A hydraulic device driven by internal gears

Abstract

The present invention discloses a hydraulic device driven by an internal gear, comprising a motor and a motor shaft arranged on the motor, wherein the motor shaft is in transmission connection with an internal gear assembly, and the motor drives the internal gear assembly to introduce the hydraulic oil in the oil tank into the gear cavity, and the hydraulic oil in the gear cavity is respectively delivered to the plunger pump and the hydraulic oil pump through the high-pressure oil circuit and the low-pressure oil circuit; an eccentric block assembly is also arranged on the motor shaft, and the motor controls the plunger pump to discharge oil to the hydraulic oil pump through the eccentric block assembly. The present invention can deliver hydraulic oil to the hydraulic oil pump while the internal gear assembly is working by arranging an eccentric wheel assembly and a plunger pump matched with the eccentric wheel assembly. At the same time, a reflux control assembly is also arranged on the oil circuits at the inlet and outlet ends of the plunger pump, and corresponding adaptive control can be achieved according to the no-load, load and unloading strokes of the lifting device.

Description

Technical Field

[0001] The invention relates to the field of hydraulic devices, and in particular to a hydraulic device driven by an internal meshing gear. Background Art

[0002] The working principle of the internal gear pump is that the active internal gear on the main shaft drives the external gear to rotate in the same direction. The gears separate from each other at the inlet to form a negative pressure to suck in the liquid, and the gears continuously engage and mesh at the outlet to squeeze the liquid out.

[0003] For example, the patent document with patent number 202110055855.4 discloses a multi-inlet internal gear pump, including a pump body, a gear ring and gears meshing in the pump body, and a crescent plate sandwiched between the gear and the gear ring, and an oil distribution plate is sandwiched between the gear ring on the side close to the oil outlet of the pump body and the inner side surface of the pump body, the inner side surface of the oil distribution plate is provided with a groove, and a first through hole connected to the oil outlet is provided at the bottom of the groove, and the gear ring and the inner side surface of the pump body are not in contact; a stepped piston is provided in the oil outlet, and the length of the inner section of the stepped piston is smaller than the length of the inner section of the oil outlet; a piston boss is extended into the first through hole at the inner end of the stepped piston, and an axial through hole is provided in the center of the piston boss and the stepped piston, and at least one first inclined hole connecting the bottom of the inner section of the stepped piston and the axial through hole is provided on the stepped piston.

[0004] When the above patented solution is working, the outer cylindrical surface of the gear ring will not contact the inner surface of the pump body, which eliminates the friction and wear between the two. At the same time, the gap between the two makes it possible to arrange three oil inlets in different directions on the pump body, thereby improving the applicability of the gear pump.

[0005] However, when the existing internal gear pump is used in lifting devices such as jacks, its oil circuit control structure is relatively simple and cannot achieve corresponding adaptive control according to the no-load, loaded and unloaded strokes of the lifting device.

[0006] Therefore, it is necessary for us to improve such a structure to overcome the above-mentioned defects. Summary of the invention

[0007] The object of the present invention is to provide a hydraulic device driven by an internal meshing gear to solve the problems existing in the prior art.

[0008] The above technical objectives of the present invention are achieved through the following technical solutions:

[0009] A hydraulic device driven by an internal gear comprises a motor and a motor shaft arranged on the motor, wherein the motor shaft is drivingly connected to the internal gear assembly, the motor drives the internal gear assembly to introduce the hydraulic oil in the oil tank into the gear cavity, and the hydraulic oil in the gear cavity is respectively transported to the plunger pump and the hydraulic oil pump through the high-pressure oil circuit and the low-pressure oil circuit; an eccentric block assembly is also arranged on the motor shaft, and the motor controls the plunger pump to discharge oil to the hydraulic oil pump through the eccentric block assembly.

