Refrigerant compressor and use thereof in refrigerant circuit of vehicle

Abstract

The invention relates to a refrigerant compressor and to the use thereof in a refrigerant circuit of a vehicle, having a drive unit having a motor housing through which refrigerant can flow, which motor housing accommodates an electric motor having a rotatable shaft, and a compressor unit coupled to the drive unit, the compressor unit accommodates a scroll compressor that may be driven by a shaft, and the motor housing includes a housing wall exposed to sucked refrigerant; and an inverter unit coupled to the housing wall and housing an inverter circuit board forming a fluid-tight inverter housing, the inverter circuit board having a component arrangement formed by heat-generating electronic components, in particular at least one DC link capacitor and a plurality of electronic power switches, the heat-generating electronic components have at least two different component heights perpendicular to the inverter circuit board and are housed in a plurality of molded parts formed on the housing wall exposed to the refrigerant according to the component heights, the heat-generating electronic components being thermally coupled to the molded parts.

Description

Technical Field

[0001] The present invention relates to an electric refrigerant compressor for use in a refrigerant circuit. Background Art

[0002] In the electric refrigerant compressors often used in air conditioning systems and heat pump systems, the movable spiral (vortex) is driven by means of an electric motor. A fixed spiral eccentric to the movable spiral interacts with the movable spiral to form a plurality of chambers, so that the volume of the chamber is reduced due to the rotation of the movable spiral, which causes the refrigerant located therein to be compressed. The electric motor and the spiral are contained in a housing, which is hermetically sealed except for the opening for the refrigerant. The drive unit accommodating the electric motor can be contained in the motor housing, and the spiral can be contained in a separate compressor housing part, which are combined together during assembly. The motor electronics or inverter for supplying current to the electric motor is contained in an inverter housing that is separately combined with the motor housing. Typically, the housing wall of the motor housing forms a part of the inverter housing, so that a fluid-tight partition is formed between the motor housing and the inverter housing. Since the partition is exposed to the refrigerant inside the motor housing, the sucked refrigerant flows through the partition, so that the housing wall can be used as a radiator on the inverter housing side. It is therefore advantageous to arrange the power electronic components of the inverter, such as electronic switches, in particular transistors (IGBTs (insulated gate bipolar transistors), MOSFETs (metal oxide semiconductor field effect transistors)) and capacitors, in particular DC link capacitors, which generate power losses in the form of heat energy during operation, on the inverter housing side, preferably directly on the housing wall or partition exposed to the refrigerant. As a result, the electronic components can be protected by heat dissipation and ideal operating conditions can be created. However, to date, such an arrangement has not been possible for all heat-generating electronic components, since, for example, DC link capacitors require a relatively large installation space due to their size. Therefore, the DC link capacitors are arranged in the area of ​​the following electrical terminals: the electrical terminals are located outside the outer periphery of the motor housing or compressor housing for space reasons. This position is disadvantageous in terms of the necessary heat dissipation. Due to this arrangement, the electrical connections between the electronic components must cover relatively large distances, which makes it more difficult to optimize the design of, for example, the interaction between the DC link capacitors and the power switches, in particular IGBTs (insulated gate bipolar transistors) and MOSFETs (metal oxide semiconductor field effect transistors) according to the requirements of electromagnetic compatibility (EMC).

[0003] The concept of an inverter circuit board for an electric motor of a scroll compressor is known, in which the electronic components are selected according to their size or arrangement so that the height distribution of the electronic components is uniform. However, a disadvantage of such an arrangement of components is the increased area requirement, which requires larger dimensions of the inverter circuit board. Due to the planar extent, the electronic components to be cooled cannot all be arranged in the limited area of ​​the housing wall exposed to the refrigerant, which would lead to insufficient heat dissipation. A reduction in the distance between the components also does not lead to the desired result, because the risk of closely adjacent electronic components thermally influencing each other increases. Summary of the invention

[0004] It is therefore an object of the present invention to propose an electric refrigerant compressor in which an improved cooling of the heat-generating electronic components of the inverter, in particular the DC link capacitors and the electronic power switches, as well as an improvement in the EMC performance can be achieved.

[0005] This object is achieved by an electric refrigerant compressor having the features according to claim 1. Developments of the electric refrigerant compressor are specified in the dependent claims.

