JPH04339023A - Propeller shaft - Google Patents

Abstract

PURPOSE:To suppress vibration of a vehicle body by reducing a reaction on a supporting part of a center bearing resulting from a bending moment of a rubber coupling, without altering a division ratio of the 1st shaft to the 2nd one. CONSTITUTION:In a split type propeller shaft in which the 1st and 2nd shaft 12 and 14 are connected to each other by means of the 2nd joint 13 and a rubber coupling is provided for the 1st joint 11 at the end of the 1st shaft 12, a center bearing 16 is fitted closely onto the 2nd shaft 14 near the 2nd joint 13.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propeller shaft, and more particularly to a propeller shaft for transmitting driving force from a shaft transmission to a final reduction gear.

0002

[Prior Art] This type of propeller shaft is divided into two parts having a rubber coupling (also called a "flexible joint") and a center bearing, as described in, for example, Japanese Patent Application Laid-open No. 57-15126. There is a formula.

[0003] As schematically shown in FIG. 5, such a propeller shaft has a first joint 1, a first shaft 2, a second joint 3, a second shaft 4, and a third joint 5 that are continuously connected. , the rubber coupling provided as the first joint 1 is connected to the output shaft 6A side of the transmission 6 of the vehicle, and the third joint 5 is connected to the input shaft 7 of the final transmission 7.
The center bearing 8 connected to the A side and fitted onto the first shaft 2 is elastically supported on the vehicle body side by a center bearing support (not shown).

0004

By the way, the rubber coupling provided as the first joint 1 connects the yoke connected to the first shaft 2 side and the yoke connected to the output shaft 6A side of the transmission 6. They are connected via rubber. If a deflection angle exists between the respective rotational axes of the two yokes, the rubber coupling will rotate as if being twisted, and a bending moment will be generated.

However, in the above-mentioned conventional propeller shaft, when a bending moment M occurs in the first joint (rubber coupling) 1, a reaction force Fc1 of the formula 1 is generated in the center bearing support. Fc1
This caused the center bearing to vibrate, which was one of the causes of vibrations in the car body when the car was running at low speeds.

[0006]

[Math 1]

[0007] As a measure to prevent such vibrations, the first one is
It is conceivable to increase the length of the shaft 2 to reduce the reaction force Fc1.

However, when the first shaft 2 is lengthened, the eigenvalues of the bending and twisting of the propeller shaft change, which may worsen the muffled noise inside the car and differential noise during high-speed driving, and the second shaft 2.
Furthermore, there is a problem in that the angle at which the third joints 3 and 5 are attached to the vehicle changes, which worsens vibrations when the vehicle starts.

An object of the present invention is to reduce the reaction force of the supporting portion of the center bearing caused by the bending moment of the rubber coupling, and to reduce the vibration of the vehicle body without changing the division ratio of the first and second shafts. The objective is to provide a propeller shaft that can be suppressed.

0010

[Means for Solving the Problems] A propeller shaft of the present invention includes a first shaft having a first joint at one end, and a first shaft having a first joint at one end;
A propeller shaft having a third joint at one end and a second shaft connected to the other end by a second joint, and having a rubber coupling as the first joint connecting a pair of yokes via rubber, The vehicle is characterized in that a center bearing elastically supported by the vehicle body is fitted in a position near the second joint of the second shaft.

[0011]

[Operation] The propeller shaft of the present invention has the first and second
In a two-piece propeller shaft in which the shafts are connected by a second joint and a rubber coupling is provided at the end of the first shaft, a center bearing is provided near the second joint of the second shaft. The reaction force that vibrates the part that elastically supports the center bearing on the vehicle body, that is, the reaction force caused by the bending moment of the rubber coupling, can be reduced without changing the division ratio of the first and second axes. , suppresses vehicle body vibration.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

In FIG. 1, 11 is a first joint;
2 is a first shaft, 13 is a second joint, 14 is a second shaft, and 15 is a third joint, these are connected continuously, and a center bearing is located on the second shaft 14 near the second joint 13. A propeller shaft 17 is constructed by fitting the propeller shaft 16 so as to be relatively rotatable.

