JPH0150179B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shaft sealing device for a motor of a submersible motor pump using a liquid ring type motor, and particularly for a motor of a submersible motor pump for a well from which warm water gushes out, that is, a hot water well.

Conventionally, submersible motor pumps with a cylindrical shape that is suitable for installation in a well and have a motor in one part to drive the pump in the upper part are shown in Figures 1 to 4.
A shaft sealing device is provided so that only one side of the motor shaft is shown in the longitudinal sectional view shown in the figure. FIG. 1 shows a pair of oil seals 71 spaced apart from each other on the upper bracket 70 of the motor, filled with silicone grease 72, and fitted together to seal the motor shaft 13. A seal cover 73 is press-fitted into the upper bracket 70. 2 shows a pair of oil seals 71 in contact with each other without silicone grease 72 in FIG. 1, and the rest is the same as in FIG. 1 and FIG. In FIG. 3, a filter 74 is held in a seal cover 73 in FIG. 1, and the filter 74 rubs against the motor shaft 13.

In the embodiment shown in FIGS. 1 to 3, an oil seal is used and its pressure resistance is low. A soft porous material is used for the filter 74 as shown in FIG. wear out.

Figure 4 is an example using a mechanical seal.
Seal cover 73 fitted into upper bracket 70
A dust seal 75 that rubs against the motor shaft 13 is provided inside the motor. In the mechanical seal, a sliding ring 76 is press-fitted into the upper bracket through a sheet material 77, and a sliding ring 79 is fixed, which is held by a moving ring 78 made of a hard organic material that tightly fits into the motor shaft 13 so as to be movable in the axial direction. A compression spring 82 is provided between the movable ring 78 and a spring seat ring 81 that is press-fitted onto the motor shaft 13 so as not to move. In the conventional example using such a mechanical seal, the dust seal 75 prevents sand from entering the well water, and the mechanical seal has high pressure resistance and durability, but the difference in pressure between the inside and outside of the motor is directly applied to the mechanical seal.

When a submersible motor pump equipped with a shaft seal device as shown in Figures 1 to 4 is inserted into a deep well of 100 meters or more where the water pumped is at a high temperature or a hot spring well where hot spring water gushes out, an oil seal will be installed. Otherwise, the sliding parts of the oil seal and motor shaft will wear out faster and the shaft sealing function will be lost. As a result, well water enters the room where the motor rotor is located.

Further, the sealed liquid sealed in the motor at normal temperature and normal pressure is heated by hot water and expands together with the gas contained in the filled liquid and the gas remaining in the motor when the sealed liquid is filled. For example, an expansion absorption device such as a diaphragm is provided at the end of the motor to suppress the increase in internal pressure, but this expansion of the sealed liquid and gas was originally intended for the expansion of the filled liquid and gas due to internally generated heat. When the water is further heated by the hot spring water, it reaches an extremely high temperature, and the expansion of the sealed liquid cannot be absorbed sufficiently, resulting in high internal pressure and damage to shaft sealing devices such as motor oil seals and mechanical seals. Pressure is applied and the shaft seal device is destroyed, allowing communication between the inside and outside of the motor.

If the shaft seal device is destroyed, high-temperature hot water containing sand, acidity, alkalinity, and salt that causes corrosive wear enters the motor interior, replacing the sealed fluid. This causes wear and seizure of the bearings and corrosion of the rotor core and secondary conductor, causing the motor to lock up and burn out, making the pump unable to pump water.

The installation position of the submersible motor pump is deep, and the dynamic pressure
When the difference in static pressure is large, the external pressure applied to the submersible motor increases and the dissolved air contained in the liquid sealed in the rotor chamber is compressed. In this case, the diaphragm, which was originally intended to absorb the expansion of the sealed liquid due to the temperature rise due to the operation of the submersible motor, expanded toward the rotor chamber, damaging and damaging the diaphragm, and causing the pumped liquid to enter the rotor chamber. I will let you do it. Furthermore, if a low-pressure rotary seal such as an oil seal is used, it will not be able to withstand the external pressure, and pumped liquid will enter the rotor chamber through the oil seal. Therefore, corrosive and wear-causing fluids containing sand, acid, alkaline or salt may enter the rotor chamber, causing wear and seizure of the bearings and corrosion of the rotor core and secondary conductors, resulting in damage to the motor. The lock will burn out and the pump will be unable to pump water.

