JPH0633220Y2 - Vehicle driving force transmission structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a drive system of an automobile or the like, and more particularly to a drive force transmission structure for a vehicle using a constant velocity universal joint.

[Prior Art] FIG. 5 is a partial cross-sectional view showing a rear wheel suspension (hereinafter referred to as IRS) of a rear-wheel drive independent suspension vehicle to which the present invention is applied. In FIG. 5, a pair of constant velocity universal joints is used via a drive shaft 21 to transmit the driving force from the engine to the wheels 20.

In the IRS, for example, a plunging type double offset type constant velocity universal joint 22 (hereinafter referred to as DOJ) is provided on the wheel 20 side, and a fixed type Zeppe type constant velocity universal joint 24 (hereinafter referred to as BJ) is provided on the differential device 23 side. ) Are used respectively.

In recent years, the backlash of a power transmission system has been suppressed as an object of NVH characteristics such as feeling, that is, noise, vibration, and feeling of the ear. Among the power transmission systems, the constant velocity universal joint is a major factor, and minimizing play in the circumferential direction of the constant velocity universal joint is also the key to improving NVH characteristics. There are two types of circumferential play in the constant velocity universal joint: play in the inner ring and drive shaft, and play between the ball, inner ring and outer ring.

Conventionally, in order to suppress the backlash between the inner ring and the drive shaft, a twist angle is provided in the shaft serration between the inner ring and the drive shaft so that the backlash of the fitting portion is almost completely eliminated.
In order to suppress the looseness between the outer rings, the components are selected and combined.

[Problems to be solved by the device]

By the way, when the shaft serration is provided with a twist angle and fitted to the inner ring, there is a problem that the strength and life of the inner ring and the shaft are varied depending on the direction of the twist angle and the torque load direction.

Therefore, an object of the present invention is to suppress backlash between the inner ring and the drive shaft and to improve the strength of the inner ring and the shaft by restricting the use place and the twisting direction of the constant velocity universal joint.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the present invention is to transmit the driving force for a vehicle in which the shaft serrations of the drive shafts extending to the left and right sides of the drive source are fitted to the serrations of the inner ring inner diameter surfaces of the left and right constant velocity universal joints. In the structure, serrations on the inner diameter surface of the inner ring are formed in parallel with the axial direction, and are the same as the main load torque direction when viewed in the torque transmission direction in opposite directions to the shaft serrations of the respective drive shafts in the left and right drive shafts. The shaft serrations are twisted in the direction, and the shaft serrations are pressed into the serrations on the inner diameter surface of the inner ring.

[Action]

The drive shaft of the constant velocity universal joint according to the present invention has the maximum stress on the opposite shaft end side of the shaft serration, since the stress applied to the tooth surfaces of the inner ring serration and the shaft serration at the time of torque load is canceled by the stress due to press fitting. The strength and life of the inner ring and drive shaft are improved. Moreover, since both serrations are press-fitted, there is no backlash.

[Example of device]

FIG. 1 is a BJ sectional view of the rear wheel suspension shown in FIG. 5 on the differential device 23 side.

A serration 4 parallel to the axial direction is formed on the inner diameter of the inner ring 1, and a shaft serration 3 that fits with the serration 4 is formed on the end of the drive shaft 2. The shaft serration 3 is provided with a twist angle as a measure against the play described above, and the serration 4 is
Is pressed into.

2 and 3 are explanatory diagrams showing the relationship between the direction of the torsion angle α of the shaft serration 3 and the distribution of stress generated in the serration 4 of the inner ring 1 and the shaft serration 3 when the torque T is applied.

FIG. 2 shows a case where the twist angle α is twisted in the direction opposite to the direction of the tort T (see FIG. 2C). Above twist angle α
As a result, stress as shown in FIGS. 2 (a) and 2 (b) is generated on the tooth surfaces of the serration 4 of the inner ring 1 and the shaft serration 3 during press-fitting, and when the torque T is further applied, the opposite shaft end side 5 The stresses generated at 1 are added, and PB = P1 + P2.

Note that P1 is a stress generated when the shaft serration 3 is press-fitted into the inner ring serration 4, and P2 is a stress when the torque T is applied.

On the other hand, FIG. 3 (A) shows the BJ at the left end of the drive shaft 2,
This is the case where the twist angle α of the shaft serration 3 is in the same direction as the direction of the torque T as viewed in the torque T transmission direction (the direction in which the wheels are viewed from the engine or the differential, the same applies below).
Is applied, the stress PB generated on the opposite shaft end side 5 is subtracted, and PB = P2-P1.

That is, the stress P ₂ applied to the tooth flanks of the inner ring serration 4 and the shaft serration 3 at the time of torque load is larger on the non-shaft end side 5 than on the shaft end side 6, but as shown in FIG. 3 (A). To
In the case of the shaft serration 3 in which the right-handed twist angle α in the same direction as the torque T is applied, the stress P ₁ due to press fitting is opposite to the stress P ₂ and therefore occurs on the opposite shaft end side 5. Maximum stress is reduced. Therefore, it is effective for improving the life of the inner ring 1 and the shaft 3.

