Drive module and axle assembly for an electric vehicle and electric vehicle

Abstract

This disclosure relates to a drive module (20) for an electric vehicle. The drive module (20) includes a motor (22) having a rotor (28) and a stator (30), the rotor (28) being at least partially annular and defined in a receiving space (32) radially and axially inward of the rotor (28). The drive module (20) includes a differential gear unit (34). The drive module (20) includes a first single-stage cylindrical gear unit (36) having a first output interface (40) drivably coupled to a wheel (18a) and a second single-stage cylindrical gear unit (38) having a second output interface (44) drivably coupled to a wheel (18b). The differential gear unit (34) is at least partially arranged in the receiving space (32) and is drivably coupled to the rotor (28). The first cylindrical gear unit (36) and the second cylindrical gear unit (38) are drivably coupled to the differential gear unit (34). An axle assembly (16) for an electric vehicle and an electric vehicle are shown.

Description

Technical Field

[0001] This disclosure relates to a drive module for an electric vehicle. The drive module includes a motor having a rotor and a stator.

[0002] This disclosure also relates to an axle assembly for an electric vehicle. The axle assembly includes a drive module.

[0003] Furthermore, this disclosure relates to an electric vehicle comprising such a drive module and / or such an axle assembly. Background Technology

[0004] In the field of electric vehicles, axle assemblies that combine a motor, a differential gear unit, and optional other gear stages are known. Such vehicle axle assemblies are typically supplied as modules in electric vehicles. Summary of the Invention

[0005] One objective of this disclosure is to further improve the axle assembly for electric vehicles.

[0006] The subject matter of the independent claims of this disclosure at least partially addresses or mitigates this problem, wherein further examples are included in the dependent claims.

[0007] According to a first aspect, a drive module for an electric vehicle is provided. The drive module includes a motor having a rotor and a stator. The rotor is at least partially annular and defines a receiving space within the rotor's radial and axial inner sides. Furthermore, the drive module includes a differential gear unit. Additionally, the drive module includes a first single-stage cylindrical gear unit having a first output interface configured to be drivably coupled to a wheel and a second single-stage cylindrical gear unit having a second output interface configured to be drivably coupled to a wheel. The differential gear units are at least partially arranged within the receiving space. The differential gear units are drivably coupled to the rotor. The first and second cylindrical gear units are arranged on opposite sides of the differential gear unit and are drivably coupled to the differential gear unit. In this document, the module should be understood as a continuous unit. This means that all components of the drive module are interconnected and can be installed in an electric vehicle in one step. The fact that the differential gear units are at least partially arranged within the receiving space makes the drive module compact. Furthermore, in this drive module, the motor is arranged on the input side of the differential gear unit, while the cylindrical gear units are arranged on the respective output sides of the differential gear unit. Each cylindrical gear unit is configured to be drivenly coupled to a single wheel. Therefore, particularly compared to drive units where gear stages are arranged between the motor and the differential gear unit, cylindrical gear units only need to support relatively low drive power, i.e., relatively low torque. This is because each cylindrical gear unit only needs to transmit power to a single wheel. Thus, in an ideal configuration, each cylindrical gear unit only needs to transmit half the power that the entire drive module needs to transmit. This has the effect that cylindrical gear units can be designed in a compact and lightweight manner. Furthermore, this allows for the use of relatively small teeth on the gears forming the cylindrical gear units, i.e., allowing for a small gear module. This is advantageous in terms of noise, vibration, and harshness (NVH), i.e., such cylindrical gear units generate relatively little noise, vibration, and harshness during operation. Another advantage of cylindrical gear units is their simple structure. This is particularly true when comparing cylindrical gear units with planetary gear units. According to this disclosure, the drive module comprises two single-stage cylindrical gear units. This means that each cylindrical gear unit includes only two meshing gears. Such cylindrical gear units have the advantage of relatively low mechanical losses. This is especially true when comparing a single-stage cylindrical gear unit to a cylindrical gear unit with more than two stages. Overall, the drive module according to this disclosure is simple, compact, and highly efficient. At the same time, the drive module is capable of supporting conventional loads used in electric vehicles, i.e., conventional power levels. The simplicity and compactness of the structure also allow for the manufacture of this drive module at a relatively low cost.

[0008] In the context of this disclosure, a cylindrical gear unit should be understood as a unit or assembly comprising at least two meshing cylindrical gears. A cylindrical gear is a gear having a cylindrical pitch surface. Simply put, the surface provided with teeth has the form of the side surface of a cylinder. An example of a cylindrical gear is a spur gear. A spur gear is characterized in that the teeth extend substantially parallel to the axial direction, that is, substantially parallel to the central axis of the gear. Another example of a cylindrical gear is a helical gear. A helical gear is characterized in that the teeth are inclined relative to the axial direction, that is, inclined relative to the central axis of the gear.

[0009] It should be noted that in the drive module of this disclosure, the first output interface and the second output interface share a common central axis. Therefore, the drive unit is particularly suitable for use in the axle assembly of electric vehicles.

[0010] According to one example, at least one gear of the first cylindrical gear unit is at least partially made of sintered material. This gear may also be made entirely of sintered material. Alternatively or concurrently, at least one gear of the second cylindrical gear unit is at least partially made of sintered material. This gear may also be made entirely of sintered material. The advantage of gears made of sintered material is that they can be formed with high geometric flexibility.

[0011] Regarding the motor, this disclosure is not limited to a specific type of motor. This means that the motor of the drive module according to this disclosure can be a permanent magnet motor, an axial flux motor, an internal permanent magnet motor, a surface permanent magnet motor, an asynchronous motor, a SynRM motor, or any other suitable motor.

[0012] In this document, it will be understood that the electric motor disclosed herein can be operated as an electric motor or as a generator.

