JPH0150178B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motor for a submersible motor pump using a liquid ring type motor, and more particularly to a shaft sealing device for a motor for a submersible motor pump used in handling liquid of high pressure or high temperature or high temperature and high pressure.

Conventionally, submersible motor pumps with a motor at the bottom and a cylindrical shape suitable for installation in a well to drive a pump at the top 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 vertical cross-sectional view 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. 2. 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 held by a moving ring 78 made of a shaft organic material that is tightly fitted 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 a 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 room 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 filled 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 filled 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 filled liquid cannot be absorbed sufficiently, resulting in high internal pressure, which causes 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 static pressure difference is large, the external pressure to the submersible motor becomes high, and the dissolved air contained in the liquid sealed in the rotor chamber is compressed. As a result, the diaphragm, which was originally intended to absorb the expansion of the sealed liquid due to the temperature rise caused by the operation of the submersible motor, expands 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. or,
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 liquids 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. Rock,
The pump will be unable to pump water due to burnout.

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 hundreds of meters deep, problems arise due to the deeper water depth when installing submersible motor pumps. Ta. or,
Similar problems arise when pumping high-pressure cold water from deep wells.

The present invention aims to provide a liquid-sealed submersible motor that is suitable for high pressure, high temperature, or high temperature and high pressure, and is equipped with a shaft sealing device with high pressure resistance, in a submersible motor pump used in water under high pressure or high temperature or high temperature and high pressure environment. This is the purpose.

In the present invention, the output shaft end of the motor shaft protrudes from the upper part, and has a motor frame, a partition wall, a mechanical seal, and a mechanical seal chamber. In a vertical submersible motor in which a mechanical seal forms a shaft seal between a rotor chamber and a mechanical seal chamber, and a shaft seal between the mechanical seal chamber and the outside of the motor, the mechanical seal chamber communicates with the shaft seal chamber. The shaft sealing chamber has a filled liquid expansion and absorption chamber connected to the upper part of the shaft sealing chamber, and the mechanical seal is housed in the shaft sealing chamber. This is an underwater motor equipped with a shaft sealing device.

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. This embodiment is a canned motor including a stator can 11 that seals the stator 2 and partitions the stator 2 and rotor 12. The motor frame is attached to the upper bracket 6.
The inside communicates with the lower part of the thrust housing 20, and a sealed liquid is sealed therein.

A diaphragm 30 is fitted into the lower part of the thrust housing 20, and a press plate 32 with 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 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 dirahram 30.

FIG. 6 is a partially enlarged view of FIG. 5. A spacer (hereinafter referred to as mechanical spacer) 36 is fitted into the upper bracket 6 to support one end of a composite mechanical seal 47 via a sealing ring 35 and to form one end wall of the shaft sealing chamber A. Mechanical spacer 36 as a partition wall between the chamber C and the mechanical seal chamber
A mechanical seal case 38 is fitted through the sealing ring 37, and the bolts 39 are inserted into the mechanical seal case 38 through the bolt holes of the upper bracket 6 and the mechanical spacer 36, and the upper bracket 6, the mechanical spacer 36, and the mechanical seal case 38 are inserted. is fixed. Mechanical seal case 3
8 has a mechanical seal 47 via a sealing ring 41.
A bracket (hereinafter referred to as the mechanical bracket) 42 for supporting the other end of the mechanical bracket 42 is inserted into the mechanical bracket 42, and screws are inserted into the shaft portions on both sides that have hexagonal tool engaging portions in the center. A special bolt 43 for fastening the submersible pump is screwed into the mechanical seal case 38.

