Drive unit and vehicle

Abstract

The invention relates to a drive unit (1) for a vehicle (20), comprising a deceleration group (4) and a main transmission (5), at least two electric motors (7.1, 7.2) being mounted on the deceleration group (4), each electric motor acting on a separate torque path (8.1, 8.2), each torque path engaging with one of the two main shafts (9.1, 9.2) in the main transmission (5), at least two movable gears (Z1-Z4) run on each of the main shafts (9.1, 9.2) and are configured to mesh with fixed gears (Z5, Z6) running on a countershaft (10) of the main transmission (5), each of the fixed gears (Z5, Z6) being configured to mesh with a respective movable gear (Z1-Z4) of each of the main shafts (9.1, 9.2), and each of the fixed gears (Z5, Z6) being configured to mesh with a respective movable gear (Z1-Z4) of each of the main shafts (9.1, 9.2). And each fixed gear (Z5 and Z6) is configured to be meshed with one corresponding movable gear (Z1-Z4) of each main shaft (9.1 and 9.2) at the same transmission ratio.

Description

Field of the Invention

[0001] The present invention relates to a drive unit for a vehicle according to the preamble of claim 1 and to a vehicle according to claim 9. Background Art

[0002] DE 10 2013 218 454 A1 describes a transmission for a motor vehicle, in particular a dual-clutch transmission, comprising at least two partial transmissions, wherein each partial transmission comprises at least one input shaft, and wherein an output shaft is arranged as a common driven shaft of the two partial transmissions, wherein the at least one input shaft lies on an input shaft axis, the driven shaft lies on the input shaft axis or on a countershaft axis which is in particular parallel to the input shaft axis, and wherein a countershaft transmission with at least one countershaft is provided, wherein the at least one countershaft lies on a countershaft axis, and wherein a plurality of shifting mechanisms are provided, and wherein at least one of the at least one input shaft can be connected to the driven shaft by means of at least two gear planes and / or at least one shifting element of one of the shifting mechanisms, wherein two solid shafts on the input shaft axis can be directly engaged by means of a shifting element, and wherein on the countershaft axis there can be arranged:

[0003] a) a shifting mechanism comprising a single shifting element, or

[0004] b) a shifting mechanism comprising two shifting elements, the shifting mechanism being connected to a countershaft designed as a hollow shaft, wherein the countershaft cooperates with at least two gear planes which have transmission elements on the same axis as the input shaft axis, or

[0005] c) two or more shifting mechanisms. Summary of the Invention

[0006] The object of the present invention is to specify a novel drive unit for a vehicle and a novel vehicle.

[0007] According to the present invention, the object is achieved by a drive unit for a vehicle having the features of claim 1 and by a vehicle having the features of claim 9.

[0008] Advantageous designs of the present invention are the subject matter of the dependent claims.

[0009] The drive unit for a vehicle according to the present invention has a reduction gear and a main transmission. At least two electric motors are mounted on the reduction gear, each acting on an independent torque path, and each torque path engages with one of two main shafts in the main transmission. At least two moving gears run on each of the main shafts, and they are configured to mesh with one of at least two fixed gears running on the countershaft of the main transmission. Each of the fixed gears is configured to mesh with one of the moving gears on each main shaft respectively. According to the present invention, each of the fixed gears is configured to mesh with one of the moving gears on each main shaft at the same transmission ratio. For example, thus the even gears of the main transmission can be achieved on one of the main shafts, and the odd gears can be achieved on the other main shaft. The solution according to the present invention allows for multiple uses of the same gear variant, and the main shafts with the same structure can be adopted.

[0010] In one embodiment, the transmission ratio of one of the moving gears on each main shaft relative to its corresponding fixed gear "is" the reciprocal of the transmission ratio of the other moving gears on the same main shaft relative to their corresponding fixed gears. In this way, the number of gear variants used can be further reduced.

[0011] In one embodiment, there is a difference ratio of the transmission ratios between the two torque paths of the reduction gear. Therefore, the total transmission ratio from one of the electric motors to the countershaft is different from the total transmission ratio from the other electric motor to the countershaft. Thus, although the moving gears corresponding to the same fixed gear on the two main shafts have the same transmission ratio, different total transmission ratios can be achieved by switching the moving gears, for example, for the first and second gears, or for the third and fourth gears.

[0012] In one embodiment, each of the two torque paths is equipped with a structurally identical drive pinion, and the electric motors are respectively meshed with the corresponding drive pinions by driven pinions of different sizes. Therefore, only five gear variants are required.

