| 摘要 |
A downhole electric motor for a submersible pump has at least three phases a nd comprises a permanent magnet rotor and a stator bearing phase windings (A, B and C) in slots in the stator. Each phase winding (A, B, C) incorporates a coil extending through a respective pair of adjacent stator slots and surrounds a respective portion of the stator between the slots. Furthermore adjacent coils of each pair of phase windings (A, B, C) extend through opposite parts of a respective one of the slots, so that these coils extend alongside one another in the slot, either being separated by a gap through which cooling fluid may be pumped to cool the coils, or being separated by a thermally conductive projection, with which the coils are in thermal contact , extending at least part of the way across the slot. Such a winding arrangeme nt is advantageous in ensuring that the motor has a long life. |
