JP2009281436A - Pulley unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulley unit suppressing the durability degradation of a bearing supporting a pulley and a pulley hub in a relatively rotatable manner. <P>SOLUTION: The pulley 1 and the pulley hub 3 incorporated inside it are supported by the bearing 4 in a relatively rotatable manner. A flange 7 and a retaining ring 8 are provided on the inner diameter face of the pulley 1. Between the flange 7 and the retaining ring 8, a fixed cam disc 9 whose rotation is prevented by the pulley hub 3 and whose movement outward in the axial direction is prevented by the retaining ring 8, and a movable cam disc 10 which is rotatable and axially movable relative to the pulley 1 are incorporated. A torque cam 14 is provided between the opposed faces of the fixed cam disc 9 and the movable cam disc 10 for isolating the movable cam disc 10 from the fixed cam disc 9 with the relative rotation of both cam discs. Between the movable cam disc 10 and the flange 7, a friction plate 18 and an elastic member 21 which energizes the friction plate 18 toward the movable cam disc 10 are incorporated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention mainly relates to a pulley unit used by being mounted on a rotating shaft of an engine auxiliary machine such as an alternator using an engine as a drive source.

  In general, in an accessory drive device that transmits the rotation of the crankshaft of the engine to the rotation shaft of the engine accessory by a belt transmission device, when the engine is suddenly decelerated, a pulley attached to the rotation shaft of the engine accessory is also included. Try to decelerate suddenly.

  At this time, if the engine accessory is an alternator, the rotating shaft of the alternator has a large inertial force. Therefore, the pulley attached to the rotating shaft tries to keep rotating at a constant speed, and the pulley on the crankshaft and the alternator rotate. A large rotational speed difference is generated between the pulleys on the shaft, and the belt tension is increased and the belt is easily damaged.

  In addition, the crankshaft fluctuates in angular speed during one rotation due to intermittent in-cylinder combustion in the engine and the inertial force of a reciprocating piston. Slip occurs between the pulley and the belt, and the slip causes wear of the belt, resulting in a decrease in durability.

  In order to eliminate such inconvenience, Patent Document 1 proposes a clutch built-in type pulley device in which a one-way roller clutch is incorporated in a pulley provided on a rotating shaft of an engine accessory.

  When the pulley built-in type pulley device is mounted on the rotation shaft of the engine accessory, when the rotation speed of the pulley is lower than the rotation speed of the rotation shaft of the engine accessory, the one-way roller clutch is disengaged and the pulley Since the belt rotates freely, it is possible to prevent an increase in belt tension, to prevent slippage between the pulley and the belt, and to suppress a decrease in durability of the belt.

  By the way, in the pulley device with a built-in clutch as described above, when the one-way roller clutch is switched from the unlocked state to the locked state, the roller suddenly engages the opposing surface of the outer ring and the inner ring, so that the rotational speed fluctuation of the pulley Cannot be absorbed effectively, and the effect of reducing the belt tension cannot be said to be sufficient.

  In order to eliminate such inconvenience, in the power transmission device described in Patent Document 2, a first annular race that is prevented from rotating with respect to the pulley between the opposed surfaces of the pulley and the rotor shaft and is movable in the axial direction is provided. And a second annular race supported rotatably with respect to the rotor shaft, and the first annular race is urged toward the second annular race by pressing the coil spring, and is placed on the back side of the second annular race. A friction clutch is provided for clutch-connecting the second annular race and the rotor shaft by pressing the coil spring, and is formed on the opposing surfaces of the first annular race and the second annular race when the rotational speed fluctuation occurs in the pulley. The first annular race is moved away from the second annular race by the cam action of the arcuate slope, and the rotational speed fluctuation is caused by the movement of the first annular race in the axial direction and the compression of the coil spring. So as to absorb.

