GB938383A - Improvements to ball-bearing test rigs - Google Patents

Abstract

938,383. Bearings. SOC. DE FABRICATION D'INSTRUMENTS DE MESURE. Aug. 3, 1960 [Aug. 4, 1959; July 1, 1960], No. 26967/60. Class 12 (1). [Also in Groups XIX and XXXVIII] In a test rig for bearings the bearing 24 is supported on an adaptor 23 located on the conical end 22 of an axle 21, which is in turn supported on diaphragms 25, 26. The outer race in turn supports an adaptor 41 and a bellshaped member 42. This latter is provided with a skirt 43 extending between a field magnet 31, provided with current form a multi-phase generator, and a field closing ring 33. The current through the magnet 31 can be varied in voltage and frequency, and in use the voltage is increased steadily until the bearing starts to rotate. The voltage required is a measure of the starting torque. The mean friction torque is given by the voltage required to maintain rotation. The vibration of the bearing is measured by the movement of a coil 38 mounted on an extension of the axle 21, the coil 38 passing through the air gap of a permanent magnet yoke 40. The coil 38 is connected by leads 39 to either a noise measuring instrument or to a loud-speaker. The speed of rotation of the outer race is sensed by a device consisting of a lamp 49 the light from which is reflected on to a photo-cell 48 by a mirror 47 twice during each rotation of the bearing. Additional weights 46 may be applied to load the bearing axially. In a second embodiment the bearing is housed in an evacuated chamber, thus eliminating errors due to air resistance.