JPH0135566Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an internally sealed liquid pressure adjusting means for a sealed liquid type submersible motor, particularly a motor used in a submersible pump for deep wells, which receives external surrounding liquid pressure.

Invention of using a pressure regulating plug as a means of regulating the internal pressure of a liquid-sealed submersible motor (Patent application No. 57-232031)
No. (refer to Japanese Patent Application Laid-open No. 59-123439) is ``In a rigid submersible motor that is sealed and filled with liquid,
The motor is equipped with an internal pressure release valve that releases the motor internal gas and corrects the internal and external pressure difference, and an external pressure introduction valve that corrects a relative decrease in the motor internal pressure with respect to the external pressure and increases the motor internal pressure. It is a submersible motor that is equipped with an internal pressure release valve to automatically release harmful gases generated inside the motor, and maintains the pressure difference between the inside and outside of the motor below a certain value. It is possible to prevent the internal and external pressure difference from becoming excessive when installing the submersible motor inside the submersible motor and when the internal pressure decreases due to cooling of the motor after gas release using the internal pressure release valve. Therefore, damage to the diaphragm and shortening of the life of the shaft sealing device can be prevented. Since there is little gas in the motor, it is possible to maintain the water level of the sealed liquid at least up to the upper end of the upper radial metal of the submersible motor, which prevents the upper radial metal from operating dry. By using a pressure plug (referred to as a pressure regulating plug together with an internal pressure release valve and an external pressure introduction valve), it is also possible to eliminate the diaphragm or bellows, making it safer to adjust the internal and external pressure than using a diaphragm or bellows. It operates reliably and provides a small and inexpensive pressure regulating means.

Now, in the submersible motor of the above invention equipped with a pressure regulating plug, internal gas is released and external water is introduced into the submersible motor. Since the filled liquid must not be discharged, a check valve is suitable. Although a filter is not necessarily required for the internal pressure release valve, it is preferable to include a filter to protect the valve. When introducing external water into the submersible motor, a filter is required to prevent fine sand contained in the external water from entering. However, it is difficult to install this by piping a normal check valve and filter in order to prevent it from protruding outside from the underwater motor.

Particularly in submersible motors for submersible pumps used in deep wells, external members such as frames are thin, and it is impossible to provide a large internal space for installing a pressure regulating plug.

The purpose of this invention is to provide a compact pressure regulating plug with a small outer diameter that is suitable as a pressure regulating means for a liquid sealed submersible motor used in deep wells and the like.

This device has a plug body, a rubber valve seat, a ball valve, a compression spring, a stop rod and a porous filter,
The plug body is provided with a stepped hole consisting of a filter chamber from the liquid inlet side, a valve port whose diameter is reduced from the filter chamber, and a valve chamber whose diameter is enlarged from the valve port between the liquid inlet and the liquid outlet at both ends, and the outer periphery on the liquid inlet side. and a male screw for mounting is provided on the outer periphery of the liquid outlet side, and a valve seat, a ball valve in contact with the valve seat, and a compression spring are arranged in order from the back in the valve chamber of the plug body, and the compression spring has one end in contact with the ball valve. This is a pressure regulating plug for a liquid-sealed submersible motor, in which the other end is contracted in contact with a stopper rod driven into the plug body, and a porous filter is housed in the filter chamber.

Embodiments of this invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an internal pressure release valve or an external pressure introduction valve (hereinafter referred to as a pressure regulating plug), and FIG. 2 is a right side view of FIG. 1. The pressure regulating plug forms a hexagonal part for engaging a tool on the middle outer periphery of the plug body 1, and has male mounting screws 2 and 3 on both sides of the hexagonal part, and a circular step hole in the center is a valve chamber that continues to the liquid outlet 4 side. A porous filter 8 is lightly press-fitted into a filter chamber 10 whose diameter is reduced from the cylindrical hole 5 to become a discharge or suction valve port 6, and whose diameter is expanded from the valve port 6. is press-fitted, and the ball valve 11 and the plug body 1 are in contact with the valve seat 9.
A compression spring 13 is inserted between the stop rods 12 that are driven across. The edging part 14 provided at the edge of the hole of the liquid inlet 7 is distorted inward to prevent the porous filter 8 from escaping. The porous filter 8 is made of a sintered alloy or hard resin foam, and is permeable to liquid.

