JPH05199709A - Canned motor - Google Patents

Abstract

PURPOSE:To provide a canned motor in which a surface of a can at a stator chamber side is not dew-condensed even if a temperature of coolant to be introduced into a rotor chamber is lower than that of the air of the stator chamber. CONSTITUTION:A temperature regulating valve 22 is mounted in the vicinity of an output of a rotor chamber B of coolant. A temperature of the coolant in the chamber B is regulated by opening or closing the valve 22 so as to become substantially equal to that of the air in a stator chamber A, thereby preventing dew-condensation of the surface of a can at a stator side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a canned motor in which the interior of the machine is divided into a stator chamber and a rotor chamber by a can, and cooling water is passed through the rotor chamber for cooling.

[0002]

2. Description of the Related Art FIG. 4 is an axial half sectional view showing a conventional canned motor in which a motor flange portion is coupled to a pump portion (not shown) for driving a pump, for example. In the figure, reference numeral 1 denotes a stator, which comprises a stator core 2 having a stator winding 3 mounted thereon, and a frame 4 of the stator 1 having the stator core 2 fixed thereto. Reference numeral 5 is a lead wire of the stator winding 3, 6 is a rotor, and includes a rotor core 7, a rotor conductor 8 fixed to the rotor core 7 and joined with an end ring 9, and a rotor core 7. The rotor shaft 10 is fixed. The rotor shaft 10 is provided with a through hole 10a at its axial center. Rotor core 7
Corresponds to the stator core 2 via an air gap.

A lower bracket 11 is attached to the frame 4 with bolts 13 and has a water passage hole 11a. Reference numeral 12 is an upper bracket attached to the frame 4 with bolts 14, reference numeral 15 is a cylindrical can made of an ultrathin non-magnetic metal material (for example, stainless steel material), and the middle portion is fitted to the inner diameter portion of the stator core 2. And O on the inner surface of the upper end
It is water-tightly connected to the upper bracket 12 via the ring 16 and water-tightly connected to the lower bracket 11 via the O-ring 16 on the inner peripheral surface of the lower end. Reference numerals 17 and 18 denote sleeve bearings that radially support the rotor shaft 10 on both brackets 11 and 12, 19 denotes a thrust disk fixed to the rotor shaft 10, and 20 denotes a thrust bearing that supports the thrust load of the rotor shaft 10. Is.

The can 15 divides the interior of the machine into a stator room A and a rotor room B. The lead wire 5 is drawn out through the lead-out hole 4a of the frame 4 and is not a sealed structure. It should be noted that the frame 4 is provided with a ventilation hole as required to have an open structure.

A case where the conventional canned motor is used for driving a pump will be described below. The rotor 6 is rotated by energization, and a part of the pumped water whose pressure has risen is used as cooling water for the motor.
Flow into the rotor chamber B, rise through the gap between the can 15 and the rotor core 7, pass through the flow groove 12a provided in the upper bracket 12, pass through the through hole 10a of the rotor shaft 10, and lower the pump. Return to the suction side (low pressure side). As described above, the cooling water flowing through the rotor chamber B cools the stator core 2, the rotor 6 and the bearings that are in contact with the can 15, and lubricates the bearings. Therefore, the temperature of the can 15 that separates the rotor chamber B and the stator chamber A from each other depends on the temperature of the stator core 2.
The temperature of the intermediate portion in contact with the inner diameter of the stator core 2 rises to almost the same temperature as the stator core 2, but the temperature of the both ends of the stator core 2 outwardly becomes almost equal to the temperature of the cooling water.

On the other hand, in the stator chamber A, since the frame 4 is provided with ventilation holes and the frame penetrating portion of the lead wire 5 does not have a completely sealed structure, the outside air can freely flow into the stator chamber A. coming and going. Therefore, the air in the stator chamber A is less affected by the heat generated by the stator core 2 and the stator winding 3, and when the temperature of the cooling water is around 20 ° C., the can 15 and the stator chamber A are cooled. The temperature difference with the air inside is usually 5-10 ° C
It is a degree.

[0007]

In the conventional canned motor as described above, when the cooling water is lower than the outside air temperature (for example, for driving a room temperature water pump of about 20 ° C.), the air in the stator chamber A that communicates with the outside air. Contacts the can 15, which has a low temperature,
There is a problem that dew condensation occurs on the air side surface of the can 15 and the insulation resistance of the stator winding 3 is significantly reduced. Particularly when used in an environment with high temperature and humidity, there was a problem that dew condensation frequently occurred and water was accumulated in the stator chamber A, the insulation resistance became zero, and the pump could not be operated. .. Therefore, there is an inconvenience that the pump application is limited to hot water, and the application is limited to only hot water having a temperature equal to or higher than the outside air temperature (for example, 50 ° C.).

