GB256277A - Improvements in or relating to methods of determining the out-of-balance of rotatingbodies in balancing machines - Google Patents

Abstract

256,277. International General Electric Co., Inc., (Assignees of Allgemeine Elektricitõts-Ges.). Aug. 3, 1925, [Convention date]. Testing balance of rotary apparatus. - Comprises a method in which the deflections of the rotating body are used to produce variations in the inductance or capacity in an electric oscillating circuit, so that the distance of the deflection caused by a marker in the record of an oscillograph from the deflection caused by the unbalance is used to determine the position of the unbalance. To determine the deflection of the rotary body a in the direction of the arrow b, a coil c is brought opposite to the periphery near this point. The coil together with a coil d and a condenser e form an oscillatory circuit of a valve transmitter. While the body is at rest, the anode current ammeter f is brought to zeroby a parallel arrangement including an electromotive force E and a resistance g. If now the body is rotated the deflections due to unbalance cause a periodic variation in the deflections of the ammeter owing to the varying air-gap between the body and the coil c. If now the measuring loop of an oscillograph be substituted for the ammeter, and a small marker comprising a piece of iron h be secured to the periphery of the body, the recording sheet of the oscillograph will be as represented in Fig. 2, and the distance " a " of the deflection caused bv the marker from that caused by the want of balance will give the position of the want of balance in the body. Instead of the coil c one plate of a condenser is substituted, the other plate being formed by the body a.