DE102021102906A1 - Shaft-hub connection and drive train for a motor vehicle with at least one such shaft-hub connection - Google Patents

Abstract

The invention relates to a shaft-hub connection (1), with a hub element (2) which has a hub (3), and with a shaft element (4) which, in a first length region (L1) of the hub (3 ) arranged, second longitudinal area (L2) and is connected to the hub element (2) by means of an interference fit (P), which has a first oversize area (UB1) with a first oversize and a second oversize area (UB2) with a larger oversize than the first , second oversize, wherein the second oversize region (UB2) is at least partially overlapped towards the outside in the radial direction (5) of the shaft element (4) by a recess (6) formed in the hub element (2), which recess (6) is formed in the radial direction (5 ) of the shaft element (4) between a solid, first wall area (W1) and a solid, second wall arranged in the radial direction (5) of the shaft element (4) between the second interference area (UB2) and the first wall area (W1). area (W2) of the hub element (2) is arranged.

Description

The invention relates to a shaft-hub connection according to the preamble of patent claim 1 or 10. The invention also relates to a drive train for a motor vehicle with at least one such shaft-hub connection.

Of the DE 10 2017 203 773 A1 a shaft-hub connection can be seen as known, with a hub element, which has a hub, and with a shaft element, which has at least a first length region, which is arranged in at least a second length region of the hub, and by means of a length region encompassing Longitudinal interference fit is at least rotatably connected to the hub element. It is provided that the longitudinal interference fit has at least one first oversize area with a first oversize and at least one second oversize area following the first oversize area in the circumferential direction of the shaft element with a second oversize that is smaller than the first oversize.

the DE 10 2007 006 986 B3 discloses a rotor for a high-speed electrical machine with high dynamics. In addition, from the DE 10 2006 002 443 A1 a rotating element known.

The object of the present invention is to create a shaft-hub connection and a drive train for a motor vehicle with at least one such shaft-hub connection so that the shaft-hub connection can be made particularly easily and rotated at a particularly high speed can, without the hub element being undesirably lifted off the shaft element, and that a particularly high torque can be transmitted between the shaft element and the hub element.

This object is achieved according to the invention by a shaft-hub connection with the features of patent claim 1, by a shaft-hub connection with the features of patent claim 10 and by a drive train with the features of patent claim 11. Advantageous configurations of the invention are the subject matter of the dependent claims.

A first aspect of the invention relates to a shaft-hub connection. The shaft-hub connection according to the invention could, for example, be used particularly advantageously for a drive train of a motor vehicle. This means that the motor vehicle, which is preferably designed as a motor vehicle and very preferably as a passenger car, includes the drive train in its fully manufactured state, which in turn includes the shaft-hub connection. For example, the shaft-hub connection is part of a drive machine, by means of which the motor vehicle can be driven. The drive machine can be an electric machine, for example, by means of which the motor vehicle can be driven, in particular purely electrically. The motor vehicle can thus be designed, for example, as a hybrid vehicle or as an electric vehicle, in particular as a battery electric vehicle (BEV). For example, the drive machine, in particular the electric machine, can provide at least one torque for driving the motor vehicle via the shaft-hub connection. However, the invention is not limited to such a use of the shaft-hub connection for a motor vehicle and/or in a drive train, but can be used in any application. In particular, the shaft-hub connection according to the invention is suitable for or as high-speed or high-speed rotating shaft-hub connections.

The shaft-hub connection includes a hub element which has a hub. Furthermore, the shaft-hub connection comprises a shaft element which has at least one second length region arranged in at least a first length region of the hub. The shaft element is connected, ie joined, to the hub element at least in a rotationally fixed manner by means of an interference fit formed between the longitudinal regions. The hub member is also referred to as a hub member and the shaft member is also referred to as a shaft member. The feature that the interference fit is formed between the length regions, ie between the first length region and the second length region, means that the interference fit comprises the length regions which form the interference fit. In other words, the longitudinal areas form the interference fit with one another. In other words, for example, the first longitudinal area is pressed onto the second longitudinal area, so that the interference fit is formed between the longitudinal areas and thus between the shaft element and the hub element. In particular, at least one press fit is formed between the longitudinal regions and thus between the shaft element and the hub element, as a result of which the interference fit is formed. To produce the interference fit, the hub element and the shaft element, which are also referred to as the joining partners, are produced in such a way that after the joining partners have been joined, a press fit is created in the longitudinal areas. Preferably, it is provided that the hub element also in the axial direction of the shaft element is fixed to the shaft element and vice versa. Thus, preferably relative rotations and preferably also relative movements between the shaft element and the hub element occurring in the axial direction of the shaft element can be avoided.