Even with a mechanical seal as shown in FIG. 4, which can withstand higher pressure than an oil seal, if it is installed in the load side bracket of an underwater motor, the same result as above will occur because it is not possible to install a mechanical seal that can withstand high pressure.

As mentioned above, conventional submersible motor pumps have problems due to high temperature pumping, and in the case of wells that are several hundred meters deep, problems arise due to the deep water depth when installing submersible motor pumps. Ta.

The present invention relates to a submersible motor pump used in high temperature or high pressure, or high temperature and high pressure water,
It is an object of the present invention to provide a liquid-sealed submersible motor that is adapted to high temperatures or high pressures, or is equipped with a shaft sealing device with high pressure resistance.

In the present invention, the output shaft end of the motor shaft protrudes from the upper part,
Equipped with a mechanical seal that seals the motor shaft,
In a vertical submersible motor that has an expansion absorption device for the liquid filled in the motor chamber at the bottom and seals the liquid in the motor frame, the mechanical seal case, the mechanical seal chamber, the liquid filled in the mechanical seal chamber,
It has an expansion absorption device for the liquid filled in the mechanical seal chamber, and the mechanical seal seals the shaft between the rotor chamber and the mechanical seal chamber, and between the mechanical seal chamber and the outside of the submersible motor, and the mechanical seal case is used for the motor frame. The mechanical seal case encloses the mechanical seal to form a mechanical seal chamber, and the liquid filled in the mechanical seal chamber is sealed in the mechanical seal chamber. This is a vertical submersible motor that is equipped with an expansion absorption device for liquid.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 5 is a longitudinal sectional view. However, the figure is shown rotated 90 degrees, and the right side of the figure is the top. A stator 2 is fixed in a cylindrical sheet metal frame 1, and ring-shaped upper frame side plates 3 and lower frame side plates 4 are press-fitted and fixed on both sides. An upper bracket 6 is fitted into the upper frame side plate 3 via a sealing ring 5, and an upper radial metal 7 is inserted into the upper bracket 6.
is inserted through a rotation stopper pin (not shown). A lower bracket 9 is fitted into the lower frame side plate 4 via a sealing ring 8 and fixed with bolts 19.
A lower radial metal 10 is fitted into the lower bracket 9 via a detent pin (not shown). A motor shaft 13 is slid into the upper radial metal 7 and the lower radial metal 10 via the stator 2 and the stator can 11, to which a rotor 12, which is disposed slightly apart from the stator can 11, is press-fitted and fixed. ing. Reference numeral 14 denotes a balance ring press-fitted onto the motor shaft 13 and used to adjust dynamic balance.

The lower end of the motor shaft 13 is press-fitted with a rotary disk 16 at the upper end of a self-aligning thrust bearing 15 via a key 17. Self-aligning thrust bearing 1
Reference numeral 5 indicates an adjustment screw 21 in which the sliding member supported by the leveling disk 18 is screwed into the thrust housing 20.
It is swingably supported by being swingably supported on the hemispherical surface of the upper end, and is swingably attached to the leveling disc 18 so as not to move, and is mounted on the circumference of the end face of the leveling disc 18. An annular thrust carbon plate 24, which is fitted into the anti-load side thrust receiver 22 and the rotary disc 16 and is prevented from rotating by a pin 23, slides, and is connected to the pump connected to the submersible motor. Thrust due to operation and motor shaft 13 (not shown)
The shaft joint at the end, the weight of the rotor 12, the motor shaft 13, etc. are supported as loads. The adjustment screw 21 is attached to the motor shaft 1 in the adjustment housing 20.
Adjust the position of 3 and tighten the lock nut 2.
Fix by 5. The thrust housing 20 is screwed into the lower bracket 9 with a female thread at its end using a sealant and fixed, and is prevented from rotating using a machine screw 26. The coil 27 of the stator 2 is connected to a three-core flat cable connector 28 .
is made watertight by a sealing means in a circular hole provided in the axial direction of the upper frame side plate 3, and passes through the cable 2.
9 and receives three-phase AC power from the outside. Both sides of a cylindrical stator can 11 made of sheet metal are welded to an upper frame side plate 3 and a lower frame side plate 4 so as to be in contact with the inner circumference of the stator 2 .

