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).
Technical drawing analyzing the causes and effects of high-speed wheel wobble, including gyroscopic moments and tire wear.
| Identifier | ExFiles\Box 29\1\ Scan305 | |
| Date | 24th February 1926 | |
| DRAWING NO. I SEE ALSO THE FOLLOWING OPERATION DRAWINGS SQUARE TREAD ROUND-TREAD VELOCITY OF TIRE AT POINT A = wR AT PT B = wR' CONTACT AREA 1. INSPECTION OF WEAR OF ROUND-TREAD TIRES SHOWS THAT POINT A, HAVING GREATEST CONTACT PRESSURE, FOLLOWS THE ROAD, WHILE POINTS B ARE CONTINUALLY DRAGGED FORWARD ALONG THE ROAD, SCALLOPING AND WEARING THE SIDES OF THE TIRE AS SHOWN AT C & D.{John DeLooze - Company Secretary} 2. WHEN A ROUND-TREAD TIRE IS INCLINED AS SHOWN IT TENDS TO RUN ROUND A POINT E DUE TO VARYING VELOCITIES OF POINTS ON THE TREAD AT THE CONTACT AREA. 3. U.S. TIRES WHICH HAVE NEARLY FLAT TREADS SHOW LESS OF BOTH ABOVE EFFECTS. CONDITIONS of WOBBLE CORRESPONDING GYROSCOPIC EFFECTS SPEED - 60 M.P.H. W - ROTATION OF WHEEL = 615 R.P.M = 64.6 RADS/SEC Ω - PRECESSION OF WHEEL (FROM TRACK?) = 5.12 RADS/SEC I - MOM. OF INERTIA OF WL = 2.78 LBS FEET^2 (NEGLECTING BRAKE DRUMS) VEL 60 M.P.H GYROSTATIC MOMENT ON FRONT AXLE 2 I w Ω = 1800 LBS FEET = 380 LBS AT EACH WHEEL 1800 LBS FT 380 LBS TITLE BLOCK: Approved by: gey Date: FEB 24/26 ROLLS-ROYCE OF AMERICA, INC. TITLE: HIGH SPEED WOBBLE DRAWING NO. I | ||