An air compressor of weight-reduction type is disclosed, wherein the bearing and the main housing thereof are formed integrally, so that when the piston body conducts reciprocating motion within the cylinder at high frequencies, the bearing is firmly fixed on the main housing without nonfunctioning or falling off. Furthermore, the main housing and the cylinder thereof are made of plastic and formed integrally. The main housing is formed with a wind collecting hood to facilitate the air flow being introduced through the main housing for rapidly dissipating the heat generated by the bearing and the heat generated from the reciprocating motion of the piston body. Accordingly, the manufacturing cost of the air compressor can be reduced to achieve an economical design, and the weight of the air compressor can be reduced to facilitate the compressor being carried onto a vehicle.

A hermetic compressor accommodates in hermetic container (101) electric motor element (102) and compression element (103) driven by electric motor element (102). Compression element (103) includes crankshaft (110) including main shaft (115), eccentric shaft (114), and flange (116), cylinder block (111) having cylinder bore (123) passing through cylinder block (111) in a cylindrical shape, and piston (112) configured to reciprocate in cylinder bore (123). Compression element (103) also includes connecting rod (113) connecting piston (112) and eccentric shaft (114) and bearing (124) formed on cylinder block (111) for pivotally supporting a radial load that acts on main shaft (115) of crankshaft (110). Crankshaft (110) further includes communicating oil supply passage (118) provided in flange (116), main shaft oil supply passage (119) configured for communication between communicating oil supply passage (118) and cylindrical surface (115a) of main shaft (115), and eccentric shaft oil supply passage (120) configured for communication between communicating oil supply passage (118) and cylindrical surface (114a) of eccentric shaft (114).

A system for compressing gas from a wellbore that uses a single reciprocating compressor unit to boost pressure of the gas to an intermediate stage, and from the intermediate stage to a final stage. The final stage is at a destination pressure for distribution. Between the intermediate and final stages the gas is treated to remove water and higher molecular weight hydrocarbons so that the gas pressurized to the final stage is compressed natural gas. The reciprocating compressor is made up of a series of throw assemblies that are all driven by a single shaft. Each throw assembly includes a cylinder with a piston that reciprocates within the cylinder to compress and pressurize the fluid therein. The reciprocating compressor can be a non-lube design thereby eliminating lube oil contamination of downstream compressed natural gas or higher molecular weight hydrocarbons.

In one aspect, a fluid end portion of a reciprocating pump assembly includes a fluid end block and an inlet manifold connected thereto. The manifold includes an opening formed therethrough and including a slot portion to facilitate the connection between the inlet manifold and the fluid end block. In another aspect, a method of connecting an inlet manifold to a fluid end block includes inserting fasteners into respective openings in the fluid end block, and effecting relative movement between the inlet manifold and the fluid end block so that the fasteners pass within respective slot portions formed through a mounting plate of the inlet manifold. In yet another aspect, a manifold is adapted to be connected to a fluid end block and includes an elongated member and a mounting plate connected thereto. The mounting plate includes openings formed therethrough, the openings including respective slot portions spaced in a parallel relation.

A lubricating oil supply apparatus may include a rotational portion that rotates together with a rotational shaft and a fixed portion that maintains a fixed location thereof and supplies oil through a space that circles with respect to a rotational center of the rotational portion, thereby supplying oil regardless of a rotational direction of the rotational shaft.

A compressor and a refrigeration system having the same are provided. The compressor includes a crankcase, a thrust bearing and a crankshaft. The crankcase is formed with a crankshaft hole therein and provided with a mounting protrusion at an upper end thereof. The crankshaft hole runs upward through the mounting protrusion. The thrust bearing is fitted over the mounting protrusion. The crankshaft is rotatably disposed within the crankshaft hole, has a thrust part, and is formed with an oil supply passage therein. A lower end face of the thrust part is abutted against an upper end face of the thrust bearing. A cavity is defined by the mounting protrusion, the thrust bearing and the thrust part. A through hole is formed in a peripheral wall of the crankshaft for communicating the oil supply passage with the cavity.

A vehicle-mounted electric oil-free air compressor, including a motor, a box body, a piston, and a flywheel shaft. The motor is fixed on the box body, a cylinder cover is at the top of the box body, a main shaft of the motor includes a coupling driving end, the flywheel shaft is driven by an elastic body to rotate. The piston includes a primary intake valve piece and a primary exhaust valve piece, the box body is provided with a secondary cavity, a secondary exhaust valve piece is provided at a vent hole on one side of the cavity, and the primary exhaust valve piece is also a secondary intake valve piece of the compressor, increasing the exhaust pressure. When the piston reciprocates, the stress is balanced and the vibration is small, and with the assistance of a high-efficiency flywheel, the operation of the air compressor is stable.

Sealed container (102) houses electric unit (110) equipped with stator (114) and a rotor (116), and compression unit (112) disposed above electric unit (110). Compression unit (112) includes shaft (118) that includes main shaft portion (120) and eccentric shaft portion (122), and cylinder block (124). Compression unit (112) further includes connection portion (136) that connects piston (128) reciprocatively inserted into cylinder (130) and eccentric shaft portion (122), and a thrust bearing that supports a load of shaft (118) in a vertical direction. The thrust bearing includes an upper race in contact with a flange portion of shaft (118), a lower race in contact with a thrust surface of cylinder block (124), and a rolling element. An overall height of sealed container (102) is sized not to exceed a length six times larger than a diameter of piston (128).

A balance weight includes a main weight portion extending over a range defined by a circular-arc circumferential edge centered at a rotational shaft hole side and a pair of virtual end surfaces located on the circular-arc circumferential edge on both sides of the rotational shaft hole, a pair of extension weight portions extending from the pair of virtual end surfaces to an opposite circular-arc side of the rotational shaft hole from the circular-arc circumferential edge, the rotational shaft hole provided at the main weight portion so as to be located on a central side of the circular-arc circumferential edge, a crank shaft attachment protrusion, a crank shaft hole provided at the crank shaft attachment protrusion radially eccentrically with respect to the rotational shaft hole, and a pair of spaces formed between positions on both sides of the crank shaft attachment protrusion and the pair of extension weight portions, respectively.

A method of mounting a bearing to an air compressor including a shaft element having a first end defining a central cylindrical recess and a second is disclosed, which includes the steps of: fixing the second end of the shaft element to a center of a gear; inserting the first end of the shaft element through a central hole of a bearing to have an annular step of the shaft element abutted an inner ring of the bearing; and hitting the first end of the shaft element by a striking tool with a central pin to form an outwardly extending rim on the first end of the shaft element. With the method, the bearing can be firmly fixed between the outwardly extending rim and the annular step of the shaft element.