KR20200008787A - Swing Energy Regeneration System using Secondary Control System - Google Patents

Abstract

The present invention relates to a regeneration system which stores and regenerates energy lost by rotation and braking of an upper swing body of hydraulic equipment. The regeneration system comprises: a variable-capacity hydraulic pump connected to an engine; a swing motor which is connected to the hydraulic pump through a first and a second flow path and swings an upper swing body; a first control valve which is arranged between the hydraulic pump and the swing motor and selectively connects the first and the second flow path to the hydraulic pump; a pump motor which is connected to the swing motor and supplies torque to the swing motor or receives torque from the swing motor; an accumulator which is connected to the pump motor through a third and a fourth flow path and is capable of storing hydraulic energy; and a second control valve which is arranged between the pump motor and the accumulator and selectively connects the third and the fourth flow path to the accumulator. The present invention having the above structure is capable of immediately installing a conventional hydraulic system without excessive design changes and has an independent hydraulic structure. Therefore, the present invention is stable and facilitates maintenance and repair.

Description

Swing Energy Regeneration System using Secondary Control System

The present invention relates to a hydraulic equipment swing energy regenerative system using secondary control, and more particularly, to store hydraulic energy in the accumulator or a hydraulic pressure stored in the accumulator through a pump motor connected to the swing motor during turning and braking of the hydraulic equipment. The present invention relates to a hydraulic equipment turning energy regenerative system using secondary control that saves energy by supplying energy to a turning motor.

In general, construction machinery such as excavators have a hydraulic structure for driving the construction machinery in accordance with the hydraulic pressure of the hydraulic oil formed from the hydraulic pump connected to the engine.

The hydraulic equipment using the hydraulic pressure immediately drives the hydraulic equipment in the desired direction by using the hydraulic pressure of the working oil. A lot of energy is consumed by heat, vibration, noise, etc. It has a lot of influence, which leads to the problem of increasing the operating cost of hydraulic equipment.

Some of the energy consumed is generated in the operation of turning the upper swing structure of the hydraulic equipment to the swing motor. The high-pressure hydraulic oil discharged from the hydraulic pump by driving the engine is supplied to the swing motor to turn the upper swing structure, and when the hydraulic oil is shut off for braking, the pressure is rapidly increased at the discharge port of the swing motor to generate the braking torque. Loss occurs in the relief valve.

In order to solve the above problems, researches and efforts on a method of regenerating and recycling a part of energy consumed have been progressed.

Korean Patent Laid-Open Publication No. 10-2011-0052041 discloses a structure in which an accumulator is connected to each of a first passage and a second passage connected to a swing motor to store hydraulic energy in the accumulator and then supply the hydraulic energy back to the swing motor. In addition, Korean Patent Publication No. 10-1061194 discloses an accumulator connected to the first to fourth flow rate control valve and the hydraulic pump.

However, since the disclosed patents and registered patents have a structure in which the hydraulic pump, the swing motor, and the accumulator are supplied with or supply hydraulic energy in one circuit, many configurations are required to adjust the movement path and direction of the hydraulic fluid, and any one configuration In case of this malfunction, there is a problem affecting the entire hydraulic system. Even if hydraulic energy is stored in the accumulator, it is difficult to expect high energy efficiency because it is only passive storage and supply according to the pressure difference.

(Document 001) Republic of Korea Patent Publication No. 10-2011-0052041 (published: 2011.05.18.) (Document 002) Republic of Korea Patent Publication No. 10-1061194 (Registration Date: 2011.08.25.) (Document 003) Republic of Korea Patent Publication No. 10-2018-0044266 (Published: 2018.05.02.)

The object of the present invention in view of the above point is to provide a hydraulic energy regeneration system capable of more efficient energy regeneration when rotating the upper swing of the hydraulic equipment.

In addition, to provide a hydraulic energy regeneration system having a route independent of the hydraulic system for driving the hydraulic equipment.

Hydraulic equipment turning energy regenerative system using the secondary control according to an embodiment of the present invention is connected through a variable displacement hydraulic pump, a hydraulic pump and the first flow path and the second flow path connected to the engine to rotate the upper swing structure It is provided between the swing motor, the hydraulic pump and the swing motor, and is connected to the first control valve and the swing motor to selectively connect the first flow path and the second flow path with the hydraulic pump, and supply the rotational force to the swing motor or provide the rotational force from the swing motor. A second pump which is connected between the receiving pump motor, the pump motor and the third and fourth flow paths, and is provided between the accumulator capable of storing hydraulic energy and the pump motor and the accumulator, and selectively connects the third and fourth flow paths with the accumulator. It includes a control valve.

