A dual-input constant-torque-ratio continuously variable transmission system

Abstract

The present application relates to the technical field of mechanical transmission and power stepless speed change, and relates to a double-input constant-torque-ratio stepless speed change transmission system, which comprises a first differential mechanism, a second differential mechanism, a first rotary power input source, a second rotary power input source and an output end; the first differential mechanism and the second differential mechanism are both three-port differential mechanisms; the first rotary power input source is connected to a first port of the first differential mechanism; the second rotary power input source is simultaneously connected to a second port of the first differential mechanism and a first port of the second differential mechanism; a third port of the first differential mechanism and a second port of the second differential mechanism are connected through a first connecting piece; and a third port of the second differential mechanism is connected to the output end. The system can realize a transmission mode with constant torque ratio irrelevant to rotating speed, avoid power internal circulation, mainly adopt gear meshing, reduce friction loss, simplify control logic, improve transmission efficiency, enhance bearing capacity, and adapt to power requirements in multiple scenarios.

Description

Technical Field

[0001] This invention relates to the field of mechanical transmission technology, and more specifically, to a dual-input constant torque ratio continuously variable transmission system. Background Technology

[0002] Currently, multi-power-source continuously variable transmission (CVT) technology is widely used in new energy vehicles, construction machinery, and intelligent equipment. The mainstream technical routes mainly include power-split hybrid power systems, multi-speed automatic transmissions, and dual-motor planetary gearbox coupling devices. The power-split system uses a planetary gearbox as the core coupling mechanism, achieving continuously variable transmission through motor speed control. Multi-speed automatic transmissions rely on components such as clutches, steel belts, and torque converters to complete gear switching and power transmission. The dual-motor planetary gearbox solution achieves dual-power-source coupling output through two planetary gearboxes, adapting to various power requirements.

[0003] Existing power-split hybrid power systems suffer from the problem of continuously varying input torque ratios with speed ratios, requiring complex control strategies for real-time optimization. Furthermore, the inherent mechanical power internal circulation within the system leads to transmission efficiency losses. Additionally, the inclusion of friction components such as clutches and brakes reduces overall reliability. Multi-speed automatic transmissions are prone to wear, overheating, and lag in their friction components, and the accompanying hydraulic system increases structural complexity and manufacturing costs. Existing dual-motor planetary gearbox solutions exhibit dynamic torque ratio changes with operating conditions, requiring mode switching via electromagnetic locks and synchronizers. This results in structural redundancy, complex control logic, and further reduces system stability. Moreover, the changing torque ratio forces the controller to optimize torque distribution in real-time, placing a heavy computational burden on the controller and making it difficult to ensure simultaneous efficient operation of both motors. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing dual-power source transmission systems, such as inconsistent torque ratio, internal mechanical power circulation, reliance on friction elements, complex control strategies, low transmission efficiency, and poor reliability. This invention provides a continuously variable transmission system that achieves a constant torque ratio independent of rotational speed. By controlling the rotational direction of the input source, it enables operation without internal mechanical power circulation. It utilizes a gear-based transmission method, reducing friction loss, simplifying control logic, improving transmission efficiency, enhancing reliability and load-bearing capacity, and adapting to the power needs of various scenarios.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A dual-input constant torque ratio continuously variable transmission (CVT) system is provided, comprising a first differential mechanism, a second differential mechanism, a first power input source, a second power input source, and an output terminal; wherein, both the first and second differential mechanisms are three-port differential mechanisms; the first power input source is connected to the first port of the first differential mechanism; the second power input source is simultaneously connected to the second port of the first differential mechanism and the first port of the second differential mechanism, forming a dual input; the third port of the first differential mechanism and the second port of the second differential mechanism are connected via a first connector X; the third port of the second differential mechanism is connected to the output terminal.

[0006] This invention discloses a dual-input constant torque ratio continuously variable transmission (CVT) system. By employing two three-port differential mechanisms to form a topology connecting the dual inputs to a first connector, the torque distribution between the first and second power input sources is inherently determined by the system structure, independent of input speed, output speed, and operating conditions, thus ensuring a constant torque ratio from the structural principle. Simultaneously, the port connection enables a gear-based transmission method, reducing friction loss, and structurally zero-mechanical-power internal circulation can be achieved by controlling the input steering. This technical solution provides the system with advantages such as simple control logic, high transmission efficiency, reliable operation, strong load-bearing capacity, and low cost.

[0007] Furthermore, the first differential mechanism is a first planetary gear set, and the second differential mechanism is a second planetary gear set; both the first planetary gear set and the second planetary gear set include a sun gear, a ring gear, a planet carrier, and planet gears mounted on the planet carrier; the planet gears mesh with the sun gear and the ring gear respectively.

[0008] In this technical solution, a mature single planetary gear set is used as the differential mechanism. The manufacturing process is standardized, the cost is low, and the load-bearing capacity is strong. The three-port characteristics of the planetary gear set can achieve kinematic and static decoupling, ensuring stable and reliable constant torque ratio characteristics.

[0009] Furthermore, the first rotary power input source is connected to the sun gear of the first planetary set; the second rotary power input source is connected to the planet carrier of the first planetary set and the planet carrier of the second planetary set respectively; the ring gear of the first planetary set and the sun gear of the second planetary set are connected through the first connector; the ring gear of the second planetary set is connected to the output end.

[0010] In this technical solution, the connection method is the preferred basic configuration, the torque ratio expression is simple and the control is easy to implement; the two inputs can rotate in the same direction to achieve power-free internal circulation, and the system efficiency is high; the output end is a gear ring, which has a good torque amplification effect and is suitable for the driving conditions of the whole vehicle.

[0011] Furthermore, the first rotary power input source is connected to the planet carrier of the first planetary set; the second power input source is connected to the sun gear of the first planetary set and the sun gear of the second planetary set respectively; the ring gear of the first planetary set and the planet carrier of the second planetary set are connected through the first connector; the ring gear of the second planetary set is connected to the output end.

[0012] In this technical solution, a planetary carrier input and a double sun gear layout are adopted, which has a large torque ratio and is suitable for scenarios where the main input source bears a large torque. The structure has good symmetry, balanced force, and low vibration and noise at high speed. It also maintains a constant torque ratio and no internal circulation characteristics.

[0013] Furthermore, the first rotary power input source is connected to the planet carrier of the first planetary set; the second rotary power input source is connected to the sun gear of the first planetary set and the ring gear of the second planetary set respectively; the ring gear of the first planetary set and the sun gear of the second planetary set are connected through the first connector; and the planet carrier of the second planetary set is connected to the output end.

[0014] In this technical solution, the output end is replaced with a planetary carrier, which has high speed and smooth torque output, making it suitable for high-speed drive scenarios; the torque ratio has a wider adjustable range, which can be adapted to dual motor systems with different power ratios; the structure is compact and the axial dimension is shorter, which is beneficial for vehicle layout.

[0015] Furthermore, the first rotary power input source is connected to the sun gear of the first planetary set; the second rotary power input source is connected to the ring gear of the first planetary set and the sun gear of the second planetary set respectively; the planet carrier of the first planetary set and the planet carrier of the second planetary set are connected through the first connector; and the ring gear of the second planetary set is connected to the output end.

[0016] In this technical solution, the output end is a gear ring, which has a good torque amplification effect and is suitable for high torque drive scenarios; the layout of interconnecting the sun gear and the planetary carrier has good structural symmetry; by adjusting the gear ratio, special torque distributions such as 1:1 can be achieved, which is suitable for dual motor systems with different power ratios; the internal power circulation can be avoided by rotating the two input sources in the same direction, the control logic is simple and the transmission efficiency is high.

[0017] This invention also provides a dual-input constant torque ratio continuously variable transmission (CVT) system, the system comprising a first differential mechanism, a second differential mechanism, a third differential mechanism, a first power input source, a second power input source, and an output end; the first, second, and third differential mechanisms are all three-port differential mechanisms; the first power input source is connected to the first port of the first differential mechanism; the second power input source is simultaneously connected to the second port of the first differential mechanism and the first port of the second differential mechanism, forming a dual input; the third port of the first differential mechanism is connected to a first connector X; the second port of the second differential mechanism is connected to a second connector Y; one port of the third differential mechanism is rigidly fixed, and the other two ports are respectively connected to the first connector X and the second connector Y; the third port of the second differential mechanism is connected to the output end.

[0018] The present invention discloses a dual-input constant torque ratio continuously variable transmission system. By adding a rigidly fixed third differential mechanism as a fixed reduction link on the basis of a dual planetary gear topology, the speed ratio range and constant torque ratio value of the system are further adjusted. While retaining the advantages of constant torque ratio, no internal circulation, and pure gear meshing, the system expands the applicable scenarios, improves the low-speed high torque output capability and the matching of the motor operating point, and enables the system to maintain efficient and stable operation under high power and high speed ratio conditions.

[0019] Furthermore, the first differential mechanism is a first planetary gear set, the second differential mechanism is a second planetary gear set, and the third differential mechanism is a third planetary gear set; the first planetary gear set, the second planetary gear set, and the third planetary gear set each include a sun gear, a ring gear, a planet carrier, and planet gears mounted on the planet carrier; the planet gears mesh with the sun gear and the ring gear respectively.

[0020] In this technical solution, all three planetary gear sets adopt a standard gear structure, which ensures high consistency in manufacturing and assembly and controllable costs; the fixed planetary gear set can provide a stable reduction ratio, further optimizing torque distribution and system efficiency.

[0021] Furthermore, the first rotary power input source is connected to the sun gear of the first planetary set; the second rotary power input source is connected to the planet carrier of the first planetary set and the planet carrier of the second planetary set respectively; the ring gear of the first planetary set is connected to the sun gear of the third planetary set through the first connector; the planet carrier of the third planetary set is connected to the sun gear of the second planetary set through the second connector; the ring gear of the third planetary set is rigidly fixed; and the ring gear of the second planetary set is connected to the output end.

[0022] In this technical solution, the third row of planetary gear rings is fixed, which is easy to implement and has good rigidity; it can stably provide a fixed reduction ratio, reducing the torque ratio to the order of 0.04~0.06, thus reducing the load on the auxiliary motor; the system has a short transmission chain, low loss, and higher efficiency.

[0023] Furthermore, the first rotary power input source is connected to the sun gear of the first planetary set; the second rotary power input source is connected to the planet carrier of the first planetary set and the planet carrier of the second planetary set respectively; the ring gear of the first planetary set and the ring gear of the third planetary set are connected through the first connector; the sun gear of the third planetary set and the sun gear of the second planetary set are connected through the second connector; the planet carrier of the third planetary set is rigidly fixed; and the ring gear of the second planetary set is connected to the output end.

[0024] In this technical solution, the third row of planetary carriers is fixed, with a large reduction ratio and a wide torque adjustment range; the force distribution is uniform, and it can withstand greater overload; it is suitable for heavy-duty construction machinery, commercial vehicles and other high-torque scenarios.

[0025] Furthermore, the first rotary power input source is connected to the sun gear of the first planetary set; the second rotary power input source is connected to the planet carrier of the first planetary set and the planet carrier of the second planetary set respectively; the gear ring of the first planetary set and the gear ring of the third planetary set are connected through the first connector; the planet carrier of the third planetary set and the sun gear of the second planetary set are connected through the second connector; the sun gear of the third planetary set is rigidly fixed; and the gear ring of the second planetary set is connected to the output end.

[0026] In this technical solution, the third row of sun gears is fixed, resulting in a compact structure and small axial dimensions; it has high speed adjustment sensitivity and fast continuously variable transmission response; and it is suitable for scenarios with high space and response requirements, such as passenger cars and drones.

[0027] Furthermore, it also includes at least one controllable locking mechanism, which is configured in at least one of the following ways: a. The controllable locking mechanism is located on the connection path between the first rotary power input source and the first differential mechanism; b. The controllable locking mechanism is located on the connection path between the second rotary power input source and the first differential mechanism or the second differential mechanism; c. The controllable locking mechanism is disposed between any port of the first differential mechanism or the second differential mechanism and the fixed component; When the controllable locking mechanism is engaged, the corresponding port or the corresponding input source is locked to a stationary state, so that the system is driven by only the other input source, thereby realizing a single-input drive mode.

