JP4057283B2 - Cassette type double mechanical seal for electric pump - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cassette-type double mechanical seal that is mounted in an oil chamber of an electric pump and also has a function as an oil lifter.
[0002]
[Prior art and its problems]
Conventionally, as shown in FIG. 5, the double mechanical seal attached to the electric pump is supported by fitting the upper mating ring 108A on the lower surface of the oil chamber upper wall 101 and the lower mating ring 108B on the upper surface of the oil chamber lower wall 102. The upper seal ring 110A is pressed against the upper mating ring 108A by the spring pressure of the coil spring 106, and the lower seal ring 110B is pressed against the lower mating ring 108B. Assembled to make up.
[0003]
However, the assembly requires special assembly tools, jigs, and the like and requires skill of the operator. In addition, in order to ensure the accuracy of the mounting length H1 of the double mechanical seal 106, the fitting surface of the shaft seal member on the upper wall 101, the lower wall 102, etc. of the oil chamber 105 must be subjected to high-precision grinding. However, coupled with the requirement for skill of the operator, this increases the manufacturing cost of the electric pump. Furthermore, when removing the double mechanical seal 106, the lower wall 102 of the oil chamber 105 must be disassembled, which is troublesome and may damage the outer peripheral surface of the shaft 103.
[0004]
There are cassette-type double mechanical seals, but the conventional cassette-type structure is a spring case around the outer periphery of the coil spring and the upper and lower seal rings facing each other through the coil spring. The shaft sleeve is fixed to the rotating main shaft by screwing, and is accompanied by a threading operation by tapping the outer peripheral surface of the shaft sleeve. The surface is damaged, and the oil flow between the upper and lower seal rings is hindered by the presence of the spring case. In addition, there is a problem in that the lower wall of the oil chamber must be disassembled at the time of attachment to and removal from the oil chamber.
[0005]
OBJECT OF THE INVENTION
An object of the present invention is to install a double mechanical seal on an electric pump without using a high-precision grinding process on a fitting surface of a shaft seal member on an upper wall or a lower wall of an oil chamber as in the prior art. The accuracy of the mechanical seal mounting length can be ensured, and no special assembly tools or jigs are required, and it does not depend on the skill level of the operator. By providing a cassette-type double mechanical seal that can be mounted and removed as well as being reusable by exchanging parts with an oil lift function, it is intended to contribute to improving workability and reducing the manufacturing cost of electric pumps. is there.
[0006]
[Structure of the invention]
In the cassette type double mechanical seal for an electric pump according to the first aspect of the present invention, the shaft sleeve is detachably inserted into the rotary main shaft passing through the center hole of the oil chamber upper wall and the center hole of the oil chamber lower wall. A double mechanical seal is fitted on the outer periphery, an upper mating ring is fitted on the inner periphery of the upper end, and a lower mating ring is fitted on the inner periphery of the lower end, and the outer periphery of the double mechanical seal is surrounded by a cylindrical cassette case, the disk-shaped fixing seat inner to seal the cassette case bottom opening loosely fitted to the outer periphery the shaft sleeve, said fixing seat upper surface to the lower edge of the lower end surface and said cassette case of the lower main tailing outside periphery the cassette case bottom to abut on the flange lower surface projecting toward removably attached to form the mounting seat of the oil chamber lower wall back surface, Kasettoke A guide vane is attached to the inner peripheral surface of the tube so as to form an inclined surface having an upward slope in the direction of rotation of the main shaft, and an oil inflow hole is formed in the lower portion of the cassette case on the back side of the lower end of the guide vane. By inserting the shaft sleeve from the lower end of the cassette case, the outer periphery of the upper end of the cassette case is fitted into the center hole of the upper wall of the oil chamber, and the outer periphery of the lower end is fitted to the center hole of the lower wall of the oil chamber. Further, in the second aspect of the electric pump cassette type double mechanical seal, in addition to the configuration of claim 1, wherein a cylindrical cassette case surrounding the outer periphery of the double mechanical seal, the inner case and the outer case fit The guide vane constructed in the double structure and attached to the inner peripheral surface of the cassette case is protruded by cutting the wall surface of the inner case inward, and the through hole formed in the cut-and-raised portion is formed on the outer periphery. It is blocked from the wall surface of the outer case that fits to the surface.