In addition, the pump motor may have a variable volume.

In addition, it may further include a rotation shaft for connecting the swing motor and the pump motor.

In addition, the controller further includes a controller for controlling the operation of the pump motor, the controller receives the braking signal of the hydraulic equipment receives the rotational force from the turning motor and the turning signal of the brake module and hydraulic equipment for storing the hydraulic pressure in the accumulator by the rotational force It may include receiving a support module for converting the hydraulic pressure stored in the accumulator to the rotational force and then supply the rotational force to the swing motor.

The controller may further include a pressure control module configured to vary the volume of the pump motor based on the braking condition and the information on the change in the pressure value of the first passage or the second passage.

According to an embodiment of the present invention, in the turning process of the hydraulic equipment, after storing the high pressure hydraulic fluid which is relief at the time of turning braking after turning acceleration of the upper turning body in the accumulator, using the operating oil stored in the accumulator during turning acceleration By reducing the energy consumption is effective.

In addition, the pump motor connected to the swing motor, the second control valve connected to the pump motor, and the accumulator connected to the second control valve are easy to maintain and freely change according to the use conditions independently of the hydraulic system for driving the hydraulic equipment. .

In addition, installation costs are reduced without requiring excessive design changes when applied to existing hydraulic systems.

In addition, since the hydraulic energy can be actively stored and discharged through the pump motor, the regeneration of the hydraulic energy is more efficient and variable.

In addition, since the pressure can be adjusted by adjusting the volume of the pump motor, the limit according to the use conditions is small.

1 is a schematic diagram showing a hydraulic equipment swing energy regeneration system using secondary control according to an embodiment of the present invention.
2 is a block diagram illustrating a controller according to an exemplary embodiment of the present invention.
3 is a schematic view showing a turning state according to an embodiment of the present invention.
Figure 4 is a schematic diagram showing a braking state according to an embodiment of the present invention.

In the following description of the present invention, if it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Embodiments according to the concepts of the present invention may be variously modified and may have various forms, and specific embodiments will be illustrated in the drawings and described in detail in the present specification or application. However, this is not intended to limit the embodiments in accordance with the concept of the present invention to a particular disclosed form, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprise" or "have" are intended to indicate that there is a stated feature, number, step, operation, component, part, or combination thereof, one or more other features or numbers, It should be understood that it does not exclude in advance the possibility of the presence or addition of steps, actions, components, parts or combinations thereof.

Hereinafter, the present invention will be described in detail.

1 is a schematic diagram showing a hydraulic equipment swing energy regeneration system using secondary control according to an embodiment of the present invention.

Referring to Figure 1, the hydraulic equipment swing energy regeneration system using the secondary control according to an embodiment of the present invention is a variable displacement hydraulic pump 100, the hydraulic pump 100 and the first It is connected between the first flow path 210 and the second flow path 220 and is provided between the swing motor 300 for turning the upper swing body (M), the hydraulic pump 100 and the constant swing motor 300 and the A first control valve 200 for selectively connecting the first flow path 210 and the second flow path 220 to the hydraulic pump 100 and the turning motor 300 are connected to the turning motor 300. An accumulator connected to the pump motor 400, the pump motor 400, the third flow path 510, and the fourth flow path 520 to supply or receive rotational force from the swing motor 300 to store hydraulic energy. 600) and between the pump motor 400 and the accumulator 600, the third passage 510 and the fourth oil A 520 and a second control valve 500 for selectively connecting the said accumulator (600).

Referring to the overall structure of the present invention, the hydraulic pump 100 connected to the engine (E) in accordance with the driving of the engine (E) of the hydraulic equipment supplies the hydraulic fluid to the first control valve 200, the first control valve Optionally, the hydraulic fluid is supplied to the first flow path 210 or the second flow path 220 at 200. The operating oil passing through the first flow path 210 or the second flow path 220 drives the swing motor 300 and the upper swing body M of the hydraulic equipment connected to the swing motor 300 rotates.

