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).
Gear engineering data sheet specifying tolerances for machining gear carriers and cases.
| Identifier | ExFiles\Box 114\1\ scan0069 | |
| Date | 17th September 1936 | |
| GEAR ENGINEERING DATA SHEET Tolerances for Machining Carriers or Cases in which Straight Bevel, Spiral Bevel or Hypoid Gears are to be mounted. 1- The following housing limits are to be considered the maximum practical for the satisfactory operation of a set of gears: A.{Mr Adams} The diagrams below indicate the tolerances to be used: | Straight or Spiral Bevel | Hypoids (Pinion Above Center / Pinion Below Center) | |-------------------------------------|-----------------------------------------------------| | Axes intersection should be within | Offset dimension should be within | | Gears up to 24" Diameter: +/- .001" | +/- .001" | | Gears 24" Diam. and larger: +/- .0025"| +/- .0025" | B. The gear and pinion axis for any set of gears should not depart from the specified angle more than .005" in a 12" span and in no case should the shaft angle (gear side) be less than that specified for the job. 2- Provision should be made to enable adjustment of the pinion in an axial direction in steps not greater than .003". 3- Provision should be made to adjust the gear axially so that the backlash may be changed in steps not greater than .003". The axial movement with respect to backlash varies with the pressure angle approximately as follows: For 14½° P.A.-With axial movement of .002"- backlash is changed .001" For 20° P.A.-With axial movement of .003"- backlash is changed .002" For 17½°-25 P.A.-With axial movement of .001" backlash is changed .001" Form 532A - 200 Sept. 17, 1936 Printed in U.S.A. GLEASON WORKS Rochester, N.Y., U.S.A. | ||