Transmission Design Method and Electronic Equipment Based on Separable Planetary Gear Train Topology

Abstract

This invention discloses a transmission design method and electronic device based on a separable planetary gear train topology diagram. The design method includes topological synthesis of the separable planetary gear train topology diagram, drawing the corresponding functional diagram, converting the obtained functional diagram into a corresponding lever diagram, and adding shift control elements to the obtained lever diagram using the lever method, thereby obtaining a simplified diagram of the automatic transmission mechanism. This design method can be used to design all possible 7-speed, 8-speed, and 9-speed automatic transmission mechanism configurations and determine the characteristic parameter values ​​of the basic planetary gear train units. It can also screen out novel automatic transmission mechanisms with reasonable transmission ratios, reasonable step ratios, high transmission efficiency, and specific functions. Unlike traditional design methods, this method does not rely on the designer's experience and intuition, nor is it an improvement on an existing mechanism; rather, it is a completely new automatic transmission mechanism design method with systematicity and high efficiency.

Description

Technical Field

[0001] This invention belongs to the field of vehicle transmission technology, specifically relating to a transmission design method and electronic equipment based on a separable planetary gear train topology diagram. Background Technology

[0002] Existing methods typically rely on the designer's experience and intuition, employing a few known combinations of planetary gear sets to design automatic transmission mechanisms, or modifying existing mechanisms. These methods involve a high probability of trial and error, low design efficiency, long design time, and are prone to producing isomorphic configurations. Furthermore, they can only design a limited number of mechanisms, making it difficult to guarantee optimal performance. Many novel automatic transmission mechanisms with superior performance await further design and development. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned shortcomings of the prior art by providing a transmission design method and electronic device based on a separable planetary gear train topology diagram.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] The first objective of this invention is to provide a transmission design method based on a separable planetary gear train topology diagram. The separable planetary gear train topology diagram refers to a topology diagram where a component can be separated into an independent planetary gear train. The design method includes the following specific steps:

[0006] S1. Topological synthesis of separable planetary gear train topology diagrams, the specific synthesis process of which is as follows:

[0007] S11. Determine the 1-DOF planetary gear train sub-diagram that can be used for automatic transmission mechanism design;

[0008] S12. Identify all asymmetric vertices in each planetary gear train subgraph;

[0009] S13. Combine all asymmetric vertices of any two planetary gear train subgraphs to obtain all possible separable planetary gear train topologies.

[0010] S2. Draw the functional diagram corresponding to the topology diagram of the separable planetary gear train. The specific drawing process is as follows:

[0011] S21. Separate the separable planetary gear train topology diagram into two planetary gear train sub-diagrams;

[0012] S22. Draw all the sub-functional diagrams corresponding to each of the aforementioned planetary gear train sub-diagrams;

[0013] S23. Connect the sub-functional diagrams obtained in step S22 according to the structure of the separable planetary gear train topology diagram to obtain the functional diagram corresponding to the separable planetary gear train topology diagram;

[0014] S3. Convert the functional diagram obtained in step S2 into a corresponding lever diagram;

[0015] S4. Using the lever method, add shift control elements to the lever diagram obtained in step S3 to complete the design and obtain a simplified diagram of the automatic transmission mechanism.

[0016] Furthermore, in step S11, each of the 1-DOF planetary gear train sub-diagrams includes multiple vertices and connecting lines. The vertices include hollow vertices and solid vertices. The number of hollow vertices is the same as the number of complex hinges in the corresponding planetary gear train, and each hollow vertex corresponds to each complex hinge. The number of solid vertices is the same as the number of components in the corresponding planetary gear train, and each solid vertex corresponds to each component. The connecting lines include solid lines and dashed lines. When the connection between two components is a rotational connection, a connecting line connects the corresponding two vertices in the planetary gear train sub-diagram, and the corresponding connecting line is a solid line. When the connection between two components is a gear connection, a connecting line connects the corresponding two vertices in the planetary gear train sub-diagram, and the corresponding connecting line is a dashed line.

[0017] Furthermore, the component is any one of a gear ring, planetary gear, planet carrier, and sun gear. The planet carrier and its corresponding planetary gear are determined according to the solid line path. In the solid line path with a length of 2 starting from the compound hinge, the first solid vertex represents the planet carrier, and the second solid vertex is the planetary gear corresponding to the planet carrier. The gear ring or the sun gear meshes with the planetary gear.

[0018] Furthermore, in step S13, the separable planetary gear train topology diagram includes a 9-bar, 2-DOF separable planetary gear train topology diagram and an 11-bar, 2-DOF separable planetary gear train topology diagram.

[0019] Furthermore, the topology of the 9-bar, 2-DOF separable planetary gear train is composed of a 6-bar...