[0010] Furthermore, a flow channel block is provided on the inner wall of the gear chamber, and a

[0011] An oil inlet, the gear chamber is connected to the oil tank through the oil inlet;

[0012] A high-pressure oil outlet, the gear chamber is connected to a high-pressure oil circuit through the high-pressure oil outlet, the high-pressure oil circuit is connected to the inlet end of the plunger pump, the outlet end of the plunger pump is connected to the hydraulic oil pump through the cylinder oil circuit, and a high-pressure one-way valve for controlling on and off is respectively provided at the inlet end and the outlet end of the plunger pump;

[0013] A low-pressure oil outlet, the gear chamber is connected to a low-pressure oil circuit through the low-pressure oil outlet, the low-pressure oil circuit is connected to a hydraulic oil pump through a cylinder oil circuit, and a low-pressure one-way valve for controlling on and off is provided at the connection between the low-pressure oil circuit and the cylinder oil circuit.

[0014] Furthermore, the internal gear assembly is arranged in the gear cavity and comprises

[0015] An external gear sleeve, the external gear sleeve is an annular structure, and an inner ring of the external gear sleeve is provided with an internal gear surface for transmission connection with the internal meshing gear;

[0016] The internal meshing gear is arranged inside the external gear sleeve, and is transmission-connected to the external gear sleeve through the external gear surface arranged on the outer ring. A transmission hole connected to the motor shaft is provided in the middle position of the internal meshing gear. The motor drives the external gear sleeve to rotate by driving the internal meshing gear.

[0017] Furthermore, the eccentric block assembly comprises

[0018] An eccentric block is sleeved on the motor shaft and is provided with a stepped limiting structure for mounting a bearing;

[0019] The bearing is eccentrically mounted on the eccentric block through a stepped limiting structure, and the bearing is used to push the plunger pump core of the plunger pump driven by the motor.

[0020] Furthermore, the plunger pump comprises

[0021] A plunger pump body, wherein the plunger pump body is arranged on the side of the eccentric block assembly, and an internal flow channel is provided in the plunger pump body, the inlet end of the internal flow channel is connected to the gear chamber through a high-pressure oil circuit, and the outlet end of the internal flow channel is connected to the hydraulic oil pump;

[0022] The plunger pump core has a main body arranged in the plunger pump body, an outer end of the plunger pump core extends out of the plunger pump body, and can transport the hydraulic oil in the internal flow channel to the hydraulic oil pump under the push of the bearing.

[0023] Furthermore, it also includes a reflux control component, which includes

[0024] A piston chamber, wherein the piston chamber is provided with a pressurized oil circuit connected to the high-pressure oil circuit, and the bottom of the piston chamber is respectively connected to the oil tank and the hydraulic oil pump;

[0025] A piston, wherein the piston is disposed in a piston cavity, a pressurized oil circuit is disposed in the piston cavity at the top of the piston, and the bottom of the piston is installed through a piston rod;

[0026] A piston rod, one end of which is connected to the piston, and the other end of which extends into a return oil path connecting the oil tank and the hydraulic oil pump;

[0027] A return spring, two ends of which are respectively connected to the bottom of the piston and the bottom of the piston chamber;

[0028] A reflux check valve is arranged in the reflux oil circuit and is used to control the on-off of the reflux oil circuit.

[0029] A control method for a hydraulic device driven by an internal gear comprises the following steps:

[0030] S1. When the motor is running, the motor shaft drives the internal gear assembly and the eccentric block assembly to rotate;

[0031] S2. As the outer gear sleeve and the inner gear of the internal gear assembly rotate, negative pressure is generated in the gear cavity, thereby introducing hydraulic oil in the oil tank connected to the gear cavity into the gear cavity through the oil inlet;

[0032] S3. The hydraulic oil entering the gear cavity will be discharged through the low-pressure oil outlet and the high-pressure oil outlet respectively under the rotation of the outer gear sleeve and the inner meshing gear. The low-pressure hydraulic oil discharged through the low-pressure oil outlet will open the low-pressure check valve of the low-pressure oil circuit, and then enter the hydraulic oil pump through the oil cylinder oil circuit to achieve rapid lifting of the hydraulic oil pump when it is unloaded; the hydraulic oil discharged through the high-pressure oil outlet will open the high-pressure check valve at the inlet end of the plunger pump, and then enter the plunger pump;

