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).
The mechanics of a clutch system, focusing on motion reversal and bearing surface geometry.
| Identifier | WestWitteringFiles\R\2October1927-November-1927\ 93 | |
| Date | 1st May 1927 guessed | |
| -3- most effective in driving the secondary. From this point of view it is an advantage that the angle α should be large, as it will give a greater moment about the axis of rotation for a given frictional force parallel to the axis of a roller. The normal pressure will exercise on the secondary a retarding torque, which will be the greater the further the point of contact is from the plane (AB) of symmetry. It is therefore desirable, in order to avoid the introduction of unnecessarily large reactions, to minimise this moment and to concentrate as little pressure as possible on the ends of the rollers. 3. REVERSAL OF MOTION, AND OF SENSE OF CLUTCH. If the sense of rotation of the primary be reversed the action of the rollers will tend to displace the collar relatively to the neck of the shaft in the direction Y to X. This would naturally, if continued, cause the portions AE and BF of the collar to jam the rollers and the clutch would act in the opposite direction. This action is arrested by means of a stop and the rollers, being prevented from jamming, revolve loosely and play the part of ball bearings. If, however, it is required to make the clutch act in the opposite direction, a stop and spring can be brought into play which push the collar in the direction Y to X, while preventing its return beyond a fixed limit. The jamming then takes place when the primary is made to revolve in the sense opposite to that of the black arrow in fig. 1. 4. SHAPE OF BEARING SURFACES. With regard to the shape of the surfaces UV and AC, these are obtained as the envelope of a cylinder of radius C (the radius of a roller) whose axis is inclined at a constant angle α | ||