JP2019094994A - Clutch device - Google Patents

Abstract

To facilitate assembly of a coil spring without damaging a rotation stop function of the coil spring with respect to a shaft body and a rotor, in a clutch device.SOLUTION: A clutch device 7 includes: a shaft body 10; a cylindrical rotor 20; and a coil spring 30 provided coaxially between the shaft body 10 and rotor 20. The rotor 20 has a first seat part 19 on which a first end part 31 of the coil spring 30 is mounted on one side in the axial direction. The shaft body 10 includes a second seat part 12 on which a second end part 32 of the coil spring 30 is mounted in a fastened and fitted state on the other side in the axial direction. The first end part 31 includes: a spiral-like spiral part continuing from the second end part 32 side; and a linear part 34 extending linearly from the spiral part toward a tangential direction of a central line of the spiral part. In the first seat part 19, a linear recessed groove part 27 is provided for accommodating the linear part 34 in a state of clearance fitting.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a clutch device.

  For example, an alternator used as an accessory of an automobile engine is configured to be driven by transmitting rotational force from a crankshaft of the engine. That is, a pulley is attached to the rotation shaft of the alternator, and a belt is stretched between the pulley and a pulley on the crankshaft side, and the rotational force of the crankshaft is transmitted to the alternator through the belt. It has become.

  Since the rotational force of the crankshaft is based on the explosive force in the cylinder of the engine, the rotational speed of the crankshaft fluctuates (hereinafter, this fluctuation is also referred to as “rotational fluctuation”). On the other hand, the alternator side can not follow the rapid rotational fluctuation of the crankshaft, and a rotational speed difference temporarily occurs between the crankshaft and the alternator. Such a rotational speed difference may cause the belt to slip or apply an excessive load to the belt, which may cause abnormal noise and a decrease in life. Therefore, a pulley apparatus for an alternator is provided with a coil spring for absorbing a rotational fluctuation generated between a rotating body having a pulley portion on which a belt is to be hung and a shaft integrally rotating with a rotating shaft of the alternator. (See, for example, FIG. 6 of Patent Document 1).

JP 2008-57763 A

  The inventor of the present invention has already proposed a clutch device in which a coil spring is provided between a rotating body and a shaft body (Japanese Patent Application No. 2017-021513). In this clutch device, as shown in FIG. 7, the first end 91 on one axial side of the coil spring 90 is attached to the first seat 98 of the rotating body 99, and the other axial direction of the coil spring 90 is A side second end 92 is attached to the second seat 94 of the shaft 95. The first end portion 91 is in an interference fit with both the radially outer side surface 96 a and the radially inner side surface 96 b of the recess 97 formed in the first seat portion 98, and is fitted to the recess 97. ing. By this fitting, the first end 91 of the coil spring 90 is fixed to the rotating body 99 in a state of being locked. The second end 92 is attached to the outer circumferential surface 93 of the second seat 94 in an interference fit, and is fixed to the shaft 95 in a detent manner.

  When assembling the clutch device shown in FIG. 7, both the first end 91 and the second end 92 of the coil spring 90 are fitted to the attachment target portion (the concave portion 97 and the second seat portion 94) with an interference. It is necessary to match. However, since the assembly of the coil spring 90 is performed in a substantially closed annular space formed between the cylindrical rotating body 99 and the shaft 95 on the inner peripheral side, the assembly work is performed It becomes difficult.

  Then, an object of this invention is to provide the clutch apparatus which becomes easy to assemble | attach a coil spring, without impairing the function of rotation prevention of a coil spring with respect to a shaft and a rotary body.

  The clutch device according to the present invention includes a shaft, a cylindrical rotating body provided concentrically with the shaft, and a coil spring provided concentrically between the shaft and the rotating body. The rotary body has a first seat on one side in the axial direction, to which the first end of the coil spring is attached, and the shaft is on the other side in the axial direction of the coil spring. A second seat portion attached to the second end portion in an interference fit state, the first end portion being a helical portion continuing from the second end portion side; A linear concave groove portion having a linear portion extending linearly in a tangential direction of a center line of the spiral portion, and the first seat portion accommodating the linear portion in a state of clearance fitting Is provided.

