Electric axle system

Abstract

The utility model relates to an electric axle system. In one example, an electric axle system includes a first electric machine and a planetary reduction differential configured to receive mechanical power from the first electric machine. The planetary reduction differential includes a first planetary gear set directly rotationally coupled to a second planetary gear set. In an electric axle system, a sun gear in a first planetary gear set is directly coupled to an input shaft of a planetary reduction differential.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the priority of U.S. Provisional Application No. 63 / 515,687, filed on July 26, 2023, titled "Electric Axle". The entire content of the above - mentioned application is incorporated herein by reference. Technical Field

[0003] This description generally relates to an electric vehicle axle with two concentric planetary gear sets. Background Art

[0004] Electric vehicle axles have been used in various vehicle platforms to meet the electrification requirements of different vehicle segments. These electric vehicle axles include traction motors and transmissions, which can be installed in different ways according to the space limitations and end - use objectives of the vehicle platform. Compared with electric drives that design the traction motor, transmission, and drive axle as independent units, electric vehicle axles can simplify and efficiently integrate vehicle platforms.

[0005] In the design of electric vehicle axles for electric vehicles (or industrial applications), improving power density is an eternal pursuit. People have tried to increase the power density of electric vehicle axles by designing motors with higher rotational speeds. However, increasing the rotational speed of the motor leads to an increase in the power path to achieve the available output speed. Specifically, increasing the number of gear passes is one way to achieve a larger output ratio. Increasing the number of gear stages in the axle increases the size of the electric vehicle axle package and reduces the power density of the electric vehicle axle. Therefore, at least some electric vehicle axles fail to achieve the end - use design goals in terms of space efficiency and power density. Thus, the present inventors recognized the desire to reduce the package space and increase the power density of electric vehicle axles. In addition, the inventors also recognized the need to increase the output ratio while passively distributing mechanical power from the electric vehicle axle to multiple drive axles in a small package. Summary of the Utility Model

[0006] An electric vehicle axle system can solve the above problems. In one example, the electric vehicle axle system includes a motor and a planetary reduction differential configured to receive mechanical power from the motor. The planetary reduction differential includes a first planetary gear set directly rotationally coupled to a second planetary gear set. In the planetary reduction differential, the sun gear in the first planetary gear set is directly coupled to the input shaft of the planetary reduction differential. In addition, in the electric vehicle axle system, the carrier in the first planetary gear set is directly connected to the output shaft. In this way, a highly space - efficient and high - power - density electric vehicle axle system is achieved.

[0007] In one example, the electric vehicle axle system may further include a Ravigneaux three-speed mode planetary gear set coaxially rotationally coupled and positioned with the planetary reduction differential, and a mode clutch configured to selectively engage the carrier or ring gear in the Ravigneaux gear set in a first mode, selectively engage the sun gear in the Ravigneaux gear set in a second mode, and selectively couple the carrier or ring gear in the Ravigneaux gear set with the sun gear in a third mode. In this way, the Ravigneaux three-speed mode planetary gear set effectively implements three gear ratio modes in a space-saving package, expanding the speed-changing ability of the system.

[0008] It should be understood that the above summary is to introduce some concepts further described in the detailed description in a simplified form. It is not intended to identify the key or essential features of the claimed subject matter, the scope of which is uniquely determined by the claims that follow the detailed description. Moreover, the claimed subject matter is not limited to embodiments that solve any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1A-1B FIGS. 9 and 14 show examples of electric vehicle axles with a planetary reduction differential that includes two simple planetary gear sets.

[0010] Figures 2-4 FIG. 13 shows different example configurations of an electric vehicle axle with a planetary reduction differential that includes a combination of simple planetary gear sets and meshing planetary compound planetary gear sets.

[0011] Figures 5-9 FIG. 17 shows different example configurations of motors and gear trains in an electric vehicle axle that provide input to a planetary reduction differential with two simple planetary gear sets.

[0012] Figure 10 FIG. 21 shows an example of an input gear train for a planetary reduction differential with two simple planetary gear sets.

[0013] Figures 11-13 FIG. 25 shows different example configurations of a mode planetary gear set that provides input to a planetary reduction differential with two simple planetary gear sets.

[0014] Figure 15 FIG. 29 shows different example configurations of an electric vehicle axle with a planetary reduction differential that includes two meshing planetary compound planetary gear sets.

[0015] Figure 16 FIG. 33 shows an example of another input gear train for a planetary reduction differential with two simple planetary gear sets.

[0016] Figure 17 Shows different example structures of a planetary gear set that provides input to a planetary reduction differential with two simple planetary gear sets. Detailed implementation

[0017] This document describes a planetary reduction differential electric vehicle axle that can achieve higher compactness and power density. To achieve the goals of space efficiency and power density, in one example, the electric vehicle axle includes a planetary reduction differential that receives input from a traction motor (single-speed gear train or multi-speed mode planetary gear set) and has two simple planetary gear sets that are directly rotationally coupled to each other. In one example, the first simple planetary gear set is coupled to an input shaft through a sun gear. Additionally, an annulus gear or a carrier in the second simple planetary gear set can be rotationally coupled to an output shaft, and an annulus gear in the first simple planetary gear set can be rotationally coupled to a sun gear in the second simple planetary gear set. Using the planetary reduction differential with the above-described simple planetary gear set layout can improve the packaging efficiency of the electric vehicle axle, reduce the width of the planetary reduction differential, and, as needed, reduce the overall axial length of the electric vehicle axle, thereby achieving a more compact and higher power density electric vehicle axle structure.

[0018] As described herein, a simple planetary gear set is a planetary gear set that includes only one annulus gear, one sun gear, one carrier, and multiple planetary gears that are in the same plane as the annulus gear and the sun gear and rotate on the carrier. Each planetary gear meshes with the sun gear and the annulus gear. Additionally, as described herein, an engaged planetary compound planetary gear set is a planetary gear set that has one annulus gear, one sun gear, and multiple sets of planetary gears that mesh within the plane of the annulus gear and the sun gear and are circumferentially aligned in the same plane as the annulus gear and the sun gear. The planetary gear set includes inner planetary gears and outer planetary gears. The inner planetary gears mesh with the sun gear and the outer planetary gears. The outer planetary gears mesh with the inner planetary gears and the annulus gear.

