JP2004084610A - Water pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water chamber for a water pump with a simple construction at low costs. <P>SOLUTION: The water pump 10 is provided with a pulley 20, a shaft 25 integrally rotating with the pulley 20, an impeller 30 integrally rotating with the shaft 25, a body 12 in which the impeller 30 is arranged in one end side, a bearing 14 arranged between the body 12 and the pulley 20 and rotatably supporting the pulley 20, and a mechanical seal 50 sealing a gap between the impeller 30 and the bearing 14. The body 14 is formed by aluminum casting or resin molding, and a lid part 12a forming the water chamber 95 for storing a rotor 14 in one end side is formed. <P>COPYRIGHT: (C)2004,JPO

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]
2. Description of the Related Art A conventional water pump is disclosed in, for example, JP-A-2002-89486. The water pump includes a pulley, a shaft rotating integrally with the pulley, an impeller rotating integrally with the shaft, a body having the impeller disposed at one end thereof, and a body disposed between the body and the pulley. A water pump provided with a bearing that rotatably supports a pulley and a mechanical seal that seals between the impeller and the bearing.
[0003]
In recent years, as a water pump for cooling an engine of an automobile, a water pump using a single-row bearing, in which a body and a pulley are formed by press working and the need for cost reduction and weight reduction of parts has been considered. On the other hand, in the conventional water pump, since the body is formed by press molding, the body has no degree of freedom in shape, and the shape is limited. For this reason, the water chamber must be formed on the engine side (cylinder block or the like), which may increase the cost of the cylinder block, complicate the mold, and cause casting defects such as cavities during the production of the cylinder block.
[0004]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a water chamber for a water pump at a low cost with a simple structure.
[0005]
[Means for Solving the Problems]
The technical means taken in the invention of claim 1 to solve the above technical problem includes a pulley, a shaft that rotates integrally with the pulley, an impeller that rotates integrally with the shaft, A body provided with the impeller on one end side, a bearing provided between the body and the pulley and rotatably supporting the pulley, and a mechanical seal between the impeller and the bearing; In a water pump provided with a seal, the body is formed by aluminum casting or resin molding, and a lid forming a water chamber for accommodating the rotor is formed at the one end side.
[0006]
According to the above-described means, by forming the body by aluminum casting or resin molding, it is possible to form a lid that forms a water chamber for accommodating a rotor, and to provide a water pump water chamber with a simple structure at low cost. Can be provided.
[0007]
According to a second aspect of the present invention, there is provided a vehicle comprising: a cylindrical member made of an iron-based metal fixed to another end; The bearing is fixed to the outer periphery of the bearing.
[0008]
According to this means, since the bearing is fixed to the outer periphery of the cylindrical member made of an iron-based metal fixed to the other end of the body, the body and the bearing can obtain substantially the same linear expansion coefficient, At low and high temperatures, the difference in dimensional change between the cylindrical member and the bearing can be reduced.
[0009]
In order to solve the above-mentioned technical problem, a technical measure taken in the invention of claim 3 is to provide a through hole for communicating the space formed between the mechanical seal and the bearing with the outside in the body. The body is provided with a volume that opens to face the opening on the outside of the through hole.
[0010]
According to this means, the body is provided with a volume that opens in opposition to the opening on the outer side of the through hole that communicates the space formed between the mechanical seal and the bearing with the outside, so that the mechanical seal is provided. The cooling water leaking from the reservoir can be stored in the volume.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of the present invention will be described with reference to FIG.
[0012]
In FIG. 1, a body 12 of the water pump 10 is fixed to an engine cylinder block 90 and the like via a gasket 80 and the like by fastening means 13. The body 12 has a lid portion 12a and a stepped cylindrical portion (cylindrical bearing portion) composed of a large-diameter portion 12b and a small-diameter portion 12c from the base end (one end) side to the front end (other end) side. Have been. Since the body 12 is formed by aluminum casting or resin molding, the lid 12a can be formed on the base end side. A water chamber 95 that accommodates the impeller 30 is provided in the lid 12a. The inner race of the bearing 14 is fitted and fixed on the small diameter portion 12c of the cylindrical portion. The right end face of the inner race of the bearing 14 is adjacent to the large diameter portion 12b of the body 12. Note that there may be a gap between the right end surface of the inner race and the large diameter portion 12b. A mechanical seal 50 is fitted on the inner peripheral side of the large diameter portion 12b.
