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.

A hydraulic unit is provided with: a manifold which forms a hydraulic circuit; a tank which is joined to the manifold; and a hydraulic pump which suctions hydraulic fluid in the tank and supplies the hydraulic fluid to the manifold, wherein the base end portion of a suction strainer is fitted into the hydraulic pump, and the suction strainer has such a shape that the base end portion of the suction strainer is not separated from the hydraulic pump in a state where the leading end portion of the suction strainer is in contact with the tank and an opening through which the hydraulic fluid is introduced from the tank is provided at the leading end portion.

An air dryer control method may include a cold mode in which a controller performs a winter season condition control in which air temperature is lowered to freezing temperature if an engine starting is detected, and performs a winter season thawing control in which compressed air introduced into a valve control of an air dryer warms a purge valve of the air dryer.

The disclosure provides a pressure control device that improves the workability in assembling a body and a filter unit. The pressure control device includes a body and a filter unit. The body has a flow path that includes a groove and a widened part. The widened part is connected to the groove, extends to a bottom of the groove, and has a width larger than a width of the groove. The filter unit is housed along a depth direction of the widened part to capture foreign matter mixed in a fluid that passes through the flow path. The filter unit includes a cylindrical frame and a flat plate-shaped filter member, wherein the frame includes a through hole part that penetrates in a direction orthogonal to a central axis, and the filter member is disposed to block the through hole part.

The disclosure provides a pressure control device that improves the workability in assembling a body and a filter unit. The pressure control device includes a body and a filter unit. The body has a flow path that includes a groove and a widened part. The widened part is connected to the groove, extends to a bottom of the groove, and has a width larger than a width of the groove. The filter unit is housed along a depth direction of the widened part to capture foreign matter mixed in a fluid that passes through the flow path. The filter unit includes a cylindrical frame and a flat plate-shaped filter member, wherein the frame includes a through hole part that penetrates in a direction orthogonal to a central axis, and the filter member is disposed to block the through hole part.

There is disclosed a method of generating an alert relating to a hydraulic actuation system for actuating a hydraulic cylinder, the hydraulic control system comprising a hydraulic fluid tank and a hydraulic fluid filter. The method comprises monitoring the pressure drop over the hydraulic fluid filter; determining a rate of change characteristic relating to the rate of change of pressure drop over at least one time period in which there is a hydraulic fluid flow through the hydraulic fluid filter; determining whether the hydraulic fluid is dirty based on at least the rate of change characteristic; and generating an alert if it is determined that the hydraulic fluid is dirty.

There is disclosed a method of generating an alert relating to a hydraulic actuation system for actuating a hydraulic cylinder, the hydraulic control system comprising a hydraulic fluid tank and a hydraulic fluid filter. The method comprises monitoring the pressure drop over the hydraulic fluid filter; determining a rate of change characteristic relating to the rate of change of pressure drop over at least one time period in which there is a hydraulic fluid flow through the hydraulic fluid filter; determining whether the hydraulic fluid is dirty based on at least the rate of change characteristic; and generating an alert if it is determined that the hydraulic fluid is dirty.

A nozzle housing for a servo valve includes a circumferential wall defining a return passage extending along a longitudinal axis (A) for holding a return nozzle, the return passage having an opening for fluid communication with a spool valve and a return port for fluid communication with atmosphere, a first plate extending across the return passage, the first plate engaged with the circumferential wall and disposed between the opening and the return port, and a second plate extending across the return passage. The second plate engages with the circumferential wall and disposed between the first plate and the return port, the first plate has at least one first aperture, and the second plate has at least one second aperture that is misaligned with the at least one first aperture such that there is no linear axial flow path between the return port and the opening.

A filter assembly, in particular used as a portable service unit for hydraulic applications, at least consisting of a motor-pump unit (8), one outlet (14) of which is connected to a filter element (18) in the main flow and the other outlet (26) of which is connected to a device for measuring particles in the fluid in the bypass flow having a particle sensor (36), wherein as a component of the device for measuring particles there is a fluid line (38) of predeterminable length as a stilling section on the inflow side of the particle sensor (36) in such a way that gases carried along in the fluid re-dissolve in the fluid, is characterized in that the fluid line (38) of predeterminable length is accommodated in a housing part (52) of the assembly, combined to form at least one winding.

A filter assembly, in particular used as a portable service unit for hydraulic applications, at least consisting of a motor-pump unit (8), one outlet (14) of which is connected to a filter element (18) in the main flow and the other outlet (26) of which is connected to a device for measuring particles in the fluid in the bypass flow having a particle sensor (36), wherein as a component of the device for measuring particles there is a fluid line (38) of predeterminable length as a stilling section on the inflow side of the particle sensor (36) in such a way that gases carried along in the fluid re-dissolve in the fluid, is characterized in that the fluid line (38) of predeterminable length is accommodated in a housing part (52) of the assembly, combined to form at least one winding.