Transmission system adopting HMCVT and control method thereof

Abstract

The invention relates to a vehicle transmission system and a control method thereof, and provides a transmission system adopting an HMCVT and a control method thereof in order to solve the problems that an existing speed control system is complex in structure, difficult to adapt to complex working conditions and poor in expansibility. The transmission system adopting the HMCVT comprises a double-planet-row structure and a plurality of rotating shaft assemblies, and the rotating shaft assemblies comprise the first shaft assembly, the second shaft assembly, the third shaft assembly, the fourth shaft assembly, the fifth shaft assembly and the output assembly which are arranged in parallel; the double-planet-row structure is a Ravigneaux type planet row structure, the first input end and the second input end of the double-planet-row structure are connected with the third shaft and the fourth shaft respectively, and the output end of the double-planet-row structure is connected with the sixth shaft. According to the invention, uninterrupted power transmission and continuously adjustable speed ratio can be realized, and ramp hovering of the whole vehicle can be realized.

Description

Technical Field

[0001] The present invention relates to a vehicle transmission system and a control method thereof, and in particular to a transmission system adopting a HMCVT and a control method thereof. Background Art

[0002] The current technical level of agricultural tractors is generally not high, and most of the transmissions are manual shift products. In some regions, among tractors with more than 180 horsepower, automatic transmissions account for more than 99%, of which hydraulic continuously variable transmissions (CVT) account for more than 54%. CVT is ahead of power shift products in terms of product technical level, driving experience, and operating efficiency of agricultural machinery.

[0003] Traditional manual shift and power shift gear transmissions have a fixed speed ratio for each gear. In order to reduce the fuel consumption of the engine and reduce the impact of gear shifting, the gearbox needs to be designed with more and more gears, which makes the gearbox structure complex. At the same time, there is a power interruption during the gear shifting gap, which affects the vehicle's ability to adapt to various complex working conditions. In order to reduce the impact of gear shifting and improve the vehicle's ability to adapt to complex working conditions, traditional transmission systems mostly use a torque converter plus a parallel shaft gearbox structure, but this structure has low working efficiency when the vehicle is at a low speed.

[0004] Patent CN116557495A discloses a multi-working mode continuously variable transmission system and its use method, wherein the first gear is fixedly connected to the clutch shaft; transmission shafts are arranged on both sides of the power unit; the first planetary gear and the second planetary gear are connected to the intermediate shaft to form a Ravina planetary gear; the mode switching component can transmit the torque on the transmission shaft of the power unit to the intermediate shaft; one end of the brake clutch is connected to the second planetary gear, and the other end is fixedly connected to the gearbox housing; the gear shifting component can transmit the torque on the clutch shaft to the intermediate shaft; the planet carrier output gear is connected to the Ravina planetary gear. The invention transmits the engine power to the Ravina planetary gear through the hydrostatic system and the mechanical system respectively, so that the output speed can be continuously increased, and the power can be transmitted without interruption and the speed ratio can be continuously adjusted. At the same time, the invention is provided with a mode switching component and a gear shifting component, which can perform a combination switch of multiple modes.

[0005] However, the common problems of the above-mentioned prior arts are: the speed change system has a complex structure, is difficult to adapt to complex working conditions, and has poor scalability. Summary of the invention

[0006] The purpose of the present invention is to solve the problems of complex structure, difficulty in adapting to complex working conditions and poor scalability of existing speed change systems, and to provide a transmission system using HMCVT (Hydro-Mechanical Continuously Variable Transmission) and a control method thereof.

[0007] To achieve the above purpose, the technical solution provided by the present invention is:

[0008] A transmission system using HMCVT includes a double planetary gear structure, multiple shaft assemblies and a power unit, and its special features are:

[0009] The double planetary gear structure is a Ravina planetary gear structure; the multiple rotating shaft assemblies include a first shaft assembly, a second shaft assembly, a third shaft assembly, a fourth shaft assembly, a fifth shaft assembly, and an output assembly arranged in parallel;

[0010] The first shaft assembly includes a clutch shaft, a first gear fixed on the clutch shaft, a first gear clutch, a second gear clutch, and a reverse gear clutch whose outer rings are respectively fixed on the clutch shaft, and a first gear driving gear, a second gear driving gear, and a reverse gear driving gear which are loosely sleeved on the clutch shaft and sequentially connected to the first gear clutch, the second gear clutch, and the reverse gear clutch inner rings through splines;

