CN111649023A - An electro-hydraulic dual-control motor-driven rotary system buffer oil replenishment system and method - Google Patents

Abstract

The invention relates to a buffering oil supplementing system and method for an electro-hydraulic double-control motor driving rotation system. The oil supplementing reversing valve is connected into a hydraulic rotary motor loop, and an energy accumulator is utilized to provide an oil source for the oil supplementing reversing valve through a pressure reducing valve; when the multi-way valve for controlling the hydraulic rotary motor is positioned at the middle position, the oil supplementing reversing valve works at the middle position to automatically supplement oil for the hydraulic rotary motor pipeline; in the action process of the hydraulic rotary motor, an oil inlet of the oil supplementing and supplementing reversing valve is communicated with the low-pressure end of the hydraulic rotary motor, and the energy accumulator is stamped by utilizing the oil return back pressure of the hydraulic rotary motor. The invention solves the technical problems that the oil storage and supplement in the prior art is insufficient, the hydraulic control automatic oil supplement cannot be realized, the system automation degree is low, and the energy loss is large.

Description

An electro-hydraulic dual-control motor-driven rotary system buffer oil replenishment system and method

technical field

The invention relates to a buffer oil replenishment system and method, belonging to the field of drilling equipment, and in particular to a buffer oil replenishment system and method of an electro-hydraulic dual-control motor-driven rotary system.

Background technique

Hydraulic transmission has the advantages of high power and weight, flexible component installation and arrangement, and can realize stepless speed regulation. action. With the improvement of drilling rig capacity, the structural size of the drilling rig is getting larger and larger, resulting in an increasing height difference between the hydraulic slewing motor and the fuel tank. Since the multi-way valve that controls the action of the hydraulic swing motor is generally a spool valve, it is difficult to avoid the problem of mid-position leakage, which leads to intermittent use of the equipment, and the hydraulic oil in the swing motor pipeline returns to the oil tank, so that air enters the pipeline. , The air enters the hydraulic system, which is fatal to the system. The light one will cause the rotary motor to be weak, uncoordinated, and the action delay noise and other problems. On the other hand, when the moment of inertia of the slewing system is large, when the slewing motor stops suddenly, due to the existence of inertia, a large impact will be generated at the oil return port of the motor, and a system phenomenon will be generated at the oil inlet of the motor, thus making the motor The service life is greatly reduced,

At present, the conventional solution is to set an oil replenishment check valve and a buffer valve in the hydraulic system to passively replenish oil to the system, and at the same time the buffer valve overflows to reduce the impact of the system. This method has certain problems in practical use. The first is the oil replenishment circuit, which uses a one-way valve to replenish oil for the system. This oil replenishment method can only use the self-priming action of the motor to drive the oil replenishment unit by using the pressure difference between the atmospheric pressure and the motor oil inlet when there is negative pressure in the system. The valve is opened to replenish oil for the system. However, because the height difference between the partial rotary motor and the oil tank is too large, this method is difficult to work in a real sense. Another method is to add a low-pressure oil pump in the system. System oil replenishment, this method solves the problem of oil replenishment. However, because the oil charge pump is always working, it increases the extra energy loss of the system, and the service life of the oil charge pump is also short. In the buffer circuit, due to the use of The relief valve is used as a buffer valve. When the rotary motor stops rotating, the oil return shock of the rotary motor is unloaded through the relief valve, and finally converted into heat loss. Not only from the perspective of energy saving, this part of energy is directly wasted, but also increases the cooling system. burden.

SUMMARY OF THE INVENTION

The invention mainly solves the technical problems of insufficient oil storage and replenishment in the prior art, unable to realize hydraulic control automatic oil replenishment, low degree of system automation and large energy loss, and provides an electro-hydraulic dual-control motor-driven rotary system buffering Oil replenishment system and method.

