Hydraulic mechanical stepless speed change transmission system of single planet row

Abstract

The utility model discloses a hydraulic mechanical stepless speed change transmission system with a single planet row, which solves the problem that the existing stepless speed change transmission system needs multiple groups of wet clutches or multiple rows of planet gear structures to alternately work to complete section switching, so that the structure and the control process of the transmission system are complicated. According to the utility model, the hydrostatic unit of the variable displacement pump constant displacement motor, the confluence mechanism of the single-row planetary gear structure and the parallel shaft system are combined, and the change of the rotating speed of the output shaft, the switching of working modes and the power reversing are realized through the displacement adjustment of the variable displacement pump of the hydrostatic unit and the cooperative work of a plurality of groups of clutches; therefore, switching power between the two forward working areas and the backward working area is not interrupted, the speed ratio is continuously adjustable, and the adaptation degree to different working modes and road conditions is improved.

Description

Technical Field

[0001] The utility model relates to a continuously variable transmission system, in particular to a hydraulic mechanical continuously variable transmission system with a single planetary gear. Background Art

[0002] The working conditions of tractors are complex, and the loads are variable during the operation. The mechanical hydraulic continuously variable transmission system realizes the tractor shifting without power interruption through power splitting and converging, reduces the shifting shock, and improves the tractor's ability to adapt to various complex working conditions and transmission efficiency. This method is currently a relatively ideal tractor stepless speed regulation method. The Chinese patent with publication number CN 220748988 U and the name of "A dual-working mode transmission system" discloses a dual-working mode variable transmission system, which has two working modes. When the vehicle starts, the vehicle is in a pure hydraulic gear area, and the forward and backward movement is achieved by changing the swing angle of the hydrostatic unit. When the set speed is reached, the working area is switched. A second gear clutch and a first gear clutch are arranged on the first parallel shaft. The output ends of the second gear clutch and the first gear clutch are connected to the road mode clutch unit or the field mode clutch unit through a planetary gear mechanism. When the output shaft keeps the speed unchanged, the output shaft speed is changed and the working mode is switched according to the swing angle of the variable pump of the hydrostatic unit combined with the engagement and separation of different clutches, thereby improving the adaptability to different working modes and road conditions. However, the continuously variable transmission system requires multiple sets of wet clutches or multiple rows of planetary gear structures to work alternately to complete the section switching, which makes the transmission system structure and control process complicated and very difficult to implement. Utility Model Content

[0003] The utility model aims to provide a single planetary gear hydraulic mechanical continuously variable transmission system to solve the technical problem that the existing continuously variable transmission system requires multiple sets of wet clutches or multiple rows of planetary gear structures to work alternately to complete section switching, which makes the transmission system structure and control process complicated and difficult to implement.

[0004] The utility model provides a hydrostatic unit combined with a variable pump and a quantitative motor, a confluence mechanism of a single-row planetary gear structure, and a parallel-arranged shaft system, and realizes the change of output shaft speed, the switching of working modes, and power reversal through the variable pump displacement adjustment of the hydrostatic unit and the coordinated work of multiple clutches; thereby, the power is switched between two forward working areas and one backward working area without interruption, the speed ratio is continuously adjustable, and the adaptability to different working modes and road conditions is improved.

[0005] In order to achieve the above purpose and complete the above invention concept, the utility model adopts the following technical solutions:

[0006] A single planetary gear hydraulic mechanical continuously variable transmission system, which is special in that it comprises a first parallel shaft, a second parallel shaft, a third parallel shaft, a fourth parallel shaft and a fifth parallel shaft arranged in parallel with each other; the first parallel shaft is used for power input; the fifth parallel shaft is used for power output;

[0007] The first parallel shaft is provided with a mechanical driving gear and a variable displacement pump driving gear in sequence along its axial direction;

[0008] A hydrostatic unit is disposed on the second parallel shaft; one end of the hydrostatic unit is connected to a variable pump driving gear;

