JP2002098098A - Pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump capable of maintaining good balance of an impeller by canceling fluid force causing shaking of a shaft during rotation without providing a support blade or balance weight on the impeller to be used. SOLUTION: A magnet 6 is attached on a rotation side and a magnet 7 facing same pole to the rotation side magnet 6 is attached on a stationary side to generate an repulsion force between facing periphery surfaces of rotation side and stationary side in a pump casing 1. Shaft shaking of an impeller 3 caused by fluid force during rotation, thereby is cancelled by repulsion force of the magnet 6, 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump having a function of maintaining the balance of an impeller during operation, and is particularly effective for a pump using a single blade impeller or a bladeless impeller.

[0002]

2. Description of the Related Art As a countermeasure for maintaining the balance of an impeller during pump operation, a technical idea is to provide an auxiliary blade on the back surface of a shroud so as to maintain a hydraulic balance by the flow action of the auxiliary blade. Is known. However, the auxiliary blade does not produce the above-mentioned effect unless the blade width is made considerably large.Moreover, the auxiliary blade itself does not help the pumping action but rather significantly lowers the pump efficiency. It is not preferable to increase the size of the pump by the presence of the auxiliary blades.

[0003] As a measure for maintaining the balance of the impeller without using the above-mentioned auxiliary blades, it is widely practiced to provide a balance weight that balances the fluid force during rotation on the back surface of the shroud. However, when the impeller rotates, not only weight balance but also factors such as moment of inertia are added, so it is difficult to set the mounting position and weight of the balance weight. In addition, since the hydraulic imbalance force acting on the impeller has different load values depending on the operating point of the pump, when installing the balance weight, determine the operating point of the pump in advance and determine its mounting position and weight. Will do. In other words, the balance maintaining function only works effectively at a specific operating point, and if the flow rate becomes smaller or larger than this, the negative effect that the attached load amount causes the shaft runout is generated. It is.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pump having a function of maintaining the balance of an impeller, which can reduce a fluid force which causes shaft runout during rotation without providing an auxiliary blade or a balance weight. Is to do.

[0005]

In the pump of the present invention, a magnet is mounted on the rotating side so that a repulsive force is generated on the peripheral surface between the fixed side and the rotating side in the pump casing. An opposite magnet is mounted on the same polar surface, and the shaft runout of the impeller due to the fluid force during rotation is reduced by the repulsive force of the opposed magnet.

[0006]

During operation of the pump, the impeller in the pump casing rotates and a lateral pressure is applied to the pump shaft by the fluid force, but the repulsive force generated between the opposed peripheral surfaces of the fixed side and the rotating side in the pump casing. The lateral pressure is reduced, and the dynamic balance in the liquid is maintained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS.

1 is a pump casing of a centrifugal pump, 2 is a partition plate constituting an upper wall of the pump casing 1, 3 is an impeller housed in the pump casing 1, 4 is a blade plate, 5
Is a shroud. Reference numeral 6 denotes a magnet mounted on the rotating side such as the outer peripheral surface of the shroud 5, and 7 denotes a magnet mounted on a fixed side in the pump casing 1 such as a lower portion of the peripheral wall of the partition plate 2 so as to face the magnet 6 on the same polar surface. is there. The number of the fixed magnets may be one, but as shown in the drawing of the embodiment, a plurality of magnets 7 are arranged at equal degrees along the lower part of the peripheral wall of the partition plate 2. It is desirable to do. The mounting position of the rotating magnet 6 is set at a position where the fluid force acting when the impeller 3 rotates can be reduced by the repulsive force with the fixed magnet 7 as shown in FIG. A plurality of auxiliary magnets may be arranged on the outer peripheral surface of the shroud 5 with the magnet 6 as a main. .

[0009]

According to the present invention, the arrangement of the magnet between the fixed side and the rotating side opposed peripheral surfaces in the pump casing without attaching auxiliary blades or balance weights to the impeller used for the pump. Thus, regardless of the operating point, there is an advantage that the fluid force which causes the shaft runout can be reduced and the balance of the impeller can be maintained.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a main part of a pump casing in an embodiment of the pump of the present invention.

FIG. 2 is a cross-sectional view taken along line XX of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump casing 3 Impeller 6 Rotation side magnet 7 Fixed side magnet

Claims (1)

[Claims] 1. A magnet is mounted on a rotating side so that a repulsive force is generated on a peripheral surface between a fixed side and a rotating side in a pump casing, and the fixed side faces the rotating side magnet on the same polar plane. A pump, wherein a magnet is mounted so that shaft runout of the impeller caused by fluid force during rotation is reduced by a repulsive force of the opposed magnet.