The above-mentioned technical problems of the present invention are mainly solved by the following technical solutions:

An electro-hydraulic dual-control motor-driven rotary system buffer oil replenishment device, comprising:

The direction control port A and direction control port B of the oil charge reversing valve are respectively connected to the direction control port A and direction control port B of the hydraulic rotary motor and the direction control port A and direction control port B of the multi-way valve. Port T is connected to the oil inlet B of the one-way valve, and its hydraulic control end is connected in parallel with the hydraulic control end of the multi-way valve that controls the hydraulic rotary motor;

The oil charge circuit includes an accumulator, the accumulator is connected to the oil return port T of the oil charge reversing valve through a pressure reducing valve, and the oil return port T of the oil charge reversing valve passes through a single Connect the accumulator to the valve.

Preferably, the above-mentioned double-controlled electro-hydraulic motor-driven rotary system buffer oil replenishment device, when the oil replenishment reversing valve works in the neutral position, the direction control port A and the direction control port B of the hydraulic rotary motor are connected with the supplementary oil. The oil circuit is communicated; when the oil replenishment reversing valve works in the left position, the low pressure port of the hydraulic rotary motor is communicated with the oil replenishment circuit.

Preferably, in the above-mentioned buffer oil replenishment device for a rotary system driven by an electro-hydraulic dual-control motor, the oil replenishment circuit further includes an oil replenishment pump connected to the accumulator through a one-way valve, and the oil replenishment pump is used for When the accumulator pressure is insufficient, add oil to the accumulator.

Preferably, in the above-mentioned buffer oil replenishment device for a rotary system driven by an electro-hydraulic dual-control motor, the oil replenishment circuit further includes:

a power source, which is connected to the charge pump through a clutch;

The spring return oil cylinder is connected with the accumulator, and when the pressure of the accumulator accumulator is lower than the spring pressure of the spring return oil cylinder, the spring return oil cylinder is automatically extended to engage the clutch.

Preferably, in the above-mentioned buffer oil replenishment device for a rotary system driven by an electro-hydraulic dual-control motor, the oil replenishment circuit further includes:

The two-position two-way reversing valve is installed between the accumulator oil port and the spring return oil cylinder, and when the two-position two-way reversing valve is in the normal position, the oil passage between the accumulator and the spring return oil cylinder disconnect;

The controller controls the reversing of the two-position two-way reversing valve according to the accumulator pressure obtained by the pressure sensor installed on the accumulator and the oil circuit of the two-position two-way reversing valve.

An electro-hydraulic dual-control motor-driven rotary system buffer oil replenishment method, comprising:

The oil charge reversing valve is connected to the hydraulic swing motor circuit, and the accumulator is used to provide oil source for the oil charge reversing valve through the pressure reducing valve;

When the multi-way valve controlling the hydraulic swing motor is in the neutral position, the oil replenishment reversing valve works in the neutral position to automatically replenish oil for the hydraulic swing motor pipeline;

During the action of the hydraulic swing motor, the oil inlet of the reversing valve for oil replenishment is connected to the low pressure end of the hydraulic swing motor, and the back pressure of the oil return of the hydraulic swing motor is used to stamp the accumulator.

Preferably, the above-mentioned method for buffering and replenishing oil in a rotary system driven by an electro-hydraulic dual-control motor includes:

A hydraulically controlled automatic oil charge pump is arranged in the circuit. When the pressure of the accumulator is lower than the set value, the accumulator is charged through the clutch engagement.

Therefore, the present invention actively replenishes oil for the hydraulic rotary motor pipeline through the accumulator, avoiding the damage to the hydraulic system and components caused by leakage of the pipeline when the multi-way valve is in the neutral position, causing air to enter the hydraulic system. When the rotary motor is operating, the back pressure of the rotary motor is fully utilized to charge the accumulator, which saves energy. When the hydraulic slewing motor stops in an emergency, the oil charge reversing valve is in the neutral position to realize the connection of the A and B ports of the motor, and the motor floats, thus solving the problem of air suction and oil return at the oil inlet when the large inertia slewing emergency stops. The problem of large impact on the port and reducing the life of the motor, an electro-hydraulic dual-control oil replenishment system is installed in the system. When the pressure of the accumulator is lower than the set value, the oil replenishment pump automatically connects to the power source to charge the accumulator. , By logically controlling the connection and separation of the charge pump and the power source, the operating frequency of the charge pump can be reduced and the service life of the charge pump can be improved. When the electronic control system fails, the clutch between the charge pump and the power source is automatically converted to full hydraulic control. Improve the reliability of the system. The oil replenishment system can automatically replenish oil to the pipeline, and at the same time adjust the replenishment pressure according to the height difference between the pipeline and the fuel tank, avoiding unnecessary leakage. The hydraulic control automatic oil replenishment system does not require a complex electronic control system, and realizes automatic oil replenishment through hydraulic logic. The system composition is simple, which saves the cost of system construction and facilitates system integration. It can not only be used for new product design, but also can be easily installed in Existing equipment, optimize and improve existing equipment.

