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).
Measurement of torque exerted by a Bensport Camshaft balancing cam.
| Identifier | ExFiles\Box 84\3\ scan0138 | |
| Date | 28th September 1933 | |
| To Mx.{John H Maddocks - Chief Proving Officer} from Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer} Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}11/KT.28.9.33. TORQUE EXERTED BY BENSPORT CAMSHAFT BALANCING CAM. The balancing cam referred to in this report was made up to LeC.3542 and is identical to those made up to LOP. EB.1164. The torque exerted by the cam when fitted to the engine was measured in order to ascertain how closely the measured value agreed with the calculated value. The measurements were made on Unit B.7 after it had been run in, so that there was no undue stiffness in the camshaft bearings etc. The push rods, tappetsm and all gears meshing with the camwheel were removed, therefore, the measured torque was due only to the balancing cam and friction. A radial arm 17¼" long was attached to the camwheel and the torque obtained by means of a spring balance on the end of the arm. The balancing cam profile is symmetrical about its C.L. and it gives equal assistance and opposition to the rotation of the camshaft. Let T. be the maximum value of the balancing cam torque, and f.{Mr Friese} the friction torque. The quantities measured were :- (a) The maximum torque required to overcome the balancing cam. (b) The maximum torque exerted by the cam against the spring balance. (a) = T + f (b) = T - f T = ((A) + (b)) / 2 The measured spring balance loads were :- (a) 3 lbs. 11 ozs. (b) 1 lb. 11 Ozs. at 17¼" rad. ∴ measured value of T = ((3.11/16 + 1.11/16) / 2) X 17¼ = 47 lbs.ins. | ||