[0006] An electric refrigerant compressor is proposed, which is arranged to compress the refrigerant in an air conditioning system, in particular a vehicle air conditioning system. The electric refrigerant compressor has a drive unit and a compressor unit connected to the drive unit. The drive unit includes a motor housing through which the refrigerant can flow, and the motor housing accommodates an electric motor having a rotatable shaft. The compressor unit accommodates a scroll compressor that can be driven by the shaft. When combined together, the motor housing of the drive unit and the compressor unit form a fluid-tight compressor housing having a refrigerant inlet and a refrigerant outlet. The refrigerant inlet is preferably formed on the motor housing of the drive unit. The motor housing includes: a housing wall, which is exposed to the sucked refrigerant; and an inverter unit, which is coupled to the housing wall and accommodates an inverter circuit board, thereby forming a fluid-tight inverter housing. Therefore, the housing wall exposed to the refrigerant forms a fluid-tight partition between the motor housing and the inverter housing of the inverter unit. The housing wall is hereinafter referred to as the housing wall exposed to the refrigerant.

[0007] The inverter circuit board has a component arrangement structure, which is formed by heat-generating electronic components, in particular by at least one DC link capacitor and a plurality of electronic power switches, and is oriented perpendicular to the inverter circuit board. The component arrangement structure of the heat-generating electronic components has at least two different component heights in its vertical direction and is accommodated in a plurality of molded parts, which are formed on the housing wall exposed to the refrigerant according to the component height. The component arrangement structure of the heat-generating electronic components is thermally connected to the molded parts. According to the present invention, all heat-generating electronic components, in particular at least one DC link capacitor and a plurality of electronic power switches, are arranged to face the housing wall exposed to the refrigerant and are accommodated in the molded parts provided therefor according to their component heights to ensure better heat dissipation. Therefore, the heat-generating electronic components, in particular at least one DC link capacitor and a plurality of electronic power switches, which are oriented perpendicular to the plane of the inverter circuit board, form protrusions, which are accommodated in the molded parts in the housing wall exposed to the refrigerant. In order to better distribute heat perpendicularly to the housing wall exposed to the refrigerant, the heat-generating electronic components have different component heights.

[0008] The electronic power switches include in particular IGBTs and MOSFETs. The task of at least one DC link capacitor is to connect the energy of a plurality of power grids to one another at a common DC voltage level. The electronic power switches can also be combined in so-called power modules. This is an integrated component arrangement with a corresponding number of power semiconductors. In the context of the present invention, the electronic power switches can each be understood as an integrated component arrangement in the form of a power module. It should also be mentioned that the component arrangement can also have more than six individual electronic power switches or power semiconductors. The stated number of six electronic power switches or power semiconductors is only related to the minimum number for actuating the three-phase machine.

[0009] The end wall of the motor housing is preferably used as a housing wall exposed to the refrigerant, and the installation space for the component arrangement structure of heat-generating electronic components, in particular at least one DC link capacitor and a plurality of electronic power switches, is therefore limited by the cross-section of the end wall. This requires a small distance between the electronic components and an extension in height, i.e., an extension in an orientation perpendicular to the inverter circuit board. To this end, the component arrangement structure has heat-generating electronic components that form a height profile with at least two different component heights. Due to the different component heights, the risk of closely adjacent electronic components thermally influencing each other is reduced, and the heat dissipation of electronic components protruding into the depth of the molding is increased. Therefore, it is necessary for the present invention that the heat-generating electronic components have at least two different component heights perpendicular to the inverter circuit board to allow heat dissipation via at least two planes. These planes are parallel to the inverter circuit board at a distance corresponding to the component height of the relevant heat-generating electronic components. The following component arrangement structure does not form the subject matter of the present invention: in this component arrangement structure, the heat-generating electronic components on the inverter circuit board have substantially equal component heights only in one plane. In particular, the plurality of electronic power switches (IGBT, MOSFET) and the at least one DC link capacitor therefore have substantially unequal component heights perpendicular to the inverter circuit board.

[0010] A first component height may be provided for a plurality of electronic power switches (IGBT, MOSFET) together and a second component height may be provided for at least one DC link capacitor, the second component height protruding perpendicularly to the inverter circuit board beyond the first component height. Thus, the molding accommodating the at least one DC link capacitor is deeper than the molding for the plurality of electronic power switches.

[0011] The molded part accommodating the heat-generating electronic component can be designed as a recess in the housing wall exposed to the refrigerant. Therefore, the inner surface of the recess is composed of the material of the housing wall exposed to the refrigerant, which is usually a metal with good thermal conductivity. The heat dissipation of the heat-generating electronic component is promoted by the good thermal conductivity of the housing wall exposed to the refrigerant of the metal at the end face and on the side of the heat-generating electronic component.

[0012] The housing wall exposed to the refrigerant may have an individual recess for each electronic component so that each electronic component can be accommodated individually.

