Transmission device of electric vehicle
By introducing a countershaft and planetary gear set into the transmission, combined with a countershaft clutch and needle roller bearings, the problems of large size and insufficient functions of heavy-duty vehicle transmissions are solved, and compact and efficient transmission ratio selection and motor cost reduction are achieved.
Patent Information
- Application Number
- CN202510312662.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-03-21
- Filing Date
- 2025-03-17
- Publication Date
- 2025-09-23
AI Technical Summary
Traditional heavy-duty vehicle transmissions are either bulky or unable to achieve desired functions, such as appropriate gear ratios and torque, resulting in increased demand for electric motors and high costs.
A transmission design including a countershaft is adopted, which provides multiple gear states and a compact design through the meshing engagement between the first and second input shafts and the drive shaft, combined with a planetary gear set and a crawler unit, and utilizes a countershaft clutch and needle roller bearings to improve flexibility and efficiency.
A compact transmission device is achieved, which can flexibly select the transmission ratio according to the operating mode, reduce motor costs, improve efficiency and reduce energy loss, and adapt to the starting and driving needs of heavy vehicles.
Smart Images
Figure CN120684523A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure generally relates to vehicle transmissions. In particular aspects, the present disclosure relates to a transmission for an electric vehicle. The present disclosure may be applicable to heavy-duty vehicles such as trucks, buses, and construction equipment, among other types of vehicles. Although the present disclosure may be described with respect to a specific vehicle, the present disclosure is not limited to any particular vehicle. Background Art
[0002] Vehicle propulsion systems are constantly evolving to meet market demands. A particular concern is the reduction of environmentally harmful exhaust emissions. Consequently, vehicles propelled by electric traction motors are becoming increasingly popular, whether they are cars or heavy vehicles.
[0003] For automobiles, transmissions typically include a fixed ratio between the input and output shafts to provide the desired output torque and cruising speed. However, for heavy vehicles, the relatively high weight of these types of vehicles and the need for motor startability and suitable speed requirements necessitate a transmission capable of multiple gear states. For example, omitting a transmission for heavy vehicles would require the use of a powerful and expensive electric traction motor.
[0004] Conventional transmissions for heavy vehicles are either bulky or fail to provide the desired functionality, such as being able to achieve a desired gear ratio. Therefore, there is a need to provide a compact transmission that can achieve a desired speed and torque range. Summary of the Invention
[0005] According to a first aspect of the present invention, a transmission device for a vehicle is provided, the transmission device comprising: a first input shaft, the first input shaft being drivably connected to a first electric traction motor, the first input shaft comprising a first input shaft gear wheel fixed to the first input shaft in a steering direction; a second input shaft, the second input shaft being drivably connected to a second electric traction motor, the second input shaft comprising a second input shaft gear wheel fixed to the second input shaft in a steering direction; a drive shaft, the drive shaft being drivably connected to a pair of wheels of the vehicle, the drive shaft comprising a drive gear wheel fixed to the drive shaft in a steering direction, the drive gear wheel being arranged to mesh with the first input shaft gear wheel; and a countershaft, the countershaft comprising a first countershaft gear wheel arranged to mesh with the drive gear wheel, and a second countershaft gear wheel arranged to mesh with the second input shaft gear wheel, wherein the second input shaft is drivably connected to the drive shaft via the countershaft.
[0006] A first aspect of the present disclosure can seek to at least partially alleviate the problem of the aforementioned transmission being either bulky or insufficiently functional. Technical benefits can include the inclusion of a layshaft enabling the use of an additional input shaft, namely the second input shaft defined above, which can be connected to a second electric traction motor. This, in turn, can enable greater flexibility in selecting the desired transmission ratio depending on the operating mode. Specifically, the transmission can be driven solely by the first input shaft or by a combination of the first and second input shafts. If an electrically excited first electric traction motor is used, the transmission can alternatively be driven solely by the second input shaft. In this case, the first electric traction motor can be electrically disconnected and idle, while the second input shaft is drivingly connected to the propeller shaft via the layshaft.
[0007] Furthermore, by including the layshaft, the end locations of the first and second input shafts (to which the respective first and second electric traction motors are drivably connected) can be arranged on opposite axial sides of the transmission. This allows for a transmission with a smaller size to be provided.
[0008] In the following text and throughout the description, the expressions "rotationally connected to" and "rotationally connected" are to be interpreted as meaning that a component of the transmission is connected to another component of the transmission in such a way that the components rotate in the same direction and at the same speed. Therefore, when the components are rotationally connected to each other, they rotate in the same direction and at the same speed. Therefore, the expression "connectable" is to be interpreted as being connectable via a clutch, whereby the components are selectively connectable. Furthermore, the definition of "rotationally fixed to" is to be interpreted as meaning that two components are directly connected to each other, wherein no relative rotation can be obtained between the two components. As an example, a first input shaft gear wheel is rotationally fixed to the first input shaft. When the gear wheel is rotationally fixed to the shaft, the gear wheel can be formed integrally with the shaft or press-fitted to the shaft, etc.
