JP2019138419A - Coupling device - Google Patents

Abstract

To provide a coupling device capable of protecting a radial bearing from thermal expansion of an outside rotary member using an inexpensive means, without increasing factors of noise and vibration.SOLUTION: A coupling device comprises: a housing 21; a hollow outside rotary member 5 provided rotatably in the housing 21 via a radial bearing 22, and connected to a drive shaft 2; an inside rotary member 6 coaxially and rotatably supported in the outside rotary member 5, and connected to an input shaft 3a; a clutch 7 connecting the outside rotary member 5 to the inside rotary member 6 in a disconnectable manner; and an actuator 8 configured to drive the clutch 7. On the outer peripheral part of the outside rotary member 5, thermal expansion absorption holes 44a and 44b for absorbing thermal expansion are formed so as to extend from an end surface on the drive shaft 2 side to the position of the radial bearing 22 in an axis direction.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a coupling device that selectively transmits a rotational driving force of a drive shaft to an input shaft.

  The coupling device includes a housing, a hollow outer rotating member that is rotatably supported in the housing via a radial bearing, an inner rotating member that is rotatably provided in the outer rotating member, and an outer rotating member. And a clutch that connects the outer rotating member and the inner rotating member so as to be connectable and disconnectable.

Japanese Patent No. 5045283

  Incidentally, clutch oil is accommodated in the outer rotating member. For this reason, an outer side rotation member is thermally expanded by the heat_generation | fever by the shear resistance of clutch oil. Further, the outer rotating member is made of aluminum having a larger linear expansion coefficient than that of a steel radial bearing. For this reason, there is a problem that the outer rotating member presses the radial bearing radially outward from the inside during thermal expansion, reduces the radial gap of the radial bearing, and decreases the life of the radial bearing.

  As a means for solving such a problem, there is a method using a radial bearing having a large radial gap (a gap between the inner ring and the outer ring). However, in this method, the backlash between the inner ring 22b and the outer ring 22a at a low temperature or normal temperature is large, and the outer ring 22a is easily eccentrically rotated with respect to the inner ring 22b. For this reason, the imbalance accompanying eccentric rotation of the outer periphery ring 22a is easy to be induced, and there is a problem of causing abnormal noise and vibration.

  In the invention described in Patent Document 1, an intermediate member separate from the outer rotating member is provided between the radial bearing and the outer rotating member. For this reason, there is a problem that the number of parts increases, a new assembly man-hour is generated, and the production cost increases.

  Therefore, the present disclosure has been created in view of such circumstances, and the purpose thereof is to provide a coupling device that can protect the radial bearing from the thermal expansion of the outer rotating member by inexpensive means without increasing the cause of abnormal noise and vibration. It is to provide.

According to one aspect of the present disclosure, the housing, a hollow outer rotating member that is rotatably provided in the housing via a radial bearing and connected to the drive shaft, and the outer rotating member is coaxially and rotated. An inner rotating member that is freely supported and connected to the input shaft, a clutch that connects the outer rotating member to the inner rotating member so as to be connectable and disconnectable, and an actuator that drives the clutch,
A heat expansion absorbing hole for absorbing thermal expansion is formed in an outer peripheral portion of the outer rotating member so as to extend from an end surface on the drive shaft side to the position of the radial bearing in the axial direction. A ring device is provided.

  Preferably, a plurality of the thermal expansion absorption holes may be formed in the circumferential direction on the outer peripheral portion of the outer rotating member.

  Preferably, an internal thread portion for bolting the drive shaft may be formed on the drive shaft side of the thermal expansion absorption hole.

  Further, a fitting portion for positioning the drive shaft may be formed on the drive shaft side of the thermal expansion absorption hole.

  Preferably, the thermal expansion absorption hole is formed to have a circular cross section.

  Preferably, a filler is provided in the thermal expansion absorption hole.

  Preferably, the filler is made of an elastic material.