[0011] The second shaft assembly includes a power unit shaft, a power unit arranged on the power unit shaft, a second gear fixed on the power unit shaft and meshing with the first gear, and a third gear; the power unit includes a power input end and a power output end; the second gear is connected to the input end of the power unit, and the third gear is connected to the output end of the power unit;

[0012] The third shaft assembly includes a first intermediate shaft, a fourth gear fixed on the first intermediate shaft and meshing with the third gear;

[0013] The fourth shaft assembly includes a hollow shaft with an idle sleeve on the first intermediate shaft, a first gear driven gear and a reverse gear driven wheel fixed on the hollow shaft, and a second gear / hydraulic gear driven gear with an idle sleeve on the first intermediate shaft; the first gear driven gear is meshed with the first gear driving gear, and the reverse gear driven wheel is meshed with the reverse gear driving gear through the reverse gear idler wheel;

[0014] The fifth shaft assembly includes a second intermediate shaft, a hydraulic gear clutch with an outer ring fixedly connected to the second intermediate shaft, a hydraulic gear input gear which is loosely mounted on the second intermediate shaft and connected to the inner ring of the hydraulic gear clutch via a spline, and a hydraulic gear output driving gear which is fixedly mounted on the second intermediate shaft and meshed with the second gear / hydraulic gear driven gear;

[0015] The output assembly is connected to the output end of the double planetary gear structure for power output.

[0016] Further, the output assembly includes a sixth shaft assembly, a power output shaft assembly, a field mode clutch and a road mode clutch; the sixth shaft assembly includes a sixth shaft connected to the output end of the double planetary gear structure, and a field mode driving gear and a road mode driving gear fixed on the sixth shaft; the power output shaft assembly includes a power output shaft, and a field mode passive gear and a road mode passive gear loosely mounted on the power output shaft; the field mode driving gear is meshed with the field mode passive gear, and the road mode driving gear is meshed with the road mode passive gear; the outer rings of the field mode clutch and the road mode clutch are both connected to the power output shaft, the inner ring of the field mode clutch is connected to the field mode passive gear, and the inner ring of the road mode clutch is connected to the road mode passive gear.

[0017] Furthermore, the double planetary row structure includes a first planetary row, a second planetary row, a ring gear and a planet carrier; the planet carrier is the output end of the double planetary row structure; the first planetary row includes a first sun gear and a plurality of first planetary gears meshing with the first sun gear; the first sun gear is the second input end of the double planetary row structure; the second planetary row includes a second sun gear and a plurality of second planetary gears meshing with the second sun gear; the second sun gear is the first input end of the double planetary row structure; the ring gear is meshed with the plurality of first planetary gears; the ring gear is fixedly connected to the second intermediate shaft; the second planetary gear is meshed with the first planetary gear; the plurality of first planetary gears are arranged on the outer ring of the planet carrier, and the plurality of second planetary gears are arranged on the inner ring of the planet carrier.

[0018] Furthermore, the transmission system using HMCVT also includes a power take-off unit, which includes a power take-off driving gear loosely mounted on the clutch shaft, a power take-off output shaft, a power take-off passive gear fixed on the power take-off output shaft, and a power take-off clutch whose outer ring is fixedly connected to the clutch shaft, the power take-off passive gear is meshed with the power take-off driving gear, and the power take-off driving gear is fixedly connected to the inner ring of the power take-off clutch.

[0019] Furthermore, the power input end of the power unit is a hydraulic pump; the power output end of the power unit is a hydraulic motor; or, the power input end of the power unit is a generator; the power output end of the power unit is an electric motor.

[0020] Furthermore, the second gear and the first gear, and the third gear and the fourth gear are meshedly connected via idle gears.

[0021] At the same time, the present invention also provides a control method for the transmission system using the HMCVT, which is special in that it includes the following steps:

[0022] Step 1, selecting working areas with different working modes, controlling the engagement state of each clutch, the engine power is input from the clutch shaft, part of the power is transmitted through the hydraulic flow, and the other part of the power is transmitted through the mechanical flow, and the power is combined by the double planetary gear structure and transmitted to the power output shaft for output; the working modes include field mode and road mode; the working areas include pure hydraulic gear working area, forward first gear working area, forward second gear working area and reverse gear working area;

[0023] Field Mode:

[0024] Pure hydraulic gear working area: hydraulic gear clutch and field mode clutch are in the engaged state;