[0009] The third parallel shaft is fixed with a motor driven gear, an empty mechanical driven gear, and a fixed planetary gear; the motor driven gear is connected to the other end of the hydrostatic unit; the mechanical driven gear is meshed with the mechanical driving gear; the sun gear of the planetary gear is fixedly connected to the third parallel shaft, and its ring gear is coaxially fixedly connected with the mechanical driven gear;

[0010] The fourth parallel shaft is coaxially connected to the planetary gear through the planet carrier; the fourth parallel shaft has an empty R-segment driving gear, a fixed R-segment clutch, a fixed F1-segment clutch, an empty F1-segment driving gear, a fixed F2-segment clutch, and an empty F2-segment driving gear; the R-segment clutch is connected to the R-segment driving gear; the F1-segment driving gear is connected to the F1-segment clutch; the F2-segment driving gear is connected to the F2-segment clutch;

[0011] The fifth parallel shaft is fixed with a set of R-segment passive gear, a fixed set of F1-segment passive gear, and a fixed set of F2-segment passive gear; the R-segment passive gear is connected with the R-segment active gear; the F1-segment passive gear is meshed with the F1-segment active gear; the F2-segment passive gear is meshed with the F2-segment active gear.

[0012] Furthermore, the second parallel shaft is also fixedly mounted with a motor driving gear and a variable displacement pump passive gear;

[0013] The motor driving gear and the variable pump driven gear are respectively located at two ends of the hydrostatic unit; the motor driving gear is connected with the motor driven gear; and the variable pump driven gear is meshed with the variable pump driving gear.

[0014] Further, the R-segment passive gear is connected to the R-segment driving gear via the R-segment idler gear;

[0015] The R-segment idler gear is meshed with the R-segment driven gear and the R-segment driving gear respectively.

[0016] Furthermore, a power take-off unit is also provided on the first parallel shaft;

[0017] The power take-off unit is used to achieve power take-off output.

[0018] Further, the power take-off unit comprises a power take-off drive gear, a power take-off clutch, a sixth parallel shaft and a power take-off output driven gear;

[0019] The power take-off driving gear is loosely sleeved on the first parallel shaft;

[0020] One end of the power take-off clutch is coaxially fixedly connected to the first parallel shaft, and the other end is connected to the power take-off driving gear;

[0021] The sixth parallel shaft is parallel to the first parallel shaft and is used for power take-off power output;

[0022] The power take-off output driven gear is fixedly sleeved on the sixth parallel shaft and meshes with the power take-off driving gear.

[0023] Further, a seventh parallel axis is included;

[0024] The seventh parallel shaft is parallel to the fifth parallel shaft, and a front drive passive gear is fixedly mounted thereon;

[0025] A front drive driving gear is also fixedly mounted on the fifth parallel shaft; the front drive driving gear is arranged on a side of the F2 section passive gear away from the F1 section passive gear and meshes with the front drive passive gear.

[0026] Furthermore, a front-drive clutch is fixedly mounted on the seventh parallel shaft.

[0027] Furthermore, the motor driven gear, the mechanical driven gear, and the planetary gear are sequentially arranged along the axial direction of the third parallel axis;

[0028] The R-segment driving gear, the R-segment clutch, the F1-segment clutch, the F1-segment driving gear, the F2-segment clutch, and the F2-segment driving gear are sequentially arranged along the axial direction of the fourth parallel axis;

[0029] The R-section driven gear, the F1-section driven gear, and the F2-section driven gear are sequentially arranged along the axial direction of the fifth parallel axis.

[0030] Furthermore, the axis of the fourth parallel axis is located on the same straight line as the axis of the third parallel axis.

[0031] Further, the F1 section driving gear is connected to the F1 section clutch via a spline;

[0032] The F2 section driving gear is connected to the F2 section clutch via a spline;

[0033] The R-section clutch is connected to the R-section driving gear via a spline;

[0034] The power take-off clutch is connected to the power take-off driving gear via a spline.

