Drive system and axle drive system for a motor vehicle

Abstract

Drive device (5) for a motor vehicle, comprising an output shaft (23) and an electric machine (7) comprising a stator (8) and a rotor (8') rotatably mounted about an axis of rotation (13) relative to the stator (8), the rotor being coupled to the output shaft (23) via a bevel gear (20), wherein an electrical winding (10) of the stator (8) and / or an electrical winding of the rotor (8') projects axially with respect to the axis of rotation (13) over a coil former (9) to form a winding head (11), and the bevel gear (20) being arranged at least partially in axial alignment with the winding head (11), wherein the bevel gear (20) comprising at least one bevel gear (21) being rotationally fixed to a drive shaft (14) which is in permanent operative connection with the rotor (8'), and is coaxial to the axis of rotation (13) and extends in the axial direction is arranged in overlap with the winding head (11),characterized in that the drive shaft (14) is coupled to the rotor (8') via a planetary gear transmission (15), which is arranged in the axial direction on the side of the rotor (8') opposite the bevel gear (20).

Description

[0001] The invention relates to a drive device for a motor vehicle, comprising an output shaft and an electric machine, which has a stator and a rotor rotatably mounted about an axis of rotation relative to the stator and which is coupled to the output shaft via a bevel gear. The invention further relates to an axle drive device for a motor vehicle.

[0002] For example, the prior art document US 1,613,053 is known. This relates to a starter device which has an electric machine that is operatively connected to another device via a bevel gear.

[0003] The object of the invention is to propose a drive device which has advantages over known drive devices, in particular a compact design and / or excellent acoustic properties and / or excellent bearing of at least one gear element of the angle gear.

[0004] According to the invention, this is achieved with a drive device having the features of claim 1. It is provided that an electrical winding of the stator and / or an electrical winding of the rotor projects in the axial direction with respect to the axis of rotation over a coil former to form a winding head, and that the bevel gear is arranged, at least partially in the axial direction, in overlap with the winding head.

[0005] The drive unit is, for example, a component of a motor vehicle. In this case, it serves to propel the motor vehicle, i.e., to provide torque directed towards propelling the motor vehicle. The drive unit has an output shaft at which it provides, or can provide, the drive torque. The drive unit has an electric motor to provide the drive torque.

[0006] The electric machine is preferably capable of operating in both motor and generator modes. In the former case, electrical energy is supplied to the electric machine to provide the drive torque. This drive torque can, for example, be used to accelerate or decelerate the vehicle. In generator mode, on the other hand, a torque applied to the output shaft is used to provide electrical energy. This means that the mechanical or kinetic energy of the output shaft is converted into electrical energy.

[0007] The electric machine has a stator and a rotor. The rotor is rotatably mounted relative to the stator about the axis of rotation. For example, the stator and the rotor are arranged on a common machine housing of the electric machine, with the stator preferably being rigidly connected to the machine housing, whereas the rotor is rotatably mounted in and / or on the machine housing.

[0008] The rotor is operatively connected to the output shaft, specifically permanently. This connection is achieved via the bevel gear. The bevel gear serves to convert the direction of the torque provided by the electric machine. Accordingly, the output shaft is angled relative to the axis of rotation or even skews.

[0009] In the first case, the axis of rotation of the output shaft, about which the output shaft is rotatably mounted, intersects the axis of rotation of the rotor. In the case of the skew arrangement, the axes of rotation of the output shaft and the rotor are spaced apart and therefore do not intersect. The bevel gear unit, for example, has two gear elements, a first gear element being coupled to the rotor and a second gear element being coupled to the output shaft, preferably permanently.

[0010] The stator or rotor has a coil former and an electrical winding arranged on the coil former. In other words, the winding is wound onto the coil former, preferably with a multitude of turns. For example, the coil former has a multitude of pole pieces, each of which is wrapped by the electrical winding or turns of the electrical winding. Of course, there can also be multiple electrical windings, each of which is assigned to and wound onto at least one of the pole pieces. Naturally, both the stator and the rotor can each have a coil former configured in the manner described.