FIG. 3 is a longitudinal sectional view of an embodiment of an underwater motor equipped with a pressure regulating plug. A stator 16 is fixed within the cylindrical frame 15 made of sheet metal, and the frame 15
An upper bracket 17 is fixed to the upper bracket 17, and an upper radial metal 18 is fitted and fixed to the upper bracket 17. The frame 15 has a lower bracket 19
is fixed, and a lower radial metal 20 is fitted and fixed into the lower bracket 19.

A motor shaft 22 is slid into the upper radial metal 18 and the lower radial metal 20 to which a rotor 21 is press-fitted and fixed with a slight gap from the stator 16.

A thrust disk 25 is rigidly fitted into and fixed to the lower end of the motor shaft 22 via a key 23 in the rotational and axial directions. A thrust carbon plate 26 in the form of an annular flat plate is fixed to the thrust disk 25.

A thrust housing 27 having the same outer diameter as the frame 15 is fitted into and fixed to the lower bracket 19. A collar 28 with a flange and a female thread cut on the inner diameter is fitted and fixed into a circular hole at the center of the bottom of the bearing chamber of the thrust housing 27, and an adjusting screw 29 having a hemispherical tip is screwed into the female thread.
A leveling disk 30 is swingably supported at the tip of the adjusting screw 29, and a tailing pad 31 that slides on the thrust carbon plate 26 on the leveling disk 30 is swingably supported (explanation of the supporting method is omitted) has been done.

A cylindrical diaphragm chamber 32 is provided in the lower part of the thrust housing 27 and partitioned by the bottom of the bearing chamber. A rubber cylindrical container-shaped diaphragm 33 is fitted into the diaphragm chamber 32, and a holding plate 37 having a hole 36 in a cylindrical hole at the lower end of the thrust housing 27 is fitted so as to press the flange 35 of the diaphragm 33. Bolts 38 are screwed into the thrust housing 27 by passing through bolt holes in the holding plate 37 and the flange 35 of the diaphragm. A compressed conical coil spring 40 is inserted between the presser plate 37 and a spring receiving plate 39 that is in contact with the bottom surface of the diaphragm 33. At the lower end of the adjustment screw 29 is a circular partition plate 4.
1 is attached with a machine screw 42 via a washer. The partition plate 41 prevents the diaphragm 33 from expanding when the external pressure is higher than the internal pressure and the diaphragm 33 expands abnormally, thereby preventing the diaphragm 33 from being damaged.

A shaft sealing device such as an oil seal 43 is fitted into the upper bracket 17 to seal the motor shaft 22. Following the oil seal 43, a cylindrical seal cover 45 with an L-shaped cross section as shown is attached to the upper bracket 17.
The lip of a sand slinger 46 press-fitted into the upper end and fixed to the motor shaft 22 is close to the cylindrical outer periphery of the seal cover 45 .

The lead wire of the stator 16 is a three-core flat cable 4.
The cable 47 is sealed in the axial direction of the flange of the upper bracket 17 and exits to the outside.

An inlet for filling liquid is provided in the flange of the upper bracket 17 so as to extend obliquely upward from the top of the motor interior space toward the outside, and a hexagon socket plug 48 is screwed into the inlet.

An internal pressure release valve 49 that communicates between the inside and outside of the motor is screwed into the flange of the upper bracket 17, and an external pressure introduction valve 50 that connects the inside and outside of the motor is similarly screwed into the thrust housing 27. It is desirable that the internal pressure release valve 49 be placed at the highest position in the motor internal space. In this embodiment, the same internal pressure release valve 49 and external pressure introduction valve 50 are used, but they do not necessarily have to be the same.

The internal pressure release valve 49 has a liquid inlet 7 on the inside of the submersible motor, and the external pressure introduction valve 50 has a liquid inlet 7 on the outside of the submersible motor.

Such a motor is used by connecting a pump shaft at the end of the motor shaft 22, and installing a pump having the same diameter as the motor using the mounting flange of the upper bracket 17 in a deep well.

