Center bearing mounting device for propeller shaft

Abstract

The present invention provides a center bearing mounting device for a propeller shaft, which allows the height of a center bearing to be varied according to an axle force generated by the movement of a rear axle based on the speed of a vehicle, thereby minimizing a change in the relative tilt angle (θ) between the axis of rotation of an engine and a transmission and the axis of rotation of the rear axle, and thus simultaneously improving shuddering during initial startup and the vibration of the vehicle body during driving.

Description

Center bearing mounting device for propeller shaft

[0001] The present invention relates to a center bearing mounting device for a propeller shaft, and more particularly, to a center bearing mounting device for a propeller shaft that can simultaneously improve shudder vibration at the time of initial start and body vibration during driving by minimizing changes in the relative angle (θ) between the rotational center axes of an engine and a transmission and the rotational center axes of a rear axle by varying the height of the center bearing according to the axial force generated by the behavior of a rear axle according to vehicle speed.

[0002] Typically, rear-wheel drive 2WD vehicles, unlike 4WD vehicles, are configured with a two-section propeller shaft due to the special nature of rear-wheel drive, and are installed on one side of the exhaust system in the longitudinal direction of the vehicle body as a power transmission shaft that connects the engine's driving force to the rear axle.

[0003] The power transmission system of this rear-wheel drive 2WD vehicle, as illustrated in Fig. 1, transmits driving power by connecting the engine (101), the transmission (103), and the rear axle (105) with two propeller shafts (107, 109).

[0004] The above two propeller shafts (107, 109) are connected by a universal joint (UT) as shown in FIG. 2 so as to compensate for the relative angle (θ) of the rotational center axes (S1, S2) of the engine (101), the transmission (103), and the rear axle (105), and a center bearing (111) is installed on the front propeller shaft (107) and supported on a frame cross member (115) via a mounting device (113).

[0005] The above center bearing mounting device (113) is composed of a mounter (121) that fixes the outer surface of the center bearing, support brackets (123) formed on both sides of the frame cross member (115), bolts (125) for fastening both ends of the mounter (121) to the upper ends of the support brackets on both sides, and a rubber bush (127) interposed between the mounter (121) and the support bracket and between the bolts to dampen vibration.

[0006] Here, the above-mentioned universal joint (UT) has the function of transmitting rotational force even when the centers of the rotation axes do not match, but torque fluctuation occurs in proportion to the relative angle of the universal joint (UT), and the resulting imbalance of driving force adversely affects the driving performance and ride comfort of the vehicle. Therefore, in order to set the relative angle of the universal joint (UT) as small as possible, the relative angle (θ) of the rotational center axis (S1) of the engine (101) and transmission (103) and the rotational center axis (S2) of the rear axle (105) must be kept as small as possible.

[0007] In particular, in 2WD vehicles, shock vibration (hereinafter referred to as shudder vibration) is a problem due to insufficient vibration damping of the propeller shaft at the time of departure, and this is caused by the relative cutting angle (θ) of the front propeller shaft (107) and the rear propeller shaft (109), and the closer the relative cutting angle (θ) is to 0, the better the shudder vibration is at the time of departure.

[0008] However, when tuning the relative cutting angle (θ) to be close to 0 to improve the shudder vibration at the start, it causes a vibration problem during driving, and this is because the relative cutting angle (θ) changes due to the behavior of the rear axle (105) during driving (the rear axle moves forward due to engine behavior during driving), causing body vibration due to the eccentricity of the propeller shaft. (Normally, body vibration occurs at a speed of 70 to 90 MPH depending on the relative cutting angle.)

[0009] Accordingly, in the case of the conventional center bearing mounting device (113), vehicle development is carried out by accepting the body vibration caused by changing the relative angle (θ) in order to improve the shudder vibration at the time of departure, or the relative angle (θ) is tuned within an appropriate range in consideration of the two problems.

[0010] The present invention has been made to solve the above-mentioned conventional problems, and the purpose of the present invention is to provide a center bearing mounting device for a propeller shaft that can simultaneously improve shudder vibration at the time of initial start and body vibration during driving by minimizing the change in the relative angle (θ) between the rotational center axes of the engine and transmission and the rotational center axes of the rear axle by varying the height of the center bearing according to the axial force generated by the behavior of the rear axle according to the vehicle speed.