[0011] The electrical winding of the stator or rotor projects axially beyond the coil former with respect to the axis of rotation. This projection is also referred to as the winding head. To save space in the drive unit, the bevel gear should, at least partially, overlap the winding head in the axial direction. The winding head is preferably positioned further outwards than the bevel gear in the radial direction. It is particularly preferred that the winding head at least partially surrounds the bevel gear in the circumferential direction. For example, in longitudinal section, the winding head is located on opposite sides of the bevel gear with respect to the axis of rotation.

[0012] In this drive configuration, the bevel gear is positioned significantly closer to the stator or rotor, or its coil former, than in other drive configurations. Consequently, the required installation space in the axial direction is reduced compared to these other configurations. Furthermore, the close proximity of the bevel gear to the coil former allows for excellent bearing support of the gear element coupled to the rotor, although this coupling is not achieved via the bevel gear itself.

[0013] If both the rotor and the stator each have a winding head, the bevel gear is preferably arranged, at least partially in the axial direction, in overlap with both winding heads. The winding head of the rotor can have a smaller axial extension in the direction away from the rotor than the winding head of the stator. In other words, the winding head of the stator projects axially beyond the winding head of the rotor.

[0014] A further embodiment of the invention provides that the bevel gear has at least one bevel gear which is coaxial to the axis of rotation and arranged in axial contact with the winding head. The bevel gear constitutes the at least one gear element of the bevel gear. Preferably, in addition to the bevel gear, the bevel gear has another bevel gear which meshes with the bevel gear, in particular permanently meshing with it.

[0015] The bevel gear is arranged coaxially to the axis of rotation, whereas the other bevel gear is arranged, for example, coaxially to the axis of rotation of the output shaft. To save space in the drive unit, the bevel gear is arranged such that it overlaps the winding head in the axial direction. As explained above, it is preferably provided that the winding head at least partially, but preferably completely, surrounds the bevel gear in the circumferential direction.

[0016] In a further preferred embodiment of the invention, the bevel gear can be non-rotatably coupled to a drive shaft that is in permanent operative connection with the rotor. In other words, the bevel gear is coupled to the rotor via the drive shaft. This means that the drive shaft is non-rotatably coupled to the bevel gear on the one hand and connected to the rotor on the other.

[0017] The drive shaft is preferably arranged coaxially with the rotor, meaning it has an axis of rotation that coincides with the rotor's axis of rotation. The drive shaft can, for example, be directly coupled to the rotor, so that the drive shaft and the rotor are in a fixed-speed connection and therefore always rotate at the same speed. The drive shaft allows for excellent bearing support of the bevel gear.

[0018] A further development of the invention provides that the drive shaft is rotatably mounted by means of a bearing, the bearing being arranged axially between the bevel gear and the coil former. The bearing is, for example, a plain bearing or – preferably – a rolling bearing. The bearing serves to support the drive shaft and preferably also the bevel gear of the right-angle drive. For this purpose, the bearing is arranged axially between the bevel gear and the coil former.

[0019] It is therefore particularly preferred that the bearing, viewed axially, is arranged at least partially, but more preferably completely, in overlap with the winding head. In other words, the bearing is at least partially, but preferably completely, encompassed by the winding head in the circumferential direction. This means that no additional installation space is required in the axial direction for the bearing arrangement, allowing the drive unit to be designed to be particularly compact.

[0020] Another preferred embodiment of the invention provides that the bevel gear additionally comprises a further bevel gear meshing with the bevel gear, which is mounted at an angle or skew relative to the axis of rotation and is rotationally fixed to the output shaft. In summary, the bevel gear thus comprises the bevel gear and the further bevel gear. The bevel gear is located on the rotor side and the further bevel gear on the output shaft side. The bevel gear and the further bevel gear are each mounted rotatably about an axis of rotation, the two axes of rotation being angled relative to each other or skew relative to each other. The axis of rotation of the bevel gear preferably coincides with the axis of rotation of the rotor, whereas the axis of rotation of the further bevel gear particularly preferably coincides with the axis of rotation of the output shaft.

[0021] The additional bevel gear is rotationally fixed to the output shaft, for example, it is mounted directly on the output shaft. However, it can also be provided that the additional bevel gear is operatively connected to the output shaft via a differential gear, such as an axle differential. For example, the additional bevel gear is connected to a differential gear cage of the differential gear, particularly rigidly and / or permanently. For example, the additional bevel gear is formed by the differential gear cage. Integrating the bevel gear, which includes the bevel gear and the additional bevel gear, into the drive unit such that axial overlap with the winding head is present enables a particularly compact design of the drive unit.

