JP2006022884A - Pulley with damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulley with a damper capable of effectively absorbed for a variation in rotation. <P>SOLUTION: There are provided with a first rotor 11 capable of winding a belt, and a second rotor 12 relatively rotatable with the first rotor 11. An interval 9 (it is preferable to be thickness of 0.05-0.5 mm) is formed between the first rotor 11 and the second rotor 12. Viscous fluid L is intervened in the interval 9. A cylindrical spring housing chamber 8 is formed between the first rotor 11 and the second rotor 12. A coil spring 10 is stored in the spring housing chamber 8, The coil spring 10 is secured to the inner wall of the first rotor 11 at one end, and to the inner wall of the second rotor 12 at the other end. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a configuration of a pulley having a damper function.

  For example, in a rotation transmission system that connects a crankshaft and an alternator of an automobile, rotational fluctuations occur such that acceleration and deceleration in the rotational direction are frequently repeated. The alternator has a large moment of inertia of the power generation shaft. Therefore, in the configuration in which a pulley is attached to the power generation shaft and the engine power is transmitted via the belt, the drive pulley and the belt are driven when the belt speed increases or decreases. Slip easily occurs between the belts, and belt squealing is easily induced. In addition, when engine rotation fluctuations are transmitted to the power generation shaft, there is a problem in that durability of the alternator is reduced and power generation efficiency is adversely affected.

  Therefore, as a pulley suitable for installation in the rotation transmission system as described above, for example, a pulley with a damper disclosed in Patent Document 1 is known. The pulley with a damper disclosed in Patent Document 1 increases in viscosity due to an increase in shearing force generated by a rubber elastic member and rotational fluctuation between a first rotating member and a second rotating member that can rotate relative to each other. It is constituted by interposing a viscous fluid having the property of With this configuration, deformation beyond the elastic limit of the elastic member is prevented by the viscous fluid, and damage to the elastic member is prevented.

In the configuration disclosed in Patent Document 2, a one-way clutch is built in between the outer ring and the inner ring, and the one-way clutch is free according to the rotational speed difference between the outer ring and the inner ring. It is configured to switch between a state and a locked state. And in order to delay the power transmission of both the ring bodies when the said one-way clutch locks, the cyclic | annular rubber material as a power transmission delay means is interposed. By doing so, it is difficult to transmit the impact accompanying the locking of the one-way clutch, the belt slip can be suppressed, and adverse effects such as belt wear and heat generation can be prevented.
JP-A-8-240246 (FIG. 1, paragraph numbers 0015, 0017, 0023) Japanese Patent Laid-Open No. 11-287311 (FIG. 1, paragraph numbers 0025 to 0028)

  However, in the pulley with a damper disclosed in Patent Document 1, the rotational deviation angle allowed between the first rotating member and the second rotating member is limited by the elastic limit of the elastic member. On the other hand, since the elastic member is made of an annular rubber, its elastic limit is generally small. Therefore, even if the damping effect by the viscous fluid is taken into account, there remains room for further improvement in terms of ease of absorbing rotational fluctuations.

  In the configuration of Patent Document 2, the rotational deviation angle allowed between the outer ring body and the inner ring body is limited by the elastic limit of the annular rubber material. Accordingly, there remains room for improvement in the same manner as Patent Document 1 in terms of ease of absorbing rotational fluctuations.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  According to the viewpoint of this invention, the pulley with a damper comprised as follows is provided. A first rotating body capable of winding a belt; a second rotating body capable of rotating relative to the first rotating body inside the first rotating body; the first rotating body and the second rotating body; A gap formed between the first rotating body and the second rotating body, a viscous fluid interposed in the gap, a spring accommodating chamber formed between the first rotating body, and the spring accommodating chamber. And a coil spring having one end fixed to the inner wall of the first rotating body and the other end fixed to the inner wall of the second rotating body.

  As a result, the viscous fluid existing as a thin film in the gap exhibits a large shear viscosity resistance and can attenuate the rotational fluctuation (damper effect). Moreover, the coil spring which connects two rotary bodies can enlarge the allowable torsion angle on the spiral structure. Accordingly, the allowable rotational deviation between the first rotating body and the second rotating body can be increased, and the rotational fluctuation can be efficiently absorbed together with the damper effect by the viscous fluid.

  In the pulley with a damper, the gap is preferably formed with a thickness of 0.05 mm or more and 0.5 mm or less. According to this, the viscous fluid in the gap portion exhibits an appropriate shear viscosity resistance with respect to the relative rotation of the two rotating bodies, and the rotational fluctuation can be appropriately attenuated.