The first control valve 200 controls the start, stop and direction change of the swing motor 300. The first control valve 200 may be a three-position valve. In FIG. 1, the switching positions of the first control valve 200 are represented by x, y, and z for convenience of description. When the first control valve 200 is switched to the x position, the operating oil supplied from the hydraulic pump 100 passes through the second flow path 220 and is supplied from the hydraulic pump 100 when switched to the z position The hydraulic fluid passes through the first flow path 210. The revolving motor 300 has a structure in which the upper revolving body M connected to the revolving motor 300 is rotated with different directions depending on the hydraulic fluid passing through the first flow path 210 and the second flow path 220. When the turning motor 300 is stopped to brake the upper swinging body M, the first control valve 200 is switched to the y position and the first flow path 210 or the first flow path in the hydraulic pump 100 is stopped. The operating oil supplied to the second flow path 220 is cut off, and a part of the working oil remaining in the first flow path 210 or the second flow path 220 is discharged to the tank 700 through the relief valve 230.

The hydraulic fluid remaining in the first flow passage 210 or the second flow passage 220 discharged to the tank 700 may be connected to the first control valve 200, in which case the first control valve 200 It may be connected to the tank 700. That is, the first control valve 200 is connected to the first passage 210 and the second passage 220 on one side and the hydraulic pump 100 and the tank 700 on the other side.

In addition, the hydraulic pump 100 and the tank 700 may be connected to each other, the non-load relief valve 110 is provided between the hydraulic pump 100 and the tank 700 in an embodiment of the present invention. The non-load relief valve 110 serves to return the hydraulic oil from the hydraulic pump 100 to the tank 700 while not working in the repetitive operation. The no-load relief valve 110 prevents aging of the working oil and prevents heating or deterioration of the hydraulic pump 100. Various types of the no-load relief valve 110 may be used.

A first discharge line 211 and a first supply line 212 are connected to the first flow path 210, respectively, and the first discharge line 211 and the first supply line 212 have different directions from each other. Valve V may be provided. A second discharge line 221 and a second supply line 222 are connected to the second flow path 220, respectively, and the first discharge line (222) to the second discharge line 221 and the second supply line 222. 211 and the first supply line 212 may be provided with a check valve (V) that is different in direction from each other. The hydraulic oil passing through the first discharge line 211 or the second discharge line 221 moves in the direction of the relief valve 230, and the hydraulic oil passes through the relief valve 230 at a predetermined pressure or more to the tank. Discharged to 700. Some of the hydraulic oil passing through the relief valve 230 passes through the first supply line 212 and / or the second supply line 222 to the first flow path 210 or the second flow path 220. Supplied.

In one embodiment of the present invention having the configuration as described above passed through the first control valve 200 through the hydraulic fluid, the first passage 210 or the second passage 220 passing through the relief valve 230. Hydraulic oil, the hydraulic oil passed through the no-load relief valve 110 in the hydraulic pump 100 may be discharged to the tank 700. In the present invention, the hydraulic oil discharged to the tank 700 may pass through the return filter 710, the return filter 710 filters the contaminants of the hydraulic oil discharged to the tank 100 and the return filter 710 In case of clogging), a bypass check valve 720 connected in parallel with the return filter 710 may be provided. The bypass check valve 720 bypasses the hydraulic fluid when the filtration performance of the return filter 710 is poor.

The first discharge line 211, the second discharge line 221, the first supply line 212, the second supply line 222, the relief valve 230, the no-load relief valve 110, the return filter ( 710, the bypass check valve 720, the tank 700, and the like may be variously changed or omitted within the scope of the present invention, and various sensors or valves may be additionally provided according to conditions.

The swing motor 300 receives hydraulic energy from the hydraulic oil passing through the first flow path 210 or the second flow path 220 to generate a rotation force, and rotates the upper swing body M according to the rotation force. The swing motor 300 may perform both the motor and the pump. As shown in FIG. 1, the swing motor 300 has an A port and a B port. The hydraulic oil flowing into the A port is discharged into the B port, and the hydraulic oil flowing into the B port is discharged into the A port. The port A of the swing motor 300 may be connected to the first flow path 210 and the port B of the swing motor 300 may be connected to the second flow path 220.

