GB1461640A - Electronic measuring apparatus for assessing the noise p - Google Patents

Abstract

1461640 Testing gears W FERD KLINGELNBERG SOHNE GmbH 2 April 1974 [26 May 1973] 14622/74 Heading GIG Vibrations produced by two meshing gears are assessed by arranging respective angular accelerometers on the gear shafts, combining the two accelerometer ouput signals to derive the difference therebetween, and applying the difference signal via an amplifier to an optical indicator device or to a device for identifying or marking damaged gear teeth. In the Fig. 1 system, gears 1, 2 are on shafts 3, 4 which are driven and braked respectively. The difference between the outputs of angular accelerometers 8, 9 is formed at 14. The difference signal, after amplification and filtering, is fed to meter 20 and displayed on CRT's 21, 22. Pulses at the rotation frequencies of the shafts are obtained from sensors 11 and trigger the CRT time-bases. Each accelerometer comprises Figs. 2 and 3 a housing 23 for two diametrically opposed Piezo-electric elements 24, 25 inter-connected so that their combined output is independent of disturbing vibrations of the shaft which are not purely angular, and for preamplifier 26. Various modifications are described in which (a) the difference signal is applied to a Schmitt trigger circuit having a threshold which is lowered until a regularly repeating signal peak indicative of a faulty gear tooth exceeds the threshold and actuates a strobe lamp to illuminate the gears, (b) the signal exceeding the threshold is amplified and caused to mark the gear alongside the faulty tooth by spark discharge, or (c) the occurrence of the repeating signal peak causes storage of the corresponding angular position of the shaft or shafts Fig. 5 (not shown) as measured by a shaft angle encoder.