Rotary hydraulic system and crane

Abstract

The present invention discloses a slewing hydraulic system and a crane. The slewing hydraulic system includes a slewing working oil circuit connected between a slewing motor and a main valve; a pilot control oil circuit including a handle oil circuit provided with a hydraulic control handle and a brake pilot oil circuit connected to a slewing brake; a brake reversing valve for conducting or blocking the brake pilot oil circuit; and a remote control reversing valve for selectively guiding the hydraulic oil of the handle oil circuit or the brake pilot oil circuit to the hydraulic control end of the main valve. The integrated crane slewing hydraulic circuit with remote control slewing function of the present invention integrates multiple valve groups into one and optimizes them. Through the internal oil passages of the valve body being interconnected, it can achieve both handle operation and remote control operation, reducing the number of hydraulic pipelines and oil leakage points, improving the simplicity and aesthetics of the product, greatly reducing the use of control pipelines, improving the action responsiveness, and facilitating the control of the slewing speed during remote control operation.

Description

Technical Field

[0001] The present invention belongs to the field of construction machinery, and particularly relates to a swing hydraulic system and a crane. Background Art

[0002] In a crane, the swing action is usually driven and controlled by a swing hydraulic system. The swing hydraulic system generally includes a hydraulic pump as a power source, a hydraulic valve group as a control element, a hydraulic motor as a driving device, and so on.

[0003] Among them, for a crane with a movable counterweight, users hope to have two operating modes: operating with a handle in the cab during normal operation and operating remotely outside the cab when removing the movable counterweight. However, currently, the swing hydraulic system of a crane with a movable counterweight generally includes multiple control valve groups, the valve groups are scattered in layout, the pipeline connections are complex, and there are many oil leakage points, which affect the reliability and aesthetics of the product. Moreover, when operating the left swing or right swing remotely, manual operation is still required to adjust the swing speed, which brings inconvenience to the operation process. Summary of the Invention

[0004] In view of the above defects or deficiencies, the present invention provides a swing hydraulic system and a crane, which can be operated by a handle or remotely, and the control valve group has a high integration degree.

[0005] To achieve the above object, the present invention provides a swing hydraulic system, comprising:

[0006] A swing working oil circuit, connected between a swing motor and a main valve;

[0007] A pilot control oil circuit, including a handle oil circuit provided with a hydraulic control handle and a brake pilot oil circuit connected to a swing brake;

[0008] A brake reversing valve, for conducting or blocking the brake pilot oil circuit;

[0009] A remote control reversing valve, for selectively guiding the hydraulic oil in the handle oil circuit or the brake pilot oil circuit to the hydraulic control end of the main valve.

[0010] In some embodiments, the brake reversing valve includes a first brake reversing valve and a second brake reversing valve for independently controlling the conduction or blocking of the brake pilot oil circuit, and the first brake reversing valve is an electromagnetic reversing valve.

[0011] In some embodiments, the second brake reversing valve is a hydraulic control reversing valve, and the hydraulic control pilot oil circuit of the second brake reversing valve is connected to the outlet end of the remote control reversing valve to selectively communicate with the handle oil circuit or the brake pilot oil circuit.

[0012] In some embodiments, the handle oil circuit includes a first handle oil circuit and a second handle oil circuit independently branched from two outlet ends of the hydraulic control handle. The remote control reversing valve includes a first remote control reversing valve connected to the first handle oil circuit and a second remote control reversing valve connected to the second handle oil circuit. Both the first remote control reversing valve and the second remote control reversing valve are electromagnetic reversing valves.

[0013] In some embodiments, a shuttle valve is provided in the hydraulic control pilot oil circuit of the second brake reversing valve. Two comparison ends of the shuttle valve are respectively connected to the first remote control reversing valve and the second remote control reversing valve, and the other end is connected to the hydraulic control end of the second brake reversing valve.

[0014] In some embodiments, throttle check valve groups are respectively provided in the first handle oil circuit, the second handle oil circuit and the brake pilot oil circuit. The throttle check valve group includes a check valve and a throttle element arranged in parallel.