[0035] Beneficial effects of the utility model:

[0036] 1. The utility model realizes stepless speed change with two forward sections and one reverse section through a single planetary gear and three clutches. Compared with the prior art, the number of planetary gears and clutches is reduced, so the transmission system structure is simpler; at the same time, the reduction in the number of clutches reduces the control difficulty. Compared with the prior art, the clutch gear pair combination used for mechanical speed change is placed at the rear end of the planetary gear (near the power output end), which can achieve a larger speed regulation range with fewer clutches. Compared with the prior art, there is no pure hydraulic section, and all three sections are hydraulic mechanical stepless speed regulation, which is conducive to improving the efficiency of the transmission system, thereby improving the power transmission performance and fuel economy of the vehicle.

[0037] 2. The continuously variable transmission system provided by the utility model includes two forward working areas and one reverse working area. The power is switched between the working areas without interruption, and the speed ratio is continuously adjustable, which improves the adaptability to different working modes and road conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The utility model is a structural schematic diagram of a hydraulic mechanical continuously variable transmission system embodiment of a single planetary gear.

[0039] Figure Number:

[0040] S1-first parallel shaft, S2-second parallel shaft, S3-third parallel shaft, S4-fourth parallel shaft, S5-fifth parallel shaft, S6-sixth parallel shaft, S7-seventh parallel shaft, G1-mechanical driving gear, G2-mechanical passive gear, G3-variable pump driving gear, G4-variable pump passive gear, G5-motor driving gear, G6-motor passive gear, G7-R segment driving gear, G8-R segment passive gear, G9-R segment idler, G10-F 1-stage driving gear, G11-F1-stage driven gear, G12-F2-stage driving gear, G13-F2-stage driven gear, G14-front drive driving gear, G15-front drive driven gear, G16-power take-off driving gear, G17-power take-off output driven gear, H1-static hydraulic unit, C1-F1-stage clutch, C2-F2-stage clutch, CR-R-stage clutch, C-PTO-power take-off clutch, C4WD-front drive clutch, P-planetary gear. DETAILED DESCRIPTION

[0041] The following will be combined with the accompanying drawings and embodiments to clearly and completely describe the technical solution of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0042] This embodiment provides a single planetary gear hydraulic mechanical continuously variable transmission system, such as Figure 1 As shown, the continuously variable transmission system includes a first parallel shaft S1, a second parallel shaft S2, a third parallel shaft S3, a fourth parallel shaft S4, a fifth parallel shaft S5, a sixth parallel shaft S6 and a seventh parallel shaft S7 which are arranged in parallel.

[0043] The first parallel shaft S1 is connected to the power source through a spline, and the following parts are mounted on it: a mechanical drive gear G1, which is fixedly connected to the first parallel shaft S1; a variable pump drive gear G3, which is fixedly connected to the first parallel shaft S1; a power take-off drive gear G16, which is loosely mounted on the first parallel shaft S1 and is splined to the power take-off clutch C-PTO; a power take-off clutch C-PTO, which is fixedly connected to the first parallel shaft S1.

[0044] The second parallel shaft S2 is provided with the following parts: a hydrostatic unit H1, which is fixedly connected to the variable pump driven gear G4 and the motor driving gear G5, while the variable pump driven gear G4 is meshed with the variable pump driving gear G3, and the motor driving gear G5 is meshed with the motor driven gear G6.

[0045] The following parts are mounted on the third parallel shaft S3: a motor driven gear G6, which is fixedly connected to the third parallel shaft S3; a planetary row P, whose sun gear is spline-connected to the third parallel shaft S3; a mechanical driven gear G2, which is loosely mounted on the third parallel shaft S3, connected to the ring gear of the planetary row P through a spline, and meshed with the mechanical drive gear G1.

[0046] The fourth parallel shaft S4 is connected to the planet carrier of the planetary gear P through a spline, and the following parts are mounted on it: R-segment driving gear G7, which is loosely sleeved on the fourth parallel shaft S4 and connected to the R-segment clutch CR through a spline; R-segment clutch CR, which is fixedly connected to the fourth parallel shaft S4; F1-segment driving gear G10, which is loosely sleeved on the fourth parallel shaft S4 and connected to the F1-segment clutch C1 through a spline; F1-segment clutch C1, which is fixedly connected to the fourth parallel shaft S4; F2-segment driving gear G12, which is loosely sleeved on the fourth parallel shaft S4 and connected to the F2-segment clutch C2 through a spline; F2-segment clutch C2, which is fixedly connected to the fourth parallel shaft S4.

