End connection structure for a hollow conductor assembly

摘要

A coupling structure for a hollow conductor assembly in which the hollow conductors form at least a part of the winding of an electrical machine to be cooled by passing a fluid coolant through the conductors. A nipple made from a hard material such as a nickel-chrome steel and which serves as an electrical as well as a fluid coolant connection to the hollow conductors is shrunk onto a sleeve made of a relatively softer material such as copper in which the end portions of the hollow conductor assembly are embedded and soldered to form a gas-tight connection. The inner wall of a cylindrical section of the nipple is provided with a series of circumferentially extending ribs and these ribs press into the surface of the softer sleeve during the nipple-shrinking operation. The nipple is also provided with a second section of smaller diameter than the sleeve-receiving section for connection to a fluid coolant carrying pipe.