[0015] In some embodiments, the swing working oil circuit includes a first swing working oil circuit and a second swing working oil circuit respectively connected to two ends of the swing motor. The swing hydraulic system further includes a free return reversing valve for conducting or cutting off the first swing working oil circuit and the second swing working oil circuit.

[0016] In some embodiments, the swing hydraulic system includes:

[0017] A main pump oil circuit and a main return oil circuit, respectively connected to the inlet port and the return port of the main valve;

[0018] A safety overflow valve, arranged between the main pump oil circuit and the main return oil circuit.

[0019] In some embodiments, the brake reversing valve, the remote control reversing valve, the safety overflow valve and the free return reversing valve are integrated into a swing buffer valve group.

[0020] In some embodiments, the swing hydraulic system includes:

[0021] A common hydraulic pump, and the main pump oil circuit and the pilot control oil circuit are connected in parallel to the outlet of the common hydraulic pump.

[0022] In some embodiments, the swing hydraulic system includes:

[0023] A first hydraulic pump for pumping hydraulic oil for the main pump oil circuit;

[0024] A second hydraulic pump for pumping hydraulic oil for the pilot control oil circuit;

[0025] Wherein, the first hydraulic pump and the second hydraulic pump are single pumps independently driven respectively, or the first hydraulic pump and the second hydraulic pump form a double pump.

[0026] In some embodiments, the slewing hydraulic system includes:

[0027] An electro-hydraulic proportional reducing valve, arranged at the front end of the pilot control oil circuit.

[0028] In addition, the present invention also provides a crane, which includes the above-mentioned slewing hydraulic system.

[0029] In the slewing hydraulic system of the present invention, a hydraulic control handle and a remote control reversing valve are provided. The slewing can be controlled by the hydraulic control handle or by the remote control reversing valve. Each functional valve is compactly arranged and can be integrated in the same slewing buffer valve group, and is interconnected through internal oil circuits, so that the slewing action can be controlled either by the handle or remotely. Moreover, the layout points of the valve group are simplified, the number of hydraulic pipelines and oil leakage points are reduced, the simplicity and aesthetics of the product are improved, and at the same time, the use of control pipelines is greatly reduced, and the action response is improved.

[0030] Other features and advantages of the present invention will be described in detail in the subsequent specific embodiment part. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings are used to provide an understanding of the present invention and form a part of the specification, and are used to explain the present invention together with the following specific embodiments, but do not constitute a limitation to the present invention. In the drawings:

[0032] Figure 1 is the hydraulic schematic diagram of a conventional crane slewing hydraulic control system;

[0033] Figures 2 to 4 is the hydraulic schematic diagram of the slewing hydraulic control system according to different embodiments of the present invention.

[0034] DESCRIPTION OF THE REFERENCE NUMERALS

[0035] 1 Hydraulic oil tank 2 Common hydraulic pump

[0036] 3 Electro-hydraulic proportional reducing valve 4 Hydraulic control handle

[0037] 5 Slewing buffer valve group 6 Slewing motor

[0038] 7 Slewing brake 8 Main valve

[0039] 9 Shuttle valve 10 Throttle check valve group

[0040] 11 Electromagnetic reversing valve 12 Shuttle valve group

[0041] 13 Swing braking valve 14 Pressure reducing valve

[0042] 21 First hydraulic pump 22 Second hydraulic pump

[0043] 51 First braking directional valve 52 Second braking directional valve

[0044] 53 First remote control directional valve 54 Second remote control directional valve

[0045] 55 Safety overflow valve 56 Free return and changeover valve

[0046] L1 First swing working oil circuit L2 Second swing working oil circuit

[0047] L3 Main pump delivery oil circuit L4 Main return oil circuit

[0048] L5 Braking pilot oil circuit L6 Handle oil circuit

[0049] L7 Hydraulic control pilot oil circuit L8 Spool pilot oil circuit

[0050] L61 First handle oil circuit L62 Second handle oil circuit Detailed implementation manners

[0051] The following describes in detail specific embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining and understanding the present invention, and are not used to limit the present invention.

[0052] The swing hydraulic system and crane of the present invention are described below with reference to the drawings.