[0019] Figure 1A Shows an example of an electric vehicle axle 100 with a transmission 102 that includes a planetary reduction differential 104. The transmission 102 can be a single-speed transmission or a multi-speed transmission, as detailed in Figures 11-13 and Figure 17 .

[0020] In the illustration, the electric vehicle axle 100 is included in an electric vehicle (EV) 103. It can be understood that other electric vehicle axles described herein can also be included in similar electric vehicles. The electric vehicle 103 can be, in one example, a fully electric vehicle (e.g., a battery electric vehicle (BEV)), and in another example, a hybrid electric vehicle. Thus, in some examples, a vehicle using the electric vehicle axle described herein can also have an internal combustion engine (e.g., a spark ignition engine, a compression ignition engine, a combination thereof, etc.). Accordingly, the electric vehicle axles described herein can be used in automobiles, trucks, all-terrain vehicles (ATVs), commercial vehicles, light vehicles, off-road vehicles, mining vehicles, rail vehicles, manufacturing machinery, industrial machinery, etc.

[0021] The planetary reduction differential 104 includes a first simple planetary gear set 106 and a second simple planetary gear set 108. In the illustration, the first and second simple planetary gear sets are coaxially arranged. In this way, the space efficiency of the planetary reduction differential is improved. In an example, the input shaft 110 is directly or indirectly rotationally connected to the electric machine through a gear train, and the input shaft 110 is connected to the sun gear 112 in the first simple planetary gear set 106.

[0022] The first and second simple planetary gear sets 106 and 108 are directly rotationally connected to each other, which can reduce the axial length of the planetary reduction differential 104 compared to a more complex structure. Specifically, in the illustration, the ring gear 111 in the first simple planetary gear set 106 is rotationally connected to the sun gear 113 in the second simple planetary gear set 108. The first simple planetary gear set 106 also includes a set of planetary gears 114 that are rotatably mounted on a carrier 116. In the illustrated example, the carrier 116 is directly rotationally coupled to the output shaft 118 (e.g., a shaft such as a half shaft), and the output shaft 118 is in turn rotationally coupled to the drive wheel 120. Alternatively, the output shaft 118 can be connected to a wheel end gear reducer and / or other suitable mechanical components connected to the drive wheel 120. Additionally, in the illustrated example, the ring gear 122 in the second simple planetary gear set 108 is rotationally coupled to another output shaft 124 through a shaft 125. Additionally, in the illustrated example, a carrier 126 (on which a set of planetary gears 128 are rotatably mounted) is fixed by a fixing member 130. Additionally, in the illustrated example, the output shaft 124 is rotationally coupled to the drive wheel 132, or is coupled to the drive wheel through a wheel end gear reduction device and / or other suitable mechanical components as described above. Additionally, in other examples, other coupling configurations can also be used between the first and second simple planetary gear sets.

[0023] The axle 134 can be connected to the input shaft 110 of the planetary reduction differential 104. As described herein, the axle can include an inner raceway, roller elements (such as cylindrical rollers, spherical balls, tapered cylindrical rollers, needle rollers, bushings, etc.), and an outer raceway. In the illustrated example, the axle 136 is connected to the sun gear 113. In other embodiments, the axles in the transmission can be arranged in other suitable manners, and / or additional axles can be used in the planetary reduction differential.

[0024] Figure 1A and Figures 2-17 A coordinate axis system is provided for reference and to determine the orientation of the views when appropriate. In one example, the Z-axis can be the vertical axis (e.g., parallel to the axis of gravity), the X-axis can be the intersecting axis (e.g., the horizontal axis), and the Y-axis can be the longitudinal axis. However, in other examples, these axes may have other orientations. As previously mentioned, Figure 1A The rotation axis 180 of the sun gear 113 is further provided for reference. In the illustrated example, the simple planetary gear sets are coaxially arranged. Other electric transmissions described herein also employ a coaxial arrangement between the simple planetary gear sets in the planetary reduction differential. In this way, the electric transmission can achieve an ideal space efficiency.

[0025] As Figure 1A shown, the electric vehicle 103 can further include a control system 150 with a controller 152. The controller 152 can include a microcomputer, and its components include a processor 154 (such as a microprocessor unit), input / output ports, an electronic storage medium 156 for executable programs and calibration values (such as a read-only memory chip, random access memory, keep-alive memory, data bus, etc.). The storage medium can be programmed with computer-readable data representing instructions that can be executed by the processor to perform the methods, control techniques, etc. described herein, as well as other variants that are expected but not specifically listed. Thus, the electronic storage medium 156 can store instructions that, when executed by the processor 154, cause the controller 152 to perform the various method steps described herein.

[0026] The controller 152 can receive various signals from sensors 158 that are coupled to different regions of the electric vehicle 103, particularly the electric vehicle axle 100. For example, the sensors 158 can include one or more motor speed sensors (described in detail below), shaft / gear speed sensors, thermocouples, pressure sensors, pedal position sensors for detecting the depression of an operator's manipulation pedal (such as an accelerator pedal and / or a brake pedal), wheel speed sensors, etc. An input device 160 (such as an accelerator pedal, a brake pedal, a gear selector, a combination thereof, etc.) can further provide input signals indicating the vehicle control intent of the operator.

[0027] After receiving signals from Figure 1A the various sensors 158 in Figure 1A , the controller 152 processes the received signals and adjusts the components using various actuators 162 of the vehicle components according to the received signals and the instructions stored in the memory of the controller 152. For example, the controller 152 may receive an accelerator pedal signal indicating that the operator requests an adjustment of the vehicle acceleration. In response, the controller 152 may command the operation of an inverter that is electrically coupled to a motor that powers a gear set to increase the power delivered from the motor to the transmission 102. For example, other controllable components in the vehicle may be adjusted in a similar manner to the sensor signals, control commands, and actuators. In addition, the control system 150 can be used for any electric axle system and transmission described herein.