[0013] The individual recesses or mouldings are preferably separated by partitions. Thus, a spatial separation between the electronic components accommodated in the recesses or cutouts is achieved. It can also be provided that a plurality of electronic components of the same type, for example all electronic power switches, are accommodated together in a single cutout or moulding.

[0014] Advantageously, the individual recesses or moldings are designed such that the at least one DC link capacitor and the plurality of electronic power switches are in contact with the housing wall exposed to the refrigerant on at least two sides of their surface, respectively. Thus, the at least one DC link capacitor and the plurality of electronic power switches can each be in contact with the housing wall exposed to the refrigerant at an end face, wherein in each case at least one side wall of the at least one DC link capacitor and the plurality of electronic power switches is in contact with a side wall of the molding accommodating them.

[0015] It can also be provided that at least one DC link capacitor and a plurality of electronic power switches are each accommodated in a form-fitting manner in a molded part in the housing wall exposed to the refrigerant. In this case, the molded part formed in the housing wall exposed to the refrigerant has an inner contour which accommodates the projections of the at least one DC link capacitor and the plurality of electronic power switches protruding vertically beyond the inverter circuit board in a form-fitting manner. The inner contour of the recess thus corresponds to the negative value of the height contour of the component arrangement consisting of the at least one DC link capacitor and the plurality of electronic power switches.

[0016] The invention optimizes the power electronic load flow in relation to the distance between heat generating electronic components. Thanks to the optimized positioning of the heat generating electronic components, inductive and capacitive coupling effects are reduced. As a result, voltage peaks and current peaks between the converter DC link and the electronic power switches are significantly reduced. This leads to improved electromagnetic compatibility (EMC).

[0017] According to a preferred embodiment, at least one DC link capacitor can be positioned in a central area of ​​the housing wall exposed to the refrigerant, while a plurality of electronic power switches are arranged in a semicircular or circular arrangement around the at least one DC link capacitor. This arrangement is advantageous when the housing wall exposed to the refrigerant forms the end wall of the motor housing on which the electric motor is accommodated on the motor housing side. In this case, the sucked refrigerant flows around the centrally arranged electric motor during operation, so that a refrigerant flow path is formed in the area of ​​the periphery of the end wall, which refrigerant flow path has an effect on the heat dissipation on the inverter housing side on the housing wall exposed to the refrigerant. Thus, inside the motor housing, a refrigerant flow path extending along the housing wall exposed to the refrigerant is formed, wherein at least a plurality of electronic power switches are arranged on the housing wall exposed to the refrigerant along the route of the refrigerant flow path. This is advantageous because the heat dissipation in the area of ​​the refrigerant flow path on the inverter housing side on the housing wall exposed to the refrigerant is the greatest.

[0018] According to the above embodiment, in which the refrigerant flows around the centrally arranged electric motor during operation, the course of the refrigerant flow path is evident on the edge of the housing wall exposed to the refrigerant. Therefore, a plurality of electronic power switches can be arranged in a semicircular or circular arrangement along the refrigerant flow path, wherein at least one DC link capacitor is located in the middle of the circular or semicircular arrangement.

[0019] According to this particularly simple embodiment of the motor housing, the housing wall exposed to the refrigerant has a motor bearing, which is formed on the motor housing side of the housing wall exposed to the refrigerant to accommodate the electric motor. In this embodiment, at least one DC link capacitor is preferably arranged on the inverter housing side of the housing wall exposed to the refrigerant in the region of the motor bearing formed on the motor housing side of the housing wall exposed to the refrigerant. Thus, the arrangement of the at least one DC link capacitor is located on the side of the housing wall exposed to the refrigerant facing the inverter housing in the region of the electric motor arranged on the opposite side of the housing wall exposed to the refrigerant.

[0020] According to a preferred embodiment, the motor housing has a tangential refrigerant inlet so that the sucked refrigerant can flow tangentially into the motor housing. This is particularly advantageous in embodiments in which the electric motor is arranged in the center of the motor housing, so that a gap is formed around the circumference of the electric motor between the outer side of the electric motor and the inner side of the motor housing, which gap forms a flow path for the inflowing refrigerant. Unlike a radial refrigerant inlet, through which the refrigerant flow sucked in rebounds from the centrally arranged electric motor, the sucked refrigerant flows unhindered into the gap through the tangential refrigerant inlet, so that the refrigerant can flow unimpeded along the refrigerant flow path.

[0021] The housing wall exposed to the refrigerant can be designed as a separate housing cover of the motor housing.

[0022] The housing wall exposed to the refrigerant can be designed either as part of the motor housing or as a separate housing part that contains the inverter and encloses the motor housing. It is also possible to envisage a design in the form of a hermetically sealed motor housing and a further housing that is joined to the hermetically sealed motor housing and accommodates the inverter as an inverter housing.

