From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Interim report on measured and suggested maximum errors for Phantom Gear Box contact mesh gears.
| Identifier | ExFiles\Box 94\2\ scan0208 | |
| Date | 16th April 1937 | |
| RHC.{R. H. Coverley - Production Engineer} RHC{R. H. Coverley - Production Engineer}/cy. Hs.{Lord Ernest Hives - Chair} Rm.{William Robotham - Chief Engineer} c.c. DY.{F R Danby} [Handwritten]: For the last para GRT 328 RHC{R. H. Coverley - Production Engineer}/ABC.1/JWA. 16.4.37. PHANTOM GEAR BOXES. INTERIM REPORT (SEE RHC{R. H. Coverley - Production Engineer}/ABC.1/LS. 3.4.37.) Examination of the teeth of Contact Mesh Gears taken from production. SUMMARY OF MEASURED ERRORS. SUGGESTED MAXIMUM ERRORS. 1. Run out of pitch line. Teeth not ground (Showing hardening distortion). Run into a master gear. .005 to .010. .003. 2. Run out of pitch line. Teeth ground. Fair run together. .0015. to .0025. .0015 3. Spacing of teeth (ground). From the involute face of one tooth to the next tooth. .00008 to .00016. .00004 to .00008. Max. variation around the gear. .00012. to .0003. .00012. 4. Profile of teeth, and radial alignment. Errors away from a true involute and true radial alignment. 0 to .002 .0002 to .0003. 5. Finish on teeth. Depth of roughness of cross lacing. 0 to .0005. 0 to .0002. 6. Depth of profile. Interference found on many teeth, due to profile not being taken deep enough. Minimum clearance .010. In order to obtain an accurate gear, the care in gear grinding must be made proportionate to the amount of distortion found in the gear. | ||