Stepless speed change, constant power and power confluence and shunt hybrid power device

Abstract

The invention provides a stepless speed change, constant power and power converging and shunting hybrid power device, and belongs to the technical field of gearboxes. The device structurally comprises a high-low speed planetary structure, a forward gear planetary structure and a reverse gear planetary structure which are sequentially arranged from front to back, a variable pump is connected with a sun gear in the planetary structure, and a variable motor is connected with a sun gear in the high-low speed planetary structure; the high-low speed planet carrier is connected with the forward gear clutch and the reverse gear clutch, the forward gear clutch is connected with the forward gear ring through a friction plate, and the reverse gear clutch is connected with the reverse gear ring through a friction plate. Full-automatic transmission is achieved, safety and maneuverability are remarkably improved, meanwhile, a transmission system is protected, and performance is optimized. Compared with the prior art, the invention has the best driving comfort, and can be widely applied to engineering machinery, agricultural machinery, forestry machinery, vehicle engineering, urban buses and other machines capable of walking.

Description

Technical Field

[0001] This invention relates to the field of gearbox technology, specifically to a continuously variable transmission (CVT), constant power, power confluence, and power split hybrid device. Background Technology

[0002] A gearbox is a mechanism used to change the speed and torque from an engine, altering the transmission ratio between the output and input shafts in a fixed or progressively changing manner. With continuous technological innovation, new gearbox technologies are constantly being developed. For example, Caterpillar's power-split torque converter is used in bulldozers; Dana's synchronized shift gearbox is used in front-end forklifts; Beijing Institute of Technology's HMT gearbox is used in tanks; and Toyota's THS hybrid gearbox is used in the automotive industry.

[0003] However, these existing technologies generally have the following drawbacks: 1. They cannot achieve constant power for the vehicle; 2. They cannot meet the requirements of continuously variable transmission and synchronous shifting; 3. The vehicle always operates at the rated power point or at any point of the engine's external characteristic limit under any operating condition; 4. The vehicle can combine power in two dimensions under any operating condition; 5. Because it always operates at the maximum power point, its production efficiency is maximized. Summary of the Invention

[0004] The technical problem to be solved by this invention is: how to design a gearbox device that has the following functions: 1. continuously variable transmission; 2. constant power; 3. matching with the engine under various working conditions; 4. energy saving and consumption reduction; 5. always working at the maximum power point; 6. maximum production efficiency; 7. able to realize power convergence, i.e., hybrid electric and hydraulic-engine hybrid, etc.

[0005] To achieve the above technical objectives, the present invention adopts the following technical solution: A continuously variable transmission (CVT) hybrid device with constant power, power merging, and power splitting includes a forward planetary gear structure, a reverse planetary gear structure, a high-speed and low-speed planetary gear structure, a variable pump, a variable motor, a high-speed clutch, a low-speed clutch, a forward gear clutch, and a reverse gear clutch. The high-speed and low-speed planetary gear structures, forward gear planetary gear structure, and reverse gear planetary gear structure are arranged sequentially from front to back. The variable pump is connected to the sun gear in the planetary gear structure, and the variable motor is connected to the sun gear in the high-speed and low-speed planetary gear structure. The high-speed and low-speed planetary carriers are connected to the forward gear clutch and the reverse gear clutch. The forward gear clutch is connected to the forward gear ring via friction plates, and the reverse gear clutch is connected to the reverse gear ring via friction plates.

[0006] Preferably, the engine or electric motor power is split into two paths at the sun gear. One path is directly transmitted from the sun gear, while the other path is transmitted sequentially through a variable displacement pump, a variable displacement motor, a forward clutch, a reverse clutch, and a ring gear. The two paths merge in the planetary carrier and are then output. Preferably, under low-speed forward operation, the low-speed clutch and forward gear clutch are engaged, and the power is transmitted to the forward gear clutch through the planetary carrier, and then to the ring gear in the forward gear planetary structure through the friction plates. The power from the ring gear and the power from the sun gear are combined in the planetary carrier and output outward.

[0007] As a preferred embodiment, under high-speed forward operation, the high-speed clutch and forward gear clutch are engaged, and the variable motor transmits power at a certain speed through the planetary carrier to the forward gear clutch, and through the friction plates to the gear ring in the forward gear planetary structure, where it merges with the power in the sun gear in the planetary carrier and outputs it outward.

