Abstract: A rotary electrical machine includes a two pole rotor carrying a winding. The rotor is contained within a thin sleeve of non-magnetic material which supports the rotor within bearings in the machine.

Abstract: A dynamo electric machine wherein a hollow rotor shaft carries cooling oil, there being outlet means in the wall of the hollow shaft whereby the oil is discharged from the shaft onto the windings of the machine to cool the windings. The outlet includes a hollow tubular screw which extends through the rotor shaft wall and which protrudes inwardly from the inner surface of the shaft so as to receive oil from a region of the shaft interior which is spaced radially inwardly of the inner surface of the shaft. The hollow screw discharges oil at the exterior of the shaft into an annular weir member which is carried by and encircles the shaft and from which oil is thrown onto the windings of the machine to cool the windings. The hollow screw in addition to defining the oil outlet from the shaft serves at least in part, to secure the weir member to the shaft.