JPH0960732A - Sealing structure for water pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely perform sealing, and eliminate the occurrence of noise by forming each sliding layer one constituent of which is ethylene tetrafluoride, in the inner surfaces of seal lip parts. SOLUTION: The lip end part of the auxiliary seal lip part 33 of an auxiliary seal member 3O mounted between a housing 2 and a rotating shaft 3 is brought into contact with the outer circumferential surface of the rotating shaft 3 so as to allow sealing performance to be exhibited. Besides, two seal members 21 provided with seal lip parts 26 are arranged in parallel in the axial direction, and are brought into contact with the rotating shaft 3 so as to allow double sealing to be functionally carried out, and furthermore, grease 23 is filled in a closed space 22 so as to allow cooling water for the impeller side to be sealed. Sliding layers 27 are formed in the inside of the seal lip parts 26. Each sliding layer 27 is formed out of raw material where 3 to 10% carbon fibers by weight, 5 to 30% brass powder by weight and the remaining composed of ethylene tetrafluooride resin power, are mixed so as to be sintered. By this constitution, solid particles in cooling water are sealed, and thereby sealing is excellent in durability, and corrosion resistance, and is free from the occurrence of noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water pump sealing structure for liquid-tightly sealing the inside and outside of a water pump mounted for water cooling of a water cooled internal combustion engine such as an automobile engine.

[0002]

2. Description of the Related Art Generally, as a seal structure of this type of water pump, a structure utilizing a mechanical seal is known.

FIG. 6 shows an example of the conventional example. A housing 2 of a water pump 1 is fixed to an engine body (not shown) by bolts or the like, and is rotatably supported by a bearing 4 on the housing 2. The cooling water is circulated by rotating the rotating shaft 3 and rotating the impeller 5 fixed to the inner end of the rotating shaft 3. A mechanical seal 6 is mounted between the impeller 5 and the housing 2 to seal the outside. That is, with respect to the annular rotation-side sliding member 8 fixed to the recess 7 facing the housing 2 of the impeller 5, the casing 9 fixed to the inner end of the housing 2 is movable in the axial direction. The annular fixed-side sliding member 10 mounted on the coil spring 1
Sealing is performed by pressing by the elastic force of 1 and rotating and sliding them on the contact surface A. A flexible member 12 made of an elastic material is interposed between the fixed-side sliding member 10 and the casing 9 for sealing.

[0004]

However, in the above-mentioned conventional example, the rotary side sliding member 8 and the fixed side sliding member 1 are provided.
Since the seal is performed on the contact surface A where the planes of 0 and 0 are in contact with each other, it is incomplete that both surfaces are completely intimately slid over the entire circumference, and a slight leakage occurs. It was a thing. In particular, there was a disadvantage that the amount of leakage was larger in the initial stage of use until both sides became compatible with each other. Further, when both of them rotate and slide on the contact surface A,
There was the inconvenience that sticky slips occurred and noise (squeaking) occurred. Further, the conventional mechanical seal 6 is composed of a rotating side that fits into the impeller 5 and a fixed side that fits into the housing 2, and has a large number of parts and a large number of press-fitting points, and the assembly work is complicated. There was an inconvenience. Further, the mechanical seal 6 requires a large installation space, which has been an obstacle to downsizing the water pump 1 itself.

Also, the housing 2 of the water pump 1
If the engine body side where the cooling water channel to which is adhered is drilled is made of casting, solid matter such as casting sand cast inside during casting will mix into the cooling water over time, or The additives and the like are crystallized or sludged to produce solids, or the solids are bitten into the abutting surface A and the mutual sliding surfaces are abraded, resulting in poor sealing or durability. There was a problem that the property deteriorates rapidly.

The present invention has been made in view of these points, and it is possible to completely seal, no noise is generated, the structure is simple, the assembly is easy, the size is small, and the water is small. An object of the present invention is to provide a seal structure for a water pump, which can also make the pump compact, completely eliminate the intrusion of solid matter in the cooling water into the seal part, and improve the sealability and durability. I am trying.

