WO2011157410A1

WO2011157410A1 - Method of assembling an electrical compressor

Info

Publication number: WO2011157410A1
Application number: PCT/EP2011/002942
Authority: WO
Inventors: Imed Guitari
Original assignee: Valeo Japan Co, Ltd
Priority date: 2010-06-15
Filing date: 2011-06-15
Publication date: 2011-12-22
Also published as: FR2961269A1; FR2961269B1

Abstract

The invention relates to a method of assembling an electrical compressor, comprising the following steps: a first subassembly is assembled by mounting a rotor of an electric motor in a main casing of said compressor; a second subassembly is assembled by fastening a stator of said electric motor to a secondary casing of said compressor, said secondary casing comprising a device for controlling said electric motor; and the second subassembly is inserted into the first subassembly. Application to motor vehicles.

Description

METHOD FOR ASSEMBLING AN ELECTRIC 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.

Compressors driven by a dedicated electric motor exist in the literature. An example of such a compressor is disclosed in JP2009-287492 which shows a compressor using an electric motor in which the rotor is installed externally and peripherally to the stator. With this structure, a part of the compressor comprising an electrical device and the electric motor as a whole can be separated from the rest of the compressor.

However, such separation is problematic because this part of the compressor involves both electrical components (motor and control device) and mechanical components (shaft and bearing). The assembly of mechanical components, and in particular the mounting of the bearing in the vicinity of electrical components, creates mechanical forces on the electrical components that must be avoided in order to meet the reliability constraints of the electrical components. .

Another disadvantage lies in the fact that the assembly of the compressor according to the prior art is not suitable when the electric motor is of the type to rotor internal to the stator.

Another disadvantage of the state of the art cited above is that the part comprising the electrical device and the electric motor as a whole are not checked or tested prior to mounting this part on the rest of the compressor.

The object of the present invention is therefore to solve the disadvantages described above mainly by separating the compressor into two subsets, a first subset comprising a support receiving the electrical components and on which no mechanical stress is operated, and a second subset receiving the mechanical components.

The invention therefore relates to a method of assembling an electric compressor comprising the following steps:

assembling a first subassembly by mounting a rotor of an electric motor in a main casing of said compressor,

assembling a second subassembly by solidifying a stator of said electric motor on a secondary housing of said compressor, said secondary housing comprising a device for controlling said electric motor,

- insert the second subset into the first subset.

According to a first characteristic of the invention, prior to the insertion step of the second subset in the first subset, an electrical verification step is performed.

According to a second characteristic of the invention, the first subassembly is assembled beforehand according to the following steps:

- It forces said rotor on a compressor shaft,

- Forcibly engages a first rotation means in a transverse plate of the main housing,

the shaft is force-fitted into the first rotation means.

According to another characteristic of the invention, prior to the force-fitting step of the rotor on the compressor shaft, a second rotation means is mounted at one end of the shaft.

According to another characteristic of the invention, the second subassembly is assembled beforehand according to the following steps: - An electrical connector is mounted on the secondary housing, said connector passing through a bottom constituting the secondary housing,

the control device is secured to the secondary housing,

- The stator is secured to the secondary housing.

According to yet another characteristic of the invention, prior to the step of mounting the electrical connector through the secondary housing, a second rotation means is engaged in a protrusion formed on the secondary housing.

Advantageously, the method provides a step of welding the stator supply conductors on the electrical connector.

Advantageously, the stator is secured to the secondary housing by press fitting.

Finally, the method provides that the stator is secured to the secondary housing by at least one screw passing through the outer periphery of the stator.

A first advantage of the invention lies in the possibility of assembling the first subset comprising the mechanical components of a specialist in the mechanical field, for example a compressor operator, separately from the assembly of the second subset of so as not to create mechanical stress on electrical components.

Another advantage according to the invention lies in the possibility of assembling the second subassembly receiving the electrical components from a specialist in the electrical field, for example the supplier of the electrical control device, and to ensure the verification thereof before its mounting on the first subassembly, which avoids repelling a fully assembled compressor.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the description given below as an indication in relation to drawings in which:

FIG 1 is a sectional view of the first subassembly and the second subassembly according to the invention,

FIG. 2 is a sectional view of the compressor when the second subassembly is inserted into the first subassembly.

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

FIG. 1 illustrates a compressor comprising a first subassembly 1 distinct and separated from a second subassembly 2.

