Abstract
A refrigerant compressor which has a drive unit and a compressor unit coupled thereto, wherein the drive unit has a motor housing through which refrigerant can flow and accommodates an electric motor with a rotatable shaft, wherein the compressor unit accommodates a scroll compressor which is driven by the shaft, wherein the motor housing includes a housing wall exposed to sucked-in refrigerant and an inverter unit joined thereto and accommodates an inverter circuit board, forming a fluid-tight inverter housing, wherein the inverter circuit board has a component arrangement formed with heat-producing electronic components, in particular with at least one DC link capacitor and multiple electronic power switches, and has at least two different component heights perpendicular to the inverter circuit board and is accommodated in multiple mouldings, which are formed according to the component heights, on the refrigerant-exposed housing wall and is thermally coupled to said mouldings.
Claims
1. A refrigerant compressor comprising: a drive unit; and a compressor unit coupled to the drive unit, wherein the drive unit has a motor housing through which a refrigerant can flow and which accommodates an electric motor with a rotatable shaft, wherein the compressor unit accommodates a scroll compressor which can be driven by the shaft, wherein the motor housing comprises a housing wall which is exposed to sucked-in refrigerant and an inverter unit which is joined thereto and accommodates an inverter circuit board, forming a fluid-tight inverter housing, wherein the inverter circuit board has a component arrangement which is formed with heat-producing electronic components including at least one DC link capacitor and multiple electronic power switches, and has at least two different component heights perpendicular to the inverter circuit board and is accommodated in multiple mouldings, which are formed according to the component heights, on the refrigerant-exposed housing wall and is thermally coupled to the mouldings.
2. The refrigerant compressor according to claim 1, wherein the multiple electronic power switches together have a first component height, wherein the at least one DC link capacitor has a second component height which protrudes beyond the first component height perpendicularly to the inverter circuit board.
3. The refrigerant compressor according to claim 1, wherein the mouldings are designed as recesses in the refrigerant-exposed housing wall.
4. The refrigerant compressor according to claim 1, wherein the at least one DC link capacitor and the multiple electronic power switches are each in contact with the refrigerant-exposed housing wall on at least two sides of their surface.
5. The refrigerant compressor according to claim 1, wherein the at least one DC link capacitor and the multiple electronic power switches are each accommodated form-fittingly in the mouldings.
6. The refrigerant compressor according to claim 1, wherein the at least one DC link capacitor is positioned in a region of a center of the refrigerant-exposed housing wall, wherein the multiple electronic power switches are arranged in a semicircular or circular arrangement around the at least one DC link capacitor.
7. The refrigerant compressor according to claim 1, wherein a refrigerant flow path which runs along the refrigerant-exposed housing wall is formed within the motor housing, wherein at least the multiple electronic power switches are arranged along the course of the refrigerant flow path on the refrigerant-exposed housing wall.
8. The refrigerant compressor according to claim 1, wherein the at least one DC link capacitor is positioned on the inverter housing side of the refrigerant-exposed housing wall in a region of an electric motor bearing formed on the motor housing side of the refrigerant-exposed housing wall.
9. The refrigerant compressor according to claim 1, wherein the motor housing has a tangential refrigerant inlet.
10. The refrigerant compressor according to claim 1, wherein the refrigerant-exposed housing wall is designed as a separate housing cover of the motor housing.
11. The refrigerant compressor according to claim 1, wherein a thermal paste is introduced between the heat-producing electronic components and a surface of the refrigerant-exposed housing wall for thermal coupling.
12. A use of the refrigerant compressor according to claim 1 in a refrigerant circuit of a vehicle.
Description
DRAWINGS
[0026] Further details, features and advantages of embodiments of the invention can be found in the description of exemplary embodiments below with reference to the associated drawings. In the drawings:
[0027] FIGS. 1A to 1C: show schematic diagrams of different views of a refrigerant compressor according to the prior art,
[0028] FIG. 2: shows an inverter circuit board of a refrigerant compressor according to the prior art.
