JP2010001987A - Pulley device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulley device for reducing the thickness of a pulley by loosening stress concentration of the V-grooved bottom part of the pulley of the pulley device. <P>SOLUTION: The pulley device 10 includes a pulley formed by a belt groove 12a which is wound by a belt B in the outer peripheral part and the belt groove 12a includes a raceway groove depth which includes a plurality of mutually different V grooves 12a1, 12a2 in the axial direction of the pulley 12, and the raceway groove depth of the V groove 12a1 in the axial direction central part is formed more shallowly than the V groove 12a2 in the axial direction end part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pulley apparatus, and more particularly to a one-way clutch built-in pulley apparatus including a one-way clutch.

  In general, the pulley device is driven by the power of the crankshaft of the engine. The oil pump for power steering, the compressor for air conditioners, the cooling fan, the water pump, the input shaft of auxiliary equipment such as an alternator, and the reverse In addition, it is used for the output shaft of a starter motor that provides power to the crankshaft of the engine.

  For example, a driven pulley is fixed to an end of an input shaft of an automobile auxiliary machine such as an alternator, and an endless belt is stretched between a driving pulley fixed to an end of an engine crankshaft. Used to drive The driven pulley has a built-in one-way clutch, and when the running speed of the endless belt is constant or tends to increase, power can be freely transmitted from the endless belt to the rotating shaft, and the running speed of the endless belt tends to decrease. In this case, the relative rotation between the driven pulley and the rotating shaft can be freely performed. Therefore, even when the rotational angular speed of the crankshaft fluctuates, the endless belt and the driven pulley are prevented from rubbing due to the action of the one-way clutch, and the endless belt is prevented from being shortened due to the generation of abnormal noise called wear and wear. At the same time, the power generation efficiency of the alternator can be prevented from decreasing (see, for example, Patent Documents 1 and 2).

In the pulley device with a built-in one-way clutch described in Patent Document 1, a radial ball bearing and a radial roller bearing are used. In addition, the pulley inner diameter is made uniform to ensure the thickness of the pulley, and the entire apparatus is reduced in the diameter direction.
JP 2000-320650 A Japanese Patent Laid-Open No. 2001-4011

  By the way, in order to increase the torque transmission capacity of the one-way clutch without changing the outer diameter of the pulley, it is required to reduce the thickness of the pulley, but it is necessary to reduce the thickness due to the fatigue life of the pulley and plastic deformation. There are limits.

  Further, stress concentration acts on the V-groove bottom portion of the outer diameter of the pulley, which is on the outside near the center of the pulley device with a built-in one-way clutch, due to the load caused by press-fitting the clutch outer ring and the load from the roller when the clutch is engaged. For this reason, when reducing the thickness of the pulley, it is required to reduce the stress concentration at the bottom of the V groove of the pulley near the center of the pulley device.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to reduce the concentration of stress at the bottom of the V groove of the pulley of the pulley device and reduce the thickness of the pulley. To provide an apparatus.

The above object of the present invention can be achieved by the following constitution.
(1) A pulley apparatus having a pulley in which a belt groove around which a belt is wound is formed.
The belt groove includes a plurality of V-grooves having different groove depths in the pulley axial direction, and the groove depth of the V-groove near the axial position where loads acting on the pulley are concentrated is shallower than other V-grooves. A pulley apparatus characterized by being formed.
(2) The pulley is arranged around the rotation axis and concentric with the rotation axis.
The pulley apparatus according to (1), further comprising a one-way clutch that is disposed inside the pulley and transmits power between the pulley and the rotating shaft.

  The axial position where the load acting on the pulley is concentrated includes the axial position where the concentrated load equivalent to this distributed load is applied when the load acting on the pulley is a distributed load.

  According to the present invention, the belt groove includes a plurality of V grooves having different groove depths in the axial direction of the pulley, and the groove depth of the V groove in the vicinity of the axial position where the load acting on the pulley is concentrated is Since it is formed shallower than the other V-grooves, it is possible to reduce the stress concentration at the bottom of the V-groove of the pulley of the pulley device and to reduce the thickness of the pulley.

  Hereinafter, a pulley apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view for explaining a pulley device with a built-in one-way clutch for an alternator as a pulley device of the first embodiment. As shown in FIG. 1 (a), a pulley apparatus 10 with a built-in one-way clutch according to this embodiment is for driving an automobile auxiliary machine such as an alternator, and a sleeve 11 into which a rotary shaft (not shown) is fitted. Have Around the sleeve 11, a pulley 12 having a belt groove 12a formed on the outer peripheral surface is arranged concentrically with the sleeve 11. The pulley 12 can be arranged around the rotating shaft concentrically with the rotating shaft. . In addition, a one-way clutch 13 that is a clutch is disposed between the outer peripheral surface of the sleeve 11 and the inner peripheral surface of the pulley 12 at an axially intermediate portion of the annular space formed therebetween. A pair of support bearings 14 such as, for example, deep groove ball bearings are disposed at both end portions in the axial direction so as to sandwich the one-way clutch 13.