[0023] For the thermal connection between the heat generating electronic component and the surface of the housing wall exposed to the refrigerant, the electronic component can be in flat contact with the housing wall exposed to the refrigerant. It can also be provided that a thermally conductive paste is introduced between the heat generating electronic component and the surface of the housing wall exposed to the refrigerant.

[0024] The refrigerant compressor according to the invention is provided in particular for use in a refrigerant circuit of a motor vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further details, features and advantages of embodiments of the present invention can be found in the following description of exemplary embodiments with reference to the relevant drawings. In the drawings:

[0026] Figure 1a to Figure 1c : A schematic diagram showing different views of a refrigerant compressor according to the prior art,

[0027] Figure 2 : shows an inverter circuit board of a refrigerant compressor according to the prior art,

[0028] Figure 3a : A schematic diagram showing an exemplary embodiment of a refrigerant compressor according to the present invention,

[0029] Figure 3b : A schematic cross-sectional view showing an exemplary embodiment of a refrigerant compressor according to the present invention,

[0030] Figure 3c : shows another schematic cross-sectional view of an exemplary embodiment of a refrigerant compressor according to the present invention,

[0031] Figure 3d : A schematic diagram showing an exemplary embodiment of an inverter circuit board for a refrigerant compressor according to the present invention,

[0032] Figure 3e : A schematic plan view showing a housing wall of an inverter housing of a refrigerant compressor according to the present invention, which is exposed to the refrigerant, and

[0033] Figure 3f : A schematic plan view showing a housing wall of a motor housing of a refrigerant compressor according to the present invention, which is exposed to the refrigerant. DETAILED DESCRIPTION

[0034] Figure 1a to Figure 1c Schematic diagram showing different views of a refrigerant compressor according to the prior art.The directional terms axial and radial used to describe the drawings relate to the direction of the axis of rotation of an electric motor accommodated in the refrigerant compressor. Figure 1a A refrigerant compressor 1 is shown in a longitudinal orientation, which has a drive unit 2 and a compressor unit 3 coupled to the drive unit 2. The drive unit comprises a motor housing 2.1, an inverter unit 4 having an inverter housing 4.1, and an electric motor 6 (see Figure 1b ) and is coupled to the motor housing 2.1 in an axial orientation. The compressor unit 3 comprises a compressor housing 3.1 in which a scroll compressor 5 (see Figure 1bThe motor housing 2.1 and the compressor housing 3.1 form a fluid-tight unit having a substantially cylindrical shape. The inverter housing 4.1 axially coupled to the motor housing 2.1 accommodates an inverter circuit board 7 (see Figure 1b to Figure 1c ), which extends radially around the circumference of the motor housing 2.1, so that the inverter housing 4.1 also protrudes radially beyond the circumference of the motor housing 2.1 and the circumference of the compressor housing 3.1. The housing portion of the inverter housing 4.1 that protrudes beyond the radial circumference of the motor housing 2.1 and the radial circumference of the compressor housing 3.1 includes a plug-in terminal 8, which is provided for electrical contact or for the connection of a cable. Figure 1c Section A is shown in FIG.

[0035] Figure 1b Shows Figure 1a Schematic diagram of an axial longitudinal section of a refrigerant compressor 1 shown in . Inside the refrigerant compressor 1, from left to right, an inverter circuit board 7 is arranged in the inverter housing 4.1, an electric motor 6 is arranged in the motor housing 2.1, and a scroll compressor 5 coupled via a shaft 6.1 is arranged in the compressor housing 3.1. The inverter circuit board 7 includes a DC link capacitor 9, which is arranged in a portion of the inverter housing 4.1 that radially protrudes beyond the circumference of the motor housing 2.1 and the circumference of the compressor housing 3.1.

[0036] Figure 1c Shown along with Figure 1a The dashed line in FIG. 4 is a view of the interior of the inverter housing 4.1 from the section A indicated by the dashed line in FIG. 4 . Therefore, this is an axial plan view of the inverter circuit board 7 in the inverter housing 4.1. As can be seen, the area provided by the inverter housing 4.1 is completely occupied by the shape of the inverter circuit board 7, so that the outer contour of the inverter circuit board 7 matches the inner contour of the inverter housing 4.1.

