FR2977407A1 - DEVICE FOR ELECTRICALLY CONNECTING AN ELECTRICAL COMPRESSOR - Google Patents

Abstract

The invention relates to a compressor (9) comprising: - an engine compartment (20) housing an electric motor (2) which drives a compression mechanism (3), - a control compartment (10) housing a control device ( 1) of the motor (2), the compartments (10), (20) being separated by a wall (4), - an electrical connection device (5) connecting the device (1) and the motor (2), comprising: i. at least one connection terminal (6) of the device (1), and ii. a connection block (7) of the motor (2). The device (5) comprises at least one electrically insulating element (8) removably mounted on the block (7) and disposed between the wall (4) and the block (7).

Description

1 DEVICE FOR ELECTRICALLY CONNECTING AN ELECTRICAL COMPRESSOR

The technical sector of the present invention is that of compressors constituting a refrigerant circuit fitted to a motor vehicle.

The refrigerant fluid is conventionally circulated inside an air conditioning circuit via a compressor. In vehicles equipped with an internal combustion engine, this compressor is mechanical type because its rotation is driven by means of a pulley connected to the internal combustion engine by a belt.

The number of hybrid vehicles, that is to say with internal combustion engine coupled to an electric motor, or all electric, that is to say exclusively powered by an electric motor, is constantly increasing because of the rarefaction of fossil fuels that fuel vehicles equipped with internal combustion engines.

The mechanical energy usually supplied by the internal combustion engine is therefore less available or completely unavailable for the case of all-electric vehicles.

However, the transition between the use of an internal combustion engine and the use of an electric propulsion motor of the vehicle is not instantaneous. Indeed, a particular vehicle model can be sold in a version equipped with an internal combustion engine and a mechanical compressor but also in a version equipped with an electric propulsion engine requiring the use of a electric compressor.

Both types of compressors are based on different technologies that require the use of a different lubricant. Indeed, the presence of high electric potentials in an electric compressor requires the use of a dielectric lubricant which has electrical insulation properties superior to those of a conventional lubricant used in a mechanical compressor. In addition to the fact that the cost of a dielectric lubricant is higher than that of a conventional lubricant used for a mechanical compressor, such a situation requires the motor vehicle manufacturer to provide for the management of two types of lubricant at the level of the engine. vehicle production line. This management of two lubricants is particularly cumbersome to implement and increases the risk of errors in the production line.

In order to solve this drawback, the Applicant proposes an electric compressor adapted to use a conventional lubricant (non-dielectric) traditionally used for a mechanical compressor. Such an approach goes against established prejudices that consider that a conventional lubricant is inherently unsuitable for an electric compressor since its electrical insulation properties are lower than those of a dielectric lubricant. .

For this purpose, the invention relates to a compressor comprising a motor compartment housing an electric motor which drives a compression mechanism, a control compartment housing an electric motor control device, the motor compartment and the control compartment being separated. by a wall, an electrical connection device connecting the control device and the electric motor, the electrical connection device comprising at least one connection terminal of the control device, mounted through the wall and projecting into the engine compartment, and a connection block of the electric motor, mounted in the engine compartment and arranged to releasably cooperate with said connection terminal, wherein the electrical connection device comprises at least one electrically insulating element removably mounted on the block connection and disposed between the wall and the block connection.

The electrically insulating element, also referred to as an insulation cover, advantageously makes it possible to increase the distance between the wall, whose electrical potential is grounded, and an electrical element of the connection block having a high electrical potential. Thus, even if the wall of the engine compartment is coated with lubricant, the risk that an electric arc is formed between the wall and an electrical element is low since the element compensates for a lack of electrical insulation of the lubricant. The insulation cover also performs a sealing function by preventing the lubricant from entering the connection block.

In addition, the electrical connection block can be used without the electrically insulating element, the latter being advantageously removable from the connection block. This advantageously makes it possible to use conventional connection blocks whose cost is low.

Preferably, the connection block comprises a body in which is mounted at least one electrical connection element adapted to cooperate with the connection terminal. The body of the connection block advantageously makes it possible to precisely position the connection element in the connection block to facilitate the electrical connection with the connection terminal.

