Hydro-mechanical hybrid transmission device with energy management mechanism

Abstract

A hydro-mechanical hybrid transmission device with an energy management mechanism includes an input member, a mechanical transmission mechanism, an energy management mechanism, a power output mechanism, an output member, a convergence mechanism, a start mechanism, a hydraulic transmission mechanism, a clutch assembly, and a brake assembly. The clutch assembly connects the input member to the mechanical transmission mechanism, the power output mechanism, and the hydraulic transmission mechanism, and connects the energy management mechanism to the mechanical transmission mechanism and the power output mechanism. The clutch assembly and the brake assembly provide a continuous transmission ratio between the input member and the output member and/or the power output mechanism, between the energy management mechanism and the output member and/or the power output mechanism, and between the energy management mechanism together with the input member and the output member and/or the power output mechanism.

Description

CROSS REFERENCE TO THE RELATED APPLICATIONS

This application is the national phase entry of International Application No. PCT/CN2020/106674, filed on Aug. 4, 2020, which is based upon and claims priority to Chinese Patent Application No. 202010697161.6, filed on Jul. 20, 2020, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to the field of automatic transmission devices, and in particular, to a hydro-mechanical hybrid transmission device with an energy management mechanism.

BACKGROUND

Hydro-mechanical hybrid transmission devices integrating hydraulic transmission and mechanical transmission are suitable for high-power agricultural or engineering vehicles. Hydraulic transmission that features low speed and high torque is suitable for startup, hydro-mechanical transmission that features efficient stepless speed regulation is suitable for operation, and mechanical transmission that features efficient speed variation is suitable for traveling. A hydro-mechanical hybrid transmission device integrating hydraulic transmission, hydro-mechanical transmission, and mechanical transmission has high engineering application values.

High-power vehicles require a large amount of power mainly because a power source supplies power not only to a transmission system, but also to a power output system to drive other devices to do external work. Therefore, the reasonable distribution of energy to the transmission system and the power output system and the recovery and reuse of residual energy are critical to improve the traction power and transmission efficiency of such vehicles.

SUMMARY

To eliminate the defects in the prior art, the present invention provides a hydro-mechanical hybrid transmission device with an energy management mechanism. The present invention integrates hydraulic transmission, hydro-mechanical transmission, and mechanical transmission, and realizes energy recovery and reuse of transmission mechanisms and a power output mechanism.

The present invention achieves the above objective through the following technical solution.

A hydro-mechanical hybrid transmission device with an energy management mechanism includes an input member, a mechanical transmission mechanism, an energy management mechanism, a power output mechanism, an output member, a convergence mechanism, a start mechanism, a hydraulic transmission mechanism, a clutch assembly, and a brake assembly, wherein the clutch assembly connects the input member to the mechanical transmission mechanism, the power output mechanism, and the hydraulic transmission mechanism, connects an output of the hydraulic transmission mechanism to the mechanical transmission mechanism and the output member, connects an output of the mechanical transmission mechanism to the convergence mechanism, connects the output member to the convergence mechanism, and connects the energy management mechanism to the mechanical transmission mechanism and the power output mechanism; and the clutch assembly and the brake assembly provide a continuous transmission ratio between the input member and the output member and/or the power output mechanism, provide a continuous transmission ratio between the energy management mechanism and the output member and/or the power output mechanism, and provide a continuous transmission ratio between the energy management mechanism together with the input member and the output member and/or the power output mechanism.

Further, transmission modes including hydraulic transmission, hydro-mechanical transmission, and mechanical transmission are provided between the input member and the output member by adjusting a displacement ratio of the hydraulic transmission mechanism and selectively controlling engagement of the clutch assembly and the brake assembly.

Further, the mechanical transmission mechanism includes a front planetary gear mechanism and a middle planetary gear mechanism, a planet carrier of the front planetary gear mechanism is connected to the input member, the planet carrier of the front planetary gear mechanism is connected to a ring gear of the middle planetary gear mechanism, a sun gear of the front planetary gear mechanism is connected to a sun gear of the middle planetary gear mechanism, and the sun gear of the middle planetary gear mechanism is connected to an output end of the hydraulic transmission mechanism; the convergence mechanism includes a rear planetary gear mechanism, a ring gear of the rear planetary gear mechanism is connected to the output member, and the clutch assembly connects a ring gear of the front planetary gear mechanism or a planet carrier of the middle planetary gear mechanism to a sun gear of the rear planetary gear mechanism;

the clutch assembly includes a clutch C₂ and a clutch C₃; the clutch C₂ is used for selectively connecting an input end of the hydraulic transmission mechanism to the input member to achieve synchronous rotation; the clutch C₃ is used for selectively connecting the output end of the hydraulic transmission mechanism to the output member to achieve synchronous rotation; and continuous forward or reverse hydraulic transmission is provided between the input member and the output member by adjusting the displacement ratio of the hydraulic transmission mechanism and selectively controlling engagement of the clutch C₂ and the clutch C₃.

Further, the clutch assembly further includes a clutch C₁, a clutch C₄, a clutch C₅, and a clutch C₆; the clutch C₁ is used for selectively connecting the input member to the planet carrier of the front planetary gear mechanism to achieve synchronous rotation; the clutch C₄ is used for selectively connecting the planet carrier of the middle planetary gear mechanism to the sun gear of the rear planetary gear mechanism to achieve synchronous rotation; the clutch C₅ is used for selectively connecting the ring gear of the front planetary gear mechanism to the sun gear of the rear planetary gear mechanism to achieve synchronous rotation; the clutch C₆ is used for selectively connecting the ring gear of the rear planetary gear mechanism to the sun gear of the rear planetary gear mechanism to achieve synchronous rotation; the brake assembly includes a brake B₂, and the brake B₂ is used for selectively connecting a planet carrier of the rear planetary gear mechanism to a fixed member; and continuous forward or reverse hydro-mechanical transmission is provided between the input member and the output member by adjusting the displacement ratio of the hydraulic transmission mechanism and selectively controlling engagement of the clutch C₁, the clutch C₂, the clutch C₄, the clutch C₅, the clutch C₆, and the brake B₂.

Further, the clutch C₁, the clutch C₂, the clutch C₄, and the clutch C₆ are engaged, the clutch C₁, the clutch C₂, the clutch C₅, and the clutch C₆ are engaged, the clutch C₁, the clutch C₂, the clutch C₄, and the brake B₂ are engaged, and the clutch C₁, the clutch C₂, the clutch C₅, and the brake B₂ are engaged, to respectively provide different forward or reverse hydro-mechanical transmission between the input member and the output member.