  According to this clutch device, the first seat portion of the rotating body is provided with the linear concave groove portion that accommodates the linear portion of the first end portion of the coil spring. Since the linear portion is accommodated in the linear recessed groove portion in a clearance fit state, assembling of the first end portion of the coil spring and the rotating body (first seat portion) is easy when assembling the clutch device Become. Then, when the linear portion is accommodated in the linear recessed groove portion, when the coil spring is twisted, the linear portion contacts the radial direction surface of the recessed groove portion, and the first end portion of the coil spring and the rotating body And the rotation stop is made. As a result, even if rotational fluctuation occurs between the shaft and the rotating body, the coil spring can be twisted to absorb the rotational fluctuation.

In addition, the second end of the coil spring is attached to the outer peripheral surface of the second seat in an interference fit and elastically deformable in the radial direction, and the rotor is mounted on the shaft. Rotates in one direction, the coil spring is twisted and elastically reduced in diameter, and the interference between the second end and the second seat increases, and the rotating body is rotated relative to the shaft. When the coil spring is rotated in the other direction, the coil spring is twisted to elastically expand the diameter, and the interference between the second end and the second seat decreases, and the second end and the second seat It is preferable to make it the structure which accept | permits the slip between them.
According to this configuration, for example, when the rotating body rotates in one direction with respect to the shaft by accelerating the rotating body, the coil spring is twisted in one direction, and the second end of the coil spring is the second end of the shaft Tighten the second seat further. By twisting the coil spring in one direction in this way, it is possible to absorb the rotational fluctuation that occurs between the shaft and the rotating body. On the other hand, when the rotating body is decelerated, for example, when the rotating body rotates in the other direction with respect to the shaft body, the coil spring is twisted in the opposite direction (in the other direction) to expand the diameter. The end portion weakens the force of tightening the second seat of the shaft, and slippage may occur between the second end and the second seat. As described above, when the rotating body rotates in one direction with respect to the shaft, the shaft and the rotating body can be integrally rotated, and when the rotating body rotates in the other direction with respect to the shaft, the shaft is slipped by the slip. It is possible to idle the rotating body against the body. For this reason, even if there is no one way clutch which has an engaging element, a clutch apparatus can be equipped with the function (function of one way clutch), and a clutch apparatus is simplified.

  Further, the first seat portion is constituted by a member separate from the rotating body, and the first seat portion and the rotating body are fitted by fitting the first seat portion to the rotating body with an interference. It is preferable that and are united. Thus, by making the first seat portion separate from the rotating body, it is advantageous in terms of manufacturing of the rotating body and assembly of the clutch device. Also, even if the first seat portion is separated from the rotating body, these first seat portion and the rotating body are fitted and integrated with an interference, so the number of parts for this integration is not increased. That's it. In addition, about the operation | work which fits a 1st seat part and a rotary body, since it can do in the open space, the operation | work is easy.

Further, the first seat portion is an outer cylindrical portion provided radially outside the first end portion, an inner cylindrical portion provided radially inside the first end portion, and the outer cylinder And the annular portion connecting the inner cylindrical portion, and the linear concave groove portion is formed in a part of a region surrounded by the outer cylindrical portion, the inner cylindrical portion, and the annular portion. A bearing is interposed between one axial side of the shaft and the inner cylindrical portion, and the first end side of the coil spring has an inner diameter smaller than the second end side. It is preferable to be large. According to this configuration, it is possible to obtain a configuration in which the shaft body and the rotating body are supported relatively rotatably on one side in the axial direction by the bearing (first bearing). Of the rotating body, the portion directly supported by the bearing is the inner cylindrical portion of the first seat. Therefore, by increasing the inner diameter on the first end side of the coil spring, the radial dimension of the inner cylindrical portion can be increased, and the rigidity of the inner cylindrical portion can be secured.

  Further, a bearing is interposed between the other axial side of the shaft and the other axial side of the rotating body, and the shaft is interposed between the bearing and the second end of the coil spring. It is preferable that an annular member which is a separate body is interposed, and that the second end portion contacts the annular member to prevent movement of the coil spring to the other side in the axial direction. According to this configuration, it is possible to obtain a configuration in which the shaft and the rotating body are relatively rotatably supported on the other side in the axial direction by the bearing (second bearing). Further, since the annular member is separate from the shaft, the material of the annular member can be changed or an annular member provided with a coating layer can be adopted according to, for example, a coil spring.

  ADVANTAGE OF THE INVENTION According to this invention, the assembly | attachment of a coil spring becomes easy, without impairing the function of rotation prevention of a coil spring with respect to a shaft and a rotary body.