The pump motor 400 of the present invention is connected to the swing motor 300, has a structure to receive a rotational force from the swinging motor 300 or to transmit a rotational force to the swinging motor (300). The pump motor 400 may perform a role of a motor as well as a pump.

As shown in FIG. 1 of the present invention, the pump motor 400 has a C port and a D port. The third flow path 510 connected to the pump motor 400 is connected to the C port and the fourth flow path. 520 may be connected to the D port. The pump motor 400 preferably has a structure capable of both inflow and outflow of the working oil into the C port or the D port, respectively.

In one embodiment of the present invention may further include a rotary shaft 310 for connecting the swing motor 300 and the pump motor 400. The rotating shaft 310 may be connected to the swing motor 300 at one end thereof and the pump motor 400 at the other end thereof. The rotational force according to the rotation of the turning motor 300 may be transmitted to the pump motor 400 or the rotational force according to the rotation of the pump motor 400 may be transmitted to the turning motor 300.

The third flow path 510 and the fourth flow path 520 are respectively connected to the pump motor 400 so that the working oil is moved therein. In addition, the third passage 510 and the fourth passage 520 may be connected to the second control valve 500, and the second control valve 500 may be connected to the accumulator 600 and the tank 700. . That is, the second control valve 500 is connected to the third passage 510 and the fourth passage 520 on one side and the accumulator 600 and the tank 700 on the other side.

In an embodiment, the second control valve 500 may have a structure substantially the same as that of the first control valve 200, and may adjust the directionality of the hydraulic oil as a three-position valve. In FIG. 1, the switching positions of the second control valve 500 are represented by x, y, and z for convenience of description, and the third flow path 510 when the second control valve 500 is switched to the x position. Is connected to the tank 700 and the fourth flow path 520 is connected to the accumulator 600. When the second control valve 500 is switched to the z position, the third passage 510 is connected to the accumulator 600 and the fourth passage 520 is connected to the tank 700. In addition, when switching to the y position of the second control valve 500, the third passage 510 and the fourth passage 520 is disconnected from the accumulator 600 and the tank 700.

The accumulator 600 is a device for accumulating hydraulic energy and releasing the accumulated hydraulic energy, the configuration and type is not particularly limited.

The tank 700 connected to the second control valve 500 may be separate from the tank 700 connected to the hydraulic pump 100 and the tank 700 connected to the first control valve 200, or may be separated from each other. It may be the same object or in communication with each other.

In the present invention having the configuration as described above to accumulate the hydraulic energy consumed by the operation or braking of the swing motor 300 in the accumulator 600 in a structure independent of the hydraulic system for turning the upper swing body (M). As it can be reused, it can be immediately applied to the existing hydraulic system and it is economical because it does not require a separate design change.

Hereinafter, the controller 800 and the hydraulic energy regeneration structure of the present invention will be described.

2 is a block diagram showing a controller 800 according to an embodiment of the present invention, Figure 3 is a schematic diagram showing a turning state of the upper swing body (M) according to an embodiment of the present invention, Figure 4 Schematic diagram showing a braking state of the upper swing body (M) according to an embodiment of the invention.

Referring to FIG. 2, in an embodiment of the present disclosure, a controller 800 for controlling the operation of the pump motor 400 may be included. The controller 800 receives the braking signal of the hydraulic equipment and receives the rotational force from the turning motor 300 and stores the hydraulic pressure in the accumulator 600 by the rotational force and the turning of the hydraulic equipment It may include a support module 820 for receiving the signal to convert the hydraulic pressure stored in the accumulator 600 into a rotational force and then supply the rotational force to the swing motor 300.

The braking module 810 prevents the loss of hydraulic energy as the hydraulic oil is discharged to the tank 700 through the relief valve 230 above the set pressure during braking of the upper swinging body M, The support module 820 regenerates hydraulic energy as the upper swinging body M in a braking state assists the rotation of the swinging motor 300 when turning again. This will be described in more detail by dividing it into a turning state and a braking state.

