Ball screw repair are more easily damaged when installed than conventional lead screws. To help prevent damage, ensure accuracy, and longer life; proper installation is requir
ed. Barnes Industries ball screws are manufactured, inspected, and tested by skilled mechanics to engineered specifications, ready for installation. Ball screws are super high precision, preloaded ball bearings running on a helical raceway. To build a new unit, or recondition a unit to new high quality condition, extensive ball screw engineering analysis is a basic requirement superior ball screw repair.
Ball screw life can be calculated. Parameters used in calculations include contact angle, ball conformity to the thread radius, number of balls in contact with the raceway, preload, materials, heat treatment case depth and raceway hardness. Ball screw repair control of parallelism, squareness, concentricity, and lead are also necessary to achieve ball screw accuracy and long wear life.
Since the formation of the company, Barnes Industries engineers have analyzed many failures on major U.S. and foreign ball screws.
To prevent failures and give extended life, designs have been continually improved, manufacturing tolerances reduced, and design recommendations made to customers. Engineering analysis of failed ball screws since the formation of Barnes Industries has permitted “Barnes” to establish engineering and manufacturing specifications in which 98% reliability has been attained. “Barnes” new ball screws are warranted for 24 months or 20 million inches of nut travel. Reconditioned ball screw warranties fall into two categories (1) 18 months or 15 million inches of nut travel (2) 15 months or 12.5 million inches of nut travel. See specifications for each of the services provided for complete details.
Ball screw repair ratings for ball lead screws are comparable to the L-10 rating for ball bearings as determined by the American Bearing Manufacturers Association. The L-10 or B-10 rating is defined as a reliability requirement * where a failure rate of 10% is allowable. This means that about 90% of any large group of identical screws will meet or exceed this life rating, 50% will last five times as long, and about 10% will fail before reaching that rating.