A critical problem for wind turbine gearboxes is failure of rolling element bearings where axial cracks form on the inner rings. This article presents field experience from operating wind turbines that compares the performance of through-hardened and carburized materials. It reveals that through-hardened bearings develop WEA/WECs and fail with axial cracks, whereas carburized bearings do not. The field experience further shows that a carburized bearing with a core having low carbon content, high nickel content, greater compressive residual stresses, and a higher amount of retained austenite provides higher fracture resistance and makes carburized bearings more durable than through-hardened bearings in the wind turbine environment.

In this paper, Edward Hage, founder of specAmotor.com, an online motor calculation and selection tool, focuses on the overheating of electric motors. Presented here is a calculation method with which the temperature and heat development of a direct current (DC) motor and a brushless motor can be predicted accurately.

Th e signing of a contract for more than 5,000 sets of SKF’s latest high-capacity cylindrical roller bearings (HCCRB) for wind turbines will impart added load-carrying capacity, more reliability and longer life to the Nanjing Gear Company’s (NGC) line of gearboxes for wind generation applications.

U.S. wind turbine growth puts a new spin on bearing manufacture.