[0013]
A pulley 20 having a concave shape is fitted on the outer race of the bearing 14 so as to be integrally rotatable. Openings 22a for discharging steam leaked from the mechanical seal 50 to the outside are formed at equal angular intervals on the bottom portion 22 of the rotating body 18 composed of the pulleys 20. A hollow (cylindrical) shaft 25 extending in a direction away from the bottom 22 (rightward in FIG. 1) is integrally formed with the center of the bottom 22 of the rotating body 18. The rotating body 18 in which the pulley 20, the bottom 22 and the shaft 25 are integrated is press-formed from a steel plate so that the pulley 20 and the shaft 25 are concentric. Further, the pulley 20, the bottom portion 22, and the shaft 25 may or may not be subjected to the corrosion-resistant treatment.
[0014]
An impeller 30 is fixed to the right end of the shaft 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 fixed to the right end 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. Further, the impeller 30 may be formed by a method other than pressing, such as resin molding. The impeller 30 is provided in a water chamber 95 provided in the lid 12 a of the body 12. The water chamber 95 is a component of an engine cooling water circuit (not shown).
[0015]
A cylindrical space defined between the mechanical seal 50 and the bearing 14 (a space defined between the outer peripheral surface of the shaft 25 and the inner peripheral surfaces of the large-diameter portion 12b and the small-diameter portion 12c of the body 12). A mechanical seal 50 is provided on one end side (boundary portion with the water chamber 95) of the (space) 26, and the mechanical seal 50 prevents the cooling water from leaking to the outside so that the outside and the water chamber 95 are connected to each other. Are isolated in a watertight manner. The mechanical seal 50 is fixed to the shaft 25 and a fixed ring 50a fixed to the inner peripheral side of the large-diameter portion 12b of the cylindrical portion of the body 12, 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.
[0016]
The body 12 is provided with a through hole 27 for communicating the cylindrical space 26 formed between the mechanical seal 50 and the bearing 14 with the outside. The fixed ring 50a and the rotating ring 50b of the mechanical seal 50 slide. A small amount of cooling water that does not hinder the operation of the engine that temporarily leaks due to foreign matter entering the moving surface is discharged to the outside.
[0017]
Next, the operation of the first embodiment will be described.
[0018]
The pulley 20 is rotated by the torque transmitted from the output shaft of the engine (not shown) via the belt 85 engaged with the belt engaging surface 20a of the pulley 20. With the rotation of the pulley 20, the shaft 25 integrally formed with the pulley 20 also rotates in the same direction. Then, the impeller 30 integrated with the shaft 25 rotates in a water chamber 95 provided in the lid 12 a of the body 12.
[0019]
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 the pump action of the impeller 30 and supplied to each part to be cooled of the engine from a discharge port (not shown) provided on the outer peripheral side, and the cooling water circulates.
[0020]
Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in that the body 12 is composed of a cylindrical member 15 made of an iron-based metal fixed to the tip (the other end) side, that is, in the first embodiment. The only difference is that the cylindrical member 15 is replaced at the position of the small-diameter portion 12c. Therefore, the same components as those of the first embodiment are denoted by the same reference numerals used in the first embodiment, and the description is omitted.