  In the pulley with a damper, it is preferable that the spring accommodating chamber is provided inside the gap portion and a communication path that communicates the spring accommodating chamber and the gap portion. According to this, the spring accommodating chamber or the communication path can also serve as a viscous fluid replenishing chamber for the gap, and the configuration can be made compact. Further, the viscous fluid can be reliably supplied to the gap portion by utilizing the centrifugal force during the rotation of the pulley.

  In the pulley with a damper, it is preferable that the viscous fluid is put in the spring accommodating chamber in addition to the gap portion. According to this, the viscous fluid in the spring accommodating chamber can be lubricated with a member such as a coil spring, and the generation of abnormal noise is prevented.

  In the pulley with a damper, the viscous fluid is preferably silicone oil. In this case, even if the temperature changes, the viscosity change is small and the damper effect can be exhibited stably.

  In the pulley with a damper, the viscous fluid preferably has a viscosity of not less than 100,000 centistokes and not more than 1.2 million centistokes at 25 ° C. Thereby, a moderate damper effect can be exhibited in viscous fluid, and a rotation fluctuation can be absorbed appropriately.

  In the pulley with a damper, the first rotating body and the second rotating body have a groove in which the spring accommodating chamber side is opened, and an end of the coil spring is accommodated in the groove. preferable. Thereby, it becomes easy to attach the coil spring straight without tilting. As a result, unevenness of the force applied to the coil spring when rotation fluctuation occurs is prevented, and the coil spring can have a long life.

  Next, embodiments of the invention will be described. FIG. 1 is a cross-sectional perspective view of a pulley with a damper according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a state when the pulley with a damper is rotated.

  The pulley 1 with a damper shown in FIG.1 and FIG.2 is installed on the generator shaft of the alternator (not shown) of a motor vehicle, and rotates when the motive power of an engine is transmitted via a belt not shown. The pulley 1 with a damper includes a pulley body 2 that can wind the belt around the outer periphery thereof. The pulley body 2 is configured in a substantially cylindrical shape, and a cylindrical first spring receiver 3 is fixed by press-fitting inside one axial end thereof.

  A bearing 4 is disposed on the inner circumference on the other axial end side of the pulley body 2, and the second spring receiver 5 is supported by the bearing 4 so as to be rotatable relative to the pulley body 2. The second spring receiver 5 is housed inside the pulley body 2, and a pulley hub 6 is fixed to one end in the axial direction by press-fitting.

  The pulley hub 6 is housed almost entirely inside the first spring receiver 3 and is rotatably supported by the first spring receiver 3 via a bearing 7. In addition, a generator shaft (not shown) of the alternator can be fixed to the shaft hole of the pulley hub 6.

  The pulley body 2 and the first spring receiver 3 constitute a first rotating body 11, and the second spring receiver 5 and the pulley hub 6 constitute a second rotating body 12. The second rotating body 12 is disposed inside the first rotating body 11, and the first rotating body 11 and the second rotating body 12 are configured to be relatively rotatable by two bearings 4 and 7. Stop members 18 and 19 for fixing the second spring receiver 5 and the pulley hub 6 so as not to disengage the bearings 4 and 7 are fixed by press-fitting.

  The first spring receiver 3 forms a cylindrical wall portion 3b extending toward the second spring receiver 5 side. The second spring receiver 5 has a flange portion 5a, and forms a cylindrical wall portion 5b extending from the outer end of the flange portion 5a toward the first spring receiver 3 side. A cylindrical spring accommodating chamber 8 is formed inside the both wall portions 3b and 5b.

  Further, a gap portion 9 is defined between the second spring receiver 5 and the pulley body 2. The gap portion 9 includes a thin cylindrical portion between the outer peripheral surface of the wall portion 5b of the second spring receiver 5 and the inner peripheral surface of the pulley body 2, the flange portion 5a of the second spring receiver 5, and the pulley. A thin disk-shaped portion between the body 2 and the body 2 is formed in a continuous shape. The thickness of the gap 9 is preferably 0.05 mm to 0.5 mm. If the thickness is less than 0.05 mm, the resistance of the viscous fluid described later becomes too large to absorb the rotational fluctuation. On the other hand, if it exceeds 0.5 millimeters, the resistance of the viscous fluid becomes too small to efficiently attenuate the rotational fluctuation.

  A coil spring 10 is interposed between the first spring receiver 3 and the second spring receiver 5. The coil spring 10 is arranged inside the spring accommodating chamber 8 so that the axis of rotation of the pulley 1 coincides with the axis, and one end is on the inner wall of the first spring receiver 3 and the other end is the second spring receiver. The inner wall 5 is locked and fixed. As a result, the first rotating body 11 and the second rotating body 12 are elastically coupled via the coil spring 10.

