A transmission structure of a nine-speed automatic transmission

Abstract

The present invention relates to the technical field of automotive transmission, and particularly to a transmission structure of a nine-speed automatic transmission, which includes a transmission housing and an input shaft, an output shaft, a planetary gear train group, a coupling member group, and a torque transmission device installed inside the transmission housing. The planetary gear train group includes a first planetary gear train, a second planetary gear train, a third planetary gear train, and a fourth planetary gear train. The torque transmission device can be selectively engaged in a combination of three to establish nine forward gear ratios and one reverse gear ratio between the input shaft and the output shaft. The forward gears include four reduction gears, one direct gear, and four overdrive gears. The nine-speed automatic transmission provided by the present invention adopts a planetary gear train for transmission. The four planetary gear trains are compact in structure, small in size, light in weight, and high in transmission efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive transmissions, and particularly to a transmission structure of a nine-speed automatic transmission. Background Art

[0002] Automatic transmissions are widely used in traditional fuel vehicles in the international market, and a large number of vehicles use automatic transmissions with five to eight gears. Due to their greater design difficulty and more complex manufacturing process, they are currently only applied to most high-end luxury vehicles. However, nine-speed automatic transmissions have characteristics such as a larger transmission ratio, lower fuel consumption, and a smoother shifting process, making them one of the important future development directions in the field of automotive transmissions.

[0003] Due to the complex structure of the nine-speed automatic transmission, a large number of shifting control elements (clutches, brakes), complex shifting control strategies, and the need for a more precise machining and manufacturing process, the design difficulty is large. Currently, the number of transmission configurations of nine-speed automatic transmissions with planetary gear train structures in the market is extremely small. With the increasing demand for automotive performance, there are more and more high-gear vehicles. Therefore, it is very necessary to design a new transmission configuration for a nine-speed automatic transmission. Summary of the Invention

[0004] In view of this, the present invention provides a transmission structure of a nine-speed automatic transmission that can reduce the volume of the reducer and reduce the control difficulty. The step ratio between each gear of the transmission structure of the nine-speed automatic transmission is small, and the speed ratio range meets the requirements.

[0005] The present invention provides a transmission structure of a nine-speed automatic transmission, including a transmission housing and an input shaft, an output shaft, a planetary gear train group, a connection member group, and a torque transmission device installed inside the transmission housing. The planetary gear train group includes a first planetary gear train, a second planetary gear train, a third planetary gear train, and a fourth planetary gear train installed in sequence from front to back. The torque transmission device includes a first clutch, a second clutch, a third clutch, a first brake, a second brake, and a third brake. The first brake, the second brake, and the third brake are all fixedly connected to the transmission housing; wherein:

[0006] The first planetary gear train is composed of a first ring gear, a first planetary gear, a first planetary carrier, and a first sun gear. The first sun gear and the first planetary gear are in external meshing transmission, the first planetary gear and the first ring gear are in internal meshing transmission, and the first planetary gear is rotatably supported on the first planetary carrier;

[0007] The second planetary gear train is composed of a second ring gear, a second planetary gear, a second planetary carrier, and a second sun gear. The second sun gear and the second planetary gear are in external meshing transmission, the second planetary gear and the second ring gear are in internal meshing transmission, and the second planetary gear is rotatably supported on the second planetary carrier;

[0008] The third planetary gear set consists of a third ring gear, third planet gears, a third planet carrier, and a third sun gear. The third sun gear and the third planet gears are in external meshing transmission, the third planet gears and the third ring gear are in internal meshing transmission, and the third planet gears are rotatably supported on the third planet carrier;

[0009] The fourth planetary gear set consists of a fourth ring gear, fourth planet gears, a fourth planet carrier, and a fourth sun gear. The fourth sun gear and the fourth planet gears are in external meshing transmission, the fourth planet gears and the fourth ring gear are in internal meshing transmission, and the fourth planet gears are rotatably supported on the fourth planet carrier; the fourth ring gear is connected to the output shaft;

