US 4,395,649 AGranted

Linear electromagnetic vibrator

AssigneeRobert Bosch GmbH

InventorsLudwig Thome, Karl Wanner, Karlheinz Bretthauer

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Abstract

An electrically driven linear vibrator has swing drive for vibrating troughs, jarring tables or the like comprises a stator with an exciter winding, an armature guided for linear movement in a direction transverse to the field produced by the stator and a pair of oppositely acting return springs forming together a swing drive, the vibration of which may be used to drive a device connected to the vibrator. The return springs may be constituted by metal springs, gas springs or a combination of both. The swing drive may be constructed as single-acting or double-acting drives. A diode may be connected with the electrical conductors leading to exciter winding so that at a line frequency of 50 Hz, an oscillation frequency of 100 Hz, 50 Hz or 25 Hz may be obtained. The vibrator may also be provided with a piston blower for cooling the windings of the stator.

Claims31

Dependent claims

A linear electromagnetic vibrator comprising a stator having a pair of spaced poles having parallel planar end faces, said stator being composed of a stack of laminations extending parallel to each other and normal to said end faces of said poles;

a winding for said stator producing an energizing magnetic field extending in a first direction normal to said end faces;
an armature guided for linear movement in a direction transverse to said first direction to be moved upon excitation of said winding towards a rest position, said armature having opposite parallel faces extending parallel to the direction of movement of said armature and parallel to said end faces of said poles, said armature being composed of a stack of laminations extending parallel to each other and normal to said opposite faces of said armature and normal to the direction of movement of said armature whereas said stator laminations extend parallel to said direction of movement;
and a pair of return spring means acting in opposite direction on said armature for exerting at least in the end regions of the movement of the armature a force to said armature in a direction towards the rest position.

Dependencies are inferred from the claim text.