Drive

Abstract

The invention relates to a drive having an electric motor, the stator winding of which can be electrically fed by an inverter assembly of the drive, said inverter assembly having an annular structure composed of segments arranged one behind the other in the circumferential direction. A housing part of the drive has an annular gap which is situated radially between a conical region of the housing part and an inner surface of the housing part, said annular part being inserted into the annular gap and pressing the annular structure against the inner surface.

Description

[0001] drive

[0002] Description:

[0003] The invention relates to a drive.

[0004] It is generally known that a drive has an electric motor that can be fed by an inverter, for example a converter, so that the speed of the electric motor can be controlled or regulated.

[0005] From US 5 932 942 A, the closest prior art is a DC motor with improved thermal characteristics.

[0006] A drive unit is known from JP 2011 - 30405 A.

[0007] A drive device is known from DE 102010 017 522 A1.

[0008] An engine kit is known from DE 102015219 867 A1.

[0009] The invention is therefore based on the object of developing a drive that is as compact as possible.

[0010] According to the invention, the object is achieved by the drive according to the features specified in claim 1.

[0011] Important features of the invention in the drive, comprising an electric motor whose stator winding, in particular a three-phase stator winding or a three-phase stator winding, can be electrically fed by an inverter arrangement of the drive, are that the inverter arrangement has a ring-like structure made up of segments arranged one behind the other in the circumferential direction, in particular wherein the radial direction and the circumferential direction are related to the ring axis of the ring-like structure and / or the axial direction is aligned parallel to the ring axis of the ring-like structure, wherein a housing part of the drive has an annular gap which is arranged radially between a conical region, in particular an outer conical region, of the housing part and an inner surface, in particular a hollow surface, of the housing part, wherein the annular part is inserted into the annular gap and the annular structure presses against the inner surface,in particular the ring-like structure presses radially outwards against the inner surface, in particular wherein the ring part is arranged radially between the ring-like structure and the conical area.,

[0012] The advantage here is that the heat from the power semiconductors mounted on the ring-like structure can be dissipated via the ring part to the housing part, on the one hand, and via conductors of the ring-like structure and an insulating layer to a respective carrier, which in turn conducts the heat flow to the housing part, on the other hand. Thus, the heat loss from the power semiconductors is dissipated radially outwards on the one hand and radially inwards on the other, and in both cases is conducted to the housing part. The ring part is preferably made of aluminum, thus being a good heat conductor.

[0013] Furthermore, a particular advantage of the invention is that simply inserting the ring part expands the ring part, thus pressing the ring-like structure radially outward against the housing part. This is because the outer diameter of the conical area increases strictly monotonically in the axial direction. The ring part is preferably designed with a radial wall thickness that decreases in the axial direction, particularly of its base ring, and thus has a cylindrical outer circumference, except for its radial elevations.

[0014] In an advantageous embodiment, the ring axis is aligned coaxially with the rotational axis of a rotatably mounted rotor shaft of the electric motor. This is advantageous because it allows for simple manufacturing. In an advantageous embodiment, the ring part is pressed in the axial direction by a pressure disc, either directly or via an intermediate sealing ring. The advantage here is that the sealing ring not only transmits the axially directed force into the ring part, but also enables sealing of the contact area between the ring part and the conical area from the environment.

[0015] In an advantageous embodiment, the pressure washer is pressed in the axial direction by a screw screwed into a threaded hole in the housing part, in particular the conical area, in particular by the screw head of the screw, which protrudes axially through the pressure washer, in particular in such a way that the ring part is radially spread apart by the conical area. This is advantageous in that a permanently high contact force for pressing the power semiconductors against the respective conductors of the ring-like structure is ensured in a simple manner.

[0016] In an advantageous embodiment, the outer diameter of the conical area increases strictly monotonically with increasing axial distance from the pressure disc. The advantage here is that sliding the ring part in the axial direction causes it to expand radially, thus pressing the ring part onto the power semiconductors.

[0017] In an advantageous embodiment, the cone axis of the conical region is aligned parallel to the annular axis of the annular gap and / or the annular structure and / or is aligned parallel to the axial direction. This is advantageous because it enables simple manufacturing.

