JPS6030867A - Mechanical seal for water pump - Google Patents

Abstract

PURPOSE:To simplify the structure and to facilitate assembling by utilizing the seal member for maintaining between an inverted ring and case liquid-tight as a member for blocking removal of the inverted ring from the case. CONSTITUTION:An inverted ring 1 is fitted slidably over the tubular section of a case 2 while three projections 10 are projected radially at the end of the tubular section 3 with same interval. Then a groove 11 engagable with each projection 10 is formed in the innercircumferential face of the inverted ring 1 to engage them. Consequently, the inverted ring 1 can slide against the case 2 but can not rotate while a sealing member 25 is placed between the projection 10 and the wall section 23 for forming an annular groove 25 to the utilized as a member for blocking removal of the inverted ring 1 from the tubular section 3 through the resiliency of the coil spring 16.

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 have a driven ring that is slidably housed in a case fixed to a housing, and a seal plate that is attached to the rotating shaft that passes through the driven ring's shaft. 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 to assemble the case and driven ring as one unit from the viewpoint of ease of assembly, but since they are generally easily separated from each other, it is difficult to assemble them as a mechanical seal assembly. Since they were glued together, assembly workability was poor. In addition, since the coil springs that start the driven ring are arranged in series so that they are in direct elastic contact with the end face of the driven ring, the axial length of the mechanical seal becomes longer and the length of the coil spring increases. It was a complicated work to assemble the driven ring so that its axis substantially coincided with the axis of the driven ring.

Mechanical seals that are unitized to prevent them from being easily separated from each other have been proposed in the past, but such mechanical seals generally have a complicated structure and are difficult to assemble themselves, and are also large and expensive. There was a drawback.

In view of such circumstances, the present invention utilizes a seal 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 unitizing them with a simple structure. The present invention provides a mechanical seal for a water pump that can be assembled easily 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. The purpose of the present invention is to provide a mechanical seal for a water pump in which the retainer can be used as a guide for the spring.

The present invention will be described below with reference to the illustrated embodiment. The case 2 that slidably houses the driven ring l has a cylindrical portion 3 of its shaft portion and extends radially outward in succession with the cylindrical portion 3. A wall portion 4, an outer cylindrical portion 5 extending from the outer periphery of the wall portion 4 in the direction of the cylindrical portion 3, and a flange portion 6 extending radially outward continuously from the outer cylindrical portion 5. It consists of The outer periphery of the outer cylindrical portion 5 is coated with rubber as a sealing member 7, and the external force cylindrical portion 5 is fitted into the housing 8 to keep that portion liquid-tight with the sealing member 7. There is.

The driven ring l 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. IO, and by forming engagement grooves 11 on the inner circumferential surface of the driven ring l that engage with each of the protrusions 1o so that they engage with each other, the sliding of the driven ring l 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 of the cylindrical portion 3, and an impeller 13 constituting a water pump is attached to the tip of the shaft.
The seal plate 15 is added through the seal plate 15. and,
The driven ring l is brought into elastic contact with the seal plate 15 by a coil spring 16, and the sliding contact between the seal plate 15 and the driven ring l prevents water from leaking from the outer periphery of the sliding surface to the inner periphery. ing.

The coil spring 16 is connected to the wall 4 of the case 2 and the driven ring l.
The retainer 2o has a cylindrical portion 21 fitted with the driven ring l, and
The cylindrical portion 21 includes a flange portion 22 extending radially outward from the end on the seal plate 15 side, and a wall portion 23 extending radially inward from the opposite end of the L-shaped cylindrical portion 21. . Then, the coil spring 1B 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 disposed so as to overlap in the axial direction, thereby shortening the length of both in the axial direction.

