JP2000064980A - underwater pump - Google Patents

Abstract

(57) [Summary] [PROBLEMS] By using a simple structure to lubricate and cool a bearing under high load and high temperature conditions during operation of a large submersible pump, seizure and burnout due to the high temperature of the bearing are ensured. A submersible pump that prevents and allows the production of large specifications that were previously limited. SOLUTION: A rotary output shaft 11 having a rotary shaft 7 fixed to a rotor 6 of an electric motor 5, and a pump shaft 12 having an impeller 8 fixed thereto.
The two shafts 11 and 12 are connected to each other by a coupling 13 so as to be rotatable simultaneously outside the housing 3. Both ends of the rotary output shaft 11 are rotatably supported by grease-lubricated motor-side bearings 14 and 15, respectively, and the coupling 13 side and the impeller 8 side of the pump shaft 12 are oil bath lubricated outside the housing 3 respectively. The bearings 16 and 17 are rotatably supported by pump-type bearings 16 and 17, and the coupling 13 and the pump-side bearing 1 are provided outside the housing 3.
A lubricating oil tank 18 for oil bath lubrication of 6, 17 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submersible pump for pumping water by rotating an impeller by an electric motor.

[0002]

2. Description of the Related Art Conventionally, as a submersible pump, as shown in FIG. 2, a vertical cylindrical housing 3 installed in a pumping passage 2 on the inner periphery of a column 1 and a motor housing 4 of the housing 3 are housed. Motor 5, a series of rotating shafts 7 fixed to the rotor 6 of the motor 5, and an impeller 8 attached to the tip (lower end) of the rotating shaft 7, and the suction is performed by the rotation of the impeller 8. There is known a configuration in which fresh water is pumped to the pumping channel 2 and discharged.

In a conventional submersible pump, a series of rotating shafts 7 are rotatably supported in a housing 3 by grease-lubricated bearings 9 and 10 arranged above and below a rotor 6 of an electric motor 5. Therefore, the radial load generated by the rotation of the rotor 6 is reduced by the upper and lower bearings 9,
The weight of rotating parts such as the rotor 6, the rotating shaft 7 and the impeller 8 and the thrust load generated by the rotation of the impeller 8 are supported by the lower bearing 10.

[0004]

However, when the size of the pump is increased and the output of the motor 5 is increased, the calorific value of the motor 5 is significantly increased, and the heat storage of the bearings 9 and 10 is increased due to heat conduction. , The temperature of 10 increases.
Even if the bearings 9 and 10 become hot, the upper bearing 9 only supports the main shaft 7 under light load and high temperature conditions in which a radial load generated by the rotation of the rotor 6 is applied. We can respond enough. However, the lower bearing 10 is subjected to a severe load in which the radial load generated by the rotation of the rotor 6, the weight of the rotating parts such as the rotor 6, the rotating shaft 7, the impeller 8, and the thrust load generated by the rotation of the impeller 8 are applied. Since the rotating shaft 7 must be supported under high load and high temperature conditions, the grease lubrication type may cause seizure or burnout, which limits the production of large underwater pumps.

[0005] Therefore, in the case of a large underwater pump having a large output, the bearing 10 is lubricated by an oil bath lubrication system which is superior to the grease lubrication system in lubricating conditions, so that the lubricating oil has a function as a heat transfer medium. Thus, it is conceivable to actively cool the bearing 10 to suppress heat storage. However, the dry electric motor (dry motor) 5 has an air layer around the rotor 6 and the stator 6A, and has essentially the same structure as the land motor.
In a structure in which the lubricating oil is lubricated by an oil bath lubrication method, a sealing measure for preventing the lubricating oil from entering the motor accommodating section 4 must be taken. For this reason, the oil seal structure becomes considerably complicated, making it difficult to manufacture and assemble. In addition, there is a problem that the initial cost of the large submersible pump becomes unnecessarily high.

Accordingly, the present invention reliably lubricates bearings subjected to high load and high temperature conditions during operation of a large submersible pump by performing oil bath lubrication with a simple structure to prevent seizure and burnout due to high temperature of the bearings. It is another object of the present invention to provide a submersible pump capable of manufacturing a large-sized specification which has been conventionally restricted.

