JPH11153096A - Water pump bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of rust at a fitting part between the slinger of a sealing device on the impeller side and a pump shaft and to stabilize sealing ability of the sealing device on the impeller side for a long period. SOLUTION: In the outer peripheral surface of the large diameter part of a pump shaft, a region between a sealing device 5 on the impeller side and a mechanical seal 3 is covered with the inside cylinder part 52b of the slinger 52 of the sealing device 5 on the impeller side. The free end face of the inside cylinder part 52b of a slinger 52 makes access to or is brought into contact with the inside annular body 32 of a mechanical seal 3. This constitution, even when tentatively cooling water in a pump chamber leaks through the mechanical seal 3, leaking cooling water makes only slight touch with the inside cylinder part 52b of the slinger 52 or an annular plate part 52a and is prevented from making touch with the pump shaft. Mush less, the leaking cooling water is prevented from seeping into a fit-in part between the pump shaft and the inside cylinder part 52b of the slinger 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a water pump bearing.

[0002]

2. Description of the Related Art FIG. 3 is a longitudinal sectional view of an upper half showing a structure of a conventional water pump, and FIG. 4 is an enlarged view of a main part of FIG.

In the drawing, reference numeral 1 denotes a boss of a pump housing;
Denotes an impeller, 3 denotes a mechanical seal, and 4 denotes a water pump bearing.

[0004] The mechanical seal 3 has a generally well-known structure, but has an outer ring 31 internally fitted and fixed to the boss 1.
And an inner ring 3 externally fitted and fixed to a small diameter portion of the pump shaft 41.
2, a rubber sleeve 33 provided on the inner cylindrical portion 31a of the outer ring 31, a rotating ring 34 provided on the impeller 2 side of the inner ring 32, and an inner cylindrical portion 3 of the outer ring 31.
1a includes a fixed ring 35 slidably fitted to the impeller 2 side and a coil spring 36 provided on the outer periphery of the rubber sleeve 33 in a compressed state and pressing the fixed ring 35 against the rotating ring 34.

The water pump bearing 4 is a so-called integral shaft bearing, which has a pump shaft 41 whose outer diameter is formed in two stages, large and small, as an inner ring. The outer ring 44 is externally arranged via a cylindrical roller group 42 and a ball group 43 in two rows. Between the shoulders of the inner peripheral surfaces of both ends in the axial direction of the outer ring 44 and the outer peripheral surface of the large-diameter portion of the pump shaft 41, two different types
Two sealing devices 5, 6 are mounted.

The pump shaft 4 of the water pump bearing 4
The impeller 2 is provided at the shaft end of the small-diameter portion 1 and the pump shaft 41
Pulleys 7 are attached to the shaft ends of the large diameter portions, respectively. The pulleys 7 are rotationally driven by a crankshaft of an automobile engine via a belt (not shown).

The sealing device 5 on the impeller 2 side is
As shown in FIG. 4, the seal member 51 and the slinger 52 are combined to ensure high sealing performance. That is, the sealing member 51 is
a, one axial lip 51b and two radial lips 51c, 51d made of an elastic material such as synthetic rubber;
Is attached. The slinger 52 is formed of a metal ring whose upper half section is bent in a substantially U-shape.
The inner cylindrical portion 52b and the outer cylindrical portion 52c are formed so as to extend to one and the same side in the axial direction on the inner circumference and the outer circumference of a.
The inner cylindrical portion 52b of the slinger 52 is
The three lips 51b to 51d of the seal member 51 are fixed in a state where the seal member 51 is fixedly engaged with the shoulder portion of the outer ring 44 by press-fitting to the large-diameter portion.
Inner cylindrical portion 52b and annular plate portion 52 of slinger 52
a.

In such a water pump, even if the cooling water in the pump chamber leaks out of the mechanical seal 3, the sealing device 5 on the impeller 2 side prevents the cooling water from entering the inside of the water pump bearing 4. The leaked cooling water is drained to the outside through a drain hole 11 provided in the boss 1 of the pump housing.

[0009]

In the prior art as described above, the cooling water leaking from the mechanical seal 3 is prevented from entering the inside of the water pump bearing 4 and discharged to the outside. However, the leaked cooling water causes the pump shaft 41 of the water pump bearing 4 and the slinger 52 of the sealing device 5 on the impeller 2 side.
It is pointed out that there is a high possibility that rust is generated at the fitting portion with the rust.

