rotor that rotates integrally with the inner member is disposed between axially facing surfaces of the armature and the electromagnet so that the armature is attracted to the rotor by energization of the electromagnet. Can be configured.

The present invention also provides the following as a rotary braking device using the armature buffer structure described above.
The above armature buffer structure,
An outer ring supported in a state where rotation is restricted,
An inner member supported to be rotatable relative to the outer ring;
An engagement member incorporated between the inner periphery of the outer ring and the outer periphery of the inner member;
It is movable between an engagement position for engaging the engagement element between the outer ring and the inner member and an engagement release position for releasing the engagement of the engagement element between the outer ring and the inner member. An engaging cage supported by
An operation conversion mechanism that converts the movement of the armature in the axial direction by energization of the electromagnet into the movement of the engagement holder moving from one of the engagement position and the engagement release position to the other. Rotating braking device.

The rotary braking device can be configured such that the armature is attracted to the electromagnet when the electromagnet is energized.

The shock absorbing structure of the armature of the present invention is a process of compressing the shock absorbing rubber in the axial direction, and at the stage where the amount of compressing rubber in the axial direction is small, a soft compressive load characteristic is obtained by the low hardness rubber portion. In the stage where the amount of compression in the axial direction is large, the hard rubber part can obtain a hard compression load characteristic, so the cross-sectional shape with a narrow tip as in the case of forming the buffer rubber with a single rubber material It is not necessary to provide protrusions, and the cushioning rubber is excellent in durability. Also, by adjusting the axial thickness of each of the low-hardness rubber part and the high-hardness rubber part, the compression load characteristics of the shock-absorbing rubber can be easily adjusted, so the cross-sectional shape of the shock-absorbing rubber can be easily designed. is there.

Sectional drawing which shows the rotation transmission apparatus which employ | adopted the armature buffer structure concerning embodiment of this invention Sectional view along the line II-II in FIG. The expanded sectional view which shows the state which moved each roller in the direction where the space | interval of a pair of opposing roller narrows by rotating the 1st division holder shown in FIG. 2 and the 2nd division holder relatively Sectional view along line IV-IV in FIG. Sectional view along line VV in FIG. Sectional view along line VI-VI in Fig. 1 Sectional view along line VII-VII in FIG. Sectional drawing which shows the state which the 1st division | segmentation holder | retainer and the 2nd division | segmentation holder | retainer rotated relatively, when the ball | bowl shown to FIG. 7A rolls toward the deepest part of each inclination groove | channel. Sectional drawing which expands and shows the vicinity of the low-hardness rubber part of the buffer member shown in FIG. Sectional drawing which expands and shows the vicinity of the high hardness rubber | gum part of the buffer member shown in FIG. The figure which took out the buffer member shown in FIG. 1, and looked at the axial direction from the buffer rubber side Sectional view along line XI-XI in FIG. Sectional view along line XII-XII in FIG. Sectional view along line XIII-XIII in FIG. The figure which shows the buffer structure of the armature concerning other embodiment of this invention corresponding to FIG. Sectional view along line XV-XV in FIG. Sectional view along line XVI-XVI in FIG. In the rotation transmission device employing the armature buffer structure according to the embodiment of the present invention, the force with which the armature is attracted to the rotor and the rubber compression load change in accordance with the distance between the armature and the rotor. Figure showing The figure which shows the modification of the rotation transmission apparatus of FIG. The figure which shows an example of the rotary braking device which employ | adopted the armature buffer structure concerning embodiment of this invention

FIG. 1 shows a rotation transmission device employing an armature buffer structure according to an embodiment of the present invention. This rotation transmission device transmits and blocks rotation between the outer ring 1 that is rotatably supported, the inner member 2 that is supported to be rotatable relative to the outer ring 1, and the outer ring 1 and the inner member 2. And an electromagnetic clutch 3 for switching between.

The electromagnetic clutch 3 has a plurality of

rollers

4a and 4b incorporated between the inner periphery of the outer ring 1 and the outer periphery of the inner member 2, and a roller holder 5 that holds these

rollers

4a and 4b. An input shaft 6 is connected to the inner member 2, and an output shaft 7 is connected to the outer ring 1. The input shaft 6 and the output shaft 7 are arranged on the same axis. The electromagnetic clutch 3 switches between energization of the electromagnet 32 and stop of energization, whereby the transmission of rotation from the input shaft 6 to the output shaft 7 is interrupted, and the rotation is transmitted from the input shaft 6 to the output shaft 7. It is a clutch which switches the state to be made.

The input shaft 6 has a serration shaft portion 8 having serrations formed on the outer periphery. The serration shaft portion 8 is fitted into a serration hole 9 formed at the center of the inner member 2. By fitting the serration shaft portion 8 and the serration hole 9, the input shaft 6 is connected to the inner member 2 so as to rotate integrally with the inner member 2. In this embodiment, the input shaft 6 and the inner member 2 are separate members. However, the input shaft 6 and the inner member 2 may be formed as a seamless integral member.

The output shaft 7 is formed integrally with the outer ring 1. In this embodiment, the output shaft 7 and the outer ring 1 are integrally formed as a seamless member. However, the output shaft 7 and the outer ring 1 are separate members, and the output shaft 7 is attached to the outer ring 1 so as to rotate integrally with the outer ring 1. You may connect. A rolling bearing 10 is incorporated between the outer ring 1 and the inner member 2 to support the inner member 2 so as to be rotatable relative to the outer ring 1. A rolling bearing 12 that rotatably supports the output shaft 7 is incorporated in an end portion on the output shaft 7 side of the cylindrical housing 11 that houses the constituent members of the rotation transmission device.

2 and 3, a plurality of cam surfaces 13 are provided on the outer periphery of the inner member 2 at equal intervals in the circumferential direction. The cam surface 13 includes a front cam surface 13a and a rear cam surface 13b disposed behind the inner cam 2 in the forward rotation direction with respect to the front cam surface 13a. A cylindrical surface 14 that is opposed to the cam surface 13 in the radial direction is provided on the inner periphery of the outer ring 1.

