JPH0544660U - Vehicle Propeller Shaft - Google Patents

Abstract

(57) [Summary] [Purpose] Only the first joint has a rubber coupling 3
Provided is a split-type vehicle propeller shaft capable of suppressing vibration due to a rubber coupling. [Structure] 3 in which the first joint 34 is a rubber coupling
In the split vehicle propeller shaft 30, the second shaft 32
The first center bearing support 48 and the second center bearing support 49 are provided near the second joint 35 and near the third joint 36 of the third shaft 33 to elastically support the vehicle body.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vehicle propeller shaft, and more particularly to a three-part vehicle propeller shaft in which a first shaft and a transmission-side output shaft are connected by a rubber coupling.

[0002]

[Prior Art]

 An example of a conventional vehicle propeller shaft of this type is shown in FIGS. 5 and 6. In these figures, 30 is a propeller shaft for a vehicle divided into three parts, 31 is the first shaft, 32 is the second shaft, 33 is the third shaft, and 34 is the first shaft 31 and FIG. It is a first joint that connects the output shaft 21 of the transmission 20 shown, and a rubber coupling is used for the first joint 34. Reference numerals 35 and 36 respectively denote a second joint connecting the first shaft 31 and the second shaft 32 and a third joint connecting the second shaft 32 and the third shaft 33. It is a fourth joint that connects the third shaft 33 to the input shaft 41 of the final reduction gear unit 40 shown in FIG. 6, and the second joint 35, the third joint 36, and the fourth joint 37 are all in this case. Cardan type constant velocity joints are used.

Reference numeral 38 is a first center bearing support that elastically supports the first shaft 31 on the vehicle body side, 39 is a second center bearing support that also supports the second shaft 32, and in FIG. Indicates the engine, and B indicates the elastic support of the drive system to the vehicle body side.

[0004]

[Problems to be solved by the device]

 However, in the above-mentioned conventional vehicle propeller shaft, when the propeller shaft 30 is mounted on the vehicle body and the vehicle travels in a state where a deflection angle exists between the output shaft 21 of the transmission 20 and the first shaft 31, The first joint (rubber coupling) 34 connecting the shaft 21 and the first shaft 31 is rotated while being twisted due to the vibration, and the deflection angle and the bending rigidity of the rubber coupling 34 itself. Accordingly, a bending moment M is generated at the rubber coupling 34 as shown in FIG. On the other hand, since the center bearing supports 38 and 39 are elastically supported by the vehicle body as indicated by B in FIG. 6, the reaction force F due to the bending moment M is generated. ₁ 'And F₂ ′ Was to excite these, which was one of the causes of the vibration of the car body. Particularly, since the natural frequency of the insulator provided in the portion supporting the center bearing supports 38 and 39 on the vehicle body is around 15 Hz (900 rpm), the vehicle speed at which the natural frequency of the center bearing support and the insulator resonates. The vehicle body vibration as described above particularly occurs at a low speed (30 km / h).

[0007] Therefore, as a countermeasure against the above-mentioned vibration, it is conceivable to lengthen the first shaft 31 to reduce the reaction forces F ₁ ′ and F ₂ ′ that vibrate the center bearing support. When 31 is lengthened, the eigenvalues related to bending and twisting of the propeller shaft 30 itself change, which causes problems such as muffled noise in the vehicle during high speed running and worsening noise of the differential gear. Since the vehicle mounting angles of the second joint 35, the third joint 36, and the fourth joint 37 may change, there is a risk that vibration during oscillation may be increased.

An object of the present invention is to suppress the vibration caused by a rubber coupling in a three-part propeller shaft having a similar joint arrangement in order to solve the above-mentioned conventional problems. It is to provide a propeller shaft for a vehicle that can be used.

[0007]

[Means for Solving the Problems]

 In order to achieve such an object, the present invention provides a first shaft connected to a transmission side via a first joint, a second shaft connected to the first shaft via a second joint, and A third shaft connected to the second shaft via the third joint and to the final reduction gear side via the fourth joint, and a rubber coupling is used for the first joint; A three-split type vehicle propeller shaft in which hook joints or constant velocity joints other than rubber couplings are used for the second, third and fourth joints, respectively, in the vicinity of the second joint of the second shaft and the third shaft. A center bearing support that is elastically supported is provided near the third joint.

[0008]

[Action]

 When a rubber coupling is used for the first joint that connects the transmission side and the first shaft to reduce the torsional vibration, if a deflection angle exists at the first joint, it occurs here. Since the center bearing support is vibrated by its reaction force due to the bending moment, it is desirable to provide the center bearing support as far as possible from the first joint and elastically support it. Therefore, in the present invention, the reaction force is reduced by supporting the second shaft and the third shaft by the center bearing support instead of supporting the first shaft and the second shaft by the center bearing support. I did it.

[0009]

【Example】

 Embodiments of the present invention will be specifically described below with reference to the drawings.

1 and 2 show an embodiment of the present invention. Also in this embodiment, the propeller shaft 30 comprises three split shafts of a first shaft 31, a second shaft 32 and a third shaft 33, and a rubber coupling is used for the first joint 34 thereof. Further, it is no different that cardan joints are respectively used for the second joint 35, the third joint 36, and the fourth joint 37 of the input shaft 41 and the third shaft 33 of the final reduction gear device 40. However, the first center bearing support 48 is provided in the vicinity of the second joint 35 of the second shaft 32, and the second center bearing support 49 is provided in the vicinity of the third joint 36 of the third shaft 33. Is elastically supported (B).

