JPH0733868B2 - Pump bearing sealing device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sealing device for a pump bearing in a water pump of, for example, an automobile.

<Prior Art> A conventional sealing device for a pump bearing of this type will be described with reference to FIG.

In the illustrated water pump, reference numeral 1 is a pump shaft,
The pump shaft 1 is supported by a housing 4 via a bearing 3 having sealing plates 2a, 2b mounted thereon.

An impeller 5a is attached to the tip of the pump shaft 1, and the pump shaft 1 is provided at the opening end side of the pump chamber 41 of the housing 4.
It is designed to rotate with it. Also, the pump shaft 1
Pulley with a drive belt (not shown) on the rear end
5b is installed.

The bearing 3 supporting the pump shaft 1 is provided in the bearing chamber 42 of the housing 4.
It is located inside.

The bearing 3 includes a cylindrical outer ring 31, a plurality of spherical rolling elements 32 and a plurality of cylindrical rolling elements which are distributed between the outer ring 31 and the pump shaft 1 in two rows and are interposed in a pressure contact state. It has 33 and.

The bearing 3 is axially positioned by the spherical rolling element 32 and the guide groove 11 of the pump shaft 1 through which the rolling element 32 is guided. The cylindrical rolling element 33 is positioned by a groove 31a formed in the inner peripheral surface of the outer ring 31.

In the pump shaft 1, between the bearing 3 and the impeller 5a,
A mechanical seal 6 is arranged.

This mechanical seal 6 is provided in the pump chamber 41 of the housing 4.
Which separates the bearing chamber 42 from the bearing chamber 42, and
A rotary member 62 fitted onto the pump shaft 1 so as to face the seal case 61, an annular movable seal 63 fixed to the inner peripheral surface of the rotary member 62, and provided on the seal case 61 side. And an annular fixed seal 64 that comes into pressure contact with the movable seal 63, and a coil spring 65 that urges the fixed seal 64 toward the movable seal 63.

A relatively small internal space 66 is formed between the inner peripheral surface of the movable seal 63 and the fixed seal 64 and the outer peripheral surface of the pump shaft 1 in a predetermined width.

This internal space 66 is a seal case for the mechanical seal 6.
Although it communicates with the bearing chamber 42 of the housing 4 through a gap 67 formed between the pump shaft 1 and the pump shaft 1, it has a movable seal.
Due to the abutting relationship between 63 and the fixed seal 64, the bearing chamber 42 and the pump chamber 41 are almost airtightly partitioned from each other.

That is, the mechanical seal 6 prevents the cooling water existing in the pump chamber 41 from leaking to the bearing chamber 42.

<Problems to be Solved by the Invention> However, the conventional example having such a configuration has the following problems.

During use, the cooling water may soak into the sliding contact portion between the movable seal 63 and the fixed seal 64 of the mechanical seal 6, and the cooling water soaked by the frictional heat generated by the sliding contact between the movable seal 63 and the fixed seal 64. Became steam, and this steam flowed into the bearing chamber 42 side through the internal space 66 of the mechanical seal 6.

The inflowing steam cools into water droplets and flows into the bearing 3 from the sealing plate 2a even though the sealing plate 2a is attached to the bearing 3.

Therefore, conventionally, the through hole 43 communicating with the outside of the bearing chamber 42 of the housing 4 is formed to discharge the steam or water flowing into the bearing chamber 42 to the outside.

However, even if the steam or water is discharged from the bearing chamber 42 through the through hole 43 for discharging steam of the housing 4, since the steam or water flows into the bearing chamber 42, Inevitably some of the steam or water is in the bearing 3
Flows into the interior of the.

As described above, in the conventional device, although the mechanical seal 6 having a relatively high reliability is used, the cooling water flows into the bearing 3 and the bearing function is inevitably deteriorated.

The present invention was devised in view of such circumstances, and an object thereof is to prevent cooling water from flowing into the inside of the bearing and prevent deterioration of the bearing function.

<Means for Solving Problems> The present invention has the following configuration in order to achieve such an object.

That is, a pump bearing sealing device according to the present invention includes a pump chamber in a housing, a pump shaft inserted through the bearing chamber in a penetrating state, and a bearing rotatably supporting the pump shaft in the bearing chamber of the housing. A mechanical seal externally fitted to the pump shaft so as to partition the pump chamber and the bearing chamber of the housing, and an airtight partition provided between the mechanical seal and the bearing to partition the pump chamber and the bearing chamber. A seal ring is provided, and a drainage passage is formed inside the pump shaft for communicating the internal space of a mechanical seal formed between the seal ring and the pump shaft to the outside air. is there.

<Operation> The operation of the configuration of the present invention is as follows.

Since the mechanical seal is used, it is inevitable that the cooling water vapor will flow into the internal space of the mechanical seal.

Since the internal space of the mechanical seal communicates with the water drain passage formed inside the pump shaft, the steam in the internal space or the water produced by cooling the steam is the water drain passage. Is released to the outside via.

Since the internal space of the mechanical seal is airtightly partitioned from the inside of the bearing by the seal ring, steam or water in the internal space will not flow into the inside of the bearing.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

1 and 2 show an embodiment of the present invention.
FIG. 1 is a view corresponding to FIG. 3 which is a conventional example, and the same reference numerals as those given in FIG. 3 indicate the same parts or corresponding portions also in this embodiment.

In the present embodiment, a configuration different from the conventional example will be described in detail, and a description of other similar configurations will be omitted.

That is, the configuration of the pump shaft 1, the arrangement of the mechanical seal 6 and the adoption of the seal ring 7 are mainly different from the conventional example.