[0011] In order to achieve the above object, the present invention provides a center bearing mounting device for a propeller shaft, which supports a center bearing for rotatably supporting a front propeller shaft connected to a front transmission output shaft and a rear propeller shaft connected to a rear axle pinion shaft, on a vehicle body, the center bearing mounting device for a propeller shaft, the center bearing mounting device comprising: a support bracket formed on both sides of a frame cross member of the vehicle body; an inclined guider formed on the upper end of the support bracket in the front-rear direction of the vehicle body, the inclined guider forming an inclined surface inclined upward from the front to the rear of the vehicle body, and forming a slot of a predetermined section on the inclined surface; a mounter which is fixed to the outer circumference of the center bearing, has a fastening bracket integrally formed on both ends, and integrally forms a slot guide bar which is installed through a slot of the fastening bracket on one side of the lower surface of the fastening bracket and guides along the inclined surface; a lower rubber interposed on both sides between the support bracket and the fastening bracket of the mounter; an upper rubber formed on an upper surface of the fastening bracket of the mounter; It is characterized by including a fastening bushing formed on the upper surface of the upper rubber; and a fastening bolt that penetrates both sides of the fastening bushing, the upper rubber, the fastening bracket, and the lower rubber and is mounted on the support bracket.

[0012] The above-mentioned double-sided fastening bolts are characterized in that they are fastened with a nut at their end to the lower surface of the support bracket, and a support spring is interposed between the lower surface of the support bracket and the nut.

[0013] According to the center bearing mounting device for a propeller shaft according to the present invention, by varying the height of the center bearing according to the axial force generated by the behavior of the rear axle according to the vehicle speed, the change in the relative angle (θ) between the rotational center axes of the engine and transmission and the rotational center axes of the rear axle is minimized, thereby achieving the effect of simultaneously improving the shudder vibration at the time of initial start and the body vibration during driving.

[0014] Figure 1 is a schematic diagram of a typical rear-wheel drive power transmission system.

[0015] Figure 2 is a perspective view of a center bearing mounting portion for a typical propeller shaft.

[0016] Figure 3 is a side cross-sectional configuration diagram of a center bearing mounting device for a propeller shaft according to an embodiment of the present invention.

[0017] Figure 4 is an operating state diagram of a center bearing mounting device for a propeller shaft according to an embodiment of the present invention.

[0018] Hereinafter, a preferred embodiment of the present invention will be described in more detail with reference to the attached drawings.

[0019] FIG. 3 is a side cross-sectional diagram of a center bearing mounting device for a propeller shaft according to an embodiment of the present invention, and FIG. 4 is an operating state diagram of a center bearing mounting device for a propeller shaft according to an embodiment of the present invention.

[0020] A power transmission system to which a mounting device according to an embodiment of the present invention is applied is configured such that a center bearing rotatably supports a front propeller shaft (107; see FIG. 1) connected to an output shaft of a front transmission (103; see FIG. 1) and a rear propeller shaft (109; see FIG. 1) connected to a pinion shaft of a rear axle (105; see FIG. 1), and the power of an engine (101; see FIG. 1) is transmitted to the rear axle (105; see FIG. 1) by shifting the power through a transmission (103; see FIG. 1).

[0021] That is, the mounting device according to the embodiment of the present invention, as shown in FIG. 3, is for supporting a center bearing (1) to a vehicle body, and its configuration includes support brackets (3) formed on each side of a frame cross member (not shown) of the vehicle body.

[0022] At the top of the above support bracket (3), an inclined guider (5) is formed in the front-rear direction of the vehicle body. The inclined guider (5) forms an inclined surface (7) that slopes upward from the front of the vehicle body to the rear, and a slot (9) of a certain section is formed on the inclined surface (7).

[0023] And, a mounter (11) is fixed to the outer surface of the center bearing (1), and the mounter (11) is integrally formed with a fastening bracket (13) at both ends thereof, and a slot guide bar (15)) that is installed through the slot (9) of the inclined guider (5) and guided along the inner side of the inclined surface (7) is integrally formed on one side of the lower surface of the fastening bracket (13).

[0024] A lower rubber (17) is interposed on both sides between the support bracket (3) and the fastening bracket (13) of the mounter (11), an upper rubber (19) is interposed on the upper surface of the fastening bracket (13) of the mounter (11), and a fastening bush (21) is arranged on the upper surface of the upper rubber (19) and fastened with a fastening bolt (23).

