## 1 Introduction
studied the lubrication characteristics of the water-lubricated thrust bearing of submersible pumps through simulation and experiment [8]. Scholars have studied the performance of the water-lubricated thrust bearing in a variety of machines; however, there are few studies on HTBs used in WSSCs. [PERSON] and [PERSON] both proposed to use a water-lubricated sliding bearing in WSSCs, but they did not give a detailed introduction [9; 10]. [PERSON] analyzed the thermal deformation mechanism of the meshing pairs in single-screw compressors and proposed that the thermal deformation could be controlled by adjusting the bearing position [11]. The bearing performance plays an important role in the operation of WSSCs, especially the HTB of the star wheel shaft. The performance of water-lubricated thrust bearings is investigated by various methods. [PERSON] et al. assembled a water-lubricated test rig to measure the performance of hydrostatic thrust bearings [12]. [PERSON] et al. simulated  
Figure 1: Structure of a single-screw compressor. the influence of structure and working parameters, such as water film thickness, water injection hole diameter, and speed, on the bearing capacity of hydrostatic bearings [13]. [PERSON] et al. calculated the pressure distribution of water film in a water-lubricated thrust bearing using MATLAB and studied the influence of operating and bearing geometry parameters on a bearing's main lubricating performance [14]. [PERSON] et al. investigated the relationships between the main parameters of water-lubricated HTBs, such as bearing clearance, water injection pressure, water film thickness and bearing capacity, by conducting experiments [15]. [PERSON] et al. analyzed the bearing capacity of the HTB after the optimization design, then verified the simulation results by experiment [16].The effect of the groove shape on the bearing performance was also studied in the relevant literature. [PERSON] and [PERSON], [PERSON], [PERSON] and [PERSON] derived formulas for the lubricant flow rate and load capacity of a single circular groove HTB and annular multi-recess HTBs and verified their accuracies against experimental results [17; 18; 19; 20]. [PERSON] analyzed and compared the bearing capacity of the hydrostatic with a circular and annular groove and deduced the calculation method of the dynamic characteristics [21]. In summary, the bearing performance of various thrust bearings and their applications have been studied globally. However, research on their working stability under a large pulsating force has rarely been conducted. Given that the forces of a star wheel acted on by compressed air pulsate significantly with the pressure of compressed air, the following question should be answered: would this pulsation make the rotating ring of a bearing to move up and down in the axial direction and destroy the star wheel piece? Therefore, one of the major problems in the current study is the question of how to avoid large changes in water film thickness and large axial displacement of the star wheel in a compressor. For star wheel bearings, it is necessary to consume less water while maintaining its stability because the liquid supply of the single-screw compressor is limited. To bring out frictional heat in an HTB via water film flow and increase the distance of water flowing in an HTB, an annular liquid groove crossing with numerous short channels was arranged on the surface of a studied HTB, as shown in Figure 2a. Liquid pressure, \(\mathrm{p_{r}}\), in the groove on the sliding surface of an HTB is directly proportional to the compressor discharge pressure. Moreover, pressure on its inner and outer edges is lower than the compressor suction pressure. However, an annular water groove is often arranged on a conventional HTB surface, as shown in Figure 2b [22]. Evidently, frictional heat and wear particles on the sliding surface of an HTB can hardly be discharged out of the sliding surface.