The method for monitoring the condition of the hydraulic system for predicting the risk of failure is designed for hydraulic systems, whose components include at least one pump (1) for transporting fluid through the distribution system of the hydraulic system. The hydraulic system simultaneously detects at least one current magnitude of pressure and the current value of speed of the pump (1), whereupon the current speed value is compared with the trend speed value obtained from the statistically processed archived data of speed from the previous operation of the pump (1) and/or with the reference speed value of the pump (1), whereupon the comparison result provides the condition and risk of failure of the hydraulic system.

An apparatus and method to be implemented with a control loop system that includes machine set, wherein the machine set includes a working machine, an electric motor driving the working machine, and a final control element, and wherein the apparatus and method optimize the state of the machine set to minimize power consumption of the motor and maximize reliability of the machine set.

Even when abnormal heat generation occurs during operation in a state where the temperature of a compressor is not increased, abnormality cannot be detected. A fluid machine includes a fluid machine body; a motor that drives the fluid machine body; a temperature sensor that measures a temperature of the fluid machine body; and a control unit that controls the fluid machine body. The control unit changes a temperature threshold value based on at least one of a pressure of a fluid discharged by the fluid machine body and a frequency of a voltage input into the motor, and issues a notification when the temperature of the compressor body measured by the temperature sensor exceeds the temperature threshold value.

Systems and methods to pump fracturing fluid into a wellhead may include a gas turbine engine including a compressor turbine shaft connected to a compressor, and a power turbine output shaft connected to a power turbine. The compressor turbine shaft and the power turbine output shaft may be rotatable at different rotational speeds. The systems may also include a transmission including a transmission input shaft connected to the power turbine output shaft and a transmission output shaft connected to a hydraulic fracturing pump. The systems may also include a fracturing unit controller configured to control one or more of the rotational speeds of the compressor turbine shaft, the power turbine output shaft, or the transmission output shaft based at least in part on target signals and fluid flow signals indicative of one or more of pressure or flow rate associated with fracturing fluid pumped into the wellhead.

An electric motor pump system includes a variable displacement pump, an electric motor connected to drive the variable displacement pump, a first control piston configured to limit an output pressure characteristic of the pump, and a second control piston controlled via a servo valve according to an output speed of the electric motor. In embodiments, the second piston is configured to maintain a substantially constant output flow of the pump as the output speed of the electric motor changes. With embodiments, the first and second control pistons may be configured to act on a yoke of the variable displacement pump.

Method and apparatus for improving the performance, response, and durability of an electro-hydraulic active suspension system. The noise caused by hydraulic flow ripple is reduced and system response is improved.

A method for determining a current wear (w) of a hydrostatic pump, particularly of a radial piston pump, with a variable-speed drive, where the pump is connected to a fluid passage, in which a fluid is pumped by the pump to create a current actual volume flow in the fluid passage. A current actual volume flow (Q.sub.act) is determined, by measuring the volume flow in the fluid passage at a predetermined drive-vector, a computed volume flow (Q.sub.comp) is determined, by a first computational method, at the predetermined drive-vector, and the current wear (w) of the pump is determined, by a second computational method, which relates the current actual volume flow (Q.sub.act) to the computed volume flow (Q.sub.comp).

Method and apparatus for improving the performance, response, and durability of an electro-hydraulic active suspension system. The noise caused by hydraulic flow ripple is reduced and system response is improved.

Systems and methods to pump fracturing fluid into a wellhead may include a gas turbine engine including a compressor turbine shaft connected to a compressor, and a power turbine output shaft connected to a power turbine. The compressor turbine shaft and the power turbine output shaft may be rotatable at different rotational speeds. The systems may also include a transmission including a transmission input shaft connected to the power turbine output shaft and a transmission output shaft connected to a hydraulic fracturing pump. The systems may also include a fracturing unit controller configured to control one or more of the rotational speeds of the compressor turbine shaft, the power turbine output shaft, or the transmission output shaft based at least in part on target signals and fluid flow signals indicative of one or more of pressure or flow rate associated with fracturing fluid pumped into the wellhead.

A pumping system including a pump, a motor coupled to the pump, an automation system, and a pump controller located remotely from the automation system. The pump controller is coupled to at least one pump and the motor, and the pump controller is in digital communication with the motor, the automation system, and at least one auxiliary device. The pump controller transmits data to, and receives data from, the automation system and at least one auxiliary device over at least one communication link and operates the motor based on information entered into the automation system and received from the automation system. The pump controller selectively alters an operation of the motor based on the information received from one of the automation system or parameters received from the at least one auxiliary device. During a lockout state, the pump controller selects one of ignoring, delaying, or rescheduling a water