  Preferably, the filler is a weight.

  According to the present disclosure, the radial bearing can be protected from the thermal expansion of the outer rotating member by an inexpensive means without increasing the cause of abnormal noise and vibration.

1 is a schematic plan view of a vehicle to which a coupling device according to an embodiment of the present disclosure is applied. It is sectional drawing of a coupling apparatus. It is principal part sectional drawing of the coupling apparatus which shows other embodiment. It is principal part sectional drawing of the coupling apparatus which shows other embodiment.

  Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In addition, each direction of front and rear, right and left and up and down in the embodiment described later refers to each direction of the vehicle to which the coupling device according to this embodiment is applied. However, it should be noted that these directions are merely defined for convenience of explanation.

  FIG. 1 is a schematic plan view of a vehicle C to which a coupling device 1 according to this embodiment is applied.

  As shown in FIG. 1, in the present embodiment, the vehicle C is a part-time 4WD vehicle (four-wheel drive vehicle) based on an FF vehicle (front engine / front drive vehicle). The propeller shaft 2 as a drive shaft extends rearward from the front portion of the vehicle. A rotational driving force from the engine E is transmitted to the propeller shaft 2 via a transmission and a transfer (not shown). The differential gear 3 is connected to the left and right rear wheels R, R and is housed in a differential case 4 fixed to the vehicle body. Differential oil is accommodated in the differential case 4. The coupling device 1 is provided between the propeller shaft 2 and the differential gear 3, and is configured to selectively transmit the rotational driving force of the propeller shaft 2 to the input shaft 3 a of the differential gear 3.

  FIG. 2 is a cross-sectional view of the coupling device 1. As shown in FIG. 2, the coupling device 1 includes a housing 21 provided with a differential case 4, and a hollow outer rotating member 5 that is rotatably provided in the housing 21 via a radial bearing 22 and connected to the propeller shaft 2. An inner rotating member 6 that is coaxially and rotatably supported in the outer rotating member 5, a clutch 7 that connects the outer rotating member 5 to the inner rotating member 6 so as to be connectable and disengageable, and an actuator 8 that drives the clutch 7. Is provided.

  The housing 21 is formed in a substantially cylindrical shape (specifically, a cylindrical shape) and covers the outer periphery of the outer rotating member 5. The housing 21 is liquid-tightly fixed to the differential case 4 at the rear end. A lip seal 23 that seals between the housing 21 and the outer rotating member 5 is provided on the inner peripheral surface of the housing 21 in front of the radial bearing 22.

The radial bearing 22 includes an outer ring 22a, an inner ring 22b, and a ball 22c interposed between the outer ring 22a and the inner ring 22b. The outer peripheral ring 22a is fitted to the inner peripheral surface of the housing 21, and its axial position is restricted by a snap ring (not shown). Thereby, the outer peripheral ring 22 a is fixed to the inner peripheral surface of the housing 21. Further, the inner peripheral ring 22b is fitted to the outer peripheral surface of the outer rotating member 5, and the position in the axial direction is restricted by a snap ring (not shown). As a result, the inner peripheral ring 22 b is fixed to the outer peripheral surface of the outer rotating member 5. The outer ring 22a, the inner ring 22b, and the ball 22c are each formed of steel.
The ball 22c may be a roller.

  The outer rotating member 5 is made of aluminum and is arranged coaxially with the housing 21. The outer rotating member 5 includes a front rotating portion 9 formed in a bottomed cylindrical shape (specifically, a bottomed cylindrical shape), and a rear rotating portion that is fitted into the front rotating portion 9 from behind and is fixed by screws or the like. Part 10.

  The front rotating portion 9 includes a base portion 40 formed at the front portion and fastened to the propeller shaft 2 with a bolt (not shown), and a case portion 41 formed at the rear portion and accommodating the clutch 7 and the like.

