Magnetic toothed disc preventing gearbox rattle in vehicles is produced using low-cost injection molding process which integrates hard magnetic material

摘要

The hard magnetic material (high retentivity and -coercivity) included in the toothed wheel, is annular in shape. It is contained in a holder (5) comprising soft magnetic material, the assembly being embedded in core material (12) of the anti-rattle disc. An Independent claim is included for the corresponding method of making the device. The holder is preferably a ring which is U-shaped in cross section. An open face of the ring coincides with a face of the gear wheel. The holder has locating projections (8) at its inner- (7) and outer- (6) circumferences. The raw material of the holder is metal sheet, which is formed to shape by pressing and/or stamping. The hard magnetic substance (11) is largely homogeneous, being embedded in a plastic material. Preferably a magnetic field is applied to magnetize it. The holder has no injected plastic on the exposed side face.