[0008] The present invention has the following beneficial effects: (a) Fully automatic transmission system: The hydraulic (electric) mechanical solution maximizes the advantages of hydraulic (electric) components. This invention combines a two-degree-of-freedom planetary mechanism with a closed-loop hydraulic (electric) drive, ensuring the vehicle always operates at its optimal point—either the highest efficiency range, the rated power point, or the optimal fuel-saving point. Vehicle speed is independent of engine speed, and the output power is constant. Furthermore, hydraulic (electric) drive and mechanics are a perfect match.

[0009] (ii) Significantly improved safety and mobility: When a vehicle is going uphill or downhill, accelerating or decelerating, the output torque and output speed are continuously controlled. This allows the vehicle to decelerate or stop even without braking acceleration. The main function of this invention is to store and release energy, enabling the vehicle to decelerate or accelerate smoothly. This system avoids overheating during braking and allows for smooth starts from a standstill.

[0010] (III) Protection and optimization performance of the transmission system: 1. The engine always operates at a single point on the external characteristic curve. 2. The engine does not overheat. 3. There is no wear or burning during clutch engagement due to synchronization. 4. The engine does not stall. 5. The engine can operate under the conditions required by the customer. 6. Forced downshifting is possible while driving at high speeds. 7. Wear during braking is significantly reduced.

[0011] (iv) Optimal driving and comfort: Sudden acceleration and deceleration allow for continuous and uninterrupted torque output, enabling automatic transmission. The vehicle remains unaffected by negative impacts, maintaining constant power output and improving production efficiency. Integrated cruise control simplifies operation. Simultaneously, autonomous driving becomes possible.

[0012] (v) Scope of application: This invention applies to all mobile machinery, including construction machinery, agricultural machinery, forestry machinery, vehicle engineering, and city buses. It can replace AT, AMT, MT, ACT, DCT, and even the currently researched HMT and EMT transmissions. Attached Figure Description

[0013] Figure 1 This is a structural diagram of the present invention; Figure 2 This is a schematic diagram illustrating the compatibility of the invention with an engine under different operating conditions; Figure 3 This is a schematic diagram illustrating the matching range of the present invention with the engine; Figure 4 This is a schematic diagram of the LHS-two-stage power combined hybrid system of the present invention; In the picture: Detailed Implementation

[0014] The specific embodiments of the present invention will be described in detail below. To avoid excessive and unnecessary detail, well-known structures or functions will not be described in detail in the following embodiments. The approximate language used in the following embodiments is for quantitative purposes, indicating that a certain degree of variation in quantity is permissible without changing the basic function. Unless otherwise defined, the technical and scientific terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art to which this invention pertains.

[0015] like Figure 1 As shown, the structure of this invention includes a forward planetary gear system, a reverse planetary gear system, a high-speed and low-speed planetary gear system, a variable displacement pump, a variable displacement motor, a high-speed clutch, a low-speed clutch, a forward gear clutch, and a reverse gear clutch. The first row of this invention is a high-speed and low-speed planetary gear system, the second row is a forward planetary gear system, and the third row is a reverse planetary gear system. The variable displacement pump 3 is connected to the second sun gear 2 in the planetary gear system, and the variable displacement motor 4 is connected to the second sun gear 2 in the high-speed and low-speed planetary gear system. The first planetary carrier 7 (also referred to as a high-speed and low-speed planetary carrier) is connected to the forward gear clutch 8 and the reverse gear clutch 9. The forward gear clutch 8 is connected to the forward gear ring via friction plates, and the reverse gear clutch 9 is connected to the reverse gear ring via friction plates. The power from the engine or motor is divided into two paths at the sun gear. One path is directly transmitted from the first sun gear 1; the other path is transmitted from the variable pump 3 to the variable motor 4, then to the forward clutch 8 and the reverse clutch 9, and finally to the ring gear. The two paths merge in the planetary carrier and are output outward.

[0016] During operation, in low-speed forward mode, the low-speed clutch 6 and the forward gear clutch 8 are engaged. The variable displacement motor 4 achieves a large speed ratio in the high-low speed planetary structure. Power is transmitted through the first planetary carrier 7 to the forward gear clutch 8, and then through the friction plates to the ring gear in the forward gear planetary structure. The power from the first sun gear 1 merges with the power from the second planetary carrier 10 and is output outwards. In low-speed mode, the large speed ratio overcomes significant resistance. In high-speed forward mode, the high-speed clutch 5 and the forward gear clutch 8 are engaged. With the high-speed clutch 5 engaged, the speed ratio of the high-low speed planetary structure is 1. The variable displacement motor 4 transmits power at a higher speed through the first planetary carrier 7 to the forward gear clutch 8, and then through the friction plates to the ring gear in the forward gear planetary structure. The power from the first sun gear 1 merges with the power from the second planetary carrier 10 and is output outwards. In high-speed mode, the speed ratio is smaller, resulting in higher driving speeds. The reverse gear operates similarly; this invention has four gears: two forward and two reverse.