  The one-way clutch 13 transmits the rotational force from the pulley 12 to the sleeve 11 only when the pulley 12 tends to rotate relative to the sleeve 11 in a predetermined direction. Further, the pair of support bearings 14 enables the relative rotation between the sleeve 11 and the pulley 12 while supporting a radial load applied to the pulley 12.

  Each support bearing 14 includes a bearing inner ring 15 fitted on the outer peripheral surface of the sleeve 11, a bearing outer ring 16 fitted on the inner peripheral surface of the pulley 12, and both raceway surfaces of the bearing inner ring 15 and the bearing outer ring 16. A plurality of balls 17 that are arranged rolling elements, a cage 18 that holds the balls 17 in a freely rolling manner, and a seal member 19 that prevents the intrusion of foreign matter from the outside and the leakage of a lubricant such as grease from the inside. have.

  The one-way clutch 13 includes a clutch outer ring 20 that is press-fitted and fixed to the inner peripheral surface of the pulley 12, a clutch inner ring 21 that is press-fitted and fixed to the outer peripheral surface of the large-diameter portion of the sleeve 11, and the clutch outer ring 20 and the clutch inner ring 21. And a plurality of rollers 22 which are engaging members disposed between the rollers. The outer peripheral surface of the clutch inner ring 21 forms a cam surface in which a plurality of ramp surfaces 21a are provided at predetermined intervals in the circumferential direction. The rollers 22 are rotatably held in a wedge space composed of each ramp surface 21 a and a cylindrical surface 20 a formed on the inner peripheral surface of the clutch outer ring 20.

  The one-way clutch 13 includes a clutch holder 23 having a plurality of pockets for individually accommodating the rollers 22 and a spring 24 that elastically presses the rollers 22 in the locking direction.

  In the pulley apparatus 10 with a built-in one-way clutch configured as described above, when the rotational angular speed of the pulley 12 is faster than the rotational angular speed of the rotating shaft of the alternator, for example, the roller 22 of the one-way clutch 13 is engaged by the wedge action. Engaged between the ramp surface 21a of the inner ring 21 and the cylindrical surface 20a of the clutch outer ring 20, the pulley 12 and the sleeve 11 become non-rotatable (locked), and the engine torque is transmitted to the rotating shaft of the alternator. Is done. On the other hand, when the rotational angular velocity of the pulley 12 is slower than the rotational angular velocity of the alternator, the engagement of the rollers 22 is released, and the relative rotation between the pulley 12 and the sleeve 11 becomes free (overrun state).

  Here, as shown in FIG. 1B, the belt groove 12 a of the pulley 12 includes a plurality of V grooves 12 a 1 and 12 a 2 formed at equal intervals in the axial direction of the pulley 12. The groove depth of the V groove 12a1 in the vicinity of the axial center where the load acting on the pulley 12 concentrates is shallower than the other V grooves 12a2 in the vicinity of the axial end. In the present embodiment, it is gradually formed deeper toward the vicinity of the end in the axial direction. Further, the bottom curvature radius R1 of the V groove 12a1 near the center in the axial direction is also set larger than the bottom curvature radius R2 of the other V groove 12a2 near the end in the axial direction.

  The belt B wound around the belt groove 12a is also formed along the shape of the belt groove 12a.

  Therefore, according to the pulley apparatus 10 with a built-in one-way clutch of the present embodiment, the belt groove 12a includes a plurality of V grooves 12a1 and 12a2 having different groove depths in the axial direction of the pulley 12, Since the groove depth of the V-groove 12a1 near the center in the direction is shallower than the other V-grooves 12a2 near the end in the axial direction, the stress concentration at the bottom of the V-groove of the pulley 12 of the pulley device 10 is alleviated. The wall thickness of the pulley 12 can be reduced.

  Further, the bottom curvature radius R1 of the V groove 12a1 near the axial center of the pulley 12 is formed larger than the bottom curvature radius R2 of the other V groove 12a2 near the axial end, so the V groove of the pulley 12 The stress concentration at the bottom can be further relaxed. In particular, it is considered by calculation that the transmission torque is almost the same as that of a belt groove having a single V-shaped groove by making the wedge angles of the V-shaped grooves 12a1 and 12a2 equal. When a plurality of different V-grooves are formed at equal intervals, the curvature radius of the V-groove bottom is the above configuration, which is more effective in terms of transmission torque and stress concentration relaxation.