That is, the area between the mechanical seal 3 and the sealing device 5 on the impeller 2 side of the water pump bearing 4 is exposed over a wide area on the outer peripheral surface of the pump shaft 41 of the water pump bearing 4, Since the connecting portion between the cylindrical portion 52b and the annular plate portion 52a is rounded and curved along with the bending, the cooling water easily permeates into the fitting portion between the pump shaft 41 and the slinger 52. In this fitting portion, since there is a high possibility that the permeated cooling water remains for a long period of time, the pump shaft 41
Even when the slinger 52 and the slinger 52 are formed of a material having excellent corrosion resistance such as stainless steel, rust is easily generated.

Incidentally, when such rust is generated, the mounting accuracy of the slinger 52 to the pump shaft 41 is reduced, and the slinger 52 may rattle, so that the three lips 51b to 51d of the seal member 51 come into contact with each other. There is a concern that the hermeticity may deteriorate, such as adversely affecting the condition.

Therefore, the present invention prevents the generation of rust at the fitting portion between the slinger of the impeller side sealing device and the pump shaft in the water pump bearing, and stabilizes the sealing performance of the impeller side sealing device for a long time. The purpose is to:

[0013]

According to a first aspect of the present invention, there is provided a water pump bearing in which a pump shaft provided with an impeller at one end and a pulley at the other end is an inner ring, and a rolling element is provided on an outer peripheral surface of the pump shaft. A mechanical seal is mounted between the outer peripheral surface of the pump shaft and the pump housing, and a sealing device is provided between the outer peripheral surface of the pump shaft and both axial ends of the outer ring. Each provided, the impeller-side sealing device is constituted by a seal member fixed to a shoulder at one axial end of the outer ring, and a slinger externally fixed to the outer peripheral surface of the pump shaft, and the slinger is An annular plate portion, including an inner cylindrical portion extending from the inner periphery of the annular plate portion to the impeller side, wherein the sealing member is
An axial lip contacting the annular plate portion of the slinger, and a radial lip contacting the outer peripheral surface of the pump shaft, the free end surface of the inner cylindrical portion of the slinger is provided on the outer peripheral surface of the pump shaft in the mechanical seal. It extends to a position close to or in contact with the ring body to be fitted and fixed.

In the present invention, the area between the impeller-side sealing device and the mechanical seal on the outer peripheral surface of the pump shaft is covered with the inner cylindrical portion of the slinger of the impeller-side sealing device. The free end surface of the cylindrical portion is made to approach or abut on the inner ring of the mechanical seal. Thereby, if the cooling water in the pump chamber leaks out of the mechanical seal, whether the outer peripheral surface of the pump shaft is completely exposed,
Alternatively, since the cooling water is only slightly exposed, the leaked cooling water only touches the inner cylindrical portion and the annular plate portion of the slinger, but hardly touches the pump shaft. Furthermore, it is possible to prevent the permeation into the fitting portion between the pump shaft and the inner cylindrical portion of the slinger as much as possible. Therefore, it is possible to prevent the occurrence of rust at the fitting portion as in the related art.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on embodiments shown in FIGS.

1 and 2 relate to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of an upper half showing a structure of a water pump, and FIG. 2 is an enlarged view of a main part of FIG.

In these figures, the same or corresponding parts as those in FIGS. 3 and 4 presented as conventional examples are denoted by the same reference numerals. In the drawing, reference numeral 1 denotes a boss portion of a pump housing, 2 denotes an impeller, 3 denotes a mechanical seal, and 4 denotes a water pump bearing.

The difference between this embodiment and the conventional example is that
This is the shape of the slinger 52 of the impeller-side sealing device 5 mounted on the water pump bearing 4.

In the slinger 52 of this embodiment, the inner cylindrical portion 52b is closer to the impeller 2 (right side in the figure) than the annular plate portion 52a, and the outer cylindrical portion 52c is closer to the bearing inner side than the annular plate portion 52a (see FIG. (Left side), the inner cylindrical portion 52b and the outer cylindrical portion 52
c does not overlap in the radial direction. That is, the slinger 52 in this embodiment has a shape in which the inner cylindrical portion 52b extends in a direction opposite to that of the conventional slinger. Therefore, the two radial lips 51c of the sealing member 51,
51d is in direct contact with the outer peripheral surface of the large diameter portion of the pump shaft 41.