The interference fit has at least a first oversize area with a first oversize. In addition, the interference fit has at least one second oversize region with a second oversize that is greater than the first oversize. The second oversize range follows, in particular directly, the first oversize range in the circumferential direction of the shaft element running around the axial direction of the shaft element. The feature that the second oversize is greater than the first oversize means in particular that the first oversize has a first value and the second oversize has a second value that is greater than the first value, so that the respective oversize and thus the Although a respective interference fit is formed between the longitudinal areas or between the shaft element and the hub element in the respective oversize area, the oversize areas have different oversizes or the oversizes have different values from one another. Thus, the interference fit is provided with a variable or varying oversize in the circumferential direction of the shaft element and thus of the hub element.

The different oversizes can be realized, for example, in the following way: In a state in which the joining partners are separated from one another, i.e. not yet connected to one another, so that the press fit has not yet been produced in this state, the shaft element, for example, has in the first oversize area has a first outer diameter or a first outer radius relating in particular to the center point or the axis of rotation of the shaft element, and the shaft element has a second outer diameter or a second outer radius relating to the center point of the shaft element in the second interference range. The second outer diameter or the second outer radius is preferably larger than the first outer diameter or the first outer radius. Alternatively or additionally, it is conceivable that the hub element in the state described above has a first inner diameter or a first inner radius relating in particular to the center point of the shaft element in the first interference area, and in the state the shaft element has a second one in the second oversize area Inner diameter or a reference to the center point of the shaft element, second inner radius. In this case, for example, the second inner diameter or the second inner radius is smaller than the first inner diameter or the first inner radius. The first inner diameter is also referred to as the base diameter or as the first joining diameter, for example, with the second inner diameter being referred to as the second joining diameter, for example. It is therefore conceivable that in the state described above the second joining diameter is smaller than the base diameter in order to thereby realize the different oversizes.

In order to be able to rotate the joining partners together or simultaneously, in particular about an axis of rotation that is common to the joining partners and, for example, coincides with the axial direction of the shaft element and on which, for example, the center point of the shaft element lies, particularly quickly, i.e. at a particularly high speed, without there is an undesirable or excessive lifting of the hub element from the shaft element or while a particularly high torque can still be transmitted between the joining partners in order to be able to transmit particularly high torques between the joining partners without slipping, i.e. a undesired relative rotation between the joining partners, and in order to be able to produce the shaft-hub connection particularly easily and thus inexpensively, it is provided according to the invention that the second oversize area in the radial direction of the shaft element and s omit in the radial direction of the hub element and the shaft-hub connection as a whole outwardly at least partially, in particular at least predominantly and thus at least more than half or completely, is overlapped by a recess formed in the hub element and also referred to as a recess. The recess is arranged in the radial direction of the shaft element between a solid, first wall area of the hub element and a solid, second wall area of the hub element, the second wall area being arranged in the radial direction of the shaft element between the second oversized area and the first wall area. Thus, in particular, the second wall area is at least partially, in particular at least predominantly or completely, overlapped outwards in the radial direction of the shaft element by the first wall area. Whenever the radial direction is mentioned below, this means—unless otherwise stated—the radial direction of the shaft element, the radial direction of which corresponds to the radial direction of the hub elements and the shaft-hub connection as a whole. In this case, the radial direction runs perpendicularly to the axial direction of the shaft element, whose axial direction coincides overall with the axial direction of the hub element and the shaft-hub connection. Since the recess is arranged between the wall regions in the radial direction, so that the second wall region is at least partially, in particular at least predominantly or completely, overlapped or covered by the recess in the radial direction towards the outside, at least one can also be used as a spring region indicated first part of the second wall area under the action of centrifugal force and with a reduction in a width running in the radial direction of at least a second part of the recess resiliently deflect outwards in the radial direction, thus springing outwards in the radial direction, i.e. moving outwards in the radial direction. The fact that at least the first part (spring area) of the second wall area springs outwards in the radial direction, and can therefore be resilient in the radial direction outwards, means in particular that the second wall area can function as a spring area or spring element, i.e. that the second wall area is at least partially elastically deformable under the action of centrifugal force, so that when the joining partners rotate together about the aforementioned axis of rotation and in particular relative to a component such as a housing, centrifugal forces act on the shaft-hub connection and in particular on the hub element and act on the second wall area, at least the first part of the second wall area can be moved or is being moved outwards in the radial direction, the second wall area being at least partially elastically deformed, thus behaving like a spring.

