Motor gearbox arrangement

Abstract

An electric motor gearbox arrangement comprising a gearbox (3) comprising: a first input (4); a second input (5); an output (6); a plurality of epicyclic gears (9, 10, 11) each comprising: a sun gear (9a, 10a, 11a); a carrier (9b, 10b, 11b); a plurality of planet gears (9c, 10c, 11c) carried on the carrier and each engaging the sun gear (9a, 10a, 11a); and a ring gear (9d, 10d, 11d) engaging each of the planet gears (9c, 10c, 11c); and a plurality of clutches (12, 13, 14, 15) arranged to selectively couple the first input (4) and the second input (5) to the output (6) through the plurality of epicyclic gears (9, 10, 11); the electric motor gearbox arrangement further comprising: a first electric motor (1) coupled to the first input (4) to rotate the first input (4); and a second electric motor (2) coupled to the second input (5) to rotate the second input (5); wherein the clutches (12, 13, 14, 15) and the epicyclic gears (9, 10, 11) define a plurality of states of the gearbox, wherein in each state the first input (4) and the second input (5) are coupled to the output (6) through at least one of the epicyclic gears (9, 10, 11) to form a gear train, the plurality of states differing from one another in at least one of a selection of the epicyclic gears (9, 10, 11) forming the gear train and a selection of components of each epicyclic gear (9, 10, 11) connected to the inputs and the output and other epicyclic gears of the gear train. Typically, there is a transmission ratio in the gearbox that varies depending on a rotational speed of the second input (5), and there is at least a pair of states such that at a crossover rotational speed of the second input (5) the transmission ratio of the gearbox is the same for the pair of states.

Description

Technical Field

[0001] The present invention relates to an electric motor gearbox device and a method for controlling such an electric motor gearbox device. Background Technology

[0002] A continuously variable transmission (CVT) is an efficient way to provide traction to a vehicle because it delivers continuous torque and power to the wheels across the entire speed range without interrupting the transmission. The transmission is always able to operate at the optimal speed and power required to meet the specific traction requirements of the vehicle.

[0003] The need to reduce diesel emissions, particularly in commercial vehicles operating in urban environments, has opened up new markets for high-power, high-torque CVTs, especially for electric or hybrid vehicles. Summary of the Invention

[0004] According to a first aspect of the present invention, an electric motor gearbox device is provided, comprising a gearbox, the gearbox including:

[0005] First input;

[0006] Second input;

[0007] Output;

[0008] Multiple planetary gears, each comprising the following components:

[0009] Sun gear;

[0010] Planetary support;

[0011] A plurality of planetary gears mounted on the planet carrier and each meshing with the sun gear; and

[0012] The ring gear meshing with each of the planetary gears; and

[0013] Multiple clutches are arranged to selectively connect the first input and the second input to the output via multiple rotary gears;

[0014] The electric motor gearbox assembly further includes:

[0015] A first electric motor, connected to the first input to rotate the first input; and

[0016] A second electric motor is connected to the second input to rotate the second input;

[0017] The clutch and the planetary gear define multiple states of the gearbox, wherein in each state, the first input and the second input are coupled to the output via at least one of the planetary gears to form a gear train, and the multiple states differ from each other in at least one selection of the planetary gears forming the gear train and the selection of the components of each planetary gear connected to the input and the output as well as other planetary gears of the gear train.

[0018] Therefore, this electric motor gear unit can provide a continuously variable transmission (CVT) in which the second electric motor can change the gearbox's transmission ratio. Thus, the first electric motor can operate at its optimal speed and power. Therefore, the gearbox can have a transmission ratio that is the number of rotations of the output relative to a single rotation of the first input. The transmission ratio can vary depending on the second input and the rotational speed of the selected gear unit.

