GB1320071A - Rotary vibrator - Google Patents

Abstract

1320071 Mounting rotors for dynamoelectric machines P U POULSEN 17 May 1971 [19 May 1970] 15370/71 Heading H2A [Also in Division F2] A rotary vibrator, comprising an electromotor connected to the object to be vibrated so that the vibrations of the rotor of the motor are transmitted to the object through the base of the vibrator via bearings for the rotor and the stator of the motor, has at least one end of the motor shaft journalled in a roller or ball vibration bearing of a type adapted to impart to the shaft a translatory movement of a frequency which is a multiple of the rate of revolution of the motor shaft. A vibration bearing of this type is described in Specification 1,295,847 and is illustrated diagrammatically in Fig. 2 (not shown). The vibrator illustrated in Fig. 3 has a stator 21, a rotor 22 and a shaft 13 journalled at both ends in vibration bearings 14 with the central member attached to the shaft 13 and the ring member 17 secured to the stator 21. Where stronger vibration than provided by shaft and armature is desired, additional masses (e.g. masses 12) may be placed on the shaft ends concentrically with respect to the shaft. By positioning the additional masses eccentrically, however, it is possible to obtain a lower frequency vibration superimposed on the vibration caused by the vibration bearings. The eccentricity of these masses may be adjustable. A greater clearance than normal must be provided between the armature and stator of the motor, and on account of the eccentricity of the translatory movement the distance between the two parts will always be greater at one side of the armature than at the other. This drawback can be overcome by using a motor in which the armature and stator are placed end to end. Only one vibration bearing may be used instead of two (Fig. 1, not shown) and the other end of the shaft is then journalled in an ordinary bearing which, however, must be able to permit a certain angular movement. In this case the rotor axis moves around a conical surface about the stator axis and only half the mass of the rotor can be calculated as rotating mass. Additional mass may be provided close to the vibration bearing and, as described above, may be formed concentrically or eccentrically according to the desired vibration.