More preferably, the body comprising at least one opening, the electrically insulating member is mounted on the connection block so as to close said opening.

The element advantageously makes it possible to close the opening or openings in the body which are necessary for mounting the connection elements or for the manufacture of the body, for example when it is molded by plastic injection molding. This closure makes it possible to increase the electrical insulation by increasing the distance connecting the wall (of zero electrical potential) to a connecting element of the connection block (of high electric potential).

Preferably, the electrically insulating element comprising an interface partition placed between the wall and the body of the connection block, said interface partition comprises at least one through opening in which the connection terminal extends.

The body of the connection block comprises in the same wall terminal insertion openings and connection element mounting openings. The interface wall of the element advantageously makes it possible to close the mounting apertures while allowing insertion of the connection terminals. In other words, it prevents the formation of an electric arc by closing any unnecessary opening to the electrical connection of the connection block to a connection terminal.

Preferably, the interface partition is resilient to allow it to be mounted on the body of the connection block. The interface partition is advantageously elastically deformed when it is mounted on the connection block. Once in mounted position, the interface partition is in plane support on the body of the connection block which limits the overall size of the assembly.

According to one aspect of the invention, the connection block comprising at least one connection cable electrically connecting the electrical connection element to the motor, the electrically insulating element comprises a guide sheath in which said cable is mounted. The guide sheath advantageously makes it possible to electrically isolate the connection between an electrical connection element and its connection cable. Preferably, the connection block comprising an open rear portion from which extends a connection cable electrically connecting the electrical connection member to the motor, the electrically insulating member comprises a rear wall arranged to close the rear portion of the block. connection. Advantageously, the rear wall improves the electrical insulation between the electrical connection element and the wall.

More preferably, the rear wall of the electrically insulating member has a shape complementary to the rear portion of the connection block. Advantageously, the rear partition is complementary to the rear portion in order to precisely position the element on the connection block and limit the formation of electric arcs with the connection elements mounted in the body. Preferably, the guide sheath is formed from the side wall.

More preferably, the connection block comprises a front portion opposite its rear portion, the front portion comprising at least one front opening, the electrically insulating member 40 comprises a front wall closing said front opening. 4 The front opening of the connection block, resulting from the manufacture of the connection block, is thus closed so as to avoid any arcing through said front opening.

According to one aspect of the invention, the electrically insulating element is made of plastic material and preferably monobloc. Such an electrically insulating element has a low manufacturing cost and can be mounted in a few steps since it is monobloc.

According to another aspect of the invention, the electrically insulating element comprises locking means configured to allow the assembly and disassembly of the electrically insulating element on the connection block. The locking means advantageously facilitate the manual assembly and disassembly of the electrically insulating element.

Preferably, the locking means are in the form of a lug. Such a lug is simple to manufacture and allows effective attachment of the insulating element to the connection block.

According to one aspect of the invention, the connection terminal of the control device comprises a seal allowing, on the one hand, to prevent any penetration of liquid into the connection block and, on the other hand, to prevent increase the isolation distance between the controller and the connection block.

The invention will be better understood on reading the description which will follow, given solely by way of example, and referring to the appended drawings in which: FIG. 1 is a schematic view of an electric compressor according to the invention ; - Figure 2 is a schematic view showing the electrical connection of the connection block with a connection terminal of the compressor; - Figure 3 is a schematic sectional view, according to another angle of view, showing the connection block connected to the connection terminals of the compressor; FIG. 4 is a perspective view of a connection block mounted with its electrical insulation cover; - Figure 5 is a top view of the connection block of Figure 4 without its cover; Figure 6A is a view from the rear of the connector block of Figure 4 without its cover; FIG. 6B is a view from the front of the connection block of FIG. 4 without its cover; Figure 7A is a view from the front of the hood of Figure 4 without its connection block; FIG. 7B is a view from the front of the cover of FIG. 4 without its connection block; FIGS. 8A-8F represent steps for assembling the connection block with its insulation cover; FIG. 9 is a diagrammatic sectional view showing the electrical connection of the connection block with a connection terminal of the compressor in which the electrical insulation distances are represented; FIG. 10 is a schematic sectional view of the front; of the connection block connected to the compressor connection terminals provided with a seal, and - Figure 11 is a side sectional view of the connection block connected to connection terminals of the compressor of Figure 10 .