[0025] That is, the above-mentioned fastening bolt (23) penetrates both sides of the above-mentioned fastening bush (21), upper rubber (19), fastening bracket (13) and lower rubber (17) and is mounted on the above-mentioned support bracket (3).

[0026] Here, the above-mentioned double-sided fastening bolts (23) are fastened with a nut (25) at their ends to the lower surface of the support bracket (3), and a support spring (27) is interposed between the lower surface of the support bracket (3) and the nut (25).

[0027] And it is preferable that the upper rubber (19) is formed as an integral body, and it is preferable that the lower rubber (17) is mounted on both left and right sides in a cylindrical shape.

[0028] Accordingly, the center bearing mounting device for a propeller shaft having the configuration as described above is tuned to have a relative cutting angle (θ) close to 0 in order to improve shudder vibration at the time of departure, as shown in FIG. 3, and when driving, as shown in FIG. 4, when the mounter (11) supporting the center bearing (1) moves forward according to the axial force generated by the behavior of the rear axle (during driving, the rear axle moves forward due to engine behavior), a slot guide bar (15) integrally formed at the lower part of the fastening bracket (13) of the mounter (11) is installed through the slot (9) of the inclined guider (5) and guided along the inner side of the inclined surface (7) to lower the entire mounter (11) and lower its height (h1-->h2), and accordingly, the relative cutting angle (θ) is maintained without significant change from the initially set relative cutting angle (θ).

[0029] As a result, body vibration is prevented from occurring due to eccentricity between the front propeller shaft (31) and the rear propeller shaft (not shown).

[0030] That is, the axial force generated by the rear axle is proportional to the vehicle speed (the axial force increases during acceleration and decreases during deceleration), and as the vehicle speed increases, the axial force generated forward from the rear axle is used to control the height of the mounter (11) supporting the center bearing (1), thereby enabling the relative cutting angle (θ) to always be kept constant, as described above.

[0031] At this time, the change in height of the mounter (11) is absorbed as the lower rubber (17) is deformed, and the change in length of the fastening bolt (23) resulting from this is absorbed by the support spring (27).

[0032] That is, when a mounting device according to an embodiment of the present invention is applied, when the vehicle starts, the initial set relative angle (θ) is maintained to control the occurrence of shudder, and the angle can be variably controlled during acceleration and deceleration, so that the occurrence of body vibration can be suppressed during driving.

[0033] According to the present invention, by varying the height of the center bearing according to the axial force generated by the behavior of the rear axle according to the vehicle speed, the change in the relative angle (θ) between the rotational center axes of the engine and transmission and the rotational center axes of the rear axle is minimized, thereby simultaneously improving the shudder vibration at the time of initial start and improving the body vibration during driving. The present invention is a technology that can be widely used in the vehicle and parts industries to realize its practical and economic value.

Claims

1. In a center bearing mounting device for a propeller shaft that supports a center bearing for rotating a front propeller shaft connected to a front transmission output shaft and a rear propeller shaft connected to a rear axle pinion shaft, Support brackets configured on both sides of the frame cross members of the body; An inclined guide configured in the front-rear direction of the vehicle body at the top of the above support bracket, forming an inclined surface that slopes upward from the front to the rear of the vehicle body, and forming a slot of a certain section on the inclined surface; A mounter which is fixed to the outer surface of the center bearing, has a fastening bracket formed integrally at both ends, and has a slot guide bar formed integrally at one side of the lower surface of the fastening bracket through the slot of the inclined guide and guided along the inclined surface; Lower rubber interposed on both sides between the above support bracket and the fastening bracket of the mounter; Upper rubber configured on the upper surface of the fastening bracket of the above mounter; A fastening bushing formed on the upper surface of the upper rubber; A center bearing mounting device for a propeller shaft, characterized in that it includes a fastening bolt that penetrates both sides of the fastening bushing and the upper rubber, the fastening bracket, and the lower rubber, respectively, and is mounted on the support bracket.

2. In paragraph 1, A center bearing mounting device for a propeller shaft, characterized in that the above-mentioned double-sided fastening bolts are fastened with nuts at their ends to the lower surface of the above-mentioned support bracket, and a support spring is interposed between the lower surface of the above-mentioned support bracket and the nuts.

3. In paragraph 1, A center bearing mounting device for a propeller shaft, characterized in that the upper rubber is formed as an integral piece.

4. In paragraph 1, A center bearing mounting device for a propeller shaft, characterized in that the lower rubber is mounted on each of the left and right sides in a cylindrical shape.

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