JPH0415317A - Spline connecting mechanism - Google Patents

Abstract

PURPOSE:To reduce the amplitude of a resonance point of the lateral vibration and to move the frequency of a resonance point by bolting a spline portion having a spline on the outer peripheral surface of a shaft and a spline portion having a spline on the inner peripheral surface in the axial direction through an elastic body. CONSTITUTION:A tapped hole 1a is formed in the axial direction on a spline portion 1, and an insert hole 2a where a fitting bolt 8 is inserted is formed on a spline portion 2. The spline portion 2 connected to a propeller shaft tube 4 through a universal joint 3 is fitted to a half rigid axle while tensile force is applied in the axial direction using elastic bodies 10, 12 by the screw- engagement of the fitting bolt 8 with the tapped hole 1a. As the tensile force is loaded in the axial direction on the propeller shaft tube 4 and the tensile force can be controlled by the fitting bolt 8, the lateral natural frequency can be controlled. Furthermore, as the spring rigidity is given by the elastic body, the lateral vibration amplitude of the propeller shaft tube 4 does not depend on the external damping, and as the spring rigidity is increased, the resonance point amplitude can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a spline coupling mechanism that can be used to slidably connect in the axial direction in a power transmission system.

(Prior Art) A spline connection is a connection in a power transmission system in which a male spline and a female spline are fitted together to allow axial movement between rotating members to be connected so that power can be transmitted.
It can be used for attaching a spline part of a propeller shaft in a vehicle.

FIG. 3 is an example of this, and shows a connection structure on the rear end side of the transmission in a propeller shaft that transmits torque from the vehicle's transmission to the differential. In the figure, 1 is a male spline part having a spline (male spline) formed on the outer circumferential surface of the shaft tip, here it is the output shaft of the transmission, and 2 is a spline (male spline) formed on the inner circumferential surface of the hole.
shows a female spline portion with a female spline);
A spline portion 2 is spline-fitted into the spline portion 1 . One end of the spline portion 2 is connected to a propeller shaft tube 4 via a universal joint 3.

In the figure, 5 is a transmission case, 6 is an oil seal attached to the transmission case 5, which prevents the grease sealed in the spline fitting part from scattering, and 7 is a rotary force transmission This is a spline part cover that rotates together with the spline part 2 on the propeller shaft side.

Engine torque transmitted to the spline section 1 through the transmission is transmitted to the spline section 2 by the teeth of the spline, and the torque is further transmitted to the propeller shaft tube 4 via the universal joint 3. Power is transmitted in this way, and during such driving rotation, the spline joint moves back and forth in the axial direction (in this case, the spline joint 2 moves in the left-right direction in the figure with respect to the spline part 1 on the output shaft of the transmission attached to the vehicle body). (sliding motion).

(Problem to be Solved by the Invention) However, in a power transmission system having the above-mentioned spline part attachment structure, movement in the axial direction is allowed even during rotation, but when the shaft rotates, the shaft moves at a predetermined rotational speed. Conventionally, for use in transmission systems where the lateral vibration amplitude increases due to resonance, the spline coupling mechanism itself is
It does not have the function of suppressing, adjusting, or alleviating it.

In the case of the propeller shaft transmission system with spline parts attached as shown in Fig. 3, spline parts I and spline parts 2 can slide in the axial direction even when the propeller shaft rotates, and due to the clearance of the spline contact parts, there is no slight play. Because of this structure, if the external damping is not increased when the propeller shaft rotates at a critical speed, the amplitude of the lateral vibration will increase. However, the spline coupling mechanism itself shown in FIG. 3 does not have the function of suppressing the resonance point amplitude of such lateral vibration. Resonance points of lateral vibrations Measures to deal with large resonances must rely solely on the external damping force applied to the propeller shaft. In addition, when the spline joint slides a lot and automatic vibrations occur due to the frictional force of the spline contact part, this propagates to the propeller shaft. I don't have one.

An object of the present invention is to reduce the resonance point amplitude of shaft lateral vibration without relying on external damping in a power transmission system that transmits rotational force to a rotating shaft via a spline connection, and to easily adjust the resonance frequency. The object of the present invention is to provide a spline coupling mechanism that can be moved.

(Means for Solving the Problems) For this purpose, the spline coupling mechanism of the present invention is a spline coupling mechanism in a power transmission system that transmits rotational force to a rotating shaft via a spline coupling, which has a spline on the outer peripheral surface of the shaft. The spline part and the spline part having a spline on the inner circumferential surface into which the spline part fits are fastened together with a bolt through an elastic body while applying a tensile force in the axial direction.

(Function) Both spline parts that are spline-fitted are fastened together with a bolt through an elastic body while applying a tensile force in the axial direction, so that both spline parts are fixed semi-rigidly.