[0019] There can exist at least one pair of states such that, at the cross rotational speed of the second input, the gearbox transmission ratio is the same for that pair of states. The states can form a sequence from a first state through at least one intermediate state to a final state, with each intermediate state forming a pair with the state preceding and following it in the sequence. Typically, each pair of states causes the transmission ratio to vary with the rotational speed of the second input in opposite directions in each state of the pair (such that increasing the rotational speed in the first direction increases the transmission ratio in one state of each pair, but decreases it in another).

[0020] Therefore, the state can provide a wider range of transmission ratios compared to a second motor with a single state and a given speed range, and allows switching between ranges (i.e., under load arrangement) without disconnecting the output from the first and second inputs.

[0021] The device may include a brake for at least one of the planetary gears, the brake being selectively applied to selectively brake a component of the planetary gear. At least one state may differ from another depending on whether the brake brakes a component. Therefore, each brake may also be used to change the gear ratio of the gearbox.

[0022] An electric motor geared device can represent a fully electric drive. The device may include an electrical power source for a first electric motor and a second electric motor, the power source including a battery, fuel cell, or generator.

[0023] The planetary gears may include a first planetary gear, a second planetary gear, and a third planetary gear, as well as a first clutch, a second clutch, a third clutch, and a fourth clutch. A first input may be connected to the planet carrier of the first planetary gear and the ring gear of the second planetary gear. A second input may be connected to the sun gear of the first planetary gear and the second planetary gear.

[0024] The first clutch selectively connects the planetary carrier of the second planetary gear to the sun gear of the third planetary gear. The second clutch selectively connects the ring gear of the first planetary gear to the sun gear of the third planetary gear. The third clutch selectively connects the planetary carrier of the second planetary gear to the output. The fourth clutch selectively connects the ring gear of the first planetary gear to the planetary carrier of the third planetary gear. The ring gear of the third planetary gear may be equipped with a brake. The planetary carrier of the third planetary gear may be connected to the output.

[0025] In the first state, the first clutch engages to connect the planetary carrier of the second planetary gear to the sun gear of the third planetary gear, and the second, third, and fourth clutches disengage to disengage any components, and the brake of the ring gear of the third planetary gear brakes the ring gear of the third planetary gear.

[0026] In this state, the first and second motors can increase from zero speed to maximum speed in different directions, with the rotation of the second motor in the first direction reducing the rotation of the first motor in the second opposite direction. Once the first and second motors reach their maximum speeds, the speed of the second motor can be reduced to zero and then increased to its maximum speed in the second direction to increase the transmission ratio and thus increase the output speed (considering that the speed of the first motor will now be constant).

[0027] In the second state, the second clutch engages to connect the ring gear of the first planetary gear to the sun gear of the third planetary gear, wherein the first clutch, the third clutch, and the fourth clutch disengage so as not to engage any components, and the brake of the ring gear of the third planetary gear brakes the ring gear of the third planetary gear.

[0028] This state typically forms a pair with the first state. Then, the transmission ratio will be the same as in the first state when the second motor is at its maximum speed in the second direction. Reducing the rotational speed of the second motor to zero and then increasing it to its maximum speed in the first direction further increases the transmission ratio, and thus increases the output speed.

[0029] In the third state, the third clutch engages to connect the planetary carrier of the second planetary gear to the output, and the first, second, and fourth clutches disengage so that no components are engaged. Typically, the brake on the ring gear of the third planetary gear is released.

[0030] This state typically forms a pair with the second state. The transmission ratio will then be the same as in the second state when the second motor is at its maximum speed in the first direction. Reducing the rotational speed of the second motor to zero and then increasing it to its maximum speed in the second direction further increases the transmission ratio, and thus increases the output speed.

[0031] In the fourth state, the fourth clutch engages to connect the ring gear of the first planetary gear to the planetary carrier of the third planetary gear, and the second, third, and fourth clutches disengage so that no components are engaged. Typically, the brake on the ring gear of the third planetary gear is released.

