Hydraulic driving system and engineering machinery

Abstract

The invention relates to the technical field of engineering machinery, and discloses a hydraulic driving system and engineering machine.The hydraulic driving system is characterized in that a first valve body communicates with a first variable pumping assembly through a first main pipeline, and the first valve body communicates with a supporting leg oil supply pipeline and an auxiliary steering oil supply pipeline; at the first working position, the first valve body communicates with the first main pipeline and the supporting leg oil supply pipeline, and at the second working position, the first valve body communicates with the first main pipeline and the auxiliary steering oil supply pipeline; one end of the first control assembly communicates with the first main pipeline, the other end of the first control assembly communicates with a loading oil supply pipeline, and the first variable pumping assembly selectively communicates with the first valve body or the loading oil supply pipeline through the first control assembly. The lower vehicle and the upper vehicle share the first variable pumping assembly, so that the arrangement of one set of pumping assembly is reduced, the overall structure of the hydraulic driving system is simplified, the system cost is effectively controlled, the occupied space on the vehicle body is reduced, and the space utilization rate of engineering machinery is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering machinery, and in particular to a hydraulic drive system and engineering machinery. Background Art

[0002] The hydraulic drive system of construction machinery, such as cranes, is mainly divided into two parts, namely the hydraulic drive of the upper vehicle actuator and the hydraulic drive of the lower vehicle. These two parts work completely independently during the entire crane operation process, that is, during the entire operation process, it is not allowed to operate the lower vehicle while operating the upper vehicle actuator. In the prior art, the upper vehicle's luffing mechanism, telescopic mechanism, etc. are driven by independent oil pumps, and the lower vehicle's outrigger mechanism, steering mechanism, etc. are also driven by independent oil pumps. Therefore, the hydraulic drive system has a complex structure, high cost, and occupies a large space. Summary of the invention

[0003] In view of this, the present invention provides a hydraulic drive system and engineering machinery to solve the problems of the hydraulic drive system in the prior art being complex in structure, high in cost, and occupying a large space.

[0004] In a first aspect, the present invention provides a hydraulic drive system, comprising: a first variable pumping component; a first valve body, connected to the first variable pumping component through a first main pipeline, the first valve body being connected to an outrigger oil supply pipeline and an auxiliary steering oil supply pipeline, the first valve body having a first working position and a second working position, in the first working position, the first valve body is connected to the first main pipeline and the outrigger oil supply pipeline, and in the second working position, the first valve body is connected to the first main pipeline and the auxiliary steering oil supply pipeline; a first control component, one end of the first control component is connected to the first main pipeline, the other end of the first control component is connected to the vehicle oil supply pipeline, and the first variable pumping component can be selectively connected to the first valve body or the vehicle oil supply pipeline through the first control component.

[0005] In an optional embodiment, the first control component includes a second valve body and a third valve body, the second valve body is divided into a first oil delivery chamber and a first control oil chamber by a valve core, the first main oil inlet and the first main oil outlet of the second valve body are both connected to the first oil delivery chamber, the first main oil inlet is connected to the first main pipeline, and the first main oil outlet is connected to the on-vehicle oil supply pipeline; the first control component also includes a first control pipeline, and the two ends of the first control pipeline are respectively connected to the first main pipeline and the first control oil chamber, and the third valve body is arranged in the first control pipeline to control the connection and disconnection of the first main pipeline and the first control oil chamber and adjust the position of the valve core to control the connection and disconnection of the first main oil inlet and the first main oil outlet.

[0006] In an optional embodiment, the first variable pumping assembly includes a first variable pump, a first feedback pipeline and a first one-way valve body, the inlet of the first feedback pipeline is connected to the outrigger oil supply pipeline, the auxiliary steering oil supply pipeline and the on-vehicle oil supply pipeline, the outlet of the first feedback pipeline is connected to the first feedback port of the first variable pump, and the first one-way valve body is arranged on the first feedback pipeline.

[0007] In an optional embodiment, the first main pipeline is connected to a first filter element.

