Electrically actuated aircraft brakes

In a brake assembly comprising a brake disk stack and a pressure plate in communication with the stack, the improvement comprising:

• a recirculating-ball screw drive operatively positioned with respect to the pressure plate comprising
• (a) a relatively stationary annular-shaped member having a bore and a ball bearing race formed within its bore;
• (b) an annular-shaped ram member mounted within the bore of the stationary member and adapted for axial linear motion therethrough for effecting contacting engagement with the pressure plate, said ram having a plurality of helical ball grooves of a particular pitch about an outwardly facing surface thereof;
• and
• (c) a relatively rotatable annular-shaped member mounted coaxially between the relatively stationary and ram members and having a ball bearing race formed in an outwardly facing surface and in relative position to the ball race within the bore of the stationary member, the two races and a plurality of ball bearings carried between them forming a thrust bearing as between the two members, said rotatable member further comprising a plurality of ring gear teeth about a peripheral edge surface thereof and at least one helical ball groove turn formed within its bore of the same pitch as the ball grooves in the ram member, said ball grooves carrying a plurality of balls therebetween to drive the ram member upon rotation of the rotatable member, said balls being recirculated through a ball transfer passageway formed within the bore of the rotatable member to effect continued ball-screw drive motion of the linearly moving ram member;
• and
• a plurality of torque motors mounted within the relatively stationary member, each said motor carrying a pinion gear operatively engageable with the ring gear of the relatively rotatable member, said torque motors regulated by an operator for selectively moving the ram into and out of forceful contacting engagement with the pressure plate.