Patent ID: 9175645
Filing Date: 2015-11-03
Classification: F01D,F02B,F02M,Y02T

Abstract:
1. An electro-pneumatic actuator for a turbocharger waste gate, comprising: an actuator shaft having a first end and a second end and defining an axis extending between the first and second ends, the second end being arranged for connection to a waste gate; an electric actuator coupled to the actuator shaft, the electric actuator being structured and arranged to exert a force on and impart linear motion to the actuator shaft along a direction defined by the axis, for advancing and retracting the actuator shaft so as to adjust a position of the waste gate; a pneumatic chamber defining a passage extending therethrough, the actuator shaft extending through the passage, the pneumatic chamber being sealed with respect to the actuator shaft; a piston disposed in the pneumatic chamber and arranged for movement in the pneumatic chamber along said direction, the piston being affixed to the actuator shaft such that the actuator shaft and the piston move together as a unit; a port into the pneumatic chamber for feeding a gas into the pneumatic chamber or exhausting the gas therefrom so as to exert a pressure force on the piston and thereby provide a pneumatic assist to the force exerted on the actuator shaft; and a valve in communication with the port for selectively controlling the gas fed into or exhausted from the pneumatic chamber, wherein the electric actuator is operable for providing a position signal indicative of a position of the actuator shaft with respect to end points of a full stroke of the actuator shaft, and the pneumatic assist is provided for only certain parts of the stroke of the actuator shaft.