Propeller brake for a turbo-prop engine
AssigneeThe Bendix Corporation
InventorFrank Woodruff
Life of this patent
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Abstract
A propeller brake for a twin spool turbo-prop engine which permits the propeller to be locked in a stationary position with the engine running is disclosed. The propeller brake has a hydraulically actuated friction brake and hydraulically actuated locking mechanism rotatably connected to the engine spool turning the propeller. The friction brake stops the propeller from rotating in response to an external command. A hydraulic signal indicating the propeller has stopped rotating actuates the mechanical lock holding the propeller in a stationary position. A safety latch prevents the mechanical lock from being actuated in event of a hydraulic pressure or engine failure in flight.
Claims26
A propeller brake for a twin spool turbo-prop engine wherein the engine's propeller is independently driven by one of said twin spools, comprising:
- a housing having an internal chamber and means for attaching said housing to the engine;
- a shaft having one end adapted to be rotatably connected to the one spool driving the engine's propeller and the other end and supported for rotation relative to said housing disposed in said chamber;
- means for generating a propeller signal in response to the rotation of the one spool;
- means for generating an engine signal in response to the rotation of the other spool;
- signal generator means for generating a first input signal in response to said engine signal and an external command to stop the rotation of the propeller and for generating a second input signal in response to either the simultaneous absence of said engine and propeller signals or to the absence of said propeller signal and an external command to stop the rotation of the propeller;
- brake means disposed in said chamber for frictionally interconnecting said shaft and said housing in response to said first input signal to generate a force retarding the rotation of said shaft relative to said housing;
- and
- lock means disposed in said chamber for non-rotatably interconnecting said shaft and said housing in response to said second input signal to inhibit the rotation of said shaft relative to said housing.
A propeller brake for a twin spool turbo-prop engine having the propeller independently driven from one of said twin spools, a propeller actuating pump providing actuator fluid at a first pressure when the propeller is turning and an engine lubrication pump providing lubrication fluid at a second pressure when the engine is running, comprising:
- a housing having an internal chamber and means for fixedly attaching said housing to the engine;
- a shaft having one end adapted to be rotatably connected to the one spool, the other end disposed in said internal chamber, and supported for rotation relative to said housing;
- a brake drum means disposed in said internal chamber, non-rotatable with respect to said housing and axially displaceable in a direction parallel to the axis of said shaft;
- brake shoe means disposed in said internal chamber fixedly attached to said shaft and rotating therewith;
- first means for engaging said brake drum means with said brake shoe means in response to a first input signal to generate a frictional force retarding the rotation of said shaft with respect to said housing;
- first lock member means disposed in said internal chamber, non-rotatable with respect to said housing and axially displaceable in a direction parallel to the axis of said shaft;
- second lock member means disposed in said housing, fixedly attached to said shaft and rotating therewith;
- second means for engaging said first lock means with said second lock means in response to the absence of a second input signal to inhibit the rotation of said shaft relative to said housing;
- signal generator means for generating said first and second input signal in response to the pressure of said actuator and lubrication fluids and an external command to stop said propeller from rotating, said signal generator means generating said first input signal in response to the lubrication fluid having said second pressure indicating the engine running and an external command to stop the propeller from turning and generating said second input signal when the pressure of the propeller actuator fluid is above a predetermined pressure and when the pressure of the lubricating fluid is above said same predetermined pressure in the absence of a command to stop the propeller from rotating.
Dependencies are inferred from the claim text.