Between the cam surface 13 and the cylindrical surface 14, a pair of

rollers

4a and 4b that are opposed to each other in the circumferential direction with a spring member 15 interposed therebetween are incorporated. Of the pair of

rollers

4a and 4b, the forward roller 4a in the forward rotation direction is incorporated between the front cam surface 13a and the cylindrical surface 14, and the rear roller 4b in the forward rotation direction is the rear cam surface 13b and the cylindrical surface 14. Is built in between. The spring member 15 is incorporated between the pair of

rollers

4a and 4b so as to press the

rollers

4a and 4b in a direction in which the distance between the pair of

rollers

4a and 4b is increased.

The front cam surface 13a is formed such that the radial distance from the cylindrical surface 14 gradually decreases from the position of the roller 4a toward the front in the forward rotation direction. The rear cam surface 13b is formed such that the radial distance from the cylindrical surface 14 gradually decreases from the position of the roller 4b toward the rear in the forward rotation direction. In the figure, the front cam surface 13a and the rear cam surface 13b are formed so as to be separate planes inclined in opposite directions, but the front cam surface 13a and the rear cam surface 13b are in a single plane normal rotation. It is also possible to form them on the same plane so that the front part in the direction is the front cam surface 13a and the rear part is the rear cam surface 13b. Further, the front cam surface 13a and the rear cam surface 13b can be curved surfaces. However, if the front cam surface 13a and the rear cam surface 13b are flat as shown in the figure, the processing cost can be reduced.

As shown in FIGS. 1 to 3, the roller holder 5 includes a first divided holder 5A that supports one roller 4a of a pair of

rollers

4a and 4b that are opposed to each other in the circumferential direction with a spring member 15 therebetween. And a second divided holder 5B that supports the other roller 4b. The first divided holder 5A and the second divided holder 5B are supported so as to be rotatable relative to each other, and the pair of

rollers

4a, 4b is changed so that the distance between the pair of

rollers

4a, 4b changes according to the relative rotation. Are supported individually.

The first split cage 5A has a plurality of column portions 16a arranged at intervals in the circumferential direction, and an annular flange portion 17a that connects the ends of these column portions 16a. Similarly, the 2nd division | segmentation holder | retainer 5B also has the some pillar part 16b arrange | positioned at intervals in the circumferential direction, and the cyclic | annular flange part 17b which connects the edge parts of these pillar parts 16b.

The column portion 16a of the first divided cage 5A and the column portion 16b of the second divided cage 5B sandwich the pair of

rollers

4a and 4b facing each other in the circumferential direction with the spring member 15 in between. Thus, it is inserted between the inner periphery of the outer ring 1 and the outer periphery of the inner member 2.

As shown in FIG. 1, the flange portion 17a of the first split cage 5A and the flange portion 17b of the second split cage 5B are the same as the flange portion 17b of the second split cage 5B. It is arranged so as to face the axial direction in a direction closer to the axial direction with respect to the inner member 2 than the flange portion 17a of 5A. The flange portion 17b of the second split cage 5B is provided with a plurality of notches 18 at intervals in the circumferential direction to avoid interference with the column portion 16a of the first split cage 5A. .

The inner circumference of the flange portion 17a of the first split cage 5A and the inner circumference of the flange portion 17b of the second split cage 5B are respectively rotatably supported by a cylindrical surface 19 provided on the outer circumference of the input shaft 6. ing. As a result, the first divided holder 5A and the second divided holder 5B engage each

roller

4a, 4b between the cylindrical surface 14 and the cam surface 13 by widening the distance between the pair of

rollers

4a, 4b. Between the engagement position to be combined and the engagement release position for releasing the engagement of the

rollers

4a and 4b between the cylindrical surface 14 and the cam surface 13 by narrowing the distance between the pair of

rollers

4a and 4b. It is movable. The flange portion 17a of the first split cage 5A is supported in the axial direction by an annular projection 21 provided on the outer periphery of the input shaft 6 via the thrust bearing 20, and thereby movement in the axial direction is restricted. .

As shown in FIG. 4, a side plate 22 is fixed to the side surface of the inner member 2. The side plate 22 has a stopper piece 23 positioned between both

pillar portions

16a and 16b that face each other in the circumferential direction with the pair of

rollers

4a and 4b interposed therebetween. In the stopper piece 23, when both the

pillar portions

16a and 16b are moved in the direction of narrowing the distance between the pair of

rollers

4a and 4b, the edges on both sides of the stopper piece 23 receive the

pillar portions

16a and 16b. Accordingly, the spring member 15 between the pair of

rollers

4a and 4b is prevented from being excessively compressed and broken, and each roller with respect to the inner member 2 when the distance between the pair of

rollers

4a and 4b is narrowed. The positions of 4a and 4b can be made constant.

As shown in FIG. 5, the side plate 22 has a spring holding piece 24 that holds the spring member 15. The spring holding piece 24 is formed integrally with the stopper piece 23 so as to extend in the axial direction between the inner circumference of the outer ring 1 and the outer circumference of the inner member 2. The spring holding piece 24 is disposed so as to face the spring support surface 25 (see FIG. 2) formed between the front cam surface 13a and the rear cam surface 13b on the outer periphery of the inner member 2 in the radial direction. Yes. A concave portion 26 for accommodating the spring member 15 is formed on the surface of the spring holding piece 24 that faces the spring support surface 25. The spring member 15 is a coil spring. The spring holding piece 24 prevents the spring member 15 from dropping in the axial direction from between the inner periphery of the outer ring 1 and the outer periphery of the inner member 2 by restricting the movement of the spring member 15 by the recess 26. ing.

As shown in FIG. 1, as a means for moving the first divided holder 5A and the second divided holder 5B from the engaged position to the disengaged position, the armature 30 supported so as to be movable in the axial direction. A rotor 31 disposed opposite to the armature 30 in the axial direction, an electromagnet 32 that attracts the armature 30 to the rotor 31 by energization, and an operation in which the armature 30 is attracted to the rotor 31. 5A and the second divided holder 5B have a ball ramp mechanism 33 that converts the movement from the engagement position to the engagement release position.