[0010] The connection member group includes a first connection member, a second connection member, a third connection member, and a fourth connection member;

[0011] The first connection member interconnects the first ring gear and the second ring gear, the second connection member interconnects the first planet carrier and the second planet carrier, the third connection member interconnects the second sun gear, the third sun gear, and the fourth sun gear, and the fourth connection member interconnects the third planet carrier and the fourth ring gear;

[0012] The first brake interconnects the first sun gear and the transmission housing, the second brake interconnects the second planet gears and the transmission housing, and the third brake interconnects the third ring gear and the transmission housing;

[0013] The first clutch interconnects the input shaft and the first ring gear; the second clutch interconnects the input shaft and the first planet gears; the third clutch interconnects the input shaft and the fourth planet gears;

[0014] The first clutch, the second clutch, the third clutch, the first brake, the second brake, and the third brake are selectively engaged to establish nine forward gear ratios and one reverse gear ratio between the input shaft and the output shaft, where the nine forward gears include four reduction gears, one direct gear, and four overdrive gears.

[0015] Further, by engaging the first clutch, the first brake, and the third brake, a first gear transmission ratio is established between the input shaft and the output shaft;

[0016] Further, by engaging the first brake, the second clutch, and the third brake, a second gear transmission ratio is established between the input shaft and the output shaft;

[0017] Further, by engaging the first clutch, the second clutch, and the third brake, a third gear transmission ratio is established between the input shaft and the output shaft;

[0018] Further, by engaging the third clutch and the third brake, a fourth gear transmission ratio is established between the input shaft and the output shaft;

[0019] Further, by engaging the first clutch, the second clutch and the third clutch, a fifth gear transmission ratio is established between the input shaft and the output shaft;

[0020] Further, by engaging the first brake, the second clutch and the third clutch, a sixth gear transmission ratio is established between the input shaft and the output shaft;

[0021] Further, by engaging the first clutch, the first brake and the third clutch, a seventh gear transmission ratio is established between the input shaft and the output shaft;

[0022] Further, by engaging the first brake, the second brake and the third clutch, an eighth gear transmission ratio is established between the input shaft and the output shaft;

[0023] Further, by engaging the first clutch, the second brake and the third clutch, a ninth gear transmission ratio is established between the input shaft and the output shaft;

[0024] Further, by engaging the third brake, the first clutch and the second brake, a reverse gear transmission ratio is established between the input shaft and the output shaft.

[0025] The beneficial effects brought by the technical solution provided by the present invention are as follows:

[0026] 1. The nine-speed automatic transmission drive structure provided by the present invention adopts a planetary gear train drive. The four planetary gear sets are closely connected to each other, with a compact structure. The planetary gears adopt single planetary gears or double planetary gears, and their manufacturing processes are mature, making them more convenient for processing and manufacturing.

[0027] 2. The nine-speed automatic transmission drive structure provided by the present invention does not have complex component interference and nesting, and can reduce the transmission control difficulty and the corresponding volume to a certain extent.

[0028] 3. The control of each gear of the nine-speed automatic transmission drive structure provided by the present invention only requires the combination of three control elements (clutch or brake), and only one pair of torque transmission components needs to be replaced for engagement and disengagement when changing between adjacent gears, with simple control. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a structural schematic diagram of a nine-speed automatic transmission drive structure of the present invention.

[0030] In the figure: 1 - input shaft, 2 - output shaft, 3 - transmission housing, 4 - first connecting member, 5 - second connecting member, 6 - third connecting member, 7 - fourth connecting member, 8 - first ring gear, 9 - first planet gear, 10 - first planet carrier, 11 - first sun gear, 12 - second ring gear, 13 - second planet gear, 14 - second planet carrier, 15 - second sun gear, 16 - third ring gear, 17 - third planet gear, 18 - third planet carrier, 19 - third sun gear, 20 - fourth ring gear, 21 - fourth planet gear, 22 - fourth planet gear, 23 - third sun gear, B1 - first brake, B2 - second brake, B3 - third brake, C1 - first clutch, C2 - second clutch, C3 - third clutch. Detailed implementation

[0031] To make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0032] Please refer to Figure 1 , the embodiment of the present invention provides a nine-speed automatic transmission drive structure, including a transmission housing 3 and an input shaft 1, an output shaft 2, four planetary gear train groups, four connecting member groups, and three torque transmission devices installed inside the transmission housing 3.

