Controller for pneumatically-operated starter motor

摘要

The starter circuit is fully pneumatic. An air-powered motor (3) drives the sprocket wheel (10), and a pneumatic actuator (14,15) engages the sprocket (10) with the gear ring (18) on the engine flywheel. To overcome the problem of tooth misalignment and consequent failure to mesh (19,18) a by-pass circuit (35) is provided. This contains a pressure reducing valve (37) and 2/2-way valve (34). When the sprocket actuator (14,15) is activated through its air supply (25) and the teeth mesh a certain pressure results in the cylinder which activates the 2/2-way valve (34) which in turn closes the by-pass circuit (35). The main valve (21) opens and the motor runs up. - If the teeth do not mesh the piston travel (15) is limited and the cylinder pressure rises to a higher value. The relief valve in the by-pass operates. The cylinder pressure falls and the gears part. At the same time low pressure air spills into the motor transiently and the motor turns slowly for a short time. The gear teeth are then in a different position and a new attempt at starting can be made.