GB2189087A - Improvements in or relating to rotor assembly for an electric machine - Google Patents

Abstract

Electric machine 12 has three superposed electromagnets 14, 15, 16 of a rotor arranged to have like poles facing rotary axis 13 and, another electromagnet 17 arranged to have like pole facing magnet 15. The rotor assembly may be between two parallel stator magnets 10, 11 having confronting like poles. AB are electrical input or output points. An alternative embodiment discloses an electromagnet magnet on outer side of the rotor axis. <IMAGE>

Description

SPECIFICATION Improvements in or relating to electrical apparatus This invention relates to electrical apparatus.

According to this invention, electrical apparatus comprises two stator magnets and a rotor assembly rotatable between the magnets about an axis of rotation, the rotor assembly comprising a plurality of superposed electromagnets on one side of the axis and electrically connected in series and arranged when energized to have magnetic poles of the same polarity nearer the axis, and an electromagnet on the opposite side of the axis electrically connected in parallel with the plurality of electromagnets and arranged when energized to have a magnetic pole of said same polarity nearer the axis.

There may be three superposed electromagnets.

The stator magnets may be parallel and with axes at right angles to the axis and having unlike magnetic poles nearest to each other.

The invention also includes electrical apparatus comprising two stator magnets and a rotor assembly rotatable between the magnets about an axis, the rotary assembly comprising two electromagnets respectively on opposite sides of the axis and electrically in parallel and arranged when energized to have like magnetic poles nearer the axis.

The invention may be performed in various ways and one specific embodiment with possible modifications will now be described by way of example with reference to the accompanying schematic drawings, in which: Fig. 1 is a plan view of electrical apparatus; and Fig. 2 is a side view of part of Fig. 1.

The electrical apparatus comprises two stator permanent magnets 10,11 (not shown in Fig. 2) which are parallel and with unlike poles nearest each other. Between the stator magnets is a rotor assembly 12 which can rotate on axis 13.

The rotor assembly 12 comprises, on one side of the axis, three superposed electromagnets 14, 15, 16 comprising respectively coils 14a, 15a, 1 6a wound in the same sense on respective armatures 14b, 15b, 16b and electrically connected in series. On the other side of the axis and in line with electromagnet 15 is electromagnet 17 having a coil 17a wound on armature 17b but arranged so that when current flows in the coils the electromagnets 15, 17 produce like poles facing each other. Coil 17a is in parallel with coils 14a, 15a, 16a.

Either the apparatus is operated as a motor, in which case electric voltage is applied at points A, B to cause the rotor assembly to rotate about axis 13; or the apparatus is operated as an electric generator, in which case a motor rotates the rotor assembly about axis 13 and electric current can be drawn from between points A, B.

The arrangement provides less resistance to rotation of the rotor assembly, for a given current produced or consumed, than an arrangement with a conventional rotor assembly and stator.

The electromagnet 17 is symmetrically disposed in reiation to magnets 14a, 15a, 16a.

1. Electrical apparatus comprising two stator magnets and a rotor assembly rotatable between the magnets about an axis of rotation, the rotor assembly comprising a plurality of superposed electromagnets on one side of the axis and electrically connected in series and arranged when energized to have magnetic poles of the same polarity nearer the axis, and an electromagnet on the opposite side of the axis electrically connected in parallel with the plurality of electromagnets and arranged when energized to have a magnetic pole of said same polarity nearer the axis.

2. Apparatus as claimed in Claim 1, comprising three superposed electromagnets.

3. Apparatus as claimed in Claim 1 or Claim 2, in which the stator magnets are parallel and have axes at right angles to said axis and having unlike magnetic poles nearest to each other.

4. Electrical apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

5. Electrical apparatus comprising two stator magnets and a rotor assembly rotatable between the magnets about an axis, the rotary assembly comprising two electromagnets respectively on opposite sides of the axis and electrically in parallel and arranged when energized to have like magnetic poles nearer the axis.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in or relating to electrical apparatus This invention relates to electrical apparatus. According to this invention, electrical apparatus comprises two stator magnets and a rotor assembly rotatable between the magnets about an axis of rotation, the rotor assembly comprising a plurality of superposed electromagnets on one side of the axis and electrically connected in series and arranged when energized to have magnetic poles of the same polarity nearer the axis, and an electromagnet on the opposite side of the axis electrically connected in parallel with the plurality of electromagnets and arranged when energized to have a magnetic pole of said same polarity nearer the axis. There may be three superposed electromagnets. The stator magnets may be parallel and with axes at right angles to the axis and having unlike magnetic poles nearest to each other. The invention also includes electrical apparatus comprising two stator magnets and a rotor assembly rotatable between the magnets about an axis, the rotary assembly comprising two electromagnets respectively on opposite sides of the axis and electrically in parallel and arranged when energized to have like magnetic poles nearer the axis. The invention may be performed in various ways and one specific embodiment with possible modifications will now be described by way of example with reference to the accompanying schematic drawings, in which: Fig. 1 is a plan view of electrical apparatus; and Fig. 2 is a side view of part of Fig. 1. The electrical apparatus comprises two stator permanent magnets 10,11 (not shown in Fig. 2) which are parallel and with unlike poles nearest each other. Between the stator magnets is a rotor assembly 12 which can rotate on axis 13. The rotor assembly 12 comprises, on one side of the axis, three superposed electromagnets 14, 15, 16 comprising respectively coils 14a, 15a, 1 6a wound in the same sense on respective armatures 14b, 15b, 16b and electrically connected in series. On the other side of the axis and in line with electromagnet 15 is electromagnet 17 having a coil 17a wound on armature 17b but arranged so that when current flows in the coils the electromagnets 15, 17 produce like poles facing each other. Coil 17a is in parallel with coils 14a, 15a, 16a. Either the apparatus is operated as a motor, in which case electric voltage is applied at points A, B to cause the rotor assembly to rotate about axis 13; or the apparatus is operated as an electric generator, in which case a motor rotates the rotor assembly about axis 13 and electric current can be drawn from between points A, B. The arrangement provides less resistance to rotation of the rotor assembly, for a given current produced or consumed, than an arrangement with a conventional rotor assembly and stator. The electromagnet 17 is symmetrically disposed in reiation to magnets 14a, 15a, 16a. CLAIMS

1. Electrical apparatus comprising two stator magnets and a rotor assembly rotatable between the magnets about an axis of rotation, the rotor assembly comprising a plurality of superposed electromagnets on one side of the axis and electrically connected in series and arranged when energized to have magnetic poles of the same polarity nearer the axis, and an electromagnet on the opposite side of the axis electrically connected in parallel with the plurality of electromagnets and arranged when energized to have a magnetic pole of said same polarity nearer the axis.

2. Apparatus as claimed in Claim 1, comprising three superposed electromagnets.

3. Apparatus as claimed in Claim 1 or Claim 2, in which the stator magnets are parallel and have axes at right angles to said axis and having unlike magnetic poles nearest to each other.

4. Electrical apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

5. Electrical apparatus comprising two stator magnets and a rotor assembly rotatable between the magnets about an axis, the rotary assembly comprising two electromagnets respectively on opposite sides of the axis and electrically in parallel and arranged when energized to have like magnetic poles nearer the axis.