Scroll compressor, Three-dimensional compression, Efficiency improvement
A novel three-dimensional scroll compressor was developed. The authors have produced 3D scroll compressor since 2004. The 3D scroll is able to compress refrigerant in axial direction as well as in existing radial direction by employing steps at the bottom and the tip of the scroll which change the height of compression chamber on the middle of the compression process. For the purpose of further performance improvement, the authors developed an evolutionary three-dimensional compression mechanism, named "e-3D scroll". The e-3D scroll is equipped with a sloped tip and a sloped end plate in each scroll instead of the steps in the conventional 3D scroll. The height of compression chamber decreases continuously with progression of compression by the sloped shape. The e-3D scroll achieved considerable efficiency improvement compared to the conventional 3D scroll since there is no leakage loss in the steps while keeping the advantages of high compression ratio, large capacity and small size by the sloped tip and end plate. In addition, the noise and vibration of the e-3D scroll compressor reduced significantly since the rate of change of cylinder volume throughout the compression process and the torque variation in the rotation became smaller than the conventional 3D scroll. This article describes the compression mechanism and the performance improvement technology in the e-3D scroll.