# Research on the Technologies of the Compressor Remanufacturing Process
## 1 Introduction  
Nowadays, home appliances are essential in our daily lives. An increasing number of products are being discarded or eliminated with the end of product life and the increase in people's requirements. A compressor, as the core component of home appliances such as refrigerators and air conditioners, is a relatively high value-added product. At present, waste compressors are mainly dismantled and recycled, not only causing a huge waste of resources but also posing a serious burden to the environment. Remanufacturing is a more economical and environmentally friendly approach to disposing of waste than is recycling materials [1; 2]. Remanufacturing is the process of returning a used product to at least its original performance or better than that of a newly manufactured product [3]. Compared with new products, the remanufactured products can save energy and materials and reduce waste emissions [4; 5]. The remanufacturing process includes the inspection, disassembly, cleaning and testing of used products, followed by the remanufacturing of failed parts using advanced technology, and the finally reassembly into new products [6]. The concept of remanufacturing was initially formally proposed by the United States in the early 1980s [7]. After more than 20 years of development, it is widely used in military, automobile, construction machinery and other high value-added products [8; 9]. The United States has the largest remanufacturing industry, which reached USD 75 billion total value in 2005, with the remanufacturing of automobile and machinery accounting for more than two-thirds. Europe, which is represented by Germany and France, mainly focuses onremanufacturing research of automobile products. It has adopted positive remanufacturing related laws and regulations, and established the remanufacturing technology research centre in Germany [10]. In automotive engines, transmission and construction machinery and other high value-added products of the remanufacturing process have made greater progress and formed a certain industrial scale. However, in the case of low value-added products, such as used appliances, the experience of automobiles and construction machinery cannot be fully borrowed due to the higher economic requirements of the remanufacturing process [10,11]. However, with the popularity of refrigerators, air conditioners and other household appliances, the number of used compressors has increased year by year, and the traditional recycling methods are no longer being adapted. In recent years, with the requirement for resource conservation and environmental protection, the scale of compressor remanufacturing has gradually expanded. Some original equipment manufacturers have established services that offer compressor reuse options [10,12]. The design of the compressor has not changed particularly dramatically over the decades, indicating that it is particularly suitable for remanufacturing. Compressor failures are associated with components, such as motors, bearings and shafts. These components are subject to more severe wear than are others. Therefore, they are the key components that require remanufacturing. This study describes the remanufacturing process from the technical characteristics of compressors for home appliances. This process is informed by the waste failure form of the products in combination with considerations of environmental friendliness, economy and production feasibility of remanufacturing; it allows for the standardised batch remanufacturing of compressors. The key technologies, such as stator cleaning and crankshaft remanufacturing, are highlighted. The remainder of this paper is presented as follows. Section 2 introduces the technical features of compressors that should be considered in the remanufacturing process. Section 3 describes the methods of compressor remanufacturing. Section 4 describes two key processes in the compressor remanufacturing process: the motor stator cleaning technology and the crankshaft remanufacturing process. Section 5 presents the main conclusion.