JPH0575562U - Crankshaft oil seal structure - Google Patents

Abstract

(57) [Abstract] [Purpose] An oil seal structure that has a high oil sealability due to the oil seal member of the crankshaft, and that does not cause wear damage due to dust entering the sliding part of the oil seal, and that can be used permanently. The purpose is to provide. A main lip portion 16 for preventing engine oil from leaking outside to a circumferential contact surface of an oil seal member 14 for partitioning the crankshaft 10 between the engine inside side and the outside air side with the crankshaft inside the engine. Is provided in close contact with the oil seal member 14, and a dust lip portion 20 having two lip rings is similarly provided around the crank shaft 10 on the outside air side of the oil seal member 14. Vent holes (30, 32) are provided in the side lip ring 24 and the inner lip ring 26 at positions that are out of phase with each other in the circumferential direction of the crankshaft.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention mainly relates to a crankshaft oil seal structure in an automobile engine.

[0002]

[Prior Art]

 It is well known that a crankshaft in an automobile engine is divided into an engine inside side and an outside air side by an oil seal member. As the oil seal structure of the crankshaft, for example, the one shown in FIG. 7 is generally known. In the illustrated oil seal structure, the crankshaft 64 is inserted through the oil seal member 62 supported by the oil seal retainer 60, and the main lip portion is provided on the circumferential contact surface of the oil seal member 62 with the crankshaft 64 on the engine inner side. 66 is provided in close contact with the ring spring 68, and a dust lip portion 70 is provided on the outside air side of the oil seal member 62 with a slight gap g between the oil seal member 62 and the crankshaft 64.

With this structure, a negative pressure does not occur in the space 72 provided between the main lip portion 66 and the dust lip portion 70, and the negative pressure phenomenon causes the main lip portion 66 to move to the crankshaft 64. It prevents the sliding surface between the crankshaft 64 and the main lip 66 from being worn and damaged by being absorbed and pressed by the crankshaft 64 and the main shaft by preventing dust from entering from the outside air. The sliding surface between the lip portions 66 is prevented from being worn and damaged due to invasion of dust.

[0004]

[Problems to be solved by the device]

 However, if the gap g is provided between the crankshaft 64 and the dust lip portion 70 as described above, it is still impossible to completely prevent dust from entering from the outside air side. Therefore, the dust that has entered the space 72 between the main lip portion 66 and the dust lip portion 70 through the gap g between the crank shaft 64 and the dust lip portion 70 causes the dust to enter between the crank shaft 64 and the main lip portion 66. There was a problem that the sliding surface of the crankshaft 64 and the main lip portion 66 was worn and damaged by the dust that entered the sliding surface.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a main lip portion of an oil seal member that divides a crankshaft into an engine inner side and an outside air side and a duster. It is an object of the present invention to provide an oil seal structure that prevents negative pressure from being generated between the strip portion and at the same time prevents dust of outside air from entering the sliding surface between the main lip portion and the crankshaft. This effectively avoids wear and damage on the sliding surfaces of the crankshaft and the main lip, permanently securing the oil sealability and extending the service life of the oil seal member.

[0006]

[Means for Solving the Problems]

 In order to achieve this object, an oil seal structure of a crankshaft according to the present invention has an oil seal member for partitioning the crankshaft into the engine inner side and the outside air side. The main lip part to prevent the oil from leaking to the outside is closely attached, and the dust lip part having a plurality of lip rings on the outside air side of the oil seal member is also closely attached to the crankshaft. Vent holes are provided in each lip ring of the dust lip portion at positions where the mutually adjacent lip rings are out of phase with each other in the circumferential direction of the crankshaft. is there.

[0007]

[Action]

 According to the crankshaft oil seal structure of the present invention having the above-mentioned configuration, the engine oil circulated to various parts inside the engine by the engine drive is transmitted to the crankshaft and the like, and also on the sliding surface with the oil seal member. Although it flows, the sliding surface is sealed by the main lip, so engine oil will not leak to the outside from the sliding surface. Since the outside air communicates with its main lip through the air holes provided in each lip ring of the dust lip, there is no negative pressure, and the main lip is attracted to the crankshaft by its negative pressure suction force. It is not pressed due to excessive suction pressure. The dust in the outside air is provided at the position where the vent holes provided in each lip ring are out of phase with each other in the circumferential direction of the crankshaft between adjacent lip rings, so the sliding surface between the main lip and the crankshaft Invasion of the crankshaft and sliding surfaces of the main shaft and the crankshaft will not be damaged by dust.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the crankshaft 10 is inserted and held by an oil seal member 14 supported by an oil seal retainer 12 and is divided into an engine inside side and an outside air side.

