Constant-velocity joint with torque-combining differential

1. A constant-velocity drive system for an aircraft rotor, the rotor being configured for rotation with a rotor mast, the constant-velocity drive system comprising:

a gimbal mechanism having a first gimbal and second gimbal, the first and second gimbals adapted to be driven in rotation by a rotor mast about a mast axis, the first and second gimbals providing for gimballing relative to the mast about gimbal axes generally perpendicular to the mast axis; and

a differential torque-combining mechanism connected to the gimbal mechanism and configured to be driven in rotation about the mast axis by the gimbal mechanism, the differential torque-combining mechanism being capable of gimballing relative to the mast about the gimbal axes and having an middle ring adapted to be attached to a yoke of the rotor for driving the yoke in rotation with the differential torque-combining mechanism;

a trunnion carrier affixed to the rotor mast, the trunnion carrier having a plurality of trunnions extending radially, each trunnion aligning with one of the gimbal axes, the plurality of trunnions configured to engage the first and second gimbals.

2. The constant-velocity drive system according to claim 1 , wherein the differential torque-combining mechanism comprises:

a first ring connected to the first gimbal;

a second ring connected to the second gimbal; and

a plurality of pin assemblies connecting the first and second rings to the middle ring, the pin assemblies allowing for relative motion of the rings while providing for transfer of forces from the first and second rings to the middle ring.

3. The constant-velocity drive system according to claim 1 , wherein the differential torque-combining mechanism comprises:

a first ring connected to the first gimbal;

a second ring connected to the second gimbal; and

a plurality of pin assemblies connecting the first and second rings to the middle ring, the pin assemblies each allowing for relative motion of the first and second rings while providing for transfer of forces from the first and second rings to the middle ring.

4. The constant-velocity drive system according to claim 1 , wherein the differential torque-combining mechanism comprises:

a first ring connected to the first gimbal;

a second ring connected to the second gimbal; and

a plurality of pin assemblies connecting the first ring and second ring to the middle ring, the middle ring being located between the first and second rings, the pin assemblies allowing for relative motion of the first and second rings while providing for transfer of forces from the first and second rings to the middle ring.

5. A constant-velocity drive system for an aircraft rotor, the rotor being configured for rotation with a rotor mast, the constant-velocity drive system comprising:

a gimbal mechanism having a first gimbal and a second gimbal adapted to be driven in rotation by the rotor mast about a mast axis, the first and second gimbals providing for gimballing relative to the rotor mast about gimbal axes generally perpendicular to the mast axis;

a trunnion carrier affixed to the rotor mast, the trunnion carrier having a plurality of trunnions extending radially, each trunnion aligning with one of the gimbal axes, the plurality of trunnions configured to engage the gimbals; and

a differential torque-combining mechanism connected to the gimbal mechanism and configured to be driven in rotation about the mast axis by the gimbal mechanism and being capable of gimballing relative to the rotor mast about the gimbal axes, the differential torque-combining mechanism comprising:

a first ring connected to a first gimbal;

a second ring connected to a second gimbal,

a middle ring adapted to be attached to a yoke of the rotor for driving the yoke in rotation with the differential torque-combining mechanism; and

a plurality of pin assemblies connecting the first and second rings to the middle ring, the pin assemblies allowing for relative motion of the first and second rings while providing for transfer of forces from the first and second rings to the middle ring.

6. The constant-velocity drive system according to claim 5 , wherein each pin assembly is configured for pivotally engaging one of the first, middle, and second rings.

7. The constant-velocity drive system according to claim 5 , wherein the middle ring is located between the first and second rings.

8. A constant-velocity drive system for an aircraft rotor, the rotor being configured for rotation with a rotor mast, the constant-velocity drive system comprising:

a gimbal mechanism having gimbals adapted to be driven in rotation by a rotor mast about a mast axis, the gimbals providing for gimballing relative to the mast about gimbal axes generally perpendicular to the mast axis; and

a differential torque-combining mechanism connected to the gimbal mechanism and configured to be driven in rotation about the mast axis by the gimbal mechanism and being capable of gimballing relative to the mast about the gimbal axes, the differential torque-combining mechanism comprising:

a first ring connected to a first gimbal;

a second ring connected to a second gimbal,

a middle ring adapted to be attached to a yoke of the rotor for driving the yoke in rotation with the differential torque-combining mechanism, the a middle ring being located between the first and second rings; and

a plurality of pin assemblies connecting the first ring and second ring to the middle ring, the pin assemblies allowing for relative motion of the first and second rings while providing for transfer of forces from the first and second rings to the middle ring.

9. The constant-velocity drive system according to claim 8 , wherein each pin assembly is configured for pivotally engaging one of the first and second rings or the middle ring.