A work vehicle includes a rotary member, a support member, a sealing ring, a pressure controller, and a vehicle speed determination component. The rotary member has a first hydraulic fluid supply channel to supply the hydraulic fluid to the steering clutch, and is rotated by power from the transmission when the steering clutch is engaged. The sealing ring is disposed between the rotary member and the support member and is mounted adjacent to the connected part between the first hydraulic fluid supply channel and the second hydraulic fluid supply channel. The pressure controller controls the engagement pressure to be a specific first pressure when the vehicle speed is determined not to be equal to or greater than a specific speed, and controls the engagement pressure to decrease from the first pressure when the vehicle speed is determined to be equal to or greater than a specific speed.

A work vehicle includes a rotary member, a support member, a sealing ring, a pressure controller, and a vehicle speed determination component. The rotary member has a first hydraulic fluid supply channel to supply the hydraulic fluid to the steering clutch, and is rotated by power from the transmission when the steering clutch is engaged. The sealing ring is disposed between the rotary member and the support member and is mounted adjacent to the connected part between the first hydraulic fluid supply channel and the second hydraulic fluid supply channel. The pressure controller controls the engagement pressure to be a specific first pressure when the vehicle speed is determined not to be equal to or greater than a specific speed, and controls the engagement pressure to decrease from the first pressure when the vehicle speed is determined to be equal to or greater than a specific speed.

A differentially steered vehicle includes brakes on the powered wheels which are applied via a controller according to different methods to inhibit freewheeling during turns and improve steering responsiveness and stability. The methods include applying braking force to the wheel on the inside of a turn in response to the rate of turn as indicated by the position of the steering control, to the pressure differential across the hydraulic motors driving the wheels and the rotational speed of the wheels.

A differentially steered vehicle includes brakes on the powered wheels which are applied via a controller according to different methods to inhibit freewheeling during turns and improve steering responsiveness and stability. The methods include applying braking force to the wheel on the inside of a turn in response to the rate of turn as indicated by the position of the steering control, to the pressure differential across the hydraulic motors driving the wheels and the rotational speed of the wheels.

A steering axle drive assembly includes a steering axle having opposite ends, a wheel pivotally connected with each steering axle end, and a control mechanism. The wheels are operated by the control mechanism for rotation about a vertical axis and a horizontal axis. When the axle is connected with a vehicle, the control mechanism controls the steering axle wheels independent of other wheels of the vehicle, such as the main drive wheels, to steer and drive the vehicle from an origin in any direction without passing through the origin. Preferably, a motor or linear actuator controls the rotation of the steering axle wheels. The steering axle drive assembly can be further improved by including an angled axle.

A controller controls the steering device so as to cause a vehicle body to turn toward the left when a left steering lever is operated without a right steering lever being operated. The controller controls the steering device so as to cause the vehicle body to turn toward the right when the right steering lever is operated without the left steering lever being operated. The controller reduces the rotation speed of the engine when both the left steering lever and the right steering lever are operated and both the operation amount of the left steering lever and the operation amount of the right steering lever are equal to or greater than a first threshold.

A controller controls the steering device so as to cause a vehicle body to turn toward the left when a left steering lever is operated without a right steering lever being operated. The controller controls the steering device so as to cause the vehicle body to turn toward the right when the right steering lever is operated without the left steering lever being operated. The controller reduces the rotation speed of the engine when both the left steering lever and the right steering lever are operated and both the operation amount of the left steering lever and the operation amount of the right steering lever are equal to or greater than a first threshold.

A combine harvester is provided with: a threshing device that performs a threshing process of threshing a crop; a grain tank that stores grain obtained by the threshing process; a grain discharging device that discharges grain to be stored in the grain tank to the outside of the vehicle body; a travel driving device that drives travel of the vehicle body; and an engine that serves as a power source. The combine harvester includes a first relay shaft to which power is transmitted from an output shaft of the engine, and the power of the engine is transmitted from the first relay shaft to the grain discharging device and the travel driving device in a branched manner.

A method for executing multi-mode turns with a work vehicle includes transmitting initial steering and braking commands for controlling an operation of a steering actuator(s) and a steering brake(s), respectively, of the work vehicle to initiate execution of a multi-mode turning operation. The method also includes determining allowable steering and braking rates for the work vehicle based at least in part on an actual steering rate and an actual braking rate, respectively, of the work vehicle during execution of the multi-mode turning operation, and determining updated steering and braking commands based at least in part on the allowable steering and braking rates. In addition, the method includes transmitting the updated steering and braking commands to control the operation of the steering actuator(s) and the steering brake(s), respectively, to continue execution of the multi-mode turning operation.

A number of illustrative variations may include a system and method of controlling vehicle slowing while implementing brake-to-steer functionality that may include providing a feed-forward gain on vehicle propulsion torque to achieve or maintain target longitudinal acceleration and replicate the behavior of a vehicle not using brake-to-steer. The system may manipulate propulsion of the vehicle to manage longitudinal acceleration disturbance and speed disturbance during brake-to-steer.