Further, the brake assembly further includes a brake B₁; the brake B₁ is used for selectively connecting the output end of the hydraulic transmission mechanism to the fixed member; and the clutch C₁, the clutch C₄, the clutch C₆, and the brake B₁ are engaged, the clutch C₁, the clutch C₅, the clutch C₆, and the brake B₁ are engaged, the clutch C₁, the clutch C₄, the brake B₁, and the brake B₂ are engaged, and the clutch C₁, the clutch C₅, the brake B₁, and the brake B₂ are engaged, to respectively provide different forward or reverse mechanical transmission between the input member and the output member.

Further, the energy management mechanism includes a pump/motor mechanism, a solenoid directional valve V₁, a pilot-operated proportional relief valve V₂, an accumulator A₁, a solenoid directional valve V₃, a pilot-operated proportional relief valve V₄, and an accumulator A₂; the pump/motor mechanism is connected to the accumulator A₁ and the accumulator A₂; the solenoid directional valve V₁ is used for controlling the pump/motor mechanism to be connected to the accumulator A₁, the pilot-operated proportional relief valve V₂ is mounted between the pump/motor mechanism and the accumulator A₁, the solenoid directional valve V₃ is used for controlling the pump/motor mechanism to be connected to the accumulator A₂, and the pilot-operated proportional relief valve V₄ is mounted between the pump/motor mechanism and the accumulator A₂; the clutch assembly further includes a clutch C₇, a clutch C₈, and a clutch C₉, the clutch C₇ is used for selectively connecting the pump/motor mechanism to the planet carrier of the front planetary gear mechanism to achieve synchronous rotation; the clutch C₉ is used for selectively connecting the pump/motor mechanism to the power output mechanism to achieve synchronous rotation; and the clutch C₅ is used for selectively connecting the input member to the power output mechanism to achieve synchronous rotation.

Further, when the output member is braked, the clutch C₇, the brake B₁, and the clutch C₄ are engaged, or the clutch C₇, the brake B₁, and the clutch C₅ are engaged, to respectively provide a continuous transmission ratio between the output member and the pump/motor mechanism; and the solenoid directional valve V₁ and the solenoid directional valve V₃ are selectively controlled to input, into the accumulator A₁ or/and the accumulator A₂, energy produced when the output member is braked;

when the power output mechanism is braked, the clutch C₉ is engaged to provide a continuous transmission ratio between the power output mechanism and the pump/motor mechanism; and the solenoid directional valve V₁ and the solenoid directional valve V₃ are selectively controlled to input, into the accumulator A₁ or/and the accumulator A₂, energy produced when the power output mechanism is braked.

Further, the solenoid directional valve V₁ and/or the solenoid directional valve V₃ are selectively controlled to make the accumulator A₁ or/and the accumulator A₂ serve as an output of the energy management mechanism;

the clutch C₁, the clutch C₂, the clutch C₃, and the clutch C₇ are engaged to provide a continuous transmission ratio between the energy management mechanism and the output member and provide a continuous transmission ratio between the energy management mechanism together with the input member and the output member;

the clutch C₉ is engaged to provide a continuous transmission ratio between the energy management mechanism and the power output mechanism;

the clutch C₅ and the clutch C₉ are engaged to provide a continuous transmission ratio between the input member together with the energy management mechanism and the power output mechanism.

Further, the clutch C₈ and the clutch C₉ are engaged and the clutch C₁ and the clutch C₇ are engaged, to respectively provide a continuous transmission ratio between the input member and the pump/motor mechanism; and the solenoid directional valve V₁ and the solenoid directional valve V₃ are selectively controlled to input energy of the input member into the accumulator A₁ or/and the accumulator A₂.

The present invention has the following beneficial effects:

1. The hydro-mechanical hybrid transmission device with an energy management mechanism of the present invention is a multi-mode hydro-mechanical hybrid transmission device that integrates hydraulic transmission, hydro-mechanical transmission, and mechanical transmission and meets the requirements of different working conditions.

2. The hydro-mechanical hybrid transmission device with an energy management mechanism of the present invention adopts different accumulation systems to increase the degree of freedom of the energy management mechanism. The energy management mechanism can drive the transmission mechanism or the power output mechanism alone or together with an engine.

3. According to the hydro-mechanical hybrid transmission device with an energy management mechanism of the present invention, the energy management mechanism stores energy from the engine, and then releases the energy to meet the power requirements of extreme working conditions together with the engine.

4. According to the hydro-mechanical hybrid transmission device with an energy management mechanism of the present invention, the rotation direction of the pump/motor mechanism in the energy management mechanism is controlled by controlling the engagement of the clutch C₆ or the brake B₂ in the convergence mechanism or changing the positive or negative sign of the displacement ratio of the hydraulic transmission mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of the present invention;

FIG. 2 is a schematic diagram showing the power flow in an F(H) gear in the present invention;

FIG. 3 is a schematic diagram showing the power flow in an F₁(HM) gear in the present invention;

FIG. 4 is a schematic diagram showing the power flow in an F₂(HM) gear in the present invention;

FIG. 5 is a schematic diagram showing the power flow in an R(H) gear in the present invention;

FIG. 6 is a schematic diagram showing the power flow in an R₁(HM) gear in the present invention;

FIG. 7 is a schematic diagram showing the power flow in an R₂(HM) gear in the present invention;

FIG. 8 is a diagram showing relationships between output-input speed ratios and displacement ratios in the present invention;

FIG. 9 is a schematic diagram showing the power flow in energy recovery of a transmission mechanism in the present invention;

FIG. 10 is a schematic diagram showing the power flow in energy recovery of a power output mechanism in the present invention;

FIG. 11 is a schematic diagram showing the power flow when an energy management mechanism drives the transmission mechanism alone in the present invention;

FIG. 12 is a schematic diagram showing the power flow when the energy management mechanism and an engine together drive the transmission mechanism in the present invention;

FIG. 13 is a schematic diagram showing the power flow when the energy management mechanism drives the power output mechanism alone in the present invention;

FIG. 14 is a schematic diagram showing the power flow when the energy management mechanism and the engine together drive the power output mechanism in the present invention; and

FIG. 15 is a schematic diagram showing the power flow when the energy management mechanism stores energy from the engine in the present invention.