[0032] This state typically forms a pair with the third state. The transmission ratio will then be the same as in the third state when the second motor is at its maximum speed in the second direction. Reducing the rotational speed of the second motor to zero and then increasing it to its maximum speed in the first direction further increases the transmission ratio, and thus increases the output speed.

[0033] The first and second motors can be mounted coaxially relative to each other, such that the output of one motor rotates within the output of the other motor, where the outputs of each motor are coaxial. This can result in a particularly compact device.

[0034] According to a second aspect of the present invention, a method for controlling an electric motor gearbox device according to a first aspect of the present invention is provided, the method comprising changing the rotational speed of a second electric motor in order to change the gearbox transmission ratio.

[0035] With first to third planetary gears and first to fourth clutches provided, the method may include operating the motor gearbox assembly sequentially in the first to fourth states. Typically, the method will include starting with both inputs at rest and the motor gearbox assembly in the first state. The method will then include increasing the rotational speed of the second input from zero to a maximum speed in a first direction, while simultaneously increasing the rotational speed of the first input from zero to a maximum speed in a second direction. The method may then include, while the first input remains at its maximum speed, reducing the speed of the second input to zero, and then reducing it to the maximum speed in the first direction.

[0036] The method may then include placing the device in a second state and reducing the speed of the second input to zero, and then to a maximum speed in a second direction. The method may then include placing the device in a third state and reducing the speed of the second input to zero, and then to a maximum speed in a first direction. The method may then include placing the device in a fourth state and reducing the speed of the second input to zero, and then to a maximum speed in a second direction. Attached Figure Description

[0037] Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

[0038] Figure 1 A schematic diagram of an electric motor gearbox device according to a first embodiment of the present invention is shown;

[0039] Figure 2 It shows Figure 1 A perspective view of the electric motor gearbox assembly;

[0040] Figure 3 It shows Figure 1 A cross-sectional view of the electric motor gearbox assembly;

[0041] Figure 4 and 5 The first state is shown respectively. Figure 1 A schematic diagram and cross-sectional view of an electric motor gearbox assembly;

[0042] Figure 6 and 7 The second state is shown respectively. Figure 1 A schematic diagram and cross-sectional view of an electric motor gearbox assembly;

[0043] Figure 8 and 9 The third state is shown respectively. Figure 1 A schematic diagram and cross-sectional view of an electric motor gearbox assembly;

[0044] Figure 10 and 11 The fourth state is shown respectively. Figure 1 A schematic diagram and cross-sectional view of an electric motor gearbox assembly;

[0045] Figure 12 It shows Figure 1 Typical curves of torque, speed, and power of an electric motor gearbox assembly;

[0046] Figure 13 A perspective view of an electric motor gear assembly according to a second embodiment of the present invention is shown;

[0047] Figure 14It shows Figure 13 A partial sectional view of the electric motor gear assembly;

[0048] Figure 15 It shows that it is equipped with Figure 13 Side view of a heavy-duty truck with an electric motor and gear system;

[0049] Figure 16 It shows Figure 15 The plan view of the vehicle shown indicates that the electric motor and gear unit are in the appropriate position; and

[0050] Figure 17 and 18 It is installed Figure 13 electric motor gear mechanism Figure 15 Efficiency curves of different electric motor speeds and torques for vehicles. Detailed Implementation

[0051] Please refer to the attached diagram. Figures 1 to 12 A motor gearbox device according to a first embodiment of the present invention is described, which provides a continuously variable transmission (CVT). In this embodiment, the motor gearbox device is based on two motors: a first main motor 1 and a second reaction motor 2. These motors can be powered by any suitable means, but may typically be powered by a generator powered by a gasoline or diesel internal combustion engine, a hydrogen fuel cell combined with a battery, or solely by a battery.

[0052] The electric motor gearbox assembly includes a gearbox 3 having a first input 4 connected to the rotor of a first electric motor 1 and a second input 5 connected to the rotor of a second electric motor 2. The gearbox also has an output 6 that may typically be connected to the road wheels of the vehicle.