Provision is particularly preferably made for the shaft element to have only one continuous outside diameter, ie the shaft element to have the same or the same outside diameter in the first oversize area and in the second oversize area. As a result, the shaft element, which is designed as a rotor shaft, for example, can be produced particularly cost-effectively. In addition, the rotor shaft then does not have to be mounted in a certain angular position in relation to the hub element, which is designed, for example, as a laminated core. The different oversizes are then realized by the different inner diameters of the hub element or the laminated core, which is stamped simply and inexpensively in a series process, for example, so that the different inner diameters can be produced particularly easily by stamping and no additional costs are incurred as a result.

• Bei schnell drehenden beziehungsweise schnell laufenden Welle-Nabe-Verbindungen, wie sie beispielsweise bei elektrischen Maschinen für Fahrzeuganwendungen verwendet werden, kann das Problem einer zu geringen Abhebedrehzahl eines insbesondere thermischen Querpressverbands insbesondere zwischen einem Rotorblechpaket und einer Rotorwelle bestehen, insbesondere bei großen rotierenden Massen und insbesondere in Verbindung mit der Randbedingung, dass eine maximale Fügetemperatur, auf welche das beispielsweise als das zuvor genannte Rotorblechpaket ausgebildete Nabenelement höchstens erwärmt werden kann, um den Pressverband, insbesondere den Querpressverband, auszubilden, auf einen relativ geringen Wert beschränkt ist. Zudem sinkt die Abhebedrehzahl weiter mit steigendem Fügedurchmesser, was eine Gestaltungsfreiheit bei der Rotortopologie und Rotorgestalt einschränken kann. Dies gilt insbesondere bei gleichbleibender Rotortopologie und/oder Rotoraußendurchmesser. Es ist wünschenswert, den Fügedurchmesser so groß wie möglich zu wählen, um einen möglichst leichten und gut zu kühlenden (falls eine Rotorwellenkühlung o.ä. vorhanden ist) Rotor zu bauen.

In order to realize a particularly strong connection between the joining partners and to be able to produce the shaft-hub connection particularly inexpensively, one embodiment of the invention provides for the interference fit to be a transverse interference fit. Consequently, the interference fit is preferably designed as a transverse interference fit. Thus, the shaft-hub connection and thus the transverse interference fit are preferably produced in that the shaft element is cooled, in particular actively, at least in the second shaft area and/or the hub element is heated, in particular actively, at least in the first length area, which leads to a reduction in the outer circumference of the shaft element at least in the second length range or an enlargement of the inner circumference of the hub element at least in the first length range. While the outer circumference is reduced or the inner circumference is enlarged, the second length area is arranged in the first length area, whereupon a temperature equalization between the hub element and the shaft element, in particular between the length areas, is permitted. As a result, the hub element is pressed onto the shaft element or the shaft element is pressed into the hub element. In other words, the transverse interference fit is thereby formed. Since the outer circumference is reduced by cooling and/or the inner circumference is increased by heating, the press fit is produced thermally, so that the press fit is also referred to as a thermal press fit. A particularly high lifting speed of the shaft-hub connection can be realized by the invention. The lift-off speed is to be understood as a speed at which the shaft-hub connection rotates about the axis of rotation, it being the case at or from the lift-off speed that the hub element or the first length area lifts off from the shaft element or the second length area in such a way that that there is a relative rotation between the joining partners around the axis of rotation and/or that at most such a torque can be transmitted around the axis of rotation between the joining partners that falls below a specifiable or predetermined threshold value, for example. The invention is based on the following findings and considerations:

• In the case of fast-rotating or fast-running shaft-hub connections, such as those used in electrical machines for vehicle applications, the problem of too low a lift-off speed, in particular of a thermal cross press fit, in particular between a laminated rotor core and a rotor shaft, especially with large rotating masses and in particular in connection with the boundary condition that a maximum joining temperature, to which the hub element designed, for example, as the aforementioned laminated rotor core, can be heated at most, in order to prevent the press fit, in particular the Transverse interference fit is limited to a relatively small value. In addition, the lift-off speed continues to decrease as the joint diameter increases, which can limit freedom of design in the rotor topology and rotor shape. This applies in particular to the same rotor topology and/or rotor outer diameter. It is desirable to choose the joint diameter as large as possible in order to build a rotor that is as light as possible and easy to cool (if a rotor shaft cooling or similar is available).

