An air compressor improves the dustproof performance of an intake path to a crankcase. The air compressor includes a compression assembly that reciprocates a piston in a cylinder to produce compressed air, a crankcase accommodating the compression assembly and having an inner inlet to allow outside air to be drawn, a filter located in the crankcase and covering the inner inlet from outside, a filter cover having an outer inlet and covering the filter from outside, and a dust cover covering the filter cover from outside, covering the outer inlet, and including an outer circumferential portion. The outer circumference portion and the filter cover have a space to draw outside air between the outer circumference portion and the filter cover.

A power end frame assembly for a reciprocating pump that includes a first and second end plate segment each including annular bearing support surfaces configured to support a crankshaft bearing assembly. At least one middle plate segment is disposed between the first and second end plate segments and includes an annular bearing support surface configured to support a crankshaft bearing assembly. The annular bearing support surfaces of the first and second end plate segments and the at least one middle plate segment each have a diameter and are coaxially aligned. The diameter of at least one of the first and second end plate segments is different from the diameter of the at least one middle plate segment to facilitate insertion and removal of the crankshaft bearing assembly from the power end frame assembly.

An apparatus and method for substantially reducing or eliminating the introduction of ambient air into an open-crankcase compressor is disclosed. The method employs a compressed gas recycle control loop to reduce the magnitude of vacuum inside the open-crankcase compressor relative to ambient air pressure, thereby reducing or eliminating the introduction of ambient air into the open-crankcase compressor during the gas compression process.

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 compressor may include a shell, a crankshaft, a piston and a connecting rod. The shell may define a cylinder. The crankshaft is supported for rotation relative to the shell. The piston reciprocates within the cylinder in response to rotation of the crankshaft. The piston and the cylinder define a compression chamber therebetween. The connecting rod includes a first bushing rotatably coupled to the piston and a second bushing rotatably coupled to the crankshaft. The second bushing may include a driving surface contacting the crankshaft and having a recess formed therein. The recess receives an insert.

Provided is a compressor as a device which can solve a contradictory technical problem of installing an intake sound muffler while downsizing the device under a circumstance that installation of the intake sound muffler is indispensable to reduce intake noise of the compressor, and the compressor comprises: a first lid part provided with a small hole which forms an intake port of the compressor, the lid part constituting a portion of a cylindrical casing of the compressor; a cylindrical part; and a second lid part which forms a small chamber together with the first lid part, wherein the second lid part is provided with a suction nozzle for sucking air into the small chamber.

A power end frame assembly for a reciprocating pump that includes a first and second end plate segment each including annular bearing support surfaces configured to support a crankshaft bearing assembly. At least one middle plate segment is disposed between the first and second end plate segments and includes an annular bearing support surface configured to support a crankshaft bearing assembly. The annular bearing support surfaces of the first and second end plate segments and the at least one middle plate segment each have a diameter and are coaxially aligned. The diameter of at least one of the first and second end plate segments is different from the diameter of the at least one middle plate segment to facilitate insertion and removal of the crankshaft bearing assembly from the power end frame assembly.

A compressor crankcase assembly is provided for an air compressor. In one example, a compressor crankcase assembly includes a crankcase made of a material comprising at least 50% by weight aluminum and a crankcase liner disposed within the crankcase. The crankcase has a protrusion that is at least partially disposed within the groove of the crankcase liner.

A skid for supporting a reciprocating pump assembly, the reciprocating pump assembly including a power end frame assembly having a pair of end plate segments and a plurality of middle plate segments disposed between the end plate segments. The end plate segments each have at least a pair of feet and the middle plate segments each having at least one foot. The skid includes a base and a plurality of pads extending from the base. At least a portion of the plurality of pads correspond to the end plate segment feet and at least another portion of the plurality of pads correspond to the at least one foot of each middle plate segment.

A noise mitigation boot that can be installed on or integrated into a miniature diaphragm pump to reduce the overall noise and improve sound quality during operation. The diaphragm pump includes a housing having first and second ports and an interior chamber, a pumping diaphragm disposed in the interior chamber and dividing the interior chamber into a pumping chamber and a backside chamber, a motor for reciprocating the pumping diaphragm for pumping air into and out of the pumping chamber, and flow passages connecting the pumping chamber to the first and second ports. The first port is configured for attachment to a flow line and the second port opens to an exterior surface of the housing. The noise mitigation boot has a muffler wall overlying the exterior surface of the housing. The muffler wall has formed therein a passage extending from the second port to the backside chamber for effecting fluid communication between the second port and the backside chamber.