[0025] Forward first gear working area: the first gear clutch and field mode clutch are in the engaged state;

[0026] Forward second gear working area: the second gear clutch and field mode clutch are in the engaged state;

[0027] Reverse gear working area: reverse gear clutch and field mode clutch are in the engaged state;

[0028] Road Mode:

[0029] Pure hydraulic gear working area: hydraulic gear clutch and road mode clutch are in the engaged state;

[0030] Forward first gear working area: the first gear clutch and road mode clutch are in the engaged state;

[0031] Forward second gear working area: the second gear clutch and road mode clutch are in the engaged state;

[0032] Reverse gear working area: reverse gear clutch and road mode clutch are in the engaged state;

[0033] Step 2: Under the condition that the engine speed remains unchanged, the swing angle of the hydraulic pump in the power unit is controlled to continuously change or the speed of the generator is controlled to continuously change, so as to continuously increase the output shaft speed of the output unit, and finally realize the continuous adjustable speed ratio of the transmission system.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The transmission system using HMCVT provided by the present invention integrates a double planetary gear structure and multiple rotating shaft components, which can realize uninterrupted power transmission and continuously adjustable speed ratio; by making the vehicle enter the pure hydraulic gear and controlling the swing angle of the power unit to zero, the whole vehicle can be hovered on the ramp;

[0036] 2. The transmission system using HMCVT provided by the present invention can control the output state of the power take-off by controlling the working state of the power take-off clutch CP, and can realize the power take-off output by controlling the engagement of the power take-off clutch.

[0037] 3. The control method of the transmission system using HMCVT provided by the present invention is divided into field mode and road mode. The working range of the field mode meets the actual rotation speed required for farming, and the road mode speed can be expanded according to user needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the structure of a transmission system embodiment of the present invention using HMCVT;

[0039] Figure 2 A schematic diagram of a double planetary gear structure in an embodiment of the present invention;

[0040] Description of reference numerals:

[0041] S1-clutch shaft; S2-power unit shaft; S3-first intermediate shaft; S4-hollow shaft; S5-second intermediate shaft; S6-sixth shaft; S7-power output shaft; S8-power take-off output shaft;

[0042] G1-first gear; G2-second gear; G3-third gear; G4-fourth gear; G5-hydraulic gear input gear; G6-hydraulic gear output driving gear; G7-reverse gear driving gear; G8-reverse gear idler; G9-reverse gear passive gear; G10-first gear driving gear; G11-first gear passive gear; G12-second gear driving gear; G13-second gear / hydraulic gear passive gear; G14-field mode driving gear; G15-field mode passive gear; G16-road mode driving gear; G17-road mode passive gear; G18-power take-off drive gear; G19-power take-off passive gear;

[0043] H-power unit;

[0044] C1-first gear clutch, C2-second gear clutch, CR-reverse gear clutch, CHY-hydraulic gear clutch, CL-field mode clutch; CH-road mode clutch; CP-power take-off clutch;

[0045] P1-first planetary gear; P2-second planetary gear, P10-first sun gear, P11-ring gear, P12-first planetary gear, P13-planet carrier, P20-second sun gear, P21-second planetary gear. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0047] A transmission system using HMCVT, see Figure 1 and Figure 2 , including a double planetary gear structure, a plurality of rotating shaft components and a power unit H;

[0048] The double planetary gear structure is a Ravina planetary gear structure; the plurality of rotating shaft assemblies include a first shaft assembly, a second shaft assembly, a third shaft assembly, a fourth shaft assembly, a fifth shaft assembly, an output assembly and a power take-off unit arranged in parallel;

[0049] The first shaft assembly includes a clutch shaft S1, a first gear G1 fixed on the clutch shaft S1, a first gear clutch C1, a second gear clutch C2, and a reverse gear clutch CR whose outer rings are respectively fixed on the clutch shaft S1, and a first gear driving gear G10, a second gear driving gear G12, and a reverse gear driving gear G7 which are loosely sleeved on the clutch shaft S1 and sequentially connected to the first gear clutch C1, the second gear clutch C2, and the inner rings of the reverse gear clutch CR through splines;

[0050] The second shaft assembly includes a power unit shaft S2, a power unit H arranged on the power unit shaft S2, a second gear G2 fixed on the power unit shaft S2 and meshing with the first gear G1, and a third gear G3; the power unit H includes a power input end and a power output end; the second gear G2 is connected to the input end of the power unit H, and the third gear G3 is connected to the output end of the power unit H;

