Patent GB-903463-A (GB)
Title: Improvements relating to apparatus for providing an electric current path between rotary and stationary conductive members
Inventor: KENYON HAROLD FREDERICK
IPC: H01R39/30
Filed: 1959-09-22
Abstract: 903,463. Current collecting gear for dynamoelectric machines. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Sept. 22, 1960 [Sept. 22, 1959], No. 32263/59. Class 35. [Also in Group XXXVI] An arrangement for making a conductive connection between a rotary conductive member (which may be a shaft on an annular disc) and a stationary member, in which a conductive liquid is held in an annular chamber, bounded by the rotary member and an intermediate member which is itself connected to the stationary member by further conductive liquid. In one arrangement (Fig. 1), two shafts rotating coaxially with a hollow alternator shaft 2, subject to lateral and axial movement, are connected to stationary member 8, through mercury in annular chambers 11, conducting intermediate bodies 6a, 6b and pools of mercury which are of such a size as to allow movement of the intermediate members 8 during expansion or flexion of the conductors 4b, 4a, or alternator shaft 2. Bearing members 9 and journal sleeves 10 with oil lubrication means 12, serve to enclose the mercury in the clearance space 11, further support for the inner conductor being provided by ball bearing 13, with the two intermediate members 6b, 6a loosely coupled by insulating arm 19. Torque on the intermediate members and their weight on the concentric conductors is counteracted by springs (Fig. 2, not shown) on either side thereof connected to a centre pivoted cross-bar. The overall axial length of the assembly may be reduced by having only one journal sleeve lubricating groove (Fig. 3, not shown) or by rigidly connecting the two contact assemblies by a common bearing member (Fig. 4, not shown), the inner conductor, intermediate member having an axially offset portion for immersion in the mercury pool. In another embodiment (Fig. 5) the two conducting blocks 38a, 38b, for immersion in the mercury pools, are separately connected to two fixed, concentric, mutually insulated conductors 35a, 35b supported on ball bearings 42 and passing through bores in the rotating shaft discs 1a, 1b the inner water-cooled conductor 35b extending beyond the outer conductors at both ends. Clearance spaces 37 formed between the concentric conductors and the rotating shaft disc bores are filled with mercury and enclosed by bearing members 40 and journal sleeves 41, the lubricating oil thereof being supplied through passages 69 and 70 in the concentric conductors and caught, after use, by the splash shield 53. A wheel 58 on the end of an arm 57, fixed to the conductive blocks 38a, 38b, rides along a fixed rail 59. In a variation of this embodiment (Figs. 7, 8, 9, not shown), the ball bearings 42 are dispensed with and eccentric vibration of the rotating shaft discs allowed for, by providing the bearing members with holes larger than the diameter of the bolts loosely securing them to the rotating shaft discs. Insulated plates are bolted on to each side of the conducting blocks 38a, 38b and have rollers fixed thereto for axial movement along a pair of fixed rails.