  The base portion 40 is formed in a cylindrical shape having a thick wall (the dimension between the inner diameter and the outer diameter is large) and forms a front outer peripheral portion of the outer rotating member 5, and closes a hole 42 a in the cylindrical portion 42. And a lid 43. An inner ring 22 b of the radial bearing 22 is fixed to the front portion of the cylindrical portion 42. The rear part of the cylindrical part 42 is formed with a diameter larger than that of the front part. Further, a plurality of thermal expansion absorption holes 44 a and 44 b for absorbing thermal expansion of the cylindrical portion 42 and the lid portion 43 are formed in the cylindrical portion 42 in the circumferential direction.

  The thermal expansion absorption holes 44a and 44b are formed to extend rearward from the front end surface of the cylindrical portion. Further, the thermal expansion absorption holes 44a and 44b extend rearward beyond the position of the radial bearing 22 in the axial direction. The thermal expansion absorption holes 44a and 44b do not necessarily extend rearward beyond the position of the radial bearing 22, and need only reach at least the position of the radial bearing 22 in the axial direction. That is, it is sufficient that at least a part of the thermal expansion absorption holes 44 a and 44 b is in the axial region on the radially inner side of the radial bearing 22. The thermal expansion absorption holes 44a and 44b include a first thermal expansion absorption hole 44a and a second thermal expansion absorption hole 44b. A female screw portion 45a is formed on the front side (propeller shaft 2 side) of the first thermal expansion absorption hole 44a. A bolt 45b for fastening the flange 2a of the propeller shaft 2 to the base portion 40 is screwed into the female screw portion 45a. A fitting portion 46a is formed on the front side (propeller shaft 2 side) of the second thermal expansion absorption hole 44b. A positioning protrusion 46b formed on the flange 2a of the propeller shaft 2 is fitted into the fitting portion 46a. A plurality of (for example, four) first thermal expansion absorption holes 44 a are formed at equal intervals in the circumferential direction of the cylindrical portion 42. The second thermal expansion absorption holes 44b are formed in a smaller number (for example, three) than the first thermal expansion absorption holes 44a and at equal intervals in the circumferential direction. The first thermal expansion absorption hole 44a and the second thermal expansion absorption hole 44b are formed in a circular cross section.

  The first thermal expansion absorption holes 44a do not necessarily have to be formed at equal intervals in the circumferential direction. Further, when the positioning fitting portion 46a is not required, the second thermal expansion absorption hole 44b may be omitted.

  Further, a cover member 47 for closing the front end opening of the housing 21 is provided on the front outer peripheral surface 42 b of the cylindrical portion 42. The cover member 47 is formed in an annular shape when viewed from the front, and the inner peripheral end is fixed to the front outer peripheral surface 42 b of the cylindrical portion 42. The inner peripheral end of the cylindrical portion 42 is formed in a cylindrical shape. Further, the outer peripheral end of the cover member 47 is formed in a cylindrical shape extending rearward and covers the outer periphery of the front end portion of the housing 21. The lid portion 43 is formed integrally with the front end portion of the cylindrical portion 42.

  The case portion 41 is formed in a cylindrical shape that is thinner than the cylindrical portion 42. A first spline 11 is formed on the inner periphery of the case portion 41.

  The rear rotating portion 10 is formed in a cylindrical shape (specifically, a cylindrical shape) and covers the outer periphery of the rear portion of the inner rotating member 6. The rear rotating portion 10 extends from the sheath tube portion 12 to the outer peripheral side. And a flange 13 fitted to the rear end. An electromagnet accommodating portion 14 for accommodating the electromagnet 35 is formed in a concave shape on the rear surface of the flange portion 13. The sheath tube portion 12 is provided with a seal ring 15 for sealing the space between the sheath tube portion 12 and the inner rotary member 6 in a liquid-tight manner. The seal ring 15 prevents the clutch oil housed in the outer rotating member 5 on the front side of the seal ring 15 from being mixed with the differential oil housed in the differential case 4 behind the seal ring 15. The sheath tube portion 12 is rotatably supported via a bearing 16 by a fixed-side mounting member 36 described later.

