JP2001355678A - Torque fluctuation absorbing damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce parts cost and to provide an inexpensive product. SOLUTION: A sleeve 2 is connected with an outer peripheral side of a hub 1 mounted on a rotary shaft so as to be circumferentially and relatively displaceable via damper rubber 3. A circular mass 4 is fixedly fitted and mounted on an outer periphery of the sleeve 2. A pulley 5 made of low friction synthetic resin is supported so as to be circumferentially slidable on an outer periphery of the circular mass 4. The sleeve 2 and the pulley 5 are connected so as to be circumferentially and relatively displaceable via a coupling part 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque fluctuation absorbing damper that absorbs fluctuations in a transmission torque from a drive shaft of an engine or the like to another rotating device.

[0002]

2. Description of the Related Art A part of driving force from an automobile engine is supplied from a pulley provided at a tip of a crankshaft to an auxiliary device such as an alternator or a water pump through an endless belt. Is rotated with the torque fluctuation due to each stroke of
The pulley is provided with a torque fluctuation absorbing damper for absorbing torque fluctuation and smoothing transmission torque.

Conventionally, this type of torque fluctuation absorbing damper has been
For example, as shown in FIG. 6, a hub 101 attached to the shaft end of a crankshaft, a pulley 103 supported on its outer periphery via a bearing 102 so as to be relatively displaceable in a circumferential direction, and the hub 101 and the pulley A coupling rubber 104 for elastically connecting the hub 103 and the hub 1
An annular mass 106 elastically connected to a coupling rubber 104 via a damper rubber 105 provided in the axial direction on the outer periphery of 01 is provided. That is, the torque fluctuation absorbing damper absorbs the input torque fluctuation between the hub 101 and the pulley 103 by the shearing deformation action of the coupling rubber 104 between the hub 101 and the pulley 103, and is constituted by the damper rubber 105 and the annular mass 106. In a predetermined frequency range where the torsional amplitude of the crankshaft is large, the vibration absorber resonates at a phase angle different from the torsional vibration of the crankshaft, thereby exhibiting a vibration damping function of reducing the torsional vibration.

[0004]

However, according to the torque fluctuation absorbing damper having the conventional structure, since the pulley 103 is supported on the outer periphery of the hub 101 via the ball bearing 102, the cost of parts is high. Is pointed out.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its main technical object to reduce the cost of parts and to provide an inexpensive product.

[0006]

As a means for effectively solving the above-mentioned technical problems, a torque fluctuation absorbing damper according to the present invention comprises a hub mounted on a rotating shaft and a damper rubber on the outer peripheral side of the hub. A sleeve connected to the sleeve so as to be relatively displaceable in the circumferential direction, an annular mass fixedly fitted to the sleeve, and a low-friction synthetic resin supported on the outer periphery of the annular mass so as to be slidable in the circumferential direction. And a coupling unit that connects the sleeve and the pulley so as to be relatively displaceable in the circumferential direction. In this case, more preferably, the sleeve, the pulley, and the coupling portion are formed integrally with each other by a synthetic resin, and the coupling portion is formed in a bellows shape extending between the sleeve and the pulley.

As another means for effectively solving the above-mentioned technical problem, a torque fluctuation absorbing damper according to the present invention comprises a hub mounted on a rotating shaft and a damper rubber on the outer peripheral side of the hub. An annular mass connected to be displaceable in the circumferential direction, a pulley supported on the outer periphery of the annular mass via a synthetic resin bearing, and a coupling portion for connecting the hub and the pulley so as to be displaceable in the circumferential direction. Wherein an inward flange formed on the inner periphery of the pulley is located between an outward flange formed on the hub and the annular mass, and an engagement projection formed on the inward flange and the outward flange are provided. Are loosely fitted to each other with an appropriate gap in the circumferential direction.