JP 2003-232433 A JP 2006-38183 A

  By the way, in the power transmission device described in Patent Document 2, the second annular race and the friction clutch are positioned in the axial direction by a rolling bearing that relatively rotatably supports the pulley and the rotor shaft. Since the rolling bearing receives the pressing force of the coil spring and receives the reaction force of the axial force applied to the first annular race by the cam action of the arcuate slope, the durability of the rolling bearing is reduced. There is an inconvenience.

  The subject of this invention is providing the pulley unit which enabled it to suppress the fall of durability of the bearing which supports a pulley and a pulley hub rotatably relatively.

  In order to solve the above problems, in the present invention, a pulley and a pulley hub incorporated inside the pulley are supported relatively rotatably by a bearing incorporated between one end portions of both members, Two protrusions are provided on the inner diameter surface of the pulley at an interval in the axial direction, and the pulley hub is prevented from rotating between the two protrusions, and one protrusion prevents movement outward in the axial direction. A fixed cam disk and a movable cam disk supported so as to be rotatable with respect to the pulley and movable in the axial direction are incorporated, and one cam disk is placed between the fixed cam disk and the opposed surface of the movable cam disk. A torque cam is provided to move the movable cam disk away from the fixed cam disk by relative rotation in the direction, and to engage both cam disks in the rotation direction at the time of relative rotation in the other direction. Between the movable cam disk and the other protrusion, the friction plate is prevented from rotating with respect to the pulley and forms a friction clutch with the movable cam disk, and the movable cam disk is a fixed cam. A configuration incorporating an elastic member that is pushed by the friction plate during the movement away from the disk and elastically deforms to bring the friction clutch into a coupled state is adopted.

  In the pulley unit configured as described above, when the pulley is stopped from rotating, the friction clutch formed by the movable cam disk and the friction plate is in a disengaged state in which slipping occurs.

  When a rotational torque in the positive rotation direction is input to the pulley from the above state, the fixed cam disk and the movable cam disk rotate relative to each other in one direction. The torque cam acts by the relative rotation, and the movable cam disk moves away from the fixed cam disk. The friction plate also moves together with the movable cam disk to elastically deform the elastic member. Due to the elastic deformation of the elastic member, the friction plate is strongly pressed against the movable cam disk, and the friction clutch formed by the friction plate and the movable cam disk is connected.

  For this reason, the rotation of the pulley is transmitted from the friction plate to the movable cam disk and also transmitted to the pulley hub via the torque cam and the fixed cam disk, and the pulley hub rotates in the same direction as the pulley.

  In the state of transmission of rotation from the pulley to the pulley hub, if rotation fluctuation occurs in the pulley, the fixed cam disk and the movable cam disk rotate relative to each other, the torque cam acts to move the movable cam disk in the axial direction, and the pressure from the friction plate As a result, the elastic member is elastically deformed. The rotational deformation of the pulley is absorbed by the elastic deformation of the elastic member, and the rotational fluctuation is prevented from being transmitted to the pulley hub, and the friction clutch is maintained in the coupled state.

  When the pulley stops, the torque cam returns to the state where the movable cam disk is released by the rotation of the pulley hub due to the inertial force, and the elastic member expands to weaken the pressing force, which is formed by the movable cam disk and the friction plate. The friction clutch is disengaged, slipping occurs at the contact portion between the movable cam disk and the friction plate, and the pulley hub continues to rotate due to the inertial force.

  As described above, when the rotational fluctuation occurs in the pulley, the elastic member elastically deforms to absorb the rotational fluctuation of the pulley, and when the pulley stops, the pulley hub slips at the contact portion between the movable cam disk and the friction plate. Since the rotation is continued by the inertial force, the belt tension does not increase suddenly, and there is no inconvenience that slip occurs between the pulley and the belt.

  In the pulley unit according to the present invention, the torque cam has an inclined cam surface inclined with a downward gradient in the circumferential direction and an engagement surface formed continuously at the lower end of the inclined cam surface at the groove bottom, A pair of opposed cam grooves formed on the opposed surfaces of the fixed cam disk and the movable cam disk so that the gradient of the inclined cam surface is opposite, and a ball or roller incorporated between the opposed cam grooves. Or a cam groove having an inclined cam surface inclined downwardly in the circumferential direction and an engagement surface formed continuously at the lower end of the inclined cam surface at the groove bottom, It may consist of a cam projection that fits into the cam groove.