[0022] A further embodiment of the invention provides that the additional bevel gear is also partially overlapping the winding head when viewed axially. Particularly preferably, the additional bevel gear also engages with the conical head or approaches the coil body in such a way that it is at least partially encompassed by the winding head in the circumferential direction. This is particularly preferred for an outer edge of the additional bevel gear.

[0023] With this design, a large portion of the bevel gear can be in contact with the winding head. For example, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, or at least 75% of the bevel gear, viewed axially, is in contact with the winding head. Due to this contact of the remaining bevel gear with the winding head, the overall length of the drive unit is further reduced in the axial direction.

[0024] Another embodiment of the invention provides that the drive shaft is coupled to the rotor via an epicyclic gear unit, which is arranged axially on the side of the rotor opposite the bevel gear. The drive shaft is therefore not directly coupled to the rotor. Rather, this coupling is only indirect via the epicyclic gear unit. The epicyclic gear unit has several gear elements, with the drive shaft being coupled to a first gear element and the rotor to a second gear element. The epicyclic gear unit can also be referred to as a planetary gear unit or planetary gearbox.

[0025] The planetary gear set is located on the side of the rotor opposite the bevel gear set. Accordingly, the drive shaft extends axially through the coil former of the stator or rotor, preferably completely, to be connected to the planetary gear set on one side and to the bevel gear on the other. This results in excellent support for the drive shaft due to the large bearing distance between the bearing already described above and the planetary gear set, or another bearing that supports the drive shaft on the side of the coil former facing away from the bearing.

[0026] The planetary gear drive serves to reduce the rotational speed, so that the drive shaft rotates at a lower speed than the rotor. This results in a lower rotational speed of the bevel gear, leading to reduced noise compared to other drive systems where the bevel gear rotates at the same speed as the rotor. The drive system described here therefore offers significant acoustic advantages.

[0027] Another embodiment of the invention provides that the rotor or stator has a further winding head on its side facing away from the winding head, which projects beyond the coil former, wherein the planetary gear drive is arranged at least partially in axial overlap with the further winding head. The electrical winding of the rotor or stator thus projects axially with respect to the axis of rotation beyond the coil former on the side facing away from the winding head and forms the further winding head there.

[0028] To further reduce the axial dimensions of the drive unit, the planetary gear drive is now arranged in axial overlap with the additional winding head. Analogous to the descriptions of the winding head and the bevel gear, this means that the additional winding head encompasses the planetary gear drive at least partially, and preferably completely, in the circumferential direction. For example, the planetary gear drive is in axial overlap with the additional winding head by at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, or at least 75%.

[0029] Finally, in a further preferred embodiment of the invention, the drive shaft can be provided with a first gear element of the planetary gear set, and the rotor with a second gear element of the planetary gear set, in a rotationally fixed manner. This has already been mentioned above. The planetary gear set typically has three gear elements: a sun gear, a ring gear, and a planetary gear carrier on which at least one planetary gear is rotatably mounted. The planetary gear meshes with the ring gear on one side and with the sun gear on the other.

[0030] The first gear element is, for example, the sun gear, while the second gear element is the ring gear or the planetary gear carrier. The respective third gear element is preferably fixed, particularly with respect to the machine housing, so that a defined gear ratio exists between the first and second gear elements, which can also be referred to as the fixed gear ratio. Preferably, the ring gear is used as the second gear element, so that the planetary gear carrier is correspondingly fixed. The planetary gear carrier can also be referred to as a web.

[0031] Integrating the planetary gear unit into the drive system with regard to the transmitted torque between the rotor and the bevel gear unit offers the aforementioned advantage of a comparatively low rotational speed of the bevel gear unit. This advantage is achieved with an extremely compact drive system due to the planetary gear unit's arrangement in such a way that it is overlapped with the other winding head.