[0013] According to one example, the motor's diameter is larger than its axial length. In other words, the motor's axial length is smaller than its diameter. This makes the drive module compact. In one example, the motor's diameter can be larger than its axial length. In one example, the motor's diameter is 250 mm or larger, and its axial length is 150 mm or smaller. Such a motor can also be characterized by a form factor of 1.67 or larger, where the form factor corresponds to the diameter divided by the axial length.

[0014] In one example, the differential gear unit is fully housed within the housing space. In this case, the drive module is particularly compact. This results in a particularly high capacity for integrating the drive module into the vehicle. In other words, if the drive module is compact, it can be arranged in small and / or constrained spaces within an electric vehicle.

[0015] As an example, a differential gear unit may include a planetary gear mechanism, a cylindrical gear mechanism, or a bevel gear mechanism. In this document, a differential gear unit including a planetary gear mechanism should be understood as a differential gear unit including a planetary gear stage. Therefore, the function of the differential gear unit is provided by the planetary gear stage. Similarly, a differential gear unit including a cylindrical gear mechanism should be understood as a differential gear unit including one or more cylindrical gear stages. Therefore, the function of the differential gear unit is provided by one or more cylindrical gear stages. Likewise, a differential gear unit containing a bevel gear mechanism should be understood as a differential unit including one or more bevel gear stages. Therefore, the function of the differential gear unit is provided by one or more bevel gear stages. In all these examples, the function of the differential gear unit can be provided with high reliability and high efficiency.

[0016] In one example, the differential gear unit includes a housing with a substantially constant wall thickness. Additionally or optionally, the differential gear unit includes a housing made of sheet metal. A housing with a substantially constant wall thickness is particularly suitable for use with sheet metal. The sheet metal can be, for example, a sheet metal made of steel alloy or aluminum alloy. Furthermore, a housing with a substantially constant wall thickness has a simple structure. Therefore, it can be manufactured in a cost-effective manner. This is especially true when the housing is made of sheet metal. Such a housing can also be lightweight.

[0017] In one example, the interior of the housing is oil-tightly sealed relative to the exterior. This means that the differential gear unit, located inside the housing, is oil-tightly sealed relative to the motor, particularly the rotor and stator. Therefore, the differential gear unit can operate efficiently using lubricants such as oil. Meanwhile, the motor's function is unaffected by the lubricant (e.g., oil).

[0018] In one example, the differential gear unit is axially centered within the rotor. Therefore, the sub-assembly of the drive module, which includes the differential gear unit and the rotor, is balanced along the central axis of the rotor and the differential gear unit. This enhances the sub-assembly's NVH (noise, vibration, and harshness) performance.

[0019] According to one example, the first and second cylindrical gear units are arranged symmetrically with respect to the motor and / or with respect to the differential gear unit. This configuration balances the drive module along the central axis of the motor. Furthermore, this allows for a symmetrical arrangement of the drive module within the electric vehicle, i.e., at the center of the vehicle's width. Therefore, the distance between the cylindrical gear units and their respective associated wheels is equidistant on both sides. Consequently, the drive shafts used to drive the wheels can have the same length. This avoids the so-called torque steer effect, which is essentially caused by the unequal length of such drive shafts. This results in safer driving behavior in electric vehicles equipped with the aforementioned drive module.

[0020] In one example, the differential gear unit includes a first output shaft rotatable about a first central axis. A first cylindrical gear unit includes a first input shaft. The first output shaft and the first input shaft are integrally formed. Additionally or optionally, the differential gear unit includes a second output shaft rotatable about a second axis of rotation. A second cylindrical gear unit includes a second input shaft. The second output shaft and the second input shaft are integrally formed. In one example, the first central axis and the second shaft coincide. Integrating these shafts simplifies the structure of the drive module. Furthermore, integrally forming these shafts allows for a compact design of the drive module. Additionally, integrally forming the shafts instead of drivingly connecting them improves operational efficiency.

[0021] In one example, an axial bearing (also called a thrust bearing) is arranged axially between the first and second output shafts. Therefore, using an axial bearing can balance the axial reaction forces generated within the drive module. This is particularly useful when the cylindrical gear unit includes helical gears, especially when the inclination directions of the helical gear on the first and second output shafts are opposite to each other, such that the axial reaction force acting on the first output shaft points towards the second output shaft, and the axial reaction force acting on the second output shaft points towards the first output shaft.

[0022] According to one example, each of the first and second output shafts is radially supported on the drive module housing at two axially separated locations. This means that each of the first and second output shafts is radially supported on the drive module housing at exactly two axially separated locations. Therefore, the support of the first and second output shafts reliably and precisely defines their positions. Additionally, rotation is permitted. Meanwhile, the number of locations where the first and second output shafts are supported corresponds to a theoretical minimum. Since losses occur at each support location, this also means that this configuration produces relatively low losses, i.e., relatively high efficiency. Note that in this text, the support can be direct or indirect, for example, via the differential gear unit housing. Furthermore, using fewer support locations makes the drive module structure simpler and cheaper.

[0023] According to one example, the centerlines of the first and second output ports are offset relative to the centerline of the motor. Optionally, the size of the offset can be selected by accordingly choosing a cylindrical gear unit. Having such an offset results in external dimensions of the drive module that are advantageous for packaging within an electric vehicle. Changing the size of the offset also provides packaging flexibility. For example, by modifying the amount of offset, the tilt of the drive axle that connects one of the output ports to the associated wheel can be modified. In summary, the drive module is configured for integration into different types of electric vehicles.

[0024] In one example, each of the first and second cylindrical gear units has a gear ratio of 5:1 or greater. In another example, the first and second cylindrical gear units have a gear ratio of 6:1 or greater. Therefore, the first and second cylindrical gear units are adapted to provide the necessary reduction in power in electric vehicles. The fact that this reduction is provided by a single-stage cylindrical gear unit enhances operational efficiency, as previously mentioned.

