JPH0210378Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an oil seal device. More specifically, the present invention relates to an oil seal device that prevents oil or grease under pressure from flowing out and also prevents dirt and the like from entering from the outside.

There is a prior art related to the present invention as shown in FIG. FIG. 1 is a sectional view showing an oil seal for grease. The shaft member 52 is provided with a mounting groove 53 for mounting the oil seal 51, and a mounting portion 54 of the oil seal 51 is fitted into the mounting groove 53 and is held from the outer peripheral surface by a garter spring. A seal lip 55 extending from the mounting portion 54 and having a substantially arcuate cross-sectional shape,
It is in elastic contact with a cylindrical sliding surface formed on the relative rotation member 56. With this configuration, it is intended to prevent the grease inside from flowing out to the outside, and also to prevent dirt and the like from entering from the outside. Particularly in cases where there is heavy penetration of earth and sand from the outside, pressure must be constantly applied to the internal grease. However, when pressure is applied to the grease, the seal lip 55 of the oil seal 51 elastically deforms outward as shown by the imaginary line, and the seal surface opens from the sliding surface, causing the grease to flow out and the external dirt etc. There is a problem of infiltration.

The present invention was developed in view of the above-mentioned problems, and its technical problem is to press the inner grease to prevent dirt and sand from entering, as well as to prevent the grease from flowing out. be.

The oil seal device of the present invention is configured as follows in order to solve the above-mentioned problems.

A mounting groove is formed in one of the shaft member and the relative rotation member which are combined concentrically with each other to form an oil chamber in the middle, and a mounting groove is formed in the other of the shaft member and the relative rotation member. a radial surface located rearward in the axial direction, and a sliding peripheral surface having a conical shape and sandwiching an acute angle between the shaft member and the radial surface; an oil seal disposed between the relative rotation member, a mounting portion mounted in the mounting groove, and an oil seal extending obliquely from the mounting portion toward the sliding peripheral surface;
a pressure contact surface sandwiching an acute angle smaller than the included angle between the sliding circumferential surface and the radial surface between the radial surface and the opposite end surface; It has a seal lip formed with a seal portion for contacting the.

By configuring as described above, the following unique effects are achieved. Since the included angle between the end face and the pressure contact surface of the sealing part of the oil seal is smaller than the included angle between the radial direction surface and sliding circumferential surface of the mating member for relative rotation, the inner part of the two members When no internal pressure is applied to the oil being applied, only the tip of the seal portion comes into close contact with the sliding peripheral surface, and close contact pressure is formed in the sharp shape, exerting the sealing ability.
Furthermore, when pressure is applied to the oil, the pressure contact surface also comes into contact with the sliding peripheral surface, and the annular seal lip prevents the oil from flowing outward, and also prevents the oil from flowing outward. Against intrusion,
The end face of the seal portion is brought into close contact with the radial surface of the relative rotation member to provide an effective blocking effect.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

In the embodiment shown in FIG. 2, a shaft member 1 having a mounting groove 2 formed therein, and a relative rotation member 10 having a sliding portion 12 having a sliding circumferential surface 11 and a radial surface 11 sandwiching an acute angle therebetween, The mounting grooves 2 are made to protrude from the radial surface 11 and are combined concentrically with each other, and an oil chamber 1 is provided in the middle.
3 and is made of a rubber-like elastic material.The oil seal 6 has an annular mounting portion 4 attached to the mounting groove 2, is held by a garter spring 9, and extends outward from the mounting portion 4. A seal portion 7, which is formed at the tip of the seal lip 5 and has a pressure contact surface 8 and an end surface 8' that sandwich an acute angle smaller than the included angle between the sliding circumferential surface 11 and the radial surface 11', is attached to the relative rotation member 10. It is brought into contact with the sliding portion 12.

Grease is constantly supplied into the oil chamber 13 between the shaft member 1 and the relative rotation member 10 through the oil hole 3 from a supply section (not shown), and the oil chamber 13 is pressurized as necessary.

The present invention constructed in this way has seal lips 5.
The tip of the seal portion 7 is assembled in close contact with the sliding portion 12. The present invention is used in a tunnel excavating machine, etc., and when earth and sand are thrown up, the inner oil chamber 13 between two members rotates relative to each other.
Apply pressure as if you were constantly replenishing the area with grease. When pressure is applied to the grease in this way, the seal lip 5 is pressed outward by the grease, but the seal lip 5 has its pressure contact surface 8 in contact with the sliding circumferential surface 11 and the seal lip 5 is pushed outward by the grease. This prevents elastic deformation and also prevents grease from flowing out. And, the invasion of foreign foreign matter is effectively prevented. On the other hand, even if dirt or the like comes into contact with the seal lip 5 from the outside, the end face 8' of the seal lip 5 and the sliding part 12 will be damaged as shown by the imaginary line in FIG.
The sliding peripheral surface 11' of the sliding surface 11' is in contact with the sliding peripheral surface 11' to effectively prevent foreign particles from entering.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional oil seal, and FIG. 2 is a sectional view of an oil seal device according to an embodiment of the present invention. 1...Shaft member, 2...Mounting groove, 3...Oil hole, 4
... Mounting part, 5 ... Seal lip, 6 ... Oil seal, 7 ... Seal part, 8 ... Pressure contact surface, 8'...
... End face, 9 ... Garter spring, 10 ... Relative rotating member, 11 ... Sliding peripheral surface, 11' ... Radial direction surface, 12 ... Sliding part, 13 ... Oil chamber, 51 ... Oil seal , 52... Shaft member, 53... Mounting groove,
54...Mounting part, 55...Seal lip, 56...
...Relative rotating member.

Claims (1)

[Scope of utility model registration request] A mounting groove 2 is formed in one of the shaft member 1 and the relative rotation member 10, which are combined concentrically to form an oil chamber 13 in the middle, and the other of the shaft member 1 and the relative rotation member 10 is formed with a mounting groove 2. A radial surface 1 located axially rearward relative to the mounting groove 2
1' and a conical sliding peripheral surface 11 sandwiching an acute angle between the shaft member 1 and the radial surface 11'. An oil seal 6 disposed between the mounting grooves 2 and 10 extends obliquely from the mounting portion 4 toward the sliding circumferential surface 11, and is attached to the radial surface 11'. The sliding peripheral surface 11 and the radial surface 11' are located between the opposing end surfaces 8'.
An oil seal device having a seal lip 5 having a pressure contact surface 8 which pinches an acute angle smaller than the included angle between the two.