FR3010461A1 - COMPRESSOR RELEASE PLATE AND COMPRESSOR - Google Patents

Abstract

The invention relates to a force recovery plate (70) of a compressor (7), in particular an electric compressor, comprising a compression mechanism (3) and a drive motor (2) of said compression mechanism (3), said plate (70) being intended to protect a housing (20) delimiting a compartment housing said motor (2) of the compressor (7) with a stress exerted by said compression mechanism (3), characterized in that said plate ( 70) comprises at least one receiving means (71) arranged to be traversed by a fixing device (5) for securing the plate (70), the housing (20) of the engine compartment and a housing (10) housing an organ controlling (1) the compressor (7). The invention also relates to an assembly comprising the housing (20) of the engine compartment, the housing (10) housing the control member (1) of the compressor (7), the fixing device (5) and the said plate (70). . The invention also relates to a compressor (7) comprising such an assembly.

Description

The technical sector of the present invention is that of compressors, in particular electric compressors, for example for the circulation of a refrigerant fluid inside a vehicle air conditioning circuit.

An electric compressor typically comprises a compression mechanism, driven by an electric motor, to pressurize the coolant in the air conditioning circuit. To power the electric motor, the compressor further comprises an inverter for converting the available current into a current suitable for the compressor motor. By way of example, the inverter is adapted to convert a direct current into a three-phase alternating current. Such compressors are known in the literature. They comprise a compression box in which is mounted the compression mechanism, a motor housing in which is mounted the electric motor and an inverter housing in which the inverter is mounted. To connect the housings together, the outer surfaces of the housings comprise fastening flanges adapted to allow the passage of fastening screws. The fixing screws thus make it possible to secure the fixing flange of the motor housing to that of the inverter housing. The mounting flanges protrude from the outer surfaces of the housings which increases the size of the electric compressor. In addition, the projecting mounting flanges can come into contact with other components of the vehicle and damage them which has a disadvantage.

To eliminate at least some of these drawbacks, it has been proposed to attach the housings to each other using long length fixing screws extending inside the motor housing. Thus fastening screws secures the motor housing with the housing of the inverter. They go through the engine compartment for housing in the housing of the inverter. The screw heads then bear against the motor housing. These screws must guarantee the tightness of the assembly and are therefore screwed with a large tightening torque. High stresses are thus exerted under the screw head and may cause, on tightening or in use, a plastic deformation of the contact zone resulting in a loss of clamping of the assembly. It is known to use washers disposed between the screw heads and the engine compartment to limit these deformations.

The use of washers, however, causes disadvantages such as the multiplication of the number of assembly parts, the difficulty of assembly or the risk of losses of the washers inside or outside the case.

The invention aims to improve the situation and relates to a stress recovery plate of a compressor, including an electric compressor comprising a compression mechanism and a drive motor of said compression mechanism, said plate being intended to protect a housing delimiting a compartment housing said compressor motor with a stress exerted by said compression mechanism, characterized in that said plate comprises at least one receiving means arranged to be traversed by a fixing device for securing the plate, the housing of the compartment motor and a housing housing a controller of the compressor.

Thus, thanks to the invention, the use of washers is no longer necessary since one uses a compressor element, the force recovery plate, to also receive the fixing device, so that it protects the zone of the housing against which the fastening device exerts a constraint, so as to ensure the tightening of the assembly and the integrity of the compressor.

According to one aspect of the invention, said receiving means comprises an orifice intended to be traversed by said fixing device. According to an exemplary embodiment of the invention, the plate comprises a central body. Advantageously, said receiving means is an ear projecting laterally, in particular radially, with respect to said central body. Advantageously, said ear is provided with said orifice.

According to one aspect of the invention, the central body integrates said receiving means. Advantageously, said plate is made of steel. The fixing device itself being made of steel reduces the friction between the fixing device and the plate, in particular with respect to the friction between the fixing device and an aluminum element such as the case. Indeed, the friction between aluminum and steel is greater than that between two steel elements. This further reduces the risk of deformation of the zone of the box receiving the fixing device so that the reliability of the tightening of the compressor is improved. According to one aspect of the invention, the plate comprises a damping means for damping a deformation of the receiving means. Thus, if the receiving means undergoes deformation during clamping of the fastener on the plate, this deformation will be damped by the damping means and will therefore not be transmitted to the rest of the plate. Since the clearance between the various parts of the compressor close to the plate is very small, it is important that the plate is not deformed, in particular so that the assembly of the various elements of the compressor can be achieved and that the plate retains its recovery function. 'efforts. According to an exemplary embodiment, the damping means is a light forming connecting lugs between said receiving means and the central body of the plate. Advantageously, said light is substantially in the shape of a circular arc. Advantageously, the light is at the periphery of the receiving means. The damping means is located, for example, between the ears and the central body of the plate. Said light and said corresponding orifice may in particular be concentric. The invention also relates to an assembly comprising a housing of a compartment housing a drive motor of a compressor, in particular an electric compressor, a housing housing a control member of the compressor, a fixing device and a force recovery plate. as described above, the fastening device solidarisant them plate, the housing housing the motor and the housing housing the control member.

