Rotary electric machine of the type having a liquid-cooled rotor

Claim 1

A rotary electric machine of the type having a liquid-cooled rotor, comprising: a generator shaft having an axial hole therethrough; an exciter shaft on a common axis with said generator shaft, one end surface of which exciter shaft is in contact with one end surface of said generator shaft, and which exciter shaft has a first axial hole with an end surface portion having substantially the same diameter as said generator shaft hole and communicating with said generator shaft hole and a smaller diameter portion extending in a direction away from said one end surface and communicating with said end surface portion, and a second hole extending in the radial direction from said end surface portion of said first axial hole; a first coolant path defining means constituted by a plurality of concentric tubes defining coolant paths therebetween and positioned in the axial hole in said generator shaft and extending into the end surface portion of the first axial hole in said exciter shaft and the ends of the tubes within said end surface portion turned inwardly at an angle to the axis of the shafts and having sealing surfaces on the inwardly facing ends of the inwardly turned portions; a second coolant path defining means constituted by a plurality of concentric tubes defining coolant paths therebetween and positioned in the smaller diameter portion of the axial hole in said exciter shaft and having the ends of the tubes within the end surface portion turned outwardly at an angle to the axis of the shafts and having sealing surfaces on the outwardly facing ends of the outwardly turned portions abutting the inwardly facing ends of the inwardly turned portions in sealing relationship for communicating the coolant paths of the second coolant path defining means with the respective coolant paths of the first coolant path defining means; axial conductors within the innermost tube of the first coolant path defining means in said generator shaft and extending into part of said end surface portion of the first axial hole in said exciter shaft; radial conductors in the second hole of the exciter shaft and extending through said first coolant path defining means and being connected to said axial conductors; and the junction between the one end surfaces of said generator shaft and said exciter shaft, the junctions between the ends of the tubes of the first and second coolant path defining means and the connection between the axial conductors and the radial conductors being located at different positions in the direction along said common axis.