JPS5937387Y2 - Oil seal device for front wheel support of front wheel drive vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a front wheel support device for a front wheel drive vehicle in which a front wheel drive shaft is connected to a front axle shaft via a Barfield joint.

In front-wheel drive vehicles (including all-wheel drive vehicles), it is necessary to transmit the drive rotation of the front axle shaft to the drive shaft that is integrated with the front wheels, allowing for the steering rotation of the front wheels, and transmitting the rotation evenly. are connected via constant velocity universal joints.

There are various types of constant velocity universal joints, but the Barfield joint described below is generally adopted in the case of suspension type axles of large trucks and the like.

That is, as shown in FIG. 1A, the Barfield joint J is such that the inner drive wheel 1a connected to the tip of the front axle shaft 1 and the outer drive wheel 2a formed at the tip of the front wheel drive shaft 2 are connected to the inner side. The front axle shaft 1 is engaged through a ball 4 fitted into a transmission groove 3 formed in the drive wheel, and the drive rotation of the front axle shaft 1 is caused by the inner drive wheel 1a.
This is transmitted via the ball 4 to the outer drive wheel 2a, and hence to the front wheel drive shaft 2, and the front wheel W, which is connected to the shaft 2 via the drum 5, is rotated.

A trunnion socket 7 is connected to the end of the axle shaft housing 6 and includes the end of the axle shaft 1, and a knuckle is connected to the shaft housing 8 that includes the front wheel drive shaft 2 and includes the outside of the trunnion socket 7. An annular oil seal member 10 is attached between the housing 9 and the housing 9.

That is, the oil seal member 10 is connected to the knuck housing 9.
The outer periphery of the trunnion socket 7 is slidably in contact with the outer periphery of the trunnion socket 7 to seal the gap between the two. The oil seal function can be maintained by moving while slidingly contacting the spherical surface.

By the way, in a vehicle, as shown in FIG. 2, the turning angles of the left and right steered wheels are changed when the vehicle is steered.

That is, in order to facilitate turning of the vehicle, the turning angle of the steered wheel on the side closer to the turning center (hereinafter referred to as the inner turning angle) is determined.

) θ1 is the turning angle of the steering wheel on the far side from the turning center (hereinafter referred to as the outer angle side turning angle).

) is set larger than θ2, and the difference is about 5 to 7 degrees at the maximum vehicle steering angle.

On the other hand, in the conventional front wheel support mechanism described above, the oil seal member 10 is mounted so that its center axis coincides with the center axis of the front axle shaft 1 when the vehicle is in the straight-ahead steering position.

Therefore, in FIG. 1B (the plan view of FIG. 1A), the maximum value of the inner turning angle of the front wheels W, which are the steered wheels, is the maximum value of the inner turning angle of the front wheels W, which are the steered wheels, from the position where the rear end seal surface S of the oil seal member 10 is from the position when the vehicle is traveling straight. The boundary portion between the bulb and cylinder portion of the trunnion socket 7 (hereinafter referred to as the neck portion).

) is set to the steering angle θ1.

As described above, the maximum value of the outer steering angle is set to a value θ2 smaller than the inner steering angle, so even at the maximum steering angle, the front end seal surface S of the oil seal member 10
2 still leaves some space between it and the neck of the trunnion socket 7.

Of course, since the annular oil seal member 10 is installed as close as possible to the king pin 11, it is difficult to further increase the maximum turning angle of the steered wheels using conventional oil seal members, and it is difficult to further increase the maximum turning angle of the steered wheels. It was blocking me.

The present invention has been made in view of such conventional drawbacks, and by configuring the axial width of the oil seal member that seals the gap between the knuckle housing and the trunnion socket so that the front part is wider than the rear part, An object of the present invention is to provide an oil seal device for a front wheel support portion of a front wheel drive vehicle, which increases the maximum turning angle of the steered wheels and improves the turning performance of the vehicle.

Hereinafter, the present invention will be explained based on the drawings.

However, in FIG. 3, the same components as in FIG. 1 are designated by the same reference numerals, and their explanations are omitted.

FIG. 4 is a sectional view of the oil seal.

