JPH08100782A - Submergible pump provided with cooling water self circulating device - Google Patents

Abstract

PURPOSE: To perform casting allotment of a feed water passage and a return water passage so as to make cooling action and air purge action of a motor effective by providing some difference between arrangement openings of a fixed side slot and a rotating side slot. CONSTITUTION: When an impeller 2 is rotated, a part of discharging water from the inside of a pump casing 1 is led to a feed water passage 13 by the upper half part of a back impeller 10, it is fed from an elbow pipe 14 which is bending opened in circumferential direction toward the lower part of the inside of a water cooling chamber 6, and it is circled into the water cooling chamber 6 so as to cool a motor 6. Water after cooling is returned from the upper part in the water cooling chamber 6 together with air, it falls down the inside of a water inductive pipe 16, it passes from the return water passage 15 into a falling water passage 17, it passes a fixing side slot 18 which is agreed with the rotating side slot 20 of the upper surface of the impeller 2 by the bottom half part of the back impeller 10 so as to reflux into the pump casing 1 continuously. It is thus possible to perform casting allotment of a feed water passage and a return water passage suitably. And also a part of discharge water is utilized so as to enable cooling water circulation continuously.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a submersible pump provided with a cooling water self-circulating device.

[0002]

2. Description of the Related Art In a submersible pump, a part of discharge water is introduced into a cooling chamber around the motor to cool the motor, and the cooled water is circulated into a motor casing or discharged outside the pump. Cooling devices are known.

However, in the conventional cooling device which merely utilizes the negative pressure difference on the back side of the blade, a sufficient circulation action does not occur, and in the case of a system in which the cooling water is returned to the inside of the pump casing, it is connected to the feed water passage and the return pipe. If the method of discharging the water to the outside of the pump is not possible because the division of roles of the water channel does not function properly, the discharge port may be closed, and eventually the function of the water channel will also be lost.

Therefore, the cooling effect of the motor is poor, and the air erasing action in the cooling chamber at the time of starting the pump cannot occur.

[0005]

It is an object of the present invention to properly divide the roles of the feed water channel and the return water channel, activate the cooling water circulation utilizing a part of the discharge water, and make the cooling action of the motor and the air purging action effective. An object of the present invention is to provide a submersible pump having a cooling water self-circulating device.

[0006]

According to the present invention, in a submersible pump equipped with a cooling water self-circulating device, a lower fitting hole is provided so that an outer edge of a back blade of an impeller fits from a central lower surface of an oil casing, and a boss of the impeller is further provided. An upper fitting hole that is concentric with the lower fitting hole and has a smaller diameter than that of the lower fitting hole is recessed so that the outer edge of the part fits, and a feed water channel leading from the inside of the lower fitting hole to the water cooling chamber above the oil casing periphery is provided. At the same time as drilling, a return water channel that leads from the water cooling chamber above the oil casing to the inside of the upper fitting hole is drilled, and a precipitation channel that is guided down from the terminal end of the return water channel to the back surface of the impeller is drilled. A plurality of fixed slots, which are carved from the lower part of the inner surface of the lower fitting hole toward the lower surface periphery, are arranged radially in the circumferential direction, and the rear blades that fit into the lower fitting hole are arranged. On the upper surface of the installed impeller,
A plurality of rotation-side slots, which are engraved so as to be in a closed state facing the lower portion of the inner peripheral surface of the lower fitting hole and to be in an open state facing the fixed-side slots, are arranged along the circumferential surface, and The arrangement is such that there is a slight difference in the opening degree between the fixed-side slot and the rotating-side slot.

[0007]

When the impeller rotates, a part of the discharge water from the inside of the pump casing reaches the feed water passage by the action of the back blade and circulates in the water cooling chamber to cool the motor. The water after cooling reaches the rotation side slot on the upper surface of the impeller from the return water channel through the precipitation channel together with the air in the water cooling chamber, and continuously through the fixed side slot that matches the above rotation side slot by the action of the back blade. Is refluxed in.