In the vehicle propeller 30 configured as above, the vehicle propeller 30 is mounted on the vehicle body with the deflection angle being present at the first joint 34 between the output shaft 21 and the first shaft 31 on the transmission 20 side. In this case, the bending moment M 1 is generated in the first joint 34 as described in the conventional example. Then, such a bending reaction force F ₁ and F ₂ to the first center bearing support 48 and the second center bearing support 49 as shown in FIG. 3 is generated by the moment M, these reaction forces F ₁ and F ₂ The center bearing supports 48 and 49 are vibrated at a cycle corresponding to the rotation speed of the propeller shaft 30.

A comparison of the moment M and the reaction forces F ₁ and F ₂ between the arrangement of the center bearing supports 48 and 49 according to the present embodiment and the arrangement of the center bearing supports 38 and 39 according to the conventional example will be described below with reference to FIGS. 3 and 3. 7 will be described.

In these drawings, the length of the first shaft 31 is L1, the length of the second shaft 32 is L2, the length of the third shaft 33 is L3, and the second joint of the first bearing support in each of them. The distance from 35 is L4, and the distance from the third joint 36 of the second bearing support is L5. Further, in order to derive the reaction forces F ₁ and F ₂ in FIG. 3, when the reaction force Fa generated in the second joint 35 by the moment M and the reaction force Fb generated in the third joint 36 are set,

[0014]

[Equation 1]

From equation (1)

[0016]

[Equation 2]

Substituting equation (1) into this,

[0018]

[Equation 3]

In addition,

[0020]

[Equation 4]

On the other hand,

[0022]

[Equation 5]

Substituting equation (4) into this,

[0024]

[Equation 6]

On the other hand, in FIG.

[0026]

[Equation 7]

[0027]

F ₂ ′ = 0 (8) Therefore, in the comparison of the reaction force between the propeller shaft according to the present invention and that according to the conventional example shown in FIG. 4, the elements L1 to L5 of each length are changed variously. Examples of combinations A to E will be described. As shown in (B) of this figure, in the case of A and B in which the length L1 of the first shaft 31 is shorter than the length L2 of the second shaft 32, the first center bearing is obviously It can be seen that F ₁ as the exciting force generated in the support is lower than that of the conventional F ₁ ′. In these cases, although the exciting force F ₂ generated in the second center bearing support is slightly generated, the reaction force (excitation force) F ₁ or F ₁ ′ generated in the first center bearing support is generated. It's small enough compared to that it doesn't matter.

In the above-mentioned embodiments, the hook joints are used for the second, third and fourth joints, but the joints are not limited to the hook joints, and may be, for example, a revolving joint or a double joint. Similar effects can be obtained with other constant velocity joints such as offset joints.

[0029]

[Effect of the device]

 As described above, according to the present invention, a rubber coupling is used for the first joint, and hook joints or constant velocity joints other than the rubber coupling are used for the second, third, and fourth joints, respectively. In the three-split type vehicle propeller shaft, the elastically supported center bearing support is provided in the vicinity of the second joint of the second shaft and in the vicinity of the third joint of the third shaft. It is possible to reduce the reaction force that vibrates the vehicle body via the center bearing support due to the above, and to suppress vibration that tends to occur in the vehicle body especially at low speed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of the present invention.

FIG. 2 is a configuration diagram schematically showing the embodiment shown in FIG. 1 in a connected state with devices before and after the embodiment.

FIG. 3 is an explanatory view of the operation of the power transmission mechanism according to the embodiment shown in FIG.

FIG. 4 is an explanatory diagram showing a comparison (A) relating to an exciting force between the present invention and a conventional example in an embodiment using a combination (B) of different shaft system dimensions.

FIG. 5 is a configuration diagram of a conventional example.

FIG. 6 is a configuration diagram schematically showing the conventional example shown in FIG. 5 in a connected state with the devices before and after the conventional example.

FIG. 7 is an explanatory view of the operation of the power transmission mechanism of the conventional example shown in FIG.

[Explanation of symbols]

 10 engine 20 transmission 21 output shaft 30 propeller shaft 31 first shaft 32 second shaft 33 third shaft 34 first joint (rubber coupling) 35 second joint 36 third joint 37 fourth joint 40 final reducer 41 input Shaft 48 1st center bearing support 49 2nd center bearing support

Claims (2)

[Scope of utility model registration request] 1. A first shaft connected to a transmission side via a first joint, and a second shaft connected to the first shaft via a second joint.
A shaft, and a third shaft connected to the second shaft via a third joint and to the final reduction gear side via a fourth joint, and a rubber coupling is used for the first joint. And a third joint type propeller shaft for vehicles in which hook joints or constant velocity joints other than rubber couplings are used for the second, third and fourth joints, respectively, in the vicinity of the second joint of the second shaft and the A propeller shaft for a vehicle, comprising a center bearing support elastically supported near a third joint of a third shaft. 2. The propeller shaft for a vehicle according to claim 1, wherein the first shaft is shorter than the second shaft.