Description of drawings

Figure 1 is the schematic diagram of the existing buffer oil replenishment system

Fig. 2 is the principle diagram of buffer and oil replenishment system of the present invention

Fig. 3 is the principle diagram of the present invention using back pressure to fill the accumulator with oil

Figure 4 is a schematic diagram of the charge pump for charging the accumulator

Figure 5 is a schematic diagram of the separation and standby principle of the charge pump and the power source

Detailed ways

The technical solutions of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

Example:

Referring to FIG. 1, FIG. 1 is a schematic diagram of the existing buffer oil supply hydraulic pressure. Buffer relief valves 102 and 106 are provided at the motor A and B ports, and the two oil supply single valves 103 and 105 are respectively connected to the motor A and B ports and the oil tank , Take the multi-way valve working in the left position, the motor is rotating forward as an example, the oil inlet at port A and the oil return at port B as an example, the motor rotates, during this process, when the reversing valve suddenly changes to the right, due to the inertia effect , The motor continues to rotate forward. At this time, due to the reversal of the multi-way valve, the motor is changed to B inlet oil. At this time, a high-pressure shock will be generated at the B port of the motor. When the shock pressure is greater than the set pressure of the buffer relief valve 106, the buffer overflows The flow valve is opened and unloaded to achieve the purpose of reducing the impact pressure. Similarly, when the motor is rotating forward, the multi-way valve suddenly returns to the neutral position. At this time, the motor still has a tendency to maintain the forward rotation due to the inertia effect. At this time, a large impact pressure will be generated at the B port of the motor, which also passes through the relief valve 106. Unloading, and the suction phenomenon will occur at the A port of the motor. At this time, under the action of atmospheric pressure, the hydraulic oil is replenished from the oil tank 107 to the motor A port through the check valve 103, so as to prevent the suction. From the above process, you can It can be seen that there are several problems in the conventional oil replenishment circuit. On the one hand, during the oil replenishment process, the hydraulic oil is passively replenished through the pressure difference between the hydraulic surface of the oil tank and the A port of the motor, but when there is a large height between the rotary motor and the oil tank When it is poor, the A port of the rotary motor cannot be effectively replenished, and the phenomenon of air suction will still occur; on the other hand, due to the existence of the height difference between the hydraulic rotary motor and the oil tank, the pipeline between the multi-way valve 101 and the motor 104 The hydraulic oil will flow back to the oil tank (even if it is in the O-type neutral position, the spool valve still leaks), so that the air enters the pipeline, and the air entering the pipeline will cause the hydraulic rotary impact and cavitation, which will affect the response and performance of the system. The service life of the motor; on the other hand, since the motor buffer valve is essentially a relief valve, the shock pressure is directly unloaded to the fuel tank during the operation of the buffer valve, which wastes this part of the energy.

Fig. 2 is a hydraulic principle diagram of an example of the present invention, including a power source 1, a clutch 2, a spring return cylinder 3, a two-position two-way reversing valve 4, a controller 5, a pressure sensor 6, a first one-way valve 7, an energy storage 8 , pressure reducing valve 9 , second one-way valve 10 , hydraulic swing motor 11 , charge reversing valve 12 , multi-way valve 13 , safety valve 14 , charge pump 15 .