[0029] FIG. 3A: shows a schematic diagram of an exemplary embodiment of a refrigerant compressor according to the invention,
[0030] FIG. 3B: shows a schematic sectional diagram of an exemplary embodiment of a refrigerant compressor according to the invention,
[0031] FIG. 3C: shows a further schematic sectional diagram of an exemplary embodiment of a refrigerant compressor according to the invention,
[0032] FIG. 3D: shows a schematic diagram of an exemplary embodiment of an inverter circuit board of a refrigerant compressor according to the invention,
[0033] FIG. 3E: shows a schematic plan view diagram of the refrigerant-exposed housing wall of the inverter housing of a refrigerant compressor according to the invention, and
[0034] FIG. 3F: shows a schematic plan view diagram of the refrigerant-exposed housing wall of the motor housing of a refrigerant compressor according to the invention.
DESCRIPTION OF AN EMBODIMENT
[0035] FIGS. 1A to 1C show schematic diagrams of different views of a refrigerant compressor according to the prior art. The directional terms axial and radial used to describe the figures relate to an orientation of the rotational axis of an electric motor which is accommodated in the refrigerant compressor. FIG. 1A shows a refrigerant compressor 1 in a longitudinal orientation with a drive unit 2 and a compressor unit 3 joined thereto. The drive unit comprises a motor housing 2.1, to which an inverter unit 4 with an inverter housing 4.1 is joined in an axial orientation in relation to an electric motor 6 (see FIG. 1B) accommodated in the motor housing 2.1. The compressor unit 3 comprises a compressor housing 3.1, in which a scroll compressor 5 (see FIG. 1B) is accommodated. The motor housing 2.1 and the compressor housing 3.1 form a fluid-tight unit with a substantially circular-cylindrical shape. The inverter housing 4.1 joined axially to the motor housing 2.1 accommodates an inverter circuit board 7 (see FIGS. 1B-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 of the compressor housing 3.1. The housing part of the inverter housing 4.1 protruding beyond the radial circumference of the motor housing 2.1 and of the compressor housing 3.1 comprises a plug-in terminal 8 which is provided for the electrical contact or for the connection of electrical cables. Section A is shown in FIG. 1C.
[0036] FIG. 1B shows a schematic view of an axial longitudinal section of the refrigerant compressor 1 shown in FIG. 1A. Inside the refrigerant compressor 1, from left to right, the inverter circuit board 7 is arranged in the inverter housing 4.1, the electric motor 6 is arranged in the motor housing 2.1, and the scroll compressor 5 coupled via a shaft 6.1 is arranged in the compressor housing 3.1. The inverter circuit board 7 comprises a DC link capacitor 9, which is arranged in the part of the inverter housing 4.1 which protrudes radially beyond the circumference of the motor housing 2.1 and of the compressor housing 3.1.
[0037] FIG. 1C shows a view into the interior of the inverter housing 4.1 along section A, indicated with the dashed line in FIG. 1A. This is therefore 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 fully taken up by the shape of the inverter circuit board 7, so that an outer contour of the inverter circuit board 7 matches an inner contour of the inverter housing 4.1.
[0038] FIG. 2 shows only the inverter circuit board 7 in a plan view of the side facing the motor housing 2.1. The inverter circuit board 7 comprises a DC link capacitor 9, which is arranged in the region of the dashed line 10. The DC link capacitor 9 is thus situated outside the circumference of the motor housing 2.1. In other words, the DC link capacitor 9 is situated in the region of the housing part of the inverter housing 4.1 protruding radially beyond the circumference of the motor housing 2.1 and thus outside the region of influence of the housing wall which is used jointly between the inverter housing 4.1 and the motor housing 2.1 and can also be referred to as a partition. Within the substantially circular portion of the inverter circuit board 7, there are six electronic power switches 11, which, owing to their arrangement, are located in the region of the housing wall used jointly between the inverter housing 4.1 and the motor housing 2.1 and face said housing wall.
[0039] On the 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 sucked-in refrigerant. The arrow 14 indicates a possible flow path of sucked-in 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. The electronic power switches 11 located on the refrigerant-exposed housing wall on the side of the inverter housing 4.1 are thus able to dissipate produced heat on the refrigerant-exposed housing wall. However, this does not apply to the DC link capacitor 9, which is situated in the region 10 outside the refrigerant-exposed housing wall, so that direct contact with the refrigerant-exposed housing wall for heat dissipation is not possible.
