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 manufacturing of hypoid gears, focusing on issues with tooth abrasion and proposals for a new offset.
| Identifier | ExFiles\Box 136\5\ scan0149 | |
| Date | 9th July 1927 | |
| To Mr (Springfield) [text crossed out] c.c. to AGR (Springfield) c. to Dy.{F R Danby} [text crossed out] c. to Hs.{Lord Ernest Hives - Chair} Y3066 RE HYPOID GEARS I send herewith a layout, N.Sch.2427 and details G.75836/7/8 in duplicate, showing the latest ideas on hypoid gears. R.{Sir Henry Royce} requires these to be made by Gleasons at the earliest possible moment, but first requires the benefit of Gleason's comments and suggestions accompanied by a quotation. As shown in the arrangement and details, the pinion has a 1" offset, which is the minimum which can be allowed and still obtain clearance of the propeller shaft joints from the floorboard. But the offset of the pinion in plan view, the thickness of the ring gear section, etc., are all subject to the makers' recommendations. These are required quickly however, so that necessary modifications can be made in the details and the job can proceed here. The purpose of the change is as follows :- 1. The first experimental gears with 2" offset have been received and are being installed. However, it has been ascertained that in certain cases heavily loaded hypoid gears have given trouble through abrasion of the tooth surfaces. 2. Since this has obviously been due to the relative sliding, which must vary in some proportion with the offset, and since ordinary spiral bevels have been used in this axle with complete success, it is concluded that the safest policy is to use hypoid gears having the minimum offset allowable. 3. If however, the makers have some objection to such a small offset, they should consider themselves at liberty to quote for hypoid gears having a recommended offset intermediate between 1" and 2". Prints should be submitted showing their recommendations. May I leave this job in your hands? Oy. | ||