Rotor carrier for an electric machine

Abstract

Rotor carrier for a rotor (2.2) of an electrical machine (2), wherein the rotor carrier comprises a tubular base body (13), wherein the base body (13) has means on an outer circumferential surface facing the rotor (2.2) which enable a positive and / or non-positive connection between the base body (13) and the rotor (2.2), wherein receptacles for parts of a coupling (7) are provided over part of the axial extent on an inner circumferential surface of the base body (13) facing away from the rotor (2.2), and wherein the base body (13) is connected to a hub (4) by a connecting element (14) arranged on an inner circumferential surface adjacent to the receptacles, characterized in that the connecting element (14) is formed by a radially extending annular flange, and in that the radially extending annular flange is arranged in the axial direction between the receptacles and one end of the base body (13).

Description

[0001] The invention relates to a rotor carrier for an electric machine, in particular in a hybrid drive train of a vehicle.

[0002] In addition to solid rotors, ring-shaped rotors arranged around a rotational axis are also known in the prior art for electrical machines. For example, DE 10 2005 053 887 A1 or US 2013 / 0192947 A1 disclose that a rotor core is mounted on a sleeve, and the sleeve is directly connected to a downstream torque converter.

[0003] Further examples from the prior art are DE 10 2016 215 595 A1, WO 2017 / 196601 A1, DE 10 2009 045 727 A1, DE 10 2006 056 512 A1 or DE 10 2009 059 944 A1.

[0004] The object of the invention is to provide an alternative to the prior art, which has better support of the rotor and optimized use of installation space, as well as being simple and cost-effective to manufacture.

[0005] The problem is solved by the features of the independent patent claims. Advantageous embodiments emerge from the subclaims, the description, and the figures.

[0006] According to the invention, a rotor carrier for a rotor of an electrical machine, wherein the rotor carrier comprises a tubular base body, wherein the base body has means on an outer circumferential surface facing the rotor which enable a positive and / or non-positive connection between the base body and the rotor, wherein receptacles for parts of a coupling are provided over part of the axial extent on an inner circumferential surface facing away from the rotor, and wherein the base body is connected to a hub by a connecting element arranged adjacent to the receptacles, characterized in that the connecting element is formed by a radially extending annular flange, and in that the radially extending annular flange is arranged in the axial direction between the receptacles and one end of the base body.

[0007] To connect the base body and the rotor, for example, a profile is provided on the base body, in which elevations and / or depressions are provided at least on the outer circumferential surface, which interact with corresponding counterparts on the inner surface of the rotor to create a positive connection. Alternatively or cumulatively, elevations or depressions in the circumferential direction, such as steps or annular grooves, can also be provided, which can be used for a positive or non-positive connection. Instead of a positive connection, a non-positive connection can also be provided, in which the rotor is connected to the base body via clamping devices, screw connections, rivets or the like. In principle, material-to-material connections are also possible, in which the rotor is welded to the base body.Combinations are also possible in which different types of connections are used, for example to represent or secure connections in different directions.

[0008] The base body is connected to a hub by a connecting element to transmit torque. In this context, a hub refers to and includes not only a conventional hub mounted on a shaft, but also a direct connection to a shaft or a connection to a subsequent component in the drive train, such as a converter housing.

[0009] The connection to the hub is established via a flange area of ​​the connecting element, which is shaped accordingly in the radial direction. Receptacles for clutch components are provided on the inner circumferential surface of the base body. These components are preferably grooves or elevations in the axial direction that serve as receptacles for the plates of a multi-plate clutch. The base body thus simultaneously represents the outer plate carrier of a clutch. The clutch can, for example, separate the power flow from or to an internal combustion engine located upstream in the drive train.

[0010] Further rotor supports according to the invention for a rotor of an electrical machine, wherein the rotor support comprises a tubular base body, wherein the base body has means on an outer circumferential surface facing the rotor which enable a positive and / or non-positive connection between the base body and the rotor, wherein receptacles for parts of a coupling are provided on an inner circumferential surface facing away from the rotor over part of the axial extent, and wherein the base body is connected to a hub by a connecting element arranged adjacent to the receptacles, are characterized in that the base body is formed in one piece with a converter housing, and in that the connecting element is formed by a radially extending housing wall or a housing cover of the converter housing.