[0007]
【Example】
[0008]
The embodiment will be described below with reference to FIGS.
1 is an oil chamber upper wall that also serves as the lower wall of the motor frame, 2 is an oil chamber lower wall that also serves as the upper wall of the pump casing, and 3 is a rotating main shaft guided from the pump motor. Further, the impeller in the pump casing is fitted to the leading end of the lower end of the oil chamber. 4 is a shaft sleeve that is removably inserted into the oil chamber 5 of the rotary main shaft 3, 6 is a double mechanical seal that is fitted to the outer periphery of the shaft sleeve 4, and 7 is an inner case 7A and an outer case 7B that are fitted. The cassette case has a combined double structure, and surrounds the outer periphery of the double mechanical seal 6 in such a manner that the upper mating ring 8A is fitted on the inner periphery of the upper end portion and the lower mating ring 8B is fitted on the inner periphery of the lower end portion. In the cassette case 7, the upper seal ring 10A is brought into pressure contact with the upper mating ring 8A by the spring pressure of the coil spring 9, and the lower seal ring 10B is brought into pressure contact with the lower mating ring 8B. These pressure contact portions constitute a sliding sealing surface. Assembled. Reference numeral 15 denotes a guide vane attached so as to form an inclined surface having an upward slope toward the rotation direction of the pump shaft 3 on the inner peripheral surface of the cassette case 7, for example, by cutting the wall surface of the inner case 7A inwardly. The through-hole 16 that protrudes and is generated in the cut-and-raised portion is structured to be closed by the wall surface of the outer case 7B that is fitted to the outer peripheral surface. 12B is an oil inflow hole formed in the lower part of the cassette case 7 on the back side of the lower end of the guide vane 15, and 12A is an oil outflow port. Has been. Further, the inner periphery of the disk-shaped fixed seat 11 is loosely fitted to the outer periphery of the shaft sleeve 4 so as to seal the lower end opening of the cassette case 7, and the upper end surface of the fixed seat 11 is the lower end surface of the lower mating ring 8B and the cassette. outside circumferential cassette case 7 bottom to abut on the flange lower surface projecting toward removably attached to form the mounting seat to the back of the oil chamber lower wall 2 the lower edge of the casing 7. Reference numeral 14 denotes a locking member for preventing the shaft sleeve 4 from coming out. For example, a snap ring or the like engaged with the outer periphery of the shaft sleeve 4 is locked to a constituent member of the double mechanical seal 6 or the end surface of the cassette case 7. Is prevented from coming out.
[0009]
Then, by inserting the sleeve 4 from the lower end of the rotating main shaft 3, the outer periphery of the upper end of the cassette case 7 is fitted into the center hole of the oil chamber upper wall 1, and the outer periphery of the lower end is connected to the center hole of the oil chamber lower wall 2. When the fixing seat 11 is fixed to the back surface of the oil chamber lower wall 2 by means of screws or the like, for example, a cassette type double mechanical seal having an oil lift function is attached to the oil chamber 5. In this way, it is not necessary to disassemble the oil chamber lower wall 2 for mounting the double mechanical seal 6 in the oil chamber 5, and it is not necessary to disassemble the oil chamber lower wall when the double mechanical seal 6 is removed. is there.
