JP2004293467A - Water pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water pump where water droplet leaked from a mechanical seal is not drained to the front surface or the outside of the pump. <P>SOLUTION: The water pump is equipped with a shaft part 25 integrally rotating with a pulley 20, an impeller 30 integrally rotating with the shaft part 25, a body 12 having cylinder parts 12a, 12b with an inserted shaft part 25, a bearing 14 which is disposed between an outer periphery of the cylinder parts 12a, 12b and an inner periphery of the pulley 20, and rotatably supports the pulley 20, and the mechanical seal 50 liquid tightly seals the one end side of the cylindrical space 27 partitioned between the outer peripheral surface of the shaft part 25 and the inner surface of the cylinder parts 12a, 12b. The water pump is provided with a plate 40 partitioning the space S between a body 12 and the plate, and a communication hole 12d communicating the space S with the cylindrical space 27 on the body 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a water pump, and more particularly to a water pump for an automobile.
[0002]
[Prior art]
Conventional water pumps include a pulley, a shaft that rotates integrally with the pulley, an impeller that rotates integrally with the shaft, a body having a cylindrical portion through which the shaft is inserted, A bearing disposed between the outer periphery of the shaft portion and the inner periphery of the pulley and rotatably supporting the pulley; and a bearing defined between the outer peripheral surface of the shaft portion and the inner peripheral surface of the cylindrical portion. There is a water pump equipped with a mechanical seal that seals one end side of the cylindrical space in a liquid-tight manner.When the water pump is mounted on an engine and used, a small amount of water leaks from the mechanical seal or a mechanical seal. If foreign matter is temporarily caught in the sliding part of the seal for some reason and water leaks, water leaks to the outside (atmosphere side) from the drain hole on the front of the pulley. Misidentified attached outside the water leakage problem, there is a possibility that the water pump is replaced. (For example, refer to Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2002-089486
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a water pump in which water droplets leaking from a mechanical seal are not discharged to the front or outside of the water pump.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned technical problem, the technical means taken in the invention of claim 1 includes a pulley, a shaft portion rotating integrally with the pulley, and an impeller rotating integrally with the shaft portion. A body having a cylindrical portion through which the shaft portion is inserted, a bearing disposed between an outer periphery of the cylindrical portion and an inner periphery of the pulley, and rotatably supporting the pulley; and an outer periphery of the shaft portion. A water pump having a mechanical seal that liquid-tightly seals one end side of a cylindrical space defined between a surface and an inner peripheral surface of the cylindrical portion. A plate that defines a space is provided, and a communication hole that connects the space and the cylindrical space is provided in the body.
[0006]
According to the above-described means, water droplets leaking from the mechanical seal try to leak to the atmosphere side through the cylindrical space of the body, but a plate that defines a space between the body and the body is provided, and the space and the cylindrical space are provided. Is formed in the body, water droplets are accumulated in the space through the communication hole, so that leakage to the outside can be prevented.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIG.
[0008]
In FIG. 1, a body 12 of a water pump 10 is fixed to a cylinder block 90 or a chain case of an engine by a fastening means 13 via a gasket 80 or the like. The body 12 has a stepped cylindrical portion (cylindrical bearing portion) having a large-diameter portion 12a and a small-diameter portion 12b at a base end (right end) side and a tip end (left end) side, respectively, and a water chamber 95 described later. Cover 12c. The inner race of the bearing 14 is externally fitted and fixed on the small diameter portion 12b of the cylindrical portion. The right end face of the inner race of the bearing 14 is in contact with the large diameter portion 12a of the body 12 adjacent thereto. Note that a gap may be provided between the right end surface of the inner race and the large diameter portion 12a.
[0009]
A pulley 20 is externally fitted on the outer race of the bearing 14 so as to be integrally rotatable together with the outer race. The pulley 20 is formed as a rotating body 18 having a cylindrical cup shape. Openings 22a for discharging water droplets leaking from the mechanical seal 50 to the outside are formed at equal angular intervals on the bottom portion 22 of the rotating body 18 connected to the outer peripheral portion having a concave shape. A hollow (cylindrical) shaft portion 25 extending in a direction away from the bottom portion 22 (rightward in FIG. 1) and having an open end on the side of the pulley 20 is integrated with the center of the bottom portion 22 of the rotating body 18. Is molded. The tip of the shaft portion 25 is closed. The rotating body 18 in which the pulley 20, the bottom portion 22, and the shaft portion 25 are integrated is made by press-forming a steel plate material such that the pulley 20 and the shaft portion 25 are concentric. Thereafter, the pulley 20, the bottom portion 22, and the shaft portion 25 are subjected to a corrosion-resistant treatment by plating or painting. Although a corrosion-resistant treatment is possible, it may not be necessary depending on the case.
[0010]