[0017] This invention has the following functions: ① Continuously variable transmission: According to the formula nT+Kn2=(1+K)nH, since nT and nZ are the rotational speeds of two degrees of freedom, continuously variable transmission can be achieved by combining them.

[0018] ② Constant power: According to the formula PH=PZ+PT. Regardless of whether PZ↑; Pt↓; PZ↓; PT↑; or PZ=Pt, their sum is always equal to PH, so the output power is always constant.

[0019] ③ Matching with the engine under various operating conditions: like Figure 2 As shown, HMT = hydraulic motor + engine, EMT = electric motor + engine; this invention can enable the motor, electric motor, and engine to work independently, and can also achieve deep hybridization into an electric-hydraulic hybrid system. This hydraulic-mechanical hybrid system, a two-degree-of-freedom electric-hydraulic hybrid, is no less advanced than Toyota's electric-hydraulic system.

[0020] ④ It can be perfectly matched with the engine: like Figure 3 As shown, MT can only be matched within the range of n1~n2, while AT can be matched partially within the speed range of n1~n2. Based on the fact that a two-degree-of-freedom planetary gear system can operate at any point on the external characteristic curve, it solves some special requirements of the vehicle's external characteristic curve. For example, bulldozer engines require a torque reserve coefficient of 1.25~1.5, hence their high price. However, loader engines or automobile engines can be matched with bulldozer engines, thus significantly reducing prices and saving costs.

[0021] ⑤ Energy saving and emission reduction: Based on the above statements, various combinations can achieve minimal energy loss and energy savings of over 50%, making it the most effective energy-saving device currently available. Secondly, the engine is unaffected by load and always operates at a consistent external characteristic point, thus avoiding problems such as sudden acceleration and smoke. Thirdly, while the thermal efficiency of a typical diesel engine is only 40%, with only 20% transmitted to the traveling parts, this invention ensures the engine always operates at its highest efficiency, fully utilizing the highest efficiency point and thus achieving significant energy savings.

[0022] ⑥ Highest production efficiency Under any operating condition, the engine operates at its highest efficiency point with constant power, eliminating the need for gear shifting, thus avoiding shifting losses and greatly improving work efficiency.

[0023] ⑦ Power Combining: like Figure 4 As shown, this invention constructs an LHS-two-stage power combined hybrid system. Figure 4 In this context, M represents a pure gasoline engine; D represents a pure electric motor; and K represents the planetary gear set characteristic value.

[0024] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A continuously variable, constant power, power-merge, split hybrid device, characterized in that The transmission comprises a forward planetary structure, a reverse planetary structure, a high-low planetary structure, a variable pump, a variable motor, a high-speed clutch, a low-speed clutch, a forward clutch, and a reverse clutch. The high-low planetary structure, the forward planetary structure, and the reverse planetary structure are arranged in sequence from front to back, the variable pump is connected with a sun gear in the planetary structure, and the variable motor is connected with a sun gear in the high-low planetary structure; the high-low planetary carrier is connected with the forward clutch and the reverse clutch, the forward clutch is connected with a forward ring gear through a friction plate, and the reverse clutch is connected with a reverse ring gear through a friction plate.

2. A continuously variable, constant power, power-merge, split hybrid device according to claim 1, characterized in that, Engine or motor power is divided into two routes at the sun gear, one route of power is directly transmitted by the sun gear, and the other route of power is transmitted by the variable pump, the variable motor, the forward clutch, the reverse clutch, and the ring gear in sequence, and the two routes of power are combined in the planetary carrier and then outputted outward.

3. The continuously variable, constant power, power-merge, split hybrid device of claim 1, wherein, In the forward low-speed working condition, the low-speed clutch and the forward clutch are closed, power is transmitted to the forward clutch through the planetary carrier, transmitted to the ring gear in the forward planetary structure through the friction plate, combined with power in the sun gear in the planetary carrier, and then outputted outward.

4. The continuously variable, constant power, power-merge, split hybrid device of claim 1, wherein, In the forward high-speed working condition, the high-speed clutch and the forward clutch are closed, the variable motor is transmitted to the forward clutch through the planetary carrier at a certain speed, transmitted to the ring gear in the forward planetary structure through the friction plate, combined with power in the sun gear in the planetary carrier, and then outputted outward.

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