[0010]
[Action]
When the electric pump is operated, the coil spring 9 stretched between the back surfaces of the upper and lower seal rings 10A, 10B is rotated in the cassette case 7 along with the rotation of the rotary main shaft 3, and the lubricating oil in the cassette case 7 is removed. Pushed up along the inclined surface of the guide vane 15, the lubricating oil in the oil chamber 5 outside the cassette case 7 flows into the cassette case 7 from the lower oil passage 12 </ b> B, and the forward lubricating oil in the cassette case 7 flows. Lubricating the sliding surfaces of the lower mating ring 8B and the lower seal ring 10B and the sliding surfaces of the upper mating ring 8A and the upper seal ring 10A and absorbing the sliding heat generated on both sliding surfaces, the upper oil outlet It is transferred from 12A into the oil chamber 5 outside the cassette case 7.
[0011]
【The invention's effect】
According to the present invention, when the double mechanical seal is attached to the electric pump, it is possible to double without subjecting the fitting surface of the shaft seal member on the upper wall or the lower wall of the oil chamber to high precision grinding as in the past. The installation length of the mechanical seal can be ensured, and it is not necessary to remove the lower wall of the oil chamber for loading and unloading into the oil chamber. Regardless of the degree, the pump can be easily installed and removed even at the site where the pump is used, and since it has an oil lift function, it has a heat absorption effect due to the smooth circulation of the lubricating oil. Largely, it can be reused by replacing parts , which contributes to improved workability and lower manufacturing cost of electric pumps.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a cassette type double mechanical seal of the present invention.
FIG. 2 is a longitudinal sectional side view of an essential part showing a state where the cassette type double mechanical seal of the present invention is mounted in an oil chamber of an electric pump.
FIG. 3 is a longitudinal side view of an inner case in the cassette type double mechanical seal of the present invention.
4 is a transverse plan view taken along line XX of FIG.
FIG. 5 is a longitudinal sectional side view of an essential part of an electric pump equipped with a conventional double mechanical seal.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Oil chamber upper wall 2 Oil chamber lower wall 3 Rotation main shaft 4 Shaft sleeve 5 Oil chamber 6 Double mechanical seal 7 Cassette case 7A Inner case 7B Outer case 8A Upper mating ring 8B Lower mating ring 9 Coil spring 11 Fixed seat 12A Oil outflow hole 12B Oil inflow hole 15 Guide vane 16 Through hole

Claims (2)

A double mechanical seal is fitted on the outer periphery of the shaft sleeve that is removably inserted into the rotation main shaft that penetrates the center hole in the upper wall of the oil chamber and the center hole in the lower wall of the oil chamber, and the upper mating ring is fitted on the inner periphery of the upper end. The outer periphery of the double mechanical seal is surrounded by a cylindrical cassette case in a manner in which the lower mating ring is fitted to the inner periphery of the lower end , and the inner periphery of the disk-shaped fixing seat is sealed to seal the lower opening of the cassette case. the cassette case as loosely fitted to the shaft sleeve periphery, said fixing seat upper surface abuts on the flange lower surface protruding outwardly circumferentially lower edge of the lower end surface and said cassette case of the lower main tailing guide vanes to lower the removably attached to form the mounting seat of the oil chamber lower wall rear surface to form an inclined surface of the rising gradient toward the spindle rotation direction on the inner peripheral surface of the cassette case An oil inflow hole is formed in the lower part of the cassette case on the back side of the lower end of the guide vane, and the outer periphery of the upper end of the cassette case is attached to the upper wall of the oil chamber by inserting a shaft sleeve from the lower end of the rotating spindle. A cassette type double mechanical seal for an electric pump, characterized in that it is fitted to the center hole and the outer periphery of the lower end is fitted to the center hole of the lower wall of the oil chamber. The cylindrical cassette case that surrounds the outer periphery of the double mechanical seal has a double structure in which the inner case and the outer case are fitted, and the guide vane attached to the inner peripheral surface of the cassette case is the wall surface of the inner case. projecting by cutting and raising inwardly and the through-hole produced in the cut and raised portion, characterized in that it is closed by the wall of the outer case to be fitted on the outer peripheral surface, according to claim 1 Symbol mounting of the electric Cassette type double mechanical seal for pumps.

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