[0025] In one example, each of the first and second cylindrical gear units includes a helical gear. Helical gears have the advantage of enhanced load-bearing capacity, especially compared to standard spur gears (i.e., gears whose teeth extend substantially parallel to the axial direction). This advantage is also used in the drive module. The teeth of the helical gear in the first cylindrical gear unit can be inclined in one direction, while the teeth of the helical gear in the second cylindrical gear unit can be inclined in the opposite direction. These directions can point towards each other. In this case, the axial reaction force generated by using the helical gear can be supported simply and reliably.

[0026] According to a second aspect, an axle assembly for an electric vehicle is provided. The axle assembly includes a drive module according to this disclosure. Furthermore, the axle assembly includes a first wheel drivenly connected to a first output interface via a first drive shaft and a second wheel drivenly connected to a second output interface via a second drive shaft. The axial length of the first drive shaft is equal to the axial length of the second drive shaft. It should be understood that, herein, the wheels are road wheels. Because the drive module is structurally simple and compact, the axle assembly is also compact. Furthermore, the advantages of the drive module in terms of noise, vibration, and harshness (NVH) are also reflected in the entire axle assembly. This also applies to efficiency. The equal lengths of the first and second drive shafts avoid the effects of so-called torque steer. This results in safe driving behavior in electric vehicles equipped with this axle assembly.

[0027] According to a third aspect, an electric vehicle is provided, comprising a drive module and / or an axle assembly according to the present disclosure. Therefore, the drive system of this electric vehicle is structurally simple and compact. Furthermore, the advantages of the drive module and / or axle assembly in terms of noise, vibration, and harshness (NVH) are also reflected in the overall electric vehicle. This also applies to efficiency. In addition, this electric vehicle exhibits safe driving behavior.

[0028] It should be noted that the above examples can be combined with each other, regardless of the aspects involved.

[0029] These and other aspects of this disclosure will become apparent from the embodiments described below, and will be illustrated with reference to these embodiments. Attached Figure Description

[0030] Embodiments of this disclosure will now be described with reference to the accompanying drawings.

[0031] Figure 1 An electric vehicle according to the present disclosure is shown, which includes an axle assembly according to the present disclosure and a drive module according to the present disclosure. Figure 2 A partial sectional view shows more details. Figure 1 axle assembly; Figure 3 A partial sectional view shows more details. Figure 1 and Figure 2 The driver module, Figure 4 The driver module according to another example is shown, in which Figure 4 The view corresponds to Figure 3 Details of the driver module, IV.

[0032] Figure 5 Shown in perspective Figure 3 A sub-component of the driver module, Figure 6 With Figure 3 The partial sectional view corresponding to the view shows another example of a drive module. Figure 7 Shown in a separate perspective view Figure 6 The bushing of the drive module, Figure 8 Presented in perspective and partially exploded view Figure 6 The driver module, Figure 9 It is shown in another perspective view and partially exploded view. Figure 6 The drive module, wherein the side cover component of the housing and the first single-stage cylindrical gear unit are not shown, and Appendix Figures 10 to 12 Assembly is shown Figure 6 The steps for the driver module. Detailed Implementation

[0033] The accompanying drawings are merely illustrative and are used only to illustrate embodiments of this disclosure. Identical or equivalent elements generally have the same reference numerals.

[0034] Figure 1 Electric vehicle 10 is shown.

[0035] The electric vehicle 10 has a front axle assembly 12 including front wheels 14 and a rear axle assembly 16 including rear wheels 18.

[0036] Figure 1 The electric vehicle 10 shown in the example is a rear-wheel drive vehicle.

[0037] This means that the rear axle assembly 16 includes a drive module 20 with a motor 22 configured to drive the rear wheel 18.

[0038] For this purpose, the electric vehicle 10 also includes a traction battery 24 and an inverter unit 26. Thus, the motor 22 can be powered by the traction battery 24 via the inverter unit 26.

[0039] Furthermore, in this example, the vehicle coordinate system is defined as follows: the X-axis extends along the standard forward travel direction of the electric vehicle 10. The Y-axis extends along the width direction of the electric vehicle 10. In this embodiment, when considering the standard forward travel direction of the electric vehicle 10, the Y-axis extends from right to left. The Z-axis extends along the height direction of the electric vehicle 10.

[0040] exist Figure 2 The rear axle assembly 16 is shown in more detail below. For ease of explanation, the rear axle assembly 16 will be referred to as the axle assembly 16 below.

[0041] As previously mentioned, the axle assembly 16 includes a drive module 20, and the drive module 20 includes a motor 22.

[0042] The motor 22 has a rotor 28 and a stator 30. The rotor 28 is disposed within the stator 30 and is rotatable about a first axis of rotation A1. Therefore, the first axis of rotation A1 corresponds to the central axis of the motor 22. The rotor 28 is annular and defines receiving spaces 32 provided on the radial and axial inner sides of the rotor 28.

[0043] In addition, the drive module 20 includes a differential gear unit 34, which is arranged in the receiving space 32 and is drivenly connected to the rotor 28, as will be explained in more detail below.

[0044] In this example, the differential gear unit 34 is fully housed in the housing space 32.

[0045] The differential gear unit 34 is also axially centered within the rotor 28.

[0046] In addition, the drive module 20 includes a first single-stage cylindrical gear unit 36 ​​and a second single-stage cylindrical gear unit 38.

[0047] The first single-stage cylindrical gear unit 36 ​​and the second single-stage cylindrical gear unit 38 are both drivenly connected to the differential gear unit 34. The first single-stage cylindrical gear unit 36 ​​and the second single-stage cylindrical gear unit 38 are arranged on opposite sides of the differential gear unit 34.

[0048] Furthermore, the first single-stage cylindrical gear unit 36 ​​includes a first output interface 40. The first output interface 40 is rotatable about an axis that will be designated below as the second axis of rotation A2.

[0049] The first rear wheel in the rear wheel 18, or simply the first wheel 18a, is driven to the first output interface 40 via the first drive shaft 42.

[0050] The first drive shaft 42 also extends along the second rotation axis A2, and is therefore able to rotate about the second rotation axis A2. The same applies to the first wheel 18a.