The first subassembly 1 mainly incorporates components of a mechanical nature. This first subassembly consists of a main housing 5 which delimits the outer periphery of the compressor and thus its radial space with respect to an axis A.

This main casing 5 is an aluminum or aluminum alloy piece of hollow circular shape comprising a peripheral wall which delimits an internal volume 6 terminated on one side by a first end 14 and on the other by a second end 15 These two ends 14 and 15 are open before final assembly of the compressor, in particular before an insertion of the second subassembly 2 into the first subassembly 1.

The first end 14 of the housing 5 is closed by a compression mechanism (not shown) which is of the type of compression screw (Scroll in English) or of the vane type or the piston type, these examples being given for illustrative purposes. without limiting the scope of the invention.

The compression mechanism comprises fixed parts and moving parts, the latter being rotated by a shaft 4 which extends longitudinally along the axis A. This shaft 4 therefore extends in the central part of the compressor, substantially at center of the main housing 5.

The second end 15 is closed by a secondary housing 16 constituting the second subassembly 2 and will be detailed later.

A plate 7 extends transversely in the internal volume 6 in a direction perpendicular to the axis A so as to separate the internal volume 6 into a part dedicated to the compression mechanism and a part dedicated to an electric motor consisting of a stator 3 and a rotor 8. The plate 7 has at least one passage 9 which allows the refrigerant fluid to flow from the portion dedicated to the electric motor to the compression mechanism. It will be particularly noted that a plurality of passages 9 can be made through the plate 7 at the junction between this plate 7 and the main casing 5, that is to say at the outer periphery of the plate 7. tray 7 is a piece from molding with the main housing thus forming a one-piece piece of aluminum or aluminum alloy. Alternatively, the plate 7 is a part manufactured separately from the housing 5 and insert into the latter during assembly.

This plate 7 comprises an outer wall 10 facing the compression mechanism, and this outer wall delimits a housing 11 for receiving a first rotation means 12. This housing takes the form of a cylindrical well whose opening opens on the side of the compression mechanism. The housing 11 receives the first rotation means 12 which takes the form in this embodiment of a cylindrical rolling bearing with a single row of balls. Alternatively, the first rotation means 12 may be a double row cylindrical ball bearing having an axis of rotation coinciding with the axis A of the shaft 4.

In this case, an outer ring of the bearing is mounted or force-fitted in the housing 11. The shaft 4 is in turn pressed to

15 forces in an inner ring of the same bearing. Alternatively, the shaft 4 is freely mounted in the inner ring of this bearing and the axial displacement of the shaft 4 is limited by a circlip or by a shoulder formed on the shaft which bears on the inner ring of the bearing.

The plate 7 also comprises an inner wall 13 opposite to the wall

10 external, that is to say facing the rotor 8 of the electric motor. The latter comprises the rotor 8 force-fitted on the shaft 4 and the stator 3 which is disposed at the outer periphery of the rotor 8. It is thus clear that the electric motor is of the central rotor type rotatably mounted in an internal and central volume. of the stator.

The compressor according to the invention comprises a second rotation means

38. This second rotation means 38 is mounted tightly or freely on a free end of the shaft 4. It will be particularly noted that this free end of the shaft 4 is flush with a main face of the second rotation means 38, the latter in the form of a single-row ball bearing, but it may also be a double-row ball bearing.

The second end 15 of the main housing 5 is delimited by a docking edge 17 embodied by the edge of the main housing 15. This docking edge comprises at least two centering means 18 whose function is to align the second under -set 2 on the first subset 1 during of the final assembly.

Fastening points 19 in the form of at least four internally distributed threads on the periphery of the main housing 5 are formed in the docking edge 17. These threads and the associated screws referenced 37 ensure the assembly and the joining of the first subset 1 with the second subset 2.

The first subassembly 1 thus consists of a main housing 5, a plate 7 made unitarily with the main housing 5 or distinctly from the latter, a rotor 8 of an electric motor integral with a rotation shaft 4 held on the plate 7 by means of rotation 12.

The assembly or assembly of this first subassembly is therefore carried out by a compressor operator who performs the assembly steps in the following order:

- The rotor 8 of the electric motor is force-fitted onto the shaft 4 so as to guarantee the mechanical connection between these two parts and thus ensure that the rotation of the rotor 8 causes the shaft 4 to rotate. without relative displacement of one relative to the other. Press fitting is practiced by heating the rotor so that it expands to facilitate insertion of the shaft. Once cooled, the previously heated rotor shrinks and guarantees the mechanical connection. Alternatively, the press fit can be done cold.

the first rotating means 12 is engaged or forced into the housing 11 made in the outer face 10 of the plate 7, and

- An end of the shaft 4 is engaged by force for the compression mechanism in the first rotation means 12 so as to obtain a mechanical connection between the shaft 4 and the inner ring of the bearing constituting the first rotation means.

