A linear compressor is provided. The linear compressor may include a shell having a cylindrical shape, a shell cover that covers both open ends of the shell, a cylinder accommodated into the shell and defining a compression space for a refrigerant, a piston that reciprocates within the cylinder in an axial direction to compress the refrigerant within the compression space, a motor assembly including a motor that provides power to the piston and a stator cover that supports the motor, and resonant springs seated on the stator cover that support the piston to allow the piston to perform a resonant motion. The resonant springs may be circularly arranged at three points having a same interval around a center in an axial direction.

A linear compressor is provided. The linear compressor may include a shell having a cylindrical shape, a shell cover that covers both open ends of the shell, a cylinder accommodated into the shell and defining a compression space for a refrigerant, a piston that reciprocates within the cylinder in an axial direction to compress the refrigerant within the compression space, a motor assembly including a motor that provides power to the piston and a stator cover that supports the motor, and resonant springs seated on the stator cover that support the piston to allow the piston to perform a resonant motion. The resonant springs may be circularly arranged at three points having a same interval around a center in an axial direction.

Provided herein is a mechanical resonant system, comprising a frame; at least one pump disposed on the frame; one or two masses coupled to the frame by a first plurality of resilient members; and at least one voice coil actuator disposed within the frame and coupled to the at least one pump or to the one or two masses; wherein when the system comprises two masses, a second plurality of resilient members couple the masses to each other. Also provided are methods for using these mechanical resonant systems to evacuate a chamber, to compress air, or sense changes in pressure.

A system includes, in an exemplary embodiment, a hydraulic cylinder having a barrel, a piston connected to a rod string of the rod pump, and a pressure chamber; a reversible hydraulic pump connected to the pressure chamber; and a motor-generator having a rotor shaft connected to a coupling shaft of the pump. The motor-generator operates in a motor mode to rotate the rotor and coupling shafts in a forward direction so that the hydraulic pump pumps hydraulic fluid to the pressure chamber to raise the piston and rod string in an upstroke, and operates in a generator mode in which a weight of the rod string displaces the piston in a downstroke to pump hydraulic fluid from the pressure chamber to rotate the pump coupling shaft and the rotor shaft in a reverse direction such that the motor-generator generates electricity. A variable speed drive modulates the speed of the motor-generator.

A system includes, in an exemplary embodiment, a hydraulic cylinder having a barrel, a piston connected to a rod string of the rod pump, and a pressure chamber; a reversible hydraulic pump connected to the pressure chamber; and a motor-generator having a rotor shaft connected to a coupling shaft of the pump. The motor-generator operates in a motor mode to rotate the rotor and coupling shafts in a forward direction so that the hydraulic pump pumps hydraulic fluid to the pressure chamber to raise the piston and rod string in an upstroke, and operates in a generator mode in which a weight of the rod string displaces the piston in a downstroke to pump hydraulic fluid from the pressure chamber to rotate the pump coupling shaft and the rotor shaft in a reverse direction such that the motor-generator generates electricity. A variable speed drive modulates the speed of the motor-generator.

A linear compressor is provided. The linear compressor may include a shell having a cylindrical shape, a shell cover that covers both open ends of the shell, a cylinder accommodated into the shell and defining a compression space for a refrigerant, a piston that reciprocates within the cylinder in an axial direction to compress the refrigerant within the compression space, a motor assembly including a motor that provides power to the piston and a stator cover that supports the motor, and resonant springs seated on the stator cover that support the piston to allow the piston to perform a resonant motion. The resonant springs may be circularly arranged at three points having a same interval around a center in an axial direction.

A linear compressor is provided. The linear compressor may include a shell having a cylindrical shape, a shell cover that covers both open ends of the shell, a cylinder accommodated into the shell and defining a compression space for a refrigerant, a piston that reciprocates within the cylinder in an axial direction to compress the refrigerant within the compression space, a motor assembly including a motor that provides power to the piston and a stator cover that supports the motor, and resonant springs seated on the stator cover that support the piston to allow the piston to perform a resonant motion. The resonant springs may be circularly arranged at three points having a same interval around a center in an axial direction.

An impulse pump is provided with a low power motor to store rotational kinetic energy in a flywheel. The stored kinetic energy is released using a planetary gear transmission that links the flywheel to a pusher shaft. The kinetic energy is released when the planetary gear carrier is decelerated using a caliper brake. The planetary gear carrier deceleration forces rotational acceleration of the pusher shaft and deceleration of the flywheel. Through a cam roller contact point between the pusher shaft and the cam raceway on the plunger; the rotational motion of the pusher shaft is converted to linear and translational motion of the plunger. The translational motion of the plunger allows impulse jet energy to be rapidly released from a nozzle of the pump.

An impulse pump is provided with a low power motor to store rotational kinetic energy in a flywheel. The stored kinetic energy is released using a planetary gear transmission that links the flywheel to a pusher shaft. The kinetic energy is released when the planetary gear carrier is decelerated using a caliper brake. The planetary gear carrier deceleration forces rotational acceleration of the pusher shaft and deceleration of the flywheel. Through a cam roller contact point between the pusher shaft and the cam raceway on the plunger; the rotational motion of the pusher shaft is converted to linear and translational motion of the plunger. The translational motion of the plunger allows impulse jet energy to be rapidly released from a nozzle of the pump.

A hydraulic system is provided for powering one or more external hydraulically powered devices. The system includes one or more pumping systems attached to a common crankshaft and including an inner sleeve, an outer sleeve, a valve member and an end body. The system can include a pair of high pressure fluid tanks and a low pressure fluid tank. The pumping systems can increase the fluid pressure within the high pressure fluid tanks back and forth and in a sequenced manner, and force the higher pressure fluid through the one or more powered devices. Drive systems are provided to assist the pumping systems in rotating the common crankshaft. The drive systems can include a piston assembly for rotating the crankshaft and a valving system for directing fluid into the piston assembly to power the piston assembly.