In the drawings:

1. input shaft; 2. mechanical transmission mechanism; 21. clutch C₁; 22. front planetary gear planet carrier; 23. front planetary gear sun gear; 24. middle planetary gear sun gear; 25. middle planetary gear ring gear; 26. middle planetary gear planet carrier; 27. front planetary gear ring gear; 28. clutch C₄; 29. clutch C₅; 3. energy management mechanism; 31. transmission mechanism and energy management mechanism gear pair; 32. clutch C₇; 33. pump/motor mechanism; 34. solenoid directional valve V₁; 35. pilot-operated proportional relief valve V₂; 36. accumulator A₁; 37. solenoid directional valve V₃; 38. pilot-operated proportional relief valve V₄; 39. accumulator A₂; 310. power output mechanism and energy management mechanism gear pair; 311. clutch C₉; 4. power output mechanism; 41. power output gear pair; 42. clutch C₈; 43. power output shaft; 5. output shaft; 6. convergence mechanism; 61. rear planetary gear sun gear; 62. rear planetary gear planet carrier; 63. rear planetary gear ring gear; 64. clutch C₆; 65. brake B₂; 66. mechanical transmission mechanism and convergence mechanism gear pair; 7. start mechanism; 71. start mechanism gear pair; 72. clutch C₅; 8. hydraulic transmission mechanism; 81. clutch C₂; 82. hydraulic transmission input gear pair; 83. pump input shaft; 84. variable displacement pump; 85. quantitative motor; 86. motor output shaft; 87. hydraulic transmission output gear pair; 88. brake B₁.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention is further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

As shown in FIG. 1, the hydro-mechanical hybrid transmission device with an energy management mechanism of the present invention includes an input shaft 1, a mechanical transmission mechanism 2, an energy management mechanism 3, a power output mechanism 4, an output shaft 5, a convergence mechanism 6, a start mechanism 7, a hydraulic transmission mechanism 8, a clutch assembly, and a brake assembly.

The hydraulic transmission mechanism 8 includes a clutch C₂ 81, a hydraulic transmission input gear pair 82, a pump input shaft 83, a variable displacement pump 84, a quantitative motor 85, a motor output shaft 86, a hydraulic transmission output gear pair 87, and a brake B₁ 88. The pump input shaft 83 is connected to the input shaft 1 through the hydraulic transmission input gear pair 82, the motor output shaft 86 of the quantitative motor 85 is connected to a middle planetary gear sun gear 24 through the hydraulic transmission output gear pair 87, the motor output shaft 86 of the quantitative motor 85 is also connected to the output shaft 5 through a start mechanism gear pair 71 of the start mechanism 7, and the variable displacement pump 84 is used for providing hydraulic energy to the quantitative motor 85. The brake B₁ 88 is used for selectively connecting the motor output shaft 86 to a fixed member. The clutch C₂ 81 is used for selectively connecting the pump input shaft 83 of the hydraulic transmission mechanism 8 to the input shaft 1 through the hydraulic transmission input gear pair 82 to achieve synchronous rotation. The start mechanism 7 includes the start mechanism gear pair 71 and a clutch C₃ 72. The clutch C₃ 72 is used for selectively connecting the motor output shaft 86 to the output shaft 5 through the start mechanism gear pair 71 to achieve synchronous rotation. The pump input shaft 83 forces the variable displacement pump 84 to work. By changing the angle of a swashplate, the variable displacement pump 84 forces the quantitative motor 85 to work. Then, the motor output shaft 86 outputs power to the mechanical transmission mechanism 2 or the start mechanism 7.

The mechanical transmission mechanism 2 includes a clutch C₁ 21, a front planetary gear planet carrier 22, a front planetary gear sun gear 23, the middle planetary gear sun gear 24, a middle planetary gear ring gear 25, a middle planetary gear planet carrier 26, a front planetary gear ring gear 27, a clutch C₄ 28, and a clutch C₅ 29. The front planetary gear planet carrier 22, the front planetary gear sun gear 23, and the front planetary gear ring gear 27 form a front planetary gear mechanism. The middle planetary gear sun gear 24, the middle planetary gear ring gear 25, and the middle planetary gear planet carrier 26 form a middle planetary gear mechanism. The front planetary gear planet carrier 22 serves as an input end of the mechanical transmission mechanism 2 and is connected to the input shaft 1 through the clutch C₁ 21. The front planetary gear planet carrier 22 is connected to the middle planetary gear ring gear 25. The front planetary gear sun gear 23 is connected to the middle planetary gear sun gear 24, and is connected to the motor output shaft 86 through the hydraulic transmission output gear pair 87. The front planetary gear ring gear 27 and the middle planetary gear planet carrier 26 can be respectively connected to an input end of the convergence mechanism 6 through the clutch C₅ 29 and the clutch C₄ 28. The convergence mechanism 6 includes a rear planetary gear sun gear 61, a rear planetary gear planet carrier 62, a rear planetary gear ring gear 63, a clutch C₆ 64, a brake B₂ 65, and a mechanical transmission mechanism and convergence mechanism gear pair 66. The rear planetary gear sun gear 61, the rear planetary gear planet carrier 62, and the rear planetary gear ring gear 63 form a rear planetary gear mechanism. The rear planetary gear ring gear 63 is connected to the output shaft 5. The clutch C₁ 21 is used for selectively connecting the input shaft 1 to the front planetary gear planet carrier 22. The clutch C₄ 28 is used for selectively connecting the middle planetary gear planet carrier 26 to the rear planetary gear sun gear 61 through the mechanical transmission mechanism and convergence mechanism gear pair 66 to achieve synchronous rotation. The clutch C₅ 29 is used for selectively connecting the front planetary gear ring gear 27 to the rear planetary gear sun gear 61 through the mechanical transmission mechanism and convergence mechanism gear pair 66 to achieve synchronous rotation. The clutch C₆ 64 is used for selectively connecting the rear planetary gear sun gear 61 to the rear planetary gear ring gear 63. The brake B₂ 65 is used for selectively fixing the rear planetary gear planet carrier 62.

