Motor vehicle starter provided with a thermal protection system

Patent metadata

Field	Value
Publication number	US-10107249-B2
Application number	US-201515533242-A
Country	US
Kind code	B2
Filing date	Dec 4, 2015
Priority date	Dec 5, 2014
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

The invention relates mainly to a starter for a heat engine of a motor vehicle comprising:
at least one electromagnetic contactor comprising a positive output terminal, at least one electric motor, the electric motor comprising: at least one brush cage ( 43 ), at least one positive brush ( 35 ) mounted in the brush cage ( 43 ), an electrical path ( 91 ) between the positive brush ( 35 ) and the positive output terminal ( 32 ), and at least one thermal protection ( 96 ) situated in the electrical path ( 91 ), in which the thermal protection is suitable for disconnecting the two elements ( 93, 95 ) when the thermal protection has a temperature above a temperature threshold to electrically disconnect the positive output terminal relative to the positive brush ( 35 ).

First claim

The invention claimed is:

1. Starter ( 11 ) for a heat engine of a motor vehicle comprising:
at least one electromagnetic contactor ( 25 ) comprising a positive output terminal ( 32 ),
at least one electric motor ( 15 ), said electric motor ( 15 ) comprising:
at least one brush cage ( 43 ),
at least one positive brush ( 35 ) mounted in said brush cage ( 43 ),

an electrical path ( 91 ) between said positive brush ( 35 ) and the positive output terminal ( 32 ), the electrical path comprising at least one two electrical conductor elements and
at least one thermal protection ( 96 ) situated in said electrical path ( 91 ), in which said thermal protection is suitable for disconnecting said two elements ( 93 , 95 ) when the thermal protection has a temperature above a temperature threshold (T 2 ) to electrically disconnect said positive output terminal ( 32 ) relative to said positive brush ( 35 ).

2. Starter according to claim 1 , wherein said temperature threshold (T 2 ) corresponds to a starter anomaly provoking an overheating likely to damage the vehicle.

3. Starter according to claim 1 , wherein said thermal protection ( 96 ) is arranged in said electric motor ( 15 ) in such a way that a main factor making it possible to reach the temperature threshold (T 2 ) in the case of an anomaly is a transmission by thermal conduction and/or by convection of a heat corresponding to an operating anomaly to said thermal protection ( 96 ).

4. Starter according to claim 1 comprising at least one a heat element which is in said electrical path ( 91 ) wherein the heat element heats the thermal protection and wherein said thermal protection ( 96 ) and said element are two distinct elements.

5. Starter according to claim 4 , wherein the heat element is a fuse ( 82 ) suitable for melting above a predetermined current corresponding an overload current which are above a rated current.

6. Starter according to claim 4 , wherein when the current through the heat element is above a predetermined current corresponding to an overload current which are above a rated current, the heat element heats, directly by conduction or indirectly by others conductor elements of the electrical path, the thermal protection to electrically disconnect said positive output terminal ( 32 ) relative to said positive brush ( 35 ) when the temperature of the thermal protection is above a temperature threshold (T 2 ).

7. Starter according to claim 4 , wherein, in the case of a short circuit, said heat element is a fuse and is suitable for acting by melting to electrically disconnect said positive output terminal ( 32 ) relative to said positive brush ( 35 ).

8. Starter according to claim 4 , wherein said fuse consists of a positive brush ( 35 ) braid ( 82 ).

9. Starter according to claim 1 , wherein said thermal protection ( 96 ) comprises a low-melting-point weld ( 97 ) linking together two elements ( 95 , 93 ) of said electric path ( 91 ), said weld ( 97 ) being suitable for melting above said temperature threshold (T 2 ), in which, in an operating state of the starter, the weld ( 97 ) is able to be in a solid state to link said connector ( 95 ) to said conductor ( 93 ) and, in the case of an anomaly on the starter, said weld ( 97 ) is able to change to the molten state to enable said thermal protection ( 96 ) to separate said two elements ( 93 , 95 ) from the electrical path ( 91 ).