[0020] The planetary gear train sub-diagram is composed of a 1-DOF planetary gear train sub-diagram and a 4-bar 1-DOF planetary gear train sub-diagram; the 11-bar 2-DOF separable planetary gear train topology is composed of two 6-bar 1-DOF planetary gear train sub-diagrams.

[0021] Furthermore, the conditions that the 4-bar 1-DOF planetary gear train sub-diagram and the 6-bar 1-DOF planetary gear train sub-diagram must satisfy are: they contain only one compound hinge with a vertex degree of 3 or 4, the planetary gears on the same planet carrier do not mesh with each other, each planetary gear meshes with a sun gear and a ring gear, and do not contain loops consisting only of dashed lines.

[0022] Furthermore, the lever diagram includes an input shaft, a planetary gear train, a shift control element, and an output shaft. The output shaft is directly connected to the planet carrier or ring gear of the planetary gear train, but not to the sun gear. The number of shift control elements does not exceed six, and each shift control element can achieve multiple forward gears and one reverse gear.

[0023] Furthermore, in step S4, the shift control element includes a clutch and a brake, the clutch being arranged between the input shaft and the planetary gear train components, and the brake being arranged on the non-output shaft.

[0024] A second objective of this invention is to provide a computer-readable storage medium storing a computer program configured to implement the steps of the above-described transmission design method based on a separable planetary gear train topology when invoked by a processor.

[0025] A third object of the present invention is to provide an electronic device comprising at least one processor and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the steps of the above-described transmission design method based on a separable planetary gear train topology.

[0026] Compared with the prior art, the beneficial effects of the technical solution provided by the present invention are as follows:

[0027] (1) This invention provides a transmission design method and electronic device based on a separable planetary gear train topology diagram. The design method includes topological synthesis of the separable planetary gear train topology diagram, drawing the corresponding functional diagram of the separable planetary gear train topology diagram, converting the obtained functional diagram into a corresponding lever diagram, and adding shift control elements to the obtained lever diagram using the lever method, thereby obtaining a simplified diagram of the automatic transmission mechanism. Unlike traditional design methods, the method provided by this invention does not rely on the designer's experience and intuition, nor is it an improvement on an already designed mechanism. This method is a novel automatic transmission mechanism design method, possessing systematicity and efficiency, capable of obtaining all mechanisms that satisfy design constraints, and thus enabling the selection of novel mechanisms with superior performance.

[0028] (2) This invention provides the constraints that planetary gear train sub-diagrams used in transmission design must satisfy, and determines three 6-link 1-DOF planetary gear train sub-diagrams and one 4-link 1-DOF planetary gear train sub-diagram. Through asymmetric vertex combination, all separable 9-link 2-DOF and 11-link 2-DOF planetary gear train topologies are obtained. Using the design method of this invention, the planet carrier, planetary gears, sun gear, and ring gear in the separable planetary gear train topologies are determined. This is then transformed into all feasible planetary gear train functional diagrams corresponding to the separable planetary gear train topologies, and the functional diagrams are transformed into corresponding lever diagrams. The shift control elements are rationally arranged, resulting in all automatic transmission mechanism configurations that satisfy a given number of gears. This method can design all possible 7-speed, 8-speed, and 9-speed automatic transmission mechanism configurations and determine the values ​​of the characteristic parameters of the basic planetary gear train units. Furthermore, a large number of novel automatic transmission mechanisms with reasonable transmission ratios, reasonable step ratios, high transmission efficiency, and specific functions (such as heavy-duty vehicles) can be selected from these automatic transmission mechanisms. Attached Figure Description

[0029] Figure 1 This is a flowchart of the transmission design method based on a separable planetary gear train topology diagram according to the present invention;

[0030] Figure 2 The topology diagram of the 6-bar 1-DOF planetary gear train provided by the automatic synthesis software in this invention;

[0031] Figure 3 A sub-diagram of a 6-link, 1-DOF planetary gear train to meet the design requirements of the transmission mechanism;

[0032] Figure 4 A sub-diagram of a 4-bar, 1-DOF planetary gear train to meet the design requirements of the transmission mechanism;

[0033] Figure 5 To be Figure 3 (c) and Figure 4 Topological diagrams of separable planetary gear trains with 9 links and 2 degrees of freedom, resulting in different topological structures;

[0034] Figure 6 To be Figure 3 (c) A topological diagram of an 11-bar, 2-DOF separable planetary gear train with a different topological structure obtained by combining it with itself;

[0035] Figure 7 for Figure 6 (a) The two planetary gear train sub-diagrams obtained after separation;

[0036] Figure 8 for Figure 6 (a) Corresponding function chart;

