Full-hydraulic four-wheel independent driving system and electric wheel loader

Abstract

The utility model provides a full-hydraulic four-wheel independent drive system and an electric wheel loader. The full-hydraulic four-wheel independent drive system comprises a control unit VCU, a right front wheel, a right rear wheel, a left rear wheel and a left front wheel drive axle structure assembly, wherein the right front wheel, the right rear wheel, the left rear wheel and the left front wheel drive axle structure assembly are arranged on a frame. The drive axle structure assembly comprises a four-quadrant hydraulic pump motor and a drive axle which is connected with the four-quadrant hydraulic pump motor and transmits power to wheels, the rotating speed of each wheel is controlled by controlling the hydraulic valve group to output different hydraulic energy and controlling different displacements of the four-quadrant hydraulic pump motor, and the differential speed and the torque between the wheels are guaranteed; therefore, the phenomenon of parasitic power and energy loss caused by slipping during normal running and operation of the vehicle is avoided; by utilizing the four-quadrant working characteristics of the four-quadrant hydraulic pump motor and the hydraulic energy accumulator, the kinetic energy generated during braking of the system can be recycled and stored to be reused.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicle steering systems, in particular to an electro-hydraulic driven steering axle and an electric engineering vehicle. Background Art

[0002] The electrification of construction machinery is still in its infancy, and there are widespread problems such as short battery life, heavy weight, and high cost. Improving energy utilization, reducing battery capacity, and extending battery life have become major technical issues in the electrification of construction machinery. At present, existing electric wheeled construction machinery uses centralized drive, which makes it difficult to reasonably distribute the output torque of the front and rear axles, and is prone to generate large parasitic power. Parasitic power will aggravate tire wear, cause additional energy consumption of the vehicle, and cause additional forces on the chassis transmission system, resulting in a decrease in the life of the transmission system structural parts. However, there is no suitable distributed full hydraulic drive configuration solution. Utility Model Content

[0003] In view of this, the purpose of the present invention is to provide an electro-hydraulic driven steering axle and an electric engineering vehicle to solve the above problems.

[0004] The utility model adopts the following scheme:

[0005] The present application provides a fully hydraulic four-wheel independent drive system, comprising a control unit VCU, a right front wheel, a right rear wheel, a left rear wheel and a left front wheel drive axle structure assembly arranged on a frame; the drive axle structure assembly comprises a four-quadrant hydraulic pump motor, and a drive axle connected to the four-quadrant hydraulic pump motor to transmit power to the wheels; it also comprises a hydraulic valve group connected to the drive axle structure assembly through a hydraulic pipeline, a first hydraulic accumulator connected to the hydraulic valve group through a hydraulic pipeline, a hydraulic pump motor and a hydraulic oil tank; the control unit VCU can control the hydraulic pump motor to operate to output hydraulic energy, and can independently control the speed of each wheel; the first hydraulic accumulator is used to recover hydraulic energy during braking, so as to output hydraulic energy to each drive axle structure assembly during the next drive.

[0006] Furthermore, the drive axle includes a main reducer, a wheel-side reducer, a clutch, a brake, and an input shaft.

[0007] Furthermore, it also includes a priority valve connected to the hydraulic valve group, the hydraulic pump motor and the brake, and a steering system connected to the priority valve.

[0008] Furthermore, it also includes a second hydraulic accumulator connected to the priority valve, the steering system and the brake.

[0009] An electric wheel loader comprises a frame and a fully hydraulic four-wheel independent drive system fixed on the frame.

[0010] Furthermore, the hydraulic pump motor is provided with a shock-absorbing pad between the frame.

[0011] By adopting the above technical solution, the utility model can achieve the following technical effects:

[0012] 1. The speed of each wheel is controlled by controlling the hydraulic valve group to output different hydraulic energies and controlling the different displacements of the four-quadrant hydraulic pump motor to ensure the differential speed and torque between the wheels, thereby ensuring that there is no parasitic power caused by slipping during normal driving and operation of the vehicle, resulting in energy loss;

[0013] 2. By utilizing the four-quadrant working characteristics of the four-quadrant hydraulic pump motor and the hydraulic accumulator, the kinetic energy during system braking can be recovered and stored for reuse;

