KR100448821B1 - center bearing assembly for propeller shaft of vehicles - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a center bearing for a propulsion shaft of an automobile. The present invention relates to a center bearing for a propulsion shaft of an automobile. It is possible to simultaneously control the vibration of low frequency large displacement occurring in the moving area such as acceleration and braking, so that the vibration damping can be maximized in the entire operating area of the engine and the endurance life of the center bearing can be maximized. There is this.

In order to achieve the above object, the present invention, the rubber member 22b fixed to the inner circumferential surface of the bracket 22a coupled to the support member 20 fixed to the vehicle body, and fixed to the inner circumferential surface of the rubber member 22b. In the center bearing 22 which comprises the outer ring 22d fixed to the inner peripheral surface of the retainer 22c used, and the inner ring 22e which can be rotated relative to the inner peripheral surface of this outer ring 22d via the ball 22f, The rubber member 22b forms a closed space through a separator plate 24 for hermetically dividing the internal space up and down, and a diaphragm 26 fixedly secured to the separator plate 24 and an upper portion thereof. It is characterized in that the fluid damping mechanism is provided with an upper liquid chamber 28 and a lower liquid chamber 30 that forms a closed space between the rubber member 22b at the lower portion of the separating plate 24.

Description

Center bearing assembly for propeller shaft of vehicles

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a center bearing for a propulsion shaft of a motor vehicle. More particularly, a fluid damping mechanism is introduced into a center bearing rotatably supporting a propulsion shaft to insulate against vibration of high frequency low displacement and vibration of low frequency large displacement while driving. The present invention relates to a center bearing for a propulsion shaft of a motor vehicle capable of simultaneously satisfying the control of

In general, the propeller shaft of a car is generated from an engine to transfer power through a transmission to a wheel hub, which is formed between the output shaft of the front gearbox and the differential wheel of the rear wheel. They are connected by two constant velocity joints, and these propulsion shafts are usually rotated at high speed under constant torque of the engine, so they are easy to cause torsional vibrations, and the shafts are not bent or the geometric center and the center of mass do not coincide. If not, it can cause bending vibrations called wheeling.

That is, the propulsion shaft is provided in a so-called front engine rear wheel drive car (FR) of the front engine driving the rear wheel drive is performed in the rear rear wheel while the engine is mounted in the engine compartment, the front of the vehicle body.

As shown in FIGS. 1 and 2, the conventional propulsion shafts include a front shaft member 12 directly connected to the output shaft of the transmission 10, and a shaft joint member on the front shaft member 12. 14 is connected to the rear wheel differential gear box 18 and the rear shaft member 16, which is also connected via the shaft coupling member (14).

The center bearing 22 is fixed to the front shaft member 12 adjacent to the shaft joint member 14 via the support member 20 with the vehicle body. The propulsion shaft attenuates torsional or bending vibrations generated during transmission of power from the transmission 10 to the differential gearbox 18.

In addition, as shown in FIG. 3, the center bearing 22 is a portion adjacent to the rear end of the shaft joint member 14 which pivots between the front shaft member 12 and the rear shaft member 16. In the outer side of the rear shaft member 16 is installed, the center bearing 22 is enlarged in Figure 4 as shown in detail, relative between the rear shaft member 16 and the support member 20 It is configured to promote rotation.

That is, the center bearing 22 is a bracket 22a fixed on the support member 20, a rubber member 22b fixedly vulcanized and fixed to an inner circumferential surface of the bracket 22a, and the rubber member 22b. Retainer 22c fixed to the inner circumferential surface of the outer ring, outer ring 22d fixed to the inner circumferential surface of the retainer 22c, and the inner side of the outer ring 22d can be rotated relative to each other via the ball 22f. It consists of an inner ring (22e) is in contact with the outer peripheral surface of the shaft member 16 is supported.

In addition, the rubber member 22b has a hollow cross section between the bracket 22a and the retainer 22c, and a support ring 22g is installed inside the rubber member 22b, so that the bracket It is supposed to reinforce the bearing force with 22a.

On the other hand, the physical properties of the rubber used as the material of the rubber member 22b in the center bearing 22 constituted as described above are vibrated when high frequency low displacement vibration is generated, such as when the engine is idle or running at constant speed. In order to control the vibration in case of low-frequency large displacement related to riding comfort, such as the demand of low hardness and soft material for the insulation of the vehicle and the rapid start, braking and shifting of the vehicle or the vehicle. Given the opposite conditions that require a high hardness rigid material.