The mechanical seal 6 is externally fitted to the pump shaft 1 so as to be adjacent to the impeller 5a side of the bearing 3 supporting the pump shaft 1, and is in close contact with the end surface of the bearing 3 via a seal ring 7. More specifically, the outer peripheral surface of the seal case 61 of the mechanical seal 6 closes the end surface of the bearing 3 via the seal ring 7. The rotary member 62 of the mechanical seal 6 is externally fitted and fixed to the pump shaft 1.

The mechanical seal 6 of this embodiment is different from the coil spring 65 of the conventional example. That is, the spring 65 here is a conical flat plate coil spring.

A passage 12 for draining water is formed inside the pump shaft 1. The drainage passage 12 is formed concentrically with the shaft center of the pump shaft 1 and is provided with the pulley 5b.
The end face side of the shaft hole 12a communicates with the outside air and is closed in the middle of the pump shaft 1 and a plurality of through holes 12b radially separated from each other on the closed side of the shaft hole 12a.

It should be noted that the through hole 12b is formed in the internal space 66 of the mechanical seal 6.
Is in communication with.

Therefore, the internal space 66 of the mechanical seal 6 is communicated with the outside air via the passage 12 for draining water.

At the inner peripheral edge of the seal ring 7, there is provided a lip portion 71 that bends so as to bite into the mechanical seal 6 side (second
Enlarged in the figure). The lip portion 71 airtightly partitions the internal space 66 of the mechanical seal 6 and the interior of the bearing 3 from each other, and frictional heat generated when the movable seal 63 and the fixed seal 64 of the mechanical seal 6 make sliding contact with each other causes the internal space 66 to be separated. Even if the gas in (1) expands, it keeps a sufficient seal pressure and releases the pressure from the drainage passage (12).

Further, the outer peripheral edge of the seal ring 7 is pressed against the inner peripheral surface of the bearing chamber 42 of the housing 4 with a predetermined sealing pressure so that the cooling water does not leak from the pump chamber 41 of the housing 4 to the bearing chamber 42. There is.

Next, the operation will be described.

When the cooling water soaks into the sliding contact surface between the movable seal 63 and the fixed seal 64 of the mechanical seal 6 during use, the cooling water soaked by the frictional heat generated during the sliding contact between the two becomes steam, and the inside of the mechanical seal 6 Enter the space 66.

The steam that has flowed into the internal space 66 or water droplets formed by cooling the steam is discharged to the outside through the through hole 12b of the pump shaft 1 and the shaft hole 12a, that is, the passage 12 for draining water. Moreover, no steam or water will flow into the bearing 3.

Moreover, although the gas in the internal space 66 may expand due to the frictional heat between the movable seal 63 and the fixed seal 64, the lip portion 71 of the seal ring 7 keeps the internal space 66 airtight. The expansion also prevents steam or water from flowing into the inside of the bearing 3.

As described in the above embodiment, when the mechanical seal 6 is brought into close contact with the end surface of the bearing 3, the dimension of the pump shaft 1 in the longitudinal direction can be shortened, which contributes to downsizing as a whole. .

Further, in the above embodiment, the shaft hole of the drainage passage 12
It is conceivable that a spiral groove may be formed in 12a, or the diameter may be increased toward the outside on the pulley 5b side to facilitate the escape of water.

Furthermore, the present invention is not limited to the above-described embodiment, but can be applied to, for example, the one shown in FIG. 3 showing a conventional example. In this case, although not shown, a shaft hole is formed in the pump shaft 1 and a through hole that connects the shaft hole and the internal space 66 is formed, and further, the bearing 3 and the mechanical seal 6 are formed.
The internal space 66 of the mechanical seal may be made airtight with respect to the bearing chamber 42 by interposing the seal ring as described in the above embodiment in the space between the and.

<Effects of the Invention> According to the present invention, the following effects are exhibited.

The internal space of the mechanical seal communicates with the outside air through a drainage passage formed inside the pump shaft, and the internal space and the inside of the bearing are hermetically partitioned by a seal ring. Even if the steam generated at the seal point or the water produced by cooling the steam enters the internal space of the mechanical seal, it does not flow into the bearing as in the conventional case, but the outside through the drainage passage. Will be released to.

As described above, the inflow of cooling water into the bearing can be prevented, so that the bearing function is stabilized and therefore the reliability can be improved. Further, even if the housing has a complicated shape and it is difficult to form the drain hole in the housing, according to the present invention, it is not necessary to form the drain hole in the housing itself, so that the housing shape which has been difficult to apply in the past can be obtained. It can be easily applied to things.

[Brief description of drawings]

1 and 2 relate to an embodiment of the present invention.
The drawing is a vertical side view showing the whole of the water pump, and FIG. 2 is an enlarged view of a portion surrounded by a circle in FIG. FIG. 3 is a conventional example and is a vertical sectional side view showing the entire water pump. 1 …… Pump shaft 12 …… Water passage 3 …… Bearing 6 …… Mechanical seal 66 …… Internal space 7 …… Seal ring

Claims (2)

[Claims] 1. A pump shaft inserted through a pump chamber and a bearing chamber in a housing in a penetrating state, a bearing rotatably supporting the pump shaft in the bearing chamber of the housing, and a pump chamber and a bearing chamber of the housing. A mechanical seal externally fitted to the pump shaft so as to partition the pump chamber and a seal ring that is arranged between the mechanical seal and the bearing and airtightly partitions the pump chamber and the bearing chamber. A pump bearing sealing device, characterized in that a drainage passage is formed inside the pump shaft for communicating an internal space of a mechanical seal formed between the pump shaft and the ring with the outside air. 2. The sealing device for a pump bearing according to claim 1, wherein the mechanical seal is arranged in close contact with the end surface of the bearing via the seal ring.