Ball screw drive with dynamically adjustable preload
US5704250A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 4, 1996 |
| Grant date | Jan 6, 1998 |
| Priority date | — |
| Expiry date | Apr 4, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/19902
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A threaded ball screw is stationarily non-rotatably mounted in a machine tool to extend parallel to the line of action traversed by a carriage. A pair of threaded ball nuts are laterally restrained in and mounted for free rotation thereof in a drive mechanism of the carriage and threadably and concentrically engage the ball screw in laterally spaced apart co-axial relationship therealong. A pair of digitally controlled electric drive motors are mounted in the carriage for individually imparting rotational torque to the nuts. A conventional programmably CNC controller is programmed to synchronously control both motors for causing the ball nuts to conjointly produce computer controlled linear motion and positioning of the carriage along the stationary ball screw, and to develop anti-backlash pre-load forces between the ball nuts relative to the ball screw. The system can also produce an electromotive and/or frictional braking force for decelerating and/or holding the carriage in a selected stationarily fixed position along the line of action. The two motor rotors can exert rotational torque on the ball nuts simultaneously in the same or opposite rotary directions with the carriage mo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.