A method for controlling a DC pump motor, preferably a brushed DC motor for pumping lubricant, which motor is controlled by a pulse-width modulated (PWM) control signal, wherein current parameters are acquired in an acquisition step and a duty cycle (D) of the PWM control signal (S.sub.PWM) is adapted and/or changed on the basis of the detected parameters in an adaptation step, wherein the acquisition of current parameters comprises at least the acquisition of a current input voltage (U.sub.B).

Systems, devices, and methods are disclosed that during cylinder deactivation, including skipfire, at low engines speeds and low engine loads maintain adequate oil pressure of valvetrain components or hardware required for CDA and/or skipfire operation.

Systems, devices, and methods are disclosed that during cylinder deactivation, including skipfire, at low engines speeds and low engine loads maintain adequate oil pressure of valvetrain components or hardware required for CDA and/or skipfire operation.

Machine provided with a machine element (2) and an oil pump (4) and a motor (3) to drive the machine element (2) and the oil pump (4), whereby the oil pump (4) is provided with a shaft (13) with a rotor (12), whereby the oil pump (4) is provided to pump oil from an oil reservoir (5) via an inlet channel (8) to nozzles that lead into the motor (3) and/or machine element (2) to lubricate and/or cool one or more bearings or other machine components, characterized in that in the inlet channel (8), near the oil pump (4) a dam (16) is provided that is higher than the height (A) of the central axis (18) of the shaft (13) of the oil pump (4) minus the smallest diameter (B) of the rotor (12) of the oil pump (4) divided by two.

Machine provided with a machine element (2) and an oil pump (4) and a motor (3) to drive the machine element (2) and the oil pump (4), whereby the oil pump (4) is provided with a shaft (13) with a rotor (12), whereby the oil pump (4) is provided to pump oil from an oil reservoir (5) via an inlet channel (8) to nozzles that lead into the motor (3) and/or machine element (2) to lubricate and/or cool one or more bearings or other machine components, characterized in that in the inlet channel (8), near the oil pump (4) a dam (16) is provided that is higher than the height (A) of the central axis (18) of the shaft (13) of the oil pump (4) minus the smallest diameter (B) of the rotor (12) of the oil pump (4) divided by two.

A lubricating device of a power transmitting system having a structural member. The lubricating device includes an oil piping assembly fixed to the structural member at a plurality of positions and having an oil passage through which a lubricant oil flows. The oil piping assembly is a resin piping assembly including a plurality of divisional components which cooperate to define a circumference of the oil passage along a length of the oil passage and which are formed of a resin material. The divisional components have respective interfacial surfaces and are bonded together with interfacial surfaces thereof being held in contact with each other. The divisional components of the resin piping assembly include a base divisional component provided with a plurality of fixing portions, and the resin piping assembly is fixed to the structural member at the plurality of positions through only the fixing portions.

A lubricating device of a power transmitting system having a structural member. The lubricating device includes an oil piping assembly fixed to the structural member at a plurality of positions and having an oil passage through which a lubricant oil flows. The oil piping assembly is a resin piping assembly including a plurality of divisional components which cooperate to define a circumference of the oil passage along a length of the oil passage and which are formed of a resin material. The divisional components have respective interfacial surfaces and are bonded together with interfacial surfaces thereof being held in contact with each other. The divisional components of the resin piping assembly include a base divisional component provided with a plurality of fixing portions, and the resin piping assembly is fixed to the structural member at the plurality of positions through only the fixing portions.

Embodiments of systems and methods disclosed provide a hydraulic fracturing unit that includes a reciprocating plunger pump configured to pump a fracturing fluid and a powertrain configured to power the reciprocating plunger pump. The powertrain includes a prime mover and a drivetrain, the prime mover including a gas turbine engine. The hydraulic fracturing unit also includes auxiliary equipment configured to support operation of the hydraulic fracturing unit including the reciprocating plunger pump and the powertrain. A power system is configured to power the auxiliary equipment. The power system includes a power source and a power network. The power source is configured to generate power for the auxiliary equipment. The power network is coupled to the power source and the auxiliary equipment, and configured to deliver the power generated by the power source to the auxiliary equipment. Associated systems including a plurality of hydraulic fracturing units are also provided.

A seal system for a bearing compartment of a gas turbine engine includes an annular rotating seal seat in contact with the seal element to form a dry seal interface therebetween to separate am oil-wetted zone from a dry zone. The annular rotating seal seat forms a dry zone annular space adjacent to the annular seal element and the rotating component. The annular rotating seal seat having an oil return passageway through the rotating seal seat to provide a communication path from the dry zone annular space outboard of the rotating component back to the oil-wetted zone.

A seal system for a bearing compartment of a gas turbine engine includes an annular rotating seal seat in contact with the seal element to form a dry seal interface therebetween to separate am oil-wetted zone from a dry zone. The annular rotating seal seat forms a dry zone annular space adjacent to the annular seal element and the rotating component. The annular rotating seal seat having an oil return passageway through the rotating seal seat to provide a communication path from the dry zone annular space outboard of the rotating component back to the oil-wetted zone.