摘要:
A hydraulic transmission comprising a variable displacement pump and motor, at least one having cylinders having valves which are controllable on each cycle of cylinder working volume to determine the net displacement of working fluid by the cylinder. The transmission has a valve control module which determines a displacement of the pump and the motor by specifying a displacement demand. The pump and/or motor valve control module determine the frequency of intensity peaks in the frequency spectrum of the pattern of cylinders carrying out active and inactive cycles of cylinder working volume using a first procedure and, if these will fall within disallowed frequency bands including the resonant frequency of components with which the transmission is in mechanical communication, the displacement demand, or another input, is periodically modified to suppress generation of those frequencies. The hydraulic transmission is useful for example in a wind turbine generator, or a vehicle.
摘要:
The invention relates to a device for providing fluids under a specifiable pressure, comprising at least one pump (23) which supplies said fluid from a fluid reservoir (5) to a corresponding consumer (1) in a pressurized manner. The invention is characterized in that at least one first pump (12) which suctions fluid out of the fluid reservoir (5) and at least one other pump (23) which supplies fluid to the consumer (1) are provided, and the suction side (21) of the respective other pump (23) is connected to the pressure side (17) of the first pump (12) in order to supply with a fluid filling quantity.
摘要:
The sheath flow forming device are described that include: a container for storing sample fluid and having a supply port for supplying the sample fluid; a second container for storing sheath fluid and having a supply port for supplying the sheath fluid; a flow cell having a sample fluid inlet for receiving sample fluid supplied from the supply port of the first container, a sheath fluid inlet for receiving the sheath fluid from the supply port of the second container, and an outlet for discharging the mixture of the sheath fluid and the sample fluid; a first pump for supplying a sheath fluid to the sheath fluid inlet; a second pump for suctioning fluid within the flow cell through the outlet of the flow cell; and a first drive source for driving the first pump and second pump.
摘要:
A dual chamber mixing pump design is disclosed which allows two different sources of fluid to be combined into one mixed product fluid. The pump is divided into two chambers, the proximal chamber and the distal chamber. The chambers are defined in part by a piston having proximal and distal ends and recessed sections. The pump utilizes one common driving mechanism to axially rotate and laterally reciprocate the piston to provide continuous pumping of fluids with reduced pulsations. Each fluid enters through its own pump inlet and outlet. For mixing applications, the outlets are joined together. The flow volume per stroke of each chamber is determined by the lateral stroke of the entire piston assembly and also by the annular areas of the proximal and distal ends of the piston. The flow volume per stroke may be altered by varying the piston and shaft diameters for each chamber. This allows mixing of two fluids in any ratio or proportion desired. Alternating pulses of the two chambers provide a stream which has small segments of alternating fluid from each inlet. Such segmented streams can become more thoroughly mixed through normal flow characteristics of the downstream flow path, providing more effective mixing.
摘要:
Le système de pompage comporte n (n≧1) modules de pompage primaires à piston ou à membrane (P1 à Pn) incluant chacun au moins une unité de pompage, connectés par l'intermédiaire de clapets uni-directionnels (V11-V1n) respectivement à n réservoirs (R1-Rn) contenant des fluides, une tête de collecte (CH) recevant les fluides délivrés par les différents modules primaires, et une unité de pompage secondaire à piston (S) pour refouler avec un débit sensiblement constant le mélange de fluides collecté dans cette tête. Les pistons sont déplacés alternativement par exemple par la translation de vis sans fin (9) entraînées par des moteurs (12). Un ensemble de pilotage (17-20) associé à des capteurs de position (AC1-ACn) et des capteurs de pression (C1 à Cn, Cs), dosent les fluides injectés et ajustent les phases, les courses des pistons et leurs vitesses pour obtenir un débit refoulé sensiblement constant. Chaque module primaire peut comporter aussi un deuxième module de pompage permettant d'obtenir également un débit constant à l'aspiration. Application aux installations de chromatographie en phase liquide par exemple.
摘要:
The invention is a method and apparatus for significantly improving the performance of a reciprocating pump by delivering the pumping fluid at a desired pressure and flow rate with minimal flow fluctuations. The compressibility of the pumping fluid directly effects volumetric flow rate and mass flow rate. The method includes the step of sensing various pump parameters related to said compressibility and adjusting the pumping speed to make appropriate accommodations. In particular, the compressibility of the pumping fluid is effected by the adiabatic heating of the pumping fluid during compression, variations in pumping fluid density, leaks in the check valves of cylinder/piston seals and the primary and secondary switching losses in the fluid flow occurring when the primary and secondary pistons reverse direction.