As a means for solving the above problems, as shown in FIG. 5, a dew condensation preventing heat insulating coating material 21 is attached to both ends of the can 15 which extend from both ends of the stator core 2.
Further, as shown in FIG. 6, there is a means of enclosing the stator chamber A in a completely sealed structure and enclosing a gas that does not contain moisture, but in either case, the cost becomes high and the manufacturing process becomes complicated and the workability is reduced. There was a problem such as getting worse.

The present invention has been made to solve the above problems, and even in an environment in which the temperature of the cooling water circulating in the motor is lower than the outside air temperature, dew condensation occurs on the surface of the can on the stator chamber side. The purpose is to obtain a canned motor that can be applied to a wide range of applications from cold water to hot water without causing a problem.

[0010]

A canned motor according to the present invention is provided with a temperature control valve that senses the liquid temperature of a rotor chamber and opens and closes in the vicinity of the rotor chamber outlet of a cooling water circulation path to rotate the canned motor. The liquid temperature in the sub-chamber is controlled to be almost equal to the air temperature in the stator chamber.

[0011]

In the canned motor according to the present invention, the flow rate of the cooling water is adjusted by the temperature adjusting valve installed near the outlet of the rotor chamber, and the cooling water is cooled even when the cooling water having a temperature lower than the air temperature of the stator chamber flows in. The temperature is controlled so that it is almost the same as the air temperature in the stator chamber.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a half sectional view in the axial direction, and the same or corresponding parts as those of the conventional device are designated by the same reference numerals and the description thereof is omitted. In the figure, reference numeral 22 is a temperature control valve installed in the water passage hole 12a of the upper bracket 12.

In the canned motor shown in FIG. 1, most of the heat generated in the motor stator and the rotor is cooled by the cooling water circulating in the rotor chamber B.
The temperature of the cooling water is higher at the outlet than at the inlet of the rotor chamber B. This temperature rise of the cooling water greatly changes depending on the flow rate of the cooling water as shown in FIG. Therefore, the temperature of the cooling water at the outlet of the rotor chamber B is sensed by the temperature control valve 22 and the temperature of the cooling water flowing in the rotor chamber B is controlled to a state close to the temperature of the air in the stator chamber A. Is. The operating characteristic of the temperature control valve 22 is that a low flow rate (e.g., about 0.3 liter / min) is flown below the upper set temperature and a predetermined flow rate (e.g., 2 liter / min) above the lower set temperature in a predetermined pressure difference range. Flow).

FIG. 3 shows an example of adjusting the temperature of the cooling water by the temperature adjusting valve 22. That is, the cooling water at 20 ° C is used in the rotor chamber B.
The operation is started from the state where the cooling water has flowed in to, and in this state, the temperature of the cooling water gradually rises because the temperature adjustment valve 22 allows only a low flow rate. Upper setting temperature 4 of temperature control valve 22
When the temperature reaches 5 ° C., the temperature control valve 22 opens at point a, and the flow rate increases to a predetermined flow rate. Therefore, the temperature of the cooling water decreases. Next, at the point b when the temperature of the cooling water reaches the lower preset temperature of 35 ° C., the temperature control valve 22 is closed and a low flow rate flows, so that the temperature starts to rise again. This operation is repeated thereafter, and the temperature of the cooling water is sawtooth, with the upper set temperature of 45 ° C and the lower set temperature of 35 ° C.
The temperature of the air in the stator chamber A is kept close to 40 ° C., which is the highest state throughout the year.

[0015]

As described above, according to the present invention, the temperature of the cooling water flowing through the rotor chamber can be adjusted to a temperature substantially equal to the air temperature in the stator chamber by repeating the opening / closing operation of the temperature regulating valve, so that the temperature is fixed. It is possible to prevent dew condensation on the can surface of the child room.

[Brief description of drawings]

FIG. 1 is an axial half sectional view showing an embodiment of a canned motor according to the present invention.

FIG. 2 is a diagram showing an example of a cooling water amount and a cooling water temperature rise of a canned motor.

FIG. 3 is a diagram showing an example of temperature change of cooling water according to the present invention.

FIG. 4 is an axial half sectional view showing a conventional canned motor.

FIG. 5 is an axial half sectional view showing a different conventional example.

FIG. 6 is an axial half sectional view showing still another conventional example.