The oil replenishment reversing valve 12 in this embodiment is a three-position three-way hydraulically controlled reversing valve, and the neutral position is Y type;

The oil charge pump 15P is connected to the first check valve 6A port, the accumulator 8P port is connected to the first check valve 7A port, and the charge pump 15 provides oil for the oil charge system when the pressure of the accumulator 8 is insufficient. The first check valve 7 prevents the oil from the accumulator 8 from leaking from the oil charge pump when the oil charge pump 15 does not work.

The accumulator 8P port is connected to the spring return oil cylinder (3) A port, when the accumulator 8 pressure is greater than the spring pressure, the oil cylinder retracts, and when it is less than the spring pressure, the oil cylinder automatically extends.

The spring return oil cylinder 3 controls the opening and closing of the clutch 2, the oil cylinder is extended, the clutch 2 is in the engaged position, the oil cylinder is retracted, and the clutch 2 is in the disengaged position. The clutch 2 controls the engagement and disengagement of the power source 1 and the charge pump 15 respectively. The spring return oil cylinder 3 automatically senses the pressure of the accumulator 8 , and controls the clutch ( 2 ) to realize the engagement and separation of the power source 1 and the charge pump 15 .

A two-position two-way reversing valve 4 is installed between the oil port of the accumulator 8 and the spring return oil cylinder 3 . When the two-position two-way reversing valve 4 is in the normal position, the oil circuit between the accumulator 8 and the spring return oil cylinder 3 is disconnected.

A pressure sensor is installed on the oil circuit of the accumulator 8 and the two-position two-way reversing valve 4 . The controller 5 obtains the pressure of the accumulator through the pressure sensor 7, and controls the 2/2-way 4-way valve to change direction.

The accumulator 8 is connected to the pressure reducing valve 9A port, and the pressure reducing valve 9A port is connected to the oil charge reversing valve 12T port.

The accumulator 8 supplies oil to the pipeline between the reversing valve 12 and the hydraulic swing motor 11 through the pressure reducing valve 9. The flow direction of the hydraulic oil is shown by the arrow in Figure 1, which can be adjusted according to the installation height of the hydraulic swing motor 11. Set value of pressure reducing valve 9 to avoid excessive leakage caused by excessive charging pressure.

The oil charge reversing valve 12 is connected to the hydraulic swing motor 11A, B ports and the multi-way valve 13A, B ports. The hydraulic control ends a and b of the reversing valve 12 are connected to the hydraulic control ends a and b of the multi-way valve (10). When the multi-way valve 13 is reversed, the fuel reversing valve 12 is automatically reversed, so that the fuel supply circuit is always connected to the low pressure ends of the hydraulic rotary motor 11A and B ports, and the T port of the fuel supply reversing valve is connected to the second one-way valve 10B. The port 10A of the second one-way valve is connected to the port 8P of the accumulator, and the accumulator 8 is charged by the back pressure of the motor oil.

The neutral position of the oil replenishment reversing valve 12 is the Y row position, and when the multi-way valve 13 is in the neutral position, the oil replenishing reversing valve 12 is a pipe between the ports A and B of the multi-way valve 13 and the hydraulic rotary motor (8). Road refill.

When the multi-way valve 13 is reversed from the working position to the neutral position, the oil charge reversing valve 12 automatically returns to the neutral position. Since the neutral position of the oil charge reversing valve 12 is the Y-shaped position, the hydraulic rotary motor ports A, B and The oil replenishment circuit is connected, the hydraulic rotary motor 11 is in a floating state, and the oil replenishment reversing valve acts as the oil replenishment valve of port A and the buffer valve of port B at the same time. During the buffering and oil replenishment process, the hydraulic rotary motor 11A, B Connected to the oil replenishment circuit, the high-pressure shock oil at port B can be directly supplemented to the accumulator 8, the system has no overflow loss, and has a good energy saving effect.

Referring to Fig. 3, Fig. 3 is the principle diagram of using back pressure to fill the accumulator with oil in the example of the present invention. When the multi-way valve 13 is reversed, it works in the left position as shown in Fig. 2, and the hydraulic rotary motor 11 operates. 12 and the multi-way valve 13 use a control source, so push the oil charge reversing valve 12 to work in the left position. At this time, the oil charge circuit is communicated with the low-pressure end of the multi-way valve 13, and the back pressure of the multi-way valve 8 is used to store energy. The pressure of the accumulator 8 is charged, and a second one-way valve 10 is arranged on the stamping circuit, which can effectively prevent the pressure of the accumulator 8 from leaking from the low-pressure end of the multi-way valve 13 when the oil return back pressure is small.

