JPS6335199Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shaft sealing device for a submersible motor pump.

A conventional submersible motor pump will be explained with reference to the drawings. FIG. 1 is a longitudinal sectional view of a conventional submersible motor pump. An impeller 3 is fixed to the end of the main shaft 2 protruding into the casing 1, a suction cover 4 is fixed to the suction port side of the casing 1, and a liquid sending pipe (not shown) is connected to the discharge port 5. . An intermediate casing 10 is inserted into the casing 1, and a sealed oil chamber 7 is formed between the lower bracket 6 and the intermediate casing 10, which are sealed and fixed.
A rotor 12 is fixed to the main shaft 2 with a gap between it and a stator 11 fixed to a motor frame 9 which is sealed and fixed to the lower bracket 6, and the rotor 12 is fitted into the motor frame 9. The main shaft 2 is mounted on bearings 14 and 15 mounted on a fixed electric motor cover 13 and a lower bracket 6.

The outer periphery of the lower bracket 6 is provided with an oil filler port 16 for introducing oil into the sealed oil chamber 7, and an oil filler plug 18 is screwed into the lower bracket 6 through a packing 17.

The motor cover 13 has a watertight connector 1
An underwater cable 21 is led through the cable 9, and three-phase wiring is provided to the coil of the stator 11.

When the submersible motor pump is operating, water in the water reservoir passes through the suction port of the suction cover 4, is sucked into the casing 1 from the suction port 1a, is accelerated and pressurized by the impeller 3, exits the impeller 3, and enters the volute chamber. The velocity head is converted into a pressure head, and pumped water is discharged from the discharge port 5.

A mechanical seal 8 is used to seal the shaft to prevent water from entering through the main shaft 2 of the casing 1 and to seal the shaft 2 of the lower bracket 6 through the main shaft 2.

FIG. 2 is a longitudinal sectional view showing details of the shaft sealing device.

Fixed liner ring 23 to which the sliding ring 22 is fixed
is fitted with a sealing ring 24 on its outer periphery, is fitted into the intermediate casing 10, and is prevented from coming off in the axial direction by a retaining plate 26 fixed to the intermediate casing 10 with small screws 25, and the inner diameter of the fixed liner ring 23 is different from that of the main shaft 2. It is made in a gap that creates a throttle effect. The sliding ring 27 is fitted into the central boss portion of the lower bracket 6, and a moving ring 29 made of an elastic body with a pair of sliding rings 28 fixed between the sliding rings 22 and 27 is axially sealed to the main shaft 2 and moved in the axial direction. The spring 31 is compressed and inserted between the movable rings 29 and the movable rings 2
9, the sliding ring 28 is elastically pressed against the sliding rings 22 and 27, respectively. The mechanical seal 8, that is, the sliding portion of the member described above, is cooled and lubricated with oil sealed in the sealed oil chamber 7. The oil filler port 16 of such a submersible motor is selected so that the sliding surface of the mechanical seal 8 is completely covered and the oil level is such that there is some margin, and a space of height L is provided above the oil filler port 16. A partition wall 6a of the lower bracket 6 is arranged.

When filling the liquid into the sealed oil chamber 7, in order to prevent air from remaining in the sealed oil chamber 7 and causing the sealed oil to heat up and generate a large pressure, the upper sliding ring 2
Upper sliding ring 2 to ensure lubrication between 7 and 28.
The amount of oil is measured so that air remains in the sealed oil chamber 7 between the lower bracket and the lower surface of the partition wall 6a of the lower bracket. However, if you forget to measure the amount of sealed oil when filling it, the oil will expand due to heat, and if it overcomes the pressure on the sliding ring 28 exerted by the spring 31, the oil will flow between the upper sliding ring 28 and the sliding ring 27. The sliding surface of the lower sliding ring 28 is pushed open and leaks into the motor.
The sliding surface between the and sliding ring 22 is pushed open and leaks into the pump chamber. If the amount of oil sealed is insufficient, the outer periphery of the sliding surfaces of the sliding rings 27 and 28 will be exposed to the air layer on the upper surface of the sealed oil chamber 7, and the lubrication between the sliding rings 27 and 28 will deteriorate. Measuring and filling oil into the oil chamber 7 is troublesome and requires maintenance.

The present invention eliminates the above-mentioned drawbacks of submersible motor pumps, and provides a submersible motor pump that is equipped with a means for allowing a specified amount of air to remain inside the oil chamber by simply filling the oil chamber with oil from the inlet until it overflows. The purpose is to provide

This invention has a motor on the top and a pump on the bottom, and the motor and pump are integrally connected, and the main shaft, which fixes the motor rotor and pump impeller, seals the liquid that also serves as cooling and lubrication between the pump motor. In a submersible motor pump that has a mechanical seal that seals the main shaft in the part where the oil chamber is inserted, and an oil inlet on the peripheral wall of the oil chamber, the oil chamber has an air inlet and is sealed. This submersible motor pump is characterized by having an air reservoir container provided with a space without an escape route for the incoming air driven by the liquid pressure in the oil chamber.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a longitudinal sectional view of a shaft seal including the sealed oil chamber 7 of the submersible motor pump. A donut-shaped plate member 32 is accommodated in the sealed oil chamber 7 . The donut-shaped plate member 32 has an inner flange 33 in the center and a cylindrical part 34 centered on the main shaft 2, which forms an air pocket 35 in a spiral shape at the end of the cylindrical part, and a plate end 36 forming the air pocket 35. is spaced from the cylindrical portion 34, and an air inlet 37 is provided. Therefore, the air inlet 37 communicates with an air reservoir 38 in the space within the air reservoir section 35. Since the donut-shaped plate member 32 is shown in the figure as a rotating body centered on the main shaft 2, the air reservoir 38 is provided with a donut-shaped space, and the air inlet 37 is also circular in plan view. The donut-shaped plate member 32 is assembled by inserting the flange 33 into the screw hole 39 of the boss portion of the intermediate casing 10 shown in FIG.
The donut-shaped plate member 32 shown in FIG. 3 can also be used in place of the presser plate 26.

