A scroll vacuum pump has an axially extending drive shaft with an eccentric shaft portion, such that rotation of the drive shaft imparts an orbiting motion to an orbiting scroll relative to a fixed scroll. An axial adjustment mechanism has a plurality of adjustment members angularly spaced around the drive shaft and extending through the pump housing towards the orbiting scroll, the plurality of adjustment members each being configured to provide an independently adjustable axial position of the orbiting scroll. A plurality of sealing means isolate the plurality of adjustment members from a pump chamber, the plurality of sealing means extending around each of the plurality of adjustment members and comprising at least one flexible portion such that one end of the sealing means may orbit relative to a fixed other end of the sealing means.

Turbomachines such as air dynamometers are disclosed that include a radial outflow compressor and gas collector. In some examples, the gas collector is designed as a separate component that is coupled to the machine, such as coupled to a frame. In some examples, the collector and frame are intentionally spaced and coupled at discrete points to minimize the transfer of mechanical and thermal energy therebetween. Aspects of the present disclosure also include turbomachines that include at least one impeller bypass flow path for the direct transfer of air between ambient and a location in the collector downstream of the impeller blades. In some examples, such flowpath(s) may allow for the inflow of external ambient air into the collector.

An actuation assembly for a variable pitch fan for a gas turbine engine is provided. The actuation assembly generally includes a plurality of fan blades, a scheduling ring, and a plurality of linkage arms. The plurality of fan blades are rotatably coupled to a disk and extend radially therefrom. The scheduling ring is rotatable relative to the disk and has a plurality of slots. Each of the plurality of linkage arms are operatively coupled to one of the plurality of fan blades and to one of the plurality of slots. Each of the plurality of fan blades rotate according to a blade pitch schedule defined by the slot to which it is operatively coupled, and at least two of the plurality of slots define different blade pitch schedules.

A compressor comprising a housing having an axial intake defining an intake passage and an annular outlet volute defining an annular outlet volute passage, an impeller mounted on a shaft for rotation about a shaft axis between the axial intake and the annular outlet volute, the impeller having a plurality of blades, a diffuser defining an annular diffuser passage surrounding the impeller, the annular diffuser passage having a diffuser inlet downstream of said plurality of blades, the tips of the blades sweeping across said diffuser inlet during use, wherein the compressor further comprises at least two vane members, each having a vane receivable in the diffuser passage and an actuator is coupled to the vane members to move each such that the axial length of it's vane within the diffuser passage is varied.

A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a two-piece integral impeller shroud with a fixed inner member and a variable outer member. An actuator is coupled to an aft end of the variable outer member and imparts axially forward and aft motion on the aft end, causing deflection of the outer member.

A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a high pressure air source, an air piston mounted between an engine casing and the shroud and adapted to receive high pressure air from the high pressure air source, a mounting arm coupling the shroud and air piston, and a slidable coupling adapted to allow axial movement of the shroud and joining the shroud to an axial member.

A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a thermal driver coupled between the impeller shroud and engine casing by hinged linkages. The thermal driver includes an annular ring and annular seal which together define thermal driver cavity. Relatively warm or relatively cool air supplied to the thermal driver cavity cause expansion and contraction, respectively, of the annular ring which is translated by linkages into axially forward and aft motion, respectively.

A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of a segregated impeller shroud in a turbine engine. The system comprises a driving mechanism coupled to a portion of a segregated impeller shroud. The driving mechanism comprises a driving arm and threaded axial member configured to translate motion of an actuator ring into axially forward and aft motion of the portion of the segregated impeller shroud.

A control device configured to control an inflow adjusting unit that quantitatively adjusts an inflow of a gas into a compressor and to control a valve provided in a second flow passage branching from a first flow passage from the compressor to a compressed gas supply destination includes: a command calculating unit that is configured to calculate a command value for at least any one of the inflow adjusting unit and the valve; and a correction value calculating unit that is configured to calculate a correction value with respect to a command value for at least any one of the inflow adjusting unit and the valve.

A method for detecting a rotating stall includes: determining a level of variation of a static pressure in a combustion chamber of the turbojet engine around an average value of this static pressure; comparing the level of variation of the static pressure relative to a first threshold; comparing a temperature measured at the outlet of a turbine of the turbojet engine relative to a second threshold; and if the level of variation of the static pressure is greater than the first threshold and the temperature at the outlet of the turbine is greater than the second threshold, detecting a presence of a rotating stall.