A diaphragm 30 is fitted into the lower part of the thrust housing 20, and a holding plate 32 having a hole 31 formed in a cylindrical hole at the lower end of the thrust housing 20 is press-fitted so as to press the outer flange portion of the diaphragm 30. is fixed in a watertight manner. A conical coil spring 34 is inserted in a compressed state between the holding plate 32 and the spring receiving plate 33 that is in contact with the bottom surface of the diaphragm 30. A center hole of the spring receiving plate 33 is positioned and fitted into a boss 30a provided at the center of the diaphragm 30. The diaphragm 30, the presser plate 32,
The spring receiving plate 33 and the coil spring 34 constitute an expansion absorption device for the liquid 58 sealed inside the rotor chamber C.

FIG. 6 is a partially enlarged view of FIG. 5. The upper bracket 6 supports one end of a composite mechanical seal 47 via a sealing ring 35, and the sealing ring 37
The mechanical seal case 38 is fitted through the
Insert the bolt 3 through the bolt hole of the upper bracket 6.
9 is inserted into the mechanical seal case 38, and the upper bracket 6 and the mechanical seal case 38 are fixed. A bracket (hereinafter referred to as a mechanical bracket) 42 for supporting the other end of the mechanical seal 47 is fitted into the mechanical seal case 38 via a sealing ring 41.
A special bolt 43 is screwed into the mechanical seal case 38, and is inserted through the two bolt holes to fasten the submersible pump.

The mechanical bracket 42 has a cylindrical portion 44 spaced apart from the motor shaft 13 and a mechanical seal cover portion 46. Both sides of the mechanical seal cover part 46 are communicated with each other. The inside of the mechanical seal case 38 between the mechanical bracket 42 and the mechanical seal cover section 46 is an expansion absorption chamber B for the filled liquid. A composite mechanical seal 47 is provided between the mechanical seal cover portion 46 and the upper bracket 6. In this way, the shaft sealing chamber A and the filled liquid expansion and absorption chamber B form a mechanically sealed chamber that communicates with each other.

A composite mechanical seal 47 connects the upper bracket 6 and the mechanical bracket 42 through a sealing ring 48, respectively.
A sliding ring 51 is fitted into the mechanical seal cover part 46 and held down by a retaining plate 50 which is fixed to the upper bracket 6 and the mechanical seal cover part 46 by bolts 49, respectively, and is tightly attached to the motor shaft 13 so as to be movable in the axial direction. a pair of moving rings 52 that fit into the
A sliding ring 53 on the moving side that is held by the moving ring 52 and moves with the sliding ring 51 on the fixed side, and a pair of moving rings 52
A compression spring 54 is inserted between the movable rings 52 and axially biases the movable ring 52 to press the movable sliding ring 53 against the fixed sliding ring 51. The protrusion 50a of the holding plate 50 engages with the groove 51a of the sliding ring 51, and prevents the sliding ring 51 from rotating.

External cylindrical tongue 55 of mechanical bracket 42
The outer periphery of the motor shaft 13 and the sand slinger 56 press-fitted into the motor shaft 13 are slightly close to each other, and the centrifugal force generated by the rotation of the sand slinger 56 removes foreign substances such as sand. Therefore, the well water flows through the cylindrical part 44 of the mechanical bracket 42, the mechanical seal cover part 46, and the upper sliding ring 51.
The liquid that does not contain sand passes through the gap between the
1 and 53, and operation without lubrication of the external sliding surfaces is prevented.

The rotor chamber C containing the rotor 12 of the motor is filled with a liquid 58 so as to avoid any voids as much as possible. The filling liquid 58 may be injected from the center hole of the upper bracket 6 when the upper bracket 6 is assembled from the bottom.
do. The stator chamber D containing the stator 2 is filled with the filled liquid 61, leaving a space in the upper part where the sealed air 59 at normal pressure remains.
is included. The shaft sealing chamber A containing the composite mechanical seal 47 and the filling liquid expansion absorption chamber B are filled with the filling liquid 63 by providing a filling liquid inlet with a plug 89 screwed into the mechanical seal case 38 so as not to leave any residual air. It has been done.

