FR2532488A1 - ELECTRIC MACHINE, IN PARTICULAR FOR THE DRIVE OF A CIRCULATION PUMP - Google Patents

Abstract

A. ELECTRICAL MACHINE SERVING, IN PARTICULAR, FOR DRIVING A CIRCULATION PUMP. B. ELECTRICAL MACHINE CHARACTERIZED IN THAT STATOR 1 CONSISTS OF A BAND OF SHEET ROLLED ON EDGE, GOING FROM ONE END TO ANOTHER, AND WHOSE CONTIGUOUS COILS FORM SURFACES ENCLOSED OF CONES WITH BLOCKED ANGLES AND HAVE SEVERAL 3 GROOVES DISTRIBUTED IN PERIPHERAL DIRECTION AND OPEN TOWARDS THE GAP, THESE 3 GROOVES BEING CUT FROM THE BAND BEFORE WINDING AND CONTAINING RESPECTIVELY ONE OF THE WINDING PHASES THROUGH THE ENTIRE AXIAL THICKNESS OF STATOR 1 OF THE DIPHASE OR POLYPHASE WINDING OF THIS STATOR SERVING TO GENERATE A ROTATING ELECTROMAGNETIC FIELD. C. THE INVENTION CONCERNS ELECTRIC MOTORS FOR CIRCULATION PUMPS.

Description

ELECTRICAL MACHINE SERVING 2 IN PARTICULAR, FOR THE PURPOSE OF

MOTION OF A CIRCULATION PUMP

  The invention relates to an electric machine which serves in particular as a drive motor for a circulation pump, with a rotor in the shape of a half-sphere and an annular stator inducing this rotor, with a concave spherical recess in which the rotor is placed with respect to the stator with a spherical air gap extending over an imaginary sphere, a gap in which is disposed a non-magnetic cap separating the space of the stator from the rotor space, a spherical pivot being placed in the center of the sphere for an assembly of the rotor allowing tilting movements thereof. The documents DEEPS 1 463 800 (INT CL H 02 k, 46/06) and DE-PS 1 538 715 (H 02 K 49/00) disclose electrical machines with a sphere-shaped air gap which are intended for the training of circulation pump and which form a unit of

construction with such a pump.

In circulation pumps

  available on the market for domestic heating

  and water supply, the blocking of the rotor, after a prolonged shutdown, is a source of relatively frequent faults The causes of such failures are small foreign bodies which are deposited in the magnetic gap during the shutdown of the rotor. pump In the case of a circulation pump with a spherical rotor, this rotor when the pump is switched on, can make tilting movements around its spherical pivot placed in the center of the sphere and can thus evacuate the bodies air gap area When rotated without impediment, the rotor is stabilized by the magnetic forces in

  its preferential magnetic position.

  The invention aims to create an electric machine, of the type initially described, which is able to drive a circulation pump and which, for a small footprint and a good electromechanical efficiency, has a low iron expense.

of stator.

An example of realization of

the invention is described below.

  Figure 1 shows this example in axial longitudinal section; Figure 2 shows a variant

  of the rotor with respect to FIG.

  The electric motor shown with a spherical rotor consists of the stator 1 with a polyphase winding 2 which is embedded in grooves 3 The stator 1 is annular in shape and is made from a mild steel strip extending from one end to the other, and not shown in more detail, which is wound on edge on a core indicated by Before winding, the grooves 3 are stamped

  in the band with an identical cross-section

  relative to each other, taking into account the change in the diameter of the cores.

  coil for the stator strip starts at the

  Immediate sinage of the plane 21 delimiting the half-sphere forma of the core 20 The different windings of the band are closely joined to each other and constitute enveloped surfaces of

  cones that delimit with plane 21 of the half

  sphere an angle o (from about 15 to 20, so that an angle of c 8 does not obtuse from 180 -2 = to 150 It is found, at the same time, that the stator surrounds a recess according to the outer contour half-spherical core 20, recess in which is also housed a rotor 5 having an outer envelope shaped hemisphere In the stabilized operating position shown, the rotor 5 mounted on a spherical pivot 8 rotates around the axis of rotation A and may, in

  cases of necessity, to carry out movements of

  lement, around the center of the spherical pivot 8 placed at the intersection of the plane 21 and the A-axis, and thus evacuate possible foreign objects out of 1 Centerfer

  spherical between the rotor 5 and the stator 1.

  In the spherical air gap between the stator 1 and the rotor 5, there is disposed a spherical cap 4 in t 8, which is non-magnetizable or made of plastic material, which separates the internal space 6 c 8 té rotor

  the internal space 7 c 8 té stator of the electric motor.

  The rotor 5 forms a construction unit with the turbine 25 of a centrifugal discharge pump, not shown in detail and indicated only in half section. In the case of the embodiment shown in FIG. 1, the rotor 5 comprises a package of t 8 the iron 11 consisting of a

  stack of disks of 8 t and a cage of short

  circuit 26 casting aluminum in the manner of a short-circuit rotor when a rotating magnetic field is generated in the stator I by the two-phase winding or polyphase 2, the rotor 5 can be driven by this field and thus the circulation pump can

to be trained.

  In the case of the exemplary embodiment according to FIG. 1, the width of the rotor I measured in the direction of the axis A is about 55 to 600 per cent of the radius of the sphere indicated by r of FIG. 1 Thanks to the embodiment according to the invention of the stator 1, there is only a slight cantilever of the electric machine in the direction of the axis A, but, however, a stator of comparable dimensions spherical rotor drive motors known up to now, but noticeably more compact, which only slightly yields to those of electric motors with a

  induced in the form of drum not likely to tip.

  In the case of the example of

  According to FIG. 2, the rotor 5 comprises a bundle of iron rods 12 wound end-to-end from a strip, which is wound on the spherical outer shell 27 of the rotor and which is provided, in its through grooves, with a short-circuit cage

in situ casting.

  An embodiment of the rotor in the form of a hysteresis rotor is also conceivable.

Claims (3)

  1 Electrical machine used, in particular, for driving a circulation pump, with a rotor in the shape of a hemisphere and an annular stator inducing this rotor, with a concave spherical recess in which the rotor is located with respect to the stator with a spherical air gap extending over an imaginary sphere, air gap in which is disposed a non-magnetic cap separating the space of the stator from the space of the rotor, and with a spherical pivot placed in the center of the sphere for a rotor assembly for tilting movements, an electric machine characterized in that the stator (1) consists of a strip of plate rolled on edge, going from one end to the other and whose contiguous turns form enveloped surfaces of c 8 nes obtuse angles and comprise several grooves (3) distributed in the peripheral direction and open towards the air gap, these grooves (3) being stamped from the strip before winding t   and containing respectively one of the phases of   bearing traversing the entire axial thickness of the stator (1) of the two-phase or multiphase winding of this stator for generating a field electromagnetic rotating. 2 electric machine according to   claim 1, characterized in that the sur-   envelope faces of c 8 nes delimit a cone angle of 1800 2 t <, where <is between 100 and   250 and preferably from 150 to 17.50.   Electric machine according to claim 1 or 2, characterized in that the strip constituting the stator (1) is wound on   a half-sphere constituting a core (20), the coil   the strip extending in the axial direction over an extent towards the cap, which is parallel to the plane (21) delimiting the hemisphere, and having a height (h) which represents   feels about 55 to 60% of the radius (r) of the sphere.