[0008]

FIG. 1 is a half sectional view showing a first preferred embodiment of a torque fluctuation absorbing damper according to the present invention, cut along a plane passing through an axis O thereof. That is, the torque fluctuation absorbing damper is a hub 1 attached to a shaft end of a crankshaft (not shown) of an automobile engine.
A sleeve 2 connected to an outer peripheral side of the hub 1 via a damper rubber 3 so as to be relatively displaceable in a circumferential direction; an annular mass 4 fixedly fitted to the sleeve 2; And a coupling rubber 61 as a coupling part 6 for connecting the sleeve 2 and the pulley 5 so as to be relatively displaceable in the circumferential direction.

The hub 1 is formed by press-molding a metal plate, and has a disk portion 11 having an inner periphery provided with a shaft hole 11a to be connected to a shaft end of a crankshaft, and extending from the outer periphery of the disk portion 11. It consists of a cylindrical part 12. Also, sleeve 2
The damper rubber 3 made of metal is formed in a cylindrical shape having a larger diameter than the cylindrical portion 12 of the hub 1, and the damper rubber 3 made of an elastomer is arranged concentrically with the cylindrical portion 12 of the hub 1 on the outer peripheral side thereof. And is integrally vulcanized and bonded between the peripheral surfaces facing the sleeve 2.

The annular mass 4 is made of a sintered body or a casting obtained by impregnating micropores of a porous structure with lubricating oil, and its inner peripheral surface 4a is press-fit into the outer peripheral surface of the sleeve 2. The outer peripheral surface 4b of the annular mass 4 is formed into a smooth cylindrical surface, and the entire surface thereof is
Slidably in contact with the inner peripheral surface of the. The pulley 5 is made of a synthetic resin material having excellent wear resistance and low friction, for example, GF-PET.
(Glass reinforced polyethylene terephthalate), PEEK
(Polyetheretherketone) or a cylinder formed of polyketone or the like, having a poly-V groove 5a formed on the outer peripheral surface, and having a smooth sliding contact portion 5b with the outer peripheral surface 4b of the annular mass 4. It is formed in a planar shape.

The sleeve 2 has a coupling mounting portion 2a extending from the fitting portion to the annular mass 4 to one side in the axial direction, and the pulley 5 is also moved from the sliding contact portion to the annular mass 4 to one side in the axial direction. A coupling rubber 61 made of an elastomer is integrally vulcanized and bonded between opposing peripheral surfaces of the coupling mounting portions 2a and 5c, and has a torsional spring constant in the torsional direction. It is set to about 2 to 10 Nm / deg.

A dynamic vibration absorbing portion is constituted by the annular mass 4, the sleeve 2, and the damper rubber 3, and its natural frequency in the torsional direction is tuned to a predetermined frequency range in which the torsional angle of the crankshaft is maximized. ing.

The torque fluctuation absorbing damper according to the above-described embodiment is rotated together with the crankshaft of the engine by mounting the hub 1 on the shaft end of the crankshaft of the engine. The torque of the crankshaft is
It is transmitted to the pulley 5 via the damper rubber 3, the sleeve 2 and the coupling rubber 61. A V-belt (not shown) for transmitting a rotational torque to a rotating shaft of the auxiliary device is wound around a poly-V groove 5 a formed on the outer peripheral surface of the pulley 5.

The driving of the engine is performed while repeating the steps of intake, compression, explosion (expansion) and exhaust, and the reciprocating motion of the piston is converted into the rotational motion of the crankshaft. Periodic torque fluctuations occur with rotation, but the torque fluctuations are effectively absorbed by torsional deformation of the coupling rubber 61 having a low spring constant, and the transmission torque is smoothed. On the other hand, the dynamic vibration absorbing portion composed of the annular mass 4 and the sleeve 2 and the damper rubber 3 resonates in the torsional direction in a predetermined frequency range where the torsional angle due to the torsional vibration of the crankshaft is maximized, and the resonance is caused by the resonance Since the direction of the torque is opposite to the direction of the torque of the input vibration, the peak of the torsion angle of the crankshaft can be effectively reduced.

The annular mass 4 and the pulley 5 are slid in the circumferential direction by the torque fluctuation absorbing operation due to the torsional shearing deformation of the coupling rubber 61 and the resonance operation of the dynamic vibration absorber as described above. The sliding load caused by this is that the pulley 5 is made of a low friction synthetic resin material,
Since the annular mass 4 is made of a sintered body impregnated with lubricating oil, the mass can be kept low.