For the transmission of large torques between the joining partners in limited installation spaces, there are basically frictional, form-fitting and material-to-material forms of a shaft-hub connection. Frictional connections such as transverse interference fits, longitudinal interference fits or tapered interference fits transmit the torque through frictional force, which is determined by a normal force acting on the joining surfaces of the joining partners between the joining partners, i.e. between the shaft element, also simply referred to as the shaft, and the hub element. Both joining partners are joined by means of temperature and/or force. In the case of a transverse interference fit, for example, the shaft element is cooled and/or the hub element is heated, i.e. heated, in order to be able to eliminate any overlapping of the two joining partners, with the aforementioned overlapping of the joining partners existing in particular in a state in which the joining partners, in particular at least in the longitudinal areas of the have the same temperature and, for example, are still separated from one another, that is to say are not yet joined together. By removing the geometric overlap of the joining partners, the joining partners can be joined together. In other words, the second length area can be arranged in the first length area, in particular by the shaft element being moved along its axial direction relative to the hub element, such that the first length area completely surrounds the second length area in the circumferential direction of the shaft element. The previously described temperature equalization then takes place, during which the hub element shrinks at least in the first length range, thus reducing the inner circumference, and/or the shaft element expands at least in the second length range, thus leading to an enlargement of the outer circumference. Conventionally, producing a transverse interference fit requires a great deal of energy, time, and space and care, and in particular nitrogen storage, for example, along a production line. In the case of form-fitting shaft-hub connections such as feather keys, splined shafts or polygonal profiles, the torque transmission function is ensured via a geometric form-fitting connection between the joining partners. Here, too, high torques can be transmitted, but here too there is the problem of lifting at high speeds and the loss of self-centering. The advantage of a form-fitting shaft-hub connection is that it can be manufactured or assembled with particularly little effort. A disadvantage, however, is that the production of the joining partners is more complex than with press fits, especially in the case of a polygon profile.

In the case of rapidly rotating shaft-hub connections, due to the centrifugal force that increases with increasing speed, the normal force between the joining partners decreases to a point at which the hub element lifts off the shaft element or the first length area lifts off the second length area, this point also being referred to as the lifting speed is achieved when the shaft-hub connection and thus the joint partners are rotated at the above-mentioned lift-off speed. In addition, the maximum torque that can be transmitted between the joining partners and a centering of the joining partners relative to one another also depend on the speed. Consequently, when mechanically designing a shaft-hub connection, the lifting speed and torque requirements should be taken into account, in particular with regard to how high the torque should be that can still be transmitted between the joining partners at a certain or specifiable or predetermined speed. A particularly advantageous shaft-hub connection is thus characterized by a very high lifting speed, the ability to be able to transmit high torques between the joining partners, as well as simple manufacture and simple assembly. This can be realized by the invention.

The transverse interference fit comprises, for example, an inner peripheral joint surface of the hub element arranged in the first length region and an outer peripheral joint surface of the shaft element arranged in the second length region, so that the transverse interference fit is formed in particular by the joint surfaces or between the joint surfaces. in particular more specifically, it is intended that the joining surfaces touch each other directly. The joining surfaces can, in particular, ensure mutual centering of the joining partners. Provision is preferably made for the hub element and the shaft element to be connected to one another exclusively by the interference fit, in particular the transverse interference fit.

In principle, it is also possible to use the spring effect with a form-fitting shaft-hub connection in which, for example, the interference fit is then omitted. Especially with high-speed components such as rotors, since centrifugal forces break the positive connection and the centering of shaft to hub is lost and at least axial displacement from hub to shaft cannot be ruled out.