[0037] Figure 2 The inverter circuit board 7 is shown only in a plan view facing the side of the motor housing 2.1. The inverter circuit board 7 includes a DC link capacitor 9 arranged in the area of ​​the dashed line 10. Therefore, the DC link capacitor 9 is located outside the circumference of the motor housing 2.1. In other words, the DC link capacitor 9 is located in the area of ​​the housing part of the inverter housing 4.1 that radially protrudes beyond the circumference of the motor housing 2.1, and is therefore located outside the influence area of ​​the housing wall, which is used in common between the inverter housing 4.1 and the motor housing 2.1 and can also be called a partition. In the roughly circular part of the inverter circuit board 7, six electronic power switches 11 are arranged, which, due to their arrangement, are located in the area of ​​the housing wall used in common between the inverter housing 4.1 and the motor housing 2.1 and face the housing wall.

[0038] On one side of the motor housing 2.1, the housing wall used jointly by the inverter housing 4.1 and the motor housing 2.1 is exposed to the sucked refrigerant. Arrow 14 indicates a possible flow path of the sucked refrigerant in the motor housing 2.1 in relation to the relative position of the inverter circuit board 7 in the inverter housing 4.1. Therefore, the electronic power switch 11 located on the housing wall exposed to the refrigerant on one side of the inverter housing 4.1 is able to dissipate the generated heat on the housing wall exposed to the refrigerant. However, this does not apply to the DC link capacitor 9, which is located in the area 10 on the outside of the housing wall exposed to the refrigerant, making it impossible to make direct contact with the housing wall exposed to the refrigerant for heat dissipation.

[0039] Figure 3a A schematic diagram of an exemplary embodiment of a refrigerant compressor 1 according to the invention is shown. The refrigerant compressor 1 has a drive unit 2 having a motor housing 2.1 and a compressor unit 3 coupled to the drive unit 2, wherein the compressor unit 3 comprises a housing for accommodating a scroll compressor 5 (see Figure 3b ) of the compressor housing 3.1. The motor housing 2.1 and the compressor housing 3.1 have a generally cylindrical shape. The inverter unit 4 having the inverter housing 4.1 is also coupled to the motor housing 2.1 of the drive unit 2. The inverter housing 4.1 radially protrudes beyond the circumference of the motor housing 2.1 and the circumference of the compressor housing 3.1. The plug-in terminals 8 formed on the inverter housing 4.1 are used for the inverter circuit board 7 (see Figure 3b , Figure 3c and Figure 3d ) electrical contact. The inverter housing 4.1 is closed in a fluid-tight manner by a housing cover 4.2. A tangential refrigerant inlet 13 is formed on the circumference of the motor housing 2.1. When viewed from the outside, the refrigerant compressor 1 according to the present invention is Figure 1a The refrigerant compressor 1 shown in FIG. 1 has only minor differences. Therefore, recurring features are marked with the same reference numerals. Figure 3c Section B is shown in FIG.

[0040] Figure 3bA schematic cross-sectional view of an exemplary embodiment of a refrigerant compressor 1 is shown, and is an axial longitudinal section allowing observation of the interior of the refrigerant compressor 1. An inverter circuit board 7.1 containing motor electronics is housed in a fluid-tight inverter housing 4.1, which is coupled to the motor housing 2.1. A compressor housing 3.1 is coupled to the other side of the motor housing 2.1, and a scroll compressor 5 is housed in the compressor housing 3.1. The scroll compressor 5 is coupled to an electric motor 6 housed in the motor housing 2.1 via a drive shaft 6.1. The motor housing 2.1 has an electric motor bearing 15, and the electric motor 6 is housed inside the motor housing 2.1 on the electric motor bearing 15, so that a gap is formed between the outer circumference of the electric motor 6 and the radial inner circumference of the motor housing 2.1. During operation, the gap is filled with refrigerant, wherein a refrigerant flow path for the sucked refrigerant is formed along the gap. Refrigerant flow path 14 (see Figure 3c ) extends along the end wall of the motor housing 2.1 and, therefore, this housing wall is continuously exposed to the refrigerant during operation. The housing wall 12 exposed to the refrigerant, which is highlighted with diagonal shading in certain areas, forms a fluid-tight partition between the motor housing 2.1 and the inverter housing 4.1 coupled to the motor housing 2.1. Therefore, the motor housing 2.1 and the inverter housing 4.1 share the housing wall 12 exposed to the refrigerant. The contour of the housing wall 12 exposed to the refrigerant facing the inverter housing 4.1 has a molding 16 and a molding 17, which are arranged to accommodate heat-generating electronic components of the inverter circuit board 7.1. Therefore, the inverter circuit board 7.1 has two DC link capacitors 9.1 and six electronic power switches 11.1, which are vertically raised from the plane of the inverter circuit board 7.1 and extend in the axial direction. The electronic power switch 11.1 is accommodated in a molding 17, wherein the dashed line 18 shows a first component height of the electronic power switch 11.1 perpendicular to the inverter circuit board plane. The first component height 18 corresponds substantially to the axial depth of the molding 17 in the housing wall 12 exposed to the refrigerant. The two DC link capacitors 9.1 are each accommodated in a molding 16 in the housing wall 12 exposed to the refrigerant. The dashed line 19 indicates a second component height, which corresponds to the component height of the two DC link capacitors 9.1 perpendicular to the inverter circuit board plane. Furthermore, the second component height 19 corresponds substantially to the axial depth of the molding 16 in the housing wall 12 exposed to the refrigerant.

