JPH022954Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to an improvement of a sealing device for a water pump bearing installed in, for example, an automobile engine.

Prior Art The bearing 3 used in the conventional water pump 1 has a fifth bearing.
As shown in the figure, two rows of raceways 5, 6 formed on the inner circumferential surface 4a of the outer ring 4 fitted and fixed in the pump case 2, and the said raceways 5, 6 formed on the circumferential surface 7a of the pump shaft 7. A ball 10 is interposed between the two rows of opposing tracks 8 and 9, and sealing plates 14 and 15 are fitted and fixed in the inner circumferential grooves 12 and 13 at both ends of the outer ring 4, respectively. , 15 inner circumference lip 14a,
A structure is known in which the outer ring 4 and the pump shaft 7 are sealed by making the outer ring 15a slide into contact with the circumferential surface 7a of the pump shaft 7. Here, 16 is an impeller fixed to the end 7b of the pump shaft 7, 17 is a mechanical seal as a water pump seal that seals the pump chamber 11, and 19 is formed between the bearing 3 and the mechanical seal 17. This is a drain hole provided in the pump case 2 to communicate the space 18 and the outside.

Problems to be Solved by the Invention In the conventional structure, the coolant (arrow) circulating inside the pump chamber 11 leaks, albeit slightly, through the mechanical seal 17.
Although the coolant accumulates in the space 18 between the bearing 3 and the bearing 3, this accumulated cooling liquid is discharged to the outside through a drain hole 19 so as not to adversely affect the bearing 3. However, since there is no difference in sealing performance between the two sealing plates 14 and 15 of the bearing 3,
It is not known at all which of the two sealing plates 14 and 15 the breathing action of intake and exhaust air due to internal pressure fluctuations takes place. For this reason, for example, if the intake action is performed by the sealing plate 15 on the side of the pump chamber 11, there is a risk that the coolant leaked into the space 18 during the intake action may be sucked into the bearing, and the exhaust action may be performed on the pump chamber 11 side. If this is done with the side sealing plate 15, there is a risk that the grease in the bearing will leak into the space 18 during the exhaust action, solidify inside the drain hole 19, and block the hole 19. In either case, the life and performance of the bearing will be reduced.

Means for Solving the Problems This invention solves the above problems by arranging double rows of rolling elements between the outer ring and the pump shaft, and fitting sealing rings on the inner peripheral surface of both ends of the outer ring. In the water pump bearing, the sealing ring on the pump chamber side, which is arranged adjacent to the water pump seal, is connected to the outer ring from the cylindrical fitting part and one end of the fitting part. A main body extending radially inward, extending axially from the inner periphery of the main body toward the pump chamber, and having a tension force on the pump shaft circumferential surface that is greater than the tension force on the pump shaft circumferential surface of the seal lip of the sealing ring on the side opposite to the pump chamber. This problem is solved by configuring a sealing device for a water pump bearing, which is characterized in that it is configured with a seal lip that has a large tension force.

Function When using a water pump, pressure fluctuations occur inside the bearing due to rising temperature of the bearing, but the breathing action of intake and exhaust air is not carried out in the sealing ring on the pump chamber side, but rather on the seal lip rather than the sealing ring on the pump chamber side. This is done on the sealing ring on the side opposite to the pump chamber where the tension force against the circumferential surface of the pump shaft is small.

Embodiment An embodiment of this invention will be described based on FIGS. 1 and 2. In addition, the same parts are given the same reference numerals in FIG. 5, which shows the conventional structure. The bearing 3 includes two rows of raceways 5 and 6 formed on the inner circumferential surface 4a of an outer ring 4 fitted and fixed in the pump case 2 of the water pump 1, and the raceways 5 and 6 formed on the circumferential surface 7a of the pump shaft 7. 6
A ball 10 is placed between the two opposing rows of tracks 8 and 9.
A sealing plate 14 having an inner circumferential lip 14a in sliding contact with the shaft circumferential surface 7a is fitted and fixed in a circumferential groove 12 formed on the inner circumferential surface of the end of the outer ring 4 on the side opposite to the pump chamber. A main lip 21a is formed on the circumferential step 20 formed on the inner circumferential surface of the end on the pump chamber 11 side.
This structure has an oil seal 21 that is fitted and fixed in sliding contact with the outer ring 4 to seal the space between the outer ring 4 and the pump shaft 7. The oil seal 21 has an inner cylinder fitting portion 21c to the outer ring 4.
, a main body portion 21b extending radially inward from one end of the fitting portion 21c, and a seal lip 2 extending axially from the inner periphery of the main body portion 21b toward the pump chamber 11 side.
1a, and a coil spring 23 is attached to the outer periphery of the lip 21a to make the tension force larger than the tension force of the inner lip 14a against the pump shaft peripheral surface 7a. 16
is fixed to the end 7b of the shaft 7 with an impeller.
Furthermore, 17 seals the pump chamber 11 with a mechanical seal. A space 18 provided between the mechanical seal 17 and the bearing 3 and the outside of the pump case 2 communicate with each other through a drain hole 19 provided in the pump case 2.

FIG. 3 shows another embodiment of the bearing 3, in which a circumferential groove 24 is provided in place of the circumferential stepped portion 20 of the outer ring 4, and this circumferential groove 2
4 has an oil seal 21 fitted and fixed thereto. With this structure, the outer ring width becomes smaller than that of the one shown in FIG.

Furthermore, in FIG. 4, the rolling element on the opposite side of the pump chamber of the bearing 3 is a roller 25 instead of the ball 10.

Effect When using a water pump, even if pressure fluctuations occur inside the bearing due to rising temperature of the bearing, the sealing plate on the opposite side of the pump chamber, which has less tension on the pump shaft circumferential surface of the lip, allows intake and exhaust air to breathe. perform an action. As a result, there is no grease leakage from the sealing ring on the pump chamber side, and the water drain hole is not blocked as in conventional structures, causing coolant to accumulate in the space between the bearing and the mechanical seal. No liquid enters, and as a result, deterioration in bearing life and performance can be prevented.

[Brief explanation of the drawing]

Figure 1 is a vertical sectional view of a water pump according to an embodiment of this invention, Figure 2 is an enlarged vertical sectional view of the bearing shown in Figure 1, and Figure 3 is an enlarged vertical sectional view of the bearing shown in Figure 1.
FIG. 4 is a longitudinal sectional view of another embodiment, and FIG. 5 is a longitudinal sectional view of a conventional water pump. 1...Water pump, 2...Pump case, 3...
Bearing, 4... Outer ring, 5, 6, 8, 9... Raceway, 7
... Pump shaft, 10, 25 ... Rolling element, 11 ...
Pump chamber, 14... Sealing plate, 16... Impeller, 17... Mechanical seal, 18... Space, 19... Drain hole, 21... Oil seal,
23...Coil spring.

Claims (1)

[Scope of utility model registration request] In a water pump bearing, in which double rows of rolling elements are arranged between the outer ring and the pump shaft, and sealing rings are fitted on the inner circumferential surface of both ends of the outer ring to seal the space between the outer ring and the pump shaft, the water between the seals is A sealing ring on the pump chamber side, which is arranged adjacent to the pump seal, has a cylindrical fitting portion to the outer ring, a main body portion extending radially inward from one end of the fitting portion, and an inner periphery of the main body portion. A water pump comprising a seal lip that extends in the axial direction toward the pump chamber and has a greater tensioning force on the pump shaft circumferential surface than that of the seal lip of the sealing ring on the side opposite to the pump chamber. Bearing sealing device.