  Here, if a stopper that restricts the amount of movement of the movable cam disk in the axial direction within the range of the maximum amount of movement of the movable cam disk that is moved by the torque cam is provided on the inner diameter surface of the pulley, It is possible to suppress a decrease in durability due to excessive bending.

  Further, if a second friction plate that is prevented from rotating with respect to the pulley is provided between the fixed cam disk and one of the protrusions, the transmission torque from the pulley can be transmitted from each of the two friction plates to the pulley hub. Therefore, the transmission power per friction plate can be reduced, and the effect of preventing wear and seizure of the friction plate can be obtained.

  In addition, since the torque transmitted by the torque cam can be reduced, the surface pressure of the contact portion can be reduced and the deterioration of durability can be suppressed. Furthermore, since the load applied to the elastic member from the movable cam disk is also reduced, it is possible to suppress a decrease in durability of the elastic member.

  Further, when the friction material is bonded to at least one of the opposing surfaces of the movable cam disk and the friction plate forming the friction clutch and at least one of the opposing surfaces of the fixed cam disk and the second friction plate, each contact portion Since the coefficient of friction at can be increased, the capacity of the transmission torque can be increased. Conversely, it is possible to reduce the pressing force applied to the friction plate and suppress the decrease in the durability of the friction plate.

  In addition, a radial bearing is incorporated between the outer diameter surface of the fixed cam disk and the inner diameter surface of the pulley, or a bearing holding member is provided between one projecting portion and the opposite surface of the fixed cam disk, and the inner diameter surface of the bearing holding member is When a radial bearing is incorporated between the outer diameter surfaces of the pulley hub, the radial load applied to the pulley can be received by each of the radial bearing and the bearing provided at one end of the pulley, thereby stabilizing the load support. be able to.

  Further, when a thrust bearing is incorporated between the one projecting portion and the opposing surface of the fixed cam disk, the rotational torque transmitted from the one projecting portion to the pulley hub can be reduced, and therefore the torque is transmitted to the torque cam. Torque can be stabilized, and the absorption performance of fluctuations in rotational speed can be further improved.

  In the present invention, the axial force applied to the movable cam disk is received by the pressing force of the elastic member that presses the friction plate against the movable cam disk and the action of the torque cam by the two protrusions formed on the inner diameter surface of the pulley. Therefore, the pressing force and the axial force are not applied to the bearing that relatively rotatably supports the pulley and the pulley hub, and a decrease in the durability of the bearing can be suppressed.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the pulley 1 has double rows of V-grooves 2 on the outer peripheral surface, and a pulley hub 3 is incorporated inside the pulley 1. The pulley 1 and the pulley hub 3 are relatively rotatably supported by a bearing 4 with a single seal that is incorporated between opposite ends thereof.

  The outer periphery of the seal member 5 is press-fitted into the inner periphery of the other end of the pulley 1, and the lip 6 formed on the inner periphery of the seal member 5 is in elastic contact with the outer periphery of the other end of the pulley hub 3. As a result, the opening of the other end of the pulley 1 is closed, and foreign matter is prevented from entering the inside.

  A flange 7 is provided at one end portion of the inner diameter surface of the pulley 1 as a protruding portion for positioning the bearing 4 in the axial direction. A retaining ring 8 as a protruding portion is attached to the inner periphery of the other end of the pulley 1.

  As shown in FIG. 4, a fixed cam disk 9 and a movable cam disk 10 are assembled between the flange 7 and the retaining ring 8, and a washer 11 is assembled between the fixed cam disk 9 and the retaining ring 8.