[0008] In an optional embodiment, the hydraulic drive system also includes: a second variable pumping component; a fourth valve body, which is connected to the second variable pumping component through a second main pipeline, the fourth valve body is connected to a main steering oil supply pipeline, and the fourth valve body controls the connection and disconnection of the second main pipeline and the main steering oil supply pipeline; a second control component, one end of the second control component is connected to the second main pipeline, and the other end of the second control component is connected to the on-vehicle oil supply pipeline, and the second variable pumping component can be selectively connected to the fourth valve body or the on-vehicle oil supply pipeline through the second control component.

[0009] In an optional embodiment, the second control component includes a fifth valve body and a sixth valve body, the fifth valve body is divided into a second oil delivery chamber and a second control oil chamber by a valve core, the second main oil inlet and the second main oil outlet of the fifth valve body are both connected to the second oil delivery chamber, the second main oil inlet is connected to the second main pipeline, and the second main oil outlet is connected to the on-vehicle oil supply pipeline; the second control component also includes a second control pipeline, the two ends of the second control pipeline are respectively connected to the second main pipeline and the second control oil chamber, the sixth valve body is arranged in the second control pipeline to control the connection and disconnection of the second main pipeline and the second control oil chamber and adjust the position of the valve core to control the connection and disconnection of the second main oil inlet and the second main oil outlet.

[0010] In an optional embodiment, the second variable pumping assembly includes a second variable pump, a second feedback pipeline and a second one-way valve body, the inlet of the second feedback pipeline is connected to the main steering oil supply pipeline and the on-vehicle oil supply pipeline, the outlet of the second feedback pipeline is connected to the second feedback port of the second variable pump, and the second one-way valve body is arranged on the second feedback pipeline.

[0011] In an optional embodiment, the second main pipeline is connected to a second filter element.

[0012] In an optional embodiment, the hydraulic drive system further includes a quantitative pumping component.

[0013] In a second aspect, the present invention further provides an engineering machine, comprising the above-mentioned hydraulic drive system.

[0014] The technical solution of this application has the following advantages:

[0015] The first variable pumping component is shared by getting off the vehicle and getting on the vehicle, thereby reducing the setting of a set of pumping components, simplifying the overall structure of the hydraulic drive system, effectively controlling the system cost, reducing the space occupied on the vehicle body, and improving the space utilization rate of the construction machinery; and, through the first control component, oil can be selectively supplied to getting on or getting off the vehicle, so that getting on or getting off the vehicle can be operated independently, thereby ensuring driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the connection structure of a hydraulic drive system according to an embodiment of the present invention;

[0018] Figure 2 for Figure 1 A partial enlarged schematic diagram of a portion of the hydraulic drive system shown;

[0019] Figure 3 for Figure 1 A partially enlarged schematic diagram of another part of the hydraulic drive system is shown.

[0020] Description of reference numerals:

[0021] 1. First variable pumping assembly; 101. First variable pump; 102. First feedback pipeline; 103. First non-return valve body; 104. Overflow valve; 2. First valve body; 3. First main pipeline; 4. Outrigger oil supply pipeline; 5. Auxiliary steering oil supply pipeline; 6. First control assembly; 601. Second valve body; 6011. First main oil inlet; 6012. First main oil outlet; 602. Third valve body; 603. First control pipeline; 7. Onboard oil supply pipeline; 8. First filter element; 9. Second variable pumping assembly; 901. Second variable pump; 902. Second feedback pipeline; 903. Second one-way valve body; 10. Fourth valve body; 11. Second main pipeline; 12. Main steering oil supply pipeline; 13. Second control assembly; 1301. Fifth valve body; 13011. Second main oil inlet; 13012. Second main oil outlet; 1302. Sixth valve body; 1303. Second control pipeline; 14. Second filter element; 15. Dosed pumping assembly; 16. Damping element. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0023] Combine the following Figures 1 to 3 , describing an embodiment of the present invention.