  The inner rotation member 6 is formed in a substantially cylindrical shape (specifically, a cylindrical shape). A front end portion of the inner rotating member 6 is rotatably supported by the outer rotating member 5 via a bearing 16. Further, an enlarged diameter portion 17 whose outer diameter is enlarged is formed at the front portion of the inner rotating member 6. A second spline 18 is formed on the outer periphery of the enlarged diameter portion 17. The enlarged diameter portion 17 and the second spline 18 are formed shorter than the first spline 11 and are disposed so as to face the front portion of the first spline 11 in the radial direction. A third spline 19 as an engaging portion is formed on the inner periphery of the rear portion of the inner rotating member 6. The third spline 19 is engaged with the input shaft 3a of the differential gear 3, and specifically, is fitted into a spline 3b formed on the outer periphery of the input shaft 3a. Thereby, the rear part of the inner rotation member 6 is coaxially connected to the input shaft 3 a of the differential gear 3. Moreover, the hole 6a at the center in the radial direction of the inner rotating member 6 is penetrated in the axial direction.

  In addition, a plug 20 that partitions the inside of the inner rotating member 6 is provided. Here, the space in the inner rotating member 6 communicates with the space in the outer rotating member 5 and the space in the differential case 4. The plug 20 is provided to isolate the space in the outer rotating member 5 from the space in the differential case 4. The plug 20 prevents the clutch oil housed in the outer rotating member 5 from being mixed with the oil on the input shaft 3a side, specifically, the differential oil in the differential case 4. The plug 20 is formed in a bottomed cylindrical shape (specifically, a bottomed cylindrical shape). In addition, the plug 20 does not need to be a bottomed cylindrical shape, and may be an arbitrary shape. For example, it may be a simple solid shape. Further, the plug 20 may be formed integrally with the inner rotating member 6.

  The clutch 7 includes an annular first clutch plate 25 a that is spline-fitted to the first spline 11, and an annular second clutch plate 25 b that is fitted to the second spline 18. The first clutch plates 25a and the second clutch plates 25b are alternately arranged in the front-rear direction. A clutch receiving portion 27 for receiving the clutch 7 is formed on the outer rotating member 5 in front of the clutch 7.

  The actuator 8 includes an electromagnet 35, an armature 34 attracted by the electromagnet, and a booster 37 that amplifies the force that the electromagnet 35 attracts the armature 34 and transmits the amplified force to the clutch 7. The booster 37 includes a first cam block 28 that is spline-fitted to the second spline 18, a second cam block 29 that is disposed behind the first cam block 28, the first cam block 28, and the second cam block 28. A ball 30 disposed between the cam blocks 29, a fourth spline 31 formed on the outer periphery of the second cam block 29, a third clutch plate 32 that is spline-fitted to the first spline 11, and a fourth spline. And a fourth clutch plate 33 that is spline-engaged with 31.

  The first cam block 28 is formed in an annular shape. The first cam block 28 includes a first cam plate portion 28a for receiving the ball 30, and a pressing portion 28b formed on the outer periphery of the first cam plate portion 28a for pressing the clutch 7 forward. A plurality of first cam grooves 28c for receiving the balls 30 are formed in the first cam plate portion 28a in the circumferential direction. The first cam grooves 28c are each formed in a crescent shape extending in the circumferential direction. The first cam groove 28c is formed so that the groove width becomes narrower and the groove depth becomes shallower from the central part toward both ends.

