DESIGN OF THE LEVER AND REACTION BEAMS FOR THE UK TORQUE MACHINE

摘要

The IMEKO - XV, World Congress provided the opportunity to describe the design of the first UK national torque calibration machine. Torque is realised by a lever-deadweight system with the transducer under calibration mounted vertically. The vertical deadweight forces are converted to a horizontal torque using castored pulley bearings mounted on a reaction beam positioned underneath the lever beam. The two beams are of identical material construction, consisting of high modulus carbon fibre tubes with stainless steel end fittings and central boss. To provide confidence in the design and modelling of the composite lay-up to optimise material properties, a detailed finite element (FE) analysis of the lever beam and reaction beam were undertaken. The FE analysis considered the beam structures both singly and as a sub-assembly. The results predicted the deflection of the beam under self-weight and at the full torque application. In addition, the frequency responses of the beams and sub-assembly were analysed. During commissioning of the machine the lever beam and reaction beam deflections will be measured and the frequency response established to close the design loop with the FE analysis.