[0028] In the extended multi-speed transmission example herein, the controller 152 may include instructions that, when executed, cause the mode clutch to switch between different operating modes (e.g., in one example, a first mode and a second mode, or in another example, a first mode, a second mode, and a third mode) according to the operating conditions of the vehicle and the axle. However, electric axles with more speeds have also been considered, such as four-speed electric axles, five-speed electric axles, etc. For example, when the vehicle is traveling at a lower speed, the electric axle 100 may operate in the first mode. When the vehicle speed exceeds a first threshold, the mode clutch may switch to the second mode, and when the vehicle speed exceeds a second threshold, the clutch may switch from the second mode to the third mode. This shift sequence can also be performed in the reverse order by the mode. In addition, the shift sequence can be non-sequential, so that modes can be skipped as needed. For example, the electric axle can be commanded to start in the second mode, or downshift from the third mode to the first mode. The above control system 150 can be used for any electric axle and transmission described herein and can be used to implement the methods, control techniques, etc. discussed herein.

[0029] Figure 1B Shows Figure 1A a lever diagram 190 of the structure of the planetary reduction differential 104 described in Figure 1A . The input of the planetary reduction differential 104 is indicated by an arrow 176 at the sun gear node 112, and the output of the planetary reduction differential is indicated by an arrow 178. Line 179 represents the connection formed between the carrier node 116 and the ring gear node 122 through the drive wheels and the road surface. In the illustrated example, the rotation direction of the input of the planetary reduction differential is the same as the rotation direction of the output of the planetary reduction differential. However, those who understand the lever diagram and the planetary gear design will quickly realize that other planetary reduction differential designs can also be employed, which utilize the same lever diagram shape but connect different planetary gear elements at the lever diagram nodes. The inventors have also considered these designs.

[0030] Figure 14Shows another example of a planetary reduction differential 1400 with a coaxial arrangement. Specifically, the planetary reduction differential 1400 includes a first simple planetary gear set 1402 coaxial with a second simple planetary gear set 1404. The axis of rotation 1406 of the sun gear 1408 of the second simple planetary gear set 1404 is for reference.

[0031] For Figure 1A the coaxial planetary reduction differential shown, in order to reduce (e.g., minimize) the overall diameter and potentially reuse components (if needed), in one use case, the ratio of the two simple planetary rings to the sun (RTS) may be close to 1.618, and the output reduction ratio will be 5.236. The ratio of 1.618 requires 2P = 2 * #T planet , S = #T sun and R = #T ring the number of teeth is consecutive numbers in the Fibonacci sequence. Additionally, there is an additional constraint that 2P = 2 * #T planet must be even. Within the range of feasible and manufacturable tooth numbers, there may be a minimum number of ranges that satisfy these conditions. The range actually used may be 34 / 55 / 89. Where 2P = 34, S = 55, and R = 89. Additionally, it can be understood that the actual range of 34 / 55 / 89 contains tooth numbers of two prime numbers.

[0032] For a concentric planetary reduction differential, such as Figure 14 the planetary reduction differential 1400 shown, as the ratio of the inner input planet RTS increases and the ratio of the outer output planet RTS decreases, the simple planetary ratio deviates from 1.618. In one use instance, the inner planet RTS is 3.000, the outer planet RTS is 1.333, and the output reduction ratio is 8.000.

[0033] Figures 2-4 and Figure 14 Shows an alternative structure of a planetary reduction differential, which includes a combination of a simple planetary gear set and / or meshing planetary compound planetary gears in an electric vehicle axle. In Figures 2-4 and Figure 14 all the planetary reduction differential embodiments shown, the input shaft 200 is connected to the sun gear 202 in the first planetary gear set, similar to Figure 1A the planetary reduction differential 104 shown. Therefore, the input shaft and the sun gear are numbered similarly in Figures 2-4 and for the sake of brevity, the redundant description is omitted.

[0034] Figure 2Shows a planetary reduction differential 210 with a first simple planetary gear set 212 and a second meshing planetary compound planetary gear set 214. In the illustration, the meshing planetary compound gear set 214 includes two sets of planetary gears 228 and 230, where the planetary gears mesh with each other. Additionally, the planetary gears in planetary gear set 228 mesh with the sun gear 226, and the planetary gears in planetary gear set 230 mesh with the ring gear 220. The planetary gear sets 228 and 230 are rotatably mounted on a carrier 216, where the carrier 216 is connected to an output shaft 218, and the ring gear 220 is fixed by a fixing member 222 (e.g., a housing, such as a housing that at least partially encloses a transmission and / or a traction motor). The meshing planetary compound planetary gear set 214 is rotationally coupled to the simple planetary gear set 212. The ring gear 206 in the simple planetary gear set 212 is rotatably coupled to the sun gear 226 in the meshing planetary compound planetary gear set 214. Figure 2 The other components in the first and second planetary gear sets shown are the same as Figure 1A the planetary gear sets shown, and thus, for the sake of brevity, redundant descriptions are omitted.

[0035] Figure 3 Shows a transmission 300 with a first single planetary gear set 302 and a second meshing planetary compound gear set 304, which are rotationally coupled respectively through the ring gears 306 and the carriers 308 in the first and second single planetary gear sets. Additionally, in the illustration, the ring gear 310 in the second meshing planetary compound gear set is fixed, and the sun gear 312 is rotationally coupled to an output shaft 314.

[0036] Figure 4 Shows a transmission 400 with a first meshing planetary compound planetary gear set 402 and a second meshing planetary compound planetary gear set 404, which are rotationally coupled respectively through the ring gears 406 and the carriers 408 in the first meshing planetary compound planetary gear set and the second meshing planetary compound planetary gear set. Additionally, in the illustration, the ring gear 410 in the second meshing planetary compound gear set is fixed, and the sun 412 is rotationally coupled to an output shaft 414.

[0037] Figures 5-9 Shows different example structures of a gear train and a traction motor (e.g., a motor generator) that can provide input to a planetary reduction differential 104, such as Figure 1A shown and described previously. Thus, for the sake of brevity, redundant descriptions of the planetary reduction differential are omitted.

[0038] Figure 5Specifically shown is an electric vehicle axle 500, whose electromechanics 502 is concentrically arranged with the output shaft 118 and circumferentially surrounds at least partially the first and second simple planetary gear sets 106 and 108 in the planetary reduction differential 104. Specifically, the inner diameter 504 of the rotor 506 of the electric motor 502 at least partially surrounds the first and second simple planetary gear sets 106 and 108 in the planetary reduction differential 104.