[0013] In one embodiment, the countershaft is connected to a rear transmission, and the rear transmission has at least two shift positions with different transmission ratios. In this way, the number of shiftable gears is doubled. This can be used to distinguish usage forms, such as off-road and on-road.

[0014] In one embodiment, the rear transmission has a planetary gear train, which includes a central gear, a ring gear, and a planetary gear set. In a certain shift position, the central gear and the ring gear are interlocked together, so the planetary gear set rotates at a transmission ratio of 1. This shift position is particularly suitable for road / paved road scenarios. At this time, there is no gear rolling in the rear transmission, making the power transmission of the drive unit very efficient.

[0015] In one embodiment, at least one power take-off can be arranged on the drive unit, particularly on the driven wheel of at least one of the motors and / or on the driving wheel of at least one of the torque paths of the speed reducer and / or on one of the driving gears of the main transmission.

[0016] In one embodiment, the retarder is connected to the drive unit, particularly to the universal shaft at the output end of the drive unit.

[0017] According to one aspect of the present invention, a vehicle is proposed, which includes at least one driven shaft and the above-mentioned drive unit, wherein the drive unit is connected to the driven shaft through the universal shaft at the output end of the drive unit.

[0018] In one embodiment, the vehicle can be designed as a commercial vehicle.

[0019] By adjusting the speed reducer, motors with different characteristics and structural dimensions can be applied without redesigning the entire drive unit.

[0020] Through the solution according to the present invention, multiple gear types can be adopted. In particular, the two main shafts can have the same structure as each other.

[0021] The drive unit according to the present invention covers two application scenarios distinguished by a rear-mounted transmission, for example: off-road (focusing on driving performance) and on-road (focusing on efficiency).

[0022] The drive unit according to the present invention is applicable to construction vehicles of different scales (with large differences, such as 20 tons to 120 tons), for example. The drive unit can achieve sequential power shifting in various application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The embodiments of the present invention will be explained in detail below in conjunction with the drawings, wherein:

[0024] Figure 1 A schematic diagram showing an embodiment of a drive unit for a vehicle,

[0025] Figure 2 A schematic diagram showing another embodiment of a drive unit for a vehicle,

[0026] Figure 3 A schematic diagram showing a vehicle.

[0027] Corresponding components are labeled with the same reference numerals in all the figures. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Figure 1 is for a vehicle 20 (see Figure 3Schematic diagram of an embodiment of the drive unit 1, particularly suitable for heavy commercial vehicles that can travel off-road and on roads / paved surfaces. The drive unit 1 is mounted to the axle 3 (such as the rear axle) of the vehicle 20 via a cardan shaft 2 with a suitable transmission ratio. With this configuration, the drive unit 1 can drive, for example, vehicles with a gross mass of 20 to 120 tons.

[0029] The axle 3 can, for example, have a differential transmission 14.

[0030] The drive unit 1, for example, adopts a geometric stepped design and has three sub-assemblies: a reduction gear 4, a main transmission 5, and a rear transmission 6. At least two electric motors 7.1, 7.2 are mounted on the reduction gear 4. The power of the electric motors 7.1, 7.2 is distributed via the reduction gear 4 to two independent torque paths 8.1, 8.2 and converted into the desired speed / torque ratio. These two independent torque paths 8.1, 8.2 then connect to the main transmission 5. The main transmission 5 has two main shafts 9.1, 9.2 and a countershaft 10.

[0031] The main shafts 9.1, 9.2 are differentiated as follows: All even-numbered or even gears G2, G4 are configured on one of the main shafts 9.2, and all odd-numbered or odd gears G1, G3 are configured on the other main shaft 9.1. In the main transmission 5, each pair of even gears G2, G4 and odd gears G1, G3 has the same transmission ratio and meshes with the same fixed gears Z5, Z6 on the countershaft 10. The main transmission 5 can be switched completely sequentially and without power interruption by this arrangement. The two main shafts 9.1, 9.2 can have exactly the same structure, so common parts can be used. The countershaft 10 then transmits the resultant torque to the rear transmission 6. The rear transmission 6 has two shift positions: a low position (short / large transmission ratio) and a high position (long / small transmission ratio). The low shift position is set for off-road operation and starting with a large tonnage. The high shift position is mainly set for road applications. The rear transmission 6 has a planetary gear transmission mechanism, which includes a sun gear 11, a ring gear 12, and a planetary gear set 13. In the high shift position, the sun gear 11 and the ring gear 12 are interlocked as a whole, and the planetary gear set 13 rotates at a transmission ratio of 1.