10. Starter according to claim 9 , wherein one of the elements of said electrical path ( 91 ) is a conductor ( 93 ) and another element of said electrical path ( 91 ) is a connector ( 95 ) electrically linking said conductor ( 93 ) to the at least one positive brush ( 35 ), these two elements being linked together by said weld.

11. Starter according to claim 9 , wherein said electrical protection ( 96 ) comprises an elastic member ( 98 ) suitable for exerting a pressure on one of the elements ( 93 , 95 ) of said electrical path ( 91 ) linked together by said weld.

12. Starter according to claim 9 , wherein said thermal protection ( 96 ) comprises an abutment ( 101 ) suitable for retaining one of the two elements of said electrical path ( 91 ) following the melting of the weld.

13. Starter according to claim 9 , wherein said thermal protection ( 96 ) comprises a guiding device ( 103 ) for guiding the displacement of one of the two elements of said electrical path ( 91 ) following the melting of the weld.

14. Starter according to claim 10 , wherein the electrical motor comprises a field frame ( 21 ) and in which said conductor ( 93 ) consists of an elongate terminal passing through a grommet ( 94 ) mounted on said field frame ( 21 ).

15. Starter according to claim 11 , wherein said thermal protection ( 96 ) comprises an abutment ( 101 ) suitable for retaining one of the two elements of said electrical path ( 91 ) following the melting of the weld, in that said thermal protection ( 96 ) comprises a guiding device ( 103 ) for guiding the displacement of one of the two elements of said electrical path ( 91 ) following the melting of the weld, and in that the electrical motor comprises a field frame ( 21 ) and in which said conductor ( 93 ) consists of an elongate terminal passing through a grommet ( 94 ) mounted on said field frame ( 21 );
wherein said elastic member ( 98 ), said abutment ( 101 ), and said guiding device ( 103 ) are of the same material as said grommet ( 94 ).

16. Starter according to claim 10 , wherein a portion ( 951 ) of said connector ( 95 ) linked to said conductor ( 93 ) through said weld ( 97 ) is omega-shaped.

17. Starter according to claim 1 , wherein an insulating layer ( 77 ) arranged to electrically insulate said brush cage ( 43 ) relative to a support plate ( 75 ) is deformable from another temperature threshold (T 1 ), and
an elastic means ( 44 ) stressing said positive brush ( 35 ) against a contact blade ( 38 ) of a collector ( 39 ) is suitable for establishing a contact between said brush cage ( 43 ) and said support plate ( 75 ) following a deformation of said deformable insulating layer ( 77 ).

18. Starter according to claim 2 , wherein said thermal protection ( 96 ) is arranged in said electric motor ( 15 ) in such a way that a main factor making it possible to reach the temperature threshold (T 2 ) in the case of an anomaly is a transmission by thermal conduction and/or by convection of a heat corresponding to an operating anomaly to said thermal protection ( 96 ).

19. Starter according to claim 2 comprising at least one a heat element which is in said electrical path ( 91 ) wherein the heat element heats the thermal protection and wherein said thermal protection ( 96 ) and said element are two distinct elements.

20. Starter according to claim 3 comprising at least one a heat element which is in said electrical path ( 91 ) wherein the heat element heats the thermal protection and wherein said thermal protection ( 96 ) and said element are two distinct elements.

Assignees

• Valeo Equip Electr Moteur
• Jv Sves

Inventors

• Verot Jacques
• Mao Jiajun

Classifications

• H01H37/002

  combined with protective means · CPC title

• H01H85/055

  Fusible members · CPC title

• H02K11/25

  Devices for sensing temperature, or actuated thereby · CPC title

• H02K11/33

  Drive circuits, e.g. power electronics (H02K11/38 takes precedence) · CPC title

• F02N11/10 Primary

  Safety devices (F02N11/08 takes precedence) · CPC title