  The fixed cam disk 9 is prevented from rotating around the pulley hub 3 by the fitting of the spline 12 and is rotated integrally with the pulley hub 3. A radial bearing 13 composed of a needle roller bearing is incorporated between the fixed cam disk 9 and the movable cam disk 10 and the fitting surface of the pulley 1, and the radial bearing 13 is loaded on the pulley 1 with the bearing 4. It is designed to support the load.

  The movable cam disk 10 is supported by the radial bearing 13 so as to be rotatable and movable in the axial direction, and a torque cam 14 is provided between the opposing surfaces of the movable cam disk 10 and the fixed cam disk 9.

  As shown in FIGS. 2 and 3, the torque cam 14 is assembled between a pair of opposed cam grooves 15 and 16 formed on the opposed surfaces of the fixed cam disk 9 and the movable cam disk 10, and the cam grooves 15 and 16, respectively. The ball 17 is made up of.

  The pair of opposed cam grooves 15 and 16 include inclined cam surfaces 15a and 16a that are inclined with a downward gradient in the circumferential direction, and arcuate engagement surfaces 15b and 16b that are continuous to the lower ends of the inclined cam surfaces 15a and 16a. The inclined cam surfaces 15a and 16a are formed on the opposing surfaces of the fixed cam disk 9 and the movable cam disk 10 so that the slopes of the inclined cam surfaces 15a and 16a are opposite to each other.

  The torque cam 14 separates the movable cam disk 10 from the fixed cam disk 9 by the rolling movement of the ball 17 along the inclined cam surfaces 15 a and 16 a during relative rotation of the fixed cam disk 9 and the movable cam disk 10 in one direction. It is designed to move in the direction. Further, during relative rotation of the fixed cam disk 9 and the movable cam disk 10 in the other direction, the ball 17 is engaged with the engagement surfaces 15b and 16b, and the fixed cam disk 9 and the movable cam disk 10 are engaged in the rotation direction. It is supposed to let you.

  As shown in FIG. 4, a friction plate 18 that forms a friction clutch with the movable cam disk 10 is incorporated between the movable cam disk 10 and the flange 7. The friction plate 18 is prevented from rotating around the pulley 1 by the fitting of a spline 19 formed between the fitting surfaces with the pulley 1, and rotates integrally with the pulley 1.

  A friction material 20 mainly composed of a non-metallic material is fixed to the friction plate 18 on the surface facing the movable cam disk 10 by means of adhesion. The friction material 20 may be provided only on the movable cam disk 10 or may be provided on both the friction plate 18 and the movable cam disk 10.

  An elastic member 21 is incorporated between the friction plate 18 and the flange 7. Here, a disc spring is employed as the elastic member 21. The elastic member 21 is pressed and elastically deformed by the friction plate 18 when the movable cam disk 10 moves in the axial direction away from the fixed cam disk 9, and the friction plate 18 is pressed against the movable cam disk 10 by the elastic deformation. The friction clutch is switched to the engaged state.

  A ring-shaped stopper 22 is fitted between the friction plate 18 and the flange 7 on the inner diameter surface of the pulley 1, and the movable cam disk 10 is moved by the torque cam 14 in the axial direction of the movable cam disk 10. It is regulated within a range of 10 maximum movement amounts.

  The pulley unit shown in the embodiment has the above-described structure, and when driving an alternator as an engine auxiliary machine, the pulley hub 3 is fitted to the rotating shaft of the alternator to prevent rotation, and the pulley 1 of the pulley unit and the engine A belt is stretched between pulleys attached to the crankshaft so that the rotation of the crankshaft is transmitted to the pulley 1.

  In the use state as described above, when the pulley 1 is in the rotation stop state, as shown in FIG. 3A, the ball 17 is engaged with the engagement surfaces 15b and 16b of the cam grooves 15 and 16, and the movable cam The friction clutch formed by the disk 10 and the friction plate 18 is in a disengaged state.