[0039] Figure 6 Specifically shown is an electric axle 600 with an electric motor 602, which is concentric with the output shaft 118 axially 604 outside the first simple planetary gear set 106. In the illustrated example, a portion of one of the output shafts passes through an opening of the electric motor. In this way, the space efficiency of the electric axle is improved.

[0040] Figure 7 Shown is an electric vehicle axle 700 with two electric motors 702 and 704, each electric motor 702 and 704 being arranged parallel to the output shaft 118 and mechanically connected to the input of the planetary reduction differential through gear trains 705 and 706. A gear 708 meshes with the gears in each of the gear trains 705 and 706 and provides a mechanical connection between the input shafts 110 of the planetary reduction differential 104. It can be understood that the electromechanics 704 and the corresponding gear pattern 706 are optional, so the electric axle can be omitted in other embodiments. More generally, various gear train layouts connected to the input of the planetary reduction differential can be used. For example, the gear train for connecting the first electric motor and / or the second electric motor can include fewer gear channels or additional gear channels. In other examples, one or more planetary gear sets (e.g., simple planetary gear sets, compound planetary gear sets, etc.) can be used to connect one or more electric motors to the planetary reduction differential. For example, a planetary gear set coaxial with the electric motor can be used to connect the electric motor to the planetary reduction differential. In addition, a planetary gear set coaxial with the rotational axes of the output shafts 118 and 124 can also be used to rotationally couple the electric motor with the planetary reduction differential. In any embodiment where one or more additional planetary gear sets provide an input connection to the planetary reduction differential gear set, the carrier in the additional planetary gear set can be fixed, the ring gear in the additional planetary gear set can be fixed, or the sun gear in the additional planetary gear set can be fixed, in different examples. In addition, additional gear transmissions, chains, belts, combinations thereof, etc. can also be used to transmit mechanical power between one or more electric motors and the planetary reduction differential.

[0041] In addition, it can be understood that, if desired, any of the electric vehicle axles described herein may include a second electric motor. For example, in one instance, the second electric motor may be connected to the input of the planetary reduction differential in the same manner as the mechanical connection formed between the first electric motor and the input of the planetary reduction differential. In another instance, the second electric motor may be connected to the input of the planetary reduction differential using a different gear train to achieve a different electric motor to planetary reduction differential input ratio, such that the second electric motor has different characteristics than the first electric motor. Additionally, in some cases, a disconnect clutch may be arranged between the second electric motor and the planetary reduction differential to disconnect the second electric motor from the planetary reduction differential assembly to further improve efficiency.

[0042] Figure 8 An electric vehicle axle 800 is shown with an electric motor 802 arranged perpendicular to the axis of rotation of the planetary reduction differential 104. A gear train 804 including bevel gears 806 provides an input to the planetary reduction differential 104. Similar to Figure 7 the exemplary electric vehicle axle 700 described in, the addition of a second electric motor and a second electric motor disconnect clutch is contemplated.

[0043] Figure 9 An electric vehicle axle 900 is shown with an electric motor 902 arranged perpendicular to the axis of rotation of the planetary reduction differential 104. In the illustration, the electric vehicle axle includes an input gear train 904 having a plurality of gear reduction devices 906 and 908 that can be selected via a clutch 910. In this way, the available gears in the transmission can be further expanded, resulting in a more efficient electromechanical operation. Similar to Figure 7 the exemplary electric vehicle axle 700 described in, the addition of a second electromechanical and a second electromechanical disconnect clutch is also contemplated. As described above, various gear train layouts have been considered that provide an input to the planetary reduction differential or the mode planetary gear set (expanded herein).

[0044] It can be understood that the electric vehicle axle includes Figures 5-9 two or more of the combined input gear train and / or electric motor arrangement features described in. Additionally, any different electric motor and / or input gear train arrangement may be used with any of the transmission structures or combinations of transmission structures described herein.

[0045] Figure 10Shows another example of a transmission 1000 with a planetary reduction differential 104 and an engaged planetary compound planetary gear set 1002 that provides an input to the planetary reduction differential. The engaged planetary compound planetary gear set 1002 includes two sets of planetary gears 1004 and 1012, where the planetary gears mesh with each other. Additionally, the planetary gears in the planetary gear set 1012 mesh with an annulus gear 1006, and other planetary gears in the planetary gear set 1004 mesh with a sun gear 1008. The planetary gear sets 1004 and 1012 are rotatably mounted on a carrier 1010. In the illustrated example, the carrier 1010 is rotationally coupled to the planetary reduction differential sun gear 1014, and the sun gear 1008 is rotationally coupled to an upstream component (such as a gear train, an electric motor, a combination thereof, etc.). Additionally, in the illustrated example, the annulus gear 1006 is fixed. Alternatively, in another example, the engaged planetary compound planetary carrier 1010 can be fixed, and the engaged planetary compound planetary annulus gear 1006 can be rotationally coupled to the planetary reduction differential sun gear 1014.

[0046] Figures 11-13 Shows an example of a multi-mode planetary gear set that can be connected to the planetary reduction differential 104 via an input shaft 110. The multi-mode planetary gear set can provide a multi-speed function for an electric vehicle axle transmission, thereby improving the axle efficiency of any other planetary reduction differential or combination of planetary reduction differentials described herein. Additionally, the multi-mode planetary gear set can be used with Figures 2-9 any traction motor and gear train configuration or combination of motor and gear train configurations shown in FIGS. 10, 14, 15. Figures 11-13 and Figure 17 each multi-mode planetary gear set shown in FIGS. includes a mode clutch that is configured to switch the corresponding transmission between operating modes, as discussed in more detail herein.

[0047] Figure 11Specifically disclosed is a transmission 1100 for an electric vehicle axle. The transmission 1100 includes a two-speed mode planetary gear set 1102, which is embodied as a meshing planetary compound planetary gear set. The two-speed mode planetary gear set 1102 includes a first set of planetary gears 1106 meshing with a second set of planetary gears 1108. The first set of planetary gears 1106 meshes with a ring gear 1110, and the second set of planetary gears 1108 meshes with a sun gear 1112. The planetary gears 1106 and 1108 are rotatably mounted on a carrier 1114. A mode clutch 1116 is configured to fix the carrier 1114 in a first mode and rotationally couple the carrier 1114 to the ring gear 1110 in a second mode. It can be understood that the first mode can be used during low-speed axle operation, and the second mode can be used during high-speed axle operation. Additionally, in the illustrated example, the ring gear 1110 is rotationally coupled to the sun gear 112 of the planetary reduction differential.