In FIG. 3, the flow of hydraulic energy when the upper swing body M is turning is illustrated. Referring to FIG. 3, the first control valve 200 is located at the x position according to the turning signal of the upper swing body M. Referring to FIG. (In the case of the y position, the same principle is applied but the orientation is different. Hereinafter, the case of switching to the x position will be described.) And the hydraulic pump 100 and the second flow path 220 are connected. The hydraulic oil supplied through the hydraulic pump 100 passes through the second flow path 220 and flows into the B port of the swing motor 300 to transfer hydraulic energy and exits to the A port to release the relief valve 230. The tank is discharged to the tank 700 via the first control valve 200. In this case, the support module 820 of the controller 800 is operated, and the pump motor 400 is rotated in the same direction as the rotational direction of the swing motor 300 by the support module 820. Rotation of the 300 may be assisted.

The support module 820 of the controller 800 switches the second control valve 500 to the x position similarly to the first control valve 200 to connect the fourth flow path 520 and the accumulator 600. Let's do it. The hydraulic energy accumulated in the accumulator 600 is transmitted to the hydraulic oil passing through the fourth flow path 520 and the hydraulic oil flowing into the D port of the pump motor 400 rotates the pump motor 400. The rotational energy according to the rotation of the pump motor 400 is transmitted to the swing motor 300 to assist the swing of the upper swing body M through the swing motor 300. The working oil passing through the fourth flow passage 520 is discharged to the tank 700 via the third flow passage 510. Hydraulic energy accumulated in the accumulator 600 may be regenerated through the above mechanism. As a result, the energy consumption of the turning motor 300 may be reduced by the energy provided by the accumulator 600.

In FIG. 4, the flow of hydraulic energy when braking the upper swing body M is illustrated. Referring to FIG. 4, the first flow path 210 and the second flow path 220 when the upper swing body M is turned. In the state in which the hydraulic oil is filled), the first control valve 200 is switched to the y position to stop the supply of the hydraulic oil through the hydraulic pump (100). Conventionally, hydraulic energy is lost through the relief valve 230 as the discharge pressure is increased in the first flow path 210 or the second flow path 220 according to the inertia of the upper swing structure M or the swing motor 300. The energy stored in the braking module 810 of the present invention is accumulated in the accumulator 600.

In the braking module 810, the pump motor 400 is rotated by the rotational force according to the inertia of the upper swinging body M or the swinging motor 300, and the second control valve 500 is moved to the z position. As switched, the energy of the rotation of the pump motor 400 is transferred to the working oil of the third channel 510 and stored in the accumulator 600. Hydraulic energy lost through the above mechanism may be stored in the accumulator 600.

Since the rotational force according to the inertia of the turning motor 300 is transferred to the accumulator 600 by the separate pump motor 400, it is lost when braking according to the control of the volume, speed, etc. of the pump motor 400. The efficiency of storing the hydraulic energy in the accumulator 600 can be maximized to about 100%.

That is, the braking module 810 controls the operating conditions (volume, operating speed, etc.) of the pump motor 400 by reflecting the type, state or braking condition of the hydraulic equipment, so that the upper turning body M The rotational force due to the inertia generated during braking and the hydraulic energy lost due to this may be maximized in storing the accumulator 600.

Comparing the support module 820 and the braking module 810, in the support module 820, the flow direction of the hydraulic energy is made in the order of the accumulator 600, the pump motor 400, the swing motor 300. In the braking module 810, the turning motor 300, the pump motor 400, and the accumulator 600 are reversed.

In the present invention, it is possible to provide a hydraulic system that stores and regenerates hydraulic energy lost by the control of the controller 800 including the support module 820 and the braking module 810 and at the same time establishes an independent hydraulic structure.

In one embodiment of the present invention, the controller 800 adjusts the volume of the pump motor 400 based on the braking condition and information on the change in the pressure value of the first passage 210 or the second passage 220. It may further include a variable pressure control module 830. To this end, the pump motor 400 is preferably variable in volume.

The pressure control module 830 may change the pressure of the third passage 510 or the fourth passage 520 by varying the volume of the pump motor 400. The pressure of the first passage 210 or the second passage 220 depends on the type, state, condition, etc. of the hydraulic equipment, and depends on the braking conditions of the upper swing body M. The pressure control module of the present invention ( 830 adjusts the energy regeneration amount and the braking speed since the volume of the pump motor 400 is changed to reflect the type, state or braking condition of the hydraulic equipment. For example, when rapid braking of the upper pivot M is required, the volume of the pump motor 400 may be reduced. In this case, the amount of hydraulic energy stored through the accumulator 600 is somewhat reduced. In addition, when rapid braking is not required, the volume of the pump motor 400 may be increased to increase the amount of hydraulic energy stored in the accumulator 600.

