A slewing hydraulic work machine includes a slewing control device performing a slewing control in accordance with an applied slewing command operation, a boom control device performing a boom-raising control in accordance with an applied boom-raising command operation, a boom angle detector, and a capacity control section. The capacity control section calculates a command motor capacity based on a boom angle, generates a capacity command signal corresponding to the command motor capacity and inputs the signal to a slewing motor. During the performance of slewing and boom-raising operation, the capacity control section sets the command motor capacity to a value equal to or less than a base capacity when the boom angle is equal to or less than a slewing priority angle and sets the command motor capacity to a value greater than the base capacity when the boom angle is greater than the slewing priority angle.

In a valve device, travel control valve unit has a communication path causing the lead-out passages of the left and right travel control valve units to communicate with each other, and a spool has a lead-out side land portion configured to cause communication or shut-off of the communication between the lead-out passage and the communication path, a discharge-side land portion configured to cause communication or shut-off of the communication between the actuator passage and the discharge passage, a discharge portion configured to discharge a part of the working fluid led from the supply passage to the lead-out passage to the discharge passage at a movement initial stage of the spool, and a communication portion configured to cause the lead-out passage and the communication path to communicate with each other at a movement final stage of the spool.

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.

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.

A powertrain may include drive gears provided in an input shaft; an output shaft configured such that a differential is connected thereto; a first driven gear and a second driven gear rotatably provided in the output shaft to be engaged with the drive gears to form respective gear stages; a first clutch and a second clutch; two driveshafts provided to output power in opposed directions from the differential; and a third clutch configured to change a connection relationship among a selected driveshaft of the two driveshafts, the second driven gear, and the output shaft by sliding along an axial direction of the input shaft while being connected to the output shaft via the second clutch.

A rotary mixer can include a frame, a rotor attached to the frame, four wheels attached to the frame for moving the rotary mixer, and a drive system for driving the four wheels, the drive system can include four independent hydrostatic drive loops, each of the independent hydrostatic drive loops associated with one of the wheels such that each one of the independent hydrostatic drive loops independently drives one of the four wheels; wherein the drive system includes a pressure balance mode of operation for relatively good traction ground or road conditions, and a wheel speed synchronization mode of operation for relatively poor traction ground or road conditions.

A rotary mixer can include a frame, a rotor attached to the frame, four wheels attached to the frame for moving the rotary mixer, and a drive system for driving the four wheels, the drive system can include four independent hydrostatic drive loops, each of the independent hydrostatic drive loops associated with one of the wheels such that each one of the independent hydrostatic drive loops independently drives one of the four wheels; wherein the drive system includes a pressure balance mode of operation for relatively good traction ground or road conditions, and a wheel speed synchronization mode of operation for relatively poor traction ground or road conditions.

By using various feedback data on a sprayer system, such as engine speed, wheel speed, sensed temperatures and/or sensed pressures, an onboard logic controller can be used to fine tune parameters of the driveline system in an automatic calibration process. In one aspect, a controller can drive up engine speed and manipulate electrical current being sent to coils of propel pumps and/or wheel motors as current reaches a point where there is no more change in wheel speed as detected by the system, thereby achieving a. calibration setpoint. Additionally, during the automatic calibration process, the machine as a whole can be monitored with respect to several sensors, such as pressures, temperatures, and the like, so that if any parameter being monitored is out of a predetermined range, the calibration can be stopped and not set.

A working machine includes a first traveling fluid passage connected to a first pressure-receiving portion, a second traveling fluid passage connected to a second pressure-receiving portion, a third traveling fluid passage connected to a third pressure-receiving portion, a fourth traveling fluid passage fluidly connected to a fourth pressure-receiving portion, and a connection fluid passage connecting at least two of the first, second, third and fourth pressure-receiving portions to each other. When a traveling operation member is operated, operation fluid flows to the first pressure receiving portion through the first traveling fluid passage, to the second pressure receiving portion through the second traveling fluid passage, to the third pressure receiving portion through the third traveling fluid passage, and to the fourth pressure receiving portion through the fourth traveling fluid passage.

A hydraulic control valve maintains the pressure at a control port at a desired percentage of the pressure at two other ports as the pressure at the two other ports varies. Upon the pressure at the control port reaching a predetermined pressure setting, a fourth port will open to maintain the control port at a second desired percentage of the two other ports.