[0024] According to an embodiment of the present invention, on the one hand, a hydraulic drive system is provided, including: a first variable pumping component 1; a first valve body 2, which is connected to the first variable pumping component 1 through a first main pipeline 3, the first valve body 2 is connected to an outrigger oil supply pipeline 4 and an auxiliary steering oil supply pipeline 5, the first valve body 2 has a first working position and a second working position, in the first working position, the first valve body 2 is connected to the first main pipeline 3 and the outrigger oil supply pipeline 4, in the second working position, the first valve body 2 is connected to the first main pipeline 3 and the auxiliary steering oil supply pipeline 5; a first control component 6, one end of the first control component 6 is connected to the first main pipeline 3, and the other end of the first control component 6 is connected to the vehicle oil supply pipeline 7, the first variable pumping component 1 can be selectively connected to the first valve body 2 or the vehicle oil supply pipeline 7 through the first control component 6.

[0025] By applying the hydraulic drive system of this embodiment, the first variable pumping component 1 is shared by both getting off the vehicle and getting on the vehicle, thereby reducing the number of pumping components, simplifying the overall structure of the hydraulic drive system, effectively controlling the system cost, reducing the space occupied on the vehicle body, and improving the space utilization rate of the construction machinery; and, through the first control component 6, oil can be selectively supplied to getting on or off the vehicle, so that getting on or off the vehicle can be operated independently, thereby ensuring driving safety.

[0026] It is worth noting that when the first control assembly 6 is in the closed state, the first variable pumping assembly 1 is connected to the first valve body 2 through the first main pipeline 3. At this time, when the first valve body 2 is in the first working position, the first main pipeline 3 is connected to the outrigger oil supply pipeline 4, thereby providing power for the outrigger suspension action. When the first valve body 2 is in the second working position, the first main pipeline 3 is connected to the auxiliary steering oil supply pipeline 5, thereby providing power for the auxiliary steering action. When the first control assembly 6 is in the open state, the first variable pumping assembly 1 is connected to the upper vehicle oil supply pipeline 7 through the first control assembly 6, thereby providing power for the action of the upper vehicle's variable amplitude mechanism, telescopic mechanism, etc.

[0027] In one embodiment, Figure 2 As shown, the first control assembly 6 includes a second valve body 601 and a third valve body 602. The second valve body 601 is separated by a valve core to form a first oil delivery chamber and a first control oil chamber. The first main oil inlet 6011 and the first main oil outlet 6012 of the second valve body 601 are both connected to the first oil delivery chamber. The first main oil inlet 6011 is connected to the first main pipeline 3, and the first main oil outlet 6012 is connected to the vehicle oil supply pipeline 7. Figure 2 As shown, the first control component 6 also includes a first control pipeline 603, both ends of which are connected to the first main pipeline 3 and the first control oil chamber respectively, and the third valve body 602 is arranged on the first control pipeline 603 to control the connection and disconnection between the first main pipeline 3 and the first control oil chamber and adjust the position of the valve core to control the connection and disconnection of the first main oil inlet 6011 and the first main oil outlet 6012.

[0028] Specifically, when it is necessary to supply oil to the vehicle below, that is, the first control component 6 is in a closed state, at this time, the first control pipeline 603 connects the first main pipeline 3 and the first control oil chamber through the third valve body 602, so that the two end surfaces of the valve core of the second valve body 601 are subjected to pressure, so that the valve core of the second valve body 601 blocks the first main oil inlet 6011 and the first main oil outlet 6012, that is, the second valve body 601 is closed, and the first main pipeline 3 cannot supply oil to the oil supply pipeline 7 of the vehicle above. When it is necessary to supply oil to the vehicle, that is, the first control component 6 is in the open state, at this time, the third valve body 602 blocks the first control pipeline 603 to relieve the pressure in the first control oil chamber, and the valve core of the second valve body 601 is subjected to the pressure applied by one side of the first oil delivery chamber, so that the valve core of the second valve body 601 moves away to connect the first main oil inlet 6011 and the first main oil outlet 6012, that is, the second valve body 601 is opened, and at the same time, the first valve body 2 is in the closed position, and the first main pipeline 3 cannot supply oil to the outrigger oil supply pipeline 4 and the auxiliary steering oil supply pipeline 5.

