Research on the Calculation Method for the Contact Stress of Wind Turbine Main Shaft Bearings Based on Finite Element Analysis

Under alternating loads, the contact situation for self-aligning roller bearings in the main shaft of a wind turbine is complex. Few methodologies exist for calculating the contact stress of main shaft bearings. We propose a method for calculating the contact stress of main shaft bearings in wind turbines; by simulating alternating loads that affect the turbine’s lifespan with a probability of 99%, analyzing the operational characteristics of the bearings under these loads using the roller slice method, and establishing a load–displacement model, this model serves as the boundary condition for contact stress simulation. We present the approach for building a three-dimensional finite element simulation model of contact stress, followed by model validation. The findings reveal that the maximum stress within the spindle bearing is concentrated in the contact zone, taking on an elliptical configuration. The maximum contact stress, as computed by the proposed method, amounts to 1356.3 MPa, and the bearing’s load-bearing performance adequately fulfills the design requirements. A comparative analysis with the calculation results documented in the existing literature shows that the average discrepancies in the computed outcomes for the roller’s contact with the inner and outer rings are 2.55% and 2.48%, respectively, and this validates the high reliability of the proposed approach. The research conducted in this thesis can further enhance the credibility of the contact stress calculation method for large-scale wind turbine spindle bearings.