Therefore, in the actual vehicle, since the hardness of the rubber member 22b can only be determined at the level that compromises the NVH performance and the riding comfort, a satisfactory result can be obtained in the insulation of vibration.

In addition, since the engine has a wide frequency range from 0 to 6000 RPM until the engine is started and the high-speed driving, when the vibration occurs in the RPM band matching the natural frequency of the propulsion shaft, the vibration of the propulsion shaft is concentrated. There is a disadvantage that the durability of the center bearing 22 is weak.

Accordingly, the present invention has been made in view of the above, and the fluid damping mechanism is introduced into the center bearing to insulate against the vibration of high frequency low displacement generated in a moving region such as when the engine is idle or running at constant speed, and the engine It is possible to simultaneously control the vibration of low frequency large displacement occurring in the moving area such as rapid acceleration or braking, so that the vibration damping is not only effective in the entire operating area of the engine but also the durability of the center bearing is maximized. The purpose is to provide a center bearing for the propulsion shaft of the motor.

The present invention for achieving the above object, the bracket coupled to the support member fixed to the vehicle body, the rubber member fixed to the inner peripheral surface of the bracket, the retainer fixed to the inner peripheral surface of the rubber member, fixed to the inner peripheral surface of the retainer A center bearing comprising an outer ring, which is capable of rotating relative to the inner circumferential surface of the outer ring via a ball, and an inner ring that is adhered to and supported on the outer circumferential surface of the propulsion shaft, wherein the rubber member divides the inner space up and down in an airtight manner. And an upper liquid chamber for forming a closed space through the separator and a diaphragm fixedly secured to the upper portion thereof, and a lower liquid chamber for forming a closed space between the rubber member and the lower portion of the separating plate. It is characterized in that the mechanism is installed.

1 is a side view showing an installation state of a conventional vehicle propulsion shaft.

FIG. 2 is a schematic perspective view of the propulsion shaft shown in FIG. 1. FIG.

3 is a half sectional view showing the propulsion shaft shown in FIG.

4 is an enlarged half sectional view showing the center bearing shown in FIG.

5 is an enlarged half sectional view showing a center bearing according to the present invention;

<Description of Symbols for Main Parts of Drawings>

10-transmission 12-front shaft member

14-axis joint member 16-rear shaft member

18-differential gearbox 20-support member

22-center bearing 22a-bracket

22b rubber member 22c retainer

22d-outer ring 22e-inner ring

24-separator 26-diaphragm

28-Upper chamber 30-Lower chamber

32-displacement separator 34-circular passage

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is an enlarged half sectional view showing a center bearing according to the present invention. For the detailed description of the present invention, the same reference numerals will be given to the same reference numerals as in FIG. The configuration of the propulsion shaft in which the center bearings are installed will be described with reference to FIGS. 1 to 3, respectively.

As shown in the drawing, the propulsion shaft installed for transmitting the driving force between the transmission 10 and the rear wheel side differential gearbox 18 of the automobile is fixedly rotatable with respect to the vehicle body so as to be generated during the transmission of the driving force. Regarding the center bearing 22 to damp the torsional vibration or bending vibration of the propulsion shaft, the center bearing 22 is rotatably installed on the vehicle body via the support member 20.

That is, the center bearing 22 is a bracket 22a fixed on the support member 20, a rubber member 22b fixedly vulcanized and fixed to an inner circumferential surface of the bracket 22a, and the rubber member 22b. Retainer 22c fixed to the inner circumferential surface of the outer ring, outer ring 22d fixed to the inner circumferential surface of the retainer 22c, and the inner side of the outer ring 22d can be rotated relative to each other via the ball 22f. It consists of an inner ring (22e) is in contact with the outer peripheral surface of the shaft member 16 is supported.

In addition, a fluid damping mechanism is built in the rubber member 22b, and the fluid damping mechanism is installed in the transverse direction in an airtight manner in the rubber member 22b to divide the internal space up and down ( a separator 24, an upper liquid chamber 28 formed as a closed space therebetween via a separator plate 24 and a diaphragm 26 hermetically fixed to an upper portion thereof, and the separator plate 24. The lower liquid chamber 30 formed as a closed space between the rubber member 22b at the lower part of the structure is provided.

Here, the lower liquid chamber 30 is composed of a lower space between the rubber member 22b and the separator plate 24, which corresponds to the liquid injection chamber, and a predetermined amount of fluid is sealed therein, and through the liquid injection chamber. Through the lower expansion stiffness delivered, the separator 24 receives dynamic load from the fluid.