[0029] In this embodiment, if Figure 2 As shown, the first valve body 2 is a three-position four-way electromagnetic reversing valve, the second valve body 601 is a two-way cartridge valve or a two-way logic valve, and the third valve body 602 is a two-position four-way electromagnetic reversing valve.

[0030] Specifically, Figure 1 and Figure 2 As shown, when oil needs to be supplied to the outrigger oil supply pipeline 4, the first variable pumping component 1 outputs the hydraulic oil to point P1. At this time, DT1 of the third valve body 602 is not energized, so that the third valve body 602 works in the right position, so that the second valve body 601 is closed, and the hydraulic oil at point P1 cannot reach point B1. At the same time, DT3 of the first valve body 2 is energized, so that the first valve body 2 works in the right position (that is, the first working position), and the hydraulic oil at point P1 can be delivered to point A2.

[0031] Specifically, Figure 1 and Figure 2 As shown, when it is necessary to supply oil to the auxiliary steering oil supply pipeline 5, the first variable pumping component 1 outputs the hydraulic oil to point P1. At this time, DT1 of the third valve body 602 is not energized, so that the third valve body 602 works in the right position, so that the second valve body 601 is closed, and the hydraulic oil at point P1 cannot reach point B1. At the same time, DT2 of the first valve body 2 is energized, so that the first valve body 2 works in the left position (that is, the second working position), and the hydraulic oil at point P1 can be delivered to point B2.

[0032] Specifically, Figure 1 and Figure 2As shown, when it is necessary to supply oil to the upper vehicle oil supply pipeline 7, the first variable pumping component 1 outputs the hydraulic oil to point P1. At this time, DT1 of the third valve body 602 is energized, so that the third valve body 602 works in the left position, so that the second valve body 601 is opened, and the hydraulic oil at point P1 can be delivered to point B1. At the same time, the first valve body 2 is in the middle position, and the hydraulic oil at point P1 cannot reach points A2 and B2.

[0033] In one embodiment, Figure 1 and Figure 2 As shown, the first variable pumping assembly 1 includes a first variable pump 101, a first feedback pipeline 102 and a first non-return valve body 103. The inlet of the first feedback pipeline 102 is connected with the outrigger oil supply pipeline 4, the auxiliary steering oil supply pipeline 5 and the vehicle oil supply pipeline 7. The outlet of the first feedback pipeline 102 is connected with the first feedback port of the first variable pump 101. The first non-return valve body 103 is arranged on the first feedback pipeline 102. In this way, the higher pressure signals of getting off and getting on are led to the first variable pump 101, so that the first variable pump 101 can adaptively output the corresponding displacement of oil, thereby achieving the purpose of energy saving.

[0034] Specifically, the first variable pump 101 is a variable plunger pump, and the first one-way valve body 103 is a shuttle valve, and one or more shuttle valves may be provided. The variable plunger pump is a load-sensitive pump, and its variable displacement is to guide the high-pressure hydraulic oil through the LS1 point to the X1 point of the variable plunger pump through the shuttle valve, so as to realize the adaptive regulation of the variable plunger pump.

[0035] Further, such as Figure 1 and Figure 2 As shown, the first feedback line 102 is also connected to a relief valve 104 .

[0036] In one embodiment, Figure 1 and Figure 2 As shown, a damping element 16 is further provided on the auxiliary steering oil supply pipeline 5 and the first feedback pipeline 102 .

[0037] In one embodiment, Figure 1 As shown, the first main pipeline 3 is connected with a first filter element 8. Specifically, the first filter element 8 is a high-pressure filter.

