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).
Tests conducted to reduce excessive dynamo brush wear.
| Identifier | ExFiles\Box 166\1\ img019 | |
| Date | 8th March 1933 | |
| x6093 R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Wst. c. to Sg.{Arthur F. Sidgreaves - MD} c. to Wor.{Arthur Wormald - General Works Manager} c. to M.{Mr Moon / Mr Moore} c. to Da.{Bernard Day - Chassis Design} c. to Hdy.{William Hardy} c. to Ry. Hs{Lord Ernest Hives - Chair}/Wst.1/MA. 8.3.33. ------------------ DYNAMO BRUSH WEAR. ------------------ Further to our Hs{Lord Ernest Hives - Chair}/Wst. 2/MA. 23.2.33. dealing with high speed tests we have been carrying out on chassis dynamos with a view to reducing the excessive wear a further test has now been completed on a standard 20/25 dynamo with another grade of brush recommended to us e.g. the Morganite Link B. This grade is a Battersea Carbon brush much harder than the EGO or the standard RG{Mr Rowledge}2 grade of Electro-graphite brush. Although the current density of this brush is slightly lower than our standard its contact drop is higher which directly helps to suppress, commutator sparking. The average brush wear experienced with this brush was .030" this being .007" less than the wear experienced on the same test with the EGO grade (our best so far). In view of the hardness of this brush however we are anticipating more brush noise and we are fitting a set of these Link B brushes to a chassis dynamo for road test in order to confirm the wear and to ascertain the degree of noise experienced. Hs{Lord Ernest Hives - Chair}/Wst. | ||