Aktiebolaget Skf

Kenred Stadler

Armin Olschewski

Arno Stubenrauch

Markus Volkmuth

Guillermo Enrique Morales Espejel

Victor Brizmer

Juergen Gegner

Wolfgang Nierlich

Guillermo Morales Espejel

A bearing comprising a plurality of rolling elements arranged between an inner and outer raceway thereof. A rolling contact interface is between a first rolling contact surface on at least one rolling element and a second rolling contact surface formed by one of the inner and outer raceways. The first rolling contact surface has a first RMS roughness Rand a first roughness pattern &#x3b3;, expressed in terms of the Peklenik number &#x3b3;. The second rolling contact surface has a second RMS roughness Rand a second roughness pattern &#x3b3;. To minimize micropitting in the bearing, the rolling contact interface has a surface topography wherein (a) the roughness pattern of the first and second rolling contact surfaces are oriented in the direction of rolling, whereby &#x3b3;&#x2267;3.0 and &#x3b3;&#x2267;10.0; and (b) the first and of the second rolling contact surfaces have substantially equal roughness heights, whereby 0.8&#x2266;R/R&#x2266;1.25.

Bearing with improved resistance to micropitting

A method for manufacturing a rolling-element bearing includes forming an inner ring from a steel having a sulfur content of 0.002 to 0.015 mass % and an oxygen content of less than 15 ppm, subjecting the inner ring to a hardening heat treatment that ends by performing a final heat treatment step at a predetermined temperature, cold working the inner-ring raceway to generate compressive residual stresses at least in a surface layer of the inner-ring raceway, subjecting the inner ring to a bluing treatment and subjecting the blued inner ring to a thermal post-treatment process at a temperature below the predetermined temperature of the final hardening heat treatment step. The resulting rolling-element bearing may exhibit compressive residual stresses having an absolute value of at least 200 MPa at 0.1 mm beneath the outer surface of the inner-ring raceway and a maximum value of 1500 MPa or less throughout the inner ring.

Method for manufacturing a rolling element bearing

Growing community of inventors

Schweinfurt, Germany

Kenred Stadler