Abstract: A variable pipe diffuser for use in a centrifugal compressor. The variable pipe diffuser includes an outer ring and an inner ring which is rotatable circumferentially within the outer ring between a first, open position and a second, closed position. In an open position, complementary air channel sections of the inner and outer rings are aligned with one another to allow a maximum flow of refrigerant through the diffuser. In a closed position, the flow channels of the ring sections are misaligned and the flow of refrigerant through the diffuser is restricted. By adjusting the diffuser rings toward a closed position, surge conditions can be avoided even in the case where a high compressor pressure ratio is required.

Abstract: Pivoting vane internal extremity bearing (1) whose internal extremities are connected by a linking ring (12). The bearing elements (18) connecting the internal extremity pivots (10) to the ring (12) are composed of a bush (19) prolonged by bearing necks (20) with a spin axis (X') parallel to that of the ring (12). The forces undergone by the vanes, which transversally move the pivots (10), do not cause any wear of the bush (19), but a rotation of the latter around the axis (X'). Application for turbine aero engine stator vanes.

Abstract: A bypass air valve is provided which includes a liner, a strap, apparatus for biasing the strap into contact with the liner, a selective actuator, and apparatus for passage of bypass air. To open and close the valve, the selective actuator unwraps a segment of the strap from the liner before the strap is translated a distance around the circumference of the liner. The biasing apparatus biases the strap back into contact with the liner.

Abstract: A power turbine includes a stage of pivotable nozzle vanes. The individual vanes are pivoted by connecting them to a toothed unison ring via actuating levers in the form of gear segments. The gear segments only have sufficient teeth to enable pivoting of the vanes between normal maximum and minimum operating angles. If an emergency closure of the nozzle is required, the unison ring pivots the gear therewith, whereupon pins on the unison ring engage projections on each segment, thus causing the segments to continue pivoting the vanes to a closed position.

Abstract: A turbine device and a method of driving the turbine device are disclosed. The turbine device includes an admission channel, a turbine, and an injection channel. The turbine device may also include a regulator. The turbine is driven by injecting a primary fluid into the admission channel at a given velocity and simultaneously causing a secondary fluid to flow into the admission channel at a lower velocity. The primary fluid and the secondary fluid form a mixture in the admission channel, which flows toward the turbine. The velocity of the mixture is less than that of the primary fluid, while the mass flow of the mixture is approximately equal to the sum of the mass flows of the primary and secondary fluids. The regulator compares the rotational speed of the turbine to a target speed and regulates parameters associated with the turbine device if the rotational speed of the turbine and the target speed differ by more than a predetermined amount.

Abstract: The linkage system for the variable vane stators includes a pumphandle driven by the linear actuator and a cooperating pumphandle slider bracket where the slider bracket includes a machined hard coated stop for limiting travel of the pumphandle when the vanes are at the full opened position. The pumphandle through the drive link circumferentially positions a synchronizing ring that is connected through a plurality of drive links to each of the vanes circumferentially spaced in the stator for changing the angle of each of the vanes as scheduled by a control and actuator for optimizing the performance of the compressor and gas turbine engine. The steps for assembling the linkage system and actuator for synchronizing the positions of the stops on the actuator and slider bracket relative to a given position of the stator vanes defines a method for providing a rigless variable vane system.

Abstract: A control valve for a water treatment system which includes a turbine rotatably mounted within a water receiving chamber. A pair of nozzles communicate water from a water receiving chamber to the turbine in a driving relationship. The nozzles each define a passage, preferably converging slightly in cross-section and defining centerlines that converge and intersect at a region swept by the turbine. Preferably, the intersection of the centerlines occurs intermediate a circle defined by central regions of the turbine blades and a circle defined by peripheral edges of the turbine blades. At least one of the nozzles is slidably held in a slot formed in a dividing wall forming part of the control valve and is replaceable by a plug. A confronting surface defines a uniform gap between an outlet side of the nozzles and a peripheral portion of the turbine.

Abstract: A ventilation system for a car including an outside air channel, an interior air channel, and a radial fan having a suction side and an exhaust side. The fan is situated at junction between the outside air and interior air channels, so that the outside air and interior air channels are axially connected to the suction side of the fan. A partition wall is movable within an unrestricted cavity, so that the outside air and interior air channels are situated at different sides thereof.