The oil seal member 14 is made of a wear-resistant rubber material, and a main lip portion 16 is provided on the inner peripheral surface of the crankshaft 10 on the inner side of the engine by a spring ring 18 so as to be appropriately located on the crankshaft 10 surface. It is installed closely in the state of being pressed by the pressing force of, so that the engine oil circulating in each part inside the engine does not leak to the outside from the sliding contact surface between the crank shaft 10 and the main lip part 16. The oil sealability is improved.

On the other hand, on the outside air side of the oil seal member 14, a dust lip portion 20 having a double ring structure having two lip rings is provided in a state of being closely contacted with the crank shaft 10 as well. An internal space 22 is provided between the dust lip portion 20 and the main lip portion 16, and an air passage is provided between the dust lip ring 24 on the outside air side of the dust lip portion 20 and the inner dust lip ring 26. 28 is formed.

As shown in detail in FIGS. 2 and 3, the outside air side dust lip ring 24 of the dust lip portion 20 has a plurality of passages communicating with the air passage 28 on the circumferential contact surface with the crankshaft 10. .. are provided at substantially equal intervals, and the inner dust lip ring 26 is also provided with a plurality of vent holes 32, 32 for communicating the air passage 28 with the internal space 22. .. are provided at substantially equal intervals. Moreover, the ventilation holes 32, 32 ... Provided in the inner dust lip ring 26 and the ventilation holes 30, 30 ... Provided in the outside air side dust trip ring 24 are in phase with each other in the circumferential direction of the crankshaft 10. It is provided at a position shifted.

The inside diameters of the outside air side dust lip ring 24 and the inside dust lip ring 26 are slightly smaller than the diameter of the crankshaft 10, so that the space between the dust lip rings 24 and 26 and the crankshaft 10 is increased. It is designed so that it has a tight margin due to rubber elasticity and enhances adhesion.

According to the oil seal structure of the crankshaft configured as described above, however, the engine oil is circulated to the various parts inside the engine for lubrication by the engine drive, and is collected in the oil pan along the inner wall of the engine. Repeat the cycle. Then, a part of the engine oil flows along the crankshaft 10 to the sliding surface with the oil seal member 14, but since the sliding surface is sealed by the main lip portion 16, the main lip portion is sealed. Leakage from the sliding surface of the crankshaft 16 and the crankshaft 10 to the outside is avoided.

On the other hand, outside air flows into the air passage 28 between the outside air side dust lip ring 24 and the inside dust lip ring 26 through the ventilation holes 30, 30 ... The gas flows into the internal space 22 between the dust lip portion 20 and the main lip portion 16 through the vent holes 32, 32 ... Of the strip ring 26. Therefore, the internal space 22 between the dust lip portion 20 and the main lip portion 16 is kept at the same atmospheric pressure as the external atmospheric pressure, and the main lip portion 16 is attached to the crankshaft 10 by the negative pressure suction force of the internal space 22. It is not pressed against by excessive suction pressure. Therefore, abrasion damage to the sliding contact surfaces of the crankshaft 10 and the main lip portion 16 due to the negative pressure suction force is avoided.

On the other hand, the dust in the outside air that has flowed into the air passage 28 through the ventilation holes 30, 30 ... Of the outside air side dust lip ring 24 is blocked by the ring wall of the inside dust lip ring 26 in its path. , Will be deposited in the air passage 28 to prevent further intrusion. Therefore, clean air containing no dust flows into the internal space 22 through the ventilation holes 32, 32 ... Of the inner dust lip ring 26. Therefore, dust hardly enters the sliding contact surface between the main lip portion 16 and the crankshaft 10, and the crankshaft surface or the sliding surface of the main lip portion 16 is prevented from being worn and damaged by the dust entering. To be done.

FIGS. 4 and 5 show an oil seal structure according to another embodiment of the present invention. The illustrated one is provided with a so-called triple ring structure dust lip portion 40 in which the dust lip portion 20 of the oil seal structure shown in FIGS. 1 to 3 has three lips. That is, the dust lip portion 40 shown in FIGS. 4 and 5 comprises an outside air-side dust lip ring 42, an intermediate dust lip ring 44, and an inner dust strip ring 46. The dust lip rings 42, 44, and 46 respectively have crankshafts. A plurality of vent holes 48, 48 ..., 50, 50 ... And 52, 52 ... Are provided at equal intervals on the circumferential contact surface with the shaft 10. In the illustrated example, the ventilation holes 48, 48 ... Provided in the outside air dust lip ring 42 and the ventilation holes 50, 50. The vent holes 50, 50 ... Provided in the inner dust lip ring 44 and the vent holes 52, 52 ... Provided in the inner dust lip ring 46 are provided so as to be out of phase with each other in the circumferential direction. Again, they are provided so as to be out of phase with each other in the circumferential direction of the crankshaft 10.