[0032] In particular, two motors 7.1, 7.2 with the same structure can be provided. Additionally, the motors 7.1, 7.2 can be designed to directly drive the reduction gear 4, or drive it through a reduction device. It is also conceivable that one of the motors 7.1 is designed for direct drive, and the other motor is designed to drive through a reduction device. The characteristics of the motors 7.1, 7.2 are designed such that their peak power is approximately equal to 70% of the continuous power. The reduction gear 4 converts the torque and rotational speed to the input end of the main transmission 5. The characteristic in this case is that there is a gear ratio jump between the two torque paths 8.1, 8.2 of the reduction gear 4. That is, with the same driving pinions in the torque paths 8.1, 8.2, the driven pinions of the motors 7.1, 7.2 have different sizes (a total of three different gears). Therefore, in the main transmission 5, the transmission ratios of the first and second gears G1, G2 are the same, and the transmission ratios of the third and fourth gears G3, G4 are the same, where the transmission ratios of the third and fourth gears G3, G4 can be the reciprocal of the transmission ratios of the first and second gears G1, G2. Each of the four gears G1, G2, G3, G4 consists of a pair of gears, where one gear is the driving gear Z1 - Z4 on each main shaft 9.1, 9.2, and the other gear is the fixed gear Z5, Z6 on the countershaft 10. Theoretically, 8 gears are required, but the number can be reduced to 6. Specifically, on the countershaft 10: one gear designed as the fixed gear Z5 meshes with the gear designed as the driving gear Z1 for the first gear G1 and the gear designed as the driving gear Z2 for the second gear G2 at the same time, and the other gear designed as the fixed gear Z6 meshes with the gear designed as the driving gear Z3 for the third gear G3 and the gear designed as the driving gear Z4 for the fourth gear G4 at the same time. The transmission ratios of the first and second gears G1, G2 are the same, and the transmission ratios of the third and fourth gears G3, G4 are the same, thereby achieving double tooth meshing of the fixed gears Z5, Z6 at the same wheelbase / center distance. In this way, two gears are saved. The remaining six gears only require two gear variant forms.

[0033] This means that a total of five gear variants are used, namely, three gear variants for the reduction gear 4 and two gear variants for the main transmission 5. The countershaft 10 is connected to a switchable planetary gear set 13. It meets the range of driving performance requirements for the vehicle 20 to operate in off - road and on - road modes.

[0034] The low gear position (short / large transmission ratio) is suitable for off - road applications, especially for starting on loose ground, large slopes, and / or high climbing angles. The high gear position (long transmission ratio = 1) is especially used in on - road applications. At this time, there is no longer gear rolling, making the power transmission of the drive unit 1 very efficient.

[0035] Through the drive unit 1 of the present invention, eight gears can be achieved using five gear variants and a planetary gear transmission mechanism, where four are off - road gears and four are on - road gears.

[0036] In an exemplary embodiment, the gears used, their number of teeth n, and the corresponding transmission ratios i are as follows:

[0037] - Driven gear of motor 7.1: n = 27

[0038] - Driving gear of torque path 8.1: n = 102

[0039] - Transmission ratio of torque path 8.1: i = 3.788

[0040] - Driven gear of motor 7.2: n = 27

[0041] - Driving gear of torque path 8.2: n = 53

[0042] - Transmission ratio of torque path 8.2: i = 1.988

[0043] - Moving gears Z1, Z2: n = 26

[0044] - Fixed gear Z5: n = 49

[0045] - Transmission ratio of gears G1 and G2: i = 1.884

[0046] - Moving gears Z3, Z4: n = 49

[0047] - Fixed gear Z5: n = 26

[0048] - Transmission ratio of gears G3 and G4: i = 0.510

[0049] - Ring gear 12: n = 90

[0050] - Central gear 11: n = 25

[0051] - Planetary gear set: n = 31

[0052] - Transmission ratio in low gear position: i = 4.6

[0053] - Transmission ratio in high gear position: i = 1

[0054] Figure 2 is a schematic view of a drive unit 1 with an exemplary power take-off mPTO.

[0055] The drive unit 1 can be equipped with one or more power take-offs mPTO (especially motor PTO, transmission PTO, side-mounted PTO, shaft-mounted PTO), which can engage with the following components:

[0056] - At least the driven gear of one of the motors 7.1, 7.2,

[0057] - The driving wheel of at least one of the torque paths 8.1, 8.2 of the speed reducer 4, and / or

[0058] - One of the driving gears Z1-Z4 of the main transmission 5.