  In the first spring receiver 3, an accommodation groove 16 is formed at the axial end of the spring accommodation chamber 8 so as to surround the three sides of the spring wire of the coil spring 10 and to open the spring accommodation chamber 8 side. Is formed. Also in the second spring receiver 5, an accommodation groove 17 is provided at the axial end of the spring accommodation chamber 8 so as to surround the three sides of the spring wire of the coil spring 10 and to open the spring accommodation chamber 8 side. Is formed. The vicinity of both ends of the spring wire of the coil spring 10 is housed in the housing grooves 16 and 17 of the spring receivers 3 and 5, respectively.

  An appropriate gap is formed between the end surface of the wall portion 3b of the first spring receiver 3 and the end surface of the wall portion 5b of the second spring receiver 5, and a communication path 14 is formed in this portion. The communication path 14 communicates between the spring accommodating chamber 8 and the gap 9.

  An appropriate amount of viscous fluid L is interposed in the gap 9. Various viscous fluids L are conceivable. For example, silicone oil is preferable because its viscosity change is smaller than mineral oil or the like even if the temperature changes. Moreover, the thing whose viscosity in 25 degreeC shows 100,000-1.2 million centistokes, Preferably what shows 500,000-1.2 million centistokes can attenuate | dampen a rotation fluctuation suitably. Specifically, modified with polydimethylsiloxane, polymethylphenylsiloxane, olefin-modified silicone, amino-modified silicone, carboxyl-modified silicone, α-methylstyrene-modified silicone, polyether-modified silicone modified with polyerylene glycol or polypropylene glycol, etc. Those containing siloxane bonds are conceivable.

  In order to prevent leakage of the viscous fluid L in the gap 9, a ring-shaped sealing material is provided between the pulley body 2 and the second spring receiver 5 and between the first spring receiver 3 and the pulley hub 6. 21 and 22 are interposed.

  As described above, the damper-equipped pulley 1 of the present embodiment has the viscous fluid L having a high viscosity interposed in the gap portion 9 formed between the first rotating body 11 and the second rotating body 12. Therefore, the viscous fluid L exists in the gap 9 as a thin film, and when the rotation fluctuation is transmitted and the first rotating body 11 and the second rotating body 12 rotate relative to each other, the viscous fluid L undergoes a large shear deformation. It will be. This means that the viscous fluid L can exhibit a large shear viscosity resistance with respect to the above relative rotation to attenuate the rotational fluctuation (damper effect). In addition, a rotation fluctuation | variation can be attenuate | damped appropriately by the thickness of the clearance gap part 9 being 0.05 millimeters-0.5 millimeters.

  Moreover, in this embodiment, the coil spring 10 is employ | adopted as an elastic body which connects the 1st rotary body 11 and the 2nd rotary body 12 elastically. That is, a cylindrical spring accommodating chamber 8 is provided between the first spring receiver 3 and the second spring receiver 5 facing each other in the axial direction, and a coil spring 10 is installed in the spring accommodating chamber 8 to Is fixed to the first spring receiver 3 and the other end is fixed to the second spring receiver 5. Here, the coil spring 10 can have an allowable torsion angle larger than that of an annular rubber or the like for the structural reason of winding the spring wire in a spiral shape. Therefore, the allowable rotational deviation between the first rotating body 11 and the second rotating body 12 can be increased, and the rotational fluctuation can be efficiently absorbed together with the damper effect by the viscous fluid L described above.

  Further, in this embodiment, the spring accommodating chamber 8 is provided inside the gap portion 9 (on the center side of the pulley), and the spring accommodating chamber 8 and the gap portion 9 are communicated with each other by the communication path 14. . Thereby, the spring accommodating chamber 8 and the communication path 14 can also serve as a reservoir (replenishment chamber) for the viscous fluid L with respect to the gap portion 9. Further, when the pulley 1 rotates, the viscous fluid L is reliably supplied to the outer gap 9 by centrifugal force as indicated by the arrow in FIG. 2, and the rotational fluctuation can be attenuated accurately.