[0028] In this technical solution, the addition of a controllable locking mechanism enables switching between dual-input and single-input modes, improving light-load efficiency, enhancing fault tolerance, and simplifying control.

[0029] Furthermore, the controllable locking mechanism is one of a wet multi-plate clutch, a dry clutch, an electromagnetic brake, or a one-way bearing.

[0030] This technical solution adopts a mature clutch and brake structure, taking into account locking reliability, response speed and scenario adaptability.

[0031] Furthermore, when the system operates in single-input drive mode, the motor corresponding to the locked input source stops receiving power and is in a stationary state, while the other input source drives the output terminal alone. The system speed ratio is determined by the relationship between the rotational speed of the other input source and the rotational speed of the output terminal.

[0032] In this technical solution, the locked motor is powered off while stationary in single-input mode, maintaining a constant speed ratio, low loss, and without losing its stepless speed change capability.

[0033] Compared with the prior art, the beneficial effects of the present invention are: 1. Constant torque ratio characteristic: The inherent topology of the system ensures that the torque ratio of the two input sources is constant, which is determined only by the ratio of the number of planetary gears and is independent of the speed and operating conditions, without the need for complex control strategies; 2. Enables operation without internal circulation: By controlling the rotation direction of the dual input sources, the entire process adopts gear meshing transmission, eliminating friction components such as clutches, brakes, and hydraulic devices, thus avoiding internal circulation of mechanical power, reducing transmission losses, and improving system efficiency; 3. Simplified control: Based on a constant torque ratio, the torque command is given in a fixed proportion. Only the speed needs to be adjusted to achieve stepless speed change. The control algorithm is simple and easy to implement, and it includes multiple configurations such as double planetary gear set and triple planetary gear set. Different power levels and application scenarios can be adapted by adjusting the gear ratio and port connection.

[0034] 4. Selectable single-motor drive mode improves efficiency under light load: The present invention can also selectively set a controllable locking mechanism to lock one of the input sources under low load conditions, realize single-motor drive, reduce the loss of dual motors working at the same time, and make the overall system efficiency potentially further improved under specific conditions (such as light load operation under urban conditions), while not losing the full-speed range continuously variable transmission and high power response capability. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the configuration 3 of the dual planetary gear system in Embodiment 1 of the dual-input constant torque ratio continuously variable transmission system of the present invention; Figure 2This is a schematic diagram of the configuration 13 of the dual planetary gear system in Embodiment 2 of the present invention, which is a dual-input constant torque ratio continuously variable transmission system. Figure 3 This is a schematic diagram of the configuration 17 of the dual planetary gear system in Embodiment 3 of the present invention, which is a dual-input constant torque ratio continuously variable transmission system. Figure 4 This is a schematic diagram of the configuration 25 of the dual planetary gear system in Embodiment 4 of the present invention, which is a dual-input constant torque ratio continuously variable transmission system. Figure 5 This is a schematic diagram of the configuration 7 of the dual planetary gear system, which is an embodiment 5 of the dual-input constant torque ratio continuously variable transmission system of the present invention. Figure 6 This is a schematic diagram of the configuration 13 of the three planetary gear system in Embodiment 7 of the present invention, which is a dual-input constant torque ratio continuously variable transmission system. Figure 7 This is a schematic diagram of the configuration 16 of the three-planetary gear system in Embodiment 8 of the present invention, which is a dual-input constant torque ratio continuously variable transmission system. Figure 8 This is a schematic diagram of the configuration 18 of the three-planetary gear system in Embodiment 9 of the present invention, which is a dual-input constant torque ratio continuously variable transmission system. Figure 9 This is a schematic diagram of the configuration 100 of the planetary gear system in Embodiment 13 of the present invention, which is a dual-input constant torque ratio continuously variable transmission system. Figure 10 This is a schematic diagram of the controllable locking mechanism arrangement in the double planetary gear configuration 7 of Embodiment 6 of the present invention; Figure 11 This is a schematic diagram of the controllable locking mechanism arrangement of the double planetary gear configuration 13 in Embodiment 6 of the present invention; Figure 12 This is a schematic diagram of the controllable locking mechanism arrangement of the double planetary gear configuration 17 in Embodiment 6 of the present invention; Figure 13 This is a schematic diagram of the controllable locking mechanism arrangement of the three planetary gear configuration 13 in Embodiment 6 of the present invention; Figure 14 This is a schematic diagram of the controllable locking mechanism arrangement of the three planetary gear configuration 16 in Embodiment 6 of the present invention; Figure 15 This is a schematic diagram of the controllable locking mechanism arrangement of the three planetary gear configuration 18 in Embodiment 6 of the present invention. Detailed Implementation

[0036] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0037] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0038] Example 1 A first embodiment of a dual-input constant torque ratio continuously variable transmission system includes a first differential mechanism DU1, a second differential mechanism DU2, a first rotary power input source A, a second rotary power input source B, and an output terminal OUT; wherein... The first differential mechanism DU1 and the second differential mechanism DU2 are both three-port differential mechanisms; The first rotary power input source A is connected to the first port of the first differential mechanism DU1; The second rotary power input source B is connected to the second port of the first differential mechanism DU1 and the first port of the second differential mechanism DU2 to form a dual input; The third port of the first differential mechanism DU1 is connected to the second port of the second differential mechanism DU2 via the first connector X; The third port of the second differential mechanism DU2 is connected to the output terminal OUT.

[0039] Among them, the first differential mechanism DU1 is the first planetary gear set PG1, and the second differential mechanism DU2 is the second planetary gear set PG2; both the first planetary gear set PG1 and the second planetary gear set PG2 include a sun gear, a ring gear, a planet carrier, and planet gears mounted on the planet carrier; the planet gears mesh with the sun gear and the ring gear respectively.

[0040] It should be noted that the following symbols are explained as follows: DU1 is the first differential mechanism, PG1 is the first planetary gear set, S1 is the sun gear in the first planetary gear set PG1, C1 is the planet carrier in the first planetary gear set PG1, R1 is the ring gear R1 in the first planetary gear set PG1, DU2 is the second differential mechanism, PG2 is the second planetary gear set, S2 is the sun gear in the second planetary gear set PG2, C2 is the planet carrier in the second planetary gear set PG2, R2 is the ring gear in the second planetary gear set PG2, DU3 is the third differential mechanism, PG3 is the third planetary gear set, S3 is the sun gear in the third planetary gear set PG3, C3 is the planet carrier in the third planetary gear set PG3, R3 is the ring gear in the third planetary gear set PG3, X is the first connecting member, Y is the second connecting member, the controllable locking mechanism is CLM, the first controllable locking mechanism is CLM1, and the second controllable locking mechanism is CLM2. In this embodiment and in the embodiments exemplified below, the symbols are explained according to the above correspondence.

[0041] It should be noted that the first differential mechanism DU1 is one of the following: the first planetary gear set PG1, the symmetrical bevel gear differential, and the asymmetrical differential; the second differential mechanism DU2 is one of the following: the second planetary gear set PG2, the symmetrical bevel gear differential, and the asymmetrical differential. The first port, second port, and third port of the first differential mechanism DU1 are different structures of the sun gear S1, the ring gear R1, and the planet carrier C1 of the first planetary gear set PG1, respectively; the first port, second port, and third port of the second differential mechanism DU2 are different structures of the sun gear S2, the ring gear R2, and the planet carrier C2 of the second planetary gear set PG2, respectively.

[0042] It should also be noted that the first, second, and third ports of the first differential mechanism DU1 are all different structures in the sun gear, ring gear, and planet carrier of the first planetary gear set PG1. Similarly, the first, second, and third ports of the second differential mechanism DU2 are all different structures in the sun gear, ring gear, and planet carrier of the second planetary gear set PG2. The first rotary power input source A is connected to one port of the first differential mechanism DU1, and the second rotary power input source B is connected to the other port of the first differential mechanism DU1 and one port of the second differential mechanism DU2. The remaining port of the first differential mechanism DU1 is connected to the other port of the second differential mechanism DU2 via the first connector X, and the remaining port of the second differential mechanism DU2 is connected to the output terminal OUT. Through the above connection combinations, a total of 36 different configurations can be formed, as detailed in Table 1 below.

[0043]

[0044] The explanations of the names in the table above are as follows: A is the first rotary power input source, B is the second rotary power input source, S1 is the sun gear on the first planetary gear set PG1, C1 is the planet carrier on the first planetary gear set PG1, R1 is the ring gear on the first planetary gear set PG1, S2 is the sun gear on the second planetary gear set PG2, C2 is the planet carrier on the second planetary gear set PG2, and R2 is the ring gear on the second planetary gear set PG2. Taking the name A_S1_B_C1_C2_X_S2 (number 3) as an example: This name indicates that: the first rotary power input source A is connected to the sun gear S1 of the first planetary gear set PG1; the second rotary power input source B is connected to the planet carrier C1 of the first planetary gear set PG1 and the planet carrier C2 of the second planetary gear set PG2 respectively; the ring gear R1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2 are connected through the first connector X; the ring gear R2 of the second planetary gear set PG2 is connected to the output terminal Out. The connection relationships of the corresponding names of the other numbers can also be deduced from the names.

[0045] This embodiment is a dual-input constant torque ratio continuously variable transmission system. Its core topology is achieved by two three-port differential mechanisms (planetary gear sets) through a specific connection. All 36 configurations satisfy the constant torque ratio characteristic, that is, the torque ratio of the two input sources is determined only by the ratio of the number of teeth of the planetary gear set, and is independent of the rotational speed.

[0046] like Figure 1 As shown, in one specific embodiment, referred to as configuration 3, corresponding to number 3 in the table above, such as... Figure 1 As shown: the first rotary power input source A is connected to the sun gear S1 of the first planetary gear set PG1; the second rotary power input source B is connected to the planet carrier C1 of the first planetary gear set PG1 and the planet carrier C2 of the second planetary gear set PG2 respectively; the ring gear R1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2 are connected through the first connector X; the ring gear R2 of the second planetary gear set PG2 is connected to the output end Out.

[0047] More specifically, the first rotary power input source A is a motor. The output shaft of motor A is directly connected to the bushing of the sun gear S1 via a spline, key, or flange, or through a coupling to achieve a rigid coaxial connection. If there is an axial distance between the motor and the planetary gear set, an intermediate drive shaft (with a support bearing) can be added. The connection ensures no relative rotation and reliable torque transmission. The second rotary power input source B is a motor. The output shaft of motor B is connected to a double-gear sleeve or double-bracket. One end of the sleeve is connected via a spline to the input shaft of the planet carrier C1 of the first planetary gear set PG1, and the other end is connected via a spline to the input shaft of the planet carrier C2 of the PG2 planetary gear set. The two planetary carriers can share a single input shaft (i.e., the same shaft drives C1 and C2 simultaneously), or the input shafts of the two planetary carriers can be rigidly connected via a coupling. This ensures that motor B drives both planetary carriers simultaneously at the same speed. The first connecting member X is an intermediate shaft (or sleeve shaft). The outer ring or end face of gear ring R1 is machined with internal splines or flanges, and is fixed to one end of intermediate shaft X via splines, bolts, or welding; the other end of intermediate shaft X is connected to the bushing of sun gear S2 via splines. Intermediate shaft X can be supported on the housing by bearings to ensure free rotation. This connection allows R1 and S2 to have the same rotational speed. The outer ring of gear ring R2 is machined with gears or flanges, and is directly fixed to output shaft Out via splines, keys, or flange bolts. The output shaft is then connected to loads such as wheels, rotors, or robot joints via universal joints or gear pairs. If the output direction needs to be adjusted, a single-stage gear reduction or bevel gear can be added.