Submersible motors, which have been widely used in the past, are not equipped with a pressure regulating plug, so as the water depth at the location where they are installed increases, the external pressure increases, and pressure is applied to the fluid sealed inside the motor via the diaphragm, causing the fluid sealed inside the motor to increase. The remaining air at the time, air dissolved in the internally sealed liquid, and H ₂ gas generated by corrosion of copper, aluminum, etc. are compressed. Thus, the diaphragm, which normally absorbs the thermal expansion of the fluid sealed inside the motor due to heat generated during motor operation by deforming to the outside of the motor, is instead deformed to the inside of the motor. As a result, the rubber of the diaphragm gets stuck in the communication hole between the diaphragm chamber and the thrust bearing chamber and breaks, causing sand, broken pieces of rubber, etc. to enter the rotor chamber, causing bearing seizure, increased wear, and other problems, which can lead to accidents.

Furthermore, if air or other gas inside the motor accumulates in the upper part of the motor, the radial metal in the upper part of the motor may run dry and burn out.

When a submersible motor pump, which has a pump connected to a submersible motor equipped with a pressure regulating plug, is submerged in a well, the external pressure of the submersible motor increases as the water depth increases, and pressure is applied to the motor sealed liquid via the diaphragm 33. At this time, if there is gas in the motor, the diaphragm 33 expands and is pressed against the partition plate 41, and the partition plate 41 prevents abnormal deformation to some extent, but when the pressure difference between the inside and outside of the underwater motor increases, the communicating partition Plate 41 outer periphery and thrust housing 27
However, since there is an external pressure introduction valve 50, if the hydrostatic pressure at the location where the underwater motor is installed is P _p and the internal pressure of the motor is P _i , then the pressure difference between the inside and outside of the underwater motor is Within the allowable pressure of the diaphragm 33, for example, P _p −P _i =
If △P _s = 0.5Kg/ ^cm2 , then when the external pressure of the underwater motor becomes 0.5Kg/ ^cm2 higher than the internal pressure, the ball valve 11 of the external pressure introduction valve 50 is pushed by the external pressure and moves against the spring 13. When opened, external liquid is introduced into the submersible motor through the filter 8, so that the external pressure applied to the diaphragm 33 does not exceed 0.5 kg/cm ² and the diaphragm 33 maintains its normal shape. At this time, the internal pressure release valve 49 remains closed due to the action of the check valve.

A rotating magnetic field is generated by the stator 16 and rotor 21, which serve as an induction motor, by supplying power from the ground through a cable 47, and the motor shaft 22 rotates.
At this time, the weight of the rotor 21 and other components carried by the motor shaft 22 is transmitted as thrust to the tailing pad 31 via the thrust disk 25 and the thrust carbon plate 26, and is supported. The tailing pad 31 is then subjected to balanced and uniform pressure.

When the temperature of the sealed liquid increases and expands due to the operation of the motor, the diaphragm 33 is deformed against the diaphragm 33 and the coil spring 40 to balance the external pressure and keep the pressure of the sealed liquid almost constant. Hydrogen gas generated by the reaction between the air in the motor's internal liquid and the copper and iron-based metals inside the motor rises in the liquid, collects at the top, and expands as the motor operates. This expansion of hydrogen gas pushes down the sealed liquid and is absorbed to some extent by the diaphragm 33. However, if the pressure increases further, the diaphragm 33 will be compressed abnormally. Of course, it is desirable to remove hydrogen gas because it corrodes internal parts. So, for example, P _i −P _p ≧
When it becomes 0.5Kg/ ^cm2 , the ball valve 1 of the internal pressure release valve 49
1 is pushed by the internal pressure and moves against the compression spring 13 to open, releasing the air and corrosive gas inside. At this time, the external pressure introduction valve 50 remains closed due to the action of a check valve. This internal pressure release pressure P _i −P _p =
ΔP _b is determined experimentally and may be an extremely small amount. After the gas inside the motor is released, the space occupied by the gas is filled with the filled liquid, but since the filled liquid is constant, the diaphragm 33 returns slightly to the inside of the motor. Even if there is gas in the motor, if the motor is cooled down by stopping the motor and the difference P _p -P _i between the external and internal pressures becomes too large, the amount of expansion of the diaphragm 33 becomes too large. So, for example, P _p −P _i =△P _s ≧
When it is 0.5Kg/ ^cm2 , ball valve 1 of external pressure introduction valve 50
1 is pushed by the external pressure and moves against the compression spring 13 to open, and the well water at the location where the motor is installed is filtered by the porous filter 8 and enters the motor, and the external pressure is introduced. And the pressure difference applied to the diaphragm 33 is
When the temperature falls below 0.5Kg/cm ² , the ball valve 11 closes.