The spline connection, which has spring rigidity in the axial direction using an elastic body, makes it possible to reduce the resonance point amplitude of shaft lateral vibration during shaft rotation without depending on external damping, and also, Bolts used for fastening with such an elastic body interposed therebetween make it possible to adjust the tensile force applied in the axial direction by adjusting the tightening condition of the bolt, and the resonance frequency can also be easily moved. .

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows an embodiment of the spline coupling mechanism of the present invention, and shows the configuration when applied to attaching a spline portion of a propeller shaft to a transmission output shaft.

As shown in the figure, a male spline part 1 has a spline (male spline) on the outer peripheral surface of the shaft tip, and a female spline part 2 has a spline (female spline) on the inner peripheral surface of the hole. By being inserted into the spline part 2 and fitted with a spline, it is assembled so that it can slide in the axial direction and torque is transmitted through the teeth of the spline. On the other hand, a structure is adopted in which bolts are used to assemble the spline part 2 while applying a tensile force to the spline part 2 through an elastic body.

For this reason, as shown in the figure, a tapped hole 1a is formed in the spline part 1 in the axial direction, and an insertion hole 2a is formed in the spline part 2, through which the mounting bolt 8 is inserted. 3 to the propeller shaft tube 4 is semi-rigidly attached in the axial direction using an elastic body by screwing a mounting bolt 8 into the threaded hole 1a. In this embodiment, the elastic bodies used to provide spring rigidity in the axial direction are two types: a ring-shaped elastic body that applies compressive force in the axial direction of the propeller shaft, and a ring-shaped elastic body that applies tensile force in the axial direction of the propeller shaft. The structure shall be divided into two parts. Specifically, as shown in the figure, the male spline part 1 and the female spline part 2 are connected to a ring-shaped elastic body 10 sandwiched between the outer end surface of the spline part 2 and the bolt head by a washer 9.9. and,
A ring-shaped elastic body 12 is sandwiched between washers 11 and 11 between the tip of the spline part 1 and the inner end surface of the spline part 2, and a half bolt is attached by a mounting bolt 8 passing through these washers and the ring-shaped elastic body. Fixed in the axial direction.

Note that the other configurations may be the same as in the case of FIG. 3 above. That is, although grease is sealed in the spline fitting part, the oil seal 6 attached to the transmission case 5 prevents the grease from scattering, and furthermore, to ensure safety, the spline part 2 rotates integrally with the grease. A spline section cover 7 is attached.

The spline coupling mechanism of this embodiment connects the spline part 1 of the output shaft and the spline part 2 that transmits torque to the propeller shaft by attaching the mounting bolt 8 through an elastic body divided into two parts while applying a tensile force to the propeller shaft. It is possible to fix the propeller shaft to a half pitch in the axial direction, and it is possible to reduce the resonance point amplitude of the axial vibration of the propeller shaft without relying on external damping, and it is possible to move this resonance point frequency. . Furthermore, the axial high frequency vibration component transmitted from the engine can be blocked, and the axial movement of the spline can be appropriately restricted.

To explain these below, first, torque on the engine side is transmitted via the teeth of the spline part 1 and the spline part 2, and that torque is transmitted to the propeller shaft tube holder via the uninor-salge joint 3, and , normal power transmission is possible even if elastic bodies 10 and 12 are used (c).

(I will discuss crashes later).

Here, in this embodiment, when attaching the spline part of the propeller shaft, the spline part 1 and the spline part 2 are
Since the propeller shaft is fixed via the elastic body 10.1.2 while applying tension in the axial direction with the mounting bolt 8, the dimensional error in the axial installation of the propeller shaft can be freely displaced in the axial direction. This is allowed by the amount of threading of the spline and the mounting bolt 8 that restrains the axial movement of the spline.

The spline coupling mechanism shown in FIG. 1 allows a tensile force to be applied to the propeller shaft in the axial direction, and the tensile force can be finely adjusted by the tightening torque of the above-mentioned mounting bolt 8. When applied to a propeller shaft power transmission system, the lateral natural frequency of the target propeller shaft can be adjusted.

In addition, by providing spring stiffness in the axial direction with an elastic body, the lateral vibration amplitude of the propeller shaft can be reduced by the third
As shown in the figure, the resonance point amplitude can be made small without depending on external damping. This figure shows response characteristics 11 to 14 of the propeller shaft lateral vibration amplitude with respect to the propeller shaft rotation speed when the spring stiffness of the elastic body is changed. According to this, as the spring stiffness increases, the resonance point The amplitude can be reduced, and this can be done without relying on external attenuation.