[0051] The third shaft assembly includes a first intermediate shaft S3, a fourth gear G4 fixed on the first intermediate shaft S3 and meshing with the third gear G3;

[0052] The fourth shaft assembly includes a hollow shaft S4 which is sleeved on the first intermediate shaft S3, a first gear driven gear G11 and a reverse gear driven gear G9 which are fixed on the hollow shaft S4, and a second gear / hydraulic gear driven gear G13 which is sleeved on the first intermediate shaft S3; the first gear driven gear G11 is meshed with the first gear driving gear G10, and the reverse gear driven gear G9 is meshed with the reverse gear driving gear G7 through the reverse gear idler gear G8;

[0053] The fifth shaft assembly includes a second intermediate shaft S5, a hydraulic gear clutch CHY whose outer ring is fixedly connected to the second intermediate shaft S5, a hydraulic gear input gear G5 which is loosely mounted on the second intermediate shaft S5 and connected to the inner ring of the hydraulic gear clutch CHY via a spline, and a hydraulic gear output driving gear G6 which is fixedly mounted on the second intermediate shaft S5 and meshes with the second gear / hydraulic gear driven gear G13;

[0054] The output assembly is connected to the output end of the double planetary gear structure for power output, and includes a sixth shaft assembly, a power output shaft assembly, a field mode clutch CL and a road mode clutch CH;

[0055] The sixth shaft assembly includes a sixth shaft S6 connected to the output end of the double planetary gear structure, and a field mode driving gear G14 and a road mode driving gear G16 fixedly mounted on the sixth shaft S6;

[0056] The power output shaft assembly includes a power output shaft S7, and a field mode passive gear G15 and a road mode passive gear G17 which are loosely sleeved on the power output shaft S7; the field mode driving gear G14 is meshed with the field mode passive gear G15, and the road mode driving gear G16 is meshed with the road mode passive gear G17;

[0057] The outer rings of the field mode clutch CL and the road mode clutch CH are connected to the power output shaft S7, the inner ring of the field mode clutch CL is connected to the field mode driven gear G15, and the inner ring of the road mode clutch CH is connected to the road mode driven gear G17.

[0058] In this embodiment, the double planetary row structure includes a first planetary row P1, a second planetary row P2, a ring gear P11 and a planet carrier P13; the planet carrier P13 is the output end of the double planetary row structure; the first planetary row P1 includes a first sun gear P10 and a plurality of first planetary gears P12 meshing with the first sun gear P10; the first sun gear P10 is the second input end of the double planetary row structure; the second planetary row P2 includes a second sun gear P20 and a plurality of second planetary gears P21 meshing with the second sun gear P20; the second sun gear P20 is the first input end of the double planetary row structure; the ring gear P11 meshes with the plurality of first planetary gears P12; the ring gear P11 is fixedly connected to the second intermediate shaft S5; the second planetary gear P21 meshes with the first planetary gear P12; the plurality of first planetary gears P12 are arranged on the outer ring of the planet carrier P13, and the plurality of second planetary gears P21 are arranged on the inner ring of the planet carrier P13.

[0059] The power take-off unit includes a power take-off drive gear G18 loosely mounted on the clutch shaft S1, a power take-off output shaft S8, a power take-off passive gear G19 fixedly mounted on the power take-off output shaft S8, and a power take-off clutch CP whose outer ring is fixedly connected to the clutch shaft S1. The power take-off passive gear G19 is meshed with the power take-off drive gear G18, and the power take-off drive gear G18 is fixedly connected to the inner ring of the power take-off clutch CP.

[0060] In particular, the power input end of the power unit H is a hydraulic pump; the power output end of the power unit H is a hydraulic motor; or, the power input end of the power unit H is a generator; the power output end of the power unit H is an electric motor.