[0047] The fifth parallel shaft S5 is provided with the following parts: R-section driven gear G8, which is fixedly connected to the fifth parallel shaft S5 and meshes with R-section idler gear G9, which meshes with G7; F1-section driven gear G11, which is fixedly connected to the fifth parallel shaft S5 and meshes with F1-section driving gear G10; F2-section driven gear G13, which is fixedly connected to the fifth parallel shaft S5 and meshes with G12; front drive driving gear G14, which is fixedly connected to the fifth parallel shaft S5.

[0048] The sixth parallel shaft S6 is provided with the following parts: a power take-off output driven gear G17, which is fixedly connected to the sixth parallel shaft S6 and meshes with G16.

[0049] The seventh parallel shaft S7 is provided with the following parts: a front drive driven gear G15, the gear idler is fixedly connected to the seventh parallel shaft S7 and meshes with the front drive gear G14; a front drive clutch C4WD, the part is fixedly connected to the seventh parallel shaft S7.

[0050] The system utilizes the coordinated work of clutches C1 / C2 / CR to achieve vehicle starting, power reversing, two forward working areas, and one reverse working area. The power is switched between the working areas without interruption, and the speed ratio is continuously adjustable.

[0051] Combine the following Figure 1 Further explanation of the power transmission routes in different working areas of the above system:

[0052] Forward working area F1: F1 clutch C1 is engaged, engine power is input from the first parallel shaft S1, part of the power is transmitted through hydraulic flow: variable pump drive gear G3 → variable pump passive gear G4 → hydrostatic unit H1 → motor drive gear G5 → motor passive gear G6 → sun gear of planetary gear P; the other part of the power is transmitted through mechanical flow: mechanical drive gear G1 → ring gear of planetary gear P. After the two powers are combined in the planetary gear P, they are output to the fourth parallel shaft S4 through the planet carrier. Then through F1 driving gear G10 → F1 passive gear G11, the power is transmitted to the fifth parallel shaft S5.

[0053] In the forward working area, when the engine speed remains unchanged, by controlling the swing angle of the variable pump in the hydrostatic unit H1 to continuously change from positive to negative, the speed of the fifth parallel shaft S5 increases continuously, and the speed ratio of the transmission system is continuously adjustable.

[0054] Forward second working area F2 section: F2 section clutch C2 is engaged, and the transmission route before power convergence is consistent with the previous forward working area F1 section. The two powers converge at the planetary gear P and are output to the fourth parallel shaft S4 through the planetary carrier. Then through the F2 section driving gear G12 → F2 section driven gear G13, the power is transmitted to the fifth parallel shaft S5.

[0055] In the forward second working area, under the condition that the engine speed remains unchanged, by controlling the swing angle of the variable pump in the hydrostatic unit H1 to continuously change from positive to negative, the speed of the fifth parallel shaft S5 increases continuously, and the speed ratio of the transmission system is continuously adjustable.

[0056] Reverse working area R section: R section clutch CR is engaged, and the transmission route before power convergence is consistent with the forward working area F1 section. After the two powers converge at the planetary gear P, they are output to the fourth parallel shaft S4 through the planetary carrier, and then transmitted to the fifth parallel shaft S5 through the R section driving gear G7 → R section idler gear G9 → R section driven gear G8.

[0057] In the reverse working area, under the condition that the engine speed remains unchanged, by controlling the swing angle of the variable pump in the hydrostatic unit H1 to continuously change from positive to negative, the speed of the fifth parallel shaft S5 increases continuously, and the speed ratio of the transmission system is continuously adjustable.

[0058] When the vehicle starts, the F1 clutch C1 or the R clutch CR is controlled to engage according to whether the vehicle is moving forward or backward. The vehicle speed is continuously increased by changing the displacement of the pump in the hydrostatic unit H1, and the working area is switched when the set speed is reached.