[0018] In an advantageous embodiment, the ring-like structure comprises conductors, in particular copper conductors or copper parts, wherein the ring-like structure is equipped with power semiconductors, in particular power semiconductor switches such as IGBTs or MOSFETs, in particular wherein the contact surfaces of the power semiconductors are electrically connected, in particular force-fitting or materially bonded, in particular pressed or welded, to conductors of the ring-like structure, wherein radially directed elevations are formed on the ring part, which each press a respective one of the power semiconductors, in particular a respective contact surface of the respective power semiconductor, onto at least one of the conductors and thus establish an electrical contact between the respective conductor and the respective contact surface, in particular wherein the ring-like structure pressed radially outwards by the ring part by means of the power semiconductors is pressed against the inner surface of the housing part.The advantage here is that the ring part presses the power semiconductors radially outwards by means of its radial elevations in that the radial elevations are elastically prestressed. A free space is formed in the circumferential direction between each of the radial elevations, but in particular at the same radial distance. The design and arrangement of the radial elevations of the ring part thus corresponds to the configuration of the conductors with power semiconductors. Each conductor can be designed as a copper part and serves as a conductor track for conducting electrical current. The conductors of the ring-like structure are preferably welded to contact surfaces, in particular contact pads, and the power semiconductor or the power semiconductors are pressed with their contact surfaces against a respective conductor. In this way, the power semiconductors can be interconnected to form an inverter arrangement and the inverter can be implemented on the ring-like structure.The ring-like structure can be manufactured in an unwound state and then deformed into a ring-like structure. This is because the conductor regions arranged circumferentially between the segments act as pivot joints, allowing the segments to pivot relative to each other. This allows the ring-like structure to be easily manufactured from the flat, unwound structure. This ring-like structure is then inserted into the annular gap of the housing part, followed by the ring part, which is spread open at the conical area during insertion, thus pressing the ring-like structure radially outward.

[0019] In an advantageous embodiment, the housing part is connected to a stator housing of the electric motor, in particular wherein the stator housing radially surrounds the stator winding. It is advantageous in this case that the inverter arrangement, in particular the ring-like structure, is inserted into the housing part in a first method step, in particular is inserted into the annular gap of the housing part, and then the housing part is axially plugged onto the stator housing, such that during this plugging in the inverter arrangement is electrically connected to the stator winding. In an advantageous embodiment, a bearing for rotatably supporting the rotor shaft of the electric motor is accommodated in the housing part, in particular radially within the conical region, in particular wherein the housing part functions as a bearing shield.The advantage here is that the housing part has, on the one hand, a mechanical holding function for the bearing and, on the other hand, a holding function for the inverter arrangement, and, on the other hand, the heat loss from the bearing and the inverter arrangement is absorbed and dissipated to the environment.

[0020] In an advantageous embodiment, the ring part is made of a plastic, in particular one that is electrically insulating and elastically deformable. This is advantageous because elastic prestressing is easily established, thus allowing a power semiconductor to be releasably pressed against a respective conductor with at least one of its contact surfaces.

[0021] In an advantageous embodiment, the ring part is interrupted in at least one circumferential direction. This is advantageous because there is no further risk of damage when the ring part is spread out over the conical area.

[0022] In an advantageous embodiment, each segment has a respective carrier, in particular a metallic carrier, wherein an insulating layer, in particular for electrical insulation, is arranged between the carrier and the respective conductor held by the carrier. It is advantageous that the conductors can be arranged on a stable base.

[0023] In an advantageous embodiment, the carrier is arranged radially outside the insulating layer, wherein the insulating layer is arranged radially outside the conductors, wherein the conductors are arranged radially outside the power semiconductor(s), wherein the power semiconductors are arranged radially outside the ring part. The advantage here is that a layered structure is possible in the radial direction and thus the ring part presses its radially outer next adjacent layer, in particular the power semiconductors, onto the conductors of the ring-like structure and thus electrically connects contact between contact surfaces of the power semiconductors and respective conductors of the ring-like structure. In addition, the ring part is elastically prestressed and thus presses the ring-like structure permanently against the inner surface of the housing part without generating any energy loss.

[0024] In an advantageous embodiment, either the inner surface is a cylindrical surface and the support is a cylinder section, in particular which has a circular segment-shaped cross-section, or the inner surface is polygonal, in particular has a polygonal cross-section, and the support is a cuboid-shaped plate.

[0025] The advantage here is that either a cost-effectively manufactured cylindrical inner surface can be used and the relative rotational position of the ring part to the ring-like structure must be maintained with a means for alignment, or easily manufactured cuboid-shaped segments can be used.

[0026] In an advantageous embodiment, the ring part has a base ring onto which the radial elevations are formed, with the power semiconductor being radially spaced from the base ring and being pressed radially outward by one of the radial elevations. Advantageously, the distribution and arrangement of the radial elevations on the ring part corresponds to the configuration of the ring-like structure with power semiconductors and components. Thus, the assembly plan influences the arrangement of the radially projecting elevations. The relative rotational position of the ring part to the ring-like structure must thus be ensured.

