A piston of an air compressor is actuated by a motor to move in a cylinder. The piston includes a head, an air stop sheet having a first bending section which is a boundary line of an acting area and a positioning zone of the air stop sheet, and a back surface of the acting zone backing the top of the cylinder turns on relative to a plane of a top of the head at an open angle θ1. The acting zone has a noncircular spacing groove, a neck, and a second bending section. The head includes a piston rod having a cavity, an air conduit, a column, and a spring. The air stop sheet is forced by the spring to locate in the acting zone backing the cylinder and a plane of a top of the head at an open angle θ1.

An air compressor contains a piston which is actuated by a motor to move upward and downward in a cylinder. The piston includes an air stop sheet mounted on a head thereof, and the air stop sheet has a bending section, a positioning zone, and an acting zone. A piston rod extends downward from the head and includes a cavity, an air conduit, a column extending from a bottom thereof, and a spring fitted on the column and inserting through the air channel of the head along the cavity of the piston rod so that the spring abuts against a back surface of an acting zone of an air stop sheet, the air stop sheet is forced by the spring to locate in the acting zone at an open angle θ, and the air conduit and the air channel communicate with atmosphere.

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 fluid end for use with a power end. The fluid end comprises a plurality of fluid end sections positioned adjacent one another. Each section includes a single horizontally positioned bore. A plunger is installed within the bore and includes a fluid passageway. Low-pressure fluid enters the bore through the plunger and high-pressure fluid exits the fluid end through an outlet valve installed within the bore. The intake of low-pressure fluid within the fluid end section is regulated by an inlet valve installed within the plunger. Low-pressure fluid enters the plunger through an inlet component attached to both the plunger and an inlet manifold.

A gas transport and pressurization system, including a static valve, a compartment concentrically arranged around the static valve, a dynamic valve axially displaceable relative to the static valve, and a crankshaft connected to the dynamic valve, wherein gas from a ground gas well flows through the compartment, the dynamic valve, and the static valve to a gas outlet.

A stator includes a stator core having a plurality of teeth, an insulator, a plurality of coils, a first region in which distal ends of feeder lines are connected to each other, and a second region in which distal ends of neutral lines are connected to each other. The insulator has inner and outer walls spaced from each other in a radial direction. In a cross section at a gap between two adjacent coils, along a plane including an axis of the stator core, a center of gravity of the first region is positioned above a center of gravity of the second region in an axial direction. B < A and C < A, where a radial length of the first region is B, a radial length of the second region is C, and a radial length between the inner wall and the outer wall of the insulator is A.

Disclosed is a compressor including a vibration attenuating member that fixes a driving assembly to be spaced apart from an inner circumferential face of a shell and reduces vibration or noise generated in the driving assembly.

A compressor is provided. The compressor compressing and discharging a refrigerant sucked into a cylinder comprises the cylinder configured to form a compressed space of the refrigerant and having a cylindrical shape; a piston configured to reciprocate axially in the cylinder and having a cylindrical shape; an intake valve disposed at a front of the piston; a fixing member disposed outside the piston; a rod comprising one end disposed at the intake valve and configured to extend axially; a first elastic member connected to the fixing member and other side of the rod; a second elastic member disposed to be spaced apart from a rear of the first elastic member and connected to the fixing member and the other side of the rod; and a first spacer insert-injected with the first elastic member and the second elastic member.

Systems and methods to enhance the flow of fracturing fluid into a wellhead during a high-pressure fracturing operation may include providing a pump frame and a crankshaft. A plurality of first plungers may be connected to the crankshaft and may reciprocate in a first plane. The hydraulic fracturing pump also may include a plurality of second plungers connected to the crankshaft and positioned to reciprocate in a second plane. The first plane and the second plane may define a non-zero offset angle between the first plane and the second plane. The crankshaft may include a plurality of crankpins, and each of the crankpins may be connected to one of the first plungers and one of the second plungers. The first plungers may pump a first fracturing fluid and the second plungers may pump a second fracturing fluid different from the first fracturing fluid.

End element for the stator of an electric motor of a hermetically sealed refrigerant compressor including at least one isolating element, having a ring-like core, to cover an axial end portion of the stator and to isolate a stator core and stator windings. The end element includes several spring holders extending radially outside the isolating element, each spring holder being adapted to hold a spring for supporting the electric motor in a housing of the hermetically sealed refrigerant compressor. The spring holders are oriented parallel to the axis of the isolating element and an insertion part of each spring holder extends in a first axial direction beyond the neighboring area of the isolating element. The spring holders and the isolating element are integral parts of the end element. The spring holders are tiltable so that an extended part of a spring holder tilts radially inwards.