[0053] The present invention provides a new type of swing hydraulic system. As Figure 2 shown, in one embodiment, the swing hydraulic system includes:

[0054] Swing working oil circuits L1, L2, connected between the swing motor 6 and the main valve 8;

[0055] Pilot control oil circuits L5, L6, including a handle oil circuit L6 provided with a hydraulic control handle 4 and a braking pilot oil circuit L5 connected to the swing brake 7;

[0056] Braking directional valves 51, 52, for conducting or blocking the braking pilot oil circuit L5;

[0057] Remote control directional valves 53, 54, for selectively guiding the hydraulic oil in the handle oil circuit L6 or the braking pilot oil circuit L5 to the hydraulic control end of the main valve 8.

[0058] Among them, the new swing hydraulic system includes two oil circuit parts, namely the swing working oil circuits L1, L2, the main pump oil circuit L3, the main return oil circuit L4 marked by solid lines, and the pilot control oil circuits L5, L6 marked by dashed lines, etc. The oil circuits marked by solid lines provide power oil source or return oil for the swing motor 6, and the oil circuits marked by dashed lines provide pilot control oil for valve components such as the swing brake 7 and the main valve 8.

[0059] Specifically, the brake reversing valves 51, 52 are used to conduct or cut off the brake pilot oil circuit L5. When the brake pilot oil circuit L5 is conducted, the swing brake 7 can be opened to release the swing restriction on the swing motor 6. Otherwise, the swing brake 7 locks the swing motor 6 when the brake pilot oil circuit L5 is cut off. The remote control reversing valves 53, 54 are used to control and select the hydraulic oil of the selector handle oil circuit L6 or the brake pilot oil circuit L5 as the pilot control oil to further control the main valve 8, so as to realize operation actions such as turning left, turning right or stopping swinging. In other words, it is used to select hydraulic control handle operation or remote control operation.

[0060] It can be seen that the swing hydraulic system of the present invention utilizes the hydraulic control handle 4 and the remote control reversing valves 53, 54, and can swing through the hydraulic control handle or through the remote control reversing valves. And as Figure 2 shown, each functional valve component is compactly arranged. As will be described below, it can be further integrated in the same swing buffer valve group 5 and communicated with each other through internal oil circuits. In this way, the layout of the valve group is simplified, the number of hydraulic pipelines and oil leakage points are reduced, the simplicity and aesthetics of the product are improved, and at the same time, the use of control pipelines is greatly reduced, and the action response is improved. This will be specifically described below.

[0061] In this embodiment, the brake reversing valve includes a first brake reversing valve 51 and a second brake reversing valve 52 for independently controlling the conduction or cut-off of the brake pilot oil circuit L5. The first brake reversing valve 51 is an electromagnetic reversing valve. That is, the conduction or cut-off of the brake pilot oil circuit L5 can be controlled separately through the first brake reversing valve 51 and the second brake reversing valve 52. In particular, the first brake reversing valve 51 of one of them is an electromagnetic reversing valve, ensuring that the conduction or cut-off of the brake pilot oil circuit L5 can be remotely controlled, that is, the swing brake 7 can be remotely controlled.

[0062] Furthermore, the second brake reversing valve 52 is a hydraulic control reversing valve, and the hydraulic control pilot oil circuit L7 of the second brake reversing valve 52 is connected to the outlet end of the remote control reversing valve (that is Figure 2The right port of the first remotely controlled reversing valve 53 and the left port of the second remotely controlled reversing valve 54 are alternatively connected to the handle oil circuit L6 or the brake pilot oil circuit L5. In other words, the pilot oil flowing to port a or port b via the handle oil circuit L6 or the pilot oil flowing to port P1 via the brake pilot oil circuit L5 flows through the remotely controlled reversing valves 53, 54 and the hydraulically controlled pilot oil circuit L7 to the hydraulically controlled end of the second brake reversing valve 52 to cause the second brake reversing valve 52 to perform a reversing operation to conduct or cut off the brake pilot oil circuit L5.

