An actuator includes a guide that extends in one direction and a slider that is movable in an axial direction with respect to the guide. Either the guide or the slider has a recessed cross-section, and the slider is guided by the guide while the other of the guide and the slider is restrained by three surfaces constituting the recessed cross-section.

A valve includes a basic body, control spool, sealing ring, and control cover. The control spool is received in the basic body to be movable along a longitudinal axis. The basic body includes a counter-sealing surface, connecting channel, and tank channel having at least one first annular groove surrounding the control spool. The control cover and at least one end face of the control spool facing toward the longitudinal axis delimits, at least in part, a control space. The control cover includes a sealing surface that abuts the counter-sealing surface of the basic body. At least one of the sealing surface and the counter-sealing surface includes a sealing groove that surrounds the control space in ring-like fashion. The sealing ring is received in the sealing groove. The connecting channel opens out into the tank channel and into the sealing groove.

A hydraulic system of a working machine includes a hydraulic pump to output a hydraulic fluid, at least one proportional valve to deliver the hydraulic fluid to a supply target, a valve body including the proportional valve, a heat-up fluid passage in the valve body and into which the hydraulic fluid flows, a switching valve switchable between an open position in which the hydraulic fluid passing through the heat-up fluid passage is supplied to a hydraulic device and a closed position in which the hydraulic fluid is not supplied thereto and the hydraulic fluid from the hydraulic device is to be returned, a controller to operate the switching and proportional valves, and a return circuit through which the hydraulic fluid flowing into the heat-up fluid passage is returned as a result of at least one of the switching and proportional valves being operated by the controller.

Actuator systems and methods of operation are disclosed. The systems include a hydraulic actuator having a primary piston having a piston head arranged within a housing defining retract and extend chambers on opposite sides of the piston head. A control element is configured to control a supply of pressure to each of the retract and extend chambers. An actuator valve is coupled to the housing and includes a secondary piston that is biased into the retract chamber in an open flow state and when the primary piston is in a fully retracted state the piston head urges the secondary piston into a closed flow state. The actuator valve defines a flow chamber where, in an open flow state, fluid can be passed through the flow chamber and in a closed flow state the fluid is prevented from passing through the flow chamber.

Disclosed is a system for status diagnosis of construction machinery. The system for status diagnosis of the construction machinery to determine the abnormality of the construction machinery may include a sensor unit including at least one or more oil property sensors for detecting oil property information and at least one or more equipment sensors for detecting operating status information, a control unit configured to determine a basic status of the construction machinery through the oil property information and determine an overall status of the construction machinery by reflecting the operating status information of the construction machinery based on the basic status of the construction machinery, and a display unit configured to display a notification according to the determination of the control unit.

A rod having a substantially-cylindrical shape with both ends being covered is provided to a lid body, which covers an upper end surface of a case having a bottomed substantially-cylindrical shape, the rod protruding in the case. A first hole is formed in a portion of a side surface of the rod, which is exposed to the inside of the case. Further, an air vent pit (passage) is formed in the lid body, and a second hole is formed in a portion of the side surface of the rod, which is exposed to the inside of the air vent pit. A moving member moves along the rod from a first position at which the moving member does not cover the first hole and a second position at which the moving member covers the first hole.

A closed loop, self-priming hydraulic system comprising a reciprocating, hydraulic piston pump, a high pressure loop and a low pressure loop is disclosed. The reciprocating, hydraulic piston pump comprises a first piston operating in a first piston bore and a second piston operating in a second piston bore. The high pressure loop is defined by a high pressure accumulator that is fluidly connected to an inlet of the first piston bore and an outlet of the second piston bore. The low pressure loop is defined by a low pressure accumulator that is fluidly connected to an inlet of the second piston bore and an outlet of the first piston bore. The closed-loop, self-priming hydraulic system manipulates a hydraulic fluid to convert energy from one form to another.

A compressed air supply system for supplying compressed air to a pneumatic system is disclosed. The compressed air supply system comprises a compressed air input port, a compressed air output port and a vent port, a pneumatic main pipe arranged between the compressed air input port and the compressed air output port, a pneumatic vent pipe arranged between the compressed air output port and the vent port and connected to the pneumatic main pipe, a purge valve arranged in the pneumatic vent pipe for venting the compressed air supply system, a regeneration valve for controlling a regeneration flow of compressed air through an air dryer arranged in the main pipe, a governor valve for generating a pressure signal, and a first and a second pneumatic control pipe.

A fluid pump system includes a housing, a motor, a fan, and a fluid conduit. The housing includes a wall having a first end and a second end, and the housing defining a first axis extending between the first end and the second end. The wall extends at least partially around the first axis and at least partially encloses a chamber. The motor is at least partially positioned within the chamber. The fan is positioned proximate the first end, and the fan generates air flow through the chamber. The fluid conduit is configured to be in fluid communication with a fluid reservoir, and at least a portion of the fluid conduit is positioned within the chamber.

A method and device for regeneration of an adsorption air dryer having at least two desiccant-filled drying vessels connected in parallel, wherein a humid compressed-air stream generated by a compressor flows through one of the drying vessels in a drying phase and a dry compressed-air stream flows through the other drying vessel, for the purpose of dewatering the desiccant, in a simultaneous regeneration phase, wherein a valve arrangement is provided for switching the drying vessels alternately between drying phase and regeneration phase during normal operation, wherein the control mechanism are provided for implementing a post-regeneration phase, which control mechanism initiates a further flow through the drying vessel with dry compressed air for complete regeneration and also a flow through the other drying vessel; with dry compressed air for complete regeneration, so that, upon the next start of operation of the adsorption air dryer, operation commences with fully regenerated drying vessels.