[0032] The invention further relates to an axle drive device for a motor vehicle, comprising several drive units, in particular drive units as described herein, wherein each of the drive units has an output shaft and an electric machine comprising a stator and a rotor rotatably mounted about an axis of rotation relative to the stator, the rotor being coupled to the output shaft via a bevel gear. It is provided that in each of the drive units, an electrical winding of the stator and / or an electrical winding of the rotor projects axially with respect to the axis of rotation beyond a coil former to form a winding head, and the bevel gear is arranged, at least partially in axial alignment, in contact with the winding head.

[0033] The advantages of such a design for the drive units or axle drive units have already been mentioned. Both the axle drive unit and its drive units can be further developed as described in this document, and reference is made to these details.

[0034] The axle drive unit serves to drive the wheels of a motor vehicle's axle. Preferably, each wheel of the axle is assigned its own drive unit, thus enabling individual wheel drive. For example, each wheel is coupled to the output shaft of its respective drive unit, particularly rigidly and / or permanently. Therefore, such individual wheel drive can be implemented in a particularly space-saving and acoustically advantageous manner using the axle drive unit or drive units.

[0035] The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing, without limiting the invention. The drawing shows: Fig. 1 a schematic representation of an axle drive device in a first embodiment, as well as Fig. 2 a schematic representation of the axle drive device in a second embodiment.

[0036] The Fig. Figure 1 shows a schematic representation of an axle drive device 1 for a motor vehicle which is used to drive a wheel axle 2 serves. The wheel axle 2 has two sub-axles 3 and 4 on, with each of the sub-axes 3 and 4 each with one wheel of the wheel axle 2 coupled, preferably rigidly and / or permanently. The axle drive unit 1 has a drive unit 5 on, which drive the wheel axle2 This is the purpose of the drive unit. 5 via a differential gear 6 with the wheel axle 2 coupled. The differential gear 6 It can also be referred to as an axle differential gear. The differential gear 6 couples the drive unit 5 both with the partial axis and the partial axis 4 The sub-axes 3 and 4 In this respect, they represent the output shafts of the differential gear. 6 dar.

[0037] The drive unit 5 has an electric machine 7 , which has a stator 8 as well as a rotor 8' exhibits. The stator 8 has a coil body 9 , on which an electrical winding 10 or multiple electrical windings 10 are wound up. The electrical winding 10 On the one hand, it forms the coil body.9 a winding head 11 and on the other hand, the coil body 9 another winding head 12 off. In other words, the electrical winding is off. 10 in the axial direction with respect to an axis of rotation 13 of the rotor 8' on both sides over the coil body 9 for the formation of the winding heads 11 and 12 above.

[0038] The rotor 8' is equipped with a drive shaft 14 coupled, namely in the embodiment shown here via a planetary gear system 15 The planetary gear system 15 has a first gear element 16 , a second gear element 17 as well as a third gear element 18 In the embodiment shown here, the first gear element is located 16 as sun gear, the second gear element 17 as a ring gear and the third gear element 18as a planetary gear carrier. At least one planetary gear is attached to the planetary gear carrier. 19 rotatably mounted, which meshes with the sun gear on one side and with the ring gear on the other.

[0039] In the embodiment shown here, the planetary gear carrier or the third gear element 18 fixed. The first gear element 16 is directly connected to the drive shaft 14 coupled, namely rigidly and / or permanently. The third gear element 18 However, it is directly connected to the rotor 8' coupled, preferably also rigidly and / or permanently.

[0040] On their planetary gear system 15 The drive shaft is on the opposite side. 14 to an angle gearbox 20 connected, which is a bevel gear 21 and another bevel gear 22 features the bevel gears 21 and 22mesh together. The bevel gear 22 is on an output shaft 23 the drive unit 5 arranged and non-rotatably connected to it. In the embodiment shown here, the output shaft 23 from a differential gear basket of the differential gear 6 shown. On the angle gear 20 facing side of the stator 8 or of the rotor 8' or the coil body 9 is the drive shaft 14 by means of a bearing 24 Rotatable mounting.

[0041] To achieve a particularly compact design of the drive unit 5 To achieve this, it is planned to use the angle gear. 20 at least partially, viewed in the axial direction, in overlap with the winding head 11 to arrange. Preferably, it is also provided to arrange the planetary gear drive. 15in the axial direction at least partially in axial overlap with the further winding head 12 to order.