The armature 30 includes an annular disk part 34 and a cylindrical part 35 that is integrally formed so as to extend in the axial direction from the outer periphery of the disk part 34. The cylindrical portion 35 of the armature 30 is press-fitted with a cylindrical portion 36 that is integrally formed so as to extend in the axial direction from the outer periphery of the flange portion 17b of the second split cage 5B. The second split holder 5B is connected to the second split holder 5B so as to move integrally with the second split holder 5B in the axial direction. The armature 30 is supported by a cylindrical surface 37 provided on the outer periphery of the input shaft 6 so as to be rotatable and movable in the axial direction. Here, the armature 30 is supported by the armature 30 so as to be movable in the axial direction at two locations separated in the axial direction (that is, the inner circumference of the armature 30 and the inner circumference of the second split cage 5B). Is prevented from tilting with respect to the direction perpendicular to the axis.

The rotor 31 is disposed between opposing surfaces of the armature 30 and the electromagnet 32 in the axial direction. In addition, the rotor 31 is fitted to the outer periphery of the input shaft 6 with a tightening margin, so that the rotor 31 rotates together with the inner member 2 and does not move in either the axial direction or the circumferential direction. It is supported by. The rotor 31 and the armature 30 are made of a ferromagnetic metal. On the surface of the rotor 31 facing the armature 30, a plurality of long holes 38 that penetrate the rotor 31 in the axial direction and extend in the circumferential direction are formed at intervals in the circumferential direction.

The electromagnet 32 is arranged to face the armature 30 in the axial direction so as to attract the armature 30 in the axial direction. The electromagnet 32 includes a solenoid coil 39 and a field core 40 around which the solenoid coil 39 is wound. The field core 40 is inserted into the end portion of the housing 11 on the input shaft 6 side and is prevented from coming off by a retaining ring 41. A rolling bearing 42 that rotatably supports the input shaft 6 is incorporated in the inner periphery of the field core 40. The electromagnet 32 energizes the solenoid coil 39 to form a magnetic path that passes through the field core 40, the rotor 31, and the armature 30, and causes the armature 30 to be attracted to the rotor 31. At this time, the surface of the armature 30 facing the rotor 31 is in surface contact with the surface of the rotor 31 facing the armature 30.

As shown in FIGS. 6, 7A, and 7B, the ball ramp mechanism 33 has an inclination provided on the surface of the flange portion 17a of the first split cage 5A facing the flange portion 17b of the second split cage 5B. The groove 43a, the inclined groove 43b provided on the surface of the flange portion 17b of the second divided retainer 5B facing the flange portion 17a of the first divided retainer 5A, and the inclined groove 43a and the inclined groove 43b are incorporated. Ball 44 formed. The inclined groove 43a and the inclined groove 43b are formed so as to extend in the circumferential direction, respectively. In addition, the inclined groove 43a has a shape having a groove bottom that is inclined so as to gradually become shallower in the circumferential direction from the deepest portion 45a having the deepest axial depth, and the inclined groove 43b is also formed in the axial direction. The shape is such that the groove bottom is inclined so as to gradually become shallower from the deepest portion 45b having the deepest depth toward the other direction in the circumferential direction. The ball 44 is disposed so as to be sandwiched between the groove bottoms.

The ball ramp mechanism 33 is configured such that when the flange portion 17b of the second split cage 5B moves in the axial direction toward the flange portion 17a of the first split cage 5A, the ball 44 is moved to each inclined groove 43a, By rolling toward the

deepest portions

45a and 45b of 43b, the first split holder 5A and the second split holder 5B rotate relative to each other, and as a result, the column part 16a of the first split holder 5A and the first The column part 16b of the two split cages 5B operates so as to move in the direction of narrowing the distance between the pair of

rollers

4a and 4b.

The armature 30 is urged away from the rotor 31 by the force of the spring member 15. That is, the force by which the spring member 15 shown in FIG. 2 presses the

rollers

4a and 4b in the direction of increasing the distance between the pair of

rollers

4a and 4b is transmitted to the first divided holder 5A and the second divided holder 5B. To do. The circumferential force received by the first split holder 5A and the second split holder 5B is axially moved away from the rotor 31 by the ball ramp mechanism 33 shown in FIGS. 6, 7A and 7B. It is converted into force and transmitted to the second divided holder 5B. Here, as shown in FIG. 1, the armature 30 is fixed to the second split cage 5 </ b> B, so that the armature 30 is eventually transmitted by the force transmitted from the spring member 15 via the ball ramp mechanism 33. It is in a state of being biased in a direction away from the rotor 31.

As shown in FIG. 1, a buffer member 50 is provided between the armature 30 and the rotor 31 to absorb an impact when the armature 30 is attracted to the rotor 31. The buffer member 50 is disposed between the armature 30 and the electromagnet 32.

8 and 9, the buffer member 50 includes a metal ring 51 and a buffer rubber 52 fixed to the metal ring 51. The metal ring 51 is supported by the armature 30 so as to be movable in the axial direction. The metal ring 51 has an annular surface 53 that faces the armature 30 in the axial direction. The buffer rubber 52 is bonded to the annular surface 53 of the metal ring 51 so that the armature 30 is compressed in the axial direction between the armature 30 and the metal ring 51 as the armature 30 approaches the rotor 31. The metal ring 51 is made of stainless steel (for example, SUS304). The buffer rubber 52 is formed of rubber (for example, ethylene propylene diene rubber (EPDM)).

The metal ring 51 includes an annular plate portion 54 having an annular surface 53 to which the buffer rubber 52 is bonded and fixed, and an outer cylindrical portion 55 that extends in the axial direction from the outer edge of the annular plate portion 54 so as to cover the outer diameter side of the buffer rubber 52. And an annular inner protrusion 56 extending from the inner edge of the annular plate portion 54 to the side where the shock absorbing rubber 52 is disposed.

On the other hand, the opposing surface of the armature 30 to the rotor 31 is provided with an annular recess 57 formed open to the outer periphery of the armature 30 and an annular groove 58 formed adjacent to the inner diameter side of the annular recess 57. Yes. In the metal ring 51, the annular plate portion 54 faces the axial direction with the annular recess 57 of the armature 30 and the buffer rubber 52 interposed therebetween, and the outer cylindrical portion 55 faces the outer periphery of the armature 30 in the radial direction. As shown, the armature 30 is attached. Here, when the energization of the electromagnet 32 is stopped and the armature 30 is separated from the rotor 31, the annular plate portion 54 is more elastic than the surface of the armature 30 facing the rotor 31 by the elastic restoring force of the buffer rubber 52. It is in a state of protruding to the side.