It is a sectional view showing an example of a clutch device of the present invention. It is sectional drawing which expands and shows one axial direction side (left side in FIG. 1) of a clutch apparatus. It is a perspective view which shows the 1st seat part in the state where the 1st end of a coiled spring, and the 1st end were attached. It is a front view of the 1st seat part. It is sectional drawing which expands and shows the axial direction other side (right side in FIG. 1) of a clutch apparatus. It is explanatory drawing which shows the middle of the assembly of a clutch apparatus. It is sectional drawing of the conventional clutch apparatus.

[Overall Configuration of Clutch Device]
FIG. 1 is a cross-sectional view showing an example of the clutch device of the present invention. The clutch device 7 shown in FIG. 1 is attached to the rotating shaft of the alternator not shown. The clutch device 7 includes a shaft 10, a rotating body 20, and a coil spring 30.

  The shaft 10 is a cylindrical member, and is connected to the rotation shaft of an alternator (not shown) on the inner peripheral side thereof. The rotating body 20 is a cylindrical member, and is provided on the radially outer side of the shaft 10. The shaft 10 and the rotating body 20 are disposed concentrically, and in order to achieve this arrangement, a first bearing and a second bearing are interposed between the shaft 10 and the rotating body 20. . In the present embodiment, the first bearing is a sliding bearing 50 and the second bearing is a rolling bearing 40.

  The coil spring 30 is provided between the shaft 10 and the rotating body 20 and is provided concentrically with the shaft 10 and the rotating body 20. An end (this end is referred to as “first end 31”) of one axial direction side (left side in FIG. 1) of the coil spring 30 is attached to a part (first seat 19) of the rotating body 20 And the end of the other side (right side in FIG. 1) of the coil spring 30 (this end is referred to as "second end 32") is a part of the shaft 10 (second seat 12) Is attached to In a state in which the coil spring 30 is assembled between the shaft 10 and the rotary body 20 (in an assembled state), the coil spring 30 is axially compressed. The winding direction of the coil spring 30 coincides with the rotation direction of the rotating body 20.

  The rotating body 20 has a first cylindrical portion 20a on one side in the axial direction, and a second cylindrical portion 20b on the other side in the axial direction having a smaller inside diameter than the first cylindrical portion 20a. A pulley portion 29 is provided on the outer peripheral side of the second cylindrical portion 20b for hooking a belt not shown. FIG. 2 is a cross-sectional view showing one axial side (left side in FIG. 1) of the clutch device 7 in an enlarged manner. The stepped portion 21 is provided on the inner periphery of the first cylindrical portion 20 a, and the annular first seat portion 19 is attached to the stepped portion 21. The first seat portion 19 is fixed to the rotating body 20 by fitting the inner circumferential surface 21 a of the stepped portion 21 with an interference. The first seat portion 19 is positioned in the axial direction by coming into contact with the annular surface 21 b directed to one side in the axial direction of the stepped portion 21. As described above, the first seat portion 19 is configured by a separate member from the rotary body 20, and the first seat portion 19 and the rotary body 20 are fitted together with the interference amount. The rotating body 20 is integrated.

  The first seat portion 19 has a radially outer outer cylindrical portion 22, a radially inner inner cylindrical portion 23, and an annular portion 24 connecting the outer cylindrical portion 22 and the inner cylindrical portion 23. ing. The outer cylindrical portion 22 and the inner cylindrical portion 23 both have a short cylindrical shape in the axial direction, and the annular portion 24 has an annular shape. The outer cylindrical portion 22 is fitted to the inner peripheral surface 21a with a margin. The first seat portion 19 receives an axial force from the coil spring 30 which is elastically deformed in the axial direction, but the axial force is generated by the first seat portion 19 being fitted to the rotating body 20 The first seat 19 does not drop out of the rotating body 20 because the friction force (fitting force) is larger.