[0037] Figure 9 for Figure 8 The lever diagram corresponding to the first planetary gear system function diagram in the diagram;

[0038] Figure 10 This is a layout diagram of the control elements in Example 1;

[0039] Figure 11 A schematic diagram of a seven-speed transmission mechanism designed in Example 1;

[0040] Figure 12 This is a layout diagram of the control elements in Example 2;

[0041] Figure 13 This is a schematic diagram of an eight-speed transmission mechanism designed for Example 2;

[0042] Figure 14 This is a layout diagram of the control elements in Example 3;

[0043] Figure 15 This is a schematic diagram of a nine-speed transmission mechanism designed in Example 3. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the present invention clearer, the specific embodiments of the present invention will be further described in detail below with reference to specific examples and accompanying drawings. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with the techniques or conditions described in the literature in this field.

[0045] The technical terms used in this invention are explained as follows:

[0046] Planetary gear train topology diagram: A diagram consisting only of vertices and connecting lines used to represent the connection relationships between components and kinematic pairs in a planetary gear train.

[0047] Asymmetric vertices: Vertices in a topological graph that have different topological characteristics.

[0048] Separable planetary gear train topology: refers to a topology in which one of the vertices can be separated into an independent planetary gear train.

[0049] The discovery process of the 6-bar 1-DOF planetary gear train sub-diagram and the 4-bar 1-DOF planetary gear train sub-diagram that can be used for the mechanism design of automatic transmissions in this invention is as follows:

[0050] The applicant combined the previously proposed topological synthesis method for inseparable planetary gear trains with corresponding computer-aided automatic synthesis software [Reference: Yang Wenjian, Ding Huafeng, The complete set of one-degree-of-freedom planetary gear trains with up to nine links. ASME Journal of Mechanical Design, 2019, 141(4): 043301-1-22]. The research results show that there are 81 planetary gear trains with 6 links and 1 degree of freedom. The interface of the developed automatic synthesis software for inseparable planetary gear trains and a partial topological diagram of a 6-link, 1-degree-of-freedom planetary gear train are shown below. Figure 2 As shown. The applicant has discovered that not all of the above-mentioned 6-bar 1-DOF planetary gear train topologies can be used for the design of automatic transmission mechanisms.

[0051] A 6-bar, 1-DOF planetary gear train topology must meet the following conditions to be used in the design of an automatic transmission mechanism:

[0052] (1) There is one and only one complex hinge with a vertex degree of 4;

[0053] (2) The topological diagram of the planetary gear train is a planar diagram to avoid interference between components;

[0054] (3) If the planetary gears on the same planetary carrier do not mesh with each other, it is a single planetary gear train;

[0055] (4) Each planet meshes with a sun gear and a ring gear;

[0056] (5) The planetary gear train topology diagram does not contain loops consisting only of gear connections.

[0057] From all 81 6-link 1-DOF planetary gear train topologies, three 6-link 1-DOF planetary gear train topologies satisfying the above conditions are identified. These three topologies are used as sub-diagrams of 6-link 1-DOF planetary gear trains, such as... Figure 3 As shown in the diagram, hollow vertices represent complex hinges, solid vertices represent components, solid lines represent revolute pairs, and dashed lines represent gear pairs.

[0058] Similarly, there are three 4-link, 1-DOF planetary gear trains. Only one 4-link, 1-DOF planetary gear train can be used in the design of an automatic transmission mechanism. This diagram is a sub-diagram of a 4-link, 1-DOF planetary gear train, as shown below. Figure 4 As shown.

[0059] The topology synthesis method for the separable planetary gear train topologies of 9-link 2-DOF and 11-link 2-DOF trains in this invention is as follows:

[0060] like Figure 3 and Figure 4 As shown, combining a 6-bar, 1-DOF planetary gear train sub-diagram and a 4-bar, 1-DOF planetary gear train sub-diagram yields a 9-bar, 2-DOF separable planetary gear train. For example, Figure 3 In (c), the asymmetric vertices of the 6-bar 1-DOF planetary gear train subgraph are vertex 2, vertex 3, and vertex 6; Figure 4 The asymmetric vertices of the 4-bar 1-DOF planetary gear train subgraph are vertices 2, 3, and 4. Figure 3 (c) and Figure 4 By combining all the asymmetric vertices, we can obtain nine separable planetary gear train topologies with different topologies, such as... Figure 5 As shown. A separable planetary gear train topology is one in which the topology can be separated into independent planetary gear trains at a certain vertex. For example, Figure 5 The separable planetary gear train topology in (a) can be separated into two independent planetary gear trains at vertex 2.