Abstract: A method and an apparatus for generating a pulsating air by communicating an air passage intermittently by rotating a valve while feeding air into a casing or discharging air from the casing by a blower connected to a connecting port of the casing. The air passage extends from the connecting port for the blower to a transmitting port of the casing for transmitting a pulsating air. The apparatus for generating a pulsating air is comprised of a casing provided with a connecting port for a blower and a transmitting port for a pulsating air. The connecting port for the blower is connected with a feeding side of the blower or a suction side of the blower. The valve is designed to be operated so as to intermittently communicate the air passage.

Abstract: A vaned diffuser is provided. The diffuser comprises a housing having a first and second flow wall defining a flow path for the exit flow from an impeller. Twisted vanes are mounted on a movable structure capable of travel inside a chamber adjacent the first flow wall. The twisted vanes extend through rotatable structures rotatably retained in the flow walls such that the twisted vanes are slidably disposed across the flow path. Lateral movement of the movable structure moves the twisted vanes through the exit flow thus varying the stagger angle of the vane depending on which section of the twisted vane is in the exit flow. The rotatable structures have twisted openings that match the vane cross-section and twist so that the rotatable structures readily rotate as the twisted vanes are moved through them.

Abstract: A variable inlet nozzle exhaust-driven turbocharger comprises a compressor (2, 5, 6) driven via a main shaft (8) by a turbine wheel (10, 11) subject to engine exhaust gas flow through an annular nozzle formed between a heat shroud (21) having slots (22) to receive vanes (17) carried by a sleeve axially movable in the exhaust duct (19) downstream of the turbine wheel the sleeve being actuable by means acting via a space (25) defined between bearing parts of the sleeve and the part of the turbine housing carrying the exhaust duct bore (19) being of uniform annular section to minimize thermal effects.

Abstract: A steam turbine includes a rotary slide for controlling steam throughput, particularly in combination with a steam offtake. The rotary slide has control slits formed therein. A stationary channel body has channel inlets formed therein with which the control slits cooperate for increasingly opening and closing the channel inlets depending on a direction of rotation of the rotary slide at the time. At least one roller bearing race is disposed between the stationary channel body and the rotary slide outside the vicinity of the control slits and the channel inlets, for reducing rotational friction. At least one of the control slits and at least one of the channel inlets is disposed at each of at least two separate orbits. One of the channel inlets is opened while others of the channel inlets to be opened remain closed, upon rotation of the rotary slide in a corresponding direction of rotation.

Abstract: A control ring for a stage of pivotable vanes on the stator of a turbomachine carries a plurality of adjustable shoes for contacting a circular surface to set and maintain the coaxiality of the control ring during rotation thereof to pivot the vanes. The radial position of each shoe is adjusted by virtue of a double screw having two screw-threaded portions, one engaging with an internally threaded portion of a bush fixed to the control ring and the other engaging with an internally threaded portion of a shoe-holder which is mounted slidably and non-rotatably in the bush, the two screw-threaded portions having slightly different pitches so as to permit very fine adjustment of the shoe postion.

Abstract: A steam turbine includes a rotary slide for controlling steam throughput, particularly in combination with a steam offtake. The rotary slide has control slits formed therein for that purpose. A stationary channel body has channel inlets formed therein. The control slits and the channel inlets cooperate with each other for increasingly opening and closing the channel inlets depending on a direction of rotation of the rotary slide at the time. The channel body has at least an adapter part in which the channel inlets are formed and a basic part having steam channels formed therein being required for conducting steam and in particular leading to nozzles. The channel inlets connect the control slits with the steam channels and are defined in accordance with an intended control characteristic.

Abstract: A bleed valve for a gas turbine engine having a housing of two segments and which form a gas flow path through the compressor, in which a first segment is movable from the second segment thereby creating an opening between the two segments. The moveable segment having one or more arms with rollers attached thereto where the stationary segment has paths on which the rollers travel, as the moveable segment is caused to move away from the stationary segment thereby opening the valve.

Abstract: The adjustment of the play separating the stators and the rotor is effected automatically and jointly with adjustment of the phase angle of the stators. For each startor, at least one slug is used, the slug being mounted for sliding in an oblique groove of a bush integral with the stator. A bush, groove and slug arrangement can also be provided for an adjustable stop on the starter to adjust the play between a free extremity of the rotor blade and the adjustable stop on the stator. Pivoting of each stator provokes a systematic modification of the play.

