JP2009063040A - Pulley unit with built-in clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulley unit with a built-in clutch capable of relieving impulsive torque input. <P>SOLUTION: A one-way clutch 10 is incorporated inside a pulley 1, a hub 40 is incorporated inside the inner ring 13 of the one-way clutch 10, the hub 40 and inner ring are relatively rotatably supported, and a coil spring 50 is incorporated between the hub 40 and the inner ring 13. Projecting parts 24, 45 circumferentially opposed to the coil ends 50a, 50b of the coil spring 50 are provided respectively on the outer periphery of the hub 40 and the inner periphery of the inner ring 13, the one-way clutch 10 is engaged when the pulley 1 unidirectionally rotates, and the coil spring 50 is elastically deformed in a radial direction when the inner ring 13 of the one-way clutch 10 is rotated for transmitting rotation of the inner ring 13 to the hub 40. Thereby, impulsive torque applied to the pulley 1 is relieved by the elastic deformation of the coil spring 50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention mainly relates to a pulley unit with a built-in clutch that is used by being mounted on a rotating shaft of an engine accessory 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.

  Also, the crankshaft has an angular velocity that changes during one rotation, and due to the change in the angular velocity, slippage occurs between the pulley on the crankshaft and the belt, and the slippage causes wear of the belt, resulting in durability. Will drop.

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

  When the pulley unit with a built-in clutch as described above 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 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.

JP 7-317807 A

  By the way, in the pulley unit with a built-in clutch as described above, the engagement member of the one-way clutch engages the metal outer ring and the inner ring without slipping. Therefore, for example, when the engine starts or suddenly accelerates, When there is a torque load of 0, the engaging bite impacts and generates an impact torque, and there is a problem that the load on the belt cannot be reduced completely.

  An object of the present invention is to provide a pulley unit with a built-in clutch capable of buffering shocking torque input.

  In order to solve the above problems, in the present invention, a one-way clutch is incorporated inside a pulley, the outer ring in which the one-way clutch is press-fitted into the inner diameter surface of the pulley, and an inner ring incorporated inside the outer ring, A retainer assembled between the inner ring and the outer ring, an engagement element accommodated in each of a plurality of pockets formed at intervals in the circumferential direction of the retainer, and the engagement element between the outer ring and the inner ring. A spring member that urges toward the direction of engagement with the opposing surface, and the engagement between the outer ring and the inner ring is caused by the relative rotation of the outer ring and the inner ring in one direction to engage the engagement surface between the outer ring and the inner ring. In a pulley unit with a built-in clutch that transmits rotational torque between the inner ring, a hub is incorporated inside the inner ring, and elastic deformation is caused by relative rotation of the hub and inner ring in one direction between the outer periphery of the hub and the inner ring. And inside Incorporating an elastic member that transmits rotational torque between the hub and the hub, the idling torque when the hub idles with respect to the inner ring is larger than the disengagement torque when the engagement element of the one-way clutch is disengaged The configuration was adopted.

  In the pulley unit with a built-in clutch configured as described above, a hub is attached to the rotating shaft of the engine accessory, and a belt is stretched between a pulley provided coaxially with the hub and a pulley attached to the crankshaft of the engine. The rotation of the crankshaft is transmitted to the pulley.

  When the rotation of the crankshaft is transmitted to the pulley in the state of use as described above, the outer ring that rotates integrally with the pulley rotates relative to the inner ring in one direction, and the relative rotation causes the engagement element of the one-way clutch to move. The outer ring and the inner ring face each other and the rotation of the outer ring is transmitted to the inner ring through the engagement element.

  The elastic member is elastically deformed by the rotation of the inner ring, the rotation of the inner ring is transmitted to the hub via the elastic member, and the rotation shaft of the engine accessory is rotated.

  As described above, when the engagement member of the one-way clutch is engaged with the opposing surfaces of the outer ring and the inner ring and the inner ring rotates, the elastic member is elastically deformed to transmit the rotation of the inner ring to the hub. When an impact torque is sometimes input to the pulley, the impact torque input is absorbed by the elastic deformation of the elastic member, and it is possible to prevent the impact torque from being applied to the belt.

  Here, the idling torque when the hub idly rotates with respect to the inner ring is set to be larger than the disengagement torque when the engagement element of the one-way clutch is disengaged. When the rotational speed of the hub that rotates integrally with the rotating shaft of the machine exceeds the rotational speed of the pulley, the inner ring that rotates together with the hub rotates relative to the outer ring. The engagement is released by the relative rotation, the rotation transmission from the outer ring to the inner ring is cut off, and the pulley rotates freely.

  As an elastic member that cushions the impact torque, a coil spring that is fitted to the outer periphery of the hub and extends long in the axial direction, or a coil spring that extends in the circumferential direction along the outer periphery of the hub can be employed.

