Rotor configuration for reaction drive rotor system
A rotor system is disclosed for a reactive drive rotary wing aircraft. Apparatus and methods are disclosed for maintaining the rigidity of the rotor and eliminating play between flight controls and the rotor by mounting swashplate actuators to a flange rigidly secured to the mast. Methods are disclosed for modulating the temperature of oil pumped over one or more of the mast bearing, swashplate bearing, and spindle bearing. The temperature of air passively or actively drawn through rotor may also be modulated to maintain bearing temperature within a predetermined range. Structures for reducing pressure losses and drag on components due to air flow through the rotor are also disclosed. A rotor facilitating thermal management by oil and air flow is also disclosed. Surfaces interfacing between the swashplate and the mast and between control rods and the swashplate or pitch horn may bear a solid lubricant layer.
1. A rotor system comprising:
a mast mounted to an airframe and defining a rotor axis;
a hub rotatably mounted to the mast and rotatable with respect to the mast only about the rotor axis, the hub defining a hub cavity; and
a plurality of blades mounted to the hub, blade of the plurality of blades defining a duct in fluid communication with the hub cavity, the blade duct being defined by a blade spar of the each blade, the blade spar extending through the hub and into the hub cavity and having a pitch horn secured thereto and positioned within the hub cavity;
a swashplate encircling the mast;
a plurality actuators coupled to the swashplate and adjusting the position of the swashplate; and
a plurality of pitch control rods coupling the swashplate to the pitch horns of the plurality of blades;
a shroud encircling the mast and rotatably engaging the hub, the shroud defining an air channel in fluid communication with the cavity, the swashplate being located within the air channel and the plurality of pitch control rods extend into the hub cavity; and
a compressed air source in fluid communication with the air channel.
2. The rotor system of claim 1 , wherein the mast is fixed to the airframe with respect to rotation about the rotor axis.
3. The rotor system of claim 1 , wherein the actuators are mounted to the mast.
4. The rotor system of claim 1 , further comprising at least one roller bearing interposed between the mast and hub.
5. The rotor system of claim 1 , further comprising at least two roller bearings interposed between the mast and hub and axially offset from one another along the rotor axis.
6. The rotor system of claim 1 , wherein the mast is mounted to a pivoting mount, the pivoting mount being pivotably secured to the airframe and defining a pivot axis perpendicular to the rotor axis.
7. The rotor system of claim 1 , further comprising at least one tapered roller bearing interposed between the blade spar and hub.
8. A rotorcraft comprising:
an airframe;
a mast mounted to the airframe and defining a rotor axis;
a hub rotatably mounted to the mast and rotatable with respect to the mast only about the rotor axis, the hub defining a hub cavity; and
a plurality of blades mounted to the hub, each blade of the plurality of blades defining a duct in fluid communication with the hub cavity, the blade duct being defined by a blade spar of the each blade, the blade spar extending through the hub and into the hub cavity and having a pitch horn secured thereto and positioned within the hub cavity;
a swashplate encircling the mast;
a plurality actuators coupled to the swashplate and adjusting the position of the swashplate; and
a plurality of pitch control rods coupling the swashplate to the pitch horns of the plurality of blades;
a shroud encircling the mast and rotatably engaging the hub, the shroud defining an air channel in fluid communication with the cavity, the swashplate being located within the air channel and the plurality of pitch control rods extend into the hub cavity; and
a compressed air source in fluid communication with the air channel.
9. The rotorcraft of claim 8 , wherein the mast is fixed with respect to rotation about the rotor axis with respect to the airframe.
10. The rotorcraft of claim 9 , further comprising a pivoting mount pivotably mounted to the airframe such that the pivoting mount is rotatable with respect to the airframe about a pivot axis perpendicular to the rotor axis.
11. The rotorcraft of claim 8 , wherein the actuators are mounted to the mast.
12. The rotorcraft of claim 8 , further comprising at least two roller bearings interposed between the mast and hub and offset from one another along the rotor axis.