[0021]
The cylindrical member 15 is provided with a flange 15a on the large diameter portion 12b side of the body 12, and is fixed to the body 12 through the flange 15a by insert molding or caulking at the time of molding the body 12. The flange 15a may not be provided, and the cylindrical member 15 may be fixed to the body 12 by insert molding or the like. The inner race of the bearing 14 is externally fitted and fixed to the outer periphery of the cylindrical member 15. The right end face of the inner race of the bearing 14 is adjacent to the flange 15a. Note that there may be a gap between the right end surface of the inner race and the flange portion 15a. As a result, the body 12 and the bearing 14 can obtain substantially equal linear expansion coefficients, and the difference in dimensional change between the cylindrical member 15 and the bearing 14 can be reduced at low and high temperatures. For this reason, in the first embodiment, the bearing life is reduced due to the detachment of the bearing 14 due to the contraction of the small-diameter portion 12c at low temperature and the reduction of the gap between the inner race and the outer race of the bearing 14 due to the expansion of the small-diameter portion 12c at high temperature. Can be prevented from decreasing.
[0022]
Next, a third embodiment of the present invention will be described with reference to FIG. The third embodiment is different from the second embodiment in that a through-hole 27 is provided in the body 12 for communicating a cylindrical space (space) 26 formed between the mechanical seal 50 and the bearing 14 with the outside. The only difference is that the body 12 is provided with a volume portion 28 that opens opposite to the opening portion 27a on the outer side of the hole 27. Therefore, the same components as those of the second embodiment are denoted by the same reference numerals as those used in the second embodiment. The reference numerals are used and the description is omitted.
[0023]
The volume portion 28 is composed of a cylindrical wall 12 d and an annular plate 29 facing the through hole 27 side of the lid portion 12 a of the body 12, and is open facing the opening 27 a on the outside of the through hole 27. . The plate 29 is fixed to the tip of the cylindrical wall 12d by press fitting or caulking. As a result, minute cooling water that does not hinder the operation of the engine discharged to the outside can be stored in the volume section 28. For this reason, temporary water leakage due to the failure of the mechanical seal 50 is not discharged to the outside, and the water pump 10 is not replaced as a defective product due to the trace of the water leakage.
[0024]
【The invention's effect】
As described above, according to the technical measures taken in the invention of claim 1, by forming the body by aluminum casting or resin molding, it is possible to form a lid portion forming a water chamber for accommodating the rotor. The water chamber of the water pump can be provided at a low cost with a simple structure.
[0025]
According to the technical measures taken in the invention of claim 2, the bearing is fixed to the outer periphery of the cylindrical member made of an iron-based metal fixed to the other end of the body, so that the body and the bearing Approximately equal coefficients of linear expansion can be obtained, and the difference in dimensional change between the cylindrical member and the bearing can be reduced at low and high temperatures.
[0026]
According to the technical measures taken in the third aspect of the present invention, the opening is formed so as to face the external opening of the through hole communicating the space formed between the mechanical seal and the bearing with the outside. By providing the volume in the body, the cooling water leaking from the mechanical seal can be stored in the volume.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a water pump according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of a water pump according to a second embodiment of the present invention.
FIG. 3 is a longitudinal sectional view of a water pump according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Water pump 12 ... Body 12a ... Lid 14 ... Bearing 15 ... Cylindrical member 20 ... Pulley 25 ... Shaft 26 ... Cylindrical space (space)
27 ... through hole 27a ... opening 28 ... volume 30 ... impeller 50 ... mechanical seal 95 ... water chamber

Claims (3)

A pulley,
A shaft that rotates integrally with the pulley;
An impeller that rotates integrally with the shaft,
A body on which the impeller is disposed at one end thereof;
A bearing disposed between the body and the pulley and rotatably supporting the pulley;
In a water pump including a mechanical seal that seals between the impeller and the bearing,
A water pump, wherein the body is formed by aluminum casting or resin molding, and a lid portion forming a water chamber for accommodating the rotor is formed at the one end side. The water pump according to claim 1, wherein the body comprises a cylindrical member made of an iron-based metal fixed to the other end, and the bearing is fixed to an outer periphery of the cylindrical member. A through hole communicating the space formed between the mechanical seal and the bearing with the outside was provided in the body, and a volume opening facing the opening on the outside of the through hole was provided in the body. The water pump according to claim 1 or 2, wherein:

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