Abstract: A gas turbine engine (10) has a compressor (14) which includes a rotary stage (16) supported for rotation by a plurality of wire wound stators (34). When the stators (34) are electrically energised, they exert Maxwell type magnetic forces on a magnetically permeable ring (18) joining the tips of compressor blades (21) in the stage (16), and lift it into a position in space where it can rotate on a common axis with the turbine of the engine (10).

Abstract: A seal gas pressure booster system for use with a gas compressor, particularly of the type used for boosting pressure in gas transmission, process or utility industries and which contains pressure about the shaft/casing interface with the use of dry gas seals. Seal supply gas is supplied from the discharge side of the compressor. During normal operation, sufficient head across the compressor exists to supply the necessary flow of seal supply gas against the restrictions provided by the filters, interconnections and components in the seal gas supply system. During startup, or during modes of operation where sufficient head across the compressor does not exist, the pressure booster system increases the pressure of a stream of compressor discharge gas to provide the necessary pressure differential to supply the dry gas seal with a continuous flow of clean, filtered gas.

Abstract: A system includes a gas turbine engine having a shroud and a rotor with one or more blades. The rotor rotates within the shroud to pressurize a fluid during operation of the engine. An electromagnetic actuator is also included that is operable to move the shroud relative to the rotor to adjust clearance between the shroud and blades. In addition, a controller is included in this system to determine a desired amount of clearance in accordance with an operating mode of the engine. The controller generates an actuation signal to change the clearance in correspondence with the desired amount. The electromagnetic actuator responds to the actuation signal to provide the desired amount of clearance.

Abstract: A reversible pump-turbine system having a discharge adjustment device such as guide vanes, which make it possible to safely stop a pump turbine at the time of emergency shutdown in a generating mode by performing a close operation using an inlet valve even if abnormality has occurred with the guide vanes, without causing abnormal water hammer. Also, at the time of pump mode emergency shutdown, reverse rotation can be prevented even if abnormality occurs in the guide vanes, and it is possible to achieve a safe stop while reducing the loads/stresses to the reversible pump-turbine.

Abstract: Water is first caused to flow through a first passage and rotate a first impeller. Rotation of the first impeller is linked to rotation of a second impeller, which is in fluid communication with a second, discrete passage. Vanes on the second impeller are constrained to move faster than vanes on the first impeller. Water is subsequently caused to flow through the second passage and to be more aggressively advanced by the second impeller.

Abstract: For an impeller pump, the seal/bearing unit has two rotor-stator pairs of tapered sleeves arranged back-to-back. The sleeves have a spiral groove, and convey barrier-liquid from an entry-mouth in an entry-chamber to an exit-mouth in an exit-chamber. Having two sleeves gives the units mechanical stability, thrust support capability, and resistence to vibrations and other abuses. The tapered sleeves may be arranged wide-narrow-wide, or narrow-wide-narrow. The sleeves may be mounted for sliding in the housing and on the shaft, or may be fixed to the housing or shaft.

Abstract: A structure and a method to form the structure are provided for an impeller bleed passage of a compressor for a gas turbine engine. The compressor has an impeller assembly which includes an impeller rotor rotatably supported within an annular shroud having an inlet and an outlet. The shroud is made of two separate annular segments which are axially spaced apart. Each of the segments is supported separately and independently in a cantilevered manner. Such that a circumferentially continuous, uninterrupted annular slot is formed between the two segments and air passes through the slot without causing a dynamic component to affect the impeller rotor. The width of the slot is adjustable for different engines depending on the requirements of use of a particular engine. The width of the slot is also self-regulating in response to changes in the air pressure within the shroud because of the deformation of the segments. The structure is relatively simple and inexpensive to manufacture.