[0048] The mode clutch 1116 can be a dog clutch, a synchronizer, a friction clutch (e.g., a wet friction clutch), a radial clutch, an end face clutch, a crank clutch, a magnetic clutch, and combinations thereof, etc. Other clutches described herein can also be any of the above types of clutches or combinations of clutch types. Additionally, the mode clutch 1116 and other clutches described herein can be actuated by an electromechanical actuator, a pneumatic actuator, a hydraulic actuator, an electromagnetic actuator, a pneumatic actuator, a hydraulic actuator, an electromagnetic actuator, a barrel cam actuator, combinations thereof, etc. A shift fork, such as a translational or rotational shift fork, can be specifically used to drive at least a portion of the clutches described herein.

[0049] Furthermore, in one use case, Figure 11 the shown two-speed mode planetary gear set has a transmission ratio of 1:1 in one of its modes. However, an electric vehicle axle can have various transmission ratios, which can be selected according to the design objectives of the final use of the vehicle platform. Therefore, Figures 1A-15 the ratio shown is the ratio in the use case, and different ratios can be used for the electric vehicle axle.

[0050] Figure 12A transmission 1200 for an electric vehicle axle is described. The transmission 1200 includes a mode planetary gear set 1202, which is embodied as an engaged planetary compound planetary gear set, in particular a Ravigneaux three-speed mode planetary gear set. The Ravigneaux three-speed mode planetary gear set 1202 includes a set of planetary gears 1204, which mesh with another set of planetary gears 1206. The planetary gears 1206 mesh with a first sun gear 1208, and the planetary gears 1204 mesh with a ring gear 1210. The sets of planetary gears 1204 and 1206 are rotatably mounted on a carrier 1212. Another set of planetary gears 1214 is rotationally coupled to the planetary gears 1204 and meshes with a second sun gear 1216. The planetary gears 1214 can be of larger, smaller, or the same size as the planetary gears 1204. Additionally, in the illustrated example, the ring gear 1210 is rotationally coupled to the planetary reduction differential sun gear 112.

[0051] The mode clutch 1218 is configured to fix the carrier 1212 in a first mode, fix the second sun gear 1216 in a second mode, and rotationally couple the carrier 1212 to the second sun gear 1216 in a third mode. In this way, the transmission can achieve a three-speed function in a space-saving package, thus expanding the speed-changing ability of the system. However, planetary gear sets with fewer or more operating modes have also been considered, such as two-speed transmissions, four-speed transmissions, etc. A shaft 1220 can be provided in the Ravigneaux three-speed mode planetary gear set 1202 to facilitate mode conversion using the second sun gear 1216.

[0052] Figure 13 Another example of a transmission 1300 for an electric vehicle axle is shown. In the illustrated example, the transmission 1300 includes a two-speed mode planetary gear set 1302, which has a different structure from the mode planetary gear set described previously. The two-speed mode planetary gear set 1302 includes a carrier 1304, which is rotationally coupled to the sun gear 112 of the planetary reduction differential 104. Additionally, in the illustrated example, the two-speed mode planetary gear set 1302 is a simple planetary gear set. The mode clutch 1306 is configured to fix the ring gear 1308 in a first mode and rotationally couple the carrier 1304 and the ring gear 1308 in a second mode. In this way, the transmission achieves a two-speed function. Compared with an engaged planetary compound planetary gear set, the mode planetary gear set 1302 is embodied as a simple planetary gear set in the illustrated example to reduce system complexity and improve system compactness. However, as described above, the two-speed mode planetary gear set can be an engaged planetary compound planetary gear set or other suitable types of planetary gear sets.

[0053] Figure 15Shows a transmission 1500 with a first engaged planetary compound planetary gear set 1502 and a second engaged planetary compound planetary gear set 1504. The first engaged planetary compound planetary gear set 1502 and the second engaged planetary compound planetary gear set 1504 are rotationally coupled respectively through the ring gears 1506 and the sun gears 1512 in the first engaged planetary compound planetary gear set and the second engaged planetary compound planetary gear set. In addition, in the illustrated example, the ring gear 1510 in the second engaged planetary compound planetary gear set is fixed, and the carrier 1516 is rotationally coupled to the output shaft 1514.

[0054] Figure 16 Shows another example of a transmission 1600 with a planetary reduction differential 104 and a simple planetary gear set 1602, which provides input to the planetary reduction differential. The planet gears in the planetary gear set 1604 mesh with the ring gear 1606 and the sun gear 1608. The planetary gear set 1604 is rotatably mounted on the carrier 1610. In the illustrated example, the carrier 1610 is rotationally coupled to the planetary reduction differential sun gear 1614, while the simple planetary sun gear 1608 is rotationally coupled to an upstream component (such as a gear train, a motor, a combination thereof, etc.). In addition, in the illustrated example, the ring gear 1606 is fixed. Alternatively, in another example, the input simple planetary carrier 1610 can be fixed, and the input simple planetary ring gear 1606 can be rotationally coupled to the planetary reduction differential sun gear 1614.

[0055] Figure 17 Describes a transmission 1700 for an electric axle. The transmission 1700 includes a mode planetary gear set 1702, which is embodied as an engaged planetary compound planetary gear set, particularly a Ravigneaux three-speed mode planetary gear set. The Ravigneaux three-speed mode planetary gear set 1702 includes a set of planet gears 1704, which mesh with another set of planet gears 1706. The planet gears 1706 mesh with the second sun gear 1716, and the planet gears 1704 mesh with the ring gear 1710. The set of planet gears 1704 and 1706 are rotatably mounted on the carrier 1712. Another set of planet gears 1714 is rotationally coupled to the planet gears 1704 and meshes with the first sun gear 1708. The planet gears 1714 can be larger or smaller in size, or the same size as the planet gears 1704. In addition, in the illustrated example, the carrier 1712 is rotationally coupled to the planetary reduction differential sun gear 112.