[0011] The basic structure is as previously described, with the base body being formed integrally with a converter housing. The connecting element is formed by a radially extending housing wall or a housing cover, which is arranged axially adjacent to receptacles for parts of a clutch. In other words, the converter housing comprises the sleeve-shaped base body to which the rotor is attached. Within this base body runs a housing wall designed as a radial connecting element, and the converter housing has an axially open area formed by the base body for receiving the clutch. This design allows the rotor carrier to be designed with a small installation space.

[0012] Embodiments of a rotor carrier are characterized in that the annular flange is formed by a separate component that is firmly connected to the inner circumferential surface in both the axial and circumferential directions. By designing the base body and connecting element as separate components, the geometry of the individual components is simplified, thus also facilitating production. Welding, riveting, clinching, or screwing are particularly suitable for the connection between the base body and the annular flange. Other positive-locking connections, in which corresponding projections on the base body or connecting element engage corresponding recesses on the counterpart, are also possible. Combinations of different connection types are also possible.

[0013] Alternative designs of a rotor carrier are characterized by the annular flange being formed integrally with the base body. A one-piece design of the base body and connecting element improves the flow of force within the component and eliminates assembly effort for the connection. Manufacturing processes such as primary forming, flow forming, or forming are particularly suitable for the production of such rotor carriers.

[0014] Rotor carriers according to embodiments are characterized in that the base body is longer than the rotor at least at one axial end. The length refers in particular to the length of the rotor's laminated core. A base body that protrudes beyond the rotor can, on the one hand, improve the positioning of the components through shoulders, projections, and the like, and, on the other hand, improve cooling with an appropriate design. Furthermore, the protruding rotor carrier, or more precisely the protruding base body, provides a certain degree of mechanical protection for the rotor.

[0015] The protruding base body can also be used in particular for balancing the rotor by attaching balancing weights to the protruding base body or by removing material locally.

[0016] Embodiments of a rotor carrier are characterized in that the base body has at least one recess extending radially through for the passage of oil. At least one recess is provided to guide oil for lubrication and cooling from the inside to the outside. This recess is preferably arranged in the region of an axial end of the laminated core or opening into an oil channel formed between the rotor carrier and the laminated core.

[0017] Preferred embodiments of a rotor carrier are characterized in that the recess is arranged in the bottom region of a groove provided on the inner circumferential surface. In addition to the recesses, further guide elements can be provided on the connecting element or base body in order to guide oil impinging from the inside to the recesses or to be able to release it in a targeted manner to the outside. These guide elements can be designed as channels, annular grooves, depressions or other grooves, preferably inclined towards the recess. Alternatively, raised guide elements can also be designed as struts, projections or steps. These guide elements can preferably also serve as receptacles for the parts of a coupling and / or can be used in the further axial course to create a positive connection between the connecting element and the base body.

[0018] Rotor carriers according to preferred embodiments are characterized by having a plurality of recesses distributed over the circumference. For a more even distribution of the oil and to avoid imbalance, a plurality of recesses are distributed, preferably symmetrically, over the circumference.

[0019] Preferred embodiments of a rotor carrier are characterized by the fact that several recesses are arranged in different axially spaced planes. Several recesses can also be provided at different axial positions, which can, for example, improve cooling in the axial direction on both sides.

[0020] Rotor carriers according to embodiments are characterized in that the base body has a different thickness in the axial direction in the region of the receptacles than in the region of the connecting element. The base body thus has a cross-section that changes in the radial direction at at least one point along its axial extent. This can be used, for example, as a stop for positioning the base body and the connecting element relative to one another in order to be able to determine the position quickly and easily during assembly of the base body and connecting element. The use of circumferential shoulders or projections is therefore preferred, as these can form stops in the axial direction against which the corresponding counterpart can be pushed. Furthermore, the different wall thicknesses allow the amount of material to be adapted to the loads in order to achieve the lightest possible construction.