FIG. 3 is a perspective view showing the first end 31 of the coil spring 30 and the first seat 19 with the first end 31 attached. FIG. 4 is a front view of the first seat portion 19.
The first seat portion 19 will be described. As shown in FIGS. 2 to 4, the outer cylindrical portion 22 is provided radially outward of the first end 31 of the coil spring 30, and the inner cylindrical portion 23 is radially inner of the first end 31. Provided in A circumferential groove 25 is formed in a region surrounded by the outer cylindrical portion 22, the inner cylindrical portion 23 and the annular portion 24. The coil spring 30 is attached to the first seat 19 by fitting the first end 31 into the circumferential groove 25. A linear concave groove 27 is provided in a part of the circumferential groove 25 (see FIG. 4). Further describing the circumferential groove 25, the circumferential groove 25 has an arc-shaped recessed groove portion 26 in addition to the linear recessed groove portion 27. In the following, the arc-shaped recessed groove portion 26 is referred to as "arc-shaped recessed groove portion 26", and the linear recessed groove portion 27 is referred to as "linear recessed groove portion 27". The arc concave groove portion 26 and the linear concave groove portion 27 are continuous.

  The first end 31 of the coil spring 30 will be described. As shown in FIG. 3, the first end 31 has a spiral portion 33 continuing from the second end 32 (see FIG. 1) and a straight portion extending linearly from the spiral portion 33. And 34. The straight portion 34 linearly extends in the tangential direction of the center line C <b> 1 of the spiral portion 33. The number of turns of the spiral portion 33 is one. The spiral portion 33 (the majority) is accommodated in the circular arc groove portion 26. The circular arc concave groove portion 26 accommodates the spiral portion 33 with gaps e3 and e4 (see FIG. 3) on the radially outer side and the radially inner side, respectively. The straight portion 34 is accommodated in the straight groove portion 27. The linear recessed groove portion 27 accommodates the linear portion 34 with gaps e1 and e2 (see FIGS. 2 and 3) on the radially outer side and the radially inner side, respectively.

  In FIG. 3, in a state where no torsional force is applied to the coil spring 30, the gap e1 formed between the radially outer side surface 22 a of the linear recessed groove 27 and the radially outer side 34 a of the linear portion 34 The gap e2 formed between the radially inner side surface 23a of the linear recessed groove portion 27 and the radially inner side surface 34b of the linear portion 34 extends in the longitudinal direction of the linear portion 34 (linear recessed groove portion 27). , Can be constant. However, when the coil spring 30 is twisted, these gaps e1 and e2 change. That is, when the coil spring 30 is twisted, the radially outer surface 22a of the linear groove 27 and the radial outer surface 34a of the linear portion 34 contact each other, and the radially inner surface 23a of the linear groove 27 and the linear portion 34 It contacts with the radially inner side surface 34b.

  The side surface of the linear portion 34 of the first end 31 of the coil spring 30 and the side surface on one side in the axial direction of the spiral portion 33 are in contact with the side surface of the annular portion 24 of the first seat 19 (see FIG. ). As shown in FIGS. 3 and 4, the outer cylindrical portion 22 of the first seat portion 19 is provided with a notch 28 in order to avoid interference with the tip 35 of the straight portion 34.

  As described above, a region surrounded by the outer cylindrical portion 22, the inner cylindrical portion 23 and the annular portion 24 which the first seat portion 19 has is a circumferential groove 25, and a part of the circumferential groove 25, A linear concave groove 27 is provided. The linear recessed groove portion 27 accommodates the linear portion 34 of the first end portion 31 of the coil spring 30 in the state of clearance fitting in the radial direction. As described above, when the linear portion 34 is accommodated in the linear recessed groove portion 27, when the coil spring 30 is twisted, the linear portion 34 faces the radial direction of the linear recessed groove portion 27, that is, the diameter of the linear recessed groove portion 27. It contacts the direction outer side surface 22a and the radial direction inner side surface 23a. Thus, the rotation of the first end 31 of the coil spring 30 and the rotating body 20 is prevented. That is, the first end portion 31 can not rotate relative to the first seat portion 19 of the rotating body 20.

  As shown in FIG. 1, although the wire cross-sectional shape of the coil spring 30 is constant, the first end 31 side of the inner diameter of the coil spring 30 is larger than the second end 32 side. The portion 36 (see FIG. 2) of the coil spring 30 that includes the first end 31 and is located radially outward of the inner cylindrical portion 23 of the first seat 19 is from the other second end 32 side Also, the inner diameter is getting larger.