The diaphragm 83 is fitted into the stepped hole in the radial direction of the mechanical seal case 38 at the position of the distended intestinal absorption chamber B of the liquid sealed in the mechanical seal case 38, and the stepped hole of the mechanical seal case 38 is inserted so as to press the outer flange of the diaphragm 83. A holding plate 80 with a hole 86 is press-fitted therein, and the diaphragm 83 is fixed to the mechanical seal case 38 in a watertight manner. A conical coil spring 84 is inserted in a compressed state between the holding plate 80 and a spring receiving plate 85 that is fixed in contact with the bottom surface of the diaphragm 83. A center hole of the spring receiving plate 85 is fitted into a boss 33a provided at the center of the diaphragm 83.

The diaphragm 83 or the like may be used as a device for expanding and absorbing the sealed liquid in place of another type of device capable of changing the volume of the expansion and absorption chamber B, such as a bellows.

As shown in FIG. 7 of the A-A cross-sectional view of FIG. It can be suppressed.

Such a submersible motor is constructed so that all the components are within the axially extending plane of the cylinder of the frame 1, and has an open relay casing at the end of the mechanical bracket 42 through which external handling liquid can freely enter. A submersible pump having a generally cylindrical shape is similarly fastened through the motor shaft 13, and the pump shaft is connected to the end of the motor shaft 13 by a shaft coupling (not shown).

To give an example of the filled liquid, the filled liquid 61 in the stator chamber D is an insulating oil, and the filled liquid 58 in the rotor chamber C is an insulating oil.
is propylene glycol or silicone oil, and the sealed liquid 63 in the shaft sealing chamber A and the sealed liquid expansion and absorption chamber B is hydraulic oil or silicone oil.

When power is supplied from the ground through the cable 29, the stator coil 27 is energized via the connector 28,
The rotor 12 receives rotational force, causing the motor shaft 13 to rotate, and a submersible pump (not shown) is rotated via a shaft coupling to pump water from the well. The motor shaft 13 carries a radial load by the radial metals 7 and 10, and the thrust bearing 15 supports the pump thrust and the weight of the object carried by the motor shaft 13. The part where the motor shaft 13 exits is between the sand slinger 56 and the tongue part 55 of the mechanical bracket 42 to prevent the intrusion of minute solids such as sand, and the well water flows between the motor shaft 13 and the cylindrical part 44 of the mechanical bracket 42.
Mechanical seal cover part 46, upper sliding ring 5
1 to the outside of the mechanical seal 47, and even if there is a difference between the inside and outside pressures, the shaft is sealed by the composite mechanical seal 47.

Now, when a submersible motor pump using the submersible motor of the present invention is installed in a hot water well from which high-temperature water gushes out, the sealed liquid 61 in the stator chamber D,
The sealed liquid 58 in the rotor chamber C, the sealed liquid 63 in the shaft sealed chamber A and the filled liquid expansion and absorption chamber B are heated. that time,
The expansion of the sealed liquid 61 in the stator chamber D compresses the sealed air 59 and suppresses the generated pressure. In the rotor chamber C, the filled liquid 58, the air remaining in the rotor chamber C, the gas contained in the filled liquid 58, and the gas generated by the reaction between the filled liquid 58 and the metal inside are heated and expanded. The diaphragm 30 is then deformed outward against the spring 34. The sum of the external pressure and the elasticity of the spring 34 is in balance with the pressure of the sealed liquid 58 in the rotor chamber C. On the other hand, the temperature of the filled liquid 63 in the mechanical seal chamber consisting of the shaft sealing chamber A and the filled liquid expansion absorption chamber B is increased by the high-temperature water and expands, causing the diaphragm 83 to deform outward against the spring 84. The sum of the side pressure and the elasticity of the spring 84 is in balance with the pressure of the sealed liquid 63.

The diaphragm 30 and the spring 34 absorb the heating of the sealed liquid 58 in the rotor chamber C by the high-temperature water and the heat generated by the motor operation, but when the deformation limit of the diaphragm 30 is reached, the rotor chamber The pressure of the C sealed liquid 58 rises rapidly and is applied to the mechanical seal 47. The sealed liquid 63 in the shaft sealing chamber A and the filled liquid expansion/absorption chamber B is heated by high-temperature water, expands, compresses the diaphragm 83, and balances the external pressure with the filled liquid 63. The liquid 63 filled in the mechanical seal chamber and the external pressure are always balanced, and the spring 84 on the sliding surfaces of the sliding rings 51 and 53 has a small spring constant and a small set compression amount, so the pressure is reduced. The mechanical seal has a longer lifespan as it does little work.