In addition, the upper liquid chamber 28 is composed of an upper space between the separator plate 24 and the diaphragm 26, and corresponds to an auxiliary liquid chamber, and has a function of storing fluid flowing from the lower liquid chamber 30. It will have some upper expansion stiffness via the diaphragm 26.

On the other hand, the separation plate 24 is provided with a fine free moving gap so that the fluid enclosed therein can be flowed between the upper liquid chamber 28 and the lower liquid chamber 30 at the time of vibration of the high frequency low displacement of the engine to its central portion. Micro-displacement vibration damping means comprising a displacement decoupler 32 capable of shaking movement over a predetermined displacement in the direction, and fluid in the upper liquid chamber 28 flows into the lower liquid chamber 30 during vibration of the low frequency large displacement of the engine. Large displacement vibration damping means each comprising a circular track 34 of a predetermined diameter, which is a kind of orifice, is provided to obtain a damping force by friction when flowing.

Meanwhile, the rubber member 22b has a hollow cross section between the bracket 22a and the retainer 22c, and a support ring 22g is installed inside the rubber member 22b. It is supposed to reinforce the bearing force with 22a.

Accordingly, the fluid damping mechanism of the center bearing 22 is more fluid than the annular passage 34 when low displacement vibration in the high frequency region or the resonant region is generated and transmitted from the propulsion shaft, such as when the engine is idle or running at constant speed. Since the flow of fluid occurs between the lower liquid chamber 30 and the upper liquid chamber 28 through the displacement separator 32 inside the separator 24 having a small flow resistance, the low rigidity coefficient and the damping coefficient As a result, the insulation characteristic against the vibration of the high frequency low displacement is improved.

On the contrary, when the large displacement vibration of the low frequency region is generated and transmitted from the propulsion shaft, such as during rapid start to rapid braking, the free moving gap of the displacement separator 32 is closed. The flow of fluid between the lower liquid chamber 30 and the upper liquid chamber 28 takes place through the annular passage 34, so that the center bearing 22 through the flow resistance received while the fluid flows through the annular passage 34. As the damping force of) increases, it has good characteristics in controlling the vibration of the low frequency large displacement of the propulsion shaft.

As described above, according to the center bearing for a propulsion shaft of an automobile according to the present invention, when the fluid damping mechanism is provided in the center bearing 22, the control against the vibration of the high frequency low displacement and the vibration of the low frequency large displacement At the same time, since the vibration of the propulsion shaft is effectively attenuated during large displacement vibration, it is possible to improve the riding comfort by eliminating shanks or jerks due to rapid torque changes in the drive system. Vibration can be effectively controlled to extend the endurance life of components, resulting in economic benefits such as maintenance costs.

Claims (2)

A bracket 22a coupled to the support member 20 fixed to the vehicle body, a rubber member 22b fixed to the inner circumferential surface of the bracket 22a, and a retainer 22c fixed to the inner circumferential surface of the rubber member 22b. The outer ring 22d fixed to the inner circumferential surface of the retainer 22c and the inner ring 22e supported on the outer circumferential surface of the propulsion shaft can be rotated relative to the inner circumferential surface of the outer ring 22d via the ball 22f. In the center bearing 22 to include, The rubber member 22b forms a closed space through a separator plate 24 for hermetically dividing the internal space up and down, and a diaphragm 26 fixedly secured to the separator plate 24 and an upper portion thereof. Propulsion shaft center of a vehicle, characterized in that the fluid damping mechanism is provided with an upper liquid chamber 28 and a lower liquid chamber 30 forming a closed space between the rubber member 22b at the lower part of the separating plate 24. bearing. The method of claim 1, The fluid damping mechanism is provided in a vertical direction with a minute free moving gap in the separation plate 24 so that the fluid enclosed therein can flow between the upper liquid chamber 28 and the lower liquid chamber 30 during the vibration of the high frequency low displacement of the engine. Microdisplacement vibration damping means comprising a displacement separator 32 installed and capable of shaking movement over a predetermined displacement, and the fluid of the upper liquid chamber 28 flows to the lower liquid chamber 30 during the vibration of the low frequency large displacement of the engine. Propulsion shaft center bearing for a vehicle, characterized in that each provided with a displacement vibration damping means consisting of an annular passageway (34) formed on the separating plate (24) to obtain a damping force due to friction.