[0059] When the transmission system speeds up and switches the working area, take the forward working area 1 to the forward working area 2 as an example, the F1 clutch is disengaged, the displacement of the pump in the hydrostatic unit H1 is adjusted, and the F2 clutch is combined to complete the working area switching process, with continuous speed ratio and uninterrupted power. There is no speed difference in the clutch during this switching process.

[0060] When the transmission system decelerates and switches the working area, take the forward second working area down to the forward first working area as an example, the F2 section clutch is disengaged, the displacement of the pump in the hydrostatic unit H1 is adjusted, and the F1 section clutch is combined to complete the working area switching process, with continuous speed ratio and uninterrupted power. There is no speed difference in the clutch during this switching process.

[0061] When the vehicle speed reaches a certain condition, the power reversing is completed by controlling the displacement of the static hydraulic unit H1 variable pump to simultaneously switch the working states of the F1 clutch and the R clutch or the F2 clutch and the R clutch.

[0062] The output state of the power take-off is controlled by controlling the working state of the power take-off clutch C-PTO.

[0063] Whether the vehicle enters the four-wheel drive mode is controlled by controlling the working state of the front drive clutch C4WD.

[0064] The continuously variable transmission system provided by the utility model is applied to a tractor. When the input shaft speed remains unchanged, the output shaft speed can be continuously changed, the power can be continuously output, and the power can be reversed by adjusting the swing angle of the variable pump swash plate and the engagement state of the clutch. The vehicle's power transmission performance, fuel economy, and ability to adapt to various complex road conditions are significantly improved. Compared with the traditional multi-section hydraulic power split continuously variable transmission, the transmission system distributes multiple clutches and planetary gears through multiple parallel shafts, realizing mechanical hydraulic power split stepless speed regulation. When accelerating across sections, the clutch has no speed difference, which increases the service life of the clutch; and the mechanical structure is simple and compact, which is conducive to reducing costs.

[0065] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or replacements within the technical scope disclosed in the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A hydraulic mechanical continuously variable transmission system with a single planetary gear, characterized in that: It comprises a first parallel shaft (S1), a second parallel shaft (S2), a third parallel shaft (S3), a fourth parallel shaft (S4) and a fifth parallel shaft (S5) which are arranged parallel to each other; the first parallel shaft (S1) is used for power input; the fifth parallel shaft (S5) is used for power output; The first parallel shaft (S1) is provided with a mechanical driving gear (G1) and a variable displacement pump driving gear (G3) in sequence along its axial direction; A static hydraulic unit (H1) is arranged on the second parallel shaft (S2); one end of the static hydraulic unit (H1) is connected to a variable pump driving gear (G3); The third parallel shaft (S3) is fixed with a motor driven gear (G6), an empty mechanical driven gear (G2), and a fixed planetary gear (P); the motor driven gear (G6) is connected to the other end of the hydrostatic unit (H1); the mechanical driven gear (G2) is meshed with the mechanical driving gear (G1); the sun gear of the planetary gear (P) is fixedly connected to the third parallel shaft (S3), and its ring gear is coaxially fixedly connected to the mechanical driven gear (G2); The fourth parallel shaft (S4) is coaxially fixedly connected with the planetary gear (P) through the planet carrier; the fourth parallel shaft (S4) is provided with an empty R-segment driving gear (G7), a fixed R-segment clutch (CR), a fixed F1-segment clutch (C1), an empty F1-segment driving gear (G10), a fixed F2-segment clutch (C2), and an empty F2-segment driving gear (G12); the R-segment clutch (CR) is connected to the R-segment driving gear (G7); the F1-segment driving gear (G10) is connected to the F1-segment clutch (C1); and the F2-segment driving gear (G12) is connected to the F2-segment clutch (C2); The fifth parallel shaft (S5) is fixed with a R-section passive gear (G8), a F1-section passive gear (G11), and a F2-section passive gear (G13); the R-section passive gear (G8) is connected to the R-section active gear (G7); the F1-section passive gear (G11) is meshed with the F1-section active gear (G10); and the F2-section passive gear (G13) is meshed with the F2-section active gear (G12).

