JP2513644Y2 - Wheel hub oil seal - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel hub oil seal for sealing between a wheel hub and an axle housing, and more particularly to a wheel hub oil seal whose outer peripheral portion is in close contact with the wheel hub side.

[0002]

2. Description of the Related Art A large-sized vehicle often employs a so-called all-floating type drive axle in which the vehicle body weight is received by an axle tube (axle housing) and the drive moment is received by an axle (axle shaft). With such an all-floating drive axle,
The vehicle body weight is transmitted from the axle housing via bearings to the wheel hub integrated with the axle shaft, and the weight is transmitted from the wheel hub to the tire side. Here, grease for lubrication or the like is sufficiently supplied to the bearing between the axle housing and the wheel hub, and the outflow of the grease or the like to the outside is blocked by an oil seal.

In an all-floating type drive axle used in a truck as shown in FIG. 5, for example, the flange portion 3 of the axle housing 1 and the axle shaft 2 is integrally tightened by a hub nut 4 as shown in FIG. To be done. Prior to that, the tubular flange 8 of the oil seal 7 is tightly fitted into the annular groove 6 at the end of the wheel hub 5. As a result, the inner space 9 of the oil seal 7 is made airtight, and the leakage of grease and the like to the outside is prevented.

[0004]

When the vehicle travels after the inner space 9 is thus hermetically sealed by the oil seal 7, the inner space of the wheel hub 5 is rotated around the rotation center line C of the axle housing 1. The temperature of the chamber 8 rises due to frictional heat or the like, and conversely when the vehicle is parked, the temperature drops due to heat radiation. Such temperature changes are repeated, and eventually, when maintenance such as replenishing grease of the wheel bearing 9 is performed, the following problems occur.

That is, during maintenance of the vehicle, the inner space 9 is cooled to a negative pressure. Therefore, the oil seal 7, which is tightly fitted in the annular groove 6, further receives an adhesion force on the inner space 9 side. Therefore, when the oil seal 7 is to be removed, it cannot be detached unless a large detaching force is applied, and as a countermeasure against this, it is necessary to apply oil to the outer peripheral rubber portion 801 of the oil seal 7 in advance at the time of assembling. was there. Also, if you forget it, the workability is very poor, which is a problem. An object of the present invention is to provide an oil seal for a wheel hub that has good workability in attachment and detachment.

[0006]

In order to achieve the above-mentioned object, the present invention provides a cylindrical flange fitted in an annular groove of an axle hub and an annular sealing surface of an axle housing pivotally supporting the axle hub. It has a contacting annular lip portion and a main portion in which the annular lip portion and the tubular flange are integrally formed on the inner and outer peripheral portions, and the tubular flange bulges toward the bottom surface of the annular groove and bulges. Sometimes the annular groove bottom
An annular seal portion is formed that abuts a surface along the axial direction of the surface, and an annular bulging portion is pressed on the main portion by the surface along the radial direction of the flange portion of the axle shaft bolted to the axle hub. Is formed, and an elastic displacement transmitting portion is formed between the annular bulging portion and the annular seal portion.

[0007]

[Action] When the flange portion of the axle shaft is bolted to the axle hub, the ring <br/> curved portions is compressed and deformed by being pressed by the surface along the radial direction of the flange, depending on the compressive deformation
The elastic displacement transmission part and the annular seal part elastically deform,
The annular seal part is expanded and deformed along the axial direction of the bottom surface of the annular groove.
Pressed against the surface . On the contrary, when the collar part of the axle hub and the axle shaft is separated , the surface of the collar part along the radial direction is separated .
The annular bulging portion, the elastic displacement transmitting portion, and the annular seal portion that have released the pressing force elastically return, and the annular seal portion is annular groove.
The inner space can be made atmospheric pressure by separating from the surface along the axial direction of the bottom surface .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The oil seals of the wheel hubs shown in FIGS. 1 and 2 are mounted on an all floating drive axle similar to that shown in FIG. 5, and when the wheel hub 5 rotates relative to the rotation center line C of the axle housing 1. It also functions to maintain the airtightness between the two. Here, the oil seal 10 in the free state is shown in FIG.
However, FIG. 2 shows the oil seal 10 when the assembly is completed. As shown in FIG. 1, the oil seal 10 here
Is a tubular flange 12 fitted in the annular groove 6 at the end of the wheel hub 5, an annular lip portion 13 slidingly contacting the annular seal surface 11 at the end of the axle housing 1, an annular lip portion 13 and a tubular flange. It is composed of a main portion 14 in which 12 is continuously formed on the inner and outer peripheral portions, and a ring spring 15 for bringing the annular lip portion 13 into contact with the annular sealing surface 11.

A rubber layer R is evenly bonded to the outer surface of the oil seal, and in particular, the central annular lip portion 13 is entirely formed of rubber. Further, in the rubber layer R, the axle shaft 2 is provided on the outer peripheral end side of the main portion 14.
An annular bulge portion a that bulges toward the flange portion 3 side is formed, and an annular seal portion b that bulges toward the bottom surface of the annular groove 6 is formed on the outer peripheral surface side of the tubular flange 12, and the annular bulge portion extends. An elastic displacement transmission portion c is formed between the portion a and the annular seal portion b (see FIGS. 3A and 3B).