In the figure, the annular oil seal member 21 attached to the inner peripheral end surface of the knuckle housing 9 has an inner rubber seal member 21A, a reinforcing flange member 21B, and an outer metal auxiliary seal member 21C that overlap each other at the outer peripheral flange portion. These are formed with a width that tapers from the front to the rear to constitute the present invention.

That is, while a circumferential groove 21a having an angular cross-section is provided from the mounting surface flange of the rubber seal material 21A whose axial width length is equal over the entire circumference in a natural state to an arm portion extending in the axial direction at right angles to the flange portion, A reinforcing flange material 21B is provided by cutting the cylindrical side of the shaped flange body with a tapered surface having an inclination angle dθ with respect to the flange surface, and this is fitted into the circumferential groove 21a by elastically deforming the circumferential groove 21a. They are brought together and adhesively secured to form an integral seal body member.

In this way, the plane including the seal edge of the rubber seal material 21A has an inclination angle dθ with respect to the mounting flange surface, and since the rubber seal material 21A has a point-symmetrical shape with respect to the central axis, its manufacturing process is easy. It's easy.

As a specific example, when the maximum inward steering angle is set to 35 degrees and the maximum outside steering angle is set to 29 degrees by the oil seal member of the conventional structure, the predetermined inclination angle dθ is set to 3 degrees.
By doing so, the maximum inside turning angle can be increased to 38 degrees, and this increase in the turning angle greatly reduces the vehicle turning radius, resulting in excellent turning performance with so-called tight turning.

As explained above, in this invention, the annular oil seal member that seals the gap between the knuckle housing that covers the barfield joint and the trunnion socket is shaped so that the axial width increases in a tapered shape from the front to the rear. from,
Since the plane containing the seal edge is inclined with respect to the mounting surface perpendicular to the center axis of the front wheel drive shaft, when the vehicle turns left and right, the seal edge of the oil seal member reaches the neck of the trunnion socket, allowing the steering wheel to move forward. Since the vehicle can be steered, the maximum inner steering angle is increased, and the vehicle turning performance can be significantly improved.

Moreover, its configuration is extremely simple and can be implemented at low cost.

[Brief explanation of drawings]

FIG. 1 shows an example of a conventional front wheel support mechanism, in which A is a longitudinal cross-sectional view, B is a simplified plan view, and FIG. 2 is a schematic diagram illustrating the difference in turning angle between left and right steered wheels of a vehicle. FIG. 3 is a partially cross-sectional plan view showing an embodiment of the present invention, and FIG. 4 is a single sectional view of the oil seal member. 7...Trunion socket, 9...Knuckle housing, 21...Oil seal member, dθ...Inclination angle.

Claims (2)

[Scope of utility model registration request] (1) The front wheel drive shaft and the front axle shaft are connected via a bar field joint, and the annular oil seal member attached to the peripheral end surface of the knuckle housing that covers the bar field and joint portion is attached to the end of the front axle shaft. In the front wheel support part of a front wheel drive vehicle, the oil seal member has a rubber seal body having an equal width around the entire circumference in a natural state, and the oil seal member has a rubber seal body having an equal width around its mounting flange in a natural state. The reinforcing flange member is formed by forming a circumferential groove having a cross-sectional shape from the part to the arm part at right angles thereto, and by making the cut surface on the cylindrical part side of the rectangular metal cylindrical flange body inclined with respect to the flange surface. The knuckle housing is fitted into the circumferential groove by elastically tensioning the circumferential groove, and is bonded and integrated so that the front part of the plane including the annular seal edge approaches the trunnion socket than the rear part when the vehicle is steered straight ahead. An oil seal device for a front wheel support portion of a front wheel drive vehicle, characterized in that the oil seal device is arranged at a predetermined angle around a kingpin that pivotally supports a trunnion socket. (2) The scope of the utility model registration claim in which the inclination angle of the plane including the inner seal edge of the oil seal member is set to 1/2 of the difference between the inner maximum rotation angle and the outer maximum rotation angle of the front wheel. 1st
An oil seal device for a front wheel support portion of a front wheel drive vehicle as described in 2.