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.