  In FIG. 1, the shaft body 10 has a shaft main body portion 11 which is axially long, and a second seat portion 12 provided in the middle of the shaft main body portion 11. In the present embodiment, the shaft body portion 11 and the second seat portion 12 are integrated (made of the same member), and the second seat portion 12 protrudes radially outward from the shaft body portion 11. The outer peripheral surface 13 of the second seat portion 12 is formed of a cylindrical surface centered on the central axis C0 of the clutch device 7. The shaft 10 has, on the other axial side, a cylindrical surface 14 centered on the central axis C0, and the inner ring 41 of the rolling bearing 40 is fitted and attached to the cylindrical surface 14 with an interference. There is.

  FIG. 5 is an enlarged sectional view showing the other axial side (right side in FIG. 1) of the clutch device 7. An annular member 15 intervenes between the rolling bearing 40 (inner ring 41) and the second seat 12. The annular member 15 is an annular member made of metal. The annular member 15 is sandwiched between the rolling bearing 40 and the second seat 12, and the annular member 15 can not move in the axial direction as the inner ring 41 is fixed to the cylindrical surface 14. The annular member 15 has an outer diameter larger than that of the second seat 12 and protrudes radially outward of the outer circumferential surface 13.

  The outer diameter D1 of the outer peripheral surface 13 of the second seat portion 12 is slightly larger than the inner diameter D2 of the second end 32 of the coil spring 30 (D1> D2), whereby the second end 32 It is attached to the second seat 12 in an interference fit with the seat 12 (the outer circumferential surface 13). That is, the second end 32 is fitted to the second seat 12 with an interference, and is fixed to the shaft 10 (second seat 12). The outer diameter D3 of the second end 32 is sufficiently smaller than the inner diameter D4 of the second cylindrical portion 20b of the rotating body 20 (D3 <D4), and between the second end 32 and the second cylindrical portion 20b A cylindrical space is provided. Therefore, the second end 32 side of the coil spring 30 can be elastically deformed in the diameter expansion direction, and even if it is elastically deformed in this manner, the second cylindrical portion 20b is not in contact with the second end 32. Become. The coil spring 30 (see FIG. 1) may be elastically deformed and enlarged in the other portions (including the second end 32 side) except the first end 31 side, even if the diameter is increased. It is non-contact. From the above, the second end 32 of the coil spring 30 is elastically deformable in the diameter expansion direction in the state of interference fit on the outer peripheral surface 13 of the second seat 12 provided on the outer peripheral side of the shaft 10 It is attached.

  The second end 32 of the coil spring 30 can contact the side surface of the annular member 15. Since the coil spring 30 is attached in a state of being compressed in the axial direction, when the second end 32 contacts the annular member 15, the annular member 15 receives the elastic force in the axial direction of the coil spring 30, The annular member 15 prevents movement of the coil spring 30 to the other side in the axial direction.

  In FIG. 5, the rolling bearing 40 is provided between the rotating body 20 and the shaft 10 so that relative rotation between the rotating body 20 and the shaft 10 is free. The rolling bearing 40 includes an outer ring 42 fixed to the rotating body 20, an inner ring 41 fixed to the shaft 10, a plurality of rolling elements interposed between the outer ring 42 and the inner ring 41, and these rolling elements An annular retainer 44 and a seal 45 are provided. The rolling element is a ball 43, and the rolling bearing 40 of the present embodiment is a deep groove ball bearing. The rolling bearing 40 can support a radial load acting between the rotating body 20 and the shaft 10 and can also support an axial load acting between the rotating body 20 and the shaft 10 is there.

  As described above, since the coil spring 30 is axially compressed and is provided between the rotating body 20 (first seat 19) and the shaft 10 (second seat 12), An axial load is applied between the shaft 10 and the rotating body 20 by the coil spring 30. Therefore, the axial load is supported by the rolling bearing 40. With this configuration, it is possible to prevent the shaft 10 and the rotating body 20 from rattling. Since the coil spring 30 is constrained so that the axial length is constant between the first seat portion 19 and the second seat portion 12, the coil spring 30 is generated between the rotating body 20 and the shaft body 10. The torque causes the coil spring 30 to elastically deform in the diameter reducing direction when it is twisted in the winding direction, and to elastically deform in the radial direction when it is twisted in the direction opposite to the winding direction.

  In FIG. 2, the slide bearing 50 is provided between the rotating body 20 and the shaft 10 so that relative rotation between the rotating body 20 and the shaft 10 is free. The slide bearing 50 of the present embodiment is configured by an annular bush provided radially inward of the inner cylindrical portion 23 of the first seat portion 19. The slide bearing 50 can support a radial load between the rotating body 20 and the shaft 10 on the other side in the axial direction.