[0061] Combining two 6-bar, 1-DOF planetary gear train sub-diagrams yields an 11-bar, 2-DOF separable planetary gear train. For example, combining... Figure 3 (c) The 6-bar 1-DOF planetary gear train can be combined with itself to obtain 9 separable 11-bar 2-DOF planetary gear train topologies with different topologies, such as Figure 6 As shown.

[0062] By applying the above method, we can synthesize the topology diagrams of separable planetary gear trains with 9 links and 2 degrees of freedom and 11 links and 2 degrees of freedom that can be used for the design of automatic transmissions.

[0063] Example 1

[0064] This embodiment provides a design for a seven-speed automatic transmission.

[0065] First, select one of the separable planetary gear train topologies obtained from the synthesis and draw the corresponding function diagram. The drawing method is as follows: (a) Separate the separable planetary gear train topology into two planetary gear train sub-diagrams; (b) In each sub-diagram, determine the planet carrier and its corresponding planetary gears based on the solid line path. In the solid line path with a length of 2 starting from the compound hinge, the first solid vertex represents the planet carrier, and the second solid vertex is the planetary gear corresponding to the planet carrier; the gear meshing with the planetary gear is the ring gear or the sun gear; (c) Draw all possible sub-function diagrams corresponding to each planetary gear train sub-diagram; (d) Connect the two sub-function diagrams according to the structure of the separable planetary gear train topology to obtain the function diagram corresponding to the separable planetary gear train topology.

[0066] For example, Figure 6(a) The two planetary gear train sub-diagrams obtained after separation are as follows Figure 7 As shown. Figure 7 In (a), the solid line paths of length 2 starting from the compound hinge are 1-2-5 and 1-4-3. From path 1-2-5, we know that component 2 is the planet carrier, component 5 is its corresponding planetary gear, and components 4 and 6 that mesh with component 5 can be either the ring gear or the sun gear; from path 1-4-3, we know that component 4 is the planet carrier, component 3 is its corresponding planetary gear, and components 2 and 7 that mesh with component 3 can be either the ring gear or the sun gear. Figure 7 In (b), the solid line paths of length 2 starting from the compound hinge are 8-9-12 and 8-11-10. From path 8-9-12, we know that component 9 is the planet carrier, component 12 is its corresponding planetary gear, and components 2 and 11 that mesh with component 12 can be either the ring gear or the sun gear; from path 8-11-10, we know that component 11 is the planet carrier, component 10 is its corresponding planetary gear, and components 9 and 13 that mesh with component 10 can be either the ring gear or the sun gear. Figure 6 (a) All possible functional diagrams are as follows Figure 8 As shown.

[0067] Each function chart can be transformed into its corresponding lever chart. For example, Figure 8 The lever diagram corresponding to the first planetary gear system function diagram is as follows: Figure 9 As shown in (a), the equivalent simplified lever diagram is as follows: Figure 9 As shown in (b). Figure 9 (b) contains two sub-lever diagrams. Component PC1 (R2) is the output component of the first sub-lever diagram, and its output speed is input to the second sub-lever diagram as the input speed. Component R3 (PC4) is selected as the output component of the second sub-lever diagram, which is also the output component of the entire planetary gear train lever diagram. Its output speed is the output speed of the designed automatic transmission mechanism.

[0068] Adding shift control elements (clutch and brake) to the planetary gear train lever diagram enables the shifting function of an automatic transmission, thus allowing the design of the automatic transmission's mechanism configuration. The arrangement of the shift control elements should meet the following rules:

[0069] (1) The output shaft is usually directly connected to the planet carrier or gear ring, and not to the sun gear, because the output torque of the sun gear is relatively small;

[0070] (2) The number of control elements should generally not exceed six, because too many control elements will make the automatic transmission too large;

[0071] (3) The clutch is generally located between the input shaft and the planetary gear train components;

[0072] (4) The brake must not be placed on the output component;

[0073] (5) In order to reduce the complexity of gear shifting, only the working state of one control element changes when shifting gears;

[0074] (6) It needs to achieve multiple forward gears and one reverse gear;

[0075] (7) After the arrangement of the control elements is completed, it is necessary to determine whether the components will interfere. Configuration schemes that cause interference will increase the manufacturing difficulty of the automatic transmission and should be eliminated.

[0076] By applying the lever method and determining a reasonable arrangement of control elements in the planetary gear train functional diagram, the design of the automatic transmission mechanism can be completed. For example, using... Figure 9 A novel seven-speed automatic transmission mechanism is designed using the planetary gear train lever diagram. The arrangement of the control elements is as follows: Figure 10 As shown in the diagram, B1, B2, and B3 represent brakes, and C1, C2, and C3 represent clutches. The designed novel seven-speed automatic transmission mechanism is as follows: Figure 11 As shown. This seven-speed automatic transmission mechanism comprises four basic planetary gear units, namely PGT1, PGT2, PGT3, and PGT4. The mechanism enables seven forward gears (two overdrive gears, one direct drive gear, and four reduction gears) and one reverse gear.