The energy management mechanism 3 includes a transmission mechanism and energy management mechanism gear pair 31, a clutch C₇ 32, a pump/motor mechanism 33, a solenoid directional valve V₁ 34, a pilot-operated proportional relief valve V₂ 35, an accumulator A₁ 36, a solenoid directional valve V₃ 37, a pilot-operated proportional relief valve V₄ 38, an accumulator A₂ 39, a power output mechanism and energy management mechanism gear pair 310, and a clutch C₉ 311. The pump/motor mechanism 33 is a device capable of switching between functions of a pump and a hydraulic motor, that is, when mechanical energy is input into the pump/motor mechanism 33, the pump/motor mechanism 33 outputs hydraulic energy, and when hydraulic energy is input into the pump/motor mechanism 33, the pump/motor mechanism 33 outputs mechanical energy. The pump/motor mechanism 33 is connected to the front planetary gear planet carrier 22 through the transmission mechanism and energy management mechanism gear pair 31. The pump/motor mechanism 33 is connected to the power output mechanism 4 through the power output mechanism and energy management mechanism gear pair 310. The solenoid directional valve V₁ 34, the pilot-operated proportional relief valve V₂ 35, and the accumulator A₁ 36 are connected to form a first accumulation system. The solenoid directional valve V₃ 37, the pilot-operated proportional relief valve V₄ 38, and the accumulator A₂ 39 are connected to form a second accumulation system. The first accumulation system and the second accumulation system are connected in parallel and are connected to the pump/motor mechanism 33. The power output mechanism 4 includes a power output gear pair 41, a clutch C₈ 42, and a power output shaft 43. The power output shaft 43 is connected to the input shaft 1 through the power output gear pair 41. The clutch C₇ 32 is used for selectively connecting the pump/motor mechanism 33 to the front planetary gear planet carrier 22 through the transmission mechanism and energy management mechanism gear pair 31 to achieve synchronous rotation. The clutch C₉ 311 is used for selectively connecting the pump/motor mechanism 33 to the power output shaft 43 through the power output mechanism and energy management mechanism gear pair 310 to achieve synchronous rotation. The clutch C₈ 42 is used for selectively connecting the input shaft 1 to the power output shaft 43 through the power output gear pair 41 to achieve synchronous rotation.

Transmission modes including hydraulic transmission, hydro-mechanical transmission, and mechanical transmission are provided between an input member and an output member by adjusting a displacement ratio of the hydraulic transmission mechanism 8 and selectively controlling engagement of the clutch assembly and the brake assembly. Specific examples are given below for illustration with reference to Table 1:

As shown in FIG. 2 and FIG. 5, the hydraulic transmission includes forward hydraulic transmission F(H) and reverse hydraulic transmission R(H).

The power flow in an F(H) gear in the present invention is shown in FIG. 2. When the clutch C₂ 81 and the clutch C₃ 72 are engaged, power supplied by an engine passes through the input shaft 1, the hydraulic transmission mechanism 8, and the start mechanism 7 and is output from the output shaft 5, and when the displacement ratio of the hydraulic transmission mechanism 8 is positive, the F(H) gear is obtained. In this case, the rotation speeds of the output shaft and the engine are in the following relationship:

$n_0=\frac{e}{i_1{i}_3}{n}_I,e\in \left[0,1\right]$

wherein n_o is the rotation speed of the output shaft, n_I is the rotation speed of the input shaft, e is the displacement ratio of the hydraulic transmission mechanism, i₁ is a transmission ratio of the hydraulic transmission input gear pair 82, and i₃ is a transmission ratio of the start mechanism gear pair 71.

The power flow in an R(H) gear in the present invention is shown in FIG. 5. When the clutch C₂ 81 and the clutch C₃ 72 are engaged, power supplied by the engine passes through the input shaft 1, the hydraulic transmission mechanism 8, and the start mechanism 7 and is output from the output shaft 5, and when the displacement ratio of the hydraulic transmission mechanism 8 is negative, the R(H) gear is obtained. In this case, the rotation speeds of the output shaft and the engine are in the following relationship:

$n_0=\frac{e}{i_1{i}_3}{n}_I,e\in \left[-1,0\right].$

As shown in FIG. 3, FIG. 4, FIG. 6, and FIG. 7, the hydro-mechanical transmission includes forward hydro-mechanical transmission F₁(HM), forward hydro-mechanical transmission F₂(HM), reverse hydro-mechanical transmission R₁(HM), and reverse hydro-mechanical transmission R₂(HM).

The power flow in an F₁(HM) gear in the present invention is shown in FIG. 3. When the clutch C₁ 21, the clutch C₂ 81, the clutch C₄ 28, and the clutch C₆ 64 are engaged, power supplied by the engine is split at the input shaft 1: one part of the power is transmitted through the front planetary gear planet carrier 22 to the middle planetary gear ring gear 25, while the other part of the power is transmitted through the hydraulic transmission mechanism 8 to the middle planetary gear sun gear 24; the mechanical power arriving in the middle planetary gear ring gear 25 and the hydraulic power arriving in the middle planetary gear sun gear 24 are converged at the middle planetary gear planet carrier 26 and then transmitted through the mechanical transmission mechanism and convergence mechanism gear pair 66 to the convergence mechanism 6; therefore, the convergence mechanism 6 is connected as a whole and the power is output from the output shaft 5. In this case, the rotation speeds of the output shaft and the engine are in the following relationship:

$n_0=\frac{k_2+\frac{e}{i_1{i}_2}}{k_2+1}{n}_I,e\in \left[-1,1\right]$

wherein i₂ is a transmission ratio of the hydraulic transmission output gear pair and k₂ is a characteristic parameter of the middle planetary gear mechanism.

The power flow in an F₂(HM) gear in the present invention is shown in FIG. 4. When the clutch C₁ 21, the clutch C₂ 81, the clutch C₅ 29, and the clutch C₆ 64 are engaged, power supplied by the engine is split at the input shaft 1: one part of the power is directly transmitted to the front planetary gear planet carrier 22, while the other part of the power is transmitted through the hydraulic transmission mechanism 8 to the front planetary gear sun gear 23; the mechanical power arriving in the front planetary gear planet carrier 22 and the hydraulic power arriving in the front planetary gear sun gear 23 are converged at the front planetary gear ring gear 27 and then transmitted through the mechanical transmission mechanism and convergence mechanism gear pair 66 to the convergence mechanism 6; therefore, the convergence mechanism 6 is connected as a whole and the power is output from the output shaft 5. In this case, the rotation speeds of the output shaft and the engine are in the following relationship:

$n_0=\frac{\left(k_1+1\right)-\frac{e}{i_1{i}_2}}{k_1}{n}_I,e\in \left[-1,1\right]$

wherein k₁ is a characteristic parameter of the front planetary gear mechanism.