[0041] Figure 3c Another schematic cross-sectional view of a refrigerant compressor according to the invention is shown. This is a schematic cross-sectional view of the inverter housing 4.1 along Figure 3a4.1. The sectional view allows observation of the inverter circuit board 7.1 accommodated in the inverter housing 4.1. A portion of the inverter circuit board 7.1 is located in the region of the housing wall 12 exposed to the refrigerant. Arrow 14 indicates the flow path of the refrigerant supplied to the motor housing 2.1 via the tangential refrigerant inlet 13. It can be seen that only a portion of the inverter circuit board 7.1 is allocated to the region of the housing wall 12 exposed to the refrigerant or to the route of the refrigerant flow path in order to ensure heat transfer and therefore heat dissipation. Therefore, a portion of the inverter circuit board 7.1 is not located in the influence area of ​​the housing wall 12 exposed to the refrigerant, but is located in the inverter housing portion of the inverter housing 4.1 that protrudes beyond the outer circumference of the motor housing 2.1.

[0042] Figure 3d A schematic diagram of an exemplary embodiment of an inverter circuit board 7.1 is shown in a plan view of an inverter housing 4.1 facing only one side of the housing wall 12 exposed to the refrigerant without the surroundings. On this side of the inverter circuit board 7.1, two DC link capacitors 9.1 and six electronic power switches 11.1 are arranged in addition to other electronic components. The electronic power switch 11.1 is an IGBT or a MOSFET. In the circular outer contour area of ​​the inverter circuit board 7.1, the two DC link capacitors 9.1 together with the six electronic power switches 11.1 arranged in a semicircular shape oriented close to the edge of the inverter circuit board 7.1 form a component arrangement structure of heat-generating electronic components. According to the present invention, when the inverter circuit board 7.1 is installed in the inverter housing 4.1, the component arrangement structure of the six electronic power switches 11.1 and the two DC link capacitors 9.1 is positioned on the inverter circuit board 7.1 in the influence area of ​​the housing wall 12 exposed to the refrigerant. The six electronic power switches 11.1 and the two DC link capacitors 9.1 face the housing wall 12 exposed to the refrigerant. With Figure 1a to Figure 1c Unlike the embodiment of the prior art refrigerant compressor 1 shown in the figure, the heat-generating electronic components including six electronic power switches 11.1 and two DC link capacitors 9.1 in the present invention are arranged in a compact component arrangement structure relative to the housing wall 12 exposed to the refrigerant, so as to dissipate the generated heat with the help of the refrigerant flow generated in the motor housing 2.1.

[0043] The six electronic power switches 11.1 extend vertically out of the inverter circuit board 7.1, wherein the six electronic power switches 11.1 have the same component height. The two DC link capacitors 9.1 also extend vertically out of the inverter circuit board 7.1, wherein the component height of the DC link capacitors 9.1 protrudes perpendicularly to the inverter circuit board 7.1 and exceeds the component height of the electronic power switches 11.1. Therefore, the component arrangement structure of the six electronic power switches 11.1 and the two DC link capacitors 9.1 has a height profile with two different component heights 18 and 19 (see Figure 3b ). The arrangement of the DC link capacitor 9.1 and the electronic power switch 11.1 on the inverter circuit board 7.1 is oriented close to the course of the refrigerant flow path 14 in the motor housing 2.1.

