JPH10238593A - Viscous damper - Google Patents

Abstract

(57) [Summary] [Problem] To improve the reliability of a damper. SOLUTION: A housing 1 attached to a rotating shaft that generates torsional vibration is provided. The housing 1 is formed in an annular shape along the circumferential direction of the rotating shaft, and accommodates an inertia ring 2 in the housing 1 and stores a viscous fluid. Enclose to form a viscous damper. The inertial ring 2 is movable along the annular housing 1 via a bearing 3, and a plurality of protrusions 1 b protruding from the inertial ring 1 and a stator 4 provided on the housing 1 so as to face the protrusions 1 b. And the metal ring spring 5 disposed along the direction of movement of the inertia ring 2 and held between them so as to be movable against the coil spring 5 made of metal. Viscous fluid is circulated through radial holes 9 formed in the inertia ring 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscous damper which is mounted on a rotating shaft of a crankshaft, a drive shaft, a propeller shaft or the like which generates torsional vibration to attenuate the vibration accompanying the rotation of the rotating shaft.

[0002]

2. Description of the Related Art As a damper for attenuating torsional vibration of a rotating shaft mainly due to resonance of a multi-cylinder engine, a rubber damper composed of rubber and an inertial mass, an inertial ring and a viscous fluid are put in a liquid-tight space, and the inertial ring is There are known a viscous damper using a viscous shear resistance force when moving by inertia, a viscous rubber damper using a viscous fluid and rubber in combination, and the like.

[0003]

However, these dampers reduce the excessive low-order torsional vibration to the normal rotation speed range due to the thermal fatigue limit of rubber, lack of damping ability, and large inertia force. It does not always satisfy the specifications of high output, clean exhaust, and low noise required for engines in recent years. More specifically, the rubber damper and the viscous rubber damper are poor in reliability because the rubber is damped by oxidative deterioration due to self-heating for environmental temperature and vibration damping, and the surface is hardened and cracked.
The viscous damper is also thermally strong and has high reliability.However, in order to obtain a large damping force, a large inertia ring is required. A new problem arises in that the natural frequency becomes lower and a large harmonic drive of a lower order is drawn into the high rotation region of the engine. Further, an inertia ring b is accommodated in the annular housing a and a viscous fluid c is accommodated in the housing a.
And a leaf spring or rod-like spring d extending in the radial direction of the housing a.
Also known is one that is coupled to the housing a via a cable (Japanese Patent Laid-Open No. 4-125340). However, in order to allow the inertia ring b to vibrate in the circumferential direction of the rotation axis, in other words, in order for the leaf spring or the rod-shaped spring d to be deformable, the leaf spring or the rod-shaped spring d is required. , At least with respect to the inertia ring b or the housing a. Therefore, the inertia ring b
Cannot be mounted at the correct position with respect to the housing a and, consequently, the rotating shaft. When the housing a is mounted on the rotating shaft and rotated, the rotational balance of the rotating shaft is lost, and vibration, noise, and the rotating shaft are abnormally worn. Such a problem occurs. An object of the present invention is to obtain a viscous damper free of such a problem.

[0004]

In order to achieve the above object, according to the present invention, there is provided a housing mounted on a rotating shaft that generates torsional vibration, and the housing extends along a circumferential direction of the rotating shaft. In a viscous damper that is annular and accommodates an inertial ring in the annular housing and encloses a viscous fluid, the inertial ring is movable along the annular housing via a bearing, and a plurality of protrusions projecting to the inner periphery. A protrusion is provided in the housing, the same number of stators as the protrusion of the inertial ring are provided inside the housing, and a metal coil spring is provided between the protrusion of the inertial ring and the stator. Characterized in that the inner side of the inertial ring in the radial direction is a liquid reservoir for viscous fluid, and by having such a configuration, the peak of vibration can be divided into two by a coil spring, , The relative amplitudes of the inertia ring and the housing worked shearing force to the viscous fluid, it is possible to suppress the divided vibration peak to a low value.

[0005] In addition, with the above configuration, the inertia ring can be mounted in a stable state in the radial direction of the housing.

