SELF-BRAKING SCREW JACK WITH AXIAL 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 motor comprises body consisting of upper and lower bearing shields fixedly fixed to each other. In inner annular cavity of which there is an axial asynchronous one-rotor single-rotor 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. Braking pad comes into contact with upper end surface of rotor and is fixedly fixed on brake disc fixedly installed on inner end side of upper bearing shield. Rotor is made in the form of barrel with base in lower part, in which there is a through hole symmetric relative to axial line. In inner cavity of barrel 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 barrel, double gears to small central gear wheel with external teeth fixed on nut. In lower part of rotor base there is a ledge in which disc with possibility of axial movement of rotor along external side surface of disc, rotor is additionally conjugated with nut by means of radial-thrust bearing, inner ring of which is located in nut ledge, and external one is in ledge made in inner lower part of disc, besides, in the upper outer part of the disc there is a ledge, on the external side surface of which there is a spring, with one end resting against the upper surface of the ledge in the upper external part of the disc, and by the other end – in the lower surface of the rotor ledge. Distance between lower surface of ledge of disc in its lower inner part and upper end surface of disc is made considering that in absence of supply on excitation winding of stator magnetic conductor distance between end surface of magnetic conductor of stator and end surface of rotor base shall be equal to total value of working air gap and axial movement of rotor along external surface of disc.;EFFECT: possibility of increasing lifting capacity of jack by reducing rotation frequency and increasing torque acting on nut.;1 cl, 4 dwg