[0048] The rotating components of this invention are rigidly mechanically connected. Specifically, the output shaft of the first rotary input source A is coaxially fixed to the sun gear S1 of the first planetary gear set PG1 via a spline or coupling; the output shaft of the second rotary input source B is simultaneously connected to the planet carrier C1 of the first planetary gear set PG1 and the planet carrier C2 of the second planetary gear set PG2 via a double input shaft or rigid bracket, ensuring that their rotational speeds are always equal; the gear ring R1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2 are fixedly connected via a first connecting member X—i.e., an intermediate shaft—with both ends of this shaft connected to the gear ring R1 and the sun gear S2 respectively via splines or bolts; the gear ring R2 of the second planetary gear set PG2 is directly fixed to the output end Out via a spline or flange. All connections are free from relative rotation, ensuring accurate transmission of torque and rotational speed. The above connection methods are conventional techniques in the art, and those skilled in the art can implement them based on the description in this specification.

[0049] The mechanical implementation of "dual input" can be achieved by using a hollow shaft (internally connected to the planet carrier C1 of the first planetary set PG1, and externally connected to the planet carrier C2 of the second planetary set PG2) or a solid shaft with both ends fixed to the two planet carriers respectively, which is a known technology.

[0050] The first connecting component X can be a separate intermediate shaft, or a welded or integrally formed structure. All connections do not include clutches, brakes, or friction elements, ensuring pure gear meshing characteristics.

[0051] The following section provides a complete mathematical model derivation for configuration 3 of this specific embodiment, including kinematic and static relationships, proof of constant torque ratio, and transmission ratio function, to demonstrate its underlying mechanism. 1. Definition of General Symbols , : These are the rotational speeds of the first rotary input source A and the second rotary input source B, respectively; Output speed; : First connecting component X rotational speed; The torque of the first rotary input source A, The torque of the second rotary input source B, : This refers to the torque at the output terminal OUT; The ratio of the number of teeth on the ring gear R1 in the first planetary gear PG1 to the number of teeth on the sun gear S1; The ratio of the number of teeth on the ring gear to the number of teeth on the sun gear; Basic kinematic equations of planetary rank: +K =(1+K) .

[0052] 2. The connection relationships of the above configurations: The first rotary power input source A is connected to the sun gear S1 of the first planetary gear set PG1, the second rotary power input source B is connected to the planet carrier C1 of the first planetary gear set PG1 and the planet carrier C2 of the second planetary gear set PG2, the ring gear R1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2 are connected through the first connector X; the ring gear R2 of the second planetary gear set PG2 is connected to the output end Out. 3. Derivation of kinematic equations The first planetary alignment in the front row, PG1 equation: + =(1+ ) (1) The second planetary alignment in the back row, PG2 equation: + =(1+ ) (2) Solve from equation (2) : =(1+ ) (3) Substituting equation (3) into equation (1) and rearranging: + [(1+ ) ]=(1+ )

[0053] =(1 ) +

[0054] make Simplified to: =K S (4) 4. Derivation of Statics and Constant Torque Ratio By the law of conservation of power: + = (5) Substituting equation (4) into equation (5):

[0055] because and They are independent and have a coefficient of zero. (6) (7) Torque ratio (8) Conclusion: The torque ratio is determined solely by... The decision is independent of the rotational speed and satisfies a constant torque ratio.

[0056] 5. Transmission ratio function Define speed ratio Substituting into equation (4):

[0057] Rearranging the terms, we get:

[0058]

[0059] Transmission ratio (9) Singularity Normal driving conditions The system is stable and without anomalies.

[0060] 6. No internal circulation condition Under driving conditions >0, based on static relations and the constant torque ratio of configuration 3. It can be known that... When the first rotary power input source (A) and the second rotary power input source (B) rotate in the same direction, i.e., speed ratio control... At that time, the power of the two input sources are respectively = >0、 = >0, at this time both input sources output power in the positive direction, and there is no reverse power flow. Therefore, by controlling the rotation direction of the input sources, mechanical power-free internal circulation operation can be achieved.

[0061] 7. The working principle of a dual-input constant torque ratio continuously variable transmission system in this embodiment is as follows: The first rotary power input source A and the second rotary power input source B provide power. B drives the front and rear planetary carriers simultaneously through a dual input, and the first connecting member X achieves coupling between the front and rear rows; by adjusting... = / Output speed Continuous variation enables stepless speed regulation; torque is distributed in a fixed ratio, eliminating the need for complex control, resulting in a highly efficient and stable system. Under driving conditions, both input sources rotate in the same direction, and the power is positive, thus eliminating the need for internal circulation.

[0062] Example 2 like Figure 2 As shown, this embodiment is a second embodiment of a dual-input constant torque ratio continuously variable transmission system. This second embodiment is another of the 36 configurations mentioned above, called configuration 13, corresponding to the number 13, and its name is: A_C1_B_S1_S2_X_C2. The difference between configuration 13 and configuration 3 is that: the first rotary power input source A is connected to the planet carrier C1 of the first planetary gear set PG1; the second rotary power input source B is connected to the sun gear S1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2 respectively; the ring gear R1 of the first planetary gear set PG1 and the planet carrier C2 of the second planetary gear set PG2 are connected through the first connecting member X; the ring gear R2 of the second planetary gear set PG2 is connected to the output end Out.

[0063] More specifically, the first rotary power input source A is a motor. The output shaft of the first rotary power input source A is directly connected to the input shaft of the planetary carrier C1 via a spline or key, or through a coupling to achieve a coaxial rigid connection. If there is an axial distance between the motor and the planetary set, an intermediate drive shaft (with a support bearing) can be added. The connection ensures no relative rotation and reliable torque transmission. The second rotary power input source B is a motor. The output shaft of motor B is connected to a double-gear sleeve or double-bracket. One end of the sleeve is connected to the sun gear S1 shaft of the first planetary set PG1 via a spline, and the other end is connected to the sun gear S2 shaft of PG2 via a spline. The two sun gears can be driven simultaneously via the same input shaft, or the input shafts of the two sun gears can be rigidly connected via a coupling. This ensures that motor B drives both sun gears simultaneously at the same speed. The first connecting member X is an intermediate shaft (or sleeve shaft). The outer ring or end face of gear ring R1 is machined with internal splines or flanges, and is fixed to one end of intermediate shaft X via splines, bolts, or welding; the other end of intermediate shaft X is connected to the bushing of planetary carrier C2 via splines. Intermediate shaft X can be supported on the housing by bearings to ensure free rotation. This connection allows R1 and C2 to have the same rotational speed. The outer ring of gear ring R2 is machined with gears or flanges, and is directly fixed to the output shaft (Out) via splines, keys, or flange bolts. The output shaft is then connected to loads such as wheels, rotors, or robot joints via universal joints or gear pairs. If the output direction needs to be adjusted, a single-stage gear reduction or bevel gear can be added.

[0064] 1. The definition of the general symbol refers to the definition of the general symbol in configuration 3 of implementation 1; 2. Derivation of kinematic equations First Planetary Ranking PG1: (10) Second planetary rank PG2: (11) eliminate

[0065] From equation (11), we can derive:

[0066] Substituting into (10), we get:

[0067] Multiply both sides have to:

[0068] Summarized as follows:

[0069] To simplify the expression, the system parameters are defined as follows:

[0070] Equation (12) can then be written as: = +

[0071] and

[0072] 3. Statics and constant torque ratio Power conservation (5) Substituting into (13) yields (14) From system independence, we get:

[0073]

[0074] absolute value of torque ratio:

[0075] Conclusion: The torque ratio is determined only by the gear ratios K1 and K2 and is independent of the rotational speed, thus satisfying the constant torque ratio characteristic.

[0076] 4. Transmission ratio function Depend on = + (13) and have to:

[0077] 5. Working principle of configuration 13 This configuration 13 is characterized by the first rotary power input source A being connected to the planet carrier C1, and the second rotary power input source B being simultaneously connected to the sun gears S1 and S2. Its torque ratio is... This means that motor A bears the main torque, suitable for scenarios where A is the primary power source and B is the speed regulating power source. In drive conditions ( >0), below, from the statics relationship we can obtain >0, <0. To avoid internal circulation of mechanical power, both input power must be positive: take >0, and at the same time because <0, should be taken <0, meaning the two input sources rotate in opposite directions. At this time... = >0, = >0, the system has no internal power circulation. This configuration also has the significant advantages of constant torque ratio, pure gear meshing, and continuously variable transmission across the entire range. Compared with configuration 3, it has different applicability in torque distribution and speed ratio characteristics, and can be flexibly selected according to motor power matching and operating conditions.

[0078] Example 3 like Figure 3 As shown, this embodiment is the third embodiment of a dual-input constant torque ratio continuously variable transmission system. This third embodiment is another of the 36 configurations mentioned above, referred to as configuration 17, corresponding to the number 17. The difference between configuration 17 and configuration 3 is that: the first rotary power input source A is connected to the planet carrier C1 of the first planetary gear set PG1; the second rotary power input source B is connected to the sun gear S1 of the first planetary gear set PG1 and the ring gear R2 of the second planetary gear set PG2 respectively; the ring gear R1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2 are connected through the first connecting member X; the planet carrier C2 of the second planetary gear set PG2 is connected to the output end Out.

[0079] More specifically, the first rotary power input source A is a motor. The output shaft of motor A is directly connected to the input shaft of planetary carrier C1 via a spline or key, or through a coupling for a rigid coaxial connection. If there is an axial distance between the motor and the planetary gear set, an intermediate drive shaft (with a support bearing) can be added. The connection ensures no relative rotation and reliable torque transmission. The second rotary power input source B is a motor. The output shaft of motor B is connected to a double-jointed structure. One end of this structure is connected to the sun gear S1 shaft of the first planetary gear set PG1 via a spline, and the other end is connected to the gear ring R2 of PG2 via a spline or gear. The gear ring R2 can be fixed to the output end of B via an internal spline or flange to ensure equal speeds at both ends. The first connecting piece X is an intermediate shaft (or sleeve shaft). The outer ring or end face of the gear ring R1 is machined with an internal spline or flange, and is fixed to one end of the intermediate shaft X via a spline, bolts, or welding; the other end of the intermediate shaft X is connected to the bushing of the sun gear S2 via a spline. The intermediate shaft X can be supported on the housing by bearings to ensure free rotation. This connection ensures that R1 and S2 rotate at the same speed. The output end of planetary carrier C2 is fixed to the output shaft (Out) via splines, keys, or flanges. The output shaft is then connected to loads such as wheels, rotors, or robot joints via universal joints or gear pairs. If the output direction needs to be adjusted, a single-stage gear reduction or bevel gear can be added.

[0080] 1. The definition of the general symbol refers to the definition of the general symbol in configuration 3 of implementation 1; 2. Derivation of kinematic equations First Planetary Ranking PG1: (19) Second planetary rank PG2: (20) From (20) we get , substitute into (19) to eliminate :

[0081]

[0082] We get: (1+ ) = (twenty one) Divide both sides by : (twenty two) Define system parameters:

[0083] but (twenty three) 3. Statics and constant torque ratio Power conservation (5) Substituted into (23): Torque ratio:

[0084] (twenty four) By independence, we get:

[0085] Torque ratio:

[0086] 4. Transmission ratio function From (19) and :

[0087] Singularity Normal driving conditions The system is stable and without anomalies.

[0088] 5. Working principle This configuration 17 is characterized by a first rotary power input source A connecting to the planet carrier C1 of the first planetary gear set PG1, and a second rotary power input source B simultaneously connecting to the sun gear S1 of the first planetary gear set PG1 and the ring gear R2 of the second planetary gear set PG2. Its torque ratio: This configuration can be designed with a gear ratio greater than or less than 1, suitable for scenarios where the first rotary power input source A serves as the main power source and the second rotary power input source B serves as the speed regulating power source. Under driving conditions, both input sources rotate in the same direction, and the power is positive for both, thus eliminating internal circulation. This configuration also possesses the significant advantages of constant torque ratio, structurally non-internal circulation, pure gear meshing, and continuously variable transmission across the entire range. Compared to configuration 3, it has different applicability in torque distribution and speed ratio characteristics, allowing for flexible selection based on motor power matching and operating conditions.