[0007]

In order to achieve the above object, in a seal structure for a water pump of the present invention, a lip rising flange portion is bent inward in a radial direction from one end portion of a cylindrical portion, and The lip holding portion is bent from the inner end of the lip rising flange portion in substantially the same direction as the cylindrical portion to form a reinforcing ring, and the reinforcing ring is formed so as to cover at least the outer side of the cylindrical portion. A seal main body portion, a lip rising flange portion, and a seal lip portion which is formed so as to gradually decrease in diameter inward from the lip holding portion are formed integrally with an elastic material, and the seal lip portion A seal formed by forming a sliding layer having an ethylene tetrafluoride resin as one component on the inner surface, and mounting an annular spring on the back surface side of the lip tip portion of the seal lip portion to provide a reducing force. At least two pieces of the material are arranged in parallel in the axial direction so that the seal lip portion is in contact with the outer peripheral surface of the rotary shaft for the impeller, and the seal main body portion is fitted and attached to the housing of the oil pump. Filled in a closed space between the seal members arranged in parallel in the direction, with respect to the contact position between the seal lip portion of the innermost seal member of the plurality of seal members and the outer peripheral surface of the rotary shaft. A reliable seal is provided by providing an auxiliary seal member for preventing the entry of solid matter in the cooling water.

Further, the sliding layer is composed of 3% to 10% by weight of carbon fiber, 5% to 30% of brass powder,
Mix the rest of the raw material with tetrafluoroethylene resin powder,
By baking this, it is formed so as to have excellent durability and corrosion resistance, and to provide an extremely excellent seal having a high PV value, which is the product of pressure and speed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
5 to FIG.

1 to 3 show an example of an embodiment of the present invention, FIG. 1 shows a state where a seal member and an auxiliary seal member are assembled to a water pump, and FIGS. 2 and 3 show Each of the seal member and the auxiliary seal member is shown alone.

In the present invention, as shown in FIG. 1, at least two (two in the present embodiment) seal members 21, 21 are axially provided between the water pump housing 2 and the rotary shaft 3. And installed in parallel with each other, filling the closed space 22 between the respective seal members 21, 21 with grease 23, and further cooling water at the inner position of the innermost seal member 21 (the left seal member 21 in FIG. 1). The auxiliary seal member 30 for preventing the intrusion of the solid matter is attached to perform the sealing.

To explain further, the seal member 21 is
As shown in FIG. 2, a seal main body portion 25 and a seal lip portion 26, which are made of an elastic member such as rubber, are integrally formed on a metallic reinforcing ring 24. That is, the reinforcing ring 24
Is formed by bending the lip rising flange portion 24b from one end of the cylindrical portion 24a inward in the radial direction and from the inner end of the lip rising flange portion 24b.
4c is bent and formed in substantially the same direction as the cylindrical portion. A seal body 25 is formed so as to cover at least the outside of the cylindrical portion 24a of the reinforcing ring 24, and a seal lip portion 26 is radially inward from the lip rising flange portion 24b and the lip holding portion 24c. It is formed so as to gradually decrease in diameter. A lip tip portion 26a having a chevron cross section is formed at the tip portion of the seal lip portion 26. On the inclined surface of the lip tip portion 26a on the lip holding portion 24c side, there is formed a sliding layer 27 having one component of tetrafluoroethylene resin. The sliding layer 27 imparts durability and corrosion resistance to the sealing property of the lip tip portion 26a, and further enables a sealing having a high PV value which is a product of pressure and speed. As a material of the sliding layer 27, the applicant of the present invention is Japanese Patent Publication No. 2-4.
It is preferable to use the sliding member already proposed in Japanese Patent No. 6633. That is, as the material of the sliding layer 27,
It is advisable to mix the raw materials in which the weight ratio is 3% to 10% of carbon fibers, 5% to 30% of brass powder, and the balance is tetrafluoroethylene resin powder, and the mixture is fired to form. Further, an annular spring 28 that gives a contact force to the outer peripheral surface of the rotary shaft 3 is mounted in the recess 26b on the back side of the lip tip portion 26a of the seal lip portion 26. The spring 28 is composed of a ring-shaped contact spring, and the diameter of the spring 28 is increased so that the spring 28 is attached to the spring 28 as a contact force. The reinforcing ring 24 and the spring 28 may be made of stainless steel to prevent rust.

