A high-pressure fluid mixing pump control system and a fluid suction control method, the system comprises a transmission threaded rod and a resolver sensor, wherein: one end of the transmission threaded rod is connected to an oil cylinder piston of a mixing pump, while the other end of the transmission threaded rod is connected to the resolver sensor either directly or via a rotary element that rotates coaxially with the transmission threaded rod. The high-pressure fluid mixing pump control system implements precision control via a mechanical means, converts a linear motion of the piston into a rotary motion, and utilizes the resolver sensor for precision measurement of a rotation angle, thus acquiring a piston displacement amount, and finally acquiring a suction volume. At the same time, an accelerator and an electric brake are also designed, for controlling starting and stopping of the mixing pump.

A fuel supply device includes: a linear actuator; a reciprocating pump having a boosting piston driven by the linear actuator and configured to reciprocate in an axial direction, the reciprocating pump being configured to suck the fuel when the boosting piston moves in a first direction and configured to boost and eject the fuel when the boosting piston moves in a second direction; and a controller configured to control driving of the linear actuator so as to adjust an amount of the fuel ejected from a boosting cylinder per reciprocating time by adjusting a ratio of a fuel ejection time and a fuel suction time of the reciprocating pump without changing the reciprocating time of the boosting piston in accordance with a load of the internal combustion engine. The adjustment adjusts a stroke length of the boosting piston and a moving speed of the boosting piston in the second direction.

A fuel supply device includes: a linear actuator; a reciprocating pump having a boosting piston driven by the linear actuator and configured to reciprocate in an axial direction, the reciprocating pump being configured to suck the fuel when the boosting piston moves in a first direction and configured to boost and eject the fuel when the boosting piston moves in a second direction; and a controller configured to control driving of the linear actuator so as to adjust an amount of the fuel ejected from a boosting cylinder per reciprocating time by adjusting a ratio of a fuel ejection time and a fuel suction time of the reciprocating pump without changing the reciprocating time of the boosting piston in accordance with a load of the internal combustion engine. The adjustment adjusts a stroke length of the boosting piston and a moving speed of the boosting piston in the second direction.

Thermal energy recovery systems include a piston assembly including a primary cylinder adapted to receive vapor; a single-acting secondary cylinder/piston assembly extending from opposite ends of the primary cylinder; a primary piston disposed for displacement in the primary cylinder; first and second secondary pistons disposed for displacement in the secondary cylinder/piston; and a piston connecting member connecting the first and second secondary pistons to the primary piston. Alternatively, a secondary piston is of the type of a double-acting piston for a more compact reciprocating function to reduce piston friction losses. Metering valves regulate the vapor pressure being introduced into displacement volume chambers at a constant pressure. A working fluid pressure-tank/accumulator/transfer-conduit is in communication with the displacement volume chambers to help regulate pressure of the working fluid. A working fluid transfer conduit forms integrally with the working fluid pressure-tank/accumulator to reduce fluid friction losses.

Thermal energy recovery systems include a piston assembly including a primary cylinder adapted to receive vapor; a single-acting secondary cylinder/piston assembly extending from opposite ends of the primary cylinder; a primary piston disposed for displacement in the primary cylinder; first and second secondary pistons disposed for displacement in the secondary cylinder/piston; and a piston connecting member connecting the first and second secondary pistons to the primary piston. Alternatively, a secondary piston is of the type of a double-acting piston for a more compact reciprocating function to reduce piston friction losses. Metering valves regulate the vapor pressure being introduced into displacement volume chambers at a constant pressure. A working fluid pressure-tank/accumulator/transfer-conduit is in communication with the displacement volume chambers to help regulate pressure of the working fluid. A working fluid transfer conduit forms integrally with the working fluid pressure-tank/accumulator to reduce fluid friction losses.

Metering device for introducing a liquid additive into a main liquid flowing along a pipe, includes a pump for withdrawing additive from a container and metering it, this pump including a first inlet for receiving a flow of main liquid which drives the pump, a second inlet for picking up additive and an outlet for the resulting mixture; a Venturi installed in the pipe, and connected in parallel with the pump, the first pump inlet connected by a first line to the Venturi inlet while the outlet connected by a second line to the Venturi throat; a first element for varying the restriction at the Venturi neck, and a second element sensitive to the pressure drop across the pump for controlling the first element to reduce the bore section when the pressure drop across the pump increases, and increase the bore section when the pressure drop across the pump decreases.

An apparatus for pumping a fluid from a fluid inlet to a fluid outlet is disclosed. The apparatus comprises: a spool axially movable within a cavity, wherein a first chamber is located at a first axial end of the cavity and a second chamber is located at a second axial end of the cavity, wherein the volume of the first chamber and the second chamber varies depending upon the axial position of the spool within the cavity; a valve movable between a first position and a second position, wherein in the first position the valve is configured to convey fluid from the fluid inlet to the first chamber and from the second chamber to the fluid outlet, and in the second position the valve is configured to convey fluid from the fluid inlet to the second chamber and from the first chamber to the fluid outlet.

A piston (8) is provided in a motor main body (4). A first motor chamber (9) is provided above the piston (8) and a second motor chamber (10) is provided below the piston (8). A pilot valve element (18) is provided so as to protrude from the piston (8). When a supply/discharge valve (13) is moved to its upper limit position or its lower limit position by the movement of the pilot valve element (18) in an up-down direction, a first valve member (25) of the supply/discharge valve (13) switches between supplying and discharging pressure fluid to and from the first motor chamber (9) and a second valve member (26) of the supply/discharge valve (13) switches between supplying and discharging pressure fluid to and from the second motor chamber (10).

A linearly actuated hydraulic piston pump is provided. The pump includes a piston disposed between a first section and a second section of a piston chamber. The pump also includes a control valve having a valve body defining a valve chamber therein. The control valve also includes an inlet port, a first port, a regeneration port, a second port, and a spool. The spool in a first spool position fluidly couples a pressurized fluid source to the first section via the inlet port and the first port, and fluidly couples an accumulator to the second section via the regeneration port and the second port. The spool in the second spool position fluidly couples the first section to a drain via the first port and a drain port, and fluidly couples the second section to the pressurized fluid source via the inlet port and the second port.

The present invention discloses a hydraulically-driven double-acting mud pump, comprising power motors, pressure oil pumps, a three-position four-way hydraulically-actuated directional valve, a hydraulic power end and a mud pump head, the power motors being connected to the pressure oil pumps in a conventional way, the pressure oil pumps being communicated with a port P of the three-position four-way hydraulically-actuated directional valve via a pipeline, a port T of the three-position four-way hydraulically-actuated directional valve being communicated with an oil tank via a pipeline, a port A and a port B of the three-position four-way hydraulically-actuated directional valve being both connected to the hydraulic power end, the hydraulic power end being connected to the mud pump head in a conventional way, a lower end of the mud pump head being communicated with a low-pressure manifold and two sides of the mud pump head being communicated with a high-pressure manifold. The hydraulically-driven double-acting mud pump of the present invention allows for more stable instantaneous flow and pressure of the discharged liquid from the mud pump and reduced fluctuation.