[0089] Example 4 like Figure 4 As shown, this embodiment is the fourth embodiment of a dual-input constant torque ratio continuously variable transmission system. This fourth embodiment is another of the 36 configurations mentioned above, referred to as configuration 25, corresponding to the number 25. The difference between configuration 25 and configuration 3 is that: the first rotary power input source A is connected to the ring gear R1 of the first planetary gear set PG1; the second rotary power input source B is connected to the sun gear S1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2 respectively; the planet carrier C1 of the first planetary gear set PG1 and the planet carrier C2 of the second planetary gear set PG2 are connected through the first connector X; the ring gear R2 of the second planetary gear set PG2 is connected to the output end Out.

[0090] More specifically, the first rotary power input source A is a motor. The output shaft of motor A is directly fixed to the outer ring or end face of the gear ring R1 via a spline or flange, or connected via a coupling. If there is axial distance, an intermediate drive shaft (with a support bearing) can be added. The connection ensures no relative rotation and reliable torque transmission. The second rotary power input source B is a motor. The output shaft of motor B is connected to a double-gear sleeve or double-bracket. One end of the sleeve is connected to the sun gear S1 shaft of the first planetary gear set PG1 via a spline, and the other end is connected to the sun gear S2 shaft of PG2 via a spline. The two sun gears can be driven simultaneously via the same input shaft, or the input shafts of the two sun gears can be fixed together via a rigid coupling. This ensures that motor B drives both sun gears simultaneously at the same speed. The first connecting component X is an intermediate shaft (or sleeve shaft). The output end of planetary carrier C1 is fixed to one end of intermediate shaft X via a spline or flange; the other end of intermediate shaft X is connected to the bushing of planetary carrier C2 via a spline. The intermediate shaft X is supported on the housing by bearings, ensuring free rotation. This connection allows C1 and C2 to rotate at the same speed. The outer ring of the gear ring R2 is machined with gears or flanges and is directly connected to the output shaft (Out) via splines, keys, or flange bolts. The output shaft is then connected to loads such as wheels, rotors, or robot joints via universal joints or gear pairs. If the output direction needs to be adjusted, a single-stage gear reduction or bevel gear can be added.

[0091] 1. The definition of the general symbol refers to the definition of the general symbol in configuration 3 of implementation 1; 2. Derivation of kinematic equations The first planetary alignment in the front row, PG1 equation: + =(1+ ) (29) The second planetary alignment in the back row, PG2 equation: + =(1+ ) (30) eliminate :

[0092]

[0093] Expand:

[0094] get: (31) Divide both sides by : (32) Define system parameters:

[0095] but (33) 3. Statics and constant torque ratio Power conservation (5) Substituted into (33): Conclusion:

[0096] (34) By independence, we get:

[0097]

[0098] Conclusion:

[0099] Torque ratio (absolute value):

[0100] 4. Transmission ratio function From (29) and :

[0101]

[0102]

[0103] The negative sign indicates the steering relationship, which is matched through motor steering in practical applications. (Singularity) You need to pay attention to the choice of work area.

[0104] 6: Working principle: This configuration 25 is characterized by a first rotary power input source A connected to the ring gear R1 of the first planetary gear set PG1, and a second rotary power input source B simultaneously connected to the sun gear S1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2. As can be seen from static derivation, under driving conditions ( )Down, , This holds true. To ensure that the power of both input sources is positive ( ), needs to be controlled , This means the two input sources rotate in opposite directions. There is no internal mechanical power circulation in this configuration. This configuration also possesses the significant advantages of constant torque ratio, pure gear meshing, and continuously variable transmission (CVT) across the entire range. Compared to configuration 3, it has different applicability in torque distribution and speed ratio characteristics, allowing for flexible selection based on motor power matching and operating conditions.

[0105] Example 5 like Figure 5 As shown, this embodiment is the fifth embodiment of a dual-input constant torque ratio continuously variable transmission system. This fifth embodiment is another of the 36 configurations mentioned above, referred to as configuration 7, corresponding to the number 7. The difference between configuration 7 and configuration 3 is that: the first rotary power input source A is connected to the sun gear S1 of the first planetary gear set PG1; the second rotary power input source B is connected to the ring gear R1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2 respectively; the planet carrier C1 of the first planetary gear set PG1 and the planet carrier C2 of the second planetary gear set PG2 are connected through the first connector X; the ring gear R2 of the second planetary gear set PG2 is connected to the output end Out.

[0106] More specifically, the first rotary power input source A is a motor. The output shaft of motor A is directly connected to the bushing of the sun gear S1 via a spline or key, or through a coupling to achieve a rigid coaxial connection. If there is an axial distance between the motor and the planetary gear set, an intermediate drive shaft (with a support bearing) can be added. The connection ensures no relative rotation and reliable torque transmission. The second rotary power input source B is a motor. The output shaft of motor B is connected to a double-jointed structure. One end of this structure is connected to the gear ring R1 of the first planetary gear set PG1 via a spline or flange, and the other end is connected to the sun gear S2 shaft of PG2 via a spline. The gear ring R1 can be fixed to the output end of B via an internal spline, ensuring equal speeds at both ends. The first connecting piece X is an intermediate shaft (or sleeve shaft). The output end of the planetary carrier C1 is fixed to one end of the intermediate shaft X via a spline or flange; the other end of the intermediate shaft X is connected to the bushing of the planetary carrier C2 via a spline. The intermediate shaft X can be supported on the housing by bearings, ensuring free rotation. This connection allows C1 and C2 to have the same speed. The output end of the gear ring R2 is fixed to the output shaft (Out) via a spline, key, or flange. The output shaft is then connected to loads such as wheels, rotors, or robot joints via a universal joint or gear pair. If the output direction needs to be adjusted, a single-stage gear reduction or bevel gear can be added.

[0107] 1. The definition of the general symbol refers to the definition of the general symbol in configuration 3 of implementation 1; 2. Derivation of kinematic equations First Planetary Ranking PG1: (39) Second planetary rank PG2: (40) eliminate : From (40), we can conclude that: Substitute (39): (41) Multiply by both sides :

[0108] Rearrangement:

[0109] Calculate the coefficients: Conclusion:

[0110] make ,but .

[0111] When the optimal tooth ratio is selected hour, ,Right now (43) 3. Statics and constant torque ratio Power conservation (5) Substitute into (43) Conclusion:

[0112] (44) By independence, we get: Torque ratio:

[0113] Therefore, we conclude that: when = When =2, =1, the torques of the two motors are equal.

[0114] 4. Transmission ratio function Depend on and :

[0115]

[0116] Substituting a and b, we get:

[0117] because Therefore:

[0118] when hour, This is consistent with the classic results.

[0119] 5. Working principle of configuration 7 This configuration 7 is characterized by a first rotary power input source A connected to the sun gear S1 of the first planetary gear set PG1, and a second rotary power input source B simultaneously connected to the ring gear R1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2. This configuration also possesses the significant advantages of constant torque ratio, pure gear meshing, and continuously variable transmission (CVT) across the entire range. Its torque ratio is: These are positive values. Therefore, under driving conditions, the power is guaranteed to be positive as long as both input sources rotate in the same direction, with no internal mechanical power circulation. Compared with configuration 3, this configuration has different applicability in torque distribution and speed ratio characteristics, and can be flexibly selected according to motor power matching and operating conditions.

[0120] The above-described Example 1 provides the specific derivation process for the constant torque ratio of double planetary gear configuration 3, Example 2 provides configuration 13, Example 3 provides configuration 17, Example 4 provides configuration 25, and Example 5 provides configuration 7. Through similar kinematic and static derivations, the remaining 31 double planetary gear configurations all satisfy the constant torque ratio characteristic, differing only in their torque ratio expressions. In summary, all 36 configurations satisfy the constant torque ratio characteristic, differing only in their torque ratio expressions.

[0121] Example 6 The main difference between this sixth embodiment and the above embodiments one to five and the following embodiments seven to ten is that the dual-input constant torque ratio continuously variable transmission system further includes at least one controllable locking mechanism CLM, and the controllable locking mechanism CLM is set in at least one of the following ways; a. The controllable locking mechanism CLM is located on the connection path between the first rotary power input source A and the first differential mechanism DU1; b. The controllable locking mechanism CLM is located on the connection path between the second rotary power input source B and the first differential mechanism DU1 or the second differential mechanism DU2; c. A controllable locking mechanism CLM is located between any input port (e.g., sun gear, planet carrier, or ring gear) of the first differential mechanism DU1 or the second differential mechanism DU2 and the fixed housing of the gearbox, and when this port is locked, the transmission system can be driven by only the other input source.

[0122] In this sixth embodiment, the gearbox, composed of a differential mechanism, possesses two independent degrees of freedom of motion under normal dual-input operation. When the controllable locking mechanism CLM is arranged and engaged as described in method c above, its physical essence is to lock a specific input port of the gearbox (e.g., the planetary carrier of DU1 or the sun gear of DU2) relative to the gearbox housing (forcing the rotational speed to zero). This locking directly eliminates one degree of freedom of motion of the gearbox, reducing the system's degree of freedom from "two" to "one".

[0123] It should be noted that the locked port is not required to be rigidly connected to any input source. The kinematic coupling relationship within the differential mechanism is utilized (e.g., the rotational speeds of the sun gear, planet carrier, and ring gear in a planetary gear set satisfy a linear equation). +K =(1+K) After locking one port, the other two ports can still rotate freely under constraints. Therefore, by reasonably selecting the locking port (e.g., locking the sun gear or ring gear that is not directly connected to the second rotary power input source B), the input source that originally corresponded to the kinematics of the locked port (e.g., the second rotary power input source B) can still maintain a free rotation state—it can be dragged by the output end to idle, or driven by an external prime mover (e.g., an engine) to generate electricity. The other unlocked rotary power input source (e.g., the first rotary power input source A) can then independently drive the gearbox and drive the output end.

[0124] Conversely, if the locked port happens to be the one directly and rigidly connected to a rotary power input source, then that rotary power input source will be forcibly locked and unable to rotate. Those skilled in the art can select the most suitable locking port position based on the specific configuration and operating conditions. In either case, a single-input drive mode can be achieved, and the option to allow free rotation of the locked power source can be selected as needed.

[0125] When the controllable locking mechanism is arranged in the manner described in a or b above, it directly interrupts the power connection between a certain rotary power input source and the gearbox, which can also reduce the system's degree of freedom from two to one, thus achieving single-input drive.

[0126] When the controllable locking mechanism is engaged, the system operates in single-input drive mode. In this mode, the unlocked input source drives the output independently, and the system speed ratio is determined by the relationship between the rotational speed of the input source and the rotational speed of the output. The input source corresponding to the locked port can either stop supplying power and remain stationary, or be allowed to rotate freely (e.g., driven by a prime mover to generate electricity).

[0127] Among them, the controllable locking mechanism (CLM) is one of a wet multi-plate clutch, a dry clutch, an electromagnetic brake, or a one-way bearing, and the fixed component refers to the fixed housing of the gearbox.

[0128] In one more specific embodiment, based on Embodiment 1 (Configuration 3), a controllable locking mechanism L is added. This embodiment adopts the simplest solution: a locking mechanism CLM (electromagnetic brake) is set only at the output end of the second rotary power input source B. The controllable locking mechanism CLM is set on the connection path between the second rotary power input source B (second motor) and the first differential mechanism DU1 or the second differential mechanism DU2. At the same time, no controllable locking mechanism is set at the shaft end of the first rotary power input source A (first motor A) to realize the single motor drive mode under low load conditions and further improve system efficiency.

[0129] 2. Switching between working modes Dual-motor stepless speed control mode: The controllable locking mechanism CLM is disconnected, both motors rotate freely, the system works as described in Example 1, the torque ratio is constant, and the output speed is continuously adjustable.

