Comparative Experimental Study on Wear Resistance of Different Types of Star Wheels in the Single Screw Compressor

Single screw compressors (SSCs) have been used in many fields. Compared with other kinds of compressors, the SSC should have many advantages due to its symmetrical structure and well balanced radial gas pressure on the screw rotor. However, its durability is not as good as expected. After operating for several thousand hours, its flow rate often decreases sharply. The essential reason is that the tooth flank of its star wheels is easily worn. In order to improve the wear resistance and operation life of the SSC, some new types of meshing pairs have been proposed. In this paper, we designed and made an eccentric wheel friction test device. In the test an eccentric wheel was used to wear samples of different meshing pairs. The wearing mechanism can ensure the angle between the sample and the surface of the eccentric wheel is similar to that between the star wheel blade and the screw groove surface. The test compared the erosion amounts of different star wheel profiles: single straight line, multi straight lines, cylinder, and single straight line second envelop meshing pairs. Results show that dispersing the abrasion area and making the load transition continuous and steady can improve wear resistance.