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).
Blueprint detailing the test rig and procedure for measuring the efficiency of a steering worm and nut.
| Identifier | ExFiles\Box 178\1\ img134 | |
| Date | 19th May 1926 guessed | |
| INSTRUCTIONS AND TACKLE FOR MEASURING THE EFFICIENCY OF STEERING WORM & NUT. 720 LEAD 'P' LBS. FORCE AT 20' LEVERAGE 'W' LBS. LOAD ANGLE PLATE & STAY ADJUSTABLE TO ACCOMODATE THE DIFFERENT TYPES OF STEERING. 317.5 LBS. LOAD SUSPENDED FROM BALL END ON PENDULUM LEVER. 20 LBS. PULL REGISTERED BY SPRING BALANCE AT END OF LEVER 18" LONG. 55% EFFICIENCY TABULATED READINGS FOR ABOVE RIG. LOAD 'W' LBS: 1200 LBS, 900 LBS, 600 LBS, 300 LBS FORCE 'P' LBS: 9 LBS. TO 9.75, 6.5 LBS. TO 7, 4 LBS. TO 4.5, 2 LBS. TO 2.25 NUT EFFICIENCY: 76.5-70.6, 79.4-73.7, 86 - 76.4, 86 - 76.4 POINTS TO BE OBSERVED :- 1 WORM TO SHEW GOOD & EVEN BEDDING ON ALL LEADS & MUST HAVE A HIGHLY POLISHED FINISH. 2 THREADS OF NUT TO BE SKIMMED OUT WITH TAP. MADE PERFECTLY SMOOTH & MUST SHOW GOOD BEDDING. 3 WORM TO BE TESTED BOTH WAYS & SHEW EQUAL EFFICIENCY (SEE ADJACENT TABLE FOR LOADS) ON EACH SIDE OF THD: 4 TOLERANCE OF .005 BACKLASH BETWEEN WORM AND NUT IS PERMISSIBLE BUT SHOULD NOT BE EXCEEDED. 5 WORM SHOULD BE TESTED FOR EFFICIENCY BEFORE BRAZING IN WORM TUBE. 6 WHEN BRAZING WORM IN TUBE, PRECAUTIONS SHOULD BE TAKEN TO PREVENT HEAT AFFECTING HARDNESS OF WORM BY SHROUDING WORM & LOADING WITH WET CLAY. IT IS IMPORTANT THE EFFICIENCY TESTS BE TAKEN OVER THE WHOLE LENGTH OF WORM TO ENSURE A GOOD AVERAGE EFFICIENCY. | ||