Objective: In order to improve the friction-increasing and wear-reducing performance of the unfolding wheel surface, the surface microstructure of the unfolding wheel used in the detection of 8 kinds of steel balls was optimized by parameter matching. Method: Firstly, based on Hertz's theory, the contact area between steel balls of different sizes and the unfolding wheel are analyzed. The wear depth model is established based on Archard adhesive wear model. Secondly, the appropriate microstructure parameters for friction and wear experiments were selected. The finite element analysis software is used to simulate the stress on the surface of the microstructure unfolding wheel and calculate the wear depth. According to the experimental results, the relationship between friction coefficient, wear depth and microstructure parameters is obtained by data fitting, and the objective function of optimization design is established. Finally, based on the genetic algorithm DNSGA-II and Python, the parameters are optimized, and the optimal solution is obtained by using the TOPSIS method. Results: The feasibility of the simulation method is verified by friction and wear experiments, and the correctness of the optimization method is verified. Conclusion: The research shows that the optimal parameters matching of microstructure for steel ball diameters of Ф16.6688mm~Ф22.2250mm: the shape is rhombus; the area of a single pit is close to the contact area, which is 0.0319mm2 ~ 0.0554mm2; the pit depth is 145μm~150μm, and the surface density of microstructure is (5.4~5.6) /mm2.

Background: Surface microtextured technology is an expansion and extension of biomimicry in the tribology field, promoting vigorous development in microtextured tribology. Through artificial means, tiny convex hulls, craters, or stripes of specific size and arrangement are processed on the friction surfaces to change the morphology and contact angle of the surfaces and improve the surface contact state or the lubrication effect. The function and properties of microtextured surfaces are determined by optimizing their geometrical parameters, but the microtextured geometrical parameters require a high-level machining quality. It is necessary to analyze and summarize the existing research on manufacturing microtextured surfaces. Objective: By summarizing the preparation methods of microtextured surfaces in the past decade, some valuable conclusions are drawn to predict the future development of technology for manufacturing microtextured surfaces and provide a reference for researchers in related fields. Method: This paper summarizes the representative patents related to the methods of manufacturing microtextured surfaces, analyzes the properties of the microtextured surfaces produced by each method, and discusses the advantages and disadvantages of these methods. Results: The existing problems are summarised through the analyses of patents related to microtextured preparation methods. The future development of new preparation methods has prospected. Conclusion: By cooperating with various processing technologies and optimizing the processing methods, the microtextured surfaces can meet various functional requirements, and the manufacturing precision is higher than before. The processing method needs further improvement according to the working conditions. More new technologies will be invented to create microtextured surfaces.

Background: Rolling bearings are the core components of mechanical equipment. Lubrication plays an important role in the operating performance of rolling bearings. The research on rolling bearing lubrication devices is beneficial to making the bearings obtain the characteristics which is suitable for the working conditions and improving the bearing's service life. Compared with the traditional lubrication devices, the new ones provide assistance to various bearings, solving many problems. Objective: To review the latest research on rolling bearing lubrication devices, analyze their solutions to rolling bearing lubrication problems, and discuss their advantages and disadvantages for the reference of scholars and engineers. Methods: The representative patents related to rolling bearing lubrication devices are reviewed according to the lubrication method of bearings, including oil lubrication, grease lubrication and solid lubrication. Oil lubrication includes oil mist lubrication, oil-air lubrication, jet lubrication, under ring lubrication and immersion oil lubrication, etc. Grease lubrication includes external and internal lubrication methods. The working principle and characteristics are explained by analyzing the structure of bearing lubrication devices. Results: By comparing different types of rolling bearing lubrication devices, the main problems of the current lubrication devices are summarized and analyzed. The future development of rolling bearing lubrication devices are prospected. Conclusion: The improvement of rolling bearing lubrication devices is conducive to developing bearing lubrication technology. Advanced mechanical equipments require the rolling bearing lubrication devices to have a simple structure, intelligence, and are easy to be installed.

Background: Smart bearing is based on the traditional bearing, which is integrated by sensing devices and control devices, formating a unique bearing structure unit. It uses information processing, automatic control, and other technologies to achieve real-time online monitoring of bearing operating conditions, fault detection, and state control. Compared with ordinary bearings, smart bearings have the characteristics of self-awareness, self-decision, and self-regulation. By analyzing the composition of various types of smart bearings and their working principles, it is beneficial to prospect the future development direction of bearings. Objective: We analyze and organize the patents on smart bearings in recent years, summarize the problems encountered in the development of smart bearings, and propose the development direction of smart bearings in the future to provide a reference for future scientific research. Method: This paper reviews the patents related to smart bearings and analyzes the composition and structure of smart bearings. The main smart bearings include rolling bearing, sliding bearing, magnetic bearing, and rubber bearing. The principle and structure of these bearings are analyzed. Their advantages and shortcomings are discussed. Results: Through the analysis of relevant patents and papers on smart bearings, the current development status and problems of smart bearings are summarized, the future design of smart bearings is proposed, and the research ideas and directions are proposed. Conclusion: The development of smart bearings is conducive to the timely detection of bearing conditions in the operation process. Except for detection, smart bearings have the functions of judgment, feedback, processing, etc. There are many factors that interfere with the accuracy of the smart bearing judgment and information transfer, so it is necessary to improve the structure and working principle of smart bearings through a variety of measures. In the future, more smart bearings will be invented.