The slinger 52 is press-fitted to the large-diameter portion of the pump shaft 41 of the water pump bearing 4 near the small-diameter portion. The shaft end of the inner cylindrical portion 52b of the slinger 52 is It is in contact with the inner ring body 32 of the mechanical seal 3 that is press-fitted to the small diameter portion. As a result, the mechanical seal 3 and the impeller-side sealing device 5 are formed on the outer peripheral surface of the large-diameter portion of the pump shaft 41.
And the area between them is completely covered without being exposed. Also,
The axial end of the inner cylindrical portion 52b of the slinger 52 may be arranged close to the inner ring 32 of the mechanical seal 3 so as to maintain a slight non-contact gap. In this case, the shaft end of the inner cylindrical portion 52 and the inner annular body 32 are sealed by a labyrinth effect.

As described above, even if the cooling water leaks from the mechanical seal 3, the cooling water permeates the fitting portion between the slinger 52 of the impeller-side sealing device 5 and the pump shaft 41. This can be prevented as much as possible, and the generation of rust at the fitting portion can be prevented. The leaked cooling water is discharged to the outside from the drain hole 11 of the boss 1 by the rotational centrifugal force along the outer surface of the slinger 52. At this time, although the cooling water touches the outer surface of the slinger 52, the cooling water does not remain continuously for a long period of time, so that rust hardly occurs here.

It should be noted that the present invention is not limited to only the above embodiment, and various applications and modifications are conceivable.

For example, the sealing member 51 in the impeller-side sealing device 5 of the above embodiment has three lips 51b to
Although the configuration includes 51d, it suffices to include at least the axial lip 51b and the main radial lip 51c, and the number and shape of these lips are not particularly limited.

The outer cylindrical portion 52c of the slinger 52
The present invention also includes a configuration in which the conical portion gradually increases in diameter toward the free end side, and the free end of the conical portion is brought close to the end surface of the outer ring.

Further, in the embodiment, the pump shaft 41 is
Although formed in steps, it may be formed in three steps or the same diameter.

[0026]

According to the present invention, the area between the impeller-side sealing device and the mechanical seal on the outer peripheral surface of the pump shaft is minimized, and the inner cylindrical portion of the slinger and the inner side of the mechanical seal of the impeller-side sealing device are minimized. Because the ring body is brought close to or in contact with the ring body, even if the cooling water in the pump chamber leaks out of the mechanical seal, this cooling water only touches the inner cylindrical portion and the annular plate portion of the slinger. In addition, the pump shaft can be prevented from touching the pump shaft as much as possible, and can be prevented from penetrating into the fitting portion between the pump shaft and the inner cylindrical portion of the slinger.

Therefore, it is possible to prevent the occurrence of rust at the fitting portion as in the conventional case, and it is possible to stably maintain the sealing performance of the impeller-side sealing device for a long time.
This can contribute to the improvement of the life and reliability of the water pump.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an upper half showing a structure of a water pump according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is a longitudinal sectional view of an upper half showing a structure of a conventional water pump.

FIG. 4 is an enlarged view of a main part of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boss part of pump housing 2 Impeller 3 Mechanical seal 4 Water pump bearing 41 Pump shaft of water pump bearing 42 Cylindrical roller of water pump bearing 43 Ball of water pump bearing 44 Outer ring of water pump bearing 5 Impeller side sealing device of water pump bearing Reference Signs List 51 sealing member of impeller side sealing device 51b axial lip of sealing member 51c main radial lip of sealing member 52 slinger of impeller side sealing device 52a annular plate portion of slinger 52b inner cylindrical portion of slinger

Claims (1)

[Claims] 1. A water pump bearing comprising a pump shaft provided with an impeller at one end and a pulley provided at the other end as an inner ring, and an outer ring externally mounted on the outer peripheral surface of the pump shaft via a rolling element. A mechanical seal is mounted between the outer peripheral surface of the shaft and the pump housing, and a sealing device is provided between the outer peripheral surface of the pump shaft and both axial ends of the outer ring. A seal member fixed to the shoulder at one axial end of the pump shaft, and a slinger fixed externally to the outer peripheral surface of the pump shaft, and the slinger is formed from an annular plate portion and an inner periphery of the annular plate portion. An inner lip extending to the impeller side, wherein the seal member contacts an axial lip of the slinger and a radial lip contacts an outer peripheral surface of the pump shaft. The provided, the free end face of the inner cylindrical portion of the slinger has extended to a position close to or abut against the ring member to be fitted around the outer peripheral surface of the pump shaft in a mechanical seal,
A water pump bearing, characterized in that: