Process of durability improvement of gear tooth flank surface

• Main Authors: FINN JEFFREY BRENGLE, CISEK ROMAN
• Format: Patent
• Language: English
• Published: 22.11.2011
• Subjects: COMBINED OPERATIONS; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GRINDING; MACHINE TOOLS; MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; METAL-WORKING NOT OTHERWISE PROVIDED FOR; OTHER WORKING OF METAL; PERFORMING OPERATIONS; POLISHING; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TRANSPORTING; UNIVERSAL MACHINE TOOLS

Pinion gears for planetary gear transmissions are hobbed, heat treated, and then ground to get better control of the leads/profiles on all the gear teeth. Then a light shot peening is applied to the tooth flanks to achieve the desired compressive residual stresses on the tooth surface. By applying the process in the controlled manner specified, the surface is not over-cold worked. Next, a chemically assisted isotropic surface treatment is applied over the pinion gears to improve the surface finish on the gear teeth. For low speed applications the surface finish improves the lambda ratio, allowing for a good oil film thickness on the surface of the gear teeth.