A rotary electrical machine (1) comprising a plurality of disc-shaped stator stages (3, 5, 7) and a plurality of disc-shaped rotor stages (2, 4, 6, 8), each of the rotor stages (2, 4, 6, 8) being respectively alternately interleaved with the stator stages (3, 5, 7). A space (94, 96) is provided between each stator stage and its adjacent rotor stage. Each of the stator stages is provided with at least two stator windings, defining a passage (82, 84) therebetween adjacent windings. A coiled pipe (100, 102 - Figures 3A and 3B) is disposed in or formed integrally with each of the passages (82, 84) in substantially the same plane as the stator stage, such that the outlet of one pipe (100) is coupled with the inlet of the pipe (102) disposed in the adjacent passage. In use, fluid, for example air, helium, water or oil is caused to flow around the coiled pipes (100, 102) in the passages between the stator windings. At the same time, cooling gas, for example, air or helium, is caused to pass through the stator-rotor spaces so as to cool the magnets (10), etc. and the retention hoops (18), etc. of the rotor stage as well as the outer surfaces of the stator stage. Alternatively, the stator-rotor spaces may be held under a vacuum.

Rotary electrical machines

Disclosed is a Segmented Coil Array "SCA" for use in rotary electromotive devices, such as motors and generators, which employ multiple coils (42, 44, 46) operating within an axial gap magnetic structure. Individual conductor coils have offset circumferentially extending portions (39) so as to allow interlocking of adjacent coils radially extending portions (37) to form a circular array in which all of the coils' working conductors, which are those in the axial magnetic field, can be oriented in the same plane. This construction allows minimum magnet gap spacing, thus, maximizing the available magnetic flux. The resulting SCA may easily be commuted as a three-phase motor, actuator, or generator. The invention also provides a structure whereby multiple coil arrays and associated magnetic rotors may be alternately stacked in layers so as to further increase the total coil working area within a motor or generator of a given diameter.

Interlocking segmented coil array

A compact miniature fan has an air-guidance housing of rectangular parallelepiped configuration. The housing has two opposite end walls and side walls. One end wall is provided with an air inflow opening. One side wall is provided with an air outflow opening. The other end wall comprises a base plate. Mounted within the housing is an electric motor of flat overall shape. The stator and rotor of the motor define a planar air gap. The stator includes a magnetically conductive flux-return structure mounted on the base plate and a stator winding comprised of a plurality of flat coils mounted on the flux-return structure. The rotation axis of the rotor extends in the direction from one to the other of the end walls of the air-guidance housing. A radial fan wheel is provided within the housing, mounted on and coaxial with the rotor of the motor.

Compact miniature fan

An electric water pump apparatus may include a body having a stator chamber and a rotor chamber therein, a stator having a hollow cylindrical shape and being disposed in the stator chamber and generating a magnetic field, wherein the stator fluidly insulates the stator chamber and the rotor chamber, a rotor disposed in the rotor chamber and enclosed by the stator, wherein the rotor is rotated by the magnetic field, and a pump cover connected to the body and forming a volute chamber therein, wherein the volute chamber and the rotor chamber are fluidly-communicated through a connecting hole formed to the body and a coolant is supplied to the rotor chamber through the connection hole, wherein the stator includes a stator groove formed in an inner circumference therein and the stator groove is fluid-connected to the rotor chamber and the volute chamber through the connection hole.

Electric Water Pump

A switched reluctance motor has groups of adjacent poles of the same polarity. A starting magnet is fitted to one side of one or more of the poles in one or more of the groups. The polarity of the magnet can be the same as that of its host pole. The starting magnet influences the rest position of the rotor when it is not being driven so that the rotor will not be in an orientation such that it will not start when the stator poles are energized.

Switched reluctance motors

The permanent magnet rotor of a brushless d.c. motor is provided with regions of reduced magnetization in the mid-portion of the poles and spaced from the pole gaps, these regions being offset towards the extremity of the rotor where a portion of the rotor extending beyond the air gap of the motor serves to control a Hall I C sensor for control of the current in the stator windings. The regions of reduced magnetization do not interfere with the rapid switching of the Hall I C, but in a cylindrical air gap motor reduce the axial thrust on the rotor resulting from the asymmetric extension of the rotor out of the air gap which is provided for commutation control. Since this thrust is of a pulsating character, its reduction is important and permits simpler bearings to be used for the rotor shaft. Apart from reducing the axial thrust, the pattern of magnetization above described reduces non-uniformity in the current flow in the windings and therefore also variation in torque during a revolution of the motor. The latter advantages are also obtainable with flat air gap motors.

Volker Schlicker

Papers

Brushless D.C. motor