SFERAX

19 Technical Information Working Life Calculations First example :_____________ The vertical charge of a cylinder is 40 kp*) and is carried by 2 ball bearings. The cylinder moves at a speed of 200 m/min., 12 hours a day. Ball bearing life expectancy : 1 year (3’600 hours). Shaft hardness : 62 HRC Working temperature : 70° C. Therefore : P = 20 kp*) per ball bearing. Working life in metres : 3’600 • 200 • 60 = 43,2 • 10 6 fl = 0,0135 Diagram 1, page 21 X = 1,07 Table 1, page 20 fl 0,0135 Y = –––– = –––––– = 0,00063 X • P 1,07 • 20 ______________ *) 1 kp = 9,81 N For the following SFERAX refer to page (Column Y) : 2032 ..................................................... page 25 122026 .............................................................. 27 1525-OUV ..................................................... 29 101824-OUV ............................................... 31 2028-CPT ...................................................... 41 1626 HT ........................................................... 43 Selected metric conversion 1 mm = 0.03937 inch 0,001 mm = 0.00004 inch 1 gram = 0.03527 ounce 1 Kp = 2.2046 lbs. charge 1 N = 0.223 lbs. charge Second example_____________ The vertical charge of the machine slide is 100 kp*), moving on 2 shafts and supported by 4 type OUV ball bearings. Each ball bearing carries 25 kp*). The stroke slide is 400 mm, moving 200 times per minute. Shaft hardness : 60 HRC. Working temperature : 120° C. Preferred shaft diameter : 30 mm P = 25 kp*) Y = 0,000152 page 29 X = 1,1 table 1, page 20 Distance run per hour = 0,4 • 2 • 60 • 200 = 9’600 m/h. fl = X • Y • P = 1,1 • 0,000152 • 25 = 0,00418 Working life = over 800’000’000 metres diagram 1 page 21 Working life at 120° C. = 0,92 • 800 • 10 6 = 736 • 10 6 . m (Z = 0,92) Working life = 736 • 10 6 = 76’666 hours. in hours 9’600