The gas released by the internal pressure release valve 49 described above is extremely small, and the amount of air initially contained in the filled liquid is about 2% by volume (standard state) of the filled liquid, and most of this air is After release, the amount of gas generated is small as it is a gas generated by the reaction of a very small amount of residual air in the filled liquid with the copper-iron metal. Additionally, the sealed liquid is also released from the internal pressure release valve 49 in the form of some steam, but the amount is very small. Therefore, the amount of liquid introduced from the external pressure introduction valve 50 is extremely small, and the amount of sealed liquid replaced by the actions of the internal pressure release valve 49 and the external pressure introduction valve 50 is extremely small, so that the motor internal pressure can be substantially adjusted. and has the function of releasing internal gas.

The pressure regulating plug for a liquid-sealed submersible motor of this invention has a check valve that opens at a constant pressure in the center of the plug body, and a filter is provided in the mounting screw of the plug body on the liquid inlet side, so it requires very little installation space. It is small and easy to install on liquid-sealed submersible motors. Suitable for filtering small amounts of liquid, opening the valve at constant pressure and blocking fluid flow in the opposite direction.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of an embodiment of a pressure regulating plug for a sealed liquid submersible motor, Fig. 2 is a side view of Fig. 1, and Fig. 3 is a longitudinal cross-sectional view of an underwater motor using the pressure regulating plug. . 1...Plug body, 2, 3...Male mounting screw,
4...Liquid outlet, 5...Valve chamber, 6...Valve port, 7...
...Liquid inlet, 8...Porous filter, 9...Valve seat, 11...Ball valve, 12...Stopping rod, 13...Spring, 14...Edging portion, 15...Frame, 16
...Stator, 17... Upper bracket, 18...
Upper radial metal, 19...lower bracket,
20... lower radial metal, 21... rotor,
22... Motor shaft, 23... Key, 25... Thrust disk, 26... Thrust carbon plate, 2
7...Thrust housing, 28...Color, 2
9...Adjustment Screw, 30...Leveling Disc, 31...Tailting Pad, 3
2...Diaphragm chamber, 33...Diaphragm,
35...flange, 36...hole, 37...pressing plate, 38...bolt, 39...spring receiving plate,
40... Coil spring, 41... Partition plate, 4
2...Machine screw, 43...Oil seal, 45...
Seal cover, 46...Sandslinger, 47
...Cable, 48...Hexagon socket plug, 49...
...Internal pressure release valve, 50...External pressure introduction valve.

Claims (1)

[Scope of utility model registration request] Plug body 1, rubber valve seat 9, ball valve 1
1. It has a compression spring 13, a stop rod 12, and a porous filter 8, and the plug body 1 has a filter chamber 10 between the liquid inlet 7 and the liquid outlet 4 at both ends from the liquid inlet 7 side.
A step hole consisting of a valve port 6 whose diameter is reduced from the filter chamber 10 and a valve chamber 5 whose diameter is enlarged from the valve port 6 is provided, and male mounting threads 2, 3, and a valve seat 9, a ball valve 11 in contact with the valve seat 9, and a compression spring 13 are disposed in order from the back in the valve chamber 5 of the plug body 1, and the compression spring 13 has one end in contact with the ball valve 11 and the other. A pressure regulating plug for a liquid-sealed submersible motor, the end of which is contracted in contact with a stop rod 12 driven into the plug 1, and a porous filter 8 is housed in the filter chamber 10.