Patent ID: 7886840
Filing Date: 2011-02-15
Classification: F01D

Abstract:
1. A motor arrangement for a pneumatic tool including a work attachment, the motor arrangement comprising: a single-piece motor cylinder defining a motor chamber, an inlet passage having an inlet longitudinal axis and adapted to receive a flow of motive fluid, forward and reverse passages communicating with the motor chamber, a throttle port, and at least one exhaust port communicating with the motor chamber for exhaust of motive fluid from the motor chamber, the motor cylinder including an outer surface; a motor rotor supported for rotation within the motor chamber and having an output shaft adapted for connection to the work attachment to drive operation of the work attachment, the rotor being operable to rotate in a forward direction in response to motive fluid flowing into the motor chamber from the forward passage and in a reverse direction in response to motive fluid flowing into the motor chamber from the reverse passage; a valve actuable to selectively place one of the forward and reverse passages in communication with the inlet passage for the provision of motive fluid from the inlet passage to the selected one of the forward and reverse passages; a throttle mechanism including a throttle actuator extending through the throttle port and actuable to control the flow of motive fluid through the inlet passage; a motor housing mounted around the motor cylinder and valve, the motor housing including an inner surface facing toward the motor cylinder and valve and an outer surface facing away from the motor cylinder and valve; and an exhaust passage defined between the inner surface of the motor housing and the outer surface of the motor cylinder; wherein a majority of the exhaust passage extends substantially parallel to the inlet longitudinal axis.