JP3216906B2 - Electric rear wheel steering system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric rear wheel steering device which is applied to an electric rear wheel steering device of a vehicle and has a transmission mechanism optimal for transmitting the rotation of an electric motor to a rod.

[0002]

2. Description of the Related Art In a conventional example shown in FIGS. 2 to 4, an electric motor m is provided on one side of a casing b, and a hypoid gear pinion shaft 1 having a large diameter portion 1a formed on an output shaft s of the electric motor m. Are combined. Bearing members 2 and 3 for radial load are provided on both left and right sides of the hypoid gear pinion shaft 1, and bearing members 4 and 5 for thrust load are provided on both side surfaces of the large diameter portion 1a.

An adjusting screw 6 is provided on the outer periphery of the bearing member 2, and the adjusting screw 6 is screw-coupled to the casing b to hold the bearing member 2 and to attach the tip of the adjusting screw 6 to the bearing member 4. , And the amount of pressurization applied to the bearing members 4 and 5 is adjusted. Therefore, the hypoid gear pinion shaft 1 is rotatably held by the bearing members 2 and 3, and the acting force acting on the hypoid gear pinion shaft 1 in the thrust direction is received by the bearing members 4 and 5.

[0004] hypoid gear pinion shaft 1 as described above is allowed to form a hypoid pinion 7, engage the hypoid pinion 7 hypoid gear 9 formed on the hypoid gear wheel 8 which is furnished to the gearbox portion b ₁ of the casing b. A support shaft 10 is fitted to the hypoid gear wheel 8 and its tip is protruded upward.
_The bearing member 1 is attached to the center of the shaft of the cover
2 so as to be rotatable. Furthermore, a hypoid gear wheel 8, a stepped portion 8a formed on the opposite to the support shaft 10, the small diameter portion 8b provided with a bearing member 13, is formed on the lower side between the gear box portion b ₁ of between the outer and the gearbox portion b _1, and fitting the bearing member 14 rotatably supports the hypoid gear wheels 8 between these bearing members 13, 14 and the support shaft 10.

The hypoid gear wheel 8 rotatably supported as described above has a spherical bearing 15 fitted on the inner periphery of the small diameter portion 8b.
The shaft center 5 is eccentric with respect to the shaft center of the hypoid gear wheel 8 by an eccentric amount e. Then, one side of the stud shaft 16 is slidably fitted into the inner ring 15a of the spherical bearing 15, and a tapered portion 16a formed at the tip thereof is inserted into a tapered hole 17a formed in the rod 17, so that the stud shaft 16 is No. 17 Note that reference numeral 15b in the drawing denotes an outer ring of the spherical bearing 15.

A plate body 18 having a notch 18a is fastened to the upper end of the support shaft 10 fitted to the hypoid gear wheel 8, while a potentiometer 19 is mounted above the cover member 11. The end of the lever member 19a connected to the plate member 18 is in contact with the notch 18a of the plate body 18. Therefore, when the support shaft 10 rotates, the lever member 19a rotates according to the amount of movement. In addition, the code | symbol 20 in a figure is:
A nut for fixing the stud shaft 16 to the rod 17.

When the electric motor m is driven, the hypoid gear pinion shaft 1 rotates, and the hypoid gear wheel 8 rotates with the rotation of the hypoid gear pinion shaft 1. When the hypoid gear wheel 8 rotates in this manner, the stud shaft 16 rotates about the axis of the hypoid gear wheel 8, but the stud shaft 16 that rotates in this manner is in a direction other than the linear direction along the axis of the rod 17. Movement to spherical bearing 1
5 is eventually absorbed by the stud shaft 16
Moves the rod 17 in its axial direction. The rod 17 is moved in accordance with the moving direction of the stud shaft 16.
Moves to the left or right in the drawing, and steers the rear wheels via side rods (not shown) connected to both ends of the rod 17.

[0008]

In the conventional apparatus as described above, the stud shaft 16 is fitted into the inner ring 15a of the spherical bearing 15, so that the number of parts is increased and the assembling man-hour is increased. There was a problem that it would increase. Further, since the stud shaft 16 is fixed with a nut, if the stud shaft 16 is excessively tightened, the rod 17 may be damaged. The purpose of this invention is
An object of the present invention is to provide an electric rear wheel steering device that reduces the number of parts and does not damage a rod.

