JPH0525924Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an air breather structure for a vehicle hub, and particularly relates to a hub in which oil is sealed.

<Prior art> There is a conventional example of the air breather structure of this type of vehicle hub as shown in Fig. 2.
59-102505 and Utility Model Application Publication No. 59-186570).

That is, a wheel hub 4 is rotatably supported at the end of the vehicle axle 1 via an inner bearing 2 and an outer bearing 3. An adjusting nut 5 and a locking nut 6 are screwed onto the outer end of the vehicle axle 1.

A hub cap 7 is attached to the outer wall of the wheel hub 4 by bolts 8 so as to cover the outer end of the vehicle axle 1, and a breather 9 is attached to the hub cap 7. An air breather hole 10 is formed in the breather 9 so as to extend substantially coaxially with the vehicle axle 1 . Lubricating oil A is sealed in the inner lower portions of the wheel hub 4 and the breather 9.

The pressure of the air inside the wheel hub 4 is maintained at substantially the same pressure as the atmospheric pressure by the pressure air breather hole 10.

Note that 11 is an oil seal and 12 is a hub bolt.

<Problems to be solved by the invention> However, in such a conventional air breather structure of a vehicle hub, since the hub cap 7 and the breather 9 protrude widely from the outer end of the vehicle axle 1, The problem is that the width of the vehicle increases accordingly. In addition, since the air breather hole 10 of the breather 9 is spaced apart from the outer end of the vehicle axle 1, the lubricating oil A
The liquid level becomes significantly higher on the outside of the vehicle as shown by B in FIG. 2, and in the worst case, the lubricating oil A leaks from the air breather hole 10 and impairs the lubricating function.

The present invention was developed in view of the above circumstances, and allows the air pressure inside the hub to be adjusted.
An object of the present invention is to provide an air breather structure for a vehicle hub that can suppress oil leakage when the vehicle turns.

<Means for Solving the Problems> For this reason, the present invention provides a hub that is rotatably attached to the outer periphery of an axle, a hub cap that is attached to the hub and covers the outer end of the axle,
An air breather structure for a vehicle hub, comprising: a breather attached to the hub cap facing the outer end of the axle; and an air breather hole formed through the breather and communicating between the hollow part of the hub and the atmosphere. A concave portion is formed in the outer end wall of the axle, a convex portion is formed in the inner wall of the breather, and the convex portion is inclined so that the outer circumferential wall becomes thinner toward the tip, and the convex portion is arranged so as to face inside the concave portion. The inner circumferential wall of the concave portion and the outer circumferential wall of the convex portion form a gap in the axle axial direction formed between the outer circumferential portion located at the outer end of the axle and the inner surface of the hub cap facing the outer end of the axle. A narrow gap is formed, and the hollow part of the hub and the air breather hole are communicated through the gap.

<Operation> In the vehicle hub, the axle does not rotate, but the hub attached to the outer periphery of the axle and the hub cap to which the breather is attached rotate.
Here, an inclined convex portion is formed on the inner wall of the breather so that the outer circumferential wall becomes thinner toward the tip. Here, when the oil in the hub hollow portion enters the air breather hole side, the oil flows along the outer peripheral wall of the convex portion.

Since the hub cap is rotating, centrifugal force is generated by the rotation, and the centrifugal force also acts on the outer peripheral wall of the convex portion. Here, since the outer circumferential wall is inclined so that the outer circumferential wall becomes thinner toward the tip, the centrifugal force generates a component force in the axle axis direction on the outer circumferential wall surface. Therefore, even if the oil in the hollow part of the hub adheres to the convex part, the oil is scattered by the component force in the axle axis direction of the centrifugal force generated by the rotation of the hub cap, and the oil is scattered through the air breather hole formed through the breather. to prevent the oil from leaking into the atmosphere from the air breather hole.

Further, a convex portion formed on an inner wall of the breather is arranged to face a concave portion formed on an outer end wall of the axle, and the inner circumferential wall of the concave portion and the outer circumferential wall of the convex portion are arranged to face the outer circumferential wall of the axle. A gap is formed that is narrower than the gap in the axle axial direction formed between the outer circumferential portion of the hub cap and the inner surface of the hub cap facing the outer end of the axle, and the hollow portion of the hub is connected to the atmosphere through the gap. Since the oil in the hollow part of the hub is squeezed when passing through the gap, the oil in the hollow part of the hub faces resistance from entering the air breather hole. be done.

In addition, by making the convex part face the concave part, the height of the hub cap can be reduced and the width of the vehicle can be reduced.

<Example> Below, an example of the present invention will be described based on the drawings. Incidentally, the same elements as those in the conventional example are given the same reference numerals as in FIG. 2, and the explanation thereof will be omitted.

FIG. 1 shows a first embodiment of the present invention.

In the figure, a truncated conical recess 21a is formed in the outer end wall of the vehicle axle 21 so as to be substantially coaxial with the axle 21. On the other hand, wheel hub 4
A hub cap 22 is attached to the outer wall of the axle 21.
A breather 23 is attached to the hub cap 22 to be substantially coaxial with the axle 21.