  When adopting a coil spring that is fitted to the outer periphery of the hub and extends in the axial direction, a protrusion is provided on the inner periphery of the inner ring and the outer periphery of the hub so as to face the coil end of the coil spring in the circumferential direction. The coil spring is elastically deformed in the radial direction during rotation.

  On the other hand, when a coil spring that extends in the circumferential direction along the outer periphery of the hub is employed, a protrusion that faces the coil end of the coil spring in the circumferential direction is provided on the inner periphery of the inner ring and the outer periphery of the hub. Sometimes the coil spring is elastically deformed in a contracting direction.

  In the pulley unit with a built-in clutch according to the present invention, between one end of the hub located outside from one end of the inner ring and the facing part of the pulley, and between the other end of the inner ring located outside from the other end of the outer ring and the facing part of the pulley. The pulley, outer ring, inner ring and hub are arranged on the same axis by assembling a rolling bearing with a single seal that supports radial load and moment load acting on the pulley so that the seal is located at the outer end. Therefore, it is possible to prevent an eccentric load from being applied to the engagement element of the one-way clutch or a radial load to be applied only to a specific engagement element, and the one-way clutch can be operated with high accuracy.

  Here, the engagement member of the one-way clutch may be a sprag or may be a roller.

  In addition, by forming a radial bearing surface that is metal-guided on the inner periphery of the inner ring and the outer periphery of the hub, and supporting the inner ring and the hub relatively rotatably, by the frictional resistance acting on the radial bearing surface, The idling torque when the hub is idling with respect to the inner ring can be set larger than the disengaging torque when the engagement element of the one-way clutch is disengaged.

  In this case, the seal groove is formed in one of the radial bearing surface of the inner ring and the radial bearing surface of the hub, and the seal member incorporated in the seal groove is brought into elastic contact with the other radial bearing surface, thereby contacting the hub and the inner ring. The frictional resistance of the portion can be set larger, and the one-way clutch can be reliably disengaged when the rotational speed of the hub exceeds the rotational speed of the pulley.

  Further, by incorporating the seal member, it is possible to prevent leakage of grease sealed between the facing surfaces of the inner ring and the hub to the outside, and to prevent dust from entering from the outside to the inside.

  As described above, in the pulley unit with a built-in clutch according to the present invention, rotational torque is input to the pulley, the engagement element is engaged between the opposing surfaces of the outer ring and the inner ring, and the rotation torque from the outer ring to the inner ring via the engagement element. Is transmitted, the elastic member is elastically deformed, and the rotation of the inner ring is transmitted to the hub via the elastic member. Therefore, when the impact torque is input, the impact torque is buffered by the elastic deformation of the elastic member. can do. For this reason, it is possible to prevent an impact torque from being applied to the belt, and it is possible to suppress a decrease in durability of the belt.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, a one-way clutch 10 and a pair of rolling bearings 30 a and 30 b with one-side seals are incorporated on both sides of the one-way clutch 10 inside the pulley 1.

  The one-way clutch 10 is provided with a cylindrical inner surface 12 on an outer ring 11 that is press-fitted into the inner diameter surface of the pulley 1, and a cylindrical outer surface 14 is formed on an inner ring 13 that is incorporated inside the outer ring 11. A plurality of pockets 16 are provided at equal intervals in the circumferential direction in a retainer 15 assembled between the cylindrical inner surfaces 12, and an engagement element 17 made of sprags in each pocket 16, and the engagement element 17 is connected to the cylindrical inner surface of the outer ring 11. 12 and a spring member 18 that urges the inner ring 13 in a direction to be engaged with the outer cylindrical surface 14 of the inner ring 13 is incorporated, and the engagement member 17 is moved in one direction relative to the inner ring 13 by the relative rotation of the outer ring 11 in one direction. The rotating torque is transmitted between the outer ring 11 and the inner ring 13 by being engaged with the outer surface 14.

  Here, the axial length of the inner ring 13 is longer than that of the outer ring 11. The inner ring 13 is incorporated so that one end of the inner ring 13 is positioned substantially at the same position as one end of the outer ring 11, and the outer ring 11 is fitted with a bearing having a smaller diameter than the cylindrical outer surface 14 on the outer periphery of the other end located outside. A surface 19 is formed.

  A cylindrical inner surface 20 and a radial bearing surface 21 having a smaller diameter than the cylindrical inner surface 20 are continuously provided in the inner circumference of the inner ring 13 in the axial direction.

  A hub 40 is incorporated inside the inner ring 13. The hub 40 has a cylindrical shape and forms an annular space 41 with the cylindrical inner surface 20 of the inner ring 13. The axial length of the hub 40 is longer than that of the inner ring 13, an outwardly facing flange 42 from one end of the inner ring 13 to the outside, and a cylindrical portion 43 that extends toward the one end of the inner ring 13 on the outer periphery of the flange 42. The annular space 41 is closed by the flange 42 and the cylindrical portion 43.

