WORM GEAR, AND ELECTRIC POWER STEERING DEVICE

摘要

Provided is a worm gear comprising a worm shaft having a tooth section of a recessed arcuate shape, and a worm wheel adapted to mesh with the worm shaft and constituted of a tooth crest, a tooth flank and a tooth face formed between the crest and the flank, such that a normal at the tooth face intersecting a pitch circle extends closer to the center side than the tooth flank.