[0053] The first input 4 is equipped with a reduction gear 7; similarly, the second input 5 is equipped with a reduction gear 8. As will be discussed in more detail, these reduction gears 7 and 8 are connected to a set of rotating gears 9, 10, and 11.

[0054] The planetary gear system includes a first planetary gear 9, a second planetary gear 10, and a third planetary gear 11. Each planetary gear has a sun gear 9a, 10a, 11a, a planet carrier 9b, 10b, 11b that carries multiple planetary gears 9c, 10c, 11c that mesh with the sun gears 9a, 10a, 11a, and an annular gear 9d, 10d, 11d that mesh with the planetary gears 9c, 10c, 11c. A first clutch 12, a second clutch 13, a third clutch 14, and a fourth clutch 15 are also provided.

[0055] The first reduction gear 7 is connected to the planet carrier 9b of the first planetary gear 9 and the ring gear 10d of the second planetary gear 10. The second reduction gear 8 is connected to the sun gears 9a and 10a of the first planetary gear 9 and the second planetary gear 10.

[0056] The first clutch 12 selectively engages the planet carrier 10b of the second planetary gear 10 to the sun gear 11a of the third planetary gear 11. The second clutch 13 selectively engages the ring gear 9d of the first planetary gear 9 to the sun gear 11a of the third planetary gear 11. The third clutch 14 selectively engages the planet carrier 10b of the second planetary gear 10 to the output 6. The fourth clutch selectively engages the ring gear 9d of the first planetary gear 9 to the planet carrier 11b of the third planetary gear 11. The ring gear 11d of the third planetary gear 11 is equipped with a brake 16 for selectively braking the component. The planet carrier 11b of the third planetary gear 11 is engaged to the output 6.

[0057] Regarding the attached diagram... Figures 4 to 12 This demonstrates the operation of this electric motor gearbox device. The electric motor gearbox device has four states, which can be used in conjunction with gradually increasing output speeds, from... Figure 4 and 5 The first state, shown in the attached diagram, begins at zero output speed. Figure 12 The graph shown is used to help understand the various states; the trace is as follows:

[0058] ●Trace 30 shows the speed of the first electric motor 1;

[0059] ●Trace 31 shows the power consumption of the second motor 2;

[0060] ●Trace 32 shows the torque at output 6;

[0061] ●Trace 33 shows the power at output 6;

[0062] ●Trace 34 shows the speed of the second motor 2; and

[0063] ●Trace 35 indicates the speed of output 6.

[0064] The first state is shown in the attached diagram. Figure 4 and 5As shown, the process begins with both motors 1 and 2 at zero speed. The first clutch 12 engages (the other clutches 13, 14, and 15 disengage). This connects the second rotary gear 10 and the third rotary gear 11 between the first reduction gear 7 and the second reduction gear 8 and the output 6. A brake 16 is applied to secure the ring gear 11d of the third rotary gear. If the first motor 1 and the second motor 2 are driven in opposite directions (e.g., the second motor 2 in the first direction and the first motor 1 in the second direction) at gradually increasing speeds, the speed of the second motor will cause the speed of the first motor to decrease, thereby reducing the speed of the output 6. This is in... Figure 12 The interval is shown as 36. The third rotating gear 11 further reduces the output speed (in a fixed manner).

[0065] Once the maximum speed of the first motor 1 and the second motor 2 is reached, the first motor 1 maintains a constant speed throughout the subsequent process. The motor gearbox assembly remains... Figure 4 and 5 In the first state shown, to increase the gearbox's transmission ratio (and thus increase the output speed while keeping the speed of the first motor 1 constant), the speed of the second motor is reduced to zero (thus reducing the speed reduction caused by the second motor) and increased to the maximum speed in the second direction (now increasing the speed of output 6). This is in Figure 12 The interval shown is 37.

