A steering rack piston assembly (10) employed in a power steering rack and piston assembly. The assembly includes a shaft (bar) (11) upon which there is mounted a piston (12). The shaft (11) has a longitudinal axis (13), that is also the longitudinal axis of the piston (12). The piston (12) has an outer groove (15) that receives a seal (16) that slidably engages in a cylindrical surface of an outer housing that is not illustrated. The piston (12) and shaft (11) move along the axis (13) relative to the outer housing as a result of pressure within the fluid located on opposite sides of the piston (12).

An electric power steering device 100 includes: an electric motor 110 configured to apply a driving force to steer a wheel in response to operation of a steering wheel; and a control device 10 configured to perform control of drive of the electric motor by estimating a degree of sloping in a transverse direction of a roadway on which a vehicle travels, determining, based on the estimated degree of sloping, a correction current for correcting a target current required for the electric motor to generate the driving force, and correcting the target current with the correction current.

An electric power steering device 100 includes: an electric motor 110 configured to apply a driving force to steer a wheel in response to operation of a steering wheel; and a control device 10 configured to perform control of drive of the electric motor by estimating a degree of sloping in a transverse direction of a roadway on which a vehicle travels, determining, based on the estimated degree of sloping, a correction current for correcting a target current required for the electric motor to generate the driving force, and correcting the target current with the correction current.

A steering device for a motor vehicle, in particular a steer-by-wire steering device, comprises a steering wheel, which is able to act on a steering sensor for measuring the rotation angle position of the steering wheel, an electromechanical actuator, which is able to act on a rack for steering wheels, and an electronic controller, which is adapted to detect the steering wheel angle position and to control the electromechanical actuator, wherein the steering device further comprises a feedback actuator acting on the steering wheel, wherein the controller is adapted to measure natural oscillations of the motor vehicle and to apply them with a corresponding amplitude to the feedback actuator.

A steering device for a motor vehicle, in particular a steer-by-wire steering device, comprises a steering wheel, which is able to act on a steering sensor for measuring the rotation angle position of the steering wheel, an electromechanical actuator, which is able to act on a rack for steering wheels, and an electronic controller, which is adapted to detect the steering wheel angle position and to control the electromechanical actuator, wherein the steering device further comprises a feedback actuator acting on the steering wheel, wherein the controller is adapted to measure natural oscillations of the motor vehicle and to apply them with a corresponding amplitude to the feedback actuator.

The present invention provides a power assist steering system for a vehicle having a wheel. The steering system includes a first reciprocating member coupled to the wheel such that reciprocating movement of the first reciprocating member provides turning movement of the wheel, a steering input engaged with the first reciprocating member such that rotation of the steering input provides reciprocating movement of the first reciprocating member, and a steering assist assembly including a second reciprocating member engaged with the steering input such that reciprocating movement of the second reciprocating member provides an assist force to the steering input. Preferably, the first and second reciprocating members engage the steering input at locations opposed to each other and also move along paths that are substantially parallel to each other.

A power steering assembly for a hydraulic power steering system of motor vehicles includes an input shaft configured for connection to a steering wheel, an output shaft coupled to the input shaft configured for operational engagement with a steering rod, a hydraulic servo valve, an actuator, a sensor system, and an evaluation unit. The coupling between the input and output shafts is realized by a torsion bar and permits a first relative rotation between the input and output shafts. The hydraulic servo valve, which controls a hydraulic pressure and thus a steering assistance depending on the steering torque applied by a driver, has a rotatable control element engaged with, and driven by, the output shaft. An engagement between the output shaft and control element provides for a second relative rotation therebetween. This engagement includes a multi-stage planetary gear unit. The steering power assistance system is controlled depending on a third relative roation between the input shaft and control element. The actuator relatively displaces the control element in relation to the output shaft to influence the steering power assistance characteristics. The sensor system measures at least one differential angle between the control element and input shaft, wherein the control element is a valve sleeve disposed coaxially with the input and output shafts and the sensor system includes an encoder sleeve non-rotatably connected to the valve sleeve.

A vehicle and vehicle drive apparatus having a hydraulic pump and a first and second hydraulic motor, each disposed on a center section, is disclosed. A main housing having a housing cover contains the hydraulic pump and the first and second hydraulic motors, which in turn drive first and second motor shafts, respectively. The first and second motor shafts are enclosed in first and second motor shaft housings, respectively, and the main housing combined with the housing cover and the first and second motor shaft housings form a sealed sump. The main housing has mounted thereon a pinion shaft, a pinion gear and a steering rack meshed with the pinion gear. A first steering arm is rotatably mounted to the first motor shaft housing and connected to the steering rack and a second steering arm is rotatably mounted to the second motor shaft housing and connected to the steering rack.

A vehicle and vehicle drive apparatus having a hydraulic pump and a first and second hydraulic motor, each disposed on a center section, is disclosed. A main housing having a housing cover contains the hydraulic pump and the first and second hydraulic motors, which in turn drive first and second motor shafts, respectively. The first and second motor shafts are enclosed in first and second motor shaft housings, respectively, and the main housing combined with the housing cover and the first and second motor shaft housings form a sealed sump. The main housing has mounted thereon a pinion shaft, a pinion gear and a steering rack meshed with the pinion gear. A first steering arm is rotatably mounted to the first motor shaft housing and connected to the steering rack and a second steering arm is rotatably mounted to the second motor shaft housing and connected to the steering rack.

A steering device includes a rack shaft that turns wheels, a bush slidably support the rack shaft, tie-rods joined to the rack shaft, boots that cover a joining portion that joins the rack shaft and the tie-rod. A protrusion part is formed on either one of the bush and a rack housing so as to protrude toward the other. A restriction groove into which the protrusion part is inserted is formed on the other. A space inside the first boot and a space inside the second boot constantly communicate with each other via the restriction groove.