One end of a cylindrical sleeve 44 spaced apart from the motor shaft 13 is press-fitted into the mechanical bracket 42, and the other end of the cylindrical sleeve 44 is press-fitted into a mechanical seal cover 46. The two sides of the mechanical seal cover 46 communicate with each other, and in this embodiment, the mechanical seal case 3
A thin strip is provided between the mechanical seal cover 8 and the mechanical seal cover 46. Alternatively, the mechanical seal cover 46 may be tightly fitted into the mechanical seal case 38, and a hole may be formed that communicates both sides of the mechanical seal cover 46. Mechanical seal case 38 between mechanical bracket 42 and mechanical seal cover 46
The inside is a sealed liquid expansion and absorption chamber B. A composite mechanical seal 47 is installed between the mechanical seal cover 46 and the mechanical spacer 36. In this way, the shaft seal chamber A and the filled liquid expansion/absorption chamber B form a mechanical seal chamber which communicates with each other.

The composite mechanical seal 47 includes a sliding ring 51 that is fitted into the mechanical spacer 36 and the mechanical seal cover 46 through a sealing ring 48 and held down by a retaining plate 50 that is fixed to the mechanical spacer 36 and the mechanical seal cover 46 with bolts 49. , a pair of movable rings 52 that tightly fit into the motor shaft 13 so as to be able to move in the axial direction, a movable sliding ring 53 that is held by the movable ring 52 and moves with the fixed sliding ring 51, and a pair of movable rings. 52 and urges the movable ring 52 in the axial direction to press the movable sliding ring 53 against the fixed sliding ring 51.

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 close to each other with a small gap, so that the centrifugal force generated by the rotation of the sand slinger 56 removes foreign substances such as sand. Therefore, the well water is supplied to the mechanical bracket 42, the sleeve 44, the mechanical seal cover 46, the upper sliding ring 51 and the motor shaft 13, and the liquid does not contain sand to the upper sliding rings 51, 53 of the mechanical seal 47. The outer sliding surface is prevented from operating without lubrication.

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 sealed liquid 58 may be injected from the center hole of the upper bracket 6 when the upper bracket 6 is assembled from the bottom.Although not shown, an injection port is provided in the upper bracket 6 or the mechanical spacer 36 to inject the filled liquid 58. Inject and stopper. The stator chamber D containing the stator 2 is filled with a liquid 61, leaving a space in the upper part in which air 59 at normal pressure remains. The shaft sealing chamber A containing the composite mechanical seal 47 and the filled liquid expansion absorption chamber B are provided with normal pressure air 62 at the top.
A filling liquid 63 is filled in so as to leave a space filled with the liquid. 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, the rotor 12 receives rotational force, the motor shaft 13 rotates, and a submersible pump (not shown) is rotated via a shaft coupling to pump water from the well. Pump up. The part where the motor shaft 13 exits is between the sand slinger 56 and the tongue portion 55 of the mechanical bracket 42 to prevent the intrusion of minute solids such as sand, and well water flows between the motor shaft 13, the mechanical bracket 42, and the sleeve 4.
4. The outer side of the mechanical seal 47 is reached from between the mechanical seal cover 46 and the upper sliding ring 51, and the shaft is sealed by the composite mechanical seal 47 even if there is a difference in internal and external pressure.

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 sealed liquid 63 in the shaft sealed chamber A and the filled liquid expansion/absorption chamber B is increased by the high-temperature water and expands, compressing the upper sealed air 62 to generate pressure.

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 filling liquid 63 in the shaft sealing chamber A and the filling liquid expansion/absorption chamber B is heated by the high temperature water and expands. The sealed air 62 in the filled liquid expansion/absorption chamber B is compressed and generates pressure. The shaft sealing chamber A and the filling liquid expand and absorb so that the pressure generated is between the hydrostatic pressure of the well and the pressure based on the aforementioned high temperature water of the filling liquid 58 in the rotor chamber C and the heat generated by motor operation. Room B
, the volume of the sealed liquid 63, the ratio between the filled liquid 63 and the sealed air 62, the expansion coefficient of the filled liquid 63, etc., so that the mechanical seal 47 is able to maintain the pressure of the filled liquid 58 in the rotor chamber C and the outside. By receiving a pressure difference smaller than that of high-temperature water, the mechanical seal 47 has the effect of increasing its pressure resistance.

