Disclosed are a novel rotation control system and method for an excavator. The novel rotation control system comprises a controller, an electrical control handle, an instrument, a rotating motor, a rotating valve trim, a main pump, a first electromagnetic valve, a second electromagnetic valve, a first pilot pressure sensor, a second pilot pressure sensor, an overflow valve and a one-way valve, and further comprises a rotation sensor used for detecting whether an excavator is rotating, a regulator used for controlling the displacement of the main pump, and a temperature sensor used for monitoring the temperature of hydraulic oil in real time.

Disclosed are a novel rotation control system and method for an excavator. The novel rotation control system comprises a controller, an electrical control handle, an instrument, a rotating motor, a rotating valve trim, a main pump, a first electromagnetic valve, a second electromagnetic valve, a first pilot pressure sensor, a second pilot pressure sensor, an overflow valve and a one-way valve, and further comprises a rotation sensor used for detecting whether an excavator is rotating, a regulator used for controlling the displacement of the main pump, and a temperature sensor used for monitoring the temperature of hydraulic oil in real time.

A refuse vehicle including an electric motor powered by a battery, a hydraulic pump driven by the electric motor, a manifold including a plurality of electrically actuated solenoid valves receiving hydraulic power from the hydraulic pump, a hydraulic actuator powered by the hydraulic pump via the manifold, and one or more processing circuits comprising one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: determine a load applied to the hydraulic actuator, operate the manifold to provide regenerative flow of hydraulic fluid to the hydraulic actuator when the load is less than a threshold load, and operate the manifold to provide non-regenerative flow of hydraulic fluid to the hydraulic actuator when the load is greater than or equal to the threshold load.

A refuse vehicle including an electric motor powered by a battery, a hydraulic pump driven by the electric motor, a manifold including a plurality of electrically actuated solenoid valves receiving hydraulic power from the hydraulic pump, a hydraulic actuator powered by the hydraulic pump via the manifold, and one or more processing circuits comprising one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: determine a load applied to the hydraulic actuator, operate the manifold to provide regenerative flow of hydraulic fluid to the hydraulic actuator when the load is less than a threshold load, and operate the manifold to provide non-regenerative flow of hydraulic fluid to the hydraulic actuator when the load is greater than or equal to the threshold load.

A hydraulic system of a construction machine includes: control valves interposed between a main pump and hydraulic actuators; and first solenoid proportional valves connected to pilot ports of the control valves. The hydraulic system further includes: a brake for a slewing motor; and a second solenoid proportional valve connected to a brake release port of the brake by a secondary pressure line and connected to an auxiliary pump by a primary pressure line. A switching valve including a pilot port connected to the secondary pressure line by a pilot line is interposed between the auxiliary pump and the first solenoid proportional valves.

A hydraulic system of a construction machine includes: control valves interposed between a main pump and hydraulic actuators; and first solenoid proportional valves connected to pilot ports of the control valves. The hydraulic system further includes: a brake for a slewing motor; and a second solenoid proportional valve connected to a brake release port of the brake by a secondary pressure line and connected to an auxiliary pump by a primary pressure line. A switching valve including a pilot port connected to the secondary pressure line by a pilot line is interposed between the auxiliary pump and the first solenoid proportional valves.

A control method for executing a floating function of a boom in a work vehicle includes determining that a predetermined floating function activation command has been inputted by the operator by means of a command input means. When the floating function activation command has been inputted by the operator, acquiring, a signal or data indicative of the current position of the boom along a travel path of the boom over time, the travel path including a first section between a boom full extension position and a deceleration position, a second section between the deceleration position and a grounding position, and a third section between the grounding position and a full retract position, and moving the boom from the current position, determined based on the signal or data indicative of the position of the boom, to the full retract position.

A control method for executing a floating function of a boom in a work vehicle includes determining that a predetermined floating function activation command has been inputted by the operator by means of a command input means. When the floating function activation command has been inputted by the operator, acquiring, a signal or data indicative of the current position of the boom along a travel path of the boom over time, the travel path including a first section between a boom full extension position and a deceleration position, a second section between the deceleration position and a grounding position, and a third section between the grounding position and a full retract position, and moving the boom from the current position, determined based on the signal or data indicative of the position of the boom, to the full retract position.

A servo valve comprising: a fluid transfer valve assembly includes: a housing having channel therethrough fluidly connecting a supply port, a return port and a control port formed in the housing; a moveable valve spool located within the channel and arranged to regulate flow of fluid between the supply port, the return port and the control port in response to a control signal; and a drive assembly configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The valve spool comprises a first spool part and a second spool part and the drive assembly comprises a piezoelectric actuator positioned between the first and the second spool parts within the channel. Then when a control signal is applied to the piezoelectric actuator it causes extension or contraction of the first and second piezoelectric actuator elements.

An air processing unit for providing compressed air to a supply port for use in a pneumatic system with a pneumatic unit pneumatically connected to the supply port. The air processing unit comprises an inlet port for receiving the compressed air from an electrically controlled compressed air supply. An air drying unit having an input port pneumatically connected to the inlet port and configured to dry the compressed air received, a supply line configured to supply dried compressed air, a return flow control unit comprising an electrically controlled valve are also included in the air processing unit. The electrically controlled valve is provided as a single and only electrically controlled valve of the return flow control unit.