[0033] The four planetary gear train groups include a first planetary gear train, a second planetary gear train, a third planetary gear train, and a fourth planetary gear train installed in sequence from front to back.

[0034] The four connecting member groups include a first connecting member 4, a second connecting member 5, a third connecting member 6, and a fourth connecting member 7.

[0035] The first planetary gear train is composed of a first ring gear 8, a first planet gear 9, a first planet carrier 10, and a first sun gear 11. The first sun gear 11 and the first planet gear 9 are in external meshing transmission, the first planet gear 9 and the first ring gear 8 are in internal meshing transmission, and the first planet gear 9 is rotationally supported on the first planet carrier 10 by rolling or sliding bearings.

[0036] The second planetary gear train is composed of a second ring gear 12, a second planet gear 13, a second planet carrier 14, and a second sun gear 15. The second sun gear 15 and the second planet gear 13 are in external meshing transmission, the second planet gear 13 and the second ring gear 12 are in internal meshing transmission, and the second planet gear 13 is rotationally supported on the second planet carrier 14 by rolling or sliding bearings.

[0037] The third planetary gear set consists of a third ring gear 16, third planet gears 17, a third planet carrier 18, and a third sun gear 19. The third sun gear 19 meshes externally with the third planet gears 17, the third planet gears 17 mesh internally with the third ring gear 16, and the third planet gears 17 are rotatably supported on the third planet carrier 18 by rolling or sliding bearings.

[0038] The fourth planetary gear set consists of a fourth ring gear 20, fourth planet gears 21, a fourth planet carrier 22, and a fourth sun gear 23. The fourth sun gear 23 meshes externally with the fourth planet gears 21, the fourth planet gears 21 mesh internally with the fourth ring gear 20, and the fourth planet gears 21 are rotatably supported on the fourth planet carrier 22 by rolling or sliding bearings.

[0039] In this embodiment, a first connecting member 4 interconnects the first ring gear 8 and the second ring gear 12, a second connecting member 5 interconnects the first planet carrier 10 and the second planet carrier 14, a third connecting member 6 connects the second sun gear 15, the third sun gear 19, and the fourth sun gear 23, and a fourth connecting member 7 interconnects the third planet carrier 18 and the fourth ring gear 20.

[0040] The torque transmission device includes a first brake B1, a second brake B2, a third brake B3, a first clutch C1, a second clutch C2, and a third clutch C3. The first clutch C1 interconnects the input shaft 1 and the first ring gear 8; the second clutch C2 interconnects the input shaft 1 and the first planet carrier 10; the third clutch C3 interconnects the input shaft 1 and the fourth planet carrier 22. The first brake B1, the second brake B2, and the third brake B3 are all fixedly connected to the transmission housing 3. The first brake B1 interconnects the first sun gear 11 and the transmission housing 3, the second brake B2 interconnects the second planet carrier 14 and the transmission housing 3, and the third brake B3 interconnects the third ring gear 16 and the transmission housing 3.

[0041] The first brake B1 is connected to the first sun gear 11, the second brake B2 is connected to the second planet carrier 14, and the third brake B3 is connected to the third ring gear 16.