[0061] At the same time, this embodiment also provides a control method for the transmission system using the HMCVT, which is characterized by comprising the following steps:

[0062] Step 1, select the working area of ​​different working modes, control the engagement state of each clutch, the engine power is input from the clutch shaft S1, part of the power is transmitted through the hydraulic flow, and the other part of the power is transmitted through the mechanical flow, and the power is combined by the double planetary gear structure and transmitted to the power output shaft S7 for output; the working modes include field mode and road mode; the working areas include pure hydraulic gear working area, forward first gear working area, forward second gear working area and reverse gear working area;

[0063] Field Mode:

[0064] Pure hydraulic gear working area: hydraulic gear clutch CHY and field mode clutch CL are in the engaged state;

[0065] First gear forward working area: first gear clutch C1 and field mode clutch CL are in the engaged state;

[0066] Forward second gear working area: the second gear clutch C2 and the field mode clutch CL are in the engaged state;

[0067] Reverse gear working area: reverse gear clutch CR and field mode clutch CL are in the engaged state;

[0068] Road Mode:

[0069] Pure hydraulic gear working area: hydraulic gear clutch CHY and road mode clutch CH are in the engaged state;

[0070] Forward first gear working area: the first gear clutch C1 and the road mode clutch CH are in the engaged state;

[0071] Forward second gear working area: the second gear clutch C2 and the road mode clutch CH are in the engaged state;

[0072] Reverse gear working area: reverse gear clutch CR and road mode clutch CH are in the engaged state;

[0073] Step 2: Under the condition that the engine speed remains unchanged, the swing angle of the hydraulic pump in the power unit H is controlled to change continuously or the speed of the generator is controlled to change continuously, so as to realize the continuous increase of the output shaft speed of the output unit, and finally realize the continuous adjustable speed ratio of the transmission system.

[0074] Combined with Figure 1 The power transmission routes of different working areas of the present invention are further described as follows:

[0075] Field mode pure hydraulic gear working area: engine power is input from the clutch shaft S1 and reaches the first gear G1; at this time, all power is transmitted through the hydraulic flow: the first gear G1 drives the second gear G2, the third gear G3, and the fourth gear G4 to work in turn; at this time, the hydraulic flow power is divided into two paths at the fourth gear G4, the first path: the fourth gear G4 drives the hydraulic gear input gear G5, the hydraulic gear clutch CHY, the intermediate shaft S5, the hydraulic gear output driving gear G6, and the second gear / hydraulic gear passive gear G13 to work in turn, and reaches the ring gear P11 of the second planetary row P2; the second path: the fourth gear G4 drives the second sun gear P20 to work, and after converging at the second planetary row P2, it is output through the planet carrier P13, and then the planet carrier output shaft S6 drives the field mode driving gear G14 and the field mode passive gear G15 to work in turn, and finally reaches the power output shaft S7;

[0076] In this working area, when the engine speed remains unchanged, by controlling the swing angle of the variable pump in the power unit H1 to continuously change from the maximum positive value to the maximum negative value, the speed of the power output shaft S7 increases continuously and the speed ratio is continuously adjustable.

[0077] Field mode forward first gear working area: the engine power is input from the clutch shaft S1 and reaches the first gear G1; at this time, part of the power is transmitted through the hydraulic flow: the first gear G1 drives the second gear G2, the third gear G3, and the fourth gear G4 to work in turn, and reaches the sun gear of the second planetary row P2; the other part of the power is transmitted through the mechanical flow: the first gear driving gear G10 drives the first gear driven gear G11 to work, and reaches the sun gear of the first planetary row P1; the two powers are combined in the double planetary row structure and output through the planet carrier P13, and then transmitted to the planet carrier output shaft S6, the planet carrier output shaft S6 drives the field mode driving gear G14 and the field mode driven gear G15 to work in turn, and finally reaches the power output shaft S7.

[0078] In this working area, when the engine speed remains unchanged, by controlling the swing angle of the variable pump in the power unit H1 to continuously change from the negative maximum to the positive maximum, the speed of the power output shaft S7 increases continuously and the speed ratio is continuously adjustable.

[0079] Field mode forward second gear working area: engine power is input from clutch shaft S1 and reaches first gear G1. At this time, part of the power is transmitted through hydraulic flow: first gear G1 drives second gear G2, third gear G3, and fourth gear G4 to work in sequence and reaches second sun gear P20; the other part of the power is transmitted through mechanical flow: first gear G1 drives second gear driving gear G12 and second gear / hydraulic gear driven gear G13 to work in sequence and reaches the ring gear of first planetary gear P1; the two-way power is output through planetary carrier after merging in the double planetary gear structure, and then transmitted to planetary carrier output shaft S6, which drives field mode driving gear G14 and field mode driven gear G15 to work in sequence and finally reaches power output shaft S7.

[0080] In this working area, when the engine speed remains unchanged, by controlling the swing angle of the variable pump in the power unit H to continuously change from the maximum positive value to the maximum negative value, the speed of the power output shaft S7 increases continuously and the speed ratio is continuously adjustable.