Power source 1, clutch 2, spring return cylinder 3, 2/2-way reversing valve 4, controller 5, pressure sensor 6, first one-way valve 7, accumulator 8, pressure reducing valve 9, second one-way Valve 10 , hydraulic rotary motor 11 , reversing valve 12 for refilling, multi-way valve 13 , safety valve 14 , and refilling pump 15 .

Referring to FIG. 4, FIG. 4 is a schematic diagram of the charging pump for the accumulator in the example of the present invention. The controller 5 obtains the working pressure of the accumulator 8 through the pressure sensor. When the pressure of the accumulator 8 is higher than the first set pressure, it controls The two-position reversing valve 4 of the accumulator 5 works in the left position, cutting off the oil circuit between the accumulator 8 and the spring return cylinder 3. When the pressure of the accumulator 8 is lower than the first set pressure, the two-position two-way The reversing valve 4 works in the right position, the oil circuit between the accumulator 8 and the spring return cylinder 3 is connected, the spring force of the spring return cylinder 3 is greater than the force acting on the cylinder by the first set pressure, and the spring return cylinder 3 The rod extends to push the clutch 2 to engage, the power source 1 is connected to the charge pump 15 , and the charge pump 15 works to punch the accumulator 8 .

Referring to Figure 5, Figure 5 is a schematic diagram of the separation and standby between the charge pump and the power source. When the accumulator 8 is punched to the second set pressure value, the force of the second set pressure acting on the oil cylinder is greater than that of the spring reset oil cylinder 3. The spring acts on the oil cylinder. At this time, the cylinder rod is retracted, the charge pump 15 is separated from the power source 1, and the charge pump 15 stops working. The controller 5 controls the two-position, two-way reversing valve 4 to switch to the left position, waiting for the next oil charge cycle. By setting the first oil charge pressure and the second oil charge pressure, and logically controlling the oil charge pump clutch, the oil charge pump can be reduced. Working frequency, from increasing the service life of the charge pump.

The two-position and two-way reversing valve 4 is always a channel, so it can realize the dual control of the charge pump. Under normal circumstances, the clutch of the charge pump 15 is realized by electronic control. The direction valve 4 works in the right position. At this time, the clutch of the charge pump 15 is fully hydraulically controlled. When the pressure of the accumulator 8 acts on the spring reset oil cylinder 3, the force is greater than the spring pressure, and the oil cylinder retracts. Otherwise, the oil cylinder is extended, and the hydraulic system automatically Realize the clutch of the charge pump, thereby improving the reliability of the system.

A first one-way valve 6 is arranged between the working accumulator 8 and the oil charge pump 15. Its function is to prevent the pressure oil of the accumulator 8 from leaking from the oil charge pump when the oil charge pump is not working. The safety valve 14 is used to prevent the oil charge. The pressure is too high, which plays a role in safety protection.

After adopting the above structure, the method for buffering oil in the electric-hydraulic dual-control motor-driven slewing system of the present embodiment is specifically as follows: connecting the reversing valve 12 for refilling in the hydraulic slewing motor circuit, and the accumulator 8 passes through the pressure reducing valve 9 to The oil replenishment reversing valve 12 provides the oil source, and can adjust the working pressure of the pressure reducing valve 9 according to the height difference between the rotary motor and the oil tank, so as to avoid excess oil loss caused by excessive oil replenishment pressure. When the multi-way valve 13 controlling the hydraulic swing motor (8) is in the neutral position, the oil replenishment reversing valve 12 works in the neutral position to automatically replenish oil for the hydraulic swing motor pipeline. The multi-way valve 13 controls the oil and controls the action of the oil-fill reversing valve 12. During the operation of the hydraulic rotary motor (8), the oil inlet of the oil-fill multi-way valve 9 is directly connected to the low-pressure end of the hydraulic rotary motor (8). The back pressure of the oil return of the rotary motor (8) presses the accumulator 8. At the same time, a hydraulically controlled automatic oil charge pump 15 is arranged in the circuit. When the pressure of the accumulator 8 is lower than the set value, the clutch 2 is engaged to charge the accumulator 8.