[0042] The first clutch C1, the second clutch C2, the third clutch C3, the first brake B1, the second brake B2, and the third brake B3 are selectively engaged to establish nine forward gear ratios and one reverse gear ratio between the input shaft 1 and the output shaft 2. The specific implementation process is as follows:

[0043] By engaging the first clutch C1, the first brake B1, and the third brake B3, a first-gear transmission ratio is established between the input shaft 1 and the output shaft 2. Specifically, the first brake B1 and the third brake B3 are engaged to connect the first sun gear 11 and the third ring gear 16 to the transmission housing 3 respectively, preventing the rotation of the first sun gear 11 and the third ring gear 16 relative to the transmission housing 3. The first clutch C1 is engaged to connect the input shaft 1 and the first ring gear 8 to rotate together. Thus, a first-gear transmission ratio is established between the input shaft 1 and the output shaft 2.

[0044] By engaging the first brake B1, the second clutch C2, and the third brake B3, a second-gear transmission ratio is established between the input shaft 1 and the output shaft 2. Specifically, the first brake B2 and the third brake B3 are engaged to connect the first sun gear 11 and the third ring gear 16 to the transmission housing 3 respectively, preventing the rotation of the first sun gear 11 and the third ring gear 16 relative to the transmission housing 3. The second clutch C2 is engaged to connect the input shaft 1 and the first planet gear 10 to rotate together. Thus, a second-gear transmission ratio is established between the input shaft 1 and the output shaft 2;

[0045] By engaging the first clutch C1, the second clutch C2, and the third brake B3, a third-gear transmission ratio is established between the input shaft 1 and the output shaft 2. Specifically, the third brake B3 is engaged to connect the third ring gear 16 to the transmission housing 3 respectively, preventing the rotation of the third ring gear 16 relative to the transmission housing 3. The first clutch C1 and the second clutch C2 are engaged to connect the input shaft 1 and the first ring gear 8, the first planet gear 9 to rotate together respectively. Thus, a third-gear transmission ratio is established between the input shaft 1 and the output shaft 2;

[0046] By engaging the third clutch C3 and the third brake B3, a fourth-gear transmission ratio is established between the input shaft 1 and the output shaft 2. Specifically, the third brake B3 is engaged to connect the third ring gear 16 to the transmission housing 3 respectively, preventing the rotation of the third ring gear 16 relative to the transmission housing 3. The third clutch C3 is engaged to connect the input shaft 1 and the fourth planet gear 22 to rotate together. Thus, a fourth-gear transmission ratio is established between the input shaft 1 and the output shaft 2;

[0047] By engaging the first clutch C1, the second clutch C2, and the third clutch C3, a fifth-gear transmission ratio is established between the input shaft 1 and the output shaft 2. Specifically, the first clutch C1, the second clutch C2, and the third clutch C3 are engaged to connect the input shaft 1 and the first ring gear 8, the first planet gear 9, the fourth planet gear 22 to rotate together respectively. Thus, a fifth-gear transmission ratio is established between the input shaft 1 and the output shaft 2, which is the direct gear;

[0048] By engaging the first brake B1, the second clutch C2, and the third clutch C3, a sixth gear transmission ratio is established between the input shaft 1 and the output shaft 2. Specifically, the first brake B1 is engaged to connect the first sun gear 11 to the transmission housing 3, preventing the rotation of the first sun gear 11 relative to the transmission housing 3. The second clutch C2 and the third clutch C3 are engaged to cause the input shaft 1 to rotate together with the first ring gear 8 and the fourth planet gear 22 respectively, thereby establishing a sixth gear transmission ratio between the input shaft 1 and the output shaft 2;

[0049] By engaging the first clutch C1, the second brake B2, and the third clutch C3, a seventh gear transmission ratio is established between the input shaft 1 and the output shaft 2. Specifically, the second brake B2 is engaged to connect the second planet gear 13 to the transmission housing 3, preventing the rotation of the second planet gear 13 relative to the transmission housing 3. The first clutch C1 and the third clutch C3 are engaged to cause the input shaft 1 to rotate together with the first ring gear 8 and the fourth planet gear 22 respectively, thereby establishing a seventh gear transmission ratio between the input shaft 1 and the output shaft 2;