[0059] Additionally, a retarder R may be provided, which can be engaged with the cardan shaft 2, for example.

[0060] Figure 3 is a schematic view of a vehicle 20, such as a commercial vehicle, especially a heavy commercial vehicle, which may have a driven shaft 3 and the above-mentioned drive unit 1, wherein the drive unit 1 is connected to the shaft 3 via a cardan shaft 2.

[0061] List of reference signs

[0062] 1 Drive unit

[0063] 2 Cardan shaft

[0064] 3 Shaft

[0065] 4 Speed reducer

[0066] 5 Main transmission

[0067] 6 Rear transmission

[0068] 7.1 Electric motor

[0069] 7.2 Electric motor

[0070] 8.1 Torque path

[0071] 8.2 Torque path

[0072] 9.1 Main shaft

[0073] 9.2 Main shaft

[0074] 10 Countershaft

[0075] 11 Sun gear

[0076] 12 Ring gear

[0077] 13 Planetary gear set

[0078] 14 Differential transmission

[0079] 20 Vehicle

[0080] G1 gear

[0081] G2 gear

[0082] G3 gear

[0083] G4 gear

[0084] mPTO power take-off

[0085] R retarder

[0086] Z1-Z4 driving gears

[0087] Z5, Z6 fixed gears

Claims

1. A drive unit (1) for a vehicle (20), having a reduction gear set (4) and a main transmission (5), wherein, At least two motors (7.1, 7.2) are mounted on the reduction gear set (4), and each motor acts on an independent torque path (8.1, 8.2). Each of the torque paths engages with one of two main shafts (9.1, 9.2) in the main transmission (5). At least two moving gears (Z1-Z4) run on each of the main shafts (9.1, 9.2), and the moving gears are configured to mesh with fixed gears (Z5, Z6) running on the countershaft (10) of the main transmission (5). Each of the fixed gears (Z5, Z6) is configured to mesh with one of the corresponding moving gears (Z1-Z4) of each of the main shafts (9.1, 9.2), Characterized in that each of the fixed gears (Z5, Z6) is configured to mesh with one of the corresponding moving gears (Z1-Z4) of each of the main shafts (9.1, 9.2) with the same transmission ratio.

2. The drive unit (1) according to claim 1, characterized in that, The transmission ratio of one of the moving gears (Z1-Z4) of each of the main shafts (9.1, 9.2) relative to its corresponding fixed gear (Z5, Z6) is the reciprocal of the transmission ratio of the other moving gears (Z1-Z4) on the same main shaft (9.1, 9.2) relative to their corresponding fixed gears (Z5, Z6).

3. The drive unit (1) according to claim 1 or 2, characterized in that, There is a gear shift jump ratio between the two torque paths (8.1, 8.2) of the reduction gear set (4).

4. The drive unit (1) according to claim 3, characterized in that, The two torque paths (8.1, 8.2) are each equipped with a pinion with the same structure, and the motors (7.1, 7.2) are meshed with the corresponding pinions with driven pinions of different sizes.

5. The drive unit (1) according to one of the preceding claims, characterized in that, The countershaft (10) is connected to a rear transmission (6), and the rear transmission has at least two shift positions with different transmission ratios.

6. The drive unit (1) according to claim 5, characterized in that, The rear transmission (6) has a planetary gear transmission mechanism, which includes a central gear (11), a ring gear (12) and a planetary gear set (13). In one of the shift positions, the central gear (11) is interlocked with the ring gear (12) to make the planetary gear set (13) rotate at a transmission ratio of 1.

7. The drive unit (1) according to one of the preceding claims, characterized in that, At least one power take-off (mPTO) is provided on the drive unit (1), especially on the driven wheel of at least one of the motors (7.1, 7.2) and / or the driving wheel of at least one of the torque paths (8.1, 8.2) of the reduction gear set (4) and / or one of the moving gears (Z1-Z4) of the main transmission (5).

8. The drive unit (1) according to one of the preceding claims, characterized in that, The retarder (R) is connected to the drive unit (1), especially to the universal shaft (2) at the output end of the drive unit (1).

9. A vehicle (20), comprising at least one driven shaft (3) and a drive unit (1) according to one of the preceding claims, characterized in that, The drive unit (1) is connected to the shaft (3) through the universal shaft (2) at the output end of the drive unit (1).

10. The vehicle (20) according to claim 9, characterized in that, The vehicle (20) is designed as a commercial vehicle.

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