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).
Dynamometer testing of a 4-speed gearbox for 20 HP cars, detailing gear engagement issues and subsequent modifications.
| Identifier | ExFiles\Box 6\4\ 04-page027 | |
| Date | 20th January 1925 | |
| X5310 To R: from Hs.{Lord Ernest Hives - Chair} c.c. to CJ. BJ. c.c. to RG.{Mr Rowledge} K.{Mr Kilner} c.c. to BA. AJS. c.c. to BY.{R.W. Bailey - Chief Engineer} Wor.{Arthur Wormald - General Works Manager} Hs{Lord Ernest Hives - Chair}6/LG20.1.25. 4-SPEED BOX FOR 20 HP. CARS. X5310 We have been carrying out tests on the road wheel dynamometer with a 4-speed box fitted to a 20 HP. car. This is the same car and box that we took to W.W. Our intention was to run on the 1st, 2nd, 3rd, and reverse speed gears for half an hour, full power maximum torque, 1000 engine revs. We ran for half an hour on 3rd. speed under this condition. We found, however, that when we tried to run on 2nd. speed, the gear continually worked out. 1st. speed was tried and the same thing happened. The box was therefore dismantled. Both 1st. and 2nd. speed gears were badly damaged, but by the appearance of them, it looked as though the damage was caused by the full power being on the gears when they were only half engaged. We could not see any reason why, in the first place, the gears worked out. The gearbox was erected again with new gears and with stronger springs on the plungers to hold the gears in position. The stronger springs however spoilt the operation of the change speed gear. We decided however, to keep the stronger springs fitted for the dynamometer tests, also to make doubly sure that the gears would not be damaged by them partly working out, we jammed the lever in the gate so that this could not possibly happen. contd :- | ||