JP3386253B2 - Submersible pump with cooling water self-circulation device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submersible pump provided with a cooling water self-circulation device. 2. Description of the Related Art In a submersible pump, in a submersible pump, a part of discharge water is introduced into a cooling chamber on the outer periphery of the motor to cool the motor, and the cooled water is returned to the motor casing or to the outside of the pump. Cooling devices for draining are known. However, in the conventional cooling device which merely utilizes the negative pressure difference behind the blades, a sufficient circulation action is not generated, and in the case of a system in which cooling water is returned to the inside of the pump casing, a feed water passage and a return line are formed. If the role of the water channel does not function properly and the system is configured to discharge the water to the outside of the pump, the outlet may be closed, and the function of the feed water channel will be lost. [0004] Therefore, the cooling effect of the motor is poor, and the air expelling action in the cooling chamber at the time of starting the pump cannot occur. SUMMARY OF THE INVENTION It is an object of the present invention to properly perform the roles of the feed water channel and the return water channel, and to activate the cooling water circulation utilizing a part of the discharge water, thereby cooling the motor and removing the air. It is an object of the present invention to provide a submersible pump provided with a cooling water self-circulation device, which effectively performs the above. In the submersible pump provided with the cooling water self-circulation device according to the present invention, a lower fitting hole is formed so as to fit the outer edge of the back blade of the impeller from the central lower surface of the oil casing, and further comprises: An upper fitting hole concentric with the lower fitting hole and having a smaller diameter than the lower fitting hole is recessed so that the outer edge of the boss portion of the impeller fits, and is opposed to the upper half of the back blade from inside the lower fitting hole. A feed channel leading to the water cooling chamber above the periphery of the oil casing is drilled, and a return channel leading from the water cooling chamber above the periphery of the oil casing to the inside of the upper fitting hole is drilled, and an impeller is formed from the end of the return channel. A plurality of fixed sides formed by drilling a rainfall channel led down to the rear surface of the lower fitting hole from the lower portion of the inner peripheral surface of the lower fitting hole toward the lower surface so as to face the lower half of the back blade. Slots are arranged radially in the circumferential direction, and the lower fitting holes On the upper surface of the impeller in which the back blades to be fitted are arranged, a plurality of cutouts are provided so as to be in a closed state facing the lower part of the inner peripheral surface of the lower fitting hole and open in facing the fixed side slot. The rotating slots were arranged along the circumferential surface. When the impeller rotates, a part of the discharge water from inside the pump casing reaches the feed water channel by the upper half of the back blade, and cools the motor around the water cooling chamber. The water after cooling returns together with the air in the water cooling chamber, reaches the rotating side slot on the upper surface of the impeller from the water path through the rainfall path, and passes through the fixed side slot which matches the above rotating side slot by the lower half of the back blades, and the water inside the pump casing. Refluxed. An embodiment will be described below with reference to the drawings. Reference numeral 1 denotes a pump casing in which an impeller 2 is provided, 3 denotes an oil casing superposed on the upper surface of the pump casing 1, 4 denotes a motor frame which stands upright above the oil casing 3, and 5 denotes an outer periphery of the motor frame 4. An outer body 7 provided so as to form the water cooling chamber 6 is a motor housed in the motor frame 4, and a lower portion of the motor shaft 8 is guided through the oil casing 3 into the pump casing 1, The impeller 2 is fitted to the tip. Reference numeral 9 denotes a boss portion of the impeller 2, and reference numerals 10 and 10 denote back blades disposed on the upper surface of the impeller 2. Reference numeral 11 denotes a lower fitting hole recessed from the central lower surface of the oil casing 3 so that the outer edge of the back blade 10 # 10 fits. 12 denotes the lower fitting hole 11 so that the outer edge of the boss portion 9 fits. An upper fitting hole 13 which is concentric and concavely formed to have a smaller diameter than the upper fitting hole 13 is a feed water channel opened from the inside of the lower fitting hole 11 to the upper surface of the peripheral portion of the oil casing 3 in opposition to the upper half of the back blade 9. , 1
Reference numeral 4 denotes an elbow pipe which is attached to the outlet of the feed water channel 13 and is bent in the circumferential direction and opened to the lower part in the water cooling chamber 6. The return water channel opened by opening, 16 is a return water guide pipe which is erected at the entrance of the return water channel 15 and the upper end is opened upward in the water cooling chamber 6, 17 is the rear end of the impeller 2 from the terminal end of the return water channel 15 Is a rainfall channel formed inside the upper fitting hole 12 so as to be guided downward, and the upper edge thereof is gradually reduced in height so as to increase the pressure in the rotation direction of the impeller 2. It is desirable to be formed on the slope surface. A plurality of fixed side slots 18 # 1 formed from the lower portion of the inner peripheral surface of the lower fitting hole 11 to the periphery of the lower surface.
