Abstract: A method and apparatus for a pressure control system for an actuator is provided. In one embodiment, the pressure control system may include a housing defining an upper chamber and a lower chamber, and a piston disposed between the upper and lower chambers. A valve may be coupled to the piston that is operable to control fluid communication between the upper chamber and the lower chamber. In one embodiment, a method of controlling over-pressurization of an actuator includes supplying a fluid pressure to a first chamber of an actuator having a piston and actuating the piston using the fluid pressure. The method may further include relieving the fluid pressure from the first chamber through a valve that is coupled to the piston when the fluid pressure exceeds a predetermined maximum pressure.

Abstract: The relief device is designed to divert a portion of a main flow toward a by-pass flow in a turbojet that includes a main flow stream, a by-pass flow stream and an intermediate casing. The relief device includes inner openings of the inner shroud, outer openings of the outer shroud, a relief circuit connecting the inner openings to the outer openings, and a blanking device capable of opening and closing the relief circuit. The relief circuit includes upstream holes of the intermediate casing, downstream holes of the intermediate casing, and an annular channel defined between the intermediate casing, the outer shroud and a connecting partition. The connecting partition rests on the intermediate casing so as to encompass the downstream holes of the intermediate casing in the annular channel and resting on the outer shroud so as to encompass the outer openings of the outer shroud in the annular channel.

Abstract: In a rotodynamic pump, a seal chamber conditioning valve mechanism is positioned at least partially within the seal chamber of the pump to selectively and intermittently deliver fluid to or discharge contents from the seal chamber to modify the condition or content of the seal chamber and effectively protect the mechanical seal from failure due to, for example, built up solids or the presence of air. The conditioning valve mechanism may be actuated by a control device in communication with monitoring apparatus that determines the condition of the seal chamber, and particularly the mechanical seal face.

Abstract: The present invention relates to an full-arc admission steam turbine having its output controlled by regulating the opening of a steam regulating valve. The full-arc admission steam turbine is run at a higher efficiency than that of the full-arc admission steam turbine of the prior art by improving the drop in the internal efficiency of the turbine due to the throttle loss of the valve. Moreover, a substantially constant high efficiency is maintained for the time period from the designed point of a partial load to the rated load if the second blade stage group is selected to provide an internal efficiency substantially equal to that of the blade stage group of the prior art.

Abstract: A rotating speed control system for a pneumatically driven spindle used in a machine tool, comprises a spindle possessing a male-threaded part, a turbine mounted on the spindle by a nut with a convexo-concave portion being formed in one face thereof, a casing for accommodating the spindle and the turbine, an air supply line connected to the casing so as to supply air to drive the turbine, a valve disposed in the air supply line so as to adjust the flow rate of the air to be supplied to the turbine, a sensor facing the convexo-concave portion of the nut so as to detect the rotating speed of the turbine, and a control circuit for comparing a sensor detected rotating speed with a predetermined rotating speed and for adjusting the valve in accordance with the difference between two rotating speeds, so as to reduce the difference.

Abstract: A turbine shutdown control system for controlling a turbine powering two load groups. Upon loss of one load group, a first control valve will close to interrupt the fluid flow to the turbine. A second modulating valve in parallel with the first valve remains open to provide sufficient fluid flow to the turbine to power the second load group.

Abstract: An exhaust gas turbo-charger for internal combustion engines of the type having turbine rotor blades rotatable about an axis and a vaned guide device located upstream of turbine rotor blades, which vaned guide device includes a butterfly valve, a main guide vane ring and an auxiliary guide vane ring. Each guide vane ring is provided with a mutually separate supply duct, and the butterfly valve controls exhaust gas flow to the auxiliary guide vane ring. The auxiliary guide vane ring is located radially inside of the main guide vane ring and the butterfly valve is located upstream of the auxiliary guide vane ring.

Abstract: A relief valve system for a pump in which control means are responsive to the occurrence of an excessive pressure on the inlet or discharge side of the pump to relieve this condition by dumping excess pressure to atmosphere.

Abstract: Temperature regulation of an air cycle refrigeration system is achieved by selectively adjusting the turbine stator geometry in response to the temperature of turbine airflow at a desired location. Such adjustment in stator geometry includes the selective positioning of a portion of the stator adjacent the turbine blades thereby controlling the amount of cooling produced by the turbine or the selective opening and closing of bypass ports provided in the turbine stator to control the flow of air through the turbine. Both of these adjustments in stator geometry are effected by an actuator comprising at least two members of differing coefficients of thermal expansion such as a bimetallic element.

