DE7936693U1 - STAND FOR A BRUSHLESS ELECTRIC MOTOR - Google Patents

Description

Stand for a *> brushless electric motor

The innovation relates to a stand for a brushless one Electric motor with an axial air gap, with a stator winding that is coaxial to the axis of rotation and roughly U-shaped, the stator winding alternately in opposite radial directions and at equal angular distances overlapping pole pieces, which have end faces lying in a radial plane perpendicular to the axis of rotation.

In a known stand of this type, the pole pieces are made of metal sheets. The face! Of all even-numbered pole pieces are elongated rectangles. Within the laminated stacks of the odd-numbered pole shoes, the laminations are alternately 180 ° in With respect to a radial axis rotated so that its pole piece face consists of alternating short and long legs of the Sheets of a pole piece is formed and the circumferential extent of the odd-numbered pole pieces relative to the axis of rotation hliiabmims. To this Way it is possible to reduce the distance between the pole shoes to a minimum distance dependent on the air gap, without the to enlarge the outer circumference of the odd-numbered pole pieces and thus that of a rotor lying on the end face of the stator, so that their moment of inertia and flying forces can be kept small. However, this arrangement requires one

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Considerable effort in the assembly of the engine. Then surrender due to the stepped shape seen from the front, see the laminated core © of the odd-numbered pole pieces and the Reohteok shape the even-numbered Folso shoe relatively high wastage.

The innovation is based on the task of creating a stand of the genusgeattDen Specify the type, its structure while observing a minimum distance between the pole pieces in the circumferential order easier and is still more compact «

According to the innovation, this problem is solved in that the Front surfaces of all Poiaehuhe equal segments are the same "ring surface"

If this training of the pole pieces fell, the result was a more uniform one Distance in initial direction between all pole pieces and a larger area of the pole piece end faces, related to the desired torque of the motor. This results in a smaller one magnetic resistance in the magnetic circuits with correspondingly lower leakage losses, so that the diameter of the Stator or motor can be reduced to achieve the same torque. This in turn leads to savings in cooling copper and correspondingly lower heat losses. Likewise, lower flying forces occur.

Then it is favorable if the yoke cross-sectional areas of all Pole shoes are ring area segments and have the same area. The effective one, which is also determined by these yoke cross-sections Magnetic circuit resistance is therefore formed in each case by a magnetic circuit between two adjacent pole pieces Magnetic poles equal and correspondingly low, so that a uniform torque with even smaller losses and results in a correspondingly more compact structure.

The pole pieces are preferably made of magnetized

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Bare particles comprising material produced. this makes possible simply «catfish the formation of the segment shape of the pole shoes, la contrast to training from sheet metal, the different blanks should have.

The sintered pole shoes know the magnetizable particles potted in binder or the pole pieces pressed.

The drawing shows schematically a preferred embodiment a stator designed according to the innovation "seen in the direction of the axis of rotation of the rotor, not shown, and partly in cut.

The stator has eight approximately U-shaped pole shoes 1 to 8 made of material containing magnetizable particles, which are arranged at equal angular intervals on a circle. The legs of the odd-numbered pole pieces 1, 3, 5 »7 protrude radially inward and the legs of the even-numbered pole pieces 2, 4, 6, 8 protrude radially outward. The cross yokes 12 of the even-numbered pole shoes 2, 4, 6, 8 are located radially on the inside and the cross yokes 14 f of the odd-numbered pole shoes 1, 3, 5> 7 are located radially on the outside. All cross yokes 12, 14 extend in the axial direction (in the direction of the rotor axis of rotation). ;

The end faces 16 of all pole shoes are identical segments of the same annular surface. The | Right radial plane lying cross-sections of all cross yokes 12 § and 14 have largely the same area, the j cross-sectional areas of all radially inner cross yokes 12 with each other the same ring surface segments and the cross-sectional areas ■ of all radially outer cross yokes 14 are also with each other the same ring surface segments.

The rotor, not shown, has two rotatably on the rotor shaft arranged discs made of ferromagnetic !!! Material that on each of the end faces ^ I6>) of the stand. On the;

the end faces 16 of the pole shoes facing sides of the running notes are alternating at equal angular intervals North and south poles made of permanent magnet material.

The emerging from the end face of the pole piece 7, for example, The magnetic field formed by the stator winding 10 enters the facing side surface via the adjacent axial air gap of the associated rotor disk and again from the same side face opposite the end face 16 of the adjacent one Pole shoe θ from and into this end face 16. On the other axially At the end of the stator, on the other hand, this magnetic field exits at the end face 16 of the same pole piece θ and via the second The rotor disk is reinserted into the end face 16 of the pole piece 7. In this way, the transverse yokes 12, 14 each have two adjacent ones Pole shoes and the running disks have a magnetic circuit each one Stator pole closed.

Due to the circular segment shape of the pole shoes, they can be close to one another in the circumferential direction with only a small angular spacing so that the stator has a compact structure with low scattering losses. This enables the training of the Motor with a, in relation to the torque, small diameter; eer, which requires less copper wire for the stator winding 10 with correspondingly lower heat losses.

The magnetizable particles of the pole piece material can alone! magnetically soft iron or iron with additives such as nickel: cobalt and silicon. The pole pieces can therefore as Moldings are produced, for example by sintering, pressing! and casting with binder.

The pole shoes and the stator winding are held together by casting in synthetic resin (not shown).

Claims (6)

m III! DR.-ING. ULRICH KNOBLAUCH '- ·' Patent Attorney β frankfurt / main ι, December 24th 197! KÜHHORNSHOFWEG 10 KRi KÜHHORNSHOFWEG 10 POSTSCHECKKOiSTO FRANKFURT / M.3425-605 DRESDNER BANK. FRANKFURT / M. 23ΟΟ3Ο8 TELEPHONE: 56 IO 78 TELEGRAM: KNOPAT TELEX: 411877 KNOPA D DA 541 DANFOSS A / S. Nordborg protection claims 1. Stand for a brushless electric motor with an axial air gap, with a stator winding coaxial to the axis of rotation and approximately U-shaped, the stator winding alternating in opposite directions radial directions and at equal angular intervals overlapping pole pieces, which are perpendicular to the axis of rotation Have end faces lying in a radial plane, characterized in that the front heights (16) of all pole shoes (1 to 8) are identical segments of the same ring surface. 2. Stand according to claim 1, characterized in that the yoke cross-sectional areas (12, 14) of all pole shoes (1 l »is 8) ring surface segments and have largely the same area. 3. Stand according to claim 1 or 2, characterized in that the pole shoes (1 to 8) are made as moldings from material having magnetizable particles. 4. Stand according to claim 3, characterized in that the pole shoes (1 to 8) are sintered. 5. Stand according to claim 3 »characterized in that the magnetizable Particles are cast in binder. 6. Stand naoh Anepruoh 3 or 4, characterized in that the pole pieces are pressed. * * t I t t III! ι, • Il Il H