Rotor assembly for an electric machine

A rotor assembly for an electric machine comprising:

• a rotating shaft,
• a rotor fixed to the rotating shaft, the rotor comprising a rotor core, a first end plate provided at a first axial end of the rotor core and a second end plate provided at a second axial end of the rotor core, and
• a fluid cooling system comprising at least one fluid cooling pathway provided internally in the rotor, the at least one fluid cooling pathway being configured to guide cooling fluid through the rotor,
• wherein the at least one fluid cooling pathway comprises:
• at least one cooling channel extending through the rotor core from the first axial end to the second axial end,
• a downstream end plate channel being fluidically connected to a downstream end of the at least one cooling channel,
• wherein a radially innermost position of a radially outer wall portion restricting the downstream end plate channel radially outwards is arranged in a range about or at or radially inwards of a radially innermost position of a radially inner wall portion restricting the at least one cooling channel (124, 126) radially inwards;
• wherein the at least one fluid cooling pathway comprises a first cooling channel and a second cooling channel, wherein the downstream end plate channel is a first downstream end plate channel which is further configured as a connector channel to fluidically connect a downstream end of the first cooling channel and an upstream end of the second cooling channel,
• wherein the at least one fluid cooling pathway further comprises a second downstream end plate channel which is configured as an outlet channel to guide cooling fluid out of the rotor, and
• wherein the outlet channel comprises a first channel portion which is radially inwardly inclined relative to the axial direction and a second channel portion which is radially outwardly inclined, and wherein the second channel portion is arranged downstream of the first channel portion.