JPS6325230B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanical seal for a water pump that maintains liquid tightness through sliding contact between a driven ring and a seal plate.

Mechanical seals for water pumps usually include a driven ring that is slidably housed in a case fixed to a housing, and a seal plate that is attached to a rotating shaft that passes through the shaft of the driven ring. The driven ring is brought into elastic contact with the seal plate by a coil spring mounted between the driven ring and the case.

It is desirable that the case and driven ring are assembled as one unit from the viewpoint of assembly workability, but since they are generally easily separated from each other, they are glued together when assembled as a mechanical seal assembly. As a result, assembly workability was poor. In addition, since the coil springs that bias the driven ring are arranged in series so as to be in direct elastic contact with the end face of the driven ring, the axial length of the mechanical seal becomes longer and the coil spring It is a complicated work to assemble the driven ring so that its axis substantially coincides with the axis of the driven ring.

In the past, mechanical seals have been proposed that are unitized so that they cannot be easily separated from each other, but such mechanical seals generally have a complicated structure and are difficult to assemble themselves, and are also large and expensive. It had the disadvantage of becoming.

In view of such circumstances, the present invention utilizes a sealing member that maintains liquid tightness between the driven ring and the case as a member to prevent the driven ring from coming off from the case, thereby integrating them into a unit with a simple structure. To provide a mechanical seal for a water pump that can be easily assembled and has good assembly workability.

Further, in the present invention, the retainer for receiving the spring is formed into a cylindrical shape, the driven ring is fitted inside the retainer, and a flange portion extending radially outward is formed at the seal plate side end of the cylindrical portion of the retainer. By bringing the spring into elastic contact with this flange portion, the driven ring and the spring can be arranged to overlap in the axial direction, thereby shortening the axial length. Moreover, the present invention provides a mechanical seal for a water pump in which a retainer can be used as a guide for the spring.

The present invention will be described below with reference to the illustrated embodiments.
The case 2 that slidably houses the driven ring 1 is
A cylindrical portion 3 of the shaft portion, a wall portion 4 extending radially outward continuously from the cylindrical portion 3, and an outer cylindrical portion extending from the outer periphery of the wall portion 4 in the direction of the cylindrical portion 3. 5
and a flange portion 6 that extends radially outward continuously from the outer cylindrical portion 5. The outer periphery of the outer cylindrical portion 5 is coated with rubber as a seal member 7, and the outer cylindrical portion 5 is fitted into the housing 8 to make that part liquid-tight. keeping.

The driven ring 1 is slidably fitted on the outer periphery of the cylindrical part 3 of the case 2, and at this time, three protrusions projecting outward in the radial direction are provided at equal intervals at the tip of the cylindrical part 3. 10, and by forming engagement grooves 11 on the inner circumferential surface of the driven ring 1 that engage with each of the protrusions 10 so that they engage with each other, the sliding of the driven ring 1 with respect to the case 2 is prevented. is allowed, but relative rotation between the two is prevented.

A rotary shaft 12 is passed through the shaft portion of the cylindrical portion 3, and an impeller 13 constituting a water pump is attached to the tip end of the rotary shaft 12.
Seal plate 1 via sheet packing 14
5 is installed. The driven ring 1 is brought into elastic contact with the seal plate 15 by a coil spring 16, and water leaks from the outer periphery of the sliding surface to the inner periphery due to the sliding contact between the seal plate 15 and the driven ring 1. We are trying to prevent this.

The coil spring 16 is elastically mounted between the wall 4 of the case 2 and a retainer 20 provided on the driven ring 1, and the retainer 20 is connected to a cylindrical portion 21 into which the driven ring 1 is fitted, It includes a flange portion 22 extending radially outward from the end of the shaped portion 21 on the seal plate 15 side, and a wall portion 23 extending radially inward from the opposite end of the cylindrical portion 21 .
Then, the coil spring 16 is attached to the flange portion 22.
By bringing them into elastic contact with each other, the driven ring 1 and the coil spring 16 are arranged so as to overlap in the axial direction, thereby shortening the length of both in the axial direction.

In addition, the cylindrical portion 3 of the case 2 and the driven ring 1
Since a sealing member 25 (described later) is elastically mounted between the cylindrical part 3 and the axis of the driven ring 1, the cylindrical part of the retainer 20 attached to the driven ring 1 coincides with the axis of the cylindrical part 3 and the driven ring 1. Since the coil spring 16 is fitted on the outer periphery of 21, the coil spring 1
6 and the driven ring 1 can be automatically positioned on the axis of the cylindrical portion 3, and therefore the assembly work of assembling them on the same axis can be facilitated. If they can be assembled on the same axis, it becomes possible to easily prevent the neck vibration of the driven ring 1 that tends to occur when assembled eccentrically.