  When rotational torque in the forward rotation direction is input to the pulley 1 from the above state, the fixed cam disk 9 and the movable cam disk 10 are relatively rotated in the direction indicated by the arrow in FIG. Due to the relative rotation of the cam disks 9, 10 in one direction, the ball 17 rolls along the inclined cam surfaces 15a, 16a of the cam grooves 15, 16 as shown in FIG. An axial pressing force is applied to the disc 10, and the movable cam disc 10 moves away from the fixed cam disc 9.

  FIG. 5 shows the moving state of the movable cam disk 10. The elastic member 21 is elastically deformed by the movement of the movable cam disk 10, the contact pressure between the movable cam disk 10 and the friction plate 18 is increased, and the friction clutch is in the coupled state. It becomes.

For this reason, the rotation of the pulley 1 is transmitted from the friction plate 18 to the movable cam disk 10 and from the movable cam disk 10 to the fixed cam disk 9 via the balls 17 of the torque cam 14. The rotation of the fixed cam disk 9 is transmitted to the pulley hub 3, and the pulley hub 3 rotates in the same direction as the pulley 1.

  In the state of transmission of rotational torque to the pulley hub 3, if a rotational fluctuation occurs in the pulley 1 due to a change in the angular speed of the crankshaft, the fixed cam disk 9 and the movable cam disk 10 rotate relative to each other. At this time, since the rotation fluctuation of the pulley 1 due to the change in the angular velocity of the crankshaft is relatively small, the ball 17 rolls along the inclined cam surfaces 15a and 16a. The movable cam disk 10 moves in the axial direction by the rolling movement, and the elastic member 21 is elastically deformed by the pressure from the friction plate 18 that moves together with the movable cam disk 10. The rotational deformation of the pulley 1 is absorbed by the elastic deformation of the elastic member 21, and the rotational fluctuation is prevented from being transmitted to the pulley hub 3. Further, the friction clutch is maintained in the coupled state.

  When the engine is suddenly decelerated or stopped, the rotating shaft of the alternator has a large inertial force, so the pulley hub 3 tries to continue rotating. Due to the rotation of the pulley hub 3 due to the inertial force, the fixed cam disk 9 rotates relative to the movable cam disk 10 in the direction indicated by the arrow in FIG. 3B, and the ball 17 engages as shown in FIG. Engages with the mating surfaces 15b, 16b. Further, the movable cam disk 10 moves toward the fixed cam disk 9, and the elastic member 21 is extended by the movement of the movable cam disk 10, so that the pressing force is weakened, and is formed by the movable cam disk 10 and the friction plate 18. The friction clutch is in a disengaged state, slippage occurs at the contact portion between the movable cam disk 10 and the friction plate 18, and the hub 3 continues to rotate due to inertial force.

  As described above, when the rotation fluctuation occurs in the pulley 1, the elastic member 21 elastically deforms and absorbs the rotation fluctuation of the pulley 1, and when the pulley 1 decelerates suddenly or stops, the movable cam disk 10 friction Since the slippage occurs at the contact portion of the plate 18 and the pulley hub 3 continues to rotate due to the inertial force, the belt tension does not increase suddenly, and slippage occurs between the pulley 1 and the belt. There is no inconvenience.

  Further, the axial force generated by the pressing force of the elastic member 21 and the operation of the torque cam 14 is received by the flange 7 and the retaining ring 8 and is not loaded on the bearing 4. Since the movable cam disk 10 that moves in a sliding manner slides on the radial bearing 13, a large axial force is not applied to the radial bearing 13. For this reason, the bearing 4 and the radial bearing 13 are hardly damaged, and a pulley unit having excellent durability can be obtained.

  Here, when the movement amount of the movable cam disk 10 in the axial direction is larger than necessary due to the operation of the torque cam 14, the ball 17 rides on the opposing surface of the fixed cam disk 9 and the movable cam disk 10 to rotate the pulley 1. There arises a problem that transmission to the pulley hub 3 becomes impossible.