Abstract: A method and an apparatus for use with a gas turbine engine receive a signal indicative of an engine operating condition, generate signals representative of thermal conditions of a rotor, blades, and a case, and in response to each of the signals above, determine a signal indicative of a difference between a instantaneous clearance for the thermal conditions and a steady state clearance for the engine operating condition. The determination includes effects related to a temporary difference that results from a difference between the steady state clearance for the engine operating condition and a steady state clearance for a preceding engine operating condition, but does not require computation of the actual temperatures or the steady state temperatures of the rotor, the blades, and the case. A signal indicative of the difference between a instantaneous clearance for the thermal conditions and a steady state clearance for the engine operating condition may be provided to various augmentation schedules.

Abstract: The steam turbine has an interior chamber through which an action steam can flow. The action steam is condensed in a condenser. The condenser is connected to the interior via a cooling-steam conduit. The cooling-steam conduit can be shut off by means of a shut-off member which opens as a function of the differential steam pressure between the condenser and the interior. The method of cooling the steam turbine is effected by cooling the steam turbine with steam from the condenser in the ventilation mode of the turbine.

Abstract: A method and apparatus for controlling the amount of gas flow through a compressor having variable geometry guide vanes and a variable geometry diffuser. The geometry variation of the diffuser is based on the geometry variation of the guide vanes. The method and apparatus ensure that the compressor will operate at peak efficiency over a broad range of load conditions.

Abstract: An impulse turbine comprises at least one runner keyed to a drive shaft in association with a distributor unit which has, for each runner, a circular outlet for the supply of fluid from the distributor unit to the blades of a respective runner. Each outlet is arranged coaxially inside the respective runner and the distributor unit is shaped in a manner such as to define a substantially circular path for the fluid and to cause the fluid to emerge from the distributor unit through the at least one outlet predominantly tangentially relative to the outlet.

Abstract: An upper reservoir-side conduit or a lower reservoir-side conduit is branched in the vicinity of pump-turbine ends and at least a first pump-turbine out of a plurality of pump-turbines which share the conduit portions located farther than the branch points with the other pump-turbine or pump-turbines is provided with a rotational speed increase detector. When it is detected that the rotational speed of the first pump-turbine has exceeded a second predetermined value higher than a rated speed, a command is issued also to at least one of the other pump-turbines to limit the guide vane closing speed in that pump-turbine to a speed approximately equal to or lower than the speed after the shift to a slow closing of the guide vanes.

Abstract: A fluid passage extends through the compressor casing from a point near the tip of the impeller to a transducer located externally of the compressor casing. Responsive to fluctuations of pressure sensed by the transducer indicative of rotating stall, the compressor is controlled by varying the diffuser or shutting down the compressor, as is appropriate.

Abstract: A system and method is provided for generating a real-time signal indicative of an energy-type instability precursor in a turbofan engine. A sensor is positioned in a compressor portion of a turbofan engine for generating a real-time signal indicative of energy of aerodynamic or aeromechanical resonance waves generated in the compression system. The signal is bandpassed to generate a filtered signal within a predetermined range of frequencies indicative of a precursor to instability such as rotating stall, surge or flutter. The bandpassed signal is squared in magnitude and then lowpassed to generate an instability precursor signal used to prevent imminent aerodynamic or aeromechanical instability from occurring in the aerocompression system.

Abstract: A compressor is disclosed having a characteristic modifier, such as air injection, adapted to modify an operating characteristic of the compressor in order to reduce the bandwidth and rate limit requirements of the compressor. The compressor includes an actuator, such as a bleed valve, whose bandwidth and rate limit parameters meet the corresponding reduced requirements of the compressor. The actuator is adapted to stabilize the compressor with respect to a likely condition in the compressor which would tend to make the compressor operate in a less stable manner. This makes it possible to stabilize the compressor using a more readily available actuator having lower bandwidth and rate limit parameters.

Abstract: The present invention is for an evacuation system which preferrably in its entirety is connected to and operates at the outlet side of a pump. The evacuation system is connected to the socket 5 by the connector 9 and one of the valves 15 or 16. In the evacuation system there is a compressor 19 and a pressurized air ejector 18. Air from the ejector exits through a pipe 24.