The power flow in an R₁(IM) gear in the present invention is shown in FIG. 6. When the clutch C₁ 21, the clutch C₂ 81, the clutch C₄ 28, and the brake B₂ 65 are engaged, power supplied by the engine is split at the input shaft 1: one part of the power is transmitted through the front planetary gear planet carrier 22 to the middle planetary gear ring gear 25, while the other part of the power is transmitted through the hydraulic transmission mechanism 8 to the middle planetary gear sun gear 24, the mechanical power arriving in the middle planetary gear ring gear 25 and the hydraulic power arriving in the middle planetary gear sun gear 24 are converged at the middle planetary gear planet carrier 26; then the power is transmitted through the mechanical transmission mechanism and convergence mechanism gear pair 66 to the rear planetary gear sun gear 61, and is transmitted through the rear planetary gear ring gear 63 and output from the output shaft 5. In this case, the rotation speeds of the output shaft and the engine are in the following relationship:

$n_0\frac{k_2+\frac{e}{i_1{i}_2}}{-\left(k_2+1\right)k_3}{n}_I,e\in \left[-1,1\right]$

wherein k₃ is a characteristic parameter of the rear planetary gear mechanism.

The power flow in an R₂(HM) gear in the present invention is shown in FIG. 7. When the clutch C₁ 21, the clutch C₂ 81, the clutch C₅ 29, and the brake B₂ 65 are engaged, power supplied by the engine is split at the input shaft 1: one part of the power is directly transmitted to the front planetary gear planet carrier 22, while the other part of the power is transmitted through the hydraulic transmission mechanism 8 to the front planetary gear sun gear 23; the mechanical power arriving in the front planetary gear planet carrier 22 and the hydraulic power arriving in the front planetary gear sun gear 23 are converged at the front planetary gear ring gear 27; then the power is transmitted through the mechanical transmission mechanism and convergence mechanism gear pair 66 to the rear planetary gear sun gear 61, and is transmitted through the rear planetary gear ring gear 63 and output from the output shaft 5. In this case, the rotation speeds of the output shaft and the engine are in the following relationship:

$n_0=\frac{\left(k_1+1\right)-\frac{e}{i_1{i}_2}}{-k_1{k}_3}{n}_I,e\in \left[-1,1\right].$

The mechanical transmission includes forward mechanical transmission F₁(M), forward mechanical transmission F₂(M), reverse mechanical transmission R₁(M), and reverse mechanical transmission R₂(M).

The power flow in an F₁(M) gear in the present invention is also shown in FIG. 3, and the hydraulic path does not transmit power. When the clutch C₁ 21, the clutch C₄ 28, the clutch C₆ 64, and the brake B₁ 88 are engaged, power supplied by the engine passes through the input shaft 1, the front planetary gear planet carrier 22, the middle planetary gear ring gear 25, the middle planetary gear planet carrier 26, the mechanical transmission mechanism and convergence mechanism gear pair 66, and the convergence mechanism 6 and is output from the output shaft 5. In this case, the rotation speeds of the output shaft and the engine are in the following relationship:

$n_0=\frac{k_2}{k_2+1}{n}_I.$

The power flow in an F₂(M) gear in the present invention is also shown in FIG. 4, and the hydraulic path does not transmit power. When the clutch C₁ 21, the clutch C₅ 29, the clutch C₆ 64, and the brake B₁ 88 are engaged, power supplied by the engine passes through the input shaft 1, the front planetary gear planet carrier 22, the front planetary gear ring gear 27, the mechanical transmission mechanism and convergence mechanism gear pair 66, and the convergence mechanism 6 and is output from the output shaft 5. In this case, the rotation speeds of the output shaft and the engine are in the following relationship:

$n_0=\frac{\left(k_1+1\right)}{k_1}{n}_I.$

The power flow in an R₁(M) gear in the present invention is also shown in FIG. 6, and the hydraulic path does not transmit power. When the clutch C₁ 21, the clutch C₄ 28, the brake B₁ 88, and the brake B₂ 65 are engaged, power supplied by the engine passes through the input shaft 1, the front planetary gear planet carrier 22, the middle planetary gear ring gear 25, the middle planetary gear planet carrier 26, the mechanical transmission mechanism and convergence mechanism gear pair 66, the rear planetary gear sun gear 61, and the rear planetary gear ring gear 63 and is output from the output shaft 5. In this case, the rotation speeds of the output shaft and the engine are in the following relationship:

$n_0=\frac{k_2}{-\left(k_2+1\right)k_3}{n}_I.$

The power flow in an R₂(M) gear in the present invention is also shown in FIG. 7, and the hydraulic path does not transmit power. When the clutch C₁ 21, the clutch C₅ 29, the brake B₁ 88, and the brake B₂ 65 are engaged, power supplied by the engine passes through the input shaft 1, the front planetary gear planet carrier 22, the front planetary gear ring gear 27, the mechanical transmission mechanism and convergence mechanism gear pair 66, the rear planetary gear sun gear 61, and the rear planetary gear ring gear 63 and is output from the output shaft 5. In this case, the rotation speeds of the output shaft and the engine are in the following relationship:

$n_0=\frac{\left(k_1+1\right)}{-k_1{k}_3}{n}_I.$

TABLE 1
Engagement/disengagement of each component
	Execution component
Mode	Direction	B1	B2	C1	C2	C3	C4	C5	C6	Gear
Hydraulic	Forward	Δ	Δ	Δ	▴	▴	Δ	Δ	Δ	F(H)
Hydro-		Δ	Δ	▴	▴	Δ	▴	Δ	▴	F1(HM)
mechanical		Δ	Δ	▴	▴	Δ	Δ	▴	▴	F2(HM)
Mechanical		▴	Δ	▴	Δ	Δ	▴	Δ	▴	F1(M)
		▴	Δ	▴	Δ	Δ	Δ	▴	▴	F2(M)
Hydraulic	Reverse	Δ	Δ	Δ	▴	▴	Δ	Δ	Δ	R(H)
Hydro-		Δ	▴	▴	▴	Δ	▴	Δ	Δ	R1(HM)
mechanical		Δ	▴	▴	▴	Δ	Δ	▴	Δ	R2(HM)
Mechanical		▴	▴	▴	Δ	Δ	▴	Δ	Δ	R1(M)
		▴	▴	▴	Δ	Δ	Δ	▴	Δ	R2(M)

In Table 1. 1. B stands for brake, C stands for clutch, F stands for forward gear, R stands for reverse gear, H stands for hydraulic transmission, M stands for mechanical transmission, and HM stands for hydro-mechanical hybrid transmission.

