GB1453076A - High frequency induction heating - Google Patents

Abstract

1453076 Induction heating DAIDO METAL CO Ltd 16 Oct 1973 [12 July 1973] 48188/73 Heading H5H To obviate overheating of collars T1 provided on a body T2 of an article to be heated, a single turn cylindrical induction coil 1 has notches or apertures therein so positioned and sized relative to the collars T1, that the flux in the collars T 1 is substantially the same as in the body T2. Terminals 3 supply the coil 1 with H.F. current, and a sinuous cooling pipe 2 surrounds the coil. The shape, size, number and disposition of the apertures or notches, in the coil 1 are varied within wide limits to ensure equalized heating of various collared bodies. The axial length of the notches or apertures must be from one third to four times the axial length of the collar and the circumferential length of the notches or apertures or the sum of the lengths must be from “ to ¥ the circumferential length of the collar. The bodies may have two end collars as shown, one end collar, or several axially spaced collars, and the apertures or notches in the coil are designed accordingly. When the notches or apertures are not equally spaced about the coil, the article to be heated must be rotated about its axis. The notched portions may be formed by brazing conductive segments to the edges of the coil. A bearing made of lead-copper alloy was centrifugally cast by passing the alloy into a mild steel collared cylinder evenly heated by the indicator.