| 摘要 |
Methods and apparatus are disclosed for providing reduced friction in drive screw assemblies, including electromechanical actuator (EMA) assemblies. A drive screw assembly is disclosed that includes a drive shaft, a drive screw, and a screw head. A stationary guide collar having a guide bore and a support surface receives the screw head or a portion of the drive screw. The guide collar may be fixed in angular relation to the screw head. As the screw head moves on a linear path during rotation of an associated drive shaft, a supported surface slides in only linear motion with respect to the support surface of the guide collar and as a result friction forces due only to linear motion are generated. Rotational friction forces and associated efficiency and power losses are consequently reduced or eliminated in the drive screw assembly. The supported surface may include a perimeter of the screw head, a circumferential surface of the second portion of the drive screw, or a circumferential surface of an intermediary screw shank.
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