GB579656A - Hydraulic dynamometer - Google Patents

Abstract

579,656. Electric speedometers and dynamometers. CLINE, E. L. June 16, 1943, No. 9684. Convention date, May 20, 1942. [Class 40 (i)] [Also in Groups XIII, XIX and XXXV] An apparatus (see Group XIX) for testing motor-car engines comprises a speedometer and a dynamometer both operated from a roller 11 driven from the wheels of the car under test, the roller being connected through universal joints 94 to a shaft 56, Fig. 9, carrying arms 157 which rotate adjacent the poles of a permanent magnet 158 on the limbs of which are wound coils 352, 353, Fig. 15. The distance between the arms 157 and the magnet is adjustable. The coil 352 is connected to a speedindicating voltmeter 350 through a resistance 354, rectifier 355 and calibrating rheostat 358. A second rheostat 359 is brought into operation by a switch 361 and the voltmeter is graduated in two speed ranges accordingly. Dynamometer. The shaft 56, Fig. 8, driven from the roller 11 has fixed to it a disc with paddles 81 rotating in a casing 52 provided with vanes 70, Fig. 11, the casing being rotatably mounted on the shaft 56 by bearings 58, Fig. 8, in brackets 57 attached to the casing. To avoid vibration the number of paddles is different from the number of vanes. A torque arm 107, Fig. 4, secured to the casing 52 operates a rod 112, Fig. 13, carrying a dash-pot piston 119 acted upon by a spring 122, the movement of the rod 112 being proportional to the torque to be measured. The rod 112 moves a sliding contact 132 over a rheostat 128, Fig. 15, connected through a rectifier to the coil 353 of the speed-indicator generator G. The voltage from the rheostat 128 is dependent upon torque and speed and is thus proportional to horse power and is fed to a voltmeter 351 graduated in horse power. Two reading ranges are provided by bringing into circuit a resistance 371.