JPH0144799Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a rubber bellows type water pump shaft sealing device relating to shaft sealing technology.

[Conventional technology]

Conventionally, the structure of the secondary seal part of a shaft sealing device for a water pump, which seals the shaft by airtightly sliding a rotating ring carried on the rotating shaft side and a fixed ring carried on the machine casing side, is shown in Fig. 5. As shown, the rotating ring 50 is press-fitted and integrated into the fitting recess of the impeller 52 which is pivotally attached to the rotating shaft 51 via a cup gasket 53 which is an annular body having an L-shaped cross section. A fixed ring 54 that slides closely is slidably inserted into an outer cylinder 56 that is press-fitted into a shaft hole of a machine casing 55, and is interposed between the rear end of the fixed ring 54 and the end wall of the outer cylinder 56. A rubber bellows 57 which is elastically biased between both ends by a coil spring 59 via a spring holder 58 is used.

[Problem that the invention attempts to solve]

However, in this type of configuration, both ends of the rubber bellows 57 are fixed to the rotating ring 50 and the outer cylinder 56 with adhesives S and S, respectively, to form a secondary seal, and the shaft sealing device assembly process This method involves steps such as blending the adhesive, bonding, and drying, which requires a great deal of labor and time, resulting in a problem of rising production costs.

The present invention has been made in view of the above problems, and aims to provide a shaft sealing device for a water pump that can reduce assembly man-hours and production costs.

[Means for solving problems]

The shaft sealing device for a water pump of the present invention has a rotating ring supported on the rotating shaft side and a fixed ring supported on the machine casing side via a support tube and a rubber bellows and coil spring inside the support tube, which are airtightly opposed to each other. A structure in which the coil spring presses flanged end plates formed at both ends of the rubber bellows in opposite directions, and presses the both end plates against the end face of the fixed ring and the end face of the support cylinder. In the shaft sealing device, a close contact portion protruding in the axial direction in an edge shape and extending concentrically with respect to the shaft center is formed on the end face of the fixed ring of the both end plates and the face facing the end face of the support cylinder. It is characterized by:

[Effect]

In the shaft sealing device for a water pump configured as described above, the edge-shaped close portions formed on the flanged end plates at both ends of the rubber bellows are pressed against the end surfaces of the fixed ring and the end surface of the support cylinder by the pressing force of the coil spring. Since it exhibits good sealing properties, it is not necessary to bond the above-mentioned both end plates to the end face of the fixed ring and the end face of the support cylinder with an adhesive.

〔Example〕

Hereinafter, embodiments of the water pump shaft sealing device of the present invention will be described with reference to the drawings. FIGS. 1 and 2 show the first embodiment.

Reference numeral 1 designates a rotating ring which is press-fitted into a fitting recess 4 formed in a boss portion of an impeller 3 which is pivotally attached to a rotating shaft 2 via a cup gasket 5 having an L-shaped annular cross section. In the shaft sealing device, the rotary ring 1 and the fixed ring 6 are closely slid against each other to form a primary seal, and the rear end of the fixed ring 6, which is inserted onto the rotating shaft 2, is formed as one end of the rubber bellows 7. The rear wall of the support cylinder 12 is formed in close contact with the end plate 8, and the end plate 9 formed at the other end of the rubber bellows 7 is press-fitted with the outer cylinder part 13 into the shaft hole 11 of the machine casing 10. It is in close proximity to the 14th side. Further, on the contact surfaces of both end plates 8 and 9, a plurality of edge-shaped close parts (in the embodiment, two
Circumferential seal shape 16, 16 composed of strips
are integrally constituted, and the rubber bellows 7
Both ends of the coil spring 17 inserted into the coil spring 17 are elastically mounted between the end plates 8 and 9 via the spring holder 18, and the edge-shaped close contact portion 15 at the tip of the annular protrusion 15
are pressed against the rear end of the fixed ring 2 and the rear wall 14 of the support cylinder 12, respectively, to form a secondary seal.