The relationship between the volume of the pump motor 400 and the pressure of the third passage 510 or the fourth passage 520 may be expressed by the equation ΔP × D = T. Here, ΔP means the pressure difference across the pump motor 400, D means the volume of the pump motor 400, T means the drive torque of the hydraulic motor (300). When the torque T according to the inertia during the braking of the upper swinging body M or the swinging motor 300 is constant, when the volume of the pump motor 400 is reduced, the third passage 510 or the fourth The pressure in the flow path 520 is increased. For example, when the rapid braking is required, as the volume of the pump motor 400 is reduced, the pressure difference between the third channel 510 or the fourth channel 520 increases, so that the amount of regenerative energy stored is reduced. The braking speed has a mechanism of increasing manner.

In the present invention having the pressure control module 830, the volume of the pump motor 400 can be varied according to the situation, so that the braking speed and the regenerative energy amount can be adjusted. It can be used and has a wide range of use because of less constraints on the use environment.

In the present invention, a specific situation is assumed for clarity of technical features, but in the present invention, the first control valve 200 and the second control valve 500 are the swing motor 300 or the upper swing body M. FIG. According to the rotation direction or the braking conditions of) can be switched to other positions other than the above-described position of x, y, z, the hydraulic fluid passing through the interior of the first flow path 210 to the fourth flow path 520 is the turning Depending on the rotational direction or braking condition of the motor 300 or the upper swinging body M, the switching position of the first control valve 200 or the second control valve 500 may be moved in a direction other than the above-described direction. have.

As described above, the present invention accumulates and regenerates energy according to the turning and braking of the upper swinging body M, and changes the volume of the pump motor 400 according to the change in the braking conditions and the pressure, and thus the use range is wide. It can be immediately installed in the existing hydraulic system and has an advantage of easy maintenance because it has an independent structure from the existing hydraulic system.

100: hydraulic pump 110: no-load relief valve
200: first control valve
210: first euro 211: first discharge line
212: first supply line 220: second euro
221: second discharge line 222: second supply line
230: relief valve
300: turning motor 310: rotating shaft
400: pump motor
500: second control valve 510: third euro
520: the fourth euro
600: accumulator
700 tank 710 return filter
720: Bypass Check Valve
800: controller 810: braking module
820: support module 830: pressure control module
M: Upper swinging body V: Check valve

Claims (5)

A variable displacement hydraulic pump connected to the engine;
A swing motor connected to the hydraulic pump through a first flow passage and a second flow passage to pivot an upper swing structure;
A first control valve disposed between the hydraulic pump and the normally turning motor and selectively connecting the first flow passage and the second flow passage to the hydraulic pump;
A pump motor connected to the swing motor to supply rotational force to the swing motor or to receive rotation force from the swing motor;
An accumulator connected to the pump motor through a third channel and a fourth channel and capable of storing hydraulic energy; And
Hydraulic equipment turning energy regenerative system using a secondary control, comprising: a second control valve provided between the pump motor and the accumulator and selectively connects the third flow path and the fourth flow path with the accumulator. .
The method of claim 1,
The pump motor is a hydraulic equipment swing energy regeneration system using a secondary control, characterized in that the volume is variable.
The method of claim 2,
Hydraulic equipment turning energy regeneration system using the secondary control, characterized in that it further comprises a rotating shaft connecting the swing motor and the pump motor.
The method of claim 2,
And a controller for controlling the operation of the pump motor.
The controller,
A braking module that receives a braking signal of hydraulic equipment and receives a rotational force from the swing motor and stores hydraulic pressure in the accumulator by the rotational force; And
Hydraulic equipment turning energy regenerative system using a secondary control, comprising: a support module for receiving the turning signal of the hydraulic equipment to convert the hydraulic pressure stored in the accumulator to the rotational force and supply the rotational force to the swinging motor .
The method of claim 4, wherein
The controller,
Hydraulic equipment turning energy using the secondary control further comprises a pressure control module for varying the volume of the pump motor based on the information on the change in the pressure value of the first passage or the second passage and the braking conditions Regenerative system.

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