This paper discusses two approaches to modeling helical suspension springs for use in a dynamic finite element compressor model. The first approach represents the spring's stiffness characteristics with a simple spring element matrix. The appropriate spring constants are calculated using a separate finite element model of the spring. The spring modeling procedure is described and supplemented w...

The scroll compressor incorporates new construction concepts and is quite different from other types of compressor. This unique and simple compression mechanism has a number of advantages such as small size, light weight, high efficiency, long life, and quiet operation. The compliant mechanism is one of the key ways to improve the performance and reliability of scroll compressors. The concept o...

Integration of system process information with expert system vibration analysis to improve the accuracy of rotating machinery fault detection in on-line condition monitoring systems is the main focus of this paper. An overview of the condition based maintenance system MPROS (Machinery Prognostics/Diagnostics System) being developed for the US Navy is presented. Details are provided regarding se...

A. D. Kelly General Signal Laboratory Equipment 275 Aiken Road Asheville, NC 28806 Low temperature refrigeration mechanically and thermally stresses a compressor's wrist journal bearing. Knowledge of bearing condition would be useful for self-diagnostics or predictive maintenance, particularly in freezers used for storage of valuable biomedical products. This initial investigation considers ext...

Motivated by the high speed of real-time data acquisition, computational power, and low cost of generic PCs and embedded-PCs running Linux, this thesis addresses new methods and approaches to fault detection, model identification, and control. Fault detection. A series of faults was introduced into a 3-Ton roof-top airconditioning unit (RTU). Supply and condenser fan imbalance were detected by ...

Reciprocating compressors are widely used in industry for various purposes and faults occurring in them can degrade performance, consume additional energy, and even cause severe damage to the machine. This paper will develop an automated approach to condition classification of a reciprocating compressor based on vibration measurements. Both the time domain and frequency domain techniques have b...

The prediction of the acoustic radiation of the compressor shell is resulting from a numerical vibro-acoustic model, involving the description of the compressor pump structure, compressor gas cavity and compressor shell structure, through the use of the FEM and BEM techniques. The presence of refrigerant and lubricating oil in the compressor cavity were taken into account, as well as the presen...

Integration of system process information with expert system vibration analysis to improve the accuracy of rotating machinery fault detection in on-line condition monitoring systems is the main focus of this paper. An overview of the condition based maintenance system MPROS (Machinery Prognostics/Diagnostics System) being developed for the US Navy is presented. Details are provided regarding se...

Very few reports have been presented to date on the noise and vibrational characteristics of oil injected screw compressors. This time. a series of extensive experimental analysis is performed. It includes the measurements and analysis of compressor casing vibrations. rotor shafts vibrations, torsional <rotational) vibrations. suction and discharge gas pulsations. pressure trans~ ient in one th...

Screw compressors have the advantage of low mechanical vibration levels similar to those found in centrifugal compressors due their rotary motion. However, screw compressors are positive displacement machines with a working principle similar to reciprocating compressors, which gives screws some advantages compared to centrifugals, such as: • The suction volume flow and power consumption grow li...