[0051] The second single-stage cylindrical gear unit 38 includes a second output interface 44. The second output interface 44 is rotatable about an axis that coincides with the second rotation axis A2.

[0052] The second rear wheel in the rear wheel 18, or simply the second wheel 18b, is driven to the second output interface 44 via the second drive shaft 46.

[0053] The second drive shaft 46 also extends along the second rotation axis A2, and is therefore able to rotate about the second rotation axis A2. The same applies to the second wheel 18b.

[0054] In this example, the axial length L1 of the first drive shaft 42 is equal to the axial length L2 of the second drive shaft 46. Therefore, the drive module 20 is centrally located relative to the width direction or Y-axis of the vehicle 10. This has the advantage of avoiding so-called torque steer.

[0055] In addition, Figure 2 In the example, the first rotation axis A1 and the second rotation axis A2 are offset from each other by a distance D, which in this example extends along the Z direction. In other words, the central axis of the first output interface 40 and the central axis of the second output interface 44 are offset relative to the central axis of the motor 22. This is due to the use of the first single-stage cylindrical gear unit 36 ​​and the second single-stage cylindrical gear unit 38.

[0056] Due to this arrangement, the central axis or first rotation axis A1 of motor 22 is shifted towards a higher positive Z value, i.e., shifted in the height direction of vehicle 10. This allows for a sufficiently large clearance C between the underside of electric vehicle 10 (more precisely, drive module 20) and the road on which electric vehicle 10 travels. This allows for... Figure 2 This is especially true when comparing the arrangement of the motor 22 and the first output interface 40 and the second output interface 44 to an arrangement in which they are coaxially arranged.

[0057] Figure 3 The drive module 20 is shown in more detail.

[0058] The drive module 20 includes a drive module housing 48. For ease of explanation, the drive module housing 48 will be referred to as housing 48 below.

[0059] The stator 30 is fixedly mounted inside the housing 48.

[0060] As previously described, the rotor 28 is rotatably housed within the stator 30. Furthermore, the rotor 28 defines a housing space 32 in which a differential gear unit 34 is arranged.

[0061] In this example, rotor 28 includes flange 50, which is arranged at an axial center position within receiving space 32.

[0062] The differential gear unit 34 includes a housing 52. The housing 52 has a substantially constant wall thickness and is made of sheet metal. More specifically, the housing 52 includes a first half-shell 54 and a second half-shell 56. Both the first half-shell 54 and the second half-shell 56 are formed of sheet metal.

[0063] The first half-shell 54 and the second half-shell 56 are connected to each other to form the housing 52. In addition, the housing 52 is fixedly connected to the flange 50 using bolts or rivets 58.

[0064] Therefore, housing 52 can be regarded as the power input interface of differential gear unit 34.

[0065] In addition, the first half-shell 54 includes a support flange 60, which is formed into a pipe segment.

[0066] With the housing 52 installed in the drive module 20, the central axis of the support flange 60 (i.e., the pipe section) coincides with the first rotation axis A1.

[0067] The first half-shell 54 is rotatably supported in the housing 48 via a first bearing 62, which is disposed between the end of the support flange 60 and the housing 48. Furthermore, the first support flange 60 serves as a sealing interface. More precisely, a first seal 64 is disposed between the first support flange 60 and the housing 48.

[0068] The second half-shell 56 also includes a support flange 66 that is shaped into a pipe section.

[0069] With the housing 52 installed in the drive module 20, the central axis of the support flange 66 (i.e., the pipe section) coincides with the first rotation axis A1.

[0070] The second half-shell 56 is rotatably supported within the housing 48 via a second bearing 68, which is disposed between the end of the support flange 66 and the housing 48. Furthermore, the support flange 66 serves as a sealing interface. More precisely, a second seal 70 is disposed between the support flange 66 and the housing 48.

[0071] In summary, the housing 52 and the rotor 28 fixedly connected thereto are rotatably supported in the housing 48 via the first bearing 62 and the second bearing 68.

[0072] The differential gear unit 34 further includes a first output shaft 72 rotatable about a first rotation axis A1.

[0073] The differential gear unit 34 also includes a second output shaft 74 that can rotate about the first rotation axis A1.

[0074] In this document, the first output shaft 72 extends through the interior of the support flange 60, and the second output shaft 74 extends through the interior of the support flange 66.

[0075] This means that the first output shaft 72 and the second output shaft 74 extend from the housing 52 on opposite sides of the housing 52.

[0076] Therefore, the first output shaft 72 and the second output shaft 74 can be regarded as the output interfaces of the differential gear unit 34.

[0077] exist Figure 3 In the example, the differential gear unit 34 includes a cylindrical gear mechanism 76. This means that the differential gear unit 34 is a cylindrical gear differential. Figure 3 In the example shown, the cylindrical gear differential is a spur gear differential.

[0078] Since cylindrical gear differentials and their functions are well known in the art, detailed descriptions are omitted here. It should be noted that in other variations, the differential gear unit can be configured as a bevel gear differential or a planetary gear differential. These types of differential gear units are also known.

[0079] The first output shaft 72 is drivably coupled to the first input shaft 78 of the first cylindrical gear unit 36. In this example, this is achieved by making the first output shaft 72 and the first input shaft 78 a single unit. This means that both functions are provided by a single shaft.

[0080] The shaft (i.e., the first output shaft 72 and the first input shaft 78) is rotatably supported in the housing 48 by the third bearing 80 and the fourth bearing 82.

[0081] The third bearing 80 is axially adjacent to the first bearing 62 for positioning.

[0082] The fourth bearing 82 is positioned at the end of the first input shaft 78 away from the differential gear unit 34.

[0083] Furthermore, the third bearing 80 and the fourth bearing 82 are positioned at an axial distance. Thus, the single shaft forming the first output shaft 72 and the first input shaft 78 is rotatably supported on the housing 48 of the drive module 20 at two axially separated positions.