On the other hand, the wall portion 23 of the retainer 20 that transmits the elastic force of the spring 16 to the driven ring 1 projects inward from the inner peripheral edge of the right end surface of the driven ring 1. An annular groove 24 is formed on the inner circumferential surface on the 23 side using the wall portion 23. Then, an annular seal member 25 such as the above-mentioned O-ring that maintains liquid tightness between the driven ring 1 and the cylindrical portion 3 is fitted into this annular groove 24.
5 prevents water on the coil spring 16 side from leaking to the inner peripheral side of the sliding contact surface between the seal plate 15 and the driven ring 1. Further, the sealing member 25 is interposed between the protrusion 10 and the wall portion 23 constituting the annular groove 25, so that in a natural state, the driven ring 1 is moved to the cylindrical portion by the elastic force of the coil spring 16. It also serves as a retaining member to prevent it from falling off.

In the above configuration, in order to assemble the case 2, the driven ring 1, etc. as one unit, first the coil spring 16 is housed in the case 2, and then the inside of the coil spring 16 and the cylindrical part 3 of the case 2 are assembled. The cylindrical part 21 of the retainer 20 is fitted between the outside of the retainer 20 and the spring 16 is brought into elastic contact with the flange part 22 of the retainer 20.

Next, the seal member 25 is fitted inside the retainer 20 while the retainer 20 is pressed against the spring 16, and the seal member 25 is inserted between the protrusion 10 and the wall portion 23 of the retainer 20. to be located. In this state, as described above, the seal member 25 prevents the driven ring 1 from falling off from the cylindrical portion 3.

Further, when this state is reached, the driven ring 1 is fitted into the cylindrical portion 21 of the retainer 20, and thereby the seal member 25 is automatically fitted into the annular groove 24, completing the assembly. .

It goes without saying that the coil spring 16 can be set to a length that does not compress the seal member 25 in its natural state. In addition, in the above embodiment, the driven ring 1
Although the annular groove 24 is formed by the wall portion 23 of the retainer 20, it is of course possible to form the annular groove by the driven ring 1 alone.

As described above, in the present invention, a sealing member that maintains liquid tightness between the driven ring and the case is interposed between the protrusion and the inner wall surface of the annular groove to serve as a member for preventing the driven ring from coming off. Therefore, it is possible to form them into a unit with a simple structure without requiring any special retaining member, and the assembly work for forming the unit can be carried out effectively.

Further, in the present invention, since the driven ring and the spring that biases the driven ring are disposed so as to overlap in the axial direction, the axial length of the mechanical seal can be shortened, and the driven ring can be Since it can be used as a guide for the spring, it is possible to achieve the effect that the assembly work for forming the unit can be made even more efficient.

[Brief explanation of the drawing]

The figure is a sectional view showing one embodiment of the present invention. 1... Seat ring, 2... Case, 3... Cylindrical part,
10...Protrusion, 11...Engagement groove, 12...Rotary shaft, 15
...Seal plate, 16...Coil spring, 20...Retainer, 21...Cylindrical part, 22...Flange part, 23
...Wall portion, 24...Annular groove, 25...Seal member.

Claims (1)

[Claims] 1. A case having a cylindrical portion on the shaft portion, a driven ring slidably provided on the outer periphery of the cylindrical portion, and maintaining liquid tightness between the driven ring and the case. A mechanical seal for a water pump, comprising: a sealing member that is elastically mounted between the case and the driven ring, and a spring that causes the driven ring to come into elastic contact with the seal plate; At the same time, the driven ring is provided to be slidable in the axial direction with respect to the cylindrical portion including the projection, and an annular groove is formed on the inner circumference of the driven ring, and the driven ring is provided in the annular groove. An annular sealing member having elasticity that maintains liquid tightness between the ring and the case is fitted, and this sealing member is interposed between the projection and the inner wall surface of the annular groove to prevent the driven ring from slipping out. A mechanical seal for a water pump characterized by being a component. 2. A case having a cylindrical portion on the shaft portion, a driven ring slidably provided on the outer periphery of the cylindrical portion, a sealing member that maintains liquid tightness between the driven ring and the case, and the above-mentioned A mechanical seal for a water pump comprising a spring that is elastically loaded between a case and a driven ring and brings the driven ring into elastic contact with a seal plate, wherein a projection that projects radially outward is formed on the cylindrical portion, and , the driven ring is provided to be slidable in the axial direction with respect to the cylindrical part including the protrusion, an annular groove is formed on the inner periphery of the driven ring, and a space between the driven ring and the case is formed in the annular groove. An annular sealing member having elasticity that maintains liquid tightness is fitted, and this sealing member is interposed between the protrusion and the inner wall surface of the annular groove to serve as a member for preventing the driven ring from slipping out. A cylindrical retainer is formed to receive the retainer, and the driven ring is fitted inside the retainer, and a flange portion extending radially outward is formed at an end of the cylindrical portion of the retainer on the side of the seal plate. A mechanical seal for a water pump, characterized by having the above spring in elastic contact.