[0040] FIG. 3A shows a schematic diagram of an exemplary embodiment of a refrigerant compressor 1 according to the invention. The refrigerant compressor 1 has a drive unit 2, which has a motor housing 2.1, and a compressor unit 3, which is coupled to the drive unit 2, wherein the compressor unit 3 comprises a compressor housing 3.1 for accommodating a scroll compressor 5 (see FIG. 3B). The motor housing 2.1 and the compressor housing 3.1 have a substantially circular-cylindrical shape. An inverter unit 4 with an inverter housing 4.1 is also joined to the motor housing 2.1 of the drive unit 2. The inverter housing 4.1 protrudes radially beyond the circumference of the motor housing 2.1 and of the compressor housing 3.1. A plug-in terminal 8 formed on the inverter housing 4.1 is used for the electrical contact of an inverter circuit board 7 (see FIGS. 3B, 3C and 3D) accommodated in the inverter housing 4.1. The inverter housing 4.1 is closed fluid-tightly with a housing lid 4.2. A tangential refrigerant inlet 13 is formed on the circumference of the motor housing 2.1. From the outside, the refrigerant compressor 1 according to the invention differs only insignificantly from the refrigerant compressor 1 shown in FIG. 1A. Recurring features are therefore labelled with the same reference signs. Section B is shown in FIG. 3C.
[0041] FIG. 3B shows a schematic sectional diagram of an exemplary embodiment of a refrigerant compressor 1 and is an axial longitudinal section allowing a view into the interior of the refrigerant compressor 1. An inverter circuit board 7.1, which contains the motor electronics, is accommodated in the fluid-tight inverter housing 4.1, which is joined to the motor housing 2.1. The compressor housing 3.1 is joined to the other side of the motor housing 2.1, and a scroll compressor 5 is accommodated in the compressor housing 3.1. The scroll compressor 5 is coupled via a drive shaft 6.1 to an electric motor 6 accommodated in the motor housing 2.1. The motor housing 2.1 has an electric motor bearing 15, on which the electric motor 6 is accommodated in the interior of the motor housing 2.1 such that an interstice is formed between the outer circumference of the electric motor 6 and the radially inner circumference of the motor housing 2.1. During operation, this interstice is filled with refrigerant, wherein a refrigerant flow path for sucked-in refrigerant is formed along the interstice. The refrigerant flow path 14 (see FIG. 3C) runs along an end wall of the motor housing 2.1, and therefore this housing wall is continuously exposed to refrigerant during operation. This refrigerant-exposed housing wall 12, which is highlighted in some regions with the diagonal shading, forms a fluid-tight partition between the motor housing 2.1 and the inverter housing 4.1 joined thereto. The motor housing 2.1 and the inverter housing 4.1 thus share the refrigerant-exposed housing wall 12. The profile of the side, facing the inverter housing 4.1, of the refrigerant-exposed housing wall 12 has mouldings 16 and 17 which are provided to accommodate heat-generating electronic components of the inverter circuit board 7.1. The inverter circuit board 7.1 thus has two DC link capacitors 9.1 and six electronic power switches 11.1, which rise perpendicularly from the plane of the inverter circuit board 7.1 and extend in the axial direction. The electronic power switches 11.1 are accommodated in a moulding 17, wherein the dashed line 18 shows a first component height of the electronic power switches 11.1 perpendicular to the inverter circuit board plane. The first component height 18 corresponds substantially to the axial depth of the moulding 17 in the refrigerant-exposed housing wall 12. The two DC link capacitors 9.1 are each accommodated in a moulding 16 in the refrigerant-exposed housing wall 12. 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. The second component height 19 furthermore corresponds substantially to the axial depth of the mouldings 16 in the refrigerant-exposed housing wall 12.
