JPH10205499A - Motor cooling device for vertical type motor-driven pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor cooling device for a vertical type motor-driven pump to be produced at a low-cost without increasing the size of a motor and effectively function even when the device is used in a state that scale and sludge are adhered on the surface of a motor frame. SOLUTION: The interior of a motor frame 5 forms oil seal structure and a pump chamber 9 communicated with the motor frame 5 is arranged. An outer periphery of a discharge pipe 3 extending from a pump casing 1 is surrounded with an oil cooling pipe 4. The upper part of the oil cooling pipe 4 is communicated with the upper part of the motor frame 5 and the lower part of the oil cool pipe 4 is communicated with the pump chamber 9. Seal oil is circulated in the pump chamber 9 during drive of a pump through the working of a circulator impeller 12 to effect cooling of a motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a motor cooling device for a vertical electric pump.

[0002]

2. Description of the Related Art It is known to provide a motor frame with an oil-sealed structure in order to prevent the motor from generating heat.

[0003] The electric pump using the oil-sealed motor has no problem in cooling the motor if it is used in a state where the motor is submerged in fresh water. However, as a practical problem, in most usage situations, scale, sludge, etc. adhere to the surface of the motor frame, and the cooling function is hindered. Even when used in fresh water, the motor frame is exposed to the air and loses the cooling function when draining residual water at a low water level.
Also, when used as a relay pump on land, it has no cooling function at all.

[0004] Conventionally, as a measure for suppressing heat generation of a motor in an electric pump using an oil-sealed motor,
2. Description of the Related Art A large-capacity motor having a margin compared to a pump load is used. It is well known that this is the cause of the increase in size and cost of the product.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to produce an oil-sealed motor at low cost without increasing the size of the motor.
It is an object of the present invention to provide a motor cooling device for a vertical electric pump that functions effectively even when scale or sludge adheres to the surface of a motor frame or the motor frame is used in a state where it is exposed to the air.

[0006]

In the cooling device for a vertical electric pump according to the present invention, the inside of the motor frame erected on the pump casing has an oil-sealed structure, and the pump communicates with the inside of the motor frame immediately below the lower bearing of the motor. A chamber is provided to house a circulation impeller, and an outer periphery of a discharge pipe extending upward from one side of the pump casing is surrounded by an oil-cooled pipe, and an upper oil feed pipe led out from an upper part of the motor frame is provided. The lower oil feed pipe led out of the pump chamber was opened to the lower part of the oil cooling pipe while being opened above the oil cooling pipe.

[0007]

When the pump is driven, the oil enclosed in the motor frame moves upward from below while absorbing the heat generated by the motor and the bearings by the rotation of the circulation impeller, and flows into the oil cooling pipe through the upper oil supply pipe. The oil that descends in the oil cooling pipe while being cooled by the pumping water passing through the discharge pipe is returned to the pump chamber through the lower oil supply pipe, and the oil that has absorbed the heat generated by the motor and bearings in the motor frame and rises in temperature again. Then, the oil cooled down in the oil cooling pipe and descending through the oil cooling pipe returns to the pump chamber through the lower oil supply pipe, and then is circulated into the motor frame, thereby causing a circulation action.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments will be described below with reference to the drawings.

1 is a pump casing, 2 is a suction opening formed in the center of the lower wall of the pump casing 1, 3 is a discharge pipe extending above one side of the pump casing 1, 4 is an outer periphery of the discharge pipe 3 , A motor frame erected on the pump casing 1, 6 an upper oil feed pipe led out from an upper part of the motor frame 5 and opened to an upper part of the oil cooling pipe 4, 7 a A lower bracket 9 fixed to the lower surface of the motor frame 5 and supporting the motor shaft 8 by a bearing 7b, 9 is a pump chamber formed on the lower surface of the lower bracket 7 through a flow hole 10 formed in the lower bracket 7a. It conducts with the inside of the motor frame 5. The lower end of the motor shaft 8 penetrates through the inside of the pump chamber 9 and is guided into the pump casing 1, and the pumping impeller 11 is fitted therein. 12 is a circulation impeller mounted on the motor shaft 8 in the pump chamber 9, 13 is a lower oil feed pipe drawn out of the pump chamber 9 and opened to the lower part of the oil cooling pipe 4, 14 is the inner circumference of the motor frame 5 The motor stator 15 fitted to the surface is a motor rotor fitted with a certain gap in the motor stator 14. Oil such as transformer oil is sealed in the upper space A and the lower space B in the motor frame 5. The upper space A and the lower space B are connected to the motor stator 14.
The motor is connected to each other through an annular gap formed between fitting surfaces of the motor rotor 15 and an oil passage groove (not shown) provided in the motor stator 14 vertically. .

When the pump is driven, the rotation of the circulation impeller 12 causes the sealed oil in the motor frame 5 to move upward from below while absorbing the heat generated by the motor and the bearings. However, the oil flowing down the oil cooling pipe 4 while being cooled by the pumping water passing through the discharge pipe 3 is returned to the pump chamber 9 through the lower oil supply pipe 13, and is again returned to the motor and the motor inside the motor frame 5. The oil heated by absorbing the heat generated by the bearing moves upward, and is cooled in the oil cooling pipe 4, and the lowered oil is returned to the pump chamber 9 through the lower oil feed pipe 13 and further into the motor frame 5. The circulation action of being sent in occurs.

[0011]

According to the present invention, even under conditions where scale or sludge adheres to the surface of the motor frame, or the pump must be used with the motor frame exposed to the air, It works effectively without impairing the cooling function of the motor and the bearing. Therefore, the capacity of the motor to be used suffices to match the pump load, and there is an advantage that the product can be reduced in size and manufactured at low cost without using a particularly large-capacity motor as in the prior art.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a vertical electric pump provided with the device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump casing 3 Discharge pipe 4 Oil cooling pipe 5 Motor frame 6 Upper oil feed pipe 7b Lower bearing 9 Pump chamber 12 Circulation impeller 13 Lower oil feed pipe

Claims (1)

[Claims] An oil seal structure is provided inside a motor frame erected on a pump casing, a pump chamber is provided immediately below a lower bearing of the motor and communicates with the motor frame, and a circulation impeller is provided therein. The outer periphery of the discharge pipe extending upward from one side is surrounded by an oil cooling pipe, and the upper oil feed pipe led out from the upper part of the motor frame is opened to the upper part of the oil cooling pipe and led out of the pump chamber. A motor cooling device for a vertical electric pump, characterized in that the lower oil feed pipe is opened below the oil cooling pipe.