JP2792007B2 - Shaft sealing device - Google Patents

Description

Description: TECHNICAL FIELD [0001] The present invention relates to a shaft sealing device in a submersible rotating device such as a submersible centrifugal pump.

[Prior art and its problems] A fixed seal ring mounting housing in a shaft sealing device of a submersible rotary device such as a submersible centrifugal pump has conventionally been made of a casting, and a spigot has been formed by machining after casting. Therefore,
It is unsuitable for mass production and costs high, and the weight of the product also increases.

The cross-sectional shape of the conventional cast housing is as shown in FIG. 3, but if it is made of a metal plate, it will have a cross-sectional shape as shown in FIG. 4, and it is difficult to integrally mold it only by pressing. Requires joining members by welding.

Even if the housing is made of a casting or a metal plate, a fixed sealing ring and a buffer packing are mounted on the housing, so it is difficult to shorten the mechanical seal mounting length, Due to the large number, it cannot be produced at low cost.

In particular, in a double seal type shaft sealing device provided with both a mechanical seal and a dust seal, there is a regret that the shaft length of the device is further increased, which is incompatible with the demand for downsizing and weight reduction.

Moreover, in the double-seal type shaft sealing device, the lip tip of the lip-type packing is brought into contact with the outer peripheral surface of the pump shaft to form a sliding sealing surface in the radial direction, so that the pump shaft is worn. Has the disadvantage of causing In addition, since the water pressure gradually acts in the direction of increasing the leakage, only the initial effect is obtained, and the shaft sealing effect decreases with time.

[Object of the Invention] An object of the present invention is, first, in a shaft seal device of a double seal type, a housing for supporting a fixed sealing ring is made of a metal plate, and furthermore, the metal plate housing can be joined by welding. An object of the present invention is to provide a compact and lightweight product at a low cost without using a structure that can be easily formed only by press working, and can reduce the number of parts and the number of assembling steps.

The second object of the present invention is to provide an excellent dust seal function,
An object of the present invention is to provide a shaft sealing device that does not wear the pump shaft.

[Constitution of the invention] In a shaft sealing device according to the present invention, in a shaft sealing device provided with a mechanical seal and a dust seal, a hard coating layer is formed on each of the front and back portions around a shaft hole of a mounting housing made of a metal plate. By forming a rotary seal ring on the mechanical seal side against the hard coating layer on the front side and a lip-type packing on the dust seal side against the hard coating layer on the back side, Each has a sliding sealing surface, and the periphery of the shaft hole of the mounting housing made of a metal plate is annularly punched out to form a convex ring on the front side and a concave ring on the back side, thereby forming a concave ring. The hard coating layer is formed in an annular shape on the groove bottom surface and the convex ring surface respectively, and the mechanical seal side rotating sealing ring is brought into contact with the convex ring side hard coating layer, and the dust seal is formed on the concave ring side hard coating layer. Side lip packing By Taise' the one in which allowed to configure each sliding sealing surfaces between these two abutment surfaces.

EXAMPLES Referring to the drawings exemplifying the embodiments, reference numeral 1 denotes a mounting housing made of a metal plate, and a peripheral portion of a shaft hole 2 formed in a plate is punched out in a ring shape, and a convex ring is formed on the front side. 4 and a concave ring 3 is formed on the back side. And concave ring 3
The coating of ceramics, cemented carbide, etc. is applied to the groove bottom surface and the surface of the convex ring 4 to form hard coating layers 5a and 5b, respectively, in a ring shape, and the hard coating layer 5a on the convex ring 4 side is mechanically formed. That is, the rotary sealing ring 6a on the seal side is brought into contact with a sliding contact surface between the contact surfaces. Reference numeral 7 denotes a pressing spring for pressing the rotary sealing ring 6a against the hard coating layer 5a.

When the present invention is applied to a shaft sealing device of a submersible centrifugal pump, a bearing 9 for supporting a pump shaft 8 is fitted in a concave ring 3 'in an upper mounting housing 1', and a bearing 9 in the lower mounting housing 1 is provided. The boss 11 of the impeller 10 is provided in the concave ring 3.
Will be inserted.

The lip-type packing 6b is made of a resilient material such as rubber or synthetic rubber in a V-shape. In the concave ring 3, a fitting portion is fitted to a pump shaft, and a lip portion is formed of a hard coating. By contacting the layer 5b, a sliding sealing surface is formed to control the dust sealing. When the pump is driven, the water pressure acts to press the lip portion against the surface on which the hard coating layer 5b is formed, and the dust sealing function is enhanced.

[Effect] As a first effect of the present invention, the mounting housing 1 made of a metal plate can be obtained by integrally molding only by press working without the need for joining members by welding. Since no buffer packing is required, the number of parts can be reduced, the mounting length of the mechanical seal can be shortened, the number of assembling steps can be reduced, and a small and lightweight product can be provided at low cost.

As a second effect of the present invention, lip-type packing
The lip portion 6b does not come into sliding contact with the pump shaft 8, but comes into sliding contact with the hard coating layer 5b on the back surface of the peripheral portion of the shaft hole, so that the pump shaft 8 does not wear even after long-term use. Also,
When the pump is driven, the water pressure acts so as to press the lip portion against the surface on which the hard coating layer 5b is formed, so that there is an advantage that the dust sealing function is enhanced.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a main part showing an example in which the shaft sealing device of the present invention is applied to a submersible centrifugal pump, FIG. 2 is a vertical side view of a main part of a mounting housing in the device of the present invention, and FIG. FIG. 4 is a vertical sectional side view of an essential part of a submersible centrifugal pump provided with a shaft sealing device having a housing-made structure, and FIG. 1 mounting housing 3 concave ring 4 convex ring 5a
... hard coating layer on concave ring side, 5b ... hard coating layer on convex ring side, 6a
…… Rotary seal ring, 6b …… Lip type packing.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16J 15/16

Claims (2)

(57) [Claims] In a shaft sealing device provided with a mechanical seal and a dust seal, a hard coating layer (5a, 5a) is formed on the front and back of a shaft hole of a mounting housing (1) made of a metal plate.
b) is formed in an annular shape, and the rotary seal ring (6a) on the mechanical seal side is brought into contact with the hard coating layer (5a) on the front side, and the lip type packing (Dust seal side) on the hard coating layer (5b) on the back side. A shaft sealing device, characterized in that sliding contact surfaces are formed between these two contact surfaces by contacting each other. 2. A shaft seal device having a mechanical seal and a dust seal, wherein a peripheral portion of a shaft hole of a mounting housing (1) made of a metal plate is annularly formed to form a convex ring (4) on the front side. And a concave ring (3) is formed on the back side, and the hard coating layers (5a) and (5b) are formed annularly on the groove bottom surface of the concave ring (3) and the surface of the convex ring (4), respectively. (4)
The rotating seal ring (6a) on the mechanical seal side is in contact with the hard coating layer (5a) on the side, and the hard coating layer (5b) on the concave ring (3) side
A lip-type packing (6b) on the dust seal side, whereby a sliding sealing surface is formed between the two contact surfaces.