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).
Design and fixing of shock dampers, specifically the square levers and shaft connection.
| Identifier | ExFiles\Box 179b\1\ img301 | |
| Date | 1st February 1933 | |
| HDY{William Hardy} ) FROM R.{Sir Henry Royce} HS{Lord Ernest Hives - Chair}/RM.{William Robotham - Chief Engineer} ) ORIGINAL. R2/M1.2.33. re. SHOCK DAMPERS. We have decided that the most hopeful fixing for both the inside and outside levers is the square, because if carefully machined, with no hand fitting, it should be inexpensive, and should give a load on each of the 4 corners of the square equal to the tightening of the bolt, so that a large proportion - quite up to the full working load - should be transmitted from the lever to the shaft by the surface which is roughly about 45o normal, and will give a normal pressure about equal to .7 of the bolt pressure at each of the 4 corners in each direction, so that if the bolt were tightened to 2000 lbs. we should get a drive of 2000 X 4 X about .7 independent of the friction. It will be noted that we shall not be in any way making a device that cannot be readily assembled or stripped for cleaning and inspection, and since RM.{William Robotham - Chief Engineer} finds that the ordinary screwed gland with asbestos grummet makes the most reliable oil retaining gland we have shewn this type to be adopted at the same time. It is thought that the lever on the inside should have a little more axial length even at the expense of robbing the bearing. We are fully aware that this type will somewhat distort the shaft if it is made hollow, so we shall have to give it extra clearance, and perhaps also leave it thicker by only cutting a small bore. We have however anticipated that the distortion, both of the shaft and lever boss, would help to equalise the load at all 4 corners of the square. It will be arranged with the middle flat of the square rendered clear by one third to one half of the length of the flat. All this is shewn on HDY{William Hardy}'s drawings - N. schemes 3660., 3661., and 3662. The split pin ought to be deleted, the hexagon of the nut should be substantial enough to get hold of properly with a box key, the spherical washer might be separate from the nut proper, and a spring washer should be tried if there is any need of additional locking. R.{Sir Henry Royce} | ||