GB2196187A - Improvements in or relating to rotor assemblies in electrical machines - Google Patents

Abstract

An electrical machine has stator poles 10, 11 with a rotor 15 having three superposed electromagnets 16, 17, 18 in series, wound in the same sense and in two of which the current flows in one radial sense and in the other the current flows in the opposite radial sense. <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 three superposed radial electromagnets on one side of the axis, the superposed magnets being wound in the same sense, two of the electromagnets being electrically connected in series, the current flowing in opposite radial senses in the two electromagnets.

The three electromagnets may be connected in series.

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 drawing which is a side view of electrical apparatus.

The electrical apparatus comprises two stator permanent magnets 10, 11 having unlike poles facing each other, the magnets extending away from each other. Mounted between the poles for rotation about an axis 12 at right angles to a line at right angles to pole faces 13, 14 is a rotor assembly 15. The assembly 1 5 comprises three equal superposed electromagnets 16, 17, 18 comprising radial coils 16a, 17a, 18a wound respectively on armatures 16b, 17b, 18b. The coils 16a, 17a, 18a are wound on their respective cores in the same sense and are electrically connected in series. The coils are connected so that the current in the coils 16a, 1 7a flows in the same radial sense (e.g. inwards) and in the opposite radial sense in coil 18a.

The apparatus is normally operated as an electric generator in which case a motor rotates the assembly 15 about the axis 12 and AC electric current can be drawn from between points A, B.

The magnets 16, 18 or 17, 18 could be interchanged.

The form of magnets 10, 11 could be different.

The assembly 15 is normally rotated anticlockwise as viewed in plan.

In some cases the apparatus could be operated as a motor.

It is considered that the induced emf in coils 16a, 17a when the assembly rotates in the magnetic field between poles 10, 11 is counteracted by the induced emf in coil 1 8a thus tending to reduce mechanical retardation on coils 16a, 17a.

The coil 1 8a may be larger than coil 1 6a or coil 17a.

The current could flow outwards in coils 16a, 17a and inwards in coil 18a, as shown.

1. Electrical apparatus comprising two stator magnets and a rotor assembly rotatable between the magnets about an axis of rotation, the rotor assembly comprising three superposed radial electromagnets on one side of the axis, the superposed magnets being wound in the same sense, two of the electromagnets being electrically connected in series, the current flowing in opposite radial senses in the two electromagnets.

2. Electrical apparatus as claimed in claim 1, in which the three electromagnets are connected in series.

3. Electrical apparatus substantially as here it before described with reference to and as shown in the accompanying drawing.

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

Claims (3)

**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 three superposed radial electromagnets on one side of the axis, the superposed magnets being wound in the same sense, two of the electromagnets being electrically connected in series, the current flowing in opposite radial senses in the two electromagnets. The three electromagnets may be connected in series. 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 drawing which is a side view of electrical apparatus. The electrical apparatus comprises two stator permanent magnets 10, 11 having unlike poles facing each other, the magnets extending away from each other. Mounted between the poles for rotation about an axis 12 at right angles to a line at right angles to pole faces 13, 14 is a rotor assembly 15. The assembly 1 5 comprises three equal superposed electromagnets 16, 17, 18 comprising radial coils 16a, 17a, 18a wound respectively on armatures 16b, 17b, 18b. The coils 16a, 17a, 18a are wound on their respective cores in the same sense and are electrically connected in series. The coils are connected so that the current in the coils 16a, 1 7a flows in the same radial sense (e.g. inwards) and in the opposite radial sense in coil 18a. The apparatus is normally operated as an electric generator in which case a motor rotates the assembly 15 about the axis 12 and AC electric current can be drawn from between points A, B. The magnets 16, 18 or 17, 18 could be interchanged. The form of magnets 10, 11 could be different. The assembly 15 is normally rotated anticlockwise as viewed in plan. In some cases the apparatus could be operated as a motor. It is considered that the induced emf in coils 16a, 17a when the assembly rotates in the magnetic field between poles 10, 11 is counteracted by the induced emf in coil 1 8a thus tending to reduce mechanical retardation on coils 16a, 17a. The coil 1 8a may be larger than coil 1 6a or coil 17a. The current could flow outwards in coils 16a, 17a and inwards in coil 18a, as shown. 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 three superposed radial electromagnets on one side of the axis, the superposed magnets being wound in the same sense, two of the electromagnets being electrically connected in series, the current flowing in opposite radial senses in the two electromagnets.

2. Electrical apparatus as claimed in claim 1, in which the three electromagnets are connected in series.

3. Electrical apparatus substantially as here it before described with reference to and as shown in the accompanying drawing.