• • 2. ▴ stands for engagement of a gear-shift component, and Δ stands for disengagement of a gear-shift component.

In an embodiment, the following parameters are selected: i₁i₂=1.00, i₁i₃=1.00, k₁=1.56, k₂=k₃=2.56.

Relationships between output-input speed ratios and displacement ratios in the present invention are shown in FIG. 8. When e∈[0, 1.00], the speed regulation range in the F(H) gear is [0, 1.00]n_I; when e∈[−1.00, 1.00], the speed regulation range in the F₁(HM) gear is [0.44, 1.00]n_I; when e∈[−1.00, 1.00], the speed regulation range in the F₂(HM) gear is [1.00, 2.28]n_I; when e∈[−1.00, 0], the speed regulation range in the R(H) gear is [−1.00, 0]n_I; and when e∈[−1.00, 1.00], the speed regulation range in the R₁(HM) gear is [−0.39, −0.17]n_I, and the speed regulation range in the R₂(HM) gear is [−0.89, −0.39]n_I. The speeds in the F₁(M) gear and F₂(M) gear are respectively 0.72n_I and 1.64n_I; the speeds in the R₁(M) gear and R₂(M) gear are respectively −0.28n_I and −0.64n_I. When e=1.00, the F(H) gear is shifted to the F₁(HM) gear to implement speed regulation without power interruption, and in this case, n_o=n_I. When e=1.00, the F(H) gear is shifted to the F₂(HM) gear to implement speed regulation without power interruption, and in this case, n_o=n_I. When e=1.00, the F₁(HM) gear is shifted to the F₂(HM) gear to implement speed regulation without power interruption, and in this case, n_o=n_I. When e=−0.25, the R(H) gear is shifted to the R₁(HM) gear to implement speed regulation without power interruption, and in this case, n_o=−0.25n_I. When e=−0.85, the R(H) gear is shifted to the R₂(HM) gear to implement speed regulation without power interruption, and in this case, n_o=−0.85 nm. When e=1.00, the R₁(HM) gear is shifted to the R₂(HM) gear to implement speed regulation without power interruption, and in this case, n_o=−0.39 nm.

The solenoid directional valve V₁ 34, the pilot-operated proportional relief valve V₂ 35, and the accumulator A₁ 36 are connected to form a first accumulation system. The solenoid directional valve V₁ 34 controls the on-off of hydraulic oil, the pilot-operated proportional relief valve V₂ 35 controls the system pressure, and the first accumulation system is used alone and is suitable for working conditions with low braking energy.

The solenoid directional valve V₃ 37, the pilot-operated proportional relief valve V₄ 38, and the accumulator A₂ 39 are connected to form a second accumulation system. The solenoid directional valve V₃ 37 controls the on-off of hydraulic oil, the pilot-operated proportional relief valve V₄ 38 controls the system pressure, and the second accumulation system is used alone and is suitable for working conditions with medium braking energy.

The first accumulation system and the second accumulation system are used together and are suitable for working conditions with large braking energy. In this case, the solenoid directional valve V₁ 34 and the solenoid directional valve V₃ 37 respectively control the on-off of hydraulic oil in the first accumulation system and the second accumulation system, and the pilot-operated proportional relief valve V₂ 35 and the pilot-operated proportional relief valve V₄ 38 have the same set pressure.

The power flow in braking energy recovery of the transmission mechanism is shown in FIG. 9. When the output shaft 5 is braked, the rotation direction of the pump/motor mechanism 33 is determined by the convergence mechanism 6; the clutch C₇ 32, the brake B₁ 88, and the clutch C₄ 28 are engaged or the clutch C₇ 32, the brake B₁ 88, and the clutch C₅ 29 are engaged to respectively provide a continuous transmission ratio between the output member and the pump/motor mechanism 33; the braking energy produced by the transmission mechanism is transmitted through the convergence mechanism 6, the mechanical transmission mechanism 2, the transmission mechanism and energy management mechanism gear pair 31, and the clutch C₇ 32 to the pump/motor mechanism 33. The solenoid directional valve V₁ 34 or the solenoid directional valve V₃ 37 is selectively controlled alone to input, into the accumulator A₁ 36 or the accumulator A₂ 39, the energy produced when the output member is braked. The capacity of the accumulator A₁ 36 or the accumulator A₂ 39 is respectively controlled by the pilot-operated proportional relief valve V₂ 35 or the pilot-operated proportional relief valve V₄ 38. The solenoid directional valve V₁ 34 and the solenoid directional valve V₃ 37 are selectively controlled together to input, into the accumulator A₁ 36 and the accumulator A₂ 39, the energy produced when the output member is braked. In this case, the pilot-operated proportional relief valve V₂ 35 and the pilot-operated proportional relief valve V₄ 38 have the same set value and determine the capacities of the accumulator A₁ 36 and the accumulator A₂ 39.

The power flow in braking energy recovery of the power output mechanism is shown in FIG. 10. When the power output mechanism 4 is braked, the clutch C₉ 311 is engaged, and the braking energy produced by the power output mechanism is transmitted through the clutch C₉ 311 and the power output mechanism and energy management mechanism gear pair 310 to the pump/motor mechanism 33. The solenoid directional valve V₁ 34 or the solenoid directional valve V₃ 37 is selectively controlled alone to input, into the accumulator A₁ 36 or the accumulator A₂ 39, the energy produced when the power output mechanism 4 is braked. The capacity of the accumulator A₁ 36 or the accumulator A₂ 39 is respectively controlled by the pilot-operated proportional relief valve V₂ 35 or the pilot-operated proportional relief valve V₄ 38. The solenoid directional valve V₁ 34 and the solenoid directional valve V₃ 37 are selectively controlled together to input, into the accumulator A₁ 36 and the accumulator A₂ 39, the energy produced when the power output mechanism 4 is braked. In this case, the pilot-operated proportional relief valve V₂ 35 and the pilot-operated proportional relief valve V₄ 38 have the same set value and determine the capacities of the accumulator A₁ 36 and the accumulator A₂ 39.