[0038] In one embodiment, Figure 1 and Figure 3As shown, the hydraulic drive system also includes: a second variable pumping component 9; a fourth valve body 10, which is connected to the second variable pumping component 9 through a second main pipeline 11, and the fourth valve body 10 is connected to a main steering oil supply pipeline 12, and the fourth valve body 10 controls the connection and disconnection of the second main pipeline 11 and the main steering oil supply pipeline 12; a second control component 13, one end of the second control component 13 is connected to the second main pipeline 11, and the other end of the second control component 13 is connected to the vehicle oil supply pipeline 7, and the second variable pumping component 9 can be selectively connected to the fourth valve body 10 or the vehicle oil supply pipeline 7 through the second control component 13.

[0039] It is worth noting that when the second control assembly 13 is in the closed state, the second variable pumping assembly 9 is connected to the fourth valve body 10 through the second main pipeline 11. At this time, when the fourth valve body 10 is in the working position, the second main pipeline 11 is connected to the main steering oil supply pipeline 12, thereby providing power for the main steering action. When the second control assembly 13 is in the open state, the second variable pumping assembly 9 is connected to the upper vehicle oil supply pipeline 7 through the second control assembly 13, thereby providing power for the action of the upper vehicle's luffing mechanism, telescopic mechanism, etc.

[0040] In one embodiment, Figure 3 As shown, the second control assembly 13 includes a fifth valve body 1301 and a sixth valve body 1302. The fifth valve body 1301 is separated by a valve core to form a second oil delivery chamber and a second control oil chamber. The second main oil inlet 13011 and the second main oil outlet 13012 of the fifth valve body 1301 are both connected to the second oil delivery chamber, the second main oil inlet 13011 is connected to the second main pipeline 11, and the second main oil outlet 13012 is connected to the vehicle oil supply pipeline 7. Figure 3 As shown, the second control component 13 also includes a second control pipeline 1303, and the two ends of the second control pipeline 1303 are respectively connected to the second main pipeline 11 and the second control oil chamber. The sixth valve body 1302 is arranged on the second control pipeline 1303 to control the connection and disconnection of the second main pipeline 11 and the second control oil chamber and adjust the position of the valve core to control the connection and disconnection of the second main oil inlet 13011 and the second main oil outlet 13012.

[0041] Specifically, when it is necessary to supply oil to the vehicle below, that is, the second control component 13 is in a closed state, at this time, the second control line 1303 connects the second main line 11 to the second control oil chamber through the sixth valve body 1302, so that the two end surfaces of the valve core of the fifth valve body 1301 are subjected to pressure, so that the valve core of the fifth valve body 1301 blocks the second main oil inlet 13011 and the second main oil outlet 13012, that is, the fifth valve body 1301 is closed, and the second main line 11 cannot supply oil to the oil supply line 7 of the vehicle above. When it is necessary to supply oil to the vehicle, that is, the second control component 13 is in the open state, at this time, the sixth valve body 1302 blocks the second control line 1303 to relieve the pressure in the second control oil chamber, and the valve core of the fifth valve body 1301 is subjected to the pressure applied by one side of the second oil delivery chamber, so that the valve core of the fifth valve body 1301 moves away to connect the second main oil inlet 13011 and the second main oil outlet 13012, that is, the fifth valve body 1301 is opened, and at the same time, the fourth valve body 10 is in the pressure relief position, and the second main pipeline 11 cannot supply oil to the main steering oil supply pipeline 12.

[0042] In this embodiment, if Figure 3 As shown, the fourth valve body 10 is a two-position four-way electromagnetic reversing valve, the fifth valve body 1301 is a two-way cartridge valve or a two-way logic valve, and the sixth valve body 1302 is a two-position four-way electromagnetic reversing valve.

[0043] Specifically, Figure 1 and Figure 3 As shown, when it is necessary to supply oil to the main steering oil supply pipeline 12, the second variable pumping assembly 9 outputs the hydraulic oil to point P2. At this time, DT4 of the sixth valve body 1302 is not energized, so that the sixth valve body 1302 works in the right position, so that the fifth valve body 1301 is closed, and the hydraulic oil at point P2 cannot reach point B1. At the same time, DT5 of the fourth valve body 10 is not energized, so that the fourth valve body 10 works in the right position (that is, the working position), and the hydraulic oil at point P2 can be delivered to point A1.