[0066] Once the second electric motor 2 reaches its maximum speed in the second direction, the electric motor gearbox assembly reaches a second state (described below) with the same gear ratio as the first state. At this speed, the second clutch 13 engages, and the transmission momentarily locks into a fixed gear ratio. Then, the first clutch 12 is released.

[0067] exist Figure 6 and 7 In the second state shown, the second clutch 13 is engaged, but the other clutches 12, 14, and 15 are not engaged. This connects the first rotary gear 10 between the reduction gears 7 and 8 and the third rotary gear 11, replacing the second rotary gear 10. Brake 16 is applied.

[0068] When the second motor 2 initially operates at its maximum speed in the second direction, its speed can be reduced to zero, thereby increasing the speed of output 6 and increasing it to its maximum speed in the first direction, thus further increasing the speed of output 6. This is in Figure 12 The interval shown is 38.

[0069] Once the second electric motor 2 reaches its maximum speed in the first direction, the electric motor gearbox assembly enters a third state (described below) with the same gear ratio as the second state. At this speed, the third clutch 14 engages, and the transmission momentarily locks into a fixed gear ratio. Then, the second clutch 13 is released.

[0070] exist Figure 8 and 9 In the third state shown, the third clutch 14 is engaged, but the other clutches 12, 13, and 15 are not engaged. The brake 16 is released. This arrangement connects the second rotary gear 10 between the reduction gears 7 and 8 and the output 6, bypassing the first rotary gear 9 and the third rotary gear 11. This eliminates the speed reduction caused by the third rotary gear.

[0071] When the second motor 2 initially operates at its maximum speed in the first direction, its speed can be reduced to zero, thereby increasing the speed of output 6, and then increasing it to its maximum speed in the second direction, thus further increasing the speed of output 6. This is in Figure 12 The interval shown is 39.

[0072] Once the second electric motor 2 reaches its maximum speed in the second direction, the electric motor gearbox assembly enters the fourth state (described below), which has the same gear ratio as the third state. At this speed, the fourth clutch 15 engages, and the transmission momentarily locks into a fixed gear ratio. Then, the third clutch 14 is released.

[0073] exist Figure 10 and 11 In the fourth state shown, the fourth clutch 15 is engaged, but the other clutches 12, 13, and 14 are not engaged. The brake 16 is released. This arrangement connects the first planetary gear 9 between the reduction gears 7 and 8 and the output 6, bypassing the second planetary gear 10 and the third planetary gear 11 (although motion is transmitted to the output via the planetary carrier 11b of the third planetary gear). This eliminates the speed reduction caused by the third planetary gear.

[0074] When the second motor 2 initially operates at its maximum speed in the second direction, the speed of the second motor 2 can be reduced to zero, thereby increasing the speed of output 6, and further increasing it in the second direction, thus further increasing the speed of output 6. This is in Figure 12 The interval is shown as 40. It should be noted that within this interval, the speed of the second motor 2 can be increased to exceed the maximum speed of other stages.

[0075] Therefore, these four states provide a wide range of transmission ratios and enable the first motor 1 to operate at a constant speed within a wide range of output speeds.

[0076] This arrangement is effective for the nominal power rating of ICE power supplies, and for vehicles, the size settings of each component can be roughly as follows:

[0077] ● Engines and generators require 70% of their nominal power;

[0078] ●The first motor requires 140% of its nominal power; and

[0079] ●The second motor requires 40% of the nominal power.

[0080] Battery packs can be provided, with their size determined by the vehicle's operating cycle. This arrangement allows for adaptation to peak loads and enables zero-emission operation via batteries when needed.

[0081] Therefore, this is an appropriate size setting for many vehicles, especially considering that the engine only needs 70% of its nominal power rating (rather than 100% of the nominal power rating if the engine is used as a direct power source for the drive wheels). Emissions are reduced by using a smaller engine that operates under steady conditions.