Abstract: The operation of quickly taking a turbocompressor off-line from a parallel configuration, of a gas pipeline compressor station, may encounter increased mechanical action (in particular, vibration) upon recycle piping and the additional risk of compressor surge. For these reasons, this invention relates to a method and apparatus for decreasing vibratory loads and for increasing surge prevention effectiveness, while initiating an off-line operation, by (1) altering the surge control line's location, at a preset rate, from its initial location to a predetermined new location; and (2) decreasing the turbocompressor's deceleration rate when the operating point intercepts the surge control line before the control line reaches its new location. Upon completion of the off-line activity, the control line returns to its initial location; and the reduction of compressor speed will cease on reaching a preset value.

Abstract: The stroking speed of an antisurge control valve is impeded by the combined damping effects of signal dead time and the inherent lag of ancillary pneumatic components within a primary control loop. Furthermore, as control valve actuator size increases, the negative influence of these two impediments (dead time and lag) is amplified. As a result, control valve response times are adversely affected; and the possibilities of surge-induced compressor damage and process upsets are heightened. For these reasons, this disclosure relates to a method for protecting turbocompressors from impending surge, and for preventing subsequent process upsets, by improving antisurge control. But more specifically, it describes a technique for decreasing damping effects by evacuating control valve actuators (diaphragm or piston) through restrictions having a lower resistance to compressible-fluid flow rather than through volume boosters--consequently, increasing a control valve's opening speed to that of an emergency shutdown.

Abstract: Driven turbomachinery for use in centrifugal and mixed flow pump overcomes operational for overcoming difficulties, such as flow separation and generation of surge at low flow rates, often encountered in similar machines of the conventional design. The turbomachinery is provided with variable-angle inlet guide vane and variable-angle diffuser vanes, and the diffuser section is constructed according to a fluid dynamic principle, and the vanes having a wing shape are distributed tangentially so that the diffuser section acts as a centrifugal diffuser. A convenient operational parameter, chosen from such variables as input current to the drive motor, rotational speed or torque of the drive motor, inlet/exit pressures, and fluid velocity, is monitored during the operation by means of sensors strategically attached to parts of the operating system.

Abstract: A pump assembly, comprising a pump with a chamber having a vacuum region therein, a priming fluid reservoir, a suction line for fluid communication between the vacuum region and a fluid source, and a priming suction line for fluid communication between the vacuum region and the priming fluid reservoir, in order to deliver priming fluids to the vacuum region so as to establish a primed condition in the pump; a suction flow control in the suction line and a priming flow control in the priming suction line; the flow controls being operable to restrict flow through the suction line and the priming suction line, in order to establish a vacuum in the vacuum region to substantially fill the suction line with fluid from the source while maintaining the primed condition, wherein the vacuum is variable up to a maximum suction capacity of the pump.

Abstract: A surge prevention control system for use with a dynamic compressor provides a multiple module controller for operating an anti-surge valve to bypass flow around the dynamic compressor. The multiple module controller includes a PID control module and a rate control module. The PID control module controls the anti-surge valve to control the operating point of the dynamic compressor about the surge control line. The rate control module uses the rate of approach of the operating point to the surge control line as its process variable. In the event of high rate of approach, the rate control module takes control of the anti-surge valve. The setpoint of the rate control module is adjusted to open the anti-surge valve to control the rate of approach to the surge control line to minimize the overshoot of the PID control.

Abstract: Active recovery from a rotating stall operating condition in an axial flow compression system is accomplished by altering the temperature and/or density of the working fluid flowing in the inlet of the compression system once rotating stall is detected. A burner is used to increase the compressor inlet flow temperature and concomitantly reduce the inlet flow density. Alternatively, a low density gas such as helium is injected into the compressor inlet. The ingestion of high temperature gases or other low density gases into the compressor energizes a dynamic response from the compression system that induces rotating stall recovery.

