JPH0632763Y2 - Submersible motor shaft seal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a shaft sealing device for an underwater electric motor used in an underwater motor pump for a deep well.

2. Description of the Related Art A shaft sealing device for an underwater electric motor, which seals liquid inside the electric motor to isolate the inside and the outside of the electric motor, has been conventionally known as a fourth type
As shown in the side sectional view in the drawing, one or more oil seals are fitted into the electric motor bracket 4, and the main shaft 2 and the oil seal 1 are inserted.
The liquid inside and outside the motor is shut off by sliding the lip portion of the motor, or as shown in FIG.
And a gap is provided between the oil seals 1 in the axial direction, and silicone grease or the like for the purpose of lubricating the sliding portion is enclosed therein to slide the main shaft and the lip portion of the oil seal. As a result, the liquid inside and outside the electric motor is shut off. In addition to these oil seals, a sand slinger 3 is installed inside the motor to prevent dust such as sand contained in the pumped water from entering, and the oil seal does not move due to the pressure difference between the inside and outside of the motor. The cover 5 sandwiches the oil seal 1 with the electric motor bracket 4.

Problems to be Solved In the conventional shaft sealing device as described above, since the main shaft 2 and the oil seal 1 directly slide, the sliding portion of the main shaft wears over time and the shaft sealing function deteriorates. However, there is no choice but to repair it, the electric motor must be disassembled and the sliding parts of the spindle must be repaired by plating or thermal spraying.

If you do not want to make such repairs, use a mechanical seal that does not slide directly on the main shaft, fix a metal shaft sleeve to the main shaft by snap fitting, or make a gap fit and use a non-rotating screw. Although there is a method such as sticking to the main shaft, the mechanical seal is expensive to manufacture, and even if a shaft sleeve is provided, it is necessary to disassemble the electric motor main body when repairing and replacing it, especially in the case of a large electric motor, onsite. It is very difficult to carry out disassembly work.

Means for Solving the Problems This invention is intended to solve the above-mentioned conventional drawbacks and to obtain a shaft sealing device which is low in manufacturing cost. “A liquid is sealed inside the electric motor, and the liquid inside the electric motor is sealed. In a shaft sealing device for an underwater electric motor provided on an electric motor shaft to separate liquid from the outside of the electric motor, at least a cylinder of a metal ring formed into an L-shaped cross section by narrowing the inner peripheral portion of a metal disc into a cylindrical shape. A shaft sleeve is obtained by lining an elastic body such as rubber on the inner circumference of the portion, and the shaft sleeve is fitted into the main shaft, and has a lip portion that slides in contact with the outer circumference of the metal ring cylindrical portion of the sealing and rotating shaft sleeve. An oil seal fitted into and fixed to the motor bracket constitutes a shaft seal device that seals the sliding part, and the disk part of the shaft sleeve is in the liquid outside the motor, and the outer diameter of the disk part is the oil. From the outer diameter of the seal Is also made large, and part or all of the surface of the disk part is a metal part, and by providing a slight gap between the oil seal end surface and the shaft sleeve disk part, A shaft sealing device for an underwater electric motor, which is characterized in that

Embodiment FIG. 1 is a side sectional view of a shaft sealing device of the present invention, FIG. 2 is a plan view of a shaft sleeve 20, and FIG. 3 is a sectional view taken along the line AA of FIG. The shaft seal device 10 has a shaft sleeve 20.
And an oil seal 1.

The shaft sleeve 20 is formed by deep drawing a plate material such as stainless steel into a metal ring 21 having an L-shaped cross section having a disc portion 24 and a cylindrical portion 25. The inner side of the cylindrical portion 25 and the disc portion 24 are formed.
It is manufactured by lining an elastic body 22 such as rubber on a part of the.
(FIGS. 2 and 3) In the illustrated embodiment, the elastic body 22 covers almost the entire surface of the disc portion 24. Elastic body such as rubber lined inside the cylindrical portion 25 22 is the shaft hole 26
When the shaft sleeve 20 is fitted into the main shaft 2 by the
It has the role of sealing the ring of 20 and the main shaft 2. Disc part 24
Although the elastic body such as rubber lined in is not so significant in terms of functions such as sealing, the elastic body on the disk portion 24 has a blade shape as in the example shown in FIGS. 2 and 3. By doing so, there is an effect of preventing the sand and the like in the liquid handled by the pump from being repelled and trying to enter the inside of the electric motor.

The disc portion 24 of the metal ring 21 of the shaft sleeve 20 has a narrow gap 8 between the oil seal 1 and the seal cover 5 driven into the electric motor bracket 4 as necessary so that the oil seal 1 does not move due to the pressure difference between the electric pressure inside and outside the electric motor. And the rotation of the shaft sleeve 20 prevents dirt and the like in the liquid handled by the pump from entering the oil seal portion, and also serves as a conventional sand slinger.