  The second cam block 29 is formed in an annular shape having a smaller outer diameter than the first cam block 28. The second cam block 29 includes a second cam plate portion 29a disposed to face the first cam plate portion 28a, a cylindrical spline base portion 29b provided on the outer periphery of the second cam plate portion 29a and extending in the front-rear direction. Is provided. A plurality of second cam grooves 29c for receiving the balls 30 are formed in the second cam plate portion 29a so as to face the first cam grooves 28c. The second cam groove 29c is formed in a shape that is symmetrical with respect to the first cam groove 28c. A fourth spline 31 is formed on the outer periphery of the spline base 29b.

  The armature 34 is formed in an annular shape having an inner diameter larger than that of the fourth spline 31, and is disposed in front of the third clutch plate 32 and the fourth clutch plate 33. The armature 34 is made of a magnetic material such as iron, and is attracted rearward toward the electromagnet 35 when receiving a magnetic force from the electromagnet 35. The armature 34 is splined to the second spline 18.

  The electromagnet 35 is attached to the attachment member 36 and attracts the armature 34 backward. The attachment member 36 is fixed to the differential case 4. The electromagnet 35 is accommodated in the electromagnet accommodating portion 14 and generates a magnetic field when energized by an external control device (not shown).

  The actuator 8 is not limited to this. The actuator 8 only needs to be able to drive the clutch 7. Specifically, the actuator 8 may include an electric motor, a hydraulic motor, an electric cylinder, a hydraulic cylinder, or the like instead of the electromagnet 35. Further, when the clutch 7 can be driven without the booster 37, the booster 37 may be omitted.

  Next, the function and effect of this embodiment will be described.

  When forming the front rotation part 9, for example, after forming the prototype of the front rotation part 9 (specifically, the front rotation part 9 having no thermal expansion absorption holes 44a, 44b) by forging, A first thermal expansion absorption hole 44a and a second thermal expansion absorption hole 44b are processed and formed in the prototype. The first thermal expansion absorption hole 44a is formed by forming a hole extending backward in the front surface of the original pattern with a drill or the like and then forming a female screw on the front side of the hole with a tap or the like. Further, the second thermal expansion absorbing hole 44b is formed by forming a hole extending rearward on the front surface of the original pattern with a drill or the like and then expanding the front side of the hole to a predetermined diameter with a reamer or the like. Here, it is compared with a case where only the bolt hole and positioning hole for fastening the drive shaft are formed without forming the thermal expansion absorption holes 44a and 44b in the prototype (referred to as a comparative example). In this case, after forming a pilot hole with a drill or the like, a female screw or an enlarged diameter portion is formed in the pilot hole. That is, the number of steps is the same between the present embodiment and the comparative example, and the only difference is the length of the hole formed by drilling. The hole of this embodiment is long and the pilot hole of the comparative example is short. Therefore, in this embodiment, the drilling time is slightly increased as compared with the comparative example, and the thermal expansion absorption holes 44a and 44b can be efficiently formed at low cost. That is, in this embodiment, the thermal expansion absorbing holes 44a and 44b can be easily formed by simply extending the bolt hole machining pilot hole originally in the comparative example.

  Next, the operation of the coupling device 1 incorporated in the vehicle C will be described.

