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 pot-shaped 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 facing away from the rotor (2.2), receptacles for parts of a coupling (7) are provided over part of the axial extent, wherein the base body (13) covers only part of the axial extent of the rotor (2.2), wherein the rotor carrier comprises a second support body (14), and wherein the support body (14) has a radially extending flange, and that the base of the base body (13) and the flange of the support body (14) are connected to one another, characterized in that that the base body (13) is connected to a hub (4) by a radially extending base, that the support body (14) also has means on an outer circumferential surface which enable a positive and / or non-positive connection between the support body (14) and the rotor (2.2), and that a converter housing (5.1) is designed as a support body (14), and wherein the base body (13) and the support body (14) have at least one recess which is continuous in the radial direction for the passage of oil.

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, annular rotors arranged around a rotational axis are also known in the prior art for electrical machines. For example, DE 10 2013 221 643 A1 discloses that a rotor core is mounted on an outer disk carrier and connected to the rotational axis. Other prior art designs are known, for example, from DE 10 2005 040 771 A1, DE 10 2015 209 898 A1, DE 10 2013 201 667 A1, DE 11 2010 003 514 T5, DE 10 2014 215 292 A1, WO 2015 / 018 575 A1, DE 10 2004 055 179 A1, or DE 101 28 424 A1.

[0003] 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.

[0004] The problem is solved by the features of the independent patent claims. Advantageous embodiments emerge from the subclaims, the description, and the figures.

[0005] According to the invention, a rotor carrier for a rotor of an electrical machine is provided, wherein the rotor carrier comprises a pot-shaped 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 on an inner circumferential surface facing away from the rotor, receptacles for parts of a coupling are provided over part of the axial extent, and wherein the base body is connected to a hub by a radially extending base, characterized in that the base body covers only part of the axial extent of the rotor, that the rotor carrier comprises a second support body which also has means on an outer circumferential surface which enable a positive and / or non-positive connection between the support body and the rotor, that the support body has a radially extending flange,and that the bottom of the base body and the flange of the support body are connected to each other.,

[0006] 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.

[0007] The base body is connected to a hub by a radially extending base 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.

[0008] The base is preferably formed integrally with the base body, giving the base body a pot-like shape. Designs are also possible in which the base is manufactured separately and firmly connected to the base body, for example, by welding.

[0009] Receptacles for clutch components are provided on the inner circumferential surface of the axial section 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 flow of power from or to an internal combustion engine located upstream in the drive train.

[0010] The base body extends only over part of the axial extent of the rotor, whereby the base body can protrude beyond the rotor in the axial direction. The radially extending base is preferably provided at one axial end of the base body. The base is preferably arranged axially within the rotor, thereby achieving a favorable force flow.

[0011] In order to support the rotor over the entire axial length, the rotor carrier has a support body which is designed as a separate component and the rotor carrier is therefore constructed in two parts.

[0012] On an outer circumferential surface, the support body also has means that enable a positive and / or non-positive connection between the support body and the rotor. These means are preferably designed analogously to the previously described means on the base body.

[0013] The support body further comprises a radially extending flange for connecting the support body to the base of the base body, whereby the base body and the support body are arranged firmly relative to one another and a rotor carrier is formed for the rotor. The connection between the base body and the support body is preferably made by riveting, screwing, or welding, although other connection types are also possible. The two-part design of the rotor carrier simplifies the geometry of the individual components and, at the same time, the modular design allows the individual components to be used in other variants of a hybrid module if necessary.

[0014] Embodiments of a rotor carrier are characterized in that the support body has a flange as a separate component, which is shorter or longer in the radial direction than the base of the base body. The rotor carrier is connected to a hub. For this connection, the base or the flange preferably extend to the hub or are connected to a converter housing which is firmly connected to the hub. In addition to the base and flange having the same radial length, with both being connected to the hub, it is preferred that only the base of the base body or the flange of the support body extend to the hub, as this can potentially save material and axial installation space at the hub.

[0015] Rotor carriers according to further embodiments are characterized in that a converter housing is designed as a support body. Instead of a separate component as the support body, the converter housing can be designed as a support body at its end facing the clutch. Here, the means for receiving the rotor are formed accordingly on a circumferential surface of the converter housing, which has the same diameter as the base body. In these embodiments, the flange of the support body is provided accordingly at the axial end of the converter housing, and the base of the base body is connected directly to the converter housing or the flange on the converter housing. This allows the number of components to be reduced and installation space to be saved. As a component of the converter housing, the support body also has a high level of rigidity.