[0050] By engaging the first brake B1, the second brake B2, and the third clutch C3, an eighth gear transmission ratio is established between the input shaft 1 and the output shaft 2. Specifically, the first brake B1 and the second brake B2 are engaged to connect the first sun gear 11 and the second planet gear 13 to the transmission housing 3, preventing the rotation of the first sun gear 11 and the second planet gear 13 relative to the transmission housing 3. The third clutch C3 is engaged to cause the input shaft 1 to rotate together with the fourth planet gear 22, thereby establishing an eighth gear transmission ratio between the input shaft 1 and the output shaft 2;

[0051] By engaging the first clutch C1, the second brake B2, and the third clutch C3, a ninth gear transmission ratio is established between the input shaft 1 and the output shaft 2. Specifically, the second brake B2 is engaged to connect the second planet gear 13 to the transmission housing 3, preventing the rotation of the second planet gear 13 relative to the transmission housing 3. The first clutch C1 and the third clutch C3 are engaged to cause the input shaft 1 to rotate together with the first ring gear 8 and the fourth planet gear 22 respectively, thereby establishing a ninth gear transmission ratio between the input shaft 1 and the output shaft 2;

[0052] By engaging the first clutch C1, the second brake B2, and the third brake B3, a reverse gear ratio is established between the input shaft 1 and the output shaft 2. The second brake B2 and the third brake B3 are engaged to connect the second planet gear 13 and the third ring gear 16 to the transmission housing 3 respectively, preventing the rotation of the second planet gear 13 and the third ring gear 16 relative to the transmission housing 3. The first clutch C1 is engaged to connect the input shaft 1 and the first ring gear 8 to rotate together, thereby establishing a reverse gear ratio between the input shaft 1 and the output shaft 2;

[0053] Among them, the operation logic tables of the first clutch C1, the second clutch C2, the third clutch C3, the first brake B1, the second brake B2, and the third brake B3 are shown in Table 1:

[0054] Table 1: Operation Logic Table

[0055] Gear position Working clutch Working brake Nature of gear position 1 C1 B1, B3 Reduction gear 2 C2 B1, B3 Reduction gear 3 C1, C2 B3 Reduction gear 4 C3 B3 Reduction gear 5 C1, C2, C3 / Direct gear 6 C2, C3 B1 Overdrive 7 C1, C3 B2 Overdrive 8 C3 B1, B2 Overdrive 9 C1, C3 B2 Overdrive 10 C1 B2, B3 Reverse gear

[0056] In this embodiment, the first clutch C1, the second clutch C2, and the third clutch C3 are multi-disc wet clutches or jaw clutches, and the first brake B1, the second brake B2, and the third brake B3 are drum brakes or multi-disc wet brakes.

[0057] In this article, the orientation words such as front, rear, up, and down are defined based on the positions of the components in the drawings and the positions of the components relative to each other, only for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the orientation words should not limit the scope of protection claimed in this application.

[0058] Without conflict, the above embodiments and the features in the embodiments in this article can be combined with each other.

