Abstract
This paper is concerned with the design and the test results of a new transmission dynamometer for the purpose of measuring static as well as dynamic torque, rpm and power of a shaft in the speed range from 0 to over 10, 000rpm. A torque and rpm transducer consists of two detecting disks fixed to the shaft (torsion bar) separated from each other by an appropriate distance, and facing them two auxiliary detecting disks fixed to a connecting pipe which rotates concentrically to the shaft with constant speed. These four disks, formed to be the same size, are made of non-magnetic material such as SUS-32 stainless steel, and have 30 high permeance tips imbedded radially in their periphery. By the rotation of the disks, voltages are induced in the pick-up coils, which are wound upon the pole pieces of permanent magnets and are arranged to couple magnetically with the pairs of disks. Thus the transducer converts the torsion angle and the rotating speed of the shaft to the phase difference and the frequency of ac voltages.
As the frequency of the signal voltage is proportional to the sum of the rotating speed both of the detecting and the auxiliary disks, the measuring circuit of the dynamometer plays roles of subtracting the frequency corresponding to the rpm of the auxiliary disk from the signal frequency, and of measuring torque and rpm. Power is calculated from these two quantities using a simple electronic multiplier circuit.
Experimental results showed the feasibility of the dynamometer, with an accurary of ±2% or better of f.s. as a torque and a power meter, and ±0.5% as a ratating speed meter.