[0077] Characteristic parameters of the basic unit of a planetary gear train K It is the gear ratio between the ring gear and the sun gear, a characteristic parameter. K The value of should be between 1.4 and 4. The step ratio of each gear in the automatic transmission should be between 1.1 and 1.8. To ensure that each gear in the automatic transmission mechanism has the maximum average transmission efficiency and reasonable transmission ratios and step ratios, the optimal characteristic parameters of the basic unit of the planetary gear train can be determined by using MATLAB programming and iterating through loops. K The value of is determined using the method described above. Figure 11 The characteristic parameters of the four basic planetary gear units PGT1, PGT2, PGT3, and PGT4 of the seven-speed transmission mechanism are as follows: K 1 = 2、 K 2 = 2、 K 3 = 2.2 and K 4 = 3.2.

[0078] Figure 11The shift control elements of the seven-speed transmission mechanism are arranged as follows: First clutch C1 connects the input shaft to the sun gear of the second basic planetary gear unit PGT2; second clutch C2 connects the input shaft to the ring gear of the first basic planetary gear unit PGT1 and the planet carrier of the second basic planetary gear unit PGT2; third clutch C3 connects the input shaft to the planet carrier of the third basic planetary gear unit PGT3 and the ring gear of the fourth basic planetary gear unit PGT4; first brake B1 connects to the sun gear of the first basic planetary gear unit PGT1; second brake B2 connects to the ring gear of the first basic planetary gear unit PGT1 and the planet carrier of the second basic planetary gear unit PGT2; third brake B3 connects to the sun gear of the fourth basic planetary gear unit PGT4.

[0079] Figure 11The working principle of the 7-speed transmission mechanism is as follows: When clutches C1, brakes B1 and B3 are engaged, the sun gear of the second basic planetary gear unit PGT2 serves as the input component, the transmission ratio is 5, and the transmission is in 1st gear. When clutches C2, brakes B1 and B3 are engaged, the ring gear of the first basic planetary gear unit PGT1 and the planet carrier of the second basic planetary gear unit PGT2 are both input components, the transmission ratio is 3, and the transmission is in 2nd gear. When clutches C1 and C2 and brakes B3 are engaged, the input shaft drives the first basic planetary gear unit PGT1 and the second basic planetary gear unit PGT2 to rotate as a whole, the transmission ratio is 2, and the transmission is in 3rd gear. When clutches C1 and C3 and brakes B3 are engaged, the sun gear of the second basic planetary gear unit PGT2, the planet carrier of the third basic planetary gear unit PGT3, and the ring gear of the fourth basic planetary gear unit PGT4 are all input components, the transmission ratio is 1.31, and the transmission is in 4th gear. 1. When C2 and C3 are in working condition, the input shaft drives the entire transmission mechanism to rotate, and the speed of the output shaft is equal to the speed of the input shaft. The transmission ratio of the transmission mechanism is 1, and the transmission is in direct drive. When clutches C2 and C3 and brake B1 are in working condition, the ring gear of the first basic planetary gear unit PGT1, the planet carrier of the second basic planetary gear unit PGT2, the planet carrier of the third basic planetary gear unit PGT3, and the ring gear of the fourth basic planetary gear unit PGT4 are all input components. The transmission ratio of the transmission mechanism is 0.87, and the transmission is in direct drive. When the transmission is in overdrive 6th gear; clutches C1 and C3 and brake B1 are engaged, the sun gear of the second basic planetary gear unit PGT2, the planet carrier of the third basic planetary gear unit PGT3, and the ring gear of the fourth basic planetary gear unit PGT4 are all input components, the transmission ratio of the transmission mechanism is 0.79, and the transmission is in overdrive 7th gear; when clutches C1, brakes B2 and B3 are engaged, the sun gear of the second basic planetary gear unit PGT2 is the input component, the transmission ratio of the transmission mechanism is -4, and the transmission is in reverse gear.

[0080] Example 2

[0081] This embodiment provides a design for an eight-speed automatic transmission.

[0082] The design method is the same as that in Example 1, except that the selection of the planetary gear train function diagram and the arrangement of the control elements are different. A novel eight-speed automatic transmission mechanism is designed using the lever method. The lever diagram corresponding to the planetary gear train function diagram and the arrangement of its control elements are as follows. Figure 12 As shown. The designed novel eight-speed automatic transmission mechanism is as follows. Figure 13As shown. This eight-speed automatic transmission mechanism comprises four basic planetary gear units, namely PGT1, PGT2, PGT3, and PGT4. The characteristic parameters of the four basic planetary gear units PGT1, PGT2, PGT3, and PGT4 are as follows: K 1 = 1.4 K 2 = 1.6 K 3 = 2.4 and K 4 = 2.6. The mechanism can achieve 8 forward gears (3 overdrive gears, 1 direct drive gear and 4 deceleration gears) and 1 reverse gear.