[0009] Furthermore, the phrases "drivingly connected to" and "drivably connected to" should be understood to mean that the two components are either directly connected to each other, i.e., the components rotate in the same direction and at the same speed, or are connected to each other via one or more gears therebetween. In the latter example, when the first component rotates, the second component also rotates at a ratio to the first component. The first and second components do not necessarily rotate in the same direction and at the same speed.
[0010] Optionally, in some examples, including at least one preferred example, the transmission further comprises a countershaft clutch arranged to selectively drivingly connect the second input shaft to the propeller shaft. As will be described below, the countershaft clutch can be arranged to selectively rotationally connect the second countershaft gearwheel to the countershaft. Alternatively, the countershaft clutch can be arranged to selectively rotationally connect the first countershaft gearwheel to the countershaft. Technical benefits may include: when it is desired to apply torque to the propeller shaft using the second electric traction motor, the clutch can be controlled in a conventional manner to drivingly connect the second input to the propeller shaft.
[0011] Optionally, in some examples, including at least one preferred example, the countershaft clutch is arranged to selectively rotationally connect the second countershaft gearwheel to the countershaft. Technical benefits may include that the countershaft clutch may be fully or partially embedded within the second countershaft gearwheel.
[0012] Optionally, in some examples, including at least one preferred example, the second layshaft gear wheel is supported to the layshaft by a bearing arrangement.
[0013] Optionally, in some examples, including at least one preferred example, the bearing device is a needle roller bearing device. Technical benefits may include: due to the larger contact area between their rollers and raceways, needle roller bearings can have a higher load capacity than similarly sized ball bearings. Furthermore, needle roller bearings have a compact design, allowing them to withstand high radial loads within a smaller space. Therefore, needle roller bearings may be advantageous in this location due to relatively limited space, as they can support relatively high loads and high speeds.
[0014] Optionally, in some examples, including at least one preferred example, the countershaft clutch is arranged to selectively rotationally connect the first countershaft gearwheel to the countershaft. Technical benefits may include that when the countershaft clutch is disengaged, the bearings supporting the countershaft are substantially stationary, thereby reducing energy losses.
[0015] Optionally, in some examples, including at least one preferred example, the second input shaft gearwheel and the second countershaft gearwheel form a first reduction gear stage, in which, during operation of the transmission, the second input shaft gearwheel rotates at a higher speed than the second countershaft gearwheel. Technical benefits may include allowing the second electric motor to rotate faster. The size of an electric motor is determined by the maximum torque it can produce. Therefore, a higher speed can compensate for a lower torque level, and the second electric motor can be made smaller, which in turn reduces the cost of such an electric motor.
[0016] Optionally, in some examples, including at least one preferred example, the transmission further comprises a first planetary gear set, the first planetary gear set comprising a first sun gear, a first ring gear, and a first planet carrier carrying a first set of planetary gears, the first set of planetary gears meshingly engaged with the first ring gear and the first sun gear, wherein the first sun gear and the first ring gear are rotatably connected to the transmission shaft, and wherein the first planet carrier is rotatably connected to the output shaft. Technical benefits may include: three gear states can be achieved by using the first planetary gear set. In addition, the planetary gear set is compact in design, and three gear states can be achieved through a compact transmission.
[0017] Optionally, in some examples, including at least one preferred example, the first sun gear of the first planetary gear set may be rotationally connected to the drive shaft via a second clutch of the transmission.
[0018] Optionally, in some examples, including at least one preferred example, the first ring gear of the first planetary gear set can be rotationally connected to the drive shaft via a third clutch of the transmission. Technical benefits may include the first ring gear being rotationally connected to the drive shaft for some gear states, but not being rotationally connected to the drive shaft for other gear states.
[0019] Optionally, in some examples, including at least one preferred example, the first ring gear of the first planetary gear set is rotationally connectable to the stationary member via the third clutch.
[0020] The third clutch should also be interpreted as being able to adopt a neutral position in which the third clutch is not connected to any one of the transmission shaft or the fixed member. In this case, the ring gear rotates without directly interacting with the transmission shaft or the fixed member.
[0021] Optionally, in some examples, including at least one preferred example, the transmission further includes a crawler unit comprising a plurality of gear members, the crawler unit being drivably connected between the first planetary gear set and the output shaft via a first clutch. Technical benefits may include the crawler unit advantageously providing a significant reduction in speed between the input and output shafts. This significant reduction in speed makes it ideal for launching large vehicles from a standstill.