At this point, the first subassembly 1 is manufactured and can be stored until it is used for final assembly.

In a complementary manner, it is possible to perform a step of mounting the second rotation means 38 on the other end of the shaft 4. This operation is carried out by a tight or free assembly of an inner ring constituting the bearing forming the second rotation means 38 on the end of the shaft 4 so that the edge of the shaft bordering its end is flush with the main face of the bearing, that is to say that facing the secondary housing 16.

The second subassembly 2 comprises the secondary housing 16 made of aluminum or aluminum alloy. This secondary housing 16 serves as a support or receptacle for the electrical components of the compressor.

The secondary housing 16 takes the form of a bowl whose bottom 20 has a first face 21 facing the plate 7. This first face 21 comprises an outer edge 22 in which holes 23 are formed through which screws 37 pass through. for cooperating with the fixing points 19. The receiving orifices 24 are also machined in the outer edge 22 to receive the centering means 18.

The first face 21 also comprises an intermediate edge 25 which takes the form of an outgrowth which emerges from the first face towards the

7 and the front view of which corresponds to a circular ring, this ring being interruptable by angular sector so as to form a plurality of excrescences. The intermediate edge 25 comprises a zone 26 which receives a first lateral blank 27 of the stator 3. The zone takes the form of a shoulder delimiting a cavity in which the lateral blank 27 is installed.

In the example of FIG. 1, the stator is mechanically fastened to the secondary housing 16. This can be achieved by means of at least two fastening screws 28 or by force-fitting the stator in the zone 26. It will be particularly noted that these screws are installed at the outer periphery of the stator 3, that is to say behind one of the stator teeth so as not to affect

The flux lines of the magnetic field generated by the stator 3. In other words, the coils 29 constituting the stator are inscribed in a circle of smaller diameter than that defined by the fixing screws 28.

The first face 21 further comprises a tubular protrusion 30 which opens out from this face towards the plate 7. This tubular protrusion 30

30 receives the second rotation means 38, in particular the outer ring of the bearing. When the second rotation means 38 is not mounted with the sub-assembly 1, the invention provides that this second rotation means 38 is mounted on the second subassembly, for example on the secondary housing 16 in the tubular protrusion 30 provided for this purpose on the first face 21 of the bottom 20. In this case, the second rotation means 38 is fitted into the tubular protrusion 30 before mounting the electrical components, in particular before mounting the device 33 and alternatively before the fastening of the stator 3 on the secondary housing 16.

The secondary housing 16 comprises a second face 31 opposite the first face 21, that is to say facing the outside of the compressor. A circumferential edge 32 is placed perpendicular to the bottom 20 and together defines a receiving zone of a control circuit 33 of the electric motor. This control circuit 33 is in this case an inverter (inverter in English) transforming a continuous-phase single-phase voltage from the vehicle into a three-phase voltage of sinusoidal shape and preferably variable frequency powering the electric motor.

The bottom 20 of the secondary housing 16 has a penetration 34 which opens on one side on the first face 21 and the other on the second face 31. This passage 34 receives an electrical connector 35, preferably sealed, electrically connected to the device The bushing 34 extends along an axis which is contained in a thickness of the stator. Such an arrangement makes it possible to electrically connect the electrical connector 35 to the conductors 36 by welding, guaranteeing perfect electrical continuity and simplicity of assembly. Alternatively, the connection between the electrical connector 35 and the conductors 36 can be effected by means of an electrical connection connector.

The second subassembly 2 thus consists, independently of the first subassembly 1, of a secondary housing 16 supporting the second rotation means 38, the stator 3 of the electric motor intended to receive at its center the rotor 8 mounted on the first subassembly 1 and a control device 33 of the electric motor.