[Function of Clutch Device 7]
The function of the clutch device 7 having the above configuration will be described. When the rotating body 20 is rotating in one direction at a constant speed, the torque of the rotating body 20 is transmitted to the shaft body 10 via the coil spring 30, and the shaft body 10 also has the same speed as the rotating body 20 in the same direction. It rotates (this state is called "stationary rotation state"). In this steady rotation state, the coil spring 30 is twisted by an amount corresponding to the torque, and is elastically deformed and reduced in diameter slightly as compared with the non-rotation state. At this time, the second end 32 of the coil spring 30 and the second seat 12 of the shaft 10 are fitted with an interference, and the force at which the second end 32 clamps the second seat 12 There is no circumferential slippage between the second end 32 and the second seat 12, and they rotate together.

  When the rotating body 20 is accelerated from the steady rotation state, the rotating body 20 tries to further rotate in one direction (rotational direction) with respect to the shaft 10. When such rotational fluctuation occurs on the acceleration side (this is referred to as "acceleration rotational state"), the coil spring 30 is further twisted by an amount of torsion corresponding to the torque increased by the acceleration, and slightly compared with the steady rotational state. It is elastically deformed and the diameter is further reduced. Therefore, no circumferential slippage occurs between the second end 32 and the second seat 12 due to the force of the second end 32 tightening the second seat 12, and these continue to rotate together. . Thus, when the coil spring 30 is reduced in diameter, the frictional force (surface pressure) between the second end 32 and the second seat 12 is increased by the increase of the tightening force, and the second end 32 and the second seat 12 is in a relative non-rotatable state (that is, locked state). Then, the rotational fluctuation due to the acceleration of the rotating body 20 is absorbed by the elastic deformation of the coil spring 30. As a result, it is possible to prevent the belt (not shown) hung on the pulley portion 29 from slipping or applying an excessive load to the belt. As described above, the rotational fluctuation on the acceleration side is absorbed by the coil spring 30.

  When the rotating body 20 is decelerated from the steady rotation state (or the acceleration rotation state), the rotating body 20 tries to rotate in the other direction with respect to the shaft 10. When such rotational fluctuation occurs on the decelerating side (this is referred to as "decelerating rotational state"), the coil spring 30 is twisted in the opposite direction (that is, the direction opposite to the winding direction) to that in the accelerating rotational state. It elastically deforms and expands in diameter compared with the rotational state. Then, since the diameter of the second end 32 is also expanded, the interference with the second seat 12 is reduced, and the tightening force to the second seat 12 by the second end 32 (a steady rotation state And the circumferential slippage between the second end 32 and the second seat 12. As described above, when the coil spring 30 is expanded in diameter, the frictional force (surface pressure) between the second end 32 and the second seat 12 is reduced due to the reduction of the tightening force, and the rotating body integrated with the coil spring 30 The shaft 20 and the shaft 10 are in a relatively rotatable state (that is, unlocked state). That is, the rotating body 20 can idle with respect to the shaft 10. As described above, since the rotating body 20 can idle with respect to the shaft body 10 when decelerating, a belt outside the figure that is hung on the pulley portion 29 slips due to rotational fluctuation caused by the decelerating, or this belt It is possible to prevent an excessive load from acting on the vehicle. As described above, the rotational fluctuation on the reduction side is also eliminated by the coil spring 30.

  As described above, when the rotary body 20 rotates in one direction (the winding direction of the coil spring 30) with respect to the shaft 10, the coil spring 30 is twisted and elastically reduced in diameter, and the second end 32 and the second end 32 The interference with the seat 12 is increased, and the second end 32 tightens the second seat 12. On the other hand, when the rotating body 20 rotates in the other direction with respect to the shaft 10, the coil spring 30 is twisted and elastically diameter-expands, and tightening between the second end 32 and the second seat 12 The margin is reduced and slippage between the second end 32 and the second seat 12 is allowed. That is, when the rotating body 20 rotates in one direction with respect to the shaft 10, the shaft 10 and the rotating body 20 can be integrally rotated with springiness, and the rotating body 20 can be rotated relative to the shaft 10. When the wheel rotates in the other direction, the sliding allows the rotating body 20 to idle relative to the shaft 10. For this reason, even if there is no one way clutch which has an engaging element, the clutch apparatus 7 of this embodiment can be equipped with the function (function of a one way clutch).