The seal member 21 formed in this manner is fitted into the recess 2a for mounting the seal member formed in the housing 2 with the seal main body 25 fitted therein. That is, the outer (right side in FIG. 1) seal member 21 is fitted until the flange portion 24b of the reinforcing ring 24 contacts the step portion 2b of the recess 2a. next,
The adjacent seal member 21 is fitted until the flange portion 24b of the reinforcing ring 24 abuts on the top of the seal main body portion 25 of the outer seal member 21. When a plurality of seal members 21 are mounted between the housing 2 and the rotary shaft 3 in this manner, the seal lip portions 26 of the respective seal members 21 contact the outer peripheral surface of the rotary shaft 3 via the sliding layer 27. As a result, a closed space 22 is formed between the rotary shaft 3 and both seal members 21, so that the closed space 22 is filled with grease 23 to lubricate the sliding layer 27 of the seal lip portion 26 of the seal member 21. And maintain a good seal.

As shown in FIG. 3, the auxiliary seal member 30 is formed to be flat as a whole as compared with the seal member 21, and is composed of a flat auxiliary reinforcement ring 31 made of metal and an elastic member such as rubber. The auxiliary seal body portion 32 and the auxiliary seal lip portion 33 are integrally formed. That is, the auxiliary reinforcing ring 31 bends the lip rising flange portion 31b inward in the radial direction from one end of the cylindrical portion 31a, and the lip holding portion 31c from the inner end of the lip rising flange portion 31b. It is formed by bending in substantially the same direction as the cylindrical portion. An auxiliary seal main body 32 is formed so as to cover at least the outside of the cylindrical portion 31a of the auxiliary reinforcing ring 31, and the auxiliary seal lip portion 33 is formed from the lip rising flange portion 31b and the lip holding portion 31c. It is formed so as to gradually decrease inward in the radial direction, and a lip tip portion 33a having a mountain-shaped cross section is formed at the tip portion thereof.

The auxiliary seal member 30 formed as described above is provided in the recess 2 formed in the housing 2.
The auxiliary seal main body portion 32 is fitted in and attached to the inside of a. That is, the auxiliary seal member 30 is fitted until the flange portion 31b of the auxiliary reinforcing ring 31 comes into contact with the top of the seal main body portion 25 of the innermost seal member 21 in the recess 2a. When the auxiliary seal member 30 is thus mounted between the housing 2 and the rotary shaft 3, the auxiliary seal member 3
The lip tip portion 33a of the auxiliary seal lip portion 33 of No. 0 is brought into contact with the outer peripheral surface of the rotary shaft 3 to exert sealing performance, and prevents solid matter in the cooling water from leaking outside beyond the auxiliary seal member 30. In this way, the solid lip in the innermost seal member 21 and the outer peripheral surface of the rotary shaft 3 are prevented from entering the contact position with solid matter in the cooling water to ensure reliable sealing.

Next, the operation of this embodiment will be described.

In this embodiment, first, the auxiliary seal member 30 mounted between the housing 2 and the rotary shaft 3 is provided.
The lip tip portion 33a of the auxiliary seal lip portion 33 is brought into contact with the outer peripheral surface of the rotary shaft 3 to exert sealing performance, thereby sealing the solid matter in the cooling water and the auxiliary seal member 3
It is surely prevented from leaking outside beyond 0. This reliably prevents the solid matter in the cooling water from entering the contact position between the seal lip portion 26 of the innermost seal member 21 and the outer peripheral surface of the rotating shaft 3, and the solid matter accompanying the intrusion of the solid matter. Abnormal wear of the seal lip portion 26 due to biting is prevented, durability is improved, and reliable sealability can be exhibited.