Abstract: Linear electric actuators powered by DC brushless servomotors are individually controlled to position steam turbine valves by way of levers, pins and links to thus eliminate hydraulics and the attendant disadvantages of fluid filtering, conditioning and leakage as well as obtaining more flexible individual valve control, vis-a-vis, camshaft operated hydraulic actuators. Additionally, low friction actuators and springs are employed to automatically close the turbine valves in the event of a power failure.

Abstract: In an annular array of stator aerofoil vanes (25 ) each of the vanes (25 ) has a flank portion (35 ) which is pivotally attached to the remainder of its associated vane (25). Actuation means (60) are provided to pivot each flank portion (35) relative to the remainder of its associated vane (25 ). Such movement of the flank portions (35 ) provides variation in the cross-sectional areas of the throat (61) defined between adjacent stator vanes (25).

Abstract: A multiple vane, variable pitch, fluid active or reactive device to move or be moved by a fluid including first and second wheels each rotatable about its axis and the axes disposed in selected parallel offset relation. Aperatures provided in the first wheel receive rotatable vane shafts. A vane is provided on each shaft and a distal end of each shaft extends through the aperture. Follower members are connected to the distal ends of the shaft and extend generally parallel to the chord line of the vanes to control the pitch angle of the vanes. The second wheel is inset a selected distance from the first wheel and provides cams that extend outwardly from the second wheel to engage the follower members of the first wheel. A drive member is provided so that a rotational force applied to either wheel is transferred by a gear drive to the other wheel.

Abstract: An aerofoil vane actuation mechanism suitable for a gas turbine engine (10) comprises an annular array of pivotable aerofoil vanes (21) which are linked to an annular actuation member (30) by a plurality of levers (27). Each aerofoil vane (21) additionally has an indication lever (31) attached to it. Each indication lever (31) cooperates with the actuation member (30) so that under normal conditions, during pivoting of the vanes (21), no load transfer takes place between them. However in the event of one or more of the vanes (21) failing to pivot properly, such load transfer does take place. Means (37) are provided to detect such load transfer to provide an indication of such failure of a vane (21) to pivot properly.

Abstract: In a turbomachine in which the stator includes at least one stage of pivole blades and a ring which is movable axially to operate the levers which rotate the blades, the ring is moved by varying the pressure of gas which is contained in sealed chambers and which exerts a force between the movable ring and another fixed ring. This arrangement enables a better distribution of the forces to be achieved than purely mechanical movement control systems.

Abstract: Apparatus for the support and adjustment of stator blades of a gas turbine, in which an adjusting ring is connected to the stator blades by adjustment levers disposed outside the turbine housing. The adjusting ring is supported for rotation in the circumferential direction on a support ring, which has elastic resilience in the radial direction, the support ring being suspended on and centered in a movable manner on radial pins fixed in an outer housing of the turbine. The connection of the adjusting ring and the support ring is achieved by a ball-bearing which is pre-stressed. When the adjusting ring is displaced circumferentially, the stator blades are pivoted around suspension shafts by levers fixed to the shafts and connected to the adjusting ring for universal pivotal movement.

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: A mounting assembly for a movable annular wall member of an inlet passageway of a variable geometry turbine. The inlet passageway is defined between the movable wall and a facing wall. The wall member is formed from a sheet material and is supported on a plurality of pins which extend parallel to the direction of movement of the wall member. The wall member comprises a tubular portion extending away from the facing wall and each pin supports a radial extending projection having a pair of spaced tabs. Each tab is engaged in a respective slot in the tubular portion of the wall member, the tabs being a relatively close fit in the direction of movement of the wall member and a relatively loose fit in a plane at right angles to the direction of movement.

Abstract: Turbine nozzle phasing device for controlling a flow of gasses to a plurality of nozzles in response to a control signal. The turbine nozzle phasing device includes a housing having a lower portion which includes a first plenum for receiving the flow of hot gasses and an upper portion which includes a second plenum integral with the first plenum, a detachable partition for separating the first plenum from the second plenum and a first nozzle which communicates with the first plenum. Hot gasses flowing into the first plenum flows through the first nozzle. A set of second nozzles is provided which communicates with the second plenum. Partition detaching apparatus is also included for detaching the detachable partition in response to the control signal to permit a portion of the hot gasses flowing into the first plenum to flow into the second plenum and through the set of second nozzles.

