FR2541389A1 - CIRCULATION PUMP WITH ROTOR WITH MAGNETIC BEARINGS - Google Patents

Abstract

A. CIRCULATION PUMP WITH MAGNETIC BEARING ROTOR; B. PUMP CHARACTERIZED BY THE COMBINATION OF THE FOLLOWING MEANS: - THE PERIPHERAL SURFACE OF THE ARMCHAIR 16 IS CYLINDRICAL; -THE TWO SUPPORT POINTS 17 ARE EACH FORMED BY A PERMANENT MAGNET CONNECTED TO THE ARMBRIDGE 16 AND CONSTITUTES IN THE FORM OF A REVOLUTION BODY SURROUNDED BY A FIXED PERMANENT MAGNET ALSO CONSTITUTES IN THE FORM OF A REVOLUTION BODY, LEAVING THE LEAST APPROX. A CONSTANT RADIAL GAP; -THE TWO PERMANENT MAGNETS FORMING PART OF A SUPPORT POINT 13 ARE POLARIZED IN RADIAL DIRECTION AND ARE IN OPPOSITION BY CORRESPONDING POLAR SURFACES; C. THE INVENTION APPLIES TO LOW POWER PUMPS FOR DRINKING WATER.

Description

CIRCULATING PUMP WITH ROTOR WITH MAGNETIC BEARINGS -

  The invention relates to a circulation pump for drinking water and small heating circuits,

  provided with a stack of fixed stator laminations with

  distributed around its bore and producing a circular magnetic field, and a rotating armature which is driven by the magnetic field and is supported by

two ends of his tree.

  In the case of small circulating pumps with electrical drive motors, whose power consumption P is less than 30 Watts, there are frequently start-up problems, because firstly the trunnion of the armature which is often supported by a

  ceramic bearing, must be capable of being

  Aunt, and we then note in particular the inconvenience

  deny that, especially after a relatively long shutdown, plots of impurities are deposited in the bearing or mime may arrive in the ventilation slot between the rotor and

the stator.

  The object of the invention is to construct an electric motor for driving a circulation pump which

  despite its very small size and small values that.

  result for the ventilation slot, to be assured of a start being made with safety, even for the case where small foreign bodies would have deposited in

  the air gap of the bearings or the machine.

  The invention relates for this purpose to a circulation pump which is characterized by the combination of the following means: a) the peripheral surface of the armature is cylindrical; b) the two bearing points are each formed by a permanent magnet connected to the armature and constituted as a body of revolution, surrounded by a fixed permanent magnet also constituted as a body of revolution, leaving at least approximately a constant radial air gap, c) the S two permanent magnets forming part of a fulcrum, are polarized in the axial direction and are in opposition by polar surfaces

corresponding.

  A special magnetic air gap is obtained

  small, requiring no machining operation

  subsequent grinding or other rectification treatment

  when, according to one embodiment of the invention, the air gap between the permanent magnets belonging to each of the support points is formed by a truncated cone,

  whose base is turned towards the front face corresponding

of the armature.

  The invention will be better understood by means of

  the following description and the accompanying drawings represent

  two examples of embodiments of the invention, drawings in which:

  FIG. 1 is a longitudinal sectional view

  nale schematic part of the circulation pump according to the invention;

  FIG. 2 is a longitudinal sectional view

  similar partial example of another embodiment.

  The circulation pump shown is intended for drinking water and comprises a pump casing P with axial inlet Z and radial outlet A for the drinking water which is indicated by arrows and that pushes a turbine wheel T the pump P is driven by an electric motor running after

  the principle of induction, which will be described next

  below. FIG. 1 shows a section of the proposed magnetic bearing circulation pump, the stator 1 provided with the windings 2 is pressed against the lower part of the casing 4 by virtue of the annular shrinkage 6 that the casing casing 3 presents. in pressed sheet metal 5 maintain the cohesion of the housing portion 4 and the casing housing 3 Due to the constitution of the pump body 7 the annular support plate 8 provided for the outer support ring 9 is pressed against the shrinkage formed in the sheath of the antimagnetic motor 11 and the seal 12 is pressed against the collar

13 of the sheath.

  On the other side, the sheath of the motor 11 is closed in a watertight manner with the outer support ring 15 by means of a pot-shaped support 14 welded or brazed on the shaft ends 17 of the armature 16

  the inner rings 18 of the magnetic bearings are

  In order to increase the permanent induction of permanent magnets, these consist of segments

  Individuals with preferential magnetic direction.

  FIG. 2 shows an embodiment in which the outer support rings 9, 15 are embedded in elastic plastics material 19,

  20 respectively and housed in the sheath 11 of the engine.

  Thanks to a suitable conformation of the sheath-side surface of the plastic elements 19, 20, as shown in FIG. 2, a ring can be provided.

  sealing 21, 22 respectively.

  Thanks to the proposed solution, the armature can be housed and supported without contact, which has the effect that there are no particular requirements for the installation of the armature.

  the starting torque of the electrical machine

  that the realization of it can be made exclusively

  from a technical point of view

  This gives smaller machines that are economically

  energizing than those used today usually The rotor can, because of the flexibility

  of the magnetic bearing, perform balance movements-

  in case a foreign object enters the air gap

  of the machine and release it again.

  The formation of the surface of the air gap of the bearings in the form of truncated c 6 of revolution makes it possible to obtain axial as well as radial guides Thanks to an appropriate choice of the angle between the conical lateral surface and the axis of rotation, and thanks to the size of the magnetic surface it is possible to fix the load capacity and the rigidity in axial and radial directions. Due to the contact-free support of the rotor,

  this kind are distinguished by their silent nature.

  If necessary, we can sink into the

  empty space located between the motor housing and the housing a synthetic resin good conductor of heat in order to

  remove any formation of condensation water which

  would be detrimental to the insulation of the coil.

  LEMENT. As for the threaded lid which, for the most part

  pumps, is usually provided on the front of the casing-

  located opposite the casing pump through which, in the case of a blocking of the rotor, it can be put back into working condition by means of a screwdriver or other element

  analogous the proposed solution allows to remove it.

25413 i 9

Claims (2)

  ) Circulating pump for drinking water   low heat output, provided with a   rotor, a stack of stationary stator laminations with   distributed around its bore and producing a circular magnetic field, and a rotating armature which is driven by the magnetic field and is   supported at both ends of the shaft, a typical pump   characterized by the combination of the following means: a) the peripheral surface of the armature (16) is cylindrical b) the two bearing points (17) are each formed by a permanent magnet connected to the armature (16) and constituted by in the form of a body of revolution, surrounded by a fixed permanent magnet also constituted in the form of a body of revolution, leaving at least approximately a constant radial air gap c) the two permanent magnets forming part of a fulcrum (13) are polarized in the direction   radial and are opposed by corresponding ones.   2) Pump according to claim 1, characterized   characterized in that the halves of ring-shaped bearings made of permanent magnet material are composed, in order to increase the remanent induction, of permanent magnet segments in the form of truncated cones of revolution. isotropic s.   Pump according to claim 2, characterized   in that the bearing supporting the gap is formed   by the lateral surfaces of two trunks of c 8 do not co-   axial with the axis of rotation of the armature (16) and whose bases are close to the front faces of the stack from t 8 the stator.   Pump according to claim 3, characterized   in that the conical envelope forms with the axis of   the induces an angle of about 100 to 300.