[0014] 3. The coordinated use of the hydraulic pump motor, hydraulic valve group, hydraulic accumulator and four-quadrant hydraulic pump motor in the fully hydraulic four-wheel independent drive system improves the transmission efficiency of the system and reduces energy loss caused by inefficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution of the implementation mode of the utility model, the drawings required for use in the implementation mode will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 This is a schematic diagram of a fully hydraulic four-wheel independent drive system installed on an electric wheel loader in an embodiment of the utility model. Figure 1 ;

[0017] Figure 2 This is a schematic diagram of a fully hydraulic four-wheel independent drive system installed on an electric wheel loader in an embodiment of the utility model. Figure 1 ;

[0018] Figure 3 It is a schematic diagram of a hydraulic system of a fully hydraulic four-wheel independent drive system provided by the first embodiment of the utility model;

[0019] Icons: right front wheel drive axle structure assembly 1, hydraulic valve group 2, hydraulic pump motor 3, hydraulic accumulator group 4, right rear wheel drive axle structure assembly 5, left rear wheel drive axle structure assembly 6, hydraulic oil tank 7, left front wheel drive axle structure assembly 8, brake 9, drive axle 10, four-quadrant hydraulic pump motor 11, first hydraulic accumulator 12, first hydraulic accumulator 13, steering system 14, priority valve 15. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents the selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0021] Example

[0022] Combination Figures 1 to 3 As shown, this embodiment provides a fully hydraulic four-wheel independent drive system, including a control unit VCU, a right front wheel, a right rear wheel, a left rear wheel and a left front wheel drive axle structure assembly arranged on a frame; the drive axle structure assembly includes a four-quadrant hydraulic pump motor 11, and a drive axle 10 connected to the four-quadrant hydraulic pump motor 11 to transmit power to the wheels; it also includes a hydraulic valve group 2 connected to the drive axle structure assembly through a hydraulic pipeline, a first hydraulic accumulator connected to the hydraulic valve group 2 through a hydraulic pipeline, a hydraulic pump motor 3 and a hydraulic oil tank 7; the control unit VCU can control the hydraulic pump motor 3 to operate, and can independently control the speed of each wheel; the first hydraulic accumulator 12 is used to recover hydraulic energy during braking, so as to output hydraulic energy to each drive axle structure assembly during the next drive.

[0023] By controlling the hydraulic valve group 2 to output different hydraulic energies and controlling the different displacements of the four-quadrant hydraulic pump motor 11, the speed of each wheel is controlled to ensure the differential speed and torque between each wheel, thereby ensuring that there is no slippage during normal driving and operation of the vehicle, resulting in parasitic power and energy loss; at the same time, by utilizing the four-quadrant working characteristics of the four-quadrant hydraulic pump motor 11 and the hydraulic accumulator, the kinetic energy during system braking can be recovered and stored for reuse. The coordinated use of the hydraulic pump motor 3, the hydraulic valve group 2, the hydraulic accumulator and the four-quadrant hydraulic pump motor 11 in the fully hydraulic four-wheel independent drive system improves the transmission efficiency of the system and reduces the energy loss caused by inefficiency.

[0024] Specifically, in this embodiment, it includes a control unit VCU, a right front wheel drive axle structure assembly 1, a right rear wheel drive axle structure assembly 5, a left rear wheel drive axle structure assembly 6 and a left front wheel drive axle structure assembly 8 arranged on the frame; the drive axle 10 includes a main reducer, a wheel-side reducer, a clutch, a brake 9, and an input shaft.

[0025] The control unit VCU controls the hydraulic valve group 2 to output different hydraulic energies and controls the oil displacement of the four-quadrant hydraulic pump motor 11, thereby controlling the rotation speed of the wheels. The hydraulic valve of the hydraulic valve group 2 can be a flow control valve or a pressure control valve, etc., to control the output of hydraulic energy; the control unit VCU controls the hydraulic pump motor 3 to output hydraulic energy, and the hydraulic valve group 2 distributes hydraulic energy to each of the four-quadrant hydraulic pump motors 11, and then the drive axle 10 transmits power to the wheels to drive the electric wheel loader forward and backward; and under the control of the control unit VCU, the hydraulic valve group 2 is used to realize the individual control of each drive axle 10 structural assembly, and the independent control of each wheel rotation speed is realized, ensuring the differential speed and torque between each wheel, thereby ensuring that there is no parasitic power caused by slipping during normal driving and operation of the vehicle, resulting in energy loss. When the vehicle needs to brake to stop, the control unit VCU controls the hydraulic pump motor 3 to stop outputting power, and each of the four-quadrant hydraulic pump motors 11 switches to the pump working state, recovering part of the braking energy into the first hydraulic accumulator 12 of the hydraulic energy storage group 4. When energy output is required next time, the first hydraulic accumulator 12 can release hydraulic energy through the hydraulic valve group 2 to drive each of the four-quadrant hydraulic pump motors 11 to work, thereby realizing energy reuse.

