Linear motor position detection system
US8362720B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2008 |
| Grant date | Jan 29, 2013 |
| Priority date | — |
| Expiry date | Dec 14, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K41/03
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A position detection system includes a linear motor having a rod in which magnetic poles of N pole and S pole are arranged alternately in an axial direction and a plurality of coils surrounding the rod a magnetic sensor for detecting change in the direction of the magnetic field of the rod caused by linear movement of the rod relative to the coils to output a sine wave signal and a cosine wave signal which are 90° phase shifted with respect to one another, and a position detecting circuit for detecting a position of the rod relative to the coils. As the magnetic sensor detects the change in the direction of the magnetic field of the rod, the sine wave signal and the cosine wave signal output from the magnetic sensor hardly vary even when the distance between the rod and the magnetic sensor is changed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.