As shown in FIG. 8, a retaining protrusion 60 that engages with a circumferential groove 59 formed on the outer periphery of the armature 30 is formed on the outer cylindrical portion 55 of the metal ring 51. The retaining protrusion 60 is in contact with the inner surface 61 of the circumferential groove 59 on the side close to the rotor 31, thereby restricting the movement range of the metal ring 51 in the direction approaching the rotor 31, and the buffer member 50 from the armature 30. Prevents falling off. The retaining protrusion 60 is formed by pressing the outer cylinder portion 55 so that an opening penetrating the outer cylinder portion 55 in the radial direction does not occur.

The circumferential groove 59 on the outer periphery of the armature 30 has a shape with axial play with respect to the retaining protrusion 60 so as to allow the metal ring 51 to move in the axial direction accompanying the compression of the shock absorbing rubber 52 in the axial direction. Has been. That is, the groove width of the circumferential groove 59 on the outer periphery of the armature 30 is larger than the axial width of the retaining protrusion 60 so that the retaining protrusion 60 can move in the direction away from the rotor 31 in the circumferential groove 59. Is set. Thereby, when the buffer rubber 52 is compressed in the axial direction, the retaining protrusion 60 is prevented from interfering with the inner side surface 62 of the circumferential groove 59 far from the rotor 31, and the metal accompanying the compression of the buffer rubber 52 is prevented. The ring 51 can be moved in the axial direction.

The annular groove 58 on the surface facing the rotor 31 of the armature 30 is disposed so as to face the inner protrusion 56 of the metal ring 51 in the axial direction. An axial gap is provided between the inner protrusion 56 and the annular groove 58 so that the inner protrusion 56 does not contact the inner surface of the annular groove 58 when the armature 30 is attracted to the rotor 31. Further, the inner protrusion 56 of the metal ring 51 is arranged such that the tip of the inner protrusion 56 is positioned in the annular recess 57 in a state where the retaining protrusion 60 contacts the inner surface 61 of the circumferential groove 59 on the side close to the rotor 31. (That is, the tip of the inner protrusion 56 is positioned on the inner side in the axial direction from the surface of the armature 30 facing the rotor 31).

The buffer rubber 52 is vulcanized and bonded to the surface (annular surface 53) of the metal ring 51 opposite to the side in contact with the rotor 31. The buffer rubber 52 has a high hardness rubber portion 63 and a low hardness rubber portion 64. The high hardness rubber portion 63 and the low hardness rubber portion 64 are formed of rubber materials having different hardness, and the rubber material forming the low hardness rubber portion 64 is lower than the rubber material forming the high hardness rubber portion 63. Those with hardness are used.

The low-hardness rubber portion 64 and the high-hardness rubber portion 63 are provided so that the low-hardness rubber portion 64 is compressed in preference to the high-hardness rubber portion 63 in the process in which the buffer rubber 52 is compressed in the axial direction. . As such a low hardness rubber portion 64 and a high hardness rubber portion 63, in this embodiment, as shown in FIGS. 10 to 13, they are arranged on the annular surface 53 of the metal ring 51 at intervals in the circumferential direction. A low-hardness rubber portion 64 and a high-hardness rubber portion 63 are employed in which the axial thickness of the low-hardness rubber portion 64 is set larger than the axial thickness of the high-hardness rubber portion 63. The low-hardness rubber part 64 and the high-hardness rubber part 63 are each formed to have a constant cross-sectional shape along the circumferential direction of the metal ring 51.

As shown in FIG. 11, the low-hardness rubber portion 64 has a root portion 64 a having a taper-shaped cross section that becomes wider toward the annular surface 53 of the metal ring 51, and a constant portion that extends from the root portion 64 a toward the armature 30. And a leading end portion 64b having a width. The distal end portion 64b has a straight cross section in which the radial width dimension is constant along the axial direction. As shown in the figure, the contact surface of the low hardness rubber portion 64 with respect to the armature 30 is easy to manufacture if it is a plane perpendicular to the axial direction, but instead, it swells slightly more than the plane perpendicular to the axial direction. It may be a convex curved surface.

As shown in FIG. 12, the high-hardness rubber portion 63 includes a root portion 63 a having a tapered cross-sectional shape that becomes wider toward the annular surface 53 of the metal ring 51, and the root portion, similarly to the low-hardness rubber portion 64. And a tip 63b having a constant width extending from the arm 63 toward the armature 30. The distal end portion 63b has a straight cross section in which the radial width dimension is constant along the axial direction. As shown in the figure, the contact surface of the high hardness rubber portion 63 with respect to the armature 30 is easy to manufacture if it is a plane perpendicular to the axial direction, but instead, it swells slightly more than the plane perpendicular to the axial direction. It may be a convex curved surface.

11 and 12, the cross-sectional shape and dimensions of the base portion 63a of the high-hardness rubber portion 63 are the same as the cross-sectional shape and dimensions of the base portion 64a of the low-hardness rubber portion 64. The width dimension in the radial direction of the tip part 63 b of the high hardness rubber part 63 is the same as the width dimension in the radial direction of the tip part 64 b of the low hardness rubber part 64. However, the axial length dimension of the distal end portion 63b of the high hardness rubber portion 63 is not the same as the axial length dimension of the distal end portion 64b of the low hardness rubber portion 64, and the distal end portion 64b of the low hardness rubber portion 64. Is longer than the axial length of the tip 63b of the high-hardness rubber portion 63.

When the compression rubber 52 is compressed in the axial direction because the axial thickness of the low hardness rubber portion 64 is larger than the axial thickness of the high hardness rubber portion 63, the cushion rubber 52 has a relatively small amount of compression. In the low hardness rubber portion 64 and the high hardness rubber portion 63, only the low hardness rubber portion 64 is compressed in the axial direction, and when the amount of compression is relatively large, the low hardness rubber portion 64 and the high hardness rubber portion 63 Is also compressed in the axial direction. For this reason, in the shock absorbing rubber 52, the method of increasing the force required to compress the shock absorbing rubber 52 in the axial direction becomes gentle when the amount of compressing in the axial direction of the shock absorbing rubber 52 is small, and the force in the axial direction of the shock absorbing rubber 52 is reduced. The compression load characteristic is steep when the compression amount is large (see FIG. 17).