In other words, according to the above-described embodiment, the annular mass 4 and the pulley 5 are directly in sliding contact with each other with low friction, so that a ball bearing is used as a conventional means for concentrically supporting the pulley 5. Then, the number of parts is small, and therefore, it can be manufactured at low cost, and an inexpensive product can be provided.

Next, FIG. 2 shows a second preferred embodiment of the torque fluctuation absorbing damper according to the present invention, cut along a plane passing through the axis O thereof. That is, in this torque fluctuation absorbing damper, what is different from the embodiment of FIG. 1 described above is that the sleeve 2, the coupling portion 6, and the pulley 5 are made of a synthetic resin material having excellent wear resistance and low friction, for example, GF- It is formed integrally with each other by PET, PEEK, polyketone, or the like. More specifically, the coupling part 6 is formed of a bellows part 62 which is formed continuously between the sleeve 2 and the pulley 5 and extends while bending repeatedly in the axial direction. The constant is set to about 2 to 10 Nm / deg. Other parts are basically the same as those in FIG.

According to the torque fluctuation absorbing damper according to the above-described embodiment, as in FIG. 1, the annular mass 4 and the pulley 5 are directly in sliding contact with each other with low friction, so that the ball bearing is omitted. In addition, since the bellows portion 62 as the coupling portion 6 for absorbing the torque fluctuation input from the crankshaft to the hub 1 is formed integrally with the sleeve 2 and the pulley 5 by a synthetic resin, these are formed once. It can be manufactured in a process, and as a result, a cheaper product can be provided.

Next, FIG. 3 is a half sectional view showing a third embodiment of a torque fluctuation absorbing damper according to the present invention by cutting along a plane passing through an axis O thereof. That is, in this embodiment, the hub 1 is formed by press-molding a metal plate, and has a shaft hole 1 formed on the inner periphery thereof and connected to the shaft end of the crankshaft.
It comprises a disk portion 11 on which 1a is opened, a cylindrical portion 12 extending from the outer periphery thereof, and an outward flange 13 further extending from the end portion to the outer peripheral side.

An annular mass 4 is concentrically arranged on the outer peripheral side of the cylindrical portion 12 of the hub 1.
An annular damper rubber 3 formed of an elastomer is press-fitted between the peripheral surfaces facing the second rubber 2. The annular mass 4 and the damper rubber 3 constitute a dynamic vibration absorbing portion, and the natural frequency in the torsional direction is tuned to a predetermined frequency range in which the torsional angle of the crankshaft is maximized.

The annular mass 4 is made of a metal such as a casting, and has a second pulley portion 41 which itself functions as a pulley, and a pulley support portion 42 extending to one side in the axial direction. A pulley 5 is arranged on the outer peripheral side of the pulley support portion 42 via a bearing 7 so as to be relatively displaceable in a circumferential direction.

The bearing 7 is made of a synthetic resin material having excellent wear resistance and a low coefficient of friction, for example, PTFE, and FIGS.
And a radial bearing portion 71 slidably in contact with the outer peripheral surface of the pulley support portion 42 of the annular mass 4 and an outer peripheral side from the front end thereof. And a thrust bearing portion 72 slidably and closely attached to the side surface of the second pulley portion 42 of the annular mass 4, and has a substantially L-shaped cross section.

The pulley 5 has a pulley body 51 having a poly-V groove 51a formed on the outer peripheral surface thereof, and an extension 52 extending cylindrically from the outer periphery of the rear end thereof. The inner peripheral surface is slidably contacted with the outer peripheral surface of the radial bearing portion 71 of the bearing 7, and the end surface of the pulley body 51 is slidably contacted with the thrust bearing portion 72 of the bearing 7.

A metal outer sleeve 63 is press-fitted on the inner peripheral surface of the extension portion 52 of the pulley 5, and an inner sleeve 64 is press-fitted on the inner peripheral surface of the end of the cylindrical portion 12 of the hub 1. Have been. The coupling part 6 is composed of the outer sleeve 63 and the inner sleeve 64 which face each other in the radial direction, and the coupling rubber 61 which is integrally vulcanized and bonded between the two sleeves 63 and 64. That is, the pulley 5 is connected to the hub 1 via the outer sleeve 63, the coupling rubber 61, and the inner sleeve 64 in a relative displacement in the circumferential direction.