[0008]

Embodiments will be described below with reference to the drawings of the embodiments.

Reference numeral 1 denotes a pump casing having an impeller 2 incorporated therein, 3 denotes an oil casing superposed on the upper surface of the pump casing 1, 4 denotes a motor frame standing above the oil casing 3, and 5 denotes an outer periphery of the motor frame 4. An outer shell provided so as to form a water cooling chamber 6, a motor 7 housed in a motor frame 4, and a lower portion of a motor shaft 8 penetrates the oil casing 3 and is guided into the pump casing 1. The impeller 2 is fitted to the tip portion thereof.

Reference numeral 9 denotes a boss portion of the impeller 2, and 10 ... 10 are rear blades arranged on the upper surface of the impeller 2. Reference numeral 11 denotes a lower fitting hole which is recessed so that the outer edges of the back blades 10 ... 10 are fitted from the central lower surface of the oil casing 3, and 12 is the lower fitting hole 11 so that the outer edge of the boss portion 9 is fitted. An upper fitting hole, which is concentric and has a smaller diameter than that, 13 is a feed water passage opened from the inside of the lower fitting hole 11 to the upper surface of the peripheral portion of the oil casing 3 so as to face the upper half of the back blade 9. 1
Reference numeral 4 denotes an elbow pipe attached to the outlet of the feed water passage 13 and bent in the circumferential direction to open downward in the water cooling chamber 6, and 15 directs from the upper surface of the peripheral portion of the oil casing 3 to the inside of the upper fitting hole 12. The return water channel is opened by 16 and 16 is a return water guide pipe that is erected at the inlet of the return water channel 15 and has an upper end opened to an upper part in the water cooling chamber 6, and 17 is a rear end of the impeller 2 from an end portion of the return water channel 15. It is a precipitation channel that is bored inside the upper fitting hole 12 so as to be guided toward the upper edge of the upper fitting hole 12. The height of the upper edge is gradually lowered so that the pressure increases in the rotation direction of the impeller 2. It is desirable to be formed on the slope surface.

A plurality of fixed slots 18 are formed by engraving the lower fitting hole 11 from the lower portion of the inner peripheral surface toward the periphery of the lower surface.
Numerals 8 are arranged in 9 grooves at equal intervals of 24 ° over almost a half circumference in the circumferential direction except near the opening of the start end of the feed water passage 13, and face the lower half of the back blade 9. A peripheral wall 19 that fits into the lower fitting hole 11 is provided on the upper surface of the impeller 2, and eight back blades 10 ... 10 that are inscribed in the peripheral wall 19 and are taller than the peripheral wall 19 are spaced at 45 ° intervals. 20 are provided, and the required portions of the peripheral wall 19 are cut away to form a plurality of rotation-side slots 20 ... 20. These rotation-side slots 20. 16 grooves are arranged at the opening. And each rotation side slot 20 ...
20 is in a closed state, facing the lower portion of the inner peripheral surface of the lower fitting hole 11, and is in an open state, facing the fixed-side slots 18 ... 18, but as described above, the fixed-side slots 18.
Since there is a difference of 1.5 ° in the opening degree between 18 and the rotation-side slots 20, ... The fixed side slot 18 of the
It is not instantaneous that all the rotating slots 20 ... 20 are closed at the same time. Further, when the upper half of the back blade 9 faces the feed water channel 13, the lower half is blocked by the lower portion of the inner peripheral surface of the lower fitting hole 11, and the lower half of the back blade 9 becomes the fixed side slot 18. When facing each other, the upper half portion is blocked by the upper portion of the inner peripheral surface of the lower fitting hole 11.