  When the electromagnet 35 is not energized, the clutch 7 is disengaged. For this reason, the rotational driving force of the propeller shaft 2 is transmitted only to the outer rotating member 5 and is not transmitted to the inner rotating member 6. At this time, the first clutch plate 25a and the second clutch plate 25b of the clutch 7 are close to each other with a small interval. For this reason, the clutch oil is rubbed against the first clutch plate 25a, and frictional heat is generated. The frictional heat is transmitted to the entire outer rotating member 5 through the clutch oil, and causes the outer rotating member 5 to thermally expand. At this time, a radial bearing 22 is fixed to the outer periphery of the outer rotating member 5. Since the radial bearing 22 has a smaller linear expansion coefficient than the outer rotating member 5, the outer rotating member 5 expands radially outward. Be regulated. If the thermal expansion absorbing holes 44a and 44b are not present, the outer rotating member 5 pushes the radial bearing 22 outward in the radial direction, reduces the radial clearance of the radial bearing 22, and shortens the life of the radial bearing 22. It becomes. However, since the thermal expansion absorption holes 44a and 44b are formed in the outer rotation member 5 according to the present embodiment, the thermal expansion absorption holes 44a and 44b are slightly deformed to absorb the thermal expansion of the outer rotation member 5. To do. For this reason, it can prevent or suppress that the radial clearance of the radial bearing 22 is reduced, and can prevent or suppress the life of the radial bearing 22 from being shortened. Further, the radial bearing 22 used in the present embodiment is a normal one and is not a radial bearing with a large radial gap. For this reason, it is possible to prevent or suppress an increase in abnormal noise and vibration. That is, according to the present embodiment, the radial bearing 22 can be protected from the thermal expansion of the outer rotating member 5 by an inexpensive means without increasing the cause of abnormal noise and vibration. Further, in the present embodiment, the thermal expansion absorption holes 44 a and 44 b are assumed to be in the entire area in the axial direction inside the radial bearing 22 in the radial direction. Thereby, the force of thermal expansion from the outer rotating member 5 toward the radial bearing 22 can be effectively absorbed. However, the thermal expansion absorption holes 44a and 44b may be provided only in a part of the axial direction region. Even in this case, the thermal expansion force from the outer rotating member 5 toward the radial bearing 22 can be absorbed.

  When the electromagnet 35 is energized from the clutch disengaged state, the armature 34 is attracted to the rear electromagnet 35 and moved rearward. The armature 34 moved rearward pushes the third clutch plate 32 and the fourth clutch plate 33 rearward. As a result, the third clutch plate 32 and the fourth clutch plate 33 are sandwiched between the armature 34 and the rear rotating portion 10 and are in contact with each other. The fourth clutch plate 33 that has received the rotational driving force from the third clutch plate 32 transmits the rotational driving force to the second cam block 29. The second cam block 29 to which the rotational driving force is transmitted is rotated with respect to the first cam block 28. Accordingly, the first cam groove 28c and the second cam groove 29c are relatively moved in the circumferential direction. Then, the ball 30 is moved along the first cam groove 28c and the second cam groove 29c to be moved to the end portions of the first cam groove 28c and the second cam groove 29c. As for the 1st cam groove 28c and the 2nd cam groove 29c, a groove depth becomes shallow as it goes to an edge part from a center part. Therefore, the first cam plate portion 28a is pushed forward with respect to the second cam plate portion 29a, and pushes the first clutch plate 25a and the second clutch plate 25b forward. Accordingly, the first clutch plate 25a and the second clutch plate 25b are sandwiched between the pressing portion 28b of the first cam block 28 and the clutch receiving portion 27 and are brought into contact with each other. The second clutch plate 25 b that receives the rotational driving force from the first clutch plate 25 a transmits the rotational driving force to the inner rotating member 6. Accordingly, the inner rotating member 6 is rotated integrally with the outer rotating member 5 and transmits a rotational driving force to the input shaft 3 a of the differential gear 3. Thus, the engine driving force is also transmitted to the rear wheels R, R, and the vehicle C enters a four-wheel drive state.

  The basic embodiment of the present disclosure has been described in detail above, but the present disclosure can also be implemented in the following other embodiments.

  (1) Although the female screw portion 45 or the fitting portion 46 is formed on the front side of the thermal expansion absorption holes 44a and 44b, the female screw portion 45 or the fitting portion 46 is not necessarily formed. For example, some or all of the plurality of thermal expansion absorption holes 44a and 44b formed in the circumferential direction may be those in which the female screw portion 45 or the fitting portion 46 is not formed. In this case, the thermal expansion absorption holes 44a and 44b in which the female screw part 45 or the fitting part 46 are not formed may not be formed in a circular cross section. The thermal expansion absorption holes 44a and 44b in which the female screw part 45 or the fitting part 46 are not formed may have, for example, an elliptical cross section or another cross sectional shape.

