JP4434396B2 - Center bearing support - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a center bearing support that elastically supports a center bearing that rotatably supports a propeller shaft of an automobile on the vehicle body side.
[0002]
[Prior art]
The center bearing support, for example, elastically supports a center bearing (ball bearing) mounted on the outer periphery of the axial middle portion of the propeller shaft of an automobile on the vehicle body side, thereby allowing the propeller shaft side and the vehicle body side during traveling to The vibration transmission between the two is reduced.
[0003]
2 and 3 show a center bearing support 100 having a conventional structure. That is, this type of center bearing support 100 elastically connects the outer sleeve 101 and the inner sleeve 102 disposed on the inner periphery thereof via an elastic body 103 made of an elastomer having a cross-sectional shape bent in the axial direction. The outer sleeve 101 is fitted to a bracket ring portion 202a of a bracket 202 attached to a vehicle body 200 via a bolt 201, and the inner sleeve 102 is an outer periphery of an intermediate portion in the axial direction of the propeller shaft 203. It is adapted to be fitted to the outer race 204a of the center bearing 204 mounted on the surface.
[0004]
[Problems to be solved by the invention]
The center bearing support 100 having the above-described conventional structure depends on the spring constant derived from the rigidity of the bracket arm portion 202b in the bracket 202, the weight of the bracket ring portion 202a in the bracket 202, the outer sleeve 101 of the center bearing support 100, and the elastic body 103. It has a determined natural frequency. For this reason, when the vibration accompanying the rotation of the propeller shaft 203 reaches a predetermined frequency, resonance in the direction of arrow V in FIG. 3 occurs, and the problem that noise and vibration reduction characteristics deteriorate is pointed out.
[0005]
The present invention has been made in view of the above problems, and a main technical problem thereof is to effectively prevent deterioration of characteristics due to resonance of a system having a bracket arm portion as a spring. .
[0006]
[Means for Solving the Problems]
The above technical problem can be effectively solved by the present invention.
That is, the center bearing support according to the present invention includes an outer sleeve fixed to the vehicle body via a bracket, an inner sleeve disposed on the inner peripheral side of the outer sleeve and fitted on the outer periphery of the bearing, and the outer sleeve An elastic body that elastically connects the inner sleeve, and a damper portion that includes a mass member and a spring portion that elastically connects the mass member to the outer sleeve side, and the damper portion is connected to the outer sleeve. And arranged in parallel with the elastic body and attached to the outer sleeve side by fitting. The damper portion is set so that its natural frequency is substantially the same as the natural frequency of a system including the bracket, the outer sleeve, and the elastic body, for example.
[0007]
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 shows an embodiment of a center bearing support 1 according to the present invention. That is, the center bearing support 1 includes an outer sleeve 11, an inner sleeve 12 disposed on the inner periphery of the outer sleeve 11, and an elastic body 13 that elastically connects the outer sleeve 11 and the inner sleeve 12. The damper portion 14 is attached to the outer sleeve 11. The outer sleeve 11 is fixed to the vehicle body side via the bracket 2, and the inner sleeve 12 is fitted to the center bearing 3 that rotatably supports the propeller shaft.
[0009]
Specifically, the outer sleeve 11 and the inner sleeve 12 are made of metal, and the outer sleeve 11 is fitted to the inner periphery of the bracket ring portion 22 of the bracket 2 whose both ends are fixed to the vehicle body (not shown). The inner sleeve 12 is fitted to the outer race 31 of the center bearing 3.
[0010]
The elastic body 13 is formed of an elastomer material such as rubber, and its outer peripheral end 13 a is integrally vulcanized and bonded to the inner peripheral surface of the outer sleeve 11, and the inner peripheral end. 13b is integrally vulcanized and bonded to the outer peripheral surface of the inner sleeve 12, and exhibits a cross-sectional shape bent in a substantially U shape so as to be folded back in the axial direction between the both end portions 13a and 13b.
[0011]
The damper portion 14 includes a metal sleeve 143, a metal annular mass member 141 disposed close to and facing the flange portion 143 a formed at one end of the sleeve 143 in the axial direction, and the flange portion 143a and a mass member and a spring portion 142 made of an elastomer vulcanized and bonded. The damper portion 14 has its natural frequency determined by the mass of the mass member 141 and the spring constant of the spring portion 142. A bracket arm portion (not shown) in the bracket 2 is used as a spring, and the bracket ring portion 22, the outer sleeve 11 and the elastic portion. It is set substantially the same as the natural frequency of the system having the body 13 as a mass.
[0012]
The damper part 14 has its natural frequency determined by the mass of the mass member 141 and the spring constant of the spring part 142, the spring constant of a bracket arm part ( not shown) in the bracket 2, the bracket ring part 22 in the bracket 2, The natural frequency determined by the weight of the outer sleeve 11 and the elastic body 13 of the center bearing support 1 is set substantially the same. The outer sleeve 11 has an outer diameter that is smaller than the inner diameter of the bracket ring portion 22 in the bracket 2, and the damper portion 14 has a sleeve 143 when the center bearing support 1 is attached to the bracket 2. Is mounted by fitting between the bracket ring portion 22 and the outer sleeve 11.
[0013]
