Centrifugal de-clutch
View Patent ↗A mechanical mechanism is used to prevent a rotor of an aircraft from rotating when the rotor is not in use. The mechanical mechanism disengages when the speed of the rotor exceeds a speed threshold and the mechanism reengages when the speed of the rotor is below the speed threshold.
1. A centrifugal de-clutch coupled to a motor including a rotating part and stationary part, the centrifugal de-clutch comprising:
a ring including an inner circumference and an outer circumference, the ring including a plurality of flexures extending circumferentially from the inner circumference of the ring in a same direction along the inner circumference of the ring, each of the plurality of flexures including a first end and a second end, the first end of each flexure extending from the inner circumference of the ring and each flexure extending circumferentially along the inner circumference of the ring from the first end of the flexure to the second end of the flexure; and
a plurality of friction pads, each friction pad coupled to one of the plurality of flexures;
wherein each of the plurality of flexures is configured to preload the friction pad coupled to the flexure against the stationary part of the motor to resist rotation of the rotating part below a speed threshold of the rotating part to engage the centrifugal de-clutch; and
wherein each of the plurality of flexures is configured to bend outward to disengage the friction pad coupled to the flexure from the stationary part of the motor to allow the rotating part to freely rotate above the speed threshold to disengage the centrifugal de-clutch.
2. The centrifugal de-clutch of claim 1 , wherein the ring further includes a plurality of stop tabs protruding from the inner circumference towards the center of the ring, each stop tab configured to prevent at least one of the plurality of flexures from bending beyond a position of the stop tab.
3. The centrifugal de-clutch of claim 1 , wherein the centrifugal de-clutch is made from a metal selected from a group of metals consisting of aluminum, steel, and titanium.
4. The centrifugal de-clutch of claim 1 , wherein the centrifugal de-clutch is made from a composite material.
5. The centrifugal de-clutch of claim 4 , wherein the composite material comprises carbon fiber.
6. The centrifugal de-clutch of claim 1 , wherein each flexure curves from the first end to the second end.
7. The centrifugal de-clutch of claim 1 , wherein each of the plurality of friction pads is coupled to a second end of one of the plurality of flexures.
8. The centrifugal de-clutch of claim 1 , wherein the plurality of friction pads is made of brake pad material.
9. The centrifugal de-clutch of claim 1 , wherein the plurality of flexures are configured to reengage the plurality of friction pads to the stationary part of the motor when a speed of the rotor decreases below the speed threshold.
10. The centrifugal de-clutch of claim 1 , wherein the plurality of flexures are configured to disengage the plurality of friction pads from the stationary part of the motor due to centrifugal force applied by a mass of each of the plurality of flexures.
11. The centrifugal de-clutch of claim 1 , further comprising a plurality of proof masses, each proof mass coupled to a flexure.
12. The centrifugal de-clutch of claim 10 , wherein the plurality of flexures are configured to disengage the plurality of friction pads from the stationary portion of the motor due to centrifugal force applied by the plurality of proof masses.