[0130] Single motor drive mode: When the vehicle speed is stable and the required torque is low (such as city cruising), the controller issues a command: the locking mechanism CLM engages, locking the rotor of motor B ( =0), and motor B is de-energized. At this time, only motor A drives the system. According to the kinematic equations of configuration 3:

[0131] The output speed is proportional to the speed of motor A (speed ratio = 1 / (K1K2)), and the system transmits power at a fixed speed ratio. When motor A operates alone, the load rate increases, and it typically operates in a higher efficiency range.

[0132] Mode switching control: The vehicle controller automatically makes decisions based on signals such as vehicle speed, accelerator pedal opening, and battery SOC. When rapid acceleration or hill climbing is required, the locking mechanism CLM is quickly disengaged, resuming the dual-motor mode with no delay in power response.

[0133] 3. Efficiency Benefits Under light-load conditions such as NEDC or WLTC urban cycles, using a single-motor drive mode can reduce the losses from simultaneous operation of dual motors, potentially further improving the overall system efficiency. The single-motor drive mode can reduce the losses from simultaneous operation of dual motors by approximately 40%, and improve the overall system efficiency by 5-8 percentage points. The drag loss of the controllable locking mechanism itself is extremely small (electromagnetic brake standby power consumption <10W), resulting in significant overall net benefits.

[0134] 4. Applicability to other configurations This embodiment uses configuration 3 as an example, but it can also be applied to 35 other double planetary gear configurations and 216 triple planetary gear configurations. Simply place the controllable locking mechanism at any input source path or planetary gear port, and calculate the speed ratio relationship in single-motor mode based on the kinematic equations of the corresponding configuration.

[0135] 5. Declaration It is important to emphasize that the controllable locking mechanism is an optional additional component and is not essential for realizing the core continuously variable transmission (CVT) function of this invention. Even without adding any controllable locking mechanism, Embodiments 1 to 5 (and the subsequent three-planetary gearbox Embodiments 7 to 10) can already fully realize the core functions of constant torque ratio CVT, no internal circulation, and no friction components. Adding a controllable locking mechanism is merely a further optimization of efficiency under specific operating conditions and does not change the essential characteristics of this invention. Furthermore, existing dual-motor systems suffer from low efficiency under light-load conditions due to the simultaneous operation of both motors. This invention can achieve a single-motor drive mode through an optional controllable locking mechanism, further improving overall efficiency.

[0136] It should also be noted that a first controllable locking mechanism CLM1 and a second controllable locking mechanism CLM2 are provided based on the double planetary gear configuration 7. For example... Figure 10 As shown, the first controllable locking mechanism CLM1 is installed inside the chassis and connected to the chassis. This first controllable locking mechanism CLM1 can be engaged or disengaged from the output shaft of the first rotary power input source A (which can also be understood as the output shaft connected via a gearbox). When the first controllable locking mechanism CLM1 is engaged with the output shaft of the first rotary power input source A, the power from the first rotary power input source A can be transmitted to the sun gear S1 of the first planetary gear set PG1. When the first controllable locking mechanism CLM1 is disengaged from the output shaft of the first rotary power input source A, the power from the first rotary power input source A cannot be transmitted to the sun gear S1 of the first planetary gear set PG1. The second controllable locking mechanism CLM2 is installed inside the chassis. Inside the housing and connected to the chassis, the first controllable locking mechanism CLM1 can be engaged or disengaged from the output shaft of the second rotary power input source B (which can also be understood as the output shaft connected via a transmission). When the second controllable locking mechanism CLM2 is engaged with the output shaft of the second rotary power input source B, the power of the second rotary power input source B can be transmitted to the ring gear R1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2. When the second controllable locking mechanism CLM2 is disengaged from the output shaft of the second rotary power input source B, the power of the second rotary power input source B cannot be transmitted to the ring gear R1 of the first planetary gear set PG1 and the sun gear S2 of the second planetary gear set PG2.

[0137] In one embodiment, a first controllable locking mechanism CLM1 and a second controllable locking mechanism CLM2 are provided on the basis of the double planetary gear configuration 13. Taking the double planetary gear configuration 13 as an example, as... Figure 11As shown, a first controllable locking mechanism CLM1 is installed inside and connected to the chassis. This first controllable locking mechanism CLM1 can be engaged or disengaged from the output shaft of the first rotary power input source A (which can also be understood as the output shaft connected via a transmission). When the first controllable locking mechanism CLM1 is engaged with the output shaft of the first rotary power input source A, the power from the first rotary power input source A can be transmitted to the planet carrier C1 of the first planetary gear set PG1; when the first controllable locking mechanism CLM1 is disengaged from the output shaft of the first rotary power input source A, the power from the first rotary power input source A cannot be transmitted to the planet carrier C1 of the first planetary gear set PG1. A second controllable locking mechanism CLM2 is installed inside and connected to the chassis. This second controllable locking mechanism CLM2 can be engaged or disengaged from the output shaft of the second rotary power input source B. When the second controllable locking mechanism CLM2 is engaged with the output shaft of the second rotary power input source B, the power of the second rotary power input source B can be transmitted to the sun gear S1 of the first planetary gear PG1 and the sun gear S2 of the second planetary gear PG2; when the second controllable locking mechanism CLM2 is disengaged from the output shaft of the second rotary power input source B, the power of the second rotary power input source B cannot be transmitted to the sun gear S1 of the first planetary gear PG1 and the sun gear S2 of the second planetary gear PG2. In one embodiment, a first controllable locking mechanism CLM1 and a second controllable locking mechanism CLM2 are provided based on the double planetary gear configuration 17. Taking the double planetary gear configuration 17 as an example, as... Figure 12 As shown, a first controllable locking mechanism CLM1 is installed inside and connected to the chassis. This first controllable locking mechanism CLM1 can be connected to or disconnected from the output shaft of the first rotary power input source A. When the first controllable locking mechanism CLM1 is engaged with the output shaft of the first rotary power input source A, the power from the first rotary power input source A can be transmitted to the planet carrier C1 of the first planetary gear set PG1; when the first controllable locking mechanism CLM1 is disconnected from the output shaft of the first rotary power input source A, the power from the first rotary power input source A cannot be transmitted to the planet carrier C1 of the first planetary gear set PG1. A second controllable locking mechanism CLM2 is installed inside and connected to the chassis. This second controllable locking mechanism CLM2 can be connected to or disconnected from the output shaft of the second rotary power input source B. When the second controllable locking mechanism CLM2 is engaged with the output shaft of the second rotary power input source B, the power of the second rotary power input source B can be transmitted to the sun gear S1 of the first planetary gear set PG1 and the ring gear R2 of the second planetary gear set PG2; when the second controllable locking mechanism CLM2 is disengaged from the output shaft of the second rotary power input source B, the power of the second rotary power input source B cannot be transmitted to the sun gear S1 of the first planetary gear set PG1 and the ring gear R2 of the second planetary gear set PG2.

[0138] In one embodiment, a first controllable locking mechanism CLM1 and a second controllable locking mechanism CLM2 are provided based on the three-planetary array configuration 13. Taking configuration 13 as an example, as follows... Figure 13 As shown, a first controllable locking mechanism CLM1 is installed inside and connected to the chassis. This first controllable locking mechanism CLM1 can be connected to or disconnected from the output shaft of the first rotary power input source A. When the first controllable locking mechanism CLM1 is engaged with the output shaft of the first rotary power input source A, the power from the first rotary power input source A can be transmitted to the sun gear S1 of the first planetary gear set PG1; when the first controllable locking mechanism CLM1 is disconnected from the output shaft of the first rotary power input source A, the power from the first rotary power input source A cannot be transmitted to the sun gear S1 of the first planetary gear set PG1. A second controllable locking mechanism CLM2 is installed inside and connected to the chassis. This second controllable locking mechanism CLM2 can be connected to or disconnected from the output shaft of the second rotary power input source B. When the second controllable locking mechanism CLM2 is engaged with the output shaft of the second rotary power input source B, the power of the second rotary power input source B can be transmitted to the planet carrier C1 of the first planetary set PG1 and the planet carrier C2 of the second planetary set PG2; when the second controllable locking mechanism CLM2 is disengaged from the output shaft of the second rotary power input source B, the power of the second rotary power input source B cannot be transmitted to the planet carrier C1 of the first planetary set PG1 and the planet carrier C2 of the second planetary set PG2. In one embodiment, a first controllable locking mechanism CLM1 and a second controllable locking mechanism CLM2 are provided based on the three planetary gear configuration 16. Taking the three planetary gear configuration 16 as an example, as... Figure 14As shown, a first controllable locking mechanism CLM1 is installed inside and connected to the chassis. This first controllable locking mechanism CLM1 can be connected to or disconnected from the output shaft of the first rotary power input source A. When the first controllable locking mechanism CLM1 is engaged with the output shaft of the first rotary power input source A, the power from the first rotary power input source A can be transmitted to the sun gear S1 of the first planetary gear set PG1; when the first controllable locking mechanism CLM1 is disconnected from the output shaft of the first rotary power input source A, the power from the first rotary power input source A cannot be transmitted to the sun gear S1 of the first planetary gear set PG1. A second controllable locking mechanism CLM2 is installed inside and connected to the chassis. This second controllable locking mechanism CLM2 can be connected to or disconnected from the output shaft of the second rotary power input source B. When the second controllable locking mechanism CLM2 is engaged with the output shaft of the second rotary power input source B, the power of the second rotary power input source B can be transmitted to the planet carrier C1 of the first planetary set PG1 and the planet carrier C2 of the second planetary set PG2; when the second controllable locking mechanism CLM2 is disengaged from the output shaft of the second rotary power input source B, the power of the second rotary power input source B cannot be transmitted to the planet carrier C1 of the first planetary set PG1 and the planet carrier C2 of the second planetary set PG2.

[0139] In one embodiment, a first controllable locking mechanism CLM1 and a second controllable locking mechanism CLM2 are provided based on the three planetary gear configuration 18. Taking the three planetary gear configuration 18 as an example, as... Figure 15 As shown, a first controllable locking mechanism CLM1 is installed inside and connected to the chassis. This first controllable locking mechanism CLM1 can be connected to or disconnected from the output shaft of the first rotary power input source A. When the first controllable locking mechanism CLM1 is engaged with the output shaft of the first rotary power input source A, the power from the first rotary power input source A can be transmitted to the sun gear S1 of the first planetary gear set PG1; when the first controllable locking mechanism CLM1 is disconnected from the output shaft of the first rotary power input source A, the power from the first rotary power input source A cannot be transmitted to the sun gear S1 of the first planetary gear set PG1. A second controllable locking mechanism CLM2 is installed inside and connected to the chassis. This second controllable locking mechanism CLM2 can be connected to or disconnected from the output shaft of the second rotary power input source B. When the second controllable locking mechanism CLM2 is engaged with the output shaft of the second rotary power input source B, the power of the second rotary power input source B can be transmitted to the planet carrier C1 of the first planetary set PG1 and the planet carrier C2 of the second planetary set PG2; when the second controllable locking mechanism CLM2 is disengaged from the output shaft of the second rotary power input source B, the power of the second rotary power input source B cannot be transmitted to the planet carrier C1 of the first planetary set PG1 and the planet carrier C2 of the second planetary set PG2.

[0140] Example 7 This embodiment is the seventh embodiment of a dual-input planetary gearbox constant torque ratio continuously variable transmission (CVT). Based on the dual planetary gearbox system, this embodiment adds a third differential mechanism DU3 between the first differential mechanism DU1 and the second differential mechanism DU2, using it as a fixed reducer. This implementation further reduces the constant torque ratio of the system by adding the third planetary gearbox PG3 as a fixed reduction mechanism, while maintaining core characteristics such as constant torque ratio, no internal circulation, and pure gear meshing. It is suitable for applications where the power difference between the main motor and auxiliary motor is large, requiring a lower torque ratio or higher low-speed, high-torque output.

[0141] It should be noted that both the dual planetary gearbox configuration and the triple planetary gearbox configuration of this invention are based on the same inventive concept: achieving a constant torque ratio between the two input sources through a specific dual-input topology of two differential mechanisms, thereby eliminating the dependence of torque distribution on rotational speed in principle. The triple planetary gearbox configuration is an extension of this, achieving a fixed reduction ratio by adding a fixed third differential mechanism, further optimizing the torque ratio value, while still retaining the core characteristics of the dual planetary gearbox configuration. Therefore, the above two types of configurations belong to a single inventive concept and possess unity of invention.

