Development of a High Performance Scroll Compressor for Automotive Air Conditioners

In order to respond to global necessities, such as the need for environmental protection and energy savings, we have succeeded in developing a highperfonnance scroll compressor for use in automotive air conditioners. The new compressor, which is compact and light in weight, has various advantages, such as high efficiency, high reliability, low noise and low vibration. The compressor uses HFC-134a as its refrigerant. All of these advantages have been made possible by incorporating various technological innovations into our original scroll compressor. The new scroll compressor features a variable rotationradius mechanism yielding an excellent sealing perfonnance, an Oldham coupling and a thrust slide bearing realizing low noise, low VIbration and low cost compared with a ball coupling type scroll compressor, and an original shape of the scroll vane resulting in high strength and high efficiency. These technological innovations contributed to a considerably higher perfonnance of the developed scroll compressor. Especially, the variable rotationradius mechanism, owing to a newly developed mechanism, has a simple structure with high rigidity. !.Introduction In the field of compressors for automotive air conditioners, which are now subject to increasingly stringent requirements, a wide range of engine driven rotation speed, extreme thennal conditions, the use of alternative HFC134a for environmental preservation, etc., there is a strong demand for reliability and energy efficiency, combined with convenience. As a result, each maker is strongly competing with all the others to develop compressors that both satisfy existing requirements and anticipate new ones. Under these conditions, the demand for scroll compressors is expanding, due to its low noise, high efficiency, and high speed. Based on our proprietary technologies for homeuse room air conditioners, we have succeeded in developing a new compact and light scroll compressor with high efficiency, low noise and vibration, and high reliability. In this paper, the structure and perfonnance of the new scroll compressor are described mainly in the context of major newly developed basic technologies. 2. Structure of the new Scroll Compressor The structure of the newly developed compressor is shown in Fig. 1 and its major specifications in Table 1. At the lap tip of the fixed scroll and the orbiting scroll that are made of aluminum alloy, a tip seal is disposed to assure sealing performance of axial direction. The drive shaft is carried by the main bearing and the subbearing. The orbiting scroll is orbited by an eccentric axis, which is integrally molded with the drive