JPH0215081Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil seal, and more particularly, to an oil seal having a compact structure and requiring a small space for installation.

In a normal oil seal, the main lip seals against internal lubricant leakage, and the auxiliary lip prevents external dust from entering, which are integrally formed, so the axial and radial dimensions are small. It is rather long, and sealing performance is forced to be sacrificed in applications where installation space is limited, such as bearing seals used between the inner and outer races of ball bearings and roller bearings. Something happened.

In the present invention, the end of the first radial part extending in the radial direction from one end of the first cylindrical part is made of a rubber-like elastic material and has a substantially truncated conical shape. Extending in the opposite direction of the cylindrical part 1, on the circumferential surface,
A first seal member formed by integrally joining a first seal lip provided with a shallow ventilation groove running approximately in the axial direction; A plurality of second sealing lips made of a rubber-like elastic material and arranged in parallel in the axial direction are integrally connected to an end of the second radial part extending and facing the first radial part. The first sealing lip is in elastic contact with the circumferential surface of the second cylindrical part, and the second sealing lip is bent in the opposite direction to the second cylindrical part, so that the first sealing member is The oil seal is constructed by combining the oil seals so as to make elastic contact with the circumferential surface of the cylindrical portion.

This oil seal is installed so that when the first seal member and the second seal member are combined, the first seal lip and the second seal lip maintain a posture bent in opposite directions. During operation of the device, due to the suction phenomenon at the contact sliding portion of the seal lip, negative pressure is generated in the annular cavity formed between the two seal members, causing the first seal lip and the second seal lip to slide. Although there is a sag that is brought into pressure contact with the target circumferential surface and increases sliding friction, the inside of the annular cavity is maintained at normal pressure by the air passing through the shallow ventilation groove provided on the circumferential surface of the second seal lip. , the above-mentioned troubles due to negative pressure generation are prevented.

The second seal lip, which is made up of multiple pieces arranged in parallel in the axial direction, may cause mutual interference at the tip when bent by the contact surface. By forming different annular grooves so that the bending portions of each piece are at different positions during bending deformation,
The mutual interference described above can be prevented.

Embodiments of the present invention will be described below with reference to the drawings. In the embodiment of FIG. 1, the first cylindrical portion 1 and the first cylindrical portion
The first part has a radial portion 2 of
The radially inner end of the ring is made of a rubber-like elastic material, has a substantially truncated conical shape and extends in the axial direction opposite to the first cylindrical part 1, details of which are shown in FIG. As shown, a first sealing member 5 is formed by integrally firing a first sealing lip 3 having a shallow ventilation groove 4 running approximately in the axial direction on the inner peripheral surface side, and a first cylindrical portion 1. A substantially L-shaped cross-sectional shape having a second cylindrical portion 6 facing the second cylindrical portion 6 and a second radial portion 7 extending outward from the second cylindrical portion 6 and facing the first radial portion 2. On the outer end of the second ring, two pieces of a second sealing lip 9 made of a rubber-like elastic material, extending radially outward and arranged in parallel in the axial direction are integrally sintered. a second seal member 10 consisting of a first seal member 10;
The sealing lip 3 is in elastic contact with the circumferential surface of the second cylindrical portion 6, and the second sealing lip 9 is bent toward the opposite side of the second radial portion to elastically contact the circumferential surface of the first cylindrical portion 1. combined with each other in such a way that they are in contact with each other,
The first cylindrical part 1 is the outer member of the two members that are arranged concentrically with each other and make relative rotational movement, and the second cylindrical part 6 is the inner member of the two members that have relative rotational movement. They are fitted and fixed, and the first seal lip 3 acts as a seal against the lubricant on the right side of the figure, and the second seal lip 9 acts as a seal against the lubricant on the right side of the figure.
It acts to prevent dust and other particles in the atmosphere from entering the lubricant side, which is shown on the left side of the figure, and due to the suction phenomenon at the sliding part of the seal lip,
When a negative pressure state is formed in the annular cavity 15 formed between 0 and 0, the negative pressure state is dissipated by the air passing through the shallow ventilation groove 4.