The present invention has a mechanical seal case, a mechanical seal chamber, a liquid filled in the mechanical seal chamber, and an expansion absorption device for the liquid filled in the mechanical seal chamber, and the mechanical seal has a rotor chamber, a mechanical seal chamber, a mechanical seal chamber and a submersible motor. The mechanical seal case is a part of the motor frame, and the mechanical seal case encloses the mechanical seal to form a mechanical seal chamber. It is a vertical submersible motor that is sealed in a chamber and has an expansion absorption device attached to the mechanical seal case for the liquid sealed in the mechanical seal chamber, so it can be used in high-temperature environments, high-temperature, high-pressure environments, or high-pressure environments. It is durable.

Although the embodiment has been described with reference to a canned motor, it goes without saying that the present invention also includes a submersible motor that does not include a stator can 11.

[Brief explanation of drawings]

1 to 4 are vertical sectional views of the conventional example, FIG. 5 is a vertical sectional view of the embodiment of the present invention, FIG. 6 is a partially enlarged view of FIG. 5, and FIG. 7 is A of FIG. 6. -A sectional view. 1...Frame, 2...Stator, 3...Upper frame side plate, 4...Lower frame side plate, 5...Sealing ring, 6...Upper bracket, 7...Upper radial metal, 8...Sealing ring, 9... Lower bracket, 10... Lower radial metal, 11... Stator can, 12... Rotor, 13... Motor shaft, 14... Balance ring, 15... Thrust bearing, 16... Rotating disk, 17...key, 18...
...Leveling disk, 19...Bolt, 20...
... Thrust housing, 21 ... Adjustment screw, 22 ... Thrust receiver, 23 ... Pin, 2
4... Thrust carbon plate, 25... Lock nut, 26... Machine screw, 27... Stator coil,
28...Connector, 29...Cable, 30...
Diaphragm, 31... Hole, 32... Holding plate, 3
3... Spring receiving plate, 34... Spring, 37... Sealing ring, 38... Mechanical seal case, 39...
Bolt, 41... Sealing ring, 42... Mechanical bracket, 43... Special bolt, 44... Cylindrical part,
46... Mechanical seal cover part, 47... Mechanical seal, 48... Sealing ring, 49... Bolt, 50... Holding plate, 51... Sliding ring, 52...
Moving ring, 53...Sliding ring, 54...Compression spring, 5
5...Tongue, 56...Sandslinger, 58...
...Filled liquid, 59...Sealed air, 61...Sealed liquid,
63... Filled liquid, 64... Vane, 70... Upper bracket, 71... Oil seal, 72... Silicone grease, 73... Seal cover, 74...
Filter, 75... Dust seal, 76... Sliding ring, 77... Sheet material, 78... Moving ring, 79
... Sliding ring, 81 ... Spring seat ring, 82 ... Compression spring, A ... Shaft sealing chamber, B ... Filled liquid expansion absorption chamber, C
...Rotor chamber, D...Stator chamber.

Claims (1)

[Claims] 1. The output shaft end of the motor shaft 13 protrudes from the upper part, and is provided with a mechanical seal 47 for sealing the motor shaft 13. An expansion absorbing device for the liquid sealed in the motor chamber is disposed at the lower part, and the sealed liquid 58 is disposed within the motor frame. A vertical submersible motor sealed with a mechanical seal case 38, a mechanical seal chamber, a sealed liquid 63 in the mechanical seal chamber, and an expansion absorption device for the filled liquid 63 in the mechanical seal chamber, and the mechanical seal 47 is connected to a rotor chamber C. The mechanical seal case 38 provides a shaft seal between the mechanical seal chamber and the outside of the underwater motor.
is a part of the motor frame, the mechanical seal case 38 encloses the mechanical seal 47 to form a mechanical seal chamber, and the liquid 63 in the mechanical seal chamber is sealed in the mechanical seal chamber. A vertical submersible motor characterized in that an expansion absorbing device for the liquid 63 contained in the mechanical seal chamber is attached to 38.