[0033] S4. After the hydraulic oil enters the internal flow channel of the plunger pump body 61, the bearing 42 eccentrically installed on the motor shaft 2 through the eccentric block 41 will periodically push the plunger pump core 62 of the plunger pump 6 under the drive of the motor 1. The hydraulic oil in the plunger pump 6 will generate high pressure under the action of the plunger pump core 62 to open the high-pressure one-way valve 101 at the outlet end of the plunger pump 6 and enter the cylinder oil circuit 12. Under the action of the high-pressure hydraulic oil, the low-pressure one-way valve 111 will be closed. At the same time, the high-pressure hydraulic oil will also open the control valve 114 through the second return line 113 to conduct the first return line 112; the hydraulic oil in the low-pressure oil circuit 11 stops entering the cylinder oil circuit 12, and returns to the oil tank 5 through the first return line 112. The hydraulic oil that subsequently enters the hydraulic oil pump 7 is the high-pressure hydraulic oil supplied by the plunger pump 6, so as to realize the load lifting of the hydraulic oil pump 7;

[0034] S5. During the above process, part of the high-pressure hydraulic oil discharged through the high-pressure oil outlet will enter the top of the piston chamber through the pressurized oil circuit, and push the piston and the piston rod downward to press against the return check valve, thereby closing the return oil circuit connecting the oil tank and the hydraulic oil pump;

[0035] S6. After the hydraulic oil pump finishes working, it starts to unload, the motor stops running, the hydraulic oil in the gear chamber is no longer output through the high-pressure oil circuit and the low-pressure oil circuit, the pressure on the top of the piston disappears, and the piston and piston rod will move upward under the action of the return spring to leave the return check valve, and the hydraulic oil in the hydraulic oil pump will flow back to the cylinder oil circuit. Under the action of the returning hydraulic oil, the low-pressure check valve and the high-pressure check valve at the outlet end of the plunger pump will be closed, and the return check valve will be opened, thereby connecting the cylinder oil circuit and the return oil circuit, and finally the hydraulic oil in the hydraulic oil pump flows back to the oil tank.

[0036] In summary, the present invention has the following beneficial effects:

[0037] By providing an eccentric wheel assembly and a plunger pump matched with the eccentric wheel assembly, hydraulic oil can be delivered to the hydraulic oil pump while the internal gear assembly is working. At the same time, a reflux control assembly is also provided on the oil circuits at the inlet and outlet ends of the plunger pump, which can realize corresponding adaptive control according to the no-load, load and unloading strokes of the lifting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of a hydraulic device driven by an internal meshing gear according to the present invention.

[0039] Figure 2 Schematic diagram of the flow channel block of the present invention.

[0040] Figure 3 It is a schematic diagram of the external gear sleeve and the internal meshing gear described in the present invention.

[0041] Figure 4It is a schematic diagram of the oil inlet state of the eccentric wheel assembly and the plunger pump described in the present invention.

[0042] Figure 5 It is a schematic diagram of the oil discharge state of the eccentric wheel assembly and the plunger pump described in the present invention.

[0043] Figure 6 It is a schematic diagram of the oil inlet end of the plunger pump and the reflux control assembly described in the present invention.

[0044] Figure 7 It is a schematic diagram of the oil outlet end of the plunger pump and the reflux control assembly described in the present invention.

[0045] Figure 8 It is a schematic diagram of the reflux state of the hydraulic oil pump described in the present invention.

[0046] Fig. 9 It is a principle diagram of a hydraulic device driven by an internal meshing gear according to the present invention. DETAILED DESCRIPTION

[0047] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with illustrations and specific embodiments.

[0048] like Figures 1 to 9 As shown, the present invention proposes a hydraulic device driven by an internal gear, including a motor 1 and a motor shaft 2 arranged on the motor 1, wherein the motor shaft 2 is transmission-connected with the internal gear assembly 3, and the motor 1 drives the internal gear assembly 3 to introduce the hydraulic oil in the oil tank 5 into the gear cavity, and the hydraulic oil in the gear cavity is respectively transported to the plunger pump 6 and the hydraulic oil pump 7 through the high-pressure oil circuit 10 and the low-pressure oil circuit 11; an eccentric block assembly 4 is also provided on the motor shaft 2, and the motor 1 controls the plunger pump 6 to discharge oil to the hydraulic oil pump 7 through the eccentric block assembly 4.

