GB1409343A - Rotary magnetic engine - Google Patents

Abstract

1409343 Electric motors operated by thermally produced changes of permeability A PIRC 29 June 1973 [24 July 1972] 31094/73 Heading H2A In a magnetic motor having two relatively movable members and including a magnetic shunt of gadolinium or thulium metal arranged in the form of flat laminµ, and in which the laminµ are periodically heated to a temperature above the Curie point of gadolinium or thulium so as to render the laminae non-magnetic and thereby permit a magnetic flux to cause relative movement of the two members, coolant passages are disposed adjacent the laminµ so as to allow coolant fluid to come into direct contact with the laminµ and thereby reduce their temperature below the Curie point when the heating is turned off. The rotor 14 of the motor shown has six permanent magnets 40-45 and the stator 11 has two permanent magnets 24, 25. Between the limbs of the stator magnets are placed respective flux shunts each comprising gadolinium or thulium laminµ 47, Fig. 3, supported in a grid structure 48 providing coolant passages 49 through which liquid nitrogen is continually pumped. As the rotor rotates, protrusions 88-93 on the rotor close switches 74, 82 to pass current through the laminµ 47 to heat them to a temperature above the Curie point. The laminae cease to act as magnetic shunts and the stator magnets then attract the rotor magnets. When the magnets are aligned, the switches 74, 82 open and the nitrogen cools the laminµ to a temperature below the Curie point, the laminµ again act as shunts for stator magnet flux and the rotor continues to rotate under its own momentum. The stator magnets are so disposed as to provide out-of-phase torques. The complete motor has a further rotor similar to the one shown and mounted on the same shaft. The further rotor interacts with a further stator similar to the one shown. The permanent magnets may be replaced by electromagnets and the gadolinium or thulium laminµ may be heated non-electrically.