[Regarding the clutch device 7 of the present embodiment]
As shown in FIG. 1, the rotary body 20 has a first seat 19 for attaching the first end 31 of the coil spring 30 on one side in the axial direction, and the shaft 10 is on the other side in the axial direction A second seat 12 is provided for mounting the second end 32 of the spring 30 in an interference fit. The first end 31 is a helical portion 33 (see FIG. 3) which continues from the second end 32 and a tangential direction of the center line C1 (see FIG. 3) from the helical portion 33. And a linearly extending straight portion 34. The first seat portion 19 is provided with a linear recessed groove 27. The linear recessed groove 27 accommodates the linear portion 34 in a clearance fit in the radial direction. Further, the spiral groove portion 26 provided in the first seat portion 19 accommodates the spiral portion 33 of the first end portion 31 in the state of clearance fit in the radial direction.

  As described above, since the first end portion 31 is accommodated in the linear recessed groove portion 27 and the spiral recessed groove portion 26 in the state of clearance fit in the radial direction, the first end of the coil spring 30 is assembled when assembling the clutch device 7 Assembling of the portion 31 and the rotary body 20 (first seat portion 19) is facilitated as compared with the case of the conventional press-fit (interference fit) shown in FIG. Then, when the linear portion 34 is accommodated in the linear recessed groove portion 27 and the coil spring 30 is twisted, the linear portion 34 faces the radial direction of the linear recessed groove portion 27 (radial direction outer surface 22 a and radial internal By contacting the side surface 23a), the rotation of the first end 31 and the rotating body 20 is prevented. As a result, even if rotational fluctuation occurs between the shaft 10 and the rotating body 20, the coil spring 30 can be twisted to absorb the rotational fluctuation.

  In FIG. 2, the first seat portion 19 and the rotating body 20 may be integral, but in this case, at the time of manufacture, it is necessary to first form by forging and then cut into a predetermined shape. Since the inner diameter of the first seat portion 19 and the inner diameter of the rotating body 20 are largely different, forging requires time and effort, and the amount of cutting also increases, and the number of manufacturing steps increases. On the other hand, in the present embodiment, the first seat portion 19 is configured by a separate member from the rotary body 20, and these are integrated by fitting with an interference. For this reason, the effort of the above forgings can be reduced, and the amount of cutting can also be small.

  Further, by making the first seat 19 separate from the rotating body 20, there is an advantage in terms of assembly. That is, FIG. 6 is an explanatory view showing a process of assembling the clutch device 7. Before the shaft 10 is positioned on the inner peripheral side of the rotating body 20, the second end 32 of the coil spring 30 is fitted to the second seat 12 of the shaft 10 with an interference. The work of this fitting is easy. Then, the shaft body 10 integrated with the coil spring 30 and the rotating body 20 are combined. At this time, the rolling bearing 40 is interposed between the shaft 10 and the rotating body 20. Thereby, the halfway state shown in FIG. 6 is obtained. Then, the first seat portion 19 is made to approach the first end 31 of the coil spring 30 from one side in the axial direction, and the linear portion 34 of the first end 31 and the linear concave groove 27 of the circumferential groove 25 are The first end portion 31 is inserted into the circumferential groove 25 of the first seat portion 19 in alignment in the circumferential direction. At this time, as shown in FIG. 3, a clearance in the radial direction between the spiral portion 33 and the straight portion 34 of the first end portion 31 and the arc concave groove portion 26 and the linear concave groove portion 27 of the circumferential groove 25. Since (e1 to e4) are provided, the work of inserting the first end portion 31 into the circumferential groove 25 is easy. Then, with the first end 31 accommodated in the circumferential groove 25, the first seat 19 is fitted to the rotating body 20. The work of this fitting is easy.

  As described above, by making the first seat portion 19 separate from the rotating body 20, the manufacturing of the rotating body 20 and the assembly of the clutch device 7 are advantageous. Further, even if the first seat portion 19 is separate from the rotating body 20, the first seat portion 19 and the rotating body 20 are fitted together with a margin and integrated, so that the first seat portion 19 and the rotating body 20 are integrated. There is no need to increase parts (eg, bolts). In addition, about the operation | work which fits the 1st seat part 19 and the rotary body 20, since it can do in the open space, the operation | work is easy.