[0022] Optionally, in some examples, including at least one preferred example, the first clutch is configured to rotationally connect one of the plurality of gear members of the crawler unit to the first ring gear, the first planet carrier, or one of the stationary members of the transmission, such that the first ring gear rotates in a direction opposite to the direction of rotation of the first planet carrier. A technical benefit may include that by providing the crawler unit with the first clutch, the crawler unit having the first clutch that causes the first ring gear to rotate in a direction opposite to the direction of rotation of the first planet carrier when the first clutch is engaged can further increase the speed reduction between the input shaft and the output shaft. Thus, a technical benefit is that when the first clutch is engaged, high torque can be provided to the wheels of the vehicle during crawling.
[0023] In the above, when one of the plurality of gear members of the crawling unit is rotationally connected to the fixed member, the gear member of the crawling unit is also fixed, which should be understood to fall within the scope of the definition of “rotationally connected to”.
[0024] Optionally, in some examples, including at least one preferred example, the crawling unit includes a second planetary gear set, and the multiple gear components of the crawling unit include a second sun gear, a second ring gear and a second planet carrier carrying a second set of planetary gears, and the second set of planetary gears are meshed with the second ring gear and the second sun gear.
[0025] Optionally, in some examples, including at least one preferred example, the second sun gear is rotationally connected to the first ring gear.
[0026] Optionally, in some examples, including at least one preferred example, the second ring gear is rotationally connected to the first planet carrier.
[0027] Optionally, in some examples, including at least one preferred example, the second planet carrier may be rotationally connected to the stationary member of the transmission via the first clutch of the crawler unit.
[0028] Technical benefits may include providing greater rotation in the opposite direction for the first ring gear, which in turn produces a greater ratio between the drive shaft and the output shaft. Additionally, the second sun gear may be provided with a smaller diameter since it is not subject to high torque loads.
[0029] Optionally, in some examples, including at least one preferred example, the first input shaft and the second input shaft are arranged parallel to each other and at radially separated positions. As indicated above, technical benefits may include achieving a compact design.
[0030] According to a second aspect, there is provided a drive train arrangement for an electric vehicle, the drive train arrangement comprising: a first electric traction motor, a second electric traction motor and a transmission arrangement according to any one of the examples described above in relation to the first aspect, wherein the first electric traction motor is drivingly connected to the first input shaft and the second electric traction motor is drivingly connected to the second input shaft.
[0031] Optionally, in some examples, including at least one preferred example, the first input shaft includes a first end position and a second end position, the first input shaft gear wheel is arranged near the first end position, and the first electric traction motor is drivingly connected to the first input shaft at the second end position.
[0032] Optionally, in some examples, including at least one preferred example, the second input shaft includes a first end position and a second end position, the second input shaft gear wheel is arranged near the first end position, and the second electric traction motor is drivingly connected to the second input shaft at the second end position.
[0033] Optionally, in some examples, including at least one preferred example, the first end position of the first input shaft and the first end position of the second input shaft are oriented axially opposite to each other.
[0034] The effects and features of the second aspect are largely similar to those described above with respect to the first aspect.
[0035] According to a third aspect, there is provided a vehicle comprising a transmission arrangement according to any one of the examples described above in relation to the first aspect or a driveline arrangement according to the examples described above in relation to the second aspect.
[0036] The effects and features of the third aspect are largely similar to those described above with respect to the first and second aspects.
[0037] Those skilled in the art will appreciate that the disclosed aspects, examples (including any preferred examples), and / or the accompanying claims may be appropriately combined with one another. Additional features and advantages are disclosed in the following description, claims, and drawings, and in part will be apparent to those skilled in the art or recognized by practicing the disclosure as described herein. BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Examples will be described in more detail below with reference to the accompanying drawings.
[0039] Figure 1 is an exemplary vehicle according to an example.
[0040] Figure 2 is an exemplary illustration of a transmission according to an example,
[0041] Figure 3 is an exemplary illustration of a transmission according to another example, and
[0042] Figure 4 yes Figure 2 An exemplary illustration of a transmission in FIG, with further details according to an example. DETAILED DESCRIPTION
[0043] The detailed description set forth below provides information and examples of the disclosed technology in sufficient detail to enable those skilled in the art to practice the disclosure.
[0044] The following disclosure is directed to a compact transmission that enables ideal gear ratio selection between input and output shafts to provide optimal gear ratio and efficiency.
[0045] First reference Figure 1 , which depicts an exemplary vehicle 10. The exemplary vehicle 10 is configured to be propelled at least in part by a first electric traction motor 110 and a second electric traction motor 110'. As will be apparent from the following description, the first electric traction motor 110 and the second electric traction motor 110' are drivingly connected to the transmission 100.
