A working machine includes a hydraulic pump, a first traveling device to be driven by a first traveling hydraulic actuator, a second traveling device to be driven by a second traveling hydraulic actuator, a first output tube to connect a first output port of the hydraulic pump to the first traveling hydraulic actuator, a second output tube to connect a second output port of the hydraulic pump to the second traveling hydraulic actuator, a first operation device to operate the first traveling device, a second operation device to operate the second traveling device and a correction mechanism to equalize a driving force of the first traveling hydraulic actuator and another driving force of the second traveling hydraulic actuator when the first operation device and the second operation device are operated each at same operation extents to perform a straight-traveling operation.

The invention relates to a self-propelled construction machine which has a drive means 5 having a left and a right crawler track 3A, 3B, in particular a slipform paver, and to a method for controlling a self-propelled construction machine, in particular a slipform paver. The construction machine comprises a machine frame 1, a working means arranged on the machine frame, a crawler track 3A on the left in the working direction A and a crawler track 3B on the right in the working direction, and a drive means 5 for driving the left crawler track at a predetermined chain speed and the right crawler track at a predetermined chain speed. In addition, the construction machine has a control unit 7 which is configured such that, on the basis of the distance a between a front reference point 9 with respect to the machine frame 1 in the working direction A and a predetermined path 8, the chain speed of the left crawler track 3A and/or the chain speed of the right crawler track 3B is predetermined such that the front reference point 9 moves on the predetermined path 8. The control unit 7 is further configured such that, during cornering, the control is corrected on the basis of the distance b between a rear reference point 10 with respect to the machine frame in the working direction and the predetermined path 8 such that the distance between the rear reference point with respect to the machine frame in the working direction and the predetermined path reduces.

The invention relates to a self-propelled construction machine which has a drive means 5 having a left and a right crawler track 3A, 3B, in particular a slipform paver, and to a method for controlling a self-propelled construction machine, in particular a slipform paver. The construction machine comprises a machine frame 1, a working means arranged on the machine frame, a crawler track 3A on the left in the working direction A and a crawler track 3B on the right in the working direction, and a drive means 5 for driving the left crawler track at a predetermined chain speed and the right crawler track at a predetermined chain speed. In addition, the construction machine has a control unit 7 which is configured such that, on the basis of the distance a between a front reference point 9 with respect to the machine frame 1 in the working direction A and a predetermined path 8, the chain speed of the left crawler track 3A and/or the chain speed of the right crawler track 3B is predetermined such that the front reference point 9 moves on the predetermined path 8. The control unit 7 is further configured such that, during cornering, the control is corrected on the basis of the distance b between a rear reference point 10 with respect to the machine frame in the working direction and the predetermined path 8 such that the distance between the rear reference point with respect to the machine frame in the working direction and the predetermined path reduces.

A small radius- or zero radius-turn vehicle that may be steered by differentially-driven rear drive wheels and by at least one electronically-controlled, steerable front wheel. A device, e.g., one or more levers, may be provided that controls both speed and direction of the drive wheels. A sensor may be provided that detects a position of the lever(s). A controller may calculate a steering angle of the front wheel based upon the position, and issue a command to an actuator associated with the front wheel. The actuator may rotate the front wheel to an electronically calculated steering angle in response to the command.

A small radius- or zero radius-turn vehicle that may be steered by differentially-driven rear drive wheels and by at least one electronically-controlled, steerable front wheel. A device, e.g., one or more levers, may be provided that controls both speed and direction of the drive wheels. A sensor may be provided that detects a position of the lever(s). A controller may calculate a steering angle of the front wheel based upon the position, and issue a command to an actuator associated with the front wheel. The actuator may rotate the front wheel to an electronically calculated steering angle in response to the command.

Various embodiments of a grounds maintenance vehicle are described herein. The vehicle includes a frame and an implement connected to the frame. The implement includes a housing, a first spindle pulley, and a second spindle pulley. The vehicle further includes a power system having a prime mover and an implement drive system. The implement drive system includes a drive pulley connected to the prime mover, an idler pulley, and an endless belt engaging the drive pulley, the idler pulley, the first spindle pulley, and the second spindle pulley. A first longitudinal distance between an idler pulley axis and a drive pulley axis is greater than a second longitudinal distance between a first spindle pulley axis and the drive pulley axis and a third longitudinal distance between a second spindle pulley axis and the drive pulley axis.

Various embodiments of a grounds maintenance vehicle are described herein. The vehicle includes a frame and an implement connected to the frame. The implement includes a housing, a first spindle pulley, and a second spindle pulley. The vehicle further includes a power system having a prime mover and an implement drive system. The implement drive system includes a drive pulley connected to the prime mover, an idler pulley, and an endless belt engaging the drive pulley, the idler pulley, the first spindle pulley, and the second spindle pulley. A first longitudinal distance between an idler pulley axis and a drive pulley axis is greater than a second longitudinal distance between a first spindle pulley axis and the drive pulley axis and a third longitudinal distance between a second spindle pulley axis and the drive pulley axis.

Various embodiments of a grounds maintenance vehicle are described herein. The vehicle includes a frame and an implement connected to the frame. The implement includes a housing, a first spindle pulley, and a second spindle pulley. The vehicle further includes a power system having a prime mover and an implement drive system. The implement drive system includes a drive pulley connected to the prime mover, an idler pulley, and an endless belt engaging the drive pulley, the idler pulley, the first spindle pulley, and the second spindle pulley. A first longitudinal distance between an idler pulley axis and a drive pulley axis is greater than a second longitudinal distance between a first spindle pulley axis and the drive pulley axis and a third longitudinal distance between a second spindle pulley axis and the drive pulley axis.

A working machine includes a pair of traveling devices, a pair of traveling motors having a first speed and a second speed higher than the first speed, a pair of traveling pumps to supply operation fluid to the traveling motors, a connector fluid tube connecting the traveling motors and the traveling pumps, a traveling-pump pressure detector to detect a traveling-pump pressure that is pressure generated in the connector fluid tube, a revolving speed detector to detect a prime-mover revolving speed, a third storage to store a second decelerating judgment table representing a relation between the prime-mover revolving speed and a second decelerating judgment pressure, and a controller having: an automatic decelerator portion to perform an automatic deceleration process for reducing a speed of the traveling motor, and a differential pressure calculator portion to calculate a traveling differential pressure between one traveling pump pressure and another traveling pump pressure.

Disclosed embodiments include steering circuits utilizing a controllable cross-feed loop between left and right drive motor sides of an articulated power machine to reduce skidding caused by a turning operation in which an articulation actuator changes an articulation joint angle between a front frame member and a rear frame member of the power machine.