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).
Letter to The Hoffman Manufacturing Co. enquiring about a replacement sealed ball race for a servo motor.
| Identifier | ExFiles\Box 121\1\ scan0065 | |
| Date | 20th October 1938 | |
| 1029. Rm{William Robotham - Chief Engineer}/AFM{Anthony F. Martindale}1/R.{Sir Henry Royce} 20th October, 1938. The Hoffman Manufacturing Co.,Ltd., Chelmsford. (For the attention of C.H. Smith, Esq.) Dear Sirs, Sealed Ball Race for Servo Motor. We are using a New Departure race No. 88503, 17 mm x 40 mm x 16.6 mm on a new servo, but we are anxious to replace this with a British made race. This race rotates at a maximum speed of 500 r.p.m., normal speed 250 r.p.m. normal load being nil. The race is loaded to 1,000 lbs in thrust (this being a maximum) when the brakes are applied. The race No.88503 has stood 86 hours on dynamometer endurance under 1,000 lbs end load applied for 3 seconds every 60 seconds, and is still in use on a motor car. The race has to be double sealed as it is impossible to lubricate it. Will you please say what race you would recommend for the job, and we will order some for test. Yours faithfully, For ROLLS-ROYCE LTD. P.S. Will you please quote a cost for the recommended race. | ||