[0044] Specifically, Figure 1 and Figure 3 As shown, when it is necessary to supply oil to the upper vehicle oil supply pipeline 7, the second variable pumping component 9 outputs the hydraulic oil to point P2. At this time, DT4 of the sixth valve body 1302 is energized, so that the sixth valve body 1302 works in the left position, so that the fifth valve body 1301 is opened, and the hydraulic oil at point P2 can be delivered to point B1. At the same time, the fourth valve body DT5 is energized, so that the fourth valve body 10 works in the left position (that is, the pressure relief position), and the hydraulic oil at point P2 cannot reach point A1.

[0045] In one embodiment, Figure 1 and Figure 3As shown, the second variable pumping assembly 9 includes a second variable pump 901, a second feedback pipeline 902 and a second one-way valve body 903. The inlet of the second feedback pipeline 902 is connected to the main steering oil supply pipeline 12 and the vehicle oil supply pipeline 7, and the outlet of the second feedback pipeline 902 is connected to the second feedback port of the second variable pump 901. The second one-way valve body 903 is arranged on the second feedback pipeline 902. In this way, the higher pressure signals of getting off and getting on are led to the second variable pump 901, so that the second variable pump 901 can adaptively output the corresponding displacement of oil, thereby achieving the purpose of energy saving.

[0046] Specifically, the second variable pump 901 is a variable plunger pump, and the second one-way valve body 903 is a shuttle valve, and one or more shuttle valves may be provided. The variable plunger pump is a load-sensitive pump, and its variable displacement is to guide the high-pressure hydraulic oil through the shuttle valve to the X2 point of the variable plunger pump through the LS2 point to achieve adaptive regulation of the variable plunger pump.

[0047] In one embodiment, Figure 1 and Figure 3 As shown, a damping element 16 is also provided on the main steering oil supply pipeline 12 and the second feedback pipeline 902 .

[0048] In one embodiment, Figure 1 As shown, the second main pipeline 11 is connected to a second filter element 14. Specifically, the second filter element 14 is a high-pressure filter.

[0049] In one embodiment, Figure 1 As shown, the hydraulic drive system also includes a quantitative pumping assembly 15. The quantitative pumping assembly 15 can provide power for auxiliary actions such as vehicle rotation, telescopic cylinder plugging and unplugging, vehicle air conditioning and counterweight. The quantitative pumping assembly 15 may include one or more quantitative pumps.

[0050] According to an embodiment of the present invention, on the other hand, there is provided an engineering machine comprising the above-mentioned hydraulic drive system.

[0051] In this embodiment, the construction machinery is a single-engine crane. The cost positioning of a single-engine crane is relatively low, resulting in the cost compression of vehicle system components; the single-engine crane can achieve cost control by applying the hydraulic drive system of this embodiment.

[0052] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A hydraulic drive system, characterized in that: include: A first variable displacement pumping assembly (1); A first valve body (2) is connected to the first variable pumping assembly (1) via a first main pipeline (3); the first valve body (2) is connected to an outrigger oil supply pipeline (4) and an auxiliary steering oil supply pipeline (5); the first valve body (2) has a first working position and a second working position; in the first working position, the first valve body (2) is connected to the first main pipeline (3) and the outrigger oil supply pipeline (4); in the second working position, the first valve body (2) is connected to the first main pipeline (3) and the auxiliary steering oil supply pipeline (5); A first control component (6), one end of the first control component (6) is connected to the first main pipeline (3), the other end of the first control component (6) is connected to the on-board oil supply pipeline (7), and the first variable pumping component (1) can be selectively connected to the first valve body (2) or the on-board oil supply pipeline (7) through the first control component (6).