Therefore, according to the oil seal structure having the configuration shown in FIGS. 4 and 5, even if dust in the outside air passes through the ventilation holes 48, 48 ... Even if it collides with the ring wall of the dust lip ring 44 and obstructs its path, and even if it can pass through the ventilation holes 50, 50 ... Of the middle dust lip ring 44, the ring wall of the inner dust lip ring 46 this time. Collided with and blocked its path. Thus, the amount of dust in the outside air finally flowing into the internal space 22 between the dust lip portion 40 and the main lip portion 16 through the ventilation holes 52, 52 ... Of the inner dust lip ring 46 is as described above. This is further reduced compared to the case of the oil seal structure of the embodiment shown in FIGS. 1 to 3. The chance of dust entering the sliding contact surface between the main lip portion 16 and the crankshaft 10 is further reduced, and the crankshaft surface or the sliding surface of the main lip portion 16 is more likely to be worn and damaged by the dust entering. It can be effectively avoided.

In the above two embodiments, the structure of the dust lip portion has two dust lip rings and three dust lip rings, but this is not to be understood. It is obvious that the dust trapping effect in the outside air can be enhanced by increasing the number of four or five dust rings and the number of dust lip rings. The avoidance of wear damage on the sliding surface of is more reliably achieved.

Further, in the dust lip portions 20 and 40 shown in FIG. 1 or FIG. 4, the gap between the lip rings 24 and 26 or the gaps between 42 and 44 and 46 is narrow. For example, as shown in FIG. 6, the engraving of the annular groove 58 formed between the lip rings 56a and 56b of the dust lip portion 54 may be deepened. With this structure, the elastic force of the rubber-made lip rings 56a, 56b softens the pressure contact force of the sliding contact surfaces of the lip rings 56a, 56b and the crankshaft 10 to make the sliding contact. Wear damage of each lip ring 56a, 56b on the surface is also avoided. The structure shown in FIG. 6 can be said to be a structure provided with two single dust lip rings, but in the present invention, the structure shown in FIG. 6 also has a plurality of lip rings. It is grasped as the provided dust trip section. It should be noted that, as in the case of FIG. 4 described above, three or four dust lip rings with deep grooves shown in FIG. 6 may be stacked.

[0020]

As described above, according to the oil seal structure of the crankshaft according to the present invention, the negative pressure suction force of the sliding surface between the main lip portion of the oil seal member and the crankshaft is exerted. To avoid excessive pressure contact, and to prevent dust from entering from the outside air, the dust lip part has a structure with multiple lip rings, and the air holes provided in each lip ring are provided between adjacent lip rings. By providing the crankshaft at a position where the phase in the circumferential direction is shifted, it is effectively prevented, and wear damage to the sliding surface between the crankshaft and the main lip portion due to intrusion of dust is also avoided. There are many advantages such as the ability to permanently secure the sealability and the extension of the service life of the crankshaft and oil seal members.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an oil seal structure for a crankshaft according to an embodiment of the present invention.

FIG. 2 is a front view showing the configuration of a dust lip portion viewed from the direction A in FIG.

FIG. 3 is a perspective view showing a main part of the dust lip section shown in FIG. 2;

FIG. 4 is a sectional view showing an oil seal structure for a crankshaft according to another embodiment of the present invention.

5 is a perspective view showing a main part of the dust lip portion shown in FIG. 4. FIG.

FIG. 6 is a sectional view of an oil seal structure according to another embodiment of the present invention.

FIG. 7 is a sectional view showing an oil seal structure of a crankshaft as a conventional example.

[Explanation of symbols]

 10 crankshaft 14 oil seal member 16 main lip portion 20 dust lip portion 22 internal space 24 outside air side dust lip ring 26 inner dust lip ring 30, 32 vent hole 40 dust lip portion 42 outside air dust lip ring 44 middle dust ring ring 46 Inner dust lip ring 48, 50, 52 Vent hole 54 dust lip portion 56a, 56b dust lip ring

Claims (1)

[Scope of utility model registration request] 1. A main lip portion for preventing engine oil from leaking to the outside on a circumferential contact surface of an oil seal member for partitioning the crankshaft into an engine inside side and an outside air side with the crankshaft inside the engine. A dust lip portion having a plurality of lip rings is closely attached to the crankshaft on the outside air side of the oil seal member, and each dust ring portion of the dust lip portion has a lip ring portion. An oil seal structure for a crankshaft, characterized in that vent holes are provided at positions that are out of phase with each other in the circumferential direction of the crankshaft between adjacent lip rings.