When the impeller 2 rotates, part of the water discharged from the pump casing 1 reaches the feed water passage 13 by the upper half of the back blades 10 ... 10 and from the elbow pipe 14 which is bent and opened in the circumferential direction. It is sent to the lower part in the water cooling chamber 6 and circulates in the water cooling chamber 6 to cool the motor 7. Then, the cooled water returns from the upper part in the water cooling chamber 6 together with the air to the water guiding pipe 1
6 through the return water channel 15 through the precipitation channel 17 and the fixed side slot 1 which matches the rotary side slots 20 ... 20 on the upper surface of the impeller 2 by the lower half of the back blades 10 ...
It is continuously refluxed into the pump casing 1 through 8 ... 18.

[0013]

According to the submersible pump provided with the cooling water self-circulating device of the present invention, when the upper half of the back blade 9 faces the feed water channel 13, the lower half is below the inner peripheral surface of the lower fitting hole 11. When the lower half of the back blade 9 faces the fixed-side slot 18, the upper half of the back blade 9 is blocked by the upper portion of the inner peripheral surface of the lower fitting hole 11. The division of roles of the return canals is properly done. Further, there is a slight difference in the arrangement opening degree between the fixed-side slots 18 and the rotating-side slots 20, so that no matter how the rotational position of the impeller 2 changes, any rotating-side slot 20 and any fixed-side slot will always be It is in an open state in which the slots 18 match each other, and all the rotation side slots 20 ...
Since 0 does not exist in the closed state at the same time,
The cooling water circulation using a part of the discharge water is continuously and actively performed without interruption even at one time, and the cooling action of the motor and the air expulsion action are extremely effective.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a pump of the present invention.

FIG. 2 is a plan view of an impeller in the pump of the present invention.

FIG. 3 is a side view of an impeller in the pump of the present invention.

FIG. 4 is a vertical sectional side view of an impeller in the pump of the present invention.

FIG. 5 is a vertical sectional side view of a lower half portion of an oil casing in the pump of the present invention.

FIG. 6 is a bottom view of an oil casing in the pump of the present invention.

FIG. 7 is a development view of inner peripheral surfaces of a first fitting hole and a second fitting hole provided in an oil casing in the pump of the present invention.

FIG. 8 is an explanatory view showing a fixed state slot and a rotation side slot of the pump of the present invention, which are opposed to each other.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump casing 2 Impeller 3 Oil casing 4 Motor frame 5 Outer case 6 Water cooling chamber 9 Imperabos part 10 Back blade 11 Lower fitting hole 12 Upper fitting hole 13 Feed water channel 15 Return water channel 17 Precipitation channel 18 Fixed side slot 20 Rotation side slot

Claims (1)

[Claims] An oil casing is provided on the pump casing, and an outer shell is provided so as to form a water cooling chamber on the outer periphery of the motor frame which is erected above the oil casing, and the water inside the pump casing flows from the back of the blades to the water cooling chamber on the outer periphery of the motor. After that, in a submersible pump equipped with a cooling water self-circulating device that recirculates from the back of the impeller to the inside of the pump casing, a lower fitting hole is formed so that the outer edge of the impeller back impeller fits from the central lower surface of the oil casing. The upper fitting hole, which is concentric with the lower fitting hole and has a diameter smaller than that of the lower fitting hole, is recessed so that the outer edge of the boss part fits, and is fed from the inside of the lower fitting hole to the water cooling chamber above the oil casing periphery. A water channel is formed, and a return water channel is formed from the water cooling chamber above the oil casing to the inside of the upper fitting hole, and the end of the return water channel is directed toward the back surface of the impeller. A lowering hole is formed by arranging a plurality of fixed-side slots that are drilled down from the lower fitting hole and are engraved from the lower part of the inner surface of the lower fitting hole toward the lower surface periphery. On the upper surface of the impeller in which the back blade that fits with the lower fitting hole is placed, the lower surface of the impeller faces the lower part of the inner peripheral surface of the impeller and is closed to face the fixed slot. The cooling water self-circulating device is characterized in that the rotation side slots are arranged along the circumferential surface, and there is a slight difference in the arrangement opening degree between the fixed side slots and the rotation side slots. Submersible pump.