[0007]

In order to achieve the above object, a submersible pump according to the present invention comprises a housing installed in a pumping passage, an electric motor housed in a motor housing of the housing, and A rotating shaft fixed to the rotor,
An impeller fixed to the tip side of the rotary shaft outside the housing, and a submersible pump that discharges water sucked by the rotation of the impeller to the water pumping channel.
The rotating shaft is divided into two shafts, a rotating output shaft fixed to the rotor of the electric motor and a pump shaft fixed to the impeller, and these two shafts are connected to each other so as to be simultaneously rotatable outside the housing. A coupling, a motor-side bearing rotatably supporting both ends of the rotary output shaft, and a pump side rotatably supporting the coupling side and the impeller side of the pump shaft outside the housing, respectively. And a lubricating oil tank for lubricating the coupling and the pump-side bearing in an oil bath.

According to the present invention, the rotary shaft is divided into two shafts, the rotary output shaft fixed to the rotor of the electric motor and the pump shaft fixed to the impeller. The motor-side bearing that supports the shaft and the pump-side bearing that must support the pump shaft that is loaded under high load and high temperature conditions can be arranged in a shared role. For this reason, use grease lubricated bearings for the motor-side bearings.
The pump shaft uses an oil-bath lubrication type pump-side bearing that has better lubrication conditions than the grease lubrication type, and the lubricating oil in the lubricating oil tank has a function as a heat transfer medium, so that it can be actively cooled. Heat storage can be suppressed.

Further, since the lubricating oil tank for lubricating the coupling and the bearing on the pump side in an oil bath is provided outside the housing, it is possible to prevent the lubricating oil from entering the motor accommodating portion without taking measures for sealing a complicated structure. It can be reliably prevented.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. The same or corresponding parts as those of the conventional example described with reference to FIG.
FIG. 1 is a longitudinal sectional view of a submersible pump according to the present invention. In this figure, the submersible pump includes a vertical cylindrical housing 3 installed in a pumping channel 2 on the inner periphery of a column 1, and an electric motor 5 housed in a motor housing 4 of the housing 3.
The conventional main shaft 7 is divided into two shafts: a motor shaft (rotation output shaft) 11 fixed to the rotor 6 of the electric motor 5, and a pump shaft 12 fixed to the tip of the impeller 8 outside the housing 3. These two shafts 11 and 12 are connected to each other via a coupling 13 so as to be rotatable simultaneously outside the housing 3. The coupling 13 is constituted by a gear coupling or a spline coupling capable of absorbing a slight eccentricity and a slight axial movement.

On the other hand, both ends of the rotary output shaft 11 are rotatably supported in the housing 3 by grease-lubricated motor-side bearings 14 and 15, respectively. That is, the radial load generated by the rotation of the rotor 6 is supported by the motor-side bearings 14 and 15.

On the other hand, both parts on the coupling 13 side and the impeller 8 side of the pump shaft 12 are provided outside the housing 3 by oil bath lubrication type pump side bearings 16 and 17 which are more excellent in lubrication conditions than grease lubrication type. It is rotatably supported. That is, the weight of the rotating parts such as the pump shaft 12 and the impeller 8 and the thrust load generated by the rotation of the impeller 8 are supported by the pump-side bearings 16 and 17.

A lubricating oil tank 18 for lubricating the coupling 13 and the pump-side bearings 16 and 17 in an oil bath is provided outside the housing 3.

In the above configuration, when the electric motor 5 is energized, the rotary output shaft 11, the pump shaft 12, and the impeller 8 rotate simultaneously, and the water sucked by the rotation of the impeller 8 is pumped to the water pumping passage 2 and discharged. I do. In this operation state, the thrust load generated by the weight of the rotor 6 and the rotary output shaft 11 and the radial load generated by the rotation of the rotor 6 are supported by grease-lubricated motor-side bearings 14 and 15, and the pump shaft 12 and the impeller 8 are supported. The thrust load and the radial load generated by the weight of the rotating part and the rotation of the impeller 8 are oil-bath lubricated pump-side bearings 16 and 17.
Supported by.

