GB1436539A - Transformers - Google Patents

Abstract

1436539 Transformers EASTERN ELECTRONICS (NORWICH) Ltd 29 Nov 1973 [30 Nov 1972] 55384/72 Heading HIT A transformer permitting power to be transferred between a fixed and movable member has a magnetic core in two sections each bearing a winding, one section rotatable relative to the other such that the reluctance of the magnetic path comprising the sections remains substantially constant for all allowable positions. As shown in Fig. 1, a fixed core section 3 comprises a ring 23 and coaxial cylinder 25 both wound from magnetic strip and resting respectively on outer limbs (19) and central limb 21 of an E- yoke 17. Ring 23 and cylinder 25 are slotted (not shown) to minimize eddy currents. The rotatable section 5 comprises an E-yoke having a secondary winding 9 disposed on its central limb 41. The primary winding 7 is disposed on the said limb 21. The core is enclosed in a casing comprising an upper part 15 which rests on a bearing plate 31, and a lower part 13 suitably recessed to take a sealing ring 33. The two parts are mutually engaged by ring 51 which allows 13 and 15 to rotate relative to one another only. A lubricating compound 49 separates the core sections. The space between the core exterior and the case is filled with an epoxy resin containing a tri-hydrolysed alumina filler 45. Supply to the winding 7 is by terminal chamber 47. In a similar embodiment (Fig. 3, not shown) the E-yokes are replaced by U-yokes.