Tribology and Lubrication Technology April 2012 : Page 32and Offset (parallel displacement be-tween the axial planes). Temperature values reflect actual machine operat-ing temperature ranges. The blue highlights shown in Table 4 reflect the hydraulic system operat-ing state where the overall vibration level is between .350 in./sec. velocity overall, the motor to pump compo-nent misalignment by 1.5 mils, and is operating at 140 F . Since the ambient temperature value is the most severe, it is used to determine the machine health frequency factor, at 0.2. Table Weighted Operating Factors Table 5 | 5. Weighted operating Factors Wr Change Rate (Fr) 0.5 0.2 0.1 0.05 0.01 0.02 Weighted Score fREqUEncY fAcTORS Reliability centered maintenance phi-losophy asks the user to optimize maintenance actions relative to the im-portance of the machine’s mission. When the mission for a given machine is high, optimizing increases attention. If the mission is low, optimizing de-creases attention. These factors are in-tended to optimize frequency based on the plant’s operation on any given day. It is reasonable to assume that any company with multiple plant sites will have a wide variety of levels of matu-rity and effectiveness for selecting fac-tors for any of these categories. The significant factors should be selected by local management to support local production priorities. The significance factors represent the level of emphasis that management applies to each of the four frequency factors. The total of the significance values should equal 1, and any combi-nation of values is acceptable. Each significance value is multiplied by the factor score to provide a weighted fac-tor score. When added together, these will produce a Weighted Sample Fac-tor (WSF), as follows: WSF = ((W r * F r ) + (W c * F c ) + (W e * F e ) + (W h * F h )) Where W x = Weighting Value F x = Selected Factor Table 5 shows weighting assigned to each of the four factor categories noted above. 32 • APRIL 2 012 TRIB OL OG Y & L UBRIC A TION TE CHNOL OG Y Wc Criticality (Fc) 0.75 Weighted Score 0.3 0.5 0.2 0.1 0.03 We Environmental (Fr) 0.75 Weighted Score 0.4 0.5 0.2 0.1 0.04 Wh Machine Health (Fh) 0.75 Weighted Score 0.1 0.5 0.2 0.1 0.02 WWW .S TLE. OR G Publication List Using a screen reader? Click Here |
