Electric motor having segmented stator windings

Patent metadata

Field	Value
Publication number	US-9470238-B2
Application number	US-201013388577-A
Country	US
Kind code	B2
Filing date	Jul 1, 2010
Priority date	Aug 3, 2009
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

A turbocompressor system including a high speed motor ( 10 ) including a rotor ( 12 ) mounted in a rotative manner relative to the stator, wherein on the rotor ( 12 ) one or more impellers ( 11 ) are directly fixed, the stator including active motor structures and a shell ( 7 ), including a ferromagnetic stator core ( 6 ) and a winding being constructed as toroidally wound coils ( 5 ), the shell ( 7 ) is constructed in such a manner as to create additional open space between the stator core ( 6 ) and the shell ( 7 ), constituting a cooling channel ( 15 ) through which process gas is passed axially for directly cooling the active motor structures and the rotor ( 12 ), prior to compression by the one or more impellers ( 11 ).

First claim

The invention claimed is:

1. A turbocompressor system comprising:
a high speed motor having a number of phases larger than one, and comprising a stator and a rotor mounted in a rotative manner relative to said stator, wherein on said rotor one or more impellers are directly fixed;
said stator comprising active motor structures and a shell;
said active motor structures comprising a ferromagnetic stator core and a winding, said ferromagnetic stator core comprising a plurality of stator core segments connected along side edges of said stator core segments to form said ferromagnetic stator core, said winding being constructed as a series of toroidal coils which are mounted around a length of each stator core segment extending in the axial direction of the rotor and said coils being physically separated from one another and from the rotor so as to form a first open space;
each of said stator core segments comprising at least one outwardly directed extension extending from each of said stator core segments;
said shell being constructed so as to create at least a second open space between said ferromagnetic stator core and said shell;
said first and second open spaces defining a cooling channel confined on the inside by said rotor and the ferromagnetic stator core and confined on the outside by said ferromagnetic stator core and the shell;
said cooling channel being configured in a way such that the cooling channel serves as a duct through which process gas is passed axially for directly cooling said active motor structures and the rotor prior to compression by said one or more impellers.

2. The turbocompressor system according to claim 1 , wherein said ferromagnetic stator core has a polygonal shape.

3. The turbocompressor system according to claim 1 , wherein said ferromagnetic stator core has a cylindrical tubular shape.

4. The turbocompressor system according to claim 1 , wherein said ferromagnetic stator core is constructed as stack of single piece ferromagnetic laminations.

5. The turbocompressor system according to claim 1 , wherein each core segment is constructed as a stack of soft magnetic non-oriented or grain-oriented steel laminations, amorphous or nanocrystalline ribbons.

6. The turbocompressor system according to claim 1 , wherein each core segment is constructed as one of a sintered soft-magnetic powder, soft-magnetic composite or ferrite part.

7. The turbocompressor system according to claim 1 , wherein each of the plurality of core segments is constructed as one of the sintered soft-magnetic powder or soft-magnetic composite, and wherein the particle size of the sintered soft-magnetic powder or sintered soft-magnetic composite is smaller than 500 μm.

8. The turbocompressor system according to claim 1 , wherein each of the outward extensions are provided along one of the side edges of each of the stator core segments.

9. The turbocompressor system according to claim 8 , wherein said outward extensions are integral parts of said ferromagnetic stator core.

10. The turbocompressor system according to claim 8 , wherein said outward extensions are formed as separate parts rigidly attached to said ferromagnetic stator core.

11. The turbocompressor system according to claim 8 , wherein said toroidal coil is mounted on a free edge of said stator core segment.

12. The turbocompressor system according to claim 1 , wherein said outward extensions define a connection between said ferromagnetic stator core and said shell.

13. The turbocompressor system according to claim 12 , wherein said shell is constructed as a sleeve wound around said outward extensions.

14. The turbocompressor system according to claim 1 , wherein said shell is constructed as a single solid piece.

15. The turbocompressor system according to claim 1 , wherein said shell is constructed from a plurality of segments.

16. The turbocompressor system according to claim 1 , wherein the number of said coils is an integer of said number of phases.

17. The turbocompressor system according to claim 1 , wherein said coils are wound with stranded conductors.

18. The turbocompressor system according to claim 1 , wherein said coils are wound with Litz-type conductors.

19. The turbocompressor system according to claim 1 , wherein said coils are directly wound over said ferromagnetic stator core.

20. The turbocompressor system according to claim 1 , wherein said coils are directly wound over said core segments.

21. The turbocompressor system according to claim 1 , wherein said coils are pre-wound on electrically insulating bobbins before being slid over and fixed to said core segments.

22. The turbocompressor system according to claim 1 , wherein said winding is a single-layer winding.

23. The turbocompressor system according to claim 1 , wherein said winding is a multiple-layer winding.

24. The turbocompressor system according to claim 1 , wherein said rotor comprises permanent magnets that enable synchronous operation with the rotating magnetic field generated by currents in said winding in said stator.

25. The turbocompressor system according to claim 1 , wherein one impeller is fixed to said rotor in such a manner that process gas flows into said impeller after having passed through said cooling channel.

26. The turbocompressor system according to claim 1 , wherein the number of said coils is a fractional multiple of said number of phases.

27. The turbocompressor according to claim 1 wherein each stator core segment has a first leg and a second leg, wherein said first leg comprises the at least one outwardly directed extension extending from the stator core segment, and said second leg comprises the toroidal coil.

28. The turbocompressor according to claim 1 , wherein at least one outward extension extends along both side edges of said stator core segments and said toroidal coil is mounted around a middle part of the stator core segment between the side edges.

29. A method for constructing a turbocompressor system, said method comprising the steps of:
providing a stator of an electric motor;
providing a shaft of a rotor of an electric motor, that is rotated by a rotating magnetic field generated in said stator;
mounting one or more impellers on the shaft of said rotor in such a manner that, during operation of the turbocompressor system, process gas is compressed after having passed through the motor for directly cooling active motor structures prior to compression;
assembling said stator comprising active motor structures and a shell, said active motor structures comprising a ferromagnetic stator core and a winding, wherein said assembling comprises connecting a plurality of stator core segments along side edges of said stator core segments to form said ferromagnetic stator core, said winding being constructed as a series of coils which are toroidally formed around a length of each stator core segment extending in the axial direction of the rotor and which are physically separated from each other and the rotor so as to form an open space, wherein each of said stator segments comprise at least one outwardly directed extension extending from each of said stator core segments; and
arranging said shell so as to create additional open space.

30. The method according to claim 29 , said method further comprising the steps of:
arranging said shell so as to retain

Assignees

• Vande Sande Hans
• Philippi Cornelis Theodorus
• Pahner Uwe
• Atlas Copco Airpower Nv

Inventors

• Vande Sande Hans
• Philippi Cornelis Theodorus
• Pahner Uwe

Classifications

• F04D25/082

  the unit having provision for cooling the motor · CPC title

• Y10T29/49009

  Dynamoelectric machine · CPC title

• H02K1/148

  Sectional cores (H02K1/141 takes precedence) · CPC title

• F04D29/584

  cooling or heating the machine (F04D29/5846, F04D29/5853 take precedence) · CPC title

• F04D13/06

  the pump being electrically driven · CPC title