Hawkins electrical guide ... : questions, answers & illustrations : a progressive course of study for engineers, electricians, students and those desiring to acquire a working knowledge of electricity and its applications ; a practical treatise (1914)
Hawkins, N. (Nehemiah), 1833-1928 · New York : T. Audel & Co. · leaf 456
Figs. 3,503 and 3,504.—Section through trolley showing lubricating bushing, and vie* of bushingremoved from trolley. Since trolleys revolve at a very high speed, some unusual means oflubrication must be provided, as shown in fig. 3,503. The trolley hub is fitted with a brassbushing, having a spiral…
Electrical engineering
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