As shown in the partial perspective view of FIG. 4, the pulley 5 has a pulley body 51 and an extension 52.
And an inward outward flange 53 extending inward from the space therebetween, and a plurality of engagement projections 54 extending inwardly on the inner diameter of the inward outward flange 53 are arranged at regular intervals in the circumferential direction. It is formed with. On the other hand, the outward flange 13 of the hub 1 has a bent portion 13a bent in a substantially S-shape toward the coupling rubber 61 at a radially intermediate portion thereof.
b is axially close to the surface of the inward and outward flange 53 on the coupling rubber 61 side.

Bent portion 13 of outward flange 13 of hub 1
a, a plurality of elongated holes 13c extending in an arc shape centered on the axis O are formed at phase intervals corresponding to the engagement protrusions 54 of the pulley 5, and each of these engagement protrusions is formed. 54 and each of the engagement holes 13c are loosely fitted to each other with an appropriate gap in the circumferential direction. This loose fitting state is achieved by pulling the pulley 5 on the outer periphery of the bearing support portion 42 of the annular mass 4 through the bearing 7 during the process of assembling the torque fluctuation absorbing damper.
And then inserting the cylindrical portion 12 of the hub 1 into the inner periphery of the annular mass 4 in the axial direction.

That is, the inward flange 53 of the pulley 5
The outward flange 13 of the hub 1 functions as an axial stopper that limits the axial movement of the pulley 5 toward the coupling rubber 61 due to mutual interference in the axial direction. Further, an engagement hole 13c formed in the outward flange 13 is provided.
And the engagement with the engagement protrusion 54 on the pulley 5 side functions as a stopper for limiting the relative displacement of the hub 1 and the pulley 5 in the torsional direction.

According to the above embodiment, since the bearing 7 supporting the pulley 5 is a synthetic resin molded product, it is possible to provide an inexpensive product as compared with a conventional case using a ball bearing.

This torque fluctuation absorbing damper is also shown in FIG.
As shown in FIG. 2 and FIG. 2, the hub 1 is rotated together with the crankshaft of the engine by being attached to the shaft end of the crankshaft of the engine. 64, coupling rubber 61 and outer sleeve 63
Through a V-belt (not shown) to an auxiliary machine or the like. In addition to the pulley 5, the annular mass 4 is also used as a pulley, that is, a V-belt is wound around the outer periphery of the second pulley portion 42.

The torque fluctuation caused by the rotation of the crankshaft is effectively absorbed by the torsional shear deformation of the coupling rubber 61 having a low spring constant, and the transmission torque is smoothed. On the other hand, the dynamic vibration absorber constituted by the annular mass 4 and the damper rubber 3 resonates in the torsional direction at a phase angle different from the input vibration in a predetermined frequency range where the torsional angle due to the torsional vibration of the crankshaft is maximized. , Effectively reducing the peak of the twist angle of the crankshaft.

The annular mass 4 and the pulley 5 are relatively displaced in the circumferential direction while sliding with the bearing 7 by the torque fluctuation absorbing operation due to the torsional shear deformation of the bellows portion 6 as described above. The vibration system composed of the bellows part 6 and the pulley 5 resonates at a relatively low speed rotation because the natural frequency in the torsional direction is low. However, the relative displacement of the hub 1 and the pulley 5 in the torsional direction increases due to this. The coupling rubber 61 is subjected to excessive torsional deformation because the coupling rubber 61 is limited by interference between the engaging hole 13 c formed in the outward flange 13 of the hub 1 and the circumferential end of the engaging protrusion 54 of the pulley 5. Nothing. Also, even if the coupling rubber 61 is broken due to fatigue or the like, the pulley 5 is prevented from falling off due to the interference between the inward flange 53 and the outward flange 13 of the hub 1, and the engagement hole 13c Since the engagement state of the engagement protrusion 54 is maintained, the torque transmission from the hub 1 to the pulley 5 is continuously performed.