[0059] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A nine-speed automatic transmission drive structure, characterized in that: It includes a transmission housing (3), an input shaft (1), an output shaft (2), a planetary gear set, a coupling member set, and a torque transmission device installed inside the transmission housing (3). The planetary gear set includes a first planetary gear set, a second planetary gear set, a third planetary gear set, and a fourth planetary gear set installed in sequence from front to back. The torque transmission device includes a first clutch (C1), a second clutch (C2), a third clutch (C3), a first brake (B1), a second brake (B2), and a third brake (B3). The first brake (B1), the second brake (B2), and the third brake (B3) are all fixedly connected to the transmission housing (3). The first planetary gear set is composed of a first ring gear (8), a first planetary gear (9), a first planetary carrier (10), and a first sun gear (11). The first sun gear (11) and the first planetary gear (9) are in external meshing transmission. The first planetary gear (9) and the first ring gear (8) are in internal meshing transmission. The first planetary gear (9) is rotatably supported on the first planetary carrier (10). The second planetary gear set is composed of a second ring gear (12), a second planetary gear (13), a second planetary carrier (14), and a second sun gear (15). The second sun gear (15) and the second planetary gear (13) are in external meshing transmission. The second planetary gear (13) and the second ring gear (12) are in internal meshing transmission. The second planetary gear (13) is rotatably supported on the second planetary carrier (14). The third planetary gear set is composed of a third ring gear (16), a third planetary gear (17), a third planetary carrier (18), and a third sun gear (19). The third sun gear (19) and the third planetary gear (17) are in external meshing transmission. The third planetary gear (17) and the third ring gear (16) are in internal meshing transmission. The third planetary gear is rotatably supported on the third planetary carrier (18). The fourth planetary gear set is composed of a fourth ring gear (20), a fourth planetary gear (21), a fourth planetary carrier (22), and a fourth sun gear (23). The fourth sun gear (23) and the fourth planetary gear (21) are in external meshing transmission. The fourth planetary gear (21) and the fourth ring gear (20) are in internal meshing transmission. The fourth planetary gear (21) is rotatably supported on the fourth planetary carrier (22). The fourth ring gear (20) is connected to the output shaft (2). The coupling member set includes a first coupling member (4), a second coupling member (5), a third coupling member (6), and a fourth coupling member (7). The first coupling member (4) interconnects the first ring gear (8) and the second ring gear (12). The second coupling member (5) interconnects the first planetary carrier (10) and the second planetary carrier (14). The third coupling member (6) interconnects the second sun gear (15), the third sun gear (19), and the fourth sun gear (23). The fourth coupling member (7) interconnects the third planetary carrier (18) and the fourth ring gear (20). The first brake (B1) interconnects the first sun gear (11) and the transmission housing (3), the second brake (B2) interconnects the second planet gear (13) and the transmission housing (3), and the third brake (B3) interconnects the third ring gear (16) and the transmission housing (3); The first clutch (C1) interconnects the input shaft (1) and the first ring gear (8); the second clutch (C2) interconnects the input shaft (1) and the first planet gear (9); the third clutch interconnects the input shaft (1) and the fourth planet gear (21); The first clutch (C1), second clutch (C2), third clutch (C3), first brake (B1), second brake (B2), and third brake (B3) are selectively engaged to establish nine forward gear ratios and one reverse gear ratio between the input shaft (1) and the output shaft (2).

2. The transmission structure of a nine-speed automatic transmission according to claim 1, characterized in that: By engaging the third brake (B3), the first clutch (C1), and the second brake (B2), a reverse gear ratio is established between the input shaft (1) and the output shaft (2).

3. The transmission structure of a nine-speed automatic transmission according to claim 1, characterized in that: By engaging the first clutch (C1), the first brake (B1), and the third brake (B3), a first gear ratio is established between the input shaft (1) and the output shaft (2); By engaging the first brake (B1), the second clutch (C2), and the third brake (B3), a second gear ratio is established between the input shaft (1) and the output shaft (2); By engaging the first clutch (C1), the second clutch (C2), and the third brake (B3), a third gear ratio is established between the input shaft (1) and the output shaft (2); By engaging the third clutch (C3) and the third brake (B3), a fourth gear ratio is established between the input shaft (1) and the output shaft (2); By engaging the first clutch (C1), the second clutch (C2), and the third clutch (C3), a fifth gear ratio is established between the input shaft (1) and the output shaft (2); By engaging the first brake (B1), the second clutch (C2), and the third clutch (C3), a sixth gear ratio is established between the input shaft (1) and the output shaft (2); By engaging the first clutch (C1), the first brake (B1), and the third clutch (C3), a seventh gear ratio is established between the input shaft (1) and the output shaft (2); By engaging the first brake (B1), the second brake (B2), and the third clutch (C3), an eighth gear ratio is established between the input shaft (1) and the output shaft (2); By engaging the first clutch (C1), the second brake (B2), and the third clutch (C3), a ninth gear ratio is established between the input shaft (1) and the output shaft (2).

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