2. The single planetary gear hydraulic mechanical continuously variable transmission system according to claim 1, characterized in that: The second parallel shaft (S2) is also fixedly sleeved with a motor driving gear (G5) and a variable displacement pump driven gear (G4); The motor driving gear (G5) and the variable pump driven gear (G4) are respectively located at two ends of the static hydraulic unit (H1); the motor driving gear (G5) is connected to the motor driven gear (G6); and the variable pump driven gear (G4) is meshed with the variable pump driving gear (G3).

3. The single planetary gear hydraulic mechanical continuously variable transmission system according to claim 1 or 2, characterized in that: The R-section driven gear (G8) is connected to the R-section driving gear (G7) via the R-section idler gear (G9); The R-segment idler gear (G9) is meshed with the R-segment driven gear (G8) and the R-segment driving gear (G7) respectively.

4. The single planetary gear hydraulic mechanical continuously variable transmission system according to claim 3, characterized in that: A power take-off unit is also provided on the first parallel shaft (S1); The power take-off unit is used to achieve power take-off output.

5. The single planetary gear hydraulic mechanical continuously variable transmission system according to claim 4, characterized in that: The power take-off unit comprises a power take-off drive gear (G16), a power take-off clutch (C-PTO), a sixth parallel shaft (S6) and a power take-off output driven gear (G17); The power take-off driving gear (G16) is loosely mounted on the first parallel shaft (S1); One end of the power take-off clutch (C-PTO) is coaxially fixedly connected to the first parallel shaft (S1), and the other end is connected to the power take-off drive gear (G16); The sixth parallel shaft (S6) is parallel to the first parallel shaft (S1) and is used for power output of the power take-off; The power take-off output driven gear (G17) is fixedly sleeved on the sixth parallel shaft (S6) and meshes with the power take-off driving gear (G16).

6. The single planetary gear hydraulic mechanical continuously variable transmission system according to claim 5, characterized in that: Also comprising a seventh parallel axis (S7); The seventh parallel shaft (S7) is parallel to the fifth parallel shaft (S5), and a front drive driven gear (G15) is fixedly mounted thereon; A front drive driving gear (G14) is also fixedly mounted on the fifth parallel shaft (S5); the front drive driving gear (G14) is arranged on a side of the F2 section passive gear (G13) away from the F1 section passive gear (G11), and meshes with the front drive passive gear (G15).

7. The single planetary gear hydraulic mechanical continuously variable transmission system according to claim 6, characterized in that: The seventh parallel shaft (S7) is also fixedly mounted with a front drive clutch (C4WD).

8. The single planetary gear hydraulic mechanical continuously variable transmission system according to claim 7, characterized in that: The motor driven gear (G6), the mechanical driven gear (G2), and the planetary gear (P) are sequentially arranged along the axial direction of the third parallel axis (S3); The R-segment driving gear (G7), the R-segment clutch (CR), the F1-segment clutch (C1), the F1-segment driving gear (G10), the F2-segment clutch (C2), and the F2-segment driving gear (G12) are sequentially arranged along the axial direction of the fourth parallel shaft (S4); The R-section passive gear (G8), the F1-section passive gear (G11), and the F2-section passive gear (G13) are sequentially arranged along the axial direction of the fifth parallel axis (S5).

9. The single planetary gear hydraulic mechanical continuously variable transmission system according to claim 8, characterized in that: The axis of the fourth parallel axis (S4) is located on the same straight line as the axis of the third parallel axis (S3).

10. The single planetary gear hydraulic mechanical continuously variable transmission system according to claim 8, characterized in that: The F1 section driving gear (G10) is connected to the F1 section clutch (C1) via a spline; The F2 section driving gear (G12) is connected to the F2 section clutch (C2) via a spline; The R section clutch (CR) is connected to the R section driving gear (G7) via a spline; The power take-off clutch (C-PTO) is connected to the power take-off drive gear (G16) via a spline.

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