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).
Summary of an article on gyroscopic torque and independent front wheel suspension.
| Identifier | ExFiles\Box 95\3\ scan0044 | |
| Date | 1st October 1934 | |
| Copy. I.A.E. RESEARCH AND STANDARDISATION COMMITTEE. Research Department, 5, Bolton Road, Chiswick, W.4. No.7298 Class 422, 28. October 1934. Gyroscopic Torque and Independent Springing. ----------------------------------- B.P.Sergayeff, Aut. Ind. Sept.29 1934. p.380. ----------------------------------- One of the chief reasons for introducing independent front wheel suspension is to eliminate gyroscopic torque due to the angular movement of the wheels when passing over an obstacle. The author states that in suspensions incorporating unequal length transverse links, the torque is not negligible and proves this with an actual example. If T is the gyroscopic torque on the wheel, then T = Iω₁ω₂ where I is the moment of inertia of the wheel in lb. in. sec; ω₁ is rotational velocity of the wheel in radians/sec; ω₂ is precessional velocity of the wheel in radians/sec. I is constant for any wheel, in the example given it is 21.015 lb. in. sec.², ω₁ depends on the speed of the car and is equal to 35.2V/D, where V is the speed in m.p.h. and D is the wheel diameter in inches. ω₂ varies with the rate of change of the angle which the wheel makes with its normal position. If this angle is ø then ω₂ = dφ/dt = dφ/dh{D. Henderson - Showroom} x dh{D. Henderson - Showroom}/dt where H is the height of the obstacle. Graphs are drawn relating h to dφ/dh{D. Henderson - Showroom} and dh{D. Henderson - Showroom}/dt, and from them it is possible to determine the maximum gyroscopic torque for any car for any height of obstacle. This maximum occurs at the mid point of the lift and the torque drops to zero at the beginning and end of the lift. In the example, D is 32.75 in. and with an obstruction 2 in. high, the maximum torque at 40 m.p.h. is 60 lb.ft., while at 80 m.p.h. it is 220 lb.ft. A.D.B. | ||