  The belt groove 12a may be formed so that the groove depth gradually increases from the V groove 12a1 near the center in the axial direction toward the end 12a2 in the axial direction as in the present embodiment, or As shown in FIG. 2, the groove depth of only the V groove 12a1 near the center in the axial direction may be made shallower than the other V grooves 12a2, or from the V groove near the center in the axial direction to the vicinity of the end in the axial direction. The groove depth may be formed stepwise toward the V groove.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

  In the above-described embodiment, the one-way clutch built-in type pulley apparatus has been described. However, the shape of the belt groove 12a of the present invention can also be applied to a resin pulley 12 'formed on a bearing 30 as shown in FIG.

  Moreover, in the said embodiment, although several V groove | channel is formed at equal intervals, it is not limited to this. Furthermore, the V-groove having a shallow groove depth according to the present invention may be in the vicinity of the axial position where the load acting on the pulley 12 is concentrated, where stress concentration is likely to occur due to the load, depending on the position of the one-way clutch 13 and the like. It may be set near the position in the axial direction where the load at the time of pressure input and engagement is concentrated. When the one-way clutch 13 is disposed between the pair of support bearings 14 as in the present embodiment, the V groove near the center in the axial direction may be shallowly formed.

  In addition, the one-way clutch of the present invention only needs to transmit a rotational force between the sleeve and the pulley, and the pulley tends to rotate relative to the sleeve in a predetermined direction as in the present embodiment. In this case, the clutch may be a one-way clutch that transmits rotational force, the outer peripheral surface of the inner ring of the clutch is a cylindrical surface, and the inner peripheral surface of the outer ring of the clutch is a cam surface having a plurality of ramp surfaces. A one-way clutch that transmits rotational force may be used only when it tends to rotate relatively in a predetermined direction.

  The one-way clutch of the present invention may be a roller clutch as in this embodiment, or may be a cam clutch or a sprag clutch. Further, the outer ring or inner ring of the one-way clutch may be separate from the pulley or sleeve as in the present embodiment, and is integrated with the pulley or sleeve, that is, constituted by the inner peripheral surface of the pulley or the outer peripheral surface of the sleeve. May be.

  Further, the pair of support bearings of the present invention may be of a type other than the deep groove ball bearing, or may be a combination of a roller bearing or a ball bearing. Further, the inner ring or the outer ring of the support bearing may be integrated with the pulley or the sleeve, that is, the inner peripheral surface of the pulley or the outer peripheral surface of the sleeve.

  Here, with respect to the pulley apparatus of the present invention having the V-groove shape shown in FIG. 1 and the conventional pulley apparatus having a single V-groove shape, a clutch outer ring is used by using an appropriate model by finite element method analysis (FEM). The stress due to the fitting and the stress due to the load from the roller during engagement were calculated. 1 is set to 0.5 mm, 0.75 mm, 1.0 mm, 1.0 mm, 0.75 mm, and 0.5 mm from the one end side in the axial direction. The curvature radius is uniformly set to 0.5 mm. Also, since all V grooves are formed at equal intervals and the wedge angle is uniform, the groove depth of any V groove is set according to the radius of curvature of the bottom. Furthermore, the load and the interference between the clutch outer ring and the pulley were the same.

  As a result of the above analysis, assuming that the maximum value of the maximum principal stress in the conventional pulley apparatus is 100%, the maximum value in FIG. 1 is about 80%, and it has been confirmed that the stress can be reduced by about 20%.

(A) is a longitudinal cross-sectional view of the pulley apparatus which concerns on one Embodiment of this invention, (b) is the I section enlarged view of (a). It is an enlarged view concerning the modification of the belt groove of a pulley corresponding to FIG.1 (b). It is sectional drawing which shows the example which applied the shape of the belt groove | channel of this invention to the belt groove | channel of the resin pulley.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Clutch built-in type pulley apparatus 11 Sleeve 12 Pulley 12a Belt groove 12a1, 12a2 V groove 13 One-way clutch 14 Support bearing

Claims (2)

A pulley apparatus having a pulley formed with a belt groove around which a belt is wound,
The belt groove includes a plurality of V-grooves having different groove depths in the axial direction of the pulley, and the groove depth of the V-groove near the axial position where loads acting on the pulley concentrate is different from other V-grooves. A pulley apparatus characterized by being formed shallower than a groove. The pulley is arranged around the rotation shaft and concentrically with the rotation shaft,
The pulley apparatus according to claim 1, further comprising a one-way clutch that is disposed inside the pulley and transmits power between the pulley and the rotating shaft.

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