US-12620871-B2 - Electric motorization device integrating an electrically insulating heat sink

US12620871B2US 12620871 B2US12620871 B2US 12620871B2US-12620871-B2

Abstract

An electric motorization device including an electric motor, an electronic system comprising power electronic elements, and a heat sink that is intended to cool the electronic system. The heat sink comprises a first shell configured to allow heat exchange between a coolant fluid and the electronic system, and a second shell configured to prevent heat exchange between the coolant fluid and the electric motor. The first shell and the second shell together define a cavity configured to allow the passage of the coolant fluid. The first shell and the second shell are each made of a material configured to ensure electrical insulation, in particular between the electronic system, the coolant fluid and the electric motor.

Inventors

Cédric Ledieu

Assignees

NOVARES FRANCE

Dates

Publication Date: 20260505
Application Date: 20210504
Priority Date: 20200529

Claims (9)

1 . An electric motorization device, comprising: an electric motor comprising a rotor intended to be set in motion, a stator and a cooling chamber configured to cool the electric motor; an electronic system comprising power electronic elements, the power electronic elements being configured to drive the electric motor; a heat sink interposed between the electric motor and the electronic system, the heat sink being intended to cool the electronic system and comprising: a first shell intended to cooperate with the electronic system, and configured to allow a heat exchange between a cooling fluid and the electronic system; a second shell intended to cooperate with the electric motor on the one hand and with the first shell on the other hand, the second shell being configured to prevent a heat exchange between the cooling fluid and the electric motor; the first shell and the second shell defining between them a cavity, the cavity being configured to allow the passage of the cooling fluid; and the first shell and the second shell each being constituted of a material configured to guarantee an electrical insulation, between the electronic system, the cooling fluid and the electric motor; wherein the heat sink comprises at least one fluid inlet which is fluidly connected with the cavity, the at least one fluid inlet being configured to allow the entry of the cooling fluid into the cavity; and at least one fluid outlet which is fluidly connected with the cavity on the one hand and with the cooling chamber on the other hand, and intended to allow the passage of the cooling fluid from the cavity to the cooling chamber and the heat sink comprises a ring of material secured to the first shell and/or to the second shell, and a plurality of walls projecting into the cavity and being configured to direct the passage of the cooling fluid into the cavity and the plurality of walls configured to define a circuit for the passage of the cooling fluid in the cavity, wherein each of plurality of walls having a first end secured to the ring of material and an opposite free end that is not secured to the ring of material and each of the plurality of walls extend from the first end to the opposite free end in a direction that is perpendicular to an axial direction of the electric motor.
2 . The electric motorization device according to claim 1 , wherein the first shell comprises first fastening means intended to make it possible to secure the electronic system to the first shell.
3 . The electric motorization device according to claim 2 , wherein the first shell and the second shell comprise second fastening means configured to secure the first shell to the second shell.
4 . The electric motorization device according to claim 3 , wherein the first shell is formed of a composite material configured to be thermally conductive, the composite material comprising thermally conductive fillers of the group comprising aluminum oxides, aluminosilicates, aluminum or magnesium hydroxides, boron nitrides.
5 . The electric motorization device according to claim 4 , wherein the second shell is formed of a thermally insulating plastic material, belonging to the group comprising polyolefins, styrene materials, polyamides, poly (phenylene sulphide), polysulphones and composites reinforced with non-conductive mineral fillers such as fiberglass.
6 . The electric motorization device according to claim 1 , wherein the first shell and the second shell comprise second fastening means configured to secure the first shell to the second shell.
7 . The electric motorization device according to claim 1 , wherein the first shell is formed of a composite material configured to be thermally conductive, the composite material comprising thermally conductive fillers of the group comprising aluminum oxides, aluminosilicates, aluminum or magnesium hydroxides, boron nitrides.
8 . The electric motorization device according to claim 1 , wherein the second shell is formed of a thermally insulating plastic material, belonging to the group comprising polyolefins, styrene materials, polyamides, poly (phenylene sulphide), polysulphones and composites reinforced with non-conductive mineral fillers comprising fiberglass.