The power flow when the energy management mechanism drives the transmission mechanism alone is shown in FIG. 11. In this case, only the clutch C₁ 21, the clutch C₂ 81, the clutch C₃ 72, and the clutch C₇ 32 need to be engaged, and power output by the energy management mechanism 3 passes through the transmission mechanism and energy management mechanism gear pair 31, the input shaft 1, the hydraulic transmission mechanism 8, and the start mechanism 7 and is output from the output shaft 5.

The power flow when the energy management mechanism and the engine together drive the transmission mechanism is shown in FIG. 12. In this case, only the clutch C₁ 21, the clutch C₂ 81, the clutch C₅ 72, and the clutch C₇ 32 need to be engaged, and power output by the energy management mechanism 3 passes through the transmission mechanism and energy management mechanism gear pair 31 and is converged with the engine power transmitted to the input shaft 1. Then, the power passes through the hydraulic transmission mechanism 8 and the start mechanism 7 and is output from the output shaft 5.

The power flow when the energy management mechanism drives the power output mechanism alone is shown in FIG. 13. In this case, only the clutch C₉ 311 needs to be engaged, and power output by the energy management mechanism 3 passes through the power output mechanism and energy management mechanism gear pair 310 and the clutch C₉ 311 and is output from the power output shaft 43.

The power flow when the energy management mechanism and the engine together drive the power output mechanism is shown in FIG. 14. In this case, only the clutch C₈ 42 and the clutch C₉ 311 need to be engaged, and power output by the energy management mechanism 3 passes through the transmission mechanism and energy management mechanism gear pair 31 and the clutch C₉ 311 and is converged with the engine power transmitted through the power output gear pair 41 and the clutch Ca 42 to the power output shaft 43. Then, the power is output from the power output shaft 43.

The solenoid directional valve V₁ 34 or the solenoid directional valve V₃ 37 is selectively controlled alone to release energy stored in the accumulator A₁ 36 or the accumulator A₂ 39 respectively. In this case, the input oil pressure of the pump/motor mechanism 33 is controlled by the pilot-operated proportional relief valve V₂ 35 or the pilot-operated proportional relief valve V₄ 38. The solenoid directional valve V₁ 34 and the solenoid directional valve V; 37 are selectively controlled together to release energy stored in the accumulator A₁ 36 and the accumulator A₂ 39 at the same time. In this case, the pilot-operated proportional relief valve V₂ 35 and the pilot-operated proportional relief valve V₄ 38 have the same set value of the oil pressure and together determine the input oil pressure of the pump/motor mechanism 33.

The power flow when the energy management mechanism stores energy from the engine is shown in FIG. 15. Two manners are provided: in a first manner, the clutch C₈ 42 and the clutch C₉ 311 are engaged, the engine power is transmitted through the power output gear pair 41, the clutch C₈ 42, the clutch C₉ 311, and the power output mechanism and energy management mechanism gear pair 310 to the energy management mechanism 3, and in this case, the pump/motor mechanism 33 rotates in the same direction as the engine; while in a second manner, the clutch C₁ 21 and the clutch C₇ 32 are engaged, the engine power is transmitted through the transmission mechanism and energy management mechanism gear pair 31 and the clutch C₇ 32 to the energy management mechanism 3, and in this case, the pump/motor mechanism 33 rotates in an opposite direction from the engine. The solenoid directional valve V₁ 34 or the solenoid directional valve V₃ 37 is selectively controlled alone to input the energy transmitted by the engine into the accumulator A₁ 36 or the accumulator A₂ 39. In this case, the capacity of the accumulator A₁ 36 or the accumulator A₂ 39 is respectively controlled by the pilot-operated proportional relief valve V₂ 35 or the pilot-operated proportional relief valve V₄ 38. The solenoid directional valve V₁ 34 and the solenoid directional valve V₃ 37 are selectively controlled together to input, into the accumulator A₁ 36 and the accumulator A₂ 39, the energy produced when the input shaft 1 is braked. In this case, the pilot-operated proportional relief valve V₂ 35 and the pilot-operated proportional relief valve V₄ 38 have the same set value and determine the capacities of the accumulator A₁ 36 and the accumulator A₂ 39.

The above descriptions are preferred embodiments of the present invention, and are not intended to limit the present invention. Any obvious improvements, replacements, or modifications made by persons skilled in the art without departing from the essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A hydro-mechanical hybrid transmission device with an energy management mechanism, comprising an input member,a mechanical transmission mechanism,the energy management mechanism,a power output mechanism,an output member,a convergence mechanism,a start mechanism,a hydraulic transmission mechanism,a clutch assembly, anda brake assembly,whereinthe clutch assembly connects the input member to the mechanical transmission mechanism, the power output mechanism, and the hydraulic transmission mechanism,the clutch assembly connects an output of the hydraulic transmission mechanism to the mechanical transmission mechanism and the output member,the clutch assembly connects an output of the mechanical transmission mechanism to the convergence mechanism,the clutch assembly connects the output member to the convergence mechanism, andthe clutch assembly connects the energy management mechanism to the mechanical transmission mechanism and the power output mechanism;the clutch assembly and the brake assembly provide a continuous transmission ratio between the input member and the output member or the power output mechanism,the clutch assembly and the brake assembly provide a continuous transmission ratio between the energy management mechanism and the output member or the power output mechanism, andthe clutch assembly and the brake assembly provide a continuous transmission ratio between the energy management mechanism together with the input member and the output member or the power output mechanism,transmission modes comprising hydraulic transmission, hydro-mechanical transmission, and mechanical transmission are provided between the input member and the output member by adjusting a displacement ratio of the hydraulic transmission mechanism and selectively controlling an engagement of the clutch assembly and the brake assembly;the mechanical transmission mechanism comprises a front planetary gear mechanism and a middle planetary gear mechanism, wherein a planet carrier of the front planetary gear mechanism is connected to the input member,the planet carrier of the front planetary gear mechanism is connected to a ring gear of the middle planetary gear mechanism,a sun gear of the front planetary gear mechanism is connected to a sun gear of the middle planetary gear mechanism,the sun gear of the middle planetary gear mechanism is connected to an output end of the hydraulic transmission mechanism;the convergence mechanism comprises a rear planetary gear mechanism, wherein a ring gear of the rear planetary gear mechanism is connected to the output member,the clutch assembly connects a ring gear of the front planetary gear mechanism or a planet carrier of the middle planetary gear mechanism to a sun gear of the rear planetary gear mechanism;the clutch assembly comprises a first clutch and a second clutch; wherein the first clutch is used for selectively connecting an input end of the hydraulic transmission mechanism to the input member to implement a second synchronous rotation;the second clutch is used for selectively connecting the output end of the hydraulic transmission mechanism to the output member to implement a third synchronous rotation; anda continuous forward hydraulic transmission or a continuous reverse hydraulic transmission is provided between the input member and the output member by adjusting the displacement ratio of the hydraulic transmission mechanism and selectively controlling an engagement of the first clutch and the second clutch.