[0044] Figure 3e A schematic plan view of a housing wall 12 exposed to the refrigerant of an inverter housing 4.1 of a refrigerant compressor 1 according to the invention is shown. On this side, the housing wall 12 exposed to the refrigerant has two moldings 16, which are arranged to accommodate two DC link capacitors 9.1. The moldings 16 are designed as recesses in the material of the housing wall 12 exposed to the refrigerant and correspond to the two DC link capacitors 9.1 arranged on the inverter circuit board 7.1 in terms of their arrangement and size, so that when the inverter circuit board 7.1 is installed in the inverter housing 4.1, the DC link capacitors are accommodated in the moldings 16. The size of the moldings 16 is selected so that the contact surface between the moldings 16 and the surfaces of the DC link capacitors 9.1 is as large as possible. In each case, at least two sides of the two DC link capacitors 9.1 are in contact with the surface of the molding 16 accommodating the DC link capacitors 9.1. These sides are in each case the end faces and one side face of the cuboid DC link capacitor 9.1. In order to produce the thermal connection, at least the rectangular top surface of the DC link capacitor 9.1 in the molding 16 is in contact with the housing wall 12 exposed to the refrigerant. Furthermore, it can be provided that at least one side surface of the DC link capacitor 9.1 is in contact with a surface of the molding 16. Preferably, the molding 16 is dimensioned such that the molding 16 accommodates the DC link capacitor 9.1 in a form-fitting manner. As a measure to improve the thermal connection, a thermally conductive paste can be introduced in each case between the DC link capacitor 9.1 and the molding 16 accommodating the DC link capacitor 9.1.

[0045] In addition, the housing wall 12 of the inverter housing 4.1 exposed to the refrigerant has three moldings 17 to accommodate the electronic power switch 11.1. The moldings 17 are designed as recesses in the material of the housing wall 12 of the inverter housing 4.1 exposed to the refrigerant, so that when the inverter circuit board 7.1 is installed in the inverter housing 4.1, the moldings 17 accommodate the electronic power switches 11.1. Each molding 17 accommodates two electronic power switches 11.1. Therefore, the protrusions of the electronic power switches 11.1 perpendicular to the plane of the inverter circuit board 7.1 are almost completely accommodated in the moldings 17. In order to promote thermal coupling, thermally conductive paste can be introduced between the electronic power switch 11.1 and the moldings 17 accommodating the electronic power switch 11.1. These moldings 17 are formed along the refrigerant flow path 14 formed in the motor housing 2.1 during operation.

[0046] The moldings 16 and 17 are not cross-connected and, due to the different component heights of the two DC link capacitors 9.1 and the different component heights of the six electronic power switches 11.1, form different depths in the housing wall 12 exposed to the refrigerant. Therefore, the molding 16 that accommodates the DC link capacitors 9.1 is deeper than the molding 17 for the six electronic power switches 11.1. Another design of the housing wall 12 exposed to the refrigerant is configured so that the planar inverter circuit board 7.1 is perpendicular to the rotation axis of the electric motor 6 in the installed state (see Figure 3b ) orientation.

[0047] Due to the spatial separation between the DC link capacitor 9.1 and the electronic power switch 11.1, which is achieved by the moldings 16 and 17, the risk of mutual thermal influence is low. The different component heights 18 and 19 additionally enhance this advantageous effect. In addition, the contact of the sides of the DC link capacitor 9.1 and the sides of the electronic power switch 11.1 with the surfaces in the moldings 16 or 17 helps to improve the heat dissipation, because the heat transfer area is enlarged overall.

[0048] Figure 3f A schematic plan view of the housing wall 12 of the motor housing 2.1 exposed to the refrigerant is shown. The side of the housing wall 12 exposed to the refrigerant facing the motor housing 2.1 is thus shown. An electric motor bearing 15 for accommodating the electric motor 6 is formed on this side.

[0049] According to the invention, the DC link capacitor 9.1 (see Figure 3d ) is arranged essentially in the middle region of the motor housing 2.1 opposite the electric motor bearing 15. Figure 1a to Figure 1cThis improves the heat dissipation of the refrigerant compared to the concept shown in , where the DC link capacitor 9 is located outside the circumference of the motor housing 2.1. In addition, the electronic power switch 11.1 is arranged in a semicircular shape on the outer diameter, radially close to the inner wall of the compressor suction space. Therefore, the position is optimized to the area of ​​maximum heat output of the refrigerant. In addition, the power electronic load flow is optimized in terms of the distance between the DC link capacitor 9.1 and the electronic power switch 11.1 to reduce inductive and capacitive interference, which is very important for sufficient electromagnetic compatibility (EMC).

[0050] The housing wall 12 exposed to the refrigerant can be designed as a separate housing part, which ensures fluid sealing of the housing wall 12 in the arrangement between the motor housing 2.1 and the inverter housing 4.1. For fastening, screws fastened to the motor housing 2.1 can be provided. For this purpose, the housing wall 12 exposed to the refrigerant can have corresponding screw holes.

