SELF-BRAKING SCREW JACK WITH AXIAL ELECTRIC MOTOR

摘要

FIELD: lifting devices.;SUBSTANCE: invention relates to screw jacks and serves for cargo lifting and lowering with an automatic stop and latching after disconnection of supply voltage. Self-braking screw jack with axial electric motor comprises housing consisting of upper and lower bearing shields motionless fixed to each other, in inner annular cavity of which there is an axial asynchronous one-stator, single-rotor electric motor, wherein the stator magnetic conductor with excitation winding located in its slots is fixed from the inner end face of the lower bearing shield, and the brake pad comes into contact with the upper end surface of the rotor and is motionless fixed on the brake disk fixedly mounted on the inner end side of the upper bearing shield. Rotor can axially move along the nut. Rotor winding is phase, the ends of phases of which are connected to contact rings located on outer side surface of rotor on one level with brushes with brush holder, which is motionless fixed on external side of upper bearing shield. Thickness of the contact rings located on the rotor is made considering the axial movement of the contact rings with the rotor disc relative to the brushes. In inner cavity of shell there is a two-stage transmission, with possibility of transfer of rotary moment from rotor through large central gear wheel with internal teeth, made in upper inner surface of shell, double gears to small central gear wheel with external teeth fixed on nut.;EFFECT: possibility to increase jack lifting capacity due to reduction of rotation speed and increase of torque acting on nut, increase of starting moment of jack drive motor, increase of positioning accuracy and expansion of its application sphere.;1 cl, 5 dwg