  Further, in the present embodiment (see FIG. 1), the first end 31 side of the coil spring 30 has a larger inner diameter than the second end 32 side. This is to ensure the rigidity by increasing the radial dimension of the inner cylindrical portion 23 of the first seat 19 as much as possible. That is, the sliding bearing 50 intervenes between one axial side of the shaft 10 and the inner cylindrical portion 23 of the first seat portion 19, and the sliding bearing 50 is directly supported by the rotating body 20. The portion to be formed is the inner cylindrical portion 23 of the first seat portion 19. Therefore, as in the present embodiment, if the inner diameter on the first end 31 side of the coil spring 30 is increased, the radial dimension of the inner cylindrical portion 23 can be increased, and the rigidity of the inner cylindrical portion 23 is secured. It is possible to

  Further, an annular member 15 is interposed between the rolling bearing 40 and the second end 32 of the coil spring 30, and the second end 32 contacts the annular member 15, whereby the axial direction of the coil spring 30 is obtained. It prevents movement to the other side. The annular member 15 may be integral with the shaft 10, but in the present embodiment, the annular member 15 is separate from the shaft 10. Therefore, for example, the material of the annular member 15 is changed according to the coil spring 30, the annular member 15 provided with the coating layer is adopted, or the change of the annular member 15 is facilitated.

The embodiments disclosed above are illustrative and non-restrictive in every respect. That is, the clutch device of the present invention is not limited to the illustrated embodiment but may be another embodiment within the scope of the present invention.
For example, although the rolling bearing 40 has been described as a ball bearing in the embodiment, it may be a roller bearing in which the rolling element is a roller.
Although the case where the clutch apparatus of this invention was provided in the alternator was demonstrated, it is also applicable to another apparatus.

7: clutch device 10: shaft 12: second seat 13: outer circumferential surface 15: annular member 19: first seat 20: rotating body 22: outer cylindrical portion 23: inner cylindrical portion 24: annular portion 27: straight concave Groove (Linear concave groove)
30: coil spring 31: first end 32: second end 33: helical portion 34: straight portion 40: rolling bearing (bearing)
50: Sliding bearing (bearing) C1: Center line

Claims (5)

A shaft body, a cylindrical rotating body provided concentrically with the shaft body, and a coil spring provided concentrically between the shaft body and the rotating body,
The rotating body has a first seat on one side in the axial direction, to which the first end of the coil spring is attached;
The shaft has a second seat on the other axial side, the second end of the coil spring being mounted in an interference fit,
The first end portion is a helical portion continuing from the second end side, and a straight portion linearly extending from the helical portion toward a tangential direction of a center line of the helical portion; Have
The clutch device according to claim 1, wherein the first seat portion is provided with a linear concave groove portion accommodating the linear portion in a state of a clearance fit. The second end of the coil spring is attached to the outer peripheral surface of the second seat in an interference fit and elastically deformable in the radial direction,
When the rotating body rotates in one direction with respect to the shaft, the coil spring is twisted to elastically reduce the diameter, and the interference between the second end and the second seat increases.
When the rotating body rotates in the other direction with respect to the shaft body, the coil spring is twisted to elastically expand the diameter, and the interference between the second end portion and the second seat portion becomes smaller, The clutch device according to claim 1, wherein slippage between the second end and the second seat is permitted.   The first seat portion is configured by a member separate from the rotating body, and the first seat portion and the rotating body are engaged by fitting the first seat portion to the rotating body with an interference. The clutch device according to claim 1, wherein the clutch device is integrated. The first seat portion includes an outer cylindrical portion provided radially outward of the first end portion, an inner cylindrical portion provided radially inward of the first end portion, and the outer cylindrical portion. The linear concave groove portion is provided in a part of a region surrounded by the outer cylindrical portion, the inner cylindrical portion, and the annular portion. Yes,
A bearing is interposed between one axial side of the shaft and the inner cylindrical portion,
The clutch device according to any one of claims 1 to 3, wherein the first end side of the coil spring has a larger inner diameter than the second end side. A bearing is interposed between the other axial side of the shaft and the other axial side of the rotor,
An annular member separate from the shaft is interposed between the bearing and the second end of the coil spring, and the second end contacts the annular member, thereby the coil spring The clutch apparatus as described in any one of Claims 1-4 which has blocked the movement to the other axial direction side.

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