Device for controlling blade angle, and propeller
View Patent ↗The invention relates to a device ( 1 ) for controlling the setting of the blades ( 2 ) of a rotor ( 3 ) of a propeller, including a radial shaft ( 6 ), the rotation of which modifies the setting of the blade ( 2 ), a main spring ( 13 ), a first end ( 14 ) of which is connected to the rotor ( 3 ) and a second end ( 15 ) of which is connected to a part ( 8, 10 ) having an axial movement which drives the rotation of the radial shaft, and has a movement, the travel of which is offset relative to the first end in a direction ( 7 ) that is orthogonal to the axial direction ( 5 ), the main spring exerting a resilient force which aims to move the parts toward a position in which the cord of the profile of the blade is orthogonal to the plane of rotation of the propeller, in the absence of part control by means of a jack.
1. A control device ( 1 ) for the blade angle of the blades ( 2 ) of a rotor ( 3 ) of a propeller ( 4 ), comprising:
a radial shaft ( 6 ) whereof the rotation modifies the blade angle of the blade ( 2 ),
pieces ( 8 , 10 ) capable of being displaced jointly according to an axial direction ( 5 ) of the device ( 1 ), so as to cause rotation of the radial shaft ( 6 ),
at least one actuator ( 12 ) controlling displacement of the pieces ( 8 , 10 ) according to the axial direction ( 5 );
characterized in that it comprises:
at least one main spring ( 13 ) with a first end ( 14 ) connected to the rotor ( 3 ), and with a second end ( 15 ) connected to one of the pieces ( 8 , 10 ), the second end ( 15 ) presenting a displacement with a course which is shifted relatively to the first end ( 14 ) according to a direction ( 7 ) orthogonal to the axial direction ( 5 ),
the main spring ( 13 ) exerting resilient force tending to displace the pieces ( 8 , 10 ) towards a position in which the cord ( 16 ) of the profile of the blade ( 2 ) is orthogonal to the plane of rotation of the propeller ( 4 ), in the absence of control of the pieces ( 8 , 10 ) by the actuator ( 12 ).
2. The device according to claim 1 , wherein the main spring ( 13 ) exerts resilient force tending to displace the pieces ( 8 , 10 ) towards a position in which the cord ( 16 ) is orthogonal to the plane of rotation of the propeller ( 4 ), from an initial position of the pieces ( 8 , 10 ) for which the cord ( 16 ) presents an angle between −30° and +90° with the plane of rotation of the propeller ( 4 ).
3. The device according to claim 1 , wherein the device ( 1 ) has at least one stop ( 17 ) for limiting axial displacement of the pieces ( 8 , 10 ).
4. The device according to claim 3 , wherein the stop ( 17 ) prevents axial displacement of the pieces ( 8 , 10 ) beyond a position for which the cord ( 16 ) presents an angle greater than a feathered position.
5. The device according to claim 1 , comprising at least one secondary spring ( 18 ) configured to exert axial resilient force on the pieces ( 8 , 10 ) which opposes the resilient force exerted by the main spring ( 13 ) on the pieces ( 8 , 10 ).
6. The device according to claim 5 , wherein the secondary spring ( 18 ) exerts axial resilient force on the pieces ( 8 , 10 ) when the latter are located in a position for which the cord ( 16 ) presents an angle greater than or equal to +(90−θ)° with the plane of rotation of the propeller ( 4 ), θ being positive.
7. The device according to claim 1 , further comprising at least one tertiary spring ( 20 ), configured to exert axial resilient force on the pieces ( 8 , 10 ), which opposes the resilient force exerted by the main spring ( 13 ) on the pieces ( 8 , 10 ), when the latter are located in a position for which the blade exerts force on the pieces ( 9 , 10 ) tending to displace them towards a position for which the cord ( 16 ) presents an angle positive with the plane of rotation of the propeller ( 4 ).
8. The device according to claim 7 , wherein the tertiary spring ( 20 ) is configured to exert axial resilient force on the pieces ( 8 , 10 ) which opposes the resilient force exerted by the main spring ( 13 ) on the pieces ( 8 , 10 ) when the latter are located in a position for which the cord ( 16 ) presents an angle in an interval whereof the terminals are (−30+β)° and (−30°), β being positive.
9. A propeller comprising a rotor ( 3 ) and blades ( 2 ), characterized in that it comprises a control device ( 1 ) of the blade angle of the blades ( 2 ), according to claim 1 .
10. The propeller according to claim 9 , wherein the device comprises a main spring ( 13 ) for each of the blade ( 2 ).