As shown in FIG. 8, the axial thickness of the low hardness rubber portion 64 is low even when the retaining projection 60 is in contact with the inner surface 61 of the circumferential groove 59 on the side close to the rotor 31. Is set to such a height as to maintain contact without separating from the inner surface of the annular recess 57. Thereby, rattling of the buffer member 50 in a state where the armature 30 is separated from the rotor 31 is prevented.

An example of operation of this rotation transmission device will be described.

As shown in FIG. 1, when the energization to the electromagnet 32 is stopped, the rotation transmission device is in an engaged state in which rotation is transmitted between the input shaft 6 and the output shaft 7. That is, the armature 30 is separated from the rotor 31 by the force of the spring member 15 when energization to the electromagnet 32 is stopped. At this time, the roller 4a on the front side in the forward rotation direction causes the cylindrical surface on the inner periphery of the outer ring 1 by the force of the spring member 15 that presses the

rollers

4a and 4b in the direction in which the distance between the pair of

rollers

4a and 4b increases. 14 and the front cam surface 13a on the outer periphery of the inner member 2 and the roller 4b on the rear side in the forward rotation direction is connected to the cylindrical surface 14 on the inner periphery of the outer ring 1 and the outer periphery of the inner member 2 The rear cam surface 13b is engaged. In this state, when the inner member 2 rotates in the forward rotation direction, the rotation is transmitted from the inner member 2 to the outer ring 1 via the roller 4b on the rear side in the forward rotation direction. Further, when the inner member 2 rotates in the reverse rotation direction, the rotation is transmitted from the inner member 2 to the outer ring 1 via the front roller 4a in the normal rotation direction.

On the other hand, when the electromagnet 32 is energized, the rotation transmission device is in an engagement disengaged state (idle state) in which the rotation transmission between the input shaft 6 and the output shaft 7 is interrupted. That is, when the electromagnet 32 is energized, the armature 30 is attracted to the rotor 31, and in conjunction with the operation of the armature 30, the flange portion 17b of the second split cage 5B is connected to the flange portion 17a of the first split cage 5A. Move axially toward At this time, the ball 44 of the ball ramp mechanism 33 rolls toward the

deepest portions

45a and 45b of the

inclined grooves

43a and 43b, so that the first divided holder 5A and the second divided holder 5B rotate relative to each other. . Then, due to the relative rotation of the first divided holder 5A and the second divided holder 5B, a pair of the column part 16a of the first divided holder 5A and the column part 16b of the second divided holder 5B are paired. The

rollers

4a and 4b are pressed in the direction in which the distance between the

rollers

4a and 4b is reduced. As a result, as shown in FIG. 3, the inner peripheral cylindrical surface 14 of the outer ring 1 and the outer cam surface of the inner member 2 are front cam surfaces. The engagement of the front roller 4a in the forward rotation direction with the forward rotation direction 13a is released, and the positive rotation between the inner peripheral cylindrical surface 14 of the outer ring 1 and the rear outer cam surface 13b of the inner member 2 is positive. The engagement of the roller 4b on the rear side in the rolling direction is also released. In this state, even if rotation is input to the inner member 2, the rotation is not transmitted from the inner member 2 to the outer ring 1, and the inner member 2 idles.

By the way, when the electromagnet 32 is energized, not only the force attracted to the rotor 31 by the energization of the electromagnet 32 but also the force in the direction away from the rotor 31 by the buffer rubber 52 and the spring member 15 acts. The armature 30 is attracted to the rotor 31 when the force that the armature 30 is attracted to the rotor 31 by energizing the electromagnet 32 exceeds the force in the direction away from the rotor 31 by the buffer rubber 52 and the spring member 15.

Here, the force with which the armature 30 is attracted to the rotor 31 by energization of the electromagnet 32 changes according to the distance between the armature 30 and the rotor 31, and increases as the armature 30 approaches the rotor 31. This increase is gradual when the armature 30 is relatively far from the rotor 31, and is abrupt when the armature 30 is relatively close to the rotor 31. That is, the armature 30 tends to accelerate greatly as it approaches the rotor 31.

On the other hand, a force that urges the armature 30 away from the rotor 31 by the spring member 15 (hereinafter referred to as “spring load”) and a force required to compress the shock absorbing rubber 52 in the axial direction (hereinafter referred to as “rubber compression load”). Also increases as the armature 30 approaches the rotor 31. The manner of increasing the spring load is approximately constant and linear. For example, when a rubber member made of a single material having a constant axial thickness over the entire circumference is used instead of the buffer rubber 52, the method of increasing the rubber compressive load is also approximately the same. Constant and linear.

Therefore, if a rubber member made of a single material having a constant axial thickness over the entire circumference is used instead of the buffer rubber 52 of the above embodiment, the distance between the armature 30 and the rotor 31 is relatively long. In the stage, the force (spring load + rubber compression load) in the direction away from the rotor 31 received by the armature 30 from the buffer rubber 52 and the spring member 15 is the force (electromagnet) that the armature 30 is attracted to the rotor 31 by energizing the electromagnet 32. There is a possibility that the suction force of 32 will be temporarily exceeded. At this time, the armature 30 is not attracted to the rotor 31 and the operation of the armature 30 may become unstable.