An impeller 30 is fitted to the right end of the shaft portion 25 so as to be integrally rotatable. The impeller 30 is integrally formed with a base 30a, a plurality of blades 30b protruding from the peripheral edge of the right side of the base 30a, and a hollow protrusion 30c protruding rightward from the center of the base 30a. By fitting the hollow projection 30c to the right end of the hollow shaft 25, the impeller 30 is fitted to the tip of the shaft 25 so as to be integrally rotatable. The impeller 30 may be subjected to a corrosion-resistant treatment after press-forming a steel plate. Alternatively, the impeller may be formed by resin molding or other means. The impeller 30 is provided in a water chamber 95 formed inside the cylinder block 90 and the like and having an opening closed by the cover 12 c of the body 12. The water chamber 95 is a component of an engine cooling water circuit (not shown).
[0011]
One end of a cylindrical space 27 defined between the outer peripheral surface of the shaft portion 25 and the inner peripheral surfaces of the large-diameter portion 12a and the small-diameter portion 12b of the body 12 (a boundary portion with the water chamber 95) is provided with a mechanical member. A seal 50 is provided to liquid-tightly isolate the outside from the water chamber 95 so that the cooling water does not leak outside. The mechanical seal 50 is fixed to the fixed ring 50a fixed to the inner peripheral side of the large-diameter portion 12a of the cylindrical portion of the body 12, and is fixed to the shaft portion 25, and is relatively rotatable with respect to the fixed ring 50a and always establishes a liquid-tight relationship. And a rotating ring 50b that comes into contact as much as possible.
[0012]
Incidentally, the body 12 has a stepped cylindrical plate 40 for closing and defining the space S in a liquid-tight manner, which is brazed and fixed to the large diameter portion 12a and the cover portion 12c. The large diameter portion 12a is provided with a communication hole 12d that communicates the space S with the cylindrical space 27. The body 12 and the plate 40 may be fixed by a method other than brazing such as welding.
[0013]
Next, the operation of the present embodiment will be described.
[0014]
The pulley 20 is rotated by a rotational force transmitted from an output shaft of an engine (not shown) via the belt 85 engaged with the belt engaging surface 20b of the pulley 20. As the pulley 20 rotates, the shaft portion 25 integrally formed with the pulley 20 also rotates in the same direction. Then, the impeller 30 integrated with the shaft portion 25 rotates in the water chamber 95 closed by the body 12.
[0015]
Now, since the water chamber 95 is filled with the cooling water, the impeller 30 conveys the cooling water near the center of the water chamber 95 toward the outer periphery of the impeller 30 by the centrifugal force generated by the rotation of the impeller 30. . In this way, a centrifugal pump action occurs from the center of the impeller 30 to the outside. As a result, a pressure difference is generated between the vicinity of the rotation center of the impeller 30 and the outer peripheral side in the water chamber 95, and the cooling water flows from the suction port 95a provided near the rotation center of the impeller 30 into the water chamber 95. Inhaled. Then, the water is pressure-fed to the outer peripheral side by a pump action of the impeller 30, and is supplied to each part to be cooled of the engine from a discharge port (not shown) provided on the outer peripheral side, so that cooling water circulates.
[0016]
As described above, in the present embodiment, the space S is formed between the plate 40 and the body 12, the communication hole 12d is provided in the large-diameter portion 12a, and water droplets leaking from the mechanical seal 50 Through the cylindrical space 27 and the opening 22a, the plate 40 is stored in the space S formed between the body 12 and the communication hole 12d and leaks out of the water pump. Absent. Thus, the water pump 10 is not erroneously recognized as a water leak from the outside, and the water pump 10 is not replaced as a water leak failure.
[0017]
【The invention's effect】
As described above, according to the technical means described in the claims, water droplets leaking from the mechanical seal try to leak to the atmosphere side through the cylindrical space of the body, but define a space between the body and the body. The provision of a plate for providing water and a communication hole for communicating the space and the cylindrical space are provided in the body, so that water droplets can be prevented from leaking to the outside because the water drops accumulate in the space through the communication hole.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a water pump according to an embodiment of the present invention.
[Explanation of symbols]
10 Water pump 12 Body 12a Large diameter part (cylindrical part)
12b: small diameter part (cylindrical part)
12d communication hole 14 bearing 16 through hole 20 pulley 25 shaft part 30 impeller 40 plate 50 mechanical seal S space

Claims (1)

A pulley,
A shaft portion that rotates integrally with the pulley;
An impeller that rotates integrally with the shaft portion;
A body having a cylindrical portion through which the shaft portion is inserted,
A bearing disposed between the outer periphery of the cylindrical portion and the inner periphery of the pulley, and rotatably supporting the pulley;
A water pump comprising: a mechanical seal that liquid-tightly seals one end side of a cylindrical space defined between an outer peripheral surface of the shaft portion and an inner peripheral surface of the cylindrical portion.
A water pump, wherein a plate defining a space is provided between the body and a pulley, and a communication hole communicating the space and the cylindrical space is provided in the body.

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