Super Smart Ball Bushing Bearing - Hollin Applications

Phone: 1-800-554-8466Website: www.thomsonballbushing.comEngineeringBall Bushing Bearing Size and SelectionThe primary factors that influence the choice of bearingsize are maximum load on a single Ball Bushing* bearingand required travel life. To determine the maximum loadon a single Ball Bushing bearing refer to load considerationson page 138. To determine the required travel liferefer to the following formula:L t = 2•s•f•L h •60Where:L t = required travel life in inchess = stroke in inchesf = frequency in cycles per minuteL h = service life in hoursOnce you have determined the maximum load on asingle Ball Bushing bearing and the required travel life,enter the chart (Figure 4) and mark where the two linesintersect. All Ball Bushing bearings with curves that passthrough, or above and to the right of that point may besuitable for the application.Sample Calculation 1:Determining the correct Ball Bushing bearing for yourapplication.In this example, a Super Smart Ball Bushing bearing endsupported system is subjected to a load of 500 lb f . Theload is distributed equally over four Super Smart BallBushing bearings. The carriage reciprocates over a 12inch stroke at a frequency of 100 complete cycles perminute. The minimum service life required is 3500 hours.The first step is to determine the average load on eachSuper Smart Ball Bushing bearing.P = 500/4 = 125 lb fNext, determine the equivalent travel life in inches.L t = required travel life in inchesL t = 2•s•f•L h •60L t = 2•12•100•3500•60L t = 5.04 x 10 8 inchesEnter Figure 4 with a maximum load capacity on a singlebearing of 125 lb f and a required travel life of 5.04 x 10 8inches. All Super Smart Ball Bushing bearing curves thatpass through or above and to the right of that point, maybe suitable for the application. For this application wewill choose the SSU-12.Sample calculation 2:Determining the correct Super Smart Ball Bushingbearing for your application.In this example, an open type Super Smart Ball Bushingbearing continuously supported system is subjected to aload of 500 lb f and is hung upside down from theceiling. The load is distributed equally over four SuperSmart Ball Bushing bearings and the factor for thedirection of the resultant load is .45 (Figure 3, page 136).The carriage reciprocates over a 12 inch stroke at afrequency of 100 complete cycles per minute. Theminimum service life required is 3500 hours.The first step is to determine the average load on eachSuper Smart Ball Bushing bearing.P = 500/4 = 125 lb fDetermine the equivalent travel life in inches.L t = 2•s•f•L h •60L t = 2•12•100•3500•60L t = 5.04 x 10 8 inchesLoad on most heavily loaded bearing (lbf)4000100010050SSU-24 (-W/-WW)SSU-20 (-W/-WW)SSU-16 (-W/-WW)SSU-12 (-W/-WW)SSU-10 (-W/-WW)1 10 100 1000Required Travel Life (millions of inches)Figure 4Enter Figure 1 and determine K LThe next step is to determine the required dynamic loadcapacity.(K S = 1, since we are using aPW R =Thomson 60 Case LinearRaceK O •K S •K L HRC 60 minimum.)125W R =.45 •1•.17W R = 1633 lb fTo determine the proper Super Smart Ball Bushingbearing size enter the specification table on page 28.Choose the Super Smart Ball Bushing bearing with aload capacity higher than 1633 lb f . The SSU-12-OPNhas a dynamic load capacity of 1130 lb f and the SSU-16-OPN has a dynamic load capacity of 1900 lb f . TheSSU-16-OPN is therefore the proper choice.©2003 Danaher Motion. Printed in the U.S.A. The specifications in this publication are believed to be accurate and reliable.However, it is the responsibility of the product user to determine the suitability of Thomson products for a specific application.While defective products will be replaced without charge if promptly returned, no liability is assumed beyond such replacement.Page 137* Trademark of Danaher Motion. DANAHER MOTION is registered in the U.S. Patent and Trademark Office and in other countries.