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).
Steering joggle and kick-back issues in cross and side steering tube joints for Bentley and 25/30 HP models.
| Identifier | ExFiles\Box 153\1\ scan0108 | |
| Date | 1st January 1938 | |
| BY.{R.W. Bailey - Chief Engineer} c. to Hs.{Lord Ernest Hives - Chair} c. to Rm.{William Robotham - Chief Engineer} c. to Mr. 1300. Hd{Mr Hayward/Mr Huddy}/SB{Mr Bull/Mr Bannister}11/HR.1.1.38. [Handwritten note] This seems a sound suggestion. Let me have your comments [End handwritten note] re CROSS AND SIDE STEERING TUBE JOINTS. Bentley and 25/30 HP. ------------------- For some years now, we have had trouble in maintaining a consistent degree of friction in the steering mechanism to avoid complaints of joggle or kick back at high speeds. Although it has been easy to increase the spring pressure by inserting packings, the resulting friction does not stay put, but falls off with further running. This has been particularly noticeable on Bentley cars, although the same applies to the 25/30 HP. since the design is similar. In investigating the complaint of persistent steering joggle on B.64-HK.{Col. T. Harker - Sales}, Young, (Owner's Complaint Report No. W.105), the following information was brought to light. The bedding of the inner contact piece G.100441 is never uniform over its whole area, but is localised to a small area of approximately .500" diameter at the centre of the ball. The value of any contact outside this area is completely lost. The reason is that the spring pressure is applied to the end of the contact piece and is transmitted up the shank to the face of the ball. The main area of the contact piece outside the shank is unsupported, and this simply caves back under load, leaving the bedding only on an area equal to that of the shank. (See sketch herewith). To overcome this, we have shortened the shank of the contact piece G.100441 to 1.325" from the shoulder, thus allowing the spring thrust to be taken by the sleeve G.100433, which then transmits the load to the shoulder of the contact piece and spreads the bedding over the outer area of the ball where it is wanted to take advantage of the wedging action due to the inclination of the contact area. We also relieved the inner area where the bedding is not wanted by counterboring the contact piece .500" diameter by .025" deep. -continued- | ||