A hydraulic steering unit includes a pressure port connected to a main flow path and a tank port connected to a tank flow path, and a working port arrangement having left and right working flow paths. A first bridge arrangement has first left and first right orifices connected to the main flow path and to first left or first right connecting points, respectively, each connecting point associated respectively with the left or right working flow paths, and second left and second right orifices connected to the tank flow path and to the first left or first right connecting points, respectively. A second bridge arrangement has a similar orifice arrangement connected to second left or second right connecting points. The first and second bridge arrangements have different steering characteristics. Selection means for connecting one of the bridge arrangements between the pressure port and the working port arrangement are provided.

A hydraulic steering unit includes a pressure port connected to a main flow path and a tank port connected to a tank flow path, and a working port arrangement having left and right working flow paths. A first bridge arrangement has first left and first right orifices connected to the main flow path and to first left or first right connecting points, respectively, each connecting point associated respectively with the left or right working flow paths, and second left and second right orifices connected to the tank flow path and to the first left or first right connecting points, respectively. A second bridge arrangement has a similar orifice arrangement connected to second left or second right connecting points. The first and second bridge arrangements have different steering characteristics. Selection means for connecting one of the bridge arrangements between the pressure port and the working port arrangement are provided.

A hydraulic auxiliary axle steering control system is provided. In detail, there is provided a hydraulic auxiliary axle steering control system that can perform quick, precise, and safe control by changing an auxiliary axle steering control angle in accordance with a vehicle speed to problems with instability of driving, wear of tires, and a turning radius when a vehicle is driven at a low speed.

A hydraulic auxiliary axle steering control system is provided. In detail, there is provided a hydraulic auxiliary axle steering control system that can perform quick, precise, and safe control by changing an auxiliary axle steering control angle in accordance with a vehicle speed to problems with instability of driving, wear of tires, and a turning radius when a vehicle is driven at a low speed.

Steering boxes currently available on the market in order to convert the rotation of the steering wheel into the angular rotation of the wheels are not suitable to be partially built into the rim of the wheels of an electric car. In addition, existing boxes do not allow the independent rotation of the wheels or wide turning radii. These limitations are overcome using a system comprising: a body into which at least one motor is built using corresponding supports, which motor(s) actuate(s) the steering rotation axle of each steered wheel in the upper part of the body, and, in the lower part, a transmission gearbox and a stationary circular crown gear with which driving pinions mesh, said pinions rotating about the crown gear, thereby rotating the entire body and the rotation axle of the wheel built into the body together with suitable means.

The description relates to a powder-metallurgical method for manufacturing components of a swivel motor for a vehicle steering system, said method involving the steps of: pressing 2, 3, 4, 5, 6 or any number of wing elements, assembling the wing elements, and sintering the assembled wing elements, and/or pressing 2, 3, 4, 5, 6 or any number of housing elements, assembling the housing elements, and sintering the housing elements.

A milling machine can include a frame; at least two tracks coupled to the frame for propelling the milling machine; first and second hydraulic cylinders configured to steer each of the at least two tracks, respectively; an adjustable hydraulic tie rod extending between the at least two tracks; first and second steering collars coupled to the each of the tracks to move the tracks, wherein the first hydraulic cylinder is coupled to the first steering collar and the second hydraulic cylinder is coupled to the second steering collar, and wherein the adjustable hydraulic tie rod is coupled to both of the steering collars; one or more sensors to determine the positions of the at least two tracks; and a hydraulic steering control system coupled to the first and second hydraulic cylinders and the adjustable hydraulic tie rod and configured to vary a steering mode of the at least two tracks between a parallel steering mode and an Ackerman steering mode, wherein if one of the one or more sensors fails, the hydraulic steering control system defaults to move the at least two tracks into the Ackerman steering mode.

A milling machine can include a frame; at least two tracks coupled to the frame for propelling the milling machine; first and second hydraulic cylinders configured to steer each of the at least two tracks, respectively; an adjustable hydraulic tie rod extending between the at least two tracks; first and second steering collars coupled to the each of the tracks to move the tracks, wherein the first hydraulic cylinder is coupled to the first steering collar and the second hydraulic cylinder is coupled to the second steering collar, and wherein the adjustable hydraulic tie rod is coupled to both of the steering collars; one or more sensors to determine the positions of the at least two tracks; and a hydraulic steering control system coupled to the first and second hydraulic cylinders and the adjustable hydraulic tie rod and configured to vary a steering mode of the at least two tracks between a parallel steering mode and an Ackerman steering mode, wherein if one of the one or more sensors fails, the hydraulic steering control system defaults to move the at least two tracks into the Ackerman steering mode.

A method for detecting a malfunction in a hydraulic-assisted steering system for a vehicle includes: measuring a steering torque; determining the steering torque exceeding a threshold torque for a predetermined length of time; and generating a malfunction signal in response to the determining the steering torque exceeding the threshold torque for the predetermined length of time. A system for detecting a malfunction in a hydraulic-assisted steering system for a vehicle includes a torque sensor configured to measure a steering torque, and a controller configured to: determine the steering torque exceeding a threshold torque for a predetermined length of time; and generate a malfunction signal in response to determining the steering torque exceeding the threshold torque for the predetermined length of time.

A milling machine can include a frame; at least two tracks coupled to the frame for propelling the milling machine; first and second hydraulic cylinders configured to steer each of the at least two tracks, respectively; an adjustable hydraulic tie rod extending between the at least two tracks; first and second steering collars coupled to the each of the tracks to move the tracks, wherein the first hydraulic cylinder is coupled to the first steering collar and the second hydraulic cylinder is coupled to the second steering collar, and wherein the adjustable hydraulic tie rod is coupled to both of the steering collars; one or more sensors to determine the positions of the at least two tracks; and a hydraulic steering control system coupled to the first and second hydraulic cylinders and the adjustable hydraulic tie rod and configured to vary a steering mode of the at least two tracks between a parallel steering mode and an Ackerman steering mode, wherein if one of the one or more sensors fails, the hydraulic steering control system defaults to move the at least two tracks into the Ackerman steering mode.