Determination of the precise static load-carrying capacity of pitch bearings based on static models considering clearance

•The static models considering the clearance are proposed for pitch ball bearings.•The new static models are easier to be described and realized.•A precise static load-carrying curves considering radial loads are presented.•Effects of bearing geometry parameters on the static load capacity are analysed.

Static models for a single row and a double row four-point contact pitch bearing, taking into account the clearances therein, were presented. A precise computation method was proposed for the static load-carrying capacity curves of such pitch bearings, which can be used to pre-select pitch bearings and slewing bearings supposing rigid bearing rings. The effects on the static load-carrying capacity induced by changing the clearance, the raceway groove radius of curvature, and initial contact angle were analysed. The clearance has a significant effect on the static load-carrying capacity of the bearing only in load cases with a rather small axial force and a large tilting moment. When the coefficient of raceway groove curvature radius increases, the static load-carrying capacity decreases. The smaller the radial load, the more significant the effect of the coefficient of raceway groove curvature radius on the static load-carrying capacity of the bearing. When radial loads range from 0 to 800 kN, the load-carrying capacity increases with increasing initial contact angle. When the radial loads are above 800 kN, the load-carrying capacity decreases with increasing initial contact angle.