JPS59138797A - Circulating pump with magnetically supported rotor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a circulating system for water and small thermal circuits, which includes a stator laminated core in a fixed position and a rotating magnetic field distributed over the entire circumference of the holes in the stator laminated core. The present invention relates to a type having a winding for generating windings and a rotor carried by a rotating magnetic field and supported at both axial ends.

Small circulation pumps with electric drive motors with an input P of less than 30 watts often experience problems during starting. This is because the bearing pins of the rotor, which are usually accommodated in ceramic bearings, must first of all be free from lifting. It is possible for particles to settle on the bearing or even to enter the air gap between the rotor and the stator.

It is therefore an object of the invention to develop a circulation pump in such a way that, despite the small dimensions of the drive motor and the resulting small gap values, reliable starting is ensured even if small foreign objects are deposited in the bearing gap. The purpose is to configure an electric drive motor.

In order to solve this problem, the present invention has a configuration in which, in the circulation pump of the type mentioned at the beginning, the outer peripheral surface of the rotor is cylindrical, and both bearing parts are connected to the rotor and formed as a rotating body. one permanent magnet, which is surrounded by at least an approximately constant radial gap by a stationary permanent magnet, which is also formed as a rotating body, and which belongs to the bearing location. Both permanent magnets are radially magnetized and face each other with equipolar magnetic pole faces.

A particularly small magnetic gap, which does not require further machining by grinding or the like, can be achieved if, as in an embodiment of the invention, the gap between the permanent magnets associated with each bearing location forms a truncated cone. , occurs if the base of the truncated cone is directed towards the associated rotor end face.

The invention will now be described in detail with reference to the drawings.

The illustrated circulation pump is designed for service water and includes a pump P with an axial inlet Z and a radial outlet A for the service water (see arrow) conveyed by a turbine wheel T. have.

This pump P is driven by an electric motor which operates according to the induction principle, which will be explained in more detail below.

FIG. 1 shows an exemplary embodiment of a circulation pump according to the invention with a magnetic bearing in a longitudinal section.

The annular step 6 in the casing 3 allows the winding 2
The stator 1 is pressed against the lower part of the casing and the casing 3
and are held together by a pressed-in thin plate tongue piece 5. By the pump casing 7 the outer race 9 of the magnetic bearing
The annular holding thin plate 8 that holds the non-magnetic slit tube 11
The shoulder 12 is pressed against the shoulder 13 of the slit tube 11. On the side facing away from the pump housing 7, the slotted tube 11 is closed off in a watertight manner by a pot-shaped bearing 1'4, which is welded or soldered to the other outer ring 15. Shaft end 17 of rotor 16
An inner race 18 of a magnetic bearing is fixed to the inner race 18 of the magnetic bearing.

In order to increase the residual magnetic induction of the permanent magnets, these permanent magnets are constructed from separate segments with magnetically favorable orientation.

In the embodiment shown in FIG. 2, the outer race 9.15 is made of elastic plastic 19. -20 and inserted into the slit tube 11. As shown in FIG. 2, the slit tube-side surfaces of the silastics 19, 20 have a suitable shape, making it possible to arrange the sealing rings 21, 22.

By virtue of the embodiment according to the invention, the rotor is supported without contact, so that there is no need to make any special arrangements for the electrical equipment with regard to the starting moment, and the electrical equipment can be designed solely from the point of view of continuous operation technology. It becomes possible. This results in smaller electrical equipment that saves energy compared to today's general purpose electrical equipment.

If a foreign object enters the air gap of the device, the rotor swings due to the flexibility of the magnetic bearing and then rotates freely again. Axial as well as radial guidance can be achieved by forming the bearing cavity surface in the form of a truncated cone. Furthermore, by suitably selecting the angle between the conical circumferential surface and the axis of rotation and the dimensions of the magnet surface, the load capacity and stiffness in the axial and radial directions can be determined.

Moreover, by supporting the rotor without contact, the noise of the circulation pump can be significantly reduced.

If necessary, it is also possible to fill the hollow space between the slit pipe and the casing with a synthetic resin with high thermal conductivity.
In this way, the formation of condensation, which could impair the reliable insulation of the windings, can be completely avoided. In addition, when the rotor is stopped, a screwdriver or similar device is used to move the rotor again.
The general-purpose screw cap provided on the casing part on the opposite side of the pump P in the P pump can be omitted by configuring it as in the present invention.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a circulation pump according to the present invention, and FIG. 2 is a longitudinal sectional view showing another embodiment of the circulation pump. Tostator, 2... winding wire, 3... casing, cow... lower part of casing, 5... thin plate tongue piece, 6°10
・Stepped portion, 7...Pump casing, 8...Holding thin plate, 9, 15・Outer race, 11...Slit pipe, 12・
... ξ Sokin, 13, collar, 14... Bowl-shaped support, 1
6 Rotor, 17... Shaft end, 18... Inner race,
19,20...Plastic, 21.22...Seal ring-A...Outlet, P...Pump, T...Turbine car, Z...Inlet (1 other person)

Claims (1)

[Scope of Claims] 1. A circulation pump for use water and a small thermal circuit, comprising: a stator laminated core with a fixed position; and windings distributed over the entire circumference of the holes of the stator laminated core to generate a rotating magnetic field; In a type having a rotor that is carried by a rotating magnetic field and supported at both shaft ends, (a) the outer circumferential surface of the rotor is cylindrical, and (b) both bearing locations are consisting of one permanent magnet connected to each other and formed as a rotating body, which permanent magnets are spaced apart by at least an approximately constant radial gap; A magnetically supported rotor surrounded by permanent magnets, characterized in that (c) both permanent magnets belonging to the bearing location are radially magnetized and face each other with equal polarity pole faces; 2. A circulation pump according to claim 1, wherein the ring-shaped bearing half made of permanent magnetic material consists of a plurality of isotropic frustoconical permanent magnet segments to increase the residual magnetic induction. Circulation pump. 3. A patent in which the bearing gap is formed by the peripheral surfaces of two truncated cones coaxial with the rotational axis of the rotor, and the bottom surface of the truncated cones is adjacent to the end surface of the stator laminated core. The circulation pump according to claim 2. 4. The peripheral surface of the truncated cone is at an angle of about 10° to 3° with respect to the rotational axis of the rotor.
The circulation pump according to claim 3, which forms an angle of 0°.