A transmission includes a plurality of pneumatic actuators for gear shifting, wherein the pneumatic actuators are arranged to discharge compressed air via a common ventilation system including at least one ventilation opening arranged in a housing arrangement of the transmission. A method for controlling ventilation of the transmission includes determining that a predetermined flushing condition is fulfilled and, in response thereto, initiating a flushing action in which at least two of the pneumatic actuators are controlled to discharge compressed air simultaneously or substantially simultaneously to the common ventilation system so as to force air through the at least one ventilation opening.

A transmission includes a plurality of pneumatic actuators for gear shifting, wherein the pneumatic actuators are arranged to discharge compressed air via a common ventilation system including at least one ventilation opening arranged in a housing arrangement of the transmission. A method for controlling ventilation of the transmission includes determining that a predetermined flushing condition is fulfilled and, in response thereto, initiating a flushing action in which at least two of the pneumatic actuators are controlled to discharge compressed air simultaneously or substantially simultaneously to the common ventilation system so as to force air through the at least one ventilation opening.

A well case brushing and surge blocking apparatus includes a housing, a frame, an actuating arm, a gear assembly, a hydraulic motor, a hydraulic speed controller, and a hydraulic counterbalance. The housing is laterally connected to the frame. The gear assembly is laterally mounted to the frame and positioned opposite of the housing. The actuating arm is positioned within the housing as a stator of the hydraulic motor is externally mounted to the gear assembly, and a rotor of the hydraulic motor and the actuating arm is torsionally coupled with each other through the gear assembly. The hydraulic speed controller and the hydraulic counterbalance are mounted to the frame. The hydraulic motor is in fluid communication with the hydraulic speed controller and the hydraulic counterbalance so that a sand line of rig can be looped and operated through the well case brushing and surge blocking apparatus.

A well case brushing and surge blocking apparatus includes a housing, a frame, an actuating arm, a gear assembly, a hydraulic motor, a hydraulic speed controller, and a hydraulic counterbalance. The housing is laterally connected to the frame. The gear assembly is laterally mounted to the frame and positioned opposite of the housing. The actuating arm is positioned within the housing as a stator of the hydraulic motor is externally mounted to the gear assembly, and a rotor of the hydraulic motor and the actuating arm is torsionally coupled with each other through the gear assembly. The hydraulic speed controller and the hydraulic counterbalance are mounted to the frame. The hydraulic motor is in fluid communication with the hydraulic speed controller and the hydraulic counterbalance so that a sand line of rig can be looped and operated through the well case brushing and surge blocking apparatus.

A lift device and a method of controlling the lift device are provided. The lift device has a lifting mechanism supporting a lifting platform relative to the chassis. An electric motor is drivingly coupled to a traction device, and a traction battery is in electrical communication with the electric motor. A user input is provided to control a speed of the lift device by inputting a requested speed. A controller is configured to, in response to the lift device being on a non-zero grade and if the requested speed is greater than a predetermined speed, command the electric motor to output a braking torque and provide electrical power to the traction battery, and limit the speed of the lift device to the predetermined speed.

A hydraulic system for a working machine includes a hydraulic pump to output a hydraulic fluid, an operation device operable to supply a pilot fluid in accordance with an amount by which the operation device is operated, a hydraulic actuator to be operated by the hydraulic fluid, a pilot fluid passage connected to the operation device, a first control valve connected to the pilot fluid passage and to be operated by the pilot fluid to control a flow of the hydraulic fluid, a second control valve to be operated by the pilot fluid to control a flow of the hydraulic fluid, a proportional valve to change a pressure of the pilot fluid to operate the second control valve, a pressure detector provided in the pilot fluid passage to detect a pressure in the pilot fluid passage, and a controller to control the proportional valve based on the pressure.

A hydraulic system for a working machine includes a hydraulic pump to output a hydraulic fluid, an operation device operable to supply a pilot fluid in accordance with an amount by which the operation device is operated, a hydraulic actuator to be operated by the hydraulic fluid, a pilot fluid passage connected to the operation device, a first control valve connected to the pilot fluid passage and to be operated by the pilot fluid to control a flow of the hydraulic fluid, a second control valve to be operated by the pilot fluid to control a flow of the hydraulic fluid, a proportional valve to change a pressure of the pilot fluid to operate the second control valve, a pressure detector provided in the pilot fluid passage to detect a pressure in the pilot fluid passage, and a controller to control the proportional valve based on the pressure.

Described herein is a fluid circuit device. The device incorporates at least one pressure balancing valve located between at least two fluid volumes that can be in a pressure differential arrangement wherein the at least one pressure balancing valve acts to address a pressure differential by opening a fluid volume or volumes to a third pressure equalising volume. In use, the fluid circuit device may in one embodiment be used in an energy absorbtion apparatus.

[Object] To provide a compact, high-output actuator device allowing force control. [Solution] An actuator device 1000 includes an electromagnetic coil member 110 provided over a prescribed width on an outer circumference of a cylinder 100, and a movable element 200 slidable as a piston in the cylinder 100. The movable element 200 has a magnetic member 202, and is moved relatively by excitation of the electromagnetic coil member 110. Fluid is supplied to first and second chambers 106a and 106b such that when the movable element 200 is to be moved relatively, the movable element 200 is driven in the same direction.

[Object] To provide a compact, high-output actuator device allowing force control. [Solution] An actuator device 1000 includes an electromagnetic coil member 110 provided over a prescribed width on an outer circumference of a cylinder 100, and a movable element 200 slidable as a piston in the cylinder 100. The movable element 200 has a magnetic member 202, and is moved relatively by excitation of the electromagnetic coil member 110. Fluid is supplied to first and second chambers 106a and 106b such that when the movable element 200 is to be moved relatively, the movable element 200 is driven in the same direction.