>> P.21
ABCDEFGHIJKLM10152030406010080150200300400Roller bearings10001000060080015002000300040006000800015000200003000040000600001.41.442001.31.21.11.00.90.80.70.60.50.40.30.280.240.220.200.180.160.140.120.10630040050060070080010009002000300040006000100008000200004000080000600000.800.850.900.951.11.21.31.41.51.61.71.81.90.761.02.02.53.03.54.04.54.610152030406010080150200300400Ball bearings10006008001500200030004000600080001500020000300004000060000100001.41.491.31.21.11.00.90.80.70.60.50.40.30.280.240.180.160.140.120.220.200.090.100.0822003004005006007008001000900200030004000600010000800020000300004000080000600000.800.901.01.11.21.31.41.51.61.71.81.92.02.53.03.54.54.05.05.4Fig. 2 Scales for rating life calculationmin-1nfnhhLfh0.74hhLfhmin-1nfnRotational speedVelciy factorBasic rating life represented by service hoursLie factorRotational speedVelciy factorBasic rating life represented by service hoursLie factorBearing life factors for various machinesThe required life of the bearing must be determined according to the machine in which the bearing is to be used and the operating conditions.Table 1 shows reference values of life factors for selecting a bearing for each machine.Table 1 Life factor of bearings fh for various machinesOperating conditions〜32〜43〜54〜76〜Machine and life factor fhOccasional or short term usage・Power tools・Agricultural machinesInfrequent usage but requiring reliable operation・Construction machinery・ConveyorsIntermittent operation but for ・Roll neck of rolling mills・Small motorscomparatively long periods・Deck cranes・Elevators・Factory motors・Machine tools・Crane sheaves・CompressorsOperated in excess of 8 hours per day or continuously for an extended timeContinuous use for 24 hours and accidental stops not allowed・General cargo cranes・General gear units・Important gear units・Passenger cars・Printing machines・Escalators・Centrifugal separators・Paper making machines・Blowers・Wood working machines・Plastic extruding machines・Water supply equipment・Power station equipmentA18
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