[0046] For a further detailed description of the transmission, refer to Figure 2 , which is a first example of a transmission device 100. The transmission device 100 includes a first input shaft 102 and a second input shaft 104. Figure 4 As described in further detail, the first input shaft 102 is drivingly connected to a first electric traction motor 110 , while the second input shaft 104 is drivingly connected to a second electric traction motor 110 ′.
[0047] The first input shaft 102 includes a first input shaft gearwheel 106 rotationally fixed to the first input shaft 102. Specifically, the first input shaft gearwheel 106 is disposed proximate a first end location 108 of the first input shaft 102, while the first electric traction motor 110 is drivingly connected to the first input shaft 102 at a second end location 109 of the first input shaft 102. The first end location 108 and the second end location 109 are disposed on opposite axial ends of the first input shaft 102.
[0048] The second input shaft 104 includes a second input shaft gear wheel 112 fixed to the second input shaft 104 in terms of rotation. In detail, the second input shaft gear wheel 112 is arranged near a first end position 114 of the second input shaft 104, while the second electric traction motor 110' is drivingly connected to the second input shaft 104 at a second end position 116 of the second input shaft 104. The first end position 114 and the second end position 116 are arranged on opposite axial ends of the second input shaft 104. Figure 2 As shown, the first end position 108 of the first input shaft 102 and the first end position 114 of the second input shaft 104 are thus oriented axially opposite to one another.
[0049] The transmission 100 also includes a drive shaft 120. The drive shaft 120 is drivably connected to a pair of wheels ( Figure 1 12 in ). From the following Figure 4 As is apparent from the description of FIG, the transmission shaft 120 can advantageously be drivingly connected to the output shaft 220 of the transmission 100 via one or more gear stages. Figure 2 10. The output shaft is in turn drivingly connected or drivably connected to a pair of wheels 12 of the vehicle 10. The drive shaft 120 includes a drive gear wheel 122. The drive gear wheel 122 is fixed to the drive shaft 120 in terms of rotation. The drive gear wheel 122 and the first input shaft gear wheel 106 are arranged to mesh with each other. Thus, when the first input shaft gear wheel 106 rotates, the drive gear wheel 122 rotates. In other words, the drive gear wheel 122 is driven by the first input shaft gear wheel 106. Figure 2 As indicated, the transfer gear wheel 122 is larger than the first input shaft gear wheel 106. Thus, the rotational speed of the transfer shaft 120 will be lower / slower than the rotational speed of the first input shaft 102.
[0050] Furthermore, the transmission 100 includes a countershaft 130. The countershaft 130 is drivably connected between the second input shaft 104 and the propeller shaft 120. In other words, the second input shaft 104 is drivably connected to the propeller shaft 120 via the countershaft 130. In further detail, the countershaft 130 includes a first countershaft gear wheel 132 and a second countershaft gear wheel 134. Specifically, the transmission preferably includes a countershaft clutch 136, which is arranged to selectively drivably connect the second input shaft 104 to the propeller shaft 120. Further details of the countershaft clutch 136 and examples of different positions will be described below. Furthermore, in Figure 2 In the depicted example, the first countershaft gear wheel 132 and the second countershaft gear wheel 134 are arranged at opposite end positions on the countershaft 130 .
[0051] The first countershaft gear wheel 132 is arranged to mesh with the transfer gear wheel 122. Therefore, when the countershaft 130 rotates, the transfer shaft 120 rotates. Figure 2 As indicated, the transfer gear wheel 122 is larger than the first countershaft gear wheel 132. As a result, the rotational speed of the transfer shaft 120 will be lower / slower than the rotational speed of the countershaft 130. On the other hand, the second countershaft gear wheel 134 is arranged to mesh with the second input shaft gear wheel 112. Thus, when the second input shaft 104 rotates, the second countershaft gear wheel 134 rotates. Figure 2 As indicated, the second countershaft gearwheel 134 is larger than the second input shaft gearwheel 112. The second input shaft gearwheel 112 and the second countershaft gearwheel 134 form a first reduction gear stage in which, during operation of the transmission 100, when the second electric traction motor is operated, the second input shaft gearwheel 112 rotates at a higher rotational speed than the rotational speed of the second countershaft gearwheel 134.
[0052] exist Figure 2 In the depicted example, the first countershaft gearwheel 132 is rotationally fixed to the countershaft 130. The second countershaft gearwheel 134, on the other hand, is supported to the countershaft 130 via a bearing arrangement 140. The bearing arrangement 140 is preferably a needle bearing arrangement. When engaged, the countershaft clutch 136 rotationally connects the second countershaft gearwheel 134 to the countershaft 130. Thus, the second countershaft gearwheel 134 is rotationally connected to the countershaft 130 via the countershaft clutch 136. Thus, the countershaft clutch 136 is arranged to selectively driveably connect the second input shaft 104 to the propeller shaft 120. The countershaft clutch 136 preferably includes an engagement sleeve 138 that is slidable in the axial direction of the countershaft 130 to rotationally connect and disconnect the second countershaft gearwheel 134 from the countershaft 130. When the engagement sleeve 138 is in the disengaged state, the second countershaft gearwheel 136 can rotate without transmitting torque to the countershaft 130.