According to a second aspect of the present invention, in the first aspect of the present invention, the inertial ring is housed in a housing with a narrow gap on both sides and a radially outer side. The chamber is communicated with a through hole formed in the inertial ring, and by having such a configuration, the narrow gap formed between the housing and both sides of the inertial ring and the outside in the radial direction is provided. A shear force acts on a certain viscous fluid to cause hysteresis, so that the temperature of the viscous fluid increases, the viscosity decreases, and the specific gravity decreases. On the other hand, since the viscous fluid in the liquid storage chamber does not receive such a force, the viscosity and the specific gravity are kept at a relatively low temperature and do not change. For this reason, the viscous fluid having a relatively large specific gravity in the liquid storage chamber is pushed out to the gap side by the centrifugal force, and the viscous fluid in the gap is pushed by this to generate a circulating flow returning to the liquid storage chamber. Further, the circulation of the viscous fluid is promoted by the pumping action due to the volume fluctuation due to the vibration of the liquid storage chamber.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes an annular housing formed of a relatively light metal such as aluminum and extending along a circumferential direction of a rotary shaft R1 for generating torsional vibration and a pulley R2 for transmitting power to auxiliary machines. The housing 1 accommodates a metal inertia ring 2 and seals silicone oil and other viscous fluid. The inertia ring 2 is movable via a bearing 3 between the inertia ring 2 and the stator 4 or the cover plate 1c provided on the housing 1 and a journal bearing 10 between the stator 4 and the inertia ring 2. And a plurality of protrusions 2a protruding from the inertia ring 2 at equal intervals.
And a metal coil spring 5 disposed along the moving direction of the inertia ring 2 and sandwiched between a stator 4 provided on the housing 1 and opposed thereto. To accommodate.

To explain this further, the inertia ring 2 is
Six protrusions 2a are projected inward at equal intervals, and six stators 4 are fixed to the housing 1 by screws 7 at regular intervals so as to be opposed to the protrusions 2a and fixed to the protrusions 2a. The spring seat 6 is attached to the surface facing the child 4,
The coil spring 5 was attached in a compressed state in advance. The spring seat 6 is, as shown in FIG.
A recess 6a is provided in the center of the back surface, and the protrusion 2a and the protruding piece 11 protruding from the stator 4 are fitted and attached, or as shown in FIG.
b, and the bulge 6b was fitted and attached to the protrusion 2a and the recess 12 provided in the stator 4.

Note that, without providing the spring seat 6, the projection 2 is directly provided.
a and the coil spring 5 may be attached to the stator 4.

When the metal coil spring 5 is directly attached to the protrusion 2a and the stator 4, or when the metal is in contact with each other such as when the spring seat 6 is made of metal, metal powder is generated. This causes deterioration of the viscous fluid. However, if the spring seat 6 is made of a material other than a metal having a cushioning property, such as nylon resin, such a deterioration of the viscous fluid can be prevented, and furthermore, the metals can be separated from each other. There is no noise due to contact.

The inertia ring 2 has an outer diameter slightly smaller than a diameter of an inner wall surface outside the housing 1 and is slightly spaced from both sides of the inertia ring 2 at equal intervals on both sides of the inertia ring 2. When the plate-shaped bearing 3 made of protruding fluororesin (Teflon) is mounted and the inertial ring 2 is mounted in the housing 1, a gap of about 0.5 mm is formed between the outer side of the inertial ring 2 and the housing 1 on both sides. To be formed. The space inside the inertia ring 2 in the radial direction, that is, the space in which the coil spring 5 is housed, is used as a viscous fluid reservoir 8. Furthermore, the inertia ring 2 has
And a gap formed between the housing 1 and the radially outer side of the inertia ring 2 through the radial through hole 9 communicating therewith.
Was provided. The diameter of the through hole 9 is about 4 mm. Although the journal bearing 10 is provided on the outer periphery of the stator 4, the mounting position of the journal bearing 10 is as follows.
The position is not limited as long as it is a position where the inertial ring 2 is restrained and supported in the radial direction.

In the above embodiment, the projections 2a and the stator 3 are provided at equal intervals. However, even when the intervals between the projections 2a and the stator 3 are not equal, the spring constants of the coil springs 5 are all the same. Then, by using coil springs (not shown) having different free lengths, the same performance as when the protrusions 2a and the stator 3 are provided at equal intervals can be obtained. Therefore, the interval between the protrusion 2a or the stator 3 is
It is not necessary that the intervals be equal. In addition, the stator 4
Was attached by screwing with screws 7, but the attachment is not limited to this, and it may be fixed using means such as welding.
The housing 1 includes a flange portion 1a fixed to the pulley R2, a housing body 1b for accommodating the inertial ring 2 and the like, and a lid 1c for covering a side opening of the accommodating space A. Further, the housing 1 is mounted on the rotary shaft R1 via the pulley R2, but may be mounted directly on the rotary shaft R1.

