PNEUMATIC CENTRIFUGAL TACHOMETER MECHANISM

Shaft A of the tachometer is driven by the shaft whose speed is to be measured. The centrifugal force of weights 1 move piston 2 to the left in cylinder 3 which is filled with compressed air. The air is delivered into the cylinder by pump 4. The higher the angular velocity of the shaft being tested, the more piston 2 uncovers ports a of cylinder 3 and the less, consequently, the pressure in the cy…