Patent ID: 7936101

Claim:
An electric machine having a rotor, comprising: a first longitudinal section which is operationally at ambient air temperature; a second longitudinal section axially connected to the first longitudinal section and operationally at least partially cooled to a cryogenic temperature; and a coolant inlet pipe running along a central longitudinal axis of the rotor, going through the first longitudinal section and extending into the second longitudinal section, wherein the inlet pipe is set at a distance from the rotor by a radial gap, in which the inlet pipe is mounted in the first longitudinal section by a plurality of bearings in different axial positions in the rotor, so the rotor is rotatable, wherein the bearings are distributed on the axial positions such that, upon action of a maximum radial force on the inlet pipe, the inlet pipe has a maximum deflection less than the radial gap, and wherein the axial positions of the bearings are determined using an iterative calculation of a deflection line defined along the inlet pipe so that the maximum deflection of the inlet pipe is less than the radial gap in response to the maximum radial force.