[0081] Reverse gear field mode working area: engine power is input from clutch shaft S1 and reaches the first gear G1. At this time, part of the power is transmitted through hydraulic flow: the first gear G1 drives the second gear G2, the third gear G3, and the fourth gear G4 in turn to reach the sun gear of the second planetary row P2; the other part of the power is transmitted through mechanical flow: the first gear G1 drives the reverse gear driving wheel G7, the reverse gear idler gear G8, and the reverse gear driven gear G9 in turn to work and reach the sun gear of the first planetary row P1; the two-way power is output through the planet carrier P13 after merging in the double planetary row structure, and then transmitted to the planet carrier output shaft S6, which drives the field mode driving gear G14 and the field mode driven gear G15 in turn to work, and finally reaches the power output shaft S7.

[0082] In this working area, when the engine speed remains unchanged, by controlling the swing angle of the variable pump in the power unit H to continuously change from the positive maximum to the negative maximum, the speed of the power output shaft S7 continuously increases in the opposite direction of the forward gear speed, and the speed ratio is continuously adjustable.

[0083] Pure hydraulic gear working area in road mode: engine power is input from clutch shaft S1 and reaches first gear G1. All power is transmitted through hydraulic flow: first gear G1 drives second gear G2, third gear G3, and fourth gear G4 to work in turn; at this time, hydraulic flow power is divided into two paths at fourth gear G4, first path: fourth gear G4 drives hydraulic gear input gear G5, hydraulic gear clutch CHY, intermediate shaft S5, hydraulic gear output driving gear G6, second gear / hydraulic gear passive gear G13 to work in turn, and reaches P2 planetary gear ring; second path: fourth gear G4 drives second sun gear P20 to work; after converging at second planetary gear P2, it is output through planet carrier P13: planet carrier output shaft S6 drives road mode driving gear G16 and road mode passive gear G17 to work in turn, and finally reaches power output shaft S7;

[0084] In this working area, when the engine speed remains unchanged, by controlling the swing angle of the variable pump in the power unit H1 to continuously change from the maximum positive value to the maximum negative value, the speed of the power output shaft S7 increases continuously and the speed ratio is continuously adjustable.

[0085] Road mode forward first gear working area: engine power is input from clutch shaft S1 and reaches first gear G1. At this time, part of the power is transmitted through hydraulic flow: first gear G1 drives second gear G2, third gear G3, and fourth gear G4 to work in sequence and reaches second sun gear P20; the other part of the power is transmitted through mechanical flow: first gear driving gear G10 drives first gear passive gear G11 to work and reaches first sun gear P10. The two-way power is output through planet carrier P13 after merging in the double planetary gear structure, and then transmitted to planet carrier output shaft S6, which drives road mode driving gear G16 and road mode passive gear G17 to work in sequence and finally reaches power output shaft S7.

[0086] In this working area, when the engine speed remains unchanged, by controlling the swing angle of the variable pump in the power unit H1 to continuously change from the negative maximum to the positive maximum, the speed of the power output shaft S7 increases continuously and the speed ratio is continuously adjustable.

[0087] Road mode forward second gear working area: engine power is input from clutch shaft S1 and reaches first gear G1. At this time, part of the power is transmitted through hydraulic flow: first gear G1 drives second gear G2, third gear G3, and fourth gear G4 to work in sequence, reaching second sun gear P20; the other part of the power is transmitted through mechanical flow: first gear G1 drives second gear driving gear G12 and second gear / hydraulic gear driven gear G13 to work in sequence, reaching the ring gear of first planetary gear P1. The two-way power is output through planetary carrier P13 after merging in the double planetary gear structure, and then transmitted to planetary carrier output shaft S6, which drives road mode driving gear G16 and road mode driven gear G17 to work in sequence, and finally reaches power output shaft S7.

[0088] In this working area, when the engine speed remains unchanged, by controlling the swing angle of the variable pump in the power unit H to continuously change from the maximum positive value to the maximum negative value, the speed of the power output shaft S7 increases continuously and the speed ratio is continuously adjustable.