  In the present embodiment, the spring receivers 3 and 5 are provided with receiving grooves 16 and 17 that are open on the spring receiving chamber 8 side, and the end portions of the coil spring 10 are respectively provided in the receiving grooves 16 and 17. Contained. Thus, by providing the end portions of the coil springs 10 in the receiving grooves 16 and 17, the coil springs 10 can be installed in a straight and stable manner without tilting. That is, if the coil spring 10 is installed at an inclination, an excessive force is easily applied to a part of the coil spring 10 due to rotational fluctuation applied to the pulley 1, and the coil spring 10 is easily damaged. In this respect, in this embodiment, since the mounting direction of the coil spring 10 can be reliably avoided by the receiving grooves 16 and 17, the rotational fluctuation applied to the pulley 1 can be uniformly received by the entire spring wire, and the coil The life of the spring 10 can be extended.

  In addition, as shown in FIG. 3, it can also be set as the structure which injected the appropriate quantity of viscous fluid L not only in the clearance part 9 but in the inside of the spring accommodating chamber 8. FIG. In this case, the contact surface between the coil spring 10 and the first spring receiver 3 and the second spring receiver 5 can be lubricated by the viscous fluid L in the spring accommodating chamber 8, and generation of abnormal noise such as frictional noise can be prevented. .

  In the present embodiment, the shape of the gap portion 9 is a shape that combines a thin cylindrical portion and a thin disc portion, but is not limited to this. For example, the gap portion 9 may be only a thin cylindrical portion or a thin wall portion. Only a disk-shaped part may be used. Moreover, you may comprise a gap | interval part in complicated structures, such as a labyrinth structure.

  In this embodiment, the spring accommodating chamber 8 and the gap portion 9 are configured to communicate with each other via the communication path 14, but the spring accommodating chamber 8 and the gap portion 9 are not in communication (viscosity fluid in the spring accommodating chamber 8). L may not be present). For example, a configuration in which a replenishing chamber (reservoir) is provided separately from the spring accommodating chamber 8 and the replenishing chamber and the gap 9 are connected via an appropriate passage is conceivable. A configuration without a replenishment chamber is also conceivable. Even with such a configuration, the effect of the present invention in which a large damper effect is obtained by the viscous fluid L interposed in the form of a film in the gap portion 9 is not lost.

  Although this embodiment demonstrated the case where the pulley 1 with a damper was provided in the generator shaft of the alternator, it is not restricted to this, For example, installing the pulley of this invention in the compressor shaft of the air conditioner of a motor vehicle is considered. Further, the pulley may be provided on the power output side, for example, the crankshaft of the engine. In this case, the rotation of the crankshaft is transmitted from the second rotating body 12 to the first rotating body 11 via the coil spring 10, and power is output from the pulley body 2 of the first rotating body 11 via the belt. Become. Moreover, the application of the pulley with a damper according to the present invention is not hindered in addition to vehicle equipment, and the pulley with a damper can be installed and used in various rotation transmission systems.

The cross-sectional perspective view of the pulley with a damper which concerns on one Embodiment of this invention. Sectional drawing which shows a mode when rotating a pulley with a damper. Sectional drawing which shows other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pulley with a damper 8 Spring accommodating chamber 9 Gap part 10 Coil spring 11 1st rotary body 12 2nd rotary body 14 Communication path 16, 17 Housing groove (groove)
L Viscous fluid

Claims (7)

A first rotating body capable of winding a belt;
A second rotating body that is rotatable relative to the first rotating body inside the first rotating body;
A gap formed between the first rotating body and the second rotating body;
A viscous fluid interposed in the gap,
A spring accommodating chamber formed between the first rotating body and the second rotating body;
A coil spring housed in the spring housing chamber, one end fixed to the inner wall of the first rotating body, and the other end fixed to the inner wall of the second rotating body;
A pulley with a damper.   2. The pulley with a damper according to claim 1, wherein the gap is formed to have a thickness of 0.05 mm or more and 0.5 mm or less. 3.   The pulley with a damper according to claim 1 or 2, wherein the spring accommodating chamber is provided inside the gap portion, and a communication path that connects the spring accommodating chamber and the gap portion is provided. This is a pulley with a damper.   The pulley with a damper according to claim 3, wherein the viscous fluid is put in the spring accommodating chamber in addition to the gap portion.   The pulley with a damper according to any one of claims 1 to 4, wherein the viscous fluid is silicone oil.   The pulley with a damper according to any one of claims 1 to 5, wherein the viscous fluid has a viscosity of not less than 100,000 centistokes and not more than 1.2 million centistokes at 25 ° C. Pulley with damper.   It is a pulley with a damper as described in any one of Claim 1- Claim 6, Comprising: The said 1st rotary body and the 2nd rotary body have a groove | channel by which the said spring accommodation chamber side is open | released, This A pulley with a damper, wherein an end of the coil spring is accommodated in a groove.

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