FIG. 3 (B) shows a case where the twist angle α of the shaft serration 3 is the same as the direction of the torque T of the right end DOJ of the drive shaft 2 when viewed in the transmission direction of the torque T. Also in this case,
When torque is applied, the stress P ₂ applied from the inner ring serration 4 to the shaft serration 3 is in the opposite direction to the stress P ₁ due to press fitting on the opposite shaft end side 5, so that the maximum stress is reduced.

The invention of the present application may be changed to a constant velocity universal joint of DOJ to BJ or DOJ, or another type, regardless of the type of constant velocity universal joint.

FIG. 4 shows a specific combination. In the figure, 15 is an engine, 16 is a front wheel, 17 is a propulsion shaft, 18 is a differential device, and 19 is a rear wheel.

The figure shows the case of all-wheel drive using constant velocity universal joints for the front and rear, but of course in the case of a front-wheel drive vehicle, if the front drive shaft is the IRS of a rear-wheel drive vehicle, the rear drive The drive axis of is targeted. As described above, the strength of the drive shaft and the life of the inner ring can be maximized by considering the direction of the twist angle α of the shaft serration 3 and making the settings shown in Table-1.

However, regarding the direction of the twist angle α of the shaft serration, the direction of the right-hand screw is the right direction and the direction of the left-hand screw is the left direction when viewed in the torque transmission direction.

For example, when the vehicle suddenly starts to move forward, the vehicle body is pitched (the front portion of the vehicle body is lifted), and the torque applied to the rear side is increased. In this case, it is more effective in terms of strength and life that the left side drive shaft L is provided with a rightward twist angle and the right side drive shaft R is provided with a leftward twist angle α on the rear side, in particular, as shown in Table 1.

On the other hand, when moving backward, the reverse is true. When the vehicle suddenly starts, the rear part of the vehicle floats up and the torque on the front side increases, and as shown in Table-1, on the front side, the left drive shaft L moves to the left,
Conversely, it can be said that it is effective to give the right drive shaft R a rightward twist angle α.

Depending on which of the above is emphasized, that is, which is the main load torque, the direction of the torsion angle of the shaft serrations is made to coincide with the direction of the main load torque as viewed in the torque transmission direction, and the left and right drive shafts are To set the twist angle in the opposite direction.

Although the torque is greater when the vehicle is retreating due to the gear ratio, it is more effective to prioritize the vehicle when the vehicle is moving forward, which has a large effect on the shaft serration or the strength and life of the inner ring due to the frequency.

〔effect〕

As described above, according to the present invention, there is provided a vehicle driving force transmission structure using a constant velocity universal joint, which is opposite to the shaft serrations of the left and right drive shafts in the same direction as the main load torque. Since a twist is applied in the direction, and this is press-fitted into the serration of the inner ring inner diameter surface, the stress applied to the tooth surfaces of the inner ring serration and the shaft serration at the time of torque load on the opposite shaft end side of the shaft serration is It is canceled by the stress due to press fitting, and the maximum stress is reduced. As a result, the strength and life of the inner ring and drive shaft are improved,
Further, it has the effect of suppressing the play between the inner ring and the drive shaft and improving the NVH characteristics.

[Brief description of drawings]

FIG. 1 is a BJ cross-sectional view of a rear wheel suspension to which the present invention is applied, on the differential side, and FIGS. 2 and 3 (A) and (B) show the distribution of stress generated in the inner ring / shaft. FIG. 4 is an explanatory view in which the embodiments of the present invention are combined in the case of front wheel drive, and FIG. 5 is a rear wheel drive to which the present invention is applied, and a rear wheel suspension (IRS) of an independent suspension vehicle. It is a fragmentary sectional view shown. 1 ... Inner ring, 2 ... Drive shaft, 3 ... Shaft serration, 4 ... Inner ring serration, 5 ... Opposite shaft end side, α ... Twist angle, T ... Torque, L ... Left drive shaft, R ...... Right drive shaft.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI technical display location 8207-3J F16D 1/06 Q (56) References: 62-166328 (JP, U) Public 47-47070 (JP, B1) Actual Public 57-30494 (JP, Y2)

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A vehicle drive force transmission structure comprising shaft serrations of drive shafts extending to the left and right sides of a drive source fitted to serrations of inner ring inner diameter surfaces of left and right constant velocity universal joints. The surface serrations are formed parallel to the axial direction, and the axial serrations of the above drive shafts are twisted in the opposite direction on the left and right drive shafts and in the same direction as the main load torque direction when viewed in the torque transmission direction. A driving force transmission structure for a vehicle, wherein the shaft serration is press-fitted into the serration on the inner diameter surface of the inner ring.