[0089] Road mode reverse gear working area: the engine power is input from the clutch shaft S1 and reaches the first gear G1. At this time, part of the power is transmitted through the hydraulic flow: the first gear G1 drives the second gear G2, the third gear G3, and the fourth gear G4 to work in sequence, and reaches the sun gear of the second planetary row P2; the other part of the power is transmitted through the mechanical flow: the first gear G1 drives the reverse gear driving gear G7, the reverse gear idler gear G8, and the reverse gear driven gear G9 to work in sequence, and reaches the sun gear of the first planetary row P1. The two-way power is output through the planet carrier P13 after merging in the double planetary row structure, and then transmitted to the planet carrier output shaft S6. The planet carrier output shaft S6 drives the road mode driving gear G16 and the road mode driven gear G17 to work in sequence, and finally reaches the power output shaft S7.

[0090] In this working area, when the engine speed remains unchanged, by controlling the swing angle of the variable pump in the power unit H to continuously change from the positive maximum to the negative maximum, the speed of the power output shaft S7 increases continuously (opposite to the forward gear speed direction), and the speed ratio is continuously adjustable.

[0091] The following Table 1 lists the working states of the clutches in the above-mentioned working areas. The cells with "●" in Table 1 indicate that the corresponding clutch is in the engaged state, and the cells without "●" indicate that the corresponding clutch is in the disconnected state.

[0092] Table 1 Clutch working status table in each working area of ​​the transmission system using HMCVT

[0093]

[0094]

[0095] In the above table, C1, C2, CR, CHY, CL, and CH represent first gear clutch, second gear clutch, reverse gear clutch, hydraulic gear clutch, field mode clutch, and road mode clutch respectively.

[0096] It should be noted that the above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A transmission system using HMCVT, comprising a double planetary gear structure, a plurality of rotating shaft assemblies and a power unit (H), characterized in that: The double planetary gear structure is a Ravina planetary gear structure; the multiple rotating shaft assemblies include a first shaft assembly, a second shaft assembly, a third shaft assembly, a fourth shaft assembly, a fifth shaft assembly, and an output assembly arranged in parallel; The first shaft assembly comprises a clutch shaft (S1), a first gear (G1) fixed on the clutch shaft (S1), a first gear clutch (C1), a second gear clutch (C2), and a reverse gear clutch (CR) whose outer rings are respectively fixed on the clutch shaft (S1), and a first gear driving gear (G10), a second gear driving gear (G12), and a reverse gear driving gear (G7) which are loosely sleeved on the clutch shaft (S1) and sequentially connected to the first gear clutch (C1), the second gear clutch (C2), and the inner rings of the reverse gear clutch (CR) through splines; The second shaft assembly comprises a power unit shaft (S2), a power unit (H) arranged on the power unit shaft (S2), a second gear (G2) fixed on the power unit shaft (S2) and meshing with the first gear (G1), and a third gear (G3); the power unit (H) comprises a power input end and a power output end; the second gear (G2) is connected to the input end of the power unit (H), and the third gear (G3) is connected to the output end of the power unit (H); The third shaft assembly comprises a first intermediate shaft (S3), a fourth gear (G4) fixed on the first intermediate shaft (S3) and meshing with the third gear (G3); The fourth shaft assembly comprises a hollow shaft (S4) sleeved on the first intermediate shaft (S3), a first gear driven gear (G11) and a reverse gear driven wheel (G9) fixed on the hollow shaft (S4), and a second gear / hydraulic gear driven gear (G13) sleeved on the first intermediate shaft (S3); the first gear driven gear (G11) is meshed with the first gear driving gear (G10), and the reverse gear driven wheel (G9) is meshed with the reverse gear driving gear (G7) through the reverse gear idler wheel (G8); The fifth shaft assembly comprises a second intermediate shaft (S5), a hydraulic gear clutch (CHY) whose outer ring is fixedly connected to the second intermediate shaft (S5), a hydraulic gear input gear (G5) which is loosely mounted on the second intermediate shaft (S5) and connected to the inner ring of the hydraulic gear clutch (CHY) via a spline, and a hydraulic gear output driving gear (G6) which is fixedly mounted on the second intermediate shaft (S5) and meshed with the second gear / hydraulic gear driven gear (G13); The output assembly is connected to the output end of the double planetary gear structure for power output.