[0083] Figure 13 The shift control elements of the eight-speed transmission mechanism are arranged as follows: First clutch C1 connects the input shaft to the sun gear of the first basic planetary gear unit PGT1 and the sun gear of the second basic planetary gear unit PGT2; second clutch C2 connects the input shaft to the ring gear of the first basic planetary gear unit PGT1; third clutch C3 connects the input shaft to the planet carrier of the third basic planetary gear unit PGT3 and the ring gear of the fourth basic planetary gear unit PGT4; first brake B1 connects the planet carrier of the first basic planetary gear unit PGT1 and the ring gear of the second basic planetary gear unit PGT2; second brake B2 connects the ring gear of the first basic planetary gear unit PGT1; third brake B3 connects the sun gear of the third basic planetary gear unit PGT3 and the sun gear of the fourth basic planetary gear unit PGT4.

[0084] Figure 13The working principle of the 8-speed transmission mechanism is as follows: When clutch C1, brakes B1 and B3 are engaged, the sun gears of the first basic planetary gear unit PGT1 and the second basic planetary gear unit PGT2 are both input components, the transmission ratio is 5.1, and the transmission is in 1st gear. When clutch C1, brakes B2 and B3 are engaged, the sun gears of the first basic planetary gear unit PGT1 and the second basic planetary gear unit PGT2 are both input components, the transmission ratio is 3.06, and the transmission is in 2nd gear. When clutches C1 and C2 and brake B3 are engaged, the input shaft drives... When the first and second basic planetary gear train units PGT1 and PGT2 rotate as a whole, the transmission ratio of the gearbox is 1.96, and the gearbox is in 3rd gear. When clutches C1 and C3 and brake B3 are engaged, the sun gear of the first basic planetary gear train unit PGT1, the sun gear of the second basic planetary gear train unit PGT2, the planet carrier of the third basic planetary gear train unit PGT3, and the ring gear of the fourth basic planetary gear train unit PGT4 are all input components, the transmission ratio of the gearbox is 1.38, and the gearbox is in 4th gear. When clutches C1, C2, and C3 are engaged, the input shaft drives the entire transmission mechanism to rotate, and the output shaft... When the speed is equal to the input shaft speed, the transmission ratio of the transmission mechanism is 1, and the transmission is in direct drive; when clutches C1 and C3 and brake B2 are engaged, the sun gear of the first basic planetary gear train unit PGT1, the sun gear of the second basic planetary gear train unit PGT2, the planet carrier of the third basic planetary gear train unit PGT3, and the ring gear of the fourth basic planetary gear train unit PGT4 are all input components, the transmission ratio of the transmission mechanism is 0.81, and the transmission is in overdrive 6th gear; when clutches C1 and C3 and brake B1 are engaged, the sun gear of the first basic planetary gear train unit PGT1, the sun gear of the second basic planetary gear train unit PGT2, the planet carrier of the third basic planetary gear train unit PGT3, and the ring gear of the fourth basic planetary gear train unit PGT4 are all input components, the transmission ratio of the transmission mechanism is 0.81, and the transmission is in overdrive 6th gear; The planet carrier of the third basic planetary gear unit PGT3 and the ring gear of the fourth basic planetary gear unit PGT4 are both input components, the transmission ratio of the transmission mechanism is 0.71, and the transmission is in overdrive 7th gear. When clutch C3, brakes B1 and B2 are engaged, the planet carrier of the third basic planetary gear unit PGT3 and the ring gear of the fourth basic planetary gear unit PGT4 are both input components, the transmission ratio of the transmission mechanism is 0.6, and the transmission is in overdrive 8th gear. When clutch C2, brakes B1 and B3 are engaged, the ring gear of the first basic planetary gear unit PGT1 is the input component, the transmission ratio of the transmission mechanism is -3.64, and the transmission is in reverse gear.

[0085] Example 3

[0086] This embodiment provides a design for a nine-speed automatic transmission.