Abstract: A process and a device for avoiding regulator instabilities in surge limit regulators for protecting a turbocompressor from surging if a high proportional gain is selected for the surge limit regulator by a blow-off via a blow-off valve. The control of the velocity of closing of the blow-off valve over time is performed by a gradient limiter of asymmetric design, wherein no velocity limitation acts in the opening direction, but a freely parameterizable velocity limitation of the closing process of the blow-off valve is provided in the closing direction. The gradient limiter is inserted between the surge limit regulator, which receives the control signals on the actual value of flow and the desired value of flow from a subtracter, and the control line for a pneumatic or hydraulic operating device of the blow-off valve.

Abstract: A process and to a device for protecting a turbocompressor from operating in the unstable working range by means of a blow-off device, wherein a control parameter is determined from measured values for the compressor flow, the compressor final pressure and the temperature measurement, as well as from preset or presettable desired values, and controlled opening of the blow-off fittings is performed by a pump surge limiter by means of a pneumatic actuating device each on the basis of the said control parameter. The measured values for the temperature, flow and pressure entered into the pump surge limiter are coupled with a dynamic blow-off line. The blow-off fittings are operated in sequence, and the control signals for the quick opening of the blow-off fittings are first sent to a small blow-off fitting, and then to a large blow-off fitting after the opening of the small blow-off fitting. In cooperation with the dynamic blow-off line, the pump surge limiter provides for continuous control, i.e.

Abstract: A turbomachine having variable-angle diffuser vanes operates by regulating the angle of the diffuser vanes on the basis of the sensors disposed on the pump body or pipes of a surge detection device. The onset of surge can be forecast by measuring the fluctuations in the operating parameter(s) over a measuring interval of time computed on the basis of the operating characteristics of the impeller of the turbomachine. The onset of surge is prevented by adjusting the angle of the diffuser vanes in accordance with the sampling duration for parameter fluctuations over the measuring interval of time, and by adjusting the diffuser vanes to maintain the operating parameter fluctuations of the fluid machinery below a threshold value of the turbomachine derived from the design flow rate of the turbomachine. Application of the surge detection device in combination with fluid flow guide vanes and blades of the turbomachine enables full utilization of the potential capability of the turbomachine.

Abstract: An integrated system for controlling the positioning of a rotating rotor within a compressor to enhance the performance of a gas turbine engine. The rotor being attached to a rotating shaft that is coupled to the compressor housing by a magnetic bearing system. The magnetic bearings support and position the rotor within the high speed tubomachine. During operation of the compressor the magnetic bearings non-axially position the rotor relative to the compressor housing to provide compressor instability control. By non-axially displacing the rotor relative to the compressor housing there is a resulting local disturbance to the fluid flow field, which in turn serves as the disturbance to alter the dynamics of the aerodynamic system and displace the compressor surge line.

Abstract: A process and a computer implemented system for controlling an axial compressor through measurement of pressure fluctuations of the turbulent fluid layer in the region of the compressor housing in at least one stage of the compressor by means of at least one pressure sensing device sensitive to differential pressure fluctuations affecting the blades at the characteristic frequency of the stage. The process and computer implemented system use a characteristic peak which emerges under load in a smoothed frequency signal derived from a transform of the pressure measurement to achieve optimal efficiency while, at the same time, avoiding destructive surge and stall conditions in the compressor.

Abstract: A condensing turbine includes a live-steam inlet, an exhaust-steam outlet and at least two seals for sealing off a turbine casing in the region of a turbine shaft carrying a turbine rotor. At least one of the seals is disposed on the live-steam side and one of the seals is disposed on the exhaust-steam side. The overall construction is substantially simplified by constructing at least one respective seal as a gas-lubricated mechanical surface seal on both the live-steam side and the exhaust-steam side. The outermost mechanical surface seals in each case on the live-steam side and the exhaust-steam side seal off separate seal spaces which are acted upon through a balancing line by an identical vacuum lying below the outer atmospheric pressure. These mechanical surface seals are constructed and fitted in such a way that a flow which is necessary for gas lubrication can occur through the mechanical surface seals from the outer atmosphere into the interior of the casing.

