JPS5913181Y2 - Steering gear dustproof and waterproof device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dustproof and waterproof device suitable for a steering gear in which a yoke is removably attached to a protruding portion of a rotary shaft supported within a housing.

In conventional steering gear dustproof and waterproof devices,
Although the annular dust cover is assembled at its inner peripheral edge to the outer protrusion or yoke of the housing of the rotating shaft, there is a gap between the outer peripheral edge of the dust cover and the outer surface of the housing, so that sufficient dustproofing and You cannot expect a waterproof effect.

To deal with this, it is conceivable to simply bring the outer periphery of the dust cover into contact with the outer surface of the housing to eliminate the gap, but in that case, of course, the rotational operating torque of the rotating shaft will increase. Due to manufacturing errors and assembly errors of each member such as the housing, rotating shaft, yoke, etc., the rotational operating torque becomes non-uniform among the products, making it unsuitable for practical use.

Further, the inner peripheral edge of the dust cover, which has an annular flexible bending part in the center, is fitted and fixed to the outer periphery of the rotating shaft so that the outer peripheral edge is slidably in contact with the outer surface of the housing. Dust-proofing that positions the inner circumference with the tip of the yoke;
Waterproofing devices have also been devised.

In this case, if the pressing force on the inner peripheral portion of the dust cover is large, there is a risk that the central portion of the dust cover may be reversed in a direction away from the housing.

As a result, there is a possibility that the interference of the lip portion of the outer peripheral edge of the dust cover may be reduced, or a gap may be formed between the lip portion and the housing.

This proposal was made to eliminate such concerns, and the gist of this proposal is to reduce the gap between the dust cover and a member such as a yoke that is locked to the rotating shaft and positions the inner circumference of the dust cover. The purpose is to prevent the dust cover from turning over by inserting a flat washer so that the pressing force acting on the dust cover is uniformly received on the upper surface of the dust cover.

One embodiment will be described below with reference to the drawings.

FIG. 1 shows an example in which a dustproof and waterproof device according to the present invention is implemented in a power steering gear 10.

The rotating shaft 11 of the power steering gear 10 is the main body 12
a and a cover 12b.

Further, the right end portion of the rotating shaft 11 protrudes outside the housing 12 via the oil seal 13.

An annular dust cover 14 is attached to this housing outer protrusion 11a, and a yoke 15 is detachably attached thereto.

The yoke 15 is connected to the outer protrusion 11 of the housing 11 of the rotating shaft 11.
A is connected by a known connecting means, that is, serrations, and is clamped and fixed by a fixing bolt 16, and is prevented from coming off.

The dust cover 14 is made of an elastic body, and its inner peripheral edge 14a is fitted and fixed to the tapered step 11b of the rotating shaft 11, and its outer peripheral edge 14b is connected to the cover 12 of the housing 12.
It is in slidable contact with the outer surface of b, and has an annular flexible bent part (bellows part) 14C in the center.

Further, the dust cover 14 has its inner circumference 14d connected to the yoke 1.
It is pushed and positioned by the tip of 5.

With this configuration, the class 1 to the cover 14
is the tapered stepped portion 11b of the rotating shaft 11 at the inner peripheral edge 14a.
The cover 12b is fitted and fixed on the outer peripheral edge 14b.
Since it is in contact with the outer surface of the rotating shaft 11. housing 12,
Due to manufacturing errors and assembly errors of each member such as the yoke 15 and the pole 116, as shown in FIG. Or as shown in Figure 3,
Even if the dust cover 14 is positioned closer to the small diameter side of the tapered step portion 11b, the dust cover 14 itself bends at its bending portion 14C to absorb the uneven positioning. Outer peripheral edge 14b
Contact pressure on the outer surface of the cover 12 b (outer peripheral edge 14
Pressure due to the return force generated when b is deformed from the free state shown by the imaginary line to the attached state shown by the solid line)
is approximately constant.

Therefore, the rotational operating torque of the rotating shaft 11 does not become non-uniform between products and remains substantially constant.

Therefore, the outer peripheral edge 14b of the dust cover 14
By appropriately setting the amount of deformation A, it is possible to make the rotational operation torque relatively small.

Moreover, since the rotational operation torque is approximately equalized between products, the product performance of the power steering gear 10 can be approximately equalized.

The present invention further includes a flat washer 17 inserted between the yoke 15 and the dust cover 14 to prevent the dust cover 14 from being reversed in the direction of the yoke 15 at its central portion 14C due to the pressing force of the dust cover inner peripheral portion 14d. .

That is, by pressing the dust cover 14 uniformly over the entire surface toward the housing 12 using the flat washer 17, this reversal of the dust cover 14 is actively prevented and an appropriate tightening margin is always ensured.

This flat washer 17 may be fixed with a snap ring 18 as shown in the fourth figure.

In the above embodiment, an example in which the present invention is applied to the power steering gear 10 has been described, but the present invention can be similarly applied to a normal steering gear.

In summary, in the present invention, in a steering gear in which a yoke is removably assembled to the outer protrusion of the housing of the rotary shaft that is pivotally supported within the housing, the yoke is attached to the outer protrusion of the housing of the rotary shaft; an annular dust cover that is fitted and fixed on the outer periphery of the rotating shaft, that is in slidable contact with the outer surface of the housing at the outer periphery, and that has an annular flexible bent part in the center; The structure is characterized in that the inner circumferential portion of the dust cover is positioned by a member secured to the rotating shaft, and a flat washer is inserted between the member and the dust cover.

As a result, not only can sufficient dustproof and waterproof effects be expected, but also the rotational operating torque of the rotating shaft can be relatively small.
In addition, it is possible to substantially equalize the products, and to always ensure an appropriate tightening margin at the outer peripheral edge of the dust cover.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view showing one embodiment of the present invention;
4 through 4 are enlarged cross-sectional views of essential parts for explaining the operation. 10: Power steering gear, 11: Rotating shaft, 11a
: Housing outer protrusion, 11b: Tapered step (outer periphery),
12: housing, 14: dust cover, 14a: inner peripheral edge, 14b: outer peripheral edge, 14C: bent part, 14d: inner peripheral part, 15: yoke, 17: flat washer.

Claims (1)

[Scope of utility model registration request] In a steering gear in which a yoke is removably assembled to a housing external protrusion of a rotary shaft that is pivotally supported within a housing, the yoke is fitted to the housing external protrusion of the rotary shaft, and the inner peripheral edge thereof is fitted onto the outer circumference of the rotary shaft. An annular dust cover is attached and fixed and slidably contacts the outer surface of the housing at the outer periphery and has an annular flexible bent part in the center, and the inner periphery of this dust cover is attached to the rotation axis. A dustproof and waterproof device for a steering gear, in which the position is determined by a member that is engaged with the dust cover, and a flat washer is inserted between the dust cover and the member.