Lappeenrannan-lahden Teknillinen Yliopisto Lut

Ilya Petrov

Juha Pyrhönen

Jussi Sopanen

Chong Di

Eerik Sikanen

Ilkka Poutiainen

Valerii Abramenko

A variable reluctance position sensor includes a first element having magnetic sensor sections having excitation coils, first detection coils, and second detection coils, and a second element moveable with respect to the first element. An airgap surface of the second element is periodically meandering. When an alternating signal is supplied to the excitation coils, envelopes of alternating signals induced in the first and second detection coils are dependent on a position of the second element so that the envelopes have a phase shift with respect to each other. The number of the magnetic sensor sections is 1+nP/P, where Pis a spatial shift between successive magnetic sensor sections, Pis a spatial meandering period of the airgap surface, and n is an integer. The magnetic sensor section in addition to the nP/Pmagnetic sensor sections is suitable for compensating for unwanted effects caused by ends of the first element.

Variable reluctance position sensor

A stator of an electric machine comprises a stator core structure () and a stator winding comprising a plurality of stator coils (-) mechanically supported by the stator core structure. Each stator coil comprises electrical conductors and a cooling tube () for conducting cooling fluid in the longitudinal direction of the electrical conductors. The stator comprises cooling elements (-) having heat-conductive mechanical contacts with the stator core structure. The cooling elements comprise channels for conducting the cooling fluid, and the cooling tubes of the stator coils are connected to each other via the cooling elements. The cooling elements transfer heat caused by iron losses from the stator core structure to the cooling fluid. Furthermore, the cooling elements act as manifolds for conducting the cooling fluid between the cooling tubes of the stator coils.

Stator of an electric machine and an electric machine

A magnetic actuator includes a first element and a second element movable with respect to the first element in a movement direction. The first element includes teeth successively in the movement direction, two coils in slots defined by the teeth, and a permanent magnet. The second element includes teeth successively in the movement direction. The teeth of the first and second elements and the permanent magnet are arranged so that the second element is held by magnetic forces in each of three positions also when there are no currents in the coils. The second element can be moved between the three positions by supplying electric currents to the coils. Thus, the second element is held in any of the three positions also when current supply to the magnetic actuator is unintentionally lost.

Growing community of inventors

LAPPEENRANTA, Finland

Ilya Petrov