[0049] A flow channel block 31 is provided on the inner wall of the gear chamber, and a

[0050] An oil inlet 311, through which the gear chamber is connected to the oil tank 5;

[0051] A high-pressure oil outlet 312, the gear chamber is connected to the high-pressure oil circuit 10 through the high-pressure oil outlet 312, the high-pressure oil circuit 10 is connected to the inlet end of the plunger pump 6, the outlet end of the plunger pump 6 is connected to the hydraulic oil pump 7 through the cylinder oil circuit 12, and a high-pressure one-way valve 101 for controlling on and off is respectively provided at the inlet end and the outlet end of the plunger pump 6;

[0052] The gear chamber is connected to the low-pressure oil circuit 11 through the low-pressure oil outlet 313, and the low-pressure oil circuit 11 is connected to the hydraulic oil pump 7 through the cylinder oil circuit 12. A low-pressure one-way valve 111 for controlling the on-off is provided at the connection between the low-pressure oil circuit 11 and the cylinder oil circuit 12.

[0053] The internal gear assembly 3 is arranged in the gear cavity and includes

[0054] The outer gear sleeve 32 is an annular structure, and an inner ring of the outer gear sleeve 32 is provided with an inner gear surface for transmission connection with the inner meshing gear 33;

[0055] The internal gear 33 is arranged inside the external gear sleeve 32, and is connected to the external gear sleeve 32 through the external gear surface arranged on the outer ring. A transmission hole 331 connected to the motor shaft 2 is provided in the middle position of the internal gear 33. The motor 1 drives the external gear sleeve 32 to rotate by driving the internal gear 33.

[0056] The eccentric mass assembly 4 comprises

[0057] An eccentric block 41, wherein the eccentric block 41 is sleeved on the motor shaft 2, and a stepped limiting structure for mounting a bearing 42 is provided on the eccentric block 41;

[0058] The bearing 42 is eccentrically mounted on the eccentric block 41 through a stepped limiting structure. The bearing 42 is used to push the plunger pump core 62 of the plunger pump 6 driven by the motor 1 .

[0059] The plunger pump 6 comprises

[0060] A plunger pump body 61, wherein the plunger pump body 6 is arranged on the side of the eccentric block assembly 4, and an internal flow channel is provided in the plunger pump body 61, the inlet end of the internal flow channel is connected to the gear chamber through the high-pressure oil circuit 10, and the outlet end of the internal flow channel is connected to the hydraulic oil pump 7;

[0061] The plunger pump core 62 has a main body disposed in the plunger pump body 61 , an outer end of the plunger pump core 62 extends out of the plunger pump body 61 , and can deliver the hydraulic oil in the internal flow channel to the hydraulic oil pump 7 under the push of the bearing 42 .

[0062] The backflow control component 8 includes

[0063] A piston chamber 81, wherein the piston chamber 81 is provided with a pressurized oil circuit 811 communicating with the high-pressure oil circuit 10, and the bottom of the piston chamber 81 is communicated with the oil tank 5 and the hydraulic oil pump 7 respectively;

[0064] A piston 82, wherein the piston 82 is disposed in a piston cavity 81, a pressurized oil circuit 811 is disposed in the piston cavity 81 at the top of the piston 82, and a bottom of the piston 82 is installed through a piston rod 83;

[0065] A piston rod 83, one end of which is connected to the piston 82, and the other end of which extends into a return oil path 9 connecting the oil tank 5 and the hydraulic oil pump 7;

[0066] A return spring 84, two ends of which are respectively connected to the bottom of the piston 82 and the bottom of the piston chamber 81;

[0067] The reflux check valve 85 is arranged in the reflux oil circuit 9 and is used to control the on-off of the reflux oil circuit 9 .