That is, the rotating shaft 7 is connected to the rotor 6 of the electric motor 5.
The motor-side bearing 14 supports the rotary output shaft 11 to which a light load and a high temperature are loaded, since the rotary output shaft 11 is divided into two shafts, the rotary output shaft 11 fixed to the shaft and the pump shaft 12 to which the impeller 8 is fixed.
15 and the pump-side bearings 16 and 17 which must support the pump shaft 12 to which a high load / high temperature condition is loaded can be arranged in a shared role. Therefore, grease-lubricated bearings are used for the motor-side bearings 14 and 15, and oil-bath-lubricated pump-side bearings 16 and 17 are used for the pump shaft 12 with better lubrication conditions than the grease-lubricated type, and By providing the lubricating oil 18A in the lubricating oil tank 18 with a function as a heat transfer medium, the pump-side bearings 16 and 17 can be actively cooled to suppress heat storage and lubricate the coupling 13 with an oil bath.

Therefore, the size of the pump is increased and the motor 5
As the output of the motor 5 increases, even if the amount of heat generated by the motor 5 increases significantly, the pump-side bearings 16 and 17 are actively cooled to suppress heat storage, and the pump-side bearings 16 and 1 due to the high temperature are increased.
Since the seizure and burning of 7 can be reliably prevented, it is possible to manufacture a large-sized submersible pump, which was conventionally restricted.

In addition, since the lubricating oil tank 18 for lubricating the coupling 13 and the pump-side bearings 16 and 17 in an oil bath is provided outside the housing 3, the motor housing portion can be provided without taking measures for oil sealing of a complicated structure. 4 can be reliably prevented from entering the lubricating oil, so that the structure is prevented from becoming complicated, manufacturing and assembly are facilitated, and it is possible to contribute to the realization of the cost reduction of the large submersible pump. it can.

[0018]

According to the present invention, a grease lubricated bearing is used for a motor-side bearing supporting a rotary output shaft to which a light load and a high temperature are loaded, and a pump-side bearing to which a high load and a high temperature condition are loaded is used. Uses oil-bath lubricated bearings with better lubricating conditions than grease lubricated ones, and allows the lubricating oil in the lubricating oil tank to function as a heat transfer medium, thereby actively cooling the pump-side bearings and suppressing heat storage. Also, since the coupling can be lubricated, the pump becomes larger and the output of the motor increases, so even if the heat generated by the motor increases significantly, the pump-side bearings are actively cooled to suppress heat storage. In addition, since seizure and burning of the pump-side bearing due to high temperature can be reliably prevented, it is possible to manufacture a large-sized submersible pump which has been limited in the past. In addition, since the lubricating oil tank that lubricates the coupling and the bearing on the pump side in an oil bath is provided outside the housing, it is ensured that the lubricating oil enters the motor housing without taking measures for oil sealing of a complicated structure. Since this can be prevented, the structure is prevented from being complicated, the manufacturing and the assembly are facilitated, and the cost of the large submersible pump can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a conventional example.

[Explanation of symbols]

 2 Pumping path 3 Housing 4 Motor housing 5 Motor 6 Rotor 7 Rotary shaft 8 Impeller 11 Rotary output shaft 12 Pump shaft 13 Coupling 14 Motor side bearing 15 Motor side bearing 16 Pump side bearing 17 Pump side bearing 18 Lubricating oil tank 18A Lubrication oil

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 7/14 H02K 7/14 BF Term (Reference) 3H022 AA01 BA06 BA07 CA04 CA07 CA12 CA17 CA18 CA19 CA20 CA43 CA44 CA45 CA47 CA48 CA59 DA01 DA02 DA07 DA17 DA18 DA19 DA20 3J011 JA02 KA02 MA21 MA23 5H607 AA01 AA02 BB01 BB14 BB25 CC01 CC03 CC05 DD03 DD07 DD08 EE31 FF06

Claims (1)

[Claims] 1. A housing installed in a pumping passage, a motor housed in a motor housing of the housing, a rotating shaft fixed to a rotor of the motor, and a tip end of the rotating shaft outside the housing. With a fixed impeller,
In a submersible pump that pumps water sucked by the rotation of the impeller into the pumping channel and discharges the water, a dual output shaft including the rotary shaft fixed to a rotor of the electric motor and a pump shaft fixed to the impeller. A coupling that connects these two shafts to each other so as to be rotatable simultaneously outside the housing, a motor-side bearing that rotatably supports both ends of the rotary output shaft, A pump-side bearing that rotatably supports the coupling side and the impeller side of the pump shaft, and a lubricating oil tank that lubricates the coupling and the pump-side bearing with an oil bath is provided. Characterized submersible pump.