This action is due to the nonlinear motion effect of the propeller shaft itself due to the propeller shaft mechanism to which this spline connection is applied, and therefore, this action makes it possible to reduce the external damping force applied to the propeller shaft. This reduction in external damping force means that the insulator damping of the center bearing that supports the propeller shaft on the vehicle body can be reduced, and as a result, the noise inside the vehicle can be reduced. That is, it is possible to reduce the propeller shaft support reaction force that causes noise in the vehicle interior, thereby reducing noise.

Further, due to the damping effect of the elastic body, high frequency vibration components transmitted from the engine to the spline portion 1 are blocked here. Furthermore, the structure of this spline connection via an elastic body is
In addition to the above, it also has the advantage of suppressing tooth contact noise caused by rotational angle fluctuations due to spline backlash.

Furthermore, in this embodiment, the elastic bodies are an elastic body 10 and an elastic body 12.
The system is divided into two parts, thereby realizing the following functions.

First, the vibration load applied to the elastic body can always be applied by compressive deformation of either the elastic body 10 or 12 (displacement of the spline portion 2 on the propeller shaft side to the left in FIG. (The displacement to the right can be received by compression of the elastic body 10)
Therefore, the fatigue fracture life of the elastic body used can be extended. Therefore, this embodiment is particularly suitable when durability is important.

In addition, with the configuration shown in Figure 3, engine axial vibration is irregularly transmitted due to the frictional force and clearance of the spline contact part, which causes abnormal noise. This spline coupling mechanism allows
Although this problem can be solved, depending on the elastic body used, the elastic body itself may become a cause of irregular vibrations.

In other words, if the spring stiffness of the elastic body has nonlinearity, different spring stiffnesses will act on the forward and return paths of axial vibration, which will cause irregular vibrations. When attempting to further reduce vibration, it is desirable to have a structure that can also suppress the generation of such vibrations.

Therefore, the aspect in which the elastic body is divided into two is also suitable for satisfying such requirements. That is, as shown in Figure 1,
Since the propeller shaft can be supported by being sandwiched between the compression reaction forces of the two elastic bodies 10 and 12, the forward path of axial vibration,
Both return trips can be supported by compression of the elastic body, and each can be made to have the same spring stiffness, so that the occurrence of the irregular vibrations described above can be well suppressed.

Note that the present invention is not limited to the configuration of the above embodiment, and its application is not limited to propeller shafts of vehicles, but can also be applied to power transmission systems where vibration amplitude in the lateral direction of the shaft becomes a problem during shaft rotation. do not prevent you from doing so.

(Effects of the Invention) As described above, the spline coupling mechanism of the present invention connects the spline part having the spline on the outer circumferential surface of the shaft and the spline part having the spline on the inner circumferential surface to a semi-rigid state in the axial direction with a bolt via an elastic body. Because it has a structure that can be assembled, even in a power transmission system where the vibration amplitude in the shaft lateral direction is a problem when transmitting rotational force to the rotating shaft via a spline connection, the resonance point amplitude of the lateral vibration can be externally damped. The resonant frequency can be moved, and this can be easily done using bolts.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing one embodiment of the spline coupling mechanism of the present invention, Fig. 2 is a propeller shaft lateral vibration amplitude characteristic diagram for explaining the same side, and Fig. 3 is a spline portion of a propeller shaft with a conventional configuration. FIG. 3 is a cross-sectional assembly view showing the attachment. 1... Male spline part 1a... Screw hole 2... Female spline part 2a... Insertion hole 3... Universal joint 4... Propeller shaft tube 5... Transmission case 6. ... Oil seal 7 ... Spline part cover 8 ... Mounting bolt 9.11 ... Washer 10, 12 ... Ring-shaped elastic body

Claims (1)

[Claims] 1. A spline coupling mechanism in a power transmission system that transmits rotational force to a rotating shaft via a spline coupling, comprising: a spline portion having a spline on the outer peripheral surface of the shaft; and an inner periphery into which the spline portion fits. A spline coupling mechanism characterized in that a spline part having a spline on a surface is fastened with a bolt through an elastic body while applying a tensile force in the axial direction. 2. The power transmission system is a power transmission system using a propeller shaft of a vehicle, and the elastic body includes a ring-shaped elastic body that applies a compressive force in the axial direction of the propeller shaft, and a ring-shaped elastic body that applies a tensile force in the axial direction of the propeller shaft. The spline coupling mechanism according to claim 1, for attaching a spline portion of a propeller shaft, characterized in that the spline coupling mechanism is divided into two parts and an elastic body. 3. The spline coupling mechanism according to claim 2, wherein the spring rigidities of the two elastic bodies after being attached to the propeller shaft are equal.