In a broad respect, vehicles that are capable of making a low- to zero-radius turn using the independent rotation of drive wheels and by turning the non-driving steerable structure or structures (such as wheels) with a steering input device (in some embodiments, the driving wheels also may be capable of being turned). This may be accomplished using a steering system, a speed control system and an integration device (together, a control system) that are configured to work together to provide correct steering in forward and reverse, and, in some embodiments, to reduce the speed of the outboard drive wheel of the vehicle when it enters an extreme turn under constant speed input. Different systems configured for use in such vehicles are included.

Systems for controlling the speed and direction of vehicles, including vehicles that have low to zero turning radius capability.

Systems for controlling the speed and direction of vehicles, including vehicles that have low to zero turning radius capability.

An electric power steering apparatus includes left and right swing arm members, right and left tie rods pivotally connected at inner ends to arm portions of the swing arm members via a relay rod pivotally connected to the arm portions at both ends, a rack-and-pinion device in which one end of a rack bar is connected to the arm portion of one of the swing arm members, and a steering input transmission system that transmits a steering input to the rack-and-pinion device. An electric steering assist force applying device is connected to the arm portion of the other swing arm member, and applies a force to assist the other swing arm member to swing.

A steering apparatus includes left and right swing arm members, right and left tie rods pivotally connected at inner ends to arm portions of the swing arm members via a relay rod pivotally connected to the arm portions at both ends, a rack-and-pinion device in which one end of a rack bar is connected to the arm portion of one of the swing arm members, and a steering input transmission system that transmits a steering input to the rack-and-pinion device. The rack-and-pinion device includes a pair of pressing devices disposed on both sides of the pinion along the longitudinal direction of the rack bar and pressing the rack bar against the pinion.

Self-steering axle assembly has an axle with central tube having a longitudinal central axis. A king pin is connected with an end portion of the axle. A knuckle is connected with the king pin. The knuckle includes a torque plate section. A first arm of the knuckle extends from a side of the torque plate section and receives a first end portion of the king pin. A second arm extends from the torque plate section in the same direction as the first arm. The second arm receives a second end portion of the king pin. A spindle is friction welded to the torque plate section and has a longitudinal central axis. The torque plate section has at least one surface on the torque plate section extending substantially perpendicular to the longitudinal central axis of the spindle. A tool engages the surface during friction welding of the spindle to the torque plate section. The relative locations of the axle, spindle and king pin enable an air disc brake actuator to avoid contact with components of the heavy-duty vehicle during steering and with the ground and debris.

Self-steering axle assembly has an axle with central tube having a longitudinal central axis. A king pin is connected with an end portion of the axle. A knuckle is connected with the king pin. The knuckle includes a torque plate section. A first arm of the knuckle extends from a side of the torque plate section and receives a first end portion of the king pin. A second arm extends from the torque plate section in the same direction as the first arm. The second arm receives a second end portion of the king pin. A spindle is friction welded to the torque plate section and has a longitudinal central axis. The torque plate section has at least one surface on the torque plate section extending substantially perpendicular to the longitudinal central axis of the spindle. A tool engages the surface during friction welding of the spindle to the torque plate section. The relative locations of the axle, spindle and king pin enable an air disc brake actuator to avoid contact with components of the heavy-duty vehicle during steering and with the ground and debris.

Systems for controlling the speed and direction of vehicles such as tractors, including vehicles that have low to zero turning radius capability. Systems include steering and speed coordination systems that control the direction and speed of rotation of vehicle drive units.

Systems for controlling the speed and direction of vehicles such as tractors, including vehicles that have low to zero turning radius capability. Systems include steering and speed coordination systems that control the direction and speed of rotation of vehicle drive units.

Work vehicle axle device includes a wheel drive case utilizing a centrally disposed vertically extending first coupling portion, a centrally disposed vertically extending second coupling portion spaced from the first coupling portion and an input shaft located below an upper end of either the first or second coupling portions and being configured to transmit rotational power to wheels. The first and second coupling portions are configured to pivotally mount to the wheel drive case to a vehicle body of the work vehicle in a manner that allows the wheel drive case to pivot about an axis that, when viewed from above, is at least one of parallel to a front to back direction of the vehicle body and parallel to a centrally disposed front to back axis of the vehicle body.