Abstract: A magnet rotor assembly comprises a magnet sleeve held on a rotor shaft by a rigid adhesive layer that includes at least one axial wedge shape corresponding to an axial irregularity on at least one of the surfaces bonded by the adhesive layer. Improved crush strength in the magnet sleeve and in other bonded metal parts, both initially and after exposure to high temperatures is accomplished by impregnating the parts with a curable resin.

Abstract: Improved resin-bonded powdered metal components are protected against corrosion and reduction of crush strength during contact with corrosive fluids such as alcohols, ethanol-containing fuels, glycols and peroxide-containing fuels by a resin system coating that, when cured, provides a relatively high crosslink density and relatively few hydrolysable radicals. Magnetic properties of resin-bonded powdered metal magnets are protected from heat degradation by the cured resin coating. The coating can be a heat-cured resin system comprising a phenol novolac resin and a compatible hardener. In one embodiment magnetizable powdered materials have an uncured resin system coating to provide a B-stage material that can be cured after compression shaping.