FR3051024A1 - ELECTRIC COMPRESSOR WITH COOLING CIRCUIT - Google Patents

Abstract

The present invention relates to an electric compressor (1) comprising at least one body (8) in which is disposed a compressor wheel driven by an electric motor controlled by an electronic assembly, and comprising a cooling circuit (10) with at least one opening (121, 122) closed by a cover (221, 222), characterized in that the body (8) of the compressor comprises at least one element (2) for fixing at least one cover (221, 222) to the body (8) compressor disposed at an opening (121, 122).

Description

ELECTRIC COMPRESSOR WITH COOLING CIRCUIT

The present invention relates to the field of electric compressors, and more particularly to an electric supercharging compressor for a motor vehicle with a cooling circuit closed by at least one hood.

In the context of the invention, an electric compressor is a device used to supercharge a heat engine, operating with an electric motor driving a compressor wheel and having an electronic assembly.

The electric compressor is placed on the air intake line of an internal combustion engine, in addition for example a turbocharger. The electric compressor plays the same role as the turbocharger, namely increase the intake pressure of the fresh gases in the engine, but is used in particular during transient phases to overcome turbocharger response time problems.

In such devices, it is necessary to cool the electric motor as well as the electronic assembly. The electric compressor thus has a cooling circuit. The manufacturing process of this cooling circuit imposes in some cases the presence of openings to the outside of the electric compressor. It is then necessary to close these openings with additional covers. One of the disadvantages of these covers comes from their attachment mode which significantly increases the size of the compressor, its manufacturing complexity and cost.

The present invention therefore aims to overcome one or more of the disadvantages of the devices of the prior art by proposing an electric compressor

For this, the present invention proposes an electric compressor comprising at least one body in which is disposed a compressor wheel driven by an electric motor controlled by an electronic assembly, and comprising a cooling circuit with at least one opening closed by a hood, characterized in that the compressor body has at least one attachment element for at least one cover to the compressor body arranged at an opening.

Such a method of attachment according to the invention reduces the size of the compressor, its complexity of manufacture and its cost.

According to one embodiment of the invention, the fixing element is formed directly from the compressor body, in the extension of the compressor body.

According to one embodiment of the invention, the fastening element has a rod shape.

According to one embodiment of the invention, the fastening element is of round, oval, square, rectangle or any other forms compatible with the fastener.

According to one embodiment of the invention, the fastening element is of round section.

According to one embodiment of the invention, the fastening element has a diameter of between 1 and 10 mm.

According to one embodiment of the invention, the length of the fastening element is defined with respect to the thickness of the cover to be fixed, so that the element protrudes from the cover when it is inserted into openings hood, to allow fixation.

According to one embodiment of the invention, the fixing of the cover to the body is performed by crushing the end of the rod protruding from the cover so that its diameter is greater than that of the opening of the cover.

According to one embodiment of the invention, the electric motor is a permanent magnet or variable reluctance motor. The invention also relates to the use of the electric compressor according to the invention in an internal combustion engine or fuel cell. Other aims, features and advantages of the invention will be better understood and will appear more clearly on reading the description given hereinafter with reference to the appended figures given by way of example and in which: FIG. 1 is a diagrammatic representation of a sectional view of a compressor according to the invention, FIG. 2 is a schematic representation of an external view of a part of a compressor according to the invention, FIG. 3 is a schematic view in detail of a fastening element according to the invention.

The present invention relates to an electric compressor 1.

In the context of the invention, the term electric compressor 1, an air compressor, volumetric or not and for example centrifugal or radial, driven by an electric motor, for the purpose of supercharging a heat engine. According to one embodiment of the invention, the electric motor is a DC or AC motor, or any type of electric motor of the same type.

More specifically, according to one embodiment of the invention, the electric motor is a variable reluctance motor (also called SRM machine for Switched Reluctance Motor according to English terminology).

According to another embodiment of the invention, the motor is a permanent magnet motor.

