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).
Temperatures reached by dynamos during dynamometer testing on various chassis.
| Identifier | ExFiles\Box 165\6\ img031 | |
| Date | 2nd October 1926 | |
| EFC. PC.115. 2.10.26. TEMPERATURES ATTAINED BY DYNAMOS DURING DYNAMOMETER TESTS. By means of temperature indicating sentinels, an idea of the maximum temperature reached by dynamos fitted to chassis undergoing dynamometer tests, was obtained. In the first instance six 97°C sentinels were fitted: three to 40/50 chassis, and three to 20 HP. chassis. As these shewed no signs of melting, six 87°C sentinels were fitted in the same way, and also came through without mishap with the exception of one, the blob of metal of which was broken from its wire, apparently by the vibration of the engine. It remained in contact with the dynamo carcase, however, and shewed no signs of melting. From these results it would appear that at no time during the series of dynamometer tests, does the temperature of the dynamo reach 87°C. Further, from touching the dynamos by hand, it was judged that, even with the engine at its hottest the temperature of the dynamo was lower than that reached by machines on our test rig, i.e. less than 80°C. In support of this are the facts that although parts of the engine (like the exhaust pipes) get very hot, the temperature of the water is never allowed to go above 80°C. Also when the engine is hottest and heating the dynamo most, i.e. on the high speed test, the output of the dynamo, and consequently the heat produced in itself, is lowest. EFC/C.A.Pignett. | ||