[0063] It should be noted that this embodiment is only an example, and the present invention is not limited thereto. The second brake reversing valve 52 can also adopt an electromagnetic valve mode or the like.

[0064] In this embodiment, the handle oil circuit L6 includes a first handle oil circuit L61 and a second handle oil circuit L62 independently branched from the two outlet ends of the hydraulically controlled handle 4. The remotely controlled reversing valves include a first remotely controlled reversing valve 53 connected to the first handle oil circuit L61 and a second remotely controlled reversing valve 54 connected to the second handle oil circuit L62. Both the first remotely controlled reversing valve 53 and the second remotely controlled reversing valve 54 are electromagnetic reversing valves. Among them, through the electromagnetic reversing control of the first remotely controlled reversing valve 53 and the second remotely controlled reversing valve 54, when the handle is operated, the pilot oil at port a or port b can control the second brake reversing valve 52 through the hydraulically controlled pilot oil circuit L7, and flow to the hydraulically controlled end of the main valve 8 through the spool pilot oil circuit L8 parallel to the hydraulically controlled pilot oil circuit L7, thereby controlling the forward and reverse rotation and stopping the rotation of the swing motor 6.

[0065] Since the first handle oil circuit L61 and the second handle oil circuit L62 are independently branched from the two outlet ends of the hydraulically controlled handle 4, a shuttle valve 9 is provided in the hydraulically controlled pilot oil circuit L7 of the second brake reversing valve 52. The two comparison ends of the shuttle valve 9 are respectively connected to the first remotely controlled reversing valve 53 and the second remotely controlled reversing valve 54, and the other end is connected to the hydraulically controlled end of the second brake reversing valve 52. That is, when the pilot oil flows to port a through the first handle oil circuit L61 of the hydraulically controlled handle 4, the oil pressure at port a is greater than that at port b, and the pilot oil at port a controls the second brake reversing valve 52 and the main valve 8 through the hydraulically controlled pilot oil circuit L7 and the spool pilot oil circuit L8 respectively. Or, when the pilot oil flows to port b through the second handle oil circuit L62 of the hydraulically controlled handle 4, the oil pressure at port b is greater than that at port a, and the pilot oil at port b controls the second brake reversing valve 52 and the main valve 8 through the hydraulically controlled pilot oil circuit L7 and the spool pilot oil circuit L8 respectively.

[0066] In addition, Figure 2 throttle check valve groups 10 are also respectively provided in the first handle oil circuit L61, the second handle oil circuit L62 and the brake pilot oil circuit L5. The throttle check valve group 10 includes a check valve and a throttle element arranged in parallel. The check valve is used to prevent the oil from flowing back, and the throttle element can be used for voltage stabilization.

[0067] The swing working oil circuit includes a first swing working oil circuit L1 and a second swing working oil circuit L2 that are respectively connected to both ends of the swing motor 6. To achieve free swing control, the swing hydraulic system also particularly includes a free swing directional valve 56 for conducting or blocking the first swing working oil circuit L1 and the second swing working oil circuit L2. In this way, on the one hand, the braking pilot oil circuit L5 is conducted through the first braking directional valve 51 to release the locking of the swing brake 7 on the swing motor 6. On the other hand, the first swing working oil circuit L1 and the second swing working oil circuit L2 are conducted through the free swing directional valve 56 to form a motor circuit, so that the swing motor 6 can swing freely.

[0068] The swing hydraulic system also includes a main pump oil circuit L3 and a main return oil circuit L4, which are respectively connected to the oil inlet and the oil return port of the main valve 8; the safety relief valve 55 is arranged between the main pump oil circuit L3 and the main return oil circuit L4 as the system safety valve.

[0069] It should be particularly noted that the above-mentioned braking directional valves 51, 52, remote control directional valves 53, 54, safety relief valve 55, free swing directional valve 56 and even shuttle valve 9, etc. can be integrated into a valve group, that is Figure 2 the swing buffer valve group 5 shown. See Figure 2 , the swing buffer valve group 5 has multiple oil ports, such as P port, T port, P1 port, a port, b port, k port, etc. In this way, after integrating multiple functional valve components and optimizing the internal oil passages of the valve body to achieve mutual connection, both handle operation and remote control operation can be realized. Due to being integrated into a valve group, the installation position is single, reducing the number of hydraulic pipelines and oil leakage points, improving the simplicity and aesthetics of the product, and at the same time greatly reducing the use of control pipelines and improving the action response.

