Brushless electric micromotor

Claim 1

A brushless electric micromotor comprising a rotor having a shaft, a tube-like member of a magnetic material on said shaft and permanent magnets mounted on said tube-like member, said shaft, said tube-like member and said magnets being rotatably mounted in a hermetically sealed in a rotor housing, said shaft being supported at its opposite ends in bearings mounted in said housing, said permanent magnets having outer surfaces coated with a layer of an electrically conductive metal, said permanent magnets extending beyond one of the ends of said shaft and the bearing supporting said shaft end and forming a magnetic drive for a second shaft magnetically coupled thereto and a stator unit co-axially surrounding said rotor housing, said stator unit having a housing of magnetic material and field winding coils in said magnetic material stator housing arranged regularly in said stator housing coaxially around said rotor with equal angular distances between said coils, said coils being embedded in insulating material, the hermetically sealed rotor housing being provided with a recessed end forming an axial, cylindrical cavity facing to the outside, and the end of said permanent magnets extend into a recess formed inside of said rotor housing by said recessed end and the outside wall of said housing, said end of said permanent magnets extending into said sleeve forming one part of a magnetic coupling for transmitting the torque of said rotor to said second shaft having a magnetic coupling counterpart.