The basic principle of the present invention is the principle of pretensioning or tensioning of the centering joining surfaces between the joining partners. This means that a bracing mechanism is integrated in one of the joining partners and, in particular, in the present case in the hub element. This is implemented in the invention in such a way that the recess is formed in the hub element, which - as described above - enables the second wall area to spring outwards at least partially in the radial direction under the action of centrifugal force, with the second wall area in particular in the circumferential direction of the shaft element is arranged in the area of the second oversize area. This means that the second oversize area and the second wall area are at least partially, in particular at least predominantly or completely, arranged at the same height in the circumferential direction of the shaft element, and it is preferably also provided that the second oversize area and the second wall area in the axial direction of the shaft element are at least partially, in particular at least predominantly or completely, arranged at the same height. As a result, the second oversize area is covered outwards in the radial direction by the second wall area. It is therefore preferably also provided that the second oversize area and the recess are at least partially, in particular at least predominantly or completely, arranged at the same height in the circumferential direction of the shaft element, and it is preferably also provided that the second oversize area and the recess are arranged in the axial direction of the shaft element are at least partially, in particular at least predominantly or completely, arranged at the same height. As a result, the second excess area is at least partially overlapped by the second wall area and at least partially by the recess in the radial direction to the outside, and the second wall area is at least partially overlapped by the recess in the radial direction to the outside, so that the recess has the previously described in the radial direction to the outside taking place, elastic deflection, thus springs of the second wall area, allows. As a result, a first part of the joining surface of one of the joining partners, in particular the hub element, which is formed by the second oversize area or is arranged in the second oversize area, is designed in such a way that, for example, the first part deforms at least elastically when the joining partners are joined and can partially relax when or under the action of centrifugal force . This relaxation ensures that there is sufficient normal force between the joining partners, even in the case of very high centrifugal forces. This ensures safe centering of the joining partners over a required speed range and the ability to transfer a sufficiently high torque between the joining partners. In addition to or in addition to this centering first part, there is at least one second part of the joining surface, in particular on the inner circumference, the second part being formed, for example, by the first oversize area or being arranged in the first oversize area. The second part has the main task of torque transmission, but may take off at a certain speed, i.e. the lift-off speed.

The shaft element is preferably a shaft, also referred to as a rotor shaft, for an electrical machine. Alternatively or additionally, it is preferably provided that the hub element is a laminated core, in particular a laminated rotor core, for the or the electrical machine.

It has also been shown to be advantageous if the second oversize region is overlapped at least over its entire extent running in the circumferential direction of the shaft element in the radial direction outwards by the recess. As a result, a particularly high lifting speed can be achieved, and the interference fit can be produced particularly easily and thus in a time-saving and cost-effective manner.

In a further, particularly advantageous embodiment of the invention, it is provided that the recess extends in the circumferential direction of the shaft element beyond both opposite ends of the second oversize region in the circumferential direction of the shaft element. In other words, the recess is longer than the second interference area in the circumferential direction of the shaft element, such that the recess extends beyond the second interference area at both ends extends. As a result, the effects described above can be implemented particularly advantageously, so that a particularly high lift-off speed can be achieved.

In order to allow the described springing of the second wall area particularly advantageously and thus to be able to realize a particularly high lifting speed, it is provided in a further embodiment of the invention that the recess has an at least partially arcuate inner contour.

Provision is preferably made for the recess to be free of a solid body, in particular completely, so that air is preferably accommodated in the recess, in particular completely.

In order to allow the above-described springing of the second wall area in a particularly advantageous manner and thus to be able to realize a particularly high lifting speed, and therefore a particularly strong connection, it is provided in a further embodiment of the invention that the second wall area has a radial direction of the shaft element to the outside has a first wall part overlapped by a first recess part of the recess and a second wall part adjoining the first wall part in the circumferential direction of the shaft element, which overlaps outwards in the radial direction of the shaft element through a second recess part of the recess connected to the first recess part and is set back inward in the radial direction of the shaft element in relation to the first wall part.

It is preferably provided that the wall parts are formed in one piece with each other.

Furthermore, it has proven to be particularly advantageous if the first recess part is set back outwards in the radial direction of the shaft element compared to the second recess part, as a result of which the second wall region can spring particularly well.

In particular, it is provided that the second recess part has the above-described arcuate, in particular arcuate, inner contour at least in a partial area.

In a further embodiment of the invention, the first oversize region is also at least or preferably exclusively partially overlapped outwards in the radial direction of the shaft element by the recess. As a result, springing of the second wall area can advantageously be permitted on the one hand, and high torque transmissibility can be ensured on the other hand.

Finally, it has been shown to be particularly advantageous if the first oversize area is arranged outwards at least partially without overlapping in the radial direction of the shaft element with respect to the recess, so that the first oversize area is at least partly arranged outwards in the radial direction not through the recess. As a result, a particularly high torque transferability can be achieved.

