The disclosure provides a steering system for a vehicle. The steering system may include a steering rack and an electronic power steering (EPS) system. The EPS system may include an actuator that assists movement of the steering rack, a torque sensor; an angle sensor; and an EPS system controller. The EPS controller may be configured to determine a steering rack center point indicating a center of the steering rack between opposite maximum steering angles. The EPS controller may be configured to determine a vehicle center zero point. The EPS controller may be configured to store the vehicle center zero point in response to determining that the vehicle center zero point is within a threshold of the steering rack center point.

A rack bar unit of a vehicle steering device may include a rack bar body and a rack gear made of different materials, in which the rack gear may be coupled to the rack bar body.

A rack-and-pinion steering gear unit includes a rack shaft and a cylindrical portion. The rack shaft is configured as a hollow pipe as a whole by bending an elongated metal plate such that widthwise end edges of the metal plate are butted to each other. A cylindrical portion is fitted on an end portion of the rack shaft.

Rack bar 10 for transmitting a steering operation to steered wheels while converting a rotational movement of a pinion shaft rotatably connected to a steering wheel into an axial movement, the rack bar being formed by conducting a die forging process on a material having an approximately circular cross section. A pair of face width-enlarged portions 15 is provided at both ends that rack teeth 14 have in face width direction. With this, it becomes possible to ensure face width dimension W of rack teeth 14 larger than outer shape S of a circular cross section of rack main body 13 (material), which results in an improvement of a contact gear ratio between the pinion teeth and the rack teeth.

A subframe includes: a main body part; a vehicle body support part that supports the main body part to a vehicle body; and a stabilizer that is disposed above the main body part. The main body part includes a torque rod support part that supports a torque rod which is connected to a power unit. The torque rod support part includes: a front opening portion which is formed at a forward position and into which the torque rod is capable of being inserted; and a rear opening portion which is formed at a rearward position. The stabilizer is arranged at a rearward position that is overlapped with the rear opening portion in a forward/rearward direction.

According to embodiments, it is possible to prevent vibration and gaps in a coupling structure between rotation shafts, thus allowing for reduction in noise, enhanced responsiveness, accurate steering, and a better straight driving performance.

A method for manufacturing a rack bar having a first rack and a second rack is provided. The first and second racks have an angular positional difference around an axis of the rack bar. The method includes forming a first flat surface and a second flat surface on an outer circumference of a single hollow shaft member, with the angular positional difference being provided between the first and second flat surfaces, and forming the first rack on the first flat surface and the second rack on the second rack surface by press-fitting one or more mandrels into the hollow shaft member in a state in which one or more teeth dies corresponding to the first rack and the second rack is pressed against the first flat surface and the second flat surface.

A rotation-linear motion conversion apparatus (10) includes: a rack bar (30) in which a rack gear (32) is formed; a housing (40) that surrounds the rack bar (30); a pinion shaft (20) including a pinion gear (22) that engages with the rack gear (32) and that is inserted inside the housing (40); and a support part (50) that is provided on an opposed surface (41s1), which is opposed to the rack gear (32), of the housing (40) and that supports the rack bar (30) movably in a longitudinal direction of the rack bar (30).

A steering system includes a rack housing in which a rack shaft is housed, rack ends fitted to respective end portions of the rack shaft and coupled to respective steered wheels, and shock-absorbing members provided between the rack housing and the respective rack ends. When the rack shaft moves in a direction in which an end face of the rack end approaches a restricting surface of the rack housing and thus the rack shaft reaches a position after the shock-absorbing member is compressed by a compression amount, a control unit creates a normal input end through electronic stopper control of reducing an assisting force to be generated by a motor. This restricts movement of the rack shaft in a direction in which the end face approaches the restricting surface.

A steering column system includes: a rotatable steering shaft that has a proximal end attached to a steering wheel and is configured to transfer rotational input at the steering wheel to a steering rack of the vehicle; a stationary driver-side airbag (DAB) shaft that is mounted in the vehicle and extends along the steering shaft; and a DAB module that contains an airbag and is fixedly mounted to a proximal end of the DAB shaft within a region of the steering wheel. The steering wheel and the steering shaft are configured to rotate independently of the DAB module and the DAB shaft, respectively.