As mentioned at the beginning, if the submersible motor pump is installed deep and the difference between dynamic pressure and static pressure is large, the external pressure of the submersible motor will be high. In the case of a deep well where the external pressure is high, the spring water is at a high temperature, so the temperature and pressure of the filled liquid 63 in the shaft sealing chamber A and the filled liquid expansion/absorption chamber B rise, as described above. Therefore, the mechanical seal 47 receives a pressure corresponding to the difference. Furthermore, even if the temperature is not high in a cold deep well, the temperature of the liquid being handled has risen to some extent, so a similar effect occurs.

In the above explanation, the filled air 62 is sealed in the filled liquid expansion/absorption chamber B. This is done by placing a large number of air-filled containers made of soft elastic bodies, such as small spherical containers, into the filled liquid expansion/absorption chamber B. You can also leave it there. Alternatively, it may be a sealed liquid suitable for cooling and lubricating the mechanical seal 47 and capable of containing gas.

In the present invention, the output shaft end of the motor shaft protrudes from the upper part, and has a motor frame, a partition wall, a mechanical seal, and a mechanical seal chamber. In a vertical submersible motor in which a mechanical seal forms a shaft seal between a rotor chamber and a mechanical seal chamber, and a shaft seal between the mechanical seal chamber and the outside of the motor, the mechanical seal chamber communicates with the shaft seal chamber. It has a filled liquid expansion absorption chamber connected to the upper part of the shaft sealing chamber, and a mechanical seal is housed in the shaft sealing chamber. Since it is a submersible motor equipped with a shaft sealing device that encloses a The submersible pump has increased pressure resistance and 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. DESCRIPTION OF SYMBOLS 1... Frame, 2... Stator, 6... Upper bracket, 11... Stator can, 12... Rotor, 13... Motor shaft, 20... Thrust housing, 27... Stator coil, 29... Cable, 30...Diaphragm, 31...Hole, 32
... Pressing plate, 33 ... Spring receiving plate, 34 ... Spring,
35... Sealing ring, 36... Mechanical spacer, 37...
...Sealing ring, 38...Mechanical seal case, 3
9...Bolt, 41...Sealing ring, 42...Mechanical bracket, 43...Special bolt, 44...Sleeve, 46...Mechanical seal cover, 47...
Mechanical seal, 48... Sealing ring, 49... Bolt, 50... Holding plate, 51... Sliding ring, 52...
...moving ring, 53...sliding ring, 54...compression spring,
55...Tongue, 56...Sandslinger, 58
...Filled liquid, 59...Sealed air, 61...Sealed liquid, 62...Sealed air, 63...Sealed liquid, 64...
...Blade, 70...Upper bracket, 71...Oil seal, 72...Silicon 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 and absorption chamber, C...Rotor chamber, D...
Stator chamber.

Claims (1)

[Claims] 1 The output shaft end of the motor shaft 13 protrudes from the top,
Motor frame, partition wall 36, mechanical seal 47,
The motor frame has a mechanical seal chamber, and the motor frame partitions the inside of the motor in the axial direction with a partition wall 36 to form a rotor chamber C and a mechanical seal chamber, and a mechanical seal 47 provides a shaft seal between the rotor chamber C and the mechanical seal chamber. In addition, in a vertical submersible motor with a shaft sealed between a mechanical seal chamber and the outside of the motor, the mechanical seal chamber communicates with the shaft seal chamber A and the shaft seal chamber A, and is connected to the upper part of the shaft seal chamber A. Filled liquid expansion absorption chamber B
A submersible motor equipped with a shaft sealing device in which a mechanical seal 47 is housed in a shaft sealing chamber A, and a filling liquid is sealed in the mechanical seal chamber except for an air sealing portion of a filling liquid expansion/absorption chamber B.