Reduced-friction drive screw assembly
US7520192B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 18, 2004 |
| Grant date | Apr 21, 2009 |
| Priority date | — |
| Expiry date | Feb 2, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/1868
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.