GB1157264A - Car Test Bed - Google Patents

Abstract

1,157,264. Measuring speed and torque electrically. SUN ELECTRIC CORP. July 5, 1966 (July 16, 1965], No.30203/65. Heading G1N. A vehicle test bed has two rollers 13, Fig.2, on a shaft carrying an eddy current brake 20, and two rollers 14 mounted on a second shaft carrying a tachogenerator 18, a vehicle under test being arranged with one driving wheel engaging one roller 13 and one roller 14, and the other driving wheel engaging the second roller 13 and the second roller 14, the output of the tachogenerator being compared with a signal preset on a potentiometer 24 to represent a desired speed, and the brake being operated when the actual speed exceeds the desired speed so as to maintain the desired speed. The brake 20 is resiliently mounted and carries an arm (21, Fig. 1, not shown) which moves a potentiometer tapping 22 by an amount proportional to the torque developed, this being indicated on a meter 26. The test is carried out with the throttle of the vehicle fully open. A second meter 27 is connected across the tachogenerator to measure actual speed. In a second arrangement (not shown), a predetermined torque is set on a dial 30 and a corresponding electrical signal is developed and compared with the measured torque signal from the tapping 22, any positive difference being used to operate the brake to thereby maintain a constant torque. This enables simulated acceleration tests, etc., at constant torque to be carried out, the speed being measured at 27. The presetting controls 24, 30 are mounted with an amplifier 25 in a remote unit placeable within the vehicle, and a manual override may be provided for braking the vehicle. Cooling fans for the brake are provided (28, Fig. 1, not shown) and disc brakes (29) serve to retain the rollers while the vehicle is driven on to them.