[0084] The second output shaft 74 is drivably coupled to the second input shaft 84 of the second cylindrical gear unit 38. In this example, this is achieved by making the second output shaft 74 and the second input shaft 84 a single unit. This means that both functions are provided by a single shaft.

[0085] The shaft (i.e., the second output shaft 74 and the second input shaft 84) is rotatably supported in the housing 48 by the fifth bearing 86 and the sixth bearing 88.

[0086] The fifth bearing 86 is axially adjacent to the second bearing 68 for positioning.

[0087] The sixth bearing 88 is positioned at the end of the second input shaft 84 away from the differential gear unit 34.

[0088] Furthermore, the fifth bearing 86 and the sixth bearing 88 are positioned at an axial distance. Thus, the individual shafts forming the second output shaft 74 and the second input shaft 86 are rotatably supported on the housing 48 of the drive module 20 at two axially separated positions.

[0089] The first single-stage cylindrical gear unit 36 ​​includes a first helical gear 90 and a second helical gear 92 that mesh with each other. The transmission ratio of the first single-stage cylindrical gear unit 36 ​​is 6:1. The diameter of the first helical gear 90 is smaller than the diameter of the second helical gear 92.

[0090] The first helical gear 90 is integrally formed on the first input shaft 78. In the installed state, the first helical gear 90 is arranged axially between the third bearing 80 and the fourth bearing 82.

[0091] Since the helical gear generates axial reaction force, at least one of the third bearing 80 and the fourth bearing 82 needs to be able to support the axial load.

[0092] The second helical gear 92 is rotatably supported on the housing 48 via the seventh bearing 94. Furthermore, the second helical gear 92 is axially supported on the housing 48 via the eighth bearing 96. The seventh bearing 94 and the eighth bearing 96 are separate bearings.

[0093] The axis of rotation of the second helical gear 92 corresponds to the second axis of rotation A2.

[0094] The first output interface 40 is integrally formed on the second helical gear 92.

[0095] Therefore, the motor 22 can be used to drive the first output interface 40 and the first drive shaft 42 connected to the first wheel 18a. The necessary power is provided via the differential gear unit 34 and the first single-stage cylindrical gear unit 36.

[0096] The second single-stage cylindrical gear unit 38 includes a third helical gear 98 and a fourth helical gear 100 that mesh with each other. The transmission ratio of the second single-stage cylindrical gear unit 38 is 6:1. The diameter of the third helical gear 98 is smaller than the diameter of the fourth helical gear 100.

[0097] The third helical gear 98 is integrally formed on the second input shaft 84. In the installed state, the third helical gear 98 is arranged axially between the fifth bearing 86 and the sixth bearing 88.

[0098] Since the helical gear generates axial reaction force, at least one of the fifth bearing 86 and the sixth bearing 88 needs to be able to support the axial load.

[0099] The fourth helical gear 100 is rotatably supported on the housing 48 via the ninth bearing 102. Furthermore, the fourth helical gear 100 is axially supported on the housing 48 via the tenth bearing 104. The ninth bearing 102 and the tenth bearing 104 are separate bearings.

[0100] The axis of rotation of the fourth helical gear 100 corresponds to the second axis of rotation A2.

[0101] The second output interface 44 is integrally formed on the fourth helical gear 100.

[0102] Therefore, the motor 22 can be used to drive the second output interface 44 and the second drive shaft 46 connected to the second wheel 18b. The necessary power is provided via the differential gear unit 34 and the second single-stage cylindrical gear unit 38.

[0103] The first cylindrical gear unit 36 ​​and the second cylindrical gear unit 38 are arranged symmetrically with respect to the motor 22 and the differential gear unit 34. This means that the first cylindrical gear unit 36 ​​and the second cylindrical gear unit 38 have the same axial and radial distances with respect to the motor 22 and the differential gear unit 34. Furthermore, the first cylindrical gear unit 36 ​​and the second cylindrical gear unit 38 are designed to be identical, except that they are used on opposite sides (i.e., in addition to being mirror symmetrical).

[0104] In addition, Figure 3 In this example, the interior of housing 52 is sealed relative to the exterior of housing 52 by an oil seal. For this purpose, a first seal 64 and a second seal 70 are used.

[0105] In addition, the housing 48 includes a first inner wall 106, a second inner wall 108, a third inner wall 110 and a fourth inner wall 112, which further define a space connected to the interior of the housing 52 relative to the exterior of the housing 52.

[0106] Because of this arrangement, all gear components of the drive module 20 can be lubricated, for example, using oil lubrication. However, the components of the motor 22, namely the rotor 28 and the stator 30, can remain oil-free.

[0107] Figure 4 A driver module 20 according to another example is shown. In the following text, only references to... Figure 3 The difference lies in the driver module 20. Otherwise, in combination Figure 3 The explanation provided in the example also applies Figure 4 Examples.

[0108] Since the difference only involves a part of the driver module 20, Figure 4 Only a portion of the drive module 20 is shown in the image.

[0109] One difference involves the support of the shaft that forms the first input shaft 78 of the first output shaft 72 and the first single-stage cylindrical gear unit 36.

[0110] The third bearing 80 is now positioned between the shaft and the support flange 60 of the first half-shell 54. Furthermore, with... Figure 3 In contrast, the third bearing 80 is a radial bearing, meaning it is not configured to support axial loads.

[0111] Therefore, the shafts forming the first output shaft 72 and the first input shaft 78 are now radially supported in the housing 48 via the fourth bearing 82 and the combination of the first bearing 62 and the third bearing 80.

[0112] Similarly, the difference also involves the support of the shaft that forms the second output shaft 74 and the second input shaft 84 of the second single-stage cylindrical gear unit 38.

[0113] The fifth bearing 86 is now positioned between the shaft and the support flange 66 of the second half-shell 56. Furthermore, with... Figure 3 In contrast to the example, the fifth bearing 86 is a radial bearing, that is, it is not configured to support axial loads.