[0021] Embodiments of a rotor carrier are characterized by the fact that the base body is made from a formed tube section. Since the basic shape of the base body is given in a tube section, a base body can advantageously be produced from a tube section, which is formed into a base body through appropriate forming and / or processing steps. Alternatively, the base body can also be formed from sheet metal.

[0022] Rotor carriers according to embodiments are characterized in that the connecting element has an axial section that runs parallel to the base body and is connected to it. In addition to a butt contact of the connecting element with the base body, the connection area of ​​the connecting element can be formed, for example, to form a coaxial section with the base body, which section runs within the base body. This connection area can simplify positioning in the base body and the establishment of the connection. A coaxial extension also improves the stability of the connecting element.

[0023] Preferably, the axial section rests against the base body. Contact between the connecting element and the base body along the axial section can further improve the stability of the rotor arm. Furthermore, the contact area can also be used as a connection area or part of the connection area.

[0024] The axial section of the connection area is preferably arranged on the side of the connecting element facing away from the receptacles for parts of the coupling.

[0025] The connecting element is preferably provided in the region of the central half of the base body. The coaxial region of the connecting element is shorter than the base body, with the axial section of the connecting element preferably having an axial length of less than 33% of the axial length of the base body. This allows the force flow and the load on the connecting element to be reduced and overall axial space to be saved, since subsequent components on an output shaft can be provided at least partially within the rotor projecting beyond the connecting element.

[0026] A further advantageous effect of a two-part rotor carrier design with a base body and connecting element is that, if necessary, identical connecting elements can be used for different base bodies of different rotors, which is advantageous in terms of manufacturing and costs. This effect also applies analogously to the base body, since, depending on the drive train, different connecting elements can be used to install identical base bodies.

[0027] A further aspect of the invention is a hybrid module comprising an input shaft, a clutch, an electric motor, a torque converter, and an output shaft, which is characterized in that a rotor carrier according to one of the described embodiments is provided. This allows the described advantages regarding axial installation space and the like to be utilized in a hybrid module.

[0028] The embodiments are not limited to the above examples and can be achieved through further corresponding configurations. The features of the embodiments can be combined with one another in any way.

[0029] The invention is explained in more detail below with reference to the figures. Identical or similar elements are designated by identical reference numerals. The figures show in detail: Fig. 1 shows a schematic section of an embodiment of a hybrid module. Fig. 2 shows a partial area of ​​a schematic section of a hybrid module in the area of ​​the rotor carrier in one embodiment. Fig. 3 shows a partial area of ​​a schematic section of a hybrid module in the area of ​​the rotor in one embodiment. Fig. 4 shows a partial area of ​​a schematic section of a hybrid module in the area of ​​the rotor in one embodiment.

[0030] Fig. Figure 1 shows a hybrid module according to an exemplary embodiment in a schematic sectional view, with one half omitted for symmetry. The hybrid module comprises a housing (1) within which an electric machine (2) is arranged, having a stator (2.1) that is rotationally fixed relative to the housing (1) and a rotatable rotor (2.2).

[0031] The hybrid module has a torque converter (5). The converter housing (5.1) is connected to a hub (4). A pump impeller (5.3) of the torque converter (5) is fixedly connected to a converter housing (5.1) of the torque converter (5). A stator (5.4) of the torque converter (5) is non-rotatably supported in one direction of rotation via a freewheel. A turbine impeller (5.5) of the torque converter (5) is connected to a turbine shaft (5.2) of the torque converter (5). The hybrid module further has an additional, optional torsional vibration damper (10), which is arranged inside and on the converter housing (5.1). The turbine shaft (5.2) is connected to an output shaft (6) of an automatic transmission (not shown in detail). A lock-up clutch (11) is also arranged inside the converter housing (5.1). By closing the lock-up clutch (11), the converter housing (5.1) can be directly connected to the turbine shaft (5.2).

[0032] The hub (4) is designed as a hollow shaft which is arranged coaxially to the output shaft (6) and envelops it. In the example shown, the input shaft (3) is also designed as a hollow shaft and is arranged coaxially to the hub (4). Between the output shaft (6) and the hub (4), between the hub (4) and the input shaft (3), and between the input shaft (3) and the housing (1), several bearings (12) are provided which support the components relative to one another. On its outer side, the hub (4) is connected to the converter housing (5.1) and, via the rotor carrier, to one side of the clutch (7).