A rubber coupling is used as the first joint 11. The rubber coupling in this example has a shaft 11A that is serrated coupled to the output shaft 18A of the transmission 18 in FIG.
A collar 11B bolted to the 1A side and a first shaft 12
Three collars 11C bolted to the sides are arranged annularly and alternately in the same plane, and an elastic cord 11D is wound between the collars 11B and 11C adjacent to each other, and the collars 11B , 11C and the elastic cord 11D are surrounded by an elastic body 11E. Furthermore, the shaft 11A and the first shaft 12
A spherical bearing 11 provided on the former side is placed at the butting end.
At F, a centering mechanism is provided which swingably supports a centering shaft 11G provided on the latter side.

Further, as the second and third joints 13 and 15, Cardan joints are used in which a cross-shaped journal is connected between a pair of bifurcated yokes.

As shown in FIG. 2, the propeller shaft 17 configured in this manner has the first joint 1
1 is connected to the output shaft 18A of the transmission 18, the third joint 15 is connected to the input shaft 19A of the final reduction gear 19, and the center bearing 16 is elastically held in a fixed position on the vehicle body B by the center bearing support 20. By being supported, it is put into use and transmits driving force. In addition, in FIG. 2, 21 is an engine, which is mounted on the vehicle body B together with the transmission 21.

By the way, when the driving force is transmitted by the propeller shaft 17, there is a gap between the front and rear axes of the first joint 11, that is, the output shaft 18A of the transmission 18 and the first shaft 12.
If there is a deflection angle between the
A bending moment M is generated that is proportional to the bending rigidity and deflection angle of the rubber coupling. Then, due to the bending moment M, the center bearing support 2
0, a reaction force Fc2 of Equation 2 is generated.

[0018]

[Math 2]

FIG. 4 shows a comparison result between the reaction force Fc2 in the propeller shaft 17 of the present invention and the reaction force Fc1 in the conventional propeller shaft described above. In the same figure, A has L1 of 300mm, L2 of 700mm, and L
3 is 100mm, and similarly, B is 400mm, 600mm, 100mm, and C is 500mm.
, 500mm, 100mm, D is 600mm, 400m
m, 100mm, and E is 700mm, 300mm,
The length is 100 mm.

As can be seen from FIG. 4, when the length L1 of the first axis is shorter than the length L2 of the second axis, the reaction force Fc2 in the present invention is equal to the reaction force Fc in the conventional one.
becomes smaller than 1. Therefore, the vibration of the center bearing support 20 in the propeller shaft 17 of the present invention is reduced accordingly.

[0021] As the second and third joints 13 and 15, constant velocity joints such as Rebro joints and double offset joints may be used in addition to Cardan joints.In short, the first joint 11 is a rubber coupling. Good to have.

[0022]

As explained above, the propeller shaft of the present invention is a two-part propeller shaft in which the first and second shafts are connected by the second joint, and the first shaft has a rubber coupling at the end. Since the propeller shaft has a center bearing near the second joint of the second shaft, the part that elastically supports the center bearing on the vehicle body without changing the division ratio of the first and second shafts. By reducing the reaction force that excites the rubber coupling, that is, the reaction force caused by the bending moment of the rubber coupling, it is possible to suppress the vibration of the vehicle body.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a state in which the propeller shaft shown in FIG. 1 is mounted on a vehicle.

FIG. 3 is a power train diagram for explaining the action of the propeller shaft shown in FIG. 1;

FIG. 4 is an explanatory diagram comparing reaction forces generated in sensor bearing supports of the propeller shaft shown in FIG. 1 and the conventional propeller shaft.

FIG. 5 is a diagram of a power train for explaining the operation of a conventional propeller shaft.

[Explanation of symbols]

11 First joint (rubber coupling) 12
1st shaft 13 2nd joint 14 2nd shaft 15 3rd joint 16 Center bearing 20 Center bearing support

Claims (1)

[Claims] Claim 1: The other end of a first shaft having a first joint at one end and the other end of a second shaft having a third joint at one end are connected by a second joint, and the first joint is , in a propeller shaft equipped with a rubber coupling that connects a pair of yokes via rubber,
A propeller shaft characterized in that a center bearing elastically supported by a vehicle body is fitted in a position near the second joint of the second shaft.