The shaft sealing device for a water pump configured as described above presses the fixed ring 6 against the rotating ring 1 by the elastic tension of the coil spring 17 inserted into the rubber bellows 7,
It slides and rotates closely. However, since the contact surfaces of the end plates 8 and 9 formed at both ends of the rubber bellows 7 are integrally formed with circumferential seal shapes 16 and 16 consisting of concentric edge-like close contact parts, The secondary seal part is constructed at the same time as assembly.

Next, FIGS. 3 and 4 show another embodiment of the present invention, and only the configurations of the parts that are different from the previous embodiment will be explained.

The rubber bellows 19 is formed such that both end plates 20 and 21 are perpendicular to the axis, and each end surface of the end plates 20 and 21 is flat.
The rubber bellows 19 is connected between both end plates 20 and 21 of the rubber bellows 19 via spring holders 22 and 23, each of which is an annular body having a substantially L-shaped cross section.
The coil spring 17 inserted into the spring holder 9 is elastically loaded, and the end plates 20 and 21 of the rubber bellows 19 are connected to the rear end surface of the fixed ring 6 and the back of the support cylinder 12 via the end plates 24 and 25 of the spring holders 22 and 23. They are each elastically pressed against the wall 14. Both spring holders 2 above
The end plates 24 and 25 of 2 and 23 have curved cross-sections in which the outer circumferential portion protrudes in the axial direction from the inner circumferential portion, and the end plates 24 and 25 are connected to the end plates 20 and 25 of the rubber bellows 19, respectively.
When elastically pressed by a coil spring 17 along each back surface of the end plates 21, the abutment surfaces of the end plates 20, 21 are bent, and the circumferential seal shapes 16, 16 become concentric with the axis. A close contact portion 26 that protrudes in an edge shape,
27, and the circumferential seal shapes 16, 16 form a secondary seal portion.

Therefore, in the above configuration, by assembling the spring holders 22, 23 and the coil spring 17 to the rubber bellows 19, a secondary seal portion is formed on the abutting surfaces of the end plates 20, 21 of the rubber bellows 19. This configuration constitutes the circumferential seal shapes 16, 16, and the number of assembly steps can be reduced as in the first embodiment.

[Effect of idea]

As described above, in the shaft sealing device for a water pump of the present invention, both end plates of the rubber bellows come into pressure contact with the fixed ring and the support cylinder at their edge-shaped close contact parts by the pressure of the coil spring, so that a good secondary seal can be achieved. Department will be formed. Furthermore, it is not necessary to bond the secondary seal portion with an adhesive, and the shaft sealing device can be easily assembled, which is an excellent effect.

[Brief explanation of drawings]

Fig. 1 is a front sectional view of a shaft sealing part showing a first embodiment of the shaft sealing device for a water pump of the present invention, Fig. 2 is an enlarged sectional view of the same essential part, and Fig. 3 shows another embodiment. FIG. 4 is a front sectional view of the shaft sealing part, FIG. 4 is an enlarged sectional view of the main part thereof, and FIG. 5 is a front sectional view cut in half showing a conventional shaft sealing device. 1... Rotating ring, 2... Rotating shaft, 3... Impeller, 6...
Fixed ring, 7, 19...Rubber bellows, 8, 9, 2
0, 21, 24, 25...end plate, 10...machine casing, 12
...Support tube, 15...Annular protrusion, 16...Peripheral seal shape, 17...Coil spring, 18, 22, 23
... Spring holder, 26, 27... Close contact part.

Claims (1)

[Scope of utility model registration request] A rotary ring supported on the rotating shaft side and a fixed ring supported on the machine casing side via a support tube, a rubber bellows in the support tube, and a coil spring are made to airtightly slide opposite each other, and the coil spring engages the rubber bellows. In the shaft sealing device, the shaft sealing device has a structure in which brim-shaped end plates formed at both ends are pressed in opposite directions to press the both end plates into pressure contact with the end face of the fixed ring and the end face of the support cylinder. A shaft sealing device for a water pump, characterized in that a close contact portion is formed on an end surface of the fixed ring and a surface facing the end surface of the support tube, protruding in an edge shape in the axial direction and extending concentrically with respect to the shaft core.