A solvent supply system for supplying a composite includes a first supply path with a first pump unit, the first supply path being adapted for supplying a first solvent to a mixing unit, the first pump unit operating periodically, and a second supply path with a second pump unit, the second supply path being adapted for supplying a second solvent to the mixing unit, the second pump unit operating periodically. The mixing unit is adapted for mixing the first and the second solvent and for supplying a composite solvent. The solvent supply system further includes a control unit adapted for controlling operation of the first and the second pump unit.

A mechanical oil pump, an electric oil pump, and a strainer are disposed inside a transmission case. As a suction oil passage that returns an excess hydraulic pressure in a hydraulic control device to the mechanical oil pump, a common oil passage extending from the hydraulic control device, a branch point, a first oil passage extending from the branch point to the mechanical oil pump, and a second oil passage extending from the branch point to the electric oil pump are formed in the transmission case. A meeting point where an inlet oil passage for suctioning oil via the strainer and the first oil passage of the suction oil passage meet is formed inside a pump body of the mechanical oil pump. Accordingly, the suction oil passage of the mechanical oil pump and an inlet oil passage of the electric oil pump have a portion in common.

The invention relates to a pump control method for the control of the operation of a pump system with at least two pump assemblies (2) which are arranged parallel or in series to one another. The method includes determining a specific total power E.sub.S of the complete pump system which defines a total power in relation to a hydraulic total load of the complete pump system, determining a specific individual power E.sub.P,n of each pump assembly (2) which defines an individual power in relation to the individual hydraulic load of the respective pump assembly (2), computing an individual load factor E.sub.gain,n for each pump assembly (2) according to the equation $E_{\mathrm{gain},n}=\frac{E_S}{E_{P,n}}$
and adapting the individual hydraulic load (Q.sub.n; H.sub.n) of the pump assemblies (2) in dependence on a desired hydraulic load (Q.sub.D; H.sub.D) as well as on the individual load factor E.sub.gain,n of the respective pump assembly (2).

Disclosed is an apparatus for improving excavating operation characteristic and grading operation characteristic of an excavator. The apparatus includes a solenoid valve group and a hydraulically controlled selector valve. An oil controlling output A1 of the solenoid valve group is configured in series with oil controlling input a1 of the hydraulic control valve. An oil controlling output A2 of the solenoid valve group is configured in series with a pilot control end XBa2 of a multi-port valve group. An oil return port T1 of the solenoid valve group is connected to the hydraulic oil tank. An oil controlling output b1 of the hydraulically controlled selector valve is connected to a pilot control end XAb2 of the multiplexer valve group, and an oil return port T2 of the hydraulically controlled selector valve is connected with the hydraulic oil tank. The apparatus improves operational efficiency and control comfortability.

A chassis includes a base, a number of fans mounted in the base, and an air guiding member. The base includes a bottom wall and a sidewall perpendicularly connected to a side of the bottom wall. The fans are mounted on the bottom wall. The air guiding member includes a fixing portion slidably mounted to the sidewall and a guiding portion pivotably connected to the fixing portion. The guiding portion is pivotable to adjust the direction of airflow from the fans.

A hydraulic system for a hybrid module which is located between an engine and a transmission includes a parallel arrangement of a mechanical pump and an electric pump. Each pump is constructed and arranged to deliver oil to other portions of the hydraulic system depending on the operational mode. Three operational modes are described including an electric mode, a transition mode, and a cruise mode. Various monitoring and control features are incorporated into the hydraulic system.

A system and method for pumping fluid using a set of interconnected pump cassettes is disclosed. Each of the pump cassettes can receive a first solution in a first pumping chamber and each of the pump cassettes can receive separate second solutions in respective second pumping chambers, so that the first solution can be mixed with the separate second solutions, each said mixture capable of being placed in separate containers. The system includes a control assembly for operating each pump cassette, each pump cassette having a flexible membrane to pump fluid into and out of the pumping chambers, and each pump cassette configured for mating with a base unit that provides positive or negative pneumatic pressure to the flexible membrane.

A solvent supply system for supplying a composite includes a first supply path with a first pump unit, the first supply path being adapted for supplying a first solvent to a mixing unit, the first pump unit operating periodically, and a second supply path with a second pump unit, the second supply path being adapted for supplying a second solvent to the mixing unit, the second pump unit operating periodically. The mixing unit is adapted for mixing the first and the second solvent and for supplying a composite solvent. The solvent supply system further includes a control unit adapted for controlling operation of the first and the second pump unit.

A solvent supply system for supplying a composite solvent is described. The solvent supply system comprises a first supply flow path with a first pump unit, the first supply flow path being adapted for supplying a flow of a first solvent to a mixing unit, the first pump unit operating periodically, and a second supply flow path with a second pump unit, the second supply flow path being adapted for supplying a flow of a second solvent to the mixing unit, the second pump unit operating periodically. The mixing unit is adapted for mixing the first and the second solvent and for supplying a composite solvent. The solvent supply system further comprises a control unit adapted for controlling operation of the first and the second pump unit, the control unit being adapted to prevent at least one of a predefined phase relation and a predefined frequency relation between the first pump unit and the second pump unit.

A multiple pump system is disclosed. The multiple pump system may include a fluid tank and a multiple pump vessel connected to the fluid tank. The multiple pump vessel may include at least one first pump and at least one second pump located therein. In addition, the at least one first pump may be configured to dispense a fluid from the fluid tank at a first pressure, and the at least one second pump may be configured to dispense the fluid from the fluid tank at a second pressure. The first pressure may be different from the second pressure, such that the at least one first pump may be configured to dispense liquefied natural gas, and the at least one second pump may be configured to dispense compressed natural gas.