9 . The electric motorization device according to claim 1 , wherein each of the plurality of walls has at least one wall section having a curved shape.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a National Stage of PCT Application No. PCT/FR2021/050765 filed on May 4, 2021, which claims priority to French Patent Application No. 20/05693 filed on May 29, 2020, the contents each of which are incorporated herein by reference thereto. TECHNICAL FIELD The present invention relates to an electric motorization device comprising an electric motor. BACKGROUND In general, the current electric motors include a rotor secured to a shaft and a stator which surrounds the rotor. The stator is mounted in a casing which includes bearings for the rotational mounting of the shaft. The rotor includes a body formed by a bundle of laminations or polar wheels (claw pole) held in the form of a stack by means of a suitable fastening system. The body of the rotor includes internal cavities housing permanent magnets. The stator includes a body consisting of a bundle of laminations forming a crown, the inner face of which is provided with teeth delimiting two by two a plurality of slots open towards the inside of the stator body and intended to receive phase windings. The electric motors being likely to be damaged or even destroyed in the event of overheating of the rotor, it is generally necessary to equip electric motors with a cooling system to lower the general temperature of the motor, and in particular when it overheats. Furthermore, the supply of the electric motor and its driving require the integration of an electronic system. Generally, these electronic systems comprise a regulator making it possible to vary the intensity of the current, and a power converter such as an inverter, making it possible to transform a direct current into alternating current. However, depending on the type of electric motor used and depending on the electronic components used in the electronic system, the on-board voltages used may be different. Thus, during assembly of the electric motor and its operation, malfunctions may occur if the masses of the various systems are not isolated. Furthermore, to obtain a long-lasting and optimal operation of the electric motorization device, it is important to also guarantee cooling of the electronic system. It is known to use glycol water in the cooling circuit of the electric motor, and/or to use an aluminum heat sink. This solution is satisfactory in that it allows the motor to be cooled. However, glycol water has electrical conductivity, so it is not possible to integrate the electronic system. BRIEF SUMMARY The purpose of the present invention is to propose a solution which responds to all or part of the aforementioned problems: This goal may be achieved through the implementation of an electric motorization device comprising: an electric motor comprising a rotor intended to be set in motion, a stator, and a cooling chamber configured to cool the electric motor;an electronic system comprising power electronic elements, said power electronic elements being configured to drive the electric motor;a heat sink interposed between the electric motor and the electronic system, said heat sink being intended to cool the electronic system and comprising: a first shell intended to cooperate with the electronic system, and configured to allow a heat exchange between a cooling fluid and the electronic system;a second shell intended to cooperate with the electric motor on the one hand and with the first shell on the other hand, said second shell being configured to prevent a heat exchange between the cooling fluid and the electric motor. The first shell and the second shell defining between them a cavity, said cavity being configured to allow the passage of the cooling fluid. The first shell and the second shell are each constituted of a material configured to guarantee an electrical insulation, in particular between the electronic system, the cooling fluid and the electric motor. The provisions previously described make it possible to guarantee electrical insulation between the power electronic elements of a vehicle (with electric motorization, hybrid or originating from a fuel cell) which may comprise an inverter, and the electric motor. In this way, the masses of the different electric systems are isolated from each other, and the overvoltages between each network of different voltages are avoided. Furthermore, the passage of the cooling fluid in the cavity makes it possible to cool the electronic system. The electric motorization device may also have one or more of the following characteristics, taken alone or in combination. According to one embodiment, the first shell is formed of a composite material configured to be electrically insulating and thermally conductive, said composite material comprising thermally conductive fillers of the group comprising aluminum oxides, aluminosilicates, aluminum or magnesium hydroxides, boron nitrides. According to one embodiment, the second shell is formed of an electrically insulating and thermally insu