It should be noted that the figures disclose the invention in detail to implement the invention, said figures can of course be used to better define the invention where appropriate.

Figure 1 illustrates a schematic view of an electric compressor 9 according to the invention and its main components. The compressor 9 is an electric compressor in that it incorporates an electric motor 2 which drives a compression mechanism 3. The electric motor 2 comprises a stator and a rotor integral with a motor shaft which extends longitudinally along an axis U as shown in Figure 1. The compression mechanism 3 comprises fixed parts and moving parts, the latter being rotated by the shaft of the electric motor 2. The compression mechanism 3 is of the spiral compression type ( Scroll in English) or of the pallet type or the piston type, these examples being given for illustrative purposes without limiting the scope of the invention.

The compressor 9 further comprises a control circuit 1 of the electric motor 2. This control circuit 1 is notably an inverter (inverter in English) transforming a stream of continuous form coming from the vehicle into a stream of sinusoidal shape supplying the electric motor 2.

The compressor 9 is delimited vis-à-vis its external environment by a housing. This housing is an aluminum piece or aluminum alloy, hollow circular shape comprising a peripheral wall which delimits an internal volume. This housing comprises, in this example, at least three compartments, which take the form of cavity or housing formed inside the housing, in which are respectively mounted the control device 1, the electric motor 2 and the compression mechanism 3 as shown in Figure 1. These compartments are separate volumes separated from each other by at least one wall. It will therefore be understood that these compartments may be delimited by a single peripheral part which forms the housing or, for example, by separate sub-housings dedicated to each compartment and assembled together to form the compressor 9.

In this example, the compressor 9 comprises a main housing, forming a motor compartment 20, which houses the electric motor 2 and on which is reported, at a first end, a housing forming a control compartment 10 in which the device is housed. 6 and a second end, opposite the first end relative to the electric motor 2, a housing forming a compression compartment 30 in which is housed the compression mechanism 3. In other words, the engine compartment 20 is interposed between the control compartment 10 and the compression compartment 30.

In operation, a fluid or mixture consisting of a coolant mixed with a lubricant enters the engine compartment 20 and circulates around and in the electric motor 2. The coolant is a subcritical fluid such as for example the R704a but it may also be a supercritical refrigerant fluid such as for example carbon dioxide known as R244. The lubricant is for example a polyalkylene glycol type compound.

The fluid circulates in the engine compartment 20 and then in the compression compartment 30 in which the compression mechanism 3 is housed. The latter ensures the increase of pressure and temperature of the refrigerant fluid necessary for the thermodynamic operation of the compressor 9.

The engine compartment 20 is separated from the control compartment 10 by a wall 4 which prevents the penetration of the fluid into the control compartment 10. It is thus clear that the fluid present in the engine compartment 20 does not circulate in the control compartment 10 to protect the controller 1 which includes elements having high electrical potentials.

As a reminder, the control device 1 supplies the electrical energy to the electric motor 2. Since these components are in two separate compartments, it is necessary to electrically connect the control device 1 to the electric motor 2. To do this, a control device electrical connection 5 is mounted at the interface between the engine compartment 20 and the control compartment 10. The connection device 5 comprises a plurality of connection terminals 6 of the control device 1 connected to a connection block 7 of the electric motor 2. In this example, the connection terminals 6 are three in number and are respectively received in three openings 74 of the connection block 7.

Referring to Figure 2, each terminal 6 comprises a conductive rod 61 mounted in an orifice of the wall 4, the ends of the rod 61 being projecting respectively in the control compartments 10 and motor 20. In this example, the connection terminals 6 extend substantially parallel to the axis U of the motor 2. To prevent the formation of an electric arc between the conducting rod 61 and the material of the wall 4, each conducting rod 61 is mounted in an insulating plug 62, preferably ceramic, which is secured to the wall 4. For example, the plug 62 of each terminal 6 is crimped on the wall 4 and is made of ceramic.40 7 The connection block 7 is, in this example, a conventional connection block as manufactured industrially by the company TYCO ELECTRONICS. In known manner, the connection block 7 comprises a plastic body 71 of generally parallelepipedal shape which extends in length in the direction X, in width in the direction Y and in height in the direction Z as shown in FIGS. 5. The connection block 7 further comprises connection elements 72 mounted in the interior volumes of the body 71 which are electrically connected to the motor 2 by electrical cables 73 as shown in FIG. 3. The connection block 7 is removable from the connection terminals 6 mounted in the wall 4 so as to allow the mounting of the compressor 9 in a modular manner.