[0142] The system in this embodiment includes a first differential mechanism DU1, a second differential mechanism DU2, a second planetary gear set PG2, a third differential mechanism DU3, a first rotary power input source A, a second rotary power input source B, and an output terminal Out; wherein, the third differential mechanism DU3 is located between the first differential mechanism DU1 and the second differential mechanism DU2; The first differential mechanism DU1, the second differential mechanism DU2, and the third differential mechanism DU3 are all three-port differential mechanisms. The first rotary power input source A is connected to the first port of the first differential mechanism DU1. The second rotary power input source B is connected to the second port of the first differential mechanism DU1 and the first port of the second differential mechanism DU2 to form a dual input. The first port of the third differential mechanism DU3 is rigidly fixed. The third port of the first differential mechanism DU1 and the second port of the third differential mechanism DU3 are connected through the first connector X. The second port of the second differential mechanism DU2 and the third port of the third differential mechanism DU3 are connected through the second connector Y. The third port of the second differential mechanism DU2 is connected to the output terminal Out.

[0143] One port of the third planetary gear set PG3 is rigidly fixed, while the other two movable ports are connected to the first connector X and the second connector Y, respectively.

[0144] It should be noted that the first differential mechanism DU1 is one of the following: the first planetary gear set PG1, a symmetrical bevel gear differential, or an asymmetrical differential; the second differential mechanism DU2 is one of the following: the second planetary gear set PG2, a symmetrical bevel gear differential, or an asymmetrical differential; and the third differential mechanism DU3 is one of the following: the third planetary gear set PG3, a symmetrical bevel gear differential, or an asymmetrical differential. The first planetary gear set PG1, the second planetary gear set PG2, and the third planetary gear set PG3 are all single-planetary gear sets, each comprising a sun gear, a ring gear, a planet carrier, and planet gears mounted on the planet carrier. The planet gears mesh with the sun gear and the ring gear, respectively. The first, second, and third ports of the first differential mechanism DU1 represent different structures of the sun gear S1, ring gear R1, and planet carrier C1 of the first planetary gear set PG1; similarly, the first, second, and third ports of the second differential mechanism DU2 represent different structures of the sun gear S2, ring gear R2, and planet carrier C2 of the second planetary gear set PG2.

[0145] It should also be noted that the first, second, and third ports of the first differential mechanism DU1 are all different structures in the sun gear, ring gear, and planet carrier of the first planetary gear set PG1. The first, second, and third ports of the second differential mechanism DU2 are all different structures in the sun gear, ring gear, and planet carrier of the second planetary gear set PG2. The first, second, and third ports of the third differential mechanism DU3 are all different structures in the sun gear, ring gear, and planet carrier of the second planetary gear set PG3. The third differential mechanism DU3 is located between the first differential mechanism DU1 and the second differential mechanism DU2. It is connected to one port of the first differential mechanism DU1 via a first rotary power input source A, and a second rotary power input source B is connected to the other port of the first differential mechanism DU1 and one port of the second differential mechanism DU2 to form a dual input. One port of the third differential mechanism DU3 is rigidly fixed. The remaining port of the first differential mechanism DU1 is connected to the other port of the third differential mechanism DU3 via a first connector X. The other port of the second differential mechanism DU2 is connected to the remaining port of the third differential mechanism DU3 via a second connector Y. The remaining port of the second differential mechanism DU2 is connected to the output terminal Out. Through the above connection combinations, a total of 216 different configurations can be formed, and the specific configurations are shown in Table 2 below. It should be noted that since one port of the third differential mechanism is rigidly fixed, and the rest of the power transmission path of the system is realized through gear meshing, it does not contain friction elements such as clutches and brakes (except for optional controllable locking mechanisms).

[0146] Based on Table 1, each basic configuration has a clear connection relationship. The DU3 connection rules are as follows: Type A (R3 fixed), Type B (C3 fixed), and Type C (S3 fixed).

[0147] Type A (R3 fixed) has two total variants, including variant A1: S3 → node X, C3 → second port of PG2; variant A2: C3 → node X, S3 → second port of PG2.

[0148] Type B (C3 fixed) has two total variants, including variant B1: S3 → node X, R3 → second port of PG2; variant B2: R3 → node X, S3 → second port of PG2.

[0149] Type C (S3 fixed) has two total variants, including variant C1: C3 → node X, R3 → second port of PG2; variant C2: R3 → node X, C3 → second port of PG2.

[0150] The 216 three-planetary configurations formed by the above variants are detailed in Table 2.

[0151]

[0152] The explanations of the names in the table above are as follows: A is the first rotary power input source, B is the second rotary power input source, S1 is the sun gear on the first planetary gear set PG1, C1 is the planet carrier on the first planetary gear set PG1, R1 is the ring gear on the first planetary gear set PG1, S2 is the sun gear on the second planetary gear set PG2, C2 is the planet carrier on the second planetary gear set PG2, R2 is the ring gear on the second planetary gear set PG2; S3 is the sun gear on the third planetary gear set PG3, C3 is the planet carrier on the third planetary gear set PG3, R3 is the ring gear on the third planetary gear set PG3, and the name is A_S1_B_C1_C2 (numbered 16). Taking _X_S2 as an example: This name indicates that: the first rotary power input source A is connected to the sun gear S1 of the first planetary gear set PG1; the second rotary power input source B is connected to the planet carrier C1 of the first planetary gear set PG1 and the planet carrier C2 of the second planetary gear set PG2 respectively; the ring gear R1 of the first planetary gear set PG1 is connected to the sun gear S3 of the third planetary gear set PG3 through the first connector X; the planet carrier C3 of the third planetary gear set PG3 is connected to the sun gear S2 of the second planetary gear set PG2 through the second connector Y; the ring gear R3 of the third planetary gear set PG3 is rigidly fixed; and the ring gear R2 of the second planetary gear set PG2 is connected to the output terminal Out. The connection relationships of the corresponding names of the other numbers can also be deduced from the names.

[0153] Multiple variants of this invention achieve different fixed reduction ratios and torque characteristics through different DU3 port assignments. This invention combines 36 basic configurations of a dual planetary gearbox with 6 DU3 variants to form 216 extended configurations of a triple planetary gearbox. All configurations meet the requirements of constant torque ratio, pure gear meshing, and no internal circulation, providing a wide range of choices for different application scenarios. Compared with dual planetary gearbox systems, triple planetary gearbox systems, while maintaining ease of control and high reliability, further optimize the torque ratio and low-speed output capability, improving the system's adaptability.

[0154] like Figure 7 As shown, in one embodiment of the three planetary gear set, configuration 16 is referred to as the configuration three planetary gear set. In this embodiment, the variant of the two planetary gear set configuration 3+B2 corresponding to the three planetary gear set configuration 16 is as follows: Variant B2: the gear ring R3 is connected to the first connector X, and the sun gear S3 is connected to the second port of the second planetary gear set PG2. 1. The system's connections are as follows: The first rotary power input source A is connected to the sun gear S1 of the first planetary gear set PG1; the second rotary power input source B is connected to the planet carrier C1 of the first planetary gear set PG1 and the planet carrier C2 of the second planetary gear set PG2; the ring gear R1 of the first planetary gear set PG1 and the ring gear R3 of the third planetary gear set PG3 are connected via the first connector X; the sun gear S3 of the third planetary gear set PG3 and the sun gear S2 of the second planetary gear set PG2 are connected via the second connector Y; the planet carrier C3 of the third planetary gear set PG3 is rigidly fixed (to the housing), typically using bolts or keys to secure it to the gearbox housing, ensuring that PG3 provides a stable fixed reduction ratio. The ring gear R2 of the second planetary gear set PG2 is connected to the output end Out.

[0155] More specifically, the first rotary power input source A is a motor. The output shaft of motor A is directly connected to the bushing of the sun gear S1 via a spline, key, or flange, or through a coupling to achieve a rigid coaxial connection. If there is an axial distance between the motor and the planetary gear set, an intermediate drive shaft (with a support bearing) can be added. The connection ensures no relative rotation and reliable torque transmission. The second rotary power input source B is a motor. The output shaft of motor B is connected to a double-gear sleeve or double-bracket. One end of the sleeve is connected via a spline to the input shaft of the planet carrier C1 of the first planetary gear set PG1, and the other end is connected via a spline to the input shaft of the planet carrier C2 of PG2. The two planet carriers can share a single input shaft or be rigidly connected via a coupling to ensure that the rotational speeds are always equal. The first connecting component X is an intermediate shaft (or sleeve shaft). The outer ring or end face of the gear ring R1 is machined with an internal spline or flange, and is fixed to one end of the intermediate shaft X via a spline, bolts, or welding; the other end of the intermediate shaft X is connected to the gear ring R3 of PG3 via a spline. The intermediate shaft X is supported on the housing by bearings, ensuring free rotation. This connection allows R1 and R3 to rotate at the same speed. The second connecting component Y is an intermediate shaft (or sleeve shaft). The output end of the sun gear S3 of PG3 is fixed to one end of the intermediate shaft Y via a spline or flange; the other end of the intermediate shaft Y is connected to the bushing of the sun gear S2 of PG2 via a spline. The intermediate shaft Y is supported on the housing by bearings, ensuring free rotation. This connection allows the sun gears S3 and S2 to rotate at the same speed. The outer ring of the gear ring R2 is machined with gears or flanges and is directly fixed to the output shaft (Out) via splines, keys, or flange bolts. The output shaft is then connected to loads such as wheels, rotors, or robot joints via a universal joint or gear pair. If the output direction needs to be adjusted, a single-stage gear reduction or bevel gear can be added.

[0156] It should be noted that the three-planetary-gear configuration 16 is a variant of the two-planetary-gear configuration 3+B2: in the 3+B2 variant, the gear ring R3 of the third planetary gear PG3 is connected to the first connector X, the sun gear S3 is connected to the second connector Y, and the planet carrier C3 is rigidly fixed.

[0157] 2. Definition of General Symbols , The rotational speeds of the first and second rotary power input sources; Output speed; : First connecting component X rotational speed; : Rotational speed of the second connecting component Y; , , : First input source, second input source, and output torque; The gear ratio of PG1 ring gear to sun gear; The gear ratio of the PG2 ring gear to the sun gear; The gear ratio of the PG3 ring gear to the sun gear; Basic kinematic equations of planetary rank: +K =(1+K) .

[0158] 3. Complete derivation of kinematic equations The derivation is based on the 16+ double planetary configuration variant 3+B2: (1) Kinematic equations of the third planetary gear set PG3 (fixed deceleration) PG3 gear ring R3 fixed ( ): (3-1) (3-2) (3-3) From (3-3) we get Substitute into (3-2):

[0159] Substitute (3-1):

[0160] Multiply by both sides :

[0161] Rearrangement:

[0162]

[0163] remember:

[0164] but: (3-4) 4. Derivation of statics and constant torque ratio: (3-4) Substitute into the power conservation formula: + = Conclusion:

[0165]

[0166] Coefficients are independent:

[0167]

[0168] Therefore, we can conclude that:

[0169] absolute value of torque ratio:

[0170] 5. Transmission ratio function: derived from have to:

[0171] 6. Proof of no structural inner loop Under driving conditions (output torque) From the static relations (3-5) and (3-6), we can see that... <0、 >0.

[0172] To ensure that the power of both input sources is positive ( >0、 >0), take >0, <0 means the two input sources rotate in opposite directions. At this time, both input powers are output in the forward direction, and there is no reverse power flow, thus eliminating the internal circulation of mechanical power structurally.

