Electromagnet, in particular a proportional magnet for operating a hydraulic valve
US6799746B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 28, 2002 |
| Grant date | Oct 5, 2004 |
| Priority date | — |
| Expiry date | May 8, 2023 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01L2820/031
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electromagnet having a hollow cylindrical coil former fitted with a coil winding and surrounded by a magnet housing. The coil former is bounded by upper and lower pole shoes. A nonmagnetic metal tube in the hollow cylinder of the magnet defines an armature space for a magnet armature that divides the armature space into first and second chambers, which are connected via a pressure equalizing channel in the magnet armature. A push rod passes through an axial hole in the lower pole shoe, to a control piston of a hydraulic valve, whose interior is connected via a further pressure equalizing channel in the lower pole shoe to the first chamber of the armature space. The push rod is a profiled rod contacting the magnet armature, the rod is of a cross-sectional shape different than that of the axial hole in the lower pole shoe and of a cross-sectional area less than that of the axial hole. The magnet armature has a central longitudinal hole of a diameter smaller than the largest profile width and larger than the smallest profile width of the push rod.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.