  However, in the pulley unit shown in FIG. 1, a ring-shaped stopper 22 is provided on the inner diameter surface of the pulley 1, and the amount of movement of the movable cam disk 10 in the axial direction is limited by the stopper 22. The rotation of the pulley 1 can be reliably transmitted to the pulley hub 3.

  In FIG. 3, the torque cam 14 is composed of the cam grooves 15 and 16 and the ball 17, but may be composed of a roller instead of the ball. Further, as shown in FIG. 6 (c), the fixed cam disk 9 is formed continuously with the inclined cam surface 24a inclined downward in the circumferential direction and the lower end of the inclined cam surface 24a in the axial direction. The cam groove 23 having an engaging surface 24b facing the groove may be formed on the groove bottom, and the movable cam disk 10 may be provided with a cam protrusion 25 adapted to the cam groove 23. In this case, a cam protrusion may be provided on the fixed cam disk 9 and a cam groove may be formed on the movable cam disk 10. FIG. 6D shows the operating state of the torque cam 14.

  FIG. 7 shows another embodiment of the pulley unit according to the present invention. In this embodiment, a bearing holding member 26 and a second friction plate 27 are incorporated between the retaining ring 8 and the fixed cam disk 9, and between the inner diameter surface of the bearing holding member 26 and the outer diameter surface of the pulley hub 3. It differs from the pulley unit shown in FIG. 1 only in that a radial bearing 28 is incorporated. For this reason, the same components as those of the pulley unit shown in FIG.

  Here, the bearing holding member 26 is prevented from rotating with respect to the pulley 1, while the second friction plate 27 is prevented from rotating around the pulley 1 by the fitting of the spline 19 formed between the fitting surfaces with the pulley 1. Has been. Further, a friction material 29 mainly composed of a non-metallic material is bonded to the surface of the fixed cam disk 9 facing the second friction plate 27 to increase the coefficient of friction on the surface.

  As shown in FIG. 7, by providing the second friction plate 27, the transmission torque from the pulley 1 can be transmitted from each of the two friction plates 18 and 27 to the pulley hub 3, so that one friction plate is provided. It is possible to reduce the transmission power per hit, and the effect can be obtained in preventing the friction plates 18 and 27 from being worn and seized.

  Further, since the transmission torque of the torque cam 14 can also be reduced, the surface pressure at the contact portion between the movable cam disk 10 and the friction plate 18 can be reduced, and the decrease in durability can be suppressed. Furthermore, since the load applied to the elastic member 21 from the movable cam disk 10 is also reduced, it is possible to suppress a decrease in durability of the elastic member 21.

  FIG. 8 shows still another embodiment of the pulley unit according to the present invention. In this embodiment, a bearing holding member 26 is rotatably incorporated between the retaining ring 8 and the fixed cam disk 9, and a radial bearing 28 is incorporated between the inner diameter surface of the bearing holding member 26 and the outer diameter surface of the pulley hub 3. 1 is different from the pulley unit shown in FIG. 1 only in that a thrust bearing 30 is incorporated between opposing surfaces of the bearing holding member 26 and the fixed cam disk 9. For this reason, the same components as those of the pulley unit shown in FIG.

  As shown in FIG. 8, when the thrust bearing 30 is assembled between the opposed surfaces of the fixed cam disk 9 and the bearing holding member 26, the rotational resistance of the fixed cam disk 9 can be reduced, so that the torque cam 14 is transmitted. Torque can be stabilized, and the rotational fluctuation absorption performance can be further enhanced.

  As shown in FIGS. 7 and 8, when a radial bearing 28 is assembled between the inner diameter surface of the bearing holding member 26 and the outer diameter surface of the pulley hub 3, the bearing provided at one end portion of the radial bearing 28 and the pulley 1. Since the radial load applied to the pulley 1 can be received by each of the four, the load support can be stabilized.

