Abstract:
A piston type steam engine expander of the high speed, variable speed type having a poppet steam inlet valve and cylinder outlet ports and operable over a wide speed range on a throttled steam supply includes valve mechanism arranged to actuate the inlet valve through a fixed lift curve which provides a substantial change in effective steam cutoff at various speeds, as well as providing advantageous valve opening characteristics. Operating advantages similar to those of variable opening and closing inlet valves are provided by the use of a long valve open period including early opening and late closing of the valve, combined with unusually slow valve motion in the early stages of opening and the final stages of closing.
Abstract:
A gas turbine engine which may otherwise be of conventional configuration, single or plural shaft, regenerative or nonregenerative, is provided with a controlled bypass from the compressor to the turbine bypassing the combustion apparatus. Flow through this bypass is controlled so as to maintain the fuel-air ratio in the combustion chamber substantially constant notwithstanding variations in fuel flow and airflow with the load carried by the engine. Control of flow through the bypass may respond to setting of the fuel control device, to compressor discharge pressure, or to burner outlet temperature.
Abstract:
A gas turbine having a compressor and a turbine mounted on a single shaft and a throttle actuated fuel control responsive to parameters as compressor discharge pressure, engine speed and temperature to provide power increasing with engine speed as the throttle is advanced to a maximum limited by the fuel control. The engine drives a hydrodynamic torque converter having power absorption or capacity characteristics varying as a function of engine or input speed and substantially independent of output speed having variable pitch stator blades movable from a full power capacity position through a range of intermediate power capacity positions to a minimum power capacity position controlled as a function of throttle position and engine speed. When the throttle is in a closed position the fuel control provides starting or idle fuel feed and the stator control provides minimum capacity position of the stator blades for low drag during engine starting and low creep during engine idling. When the throttle is advanced to full throttle position the fuel control provides under steady state operating conditions power increasing with throttle advancement up to the maximum rated power and the stator control controls stator blade angle to provide torque converter capacity matching engine power. When the throttle is quickly advanced from some partial position to full throttle for maximum acceleration, the stator vanes are switched to an intermediate capacity position for acceleration up to maximum engine speed and then returned to the above steady state control mode.
Abstract:
A gas turbine engine connected to drive a motor vehicle includes valving to by-pass the regenerator of the engine when it is desired to decelerate the vehicle so that heat stored in the regenerator is not effective to provide positive power output from the turbine. The cold gas path of the heat exchanger only may be by-passed; or, compressed air may be diverted to atmosphere, by-passing the combustion apparatus, turbine and the entire heat exchanger. Opening of the by-pass is responsive to a request for zero or idling power output from the engine and to turbine rpm above a particular level.
Abstract:
A vehicle turbine of the gas-coupled type propels the vehicle through a change-speed transmission. To reduce vehicle acceleration time with an acceptable penalty with respect to fuel consumption, the compressor of the engine has variable inlet guide vanes which are shifted into a positive prewhirl angle at idling speeds when the transmission is shifted into a drive condition. Thus the engine gas generator has a low speed idle, with axially oriented guide vanes and normal air entrance, when the transmission is in neutral, and a high speed idle with positive prewhirl when the transmission is in drive condition. Also, the vanes are shifted at full speed of the gas generator to provide negative prewhirl and thus reduce the engine speed corresponding to maximum power output. Because of the higher idle and lower maximum speeds, the acceleration time of the gas generator, and thus of the power turbine, is reduced. Because positive prewhirl reduces compressor pressure ratio at the high speed idle, the power turbine does not have an undue tendency to cause creep of the vehicle in the high speed idle.
Abstract:
A condensable vapor engine, such as a steam engine, wherein the piston reciprocates between a top dead center position adjacent the closed end of the cylinder and a bottom dead center position in which vapor outlet ports are uncovered and the vapor escapes. The engine includes a valve located in the cylinder head and in communication with the source of vapor, this valve being disposed in a cavity having a cylindrical caging surface and facing a valve seat. The valve is arranged in spaced relation to the cylindrical surface so as to permit freedom of opening and closing movement and tilt, and the valve and valve seat define cone-to-sphere cooperating surfaces providing full seating engagement despite tilt of the valve body.