Stator and assembly method

1. A stator disk of an electric motor stator, comprising:

a set of recesses, each recess being configured to a receive a cooling pipe; and

one or more positioning elements for aligning the stator disk with another stator disk, the one or more positioning elements being positioned to the stator disk such that when the stator disk is set to a rotated position with respect to the other stator disk in order to align the recesses of the disks for receiving cooling pipes, the positioning elements of the two disks become only partly aligned with each other.

2. The stator disk according to claim 1 , wherein when the positioning elements are aligned with other, a pair of recesses of the disks hosting a same cooling pipe cause substantially opposite pressing forces on the cooling pipe.

3. The stator disk according to claim 1 , wherein the positioning element is configured to receive a positioning member for alignment of the positioning elements of the disks to each other.

4. The stator disk according to claim 1 , wherein the stator disk comprises coil slots, which coil slots become misaligned with coil slots of a similar stator disk when the two disks are in a rotated position while the recesses of the disks are aligned with each other for receiving a cooling pipe therein.

5. The stator disk according to claim 1 , wherein the recess for receiving the cooling pipe is a groove on the outer edge of the stator disk.

6. The stator disk according to claim 1 , wherein the recess for receiving the cooling pipe is a through hole in the body of the stator disk.

7. A stator of an electric motor, comprising:

a plurality of stator disks stacked together to form the stator, wherein each stator disk comprises:

a set of recesses, each recess being configured to a receive a cooling pipe; and one or more positioning elements for aligning the stator disks together, wherein the one or more positioning elements are positioned to the stator disks such that when two stator disks are set to a rotated position with respect each other in order to align the recesses of the disks for receiving a cooling pipe, the positioning elements of the two disks become only partly aligned with each other.

8. The stator according to claim 7 , wherein the positioning elements are partly overlapping to allow a positioning member to penetrate the positioning elements to align the positioning elements with each other.

9. The stator according to claim 8 , wherein when the positioning member is positioned with respect to the positioning elements for alignment of the positioning elements with each other, the recesses of the mutually rotated disks are configured to exert substantially opposite pressing forces to the cooling pipes positioned therein.

10. The stator according to claim 7 , wherein before positioning the positioning member with respect to the positioning elements of the disks, the coil slots of the mutually rotated disks are misaligned with each other.

11. A method of mounting a stator of an electric motor, comprising:

providing a plurality of stator disks, each disk having recesses for receiving cooling pipes, and one or more alignment elements for alignment of the disk to other stator disks;

rotating at least some of the stator disks to a rotated position with respect to other stator disks, such that the recesses of the mutually rotated disks are aligned, and the positioning elements are misaligned with each other;

placing the cooling pipes in the recesses; and

aligning the positioning elements with each other such that the recesses of the mutually rotated disks cause opposite pressing forces to the cooling pipes.