A system for energy recovery from a rod pump includes a reversible hydraulic pump; a variable speed reversible motor-generator connected to the reversible hydraulic pump; and a variable speed drive that operates the motor-generator to rotate the reversible hydraulic pump in a forward direction to pump hydraulic fluid to the rod pump during an upstroke, and to operate the motor-generator in a generator mode in which a weight of a rod string lowers a piston in the rod pump during a downstroke to pump hydraulic fluid to rotate the hydraulic pump in reverse such that the motor-generator generates electricity, and the variable speed drive modulates a speed of the motor-generator during the downstroke to modulate a speed of the reversible hydraulic pump to control a rate of flow of hydraulic fluid through the reversible hydraulic pump and thereby modulate a rate of downward motion of the rod string.

A system for energy recovery from a rod pump includes a reversible hydraulic pump; a variable speed reversible motor-generator connected to the reversible hydraulic pump; and a variable speed drive that operates the motor-generator to rotate the reversible hydraulic pump in a forward direction to pump hydraulic fluid to the rod pump during an upstroke, and to operate the motor-generator in a generator mode in which a weight of a rod string lowers a piston in the rod pump during a downstroke to pump hydraulic fluid to rotate the hydraulic pump in reverse such that the motor-generator generates electricity, and the variable speed drive modulates a speed of the motor-generator during the downstroke to modulate a speed of the reversible hydraulic pump to control a rate of flow of hydraulic fluid through the reversible hydraulic pump and thereby modulate a rate of downward motion of the rod string.

A linear compressor includes one spring assembly including a plurality of spring parts fixed to both side surfaces of a supporter and a rear cover and configured to support a load generated in the compressor. In addition, both side portions of the spring part are provided with fixing brackets coupled to the supporter and the rear cover, and the fixing bracket is provided with an insertion member or a bracket coupling member so that the coupling force of the spring part can be increased.

A linear compressor includes one spring assembly including a plurality of spring parts fixed to both side surfaces of a supporter and a rear cover and configured to support a load generated in the compressor. In addition, both side portions of the spring part are provided with fixing brackets coupled to the supporter and the rear cover, and the fixing bracket is provided with an insertion member or a bracket coupling member so that the coupling force of the spring part can be increased.

Pumps are provided, more particularly piston type pumps having increased energy efficiency, systems incorporating such piston type pumps, and methods of operating piston type pumps. The pumps are suitable for pumping of oil from an oil well or for pumping other liquids such as ground water, subterranean liquids, brackish water, sea water, waste water, cooling water, gas, coolants, and the like.

A wave driven variable leverage pump for water desalination is disclosed. According to one embodiment, a variable leverage pump comprises a platform and a paddle comprising at least one lever arm extending therefrom. The at least one lever arm is pivotally coupled with the platform. The pump further comprises a pump having a first end pivotally coupled with the platform, and a second end pivotally coupled with the paddle. A pivot point of the at least one lever arm is located above a pivot point of the pump relative to the platform.

A hydraulic booster using a variable-volume piston includes a main cylinder configured such that, if a fluid introduced into the upper portion of a main piston is pressurized by a pressurizing means, the fluid in the lower portion of the main piston is output. A guide moves downwards separately from the main piston and then moves to the original position by a return means. A variable-volume piston is integrally assembled on the guide such that the volume thereof increases during a downward movement and decreases during an upward movement, thereby changing the volume of the upper side of the main piston. A fluid storage-and-supply unit connects to fluid channels in the upper and lower portions of the main cylinder. This configuration boosts the pressure of the fluid discharged through the lower portion of the main cylinder due to a volume change caused by upward/downward movements of the variable-volume piston.

An aspect of the invention refers to a system for cleaning an external vehicle-mounted sensor surface. The system comprises an air nozzle arranged to discharge air onto a sensor surface; an air pump comprising a fluid inlet, an air outlet, an air-fluid interface and a variable volume compression chamber communicated with the air outlet; an air flow control device communicated with the air nozzle and the air outlet for controlling the flow of air therethrough; and a liquid pump communicated with the fluid inlet to supply a flow of pressurized liquid such that the volume of the compression chamber varies to generate a volume of pressurized air with an absolute pressure below 10 bar.

A fluid system such as a fuel system includes a fluid supply and a pump coupled between the fluid supply and a plurality of fluid delivery devices. The pump can be a cryogenic pump such as for liquefied natural gas, with valve mechanisms to control hydraulic actuation of a piston used to pump the liquefied natural gas. An electrically conductive coil is coupled with the piston. Related methodology is disclosed.

A fluid system includes a pumping flowline, wherein the pumping flowline is in selectable fluid communication with a production flowline, a cylinder including a first port and a second port, a piston slidably disposed in the cylinder, the piston sealing against an inner surface of the cylinder to form a first chamber and a second chamber, wherein the first chamber is in fluid communication with the first port and the second chamber is in fluid communication with the second port, and a first flowline in fluid communication with the first port of the cylinder and the pumping flowline, the first flowline including a first flowline valve, wherein, in response to opening the first flowline valve, the piston is displaced through the cylinder in a first direction to expand a volume of the first chamber of the cylinder.