JPH0540362Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a sealing device, and particularly to a sealing device in which oil in the sliding portion of the seal lip is increased to improve the lubrication state of the seal lip.

(Prior Art) Conventionally, as such a sealing device, there is a sealing device 100 as shown in FIGS. 3 and 4. The sealing device 100 has a single sealing lip 102 mounted with a spring 101.
02 is brought into pressure contact with the surface of the shaft 105 to prevent leakage of oil or the like. Reference numeral 103 denotes a metal ring that is integrally attached to the outer periphery of the sealing device 100 by baking or the like, and the outer peripheral surface of the metal ring 103 is the inner end in the axial direction, that is, the end in the insertion direction of the sealing device 100. (in the illustrated embodiment, the right end of the sealing device 100) includes the sealing device 100.
A guide protrusion 103 having an outer diameter larger than the inner diameter of the mounting hole of the housing into which the housing is to be inserted projects radially outward. This guide protrusion 103a is the metal ring 1
It may extend continuously over the entire circumference of 03, or it may be divided into a plurality of parts by providing a predetermined pitch in the circumferential direction. 103b is a small diameter surface portion of the outer peripheral surface of the metal ring having an outer diameter smaller than the outer diameter of the guide protrusion 103a;
The outer diameter of the housing substantially matches the inner diameter of the housing mounting hole.

Here, the seal lip 102 has a lip sliding portion 104, and the lip sliding portion 104 includes a sealed fluid side inclined surface 104a and an atmosphere side inclined surface 104b.
and has.

(Problems to be solved by the invention) However, such a conventional sealing device 100
According to the above, oil flows along the sealed fluid side inclined surface 104a in a low lubrication state (oil amount: several mm above the lower end of the shaft) using less than a specified amount of lubricating oil. As a result, the amount of oil in the lip sliding portion 104 decreases, and cracks occur in the seal lip 102 due to insufficient lubrication, causing oil leakage.

The present invention was developed in view of the above-mentioned problems, and its purpose is to secure oil in the sliding parts that lip under low lubrication conditions, to prevent cracks from occurring in the seal lip, and to prevent oil leakage. The objective is to provide a sealing device that can prevent this.

(Means for Solving the Problems) The present invention having the above-mentioned object has a seal lip that seals the fluid in contact with the movable shaft, and the lip sliding surface on the sealed fluid side is directed from the tip of the lip toward the sealed fluid side. a tapered surface portion that tapers outward perpendicular to the axis of the movable shaft; a curved surface portion that is continuous with the tapered surface portion and is concave inwardly that is perpendicular to the axis of the movable shaft; It is characterized by providing an annular groove formed by a substantially vertical inwardly facing vertical surface portion.

(Function) According to the sealing device of the present invention, there is a tapered surface portion that is tapered outward perpendicular to the axis of the movable shaft from the tip end of the lip toward the sealed fluid side, and a movable shaft that is continuous with the tapered surface portion. An annular groove formed by an inwardly concave curved surface perpendicular to the axis of the movable shaft and an inwardly directed vertical surface part that is continuous with the curved surface and is approximately perpendicular to the axis of the movable shaft. Since it is provided on the sliding surface, the sealing fluid that flows along the tapered surface in low lubrication conditions is redirected at the curved surface and flows inward approximately perpendicular to the axis at the vertical surface. Convection of the sealing fluid occurs within the annular groove, and the flowing sealing fluid is returned toward the tip of the lip.

Therefore, a specified amount of oil is retained in the lip sliding part, and cracks in the seal lip due to lack of lubrication do not occur, thereby preventing oil leakage.

(Example) The sealing device of the present invention will be described below based on the illustrated example.