Next, two seal members 21 each having a seal lip portion 26 are arranged in parallel in the axial direction so as to abut against the rotary shaft 3 for double sealing, and grease 23 is filled in the closed space 22. Since the cooling water on the impeller side is sealed by filling it, it is possible to provide a perfect leak-free seal. In addition, since the sliding layer 27 is formed on the inner surface of the seal lip portion 26 and the material thereof is a material partially containing tetrafluoroethylene resin, it is excellent in durability and corrosion resistance. Therefore, unlike the conventional example, sticking does not occur, and therefore noise does not occur, and a high PV value, which is the product of pressure and speed, can be achieved. Also, the sealing member 2
1 is small in size and is manufactured as a single product, and the assembling work is significantly easier than the conventional example, and the water pump can be easily made compact.

The material of the sliding layer 27 is 3% to 10% of carbon fiber and 5% of brass powder in weight ratio.
It is formed by mixing raw materials of 30% to 30% with the balance being tetrafluoroethylene resin powder and firing this mixture.
The following special effects are exhibited.

That is, since the sliding layer 27 is made of brass powder, carbon fiber and tetrafluoroethylene resin, it has high corrosion resistance and high mechanical strength.
In addition, since the carbon fibers are entangled with the brass powder, the brass powder does not fall off from the base material, tetrafluoroethylene resin, during sliding, so a high anti-friction effect can be maintained for a long time and durability. Excellent and long life.
Further, brass powder is transferred to the outer peripheral surface of the rotating shaft 3 which is the opposite surface of sliding in an appropriate amount, and the transferred material plastically flows to form a sliding film, which forms grease 23 due to its porosity. It is held well and its presence is sufficiently made, and this, and the tetrafluoroethylene resin, carbon fiber, and brass slide, so it does not damage the rotating shaft 3 that is the sliding material, and has high wear resistance. It becomes a product and exhibits extremely excellent lubricity.

The auxiliary seal member 30 and the closed space 34 formed between the innermost seal member 21 and the rotary shaft 3 are filled with grease 23 to fill the auxiliary seal member 30.
Of the auxiliary seal lip 33 and the seal member 21
It is also possible to maintain the lubrication of the lubricating layer 27 of the seal lip portion 26 and reliably seal the solid matter. Further, the auxiliary reinforcing ring 31 of the auxiliary seal member 30 may be made of stainless steel to prevent rust.

FIG. 4 shows another embodiment of the present invention.

In the present embodiment, the auxiliary seal body 30 and the auxiliary seal lip portion 33 of the auxiliary seal member 30 shown in FIG.
a. To further explain, the cylindrical portion 31 on the inner peripheral side of the auxiliary reinforcing ring 31 of the auxiliary seal member 30a.
The auxiliary seal main body portion 32 formed in a is fitted to the step portion 3a of the rotary shaft 3, and the auxiliary seal lip portion 33 on the outer peripheral side is attached.
The auxiliary seal member 30a is mounted so that the lip tip portion 33a of the above is brought into contact with the inner peripheral surface of the recess 2a formed in the housing 2.

In this embodiment as well, the same operation as in the above-described embodiment shown in FIG. 1 is performed, and the auxiliary seal member 30 is also integrally rotated with the rotation of the rotary shaft 3, so that the cooling water is outwardly directed. The effect of centrifugal force to fly is also added, and the sealing function of solid matter and the sealing function of cooling water are exerted.

FIG. 5 shows still another embodiment of the present invention.

In this embodiment, the outer side (the right side in FIG. 5) of the two seal members is formed in the same manner as the embodiment of FIG. 2, and is fitted inside the other seal member 21a. It is a thing. That is, the other seal member 21
a, the cylindrical portion 24a of the reinforcing ring 24 is bent further outward to form an outer cylindrical portion 24d, which is extended from the flange portion 24b by the same length as the height of the seal member 21 shown in FIG. The seal main body 25 made of a material is integrally molded. The other seal member 21a is fitted into the recess 2a of the housing 2 with the long seal body 25.