The center bearing 3 basically has a known structure comprising an outer race 31 and an inner race 32 that are concentrically arranged with each other, and a large number of steel balls 33 that are rotatably held at equal intervals in the circumferential direction therebetween. It consists of a ball bearing, and the steel ball 33 is lubricated with grease. As described above, in the center bearing 3, the outer race 31 is press-fitted and fitted to the inner sleeve 12 with an appropriate tightening allowance, and a propeller shaft (not shown) is rotatably supported on the inner periphery of the inner race 32. Is.
[0014]
When the center bearing support 1 having the above configuration generates vibrations in the propeller shaft, for example, during running of an automobile, the center bearing support 1 is elastic with the relative eccentric motion between the inner sleeve 12 on the propeller shaft side and the outer sleeve 11 on the vehicle body side. The body 13 can bend and stretch repeatedly, and the vibration transmission to the vehicle body side can be effectively insulated.
[0015]
As described above, the bracket arm portion, the bracket ring portion 22, the outer sleeve 11 and the elastic body 13 of the center bearing support 1 in the bracket 2 include the spring constant of the bracket arm portion , the bracket ring portion 22, The outer sleeve 11 and the elastic body 13 are used as a mass. For this reason, when the vibration accompanying the rotation of the propeller shaft reaches a predetermined frequency in a relatively high frequency region, the system generates a vibration indicated by an arrow V in FIG. 1 due to resonance. It is effectively reduced by the damper portion 14 in the support 1.
[0016]
That is, since the damper section 14 has the same natural frequency as that of the system composed of the bracket arm section, the bracket ring section 22, the outer sleeve 11, and the elastic body 13, when vibration due to resonance occurs in the system, The damper portion 14 resonates with this, and the vibration direction of the mass member 141 is opposite to the direction of the input vibration V, and the vibration damping due to the internal friction of the spring portion 142 made of elastomer. Demonstrate the effect. For this reason, breakage of the bracket 2 due to resonance, generation of noise, and deterioration of vibration reduction characteristics of the center bearing support 1 can be prevented.
[0017]
[0018]
[0019]
[0020]
[0021]
[0022]
[0023]
Further, in this embodiment, a thick stepped portion is formed in the radial direction at the bonded end portion of the elastic body 13 on the inner sleeve 12 side, and the bonded end portion 13a with the inner peripheral surface of the outer sleeve 11 is also formed. It is formed thick so that excessive relative displacement between the outer sleeve 11 and the inner sleeve 12 is restricted when a large amplitude vibration is input between the vehicle body and the propeller shaft.
[0024]
[0025]
Further, the frequency of the vibration V due to resonance of the system including the bracket arm portion, the bracket ring portion 22, the outer sleeve 11, the elastic body 13, and the like varies depending on the shape, rigidity, weight, and the like of the bracket 2, for example. However, since the damper portion 14 is manufactured as a vulcanized molded product separate from the main body of the center pairing support 1 including the outer sleeve 11, the inner sleeve 12, and the elastic body 13, the specifications of the main body of the center bearing support 1, etc. By changing the mass of the mass member 141 in the damper portion 14 and the spring constant and damping of the spring portion 142 without changing the frequency, it is possible to easily cope with the difference in frequency of the vibration V. For this reason, it can be excellent in versatility.
[0026]
Further, as described above, when the center bearing support 1 is mounted, the damper portion 14 is loosely fitted between the outer sleeve 11 and the bracket in the step of fixing the outer sleeve 11 to the bracket ring portion 22. Since it is only necessary to fit the sleeve 143 between the opposed peripheral surfaces of the ring portion 22, it can be easily mounted.
[0027]
【The invention's effect】
As described above, according to the center bearing support of the present invention, since the outer sleeve is provided with the damper portion that exhibits the dynamic vibration absorption effect by resonance at a predetermined frequency, the resonance peak of the system using the bracket arm portion as a spring is provided. And the deterioration of the characteristics of the center bearing support due to resonance of the system can be effectively prevented. Further, by manufacturing the damper part as a separate body from the main body of the center bearing support, it is possible to cope with the difference in natural frequency (resonance frequency) of the system without impairing versatility.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a center bearing support according to the present invention by cutting along a plane passing through its axis .
FIG. 2 is a view of a state in which the center bearing support according to the related art is mounted as viewed from a direction parallel to the axis.
FIG. 3 is a side view showing a partial cross-section of the mounting state of the center bearing support according to the prior art as seen from a direction perpendicular to the axis.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Center bearing support 11 Outer sleeve 12 Inner sleeve 13 Elastic body 13a, 13b End part 14 Damper part 141 Mass member 142 Spring part 143 Sleeve 143a collar part
2 Bracket
22 Bracket ring part 3 Center bearing 31 Outer race 32 Inner race 33 Steel ball

Claims (1)

An outer sleeve (11) fixed to the vehicle body via a bracket (2);
An inner sleeve (12) disposed on the inner peripheral side of the outer sleeve (11) and fitted on the outer periphery of the bearing (3);
An elastic body (13) for elastically connecting the outer sleeve (11) and the inner sleeve (12);
A damper part (14) comprising a mass member (141) and a spring part (142) elastically connecting the mass member (141) to the outer sleeve (11) side;
The damper portion (14) is arranged in parallel to the elastic body (13) with respect to the outer sleeve (11), and is attached to the outer sleeve (11) side by fitting. Center bearing support.

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