The heat generated by the sliding of the shaft sleeve 20 and the lip portion 11 of the oil seal 1 is transmitted mainly through the metal ring 21 and is discharged from the disk portion 24 of the metal ring 21 of the shaft sleeve 20 into the pumped liquid. Therefore, the life of the oil seal 1 and the shaft sleeve 20 can be extended.

The outer diameter of the disk portion 24 of the shaft sleeve 20 is about the same as the outer diameter of the protruding portion 41 that accommodates the oil seal 1 of the electric motor bracket 4 (outside the seal cover 5 when the seal cover 5 is driven in). The same size as the diametrical dimension) is suitable from the viewpoint of preventing slurry infiltration and from the pump / motor assembly work. That is, the outer diameter of the shaft sleeve disk portion needs to be larger than the outer diameter of the oil seal.

The structure of the oil seal 1 is formed by molding rubber or the like with a metal ring as a core. Since the internal and external liquids of the electric motor are sealed,
Seal lip with at least one or more springs 9
11 and a dust lip 12 for preventing slurry invasion, and silicone grease or the like is filled between the lips to improve lubricity.

The oil seal 1 and the electric motor bracket 4 are sealed by fitting the outer peripheral portion of the oil seal into the electric motor bracket. Further, the axial positioning of the shaft sleeve with respect to the main shaft is stopped by the stepped portion of the main shaft and the retaining ring 7.

In this invention, only the shaft sealing device can be easily replaced without disassembling the electric motor. That is, the replacement procedure is performed as follows.

(I) Remove the pump so that only the motor is available.

(Ii) Remove the retaining ring from the spindle.

(Iii) Pull out the shaft sleeve from the main shaft.

(Iv) Remove the seal cover from the motor bracket.

(V) Remove the oil seal from the bracket with an electric motor.

Assembly is the reverse of the above.

Effect (1) It is possible to easily replace only the shaft sealing device without disassembling the electric motor, which is overwhelmingly easier to repair and cheaper than the conventional structure.

(2) Since the shaft sleeve is manufactured by an easy means and also serves as the conventional sand slinger, it can be manufactured at a lower cost than the shaft sleeve or the like of the conventional method.

(3) A proper gap can be set between the shaft sleeve disk part and the oil seal storage part, and the effect of preventing slurry intrusion is high.

(4) By making part or all of the shaft sleeve disk part a metal surface, the sliding heat generation of the sleeve and the oil seal lip is discharged into the pumping liquid handled by the pump to prolong the service life.

[Brief description of drawings]

1 is a side sectional view of a shaft sealing device of the present invention, FIG. 2 is a plan view of a shaft sleeve, FIG. 3 is a sectional view taken along the line AA in FIG. 2, FIG. 4 and FIG. It is a figure which shows the example of a slave device, respectively. Explanation of symbols 10 …… Shaft sealing device, 1 …… Oil seal, 11 …… Lip part, 12 …… Dust lip, 2 …… Spindle, 3 …… Sand slinger, 4 …… Motor bracket, 41 …… Projection part , 5 ... Seal cover, 6 ... Silicon grease, 7 ... Retaining ring, 8 ... Gap, 9 ... Spring, 20 ... Shaft sleeve, 21 ... Metal ring, 22 ... Elastic body such as rubber , 23 ...... blade part, 24 ...... disk part, 25 ...... cylindrical part, 26 ...... shaft hole

Claims (3)

[Scope of utility model registration request] 1. A shaft sealing device for a submersible electric motor, wherein a liquid is sealed inside the electric motor and the liquid inside the electric motor is separated from the liquid outside the electric motor, in a shaft sealing device for an underwater electric motor. Is squeezed into a cylindrical shape, and an elastic body such as rubber is lined on at least the inner periphery of the cylindrical portion of the metal ring formed in the L-shaped section to form a shaft sleeve, which is fitted into the main shaft, and the shaft sleeve is sealed and rotated. A metal seal having a lip portion that slides in contact with the outer circumference of the metal ring cylindrical portion of the shaft seal device that seals the sliding portion by an oil seal fitted and fixed in the motor bracket, and the disk portion of the shaft sleeve. Is in the liquid outside the motor, the outer diameter of the disc is made larger than the outer diameter of the oil seal, and part or all of the surface of the disc is a metal part. And shaft sleeve circle By providing a slight gap between the parts, the shaft sealing device of the underwater electric motor, characterized in that the sand repellent mechanism. 2. The oil seal of the shaft sealing device is sandwiched and fixed by an electric motor bracket and a metal seal cover, and a slight gap is provided between the metal cover and the shaft sleeve disk portion to prevent sand. The shaft sealing device for an underwater electric motor according to claim 1, wherein the shaft sealing device is a mechanism. 3. A shaft sealing device for an underwater electric motor according to claim 1, wherein the rubber lining portion of the shaft sleeve disc portion of the shaft sealing device is formed into a blade shape to form a sand shelter mechanism. .