A longitudinal front view showing an embodiment of a pulley unit according to the present invention Sectional view along the line II-II in FIG. (A) is sectional drawing of the torque cam shown in FIG. 1, (b) is sectional drawing which shows the operating state of a torque cam. Sectional drawing which expands and shows a part of FIG. Sectional drawing which shows the operating state of the torque cam shown in FIG. Sectional view showing another example of torque cam Longitudinal front view showing another embodiment of the pulley unit according to the present invention Longitudinal front view showing still another embodiment of the pulley unit according to the present invention

Explanation of symbols

1 Pulley 3 Pulley hub 4 Bearing 7 Flange (protrusion)
8 Retaining ring (protruding part)
9 fixed cam disk 10 movable cam disk 13 radial bearing 14 torque cam 15 cam groove 15a inclined cam surface 15b engaging surface 16 cam groove 16a inclined cam surface 16b engaging surface 17 ball 18 friction plate 20 friction material 21 elastic member 22 stopper 23 cam Groove 24a Inclined cam surface 24b Engagement surface 25 Cam protrusion 26 Bearing holding member 27 Second friction plate 28 Radial bearing 29 Friction material 30 Thrust bearing

Claims (10)

  A pulley and a pulley hub incorporated inside the pulley are supported relatively rotatably by a bearing incorporated between one end of both members, and two protrusions are axially spaced on the inner diameter surface of the pulley. A fixed cam disk that is prevented from rotating by the pulley hub between the two protrusions and is prevented from moving outward in the axial direction by one protrusion, and is rotatable with respect to the pulley, and , A movable cam disk supported so as to be movable in the axial direction is incorporated, and the movable cam disk is separated from the fixed cam disk by relative rotation in one direction between the fixed cam disk and the movable cam disk. A torque cam is provided for moving the cam discs in the direction of separation and engaging the cam discs in the rotational direction during relative rotation in the other direction. A friction plate that is prevented from rotating against the rear and that is movable in the axial direction to form a friction clutch with the movable cam disk, and is elastic when pushed by the friction plate when the movable cam disk moves away from the fixed cam disk. A pulley unit that incorporates an elastic member that deforms and connects the friction clutch.   The torque cam has an inclined cam surface inclined with a downward gradient in the circumferential direction and an engagement surface formed continuously at a lower end of the inclined cam surface at the groove bottom, and the gradient of the inclined cam surface is 2. A pair of opposing cam grooves formed on the opposing surfaces of the fixed cam disk and the movable cam disk so as to be opposite to each other, and a ball or a roller incorporated between the opposing pair of cam grooves. Pulley unit.   The torque cam includes a cam groove having an inclined cam surface that is inclined with a downward slope in the circumferential direction and an engagement surface formed continuously at a lower end of the inclined cam surface at the groove bottom, and a cam that fits the cam groove The pulley unit according to claim 1, comprising a protrusion.   4. The stopper according to claim 1, wherein a stopper is provided on the inner diameter surface of the pulley for restricting an axial movement amount of the movable cam disk within a range of a maximum movement amount of the movable cam disk moved by the torque cam. The pulley unit described.   The pulley unit according to any one of claims 1 to 4, wherein a second friction plate is provided between the fixed cam disk and one projecting portion, and the second friction plate is prevented from rotating around the pulley.   The pulley unit according to any one of claims 1 to 5, wherein a friction material is bonded to at least one of opposing surfaces of the movable cam disk and the friction plate forming the friction clutch.   6. The pulley unit according to claim 5, wherein a friction material is bonded to at least one of opposing surfaces of the fixed cam disk and the second friction plate.   The pulley unit according to any one of claims 1 to 7, wherein a radial bearing is incorporated between an outer diameter surface of the fixed cam disk and an inner diameter surface of the pulley.   The bearing holding member is provided between the one projecting portion and the opposed surface of the fixed cam disk, and a radial bearing is incorporated between the inner diameter surface of the bearing holding member and the outer diameter surface of the pulley hub. Pulley unit according to item.   The pulley unit according to any one of claims 1 to 9, wherein a thrust bearing is incorporated between the one projecting portion and a facing surface of the fixed cam disk.

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