[0082] Considering that the transmission will operate with optimal traction, drivetrain efficiency can also be improved. Compared to transmissions that include torque converters, friction clutches, or synchronizers, the proposed device has virtually no wearing parts. The transmission operates continuously and smoothly without shock loads. Because the transmission is automatic, driver fatigue is reduced. This device can be installed in the drivetrain of existing vehicles without replacing the driveshaft or braking system. A separate reduction gear may not be necessary.

[0083] Figure 13 and 14 A second embodiment of the invention is shown, which is substantially the same as the first embodiment. Equivalent features have been described using corresponding reference numerals, with an addition of 100.

[0084] Figure 13 A 300kW electric motor geared assembly, including a power converter, is shown. The assembly comprises two coaxial motors: a main motor 101 (225kW) and a transmission motor 102 (75kW), which are coaxially driven through the center of the main motor 101. Each motor 101, 102 drives two sets of planetary gears 109, 110 via reduction gears (107, 108, respectively), providing coaxial dual input. The output of the planetary gears directly drives the output drive shaft 106, as described in previous embodiments. Power electronics 150 for the motors 101, 102 are mounted on top of the electric motor geared assembly.

[0085] The mechanical layout of the gears, claw clutch, and running mechanism employs a compact coaxial arrangement, achieved through the use of a multi-planetary flexible pin rotary gear design. The gearbox 103 has a smaller diameter and volume than the electric motor, while transmitting 15 times the motor torque. The mechanical transmission design is simple, robust, and reliable, with fewer potential failure modes; it lacks synchronizers, friction clutches, rotor cooling seals, and the dual-engagement failure modes typically associated with such transmissions. The selected electric motor is an 8500 rpm switched reluctance (SR) motor from AEM Ltd., 100% recyclable, robust to passive rectification and overvoltage failures, and does not use rare-earth materials. Overall, the electric motor gear unit design is robust, reliable, and compact, meeting the durability requirements of heavy-duty truck (HGV) applications.

[0086] The electric motor gear assembly 100 is contained within a sleeve with a diameter of 400 mm and a length of 1.3 m, allowing the electric motor gear assembly to be installed between the chassis rails of a 44-ton HGV 200, as shown in the attached figure. Figure 15 and 16 As shown, output 106 connects directly to the existing driveshaft without requiring any further modifications to the vehicle's drivetrain. The electric motor gear unit is applicable to all Class 8 vehicles (in the US truck class).

[0087] A digital model was constructed for a 44-ton truck driven by an electric motor and geared assembly 100 operating on a typical work cycle ("Comparison of hydrogen and battery electric trucks," from *Transport & Environment*, June 2020, by Fedor Unterlohner). Based on this model, a... Figure 17 and 18 The efficiency graph shown illustrates an extremely high computational efficiency of 91.1% (comprehensive test of a Heavy-Duty Diesel Truck (HHDDT)). This high efficiency is achieved through the ability of the electric motor gearing system to operate the electric motor at its most efficient state, avoiding the extremely low motor efficiency associated with fixed gear ratio transmissions. This maximizes regenerative energy from the duty cycle and minimizes the time spent in regenerative mode. The digital transmission model is further used to determine the dynamic performance enabling gear shifting and clutch engagement. This yields the definition of the dogtooth profile and the control input sequence for the electric motor torque to achieve rapid engagement and disengagement.

[0088] The table below lists the calculated performance of the electric motor gearbox 100 for a 44-ton 6x4 series tractor 200. All characteristics meet or exceed those of a 400kW diesel / 10-speed transmission, except for gradients of 50, 60, and 100 kph, which are limited by the installed power, comparing 300kW to a 400kW internal combustion engine (ICE) unit. Electric motors 101 and 102 can instantaneously operate at a peak power of 650kW, and under most practical operating conditions, their climbing ability will match that of the ICE. The defining characteristics of this electric motor gearbox are high stall torque, extreme starting capability, and very high duty cycle efficiency, all achieved within a compact enclosure.

[0089]

[0090] Currently, there are three electric drive solutions available on the market for heavy-duty vehicles.

