Method for producing a stator for an electric machine

Patent metadata

Field	Value
Publication number	US-12062960-B2
Application number	US-202016892241-A
Country	US
Kind code	B2
Filing date	Jun 3, 2020
Priority date	Dec 4, 2017
Publication date	Aug 13, 2024
Grant date	Aug 13, 2024

Abstract

A method for producing a stator for an electric machine includes providing a stator with an annular stator body, from which a plurality of stator teeth protrude radially inwardly, wherein an intermediate space is formed in each case between two stator teeth that are adjacent in a circumferential direction, encapsulating two stator teeth adjacent in the circumferential direction with a first plastic mass, arranging a stator winding on a stator tooth, fixing the stator winding on the stator tooth by encapsulating said stator winding with a second plastic mass, following the encapsulation with the first plastic mass and before the fixing of the stator winding, a first mask is introduced into the intermediate space between the two stator teeth, such that the volume of the intermediate space that is filled with the first mask remains free from the second plastic mass to form a cooling duct during the encapsulation.

First claim

What is claimed is:

1. A method for producing a stator for an electric machine, the method comprising:
(a) providing a stator, which comprises an annular stator body, from which multiple stator teeth for receiving stator windings that are arranged spaced from one another along a circumferential direction of the stator body protrude radially to the inside, wherein between two stator teeth adjacent in the circumferential direction, an intermediate space is formed in each case;
(b) at least partial overmolding at least two stator teeth that are adjacent in the circumferential direction with a first plastic mass;
(c) arranging at least one stator winding on at least one stator tooth;
(d) fixing the at least one stator winding on the at least one stator tooth through at least partial overmolding of this stator winding with a second plastic mass; and
following the overmolding with the first plastic mass according to step (b) and prior to the fixing of the at least one stator winding according to step (d), introducing a first mask into the intermediate space between the two stator teeth, such that the volume of the intermediate space filled out by the first mask for forming a coolant passage cooling passage remains free of the second plastic mass during the overmolding according to step (d),
wherein the first mask covers a surface portion of the stator body bounding the intermediate space radially outside, which can have been partly or completely covered with the first plastic mass in step (b), such that the surface portion during the overmolding according to step (d) is not covered with the second plastic mass.

2. The method according to claim 1 , further comprising:
introducing the first mask into a radially outer end portion of the intermediate space.

3. The method according to claim 2 , wherein the first mask completely fills out the radially outer end portion.

4. The method according to claim 1 , further comprising:
(e) removing the first mask from the intermediate space following the overmolding with the second plastic mass, such that a hollow space that is present following the removing of the first mask forms a coolant passage for a coolant to flow through.

5. The method according to claim 4 , further comprising:
(f) overmolding of the second plastic mass bounding the hollow space or the coolant passage and/or of the stator winding fixed to the stator tooth with the second plastic mass and/or of the surface portion of the stator body covered by the first mask prior to the removal of the same with a third plastic mass.

6. The method according to claim 5 , further comprising:
carrying out the overmolding with the third plastic mass after the removing of the first mask.

7. The method according to claim 5 , wherein the coolant passage is bounded by the first and/or the third plastic mass.

8. The method according to any claim 5 , further comprising:
carrying out the overmolding with the third plastic mass such that following the overmolding the overmolded hollow space and/or additional hollow space or coolant passage and/or additional coolant passage is not directly bounded by the stator winding and/or by the stator body at any point.

9. The method according to claim 8 , further comprising:
(g) overmolding at least one outer circumferential side of the stator body with a fourth plastic mass.

10. The method according to claim 9 , wherein at least one of the first plastic mass, the second plastic mass, the third plastic mass, and the fourth plastic mass comprises a thermosetting plastic or is/are a thermosetting plastic.

11. The method according to claim 9 , wherein at least one of the first plastic mass, the second plastic mass, the third plastic mass, and the fourth plastic mass comprises a thermoplastic or is a thermoplastic.

12. The method according to claim 9 , wherein:
the plastic material of the first, second, and third plastic mass comprises the same thermosetting plastic or consists of the same thermosetting plastic, and
the plastic material of the fourth plastic mass is a thermoplastic that is distinct from the thermosetting plastic of the first, second, and third plastic mass.

13. The method according to claim 12 , wherein the heat conductivity of the fourth plastic mass is lower than the heat conductivity of the first and/or second and/or third plastic mass, and/or in that the strength of the fourth plastic mass is higher than the strength of the first and/or second and/or third plastic mass.

14. The method according to claim 9 , wherein:
the plastic material of the first and of the third plastic mass comprises the same thermosetting plastic or consists of the same thermosetting plastic and is distinct from the plastic material of the second and the fourth plastic mass, and
the plastic material of the second plastic mass is distinct from the plastic material of the fourth plastic mass.

15. The method according to claim 14 , wherein at least one of:
a coolant resistance of at least one of the first plastic mass and the third plastic mass is higher than the coolant resistance of at least one of the second plastic mass and the fourth plastic mass,
the heat conductivity of at least one of the first plastic mass and the third plastic mass is lower than the heat conductivity of the second plastic mass, and
the strength of the fourth plastic mass is higher than the strength of at least one of the first plastic mass, the second plastic mass, and the third plastic mass.

16. The method according to claim 14 , wherein a layer thickness of at least one of the third plastic mass and the first plastic mass bounding the respective coolant passage amounts to at least one of a maximum of 0.8 mm, or a maximum of 0.3 mm.

17. The method according to claim 9 , wherein the plastic materials of the first, second, third, and fourth plastic mass comprise different thermoplastics or thermosetting plastics or consist of different thermoplastics or thermosetting plastics.

18. The method according to claim 17 , wherein at least one of:
a coolant resistance of at least one of the first plastic mass and the third plastic mass is higher than a coolant resistance of the second plastic mass,
the heat conductivity of the second plastic mass is higher than the heat conductivity of at least one of the first plastic mass, the third plastic mass, and the fourth plastic mass, and
the strength of the fourth plastic mass is higher than the strength of at least one of the first plastic mass, the second plastic mass, and the third plastic mass.

19. The method according to claim 9 , wherein the method further comprises:
(h1) providing a coolant distribution space and a coolant collection space on and/or in the stator, which via the at least one coolant passage and/or via the at least one additional coolant passage fluidically communicate with one another; and
(h2) at least one of overmolding and spraying of the second plastic mass bounding at least one of the coolant distribution space, the coolant collection space, and the axial end portions of at least one stator winding, or of all stator windings, with an electrically insulating insulation material, or an electrically insulating varnish.

20. The method according to claim 19 , wherein the overmolding or spraying according to step (h2) is carried out in such a manner that following the overmolding or spraying, neither the second plastic mass nor the axial end portions of the at least one stator winding, or of stator windings, bound the coolant distribution space or the co

Assignees

• Mahle Int Gmbh

Inventors

• Cunningham John
• Grabherr Philip
• Webb Ian
• Male Tim
• Markic Stojan
• Sentance Graham
• Sever Peter
• Sonntag Josef
• Witcombe Jon

Classifications

• H02K15/38

  Manufacturing or repairing cooling fluid boxes, e.g. ensuring both electrical and fluid connection of terminals of fluid cooled windings · CPC title

• H02K15/026

  Wound cores · CPC title

• H02K15/12

  Impregnating, moulding insulation, heating or drying of windings, stators, rotors or machines · CPC title

• H02K15/10

  Applying solid insulation to windings, stators or rotors, e.g. applying insulating tapes · CPC title

• H02K15/085

  by laying conductors into slotted stators · CPC title