Abstract: A method of superfinishing a large hollow wheel gear in a vibratory bowl having a center hub comprises at least partially filling the vibratory bowl with an amount of finishing media, laying the gear horizontally into the bowl over the center hub, supplying a quantity of an active chemistry into the bowl and agitating the vibratory bowl at a frequency such that the gear settles into and is fully supported by the media. By controlling the process parameters, the hollow wheel gear may be caused to rotate in the media and can be made to float at a desired level. The method is particularly suitable for hollow wheel gears for large wind turbines.

Abstract: Disclosed herein is a new improved large planetary gear system used on the input stage of wind turbine power generators. This improved planetary gear system reduces or eliminates lubricant debris traditionally generated from the gear teeth, thereby eliminating an initiating source for bearing failure. To achieve these results, some and preferably all of the gear teeth within the planetary gear system are superfinished using chemically accelerated vibratory finishing to a surface roughness of approximately 0.25 micron or less. Several objects and advantages of the invention are to provide a gearbox with reduced metal debris, improved bearing life, reduced wear, reduced vibro-frictional noise, improved contact fatigue, improved fretting resistance, improved lubrication, to simplify the run-in process, and to enhance the durability and efficiency of the gearbox.

Abstract: Disclosed herein is a new improved large planetary gear system used on the input stage of wind turbine power generators. This improved planetary gear system reduces or eliminates lubricant debris traditionally generated from the gear teeth, thereby eliminating an initiating source for bearing failure. To achieve these results, some and preferably all of the gear teeth within the planetary gear system are superfinished using chemically accelerated vibratory finishing to a surface roughness of approximately 0.25 micron or less. Several objects and advantages of the invention are to provide a gearbox with reduced metal debris, improved bearing life, reduced wear, reduced vibro-frictional noise, improved contact fatigue, improved fretting resistance, improved lubrication, to simplify the run-in process, and to enhance the durability and efficiency of the gearbox.