Kone Oy

Kone Elevator Gmbh

Elevator Gmbh

Klaus Uuskoski

A method for reducing the starting current of a squirrel-cage motor and a squirrel-cage motor unit designed for implementing the method for reducing the starting current. The squirrel-cage motor stator winding of each phase comprises at least two insulated conductor elements connected in parallel and placed in the same slots. The conductor elements are divided into at least two parallel branches. During starting one or more branches are disconnected from the supply voltage while one or more branches are connected to the supply voltage. With this arrangement, the stator resistance increases during starting, so that the starting current decreases accordingly.

Procedure for reducing the starting current of a squirrel-cage motor,

An asynchronous motor is disclosed with stator and rotor windings placed in respective grooves, at least one of the windings being a cast winding. The grooves on the stator and those on the rotor are so inclined relative to each other that the groove inclination is approximately 60 to 90% of the pole pitch. In addition, to enhance the effect of the groove inclination, the stator and/or rotor is subjected, after the casting of the windings, to a heat treatment process in which the stator and/or rotor is heated to a high temperature and then cooled. The invention facilitates construction of an asynchronous motor having a reduced magnitude of generator torque of the motor and a changed rotational speed at which it occurs in relation to a conventional asynchronous motor.

Asynchronous motor and a procedure for the manufacturing of the stator

An electric motor, for instance for a hydraulic elevator, is entirely immersed within a liquid such as oil, and is provided with a flywheel. A drawback of this kind of electric motor is that the flywheel, rotating in oil, brakes the rotation of the motor. In the present electric motor the flywheel is enclosed in a housing and an air pipe extends to the housing so that by action of centrifugal force air is drawn into the housing, and liquid in the housing escapes from the housing through a discharge aperture when the motor starts.

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Hyvinkaa, Finland

Klaus Uuskoski