[0053] Now refer to Figure 3 , which is an exemplary diagram of an electric transmission 100 according to another example. Figure 2 The transmission device in Figure 3 The difference between the transmission device and the intermediate shaft 130 is the intermediate shaft 130 and the components connected thereto. Figure 3 The examples in the above section Figure 2 Differences between the examples described.
[0054] exist Figure 3In the depicted example, the second countershaft gearwheel 134 is rotationally fixed to the countershaft 130 . The first countershaft gearwheel 132 is supported on the countershaft 130 via a bearing arrangement, preferably a needle bearing arrangement. When engaged, the countershaft clutch 136 rotationally connects the first countershaft gearwheel 132 to the countershaft 130 . Thus, the first countershaft gearwheel 132 can be rotationally connected to the countershaft 130 via the countershaft clutch 136 . Thus, the countershaft clutch 136 is arranged to selectively driveably connect the second input shaft 104 to the propeller shaft 120 . The countershaft clutch 136 preferably includes the aforementioned engagement sleeve 138 , which is slidable in the axial direction of the countershaft 130 to rotationally connect and disconnect the first countershaft gearwheel 132 from the countershaft 130 . When the engagement sleeve 138 is in the disengaged state, the first countershaft gearwheel 136 can rotate without transmitting torque to the propeller shaft 120 . In further detail, when the second traction motor propels the second input shaft 104 and the clutch sleeve 138 is in the disengaged state, the second input shaft 104 and the layshaft 130 rotate but do not transmit torque to the propeller shaft 120 .
[0055] Now refer to Figure 4 , which is Figure 2 An exemplary illustration of a transmission 100 is provided, including further details according to an example. Figure 4 The diagram in FIG also shows a transmission arrangement 500, which includes the transmission arrangement 100 and the first electric traction motor 110 and the second electric traction motor 110 ′. It should be readily understood that Figure 3 The examples in also apply to Figure 4 The transmission device 100 in FIG. 1 is easy to understand for those skilled in the art.
[0056] In addition to the above Figure 2 and Figure 3 In addition to the description above, transmission 100 also includes the aforementioned gear stage 200. Specifically, transmission 100 includes a first planetary gearset 440, which includes a first sun gear 441, a first ring gear 444, and a first planet carrier 442 that carries a first set of planetary gears 443. The first set of planetary gears 443 meshes with the first ring gear 444 and the first sun gear 441. Transmission shaft 120 is preferably hollow to accommodate additional shaft 422.
[0057] In addition, the transmission device 100 further includes a creeping unit 450. The creeping unit 450 includes a plurality of gear members 451, 453, and 454. Figure 4In the depicted example, the plurality of gear members are arranged as gear members of a second planetary gear set 460. The second planetary gear set 460 includes a second sun gear 451, a second ring gear 454, and a second planet carrier 452 carrying a second set of planet gears 453 in meshing engagement with the second ring gear 454 and the second sun gear 451.
[0058] Furthermore, second sun gear 451 is rotationally connected to first ring gear 444. Second planet carrier 452 may be rotationally connected to fixed member 459 via first clutch 455 of creeper unit 450. Fixed member 459 may be a transmission housing (not shown) housing transmission 100. Second ring gear 454 is rotationally connected to first planet carrier 442. First planet carrier 442 is rotationally connected to output shaft 220, and thus second ring gear 454 is also rotationally connected to output shaft 220.
[0059] Turning again to the first planetary gearset 440, the first sun gear 441 of the first planetary gearset 440 is rotationally connected to the aforementioned additional shaft 422. The additional shaft 422 can be rotationally connected to the transmission gear wheel 122 of the transmission shaft 120 via a second clutch 446. Thus, the first sun gear 441 can be rotationally connected to the transmission gear wheel 122 via the second clutch 446. The second clutch 446 is also configured to rotationally connect the first sun gear 441 to the stationary member 449a. Furthermore, the first ring gear 444 of the first planetary gearset 440 can be rotationally connected to the transmission shaft 120 via a third clutch 445. Thus, the third clutch 445 is configured to rotationally connect the first ring gear 444 to the transmission gear wheel 122 of the transmission shaft 120. The third clutch 445 is also configured to rotationally connect the first ring gear 444 to the stationary member 449b. Furthermore, the third clutch 445 is also configured to adopt a neutral position in which the first ring gear 444 is non-rotatably connected to any one of the transmission gear wheel 122 and the fixed member 449 , ie, the first ring gear 444 freely rotates.
