In one or more embodiments, a system for predicting health of a hydraulic pump comprises a reservoir tank temperature sensor to measure a temperature of a reservoir tank. The system further comprises a hydraulic pump temperature sensor to measure a temperature of the hydraulic pump. Also, the system comprises a differential pressure sensor to measure a differential pressure across a filter associated with the hydraulic pump. Further, the system comprises a processor(s) to determine a differential temperature by subtracting the temperature of the reservoir tank from the temperature of the hydraulic pump, to compare the differential temperature to a differential temperature threshold, to compare the differential pressure to a differential pressure threshold, and to generate an alert signal indicating failure of the hydraulic pump, when the processor(s) determines that the differential temperature exceeds the differential temperature threshold and the differential pressure exceeds the differential pressure threshold.

The subject matter of this specification can be embodied in, among other things, an electrohydraulic positioning control system that includes a shuttle valve configured to direct fluid flow between a selectable one of a first fluid port and a second fluid port, and a fluid outlet configured to be fluidically connected to a fluid actuator, a first servo valve controllable to selectably permit and block flow between the first fluid port, a fluid source, and a fluid drain, a second servo valve controllable to selectably permit and block flow between the second fluid port, the fluid source, and the fluid drain, a first servo controller configured to provide a first health signal and control the first servo valve based on a second health signal, and a second servo controller configured to provide the second health signal and control the second servo valve based on the first health signal.

The subject matter of this specification can be embodied in, among other things, a method that includes actuating a closure member at a predetermined first velocity a predetermined first number of cycles between a first configuration and a second configuration, actuating the closure member at a predetermined second velocity a predetermined second number of cycles between the first and the second configuration, actuating the closure member at a predetermined third velocity a predetermined third number of cycles and the second configuration, actuating the closure member at a predetermined fourth velocity a predetermined fourth number of cycles and the second configuration, and actuating the closure member to the second configuration at a predetermined fifth velocity for a predetermined flushing period.

An air cylinder includes a tubular cylinder and a piston which is moved by pressure of a fluid supplied to a chamber provided inside the cylinder. A monitoring device includes a heat flux sensor and a detection part. The heat flux sensor is provided to the cylinder and detects heat flux that flows between inside and outside of the cylinder due to compression or expansion of the fluid in the chamber caused in accordance with the movement of the piston. The detection part detects the moving state of the piston based on the output signal of the heat flux sensor.

A fluid leakage detection device includes: an annular member attached to a cylinder head, the annular member being configured such that a piston rod is inserted through the annular member; a passage formed in the annular member, the passage being configured such that a working fluid is guided to the passage from a gap between an outer circumference of the piston rod and an inner circumference of the cylinder head; and a detector configured to detect the working fluid guided through the passage, wherein the annular member includes a press-fitted portion, the press-fitted portion being configured to be press-fitted to an annular groove formed in the cylinder head.

A sensor unit for a fluidic cylinder having a base carrier on which a circumferential seal is formed, so that an interior of the fluidic cylinder is sealable, and having a position sensor for detecting a position of the piston, and having a pressure sensor for detecting a pressure in the interior.

Provided is a construction machine including a hydraulic system having a hydraulic pump, and a first hydraulic actuator and a second hydraulic actuator which are driven by hydraulic oil supplied from the hydraulic pump. The construction machine includes a first flow rate detector that detects a flow rate of drain hydraulic oil discharged from the first hydraulic actuator, a second flow rate detector that detects a flow rate of drain hydraulic oil discharged from the second hydraulic actuator, and an abnormality determination unit that determines abnormality of the first hydraulic actuator, based on a detection signal from the first flow rate detector, and determines abnormality of the second hydraulic actuator, based on a detection signal from the second flow rate detector. The first flow rate detector and the second flow rate detector each have a moving body.

An actuator assembly for moving a valve between an open position and a closed position includes an actuator housing forming at least a portion of a chamber. The actuator assembly also includes a support plate arranged within the actuator housing. The actuator assembly further includes a diaphragm coupled to the actuator housing and the support plate, the diaphragm expanding and contracting in response to a working fluid within the chamber. The actuator assembly also includes an indicator rod extending through the chamber and out of the actuator housing, the indicator rod being removably coupled to the support plate, wherein the indicator rod is arranged within an opening formed in the support plate, the indicator rod secured to the support plate via a coupling mechanism that releases the indicator rod in response to a pressure from the working fluid between the diaphragm and the support plate.

A hydraulic component includes a camera integrated such that the camera observes at least one surface that is prone to wear and/or at least one edge that is prone to wear to make a statement about wear relating to the at least one surface and/or the at least one edge.

A monitoring system includes a hydraulic cylinder including a piston movably disposed therein. At least one seal is provided within the hydraulic cylinder. A head end pressure sensor is configured to monitor pressure of a hydraulic fluid in a head space. A rod end pressure sensor is configured to monitor pressure of the fluid in a rod space. A displacement sensor is configured to monitor the position of the piston. A temperature sensor is disposed and configured to monitor the temperature of the hydraulic fluid. An electronic control unit is in communication with the sensors and programmed to in response to receiving pressure signals from the pressure sensors, position signals from the position sensor, and temperature signals from the temperature sensor, determine a wear volume of the at least one seal; and compare the wear volume of the at least one seal to a predetermined threshold wear volume of the at least one seal to determine the remaining useful life of the hydraulic cylinder.