[0068] A control method for a hydraulic device driven by an internal gear comprises the following steps:

[0069] S1. When the motor 1 is running, the motor shaft 2 drives the internal gear assembly 3 and the eccentric block assembly 4 to rotate;

[0070] S2. As the outer gear sleeve 32 and the inner gear 33 of the internal gear assembly 3 rotate, negative pressure is generated in the gear chamber, thereby introducing the hydraulic oil in the oil tank 5 connected to the gear chamber into the gear chamber through the oil inlet 311;

[0071] S3. The hydraulic oil entering the gear cavity will be discharged through the low-pressure oil outlet 313 and the high-pressure oil outlet 312 respectively under the rotation of the outer gear sleeve 32 and the inner meshing gear 33. The low-pressure hydraulic oil discharged through the low-pressure oil outlet 313 will open the low-pressure check valve 111 of the low-pressure oil circuit 11, thereby entering the hydraulic oil pump 7 through the cylinder oil circuit 12, and realizing the rapid lifting of the hydraulic oil pump 7 when it is unloaded; the hydraulic oil discharged through the high-pressure oil outlet 312 will open the high-pressure check valve 101 at the inlet end of the plunger pump 6, thereby entering the plunger pump 6;

[0072] S4. After the hydraulic oil enters the internal flow channel of the plunger pump body 61, the bearing 42 eccentrically installed on the motor shaft 2 through the eccentric block 41 will periodically push the plunger pump core 62 of the plunger pump 6 under the drive of the motor 1. The hydraulic oil in the plunger pump 6 will generate high pressure under the action of the plunger pump core 62 to open the high-pressure one-way valve 101 at the outlet end of the plunger pump 6 and enter the cylinder oil circuit 12. Under the action of the high-pressure hydraulic oil, the low-pressure one-way valve 111 will be closed. At the same time, the high-pressure hydraulic oil will also open the control valve 114 through the second return line 113 to conduct the first return line 112; the hydraulic oil in the low-pressure oil circuit 11 stops entering the cylinder oil circuit 12, and returns to the oil tank 5 through the first return line 112. The hydraulic oil that subsequently enters the hydraulic oil pump 7 is the high-pressure hydraulic oil supplied by the plunger pump 6, so as to realize the load lifting of the hydraulic oil pump 7;

[0073] S5. In the above process, part of the high-pressure hydraulic oil discharged through the high-pressure oil outlet 312 will enter the top of the piston chamber 81 through the pressurized oil circuit 811, and push the piston 82 and the piston rod 83 to move downward against the return check valve 85, thereby closing the return oil circuit 9 connecting the oil tank 5 and the hydraulic oil pump 7;

[0074] S6. After the hydraulic oil pump 7 finishes working, it starts to unload, the motor 1 stops running, the hydraulic oil in the gear chamber is no longer output through the high-pressure oil circuit 10 and the low-pressure oil circuit 11, the pressure on the top of the piston 82 disappears, and the piston 82 and the piston rod 83 will move upward under the action of the return spring 84 to leave the return check valve 85, and the hydraulic oil in the hydraulic oil pump 7 will flow back to the cylinder oil circuit 12. Under the action of the returning hydraulic oil, the low-pressure check valve 111 and the high-pressure check valve 101 at the outlet end of the plunger pump 6 will be closed, and the return check valve 85 will be opened, thereby connecting the cylinder oil circuit 12 and the return oil circuit 9, and finally the hydraulic oil in the hydraulic oil pump 7 flows back to the oil tank 5.

[0075] In this document, the directions or positional relationships indicated by terms such as "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "vertical", and "horizontal" are based on the directions or positional relationships shown in the accompanying drawings and are only for the clarity of expressing the technical solutions and the convenience of description, and therefore should not be understood as limitations of the present invention.

[0076] In this document, the terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of elements other than those listed and may also include additional elements not expressly listed.

