The present invention provides a rack-and-pinion steering apparatus
capable of effectively reducing reverse input, while a high degree of
design freedom is secured. The sum of the tilt angle of a rack tooth with
respect to a reference line perpendicular to the axial line of a rack
shaft and the tilt angle of a pinion tooth with respect to the axial line
of a pinion shaft does not coincide with the tilt angle of the axial line
of the pinion shaft with respect to the reference line. Crowning is given
on the tooth surface of the rack tooth (or the pinion tooth) in order to
decrease the tooth width on one end side in the direction of tooth trace
and to increase the tooth width on the other end side according to the
state of contact with the pinion tooth (or the rack tooth) opposed
thereto.