2. The hydraulic drive system according to claim 1, characterized in that: The first control assembly (6) comprises a second valve body (601) and a third valve body (602); a first oil delivery chamber and a first control oil chamber are formed in the second valve body (601) by means of a valve core; a first main oil inlet (6011) and a first main oil outlet (6012) of the second valve body (601) are both in communication with the first oil delivery chamber; the first main oil inlet (6011) is in communication with the first main pipeline (3); and the first main oil outlet (6012) is in communication with the on-board oil supply pipeline (7); The first control component (6) also includes a first control pipeline (603), the two ends of which are connected to the first main pipeline (3) and the first control oil chamber respectively. The third valve body (602) is arranged on the first control pipeline (603) to control the connection and disconnection between the first main pipeline (3) and the first control oil chamber and adjust the position of the valve core to control the connection and disconnection between the first main oil inlet (6011) and the first main oil outlet (6012).

3. The hydraulic drive system according to claim 1 or 2, characterized in that: The first variable pumping assembly (1) comprises a first variable pump (101), a first feedback pipeline (102) and a first non-return valve body (103); the inlet of the first feedback pipeline (102) is connected to the outrigger oil supply pipeline (4), the auxiliary steering oil supply pipeline (5) and the on-board oil supply pipeline (7); the outlet of the first feedback pipeline (102) is connected to the first feedback port of the first variable pump (101); and the first non-return valve body (103) is arranged on the first feedback pipeline (102).

4. The hydraulic drive system according to claim 1 or 2, characterized in that: The first main pipeline (3) is connected to a first filter element (8).

5. The hydraulic drive system according to claim 1 or 2, characterized in that: The hydraulic drive system also includes: A second variable displacement pumping assembly (9); a fourth valve body (10) connected to the second variable pumping assembly (9) via a second main pipeline (11); the fourth valve body (10) is connected to a main steering oil supply pipeline (12); the fourth valve body (10) controls the opening and closing of the second main pipeline (11) and the main steering oil supply pipeline (12); A second control component (13), one end of the second control component (13) is connected to the second main pipeline (11), the other end of the second control component (13) is connected to the on-board oil supply pipeline (7), and the second variable pumping component (9) can be selectively connected to the fourth valve body (10) or the on-board oil supply pipeline (7) through the second control component (13).

6. The hydraulic drive system according to claim 5, characterized in that: The second control assembly (13) comprises a fifth valve body (1301) and a sixth valve body (1302); a second oil delivery chamber and a second control oil chamber are formed in the fifth valve body (1301) by means of a valve core; a second main oil inlet (13011) and a second main oil outlet (13012) of the fifth valve body (1301) are both in communication with the second oil delivery chamber; the second main oil inlet (13011) is in communication with the second main pipeline (11); and the second main oil outlet (13012) is in communication with the on-board oil supply pipeline (7); The second control component (13) also includes a second control pipeline (1303), the two ends of which are connected to the second main pipeline (11) and the second control oil chamber respectively, and the sixth valve body (1302) is arranged on the second control pipeline (1303) to control the connection and disconnection between the second main pipeline (11) and the second control oil chamber and adjust the position of the valve core to control the connection and disconnection of the second main oil inlet (13011) and the second main oil outlet (13012).

7. The hydraulic drive system according to claim 5, characterized in that: The second variable pumping assembly (9) comprises a second variable pump (901), a second feedback pipeline (902) and a second one-way valve body (903); the inlet of the second feedback pipeline (902) is connected to the main steering oil supply pipeline (12) and the on-board oil supply pipeline (7); the outlet of the second feedback pipeline (902) is connected to the second feedback port of the second variable pump (901); and the second one-way valve body (903) is arranged on the second feedback pipeline (902).

8. The hydraulic drive system according to claim 5, characterized in that: The second main pipeline (11) is connected to a second filter element (14).

9. The hydraulic drive system according to claim 1 or 2, characterized in that: The hydraulic drive system further comprises a quantitative pumping assembly (15).

10. An engineering machine, characterized in that: A hydraulic drive system comprising any one of claims 1 to 9.

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