JPH02196199A - Vertical shaft centrifugal type electrically operated pump - Google Patents

Abstract

PURPOSE:To attempt to prevent damage of an impeller and mechanical seal by providing a suction hole eccentrically positioned from a cylinder-shaped separating chamber facing to the direction of tangent line, arranging that an influent in the separating chamber is forcibly rotated in a fixed direction, and separating chips, etc., that get mixed in a pump. CONSTITUTION:Upper and lower casings 2a, 2b are conjugated liquid-tight through an O-ring, and combined together by a bolt 12. And, an inner casing 7 for each of multistage impellers is provided to the lower casing 2b, and an impeller suction hole 4a of the inner casing 7 of the lowest end is connected to a separating chamber 11 formed in the lower end part of the lower casing 2b. Then, a suction hole 5 eccentrically positioned from the center of the lower casing 2b is provided so that it faces to the direction of tangent line in the separating chamber 11 in a cylinder shape, a groove 8 is provided at the outer circumferential part of the bottom surface of the separating chamber 11, and a drain hole 9 is provided on the wall surface of the separating chamber 11 of the part of the groove 8, and precipitated chips can be removed. Because of this, foreign matters are separated before they infiltrate into an impeller part or a shaft seal part to prevent damage of impeller and shaft seal device, etc., when foreign matters such as chips get mixed in a pump.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is a vertical centrifugal electric motor that prevents damage to shaft sealing devices caused by solid foreign matter such as chips in pumps that circulate cutting fluid in machine tools. Regarding pumps.

[Conventional technology]

The cutting fluid of a machine tool may contain solid foreign matter such as chips, which may damage pump members such as a shaft seal device and an impeller.

- Chips, etc. inside the shell are removed by installing a filter outside the pump, but they are not completely removed. Foreign objects may enter the pump and become caught in a gap between a rotating part such as an impeller and a fixed part such as a casing, or may damage a shaft sealing device such as a mechanical seal.

[Problem to be solved by the invention]

An object of the present invention is to provide a vertical centrifugal electric pump that separates the chips and the like in the pump and prevents damage to the impeller and mechanical seal even when foreign matter such as chips gets mixed into the pump. .

[Means to solve the problem]

This invention includes a shaft of an electric motor that penetrates through a shaft sealing device from the upper part of a casing provided with a discharge port, an impeller that is fixed to the shaft and has an impeller suction port facing downward, and communication with the impeller suction port. The casing is comprised of a cylindrical separation chamber provided at the lower end of the casing, the outer periphery of the bottom of which is lower than the center, and a suction port eccentrically located above the separation chamber and oriented tangentially.

[Effect]

Since the suction port is eccentric from the center of the cylindrical separation chamber and oriented tangentially, the liquid flowing into the separation chamber from the suction port is forced to rotate in a fixed direction. At this time, chips and the like, which have a higher specific gravity than water, are pushed to the wall surface of the separation chamber by centrifugal force, descend and settle on the outer periphery of the bottom of the separation chamber, and because the central portion is high, they are not sucked into the impeller.

〔Example〕

This will be explained with reference to FIGS. 1 and 2.

The vertical shaft centrifugal electric pump has a shaft 1a of a motor 1 that penetrates through a shaft sealing device 3 such as a mechanical seal from the upper part of a casing 2, which is composed of an upper casing 2a and a lower casing 2b, each having a discharge port 6, and this shaft. an impeller 4 which is fixed to the impeller 4 with the impeller suction port 4a facing downward; and the impeller suction port 4a.
The cylindrical separation chamber 11 is connected to the lower casing 2b and is provided at the lower end of the lower casing 2b, and the outer periphery of the bottom surface is lower than the center.

The upper casing 2a and the lower casing 2b are liquid-tightly joined via an O-ring and connected with bolts 12. The lower casing 2b is provided with an inner casing 7 for each impeller in multiple stages, and the impeller suction port 4a of the lowermost inner casing 7 communicates with a separation chamber 11 formed at the lower end portion of the lower casing 2b.

A suction port 5 is provided in a cylindrical separation chamber 1 so as to be eccentric from the center of the lower casing 2b so as to face in a tangential direction, and a groove 8 is provided in the outer periphery of the bottom surface of the separation chamber 11. A drain hole 9 is provided on the wall surface of the separation chamber 11 in the groove 8 section, so that settled chips can be removed.

A cylindrical flow path 7a is formed at the suction port of the inner casing 7, and a rectifying plate 7b is provided inside the flow path 7a to prevent the vortex flow in the separation chamber 11 from flowing directly into the impeller. This is done to ensure that the characteristics are not adversely affected. Even in the absence of the current plate 7b, the effect of separating foreign matter is not affected.

〔Effect of the invention〕

The vertical shaft centrifugal electric pump of the present invention includes: a shaft of an electric motor passing through a shaft sealing device from the upper part of a casing having a discharge port; an impeller fixed to the shaft with an impeller suction port facing downward; A cylindrical separation chamber that communicates with the impeller suction port and is provided at the lower end of the casing and has a bottom outer periphery lower than the center, and a suction port that is eccentric to the top of the separation chamber and extends tangentially. Therefore, even if foreign matter such as chips gets into the pump, it is effective in separating the foreign matter before it enters the impeller and shaft sealing device, thereby preventing damage to the impeller, shaft sealing device, etc. be.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the embodiment, and Fig. 2 is a sectional view taken along the line ■-■ of Fig. 1. 1a...shaft, 2...casing, 2a...upper casing, 2b...lower Casing, 4... Impeller, 5
... Suction port, 6... Discharge port, 11... Separation chamber. Figure 1, 2nd chapter

Claims (1)

[Claims] 1) An electric motor shaft that passes through the upper part of the casing with a discharge port through a shaft sealing device, an impeller that is fixed to this shaft and has an impeller suction port facing downward, and communicates with the impeller suction port. A vertical centrifugal electric pump comprising: a cylindrical separation chamber provided at the lower end of the casing, the outer periphery of the bottom of which is lower than the center; and a suction port eccentrically oriented in the tangential direction at the top of the separation chamber. .