[0056] The mode clutch 1718 is configured to fix the ring gear 1710 in the first mode, fix the second sun gear 1716 in the second mode, and rotationally couple the ring gear 1710 to the second sun gear 1716 in the third mode. In this way, the transmission can achieve a three-speed function in a space-saving package, thus expanding the speed-changing ability of the system. However, planetary gear sets with fewer or more operating modes have also been considered, such as two-speed transmissions, four-speed transmissions, etc. The Ravigneaux three-speed mode planetary gear set 1702 can provide a shaft 1720 to facilitate mode conversion using the second sun gear 1716.

[0057] The output shaft in the electric axle described herein can be directly connected to a drive wheel, a gear reducer (such as a planetary gear reducer in a wheel hub), or other suitable mechanical components for vehicles that require differential output (such as automobiles, trucks, boats, all-terrain vehicles, commercial vehicles, light vehicles, off-road vehicles, mining vehicles, rail vehicles, etc.) and other applications (such as manufacturing applications like manufacturing machinery, industrial applications like industrial machinery, etc.). When the electric axle described herein is used in a vehicle, it can be understood that the transmission can be used as a drive shaft for electric vehicles (EVs) such as all-electric vehicles (e.g., battery electric vehicles (BEVs)) and hybrid electric vehicles. Thus, in some examples, a vehicle using the transmission described herein may have an internal combustion engine (such as a spark-ignition engine, a compression-ignition engine, a combination thereof, etc.). In addition, the electric axle described herein may have an axle disconnect function.

[0058] The gears in the planetary gear set can be spur gears or helical gears. As described above, the second motor in the electric axle described herein is optional. In addition, in one example, the gears used to mechanically couple the motor to the transmission input end can be the same and mesh with the final gear on the output center line. In another example, the transmission associated with the second motor can be different from the transmission associated with the first motor and mesh with the final gear on the output center line. In addition, in one example, the transmission associated with the second motor can include a clutch to decouple the second motor from the planetary reduction differential group in certain cases, thereby further improving efficiency.

[0059] Furthermore, in one example, the transmission associated with the second motor can mesh with the transmission associated with the first motor before the final gear on the output center line. Furthermore, in one example, the transmission associated with the second motor can have a different transmission ratio and mesh with the transmission associated with the first motor before the final gear on the output center line.

[0060] In addition, Figures 1A-17The exact position and number of axles in the illustrated electric vehicle axle structure are indicative and exemplary. It is understood that in other examples, other axle layouts, numbers, etc. may be used. Additionally, it is understood that the electric vehicle axle may utilize one or more intersecting motors, which may be connected to the input of the transmission via hypoid gears or other suitable bevel or helical gears. In such an example, the motor may mesh with a hypoid gear via a mating pinion, and there may be other gear paths and / or shiftable gears between the motor and the pinion. In different examples, the variable speed gears may be mounted on any one of the parallel mating shafts. Additionally, if desired, additional gear paths may be added to the electric axle. Further, the planetary gear set that provides input to the planetary reduction differential described herein may take the form of a simple planetary gear set, an engaged planetary compound planetary gear set, a stepped planetary compound planetary gear set, and / or a magnetic planetary gear set.

[0061] Additionally, it is understood that Figures 5-9 the various motor arrangements shown may be used with any of the transmissions (and corresponding electric vehicle axle systems) described herein, such as Figures 1A-4 any combination of the transmissions or electric vehicle axles shown in FIGS. 10 - 17. Additionally, different combinations of motor structures and transmission structures are envisioned, including multiple features from different embodiments.

[0062] The present utility model will be further described below. In one aspect, the present utility model provides an electric vehicle axle system, which system includes a first motor; and a planetary reduction differential configured to receive mechanical power from the first motor; wherein the planetary reduction differential includes a first planetary gear set directly rotationally coupled to a second planetary gear set; wherein the sun gear in the first planetary gear set is directly coupled to the input shaft of the planetary reduction differential; and wherein the carrier in the first planetary gear set is directly coupled to the output shaft. In one example, the first planetary gear set may be a simple planetary gear set and the second planetary gear set may be a simple planetary gear set; and / or the first and second planetary gear sets may have the same ring gear to sun gear ratio. In another example, the ring gear in the second planetary gear set may be directly coupled to the output shaft; the ring gear in the first planetary gear set may be directly rotationally coupled to the sun gear in the second planetary gear set; the carrier in the second simple planetary gear set may be fixed. In another example, the first planetary gear set may be a simple planetary gear set and the second planetary gear set may be an epicyclic compound planetary gear set; the ring gear in the second planetary gear set may be fixed. In another example, the sun gear in the second planetary gear set may be directly coupled to the output shaft; the ring gear in the first planetary gear set may be directly rotationally coupled to the carrier in the second planetary gear set. In another example, the carrier in the second planetary gear set may be directly connected to the output shaft; the ring gear in the first planetary gear set may be directly rotationally connected to the sun gear in the second planetary gear set. In another example, the first planetary gear set may be an epicyclic compound planetary gear set and the second planetary gear set is an epicyclic compound planetary gear set; the ring gear in the second planetary gear set may be fixed. In another example, the sun gear in the second planetary gear set may be directly coupled to the output shaft; the ring gear in the first planetary gear set may be directly rotationally coupled to the carrier in the second planetary gear set. In another example, the carrier in the second planetary gear set may be directly coupled to the output shaft; the ring gear in the first planetary gear set may be directly rotationally coupled to the sun gear in the second planetary gear set. In another example, the electric vehicle axle system may further include a Ravigneaux three-speed mode planetary gear set rotationally coupled and positioned coaxially with the planetary reduction differential; and a mode clutch configured to, in a first mode, fix the carrier or the ring gear in the Ravigneaux three-speed mode planetary gear set; in a second mode, fix the second sun gear in the Ravigneaux three-speed mode planetary gear set; and in a third mode, rotationally couple the carrier or the ring gear in the Ravigneaux three-speed mode planetary gear set to the second sun gear; wherein the first sun gear in the Ravigneaux three-speed mode planetary gear set is rotationally coupled to the first motor.In another example, the electric vehicle axle system may further include a two-speed mode planetary gear set rotatably coupled to the input shaft; and a mode clutch configured to, in a first mode, fix the carrier or the ring gear in the two-speed mode planetary gear set; and in a second mode, rotatably couple the carrier in the two-speed mode planetary gear set to the ring gear; wherein the sun gear in the two-speed mode planetary gear set is rotatably coupled to the first motor. In another example, the first motor may be positioned coaxially, parallel, or intersecting with the planetary reduction differential. In another example, the electric vehicle axle system may further include a second motor rotatably coupled to the planetary reduction differential.