[0042] FIG. 3C shows a further schematic sectional diagram of a refrigerant compressor according to the invention. This is a sectional diagram of the inverter housing 4.1 along section B shown in FIG. 3A. The sectional diagram allows a view of the inverter circuit board 7.1 accommodated in the inverter housing 4.1. A part of the inverter circuit board 7.1 is situated in the region of the refrigerant-exposed housing wall 12. The arrow 14 indicates the flow path of a refrigerant supplied to the motor housing 2.1 via the tangential refrigerant inlet 13. It can be seen that only a part of the inverter circuit board 7.1 is assigned to the region of the refrigerant-exposed housing wall 12 or to the course of the refrigerant flow path in order to ensure heat transfer and thus heat dissipation. Therefore a part of the inverter circuit board 7.1 is not situated in the region of influence of the refrigerant-exposed housing wall 12 but in the inverter housing part of the inverter housing 4.1 which protrudes beyond the outer circumference of the motor housing 2.1.
[0043] FIG. 3D shows a schematic diagram of an exemplary embodiment of an inverter circuit board 7.1 in a plan view of the side facing the refrigerant-exposed housing wall 12 alone without the surrounding inverter housing 4.1. On this side of the inverter circuit board 7.1, the two DC link capacitors 9.1 and the six electronic power switches 11.1 are arranged in addition to further electronic components. The electronic power switches 11.1 are IGBTs or MOSFETs. Together with the six electronic power switches 11.1, which are arranged in the shape of a semicircle, oriented towards the edge of the inverter circuit board 7.1, in the region of the circular outer contour of the inverter circuit board 7.1, the two DC link capacitors 9.1 form a component arrangement of heat-generating electronic components. According to the invention, the component arrangement 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 region of influence of the refrigerant-exposed housing wall 12 when the inverter circuit board 7.1 is installed in the inverter housing 4.1. The six electronic power switches 11.1 and the two DC link capacitors 9.1 face the refrigerant-exposed housing wall 12. Unlike the embodiment of a refrigerant compressor 1 of the prior art shown in FIGS. 1A to 1C, the heat-generating electronic components, comprising the six electronic power switches 11.1 and the two DC link capacitors 9.1, in the invention are arranged in a compact component arrangement relative to the refrigerant-exposed housing wall 12 in order to achieve dissipation of produced heat by means of the refrigerant flow generated in the motor housing 2.1.
[0044] The six electronic power switches 11.1 extend perpendicularly out of the inverter circuit board 7.1, wherein the six electronic power switches 11.1 have equal component heights. The two DC link capacitors 9.1 likewise extend perpendicularly out of the inverter circuit board 7.1, wherein the component height of the DC link capacitors 9.1 protrudes beyond the component height of the electronic power switches 11.1, perpendicularly to the inverter circuit board 7.1. The component arrangement of the six electronic power switches 11.1 and the two DC link capacitors 9.1 thus has a height profile with two different component heights 18 and 19 (see FIG. 3B). The arrangement of the DC link capacitors 9.1 and the electronic power switches 11.1 on the inverter circuit board 7.1 is oriented towards the course of the refrigerant flow path 14 in the motor housing 2.1.
[0045] FIG. 3E shows a schematic plan view diagram of the refrigerant-exposed housing wall 12 of the inverter housing 4.1 of a refrigerant compressor 1 according to the invention. On this side, the refrigerant-exposed housing wall 12 has two mouldings 16, which are provided to accommodate the two DC link capacitors 9.1. The mouldings 16 are designed as recesses in the material of the refrigerant-exposed housing wall 12 and correspond with the two DC link capacitors 9.1 arranged on the inverter circuit board 7.1 in terms of their arrangement and dimensioning such that the DC link capacitors are accommodated in the mouldings 16 when the inverter circuit board 7.1 is installed in the inverter housing 4.1. The dimensioning of the mouldings 16 is selected such that the contact face between the mouldings 16 and the surface 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 moulding 16 accommodating them. These are in each case the end face and one side face of the cuboid DC link capacitors 9.1. To produce a thermal coupling, at least the rectangular top faces of the DC link capacitors 9.1 in the mouldings 16 are in contact with the refrigerant-exposed housing wall 12. Furthermore, it can be provided for at least one side face of the DC link capacitors 9.1 to be in contact with a surface of the mouldings 16. Preferably, the mouldings 16 are dimensioned such that they accommodate the DC link capacitors 9.1 form-fittingly. As a measure to improve the thermal coupling, a thermal paste can be introduced in each case between the DC link capacitors 9.1 and the mouldings 16 accommodating them.