[0077] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A hydraulic device driven by an internal gear, comprising a motor (1) and a motor shaft (2) arranged on the motor (1), characterized in that: The motor shaft (2) is transmission-connected to the internal meshing gear assembly (3); the motor (1) drives the internal meshing gear assembly (3) to guide the hydraulic oil in the oil tank (5) into the gear chamber; the hydraulic oil in the gear chamber is respectively transported to the plunger pump (6) and the hydraulic oil pump (7) through the high-pressure oil circuit (10) and the low-pressure oil circuit (11); an eccentric block assembly (4) is also provided on the motor shaft (2); the motor (1) controls the plunger pump (6) to discharge oil to the hydraulic oil pump (7) through the eccentric block assembly (4).

2. The hydraulic device driven by an internal gear according to claim 1, characterized in that: A flow channel block (31) is provided on the inner wall of the gear chamber, and a An oil inlet (311), wherein the gear chamber is connected to the oil tank (5) via the oil inlet (311); A high-pressure oil outlet (312), wherein the gear chamber is connected to a high-pressure oil circuit (10) via the high-pressure oil outlet (312), the high-pressure oil circuit (10) is connected to an inlet end of a plunger pump (6), the outlet end of the plunger pump (6) is connected to a hydraulic oil pump (7) via an oil cylinder oil circuit (12), and a high-pressure one-way valve (101) for controlling on and off is provided at the inlet end and the outlet end of the plunger pump (6); A low-pressure oil outlet (313), the gear chamber is connected to a low-pressure oil circuit (11) via the low-pressure oil outlet (313), the low-pressure oil circuit (11) is connected to a hydraulic oil pump (7) via a cylinder oil circuit (12), and a low-pressure one-way valve (111) for controlling on-off is provided at the connection between the low-pressure oil circuit (11) and the cylinder oil circuit (12).

3. The hydraulic device driven by an internal gear according to claim 1, characterized in that: The internal meshing gear assembly (3) is arranged in the gear cavity and comprises An external gear sleeve (32), the external gear sleeve (32) being an annular structure, and an inner ring of the external gear sleeve (32) being provided with an internal gear surface for transmission connection with an internal meshing gear (33); An internal meshing gear (33) is arranged inside the external gear sleeve (32) and is transmission-connected to the external gear sleeve (32) via an external gear surface arranged on the outer ring. A transmission hole (331) connected to the motor shaft (2) is provided at a middle position of the internal meshing gear (33). The motor (1) drives the external gear sleeve (32) to rotate by driving the internal meshing gear (33).

4. The hydraulic device driven by an internal gear according to claim 1, characterized in that: The eccentric mass assembly (4) comprises An eccentric block (41), wherein the eccentric block (41) is sleeved on the motor shaft (2), and a stepped limiting structure for mounting a bearing (42) is provided on the eccentric block (41); A bearing (42) is eccentrically mounted on an eccentric block (41) via a stepped limiting structure, and the bearing (42) is used to push a plunger pump core (62) of a plunger pump (6) driven by a motor (1).

5. The hydraulic device driven by an internal gear according to claim 4, characterized in that: The plunger pump (6) comprises A plunger pump body (61), wherein the plunger pump body (6) is arranged on the side of the eccentric block assembly (4), and an internal flow channel is provided in the plunger pump body (61), the inlet end of the internal flow channel is connected to the gear chamber through the high-pressure oil circuit (10), and the outlet end of the internal flow channel is connected to the hydraulic oil pump (7); A plunger pump core (62), wherein the main body of the plunger pump core (62) is arranged in the plunger pump body (61), the outer end of the plunger pump core (62) extends out of the plunger pump body (61), and can transport the hydraulic oil in the internal flow channel to the hydraulic oil pump (7) under the push of the bearing (42).

