Self-Adjusting Back Pressure Mechanism for Scroll Compressors

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 of a back pressure chamber mechanism has been widely adopted to support a scroll member with axial compliance. This paper outlines some results of analytical and empirical investigations used to evaluate the effect of several parameters on the feature of back pressure mechanism and scroll compressor performance. INTRODUCTION Energy, resource, and space saving are still major problems in the field of compressors and their applications. Noise and vibration levels under desired operating conditions are also important considerations. To meet these demands, scroll compressors for air conditioners first came onto the market in 1983 /1/,/2/. The scroll compressors used for packaged air conditioners had an excellent reputation for their high efficiency, long life and quiet operation. Following this, scroll compressors for low temperature use and cryogenic use were developed, improving various design points /3/. In recent years, small capacity scroll compressors that can be controlled over a wide range of speeds have become common in household air conditioners /4/. It is important to reduce leakage, heating loss, and mechanical loss to improve the efficiency and durability of the wide range of scroll compressors. The potential leakage through the axial gap is several times greater than that through the radial gap and its reduction would be a dominant factor in improving compressor efficiency. One method for controlling this leakage is to bias the scroll members together using gas loading with the lowest frictional force and wear 5/,/6/.