  Further, a radial bearing surface 44 is formed on the outer periphery of the other end portion of the hub 40, and the inner ring 13 and the hub 40 are relatively rotatably supported by the fitting of the radial bearing surface 44 and the radial bearing surface 21 of the inner ring 13. It is said that.

  An annular seal groove 22 is formed on the radial bearing surface 21 of the inner ring 13, and the seal member 23 formed of an O-ring incorporated in the seal groove 22 is in elastic contact with the radial bearing surface 44 of the hub 40, and the hub is thereby contacted. The idling torque when 40 rotates idly with respect to the inner ring 13 is set to a value larger than the disengagement torque when the engagement element 17 of the one-way clutch 10 is disengaged. Further, the radial bearing surfaces 21 and 44 are sealed by incorporating the seal member 23.

  Alternatively, a seal groove may be formed in the radial bearing surface 44 of the hub 40, and a seal member may be incorporated in the seal groove so as to be in elastic contact with the radial bearing surface 21 of the inner ring.

  Of the pair of rolling bearings 30 a and 30 b, one rolling bearing 30 a is assembled between the bearing fitting surface 19 of the inner ring 13 and the inner diameter surface of the pulley 1, and the other rolling bearing 30 b is outside the cylindrical portion 43 of the hub 40. It is incorporated between the radial surface and the internal diameter surface of the pulley 1. The pair of rolling bearings 30a and 30b is incorporated so that the seal is located at the outer end, and the cage that holds the rolling element 31 of one rolling bearing 30a is integrated with the cage 15 of the one-way clutch 10. Yes.

  The pair of rolling bearings 30a and 30b supports a radial load and a moment load applied to the pulley 1, and an eccentric load is applied to the engaging member 17 of the one-way clutch 10, or a load is applied to the specific engaging member 17. It is designed to prevent being loaded.

  As shown in FIG. 1, a coil spring 50 as an elastic member extending in the axial direction is incorporated in an annular space 41 formed between the inner ring 13 and the hub 40.

  As shown in FIGS. 3 to 5, a protrusion 24 is formed on the inner circumference of the inner ring 13 so as to face one coil end 50 a of the coil spring 50 in the circumferential direction. A protrusion 45 is provided opposite to the other coil end 50b of the spring 50 in the circumferential direction.

  The pulley unit with a built-in clutch shown in the embodiment has the above-described structure. When an alternator as an engine accessory is driven, a hub 40 is attached to the rotating shaft of the alternator, and the pulley 1 is provided coaxially with the hub 40. And a belt between the pulleys attached to the crankshaft of the engine so that the rotation of the crankshaft is transmitted to the pulleys.

  In the use state as described above, when the rotation of the crankshaft is transmitted to the pulley 1 and the outer ring 11 integrated with the pulley 1 rotates relative to the inner ring 13 in one direction indicated by the arrow in FIG. The engaging element 17 is engaged with the cylindrical inner surface 12 of the outer ring 11 and the cylindrical outer surface 14 of the inner ring 13, and the rotation of the outer ring 11 is transmitted to the inner ring 13 via the engaging element 17.

  Further, by the rotation of the inner ring 13 in one direction, the protrusion 24 formed on the inner circumference of the inner ring 13 presses one coil end 50a of the coil spring 50 in the circumferential direction, and the coil spring 50 is diametrically pressed. The other coil end 50b of the coil spring 50 presses the protrusion 45 formed on the outer periphery of the hub 40, and the rotation of the inner ring 13 is transmitted to the hub 40 via the coil spring 50. The rotating shaft of the engine accessory is rotated.

  As described above, when the engagement member 17 of the one-way clutch 10 is engaged with the cylindrical inner surface 12 of the outer ring 11 and the cylindrical outer surface 14 of the inner ring 13 and the inner ring 13 rotates, the coil spring 50 is elastically deformed in the radial direction and the inner ring 13 is rotated. When the impact torque is input to the pulley 1 when the engine is started or suddenly accelerated, the impact torque input is absorbed by the elastic deformation of the coil spring 50. . For this reason, no impact torque is applied to the belt, and the durability of the belt can be improved.

  Here, since the idling torque when the hub 40 idles with respect to the inner ring 13 is set larger than the disengagement torque when the engagement element 17 of the one-way clutch 10 is disengaged, the engine suddenly decelerates. When the rotational speed of the hub 40 that rotates integrally with the rotating shaft of the alternator exceeds the rotational speed of the pulley 1 due to the above, the inner ring 13 that rotates together with the hub 40 rotates relative to the outer ring 11. The engagement 17 is disengaged by the relative rotation, the rotation transmission from the outer ring 11 to the inner ring 13 is interrupted, and the pulley 1 rotates freely.