The assembly or assembly of this second subassembly is therefore performed according to the following assembly steps:

in a first step, the second rotation means 38 is mounted forcibly inside the tubular protuberance 30 formed on one face of the secondary casing 16, in a second step, the connector 35 is mounted in the passage 34 in a sealed manner so that the refrigerant does not circulate from the internal volume 6 to the control device 33, in a third step, the control device 33 of the 5 electric motor on the second face 31 of the bottom 20 forming the secondary housing 16, and electrically connecting an electronic card constituting the control device 33 to the connector 35,

in a fourth step, the stator 3 is secured to the first face 21 of the bottom 20 via the intermediate edge 25 by means of the fixing screws 28 or mounting or force-fitting of the stator on the intermediate edge 25.

Note that it is important to do the step of mounting the second rotation means 38 before the third step so as not to create mechanical stress on the control device 33.

At this stage, the second subassembly 2 is manufactured and can be stored pending its use for final assembly with the first subassembly 1.

After assembly of the second subassembly 2 but before the insertion step, the control device 33 is programmed and the control device 33, the connector 35 and the internal continuity of the stator 3 are then checked or tested electrically. This verification step consists of simulating to test the proper functioning of the electronics constituting the control device 33 prior to the complete assembly of the compressor, which makes it possible to detect any malfunctions by analyzing the currents flowing in the stator coils. .

Figure 2 illustrates the compressor after the step of insertion of the second subset 2 in the first subset 1. Outside the compression mechanism, the compressor is assembled.

This insertion step is carried out by means of a translation along the axis A of the second subassembly 2. In doing so, the stator 3 enters the internal volume 6 of the main casing 5 by translating along the rotor 8. At the end of insertion, two alternatives are possible depending on where the second means of rotation 38 was previously installed.

In the case where the second rotation means 38 is mounted on the shaft 4 of the first subassembly 1, its insertion into the tubular protrusion intervenes in such a way as not to create a mechanical force on the bottom 20 of the secondary housing. 16, for example by a recovery of effort to the right of the tubular protrusion 30.

In the case where the second rotation means 38 is mounted the secondary housing 16 constituting the second subassembly 2, the shaft 4 is mounted tight or free in the inner ring of the bearing forming the second rotation means 38, the tight fitting not creating mechanical stress that could damage the control device 33.

The secondary housing 16 is aligned with the main housing 5 by means of the cooperation of the centering means 18 with the receiving orifices 24. Screws 37 mounted through the holes 23 are then screwed into the fastening points 19 so as to close. the end 15 of the main housing 5 by means of the secondary housing 16.

In the above description, the tight fitting or press fit corresponds to any containing piece and any contained piece where the container is smaller than the contents.

It is thus clear that the invention aims at assembling the first constituent subassembly of the electric compressor and, separately and separated before the insertion step, assembling the second subassembly.

Claims

A method of assembling an electric compressor comprising the following steps:

- assembling a first subassembly (1) by mounting a rotor (8) of an electric motor in a main housing (5) of said compressor,

- assembling a second subassembly (2) by solidifying a stator (3) of said electric motor on a secondary housing (16) of said compressor, said secondary housing (16) comprising a control device (33) of said electric motor,

inserting the second subset (2) in the first subset (1).

2. Method according to claim 1, wherein prior to the insertion step of the second subset (2) in the first subset (1), an electrical verification step is performed.

3. Method according to one of claims 1 or 2, wherein the first subset (1) is assembled beforehand according to the following steps:

- Forcing said rotor (8) on a shaft (4) of the compressor,

- mounting a first rotation means (12) in a transverse plate (7) of the main housing (5),

- Fit the shaft (4) in the first rotation means (12).

4. The method of claim 3, wherein prior to the step of press fitting of the rotor (8) on the shaft (4) of the compressor, a second rotation means (38) is mounted at an end of the tree (4).

5. Method according to one of claims 1 to 3, wherein the second subset (2) is assembled beforehand according to the following steps:

- mount an electrical connector (35) on the secondary housing (16),

- secure the control device (33) on the secondary housing (16),

- Secure the stator (3) on the secondary housing (16).

6. The method of claim 5, wherein prior to the step of mounting the electrical connector (35) on the secondary housing (16), a second rotation means (38) is mounted in a protrusion (30) formed on the secondary housing (16).

7. Method according to one of claims 5 or 6, wherein is performed a welding step of the stator supply conductors (3) on the electrical connector (35).

8. Method according to one of claims 5 or 7, wherein the stator (3) is secured to the secondary housing (16) by press fitting.

9. Method according to one of claims 5 or 7, wherein the stator (3) is secured to the secondary housing (16) by at least one screw (28) passing through the outer periphery of the stator (3).