When injecting sealed oil, as shown in Figure 4, lay the submersible motor pump sideways, remove the oil filler plug 18 and packing 17, and fill the filler port 16 with the sealed oil. A sealed liquid level 42 is formed as shown by the dotted line), and the sealed oil chamber 7 and the air reservoir 38 located above the air reservoir portion 35 are filled with air, and the other portions of the air reservoir 38 are filled with sealed oil.

On the other hand, while the sealed oil is being filled, the air in the sealed oil chamber 7 is alternately discharged from the oil filling port 16, but the air in the upper part of the air reservoir 38 remains. After filling the sealed oil, attach the packing 17 and oil plug 18,
When the submersible motor pump is placed in the upright position as shown in FIG. 5, the air accumulated in the donut-shaped plate member 32 moves to the upper annular space in the air reservoir 38 of the donut-shaped plate member 32 without leaking, and the remaining air reservoir 38 The lower part and the sealed oil chamber 7 are filled with sealed oil. That is, the amount of air in the section a chamber of the air reservoir 38 shown in FIG. 4 is equal to the air amount in the section a' chamber of the air reservoir 38 shown in FIG. The air in chamber a' does not leak out from the air reservoir 38 through the air inlet 37.

Even when the submersible motor pump is operated and the sealed oil in the sealed oil chamber 7 becomes high in temperature, there is air in a part of the air reservoir 38, so the pressure increase of the sealed oil in the sealed oil chamber 7 impairs the function of the mechanical seal. Never.

As explained above, in the submersible motor pump of this invention, a donut-shaped plate member is provided in the sealed oil chamber, so when filling the sealed oil, there is no need to measure the sealed oil, and if the oil is injected until it overflows from the oil filler port, the ring-shaped Since air accumulates in the air reservoir, measuring when filling oil can be omitted and can be replaced with the simple task of simply checking to see if it is full. In this way, air is collected in the air reservoir, and an abnormal pressure rise in the sealed oil in the sealed oil chamber can be prevented. The air layer height L (Fig. 1) as in the conventional example is not required, and the length of the main shaft can be shortened by L, allowing the height of the pump to be lowered. Also, the vertical position of the oil filler port can be selected.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a conventional example, Fig. 2 is an enlarged longitudinal sectional view of a mechanical seal, Fig. 3 is a longitudinal sectional view showing an embodiment of the present invention, and Figs. 4 and 5 are implementations of the present invention. FIG. 4 is a cross-sectional view, and FIG. 5 is a vertical cross-sectional view. DESCRIPTION OF SYMBOLS 1... Casing, 1a... Suction port, 2... Main shaft, 3... Impeller, 4... Suction cover, 5... Discharge port, 6... Lower bracket, 6a... Partition wall, 7
...Sealed oil chamber, 8...Mechanical seal, 9...
Electric motor frame, 10... Intermediate casing, 11
... Stator, 12 ... Rotor, 13 ... Motor cover, 14, 15 ... Bearing, 16 ... Oil filler port,
17...Packing, 18...Lubrication plug, 19
...Connector, 21...Underwater cable, 22...
...Sliding ring, 23... Fixed liner ring, 24...
Sealing ring, 25... Machine screw, 26... Holding plate, 2
7, 28...Sliding ring, 29...Moving ring, 31...
Spring, 32... Donut-shaped plate member, 33... Flange, 34... Cylindrical part, 35... Air reservoir part, 36
... Plate end, 37 ... Air inlet, 38 ... Air reservoir, 39 ... Screw hole, 41 ... Machine screw, 42 ...
Filled liquid level, 43...Oil level.

Claims (1)

[Claims for Utility Model Registration] 1. The motor and pump are integrally connected, with the motor at the top and the pump at the bottom, and the main shaft to which the motor rotor and pump impeller are fixed provides cooling and lubrication between the pump motor. In a submersible motor pump, a mechanical seal for sealing the main shaft is arranged in the sealed oil chamber in the part where the sealed oil chamber is inserted, and an oil filler port is provided on the surrounding wall of the sealed oil chamber. A submersible motor pump characterized in that an air reservoir container is provided with an inlet and a space with no escape route for the incoming air forced in by the liquid pressure of the sealed oil chamber. 2. The container of the air reservoir is donut-shaped and arranged so as to surround the mechanical seal, and the cross section of the donut-shaped container is provided with an air inlet that opens downward on the inner diameter side, and has a spiral inner side that overlaps only at the air inlet. The submersible motor pump according to claim 1, wherein the submersible motor pump is an air reservoir.