Direct drive valve and force motor assembly including interchangeable stator assembly and alignment system or method
US4641812A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 1985 |
| Grant date | Feb 10, 1987 |
| Priority date | — |
| Expiry date | May 23, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49758
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A direct drive valve and force motor assembly including interchangeable stator assembly and method for accurately setting the magnetic spring null of the motor with respect to the servo valve hydraulic null independent of the actual motor stator assembly, whereby the motor stator assembly may be configured as an interchangeable plug-in module with interface electrical connector. This is accomplished by using a simple fixture which simulates the motor stator assembly and senses rotor magnet position. The stator simulating fixture may be used to rotatably adjust the position of the rotor casing so that the magnetic spring null corresponds to the hydraulic valve null. Both the stator simulating fixture and motor stator assembly include an index pin engageable with a stator alignment keyway in the rotor casing for maintaining the desired orientation therebetween. Also, rotor over-travel stops keyed to the rotor casing may be centered during the nulling process. Once the nulling process is complete, the stator simulating fixture may be removed and the motor stator assembly may be mounted in place. The motor stator assembly may be loosely held in an outer housing which has limited rotati…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.