The accumulator 8 oil replenishment circuit adopts electro-hydraulic dual control, the pressure of the accumulator 8 is obtained through the pressure sensor 6, and the oil circuit between the accumulator 8 and the spring reset cylinder 3 is controlled through the two-position two-way reversing valve 4. On and off, the on-off of the oil source is controlled by the spring reset cylinder 3, and the oil of the accumulator 8 is replenished to the first set pressure through logic control. When the pressure of the accumulator 8 is lower than the second set pressure, The oil circuit between the accumulator 8 and the spring return cylinder 3 is connected. At this time, the working pressure of the accumulator 8 is lower than the spring set pressure of the spring return cylinder 3, the cylinder is extended, and the rodless cavity of the spring return cylinder 3 is hydraulically stored The accumulator 8 is used to add a part of the oil to the accumulator 8, and at the same time, the clutch 2 is controlled to connect the charge pump 15 and the power source 1, and the accumulator 8 is replenished to the first set pressure. At this time, the pressure is greater than the spring return cylinder 3 The spring pressure, the cylinder rod retracts, the power source 1 and the charge pump 15 are separated, and then the controller controls the two-position two-way reversing valve to change the direction, disconnects the oil circuit between the accumulator 8 and the spring return cylinder 3, and waits for the next a cycle.

When the two-position and two-way reversing valve 4 is in the normal position, the oil circuit between the accumulator 8 and the spring return oil cylinder 3 is connected, so when the electronic control system fails, the on-off of the clutch 2 is automatically converted by the electronic control form. It is fully hydraulic automatic control.

When the hydraulic slewing motor is in emergency stop, the oil replenishment reversing valve works in the neutral position. At this time, the neutral position of the slewing motor is the Y-shaped position, and the slewing motor is in a floating state. During emergency stop, the problem of the suction of the oil inlet and the impact of the oil return port.

When the multi-way valve 13 that controls the action of the hydraulic rotary motor 11 is in the neutral position, the oil supply circuit actively replenishes oil for the working oil pipe of the multi-way valve 13, so as to prevent the air from entering the pipeline due to the leakage of the pipeline when it is in the neutral position. Causing cavitation and system shock hazards.

When the hydraulic rotary motor 11 is controlled in an emergency stop, the oil replenishment reversing valve works in the neutral position. At this time, the neutral position of the rotary motor is the Y-shaped position, and the rotary motor is in a floating state, which serves the purpose of motor buffering and oil replenishment. , to avoid the problem of emptying of the oil inlet and impact of the oil return port when the rotary motor is stopped in an emergency.

During the operation of the hydraulic swing motor 11, the oil replenishment reversing valve 12 controls the oil replenishment circuit to be always connected to the oil return port of the hydraulic swing motor 11, and the back pressure of the oil return of the hydraulic swing motor 11 is used to charge the accumulator 8. achieve the purpose of energy saving.

The pressure of the accumulator 8 controls the engagement and disengagement of the clutch 2. When the pressure of the accumulator 8 is sufficient, the charge pump 15 is automatically separated from the power source 1. When the pressure of the accumulator 8 is insufficient, the clutch 2 is engaged, and the charge pump 15 Actively charge the accumulator 8 . The safety valve 14 functions to protect the system. Through hydraulic logic control, the automatic engagement and disengagement of the charge pump is realized without the need for a complex electronic control system. The oil replenishment system is not only simple in composition and cost saving, but also improves the service life of the oil replenishment system while saving energy.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention pertains can make various modifications or additions to the described specific embodiments or substitute in similar manners, but will not deviate from the spirit of the present invention or go beyond the definitions of the appended claims range.