  As shown in the embodiment, the pair of rolling bearings 30a and 30b with single seals are assembled so that the seal is located at the outer side end, and between the radial bearing surface 21 of the inner ring 13 and the radial bearing surface 44 of the hub 40. By incorporating the seal member 23, the inside of the one-way clutch 10 and the annular space 41 in which the coil spring 50 is incorporated can be sealed, and therefore the grease enclosed in the inside of the one-way clutch 10 and the inside of the annular space 41. Can be prevented from leaking to the outside, and dust can be prevented from entering the inside from the outside.

  In FIG. 1, a coil spring 50 extending in the axial direction of the hub 40 is incorporated in the annular space 41 so that the impact torque applied to the pulley 1 is buffered by elastic deformation of the coil spring 50 in the radial direction. However, as shown in FIG. 6, protrusions 25, 46 facing the inner periphery of the inner ring 13 and the outer periphery of the hub 40 in the circumferential direction are provided, and the coil extending between the protrusions 25, 46 in the circumferential direction of the hub 40. The spring 51 may be incorporated so that the impact torque applied to the pulley 1 is buffered by contracting the coil spring 51 when the inner ring 13 rotates in one direction indicated by the arrow.

  In the embodiment, the sprag type one-way clutch is shown as the one-way clutch 10, but the one-way clutch 10 is not limited to this. For example, a roller type one-way clutch may be used.

A longitudinal front view showing an embodiment of a pulley unit with built-in clutch according to the present invention Sectional view along the line II-II in FIG. Sectional view along line III-III in FIG. Sectional view along line VI-VI in FIG. Exploded perspective view showing inner ring, coil spring and hub Sectional drawing which shows the other example of the damper mechanism which buffers an impact torque

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pulley 10 One-way clutch 11 Outer ring 13 Inner ring 15 Cage 16 Pocket 17 Engagement element 18 Spring member 21 Radial bearing surface 22 Seal groove 23 Seal member 24 Projection part 25 Projection part 30a Rolling bearing 30b with a single seal Rolling bearing 40 with a single seal Hub 44 Radial bearing surface 45 Projection 46 Projection 50 Coil spring (elastic member)
50a Coil end 50b Coil end 51 Coil spring (elastic member)

Claims (6)

A one-way clutch is incorporated inside the pulley, the outer ring in which the one-way clutch is press-fitted into the inner diameter surface of the pulley, an inner ring incorporated inside the outer ring, a cage incorporated between the inner ring and the outer ring, An engagement element housed in each of a plurality of pockets formed at intervals in the circumferential direction of the retainer, and a spring member that urges the engagement element in a direction in which the engagement element is engaged with the opposing surfaces of the outer ring and the inner ring The pulley unit with a built-in clutch is configured to transmit the rotational torque between the outer ring and the inner ring by engaging the engaging element with the opposing surfaces of the outer ring and the inner ring by relative rotation in one direction of the outer ring and the inner ring. In
Elasticity that incorporates a hub inside the inner ring and elastically deforms between the outer periphery of the hub and the inner periphery of the inner ring by relative rotation in one direction of the hub and the inner ring, and transmits rotational torque between the inner ring and the hub. A pulley unit with a built-in clutch, wherein a member is incorporated, and an idling torque when the hub is idling with respect to the inner ring is made larger than a disengagement torque when the engagement element of the one-way clutch is disengaged.   The elastic member is formed of a coil spring that is fitted to the outer periphery of the hub and extends in the axial direction. Protrusions that oppose the coil ends of the coil spring in the circumferential direction are provided on the inner periphery of the inner ring and the outer periphery of the hub. The pulley unit with a built-in clutch according to claim 1.   The elastic member is formed of a coil spring extending in the circumferential direction along the outer periphery of the hub, and provided with protrusions facing the coil end of the coil spring in the circumferential direction on the inner periphery of the inner ring and the outer periphery of the hub. 2. A pulley unit with a built-in clutch according to 1.   Radial load and moment acting on the pulley between one end of the hub located on the outside from one end of the inner ring and the facing portion of the pulley and between the other end of the inner ring located on the outside and the facing portion of the pulley from the other end of the outer ring The pulley unit with a built-in clutch according to any one of claims 1 to 3, wherein a rolling bearing with a single seal for supporting a load is incorporated so that the seal is positioned at an outer side end.   The built-in clutch according to any one of claims 1 to 4, wherein a radial bearing surface that is metal-guided is formed on an inner periphery of the inner ring and an outer periphery of the hub, and the inner ring and the hub are relatively rotatably supported. Pulley unit.   6. A pulley with a built-in clutch according to claim 5, wherein a seal groove is formed in one of the radial bearing surface of the inner ring and the radial bearing surface of the hub, and a seal member incorporated in the seal groove is brought into elastic contact with the other radial bearing surface. unit.

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