Abstract: A process and a computer implemented system for monitoring vibration in the blades of the rotor and stator of an axial compressor through measurement of pressure fluctuations of the dynamic pressure field in the region of the compressor housing in at least one stage of the compressor by means of at least one pressure sensing device sensitive to differential pressure fluctations affecting the blades at the characteristic frequency of the stage. The process and computer implemented system also assist in the control of the compressor by forwarding a status respecting rotor and stator mechanical vibration to the control unit.

Abstract: The instant invention is a self-adjusting blade insert used for improving the efficiency of low rotating disc pumps by use of pivotal disc inserts disposed between the rotating discs of a multi-disc pump turbine style pump causing a positive displacement of fluid during the low rotating conditions or low viscosity fluid environment. The blade inserts of the instant invention include a biasing spring which allows the blade inserts to pivot outward when sufficient hydraulic pressure creates force against a lower surface of the blade inserts allowing maximum flow at higher rotations or predetermined operating conditions.

Abstract: The system makes it possible to reduce the clearances existing between the rotor and stator of a turbine (40) of a turbo jet engine during the various operating phases of the latter whilst keeping the temperatures of the disks inside the limits of their mechanical behaviour. The disks (4) of the turbine (40) are ventilated via the sampling of high pressure air at a high temperature (2) and the stator via the sampling of low pressure air at a low temperature (3). The respective temperatures of these two samplings are homogenized by a heat exchanger (1). This exchanger is short-circuited by a branch circuit connection (5) on the low pressure circuit so as to keep as stable as possible the clearances inside the turbine (40) according to the various ranges of capacity of the turbo jet engine by means of a valve (6) controlled by the computer.Application for aircraft turbo jet engines.

Abstract: A novel centrifugal pumping system is disclosed for supplying fuel to aircraft gas turbines. The system has a common rotor with two different sets of impeller blades on opposite sides. A regenerative/liquid-ring starting pump is located on one side of the rotor, and a centrifugal impeller is located on the other. During engine start-up, the regenerative/liquid-ring pump is capable of priming itself and supplies engine fluid and pressure. The starting pump delivers fuel until the main pump reaches a speed sufficient to provide adequate pressure for fuel delivery. At that time, the starting pump is switched off, via a valving system.

Abstract: A method of detecting a counterflow in a pump comprises providing with detecting means for detecting variations in the discharge pressure of the pump and signal analyzing means for analyzing oscillation components contained in an output signal from the pressure detecting means, and detecting the pump's operating point to have entered a counterflow characteristic operation region when a waveform of the detection signal generated in association with the variations in the discharge pressure of the pump exhibits a predetermined spectrum distribution. Further, when it is detected that the operating point enters a counterflow characteristic operation region, the escape from that region is performed by temporally throttling the guide vane and temporally increasing the rotating speed.

Abstract: Circumferential and radial inlet pressure distortion on an aircraft gas turbine engine are detected by a plurality of static pressure sensors and a signal processor, which computes the total pressure for each sensor to determine a pressure distortion pattern which the processor correlates with stored data for the engine and inlet to determine if the airflow geometry should be altered during flight. Time varying changes in the pressure from one or more of the pressure sensors is used to determine a stall condition, causing a change in engine airflow geometry to increase stall margin.

Abstract: A braking mechanism for a rotary apparatus having a housing adapted to receive a pressurized fluid and a rotor rotatably mounted in the housing. The braking mechanism enables the rotor to rotate in the housing in response to the receipt of the pressurized fluid and inhibits the rotor from rotating in the absence of the receipt of the pressurized fluid.