  (2) As shown in FIGS. 3 and 4, a filler 48 may be provided in the thermal expansion absorption holes 44a and 44b. Preferably, the filler 48 is a weight for adjusting the rotational balance. By increasing or decreasing the amount of the filler 48 provided in the thermal expansion absorption holes 44a and 44b, the rotational imbalance can be corrected, and abnormal noise and noise due to the imbalance can be suppressed.

  The filler 48 or the weight may be made of a material having a specific gravity close to that of aluminum that is the material of the outer rotating member 5. Furthermore, the filler 48 or the weight may be formed of an elastic body such as a soft resin (for example, rubber). The deformation of the thermal expansion absorption holes 44a and 44b can be followed, and it can be prevented or suppressed from interfering with the thermal expansion absorption by the thermal expansion absorption holes 44a and 44b.

  (3) In the basic embodiment described above, the inner rotary member 6 is engaged with the outer periphery of the input shaft 3a by a spline. However, the engagement method may be other methods. For example, they may be engaged by various coaxial connection structures such as serrations, combinations of keys and key grooves, gears, or combinations of square shafts and square holes.

  (4) The coupling device 1 according to the basic embodiment described above selectively transmits the rotational driving force of the propeller shaft 2 serving as the drive shaft to the input shaft 3a of the differential gear 3 in the part-time 4WD vehicle based on the FF vehicle. So applied. However, the application of the coupling device according to the present disclosure is not limited to this. When it is desired to selectively transmit the rotational driving force of the drive shaft to any input shaft, the coupling device according to the present disclosure can be suitably used. Therefore, the coupling device according to the present disclosure can be applied to fields other than vehicles.

  The configurations of the above-described embodiments can be combined partially or wholly unless there is a particular contradiction. The embodiment of the present disclosure is not limited to the above-described embodiment, and includes all modifications, applications, and equivalents included in the concept of the present disclosure defined by the claims. Therefore, the present disclosure should not be construed as being limited, and can be applied to any other technique belonging to the scope of the idea of the present disclosure.

DESCRIPTION OF SYMBOLS 1 Coupling apparatus 2 Drive shaft 3a Input shaft 5 Outer rotating member 6 Inner rotating member 7 Clutch 8 Actuator 22 Radial bearing 44a First thermal expansion absorption hole (thermal expansion absorption hole)
44b Second thermal expansion absorption hole (thermal expansion absorption hole)

Claims (8)

A housing, a hollow outer rotating member that is rotatably provided in the housing via a radial bearing and connected to a drive shaft, and is coaxially and rotatably supported in the outer rotating member and connected to an input shaft; An inner rotating member, a clutch that connects the outer rotating member to the inner rotating member so as to be connectable / disengageable, and an actuator that drives the clutch,
A heat expansion absorbing hole for absorbing thermal expansion is formed in an outer peripheral portion of the outer rotating member so as to extend from an end surface on the drive shaft side to the position of the radial bearing in the axial direction. Ring device.   The coupling device according to claim 1, wherein a plurality of the thermal expansion absorption holes are formed in a circumferential direction on an outer peripheral portion of the outer rotating member.   The coupling device according to claim 1 or 2, wherein an internal thread portion for bolting the drive shaft is formed on the drive shaft side of the thermal expansion absorption hole.   The coupling device according to any one of claims 1 to 3, wherein a fitting portion for positioning the drive shaft is formed on the drive shaft side of the thermal expansion absorption hole.   The coupling device according to any one of claims 1 to 4, wherein the thermal expansion absorption hole is formed in a circular cross section.   The coupling device according to claim 1, wherein a filler is provided in the thermal expansion absorption hole.   The coupling device according to claim 6, wherein the filler is made of an elastic material.   The coupling device according to claim 6, wherein the filler is a weight.

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