[0060] The aforementioned fixed member 449a connectable to the second clutch 446, the fixed member 449b connectable to the third clutch 445, and the fixed member rotatably connected to the second planet carrier 452 may be the same fixed member, such as, for example, the transmission housing. However, the fixed members may be formed from different transmission components as long as they are fixed relative to the rotating components to which they are connected or connectable.
[0061] Figure 4The transmission 100 in the depicted example is configured to employ three gear states (i.e., three different speed ratios between the drive shaft 120 and the output shaft 220) and a creeper gear. The first gear state is employed by positioning the first clutch 455 in a neutral position, positioning the second clutch 446 to rotationally connect the first sun gear 441 to the drive gear wheel 122, and positioning the third clutch 445 to rotationally connect the first ring gear 444 to the stationary member 449b. As a result, the first ring gear 444 is stationary while the first sun gear 441 is driven, thereby achieving a first speed reduction between the input and output shafts.
[0062] The second gear state is adopted by positioning first clutch 455 in a neutral position, positioning second clutch 446 to rotationally connect first sun gear 441 to fixed member 449a, and positioning third clutch 445 to rotationally connect first ring gear 444 to transfer gear wheel 122. Thus, first sun gear 441 is stationary while first ring gear 444 is driven, thereby achieving a second reduction in speed between the input shaft and the output shaft. The second reduction in speed is lower / smaller than the first reduction in speed.
[0063] The third gear state is adopted by positioning the first clutch 455 in a neutral position, positioning the second clutch 446 to rotationally connect the first sun gear 441 to the transfer gear wheel 122, and positioning the third clutch 445 to rotationally connect the first ring gear 444 to the transfer gear wheel 122. Thus, a direct gear state is achieved in which the second gear wheel 432, the first ring gear 444, the first planet carrier 442, and the output shaft 220 all rotate in the same direction.
[0064] A crawler gear is engaged by positioning first clutch 455 to rotationally connect second planet carrier 452 to stationary member 459, second clutch 446 to rotationally connect first sun gear 441 to transfer gear wheel 122, and third clutch 445 in a neutral position. This results in a third reduction in speed between the input and output shafts, with first ring gear 444 and first planet carrier 442 rotating in opposite directions. The third reduction is higher / greater than the first reduction. In other words, the output shaft rotates at a lower speed relative to the input shaft during the third reduction compared to the relative speed of the input and output shafts during the first reduction.
[0065] Thus, three gear states and a creeper gear are available between the propeller shaft 120 and the output shaft 220. Further speed ratios between the input and output shafts can be achieved by controlling the transmission to be operated by only the first electric traction motor 110 or by a combination of the first electric traction motor 110 and the second electric traction motor 110'.
[0066] Example List
[0067] Example 1. A transmission for a vehicle, the transmission comprising: a first input shaft, the first input shaft being drivably connected to a first electric traction motor, the first input shaft comprising a first input shaft gear wheel fixed to the first input shaft in a steering direction; a second input shaft, the second input shaft being drivably connected to a second electric traction motor, the second input shaft comprising a second input shaft gear wheel fixed to the second input shaft in a steering direction; a propeller shaft, the propeller shaft being drivably connected to a pair of wheels of the vehicle, the propeller shaft comprising a propeller gear wheel fixed to the propeller shaft in a steering direction, the propeller gear wheel being arranged to mesh with the first input shaft gear wheel; and a countershaft comprising a first countershaft gear wheel arranged to mesh with the propeller gear wheel, and a second countershaft gear wheel arranged to mesh with the second input shaft gear wheel, wherein the second input shaft is drivably connected to the propeller shaft via the countershaft.
[0068] Example 2. The transmission of example 1, wherein the transmission further comprises a layshaft clutch arranged to selectively drivingly connect the second input shaft to the propeller shaft.
[0069] Example 3. A transmission according to example 2, wherein the countershaft clutch is arranged to selectively rotationally connect the second countershaft gearwheel to the countershaft.
[0070] Example 4. A transmission according to any preceding example, wherein the second layshaft gear wheel is supported to the layshaft by a bearing arrangement.
[0071] Example 5. The transmission device of Example 4, wherein the bearing device is a needle roller bearing device.
[0072] Example 6. A transmission according to example 2, wherein the countershaft clutch is arranged to selectively rotationally connect the first countershaft gearwheel to the countershaft.
[0073] Example 7. A transmission according to any of the preceding examples, wherein the second input shaft gear wheel and the second countershaft gear wheel form a first reduction gear stage, in which the second input shaft gear wheel rotates at a higher speed than the speed of the second countershaft gear wheel during operation of the transmission.