Abstract: The method controls gas flow in an axial flow compressor in which the flow at one or more chosen station in the direction of flow through the compressor is sensed at a series of circumferentially spaced positions. Flow variations above a predetermined limit are evaluated to initiate a response if a disturbance above a predetermined acceptable level is detected. When such a disturbance is detected, higher pressure gas bled from downstream is injected at a station to supplement the main gas flow. An incipient rotating stall cell will appear as a variation occurring sequentially at the circumferentially spaced positions. By responding to such a condition with a pressure injection, it is found possible to suppress both rotating stall and surge conditions in the compressor before this disturbance develops fully. The same method can be arranged to counter steady state distortion.

Abstract: The invention provides a method of controlling gas flow in an axial flow compressor, in which the flow at least at one chosen station in the direction of flow through the compressor is sensed at a series of circumferentially spaced positions. Flow variations above a predetermined limit are evaluated to give an actuating response if the variations indicate a disturbance above a predetermined acceptable level is present. When such a disturbance is detected, high pressure flow bled from the exit end of the compressor is injected at said station to supplement the main gas flow there. An incipient rotating stall cell will appear as a variation occurring sequentially at the circumferentially spaced positions. By responding to such a condition with a pressure injection flow, it is found possible to suppress both rotating stall and surge conditions in the compressor before the disturbance develops fully.

Abstract: An on/off surge prevention control and method for a gas turbine engine having a variable geometry diffuser is provided. This control receives exhaust gas temperature and compressor discharge pressure signals from the engine, and a signal from the aircraft indicative of a need for bleed air. When the aircraft signal is received, the control opens the diffuser to its maximum open setting, and when said aircraft signal is absent closes said diffuser to its minimum open setting. In the event that a faulty aircraft signal is received, the control senses changes in EGT, P3 and dP3/dt and compares these parameters to preselected values indicative of the compressor nearing surge. When the measured values reach the preselected values, the control closes the diffuser to it minimum open setting. By using a temperature signal in determining when to close the diffuser, unwanted closings due to operating transients in compressor discharge pressure are provided.

Abstract: To control unsteady motion phenomena in turbomachines, it has been proposed to employ an active control system to modify the flow conditions. In the present invention, the modification is effected by devices mounted in a bullet or nose bullet at the entry to a rotor of the turbomachine.

Abstract: A modulating surge prevention control and method for a gas turbine engine having a variable geometry diffuser is provided. The control calculates a maximum permissible compressor discharge pressure from a predetermined algorithim that is representative of the compressor discharge pressure when the compressor is operating at its minimum permissible surge margin with the diffuser in its maximum open position. The control also receives a signal from a sensor measuring the actual compressor discharge pressure. A error signal is formed by taking the difference between the measured pressure signal and the calculated signal. The control then continously adjusts the area of the diffuser so as to maintain the actual compressor discharge pressure at or below the calculated pressure. The calculated pressure is also corrected for variations in ambient temperature and altitude.

Abstract: Apparatus for controlling the steam pressure at the exit of the last row of blades of a steam turbine by means of an adjustable guide vane assembly having a plurality of vane segments supported by the bearing cone that are moved to change the cross-sectional area of the exhaust flow passage so as to improve turbine efficiency under varying operating conditions by minimizing the average pressure in the annulus following the last row of turbine blades.

Abstract: In conjunction with a method and apparatus for regulating the power of a steam power plant block, an improved method and an improved apparatus for restoration of a given throttling of the turbine inlet valves as a conclusion to a regulating process for stabilizing a sudden or abrupt elevation of the load set point is proposed by the invention. The necessary storage of fresh steam takes place without influencing the electrical output power or the regulating devices necessary for regulating it with the aid of a separate closed control circuit.