6. The hydraulic device driven by an internal gear according to claim 5, characterized in that: It also includes a backflow control component (8), which includes A piston chamber (81), wherein the piston chamber (81) is provided with a pressurized oil circuit (811) connected to the high-pressure oil circuit (10), and the bottom of the piston chamber (81) is respectively connected to the oil tank (5) and the hydraulic oil pump (7); A piston (82), wherein the piston (82) is disposed in a piston chamber (81), a pressurized oil circuit (811) is disposed in the piston chamber (81) at the top of the piston (82), and the bottom of the piston (82) is installed via a piston rod (83); A piston rod (83), one end of the piston rod (83) is connected to the piston (82), and the other end of the piston rod (83) extends into a return oil path (9) connecting the oil tank (5) and the hydraulic oil pump (7); A return spring (84), wherein two ends of the return spring (84) are respectively connected to the bottom of the piston (82) and the bottom of the piston chamber (81); A return check valve (85), wherein the return check valve (85) is arranged in the return oil circuit (9) and is used to control the opening and closing of the return oil circuit (9).

7. A control method for a hydraulic device driven by an internal gear, characterized in that: The steps include: S1. When the motor (1) is running, the motor shaft (2) drives the internal meshing gear assembly (3) and the eccentric block assembly (4) to rotate; S2. As the outer gear sleeve (32) and the inner gear (33) of the inner gear assembly (3) rotate, negative pressure is generated in the gear chamber, thereby introducing hydraulic oil in the oil tank (5) connected to the gear chamber into the gear chamber through the oil inlet (311); S3. The hydraulic oil entering the gear chamber will be discharged through the low-pressure oil outlet (313) and the high-pressure oil outlet (312) respectively under the rotation of the outer gear sleeve (32) and the inner meshing gear (33). The low-pressure hydraulic oil discharged through the low-pressure oil outlet (313) will open the low-pressure check valve (111) of the low-pressure oil circuit (11), thereby entering the hydraulic oil pump (7) through the cylinder oil circuit (12), thereby realizing the rapid lifting of the hydraulic oil pump (7) when it is unloaded; the hydraulic oil discharged through the high-pressure oil outlet (312) will open the high-pressure check valve (101) at the inlet end of the plunger pump (6), thereby entering the plunger pump (6); S4. After the hydraulic oil enters the internal flow channel of the plunger pump body (61), the bearing (42) eccentrically mounted on the motor shaft (2) through the eccentric block (41) will periodically push the plunger pump core (62) of the plunger pump (6) under the drive of the motor (1). The hydraulic oil in the plunger pump (6) will generate high pressure under the action of the plunger pump core (62), open the high-pressure check valve (101) at the outlet end of the plunger pump (6), and enter the cylinder oil circuit (12). Under the action of the high-pressure hydraulic oil, The low-pressure one-way valve (111) will be closed, and at the same time, the high-pressure hydraulic oil will open the control valve (114) through the second return line (113) to conduct the first return line (112); the hydraulic oil in the low-pressure oil circuit (11) stops entering the oil cylinder oil circuit (12) and returns to the oil tank (5) through the first return line (112), and the hydraulic oil that subsequently enters the hydraulic oil pump (7) is the high-pressure hydraulic oil supplied by the plunger pump (6), thereby realizing load lifting of the hydraulic oil pump (7); S5. In the above process, part of the high-pressure hydraulic oil discharged through the high-pressure oil outlet (312) enters the top of the piston chamber (81) through the pressurized oil circuit (811), and pushes the piston (82) and the piston rod (83) to move downward against the return check valve (85), thereby closing the return oil circuit (9) connecting the oil tank (5) and the hydraulic oil pump (7); S6. After the hydraulic oil pump (7) has finished its work, it starts to unload, the motor (1) stops running, the hydraulic oil in the gear chamber is no longer output through the high-pressure oil circuit (10) and the low-pressure oil circuit (11), the pressure on the top of the piston (82) disappears, the piston (82) and the piston rod (83) move upward and leave the return check valve (85) under the action of the return spring (84), and the hydraulic oil in the hydraulic oil pump (7) will flow back to the cylinder oil circuit (12). Under the action of the returned hydraulic oil, the low-pressure check valve (111) and the high-pressure check valve (101) at the outlet end of the plunger pump (6) will be closed, and the return check valve (85) will be opened, thereby connecting the cylinder oil circuit (12) and the return oil circuit (9), and finally the hydraulic oil in the hydraulic oil pump (7) flows back to the oil tank (5).

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