Propulsion engine
a technology of propulsion engine and variable pitch mechanism, which is applied in the direction of positive displacement liquid engine, piston pump, machine/engine, etc., can solve the problems of complex and heavy system required to actuate the variable pitch mechanism
Inactive Publication Date: 2014-07-31
ROLLS ROYCE PLC
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Benefits of technology
The present invention provides a propulsion engine for an aircraft that includes one or more fans rotatably linked to one or more shafts, and a driving means for the fans. The engine also includes a hydraulic pump-motor connected to one of the fan shafts, which selectively transfers power to or from the fans to control their rotational speed. The hydraulic pump-motor can selectively transfer a variable amount of power to or from the fans, and can be positioned to control the rotational speed of the fans with respect to the rotational speed of another fan. The engine can also include a speed controlling assembly for the fans, which uses a hydraulic pump-motor connected to the fan shafts. The hydraulic pump-motor can selectively transfer power to or from the fans, and can be positioned to control the rotational speed of the fans with respect to the rotational speed of another fan. The engine can also include a differential assembly to provide power to the fans. The fans can be unducted or located towards the rear of the engine. The technical effects of the invention include improved control over the speed of the fans, increased efficiency of the engine, and reduced noise from the fans.
Problems solved by technology
However, complex and heavy systems are required to actuate the variable pitch mechanisms.
Method used
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[0024]With reference to FIG. 1, a propulsion engine, according to an example of the present invention, comprises contra-rotating rotors, which may for example be first and second fans 1, 2. The first and second fans 1, 2 may be unducted fans and as such the propulsion engine may be an example of a propfan engine for an aircraft. In the example shown in FIG. 1, the first and second unducted fans are located aft of a core 3 of the propulsion engine, but may alternatively be placed fore of the engine core 3. Although the first unducted fan 1 is shown as being located fore of the second unducted fan 2, in an alternative embodiment (not shown), the first unducted fan may be aft of the second unducted fan.
[0025]The first and second unducted fans 1, 2 are driven by a driving means in the form of a free power turbine 5 via a differential gear assembly, e.g. an epicyclic differential (not shown). The free power turbine 5 is in the gas stream from the engine core 3. The differential rotatably...
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A propulsion engine for an aircraft, the propulsion engine comprising: one or more fans (1, 2) rotatably linked to one or more respective shafts (11); a driving means arranged to drive the one or more fans; and a first hydraulic pump-motor (10) connected to one of the fan shafts, the first hydraulic pump-motor comprising a cam (12) disposed about the shaft and one or more radially extending pistons (13) arranged to engage a surface of the cam, the cam and pistons being arranged such that the pistons reciprocate due to the rotation of the cam, wherein the first hydraulic pump-motor is arranged to selectively transfer a variable amount of power to or from the one or more fans so as to control the rotational speed of the one or more fans.
Description
[0001]This invention relates to a propulsion engine and particularly but not exclusively relates to a propulsion engine for an aircraft.BACKGROUND[0002]A propfan engine is a modified turbofan engine and typically comprises an unducted fan arranged on the same axis as the compressor and / or turbine of a turbofan engine. In one example of a propfan engine, thrust is produced by a pair of contra-rotating unducted fans, which are driven by a free power turbine via a differential epicyclic gearbox.[0003]FIG. 1 illustrates the basic engine architecture of such a contra-rotating propulsion engine. Contra-rotating propeller assemblies 1, 2 are driven by an engine core 3 supplying gas through a static structure 4 and inter-meshed free power turbines 5. The turbines 5 directly drive the propellers 1, 2 which, as indicated, are generally contra-rotating to provide propulsion for an aircraft, for example.[0004]The angular pitch angle of the propellers 1, 2 may be changed by an appropriate mechan...
Claims
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IPC IPC(8): F04D13/02
CPCF04D13/02B64C11/48F05D2260/406F05D2260/56F05D2260/79F05D2220/324B64D2027/005F04B1/053F04B1/06F04B7/0076F02K3/072F03C1/0409F03C1/0447F03C1/053F02C7/32F02C9/56F04B2205/03F05D2270/023Y02T50/60F04B1/04
Inventor EDWARDS, DAVID ANTHONYNICHOLSON, RICHARD
Owner ROLLS ROYCE PLC