JPH07208610A - Oil seal - Google Patents

Abstract

PURPOSE:To restrain thermal deformation of a lip, so as to enable its sealing performance to be maintained for a long period by providing blades on the outer surface of an inner ring and the side surface on the atmospheric side of an outward flange to feed air to the contact part of the lip with the outward flange. CONSTITUTION:In an inner ring 3, blades 12 are integrally provided on the outer surface and the side surface 8 on the atmospheric side of an outward flange 6 at the distances in the circumferential direction, so as to cool a lip 9 by feeding air to the contact part of the lip 9 with the outward flange 6. These blades 12 are provided by obliquely intersecting the axial direction of the inner ring 3, so as to feed air to the contact part of the lip 9 with the outward flange 6, and also it is made thinner so as to carry away heat from the outward flange 6. Since deformation of the lip, to be generated caused by frictional heat can be prevented, the constant sealing performance can be maintained for a long period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil seal provided at the end of a rotary shaft such as a crank shaft.

[0002]

2. Description of the Related Art FIG. 3 shows the structure of a conventionally proposed oil seal (Japanese Utility Model Laid-Open No. 1-174680). This conventional oil seal 1 is composed of an outer ring 2 and an inner ring 3 that is accommodated in the outer ring 2 in a double-tube manner. The oil seal 1 includes a shaft end portion of a rotary shaft 4 such as a crank shaft and a crank case. Housing 5
Is designed to eliminate oil leakage at the shaft end portion of the rotating shaft 4 and is provided between the inner and outer ends of the rotating shaft 4 to prevent oil leakage from the shaft end portion of the rotating shaft 4. An outward flange (slinger) 6 is provided at the end of the ring 3 on the inner side of the housing to shake off the oil by centrifugal force, and the outer ring 2 is separated from the outward flange 6 toward the atmosphere side and the rotary shaft 4 is provided.
An inward flange 7 surrounding the outer periphery of the inward flange 7 and the outward flange 6 so as to extend from the tip of the inward flange 7 toward the tip of the outward flange 6, and A rubber lip 9 is attached so that the extended end portion of the outward flange 6 is brought into contact with the side surface 8 on the atmosphere side to form a seal.

Further, in this conventional oil seal 1, it is said that the end portion of the inner ring 3 on the inner side of the housing is spirally expanded and oil is naturally returned to the inner side of the housing by the rotation of the inner ring. The structure is also adopted.

The oil seal is JASO F 401 11
Species, standardized.

[0005]

However, in a structure in which the tip of the lip and the side surface of the outward flange on the atmosphere side are always in contact with each other in order to prevent oil leakage, the temperature of the lip rises due to these frictions. Therefore, there is a problem that the lip is thermally deformed by the frictional heat accompanying the increase in rotation speed and the sealing function is impaired (especially for engines, the use of the exhaust brake). It has been reported that the internal pressure of the crankcase, which is the housing, rises, and the pressing force of the lip is strengthened, and the high frictional heat causes significant damage.)

An object of the present invention is to provide an oil seal constructed so as to prevent thermal deformation of the lip and maintain its sealing function for a long period of time.

[0007]

In order to achieve the above object, the present invention is provided between an end of a rotary shaft and an housing, which is composed of an inner ring and an outer ring, to prevent oil leakage from the housing. In the oil seal, an inner ring that is integrally fitted to the outer surface of the rotating shaft is formed with an outward flange that is a slinger at the inner end of the housing, and an inner surface of the outer ring that is fitted to the inner surface of the housing. , An inward flange is formed at a position distant to the atmosphere side from the outward flange so that the rotary shaft can be surrounded, and the inward flange and the outward flange extend from the inward flange to the outward flange side. A rubber lip is provided so that its extended end can contact the atmosphere side surface of the outward flange, and the lip and the outward flange are provided on the outer surface of the inner ring and the atmosphere side surface of the outward flange. To the contact portion is provided with a blade to obtain feeding air.

[0008]

The wing rotates integrally with the rotary shaft and sends air to the contact portion between the lip and the outward flange. Therefore, the temperature rise of the lip is prevented, and the thermal deformation of the lip due to frictional heat is diverted.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a cross section of a main part of a crankcase of an engine along a longitudinal direction of a crankshaft. The crankshaft 4, which is a rotating shaft, is rotatably supported by a crankcase 5 and a cylinder body, which are its housing, through a slide bearing (journal bearing) not shown. The crankcase 5 is a shaft of the crankshaft 4. At the end, the oil seal 1 seals liquid-tightly.

The oil seal 1 is composed of a metal inner ring 3 and an outer ring 2 which are fitted in a double pipe shape with each other. The inner ring 3 has an inner diameter and the outer ring 2 have an outer diameter. 3 is determined so that it can be integrally fitted to the outer surface of the crankshaft 4,
The outer ring 2 is the inner surface 1 of the bearing housing of the crankcase 5.
It has been determined that it can be fitted to zero. Also, inner ring 3
Has an outward flange 6 that extends outward in the radial direction integrally at the inner end of the crankcase 5.
Oil attached to the outward flange 6 (engine oil)
It is designed so that it can be swung outwards in the radial direction by centrifugal force. That is, this outward flange 6 becomes a slinger. On the other hand, on the outer ring 2, the crankshaft 4 is provided at a position appropriately separated from the outward flange 6 in the axial direction of the crankshaft 4.
The inward flange 7 is integrally formed so as to surround the inward flange 7.
A rubber lip 9 is attached so as to extend from the front end of the outer flange 6 toward the outward flange 6 and the extended end can be brought into contact with the front end of the atmospheric side surface 8 of the outward flange 6. In the present embodiment, the rubber lip 9 is made of a rubber material having pressure resistance, heat resistance, oil resistance, cold resistance, and abrasion resistance (for example, silicone rubber, fluororubber), and its base is It is integrally attached to the front end face of the facing flange 7 and both side faces of the front end face of the inward flange continuous with the front end face by baking or gluing. A curved portion 11 is provided at a portion on the inner side of the crankcase 5 with respect to the mounting portion so that the lip 9 has appropriate flexibility.