[0114] Therefore, the shafts forming the second output shaft 74 and the second input shaft 84 are now radially supported in the housing 48 via the sixth bearing 88 and the combination of the second bearing 68 and the fifth bearing 86.

[0115] In addition, with Figure 3 In contrast, the first output shaft 72 and the second output shaft 74 are axially supported by each other via an eleventh bearing 114. This bearing is configured to support the axial loads caused by the helical gears 90, 92, 98, and 100.

[0116] exist Figure 4 In the example, the arrangement of the seals is also different.

[0117] First seal 64 and second seal 70 and Figure 3 The examples are the same. However, Figure 4 Examples include a third seal 116 and a fourth seal 118, with the third seal 116 disposed between the first output shaft 72 and the support flange 60, and the fourth seal 118 disposed between the second output shaft 74 and the support flange 66. Therefore, in Figure 4 In the example, the interior of housing 52 is sealed with an oil seal relative to the exterior of housing 52.

[0118] Figure 5 Shown in perspective Figure 3 The drive module 20 is a sub-assembly. This sub-assembly includes a rotor 28 forming a receiving space 32, a flange 50, and a differential gear unit 34. Additionally, shafts forming a first output shaft 72 and a first input shaft 78 are shown. A first bearing 62 is also shown.

[0119] Figure 5 The location of the differential gear unit 34 within the housing space 32 is further shown, as well as the design of the shafts that integrally form the first output shaft 72 and the first input shaft 78.

[0120] Figure 6 A driver module 20 according to yet another example is shown. In the following text, only references to... Figure 3 and Figure 4 The difference lies in the driver module 20. Otherwise, in combination Figure 3 and Figure 4 The explanation provided in the example also applies Figure 6 Examples.

[0121] The first set of differences involves the axial support of the first output shaft 72 and the second output shaft 74.

[0122] exist Figure 6 In the example, the first output shaft 72 and the second output shaft 74 are axially supported by each other. This means that the first output shaft 72 and the second output shaft 74 are in contact with each other along the first axis of rotation A1.

[0123] In addition, the first output shaft 72 and the second output shaft 74 are axially connected via screws 116 and bushings 118.

[0124] For this purpose, a threaded hole 120 extending along the first rotation axis A1 is provided at the axial end of the second output shaft 74 adjacent to the first output shaft 72. This means that the threaded hole 120, which is formed as a blind hole, opens toward the axial end face of the second output shaft 74 that contacts the first output shaft 72.

[0125] The first output shaft 72 is formed as a hollow shaft with a closed end, which is adjacent to the second output shaft 74. A through hole 122 is provided in the closed end. The central axis of the through hole coincides with the first rotation axis A1.

[0126] Screw 116 extends through through hole 122 and engages with threaded hole 120, thereby axially connecting first output shaft 72 and second output shaft 74.

[0127] Note that the first output shaft 72 and the second output shaft 74 can still rotate relative to each other about the first rotation axis A1. Therefore, the screw 116 does not impede this rotation.

[0128] To prevent unintended loosening of screw 116, bushing 118 is provided.

[0129] The bushing 118 also extends through the through hole 122, thereby surrounding the screw 116. In other words, the bushing 118 has a through hole through which the screw 116 passes.

[0130] The bushing 118 also includes a collar and a head of the screw 116, with the head of the screw axially abutting against the collar when the screw is in the installed state.

[0131] Furthermore, bushing 118 includes an anti-rotation feature 124. In this example, the anti-rotation feature 124 is formed by a plurality of recesses 126 formed on the outer periphery of bushing 118 at the axial end of bushing 118 opposite to the position of the collar (see [link to relevant documentation]). Figure 7 ).

[0132] Multiple recesses 126 are evenly distributed in the circumferential direction of the bushing 118, such that the shape of the end of the bushing 118 with the recesses 126 can be described as star-shaped.

[0133] The second output shaft 74 includes an anti-rotation mating feature 128 configured to engage with an anti-rotation feature 124 of the bushing 118. The anti-rotation mating feature 128 includes a recess 130 disposed on the axial end face of the second output shaft 74 facing the first output shaft 72. The recess 130 is centrally located relative to the first rotation axis A1. The recess 130 circumferentially includes a plurality of protrusions 132 configured to engage with recesses 126 of the anti-rotation feature 124 of the bushing 118. This means that the number of protrusions 132 of the anti-rotation mating feature 128 is the same as the number of recesses 126. Furthermore, the forms of the protrusions 132 and the recesses 126 are corresponding, such that one protrusion 132 can be accommodated in one recess 126.

[0134] By axial movement, i.e., movement along the first axis of rotation A1, the end of the bushing 118, including the anti-rotation feature 124, can be placed in the recess 130. Therefore, the protrusion 132 and the recess 126 engage with each other. Thus, the bushing 118 is rotatably fixed relative to the second output shaft 74.

[0135] The open end of the threaded hole 120 is centered in the bottom surface of the recess 130.

[0136] Due to the axial connection and axial support of the first output shaft 72 and the second output shaft 74, the axial force generated by the operation of the first single-stage cylindrical gear unit 36 ​​and / or the second single-stage cylindrical gear unit 38 is canceled or eliminated. This is effective in both the driving mode and coast mode of the vehicle 10. The coast mode can also be designated as the recovery mode. The cancellation of axial force allows the use of relatively small bearings, as only a relatively small force needs to be supported by the bearings.

[0137] The second set of differences involves the housing 52 of the differential gear unit 34 and its connection with the rotor 28.

[0138] exist Figure 6 In the example, housing 52 includes a support member 134 and a cover member 136.

[0139] In this example, both the support member 134 and the cover member 136 are made of cast aluminum, with the functional surfaces machined after casting. Therefore, unlike the previous examples, sheet metal is no longer used.

[0140] The supporting component 134 and the cover component 136 are connected by screws 138 (see Figure 9 ).