Figure 1 illustrates an example of an electric compressor 1. The electric compressor 1 comprises at least one electric motor 5, and a compressor wheel 3. The electric motor 5 is disposed in a housing 4 or envelope 4 engine. The electric motor 5 comprises at least one rotor and a stator. The electric motor 5 allows the rotation of a shaft 6 of the electric compressor via bearings. The shaft 6 thus rotates the wheel 3 of the compressor 1. More precisely one end of the shaft 6 is rotated by the electric motor 5, and another end of the shaft 6 rotates the wheel 3 of the compressor. The assembly is disposed in a compressor body 8.

According to one embodiment of the invention, the compressor 1 conventionally comprises a volute 12 allowing the passage of air from the compressor 1. The wheel 3 of the compressor is disposed in the volute 12.

According to one embodiment of the invention, the wheel of the compressor 1 is a paddle wheel.

According to one embodiment of the invention, the compressor 1 comprises an electronic assembly 9 for controlling the electric compressor 1. In the context of the invention, the term "electronic assembly 9" refers to the power and / or control electronics.

According to one embodiment of the invention, the electronic assembly is composed of at least one electronic control card, and / or a power module, and / or at least one filtering capacitor, and or at least one inductor, and / or at least one sensor.

According to one embodiment of the invention, the electronic assembly 9 is composed of the electronic control card, the power module, at least two filtering capacitors, and at least two inductors.

According to one embodiment of the invention, the electronic assembly 9 is disposed at the rear 31 of the wheel 3 of the compressor 1.

According to one embodiment of the invention, the electronic assembly 9 is disposed at the rear 31 of the wheel 3 and co-axially with respect to the shaft 6 of the compressor 1.

According to one embodiment of the invention, the electronic assembly 9 is disposed between the wheel 3 of the compressor 1 and the motor 5.

In the context of the invention, the electric compressor 1 comprises a cooling circuit 10.

The cooling circuit 10 is traversed by a fluid which may be a gas or a liquid.

Whatever the configuration of the cooling circuit 10, the latter comprises an inlet of the cooling fluid and an outlet of the cooling fluid, not shown in the figures.

The cooling circuit comprises at least two parts 101, 102. A first portion 101 is disposed around the electric motor 5, parallel to the axis X of the electric compressor 1.

A second portion 102 of the cooling circuit 10 is disposed at the rear face 109 of the electronic assembly 9, perpendicular to the axis X of the electric compressor 1.

In the context of the invention, the rear face is defined with respect to the position of the wheel and the shaft. More specifically, rear face 902 of the electronic assembly 9 is the part situated opposite the wheel 3 with respect to the longitudinal axis X of the shaft 6.

According to one embodiment of the invention, the two parts 101, 102 of the cooling circuit 10 form a single cooling duct.

In the context of the invention, the two parts 101, 102 of the cooling circuit 10 are formed by a molding process.

According to one embodiment of the invention, the molding method used is a high pressure die casting (or HPDC) method.

According to another embodiment of the invention, the molding method used is a gravity molding process.

According to another embodiment of the invention, the molding method used is a low-pressure molding process.

More specifically, the body 8 of the electric compressor 1 is made from a die casting process. The body of the electric compressor 1 is thus formed of a single part forming the cooling circuit.

The body of the electric compressor 1 thus contains a demoldable cavity in at least two directions. As illustrated in FIG. 2, a first direction is parallel to the axis X of the compressor 1 and a second direction is perpendicular to the axis X of the compressor 1. It is this cavity that forms the cooling circuit 10 of the electric compressor 1.

It is thus possible to form the cavity with or without undercut, thus giving the possibility of having a demoldable body without destructive nuclei.

As illustrated in FIGS. 1 and 2, the compressor thus comprises a cooling circuit 10 comprising at least two openings 121, 122 towards the outside of the compressor 1. These two openings 121, 122 are the result of the molding under pressure in two directions . More specifically, each of the two parts 101, 102 of the cooling circuit 10 has an opening 121, 122.

According to one embodiment of the invention, a first opening 121 is disposed at the end of the compressor body 8 opposite that in which the wheel 3 of the compressor is located, in the X axis of the compressor, and a second opening 122 is disposed perpendicularly to the axis X of the compressor, on one side of the compressor at the assembly 9 electronic.

According to one embodiment of the invention, the cooling circuit 10 is closed by at least one additional cover. More specifically, according to one embodiment of the invention, the two openings 121,122 of the cooling circuit 10 are each closed by an additional cover. These covers are made of plastic or any other material compatible with the cooling fluid circulating in the cooling circuit.