[0033] A vibration damper (8) is provided on the input shaft (3), which is connected to a combustion engine (not shown). The vibration damper (8) reduces any torsional vibrations in order to supply the hybrid module with as uniform a torque or rotational movement as possible. At the same time, the vibration damper (8) can compensate for position and alignment tolerances between the combustion engine and the hybrid module. The input shaft (3) is also connected to part of the clutch (7).

[0034] The housing (1) separates a wet chamber of the hybrid module from a dry chamber. The wet chamber is sealed from the dry chamber by a seal (9), which is preferably arranged directly next to a bearing (12).

[0035] A clutch (7) is also provided within the housing (1), with which the combustion engine can be separated from the rest of the drive train. For this purpose, the clutch (7) is arranged in the power flow between the input shaft (3) and the hub (4). More precisely, the parts of the clutch (7) are connected to the input shaft (3) and to a rotor carrier. In the illustrated embodiment, the clutch (7) is designed as a multi-disk clutch.

[0036] The rotor (2.2) of the electric machine (2) is connected to a base body (13) of the rotor carrier. The base body (13) has a tubular structure, on whose outer circumferential surface the rotor (2.2) is mounted. In the illustrated embodiment, the axial end of the base body (13) facing the torque converter (5) is deformed outward to form a collar that partially covers the rotor (2.2) in the radial direction. The collar therefore protects the rotor (2.2) and can be used as a stop for positioning the rotor (2.2). By means of corresponding recesses or balancing elements (not shown), the collar can also be used to guide oil for lubricating and cooling the electric machine (2) or for balancing the electric machine (2). The opposite axial end of the base body (13) is aligned with the outer circumferential surface to enable the assembly of the rotor (2.2).To secure the axial position of the rotor (2.2) on the base body (13), a locking element (15) is provided in a groove. The locking element (15) can be at least partially resilient to compensate for manufacturing tolerances and the like.

[0037] In addition to the base body (13), the rotor carrier comprises a connecting element (14). In the illustrated embodiment, the connecting element (14) is largely radially extending, annular. A short, axial section of the connecting element (14), which runs coaxially to the base body (13), forms a connection area with which the connecting element (14) and the base body (13) are connected. The base body (13) has a shoulder on its inner circumferential surface which acts as a stop and positioning aid for the connecting element (14). The outer circumferential surface of the connection area is firmly connected to the inner circumferential surface of the base body (13), preferably by welding, although other types of connection are also possible.

[0038] The base body (13) is provided with a profile on the side facing away from the torque converter (5) to form elevations and depressions distributed around the circumference in the manner of a spline. These elevations and depressions serve as receptacles for parts of the clutch (7), in the example shown, as receptacles for the outer plates of the clutch (7), whereby the base body (13) represents the outer plate carrier of the clutch (7).

[0039] The Fig. 2, Fig. 3 and Fig. 4 each show a part of a hybrid module in the area of ​​the clutch analogous to Fig. 1 for different examples. Fig. 5 to 7 have in common that an input shaft (3) is connected to a clutch (7), more precisely its input side. Parts of the clutch, more precisely the output side, are connected to a base body (13), which also forms the outer disk carrier. The connecting element (14) is connected to the hub (4) and thus to the further drive train. Furthermore, the connecting element (14) is connected to the base body (13), and the base body (13) accommodates a rotor (2.2) on an outer circumferential surface. The connecting element (14) and the base body (13) together thus form the rotor carrier.

[0040] The connection area of ​​the connecting element (14) is in Fig. 2 is designed as a section coaxial with the base body (13) and shaped in the direction of the torque converter (5). The connection area has approximately a quarter of the length of the base body (13) in the axial direction. This length prevents the connecting element (14) from tilting relative to the base body (13) during assembly and provides a larger surface area for establishing the connection. The connection can be made, in particular, by spot welding, riveting, or clinching.

[0041] At Fig. 3 is basically like that in Fig. 1, but the rotor carrier is constructed as a single piece, consisting of the base body (13) and the connecting element (14). A single-piece design increases the manufacturing effort for the rotor carrier, but the force flow in the rotor carrier can be improved, and the assembly effort for connecting the base body (13) and the connecting element (14) is eliminated.