[0063] In another aspect, there is provided a method of operating an electric vehicle axle, which includes: operating a first motor to deliver mechanical power to a planetary reduction differential; wherein the electric vehicle axle includes: a first motor; and a planetary reduction differential configured to receive mechanical power from the first motor; wherein the planetary reduction differential includes a first planetary gear set directly rotatably coupled to a second planetary gear set; wherein the sun gear in the first planetary gear set is directly coupled to the input shaft of the planetary reduction differential; and wherein the carrier in the first planetary gear set is directly coupled to the output shaft. In one example, the method may further include operating a second motor to provide mechanical power to the planetary reduction differential. In another example, the method may further include operating a mode clutch in a Ravigneaux three-speed mode planetary gear set rotatably coupled to the planetary reduction differential to switch the Ravigneaux three-speed mode planetary gear set between two of a set of three operating modes.

[0064] On the other hand, an electric vehicle axle is provided, the electric vehicle axle including an electric motor; and a planetary reduction differential configured to receive mechanical power from the electric motor; wherein the planetary reduction differential includes a first planetary gear set directly rotationally coupled to a second planetary gear set; wherein the sun gear in the first planetary gear set is directly coupled to the input shaft of the planetary reduction differential; wherein the carrier in the first planetary gear set is directly coupled to the output shaft; wherein the ring gear in the second planetary gear set is directly coupled to the output shaft; wherein the ring gear in the first planetary gear set is directly rotationally coupled to the sun gear in the second planetary gear set; and wherein the carrier in the second planetary gear set is fixed. In one example, the electric vehicle axle may further include a Ravigneaux three-speed mode planetary gear set coaxially rotationally coupled and positioned with the planetary reduction differential; and a mode clutch configured to selectively switch the Ravigneaux three-speed mode planetary gear set between two of three modes; wherein the mode clutch is configured to: in a first mode, engage the carrier or the ring gear in the Ravigneaux three-speed mode planetary gear set; in a second mode, engage the second sun gear in the Ravigneaux three-speed mode planetary gear set; and in a third mode, rotationally couple the carrier or the ring gear in the Ravigneaux gear set to the second sun gear. In another example, the ring gear or the carrier in the Ravigneaux three-speed mode planetary gear set may be coupled to the electric vehicle axle input shaft. In another example, the electric vehicle axle may further include a two-speed mode planetary gear set directly rotationally coupled to the input shaft; and a mode clutch configured to: in a first mode, fix one of the carriers or one of the ring gears in the two-speed mode planetary gear set; and in a second mode, rotationally couple the carrier in the two-speed mode planetary gear set to the ring gear; wherein the ring gear or the carrier in the two-speed mode planetary gear set is rotationally coupled to the electric vehicle axle input shaft.

[0065] Figures 1A-17Shows an example configuration of the relative positioning of various components. If the components shown in the figure are in direct contact or directly coupled to each other, then in at least one example, these components can be referred to as being in direct contact or directly coupled respectively. Similarly, in at least one example, components shown as being contiguous or adjacent to each other can be contiguous or adjacent to each other respectively. For example, components that are in face-to-face contact with each other can be referred to as face-to-face contact components. Another example is that in at least one example, components are placed separately from each other, with only space in between and no other components, and can be referred to as being placed separately from each other. Also, components shown as being above / below each other, on either side of each other, or on the left / right side of each other relative to each other can be referred to as such components. Additionally, as shown in the figure, in at least one example, the topmost component or component point can be referred to as the "top" of the component, and the bottommost component or component point can be referred to as the "bottom" of the component. The top / bottom, upper / lower, above / below used in this article can be relative to the vertical axis in the figure and are used to describe the relative positioning of the elements in the figure with respect to each other. Thus, in one example, an element shown above other elements is vertically positioned above the other elements. As another example, the shapes of the components depicted in the figure can be referred to as having these shapes (e.g., such as circular, straight, planar, curved, rounded, chamfered, beveled, or similar shapes). Additionally, in one example, components that are coaxial with each other can be referred to as coaxial components. Furthermore, in at least one example, elements shown as intersecting each other can be referred to as intersecting elements or intersecting with each other. Additionally, in one example, an element shown inside or outside another element can be referred to as an intersecting element. In other examples, elements that are offset from each other can also be referred to as "offset elements".

[0066] A motor and shift control logic / program, frequency converter, electronic control unit (ECU), memory storage, throttle, brake, speed and inclination sensors, etc., shift actuator, etc. can be further used in any electric vehicle axle and transmission described herein.

[0067] Figures 1A-17 A method for operating an electric vehicle axle is provided, in which the transmission switches between two modes in a set of transmission operation modes according to vehicle operating conditions. The method can even further include selectively disconnecting the axle by operating the axle disconnect clutch.

[0068] In addition, the axle and transmission described herein may include a control system that includes a controller having a processor and a memory that stores instructions for performing the method steps described herein. More specifically, the control methods and routines disclosed herein may be stored as executable instructions in a non-transitory memory and may be executed by a system including the controller in combination with various sensors and actuators. Further, portions of the methods may be physical actions taken in the real world to change the state of a device. The specific routines described herein may represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multi-tasking, multi-threading, etc. Accordingly, the various actions, operations, and / or functions illustrated may be performed in the order illustrated, may be performed in parallel, or in some cases may be omitted. Also, the order of processing is not necessarily required to implement the features and advantages of the examples described herein, but is provided for ease of illustration and description. One or more of the illustrated actions, operations, and / or functions may be repeated according to the particular strategy being used. Further, the actions, operations, and / or functions described may be graphically represented as code to be programmed into the non-transitory memory of a computer-readable storage medium in a system, where the described actions are implemented by executing instructions in a system including various hardware components in combination with an electronic controller. One or more of the method steps described herein may be omitted if desired.

