GB714351A - Improvements in or relating to balancing machines for determining the running out-of-balance of rotary bodies - Google Patents

Abstract

714,351. Testing balance of rotary bodies. ROLLS-ROYCE, Ltd. Nov. 27, 1952 [Nov. 27, 1951], No. 27846/51. Class 106 (2). [Also in Group XXXVIII] A balancing machine for determining the running out-of-balance in a pair of spaced planes of a rotating unbalanced body, comprises axiallyspaced supports for the body and means adapted when the rotary body is stationary in the, supports, to produce oscillations of the supports simulating the oscillations that would be produced by a rotation of the body with a relatively large out-of-balance mass added to one of the planes. Thus the preliminary setting up operation, in which the out-of-balance indicating means is adjusted so that the out-of-balance in one plane does not cause an indication of out-of-balance in the second plane, can be performed without rotating the body and applying additional out-ofbalance masses. The. machine. Fig. 1, comprises massive end portions 10, joined by guide rods 11. Two cradles 13, adjustable along the guides by handwheels 13a. include supports 13b for the body to be balanced, the supports 13b being capable of oscillation in. a horizontal direction at right angles to the guides 11. The supports 13b are oscillated through rods 15 by a bar 14 which is mounted so as.to oscillate in a horizontal plane.' The oscillations are created by electric motors 16, Fig. 2, mounted on brackets 17 on the bar 14, the spindle of each motor carrying an out-ofbalance fly-wheel 19 which, on rotation, causes the bar 14 to oscillate. Only one motor at a time is used during the setting-up operation. The motors are not used during the actual testing of the body. The bar 14 is supported by a plurality of forked frames 21, each of which has its lower end clamped to a block 22. Gripped between the block 22 and the lower ends of the limbs are a pair of flexible steel strips 23, the upper ends of which are secured to a sliding block 24 mounted on a guide rod 25 supported by brackets 26 on the end portions 10. The bar 14 is thus free to oscillate in a horizontal plane. To rotate the body during the test for want of balance, a wheel 27 is clamped around the body near its centre of gravity, said wheel 27 being driven by a motor through suitable belt means 28 and 35. The bracket 17 may also carry a mounting 20 for the moving part of means not shown for producing electric signals corresponding to the oscillations of the nodular bar 14. The mountings 20 may carry the magnet of a moving magnet generator or a coil of a moving coil generator.