A second aspect of the invention relates to a shaft-hub connection, with a hub element, which has a hub, and with a shaft element, which has at least one second length region arranged in at least a first length region of the hub and is connected to the hub element by means of a between is at least non-rotatably connected to the longitudinal areas formed form fit.

In order to be able to rotate the joining partners together or simultaneously, in particular about an axis of rotation that is common to the joining partners and, for example, coincides with the axial direction of the shaft element and on which, for example, the center point of the shaft element lies, particularly quickly, i.e. at a particularly high speed, without there is an undesirable or excessive lifting of the hub element from the shaft element or while a particularly high torque can still be transmitted between the joining partners in order to be able to transmit particularly high torques between the joining partners without slipping, i.e. a undesired relative rotation between the joining partners, and in order to be able to produce the shaft-hub connection particularly easily and thus inexpensively, it is provided according to the invention that the form fit in the radial direction of the shaft element is outward is at least partially overlapped by a recess formed in the hub element, which is arranged in the radial direction of the shaft element between a solid, first wall area and a solid, second wall area of the hub element arranged in the radial direction of the shaft element between the form fit and the first wall area. Advantages and advantageous configurations of the first aspect of the invention are to be regarded as advantages and advantageous configurations of the second aspect of the invention and vice versa.

A third aspect of the invention relates to a drive train for a motor vehicle, wherein the Drive train has at least one shaft-hub connection according to the first and / or second aspect of the invention. Advantages and advantageous configurations of the first and second aspect of the invention are to be regarded as advantages and advantageous configurations of the third aspect of the invention and vice versa.

• 1 eine schematische Querschnittsansicht einer Welle-Nabe-Verbindung, insbesondere für einen Antriebsstrang eines Kraftfahrzeugs; und
• 2 ausschnittsweise eine schematische Querschnittsansicht der Welle-Nabe-Verbindung in einem in 1 mit B bezeichneten Bereich.

Further details of the invention result from the following description of a preferred exemplary embodiment with the accompanying drawings. It shows:

• 1 a schematic cross-sectional view of a shaft-hub connection, in particular for a drive train of a motor vehicle; and
• 2 A partial schematic cross-sectional view of the shaft-hub connection in an in 1 area marked B.

Elements that are the same or have the same function are provided with the same reference symbols in the figures.

1 shows a schematic cross-sectional view of a shaft-hub connection 1, also referred to simply as a connection, with a hub element 2. The hub element 2 has a hub 3. The hub 3 is a receptacle that is round, in particular circular, in particular in its cross section, which is explained in more detail below. The shaft-hub connection 1 also includes a shaft element 4, also referred to simply as a shaft, which has at least one second length region L2 arranged in at least a first length region L1 of the hub 3 and, by means of an interference fit P formed between the length regions L1 and L2, at least is rotatably connected to the hub element 2.

In a fully manufactured state, the motor vehicle has a drive train, by means of which the motor vehicle can be driven. The drive train includes a prime mover, by means of which the motor vehicle can be driven. For example, the motor vehicle, which is preferably designed as a motor vehicle, in particular a passenger car, has at least or exactly two axles arranged one after the other in the vehicle longitudinal direction, which each have at least or exactly two vehicle wheels spaced apart from one another in the vehicle transverse direction. In particular, the vehicle wheels can be driven at least or exactly one of the axles by means of the engine. The drive machine is preferably an electrical machine which has a stator and a rotor which can be driven by the stator and is therefore rotatable about a machine axis of rotation relative to the stator. It is preferably provided that the rotor has the shaft-hub connection 1, so that the shaft-hub connection 1, and therefore the shaft element 4 and the hub element 2, rotate about the aforementioned machine axis of rotation, also referred to simply as the axis of rotation D, relative to are rotatable with the stator. In this case, the shaft element 4 is a shaft of the rotor, also referred to as a rotor shaft, and the hub element 2 is preferably a laminated core of the rotor, also referred to as a rotor laminated core. The laminated core is preferably formed from electrical steel.

