Wound transformer core
US4814736A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 1988 |
| Grant date | Mar 21, 1989 |
| Priority date | — |
| Expiry date | Feb 1, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F41/0213
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A transformer core is made by winding a strip of ferromagnetic material, such as amorphous metal or silicon iron, on a winding mandrel to form a first annulus and cutting once through this annulus to create a plurality of individual laminations which are then assembled in packets about a nesting mandrel of a smaller diameter than the winding mandrel to form a second annulus. Each packet consist of a predetermined number of groups of laminations, with the ends of each lamination group lapping each other to form a lap joint. The lap joints of each packet are arranged in staggered positions to create a repeating step-lap joint pattern confined within a predetermined joint region. By decreasing the lap joint dimension and increasing the number of groups in successively assembled packets, the increase in build of the joint region over that of the remainder of the second annulus is minimized. The complete transformer core is uniquely characterized by its variable lap joint dimension and the absence of short sheets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.