Abstract: An actuator and associated linkage assembly combined to multiply the force applied by the actuator in moving a flow control disk of a centrifugal fan against the air pressure generated by the fan. The actuator includes an internal spring mechanism for closing the disk against the fan air pressure. For some applications the closing force provided by the return spring may be supplemented with an auxiliary spring mechanism that is mounted for providing maximum assistance in closing the control disk, yet not prohibiting the actuator from reopening the disk.

Abstract: A method of controlling a centrifugal compressor having a variable width diffuser section, the compressor being part of a chiller having a condenser and an evaporator, the method including the steps of defining the width of the diffuser which results in an optimum noise and performance level at given values of an operational parameter of the compressor, periodically sensing the operational parameter of the compressor, and periodically varying the diffuser width according to the sensed operational parameter to create a diffuser width that results in the optimum noise and performance levels at the sensed value of the operational parameter. The step of defining preferably defines the width based at least on the capacity at which the compressor is operating. The capacity is preferably determined by measuring the flow and temperature difference of the fluid passing through the evaporator. A control system for controlling the chiller system to minimize noise is also disclosed.

Abstract: A diffuser of a centrifugal compressor for guiding a fluid flowing from an impeller to a scroll. The diffuser is formed by a pair of oppositely disposed lateral walls. The diffuser is provided at a fluid outlet portion thereof with an outlet throttling portion. This outlet throttling portion is formed by gradually narrowing the passage width downstream from a starting point which is located in a position at which the fluid dynamic pressure is almost perfectly changed to a static pressure. The provision of the outlet throttling portion decreases the risk of a pressure loss, restrains the possibility of flow separation and prevents the fluid from reversely flowing from the scroll. This results in improvements in surge line and partial load efficiency.

Abstract: A vane controller for a plurality of vanes disposed in a fluid conduit has vane shafts connected to the vanes and extending radially and spaced circumferentially around the conduit, and a control ring outside the conduit and movable circumferentially and connected to said vane shafts by levers to cause the vane shafts to rotate in unison to adjust the vane position. To reduce friction, the control ring is movable both circumferentially and axially and is preferably spaced from the conduit wall. A spherical bearing on the ring slidably receives a pin carried by each lever.

Abstract: Each blade of a stage of variably settable stator blades in a compressor of gas turbine engine is supported at its outer end by a journal which is rotatably mounted in a radial bore in a parallelepipedic journal box of trapezoidal section mounted in a housing of complementary shape formed between connected upstream and downstream rings of the outer casing of the compressor. The blade is held radially in the journal box by two parallel pins arranged longitudinally through the box so as to engage in a peripheral groove extending at least partly around the journal of the blade.

Abstract: A variable stator vane arrangement for an axial flow compressor comprises a plurality of stages of variable pitch stator vanes each of which is operated by a respective control ring. The vanes in each stage are connected to the control rings by operating levers. An axially extending member is connected to each control ring by operating links. The axially extending member is arranged in a plane substantially tangential to each control ring and is movable in the plane substantially tangential to the control rings to change the pitch of the variable pitch stator vanes. Hydraulic rams are provided to move the axially extending member. The hydraulic rams may be operated to give either proportional or non-proportional movement of the variable pitch stator vanes. A controller may use signals from position detectors positioned on the control rings or position detectors positioned on the hydraulic rams together with compressor parameters to control the pitch of the vanes.

Abstract: A variable vane assembly for a gas turbine engine is disclosed having a disk member bearing against a recess formed in the inner surface of the gas turbine engine casing is formed separately from the vane. The disk member has a diametrical notch that accommodates a strip member formed integrally with the vane and which extends generally parallel to the chord of the vane. The control rod, which is also formed integrallly with the vane, passes through an opening defined by the disk member and is pivotally supported by the engine casing. A low friction sleeve may be interposed between the control rod and the opening defined by the engine casing to reduce the pivoting friction of the vane. This sleeve may be formed as a separate element, or may be formed integrally with the disk member, which may also be formed of low-friction material.