In synopsis with 2 It is particularly easy to see that the interference fit P has at least one first oversize area UB1 with a first oversize and at least one circumferential direction of the shaft element 4 running around the axis of rotation D and thus around the axial direction of the shaft element 4, in particular directly following the first oversize area UB1 , Second oversize range UB2 with a second oversize that is greater than the first oversize. The first oversize is formed in particular by the fact that the hub 3, in particular in a state in which the hub element 2 and the shaft element 4, which are also referred to collectively as the joining partner, are not yet connected to one another, i.e. not yet joined together, also as a Base diameter BD designated, first joint diameter in the oversize range UB1. The second oversize is formed in particular by the fact that the hub 3 has a second joining diameter FD, particularly in the aforementioned state and in the oversize area UB2. The base diameter BD and the second joining diameter FD are respective inner diameters of the hub 3, which is at least essentially circular, for example per se and in particular in the state. The second joining diameter FD is smaller than the base diameter BD, so that the second oversize is larger than the first oversize.

In order to achieve a particularly high lifting speed of the shaft-hub connection 1 and to be able to produce the shaft-hub connection 1 particularly easily and thus inexpensively, it is also provided that the second oversize area UB2 in the radial direction of the shaft element 4, whose radial direction perpendicular to the axis of rotation D and in 1 illustrated by a double arrow 5, is at least partially overlapped towards the outside by a recess 6 formed in the hub element 2 and also referred to as a recess. Out of 1 and 2 it can be seen that the shaft-hub connection 1, for example in the circumferential direction of the shaft element 4, has four first oversize areas UB1 and four second oversize has dimension areas UB2, which are arranged in the circumferential direction of the shaft element 4 alternately one after the other. Accordingly, four recesses 6 are provided.

The recess 6 is in the radial direction of the shaft element 4 between a solid, first wall area W1 of the hub element 2 and in the radial direction of the shaft element 4 between the second interference area UB2 and the first wall area W1 or in the radial direction of the shaft element 4 between the second interference area UB2 and the solid, second wall region W2 of the hub element 2 arranged in the recess 6 . As a result, at least one second part T2 of the wall region W2, viewed in the radial direction of the shaft element 4 towards the shaft element 4 and arranged in a first part T1 of the recess 6, can act as a spring, also referred to as a spring region, which, under the action of centrifugal force, moves in the radial direction of the shaft element 4 springing outwards, therefore springing can. The aforementioned spring area (second part T2) is in 2 shown with cross hatching. In other words, at least part T2 is a spring integrated into the hub element 2, and therefore an inherent spring, which is prestressed when the interference fit P, which is designed as a transverse interference fit, is produced, and when the hub element 2 is joined to the shaft element 4. Due to the second oversize, which is larger than the first oversize, a particularly high lifting speed of the shaft-hub connection 1 can be achieved. In addition, when designing the shaft-hub connection 1, compared to conventional solutions, specific requirements that can be specified or specified can be addressed, for example torque transmission at low speeds and a lift-off speed at high speeds.

In the exemplary embodiment shown in the figures, provision is made for the second oversize region UB2 to be overlapped by the recess 6 at least over its entire extension running in the circumferential direction of the shaft element 4 in the radial direction of the shaft element 4 to the outside. The circumferential direction of the shaft element 4 runs around the axis of rotation D and is in 1 illustrated by a double arrow 7. Furthermore, it is provided in the exemplary embodiment that the recess 6 extends in the circumferential direction of the shaft element 4 beyond both opposite ends E1 and E2 of the second interference region UB2 in the circumferential direction of the shaft element 4 . In addition, the recess 6 has an inner contour K that is at least partially arcuate.

In order to be able to achieve a particularly good spring effect, in particular of the first part T1, it is also provided that the second wall region W2 overlaps a part T1 of the recess 6 that extends outwards in the radial direction of the shaft element 4 through the part T1 of the recess 6, which is also referred to as the first recess part of the recess 6 , first wall part WT1 and second wall parts WT2 adjoining the first wall part WT1 on both sides in the circumferential direction of the shaft element 4, which each extend outwards in the radial direction of the shaft element 4 through a respective second recess part AT2 of the recess connected to the first recess part 6 overlap and are set back inward in the radial direction of the shaft element 4 in relation to the first wall part WT1. The first recess part (T1) is set back outwards in the radial direction of the shaft element 4 compared to the respective second recess part AT2.

Particularly good looking 1 and 2 it can be seen that respective ends of the respective first oversize region UB1, which are opposite in the circumferential direction of the shaft element 4, are overlapped outwards in the radial direction of the shaft element 4 by respective parts of the recesses 6 that follow one another in the circumferential direction, with a respective, between the respective ends of the respective Oversize area UB1 arranged central part of the respective oversize area UB1 is arranged in the radial direction outwards without overlapping to the respective recess 6.