[0091] 1. Large direct drive motor directly connected to the shaft input. Reference point.

[0092] 2. Electric drive (multi) dual-speed shaft.

[0093] 3. A large electric motor connected to the shaft input via a multi-speed gearbox.

[0094] We conducted a detailed performance comparison using digital model results of electric motor gearing devices and publicly available data for dedicated large direct drive electric motors. The results are listed below.

[0095] ● The power of the electric motor gear unit has increased by 15%, with a peak power of 5.4 times and a rated output torque of 5.6 times.

[0096] ●The mass of the electric motor gear unit is 1.44 times that of the motor, but its volume is only 80%.

[0097] ● An electric motor-gear assembly can start a 40-ton vehicle on a 39% gradient. Direct drive is limited to 8 tons.

[0098] ● The efficiency of the electric motor gear unit is 91% (HHDDT combined), which is far higher than any other electric drive unit (typically below 80%).

[0099] The dual-speed multi-axle solution improves climbing ability, but its maximum gross vehicle weight (GVW) is limited to 26 tons to maintain a continuous traction curve. The solution also suffers from significantly lower duty cycle efficiency due to the electric motor operating under very low efficiency regimes.

[0100] Electric motors using multi-speed gearboxes can match the climbing ability of electric motors with geared devices, but due to the lower efficiency of electric motors, their working cycle efficiency will also be lower.

[0101] Electric motor gear mechanism is superior to alternative solutions:

[0102] ● Direct drive: Large size, very poor climbing ability and efficiency.

[0103] ● Dual-speed shaft: Large size, very poor climbing ability and efficiency.

[0104] ● Multi-speed transmissions: large size and low efficiency.

[0105] The electric motor gear mechanism achieves:

[0106] ● Instantaneous and uninterrupted torque and power delivery, excellent speed / torque ratio >15, similar to direct drive, and performance similar to multi-speed.

[0107] ●High operating efficiency: The variable speed transmission ratio extends the high-efficiency operating window of the basic motor.

[0108] ● Compact, power-dense, robust and reliable design.

[0109] ●Easy to integrate into existing vehicle powertrains.

[0110] The electric motor geared system is a novel and innovative electric / mechanical transmission concept that can drive very large HGVs (26-44 tons and above) entirely electrically, with zero tailpipe emissions, while maintaining the vehicle's full traction performance with very high efficiency.

[0111] Crucially, the electric motor gearing system, with its high efficiency and compact size, unlocks a design solution for a practical 44-ton fuel cell tractor by providing sufficient range and an acceptable unloaded vehicle weight.

Claims

1. A motor gearbox assembly, comprising a gearbox, the gearbox including: First input; Second input; Output; Multiple planetary gears, each comprising the following components: Sun gear; Planetary support; Multiple planetary gears mounted on the planet carrier and each meshing with the sun gear; as well as A ring gear that meshes with each of the planetary gears; as well as Multiple clutches are arranged to selectively connect the first input and the second input to the output via multiple rotary gears; The electric motor gearbox assembly further includes: A first electric motor, connected to the first input to rotate the first input; and A second electric motor is connected to the second input to rotate the second input; The clutch and the planetary gear define multiple states of the gearbox, wherein in each state, the first input and the second input are coupled to the output via at least one of the planetary gears to form a gear train, and the multiple states differ from each other in at least one of the selection of the planetary gears forming the gear train and the selection of the components of each planetary gear connected to the input and the output as well as other planetary gears of the gear train; There exists at least one pair of states such that, at the cross rotational speed of the second input, the gear ratio of the gearbox is the same for the pair of states; The rotary gears include a first rotary gear, a second rotary gear, and a third rotary gear, and the device includes a first clutch, a second clutch, a third clutch, and a fourth clutch, wherein: The first input is connected to the planetary carrier of the first planetary gear and the ring gear of the second planetary gear; The second input is connected to the sun gear of the first and second planetary gears; The first clutch selectively engages the planetary carrier of the second planetary gear with the sun gear of the third planetary gear; The second clutch selectively engages the ring gear of the first planetary gear with the sun gear of the third planetary gear; The third clutch selectively engages the planetary carrier of the second planetary gear with the output; The fourth clutch selectively engages the ring gear of the first planetary gear with the planetary carrier of the third planetary gear; The ring gear of the third rotating gear is equipped with a brake; and The planetary carrier of the third planetary gear is connected to the output.