The second seal lip 9, which has two pieces arranged in parallel, has annular grooves on one side surface at different positions in the radial direction, so that the second seal lip 9 comes into contact with the circumferential surface of the first cylindrical portion 1. This prevents mutual interference at the tips when bending and deforming. That is, the two pieces of the second seal lip 9, which are not provided with an annular groove or are provided at the same position in the radial direction, bend when being bent and deformed due to contact with the mating circumferential surface, as shown in FIG. When the radial positions of the parts are approximately the same, mutual interference occurs and the maintenance of normal sealing performance is inhibited. However, as shown in FIG. In the case where the radial position of the annular groove 13 of the second seal lip 9 is formed outward from the radial position of the annular groove 13 of the second seal lip 9 on the atmosphere side, as shown in the figure. , the bent part of the second seal lip 9 on the first radial part 1 side is located radially outward compared to the bent part of the second seal lip 9 on the atmosphere side. The seal lip 9 of the seal lip 9 is inclined more toward the atmosphere than the second seal lip 9 on the first radial portion 1 side, and as a result,
Mutual interference between both seal lips 9,9 is avoided,
Seal performance is maintained at a high level.

As described above, the oil seal of the present invention is made of a rubber-like elastic material at the end of the radial part of the first ring, which has a substantially truncated conical shape, and has an inner part that has a substantially truncated conical shape. a first sealing member which is joined to a first sealing lip having a shallow ventilation groove running approximately axially on the circumferential surface; and a radial portion of a second ring having a generally L-shaped cross section. a second sealing member having a plurality of pieces of second sealing lips made of a rubber-like elastic material coupled to the end of the second sealing member, each sealing lip being in elastic contact with the circumferential surface of the other cylindrical portion. By having a configuration in which they are connected in such a manner that the structure is compact and the space occupied is minimized, it also has the function of preventing internal lubricant from leaking and preventing external dust from entering, and also prevents internal space from entering. Since the function of preventing negative pressure generation in both cases is well maintained, the practical value is extremely high.

In the illustrated embodiment, the first sealing lip 3 is located inwardly with respect to the first cylindrical portion 1, and the second sealing lip 9 is located outwardly with respect to the second cylindrical portion 6. However, the present invention is not limited to this, and may include a structure in which the first seal lip 3 is located outward with respect to the first cylindrical portion, and the second seal lip 9 is located inward with respect to the second cylindrical portion 6. You can also do it.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the structure of an oil seal according to the present invention, and FIG.
3 and 4 are partial cross-sectional views showing bending deformation of the parallel seal lips. 1... First cylindrical part, 2... First radial part,
3...first seal lip, 4...shallow groove for ventilation,
5...First sealing member, 6...Second cylindrical part,
7... Second radial portion, 9... Second seal lip, 10... Second seal member, 13... Annular groove, 15... Annular cavity.

Claims (1)

[Scope of utility model registration request] An end portion of a first radial portion 2 extending in the radial direction from the first cylindrical portion 1 is made of a rubber-like elastic material and has a substantially truncated conical shape. A first seal member 5 is integrally connected with a first seal lip 3 extending in the opposite direction of the first seal lip 3 and having a shallow ventilation groove 4 extending substantially in the axial direction on its circumferential surface.
A rubber-like elastic member is provided at an end of a second radial portion 7 extending radially from a second cylindrical portion 6 facing the first cylindrical portion 1 and facing the first radial portion 2. A second sealing member 10 is formed by integrally joining a plurality of second sealing lips 9 made of a material and arranged in parallel in the axial direction, the first sealing lip 3 is connected to the second cylindrical part. 6, the second seal lip 9 is bent in the opposite direction to the second cylindrical portion 6, and the second seal lip 9 is bent in the opposite direction to the second cylindrical portion 6.
An oil seal is assembled so as to come into elastic contact with the circumferential surface of a cylindrical portion 1.