Mood, Industries, 1600x230


An important workshop for wind gear units had five shafts out of specification. The bearings were rotating on the shaft causing damage to the surface. The rectification of the shafts to their initial diameter was not a viable option. Finally, the customer requested NSK to check the possibility of providing a bearing with special undersized bore diameter. NSK engineers investigated and developped a solution with a bearing design specific to the application. With this solution, it was not necessary to scrap the shafts which saved replacement costs. The special bearing were assembled following grinding of the shafts.

Wind, Micro Wind Turbine
  • Wind Turbine
Deep Groove Ball Bearing, Pressed Steel Cage, Open
  • NSK Deep Groove Ball Bearings

Key Facts

  • Repairing of the wind turbine gearbox
  • Deep Grove Ball Bearing originally specified was not suitable for the application
  • Large shafts on the wind turbines were damaged
  • With no possibility to recover the material, the shafts were due to be scrapped
  • NSK Solution: Deep Groove Ball Bearings with customised design and special bore diameter
  • Cost savings achieved as the original shafts could be re-used with the new bearings instead of being scrapped

Value Proposals

  • Analysis of the customer's request after visual imspection of disassembled shaft
  • NSK Engineers proposed a new technical design for special bearings with smaller bore diameter
  • Development and production of a specific reference for small quantity
  • Significant cost savings instead of scrapping and producing new shafts as the cost of the replacement shaft is much higher than the corresponding bearing costs

Product Features

  • Cages - Offering a number of different cage types to suit your application needs: steel, machined brass or polymer
  • High Quality Steel - Ultra clean steel to extend bearing operating life by up to 80%
  • Advanced Grease Technology - NSK lubricants that can extend grease life and performance
  • Super Finished Raceways - Specially honed finish to minimise noise and improve lubricant distribution and life
  • Patented Seals - Provide resistance to contamination in the toughest environments
  • Electrically insulated ball bearings available
  • Outer diameters up to 2500 mm
  • High Grade Balls - Quiet and smooth operation even at high speed
  • Quality Assured - 100% testing ensures total product quality
  • Low to medium radial loads
Cost Saving Breakdown
Before Cost p.a. NSK Solution Cost p.a.
Bearing Costs: Original bearing costs € 3.672 Bearing Costs: Costs for bearing with modified bore diameter € 3.948
Engineering Costs: Scrap and production of new shafts € 21.500 Engineering Costs: Regrinding of shafts € 2.000
Total Costs € 25 172 € 5 948