2. The electric motor gearbox device according to claim 1, wherein the transmission ratio is the number of rotations of the output in a single rotation relative to the first input, wherein the transmission ratio varies depending on the rotational speed of the second input.

3. The electric motor gearbox device according to claim 1, wherein the states form a sequence from a first state through at least one intermediate state to a final state, and each intermediate state forms a pair with the state preceding and following it in the sequence.

4. The electric motor gearbox device according to claim 3, wherein each pair of states causes the transmission ratio to vary with the rotational speed of the second input in opposite directions in each of the pair.

5. The electric motor gearbox device according to any of the preceding claims, comprising a brake for at least one of the planetary gears, the brake being selectively applicable to selectively brake a component of the planetary gear.

6. The electric motor gearbox device according to claim 1, wherein, In the first state, the first clutch engages to connect the planetary carrier of the second planetary gear to the sun gear of the third planetary gear, and the second clutch, the third clutch, and the fourth clutch disengage to disengage any components, and the brake of the ring gear of the third planetary gear brakes the ring gear of the third planetary gear.

7. The electric motor gearbox device according to claim 6, wherein, In the second state, the second clutch engages to connect the ring gear of the first planetary gear to the sun gear of the third planetary gear, wherein the first clutch, the third clutch, and the fourth clutch disengage so as not to engage any components, and the brake of the ring gear of the third planetary gear brakes the ring gear of the third planetary gear.

8. The electric motor gearbox device according to claim 7, wherein, In the third state, the third clutch engages to connect the planetary carrier of the second planetary gear to the output, and the first clutch, the second clutch, and the fourth clutch disengage so as not to engage any components.

9. The electric motor gearbox device according to claim 8, wherein, In the fourth state, the fourth clutch engages to connect the ring gear of the first planetary gear to the planetary carrier of the third planetary gear, and the second, third, and fourth clutches disengage so as not to engage any components.

10. The electric motor gearbox device of claim 1, wherein the first electric motor and the second electric motor are mounted coaxially relative to each other such that the output of one electric motor rotates within the output of the other electric motor, wherein the output of each of the electric motors is coaxial.

11. A method for controlling an electric motor gearbox device according to any of the preceding claims, the method comprising changing the rotational speed of the second electric motor to change the gear ratio of the gearbox.

12. A method of controlling an electric motor gearbox device according to claim 9, the method comprising changing the rotational speed of the second electric motor to change the gear ratio of the gearbox, wherein the method further comprises operating the electric motor gearbox device sequentially in the first state to the fourth state.

13. The method of claim 12, further comprising: Starting from when the first input and the second input are in a stationary state and the electric motor gearbox device is in the first state; The rotational speed of the second input is increased from zero to the maximum speed in the first direction, while the rotational speed of the first input is increased from zero to the maximum speed in the second direction.

14. The method of claim 13, further comprising reducing the speed of the second input to zero, and then reducing it to the maximum speed in the first direction, while the first input remains constant at the maximum speed.

15. The method of claim 14, further comprising then placing the device in the second state, and reducing the speed of the second input to zero, and then to the maximum speed in the second direction.

16. The method of claim 15, further comprising then placing the device in the third state, and reducing the speed of the second input to zero, and then to the maximum speed in the first direction.

17. The method of claim 16, further comprising then placing the device in the fourth state, and reducing the speed of the second input to zero, and then to the maximum speed in the second direction.

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