Abstract: An arrangement for adjusting guide blades by thermal expansion has an expansion rod which has a significantly different coefficient of linear expansion with respect to the supporting housing and is aligned in the circumferential direction of the turbo-engine and is connected with an adjusting ring by way of a step-up lever. As a result, a guide blade adjustment can be achieved easily as a function of the working gas temperature.

Abstract: Nozzle shafts and a nozzle drive mechanism are disposed on the side of a bearing casing and a compressor whose temperatures are lower than that of a turbine, and elements slidable in the radial direction of the turbine wheel are eliminated from the nozzle drive mechanism so that any adverse effects due to oxidization at high temperatures and slide wear can be eliminated. Thus durability and reliability of the device can be improved.

Abstract: In a gas turbine engine having a set of variable stator vanes, a vane actuator ring, and a set of actuator levers linking the vanes to the ring in a one-to-one relationship, an improved manner of linking the vanes to the ring comprises providing a lever of thin sheet material and clamping a trough-shaped end of the lever to a wedge-shaped end of vane stem so that the lever takes up the profile of the end of the stem.

Abstract: In a turbomachine, such as a turboshaft aero-engine, having a compressor casing composed of upstream and downstream casing rings, and a variably settable stage of stator blades which is mounted in one of said casing rings near the junction therebetween so that, in normal operation, the blades have their leading (or trailing) edges projecting into the other casing ring, the setting of the blades being adjusted by a control ring surrounding the casing, there is provided a locking system for temporarily locking the blades in an angular setting in which the leading (or trailing) edges are retracted clear of said other casing when the casing is to be dismantled or assembled.

Abstract: In a diffuser for a centrifugal compressor of the type which includes an impeller rotatably provide on a downstream side of the suction casing and a plurality of radial stator blades arranged tangentially with respect to the impeller, auxiliary blades are provided between the impeller and the stator blades, with the auxiliary blades having a chord length shorter than that of the stator blades and being slidable in the axial direction of the impeller. Further, the auxiliary blades are connected to devices designed to move them in the axial direction.

Abstract: An improved driving linkage device for adjusting a variable nozzle mechanism in a supercharger turbine or a variable diffuser mechanism in a compressor. The driving linkage device is provided with a driving ring for driving a variable nozzle mechanism in a supercharger turbine or a variable diffuser mechanism in a compressor, one or more sets of adjusting links, each set consisting of three levers connected in a U-shape and having two opposed ones coupled to the driving ring and a fulcrum for supporting the lever not coupled to the driving ring. One end of one adjusting link is coupled to an actuator to achieve the adjustment of a variable nozzle mechanism in a supercharger or of a variable diffuser mechanism in a compressor.

Abstract: A diffuser vane assembly for a centrifugal compressor includes movable vanes which are inserted or retracted from the diffuser passage through slots in one of the diffuser walls. The vane assembly is axially movable by an internally threaded drum and gear arrangement. A hand crank external to the compressor is effective to rotate the drum and thereby axially move the plate and attached vanes within the diffuser passage.

Abstract: An adjustable spacer (20) is located in a unison ring (16) disposed about a gas turbine engine case (18). The spacer (20) includes a pad bolt (44) having a flattened surface (52) for contacting the case (18). The pad bolt (44) is adjusted radially by a threaded cylinder (28) and adjusting nut (36). The assembly is locked in place by a locknut (54) which includes a frangible link (72) for separating a headed portion (70) from a threaded portion (68).

Abstract: A ring gear (20) rotates circumferentially about a plain bearing (22) secured to the housing (10) of a centrifugal gas compressor. The ring gear (20) drives sector gears (18) for positioning variable guide vanes (14). A lever arm (32), actuator (36) and linkage (38, 40, 50) is provided for driving the ring gear (20).

Abstract: A variable angle vane stator arrangement of relatively simple design is pided enabling widely variable angular stator vane positioning with little aerodynamic loss. This is accomplished by positioning the leading nose portion of each variable second row vane axially ahead of, and adjacent, the trailing edge of an associated fixed vane of a first row of vanes to produce a slot between the adjacent vanes through which air can flow. The axis of rotation of each variable vane is located off of the variable vane itself in a manner to maintain good slot geometry over a wide range of vane stagger angles. The variation of the rear vane stagger angle creates a variation in the direction of the exit air vector, which in turn enhances the performance of the following rotor blade row.