[0141] In addition, Figure 6 In the example, the support member 134 performs multiple functions. First, the support member 134 serves as a bracket for the gears of the differential gear unit 34, that is, as a bracket for the gears forming the cylindrical gear mechanism (see also...). Figure 9 This function is provided in combination with the cover component 136; that is, the support component 134 and the cover component 136 together achieve this function. Secondly, the support component 134 serves as a bracket for the rotor 28. Herein, the support component 134 performs the function achieved by the support flange 66 of the second half-shell in the foregoing embodiment. This means that the rotor 28 is rotatably supported on the housing 48 via the support component 134.

[0142] For this purpose, two bearings are used, designated as first bearing 62 and second bearing 68. In contrast to the previous embodiment, first bearing 62 and second bearing 68 are now positioned on the same side of the differential gear unit 34. The inner rings of first bearing 62 and second bearing 68 are supported on the tubular portion 140 of the support member 134. The outer rings of first bearing 62 and second bearing 68 are supported within the housing 48. This configuration improves the maintainability of the differential gear unit 34 because the cover member 136 can be easily unscrewed from the support member 134.

[0143] Furthermore, since the motor 22 (i.e., rotor 28 and stator 30) can be manufactured independently of the gear components of the drive module 20, having both the first bearing 62 and the second bearing 68 on one side is advantageous for manufacturing. The motor 22 can then be mounted on the gear components. This also enhances maintainability.

[0144] The second output shaft 74 extends through the tubular portion 140 of the support member 134 and is rotatable relative to the tubular portion 140. This is indicated by a sliding bearing 142. However, it should be noted that the sliding bearing 142 is optional. An equivalent solution can be achieved by integrating the bearing function into the second output shaft 74 and / or the tubular portion 140.

[0145] This configuration also eliminates the need for the third bearing 80 and the fifth bearing 86 described in the previous example. This simplifies the design of the drive module 20.

[0146] The third set of differences involves the support of the second helical gear 92 and the associated first output interface 40, as well as the support of the fourth helical gear 100 and the associated second output interface 44.

[0147] exist Figure 6 In the example, the second helical gear 92 and the associated first output interface 40 are rotatably supported on the housing 48 using two roller bearings, one of which is designated as the seventh bearing 94 and the other of which is designated as the eighth bearing 96.

[0148] The outer ring of the seventh bearing 94 is supported on the second helical gear 92. The inner ring of the seventh bearing 94 is supported on the outer periphery of the tubular support bushing 144.

[0149] In this example, the tubular support bushing 144 is made of steel.

[0150] The support bushing 144 also includes a thread 146 that screws into the housing 48.

[0151] Furthermore, the outer ring of the eighth bearing 96 is supported on the inner circumference of the tubular support bushing 144, wherein the inner ring of the eighth bearing 96 is supported on a component including the first output interface 40.

[0152] The component including the first output interface 40 also includes a disc-shaped connecting portion 148 through which the component is rotatably fixed relative to the second helical gear 92. For this purpose, a plurality of teeth can be provided on the outer periphery of the connecting portion 148, and these teeth can engage with associated teeth provided on the second helical gear 92.

[0153] This configuration has the following advantages: components including the first output interface 40 and the disc-shaped connector 148, the eighth bearing 96, the tubular support bushing 144, and the seventh bearing 94 can be pre-assembled. For example... Figure 10 As shown by the two arrows in the middle.

[0154] The pre-assembled component or box can be arranged within the second helical gear 92 and can be mounted on the cover component of the housing 48 by screwing into the thread 146 of the support bushing 144. In this document, the opening 150 can be used as a tool interface. For ease of illustration, Figure 10 Only some openings 150 are marked with reference numerals. It should be noted that when doing so, the first output shaft 72 and the fourth bearing 82 also need to be provided in a manner that engages the first helical gear 90 and the second helical gear 92 (see Figure 1). Figure 11 and 12 ).

[0155] The fourth helical gear 100 and the associated second output interface 44 are supported in the same manner as the second helical gear 92 and the associated first output interface 40. Therefore, the above explanation applies accordingly, wherein the second output interface 44 is used in place of the first output interface 40, the tenth bearing 104 is used in place of the eighth bearing 96, and the ninth bearing 102 is used in place of the seventh bearing 94. For ease of illustration, the tubular support bushing 144 and its components use the same reference numerals.

[0156] As used herein, the phrase “at least one” referring to a list of one or more entities should be understood to mean at least one entity selected from any one or more entities in the entity list, but not necessarily including at least one of each and all entities specifically listed in the entity list, and does not exclude any combination of entities in the entity list. This definition also allows for the optional presence of entities other than those specifically identified in the entity list referred to by the phrase “at least one,” whether related to or unrelated to those specifically identified entities. Thus, as a non-limiting example, “at least one of A and B” (or equivalently, “at least one of A or B,” or equivalently, “at least one of A and / or B”) in one instance may refer to at least one A, optionally including more than one A, with no B present (and optionally including entities other than B); in another instance, it may refer to at least one B, optionally including more than one B, with no A present (and optionally including entities other than A); and in yet another instance, it may refer to at least one A, optionally including more than one A, and at least one B, optionally including more than one B (and optionally including other entities). In other words, the phrases “at least one,” “one or more,” and “and / or” are open-ended expressions that are operationally both conjunctions and disjunctive words. For example, each of the expressions “at least one of A, B, and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C,” and “A, B, and / or C” can mean a single A, a single B, a single C, A and B together, A and C together, B and C together, A, B, and C together, and any of the above, optionally combined with at least one other entity.

[0157] Those skilled in the art, upon studying the accompanying drawings, the disclosure, and the appended claims, can understand and implement other variations of the disclosed examples when implementing the claimed disclosure. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" does not exclude a plurality. A single processor or other unit can perform the functions of several items or steps listed in the claims. The fact that certain measures are described in mutually different dependent claims does not mean that a combination of these measures cannot be used advantageously. Computer programs can be stored / distributed on suitable media such as optical storage media or solid-state media, provided together with or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems. Any reference numerals in the claims should not be construed as limiting the scope of the claims.