[0074] Example 8. A transmission according to any one of the preceding examples, further comprising a first planetary gear set, the first planetary gear set comprising a first sun gear, a first ring gear and a first planet carrier carrying a first set of planetary gears, the first set of planetary gears being meshed with the first ring gear and the first sun gear, wherein the first sun gear and the first ring gear are rotatably connected to the transmission shaft, and wherein the first planet carrier is rotatably connected to the output shaft.
[0075] Example 9. The transmission of Example 8, wherein the first sun gear of the first planetary gear set is rotationally connectable to the transmission shaft via a second clutch of the transmission.
[0076] Example 10. A transmission according to any one of Examples 8 or 9, wherein the first ring gear of the first planetary gear set is rotationally connectable to the transmission shaft via a third clutch of the transmission.
[0077] Example 11. The transmission of Example 10, wherein the first ring gear of the first planetary gear set is rotationally connectable to the stationary member via the third clutch.
[0078] Example 12. The transmission according to any one of Examples 8 to 11, further comprising a crawler unit comprising a plurality of gear members, the crawler unit being drivably connectable between the first planetary gear set and the output shaft via a first clutch.
[0079] Example 13. A transmission according to Example 12, wherein the first clutch is configured to rotationally connect one of the plurality of gear members of the crawler unit to the first ring gear, the first planet carrier, or one of the fixed members of the transmission so as to cause the first ring gear to rotate in a direction opposite to the direction of rotation of the first planet carrier.
[0080] Example 14. A transmission according to any one of Examples 12 or 13, wherein the crawling unit includes a second planetary gear set, the plurality of gear members of the crawling unit including a second sun gear, a second ring gear and a second planet carrier carrying a second set of planetary gears, the second set of planetary gears being in meshing engagement with the second ring gear and the second sun gear.
[0081] Example 15. The transmission of Example 14, wherein the second sun gear is rotationally connected to the first ring gear.
[0082] Example 16. A transmission according to any of Examples 14 or 15, wherein the second ring gear is rotationally connected to the first planet carrier.
[0083] Example 17. The transmission according to any one of Examples 14 to 16, wherein the second planet carrier is rotationally connectable to the stationary member of the transmission via the first clutch of the crawler unit.
[0084] Example 18. A transmission according to any one of the preceding examples, wherein the first input shaft and the second input shaft are arranged parallel to each other and at radially separated positions.
[0085] Example 19. A driveline arrangement comprising: a first electric traction motor, a second electric traction motor, and the transmission arrangement of any of the preceding examples, wherein the first electric traction motor is drivingly connected to the first input shaft and the second electric traction motor is drivingly connected to the second input shaft.
[0086] Example 20. A driveline arrangement according to Example 19, wherein the first input shaft includes a first end position and a second end position, the first input shaft gear wheel is arranged near the first end position, and the first electric traction motor is drivingly connected to the first input shaft at the second end position.
[0087] Example 21. A drive train arrangement according to any one of Examples 19 or 20, wherein the second input shaft includes a first end position and a second end position, the second input shaft gear wheel is arranged near the first end position, and the second electric traction motor is drivingly connected to the second input shaft at the second end position.
[0088] Example 22. The drive train arrangement of Examples 20 and 21, wherein the first end position of the first input shaft and the first end position of the second input shaft are oriented axially opposite to each other.
[0089] Example 23. A vehicle comprising a transmission according to any one of Examples 1 to 18 or a driveline arrangement according to any one of Examples 19 to 22.
[0090] The terms used herein are for the purpose of describing specific aspects only and are not intended to limit the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to also include the plural forms. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It should also be understood that the terms "include" and / or "comprising" when used herein indicate the presence of stated features, integers, actions, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, parts and / or groups thereof.
[0091] It should be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of this disclosure.
[0092] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe the relationship of one element to another, as shown in the figures. It should be understood that these terms and those discussed above are intended to encompass different device orientations in addition to the orientations depicted in the figures. It should be understood that when an element is referred to as being "connected" or "coupled" to another element, the element can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.
[0093] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It should also be understood that, unless otherwise explicitly defined herein, the terms used herein should be interpreted as having the same meaning as in the context of this specification and the relevant art, and should not be interpreted in an idealized or overly formal sense.
[0094] It should be understood that the present disclosure is not limited to the aspects described above and shown in the accompanying drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and the appended claims. In the drawings and description, various aspects have been disclosed for illustrative purposes only and not for purposes of limitation, the scope of the disclosure being set forth in the appended claims.