[0026] In this embodiment, a priority valve 15 connected to the hydraulic valve group 2, the hydraulic pump motor 3 and the brake 9, and a steering system 14 connected to the priority valve 15 are also included. During the braking process of the vehicle, when each of the four-quadrant hydraulic pump motors 11 is unable to meet the braking demand, the hydraulic pump motor 3 will provide hydraulic energy to the brake 9 through the priority valve 15, so that the brake 9 provides a part of the walking mechanical braking to participate in the vehicle braking, ensuring the safety of the vehicle during driving. At the same time, the hydraulic pump motor 3 will provide hydraulic energy to the steering system through the priority valve 15, allowing it to control the steering of the vehicle.

[0027] Furthermore, a second hydraulic accumulator 13 connected to the priority valve 15, the steering system 14 and the brake 9 is included. Part of the hydraulic energy is input into the second hydraulic accumulator 13 through the priority valve to ensure that when the hydraulic pump motor 3 loses the hydraulic energy provided by the vehicle due to an emergency failure, the second hydraulic accumulator 13 can provide sufficient hydraulic energy for the brake 9 and the steering system to ensure the steering and braking of the vehicle, thereby ensuring driving safety.

[0028] The present invention provides an electric wheel loader, comprising a frame, and also comprising a fully hydraulic four-wheel independent drive system fixed on the frame; the hydraulic pump motor 3 is installed with a shock-absorbing pad between the frame. The right front wheel drive axle structure assembly 1, the hydraulic valve group 2, the hydraulic pump motor 3, the hydraulic accumulator group 4 (including the first hydraulic accumulator 12 and the second hydraulic accumulator 13), the right rear wheel drive axle structure assembly 5, the left rear wheel drive axle structure assembly 6, the hydraulic oil tank 7, and the left front wheel drive axle structure assembly 8 are all rigidly connected to the vehicle frame through mechanical bolts. The shock-absorbing pad installed between the hydraulic pump motor 3 and the frame can effectively reduce the impact force of the electric wheel loader during operation and provide stability in its operation.

[0029] The above are only preferred implementations of the present utility model. The protection scope of the present utility model is not limited to the above embodiments. All technical solutions under the concept of the present utility model belong to the protection scope of the present utility model.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0032] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

Claims

1. A fully hydraulic four-wheel independent drive system, comprising a control unit VCU, a right front wheel, a right rear wheel, a left rear wheel and a left front wheel drive axle structure assembly arranged on a vehicle frame; the drive axle structure assembly comprises a four-quadrant hydraulic pump motor, and a drive axle connected to the four-quadrant hydraulic pump motor to transmit power to the wheels; characterized in that: It also includes a hydraulic valve group connected to the drive axle structure assembly through a hydraulic pipeline, a first hydraulic accumulator connected to the hydraulic valve group through a hydraulic pipeline, a hydraulic pump motor and a hydraulic oil tank; the control unit VCU can control the hydraulic pump motor to operate to output hydraulic energy, and can independently control the speed of each wheel; the first hydraulic accumulator is used to recover the hydraulic energy during braking, so as to output hydraulic energy to each drive axle structure assembly during the next drive.

2. The fully hydraulic four-wheel independent drive system according to claim 1, characterized in that: The drive axle includes a main reducer, a wheel reducer, a clutch, a brake, and an input shaft.

3. The fully hydraulic four-wheel independent drive system according to claim 2, characterized in that: It also includes a priority valve connected to the hydraulic valve group, the hydraulic pump motor and the brake.

4. The fully hydraulic four-wheel independent drive system according to claim 3, characterized in that: The priority valve is also connected to the steering system.

5. The fully hydraulic four-wheel independent drive system according to claim 4, characterized in that: Also included is a second hydraulic accumulator connected to the priority valve, the steering system and the brake.

6. An electric wheel loader, comprising a frame, characterized in that: It also includes a fully hydraulic four-wheel independent drive system as described in any one of claims 1 to 5 fixedly mounted on the frame.

7. The electric wheel loader according to claim 6, characterized in that: The hydraulic pump motor is provided with a shock-absorbing pad between the vehicle frames.

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