Reciprocating piston compressor having improved noise attenuation

A method for reducing the amplitude of pressure pulses having a particular wavelength in a fluid, comprising:

• flowing the pressure pulse-containing fluid through a conduit;
• attenuating the pressure pulse amplitude at a first location along the conduit;
• and
• further attenuating the pressure pulse amplitude at a second location along the conduit distanced from the first location a distance which is substantially equal to an odd multiple of one quarter of the wavelength.

A reciprocating piston compressor, comprising:

• a cylinder block having a cylinder bore;
• a piston reciprocatingly disposed in said cylinder bore;
• a cylinder head connected to said cylinder block and partially defining a suction chamber into which gas is received and from which the gas exits into said cylinder bore substantially at a suction pressure, said cylinder head partially defining a discharge chamber into which gas is received from said cylinder bore and from which the gas exits substantially at a discharge pressure;
• a valve plate having a suction port through which said cylinder bore and said suction chamber fluidly communicate, and a discharge port through which said cylinder bore and said discharge chamber fluidly communicate;
• a suction check valve disposed over said suction port and past which gas flows from said suction chamber to said cylinder bore, flow from said cylinder bore to said suction chamber being inhibited by said suction check valve;
• a discharge check valve disposed over said discharge port and past which gas flows from said cylinder bore to said discharge chamber, flow from said discharge chamber to said cylinder bore being inhibited by said discharge check valve;
• and
• a spacer disposed between said valve plate and said cylinder head, said spacer having generally opposite first and second end surfaces, each of said first and second spacer end surfaces respectively abutting an interfacing surface of said valve plate and said cylinder head, said spacer partially defining said discharge chamber, a substantial portion of the volume of said discharge chamber located between said spacer end surfaces;
• wherein said first and second spacer end surfaces are each provided with a plurality of substantially concentric ridges having tips, said ridge tips having one of a deformed state and an undeformed state, adjacent ones of said ridges separated by a valley, said ridge tips being placed in said deformed state in response to a compressive load exerted on said spacer between said valve plate and said cylinder head during assembly of said compressor, said deformed ridge tips providing a seal between said first spacer end surface and said valve plate, and between said second spacer end surface and said cylinder head.

A method of assembling a reciprocating piston compressor having a cylinder block with a cylinder bore opening, a valve plate, and a cylinder head, comprising the steps of:

• providing a spacer having first and second end surfaces each provided with a plurality of substantially concentric ridges having tips, the ridge tips having one of a deformed state and an undeformed state, adjacent ones of the ridge tips separated by a valley;
• orienting the valve plate, the spacer, and the cylinder head in a stacked arrangement over the cylinder bore opening;
• and
• exerting a compressive load on the ridge tips to deform the ridge tips to the deformed state, the deformed ridge tips providing sealing contact between the first spacer end surface and the valve plate, and between the second spacer end surface and the cylinder head.

A compressor assembly comprising:

• a compression mechanism having an inlet into which a gas substantially at suction pressure is received, and an outlet from which gas compressed by said compression mechanism is discharged substantially at a discharge pressure;
• a motor comprising a rotor and a stator, said stator substantially surrounding said rotor and having an end, said rotor operatively coupled with said compression mechanism;
• an end cap disposed over said stator end, said end cap having an interior in which is gas substantially at suction pressure;
• and
• a suction tube of variable length through which said compression mechanism inlet and said end cap interior are in fluid communication, said suction tube comprising first and second tubes which are in sliding, telescoping engagement, whereby the length of said suction tube may be adjusted through relative axial movement of said first and second tubes.

A compressor assembly comprising:

• a housing having at least one natural frequency having a wave form with amplitude large enough for said housing, when vibrated at that frequency, to produce an objectionable noise, said natural frequency wave form having a plurality of natural nodes equally distributed about the circumference of said housing and natural anti-nodes located between adjacent natural nodes;
• a motor/compressor assembly comprising a compression mechanism in which gas is compressed from substantially a suction pressure to substantially a discharge pressure, and a motor operably engaged with said compressor mechanism;
• and
• a plurality of mounts unequally distributed about the circumference of said housing, said motor/compressor assembly being supported within said housing by said mounts;
• wherein each said mount is attached to said housing at a first point, said first points not coinciding with the natural nodes of said natural frequency wave form and defining forced nodes on the circumference of said housing to which the nodes of said natural frequency wave form are forced, said natural frequency wave form being altered in response to the natural nodes being forced to the forced nodes, whereby said housing is prevented from vibrating at said natural frequency.