Stepping motor unit and rotary control valve incorporating the same
US5043649A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1989 |
| Grant date | Aug 27, 1991 |
| Priority date | — |
| Expiry date | Dec 28, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P8/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A stepping motor unit includes a stepping motor of the type wherein the interior of the stepping motor is filled with an oil, a detector for detecting the temperature of the oil in the stepping motor, a device for varying an upper limiting value of the rotational speed of the stepping motor and an upper limiting value of the rotational acceleration of the stepping motor in view of a current viscous condition of the oil based on the temperature detected by the temperature detector, and a driver for driving the stepping motor at a rotational speed and a rotational acceleration which fall in ranges, respectively, not exceeding the upper limiting values. The stepping motor unit thus constructed has rapid and accurate response characteristics and is capable of operating reliably without falling out of step even when the environmental temperature varies in a very wide range. A rotary control valve incorporating such stepping motor unit is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.