[0016] Embodiments of a rotor carrier are characterized by the base body having a different thickness than the support body. Depending on the loads encountered and the proportion of axial support of the rotor, the base body and the support body can be designed with different wall thicknesses. Due to the different wall thicknesses, which allow adaptation to the load, material and thus weight and cost savings can be achieved compared to a rotor carrier extending in one piece over the axial length.

[0017] Rotor carriers according to embodiments are characterized in that the base body and the support body are connected to each other by rivets. Rivets allow the components to be securely joined together easily and quickly without the introduction of large amounts of heat.

[0018] Rotor carriers according to embodiments are characterized in that the base body and the support body are connected by welding. Welding allows the components to be easily and securely joined together without the need for additional components such as screws or rivets.

[0019] Embodiments of a rotor carrier are characterized by the base body having a greater axial overlap with the rotor than the support body. The axial distribution between the base body and support body can, in principle, be chosen arbitrarily. However, with regard to the required installation space, it is advantageous if the base body covers a larger portion of the rotor in the axial direction, since the base body simultaneously encloses parts of the coupling.

[0020] In embodiments, rotor carriers are characterized in that the base body and / or the support body are longer than the rotor at least at one axial end. Due to the axial projection, at least partial mechanical protection is provided for the ends of the rotor. Furthermore, the axial projection provides the possibility for attaching securing elements, such as retaining rings and the like.

[0021] The protruding rotor arm can also be used in particular for balancing the rotor by attaching balancing weights to the protruding rotor arm or by removing material locally.

[0022] Rotor carriers according to the present invention are characterized in that the base body and the support body have at least one radially continuous recess 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 rotor's laminated core or opening into an oil channel formed between the rotor carrier and the laminated core.

[0023] Rotor carriers according to preferred embodiments 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, guide elements can also be provided on the support body or base body to guide oil impinging from the inside to the recesses or to discharge it in a targeted manner to the outside. These guide elements can be designed as channels, annular grooves, or depressions inclined toward the recess, or alternatively, can be designed as raised struts, projections, or shoulders. These guide elements can optionally also serve as receptacles for the parts of a coupling.

[0024] Preferred embodiments of a rotor carrier are characterized by the fact that several recesses are distributed around the circumference. For a more even distribution of the oil and to prevent imbalance, several recesses are distributed, preferably symmetrically, around the circumference. Several recesses can also be provided at different axial positions, which can, for example, improve cooling on both sides.

[0025] 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.

[0026] 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.

[0027] 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 an embodiment of a rotor carrier. Fig. 3 shows a detailed view of an embodiment.

[0028] 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).

[0029] 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).

[0030] 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). Several bearings (12) are provided 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), which support the components relative to one another. On its outer side, the hub (4) is connected to the converter housing (5.1) and to one side of the clutch (7).

[0031] 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.

[0032] 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 located directly next to a bearing (12).

[0033] 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.

[0034] The rotor (2.2) of the electric machine (2) is connected to a rotor carrier. In the illustrated embodiment, the rotor carrier is formed by a base body (13) and a support body (14), both of which have a pot-shaped basic shape and each support part of the axial length of the rotor (2.2). The base body (13) and the support body (14) have a tubular outer contour with the same outer diameter, to whose outer circumferential surface the rotor (2.2) is attached. The base body (13) here has a greater axial length than the support body (14) and accordingly approximately two-thirds of the rotor (2.2) is supported by the base body (13) and one-third by the support body (14). Preferably, the area of ​​the rotor (2.2) carried by the base body (13) lies in the range of 25% to 75% of the axial length of the rotor (2.2), whereby the bottom of the base body (13) is arranged in the central area of ​​the rotor (2.2).

[0035] The radially extending base of the base body (13) and the flange of the support body (14) face each other and are connected to each other. A connection to the hub (4) is established via the base of the base body (13). Both the base body (13) and the support body (14) protrude axially relative to the rotor (2.2); in other words, they together have a greater axial length than the rotor (2.2).

[0036] To secure the axial position of the rotor (2.2) on the base body (13), a securing element (15) is provided in a groove. The securing element (15) can be at least partially resilient in order to compensate for manufacturing tolerances and the like. On the opposite side of the rotor (2.2), axial securing is also provided by a corresponding securing element (15). Instead of a securing element (15), one or more projections, shoulders, or the like can be provided at least on one side. Alternatively, the axially projecting region of the base body (13) or the support body (14) can be formed radially outward to form a collar as an axial limitation.