Abstract: The deflection angle of a gas turbine stator is adjusted in proportion to the difference between two parameters computed from N.sub.2 and TT2 using the same function generator. One parameter is a reference adjustment under standard conditions for measured N.sub.2 adjusted to sea level and standard temperature. The second parameter is an adjustment for actual altitude conditions. The parameters manifest the clearance between the engine case and the turbine blade tips.

Abstract: Stall margin in a gas turbine compressor is controlled during acceleration by synthesizing the thermal enlargement of critical compressor stages to synthesize the temporary increase in blade-case clearance during acceleration. The change in clearance is used to produce an augmenting stator vane deflection signal which is summed with a steady state vane deflection signal to increase deflection during acceleration until the clearance returns to a nominal level when the expansion of the compressor parts stabilize.

Abstract: A method of operating a pitot pump that pressurizes a first fluid of a first viscosity and first density wherein the pump includes a rotatable housing and a stationary probe disposed within the housing includes the steps of providing a source of a second fluid having a second viscosity and second density less than the first viscosity and first density, detecting a physical condition in the housing indicative of the presence of the first fluid at a second radial position inside the first radial position and connecting the source of the second fluid to an inner annular chamber of the housing when the detected physical condition indicates that the first fluid is present at the second radial position.

Abstract: An air flow system includes a supercharger, a bypass passageway connected between an intake side and a discharge side of the supercharger, a compression machine and an air bypass valve in the bypass passageway. An intake port of the compression machine is connected with the bypass passageway such that supercharged air is delivered to the intake port of the compression machine at least during high supercharging conditions, thereby increasing the volumetric efficiency of the compressor at high engine speeds.

Abstract: An apparatus includes a compressor for compressing fluid including a sensor capable of sensing at least one function relative to the operation of the compressor. A controller controls the compressor causing the value of said one function to be within a predetermined parameter. A computer overrides the independent response of the controller wherein the controller acts in response to the computer, the computer being separate from said controller. The computer may act as a sequencing computer or as a test computer.

Abstract: An exhaust fan blower is provided for use in induced draft furnaces. An integrally molded fan housing and exhaust conduit is provided of a material impervious to the corrosive effects of exhaust gas condensates. The conduit is of a round cross section to mate with an associated flue pipe. The fan blower includes a conduit in communication with a pilot light for constantly venting the pilot light irrespective of operation of the blower. A first bore in the fan blower housing provides means for monitoring the vacuum developed therein, while another bore provides a means for thermally sensing a blocked or restricted flue condition. A flange and mounting lugs about the periphery of the fan blower housing provide a means for mounting the system to the side of a furnace panel, while sealing such mounting engagement. A motor mounting bracket for the fan blower serves as a cooling fan guard and heat sink, having a bearing contact mounting seat cast integrally to the bracket.

Abstract: The problem of providing a simple, small, lightweight and reliable flow responsive switch mechanism (32) in a fan structure, such as for aerospace applications, is solved by providing a housing (12) defining a fan involute (22). An impeller (18, 20) is mounted in the housing for forcing air through the fan involute. A vane (34) is disposed directly in the fan involute, rotatably mounted on the housing, for rotation in response to air flow through the fan involute. An electrical switch (52) is mounted on the housing and is operatively associated with the vane for altering the state of the switch in response to air flow through the fan involute from the impeller.

Abstract: An arrangement for protecting a turbocompressor against surges by blowing off through a blow-off valve, in which at least the flow-through of the compressor and the compressor outlet pressure are measured. A regulating parameter is determined from the measured results, as well as from predetermined reference values. A blow-off valve is adjusted dependent on the regulating parameter, by a surge-limit regulator through activating device with a downstream state regulator and a compressed medium. The blow-off valve is shifted in opening direction at a maximum rate of adjustment by safety controls when the regulating parameter exceeds a safe threshold. The compressed medium that activates the blow-off valve bypasses the state regulator and escapes directly when the safety controls engage. The compressed medium is prevented from escaping, on the other hand, when the safety controls disengage, and regulation is resumed only by the surge-limit regulator and the downstream state regulator.