In the context of the invention, the body 8 of the compressor comprises at least one element 2 for fixing at least one cover 221, 222 to the compressor body.

In the context of the invention, the fastening element 2 is an element formed directly from the body 8 of the compressor.

According to one embodiment of the invention, the fastening element 2 has a rod shape, also called rivet. The stem is of round section, oval, square, rectangle or any other forms compatible with the fixation.

According to one embodiment of the invention, when the rod is of round section its diameter is between 1 and 10 mm.

According to one embodiment of the invention, when the rod is of round section its diameter is between 2 and 3 mm.

According to one embodiment of the invention, the fixing element 2 is formed in the extension of the body 8 of the compressor. More specifically, the fixing element 2 is formed at the part of the compressor body 8 in contact with the cover 221, 222.

In the context of the invention, the cover 221, 222 to be fixed comprises hood openings arranged opposite the fixing elements 2. The section of the openings is adapted to the section of the fastening elements 2.

The length of the fixing element is defined relative to the thickness of the cover to be fixed. Specifically, the length of the fastener is set so that the element protrudes sufficiently from the hood as it is inserted into the hood openings to allow attachment.

Fixing the cover to the body is made by snap-in crushing the end 200 of the rod projecting from the cover so that its diameter is greater than that of the opening of the cover. The rod can no longer be removed from the hood opening. The hood is thus held in place between the body and the crushed end 200 of the rod.

According to one embodiment of the invention, the body 8 comprises at least two fastening elements 2 at at least one opening 221, 222.

According to one embodiment of the invention, the body 8 comprises at least two fixing elements 2 at the two openings 221, 222.

According to one embodiment of the invention, the body 8 comprises at least two concentric rows of five fastening elements 2 regularly distributed around the first opening 221. The diameter of the rods and 2 mm.

According to one embodiment of the invention, the body 8 comprises four fixing elements 2 distributed regularly around the second opening 222. The diameter of the rods and 3 mm

Such a method of attachment according to the invention reduces the size of the compressor, its complexity of manufacture and its cost.

An electric compressor 1 according to the invention is used in a combustion engine, and for example an internal combustion engine or fuel cell.

The scope of the present invention is not limited to the details given above and allows embodiments in many other specific forms without departing from the scope of the invention. Therefore, the present embodiments should be considered by way of illustration, and may be modified without departing from the scope defined by the claimed invention.

Claims (9)

Electric compressor (1) comprising at least one body (8) in which is disposed a compressor wheel (3) driven by an electric motor (5) controlled by an electronic assembly (9), and comprising a circuit (10). cooling device with at least one opening (121, 122) closed by a cover (221, 222), characterized in that the body (8) of the compressor comprises at least one element (2) for fixing at least one cover ( 221, 222) to the compressor body (8) disposed at an opening (121, 122). 2. Electric compressor (1) according to claim 1, wherein the element (2) of attachment is formed directly from the body (8) of the compressor, in the extension of the body (8) of the compressor. Electric compressor (1) according to claim 1 or 2, wherein the fixing element (2) is rod-shaped. 4. Electric compressor (1) according to one of claims 1 to 3, wherein the rod of the element (2) of fixing is round, oval, square, rectangle or any other forms compatible with the attachment. 5. Electric compressor (1) according to claim 4, wherein, when the element (2) of attachment is of round section and its diameter is between 1 and 10 mm. 6. Electric compressor (1) according to one of claims 1 to 5, wherein the length of the element (2) of attachment is defined relative to the thickness of the cover (221, 222) to be fixed, so that that the member (2) protrudes (200) from the hood (221, 222) when inserted into hood openings (201) (221, 222) to permit attachment. 7. Electric compressor (1) according to one of claims 1 to 6, wherein the fixing of the cover (221, 222) to the body is performed by crushing the end (200) of the rod protruding from the cover (221, 222) of so that its diameter is greater than that of the opening (201) of the cover (221, 222). 8. Electric compressor (1) according to one of claims 1 to 7, wherein the electric motor (5) is a permanent magnet motor or variable reluctance. 9. Use of the electric compressor (1) according to one of the preceding claims in an internal combustion engine or fuel cell.