[0087] The design method is the same as that in Example 1, except that the selection of the planetary gear train function diagram and the arrangement of the control elements are different. A novel nine-speed automatic transmission mechanism is designed using the lever method. The lever diagram corresponding to the planetary gear train function diagram and the arrangement of its control elements are as follows. Figure 14 As shown. The designed novel nine-speed automatic transmission mechanism is as follows. Figure 15 As shown, this nine-speed automatic transmission mechanism comprises four basic planetary gear units, namely PGT1, PGT2, PGT3, and PGT4. The characteristic parameters of the four basic planetary gear units PGT1, PGT2, PGT3, and PGT4 are K1 = 2.8, K2 = 1.5, K3 = 1.5, and K4 = 1.7, respectively. The mechanism can achieve nine forward gears (four overdrive gears, one direct drive gear, and four reduction gears) and one reverse gear.

[0088] Figure 15 The shift control elements of the nine-speed transmission mechanism are arranged as follows: First clutch C1 connects the input shaft to the sun gear of the second basic planetary gear unit PGT2; second clutch C2 connects the input shaft to the ring gear of the first basic planetary gear unit PGT1 and the planet carrier of the second basic planetary gear unit PGT2; third clutch C3 connects the input shaft to the planet carrier of the third basic planetary gear unit PGT3 and the ring gear of the fourth basic planetary gear unit PGT4; first brake B1 connects to the sun gear of the first basic planetary gear unit PGT1; second brake B2 connects to the ring gear of the first basic planetary gear unit PGT1 and the planet carrier of the second basic planetary gear unit PGT2; third brake B3 connects to the sun gear of the third basic planetary gear unit PGT3 and the sun gear of the fourth basic planetary gear unit PGT4.

[0089] Figure 15The working principle of the 9-speed transmission mechanism is as follows: When clutches C1, brakes B1 and B3 are engaged, the sun gear of the second basic planetary gear unit PGT2 serves as the input component, the transmission ratio is 5.01, and the transmission is in 1st gear. When clutches C2, brakes B1 and B3 are engaged, the ring gear of the first basic planetary gear unit PGT1 and the planet carrier of the second basic planetary gear unit PGT2 are both input components, the transmission ratio is 3.59, and the transmission is in 2nd gear. When clutches C1 and C2 and brakes B3 are engaged, the input shaft drives the first basic planetary gear unit PGT1 and the second basic planetary gear unit PGT2 to rotate as a whole. When the transmission mechanism has a gear ratio of 2.65, it is in 3rd gear. When clutches C1 and C3 and brake B3 are engaged, the sun gear of the second basic planetary gear unit PGT2, the planet carrier of the third basic planetary gear unit PGT3, and the ring gear of the fourth basic planetary gear unit PGT4 are all input components, the transmission mechanism has a gear ratio of 1.29, and it is in 4th gear. When clutches C1, C2, and C3 are engaged, the input shaft drives the entire transmission mechanism to rotate, and the speed of the output shaft is equal to the speed of the input shaft. The transmission mechanism has a gear ratio of 1, and it is in direct drive. When clutches C2 and C3 and brake B1 are engaged, the first basic planetary gear unit... The ring gear of PGT1, the planet carrier of the second basic planetary gear unit PGT2, the planet carrier of the third basic planetary gear unit PGT3, and the ring gear of the fourth basic planetary gear unit PGT4 are all input components. The transmission ratio of the gearbox is 0.87, and the gearbox is in overdrive 6th gear. When clutches C1 and C3 and brake B1 are engaged, the sun gear of the second basic planetary gear unit PGT2, the planet carrier of the third basic planetary gear unit PGT3, and the ring gear of the fourth basic planetary gear unit PGT4 are all input components. The transmission ratio of the gearbox is 0.79, and the gearbox is in overdrive 7th gear. When clutches C3 and brakes B1 and B2 are engaged, the third basic planetary gear unit PGT1... When the planetary carrier of GT3 and the ring gear of the fourth basic planetary gear unit PGT4 are both input components, the transmission ratio of the transmission mechanism is 0.64, and the transmission is in overdrive 8th gear. When clutches C1 and C3 and brake B2 are engaged, the sun gear of the second basic planetary gear unit PGT2, the planetary carrier of the third basic planetary gear unit PGT3, and the ring gear of the fourth basic planetary gear unit PGT4 are all input components, the transmission ratio of the transmission mechanism is 0.52, and the transmission is in overdrive 9th gear. When clutches C1 and brakes B2 and B3 are engaged, the sun gear of the second basic planetary gear unit PGT2 is the input component, the transmission ratio of the transmission mechanism is -3.97, and the transmission is in reverse gear.

[0090] By applying the method of this invention and considering all the separable planetary gear train topologies with 9 links and 2 degrees of freedom and 11 links and 2 degrees of freedom obtained through synthesis, all possible 7-speed, 8-speed, and 9-speed automatic transmission mechanism configurations can be designed, and the values ​​of the characteristic parameters of the basic unit of the planetary gear train can be determined. Furthermore, a large number of novel automatic transmission mechanisms with reasonable transmission ratios, reasonable step ratios, high transmission efficiency, and specific functions (e.g., suitable for heavy-duty vehicles) can be selected from these automatic transmission mechanisms.

