Abstract: The invention relates to machines which determine the unbalance in a workpiece by rotating the workpiece and measuring the unbalance forces reacted into the machine frame. A drive arrangement is disclosed for rotating a spindle supporting the workpiece in such a machine for balancing vehicle wheels. The arrangement comprises a spindle housing for rotatably supporting the spindle and mounted on a base frame in a manner whereby the forces are reacted into a single direction and measured. The invention resides in the drive arrangement which includes speed changing means in the form of a worm gear on the spindle and a worm drive mounted on the spindle housing. A drive motor for driving the worm is mounted on the machine frame, that is, away from the spindle housing and drives the worm by means of a belt drive between a motor pulley and a pulley connected to the worm.

Abstract: The machine comprises a shaft mounted in a housing to rotate about a horizontal axis and arranged to carry the body of revolution in a concentric position. The shaft is also capable of oscillating in the housing about a vertical axis intersecting the horizontal axis near to an end of the shaft. An elongated indicator member is mounted in the axial extension of the shaft by a ball articulation. A measuring scale is mounted on the housing adjacent the free end of the indicator member. A deviating element is adapted, in the course of rotation of the shaft, to come momentarily in contact with the indicator member so as to deviate the indicator member relative to the scale to an extent which is a function of the magnitude of the unbalance of the body of revolution. An arrangement is combined with the ball articulation for ensuring the remanence of the deviation. The deviating element is in the form of a cam rotatable by a driving motor about an axis parallel to the axis of the shaft.

Abstract: An apparatus for clamping and centering bodies during rotation for balancing with a body receiving plate which is mounted on a spindle and which has a pair of concentric flexible rings or gaskets mounted on the upper surface thereof to define, when the body rests on the rings, a vacuum chamber from which air is removed to lock the body in place by channels which extend through the plate and communicate with the vacuum chamber. A housing extends about and is connected to the spindle by bearings with the space between the housing and spindle communicating with the vacuum chamber and with a connection extending through the housing for removing air from the vacuum chamber. Extensions of the spindle and vent holes between the housing space and the bearing prevent a vacuum from being developed in the area of the bearings.