Rack-and-pinion steering apparatus

A rack-and-pinion steering apparatus, which includes:

• pinion teeth provided on the circumferential face of a pinion shaft;
• and
• rack teeth provided on the outer face of a rack shaft and engaged with said pinion teeth, wherein
• the rotation of said pinion shaft connected to a steering member is transmitted to said rack shaft via the engagement portions of said pinion teeth and said rack teeth;
• said rack shaft is moved in the axial direction thereof to steer;
• a sum of a rack tilt angle θr which is a tilt angle of said rack tooth with respect to a reference line perpendicular to an axial line of said rack shaft and a pinion tilt angle θp which is a tilt angle of said pinion tooth with respect to an axial line of said pinion shaft equals a sum of a housing intersecting angle θh of a tilt angle of axial line of said pinion shaft with respect to said reference line and a correction angle Δθ,
• where the angles θr and θh are positive in one rotational direction and negative in another reverse rotational direction, reading from the reference line, about an axis perpendicular to both the axial line of said rack shaft and the axial line of said pinion shaft, the angle θp is positive in the one rotational direction and negative in the another reverse rotational direction, reading from the axial line, about the axis perpendicular to both the axial lines, and the angle Δθ is different from zero;
• and
• crowning is given on the tooth surface of said 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 said rack tooth opposed thereto.

A rack-and-pinion steering apparatus, which includes:

• pinion teeth provided on the circumferential face of a pinion shaft;
• and
• rack teeth provided on the outer face of a rack shaft and engaged with said pinion teeth, wherein
• the rotation of said pinion shaft connected to a steering member is transmitted to said rack shaft via the engagement portions of said pinion teeth and said rack teeth;
• said rack shaft is moved in the axial direction thereof to steer;
• a sum of a rack tilt angle θr which is a tilt angle of said rack tooth with respect to a reference line perpendicular to an axial line of said rack shaft and a pinion tilt angle θp which is a tilt angle of said pinion tooth with respect to an axial line of said pinion shaft equals a difference between a housing intersecting angle θh of a tilt angle of axial line of said pinion shaft with respect to said reference line and a correction angle Δθ,
• where the angles θr and θh are positive in one rotational direction and negative in another reverse rotational direction, reading from the reference line, about an axis perpendicular to both the axial line of said rack shaft and the axial line of said pinion shaft, the angle θp is positive in the one rotational direction and negative in the another reverse rotational direction, reading from the axial line, about the axis perpendicular to both the axial lines, and the angle Δθ is different from zero;
• and
• crowning is given on the tooth surface of said rack 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 said pinion tooth opposed thereto.

A rack-and-pinion steering apparatus, which includes:

• pinion teeth provided on the circumferential face of a pinion shaft;
• and
• rack teeth provided on the outer face of a rack shaft and engaged with said pinion teeth, wherein
• the rotation of said pinion shaft connected to a steering member is transmitted to said rack shaft via the engagement portions of said pinion teeth and said rack teeth;
• said rack shaft is moved in the axial direction thereof to steer;
• a sum of a rack tilt angle θr which is a tilt angle of said rack tooth with respect to a reference line perpendicular to an axial line of said rack shaft and a pinion tilt angle θp which is a tilt angle of said pinion tooth with respect to an axial line of said, pinion shaft equals a difference between a housing intersecting angle θh of a tilt angle of axial line of said pinion shaft with respect to said reference line and a correction angle Δθ,
• where the angles θr and θh are positive in one rotational direction and negative in another reverse rotational direction, reading from the reference line, about an axis perpendicular to both the axial line of said rack shaft and the axial line of said pinion shaft, the angle θp is positive in the one rotational direction and negative in the another reverse rotational direction, reading from the axial line, about the axis perpendicular to both the axial lines, and the angle Δθ is different from zero;
• and
• crowning is given on the tooth surface of said 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 said rack tooth opposed thereto.