Here, the outer diameter of the oil seal 10, that is,
The outer diameter of the annular seal portion b is set to be smaller than the inner diameter of the annular groove 6 by a predetermined amount, whereby the detachability of the oil seal 10 with respect to the annular groove 6 is improved. Further, when the oil seal 10 is fitted in the annular groove 6, the annular bulging portion a is formed so as to secure a protrusion amount δ from the end portion of the wheel hub 5, as shown in FIG. There is. The elastic displacement transmitting portion c substantially keeps the wall thickness of both the annular bulging portion a and the annular seal portion b whose protruding directions are deviated by 90 degrees, and the elastic displacement of the both is moved from the annular bulging portion a to the annular seal portion b. It is formed to work together.

Such an oil seal 10 is shown in FIGS.
In the case of mounting on the all-floating type drive axle, first, the oil seal 10 is fitted into the annular groove 6 as shown in FIG. After this,
The collar portion 3 of the axle shaft 2 is brought into contact with the end portion of the wheel hub 5, the hub bolt 4 is tightened, and the collar portion 3 and the wheel hub 5 are integrated.

By this tightening, in the radial direction of the collar portion 3.
The cylindrical flange 12 receives the pressing force F1 by the surface along
When the end of is pressed to the stopper surface side of the bottom surface of the annular groove 6,
At the same time, the annular bulging portion a of the oil seal is compressed and deformed as shown in FIG. The elastic displacement transmitting portion c presses the annular seal portion b in the axial direction X in conjunction with this compressive deformation. Then, the annular seal part b is compressed in the axial direction X, and the pressing force F2 acts on the protruding end of the annular seal part b in the radial direction Y, so that the protruding end is closed.
The ring groove 6 is bulged and displaced in the radial direction so that it extends along the axial direction of the lower surface of the annular groove 6.
It will come into pressure contact with the surface . As a result, FIG. 2 and FIG.
As shown in (b), the oil seal 10 can completely seal the internal space 9 from the outside, and can prevent the grease and the like from flowing out of the internal space.

On the other hand, during maintenance, when the hub bolt 4 is loosened and the collar portion 3 of the axle shaft 2 is disengaged from the end portion of the wheel hub 5, the annular bulging portion a returns to the free state. In conjunction with this, the elastic displacement transmission part c and the annular seal part b return in the axial direction X and return to the free state. As a result, the annular tip portion of the annular seal portion b returns toward the center line C, is displaced, and is separated from the lower surface of the annular groove 6. As a result, the airtightness of the internal space 9 is released to atmospheric pressure, the tensile force due to the negative pressure of the internal space 9 does not act on the oil seal, and the oil seal 10 is smoothly removed from the annular groove 6. Will be done.

Although the rubber layer R is formed over the entire area of the oil seal 10 in the above-mentioned process, in some cases, the annular bulging portion a, the annular sealing portion b, the elastic displacement transmitting portion c and the annular lip portion are formed. The oil seal may be configured by excluding the rubber layer of other portions except 13.

[0015]

[Effect of the Invention] As described above, this invention is an axle hub.
When the collar of the axle shaft is bolted to the
The annular bulge is pressed by the surface along the radial direction of the
The elastic deformation transmission part and the annular seal are
Of the ring groove, the annular seal part expands and deforms to form an annular groove.
Since it comes into pressure contact with the surface along the axial direction of the bottom surface,
Simplifies the work of assembling the oil seal to ensure tightness
it can. Furthermore, when the collar part of the axle hub and the axle shaft is separated , the pressing force by the surface along the radial direction of the collar part
The ring-shaped bulge, the elastic displacement transmitter and the ring-shaped seal where the force has been released.
Lumpur portion is elastically restored, the annular seal portion of the annular groove bottom
Detach from the surface along the axial direction, make the inner space atmospheric pressure,
The oil seal can be taken out easily, and the oil seal detachability during maintenance can be improved.

[Brief description of drawings]

FIG. 1 is a partial sectional view of an oil seal of a wheel hub in a free state according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the wheel hub of FIG. 1 with an oil seal attached.

3A is an enlarged cross-sectional view of a main part of a rubber layer R in FIG. 1 in a free state, and FIG. 3B is an enlarged cross-sectional view of a main part of the rubber layer R in FIG. 2 when elastically deformed. is there.

FIG. 4 is a partial cross-sectional view of a conventional oil seal mounted on an all-floating drive axle.

FIG. 5 is a cross-sectional view of a main part of an all-floating drive axle.

[Explanation of symbols]

 1 Axle Housing 2 Axle Shaft 3 Collar 5 Wheel Hub 6 Annular Groove 9 Inner Space 10 Oil Seal 11 Annular Seal Surface 12 Cylindrical Flange 13 Annular Lip 14 Main Part a Annular Swelling b Annular Seal c c Elastic Displacement Transmitter

Claims (1)

(57) [Scope of utility model registration request] 1. A tubular flange fitted into an annular groove of an axle hub, an annular lip portion slidably contacting an annular sealing surface of an axle housing pivotally supporting the axle hub, and the annular lip portion and the tubular flange being inside and outside. The tubular flange has a main portion integrally formed with the peripheral portion and bulges toward the bottom surface of the annular groove, and at the time of bulging, a surface along the axial direction of the annular groove bottom surface.
An annular seal portion that abuts is formed, and an annular bulge portion that is pressed by the surface along the radial direction of the flange portion of the axle shaft that is bolted to the axle hub is formed in the main portion. An oil seal for a wheel hub, characterized in that an elastic displacement transmitting portion is formed between and the annular seal portion.