[0158] List of reference numerals 10 Electric vehicles 12 front axle assembly 14 front wheels 16. Rear axle assembly, axle assembly 18 rear wheels 18a First Round 18b Second Round 20 Driver Modules 22 motors 24 traction batteries 26 Inverter Units 28 rotors 30 stators 32 storage space 34 Differential Gear Unit 36 First single-stage cylindrical gear unit 38 Second single-stage cylindrical gear unit 40 First Output Interface 42 First drive shaft 44 Second Output Interface 46 Second drive shaft 48. Housing of the drive module 50 flange 52. Housing of the differential gear unit 54 First Half Shell 56 Second Half Shell 58 rivets 60 Support flange for the first half shell 62 First Bearing 64 First sealing element 66 Support flange of the second half shell 68 Second Bearing 70 Second seal 72 First Output Shaft 74 Second Output Shaft 76. Cylindrical gear mechanism 78 First input shaft of the first single-stage cylindrical gear unit 80 Third Bearing 82 Fourth Bearing 84 The second input shaft of the second single-stage cylindrical gear unit 86 Fifth Bearing 88 Sixth Bearing 90 First Helical Gear 92 Second Helical Gear 94 Seventh Bearing 96 Eighth Bearing 98 Third Helical Gear 100 Fourth Helical Gear 102 Ninth Bearing 104 Tenth Bearing 106 First Inner Wall 108 Second Inner Wall 110 Third Inner Wall 112 Fourth Inner Wall 114 Eleventh Bearing 116 screws 118 bushing 120 threaded hole 122 through hole Anti-rotation feature of 124 bushing 126 Depression 128 Anti-rotation pairing features 130 recess 132 protrusions 134 Load-bearing components 136 Cover component 138 screws 140 Tubular portion of the load-bearing component 142 sliding bearing 144 support bushing 146 thread 148 Connecting part 150 opening A1 First axis of rotation A2 Second axis of rotation C gap D offset Axial length of L1 first drive shaft Axial length of L2 second drive shaft

Claims

1. A drive module (20) for an electric vehicle (10), the drive module (20) comprising: An electric motor (22) having a rotor (28) and a stator (30), wherein the rotor (28) is at least partially annular and defines a receiving space (32) on the radial and axial inner sides of the rotor (28). Differential gear unit (34). A first single-stage cylindrical gear unit (36) having a first output interface (40) configured to be drivenly connected to wheels (18, 18a) and a second single-stage cylindrical gear unit (38) having a second output interface (44) configured to be drivenly connected to wheels (18, 18b). The differential gear unit (34) is at least partially arranged in the receiving space (32), and the differential gear unit (34) is drivably coupled to the rotor (28). The first cylindrical gear unit (36) and the second cylindrical gear unit (38) are arranged on opposite sides of the differential gear unit (34), and The first cylindrical gear unit (36) and the second cylindrical gear unit (38) are drivenly connected to the differential gear unit (34).

2. The driving module (20) according to claim 1, wherein, The differential gear unit (34) is fully housed in the housing space (32).

3. The driving module (20) according to claim 1 or 2, wherein, The differential gear unit (34) includes a planetary gear mechanism, a cylindrical gear mechanism (76), or a bevel gear mechanism.

4. The driving module (20) according to any one of the preceding claims, wherein, The differential gear unit (34) includes a housing (52) having a substantially constant wall thickness, and / or wherein the differential gear unit (34) includes a housing (52) made of sheet metal.

5. The driving module (20) according to claim 4, wherein, The interior of the housing (52) is sealed with an oil seal relative to the exterior of the housing (52).

6. The driving module (20) according to any one of the preceding claims, wherein, The differential gear unit (34) is axially centered within the rotor (28).

7. The driving module (20) according to any one of the preceding claims, wherein, The first cylindrical gear unit (36) and the second cylindrical gear unit (38) are arranged symmetrically with respect to the motor (22) and / or with respect to the differential gear unit (34).

8. The driving module (20) according to any one of the preceding claims, wherein, The differential gear unit (34) includes a first output shaft (72) rotatable about a first central axis, wherein the first cylindrical gear unit (36) includes a first input shaft (78), and wherein the first output shaft (72) and the first input shaft (78) are integrally formed, and / or The differential gear unit (34) includes a second output shaft (74) rotatable about a second central axis, the second cylindrical gear unit (38) includes a second input shaft (84), and the second output shaft (74) and the second input shaft (84) are integrally formed.

9. The driving module (20) according to claim 8, wherein, An axial bearing (114) is arranged axially between the first output shaft (72) and the second output shaft (74).

10. The driving module (20) according to claim 8 or 9, wherein, Each of the first output shaft (72) and the second output shaft (74) is radially supported on the drive module housing (48) at two axially separated positions.

11. The driving module (20) according to any one of the preceding claims, wherein, The central axis of the first output interface (40) and the central axis of the second output interface (44) are offset relative to the central axis of the motor (22).

12. The driving module (20) according to any one of the preceding claims, wherein, Each of the first cylindrical gear unit (36) and the second cylindrical gear unit (38) has a transmission ratio of 5:1 or greater.

13. The driving module (20) according to any one of the preceding claims, wherein, Each of the first cylindrical gear unit (36) and the second cylindrical gear unit (38) includes a helical gear (90, 92, 98, 100).

14. An axle assembly (16) for an electric vehicle (10), comprising a drive module (20) according to any one of the preceding claims, wherein, The first wheel (18a) is driven to the first output interface (40) via the first drive shaft (42), and the second wheel (18b) is driven to the second output interface (44) via the second drive shaft (46), wherein the axial length (L1) of the first drive shaft (42) is equal to the axial length (L2) of the second drive shaft (46).

15. An electric vehicle (10) comprising a drive module (20) according to any one of claims 1-13 and / or an axle assembly (16) according to claim 14.

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