According to one aspect of the invention, the fixing device is a screw comprising a screw head in contact with said receiving means. The invention also relates to a compressor comprising an assembly as described above. It may in particular be an electric compressor, said drive motor then being an electric motor. 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 an axial sectional view of an electric compressor according to FIG. invention; FIG. 2 is a view similar to FIG. 1 showing an area under a screw head of a device for fixing the electric compressor in more detail; FIG. 3 is a front view and a force recovery plate of the invention, and FIG. 4 is a view similar to FIG. 3 showing an alternative embodiment of the invention.

An electric compressor 7 according to the invention will be presented later. It goes without saying that the electric compressor can be used for the compression of fluids of different kinds and that the electric compressor 7 can be mounted on any type of device both mobile and fixed. It is however more particularly intended for the circulation of a refrigerant inside an air conditioning circuit of a motor vehicle. With reference to FIG. 1, the electric compressor 7 according to the invention comprises a compression mechanism 3, an electric motor 2 for driving the compression mechanism 3, said electric motor 2 having an axis of rotation X and an inverter 1 d supplying said electric motor 2. The inverter 1 is mounted in an inverter housing 10 and the compression mechanism 3 is mounted in a compression housing 30. The electric motor 2 is mounted in a motor housing 20 extending longitudinally along the axis of rotation X. The motor housing 20 is made of aluminum or aluminum alloy of hollow circular shape comprising a peripheral wall which delimits an internal volume terminated on one side by a first end 20P and the another by a second end 20S. These two ends 20P, 20S are open before mounting the other components of the compressor 7. The first end 20P is connected to the inverter housing 10 by a plurality of fasteners 5 while the second end 20S, opposite the first end 20P relative to the electric motor 2, is connected to the compression casing 30 by a plurality of securing devices 6. Each fixing device 5 is, in this example, in the form of a fixing screw 50 including a part of the body 51 is threaded and having a screw head 52. In the same way, the securing devices 6 are here in the form of a fixing screw 60, a portion of the body 61 is threaded and having a screw head 62.

The compression mechanism 3 may be of the spiral compression type (Scroll in English) or the paddle type or the piston type, these examples being given for illustrative purposes without limiting the scope of the invention. The inverter 1 converts a direct current from the vehicle, in particular the battery, into a sinusoidal current of variable frequency supplying the electric motor 2. As shown in FIG. 1, the engine 2 comprises a stator 2A circular peripheral mounted integrally in the motor housing 20 and a rotor 2B integral with the motor shaft 2 which rotates to drive the compressor.

In other words, the stator 2A is fixedly placed around the rotor 2B. The circular shape of the stator 2A is advantageous because it limits the magnetic losses and optimizes the efficiency of the motor 2.

The motor housing 20 includes a coolant inlet (not shown) which opens between the electric motor 2 and the inverter housing 10 to introduce coolant into the motor housing 20 so as to flow to through the engine 2 before entering the compression mechanism. The coolant can thus cool the engine. The second end 20S of the motor housing 20 is in the form of a transverse plane base as shown in the figure. The base comprises, in this example, a plurality of threads 26 formed longitudinally in the base for receiving the securing devices 6 of the compression box 30 to the motor housing 20. The securing devices 6 extend internally in the housing The head 62 of the securing devices abuts against a transverse face of the compression casing 30. The end of the body 61 of the securing devices is threaded so as to be screwed into the tapping 26 of the base. The second end 20S also includes openings 27 in which the fasteners 5 are inserted. These latter extend inside the housing of the motor and are housed in threads 29 of the housing of the inverter 10 so as to secure the housing of the motor 20 with that of the inverter. The tapped holes 29 of the housing of the inverter 10 extend longitudinally to receive the fixing devices of the motor housing 20 to the housing of the inverter 10. The fastening devices 5 extend in the motor housing 20. end of the body 51 of the fasteners is threaded so as to be screwed into the tapping 29 of the housing of the inverter 10. The pressure in the compressor housing is important and exerts a force against the compression mechanism towards the housing of the 20. In order to protect the motor housing 20 from these stresses exerted by the compression mechanism 3, the electric compressor 7 comprises a recovery plate 70 acting as a shield. This plate is located on the engine housing and in particular on the base, that is to say between the compression mechanism 3 and the housing of the engine 20. The force recovery plate is, for example, in steel. According to the invention, the force recovery plate 70 of the invention also comprises, as illustrated in FIG. 2, receiving means 71 of the fastening devices 5. These receiving means 71 are traversed by the fixing devices 5. They are therefore located between the screw heads 52 of the fasteners 5 and the base 28, that is to say between the screw heads 52 and the housing of the motor 20. In this way, the means of receptions also protect the motor housing from the stresses exerted by the fixing devices 5. The plate 70 of the invention thus has, in addition to its function of protecting the motor housing from the stresses exerted by the compression mechanism, a function of receiving fasteners and protection of the motor housing of these fasteners.