Further, in the present embodiment, the auxiliary seal member 30b is fitted to the other seal member 21a. That is, the auxiliary seal member 30b of the present embodiment is formed by bending the cylindrical portion 31a of the auxiliary reinforcing ring 31 of the auxiliary seal member 30 shown in FIG. 3 from the flange portion 31b to the side opposite to the lip holding portion 31c. Cage, its cylindrical portion 31a
Is attached by being fitted inside the seal body portion 25 of the seal member 21a, and the lip tip portion 33a of the auxiliary seal lip portion 33 is brought into contact with the outer peripheral surface of the rotary shaft 3.

Also in this embodiment, the solid-material sealing function and the cooling water sealing function are exerted by operating in the same manner as in the above-described embodiment shown in FIG.

The present invention is not limited to the above-mentioned embodiments, but can be modified as necessary.

[0030]

As described above, since the seal structure of the water pump according to the present invention is constructed and functions, the seal can be completely sealed, no noise is generated, the structure is simple, and the assembly is easy. In addition, it is small, and the water pump can be made compact. It is possible to completely eliminate the intrusion of solid matter in the cooling water into the seal part and improve the sealing property and durability. Play.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of an example of an embodiment of a seal structure for a water pump of the present invention.

FIG. 2 is a cross-sectional view showing a seal member used in the seal structure of the water pump of the present invention.

FIG. 3 is a sectional view showing an auxiliary seal member used in the seal structure of the water pump of the present invention.

FIG. 4 is a sectional view similar to FIG. 1, showing another example of the embodiment of the seal structure for the water pump of the present invention.

5 is a sectional view similar to FIG. 1, showing another example of the embodiment of the seal structure for the water pump of the present invention.

FIG. 6 is a cross-sectional view showing a seal structure of a conventional water pump.

[Explanation of symbols]

 21 Sealing Member 22 Closed Space 23 Grease 24 Reinforcing Ring 24a Cylindrical Part 24b Flange Part 24c Lip Holding Part 25 Seal Main Body 26 Seal Lip Part 27 Sliding Layer 28 Spring 30 Auxiliary Sealing Member

Claims (2)

[Claims] 1. A seal structure for a water pump, which seals the inside and outside of a water pump for a water-cooled internal combustion engine in a liquid-tight manner, wherein a lip rising flange portion is bent radially inward from one end of a cylindrical portion and the lip is formed. A seal formed by bending the lip holding portion from the inner end of the rising flange portion in substantially the same direction as the cylindrical portion to form a reinforcing ring, and covering at least the outer side of the cylindrical portion of the reinforcing ring. An inner surface of the seal lip portion is formed by integrally molding a main body portion and a seal lip portion that is formed so as to gradually decrease in diameter inward from the lip rising flange portion and the lip holding portion by an elastic material. A seal layer is formed by forming a sliding layer containing tetrafluoroethylene resin as one component on the back surface of the seal lip portion, and mounting an annular spring for applying a reducing force on the back side of the lip tip portion of the seal lip portion. At least two seal members are arranged in parallel in the axial direction so that the seal lip portion is in contact with the outer peripheral surface of the rotary shaft for the impeller, and the seal member is fitted and attached to the housing of the oil pump. , A closed space between the seal members arranged in parallel in the axial direction is filled with grease, and the seal lip portion of the innermost seal member of the plurality of seal members comes into contact with the outer peripheral surface of the rotary shaft. A seal structure for a water pump, which is provided with an auxiliary seal member for preventing solid matter in cooling water from entering a position. 2. The sliding layer is prepared by mixing raw materials of carbon fiber 3% to 10%, brass powder 5% to 30%, and balance tetrafluoroethylene resin powder in a weight ratio, and baking the mixture. The seal structure for a water pump according to claim 1, wherein the seal structure is formed as follows.