2. The transmission system using HMCVT according to claim 1, characterized in that: The output assembly includes a sixth shaft assembly, a power output shaft assembly, a field mode clutch (CL) and a road mode clutch (CH); The sixth shaft assembly comprises a sixth shaft (S6) connected to the output end of the double planetary gear structure, and a field mode driving gear (G14) and a road mode driving gear (G16) fixedly mounted on the sixth shaft (S6); The power output shaft assembly comprises a power output shaft (S7), and a field mode passive gear (G15) and a road mode passive gear (G17) which are loosely sleeved on the power output shaft (S7); the field mode active gear (G14) is meshed with the field mode passive gear (G15), and the road mode active gear (G16) is meshed with the road mode passive gear (G17); The outer rings of the field mode clutch (CL) and the road mode clutch (CH) are both connected to the power output shaft (S7), the inner ring of the field mode clutch (CL) is connected to the field mode passive gear (G15), and the inner ring of the road mode clutch (CH) is connected to the road mode passive gear (G17).

3. The transmission system using HMCVT according to claim 1 or 2, characterized in that: The double planetary gear structure comprises a first planetary gear (P1), a second planetary gear (P2), a ring gear (P11) and a planet carrier (P13); the planet carrier (P13) is the output end of the double planetary gear structure; The first planetary gear (P1) includes a first sun gear (P10) and a plurality of first planetary gears (P12) meshing with the first sun gear (P10); the first sun gear (P10) is the second input end of the double planetary gear structure; the second planetary gear (P2) includes a second sun gear (P20) and a plurality of second planetary gears (P21) meshing with the second sun gear (P20); the second sun gear (P20) is the first input end of the double planetary gear structure; the ring gear (P11) meshes with the plurality of first planetary gears (P12); the ring gear (P11) is fixedly connected to the second intermediate shaft (S5); the second planetary gear (P21) meshes with the first planetary gear (P12); the plurality of first planetary gears (P12) are arranged on the outer ring of the planet carrier (P13), and the plurality of second planetary gears (P21) are arranged on the inner ring of the planet carrier (P13).

4. The transmission system using HMCVT according to claim 3, characterized in that: The invention also comprises a power take-off unit, which comprises a power take-off drive gear (G18) loosely sleeved on a clutch shaft (S1), a power take-off output shaft (S8), a power take-off passive gear (G19) fixedly mounted on the power take-off output shaft (S8), and a power take-off clutch (CP) whose outer ring is fixedly connected to the clutch shaft (S1); the power take-off passive gear (G19) is meshed with the power take-off drive gear (G18), and the power take-off drive gear (G18) is fixedly connected to the inner ring of the power take-off clutch (CP).

5. The transmission system using HMCVT according to claim 4, characterized in that: The power input end of the power unit (H) is a hydraulic pump; the power output end of the power unit (H) is a hydraulic motor; or, the power input end of the power unit (H) is a generator; the power output end of the power unit (H) is an electric motor.

6. The transmission system using HMCVT according to claim 5, characterized in that: The second gear (G2) and the first gear (G1), and the third gear (G3) and the fourth gear (G4) are meshed and connected via idler gears.

7. A control method for a transmission system using HMCVT according to any one of claims 2 to 6, characterized in that: The following steps are involved: Step 1, selecting working areas with different working modes, controlling the engagement state of each clutch, the engine power is input from the clutch shaft (S1), a part of the power is transmitted through the hydraulic flow, and the other part of the power is transmitted through the mechanical flow, and the power is combined by the double planetary gear structure and transmitted to the power output shaft (S7) for output; the working modes include field mode and road mode; the working areas include pure hydraulic gear working area, forward first gear working area, forward second gear working area and reverse gear working area; Field Mode: Pure hydraulic gear working area: the hydraulic gear clutch (CHY) and the field mode clutch (CL) are in the engaged state; Forward first gear working area: the first gear clutch (C1) and the field mode clutch (CL) are in the engaged state; Forward second gear working area: the second gear clutch (C2) and the field mode clutch (CL) are in the engaged state; Reverse gear working area: the reverse clutch (CR) and the field mode clutch (CL) are in the engaged state; Road Mode: Pure hydraulic gear working area: the hydraulic gear clutch (CHY) and the road mode clutch (CH) are in the engaged state; Forward first gear working area: the first gear clutch (C1) and the road mode clutch (CH) are in the engaged state; Forward second gear working area: the second gear clutch (C2) and the road mode clutch (CH) are in the engaged state; Reverse gear working area: the reverse clutch (CR) and the road mode clutch (CH) are in the engaged state; Step 2: Under the condition that the engine speed remains unchanged, the swing angle of the hydraulic pump in the power unit (H) is controlled to continuously change or the speed of the generator is controlled to continuously change, so as to continuously increase the output shaft speed of the output unit, and finally realize the continuous adjustment of the transmission system speed ratio.

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