[0046] Furthermore, the refrigerant-exposed housing wall 12 of the inverter housing 4.1 has three mouldings 17 to accommodate the electronic power switches 11.1. The mouldings 17 are designed as a recess in the material of the refrigerant-exposed housing wall 12 of the inverter housing 4.1 such that they accommodate the electronic power switches 11.1 when the inverter circuit board 7.1 is installed in the inverter housing 4.1. Each moulding 17 accommodates two electronic power switches 11.1. The elevations of the electronic power switches 11.1 perpendicular to the plane of the inverter circuit board 7.1 are thus accommodated virtually fully in the moulding 17. In order to promote the thermal coupling, a thermal paste can be introduced between the electronic power switches 11.1 and the mouldings 17 accommodating them. The mouldings 17 are formed along the refrigerant flow path 14 formed in the motor housing 2.1 during operation.
[0047] The mouldings 16 and 17 have no cross connection and are formed to different depths in the refrigerant-exposed housing wall 12 owing to the different component heights of the two DC link capacitors 9.1 and of the six electronic power switches 11.1. Accordingly, the mouldings 16 accommodating the DC link capacitors 9.1 are deeper than the mouldings 17 for the six electronic power switches 11.1. The further design of the refrigerant-exposed housing wall 12 is configured such that the planar inverter circuit board 7.1 is oriented perpendicularly to the rotational axis of the electric motor 6 (see FIG. 3B) when in the installed state.
[0048] Owing to the spatial separation between the DC link capacitors 9.1 and the electronic power switches 11.1 which is achieved by the mouldings 16 and 17, the risk of mutual thermal influence is low. This advantageous effect is additionally reinforced by the different component heights 18 and 19. Furthermore, a contact of side faces of the DC link capacitors 9.1 and of the electronic power switches 11.1 with the surfaces within the mouldings 16 or 17 contributes to improved heat dissipation, since the heat transfer area is enlarged overall.
[0049] FIG. 3F shows a schematic plan view diagram of the refrigerant-exposed housing wall 12 of the motor housing 2.1. The side of the refrigerant-exposed housing wall 12 facing the motor housing 2.1 is thus shown. The electric motor bearing 15 for accommodating the electric motor 6 is formed on this side.
[0050] According to the invention, the DC link capacitors 9.1 (see FIG. 3D) are arranged substantially in the region of the middle of the motor housing 2.1 opposite the electric motor bearing 15. This improves the heat dissipation to the refrigerant in comparison with the concept shown in FIGS. 1A to 1C, in which the DC link capacitor 9 is situated outside the circumference of the motor housing 2.1. Furthermore, the electronic power switches 11.1 are arranged semicircularly on the outer radius, radially close to the inner walls of the compressor suction space. The position is thus optimised to the region of maximum heat output to the refrigerant. Furthermore, the power-electronic load flow is optimised in terms of the distances between the DC link capacitors 9.1 and the electronic power switches 11.1 in order to reduce inductive and capacitive interference, which is important for sufficient electromagnetic compatibility (EMC).
[0051] The refrigerant-exposed housing wall 12 can be designed as a separate housing part, which ensures fluid-tight sealing in its arrangement between the motor housing 2.1 and the inverter housing 4.1. For fastening, a screw-fastening to the motor housing 2.1 can be provided. For this purpose, the refrigerant-exposed housing wall 12 can have corresponding screw holes.
LIST OF REFERENCE NUMERALS
[0052] 1 Refrigerant compressor [0053] 2 Drive unit [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 shaft [0063] 7 Inverter circuit board [0064] 7.1 Inverter circuit board [0065] 8 Electrical plug-in terminal [0066] 9 DC link capacitor [0067] 9.1 DC link capacitor [0068] 10 Dashed region [0069] 11 Electronic power switches [0070] 11.1 Electronic power switches [0071] 12 Refrigerant-exposed housing wall [0072] 13 Tangential refrigerant inlet [0073] 14 Arrow/refrigerant flow path [0074] 15 Electric motor bearing [0075] 16 Moulding [0076] 17 Moulding [0077] 18 First component height [0078] 19 Second component height
