GB735673A - Driving device for belt drives - Google Patents

Abstract

735,673. Belt-tensioning devices. LEDER & CO., AKT.,-GES. April 2, 1953 [April 3, 1952], No. 9163/53. Class 80 (1). [Also in Group XXXV] An electric motor from which a drive is taken by means of a belt and a pulley 4 is pivotally supported on a single pedestal 9 by a ballbearing 7 whose axis is eccentric to the rotor axis so that the reaction on the stator tightens the belt, and the amount of eccentricity may be adjustable. A shield 6 of the stator casing is detachably fixed to the inner bearing race 10 by screws 11, Fig. 2, arranged on a circle eccentric both to the bearing and the rotor so that the amount of eccentricity of the stator on its pivotal bearing is determined by the position in which the shield 6 is bolted to the race 10. A bore 12 in the race 10 concentric with the screws 11 has a wavy inner surface whose indentations correspond with the curvature of a sleeve on the shaft 3. The balls 7 for the bearing races, which need not be accurately formed, are inserted through a radial opening closed by a cap 15 and are spaced by stays of oil-soaked material. The outer race may be integral with the pedestal 9. In a modification the shield 6 is adjustably clamped to the race 10 by bolts passing through four parallel slots in the shield. In modifications where the eccentricity is not adjustable the inner bearing race may be integral with the stator shield, or may be integral with, or secured to, a bracket supporting the stator. The rotor may carry an expanding V-pulley comprising a flange adjustably screwed on to the body of the pulley. Alternatively the rotor may have a cone pulley for flat or for V-belts. It is stated that the weight of the motor may be compensated by a counterweight or by springs, that stops may be provided to limit its movement, that a checking device may be provided to prevent its dangling in transport or during erection, and that a brake concentric with the bearing 7 may be provided to deaden its rocking, such brake comprising two smooth collars or discs having an oil film therebetween.