Abstract: An inlet guide vane assembly for a pump or a compressor having rotary blades. The guide vanes pivot in a controlled manner so that a portion of the vanes can be inserted into or withdrawn from the inlet passageway of the pump or the compressor by pivoting the guide vanes about a pivot axis.

Abstract: A variable stator vane assembly suitable for a power turbine in which each stator vane is provided at its radially inner and outer extents with disc-shaped platforms which locate on bushes provided on associated support structure. The bushes are cooled by a flow of cooling air which is of higher pressure than that of the hot gases operationally flowing over the vanes so as to prevent the leakage of such hot gases past the bushes.

Abstract: A splitter vane/shut-off valve system for use in a centrifugal pump which includes an impeller and an inlet to the impeller. A plurality of planar, anti-swirl vanes are arranged in a cross-configuration across the inlet adjacent the impeller to straighten the flow of fluid to the impeller and to prevent swirling of the fluid by the impeller. Edges of the planar vanes, facing the incoming fluid, define a valve seat. A plurality of petal valves are pivotally mounted at pivot points to the side of the inlet and movable toward and away from the center of the inlet. The petal valves engage the valve seat defined by the edges of the planar vanes for closing the inlet to allow removal of the impeller.

Abstract: An adjusting device of a compressor includes guide vanes (2) arranged in the form of a ring around a longitudinal axis (4), which vanes are in each case connected fixedly in terms of rotation to pivot pins (8) and are pivotally mounted in the housing (46). Two-armed cranks (10) are connected fixedly in terms of rotation to the pivot pins (8), cranks (10) neighboring each other in circumferential direction being linked to each other by means of coupling links (24, 26). With a lower overall volume and low use of materials, a jamming, in particular in view of thermal expansions and production tolerances, is to be avoided. For use with a radial-flow compressor, it is proposed to arrange the cranks (10) and the coupling links (24, 26) in an annular space (52) which neighbors the discharge port, into which space the pivot pins (8) parallel to the longitudinal axis (4) protrude with their free ends.

Abstract: A compressor bleed valve assembly 28 having an axially translatable valve ring 66 for a gas turbine engine 10 is disclosed. Various construction details which increase the sealing effectiveness of a valve ring 66 are developed. In one embodiment, the valve ring is adapted to engage a slot 56 as the valve ring is moved between the open to the closed position, the slot being contoured to provide a mechanical advantage as the valve ring moves to the closed position against resilient sealing members 58, 60 which axially engage the valve ring.

Abstract: A support arrangement for a unison ring in a system for varying the angles of attack of compressor vanes in an axial flow gas turbine engine compressor. The support arrangement includes a plurality of struts which provide radial support for the unison ring on the compressor case and a corresponding plurality of eccentric washers disposed between platforms on the struts and an overhanging flange on the unison ring. When the washers are rotated, the positions of the struts are adjusted radially and when the washers and struts are clamped to the unison ring, forces are reacted between the struts and the unison rings through the washers.

Abstract: A cartridge or plug-in pump for use in a fluid holding receptacle such as an aircraft fuel tank. A pump housing on the fluid holding receptacle has an inlet opening to allow passage of fluid from the receptacle into the pump housing. A plug-in pump assembly is axially and rotatably positionable in the pump housing. A pump inlet closure is mounted on the pump housing for movement between inlet open and closed postions. Seals are provided between the pump housing and the pump assembly. A first actuator moves the closure to its inlet closed position in response to rotational movement of the pump assembly relative to the pump housing. A second actuator moves the pump assembly axially relative to the pump housing to break the seals also in response to rotational movement of the pump assembly relative to the pump housing. The first and second actuators are synchronized whereby the closure is in its inlet closed position at the time the seals are broken.

Abstract: A compressor with a rotary driven centrifugal impeller which receives inlet air from an inlet passageway and this discharges compressed air through a radially extending diffuser passageway. Moveable vanes are provided both in the inlet passageway and diffuser passageway for varying the pressure and flow output from the compressor while maintaining the rotary speed of the centrifugal impeller substantially constant. In the preferred form of the invention, the centrifugal impeller and an electrical generator are rotatably driven at a constant speed and in synchronism with each other and, together, form an electrical and pneumatic power system.