Claims (7)

1. The utility model provides a two accuse motor drive revolution system of electricity liquid buffering oil supplementing device which characterized in that includes:

the direction control port A and the direction control port B of the oil supplementing reversing valve (12) are respectively connected with the direction control port A and the direction control port B of the hydraulic rotary motor (11) and the direction control port A and the direction control port B of the multi-way valve, the oil return port T of the oil supplementing reversing valve is connected with the oil inlet B of the one-way valve (10), and the hydraulic control end of the oil supplementing reversing valve is connected with the hydraulic control end of the multi-way valve for controlling the hydraulic rotary motor (11) in parallel;

the oil supplementing loop comprises an energy accumulator (8), wherein the energy accumulator (8) is connected with an oil return port T of the oil supplementing reversing valve (12) through a pressure reducing valve (9), and the oil return port T of the oil supplementing reversing valve (12) is connected with the energy accumulator (8) through a one-way valve (10).

2. The buffering oil supplementing device of the electric-hydraulic double-control motor-driven rotary system according to claim 1, wherein when the oil supplementing reversing valve (12) works in a neutral position, a direction control port A and a direction control port B of the hydraulic rotary motor (11) are communicated with an oil supplementing loop; when the oil supplementing reversing valve (12) works at the left position, a low-pressure port of the hydraulic rotary motor (11) is communicated with an oil supplementing loop.

3. The buffering oil supplementing device of the electrohydraulic double control motor-driven rotation system according to claim 1, wherein the oil supplementing loop further comprises an oil supplementing pump (15) connected with the energy accumulator (8) through a one-way valve (6), and the oil supplementing pump (15) is used for supplementing oil to the energy accumulator (8) when the pressure of the energy accumulator (8) is insufficient.

4. The buffering oil supplementing device for the electro-hydraulic double-control motor-driven rotation system according to claim 3, wherein the oil supplementing loop further comprises:

a power source (1) connected to an oil replenishment pump (15) via a clutch (2);

and the spring return oil cylinder (3) is connected with the energy accumulator (8), and when the pressure of the energy accumulator (8) is smaller than the spring pressure of the spring return oil cylinder (3), the spring return oil cylinder (3) automatically extends to enable the clutch (2) to be connected.

5. The buffering oil supplementing device for the electro-hydraulic double-control motor-driven rotation system according to claim 4, wherein the oil supplementing loop further comprises:

the two-position two-way reversing valve (4) is arranged between an oil port of the energy accumulator (8) and the spring reset oil cylinder (3), and when the two-position two-way reversing valve (4) is in a normal position, an oil way between the energy accumulator (8) and the spring reset oil cylinder (3) is disconnected;

and the controller (5) controls the reversing valve of the two-position two-way valve (4) to reverse according to the pressure of the energy accumulator obtained by a pressure sensor (7) arranged on the oil path of the energy accumulator (8) and the oil path of the two-position two-way reversing valve (4).

6. A buffering oil supplementing method for an electro-hydraulic double-control motor driving rotation system is characterized by comprising the following steps:

an oil supplementing reversing valve (12) is connected into a hydraulic rotary motor loop, and an energy accumulator (8) is used for providing an oil source for the oil supplementing reversing valve (12) through a pressure reducing valve (9);

the oil supplementing reversing valve (12) is a three-position three-way hydraulic control reversing valve, and the middle position is Y-shaped;

when a multi-way valve (13) for controlling the hydraulic rotary motor (8) is positioned at a middle position, the oil supplementing reversing valve (12) works at the middle position and automatically supplements oil for the hydraulic rotary motor pipeline;

in the action process of the hydraulic rotary motor (8), an oil inlet of the oil supplementing and supplementing reversing valve (12) is communicated with the low-pressure end of the hydraulic rotary motor (8), and the energy accumulator (8) is stamped by utilizing the oil returning back pressure of the hydraulic rotary motor (8).

7. The method for buffering and supplementing oil for the electro-hydraulic double-control motor-driven rotation system according to claim 1, comprising the following steps of:

a hydraulic control automatic oil replenishing pump (15) is arranged in the loop, and when the pressure of the energy accumulator (8) is lower than a set value, the clutch (2) is engaged to charge the energy accumulator (8).

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