Subsequently, the terms "back" and "front" are defined relative to the X axis which is oriented from back to front in FIGS. 4 and 5. Similarly, the terms "low" and "low" are are defined with respect to the Y axis which is oriented from bottom to top in Figures 4 and 5.

As illustrated in FIG. 5, the rear portion of the body 71 of the connection block 7 is bevelled so as to have a smaller width at its rear end than at its center. As illustrated in FIG. 6A, the rear face F1 of the body 71 of the connection block 7 is open to allow the introduction of three connection elements 72. These connection elements 72 are known to those skilled in the art and will not be detailed further. The front face F2 of the body 71 of the connection block 7, for its part, comprises a plurality of openings 76 used during the molding of the body 71 of the connection block 7 as shown in Figure 6B.

With reference to FIG. 5, to allow the connection of a terminal 6 to a connection element 72, the upper face F3 of the body comprises connection openings 74 of large diameter, of the order of 3 mm, preferably 3.7 mm, as well as mounting openings 75, of small diameter, of the order of 2 mm, to allow the assembly / disassembly of the connection elements 72 of the body 71.

Given all the openings formed in the body 71 of the connection block 7, there are many paths through which an electric arc can be formed between the wall 4 whose electrical potential is zero and between an electrical element of high potential. of the connecting device 5.

In order to increase the electrical insulation of the connection device 5, the invention proposes to mount an electrical insulation element 8 removably on the connection block 7 and to arrange it between the wall 4 and the connection block 7.

In this example, the electrical insulation element 8 is in the form of a cover 8. It goes without saying that the electrically insulating element 8 can be in various forms, for example 8 in the form of an insulation block, etc. For the sake of clarity, only the term "hood" is used in the following description.

With reference to FIG. 4, the insulation cover 8 mainly comprises an interface partition 81 placed between the wall 4 and the connection block 7 which covers the upper face F3 of the body 71, a rear wall 83 arranged to close the rear face F1 of the body 71 and a front wall 82 closing the front openings 76 of the front part of the body 71. In this example, the insulation cover 8 is in one piece and is adapted to elastically deform during assembly, the insulation cover 8 is then maintained on the connection block 7 by spring effect. In particular, the interface partition 81 is elastic so as to be deformable when it is mounted on the body of the connection block 7 and thus conform to the shape of the body 71 of the connection block 7.

The interface partition 81 is flat and extends in the plane (X, Y). Only through openings 85 are formed in the partition 81 to correspond with the connection openings 74 of the body 71. Thus, the interface partition 81 makes it possible to close the mounting openings 75 of the upper face F3 of the body 71 and avoid arcing. The diameter of the through openings 85 is substantially equal to that of the insulating plugs 62 of the connection terminals 6 in order to allow a complementary fit of shapes which makes it possible, on the one hand, to increase the electrical insulation during the connection 5 and, on the other hand, to prevent the penetration of liquid into the body 71 of the connection block 7 via the connection openings 74.

By way of example, FIG. 9 represents, by a continuous line, a potential path of an electric arc C1 which would be formed between the wall 4 and a connection block 7 without an insulating cover 8. As represented in this figure, a The electric arc Cl could be formed between a connection element 72 and the wall 4 via a mounting opening 75. The insulation cover 8 prevents the formation of such an arc by closing such a mounting opening 75.

Still with reference to FIG. 9, a dashed line represents the potential path of an electric arc C2 that would form between the wall 4 and a connection block 7 with an insulation cover 8. This electric arc C2 must circumvent, on the one hand, the isolation plug 62 and, on the other hand, the interface partition 81 and the front wall 82 of the cover 8 to connect a connection element 72 and the wall 4 via a connection opening 74. A such C2 path is very long and ensures effective electrical insulation preventing arc formation. Such an insulation cover 8 also makes it possible to avoid arcing between the conductive rods 61 since the insulating cover 8 makes it possible to enclose the ceramic insulating plugs 62 as shown in FIG. .