[0042] This results in a particularly compact design of the drive unit in the axial direction. 5 and thus the axle drive system 1 realized. The warehouse 24 , which runs axially between the bevel gear 21 and the coil former 9 The arrangement is also in overlap with the winding head. 11 before, preferably completely.

[0043] The Fig. Figure 2 shows a schematic representation of the axle drive unit 1 in a second embodiment. In this embodiment, the axle drive unit has 1 via multiple axle drive systems 5 , namely in the embodiment shown here two axle drive devices 5 Basically, the axle drive unit 1the second embodiment is similar to the axle drive device 1 the first embodiment is designed differently, so only the differences will be discussed below.

[0044] These lie essentially in the fact that the axle drive unit 1 via two axle drive units 5 Each of the drive units has 5 is one of the sub-axles 3 and 4 assigned so that the differential gear 6 omitted. The sub-axles 3 and 4 Now, each of the output shafts is positioned. 23 the corresponding drive unit 5 This represents the axle drive unit. 1 In its second embodiment, it features an individual wheel drive for the motor vehicle. Regarding the further design of the axle drive device 1In its second embodiment, reference is made to the explanations within this description, in particular also to the first embodiment. These can be applied essentially analogously. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 1613053

[0002]

Claims

[1] Drive device (5) for a motor vehicle, comprising an output shaft (23) and an electric machine (7) comprising a stator (8) and a rotor (8') rotatably mounted about an axis of rotation (13) relative to the stator (8), which is coupled to the output shaft (23) via an angle gear (20), characterized by , that an electrical winding (10) of the stator (8) and / or an electrical winding of the rotor (8') projects in axial direction with respect to the axis of rotation (13) over a coil body (9) to form a winding head (11) and the angle gear (20) is arranged at least partially in axial direction in overlap with the winding head (11). [2] Drive device according to claim 1, characterized by , that the angle gear (20) has at least one bevel gear (21) which is coaxial to the axis of rotation (13) and is arranged in axial direction in overlap with the winding head (11). [3] Drive device according to one of the preceding claims, characterized by , that the bevel gear (21) is coupled in a rotationally fixed manner to a drive shaft (14) which is in permanent operative connection with the rotor (8'). [4] Drive device according to one of the preceding claims, characterized by , that the drive shaft (14) is rotatably mounted by means of a bearing (24), wherein the bearing (24) is arranged in the axial direction between the bevel gear (21) and the coil body (9). [5] Drive device according to one of the preceding claims, characterized by , that the angle gear (20) additionally has a further bevel gear (22) meshing with the bevel gear (21), which is mounted at an angle or skew to rotate relative to the axis of rotation (13) and is coupled to the output shaft (23) in a rotationally fixed manner. [6] Drive device according to one of the preceding claims, characterized by, that the further bevel gear (22) is also partially in overlap with the winding head (11) when viewed in the axial direction. [7] Drive device according to one of the preceding claims, characterized by , that the drive shaft (14) is coupled to the rotor (8') via a planetary gear transmission (15), which is arranged in the axial direction on the side of the rotor (8') opposite the angle gear (20). [8] Drive device according to one of the preceding claims, characterized by , that the rotor (8') or the stator (8) has on its side facing away from the winding head (11) a further winding head (12) which projects beyond the coil body (9), wherein the planetary gear drive (15) is arranged in axial direction at least partially in overlap with the further winding head (12). [9] Drive device according to any one of the preceding claims, characterized by, that the drive shaft (14) is coupled to a first gear element (16) of the planetary gear set (15) and the rotor (8') is coupled to a second gear element (17) of the planetary gear set (15) in a rotationally fixed manner. [10] Axle drive device (1) for a motor vehicle, with several drive devices (5), in particular drive devices (5) according to one of the preceding claims, wherein each of the drive devices (5) has an output shaft (23) and an electric machine (5) which has a stator (8) and a rotor (8') rotatably mounted about an axis of rotation (13) with respect to the stator (8), which is coupled to the output shaft (23) via a bevel gear (20), characterized by, that in each of the drive devices (5) an electrical winding (10) of the stator (8) and / or an electrical winding of the rotor (8') projects in axial direction with respect to the axis of rotation (13) over a coil body (9) to form a winding head (11) and the angle gear (20) is arranged at least partially in axial direction in overlap with the winding head (11).

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