[0042] In the example in Fig. 4, the base body (13) is formed integrally with the converter housing (5.1). In this example, the sleeve-shaped base body (13) is formed by an axial end of the converter housing (5.1). The connecting element (14) is designed as a separate component, but could alternatively also be designed as a single piece. The connecting element (14) thus represents part of the converter housing (14) in the form of a housing cover. To position the connecting element (14), a shoulder is provided on the inner circumferential surface of the base body (13), against which the connecting element (14) is pushed.

[0043] The base body (13) or the converter housing (5.1) has an area that protrudes axially beyond the connecting element (14), in which receptacles for parts of the clutch (7) outside the torque converter (5) can be accommodated. Within the torque converter (5), the inner circumferential surface of the base body (13) is used to accommodate parts of the lock-up clutch (11), thereby achieving high installation space utilization and thus reducing the required axial installation space.

[0044] The invention is not limited to the described embodiments. As explained above, only individual advantageous features may be provided, or various features from different examples may be combined.

Claims

[1] Rotor carrier for a rotor (2.2) of an electrical machine (2), wherein the rotor carrier comprises a tubular base body (13), wherein the base body (13) has means on an outer circumferential surface facing the rotor (2.2) which enable a positive and / or non-positive connection between the base body (13) and the rotor (2.2), wherein on an inner circumferential surface of the base body (13) facing away from the rotor (2.2) over part of the axial extent, receptacles for parts of a coupling (7) are provided, and wherein the base body (13) is connected to a hub (4) by a connecting element (14) arranged on an inner circumferential surface adjacent to the receptacles, characterized by that the connecting element (14) is formed by a radially extending annular flange, and that the radially extending annular flange is arranged in the axial direction between the receptacles and one end of the base body (13). [2] Rotor carrier for a rotor (2.2) of an electrical machine (2), wherein the rotor carrier comprises a tubular base body (13), wherein the base body (13) has means on an outer circumferential surface facing the rotor (2.2) which enable a positive and / or non-positive connection between the base body (13) and the rotor (2.2), wherein on an inner circumferential surface of the base body (13) facing away from the rotor (2.2) over part of the axial extent, receptacles for parts of a coupling (7) are provided, and wherein the base body (13) is connected to a hub (4) by a connecting element (14) arranged on an inner circumferential surface adjacent to the receptacles, characterized by that the base body (13) is formed in one piece with a converter housing (5.1), and that the connecting element (14) is formed by a radially extending housing wall or a housing cover of the converter housing (5.1). [3] Rotor carrier according to claim 1, characterized by that the ring flange is formed by a separate component which is firmly connected to the inner circumferential surface in both the axial and circumferential directions. [4] Rotor carrier according to claim 1, characterized by that the ring flange is formed in one piece with the base body (13). [5] Rotor carrier according to one of the preceding claims, characterized by that the base body (13) is longer than the rotor (2.2) at least at one axial end. [6] Rotor carrier according to one of the preceding claims, characterized by that the base body (13) has at least one recess which is continuous in the radial direction for the passage of oil. [7] Rotor carrier according to claim 6, characterized by that the recess is arranged in the bottom region of a groove provided on the inner peripheral surface. [8] Rotor carrier according to claim 6 or 7, characterized bythat several recesses are arranged around the circumference. [9] Rotor carrier according to one of claims 6 to 8, characterized by that several recesses are arranged in different axially spaced planes. [10] Rotor carrier according to one of the preceding claims, characterized by that the base body (13) has a different thickness in the axial direction in the area of ​​the receptacles than in the area of ​​the connecting element (14). [11] Rotor carrier according to one of the preceding claims, characterized by that the base body (13) is made from a formed pipe section. [12] Rotor carrier according to one of the preceding claims, characterized by that the connecting element (14) has an axial section which runs parallel to the base body (13) and is connected thereto. [13] Hybrid module comprising an input shaft (3), a clutch (7), an electric machine (2), a torque converter (5) and an output shaft (6), characterized by that a rotor carrier according to one of claims 1 to 12 is provided.

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