The fourth embodiment shown in FIG. 5 is basically the same as the third embodiment, that is, the hub 1 is made of a casting, and the inward flange 53 of the pulley 5 and the engagement The point that the outward flange 13 engaging with the projection 54 is fitted to the outer peripheral cylindrical portion 14 of the hub 1, and the inner sleeve 64 of the coupling portion 6 fits to the outer peripheral surface of the boss 15 of the hub 1. The only difference is that they are worn.

[0033]

As described above, according to the torque fluctuation absorbing damper according to the present invention, by providing the inner peripheral surface of the pulley with a bearing function, it is not necessary to interpose a ball bearing, or to use a synthetic resin bearing. By using, it is possible to provide an inexpensive product,
By forming the coupling portion into a bellows shape extending from the pulley, a more inexpensive product can be provided.

By providing means for limiting the relative displacement of the hub and the pulley in the axial direction and the circumferential direction, excessive deformation of the coupling portion is prevented, and the coupling portion may be damaged by any chance. In addition, the pulley can be effectively prevented from falling off, and the safety can be improved.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing a first embodiment of a torque fluctuation absorbing damper according to the present invention by cutting along a plane passing through an axis O. FIG.

FIG. 2 is a half sectional view showing a second preferred embodiment of the torque fluctuation absorbing damper according to the present invention by cutting along a plane passing through an axis O;

FIG. 3 is a half sectional view showing a third preferred embodiment of a torque fluctuation absorbing damper according to the present invention by cutting along a plane passing through an axis O;

FIG. 4 is a perspective view of a main part of the third embodiment.

FIG. 5 is a half sectional view showing a fourth preferred embodiment of the torque fluctuation absorbing damper according to the present invention by cutting along a plane passing through an axis O;

FIG. 6 is a half sectional view showing an example of a torque fluctuation absorbing damper according to a conventional technique, cut along a plane passing through an axis O;

[Explanation of symbols]

 Reference Signs List 1 hub 11 disk portion 12 cylindrical portion 13 outward flange 13a bent portion 13b outer peripheral end 13c engagement hole 14 outer peripheral cylindrical portion 15 boss portion 2 sleeve 2a, 5c coupling mounting portion 3 damper rubber 4 annular mass 41 second pulley portion 42 bearing Supporting part 5 Pulley 51 Pulley main body part 52 Extension part 53 Inward flange 54 Engagement protrusion 6 Coupling part 61 Coupling rubber 62 Bellows part 63 Outer sleeve 64 Inner sleeve 7 Synthetic resin bearing

Claims (3)

[Claims] 1. A hub (1) attached to a rotating shaft; a sleeve (2) connected to an outer peripheral side of the hub (1) via a damper rubber (3) so as to be relatively displaceable in a circumferential direction; An annular mass (4) fixedly fitted to (2); a pulley (5) made of a low friction synthetic resin supported on the outer periphery of the annular mass (4) so as to be slidable in the circumferential direction; A torque fluctuation absorbing damper, comprising: a coupling part (6) for connecting the sleeve (2) and the pulley (5) so as to be relatively displaceable in a circumferential direction. 2. A sleeve (2), a pulley (5) and a coupling part (6) are formed integrally with each other, and the coupling part (6) extends between the sleeve (2) and the pulley (5). The torque fluctuation absorbing damper according to claim 1, wherein the damper is formed in a bellows shape that extends. 3. A hub (1) attached to a rotating shaft; an annular mass (4) connected to an outer peripheral side of the hub (1) via a damper rubber (3) so as to be relatively displaceable in a circumferential direction; Synthetic resin bearing (7) on the circumference of annular mass (4)
And a coupling portion (6) for connecting the hub (1) and the pulley (5) so as to be relatively displaceable in a circumferential direction. An inward flange (53) formed on the circumference is connected to an outward flange (1) formed on the hub (1).
3) and the annular mass (4), the engagement protrusion (5) formed on the inward flange (53).
4) A torque fluctuation absorbing damper characterized in that an engaging hole (13c) formed in the outward flange (13) is loosely fitted to each other with an appropriate gap in a circumferential direction.