[0051] Reference numerals

[0052] 1 Refrigerant compressor

[0053] 2 Drivers

[0054] 2.1 Motor housing

[0055] 3 Compressor unit

[0056] 3.1 Compressor housing

[0057] 4 Inverter unit

[0058] 4.1 Inverter Housing

[0059] 4.2 Housing cover

[0060] 5 Scroll compressor

[0061] 6 Electric Motor

[0062] 6.1 Rotatable axis

[0063] 7 Inverter circuit board

[0064] 7.1 Inverter PCB

[0065] 8 Electric plug-in terminals

[0066] 9 DC link capacitor

[0067] 9.1 DC Link Capacitors

[0068] 10 Dashed area

[0069] 11 Electronic power switch

[0070] 11.1 Electronic power switch

[0071] 12 Shell wall exposed to refrigerant

[0072] 13 Tangential refrigerant inlet

[0073] 14 Arrows / refrigerant flow path

[0074] 15 Electric motor bearings

[0075] 16 Molded parts

[0076] 17 Molded parts

[0077] 18 First component height

[0078] 19 Second component height

Claims

1. A refrigerant compressor (1), comprising: a drive unit (2) and a compressor unit (3) connected to the drive unit (2), wherein: The drive unit (2) comprises a motor housing (2.1) through which a refrigerant can flow and which accommodates an electric motor (6) having a rotatable shaft (6.1), wherein the compressor unit (3) accommodates a scroll compressor (5) which can be driven by the rotatable shaft (6.1), wherein the motor housing (2.1) comprises a housing wall (12) exposed to the sucked refrigerant; and an inverter unit (4) which is coupled to the housing wall (12) and accommodates an inverter circuit board (7.1), thereby forming a fluid-tight An inverter housing (4.1), wherein the inverter circuit board (7.1) has a component arrangement structure formed by heat-generating electronic components, in particular a component arrangement structure formed by at least one DC link capacitor (9.1) and a plurality of electronic power switches (11.1), and the heat-generating electronic components have at least two different component heights (18; 19) perpendicular to the inverter circuit board (7.1) and are accommodated in a plurality of molded parts (16; 17), the molded parts are formed on the housing wall (12) exposed to the refrigerant according to the component heights, and the heat-generating electronic components are thermally connected to the molded parts.

2. The refrigerant compressor (1) according to claim 1, characterized in that The plurality of electronic power switches (11.1) together have a first component height (18), wherein the at least one DC link capacitor (9.1) has a second component height (19), the second component height (19) protruding perpendicularly to the inverter circuit board (7.1) beyond the first component height (18).

3. The refrigerant compressor according to claim 1 or 2, characterized in that: The molding (16; 17) is designed as a recess in the housing wall (12) exposed to the refrigerant.

4. The refrigerant compressor (1) according to one of claims 1 to 3, characterized in that The at least one DC link capacitor (9.1) and the plurality of electronic power switches (11.1) are each in contact with the housing wall (12) exposed to the refrigerant on at least two sides of the surface of the at least one DC link capacitor (9.1) and the plurality of electronic power switches (11.1).

5. The refrigerant compressor (1) according to one of claims 1 to 4, characterized in that The at least one DC link capacitor (9.1) and the plurality of electronic power switches (11.1) are each accommodated in the molded part (16; 17) in a form-fitting manner.

6. The refrigerant compressor (1) according to one of claims 1 to 5, characterized in that The at least one DC link capacitor (9.1) is positioned in a central area of ​​the housing wall (12) exposed to the refrigerant, wherein the plurality of electronic power switches (11.1) are arranged in a semicircular or circular arrangement around the at least one DC link capacitor (9.1).

7. The refrigerant compressor (1) according to one of claims 1 to 6, characterized in that A refrigerant flow path (14) extending along the housing wall (12) exposed to the refrigerant is formed in the motor housing (2.1), wherein at least the plurality of electronic power switches (11.1) are arranged along the route of the refrigerant flow path (14) on the housing wall (12) exposed to the refrigerant.

8. Refrigerant compressor (1) according to one of claims 1 to 7, characterized in that The at least one DC link capacitor (9.1) is positioned on the inverter housing side of the housing wall (12) exposed to the refrigerant in the region of an electric motor bearing (15) formed on the motor housing side of the housing wall (12) exposed to the refrigerant.

9. The refrigerant compressor (1) according to one of claims 1 to 8, characterized in that The motor housing (2.1) has a tangential refrigerant inlet (13).

10. The refrigerant compressor (1) according to one of claims 1 to 9, characterized in that The housing wall (12) exposed to the refrigerant is designed as a separate housing cover of the motor housing (2.1).

11. The refrigerant compressor (1) according to one of claims 1 to 10, characterized in that A thermally conductive paste is introduced between the heat-generating electronic component and the surface of the housing wall (12) exposed to the refrigerant for thermal connection.

12. Use of a refrigerant compressor (1) according to one of claims 1 to 11 in a refrigerant circuit of a vehicle.

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