[Explanation of symbols]

 1 Stator 2 Stator Iron Core 3 Stator Winding 6 Rotor 11 Lower Bracket 12 Upper Bracket 15 Can 22 Temperature Control Valve A Stator Chamber B Rotor Chamber

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 9, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art FIG. 4 is an axial half sectional view showing a conventional canned motor in which a motor flange portion is coupled to a pump portion (not shown) for driving a pump, for example. In the figure, reference numeral 1 denotes a stator, which comprises a stator core 2 having a stator winding 3 mounted thereon, and a frame 4 of the stator 1 having the stator core 2 fixed thereto. Reference numeral 5 is a lead wire of the stator winding 3, 6 is a rotor, and includes a rotor core 7, a rotor conductor 8 fixed to the rotor core 7 and joined to an end ring 9 , and a rotor core 7. The rotor shaft 10 is fixed. The rotor shaft 10 is provided with a through hole 10a at its axial center. Rotor core 7
Corresponds to the stator core 2 via an air gap.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

A lower bracket 11 is attached to the frame 4 with bolts 13 and has a water passage hole 11a. 12 is an upper bracket attached to the frame 4 with bolts 14, and 15 is an extremely thin non-magnetic metal material (for example, 1
It is a cylindrical can made of 8.8 stainless steel ), the middle part of which is fitted into the inner diameter part of the stator core 2 and is watertightly coupled to the upper bracket 12 via the O-ring 16 at the inner peripheral surface of the upper end, and the lower part. The inner peripheral surface of the end is watertightly coupled to the lower bracket 11 via an O-ring 16. Reference numerals 17 and 18 denote sleeve bearings that radially support the rotor shaft 10 on both brackets 11 and 12, 19 denotes a thrust disk fixed to the rotor shaft 10, and 20 denotes a thrust bearing that supports the thrust load of the rotor shaft 10. Is.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

On the other hand, in the stator chamber A, since the frame 4 is provided with ventilation holes and the frame penetrating portion of the lead wire 5 does not have a completely sealed structure, the outside air can freely flow into the stator chamber A. coming and going. Therefore, the air in the stator chamber A is less affected by the heat generated by the stator core 2 and the stator winding 3, and when the temperature of the cooling water is around 20 ° C., the can 15 and the stator chamber A are cooled. The temperature difference with the air inside is usually 10-15
It is about ℃.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

In the conventional canned motor as described above, when the cooling water is lower than the outside air temperature (for example, for driving a room temperature water pump of about 20 ° C.), the air in the stator chamber A that communicates with the outside air. Contacts the can 15, which has a low temperature,
There is a problem that dew condensation occurs on the air side surface of the can 15 and the insulation resistance of the stator winding 3 is significantly reduced. Particularly when used in an environment with high temperature and humidity, there was a problem that dew condensation frequently occurred and water was accumulated in the stator chamber A, the insulation resistance became zero, and the pump could not be operated. .. Therefore, there is an inconvenience that the pump application is limited to hot water, and the application is limited to only hot water having a temperature equal to or higher than the outside air temperature (for example, 50 ° C.) .

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

In the canned motor shown in FIG. 1, most of the heat generated in the motor stator and the rotor is cooled by the cooling water circulating in the rotor chamber B.
The temperature of the cooling water is higher at the outlet than at the inlet of the rotor chamber B. This temperature rise of the cooling water greatly changes depending on the flow rate of the cooling water as shown in FIG. Therefore, the temperature of the cooling water at the outlet of the rotor chamber B is sensed by the temperature control valve 22 and the temperature of the cooling water flowing in the rotor chamber B is controlled to a state close to the temperature of the air in the stator chamber A. Is. The operating characteristic of the temperature control valve 22 is that a predetermined flow rate (e.g.
If flowing about 2 liters / min), the lower the set temperature below
Then, a low flow rate (for example, about 0.3 liter / min) is applied.

Claims (2)

[Claims] 1. A cylindrical can made of an ultrathin non-magnetic material has an axially intermediate portion fitted in an inner diameter portion of a stator core and both end portions extending out from both ends of the stator core. The inner surface is partitioned into a stator chamber and a rotor chamber by being water-tightly coupled to the fixed unit on the peripheral surface, respectively, and cooling water whose pressure is increased is introduced from the pump discharge side into the rotor chamber to form a void in the motor. In the canned motor of the circulation type cooling structure in the motor that returns the cooling water that has passed through to the low pressure side of the pump suction side, it operates by sensing the liquid temperature of the rotor chamber near the rotor chamber outlet of the cooling water circulation path. A canned motor that is equipped with a temperature control valve that operates. 2. The temperature control valve supplies a predetermined flow rate when the temperature of the liquid in the rotor chamber rises to a level close to the room temperature of the stator, and thereafter when the temperature of the liquid in the rotor chamber falls below a set temperature. The canned motor according to claim 1, wherein the canned motor has a characteristic of being closed.