Reference List

1

shaft-hub connection

2

hub element

3

hub

4

wave element

5

double arrow

6

recess

7

double arrow

AT2

second recess part

BD

base diameter

D

axis of rotation

E1

End

E2

End

FD

second joint diameter

K

inner contour

L1

first length range

L2

second length range

P

press bandage

T1

Part

T2

Part

UB1

first excess area

UB2

second oversize area

w1

first wall area

W2

second wall area

WT1

wall part

WT2

wall part

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102017203773 A1 [0002]
• DE 102007006986 B3 [0003]
• DE 102006002443 A1 [0003]

Claims (11)

Shaft-hub connection (1), with a hub element (2) which has a hub (3) and with a shaft element (4) which is arranged in at least one first length region (L1) of the hub (3). , second longitudinal region (L2) and is connected to the hub element (2) at least in a rotationally fixed manner by means of an interference fit (P) formed between the longitudinal regions (L1, L2), which has at least one first oversize region (UB1) with a first oversize and at least one in Circumferential direction (7) of the shaft element (4) following the first oversize area (UB1), second oversize area (UB2) with a larger second oversize than the first oversize. characterized in that the second interference area (UB2) is at least partially overlapped outwards in the radial direction (5) of the shaft element (4) by a recess (6) formed in the hub element (2), which recess (6) is formed in the radial direction (5) of the Shaft element (4) between a solid, first wall area (W1) and a solid, second wall area (W2) arranged in the radial direction (5) of the shaft element (4) between the second interference area (UB2) and the first wall area (W1). Hub element (2) is arranged. Shaft-hub connection (1) according to claim 1 , characterized in that the interference fit (P) is designed as a transverse interference fit. Shaft-hub connection (1) according to claim 1 or 2 , characterized in that the second oversize region (UB2) is overlapped at least over its entire extent in the circumferential direction (7) of the shaft element (4) in the radial direction (5) outwards by the recess (6). Shaft-hub connection (1) according to one of the preceding claims, characterized in that the recess (6) extends in the circumferential direction (7) of the shaft element (4) over both ends ( E1, E2) of the second oversize range (UB2). Shaft-hub connection (1) according to one of the preceding claims, characterized in that the recess (6) has an at least partially arcuate inner contour (K). Shaft-hub connection (1) according to one of the preceding claims, characterized in that the second wall region (W2) has a radial direction (5) of the shaft element (4) towards the outside through a first recess part (T1) of the recess (6 ) has an overlapping, first wall part (WT1) and at least one second wall part (WT2) adjoining the first wall part (WT1) in the circumferential direction (7) of the shaft element (4) and which in the radial direction (5) of the shaft element (4) overlapped towards the outside by a second recess part (AT2) of the recess (6) connected to the first recess part (T1) and is set back inwards in the radial direction (5) of the shaft element (4) compared to the first wall part (WT1). Shaft-hub connection (1) according to claim 5 , characterized in that the first recess part (T1) in the radial direction (5) of the shaft element (4) is set back to the outside compared to the second recess part (AT2). Shaft-hub connection (1) according to one of the preceding claims, characterized in that the first interference region (UB1) is also at least partially overlapped outwards in the radial direction (5) of the shaft element (4) by the recess (7). Shaft-hub connection (1) according to one of the preceding claims, characterized in that the first interference region (UB1) is arranged outwards in the radial direction (5) of the shaft element (4) at least partially without overlapping with the recess (7). Shaft-hub connection (1), with a hub element (2) which has a hub (3) and with a shaft element (4) which is arranged in at least one first length region (L1) of the hub (3). , second length region (L2) and is connected to the hub element (2) at least in a rotationally fixed manner by means of a form fit formed between the length regions (L1, L2), characterized in that the form fit is outward in the radial direction (5) of the shaft element (4). towards is at least partially overlapped by a recess (6) formed in the hub element (2), which in the radial direction (5) of the shaft element (4) is between a solid, first wall region (W1) and one in the radial direction (5) of the shaft element (4) is arranged between the positive connection and the first wall area (W1), solid, second wall area (W2) of the hub element (2). Drive train for a motor vehicle, with at least one shaft-hub connection (1) according to one of the preceding claims.

Images