[0037] In the illustrated embodiment, the support body (14) is designed with a thinner wall thickness than the base body (13), which allows for material and thus weight savings. In principle, the two components of the rotor carrier can also be designed with the same wall thickness.

[0038] By means of corresponding recesses or balancing elements (not shown), the axially projecting areas can also be used for oil guidance for lubrication and cooling of the electrical machine (2) or for balancing the electrical machine (2).

[0039] An axial section of the base body (13) is provided with a profile 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).

[0040] The flange of the support body (14) is in Fig. 1 is designed with a smaller radial extension than the base of the base body (13). The flange is connected to the base of the base body (13) via rivets (not shown). Instead of rivets, the connection can also be made, in particular, by welding, screwing, or clinching.

[0041] Fig. Figure 2 shows another embodiment of a rotor carrier. The basic structure is the same, so the above description applies. Fig. 1 is referred to.

[0042] Contrary to the example from Fig. 1, in the support body (14), the area projecting axially beyond the rotor (2.2) is deformed radially outwards to form a shoulder.

[0043] Furthermore, tongues (16) are arranged on the support body (14) distributed around the circumference to simplify the alignment and positioning of the base body (13) relative to the support body (14). Alternatively or additionally, an alignment groove (17) extending across both components can be used for this purpose, which can also be used to position the rotor (2.2).

[0044] In Fig. Figure 3 shows a portion of another exemplary embodiment. However, the support body (14) is formed integrally with the converter housing (5.1), or a portion of the converter housing (5.1) forms the support body (14). The base body (13) is directly connected to the converter housing (5.1). The connection between the base and flange can be achieved by welding, as shown, or by other connection methods mentioned above, or by combinations thereof.

[0045] On the inner circumferential surface of the base body (13), as in Fig. 1, recesses and elevations provided as a receptacle for parts of the coupling (7).

[0046] On the base body (13) and on the support body (14), elevations and depressions, here in the form of axially extending grooves, are provided on the outer circumferential surface for receiving and fastening the rotor (2.2).

[0047] Parts of the lock-up clutch (11) are still shown inside the converter housing (5.1).

[0048] 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. Reference symbol 1 housing 2 electric machine 2.1 Stator 2.2 Rotor 3 Input shaft 4 Hub 5 torque converters 5.1 Converter housing 5.2 Turbine shaft 5.3 Pump wheel 5.4 Idler 5.5 Turbine wheel 6 Output shaft 7 Clutch 8 vibration dampers 9 Seal 10 torsional vibration dampers 11 Lock-up clutch 12 camps 13 basic bodies 14 support bodies 15 Securing element 16 Tongue 17 Alignment groove

Claims

[1] Rotor carrier for a rotor (2.2) of an electrical machine (2), wherein the rotor carrier comprises a pot-shaped 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 facing away from the rotor (2.2) receptacles for parts of a coupling (7) are provided over part of the axial extent, wherein the base body (13) covers only part of the axial extent of the rotor (2.2), wherein the rotor carrier comprises a second support body (14), and wherein the support body (14) has a radially extending flange, and that the base of the base body (13) and the flange of the support body (14) are connected to one another, characterized by , that the base body (13) is connected to a hub (4) by a radially extending base, that the support body (14) also has means on an outer circumferential surface which enable a positive and / or non-positive connection between the support body (14) and the rotor (2.2), and that a converter housing (5.1) is designed as a support body (14), and wherein the base body (13) and the support body (14) have at least one recess which is continuous in the radial direction for the passage of oil. [2] Rotor carrier according to claim 1, characterized by that the support body (14) has a flange as a separate component which is shorter or longer in the radial direction than the bottom of the base body (13). [3] Rotor carrier according to one of the preceding claims, characterized by that the base body (13) has a different thickness than the support body (14). [4] Rotor carrier according to one of the preceding claims, characterized bythat the base body (13) and the support body (14) are connected to each other by rivets. [5] Rotor carrier according to one of the preceding claims, characterized by that the base body (13) and the support body (14) are connected to each other by welding. [6] Rotor carrier according to one of the preceding claims, characterized by that the base body (13) has a greater axial overlap with the rotor (2.2) than the support body (14). [7] Rotor carrier according to one of the preceding claims, characterized by that the base body (13) and / or the support body (14) is longer than the rotor (2.2) at least at one axial end. [8] Rotor carrier according to claim 7, characterized by that the recess is arranged in the bottom region of a groove provided on the inner peripheral surface. [9] Rotor carrier according to claim 7 or 8, characterized by that several recesses are arranged around the circumference. [10] 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 9 is provided.

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