Tham khảo tài liệu 'handbook of lubrication episode 2 part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Volume II 655 FIGURE 6. Bathtub failure rate curve. APPLICATION METHODOLOGY The system concept described in the preceding section can be used as a convenient framework which may help to systematize approaches to the solution of lubrication This will be illustrated in three examples of broad areas of lubrication technology. Comprehensive Characterization of Tribological Systems The value of all lubrication work whether basic or applied would be greatly increased if experimental variables would be presented in a form suitable for subsequent independent evaluation and correlation. With the help of a data sheet such as Table 4 relevant parameters can easily be compiled in a comprehensive For the typical application example in Table 4 characteristics of a journal bearing operating at the minimum of the Stribeck curve are compiled with data taken from the Since the procedure of compiling the data sheet is all that is really relevant here only some main features of the example are pointed out. 1. The technical function of the system can be described as guidance of motion . 2. Operating variables are given by the type of motion namely continuous sliding of a duration of 40 min together with load FN velocity v and bulk oil temperature T. 3. The structure of the system is described by the elements of the system their relevant properties and interrelations. In this case tribo-element 1 is given by a bearing bushing consisting of a lead-tin-bronze and tribo-element 2 is a steel shaft. Lubricant 3 is a mineral oil of the type SAE 20W-20 and the atmosphere 4 is laboratory air. Together with the designation of the elements and materials the data sheet contains all important properties of the elements. The data sheet also indicates the tribological interactions between the elements of the system which can be characterized as a running-in period leading to topographical changes which are within the initial roughness of the bearing element 2 . 4. .
