Abstract: Embodiments are directed to a drive shaft apparatus comprising a first rotary member and a second rotary member arranged coaxially with said first rotary member. The rotary members are fixedly connected at a first end so that they rotate together. Each rotary member has a set of elements spaced apart around its circumference at a second end. The elements on the first rotary member are spaced apart from the elements on the second rotary member at rest. The first rotary member undergoes torsion when a load is applied during rotation, which causes the first rotary member elements to move closer to the second rotary member elements. The first elements engage the second elements when a torque load less than a yield torque is applied to the first rotary member, which transfers at least a portion of the torque load to the second rotary member.

Abstract: Embodiments are directed to a drive shaft apparatus comprising a first rotary member and a second rotary member arranged coaxially with said first rotary member. The rotary members are fixedly connected at a first end so that they rotate together. Each rotary member has a set of elements spaced apart around its circumference at a second end. The elements on the first rotary member are spaced apart from the elements on the second rotary member at rest. The first rotary member undergoes torsion when a load is applied during rotation, which causes the first rotary member elements to move closer to the second rotary member elements. The first elements engage the second elements when a torque load less than a yield torque is applied to the first rotary member, which transfers at least a portion of the torque load to the second rotary member.

Abstract: In one embodiment, a split torque gearbox can include a first compound gear and a second compound gear. The compound gears can each include a piston housing with a fluid inlet and a piston received in the piston housing and defining a space within the first piston housing exposed to the fluid inlet. The split torque gearbox can include a fluid line coupled to each of the fluid inlets to supply a fluid to the pistons at a predetermined pressure, the fluid line coupled to the second fluid inlet to supply fluid to the second piston assembly at the predetermined pressure. Pressure developed in the pistons is equal for all gear shafts, and can equalize torque imbalances in the split torque gearbox.

Abstract: In one embodiment, a split torque gearbox can include a first compound gear and a second compound gear. The compound gears can each include a piston housing with a fluid inlet and a piston received in the piston housing and defining a space within the first piston housing exposed to the fluid inlet. The split torque gearbox can include a fluid line coupled to each of the fluid inlets to supply a fluid to the pistons at a predetermined pressure, the fluid line coupled to the second fluid inlet to supply fluid to the second piston assembly at the predetermined pressure. Pressure developed in the pistons is equal for all gear shafts, and can equalize torque imbalances in the split torque gearbox.