As shown in FIGS. 1 and 2, in order to prevent the rubber lip 9 from being deformed by frictional heat, the inner ring 3 is provided with
The wings 12 are circumferentially spaced so that air can be sent to the contact surface between the lip 9 and the outward flange 6 to cool the lip 9 by air to the outer surface and the side surface 8 of the outward flange 6 on the atmosphere side. Are provided integrally.

As shown in FIG. 2, these blades 12 are provided obliquely intersecting the axial direction of the inner ring 3 so that air can be sent toward the contact portion between the lip 9 and the outward flange 6. In addition, it is formed thin so that heat can be taken from the outward flange 6. In this case, the wing 12
May be bent three-dimensionally like a general pump blade to improve the air feeding.

Therefore, with such a structure, the rubber lip 9 is not deformed by heat, and oil leakage from the crankcase 5 to the outside is prevented. Also, the wings 12
Since the air pressure due to the air acts as it is on the lip 9 as a pressure for supporting the lip 9, the contact pressure between the outward flange 6 and the lip 9 is maintained even when the internal pressure of the crankcase is high such as in an exhaust brake. It does not become abnormally high, and also in this respect, thermal deformation of the lip 9 can be prevented.

However, in order to cool the lip 9, the atmosphere is directly supplied to the contact portion between the lip 9 and the outward flange 6, so that dust and mist in the atmosphere are supplied to these contact portions. However, there is a problem in that dust is supplied and the lip wears abnormally.

For this reason, in this embodiment, as shown in FIG. 1, the side surface of the inward flange 7 on the atmosphere side is recessed inward of the crankcase 5 to form a circle of the crankshaft 4. A step portion 13 is formed along the circumferential direction, and a disc-shaped dust seal 14 made of felt having an appropriate thickness is integrally adhered to the step portion 13. The air sent to the contact portion is filtered by the dust seal 14. I am trying to do it. As a matter of course, the dust seal 14 has a hole 15 for surrounding the outer peripheral surface of the inner ring 3 at the axial center thereof, and is folded back so as to frame the hole 15 so that it can be slidably contacted with the outer peripheral surface of the inner ring. A folded portion 16 is provided.

Therefore, the problem of abnormal wear of the lip 9 due to dust, mist, dust, etc. is eliminated, and a constant sealing function can be maintained for a long period of time.

In the description of this embodiment, the oil seal 1 is provided between the crankcase 5 and the crankshaft 4, but the oil seal 1 is applied to all axial types. It is a thing.

[0019]

In summary, according to the present invention, the following excellent effects are exhibited.

(1) Since the lip can be prevented from being deformed by frictional heat, a certain sealing function can be maintained for a long period of time.

(2) Since it is possible to prevent abnormal wear of the lip due to dust, mist, dust, etc., it is possible to maintain a certain sealing function for a long period of time.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a crankcase of an engine according to the present invention along a longitudinal direction of a crankshaft.

FIG. 2 is a detailed view of a main part of FIG.

FIG. 3 is a cross-sectional view of a main part of a crankcase showing a conventional oil seal, taken along the longitudinal direction of the crankshaft.

[Explanation of symbols]

 1 oil seal 2 outer ring 3 inner ring 4 crankshaft (rotating shaft) 5 crankcase (housing) 6 outward flange 7 inward flange 8 atmospheric side of outward flange 9 lip 12 wings

Claims (3)

[Claims] 1. An oil seal, which comprises an inner ring and an outer ring, is provided between an end of a rotary shaft and a housing to prevent oil from leaking from the housing, and is integrally fitted to the outer surface of the rotary shaft. The inner ring has an outer flange that is a slinger on the inner end of the housing, and the outer ring inner surface fitted to the inner surface of the housing is rotated to a position farther to the atmosphere side than the outer flange. Inward flanges are formed so as to surround the shaft, and these inward flanges and outward flanges extend from the inward flanges to the outward flanges, and their extension ends are in contact with the atmosphere side surface of the outward flanges. A rubber lip was provided so that it could be pressed, and wings were provided on the outer surface of the inner ring and on the atmosphere side surface of the outward flange so that air could be sent to the contact portion between the lip and the outward flange. thing An oil seal featuring. 2. The outer ring, the inner ring and the outward flange are
The blade is made of metal and is provided so as to obliquely intersect the axial direction of the outer ring so that air can be sent toward the contact portion between the lip and the outward flange, and the blade has heat dissipation properties. The oil seal according to claim 1, which is thinly formed. 3. The inward flange has a disk-shaped dust seal that extends inward in a radial direction from a side surface on the atmosphere side and is in sliding contact with an outer peripheral surface of the inner ring, the dust seal from air to dust, The oil seal according to claim 1, wherein the oil seal is made of felt capable of removing mist.