Thus, the housing of the inverter 10, the housing of the motor 20 and the plate 70 are secured together by the fixing device 5 of the housing of the motor 20 and the housing of the inverter 10. These elements, when they are secured between them, form with the fixing device 5, an assembly according to the invention.

As illustrated in FIGS. 3 and 4, the reception means 71 are here ears 71. They each have an orifice 72 traversed by a fixing device.

The plate comprises a central body 73, in the form of a ring, having an opening 74 centered with respect to the axis of rotation of the motor. This opening receives the motor shaft. It is the central body that receives the compression mechanism. The receiving means 71 project from the central body of the plate, that is to say they project laterally from the central body 73. More particularly, said receiving means 71 project radially out of shape. ring of the plate, towards the outside thereof. In another configuration, the receiving means 71 could also be part of the central body of the plate. In another configuration, some of the receiving means 71 are projecting relative to the central body of the plate while other receiving means 71 are integral with the central body of the plate. The example illustrated in FIG. 4 presents an aspect of the invention according to which the plate 70 comprises damping means 75. These damping means make it possible to damp a deformation of the reception means 71 during the fixing of the means. fixing against the plate. Indeed, the tightening torque being important, the receiving means 71 may be deformed by the stress exerted by the fixing device. Thanks to the invention, this deformation will not be transmitted to the central body 73 of the plate, that is to say the part of the plate hosting the compression mechanism. The damping means 75 are here made by means of lights made in the load-bearing plate, so that the receiving means 71 is connected to the central body only by means of connecting lugs 76. lights are, for example, in an arc, centered on the orifice 72, and in particular located at the periphery of the receiving means 71. They are in particular between the receiving means 71 and the central body 73 of the plate so as to avoid as much as possible that the deformations undergone by the reception means 71 are transmitted to the central body. Thus, only the connecting lugs 76 connecting the receiving means 71 and the central body 73 can receive the clamping force and be deformed accordingly. Although described in the context of an electric compressor, the invention can also be applied to other types of compressors.

Claims (12)

REVENDICATIONS1. Stress recovery plate (70) of a compressor (7), in particular electrical, comprising a compression mechanism (3) and a drive motor (2) of said compression mechanism (3), said plate (70) being intended to protect a housing (20) delimiting a compartment housing said compressor motor (2) from a stress exerted by said compression mechanism (3), characterized in that said plate (70) comprises at least receiving means (71) arranged to be traversed by a fastening device (5) for securing the plate (70), the housing (20) of the engine compartment and a housing (10) housing a control member (1) compressor (7). The force recovery plate (70) according to claim 1, wherein said receiving means (71) comprises an orifice (72) to be traversed by said attachment device (5). The force recovery plate (70) according to claim 1 or 2, wherein the plate (70) comprises a central body (73). The force recovery plate (70) according to claim 3, wherein said receiving means (71) is an ear protruding laterally with respect to said central body (73). The force recovery plate (70) according to claim 3 or 4, wherein the central body (73) integrates said receiving means (71). 6. force-recovery plate (70) according to any one of claims 3 to 5, comprising a damping means (75) for damping a deformation of the receiving means (71). The force recovery plate (70) according to claim 6, wherein the damping means (75) is a light forming link tabs (76) between said receiving means (71) and the central body ( 73) of the plate. The force recovery plate (70) according to claim 7, wherein the light is substantially arcuate in shape. The force recovery plate (70) according to any one of the preceding claims, wherein said plate (70) is made of steel. 10. An assembly comprising a housing (20) of a compartment housing a driving motor (2) of a compressor (7), in particular an electric compressor, a housing (10) housing a control member (1) of the compressor (7). ), a fixing device (5) and a force recovery plate (70) according to any one of the preceding claims, the fastening device (5) solidarisant between them the plate (70), the housing (20) housing the motor (2) and the housing (10) housing the control member (1). An assembly according to claim 10, wherein the securing device (5) is a screw (50) comprising a screw head (52) in contact with said receiving means (71). 12. Compressor (7), especially electrical, comprising an assembly according to claim 10 or 11.