HV conductor rod thermal expansion joint - has bellows held by sprung spacers and enclosing rods broken to provide two sliding joints

摘要

The thermal expansion joint is for a set of high voltage conductor rods enclosed within a gas - tight sleeve, the gas normally being sulphur hexafluoride. The joint may be positioned between contact breaker housings and may be single or polyphase. The conductors (16) leave their respective switching points (12, 14) etc. as solid rods within cylinders (22, 24) containing the insulating gas at several Bars pressure and are supported by conical spacers (20). The expansion joint takes up a position along the length of the conductors within a bellows (25). The rods are broken to provide two sliding joints (30) within the bellows. The bellows is held by outer rods (36) with sliding and fixed end pieces spaced by helical springs (38, 40) symmetrical about the bellows centre providing balanced tension about the joint centre.