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).
Cone assembly tests for a universal gearbox synchro-mesh.
| Identifier | ExFiles\Box 136\4\ scan0197 | |
| Date | 9th November 1937 | |
| GRY{Shadwell Grylls} To Rm.{William Robotham - Chief Engineer} from HPS{Horace Percy Smith - Experimental Factory Mgr}/WB.{Mr Brazier/Mr Bell} c. to By.{R.W. Bailey - Chief Engineer} c. to Hdy.{William Hardy} 1153 HPS{Horace Percy Smith - Experimental Factory Mgr}/WB.{Mr Brazier/Mr Bell}1/CB.9.11.37. UNIVERSAL GEAR BOX SYNCHRO-MESH. A.H. CONE ASSEMBLY TESTS. B.254 Dummy Gear. B.253 Cone - Test Models. Two cones with diametral interference of .002" and .003" were pressed on to dummy gears under the Electro-Hydraulic Ram, - the loads required to perform this operation being measured. Later, the gears were rigidly fixed and torque applied to the cones, the minimum torque required to cause relative movement between the surfaces of the cone bores and gears being noted. As produced, there was a slight radius on the gears, and no chamfer on the cone bores. Although a slight chamfer (.025") was made in the cone bores, it was insufficient, and the flange faces were not in contact with each other after assembly. It is therefore essential that either the gears be undercut, or the cones adequately chamfered. The lack of lead on the cone bores made it difficult to start them squarely on the gears during the assembly operations. Also, during this operation, the gears tended to shear the surface metal of the cone bores. On pressing the cones off again, the bores were measured, and although an average increase in the diameters of .001" to .002" was recorded, they could not be accurately measured since the surfaces of the cones and gears had picked up, leaving the cone bores badly damaged. The diameters of the gears were also measured, but no difference could be detected. Results shown on attached chart, table I. The load required to press the cones off the gears after test was approximately 4 tons. Three further cones were procured and chamfered .040" at 45° to ensure perfect contact between the flange faces of the continued. | ||