[0009]

SUMMARY OF THE INVENTION The present invention provides a hypoid pinion that rotates integrally with an output shaft of an electric motor, a hypoid gear meshed with the hypoid pinion, a hypoid gear wheel integrally formed with the hypoid gear, and one of the hypoid gear wheels. The electric motor, comprising: a spherical bearing having a shaft center eccentric with respect to the shaft center of the hypoid gear wheel; and a stud shaft having one side fitted into the spherical bearing and the other side connected to a rod. Is transmitted to the rod, the rod is moved, and the rear wheel is steered in accordance with the movement of the rod.
On the premise of the above device, the present invention forms a ball joint portion of a spherical bearing integrally with one end of a stud shaft, and fits this ball joint portion into an outer ring of the spherical bearing, while forming an insertion hole in the rod. Into this insertion hole
With the other end of the stud shaft slidable
The stud shaft in the axial direction with respect to the rod.
The feature is that it can be moved .

[0010]

Since the present invention is constructed as described above, when the hypoid gear wheel rotates, the stud shaft rotates about the axis of the hypoid gear wheel. However, the stud shaft that rotates in this manner moves along the axis of the rod. The stud shaft eventually moves the rod in its axial direction because the movement outside the linear direction is absorbed by the spherical bearing. Then, the rod moves left or right according to the moving direction of the stud shaft to steer the rear wheels.

[0011]

According to the apparatus of the present invention, the stud shaft and the ball joint are formed integrally and the ball joint is fitted to the outer ring of the spherical bearing, so that the number of parts is reduced as compared with the conventional apparatus. it can. Since the number of parts is small, as a matter of course, the number of assembly steps is also reduced.
In addition, since the ball joint at one end of the stud shaft is fitted to the outer ring of the spherical bearing and the other end is slidably fitted to the rod, the conventional nut is unnecessary, and the number of parts is reduced accordingly. The rod is not damaged by the tightening force of the nut.

[0012]

In the embodiment shown in FIG. 1, a small-diameter portion 8a of a hypoid gear wheel 8 is supported by a bearing member 21, and a spherical bearing 22 is provided on the small-diameter portion 8a.
The spherical bearing 22 is formed by fitting a ball joint 23a integrated with a stud shaft 23 into an outer ring 22a. Since the ball joint portion 23a of the stud shaft 23 is fitted to the outer race 22a, the stud shaft 23 does not fall off the stud shaft 23. The stud shaft 23 thus configured is slidably inserted into the insertion hole 24 of the rod 17 ,
It can be moved in the axial direction. The configuration other than the above is the same as the above-described conventional one, and a detailed description thereof will be omitted.

When the electric motor m is driven, the hypoid gear wheel 8 rotates to move the stud shaft 23 eccentrically as in the prior art. This stud shaft 23
Due to the eccentric movement, the rod 17 moves right and left, and steers a rear wheel (not shown). At this time, when a vertical force acts on the stud shaft 23, the shaft 23
Slides in the insertion hole 24 in the axial direction .

According to the above-described embodiment, the stud shaft 23 and the ball joint 23a are integrally formed, and the ball joint 23a is
, The number of parts can be reduced as compared with the conventional device. Therefore, as a matter of course, the number of assembly steps is reduced. Also, the stud shaft 23 is slidably inserted into the insertion hole 24 of the rod 17 so that the
, The need for a conventional nut is eliminated, the number of components is reduced, and the rod is not damaged by the tightening force of the nut.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of this embodiment.

FIG. 2 is a conventional sectional view.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a plan view of a conventional plate body.

[Sign]

 m Electric motor s Output shaft 7 Hypoid pinion 8 Hypoid gear wheel 9 Hypoid gear 17 Rod 22 Spherical bearing 22a Outer ring 23 Stud shaft 23a Ball joint 24 Insertion hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B62D 7/14

Claims (1)

(57) [Claims] 1. A hypoid pinion that rotates integrally with an output shaft of an electric motor, a hypoid gear engaged with the hypoid pinion, a hypoid gear wheel integrally formed with the hypoid gear, and an output shaft that is one side of the hypoid gear wheel. A spherical bearing whose center is eccentric with respect to the shaft center of the hypoid gear wheel, and a stud shaft whose one side is fitted into the spherical bearing and the other side is connected to a rod, transmitting the output of the electric motor to the rod. In a motor-driven rear wheel steering device configured to move a rod and steer a rear wheel in accordance with the movement of the rod, a ball joint portion of the spherical bearing is formed integrally with one end of a stud shaft. Part into the outer ring of the spherical bearing, and the rod has an insertion hole.
And slide the other end of the stud shaft into this insertion hole.
Move the stud shaft
Characterized in that it is movable in the axial direction with respect to the
That electric rear-wheel steering system.