FIG. 1 shows the entire sealing device 1 of the present invention. The sealing device 1 has a sealing lip 2. The seal lip 2 has an annular groove 3 on the outer circumferential side, and a spring 4 is fitted into the annular groove 3. The spring 4 has the function of increasing the pressing force to press the seal lip 2 against the movable shaft 5 and maintaining the seal lip 2. do. Such a seal lip 2 is pressed against the surface of the movable shaft 5 to prevent oil leakage. 6a is a metal ring that is integrally attached to the outer periphery of the seal lip 2 of the sealing device 1 by baking or the like. The seal lip 2 also includes a lip sliding portion 6 that comes into contact with the movable shaft 5 and acts to prevent oil leakage. The lip sliding portion 6 includes a lip sliding surface 7 on the sealed fluid side and a movable shaft 5.
It has a tip end portion 10 of the lip that comes into contact with the lip and a sliding surface 8 facing the atmosphere. The lip sliding surface 7 of the sealing fluid is provided with an annular groove 9, and in cross section, the annular groove 9 tapers outward perpendicular to the axis of the movable shaft 5 from the lip tip 10 toward the sealing fluid side. A tapered surface portion 9a that is continuous with the tapered surface portion 9a and concave inwardly perpendicular to the axis of the movable shaft 5; and a facing vertical surface portion 9c. The end of the curved surface portion 9b faces in a substantially vertical direction and is substantially orthogonal to the axis of the movable shaft 5.

The sealing device 1 configured as described above operates as follows. That is, when the movable shaft 5 rotates,
The oil in the lip sliding portion 6 flows along the tapered surface portion 9a of the lip sliding surface 7 toward the sealing fluid side. The oil flowing toward the sealing fluid side of the rip sliding surface 7 reaches the curved surface portion 9b of the groove. The inner surface of the curved surface portion 9b is
As described above, the direction is changed from the outward direction to the inward direction, and the vertical surface portion 9c is substantially perpendicular to the axis of the movable shaft 5. Therefore, the oil that has reached the curved surface portion 9b changes its direction from the outer circumferential direction to the inner circumferential direction along the inner surface of the curved surface portion 9b. Finally, the sealing fluid flows on the moving shaft 5 in the vicinity of the ripping sliding part 6 and becomes convection, and the flowing sealing fluid is returned toward the lip tip 10 again.

Therefore, a specified amount of oil is always supplied to the lip tip 10 of the lip sliding part 6, preventing insufficient lubrication, preventing excessive wear of the seal lip, and preventing oil leakage due to cracks, etc. Sealing performance is improved because no blemishes occur.

(Effect of the invention) According to the invention, there is a tapered surface portion that is tapered outward perpendicular to the axis of the movable shaft from the tip end of the lip toward the sealed fluid side, and a tapered surface portion that is continuous with the tapered surface portion and is perpendicular to the axis of the movable shaft. An annular groove formed by an inwardly concave curved surface and an inwardly facing vertical surface that is continuous with the curved surface and is substantially perpendicular to the axis of the movable shaft is used as a lip sliding surface on the sealed fluid side. Since the sealing fluid that flows along the tapered surface in low lubrication conditions is
The direction of the sealing fluid is changed at the curved surface portion, and is caused to flow inward substantially perpendicular to the axis at the vertical surface portion, convection of the sealing fluid occurs within the annular groove, and the flowed sealing fluid is returned toward the tip of the lip.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of the sealing device of the present invention, Fig.
The figure is a partial vertical sectional view of the main parts of the sealing device of the present invention.
FIG. 3 is a longitudinal sectional view of a sealing device according to the prior art;
FIG. 4 is a partial longitudinal sectional view of a prior art sealing device. Explanation of symbols: 1...Sealing device, 2...Seal lip, 3...Annular groove, 4...Spring, 5...Movable shaft, 6...Rip sliding part, 6a...Metal ring,
7... Rip sliding surface on the sealed fluid side, 8... Rip sliding surface on the atmospheric side, 9... Annular groove, 9a...
Plane portion, 9b...Curved surface portion.

Claims (1)

[Scope of utility model registration request] The lip sliding surface on the sealing fluid side of the seal lip that seals the fluid in contact with the movable shaft has a tapered surface portion that tapers outward perpendicular to the axis of the movable shaft from the tip of the lip toward the sealing fluid side. An annular shape formed by an inwardly concave curved surface part that is continuous with the tapered surface part and is perpendicular to the axis of the movable shaft, and a vertical face part that is continuous with the curved surface part and faces inward and is substantially perpendicular to the axis of the movable shaft. A sealing device characterized by having a groove.