[0069] Although the various embodiments have been described above, it should be understood that these embodiments are illustrative only and not limiting or restrictive. It is understood that the configurations and routines disclosed herein are exemplary in nature and these specific examples should not be considered limiting as there may be many variations. For example, the above techniques may be applied to power systems that include different types of propulsion sources, including different types of electric motors, internal combustion engines, and / or transmissions. The technology may be used alone or in combination with other power transmission systems, but is not limited to series axles, electric tag axles, P4 axles, HEVs, BEVs, agricultural, marine, motorcycles, recreational vehicles, and on-road and off-road vehicles, etc., mechanical and propulsion systems. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, as well as other features, functions, and / or properties disclosed herein. It will be apparent to those skilled in the relevant art that the disclosed subject matter may be embodied in other specific forms without departing from the spirit of the subject matter.

[0070] The following claims particularly point out certain combinations and sub - combinations regarded as novel and non - obvious. These claims may refer to "an" element or "a first" element or the equivalent thereof. These claims are to be understood as covering one or more such elements, not requiring nor precluding two or more such elements. Other combinations and sub - combinations of the disclosed features, functions, elements, and / or characteristics may be claimed by modifying these claims or presenting new claims in this application or a related application. These claims, whether broader, narrower, the same, or different in scope from the original claims, are also regarded as included in the subject matter of this disclosure.

Claims

1. An electric vehicle axle system, characterized in that, Comprising: A first motor; And A planetary reduction differential, the planetary reduction differential receiving mechanical power from the first motor; Wherein, the planetary reduction differential includes a first planetary gear set directly rotationally coupled to a second planetary gear set; Wherein, the sun gear in the first planetary gear set is directly connected to the input shaft of the planetary reduction differential; and Wherein, the carrier in the first planetary gear set is directly connected to the output shaft.

2. The electric vehicle axle system according to claim 1, wherein The first planetary gear set is a simple planetary gear set, and the second planetary gear set is a simple planetary gear set; and / or The ratio of the ring gear to the sun gear of the first and second planetary gear sets is the same.

3. The electric vehicle axle system according to claim 2, wherein The ring gear in the second planetary gear set is directly connected to the output shaft; The ring gear in the first planetary gear set is directly rotationally coupled to the sun gear in the second planetary gear set; and The carrier in the second planetary gear set is fixed.

4. The electric vehicle axle system according to claim 1, wherein The first planetary gear set is a simple planetary gear set, and the second planetary gear set is an epicyclic compound planetary gear set; and One of the ring gears in the second planetary gear set is fixed.

5. The electric vehicle axle system according to claim 4, wherein The sun gear in the second planetary gear set is directly connected to the output shaft; and The ring gear in the first planetary gear set is directly rotationally coupled to the carrier in the second planetary gear set.

6. The electric vehicle axle system according to claim 4, wherein The carrier in the second planetary gear set is directly connected to the output shaft; and The ring gear in the first planetary gear set is directly rotationally coupled to the sun gear in the second planetary gear set.

7. The electric vehicle axle system according to claim 1, wherein The first planetary gear set is an epicyclic compound planetary gear set, and the second planetary gear set is an epicyclic compound planetary gear set; and One of the ring gears in the second planetary gear set is fixed.

8. The electric vehicle axle system according to claim 7, wherein The sun gear in the second planetary gear set is directly connected to the output shaft; and The ring gear in the first planetary gear set is directly rotationally coupled to the carrier in the second planetary gear set.

9. The electric vehicle axle system according to claim 7, wherein The carrier in the second planetary gear set is directly connected to the output shaft; and The ring gear in the first planetary gear set is directly rotationally coupled to the sun gear in the second planetary gear set.

10. The electric vehicle axle system according to claim 1, characterized in that, Further comprising: A Ravigneaux three-speed mode planetary gear set rotationally coupled and positioned coaxially with the planetary reduction differential; And A mode clutch, the mode clutch being used for In the first mode, fixing a carrier or a ring gear in the Ravigneaux three-speed mode planetary gear set; In the second mode, fixing the second sun gear in the Ravigneaux three-speed mode planetary gear set; And In the third mode, the carrier or ring gear in the Ravigneaux three-speed planetary gear set is rotationally coupled to the second sun gear; Wherein, the first sun gear in the Ravigneaux three-speed planetary gear set is rotationally coupled to the first motor.

11. The electric vehicle axle system according to claim 1, characterized in that, Further included are: A two-speed planetary gear set rotationally coupled to the input shaft; And A mode clutch, which is used to In the first mode, fix a carrier or a ring gear in the two-speed planetary gear set; And In the second mode, rotationally couple the carrier in the two-speed planetary gear set to the ring gear; Wherein, one sun gear in the two-speed planetary gear set is rotationally coupled to the first motor.

12. The electric vehicle axle system according to claim 1, characterized in that, The first motor is coaxially, parallelly or intersectingly arranged with the planetary reduction differential.

13. The electric vehicle axle system according to claim 1, characterized in that, Further included is a second motor rotationally coupled to the planetary reduction differential.

14. The electric vehicle axle system according to claim 1, characterized in that, Further included are: A Ravigneaux three-speed planetary gear set rotationally coupled and positioned coaxially with the planetary reduction differential; And A mode clutch, which is used to selectively switch the Ravigneaux three-speed planetary gear set between two of the three modes; Wherein, the mode clutch is configured to: In the first mode, fix the carrier or the ring gear in the Ravigneaux three-speed planetary gear set; In the second mode, fix the second sun gear in the Ravigneaux three-speed planetary gear set; And In the third mode, rotationally couple the carrier or the ring gear in the Ravigneaux gear set to the second sun gear.

15. The electric vehicle axle system according to claim 1, wherein Further included are: A two-speed planetary gear set directly rotationally coupled to the input shaft; And A mode clutch, which is used to In the first mode, fix a carrier or a ring gear in the two-speed planetary gear set; And In the second mode, rotationally couple the carrier in the two-speed planetary gear set to the ring gear; Wherein, the ring gear or the carrier in the two-speed planetary gear set is rotationally coupled to the input shaft of the planetary reduction differential.

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