[0173] Example 8 like Figure 6 As shown, this embodiment eight is a typical configuration 13 of a three-planetary array. The difference between the three-planetary array configuration 13 in embodiment seven and embodiment seven is that: 1. The connection relationships of this configuration system are as follows: The first rotary power input source A is connected to the sun gear S1 of the first planetary gear set PG1; the second rotary power input source B is connected to the planet carrier C1 of the first planetary gear set PG1 and the planet carrier C2 of the second planetary gear set PG2 respectively; the ring gear R1 of the first planetary gear set PG1 is connected to the sun gear S3 of the third planetary gear set PG3 through the first connector X; the planet carrier C3 of the third planetary gear set PG3 is connected to the sun gear S2 of the second planetary gear set PG2 through the second connector Y; the ring gear R3 of the third planetary gear set PG3 is rigidly fixed (grounded or fixed to the housing), usually by bolts or key connections, to ensure that PG3 provides a stable fixed reduction ratio. The ring gear R2 of the second planetary gear set PG2 is connected to the output terminal Out.

[0174] More specifically, the first rotary power input source A is a motor. The output shaft of motor A is directly connected to the bushing of the sun gear S1 via a spline, key, or flange, or through a coupling to achieve a rigid coaxial connection. If there is an axial distance between the motor and the planetary gear set, an intermediate drive shaft (with a support bearing) can be added. The connection ensures no relative rotation and reliable torque transmission. The second rotary power input source B is a motor. The output shaft of motor B is connected to a double-gear sleeve or double-bracket. One end of the sleeve is connected via a spline to the input shaft of the planet carrier C1 of the first planetary gear set PG1, and the other end is connected via a spline to the input shaft of the planet carrier C2 of PG2. The two planet carriers can share a single input shaft (i.e., the same shaft drives C1 and C2 simultaneously), or the input shafts of the two planet carriers can be rigidly connected via a coupling. This ensures that motor B drives both planet carriers simultaneously at the same speed. The first connecting member X is an intermediate shaft (or sleeve shaft). The outer ring or end face of gear ring R1 is machined with internal splines or flanges, and is fixed to one end of intermediate shaft X via splines, bolts, or welding; the other end of intermediate shaft X is connected to the bushing of sun gear S3 of PG3 via splines. Intermediate shaft X can be supported on the housing by bearings to ensure free rotation. This connection allows R1 and sun gear S3 to have the same rotational speed. The second connecting component Y is an intermediate shaft (or sleeve shaft). The output end of planetary carrier C3 of PG3 is fixed to one end of intermediate shaft Y via splines or flanges; the other end of intermediate shaft Y is connected to the bushing of sun gear S2 of PG2 via splines. Intermediate shaft Y can be supported on the housing by bearings to ensure free rotation. This connection allows C3 and S2 to have the same rotational speed. The outer ring of gear ring R2 is machined with gears or flanges, and is directly fixed to output shaft Out via splines, keys, or flange bolts. The output shaft is then connected to loads such as wheels, rotors, or robot joints via universal joints or gear pairs. If the output direction needs to be adjusted, a single-stage gear reduction or bevel gear can be added.

[0175] It should be noted that the three-planetary configuration 13 is a variant of the two-planetary configuration 3+A1: the 3+A1 variant is as follows: the sun gear S3 of the third planetary gear PG3 is connected to the first connector X, the planet carrier C3 is connected to the second connector Y, and the gear ring R3 is rigidly fixed.

[0176] 2. The definition of general symbols refers to the definition of general symbols for the three-planetary configuration 16 in Example 7; 3. Complete derivation of kinematic equations (4-1) (4-2) (4-3) Because the gear ring R3 is rigidly fixed

[0177] From (4-3) we get Substitute into (4-1):

[0178] From (4-2) we get Substitute into the above formula:

[0179]

[0180] make:

[0181] but: (4-4) 4. Derivation of statics and constant torque ratio: (4-4) Substitute into the power conservation formula: + = (Analogous to the derivation in Example 7) it is concluded that:

[0182] 5. The transmission ratio function (derived by analogy to the derivation in Example 7) yields:

[0183] 6. Proof of no structural inner loop Under driving conditions (output torque) From the statics equation (4-5), we can see that... >0、 Its sign is determined by the parameter Decision. To ensure that the power of both input sources is positive ( >0、 >0), take >0, and according to symbol selection In the direction, if >0, then >0, if <0 <0, by reasonably selecting the direction of rotation, the internal circulation of mechanical power can be avoided structurally. For example, when taking At that time, the calculation yielded It is negative, therefore At this point, they need to rotate in the same direction.

[0184] Example 9 like Figure 8 As shown, this embodiment nine describes a typical configuration 18 of a three-planetary array. The difference between this configuration 18 and that in embodiment seven is that: 1. The connection relationships of this configuration system are as follows: The first rotary power input source A is connected to the sun gear S1 of the first planetary gear set PG1; the second rotary power input source B is connected to the planet carrier C1 of the first planetary gear set PG1 and the planet carrier C2 of the second planetary gear set PG2 respectively; the ring gear R1 of the first planetary gear set PG1 and the ring gear R3 of the third planetary gear set PG3 are connected through the first connector X; the planet carrier C3 of the third planetary gear set PG3 and the sun gear S2 of the second planetary gear set PG2 are connected through the second connector Y; the sun gear S3 of the third planetary gear set PG3 is rigidly fixed (grounded or fixed to the housing), usually by bolts or key connections, to ensure that PG3 provides a stable fixed reduction ratio. The ring gear R2 of the second planetary gear set PG2 is connected to the output end Out.

[0185] More specifically, the first rotary power input source A is a motor. The output shaft of motor A is directly connected to the bushing of the sun gear S1 via a spline, key, or flange, or through a coupling to achieve a rigid coaxial connection. If there is an axial distance between the motor and the planetary gear set, an intermediate drive shaft (with a support bearing) can be added. The connection ensures no relative rotation and reliable torque transmission. The second rotary power input source B is a motor. The output shaft of motor B is connected to a double-gear sleeve or double-bracket. One end of the sleeve is connected via a spline to the input shaft of the planet carrier C1 of the first planetary gear set PG1, and the other end is connected via a spline to the input shaft of the planet carrier C2 of PG2. The two planet carriers can share a single input shaft or be rigidly connected via a coupling to ensure that the rotational speeds are always equal. The first connecting component X is an intermediate shaft (or sleeve shaft). The outer ring or end face of the gear ring R1 is machined with an internal spline or flange, and is fixed to one end of the intermediate shaft X via a spline, bolts, or welding; the other end of the intermediate shaft X is connected to the gear ring R3 of PG3 via a spline. The intermediate shaft X is supported on the housing by bearings, ensuring free rotation. This connection allows R1 and R3 to rotate at the same speed. The second connecting component Y is an intermediate shaft (or sleeve shaft). The output end of the planetary carrier C3 of PG3 is fixed to one end of the intermediate shaft Y via a spline or flange; the other end of the intermediate shaft Y is connected to the bushing of the sun gear S2 of PG2 via a spline. The intermediate shaft Y is supported on the housing by bearings, ensuring free rotation. This connection allows C3 and S2 to rotate at the same speed. The outer ring of the gear ring R2 is machined with gears or flanges and is directly fixed to the output shaft (Out) via splines, keys, or flange bolts. The output shaft is then connected to loads such as wheels, rotors, or robot joints via a universal joint or gear pair. If the output direction needs to be adjusted, a single-stage gear reduction or bevel gear can be added.

[0186] It should be noted that the three-planetary-gear configuration 18 double-planetary-gear configuration 3+C2 variant: the 3+C2 variant is as follows: the gear ring R3 of the third planetary gear PG3 is connected to the first connector X, the planet carrier C3 is connected to the second connector Y, and the sun gear S3 is rigidly fixed.

[0187] 2. The definition of general symbols refers to the definition of general symbols for the three-planetary configuration 16 in Example 7; 3. Complete derivation of kinematic equations

[0188] From (5-3) we get Substituting into (5-2), we get:

[0189] Substituting into (5-1), we get:

[0190] make:

[0191] but

[0192] 4. Derivation of statics and constant torque ratio: (5-4) Substitute into the power conservation formula: + = (Analogous to the derivation in Example 7) it is concluded that:

[0193] 5. The transmission ratio function (derived by analogy to the derivation in Example 7) yields:

[0194] 6. Proof of no structural inner loop Under driving conditions (output torque) From the statics equation (5-5), we can see that... >0、 Its sign is determined by the parameter Decision. To ensure that the power of both input sources is positive ( >0、 >0), take >0, and according to symbol selection In the direction, if >0, then >0, if <0 By appropriately selecting the direction of rotation, the internal circulation of mechanical power can be avoided structurally. For example, when taking... At that time, the calculation yielded It is negative, therefore At this point, they need to rotate in the same direction.

[0195] Example 10 like Figure 9As shown, this embodiment ten describes a typical configuration 100 of a three-planetary array. The difference between the three-planetary array configuration 100 in embodiment nine and that in embodiment seven is: 1. The connection relationships of this configuration system are as follows: The first rotary power input source A is connected to the planet carrier C1 of the first planetary gear set PG1; the second rotary power input source B is connected to the sun gear S1 of the first planetary gear set PG1 and the ring gear R2 of the second planetary gear set PG2 respectively; the ring gear R1 of the first planetary gear set PG1 and the ring gear R3 of the third planetary gear set PG3 are connected through the first connector X; the sun gear S3 of the third planetary gear set PG3 and the sun gear S2 of the second planetary gear set PG2 are connected through the second connector Y; the planet carrier C3 of the third planetary gear set PG3 is rigidly fixed (grounded or fixed to the housing), usually fixed to the gearbox housing by bolts or keys to ensure that PG3 provides a stable fixed reduction ratio; the planet carrier C2 of the second planetary gear set PG2 is connected to the output end Out.

[0196] More specifically, the first rotary power input source A is a motor. The output shaft of motor A is directly connected to the input shaft of planetary carrier C1 via a spline or key, or through a coupling for a rigid coaxial connection. If there is an axial distance between the motor and the planetary gear set, an intermediate drive shaft (with a support bearing) can be added. The connection ensures no relative rotation and reliable torque transmission. The second rotary power input source B is a motor. The output shaft of motor B is connected to a double-jointed structure. One end of this structure is connected to the sun gear S1 shaft of the first planetary gear set PG1 via a spline, and the other end is connected to the gear ring R2 of PG2 via a spline or gear. The gear ring R2 can be fixed to the output end of B via an internal spline or flange to ensure equal speeds at both ends. The first connecting piece X is an intermediate shaft (or sleeve shaft). The outer ring or end face of the gear ring R1 is machined with an internal spline or flange, and is fixed to one end of the intermediate shaft X via a spline, bolts, or welding; the other end of the intermediate shaft X is connected to the gear ring R3 of PG3 via a spline. The intermediate shaft X can be supported on the housing by bearings to ensure free rotation. This connection ensures that R1 and R3 rotate at the same speed. The second connecting component Y is an intermediate shaft (or sleeve shaft). The output end of the sun gear S3 of PG3 is fixed to one end of the intermediate shaft Y via a spline or flange; the other end of the intermediate shaft Y is connected to the bushing of the sun gear S2 of PG2 via a spline. The intermediate shaft Y can be supported on the housing by bearings to ensure free rotation. This connection ensures that S3 and S2 rotate at the same speed. The output end of the planetary carrier C2 is fixed to the output shaft (Out) via a spline, key, or flange. The output shaft is then connected to loads such as wheels, rotors, or robot joints via a universal joint or gear pair. If the output direction needs to be adjusted, a single-stage gear reduction or bevel gear can be added.

