TORQUE BALANCED DRIVES FOR SPACE STATION APPLICATIONS

TO ELIMINATE DYNAMIC DISTURBANCES TO THE SPACE STATION AND ITS ONBOARD EXPERIMENTS IT WOULD BE DESIRABLE TO PROVIDE ACTUATOR DRIVES AND DRIVES FOR DYNAMIC EXPERIMENTS WHICH HAVE A ZERO NET OUTPUT TORQUE. THIS CAN BE ACCOMPLISHED BY UTILIZING DRIVES WITH DUAL, COUNTERROTATING, TORQUE BALANCEDOUTPUTS. BOTH OUTPUTS COULD BE USED AS ACTIVE DRIVES, OR ONE AS AN ACTIVE DRIVE AND THE SECOND AS A DRIVE INTO A PASSIVE POWER ABSORBER. PLANETARY TRACTION DRIVES WITH DUAL ROLLER CLUSTERS, EACH FEEDING AN OUTPUT, HAVE BEEN CONCEIVED BY NASTEC, INC./TRANSMISSION RESEARCH, INC. A TYPICAL ROLLER CLUSTER IS SHOWN IN FIGURE 1. IT HAS A ROTATING SUN ROLLER, TWO ROWS OF NON-ORBITING PLANET ROLLERS AND A ROTATING RING ROLLER. THE DUAL OUTPUT DRIVE TO BE DESIGNED WOULD INCORPORATE TWO ROLLER CLUSTERS WITH A ROTATING CLUSTER CARRIER CONNECTING THE TWO SETS OF PLANET ROLLERS. INPUT ISTO A ROTATING SUN ROLLER. ONE RING ROLLER OUTPUT IS FROM THE ROTATING SUN ROLLER CLUSTER. A SECOND, STATIONARY SUN ROLLER CLUSTER IS DRIVEN BY THE ROTATING CLUSTER CARRIER WHICH TRANSFERS TORQUE AND MOTION TO THE SECOND RING ROLLER OUTPUT. THE TWO OUTPUTS ARE AT EQUAL SPEED AND TORQUE AND OPPOSITE ROTATION. A SKETCH OF SUCH A DRIVE IS SHOWN IN FIGURE 2. A SPECIFIC DRIVE RATIO, TORQUE REQUIREMENT AND SPEED WILL BE CHOSEN FOR STUDY. DRIVE KINEMATICS, SIZE LIFE AND EXPECTED PERFORMANCE WILL BE DEFINED. A FINAL DESIGN AND MANUFACTURING DRAWINGS WILL BE COMPLETED. A TEST PROGRAM FOR PHASE II WILL BE WORKED OUT.