[0027] In an advantageous embodiment, the radial spacing area covered by the pressure ring, in particular the area of ​​radial spacing relative to the axis of rotation of the rotor shaft covered by the pressure ring, overlaps both with the radial spacing area covered by the conical area and with the radial spacing area covered by the annular part. The advantage here is that the pressure ring can be arranged axially adjacent to the conical area and also adjacent to the annular part and is pressed axially onto the annular part by at least one screw. In this way, the annular part is pushed further and further onto the conical area and thereby spread apart, so that the annular part presses radially outwards against the annular structure. To prevent failure of the annular part, this annular part has an interruption at one point on its circumference.

[0028] In an advantageous embodiment, the pressure ring has a continuously circumferentially extending step against which the ring part rests, in particular with the contact surface between the ring part and the pressure ring having a single radial distance. This is advantageous in that it enables precise centering of the pressure ring on the ring part.

[0029] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0030] The invention will now be explained in more detail using schematic illustrations:

[0031] Figure 1 shows a basic circuit diagram of an inverter arrangement for supplying a stator winding 5 of an electric motor.

[0032] Figure 2 shows a schematic diagram of an unwound conductor structure of the inverter arrangement.

[0033] Figure 3 shows the unfolded inverter arrangement in plan view.

[0034] Figure 4 shows an oblique view of the inverter arrangement before assembly, i.e. plugging it into the drive.

[0035] Figure 5 shows a top view of the cutaway drive.

[0036] In Figure 6, a ring part 53 of the drive for pressing the inverter arrangement against an inner side of a housing part 51 is shown in an oblique view.

[0037] Figure 7 shows a pressure disc 54 in an oblique view.

[0038] Figure 8 shows the drive in a partially exploded view.

[0039] Figure 9 shows a schematic diagram of the structure of each segment of the inverter arrangement.

[0040] As shown in Figure 1, the stator winding 5, comprising its winding phases II, V, W, is supplied from the AC-side terminal of an inverter 3, wherein a current detection device is arranged at the AC-side terminal of the inverter 3.

[0041] A parallel circuit consisting of an intermediate circuit capacitor 1 and a capacitor filter is connected to the DC-side connection of inverter 3. The DC-side connection is supplied from an intermediate circuit with an upper intermediate circuit potential Uz+ and a lower intermediate circuit potential Uz-.

[0042] The inverter 3 has three half-bridges of semiconductor switches, i.e. power semiconductors 10, connected in parallel.

[0043] As shown in Figure 2, the interconnection of the power semiconductors 10 with the other components is carried out by means of a structure of conductors 20, in particular copper parts.

[0044] The conductors 20 are directly welded at their nodes and with contact areas of the power semiconductors 10.

[0045] The conductors 20 are mechanically held by segments (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32) which are arranged in a row and are pivotable relative to their nearest neighbour.

[0046] The structure formed from the conductors 20 is preferably equipped with power semiconductors 10, in that contact surfaces of the power semiconductors 10 are welded to respective conductors 20, and with printed circuit boards 34, which are also welded to respective conductors 20. In addition, contact elements 33 are also equipped on the printed circuit boards 34, which protrude axially from the structure of conductors 20 and thus enable a plug-in connection of the inverter arrangement to the stator winding, in particular to its terminals (U, V, W).

[0047] Since the segments (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32) are pivotable to their next adjacent segments (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32), the entire row is deformable into a ring-like structure, as shown in Figure 4.

[0048] This ring-like structure is arranged on the B-side of the electric motor of the drive and inserted into a housing part 51, which is connected to the stator housing 81 of the electric motor. On the A-side, i.e. on the side of the stator housing 81 facing away from the housing part 51 in the axial direction, a bearing shield 80 for receiving a bearing of the rotor shaft 82 is connected to the stator housing 81. The ring-like structure, together with a ring part 53, which has radially projecting elevations 60, is inserted into an annular gap in the housing part 51, which is delimited radially inward by a conical region 56 of the housing part 51.

[0049] The outer diameter of the conical region 56 increases strictly monotonically with increasing axial distance from the stator housing 81. Thus, the gap width of the annular gap decreases strictly monotonically with increasing distance from the stator housing 81.