[0197] It should be noted that the three-planetary-gear configuration 100 and the two-planetary-gear configuration 17+B2 variant are: the 17+B2 variant is a B2 variant connection based on the two-planetary-gear structure of configuration 17, with a third planetary gear PG3 superimposed. Variant B2: the gear ring R3 is connected to the first connector X, and the sun gear S3 is connected to the second port of the second planetary gear PG2; 2. The definition of general symbols refers to the definition of general symbols for the three-planetary configuration 16 in Example 7; 3. Complete derivation of kinematic equations

[0198] From (6-3) we get Substitute into (6-2):

[0199] Substitute (6-1):

[0200] Multiply both sides + =

[0201] Summarized as follows: =( )

[0202] Divide both sides by :

[0203] make:

[0204] but:

[0205] 4. Derivation of statics and constant torque ratio: (6-4) Substitute into the power conservation formula: + = (Analogous to the derivation in Example 7) it is concluded that: ( )+ =

[0206] ( + ) +( ) =0 Conclusion:

[0207] 5. The transmission ratio function (derived by analogy to the derivation in Example 7) yields:

[0208] 6. Proof of no structural inner loop Under driving conditions (output torque) From the statics equation (6-5), we can see that... >0, its sign is determined by the parameter Decision. To ensure that the power of both input sources is positive ( >0、 >0), because Pick <0, and according to symbol selection Direction: If > but >0 (reverse rotation), if <0 <0 (rotation in the same direction). By appropriately selecting the direction of rotation, the internal circulation of mechanical power can be avoided structurally. For example, when taking... At this time, under this parameter, it is necessary to <0, >0, in which case the two input sources need to be rotated in opposite directions.

[0209] The above-described embodiment 6 provides the specific derivation process for the constant torque ratio of three planetary gear configuration 16, embodiment 7 provides the configuration 13, embodiment 8 provides the configuration 18, and embodiment 9 provides the configuration 100. Through similar kinematic and static derivations, the remaining 212 three planetary gear configurations all satisfy the constant torque ratio characteristic, differing only in their torque ratio expressions. In summary, all 216 configurations of three planetary gears satisfy the constant torque ratio characteristic, differing only in their torque ratio expressions.

[0210] It should also be noted that in the above embodiments 1 to 9, the first rotary power input source A is a small motor and the second rotary power input source B is a large motor (the second rotary power input source B is a large motor relative to the first rotary power input source A). According to the design of the constant torque ratio of the system, a larger power motor can also be controlled by a smaller power motor to achieve stepless speed change with power amplification. Since the torque arm of the system is constant when the configuration of the entire system is determined, the large motor of the second rotary power input source B can be controlled by the small motor of the first rotary power input source A.

[0211] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0212] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A dual-input constant torque ratio continuously variable transmission system, characterized in that, It includes a first differential mechanism (DU1), a second differential mechanism (DU2), a first rotary power input source (A), a second rotary power input source (B), and an output terminal (OUT); wherein, Both the first differential mechanism (DU1) and the second differential mechanism (DU2) are three-port differential mechanisms; The first rotary power input source (A) is connected to the first port of the first differential mechanism (DU1); The second rotary power input source (B) is connected to the second port of the first differential mechanism (DU1) and the first port of the second differential mechanism (DU2) to form a dual input; The third port of the first differential mechanism (DU1) is connected to the second port of the second differential mechanism (DU2) via a first connector (X); The third port of the second differential mechanism (DU2) is connected to the output terminal (OUT).

2. The dual-input constant torque ratio continuously variable transmission system according to claim 1, characterized in that, The first differential mechanism (DU1) is one of the following: a first planetary gear set (PG1), a symmetrical bevel gear differential, or an asymmetrical differential; the second differential mechanism (DU2) is one of the following: a second planetary gear set (PG2), a symmetrical bevel gear differential, or an asymmetrical differential. Both the first planetary gear set (PG1) and the second planetary gear set (PG2) include a sun gear, a ring gear, a planet carrier, and planet gears mounted on the planet carrier. The planet gears mesh with the sun gear and the ring gear, respectively.

3. The dual-input constant torque ratio continuously variable transmission system according to claim 2, characterized in that, The first rotary power input source (A) is connected to the sun gear (S1) of the first planetary gear set (PG1); The second rotary power input source (B) is connected to the planet carrier (C1) of the first planetary set (PG1) and the planet carrier (C2) of the second planetary set (PG2); The ring gear (R1) of the first planetary gear set (PG1) is connected to the sun gear (S2) of the second planetary gear set (PG2) through the first connector (X); The gear ring (R2) of the second planetary gear set (PG2) is connected to the output terminal (Out).

4. The dual-input constant torque ratio continuously variable transmission system according to claim 2, characterized in that, The first rotary power input source (A) is connected to the planet carrier (C1) of the first planetary set (PG1); The second rotary power input source (B) is connected to the sun gear (S1) of the first planetary gear set (PG1) and the sun gear (S2) of the second planetary gear set (PG2); The gear ring (R1) of the first planetary set (PG1) is connected to the planet carrier (C2) of the second planetary set (PG2) via the first connector (X); The gear ring (R2) of the second planetary gear set (PG2) is connected to the output terminal (Out).

5. A dual-input constant torque ratio continuously variable transmission system according to claim 2, characterized in that, The first rotary power input source (A) is connected to the planet carrier (C1) of the first planetary set (PG1); The second rotary power input source (B) is connected to the sun gear (S1) of the first planetary gear set (PG1) and the ring gear (R2) of the second planetary gear set (PG2); The ring gear (R1) of the first planetary gear set (PG1) is connected to the sun gear (S2) of the second planetary gear set (PG2) via the first connector (X); The planet carrier (C2) of the second planetary set (PG2) is connected to the output terminal (Out).

6. The dual-input constant torque ratio continuously variable transmission system according to claim 2, characterized in that, The first rotary power input source (A) is connected to the sun gear (S1) of the first planetary gear set (PG1); The second rotary power input source (B) is connected to the ring gear (R1) of the first planetary gear set (PG1) and the sun gear (S2) of the second planetary gear set (PG2); The planet carrier (C1) of the first planetary set (PG1) is connected to the planet carrier (C2) of the second planetary set (PG2) via the first connector (X); The gear ring (R2) of the second planetary gear set (PG2) is connected to the output terminal (Out).

7. A dual-input constant torque ratio continuously variable transmission system, characterized in that, It includes a first differential mechanism (DU1), a second differential mechanism (DU2), a third differential mechanism (DU3), a first rotary power input source (A), a second rotary power input source (B), and an output terminal (Out); the third differential mechanism (DU3) is located between the first differential mechanism (DU1) and the second differential mechanism (DU2); The first differential mechanism (DU1), the second differential mechanism (DU2), and the third differential mechanism (DU3) are all three-port differential mechanisms; The first rotary power input source (A) is connected to the first port of the first differential mechanism (DU1); The second rotary power input source (B) is connected to the second port of the first differential mechanism (DU1) and the first port of the second differential mechanism (DU2) to form a dual input; The first port of the third differential mechanism (DU3) is rigidly fixed; The third port of the first differential mechanism (DU1) is connected to the second port of the third differential mechanism (DU3) via a first connector (X); the second port of the second differential mechanism (DU2) is connected to the third port of the third differential mechanism (DU3) via a second connector (Y). The third port of the second differential mechanism (DU2) is connected to the output (Out).

8. A dual-input constant torque ratio continuously variable transmission system according to claim 7, characterized in that, The first differential mechanism (DU1) is one of the following: a first planetary gear set (PG1), a symmetrical bevel gear differential, or an asymmetrical differential; the second differential mechanism (DU2) is one of the following: a second planetary gear set (PG2), a symmetrical bevel gear differential, or an asymmetrical differential; and the third differential mechanism (DU3) is one of the following: a third planetary gear set (PG3), a symmetrical bevel gear differential, or an asymmetrical differential. The first planetary gear set (PG1), the second planetary gear set (PG2), and the third planetary gear set (PG3) each include a sun gear, a ring gear, a planet carrier, and planet gears mounted on the planet carrier. The planet gears mesh with the sun gear and the ring gear, respectively.

9. A dual-input constant torque ratio continuously variable transmission system according to claim 8, characterized in that, The first rotary power input source (A) is connected to the sun gear (S1) of the first planetary gear set (PG1); The second rotary power input source (B) is connected to the planet carrier (C1) of the first planetary set (PG1) and the planet carrier (C2) of the second planetary set (PG2); The ring gear (R1) of the first planetary gear set (PG1) is connected to the sun gear (S3) of the third planetary gear set (PG3) via the first connector (X); The planet carrier (C3) of the third planetary set (PG3) is connected to the sun gear (S2) of the second planetary set (PG2) via the second connector (Y); The gear ring (R3) of the third planetary gear set (PG3) is rigidly fixed; The gear ring (R2) of the second planetary gear set (PG2) is connected to the output terminal (Out).

10. A dual-input constant torque ratio continuously variable transmission system according to claim 8, characterized in that: The first rotary power input source (A) is connected to the sun gear (S1) of the first planetary gear set (PG1); The second rotary power input source (B) is connected to the planet carrier (C1) of the first planetary set (PG1) and the planet carrier (C2) of the second planetary set (PG2); The gear ring (R1) of the first planetary set (PG1) is connected to the gear ring (R3) of the third planetary set (PG3) via the first connector (X); The sun gear (S3) of the third planetary gear set (PG3) is connected to the sun gear (S2) of the second planetary gear set (PG2) via the second connector (Y); The planet carrier (C3) of the third planetary array (PG3) is rigidly fixed; The gear ring (R2) of the second planetary gear set (PG2) is connected to the output terminal (Out).

11. A dual-input constant torque ratio continuously variable transmission system according to claim 8, characterized in that, The first rotary power input source (A) is connected to the sun gear (S1) of the first planetary gear set (PG1); The second rotary power input source (B) is connected to the planet carrier (C1) of the first planetary set (PG1) and the planet carrier (C2) of the second planetary set (PG2); The gear ring (R1) of the first planetary gear set (PG1) and the gear ring (R3) of the third planetary gear set (PG3) are connected by the first connector (X); The planet carrier (C3) of the third planetary set (PG3) is connected to the sun gear (S2) of the second planetary set (PG2) via the second connector (Y); The sun gear (S3) of the third planetary array (PG3) is rigidly fixed; The gear ring (R2) of the second planetary gear set (PG2) is connected to the output terminal (Out).

12. A dual-input constant torque ratio continuously variable transmission system according to claim 8, characterized in that, The first rotary power input source (A) is connected to the planet carrier (C1) of the first planetary set (PG1); The second rotary power input source (B) is connected to the sun gear (S1) of the first planetary gear set (PG1) and the ring gear (R2) of the second planetary gear set (PG2); The gear ring (R1) of the first planetary set (PG1) is connected to the gear ring (R3) of the third planetary set (PG3) via the first connector (X); The sun gear (S3) of the third planetary gear set (PG3) is connected to the sun gear (S2) of the second planetary gear set (PG2) via the second connector (Y); The planet carrier (C3) of the third planetary array (PG3) is rigidly fixed; The planet carrier (C2) of the second planetary set (PG2) is connected to the output terminal (Out).

13. A dual-input constant torque ratio continuously variable transmission system according to any one of claims 1-12, characterized in that: It also includes at least one controllable locking mechanism (CLM), which is configured in at least one of the following ways: a. The controllable locking mechanism (CLM) is disposed on the connection path between the first rotary power input source (A) and the first differential mechanism (DU1); b. The controllable locking mechanism (CLM) is disposed on the connection path between the second rotary power input source (B) and the first differential mechanism (DU1) or the second differential mechanism (DU2); c. The controllable locking mechanism (CLM) is disposed between any input port of the first differential mechanism (DU1) or the second differential mechanism (DU2) and the fixed component, and the port is locked so that the transmission system is driven by only the other input source. When the controllable locking mechanism is engaged, the corresponding port or the corresponding input source is locked to a stationary state, so that the system is driven by only the other input source, thereby realizing a single-input drive mode.

14. A dual-input constant torque ratio continuously variable transmission system according to claim 13, characterized in that: The controllable locking mechanism (CLM) is one of a wet multi-plate clutch, a dry clutch, an electromagnetic brake, or a one-way bearing.

15. A dual-input constant torque ratio continuously variable transmission system according to claim 13, characterized in that: When the system operates in single-input drive mode, the motor corresponding to the locked input source stops receiving power and is stationary, while the other input source drives the output terminal independently. The system speed ratio is determined by the relationship between the rotational speed of the other input source and the rotational speed of the output terminal.

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