Referring now to FIG. 7A, the front partition 82 of the cover 8 is flat and extends in the plane (Y, Z), that is to say orthogonally to the interface partition 81. To strengthen the connection between the front partition 82 and the interface partition 81, the insulating cover 8 further comprises lateral partitions 87 of triangular shape which extend in the plane (X, Z). The front partition 82 makes it possible to close the openings 76 of the front face F3 of the body 71 and thus makes it possible to avoid the formation of an electric arc from the front openings 76.

The rear partition 83 of the cover 8 has a shape complementary to the rear part of the body 71 which is beveled (see Figure 5) so as to allow optimum cooperation between the connection block 7 and its cover 8. For this purpose , the rear partition 83 comprises mounting pins 86 which extend parallel to the plane (X, Y) and which are arranged to cooperate with the rear part of the connection block 7.

With reference to FIGS. 7A and 7B, the rear partition 83 of the cover 8 makes it possible, on the one hand, to close the rear face F1 of the connection block and, on the other hand, to allow the passage of the connection cables 73 connected to the connecting elements 72 mounted in the body 71. For this purpose, the rear wall 83 comprises a guide sheath 84 extending along the X axis and which comprises three channels for respectively guiding the three connecting cables 73 connecting the three elements. connection 72.

In other words, the hood is generally in the form of a U in which the base of the U corresponds to the interface partition 81 while the branches of the U correspond to the front and rear walls 82 and 83.

Preferably, the insulating cover 8 comprises locking means 88 configured to allow mounting and disassembly of the cover 8 vis-à-vis the connection block 7. With reference to Figure 7B, the locking means are in the form of a lug 88 formed from the front wall 82 and projecting towards the inside of the cover 8. Due to its shape, the lug 88 is able to hook onto the connection block 7 by pulling Part of the flexibility of the interface partition 81. As will be detailed later, the combination of a lug 88 and a flexible interface partition 81 allows easy mounting of the cover 8 on the connection block 7 A method of mounting the cover 8 on the connection block 7 is detailed below with reference to FIGS. 8A-8F. Thus, in FIG. 8A, the connection cables 73 are first introduced into the channels of the guiding sheath 84 of the cover 8 from the rear. Then, the free ends of the connecting cables 73 are electrically connected to the connecting members 72 as shown in FIG. 8B. The connection elements 72 are then introduced into the body 71 from the rear face F1 and thus be positioned opposite the connection openings 75 of the upper face F3 of the body 71 (FIG. 8C).

Once the connection elements 72 are mounted in the body 71, the connection block 7 is introduced into the cover 8 by pulling the connecting cables 73 backwards so as to make the rear portion of the body 71 cooperate with the rear wall 83 of the hood 8 as shown in Figure 8D. In this position, the lug 88 of the front portion 82 of the cover 8 prevents the cooperation of the cover 8 with the connection block 7. To finalize the assembly, with reference to FIG. 8E, the interface partition 81 of the cover 8 is bent (see arrow D) so that the connection block 7 avoids the lug 88 and allows the contacting of the upper face F3 of the body 71 with the interface partition 81. Taking advantage of the flexibility of the interface partition 81, it is then possible to position the lug 88 on the connection block 7 to lock it in position. Such a mounting method is simple to implement.

To remove the cover 8, an operator can simply pull the partition 82 outwardly of the cover 8 to bend the cover 8 and thus release the lug 88. The connection block 7 can then simply be removed from its cover 8.

In the end, only the connection openings 75 of the connection block 7 are visible, the other openings being closed by the insulation cover 8. This advantageously makes it possible to increase the electrical insulation of the electrical connection by increasing only slightly the In fact, the cover 8 advantageously forms an insulating skin of small thickness around the connection block 7.

During the electrical connection, the connection block 7 (on which the insulating cover 8 is mounted) is connected to the connection terminals 6 by introducing the conductive rods 61 of the connection terminals 6 into the connection openings 75 of the body 71 ( via the orifices 85 of the cover 8) in order to come into contact with the connection elements 72.