2. The hydro-mechanical hybrid transmission device with the energy management mechanism according to claim 1, wherein the clutch assembly further comprises a third clutch, a fourth clutch, a fifth clutch, and a sixth clutch;the third clutch is used for selectively connecting the input member to the planet carrier of the front planetary gear mechanism to implement a first synchronous rotation;the fourth clutch is used for selectively connecting the planet carrier of the middle planetary gear mechanism to the sun gear of the rear planetary gear mechanism to implement a fourth synchronous rotation;the fifth clutch is used for selectively connecting the ring gear of the front planetary gear mechanism to the sun gear of the rear planetary gear mechanism to implement a fifth synchronous rotation;the sixth clutch is used for selectively connecting the ring gear of the rear planetary gear mechanism to the sun gear of the rear planetary gear mechanism to implement a sixth synchronous rotation;the brake assembly comprises a second brake, and the second brake is used for selectively connecting a planet carrier of the rear planetary gear mechanism to a fixed member; andcontinuous forward hydro-mechanical transmission or continuous reverse hydro-mechanical transmission is provided between the input member and the output member by adjusting the displacement ratio of the hydraulic transmission mechanism and selectively controlling an engagement of the third clutch, the first clutch, the fourth clutch, the fifth clutch, the sixth clutch, and the second brake.

3. The hydro-mechanical hybrid transmission device with the energy management mechanism according to claim 2, wherein the third clutch, the first clutch, the fourth clutch, and the sixth clutch are engaged, the third clutch, the first clutch, the fifth clutch, and the sixth clutch are engaged, the third clutch, the first clutch, the fourth clutch, and the second brake are engaged, and the third clutch, the first clutch, the fifth clutch, and the second brake are engaged, to respectively provide different forward or reverse hydro-mechanical transmission between the input member and the output member.

4. The hydro-mechanical hybrid transmission device with the energy management mechanism according to claim 2, wherein the brake assembly further comprises a first brake;the first brake is used for selectively connecting the output end of the hydraulic transmission mechanism to the fixed member; andthe third clutch, the fourth clutch, the sixth clutch, and the first brake are engaged, the third clutch, the fifth clutch, the sixth clutch, and the first brake are engaged, the third clutch, the fourth clutch, the first brake, and the second brake are engaged, and the third clutch, the fifth clutch, the first brake, and the second brake are engaged, to respectively provide different forward or reverse mechanical transmission between the input member and the output member.

5. The hydro-mechanical hybrid transmission device with the energy management mechanism according to claim 4, wherein the energy management mechanism comprises a pump/motor mechanism, a first solenoid directional valve, a second pilot-operated proportional relief valve, a first accumulator, a third solenoid directional valve, a fourth pilot-operated proportional relief valve, and a second accumulator;the pump/motor mechanism is connected to the first accumulator and the second accumulator;the first solenoid directional valve is used for controlling the pump/motor mechanism to be connected to the first accumulator,the second pilot-operated proportional relief valve is mounted between the pump/motor mechanism and the first accumulator,the third solenoid directional valve is used for controlling the pump/motor mechanism to be connected to the second accumulator, andthe fourth pilot-operated proportional relief valve is mounted between the pump/motor mechanism and the second accumulator;the clutch assembly further comprises a seventh clutch, an eighth clutch, and a ninth clutch, the seventh clutch is used for selectively connecting the pump/motor mechanism to the planet carrier of the front planetary gear mechanism to implement a seventh synchronous rotation;the ninth clutch is used for selectively connecting the pump/motor mechanism to the power output mechanism to implement a ninth synchronous rotation; andthe eighth clutch is used for selectively connecting the input member to the power output mechanism to implement an eighth synchronous rotation.

6. The hydro-mechanical hybrid transmission device with the energy management mechanism according to claim 5, wherein when the output member is braked, the seventh clutch, the first brake, and the fourth clutch are engaged, or the seventh clutch, the first brake, and the fifth clutch are engaged, to respectively provide a continuous transmission ratio between the output member and the pump/motor mechanism; andthe first solenoid directional valve and the third solenoid directional valve are selectively controlled to input, into the first accumulator or/and the second accumulator, energy produced when the output member is braked; andwhen the power output mechanism is braked, the ninth clutch is engaged to provide a continuous transmission ratio between the power output mechanism and the pump/motor mechanism; andthe first solenoid directional valve and the third solenoid directional valve are selectively controlled to input, into the first accumulator or/and the second accumulator, energy produced when the power output mechanism is braked.

7. The hydro-mechanical hybrid transmission device with the energy management mechanism according to claim 5, wherein the first solenoid directional valve and/or the third solenoid directional valve are selectively controlled to make the first accumulator or/and the second accumulator serve as an output of the energy management mechanism;the first clutch, the second clutch, the third clutch, and the seventh clutch are engaged to provide a continuous transmission ratio between the energy management mechanism and the output member and provide a continuous transmission ratio between the energy management mechanism together with the input member and the output member;the ninth clutch is engaged to provide a continuous transmission ratio between the energy management mechanism and the power output mechanism; andthe eighth clutch and the ninth clutch are engaged to provide a continuous transmission ratio between the energy management mechanism together with the input member and the power output mechanism.

8. The hydro-mechanical hybrid transmission device with the energy management mechanism according to claim 5, wherein the eighth clutch and the ninth clutch are engaged and the third clutch and the seventh clutch are engaged to respectively provide a continuous transmission ratio between the input member and the pump/motor mechanism; andthe first solenoid directional valve and the third solenoid directional valve are selectively controlled to input energy of the input member into the first accumulator or/and the second accumulator.