An air breather hole 24 is formed in the breather 23 so as to pass through the center thereof and is substantially coaxial with the axle 21 . Further, the breather 23 has a protruding flange 23 a having a triangular cross section so as to surround the axle 21 side of the air breather hole 24 . This flange portion 23a is arranged so as to face the recessed portion 21a of the axle 21 by a predetermined amount. That is, the flange portion 23a has a triangular cross section, thereby forming a convex portion formed on the inner wall of the breather 23 such that the outer circumferential wall thereof becomes narrower toward the tip. The outer circumferential wall of the flange 23a is disposed close to the inner circumferential wall of the recess 21a, and a gap c is formed therebetween over the entire circumference.

Further, the plate-shaped lock nut 25 bolted to the adjusting nut 5 is formed to have a larger diameter than the conventional example. Further, the distance c is the distance F in the axle axial direction formed by the outer peripheral portion 21f located at the outer end of the axle 21 and the inner surface 22f of the hub cap 22 facing the outer end of the axle 21. A narrower gap 〓c is formed.

Further, in this embodiment, a radial gap D is formed between the outer circumferential wall of the lock nut 25 and the inner circumferential wall of the hub cap 22 over the entire circumference.

According to this configuration, when the liquid level of the lubricating oil A is maintained approximately horizontally (as indicated by the dashed-dotted line in FIG. Since it is communicated with the atmosphere through the hub 4, the air pressure inside the wheel hub 4 can be adjusted as in the conventional example. On the other hand, when a lateral acceleration is applied to the vehicle, such as when the vehicle turns, the liquid level of the lubricating oil A tilts as shown by B in FIG. In this embodiment, the axle 21 does not rotate, but the wheel hub 4 and the hub cap 22 to which the breather 23 is attached rotate. Here, when the lubricating oil A enters the vicinity of the air breather hole 24, the lubricating oil A passes through the gap c.
At that time, it flows along the flange 23a and adheres to the flange 23a.

Since the hub cap 22 is rotating, centrifugal force is generated by the rotation, and the centrifugal force also acts on the outer peripheral wall of the flange 23a. Here, the outer circumferential wall has a triangular cross section and is inclined so that it becomes thinner toward the tip. Generates an axial component force.

Therefore, even if the lubricating oil A adheres to the flange 23a, the lubricating oil A is scattered by the axial component of the centrifugal force generated by the rotation of the hub cap 22, and is moved away from the air breather hole 24. This prevents the lubricating oil A from leaking into the atmosphere from the air breather hole 24. Furthermore, the recess 21a of the axle 21 and the flange 23a of the breather 23
As a result, even if the liquid level of the lubricating oil A is inclined as shown by B in FIG.
After passing through the interval F, the oil passes through the interval c, which is narrower than the interval F, and is subjected to resistance due to being squeezed. This makes it possible to suppress the lubricating oil A from entering the vicinity of the air breather hole 24, thereby suppressing oil leakage. Also, the flange 2 of the breather 23 attached to the hub cap 22
3a is made to enter the recess 21a of the axle 21 by a predetermined amount, the height of the hub cap 22 (the length in the left-right direction in FIG. 1) can be made smaller than in the conventional example, so the vehicle width can be made smaller than in the conventional example. . Furthermore, since the lock nut 25 and the hub cap 22 form a radial gap D, even if the liquid level of the lubricating oil A is inclined as shown by B in FIG. D can prevent the lubricating oil A from moving to the right from the lock nut 25. Therefore, it is possible to suppress the rise in the liquid level of the lubricating oil A in the hub cap 22 on the right side in FIG. 1 from the lock nut 25.
This also makes it possible to suppress oil leakage from the air breather hole 24.

<Effect of the invention> As explained above, the present invention forms a concave portion on the outer end wall of the axle, and forms a convex portion on the inner wall of the breather that is inclined so that the outer circumferential wall becomes thinner toward the tip. and a convex portion is arranged to face inside the concave portion, and an outer circumferential portion located at an outer end of the axle and an outer circumferential portion of the hub cap are opposed to the outer end of the axle by the inner circumferential wall of the concave portion and the outer circumferential wall of the convex portion. The hollow part of the hub is configured to communicate with the air breather hole through the gap in the axle axial direction formed by the inner surface of the hub. It is possible to prevent oil from entering the air breather hole, thereby suppressing oil leakage. Also,
Since the convex portion faces the concave portion, the height of the hub cap to which the breather is attached can be suppressed, and the vehicle width can be made smaller than in the conventional example.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional example of an air breather structure for a vehicle hub. 4... Wheel hub, 21... Vehicle axle, 21a... Recess, 22... Hub cap, 2
3a... collar, 24... air breather hole.

Claims (1)

[Scope of utility model registration request] a hub rotatably attached to the outer periphery of an axle; a hub cap attached to the hub and covering the outer end of the axle; a breather attached to the hub cap opposite the outer end of the axle; In the air breather structure for a vehicle hub, the air breather hole is formed through the breather and communicates between the hollow part of the hub and the atmosphere, wherein a recess is formed in the outer end wall of the axle, and an outer peripheral wall is formed in the inner wall of the breather. is formed with a convex portion that is inclined so as to become thinner toward the tip, and the convex portion is arranged so as to face inside the concave portion, and the inner circumferential wall of the concave portion and the outer circumferential wall of the convex portion form an outer edge of the axle. A gap is formed that is narrower than a gap in the axle axial direction formed between the outer peripheral portion of the hub cap and the inner surface of the hub cap facing the outer end of the axle, and the hollow portion of the hub and the air breather are connected through the gap. An air breather structure for a vehicle hub characterized by communicating with a hole.