| 摘要 |
The present invention relates to a downhole electrical motor elongated in a longitudinal direction, comprising a housing, a stator comprised inside the housing, a rotor comprised inside the stator rotatably connected to the stator, wherein the rotor has a locked end and a non-locked end and is locked in the locked end to avoid movement of the rotor in the longitudinal direction, and the rotor is able to move along the longitudinal direction in the non-locked end of the rotor to avoid thrust loads on the rotor due to thermal expansion of the rotor during rotor heating when the electrical motor is in operation and further comprising a locked bearing connected to the stator for supporting the rotor in the locked end and a non-locked bearing connected to the stator for supporting the rotor in the non-locked end, wherein the bearings are at least partially made from a ceramic material. Furthermore, the invention relates to a downhole tool comprising an electrical motor according to the invention and to a downhole system comprising a plurality of electrical motors according to the invention. |