Except for the vicinity where the start end of the feed water channel 13 is opened, 8 grooves are arranged at regular intervals of 24 ° over substantially half a circumference in the circumferential direction at 24 ° intervals, and face the lower half of the back blade 9. On the upper surface of the impeller 2, a peripheral wall 19 that fits into the lower fitting hole 11 is protruded, and eight back blades 10 # 10, which are inscribed in the peripheral wall 19 and are taller than the peripheral wall 19, are spaced 45 ° apart. And the required portions of the peripheral wall 19 are cut away to form a plurality of rotation side slots 20 # 20, and these rotation side slots 20 # 20 are arranged at intervals of 22.5 [deg.]. In this embodiment, 16 grooves are provided according to the opening degree. And each rotation side slot 20 ‥‥
Reference numeral 20 denotes a closed state facing the lower part of the inner peripheral surface of the lower fitting hole 11 and an open state facing the fixed side slots 18 # 18, as described above.
Since there is a difference of 1.5 ° in the arrangement opening degree between the rotation side slot 20 and the rotation side slot 20, no matter how the rotation position of the impeller 2 changes, it is always possible to switch between the rotation side slot 20 and the rotation side slot 20. The fixed side slot 18 is in an open state,
It is not instantaneous that all the rotation side slots 20 # 20 are simultaneously closed. When the upper half of the back blade 9 faces the feed water channel 13, the lower half is blocked by the lower part of the inner peripheral surface of the lower fitting hole 11, and the lower half of the back blade 9 is fixed to the fixed side slot 18. When facing, the upper half is blocked by the upper part of the inner peripheral surface of the lower fitting hole 11. When the impeller 2 rotates, a part of the discharge water from the inside of the pump casing 1 reaches the feed water channel 13 by the upper half of the back blade 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 cools the motor 7 around the water cooling chamber 6. Then, the cooled water returns from the upper part in the water cooling chamber 6 together with the air, and the water guide pipe 1
6, the fixed side slot 1 matching the rotary side slot 20 # 20 on the upper surface of the impeller 2 by the lower half of the back blade 10 # 10 from the return channel 15 through the precipitation channel 17.
The gas is continuously refluxed into the pump casing 1 through 8 ‥‥ 18. According to the submersible pump provided with the cooling water self-circulation device of the present invention, when the upper half of the back blade 9 faces the feed water channel 13, the lower half is formed in the lower fitting hole 11. When the lower half of the back blade 9 is opposed to the fixed side slot 18, the upper half is blocked by the upper part of the inner peripheral surface of the lower fitting hole 11, so that the lower half of the back blade 9 is shielded. There is an advantage that the roles of the feed water channel and the return water channel are properly performed, the cooling water circulation utilizing a part of the discharge water is activated, and the cooling operation and the air purging operation of the motor 7 can be effectively performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional side view of a pump of the present invention. FIG. 2 is a side view of an impeller in the pump of the present invention. FIG. 3 is a plan 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 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 an inner peripheral surface of a first fitting hole and a second fitting hole formed in the oil casing in the pump of the present invention. FIG. 8 is an explanatory view showing a facing state of a fixed slot and a rotating slot in the pump of the present invention. [Description of Signs] 1 Pump casing 2 Impeller 3 Oil casing 4 Motor frame 5 Outer shell 6 Water cooling chamber 9 Impeller boss section 10 Back blade 11 Lower fitting hole 12 Upper fitting hole 13 Feeding water channel 15 Return water channel 17 Precipitation channel 18 Fixed side Slot 20 Rotation side slot

Claims (1)

(57) [Claims] An outer casing is provided so as to form a water-cooling chamber on an outer periphery of a motor frame which is provided above an oil casing on a pump casing, and water in the pump casing is a blade. In a submersible pump equipped with a cooling water self-circulation device that returns to the inside of the pump casing from the back of the blade after going around the water cooling chamber around the motor from the back, the lower fitting is performed so that the outer edge of the back blade of the impeller fits from the center lower surface of the oil casing. A recess is formed, and an upper fitting hole concentric with the lower fitting hole and smaller in diameter than the lower fitting hole is fitted so that the outer edge of the boss portion of the impeller fits. The feed water channel leading to the water cooling chamber above the oil casing periphery facing the upper half of the oil casing and the return water channel leading from the water cooling chamber above the oil casing periphery to the inside of the upper fitting hole are drilled. Forming a rainfall channel led down from the end of the return water channel toward the back surface of the impeller, and from the lower portion of the inner peripheral surface of the lower fitting hole toward the lower surface periphery so as to face the lower half of the back blade. A plurality of fixed side slots which are engraved are arranged radially in the circumferential direction, and an upper surface of the impeller provided with a back blade to be fitted with the lower fitting hole is provided at a lower portion of an inner peripheral surface of the lower fitting hole. The cooling water self-circulation device is characterized in that a plurality of rotating side slots engraved so as to be in a closed state facing the fixed side slot and open in a state facing the fixed side slot are arranged along the circumferential surface. underwater pump.