Abstract: An apparatus for preventing a turbine from exceeding a predetermined value of a monitored physical magnitude, the apparatus including an over-center toggle lever (3) pivotally mounted on a pivot point (6) on a stationary frame (7), the lever being capable of occupying a tripped position or a released position. In the cocked position, one arm (4) of the lever (3) presses against a stop (8) provided with a unit (20) which controls steam admission units to the turbine, the lever (3) moves away from the stop, steam is cut off, while the end (14) of the other arm (5) is pivotally mounted on the end of a connecting rod (10) which is pivotally mounted at its other end on a pin (11) which is integral with a piston (12) which a spring (16) pushes away. A mass (2) strikes the lever (3) which moves to the tripped position if the monitored magnitude exceeds the predetermined value.

Abstract: A stall control system for axial flow compressors incorporating: a plurality of pressure transducers for developing signals indicative of the nonsteady pressure variations within the compressor and wherein these signals are separately filtered and rectified; analog comparators and gate comparators for each such signal to develop an output indicative of the difference between each of the signals and an adjusted pressure reference signal which is derived from the pressure rise across the compressor; a logic circuit for generating an actuating signal if any one of such signals is higher than the reference signal for controlling the opening of a gate which passes the combined pressure signals to an integrator which develops an output control signal to take corrective action in the presence of rotating stall within the compressor: an adjustable time delay circuit providing long and short decay times to prevent over-control.

Abstract: The disclosure illustrates a turbocharger wastegate valve comprising a cylindrical chamber connected through a radial inlet to the gas stream upstream of the turbine. High pressure air is selectively directed across the inlet through a nozzle to prevent or permit flow into the chamber which is connected to a point downstream of the turbine. The pressure of the air delivered to the nozzle may be varied to proportion the gases bypassed around the turbine.

Abstract: Surge control systems are provided for compressors which supply air to a pneumatic load. A signal proportional to the pressure ratio of the outlet pressure to the inlet pressure plus a selected reference pressure is compared to a measured weight flow rate of air through the compressor to provide a vent valve command signal. If the measured pressure ratio plus the reference pressure ratio exceeds the measured flow rate, a surge condition may ensue. The vent valve position command signal causes a venting valve to vent a portion of the air provided to the load, which reduces the measured pressure ratio and increases weight flow rate. During normal operation of the compressor, the vent valve command signal is zero for all values of weight flow rate. A transient control channel is provided which is responsive to the rate of change of the measured pressure ratio and/or measured weight flow rate.

Abstract: Surge control systems prevent and control a surge condition for fixed or variable speed compressors and compressors having variable geometry which provide air to pneumatic loads. A signal proportional to the ratio of the measured compressor outlet pressure to the measured inlet pressure is combined with a signal corresponding to a selected reference pressure to provide a vent valve command signal. When the signal representing the ratio of the measured pressure exceeds the signal corresponding to the selected reference pressure, a surge condition is developing and the vent valve command signal causes a valve to vent a portion of the air to the pneumatic load. The venting of the air reduces the measured pressure ratio and the vent valve command signal decreases, to close the valve. A signal is provided to reduce the effect of the reference pressure ratio if the weight flow rate through the compressor is reduced, as by decreasing compressor speed and/or repositioning the inlet guide vanes of the compressor.

Abstract: A surge control system for controlling and preventing a surge condition and a method of controlling surge in a fixed or variable speed compressor or a compressor having a variable geometry which provides air to a pneumatic load. A transducer provides a signal proportional to the outlet pressure of the air from the compressor. The signal is differentiated with respect to time and if a surge condition is ensuing, the absolute value of the differentiated signal is greater than a reference. When the differentiated signal is greater than the reference, a portion of the air supplied to the load is vented to reduce the outlet pressure. A reduction in the outlet pressure alleviates the ensuing surge condition and the absolute value of the differentiated signal decreases, causing the venting valve to close.

Abstract: A regulation system for a steam turbine installation comprising a steam generator and a multi-stage turbine installation incorporating a high-pressure stage. The regulation system comprises a regulation valve arranged between the steam generator and the high-pressure stage of the turbine installation and a by-pass valve connected in parallel with said high-pressure stage, as well as control devices with associated control circuits for said valves. The control device for the by-pass valve is influenced by the signal from the control circuit of the regulation valve such that when the opening of the regulation valve exceeds a predetermined magnitude the control device for the by-pass valve opens such by-pass valve to a predetermined magnitude. Further, the control circuit of the by-pass valve is connected in parallel with a differentiation element which influences the degree of opening of the by-pass valve as a function of variations in the signal received from the control circuit of the regulation valve.

Abstract: A pneumatic hand tool comprises a housing having a compressed-gas inlet and provided with a pneumatically powered motor which carries on one side a tool holder such as a chuck and on the other side a governor. A speed-control valve is operated by the governor and can close a first air passage between the inlet and the motor to maintain the motor speed below a predetermined limit. Another passage is provided which bypasses the governor-controlled speed-control valve and a valve is provided in this bypass conduit which is openable in order to allow the hand tool to operate at a speed substantially above the governor-established speed.