A work machine that can keep the control accuracy of actuators irrespective of temperature variation of a hydraulic operating fluid that passes through flow rate controllers that control the flow rates of supply to the actuators is provided. For this purpose, the flow rate controllers each have a valve body that is disposed on a main hydraulic line connecting a delivery line of a hydraulic pump and the actuator and that moves according to an operation pressure from a solenoid proportional pressure reducing valve, a sampling hydraulic line that branches from the main hydraulic line, and a temperature sensor set on the sampling hydraulic line. The controller is configured to correct a command electrical signal to the solenoid proportional pressure reducing valve according to a signal from the temperature sensor.

A cowl door actuator is arranged between a head end and a rod end connected to a cowl door in an aircraft. The cowl door has a closed position and an open position, and the cowl door actuator includes a piston rod that is axially moveable between the head end and the rod end. The piston rod has an extended position in which the piston rod contacts the rod end to move the cowl door to the open position, and a retracted position in which the piston rod is axially spaced from the rod end. When the cowl door is in the closed position, the gap between the piston rod and the rod end enables an axial displacement of the piston rod toward the extended position during thermal expansion of fluid remaining in the actuator, such that the cowl door is maintained in the closed position.

A cowl door actuator is arranged between a head end and a rod end connected to a cowl door in an aircraft. The cowl door has a closed position and an open position, and the cowl door actuator includes a piston rod that is axially moveable between the head end and the rod end. The piston rod has an extended position in which the piston rod contacts the rod end to move the cowl door to the open position, and a retracted position in which the piston rod is axially spaced from the rod end. When the cowl door is in the closed position, the gap between the piston rod and the rod end enables an axial displacement of the piston rod toward the extended position during thermal expansion of fluid remaining in the actuator, such that the cowl door is maintained in the closed position.

There is provided a work machine that is capable of realizing operability and energy saving ability that are equivalent to those of work machines that have a joint line to be used during swinging/boom raising operation, without incorporating a joint line for supplying a pressurized fluid from a second pump to a bottom-side chamber of a boom cylinder. The controller is configured to compute a hypothetical flow rate representing a flow rate in a hypothetical joint line, compute a first pump provisional target flow rate on the basis of an operation amount of a boom operation device, compute a second pump provisional target flow rate on the basis of an operation amount of a swing operation device, compute a first pump final target flow rate by adding the hypothetical flow rate to the first pump provisional target flow rate, and compute a second pump final target flow rate by subtracting the hypothetical flow rate from the second pump provisional target flow rate.

A vehicle includes a chassis, a controllable vehicle component, a hydraulic circuit, a heater, a temperature sensor, and a controller. The hydraulic circuit includes a reservoir configured to store hydraulic fluid, a pump positioned to drive the hydraulic fluid from the reservoir and throughout the hydraulic circuit, and an actuator positioned to selectively receive the hydraulic fluid from the pump to selectively operate the controllable vehicle component. The heater is positioned to facilitate selectively heating the hydraulic fluid. The temperature sensor is positioned to acquire temperature data indicative of a temperature of the hydraulic fluid. The controller is configured to monitor the temperature of the hydraulic fluid and selectively activate at least one of the heater or the pump to thermally regulate the hydraulic fluid (i) to maintain the hydraulic fluid within a target temperature range and (ii) independent of (a) an operator input and (b) engagement of the actuator.

A vehicle includes a chassis, a controllable vehicle component, a hydraulic circuit, a heater, a temperature sensor, and a controller. The hydraulic circuit includes a reservoir configured to store hydraulic fluid, a pump positioned to drive the hydraulic fluid from the reservoir and throughout the hydraulic circuit, and an actuator positioned to selectively receive the hydraulic fluid from the pump to selectively operate the controllable vehicle component. The heater is positioned to facilitate selectively heating the hydraulic fluid. The temperature sensor is positioned to acquire temperature data indicative of a temperature of the hydraulic fluid. The controller is configured to monitor the temperature of the hydraulic fluid and selectively activate at least one of the heater or the pump to thermally regulate the hydraulic fluid (i) to maintain the hydraulic fluid within a target temperature range and (ii) independent of (a) an operator input and (b) engagement of the actuator.

Provided are embodiments for a system including an adaptive controller, wherein the system includes a hydraulic actuator including a fluid medium, and a sensor that is disposed on the hydraulic actuator, wherein the sensor is configured to obtain sensor data of the actuator. The system also includes a processor configured to calculate an ultrasonic velocity in the fluid medium using the sensor data, wherein the processor is further configured to determine a temperature of the fluid medium based at least in part on the calculated velocity, and a controller coupled to the actuator, wherein the controller is configured to control the actuator based at least in part on the calculated velocity and determined temperature. Also provided are embodiments for a method for operating the adaptive controller.

A hydraulic system includes: a regulator that adjusts a tilting angle of a pump; and a controller that controls the regulator such that a discharge flow rate of the pump is a lower one of an operation-requiring flow rate and a horsepower control flow rate. The controller stores a first horsepower control line and a second horsepower control line lower than the first control line. When an operating point exceeds the first horsepower control line, the controller decreases the tilting angle of the pump; when the operating point falls below the second horsepower control line, the controller increases the tilting angle of the pump. When the operating point exceeds the first control line or falls below the second control line, it is shifted and positioned between the first control line and the second horsepower control line, keeping the tilting angle of the pump as it is.

A hydraulic system includes: a regulator that adjusts a tilting angle of a pump; and a controller that controls the regulator such that a discharge flow rate of the pump is a lower one of an operation-requiring flow rate and a horsepower control flow rate. The controller stores a first horsepower control line and a second horsepower control line lower than the first control line. When an operating point exceeds the first horsepower control line, the controller decreases the tilting angle of the pump; when the operating point falls below the second horsepower control line, the controller increases the tilting angle of the pump. When the operating point exceeds the first control line or falls below the second control line, it is shifted and positioned between the first control line and the second horsepower control line, keeping the tilting angle of the pump as it is.

A hydraulic system includes: a regulator that adjusts a tilting angle of a pump; and a controller that controls the regulator such that a discharge flow rate of the pump is a lower one of an operation-requiring flow rate and a horsepower control flow rate. The controller stores a first horsepower control line and a second horsepower control line lower than the first control line. When an operating point exceeds the first horsepower control line, the controller decreases the tilting angle of the pump; when the operating point falls below the second horsepower control line, the controller increases the tilting angle of the pump. When the operating point exceeds the first control line or falls below the second control line, it is shifted and positioned between the first control line and the second horsepower control line, keeping the tilting angle of the pump as it is.