In a particular embodiment, with reference to FIGS. 10 and 11, a seal 91 is threaded onto each connecting rod 61 projecting into the engine compartment 20 so as to bear against the ceramic plug 62 of said terminal In the position of use, the seal 91 extends in a plane transverse to the axis in which the connection terminal 6 extends as shown in FIGS. 10 and 11. Such a seal sealing 91, preferably annular, improves the sealing of the connection between a connecting rod 61 and the connection block 7 by preventing any penetration of liquid into the connection block 7 via a connection opening 74.

In addition, because of its thickness, the seal 91 makes it possible to increase the insulation distance, on the one hand, between the wall 4 and the connection block 7 and, on the other hand, between two rods of 61. In this example, each seal 91 is made of rubber but it goes without saying that any other elastic material compatible with the environment of the compressor could be suitable (HNBR, etc.).

Claims (14)

REVENDICATIONS1. A compressor (9) comprising: a motor compartment (20) housing an electric motor (2) which drives a compression mechanism (3), a control compartment (10) housing a control device (1) of the electric motor (2) ), the engine compartment (20) and the control compartment (10) being separated by a wall (4), an electrical connecting device (5) connecting the control device (1) and the electric motor (2), the electrical connection device (5) comprising: i. at least one connection terminal (6) of the control device (1), mounted through the wall (4) and projecting into the engine compartment (20), and ii. a connection block (7) of the electric motor (2), mounted in the engine compartment (20) and arranged to releasably cooperate with said connection terminal (6), characterized in that the electrical connection device (5) ) comprises at least one electrically insulating element (8) removably mounted on the connection block (7) and disposed between the wall (4) and the connection block (7). 2. The compressor of claim 1, wherein the connection block (7) comprises a body (71) in which is mounted at least one electrical connection element (72) adapted to cooperate with the connection terminal (6). 25 3. The compressor according to claim 2, wherein, the body (71) comprising at least one opening (75, 76, F1), the electrically insulating element (8) is mounted on the connection block (7) so as to closing said opening (75, 76, F1). 4. The compressor according to one of claims 2 to 3, wherein the electrically insulating element (8) comprising an interface partition (81) placed between the wall (4) and the body (71) of the block of connection (7), said interface partition (81) comprises at least one through opening (85) in which the connection terminal (6) extends. The compressor of claim 4, wherein the interface partition (81) is resilient to allow mounting on the body (71) of the connection block (7). The compressor according to one of claims 2 to 5, wherein, the connection block (7) comprising at least one connection cable (73) electrically connecting the electrical connection element (72) to the motor (2), the electrically insulating member (8) comprises a guide sleeve (84) in which said cable (73) is mounted. 10 15 20 7. The compressor according to one of claims 2 to 6, wherein, the connection block (7) comprising an open rear portion (F1) from which extends a connection cable (73) electrically connecting the connection element. electrical (72) motor (2), the electrically insulating member (8) comprises a rear wall (83) arranged to close the rear part (F1) of the connection block (7). 8. The compressor of claim 7, wherein the rear wall (83) of the electrically insulating member (8) has a shape complementary to the rear portion (7F) of the connection block (7). The compressor of claims 6 to 8, wherein the guide sheath (84) is formed from the rear wall (83). 10. The compressor according to one of claims 2 to 9, wherein, the connection block (7) comprising a front portion (F2) opposite to its rear portion (F1), the front portion (F2) comprising at least one opening. before (76), the electrically insulating member (8) comprises a front partition (82) closing said front opening (76). 11. The compressor according to one of claims 1 to 10, wherein the electrically insulating element (8) is made of plastic and preferably monobloc. Compressor according to one of Claims 1 to 11, in which the electrically insulating element (8) comprises locking means (88) configured to allow the mounting and dismounting of the electrically insulating element (8) on the connection block (7). 13. Compressor according to one of claims 1 to 12, wherein the locking means (88) are in the form of a lug. Compressor according to one of Claims 1 to 13, in which the connection terminal (6) of the control device (1) comprises a seal (91).