On the other hand, in the rotation transmission device of the above embodiment, in the process in which the buffer rubber 52 is compressed in the axial direction, first, the low hardness rubber portion 64 starts to be compressed in preference to the high hardness rubber portion 63, and thereafter Further, when the cushioning rubber 52 is compressed in the axial direction and the armature 30 comes into contact with the high-hardness rubber part 63, the high-hardness rubber part 63 starts to be compressed, so as shown in FIG. The level of compression in the direction is small (that is, the low hardness rubber portion 64 is compressed in the axial direction but the high hardness rubber portion 63 is not compressed in the axial direction. In FIG. 17, the gap between the armature 30 and the rotor 31. Is still larger than about 0.4 mm), the method of increasing the rubber compression load is moderate, and the amount of compression of the shock absorbing rubber 52 in the axial direction is large (that is, the low hardness rubber portion 64 and the high hardness rubber). In the stage where both of the parts 63 are compressed in the axial direction (in FIG. 17, when the gap between the armature 30 and the rotor 31 is smaller than about 0.4 mm), the rubber compression load is suddenly increased. Become. Therefore, when the armature 30 is attracted to the rotor 31 by energization of the electromagnet 32, the force (spring load + rubber compression load) in the direction in which the armature 30 is separated from the rotor 31 received from the buffer rubber 52 and the spring member 15 is The situation in which the armature 30 exceeds the force (attraction force by the electromagnet 32) attracted to the rotor 31 by energization of the electromagnet 32 is prevented, and as a result, the operation of attracting the armature 30 to the rotor 31 is stabilized. Further, the acceleration of the armature 30 immediately before the armature 30 is attracted to the rotor 31 is effectively suppressed, and the collision sound between the armature 30 and the rotor 31 can be effectively reduced.

Further, in the process of compressing the buffer rubber 52 in the axial direction, this rotation transmission device obtains a soft compressive load characteristic by the low-hardness rubber portion 64 at a stage where the amount of compression of the buffer rubber 52 in the axial direction is small, and also provides buffering. When the compression amount of the rubber 52 in the axial direction is large, a hard compression load characteristic can be obtained by the high-hardness rubber portion 63. Therefore, as in the case where the buffer rubber 52 is formed of a single rubber material, the tip is There is no need to provide a projection having a thin and sharp cross-sectional shape, and the durability of the buffer rubber 52 is excellent.

Further, this rotation transmission device can easily adjust the compression load characteristics of the buffer rubber 52 by adjusting the axial thicknesses of the low-hardness rubber portion 64 and the high-hardness rubber portion 63. The cross-sectional shape of 52 can be easily designed.

Further, in the rotation transmission device of the above embodiment, as shown in FIGS. 8 and 9, the metal ring 51 has the outer cylindrical portion 55 extending so as to cover the outer diameter side of the buffer rubber 52. When a part of 52 (for example, a part of the low-hardness rubber part 64) breaks and becomes a broken piece, the broken piece is received by the outer cylinder part 55 of the metal ring 51, and the broken piece of the buffer rubber 52 becomes the metal ring. It is possible to prevent the foreign matter 51 from being discharged as foreign matter. As a result, it is possible to prevent poor engagement of the

rollers

4a and 4b due to mixing of fragments of the buffer rubber 52.

In the rotation transmission device of the above embodiment, the metal ring 51 has the annular inner protrusion 56 extending from the inner edge of the annular plate portion 54. Therefore, in the unlikely event, a part of the buffer rubber 52 (for example, the low hardness rubber portion 64). Can be prevented from being discharged radially inward of the metal ring 51. As a result, it is possible to more effectively prevent poor engagement of the

rollers

4a and 4b due to mixing of fragments of the buffer rubber 52.

FIG. 14, FIG. 15 and FIG. 16 show other examples of the shock absorbing rubber 52. FIG. Portions corresponding to the above embodiment are denoted by the same reference numerals and description thereof is omitted.

The low-hardness rubber portion 64 and the high-hardness rubber portion 63 are provided so that the low-hardness rubber portion 64 is compressed in preference to the high-hardness rubber portion 63 in the process in which the buffer rubber 52 is compressed in the axial direction. . As such a low hardness rubber portion 64 and a high hardness rubber portion 63, in this embodiment, the low hardness rubber portion 64 and the high hardness rubber portion arranged on the annular surface 53 of the metal ring 51 at intervals in the circumferential direction. 63, in which a low-hardness rubber portion 64 and a high-hardness rubber portion 63 are laminated in the axial direction.

As shown in FIG. 15, the high hardness rubber portion 63 is bonded to the annular surface 53, and the low hardness rubber portion 64 is bonded to the surface of the high hardness rubber portion 63. Thereby, the high-hardness rubber part 63 and the low-hardness rubber part 64 are laminated so as to overlap in the axial direction. The low-hardness rubber part 64 and the high-hardness rubber part 63 are each formed to have a constant cross-sectional shape along the circumferential direction of the metal ring 51. The high-hardness rubber portion 63 is formed in a square cross section with one side in contact with the annular surface 53. The low hardness rubber portion 64 has a cross-sectional shape covering the periphery of the high hardness rubber portion 63, and is in contact with the annular surface 53 on the radially outer side and the radially inner side with respect to the high hardness rubber portion 63. As shown in the figure, the contact surface of the low hardness rubber portion 64 with respect to the armature 30 is easy to manufacture if it is a plane perpendicular to the axial direction, but instead, it swells slightly more than the plane perpendicular to the axial direction. It may be a convex curved surface.

Since the low-hardness rubber portion 64 and the high-hardness rubber portion 63 are laminated in the axial direction, the above-described shock-absorbing rubber 52 first has a low-hardness rubber portion 64 in the process of compressing the shock-absorbing rubber 52 in the axial direction. However, after the low-hardness rubber part 64 is sufficiently compressed, the buffering action by the compression of the high-hardness rubber part 63 becomes dominant. For this reason, in the shock absorbing rubber 52, the method of increasing the force required to compress the shock absorbing rubber 52 in the axial direction becomes gentle when the amount of compressing in the axial direction of the shock absorbing rubber 52 is small, and the force in the axial direction of the shock absorbing rubber 52 is reduced. The compression load characteristic is steep when the compression amount is large (see FIG. 17).

Even when the buffer rubber 52 of this form is employed, the low hardness rubber portion 64 is compressed in preference to the high hardness rubber portion 63 when the amount of compression of the buffer rubber 52 in the axial direction is small as shown in FIG. Therefore, the method of increasing the rubber compression load becomes gradual, and at the stage where the amount of compression of the shock absorbing rubber 52 in the axial direction is large, the buffer action due to the compression of the high hardness rubber portion 63 becomes dominant, and therefore the rubber compressing load increases. The way of is sudden. Therefore, when the armature 30 is attracted to the rotor 31 by energization of the electromagnet 32, the force (spring load + rubber compression load) in the direction in which the armature 30 is separated from the rotor 31 received from the buffer rubber 52 and the spring member 15 is The situation in which the armature 30 exceeds the force (attraction force by the electromagnet 32) attracted to the rotor 31 by energization of the electromagnet 32 is prevented, and as a result, the operation of attracting the armature 30 to the rotor 31 is stabilized. Further, the acceleration of the armature 30 immediately before the armature 30 is attracted to the rotor 31 is effectively suppressed, and the collision sound between the armature 30 and the rotor 31 can be effectively reduced.