[0091] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of designing a transmission based on a separable planetary train topology, characterized by, The separable planetary gear train topology refers to being separable into independent planetary gear trains at one vertex in the topology, and the design method comprises the following specific steps: S1, topology synthesis of the separable planetary gear train topology, and the synthesis process is specifically as follows: S11, determining a 1-degree-of-freedom planetary gear train subgraph available for automatic transmission mechanism design; S12, determining all asymmetric vertices in each planetary gear train subgraph; S13, combining all asymmetric vertices in any two planetary gear train subgraphs to obtain all possible separable planetary gear train topologies; S2, drawing a function graph corresponding to the separable planetary gear train topology, and the drawing process is specifically as follows: S21, separating the separable planetary gear train topology into two planetary gear train subgraphs; S22, drawing all sub-function graphs corresponding to each of the planetary gear train subgraphs; S23, connecting the sub-function graphs obtained in step S22 according to the structure of the separable planetary gear train topology to obtain a function graph corresponding to the separable planetary gear train topology; S3, converting the function graph obtained in step S2 into a corresponding lever graph; S4, adding a shift control element to the lever graph obtained in step S3 by using the lever method, so that the design is completed, and a mechanism diagram of the automatic transmission is obtained; The asymmetric vertices are vertices with different topological characteristics in the topology. In step S11, each of the 1-degree-of-freedom planetary gear train subgraphs comprises a plurality of vertices and connecting lines, the vertices comprise hollow vertices and solid vertices, the number of the hollow vertices is the same as the number of complex hinges in the corresponding planetary gear train, and each hollow vertex corresponds to each complex hinge one by one, the number of the solid vertices is the same as the number of components in the corresponding planetary gear train, and each solid vertex corresponds to each component one by one; the connecting lines comprise solid lines and dashed lines, when the connection relationship between two components is rotary connection, a connecting line is connected between the corresponding two vertices in the planetary gear train subgraph, and the corresponding connecting line is a solid line, when the connection relationship between two components is gear connection, a connecting line is connected between the corresponding two vertices in the planetary gear train subgraph, and the corresponding connecting line is a dashed line.

2. The transmission design method of claim 1, wherein, The components are any one of a gear ring, a planetary gear, a planet carrier and a sun gear, the planet carrier and the corresponding planetary gear are determined according to the solid line path, in the solid line path with a length of 2 starting from the complex hinge, the first solid vertex represents the planet carrier, and the second solid vertex is the planetary gear corresponding to the planet carrier; The planetary gear meshes with the gear ring or the sun gear.

3. The transmission design method of claim 2 wherein, In step S13, the separable planetary gear train topologies comprise a 9-bar 2-degree-of-freedom separable planetary gear train topology and an 11-bar 2-degree-of-freedom separable planetary gear train topology.

4. The transmission design method of claim 3 wherein, The 9-bar 2-degree-of-freedom separable planetary gear train topology is composed of one 6-bar 1-degree-of-freedom planetary gear train subgraph and one 4-bar 1-degree-of-freedom planetary gear train subgraph; and the 11-bar 2-degree-of-freedom separable planetary gear train topology is composed of two 6-bar 1-degree-of-freedom planetary gear train subgraphs.

5. The transmission design method of claim 4 wherein, The 4-bar 1-DOF planetary gear train subgraph and the 6-bar 1-DOF planetary gear train subgraph both need to satisfy the conditions that only one complex hinge with a degree of 3 or 4 is contained, the planet gears on the same planet carrier do not mesh with each other, each planet gear meshes with a sun gear and a ring gear, and no loop composed of only dashed lines is contained.

6. The transmission design method of claim 1, wherein, The lever diagram includes an input shaft, a planetary gear train, shift control elements, and an output shaft, the output shaft is directly connected with a planet carrier or a ring gear of the planetary gear train, and is not connected with a sun gear; the number of the shift control elements is not more than 6, and the shift control elements can realize multiple forward gears and one reverse gear.

7. The transmission design method of claim 6 wherein, In step S4, the shift control elements include clutches and brakes, the clutches are arranged between the input shaft and components of the planetary gear train, and the brakes are arranged on non-output shafts.

8. A computer readable storage medium, characterized in that: The computer readable storage medium stores a computer program, the computer program is configured to be called by a processor to realize the steps of the transmission design method based on the separable planetary gear train topology diagram in any one of claims 1-7.

9. An electronic device, comprising: The electronic device includes at least one processor and a memory connected with the at least one processor in communication, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the steps of the transmission design method based on the separable planetary gear train topology diagram in any one of claims 1-7.

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