In addition, since the sealing member 25, which will be described later, is elastically mounted between the cylindrical part 3 of the case 2 and the driven ring l, -1=, the axis of the cylindrical part 3 and the axis of the driven ring l are aligned. Moreover, since the coil spring 16 shown in - is fitted on the outer periphery of the cylindrical part 21 of the retainer 20 attached to the driven ring l, the coil spring 16 and the driven ring l are automatically connected to the cylindrical shape. axis of the 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, which 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 link 1, and
An annular groove 24 is formed on the inner circumferential surface of the wall 23 by using the wall 23. Then, an annular seal member 25 such as the above-mentioned O-ring that maintains liquid tightness between the driven ring l and the cylindrical portion 3 is fitted into this annular groove 24, and this seal member 2
5, the water on the coil spring 16 side is
This prevents leakage to the inner peripheral side of the sliding contact surface between 15 and the driven ring l. Further, the sealing member 25 has the protrusion lO
and the wall portion 23 constituting the annular groove 25,
In the natural state, the driven ring 1 also serves as a retaining member that prevents the driven ring 1 from falling off the cylindrical portion 3 due to the elastic force of the coil spring 16.

In the above configuration, in order to assemble the case 2, the driven ring 1, etc. as one unit, the coil spring 16 is first housed in the case 2, and then the inside of the coil spring 16 and the cylindrical part 3 of the case 2 are 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, while the retainer 20 is pressed against the spring 16, the seal member 25 is fitted inside the retainer 20, and the seal member 25 is connected to the protrusion lO and the retainer 2.
0 and the wall 23 of 0. If this condition occurs,
As described above, the L sealing member 25 prevents the driven ring 1 from falling off from the cylindrical portion 3.

Furthermore, when this state is reached, the driven ring l described in "2" is fitted into the cylindrical portion 21 of the retainer 20, thereby automatically fitting the sealing member 25 described in - into the annular groove 24. Assembly is complete.

It goes without saying that the coil spring 18 can be set to a length that does not compress the seal member 25 in its natural state.

Furthermore, in the above embodiment, the annular groove 24 is formed between the driven ring 1 and the wall portion 23 of the retainer 20, but the driven ring 1
Of course, it is also possible to form the annular groove only by using the same method.

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 a special retaining member, and the assembly work for forming the unit can be performed satisfactorily.

Furthermore, in the present invention, the driven ring and the spring that biases the driven ring are arranged so as to overlap in the axial direction.
Since the axial length of the mechanical seal can be shortened and the driven ring can be used as a guide for the spring, the assembly work for making the unit into a unit can be made even better. This effect can be obtained.

[Brief explanation of drawings]

The figure is a sectional view showing one embodiment of the present invention. l...Seat ring 2...Case 3...Cylindrical part lO...Protrusion 1!・Paper engagement groove 12 ・Rotating shaft 15 ・Seal plate 16 ・Coil spring 20 ・
... Retainer 21 ... Cylindrical part 22 ... Flange part 23 ... Wall part 24 ... Annular groove 25 ... Seal member 1 ="

Claims (2)

[Claims] (1) A case with a cylindrical part provided on the shaft, a driven ring slidably provided on the outer periphery of the cylindrical part, and a seal member that maintains liquid tightness between the driven ring and the case. ,”1
In the mechanical seal for a water pump, the spring is elastically loaded between the case and the driven ring and brings the driven ring into elastic contact with the seal plate. At the same time, the driven link is provided to be slidable in the axial direction with respect to the cylindrical portion including the protrusion, and an annular groove is formed on the inner periphery of the driven ring, and the driven ring and the case are inserted into the annular groove. 1iJ with
An annular sealing member having elasticity that maintains the liquid tightness of I 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. Mechanical seal for water pumps. (2) A case with a cylindrical part on the shaft, a driven ring slidably provided on the outer periphery of the cylindrical part, and a seal that maintains liquid tightness between the driven ring and the case. A mechanical seal for a water pump comprising a member and a spring elastically loaded between the case and the driven ring and bringing the driven ring into elastic contact with the seal plate, wherein the protrusion protrudes outward in the radial direction on the cylindrical portion. At the same time, the driven ring is provided to be slidable in the axial direction with respect to the cylindrical portion including the protrusion, an annular groove is formed on the inner circumference of the driven ring, and the driven ring and the driven ring are formed in the annular groove. An annular seal member having elasticity that maintains liquid tightness with the case is fitted, and this seal member is interposed between the protrusion and the inner wall surface of the annular groove to serve as a member to prevent the driven ring from falling out. Further, a retainer for receiving the spring is formed into a cylindrical shape, a driven ring L 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 seal plate side. A mechanical seal for a water pump, characterized in that the spring is brought into elastic contact with the flange of the lever.