Claims
1. A transmission device for a vehicle, the transmission device comprising: a first input shaft drivably connected to a first electric traction motor, the first input shaft including a first input shaft gear wheel rotationally fixed to the first input shaft; a second input shaft drivably connected to a second electric traction motor, the second input shaft including a second input shaft gear wheel rotationally fixed to the second input shaft; a propeller shaft drivably connected to a pair of wheels of the vehicle, the propeller shaft comprising a propeller gear wheel fixed to the propeller shaft in a steering manner, the propeller gear wheel being arranged to meshingly engage with the first input shaft gear wheel; and a layshaft comprising a first layshaft gear wheel arranged to meshingly engage with the propeller gear wheel, and a second layshaft gear wheel arranged to meshingly engage with the second input shaft gear wheel, wherein the second input shaft is drivably connected to the propeller shaft via the layshaft. 2 . The transmission of claim 1 , further comprising a layshaft clutch arranged to selectively drivingly connect the second input shaft to the propeller shaft.
3. A transmission according to claim 2, wherein the countershaft clutch is arranged to selectively rotationally connect the second countershaft gearwheel to the countershaft.
4. A transmission according to any preceding claim, wherein the second layshaft gear wheel is supported to the layshaft by bearing means.
5. A transmission arrangement according to claim 4, wherein the bearing arrangement is a needle bearing arrangement.
6. The transmission of claim 2, wherein the countershaft clutch is arranged to selectively rotationally connect the first countershaft gearwheel to the countershaft.
7. A transmission according to any of the preceding claims, wherein the second input shaft gearwheel and the second countershaft gearwheel form a first reduction gear stage, in which the second input shaft gearwheel rotates at a higher speed than the second countershaft gearwheel during operation of the transmission.
8. A transmission according to any one of the preceding claims, further comprising a first planetary gear set, the first planetary gear set comprising a first sun gear, a first ring gear and a first planet carrier carrying a first set of planetary gears, the first set of planetary gears being meshedly engaged with the first ring gear and the first sun gear, wherein the first sun gear and the first ring gear are rotatably connected to the transmission shaft, and wherein the first planet carrier is rotatably connected to the output shaft.
9. The transmission of claim 8, wherein the first sun gear of the first planetary gear set is rotatably connected to the transmission shaft via a second clutch of the transmission.
10. A transmission according to any one of claims 8 or 9, wherein the first ring gear of the first planetary gear set is rotationally connectable to the transmission shaft via a third clutch of the transmission. 11 . The transmission of claim 10 , wherein the first ring gear of the first planetary gear set is rotatably connected to the stationary member via the third clutch. 12 . The transmission according to claim 8 , further comprising a crawler unit comprising a plurality of gear members, wherein the crawler unit is drivably connectable between the first planetary gear set and the output shaft via a first clutch.
13. The transmission of claim 12 , wherein the first clutch is configured to rotationally connect one of the plurality of gear members of the crawler unit to the first ring gear, the first planet carrier, or one of the fixed members of the transmission so as to cause the first ring gear to rotate in a direction opposite to a direction of rotation of the first planet carrier.
14. A transmission device according to any one of claims 12 or 13, wherein the crawling unit includes a second planetary gear set, the multiple gear components of the crawling unit include a second sun gear, a second ring gear and a second planet carrier carrying a second set of planetary gears, and the second set of planetary gears are meshed with the second ring gear and the second sun gear.
15. The transmission of claim 14, wherein the second sun gear is rotationally connected to the first ring gear.
16. A transmission according to any one of claims 14 or 15, wherein the second ring gear is rotationally connected to the first planet carrier.
17. The transmission according to any one of claims 14 to 16, wherein the second planet carrier is rotationally connectable to the fixed member of the transmission via the first clutch of the crawler unit.
18. A transmission according to any one of the preceding claims, wherein the first input shaft and the second input shaft are arranged parallel to each other and at radially spaced positions.
19. A transmission system device, comprising: A first electric traction motor, a second electric traction motor and a transmission as claimed in any one of the preceding claims, wherein the first electric traction motor is drivingly connected to the first input shaft and the second electric traction motor is drivingly connected to the second input shaft.
20. The drivetrain arrangement of claim 19, wherein the first input shaft includes a first end position and a second end position, the first input shaft gear wheel is disposed proximate the first end position, and the first electric traction motor is drivingly connected to the first input shaft at the second end position.
21. A driveline arrangement according to any one of claims 19 or 20, wherein the second input shaft comprises a first end position and a second end position, the second input shaft gear wheel being arranged adjacent the first end position, and the second electric traction motor being drivingly connected to the second input shaft at the second end position.
22. The drive train arrangement of claims 20 and 21, wherein the first end position of the first input shaft and the first end position of the second input shaft are oriented axially opposite to each other.
23. A vehicle comprising a transmission arrangement according to any one of claims 1 to 18 or a driveline arrangement according to any one of claims 19 to 22.