Further, in the process of compressing the buffer rubber 52 in the axial direction, at a stage where the compression amount of the buffer rubber 52 in the axial direction is small, a soft compression load characteristic is obtained by the low hardness rubber portion 64, and the axial direction of the buffer rubber 52 is increased. At a stage where the compression amount is large, a hard compression load characteristic can be obtained by the high hardness rubber portion 63, so that the tip of the buffer rubber 52 is formed with a single rubber material, as in the case where the buffer rubber 52 is formed of a single rubber material. There is no need to provide protrusions, and the cushioning rubber 52 is excellent in durability.

Further, by adjusting the axial thickness of the low-hardness rubber portion 64 (particularly the axial thickness of the portion overlapping the high-hardness rubber portion 63 in the axial direction) and the axial thickness of the high-hardness rubber portion 63, respectively, The compression load characteristic of the rubber 52 can be easily adjusted, and the cross-sectional shape of the buffer rubber 52 can be easily designed.

In the above embodiment, the buffer member 50 is mounted on the armature 30, but the buffer member 50 may be mounted on the rotor 31 instead of the armature 30.

In the above embodiment, the ball ramp mechanism 33 is employed as an operation conversion mechanism that converts the operation of the armature 30 being attracted to the rotor 31 into the operation of the roller holder 5 moving from the engagement position to the engagement release position. However, other types of motion conversion mechanisms may be employed.

Moreover, in the said embodiment, although the cylindrical surface 14 is provided in the inner periphery of the outer ring | wheel 1, and the cam surface 13 is provided in the outer periphery of the inner member 2, the cam surface 13 (front cam surface 13a and the inner periphery of the outer ring 1 is provided. A rear cam surface 13b) is provided, a cylindrical surface 14 is provided on the outer periphery of the inner member 2, and a pair of

rollers

4a, 4b is provided between the inner peripheral cam surface 13 of the outer ring 1 and the outer peripheral cylindrical surface 14 of the inner member 2. May be incorporated.

In the above-described embodiment, the

rollers

4a and 4b are employed as the engaging members incorporated between the inner periphery of the outer ring 1 and the outer periphery of the inner member 2. However, engaging members other than the

rollers

4a and 4b may be employed. Is possible. For example, between the cylindrical surface formed on the inner periphery of the outer ring 1 and the cylindrical surface formed on the outer periphery of the inner member 2, it engages between the inner periphery of the outer ring 1 and the outer periphery of the inner member 2 in a standing state. A plurality of sprags (not shown) having a shape whose height dimension changes according to the posture can be incorporated so that the engagement is released in the lying state.

FIG. 18 shows a modification of the rotation transmission device shown in FIG. In this rotation transmission device, the rotor 31 of the rotation transmission device shown in FIG. 1 is omitted, and the other configurations are the same. Therefore, the parts corresponding to those in FIG.

18, the buffer member 50 is disposed between the armature 30 and the electromagnet 32 so as to absorb an impact when the armature 30 is attracted to the electromagnet 32. The configuration of the buffer member 50 is the same as in the above embodiment.

This rotation transmission device is in an engaged state in which rotation is transmitted between the input shaft 6 and the output shaft 7 when energization to the electromagnet 32 is stopped. That is, when energization to the electromagnet 32 is stopped, the armature 30 is separated from the electromagnet 32 by the force of the spring member 15 (see FIG. 2). In this state, when the inner member 2 rotates in the forward rotation direction, the rotation is transmitted from the inner member 2 to the outer ring 1 via the roller 4b on the rear side in the forward rotation direction. Further, when the inner member 2 rotates in the reverse rotation direction, the rotation is transmitted from the inner member 2 to the outer ring 1 via the front roller 4a in the normal rotation direction.

On the other hand, when the electromagnet 32 is energized, the disengaged state is established in which the rotation transmission between the input shaft 6 and the output shaft 7 is interrupted. That is, when the electromagnet 32 is energized, the armature 30 is attracted to the electromagnet 32. At this time, as shown in FIG. 3, the engagement of the front roller 4a in the forward rotation direction between the inner cylindrical surface 14 of the outer ring 1 and the outer front cam surface 13a of the inner member 2 is released. In addition, the engagement of the roller 4b on the rear side in the forward rotation direction between the cylindrical surface 14 on the inner periphery of the outer ring 1 and the rear cam surface 13b on the outer periphery of the inner member 2 is also released. In this state, even if rotation is input to the inner member 2, the rotation is not transmitted from the inner member 2 to the outer ring 1, and the inner member 2 idles.

FIG. 19 shows an example of a rotary braking device using the armature buffer structure of the embodiment of the present invention. The rotation braking device rotates between an outer ring 1 supported in a state in which rotation is restricted, an inner member 2 supported so as to be rotatable relative to the outer ring 1, and the outer ring 1 and the inner member 2. An electromagnetic clutch 3 for switching between transmission and disconnection is provided. In this rotation braking device, the rotor 31 of the rotation transmission device shown in FIG. 1 is omitted and the outer ring 1 is prevented from rotating around the housing 11, and the other configurations are the same. Therefore, the parts corresponding to those in FIG.

In FIG. 19, the outer ring 1 is supported in a state where rotation is restricted. That is, the outer periphery of the outer ring 1 is supported by the inner periphery of the housing 11, and the anti-rotation protrusion 70 formed on the outer periphery of the outer ring 1 engages with the anti-rotation groove 71 formed on the inner periphery of the housing 11. The outer ring 1 is prevented from rotating around the housing 11 by the engagement between the protrusion 70 and the rotation preventing groove 71. The housing 11 is supported by a bolt or the like so that it cannot be rotated outside, or is allowed to rotate only within a certain range such that the wiring of the solenoid coil 39 is not broken, and further rotation is restricted. The outer ring 1 is prevented from being detached from the housing 11 by a retaining ring 72 attached to the inner periphery of the end portion of the housing 11. A seal member 73 is incorporated between the fitting surfaces of the outer ring 1 and the housing 11. The buffer member 50 is disposed between the armature 30 and the electromagnet 32 so as to absorb an impact when the armature 30 is attracted to the electromagnet 32. The configuration of the buffer member 50 is the same as in the above embodiment.