Next, the operation of the present damper will be described. The housing 1 rotates with the rotation of the rotation shaft, and the inertia ring 2 rotates together with the housing 1 via the coil spring 5 in the housing 1. At this time, when circumferential vibration (torsional vibration) occurs on the rotating shaft, the inertial ring 2 causes relative vibration between the inertial ring 2 and the housing 1, and as shown in FIG. 5, high-order (sixth-order, 4.5-order) vibrations Is divided into two, and the relative vibration between the inertia ring 2 and the housing 1 allows the divided peak vibration to be suppressed to a low value by the shearing force acting on the viscous fluid. Is also divided, and one of the peak vibrations remains in the used rotation range. However, as is clear from FIG. 5, the peak vibration is also suppressed to a low level. It should be noted that the other peak vibration does not pose a problem because it enters a higher rotation range than the used rotation range.

In addition, a shear force acts on the viscous fluid in the narrow gap formed between both sides of the inertia ring 2 and the outside in the radial direction and the housing 1 to generate heat by hysteresis, and the temperature of the viscous fluid is reduced. The viscosity rises, the viscosity decreases, and the specific gravity decreases (hereinafter, referred to as a viscous fluid having a relatively low specific gravity). On the other hand, since the viscous fluid in the liquid storage chamber 8 does not receive such a force, the viscosity and the specific gravity are maintained at a relatively low temperature (hereinafter, referred to as a viscous fluid having a relatively large specific gravity). For this reason, in this damper, the viscous fluid having a relatively large specific gravity in the liquid reservoir 8 is usually
Due to the centrifugal force, the accommodation space A passes through the through hole 9 of the inertial ring 2.
The viscous fluid having a relatively small specific gravity returns to the liquid storage chamber 8 from the outer circumference of the housing space A through both sides of the inertia ring 2. As a result, the viscous fluid becomes a circulating flow as described above. Further, as an example, when a torsional vibration occurs in which the housing 1 and the inertia ring 2 alternately move in the opposite directions, the liquid storage chamber 8a and the liquid storage chamber 8b repeatedly compress and expand. By virtue of the pumping through the viscous liquid, it circulates as described above. For this reason, the deterioration of the viscous fluid can be made uniform, the speed of performance reduction of the damper can be reduced, and the durability and the reliability of the damper can be improved.

[0015]

As described above, according to the first aspect of the present invention, the peak of vibration is reduced to two by the coil spring.
It can be divided, and the peak of the divided vibration can be suppressed to a low value by the shearing force due to the relative amplitude between the inertial ring and the housing. Moreover, with the above-described configuration, the inertia ring can be mounted in a stable state in the radial and axial directions of the housing. The reliability of the damper can be improved without causing any trouble.

According to the second aspect of the present invention, a narrow gap formed between the housing and both sides of the inertia ring and the outside in the radial direction, the liquid storage chamber, and the through hole formed in the inertia ring. The viscous fluid can be circulated over the gap, the deterioration of the viscous fluid can be made uniform, the speed of performance reduction of the damper can be reduced, and the durability and the reliability of the damper can be improved.

[Brief description of the drawings]

1 shows an example of an embodiment of the present invention, AA of FIG. 2;
Line section view

FIG. 2 is a front view showing a state where a lid is removed.

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a view corresponding to FIG. 3, showing another embodiment of the spring seat;

FIG. 5 is a diagram showing characteristics of the present invention.

FIG. 6 is a sectional view showing a part of a conventional example.

FIG. 7 is a sectional view taken along line CC of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Inertial ring 3 Bearing 4 Stator 5 Coil spring 6 Spring seat 8 Liquid reservoir

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Haruki Shimizu 3-105 Sugaya, Ageo-shi, Saitama Pref.

Claims (2)

[Claims] 1. A housing mounted on a rotating shaft that generates torsional vibrations, the housing having an annular shape along the circumferential direction of the rotating shaft, an inertial ring housed in the annular housing, and a viscous fluid sealed in the annular housing. In the viscous damper, the inertia ring is movable along the annular housing via a bearing, and is provided with a plurality of projections protruding from the inner periphery. The housing has the same interior as the projections of the inertia ring. A number of stators are provided, a metal coil spring is provided between the protrusion of the inertial ring and the stator, and a radially inner side of the inertial ring of the housing is a liquid reservoir for viscous fluid. And a viscous damper. 2. The inertial ring is housed in a housing with a narrow gap on both sides thereof and a radially outer side, and the gap and the liquid reservoir are communicated with each other through a through hole formed in the inertial ring. The viscous damper according to claim 1, wherein the viscous damper is provided.