[0050] After insertion, the ring part 53 directly contacts the conical area 56 and is elastically preloaded such that the ring part 53 presses the ring-like structure radially outward against a cylindrical inner surface of the housing part 51. The radially directed elevations 60 of the ring part 53 press against the power semiconductors 10 or other components. In this way, contact surfaces of the power semiconductors 10 that are not welded to the conductors 10 are pressed against the respective conductors 20 of the conductor structure, thus establishing electrical contact.

[0051] The conductors 20 in turn press via an insulating layer 52 onto a respective carrier 58 of a respective segment (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32).

[0052] Each of the segments (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32) is formed as a cylindrical shell surface section on its side facing the inner surface of the housing part 51, so that this respective cylindrical shell surface section is pressed flat against the cylindrical inner surface of the housing part 51. For this purpose, the cylinder radius of the cylindrical inner surface of the housing part 51 is equal to the cylinder radius of the cylindrical shell surface section.

[0053] The carrier 58 thus offers the conductors 20 a flat support surface as the radially inner surface and a bulbous, in particular cylindrical, lateral surface section as the radially outer surface. As schematically shown in Figure 9, the conductors 20 rest on the carrier 58 via an intermediate insulating layer 52 and are equipped with a power semiconductor 10 or another component on their side facing away from the carrier 58. The contact force direction 91 generated by the radial elevations 60 of the ring part 53 presses the power semiconductor 10 of Figure 9 with its contact surface 90 against the insulating layer 52. To establish electrical contact between the contact surface 90 and the electrically conductive carrier 58, recesses are provided in the insulating layer 52, thus enabling welding contact in the region of the recesses.

[0054] As shown in Figure 9, a terminal pin of the power semiconductor 10 can also be electrically connected directly to another of the conductors 20.

[0055] Since the conductors 20 are designed to be flexible, they function as a pivot joint and a pivoting movement of the segments (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32) closest to one another is possible.

[0056] The housing part 51 can be designed as a bearing receiving part, so that a further bearing of the rotor shaft 82 can be received in the housing part 51, in particular radially within the conical area 56 of the housing part 51.

[0057] Thus, after the structure has been inserted into the annular gap, the housing part 51 can be moved toward the stator housing 81 and then electrically connected using the contact elements 33. This enables simple manufacturing.

[0058] When the pressure plate 54 is screwed on by means of screws 55 passing through the pressure plate 54, the threaded areas of the screws 55 are screwed into axially directed threaded holes which are introduced into the conical area 56, and the screw heads of the screws 56 press the pressure plate 54 onto the ring part 53 via an intermediate sealing ring 57, so that the ring part 53 presses against the conical area 56 in the axial direction, i.e., the direction of force 91, whereby the ring part 53 is increasingly widened radially and the ring-like structure is thereby pressed radially outwards against the cylindrical inner surface of the housing part 51. The sealing ring 57 therefore not only generates elastic spring force for pressing the ring part 53, but also additionally seals the pressure plate 54 against the ring part 53.In further embodiments according to the invention, the supports are designed as cuboid plates instead of cylinder sections and the inner surface of the housing part 51 is correspondingly polygonal, so that each support of the respective segment lies flat and the rotational position of the ring-like structure can be clearly determined.

[0059] List of reference symbols

[0060] 1 DC link capacitance

[0061] 2 filters

[0062] 3 inverters

[0063] 4 Current measurement

[0064] 5 Stator winding

[0065] 10 power semiconductors

[0066] 20 conductors, especially copper part

[0067] 21 segments

[0068] 22 segments

[0069] 23 segments

[0070] 24 segments

[0071] 25 segments

[0072] 26 segments

[0073] 27 segments

[0074] 28 segments

[0075] 29 segments

[0076] 30 segments

[0077] 31 segments

[0078] 32 segments

[0079] 33 Contact element

[0080] 34 circuit board

[0081] 51 Housing part

[0082] 52 Insulating layer

[0083] 53 Ring part

[0084] 54 Pressure disc

[0085] 55 screw

[0086] 56 Cone area of ​​the housing part

[0087] 57 Sealing ring, especially O-ring

[0088] 58 carriers

[0089] 60 radially directed elevation, especially radial 80 bearing shield

[0090] 81 Stator housing

[0091] 90 Contact area of ​​the power semiconductor 10

[0092] 91 Contact force direction

[0093] 92 welding point

[0094] A1 first connection

[0095] A2 second connection

[0096] E1 first conductor

[0097] E2 second conductor

[0098] PE earthing connection, connection for protective conductor

[0099] C1 component

[0100] C2 component

[0101] C3 component

[0102] C4 component

[0103] C5 component

[0104] U-phase

[0105] V Phase

[0106] W phase

Claims

Patent claims:

1. Drive, comprising an electric motor, the stator winding of which, in particular a three-phase stator winding or a three-phase stator winding, can be electrically fed by an inverter arrangement of the drive, characterized in that the inverter arrangement has a ring-like structure made up of segments arranged one behind the other in the circumferential direction, in particular wherein the radial direction and the circumferential direction are related to the ring axis of the ring-like structure and / or the axial direction is aligned parallel to the ring axis of the ring-like structure, wherein a housing part of the drive has an annular gap which is arranged radially between a conical region, in particular an outer conical region, of the housing part and an inner surface, in particular a hollow surface, of the housing part, wherein the annular part is inserted into the annular gap and the annular structure presses against the inner surface,in particular the ring-like structure presses radially outwards against the inner surface, in particular wherein the ring part is arranged radially between the ring-like structure and the conical area., 2. Drive according to claim 1, characterized in that the ring axis is aligned coaxially to the axis of rotation of a rotatably mounted rotor shaft of the electric motor.

3. Drive according to one of the preceding claims, characterized in that the annular part is pressed in the axial direction by a pressure disc directly or via an intermediate sealing ring.

4. Drive according to one of the preceding claims, characterized in that the pressure disc is pressed in the axial direction by a screw screwed into a threaded bore of the housing part, in particular the conical area, in particular by the screw head of the screw which projects axially through the pressure disc, in particular in such a way that the annular part is spread radially by the conical area.

5. Drive according to one of the preceding claims, characterized in that the outer diameter of the conical area increases with increasing axial distance to the Pressure disc increases strictly monotonically and / or that the cone axis of the cone area is aligned parallel to the ring axis of the annular gap and / or the ring-like structure and / or is aligned parallel to the axial direction.

6. Drive according to one of the preceding claims, characterized in that the ring-like structure comprises conductors, in particular copper conductors or copper parts, which are equipped with power semiconductors, in particular power semiconductor switches such as IGBTs or MOSFETs, in particular wherein the contact surfaces of the power semiconductors are electrically connected, in particular force-fitting or materially bonded, in particular pressed or welded, to conductors of the ring-like structure, wherein radially directed elevations are formed on the ring part, which each press a respective one of the power semiconductors, in particular a respective contact surface of the respective power semiconductor, onto at least one of the conductors and thus establish an electrical contact between the respective conductor and the respective contact surface,in particular, wherein the ring-like structure pressed radially outwards by the ring part by means of the power semiconductors is pressed against the inner surface of the housing part., 7. Drive according to one of the preceding claims, characterized in that the housing part is connected to a stator housing of the electric motor, in particular wherein the stator housing radially surrounds the stator winding.

8. Drive according to one of the preceding claims, characterized in that in the housing part, in particular radially within the conical area, a bearing for the rotatable mounting of the rotor shaft of the electric motor is accommodated, in particular wherein the housing part functions as a bearing shield.

9. Drive according to one of the preceding claims, characterized in that the ring part is made of a plastic, in particular which is electrically insulating and elastically deformable.

10. Drive according to one of the preceding claims, characterized in that the ring part is interrupted in the circumferential direction at least at one point.

11. Drive according to one of the preceding claims, characterized in that each segment has a respective carrier, in particular a metallic carrier, wherein an insulating layer, in particular for electrical insulation, is arranged between the carrier and the respective conductor held by the carrier.

12. Drive according to one of the preceding claims, characterized in that the carrier is arranged radially outside the insulating layer, wherein the insulating layer is arranged radially outside the conductors, wherein the conductors are arranged radially outside the power semiconductor(s), wherein the power semiconductor is arranged radially outside the annular part.

13. Drive according to one of the preceding claims, characterized in that either the inner surface is a cylindrical surface and the carrier is a cylinder section, in particular which has a circular segment-shaped cross-section, or that the inner surface is polygonal, in particular has a polygonal cross-section, and the carrier is a cuboid-shaped plate.

14. Drive according to one of the preceding claims, characterized in that the ring part has a base ring on which the radial elevations are formed, wherein the power semiconductor is radially spaced from the base ring and is pressed radially outwards by one of the radial elevations.

15. Drive according to one of the preceding claims, characterized in that the radial distance region covered by the pressure ring, in particular the region of radial distances related to the axis of rotation of the rotor shaft covered by the pressure ring, overlaps both with the radial distance region covered by the conical region and with the radial distance region covered by the ring part, and / or that the pressure ring has a step which runs continuously around the circumference and against which the ring part rests, in particular wherein the contact surface between the ring part and the pressure ring has a single radial distance.

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