When the electromagnet 32 is energized, the rotary braking device is in a braking release state in which the input shaft 6 can rotate without being braked. That is, when the electromagnet 32 is energized, the armature 30 is attracted to the electromagnet 32. At this time, as shown in FIG. 3, the engagement of the front roller 4a in the forward rotation direction between the inner cylindrical surface 14 of the outer ring 1 and the outer front cam surface 13a of the inner member 2 is released. In addition, the engagement of the roller 4b on the rear side in the forward rotation direction between the cylindrical surface 14 on the inner periphery of the outer ring 1 and the rear cam surface 13b on the outer periphery of the inner member 2 is also released. In this state, the input shaft 6 and the inner member 2 can freely rotate in both forward and reverse directions.

On the other hand, when the energization to the electromagnet 32 is stopped, the braking state for braking the rotation of the input shaft 6 and the inner member 2 is established. That is, when the energization to the electromagnet 32 is stopped, the armature 30 is separated from the electromagnet 32 by the force of the spring member 15 (see FIG. 2). At this time, even if the inner member 2 is to be rotated in the forward direction, the inner member 2 does not rotate because the roller 4b on the rear side in the forward direction is engaged between the inner member 2 and the outer ring 1. Similarly, even if the inner member 2 is to be rotated in the reverse direction, the inner member 2 does not rotate because the front roller 4 a in the forward direction is engaged between the inner member 2 and the outer ring 1. Thus, the input shaft 6 and the inner member 2 are in a state in which the rotation is restricted in both the forward and reverse directions.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Inner member 3 Electromagnetic clutch 15 Spring member 30 Armature 31 Rotor 32 Electromagnet 50 Buffer member 51 Metal ring 52 Buffer rubber 53 Annular surface 63 High hardness rubber part 64 Low hardness rubber part

Claims

An axially supported armature (30);
An electromagnet (32) disposed axially opposite the armature (30) and attracting the armature (30) in the axial direction by energization;
A buffer member (50) disposed between the armature (30) and the electromagnet (32);
The buffer member (50) is an armature buffer structure including a metal ring (51) having an annular surface (53) and a buffer rubber (52) bonded to the annular surface (53).
The buffer rubber (52) includes a high-hardness rubber part (63) and a low-hardness rubber part (64) formed of a rubber material having a lower hardness than the rubber material forming the high-hardness rubber part (63). Armature buffer structure characterized by comprising:
The low-hardness rubber part (64) and the high-hardness rubber part (63) are arranged on the annular surface (53) at intervals in the circumferential direction,
The armature buffer structure according to claim 1, wherein an axial thickness of the low hardness rubber portion (64) is set larger than an axial thickness of the high hardness rubber portion (63).
The armature buffer structure according to claim 1, wherein the low-hardness rubber part (64) and the high-hardness rubber part (63) are laminated in the axial direction.
The laminated arrangement is an arrangement in which the high hardness rubber portion (63) is bonded to the annular surface (53), and the low hardness rubber portion (64) is bonded to the surface of the high hardness rubber portion (63). Item 4. The armature buffer structure according to Item 3.
A rotor (31) disposed between the armature (30) and the electromagnet (32), to which the armature (30) is attracted by energization of the electromagnet (32);
The buffer member (50) is disposed between the armature (30) and the rotor (31) so as to absorb an impact when the armature (30) is attracted to the rotor (31). Item 5. The armature buffer structure according to any one of Items 1 to 4.
The armature cushioning structure according to claim 5, further comprising a spring member (15) for biasing the armature (30) in a direction away from the rotor (31).
The metal ring (51) is supported by one member of the armature (30) and the rotor (31) so as to be movable in the axial direction,
The buffer rubber (52) is provided to be compressed in the axial direction between the one member and the metal ring (51) as the armature (30) approaches the rotor (31). Item 7. The armature buffer structure according to Item 5 or 6.
Armature buffer structure according to any one of claims 1 to 7,
An outer ring (1) rotatably supported;
An inner member (2) supported to be rotatable relative to the outer ring (1);
Engaging members (4a, 4b) incorporated between the inner periphery of the outer ring (1) and the outer periphery of the inner member (2);
An engagement position for engaging the engaging elements (4a, 4b) between the outer ring (1) and the inner member (2), and the engagement between the outer ring (1) and the inner member (2). An engagement holder (5) supported so as to be movable between an engagement release position for releasing the engagement of the coupling elements (4a, 4b);
The operation in which the armature (30) moves in the axial direction by energization of the electromagnet (32) is changed to the operation in which the engagement holder (5) moves from one of the engagement position and the engagement release position to the other. A rotation transmission device comprising: a motion conversion mechanism (33) for converting.
A rotor (31) disposed between the axially opposed surfaces of the armature (30) and the electromagnet (32) and rotating integrally with the inner member (2);
The rotation transmission device according to claim 8, wherein the armature (30) is attracted to the rotor (31) by energization of the electromagnet (32).
Armature buffer structure according to any one of claims 1 to 7,
An outer ring (1) supported in a state where rotation is restricted;
An inner member (2) supported to be rotatable relative to the outer ring (1);
Engaging members (4a, 4b) incorporated between the inner periphery of the outer ring (1) and the outer periphery of the inner member (2);
An engagement position for engaging the engaging elements (4a, 4b) between the outer ring (1) and the inner member (2), and the engagement between the outer ring (1) and the inner member (2). An engagement holder (5) supported so as to be movable between an engagement release position for releasing the engagement of the coupling elements (4a, 4b);
The operation in which the armature (30) moves in the axial direction by energization of the electromagnet (32) is changed to the operation in which the engagement holder (5) moves from one of the engagement position and the engagement release position to the other. A rotation braking device comprising: a motion conversion mechanism (33) for converting.
The rotary braking device according to claim 10, wherein the armature (30) is attracted to the electromagnet (32) by energization of the electromagnet (32).