A zero turn radius vehicle with a single steered wheel is described. The vehicle may include a pair of power transfer mechanisms driving a pair of wheels, an operator control mechanism for controlling the steering, speed and direction of the vehicle and a controller in communication with the operator control mechanism. A steerable wheel is located adjacent the front of the vehicle frame, on a first side of the vehicle frame and an electric actuator is connected to the controller for steering the front steerable wheel. A second, non-steerable front caster wheel is located on a second side of the vehicle frame. The controller controls the pair of power transfer mechanisms and the electric actuator based on operator input to the operator control mechanism.

A control system is disclosed for use in a zero turn vehicle, including an electric controller in communication with a pair of independent drive units. A joystick provides user inputs to the controller to control the rotational speed and direction of the drive units. The joystick includes a vertical stalk pivotable between a plurality of pivot positions, where each of the plurality of pivot positions corresponds to a particular rotational speed and direction of each of the driven wheels. A selector switch may be used to select one of a plurality of driving modes stored in the electric controller, wherein each of the plurality of driving modes maps a different set of speeds and directions for each of the driven wheels onto the plurality of pivot positions. The joystick may also rotate about a vertical axis to provide zero turn capability.

A control system is disclosed for use in a zero turn vehicle, including an electric controller in communication with a pair of independent drive units. A joystick provides user inputs to the controller to control the rotational speed and direction of the drive units. The joystick includes a vertical stalk pivotable between a plurality of pivot positions, where each of the plurality of pivot positions corresponds to a particular rotational speed and direction of each of the driven wheels. A selector switch may be used to select one of a plurality of driving modes stored in the electric controller, wherein each of the plurality of driving modes maps a different set of speeds and directions for each of the driven wheels onto the plurality of pivot positions. The joystick may also rotate about a vertical axis to provide zero turn capability.

A working machine includes a first pressure detector configured to detect a first pilot pressure that is a pressure of operation fluid passed through a first traveling fluid line, a second pressure detector configured to detect a second pilot pressure that is a pressure of operation fluid passed through a second traveling fluid line, a third pressure detector configured to detect a third pilot pressure that is a pressure of operation fluid passed through a third traveling fluid line, a fourth pressure detector configured to detect a fourth pilot pressure that is a pressure of operation fluid passed through a fourth traveling fluid line, and a controller configured or programed to judge in which of the left-front, right-front, left-rear and right-rear operation areas an operational position of the traveling operation member exists.

A working machine includes a first pressure detector configured to detect a first pilot pressure that is a pressure of operation fluid passed through a first traveling fluid line, a second pressure detector configured to detect a second pilot pressure that is a pressure of operation fluid passed through a second traveling fluid line, a third pressure detector configured to detect a third pilot pressure that is a pressure of operation fluid passed through a third traveling fluid line, a fourth pressure detector configured to detect a fourth pilot pressure that is a pressure of operation fluid passed through a fourth traveling fluid line, and a controller configured or programed to judge in which of the left-front, right-front, left-rear and right-rear operation areas an operational position of the traveling operation member exists.

A working machine includes a controller to perform automatic deceleration to automatically reduce a first rotation speed of a left traveling motor to output a power to a left traveling device on a left portion of a machine body and a second rotation speed of a right traveling motor to output a power to a right traveling device on a right portion of the machine body by shifting a speed stage of each of the left and right traveling motors from a second speed to a first speed that is lower than the second speed. The controller is configured or programmed to determine, based on the second rotation speed, a left threshold for judging whether to perform the automatic deceleration in left pivot turn of the machine body, and to determine, based on the first rotation speed, a right threshold for judging whether to perform the automatic deceleration in right pivot turn of the machine body.

A working machine includes a controller to perform automatic deceleration to automatically reduce a first rotation speed of a left traveling motor to output a power to a left traveling device on a left portion of a machine body and a second rotation speed of a right traveling motor to output a power to a right traveling device on a right portion of the machine body by shifting a speed stage of each of the left and right traveling motors from a second speed to a first speed that is lower than the second speed. The controller is configured or programmed to determine, based on the second rotation speed, a left threshold for judging whether to perform the automatic deceleration in left pivot turn of the machine body, and to determine, based on the first rotation speed, a right threshold for judging whether to perform the automatic deceleration in right pivot turn of the machine body.

A traveling vehicle includes a left drive wheel and a right drive wheel which are driven independently by a left driving section and a right driving section, a manual operation unit configured to provide a left speed instruction for adjusting a rotational speed of the left drive wheel and a right speed instruction for adjusting a rotational speed of the right drive wheel and a drive control unit configured to control driving of the left driving section and the right driving section based on the left speed instruction and the right speed instruction, with using a first control method and a second control method which are provided with different control properties from each other. The drive control unit includes a single mode employing either one of the first control method and the second control method and a composite mode employing the first control mode and the second control mode in time-differentiated combination. In the composite mode, based on a difference between the left speed instruction and the right speed instruction, a combination ratio between the first control method and the second control method is determined.

A traveling vehicle includes a left drive wheel and a right drive wheel which are driven independently by a left driving section and a right driving section, a manual operation unit configured to provide a left speed instruction for adjusting a rotational speed of the left drive wheel and a right speed instruction for adjusting a rotational speed of the right drive wheel and a drive control unit configured to control driving of the left driving section and the right driving section based on the left speed instruction and the right speed instruction, with using a first control method and a second control method which are provided with different control properties from each other. The drive control unit includes a single mode employing either one of the first control method and the second control method and a composite mode employing the first control mode and the second control mode in time-differentiated combination. In the composite mode, based on a difference between the left speed instruction and the right speed instruction, a combination ratio between the first control method and the second control method is determined.

An electric actuator for use with a drive apparatus is disclosed herein. An electric motor drives a reduction gear train to position a control shaft, the reduction gear train having a worm drive that motivates a spur gear reduction. A slip clutch is disposed between the worm drive and spur gear reduction to protect the components of the reduction gear train, and to also place a limit on the torque applied to the control shaft. The housing of the electric actuator features a motor chamber to accommodate the electric motor and is sealed by a cap having an electric connector.