[0070] Comparatively, as Figure 1 shown, a conventional swing hydraulic system includes multiple control valve groups, such as a swing buffer valve group 5, an electromagnetic directional valve 11, a shuttle valve group 12, a swing brake valve 13, a pressure reducing valve 14, etc. Among them, Figure 1 the valve component composition in the swing buffer valve group 5 of Figure 2 is significantly different from the valve component composition in the swing buffer valve group 5 of Figure 1 , and the number of functional valve components integrated in the swing buffer valve group 5 of Figure 1 is also significantly less. In particular, Figure 2 the arrangement positions of each valve group in

[0071] are scattered, the pipeline connection is complex, and there are many oil leakage points, which greatly affect the reliability and aesthetics of the product. In contrast, Figure 2The shown swing hydraulic system further includes an electro-hydraulic proportional reducing valve 3, which is arranged at the front ends of the pilot control oil circuits L5 and L6. The electro-hydraulic proportional reducing valve 3 can adjust the pilot oil pressure of the pilot control oil circuits L5 and L6, and further adjust the spool opening degree of the main valve 8, that is, adjust the rotational speed of the swing motor 6. Therefore, during remote control operation, the swing speed can be controlled by changing the magnitude of the current value of the electro-hydraulic proportional reducing valve 3. Comparatively, in Figure 1 when it is desired to change the swing speed during remote control operation of left swing or right swing, it is necessary to manually adjust the spring force of the reducing valve 14, which brings inconvenience to the operation process.

[0072] In addition, in Figure 2 the shown embodiment, the swing hydraulic system further includes a common hydraulic pump 2, and the main pump oil circuit L3 and the pilot control oil circuits L5 and L6 are connected in parallel to the oil outlet of the common hydraulic pump 2. The common hydraulic pump 2 can be driven by a single power source.

[0073] In Figure 3 and Figure 4 the other two shown embodiments, the swing hydraulic system includes the following:

[0074] A first hydraulic pump 21, which pumps hydraulic oil for the main pump oil circuit L3;

[0075] A second hydraulic pump 22, which pumps hydraulic oil for the pilot control oil circuits L5 and L6.

[0076] The difference is that Figure 3 in Figure 4 the first hydraulic pump 21 and the second hydraulic pump 22 form a double pump and can be driven by the same power source. Figures 2 to 4 in

[0077] the first hydraulic pump 21 and the second hydraulic pump 22 are single pumps independently driven and can be individually driven by different power sources respectively. No matter which embodiment of the hydraulic pump in Figure 2 is adopted, the hydraulic pump is used to pump the hydraulic oil in the hydraulic oil tank 1 to the main pump oil circuit L3 and the pilot control oil circuits L5 and L6.

[0078] The engine drives the shared hydraulic pump 2 through a mechanical connection. The high-pressure oil output by the hydraulic pump is divided into two paths: one path enters the P port of the swing buffer valve group 5 through the main pump oil supply path L3 and serves as the system power oil source. The oil pressure of the main pump oil supply path L3 is controlled by the safety relief valve 55; the other path is reduced in pressure by the electro-hydraulic proportional reducing valve 3 and then serves as the system pilot oil source and flows through the pilot control oil path to the pilot control end of the corresponding hydraulic control valve. The pilot oil pressure of the pilot control oil path is controlled by the electro-hydraulic proportional reducing valve 3. By adjusting the magnitude of the current value, the pilot oil path pressure can be changed, thereby realizing the control of the swing speed during remote control operation.

[0079] When using the handle to control the left swing or right swing, the electromagnets of the first remote control reversing valve 53 and the second remote control reversing valve 54 are both de-energized. At this time, the pilot oil in the pilot control oil path is divided into two paths: the first path enters the P1 port of the swing buffer valve group 5 through the brake pilot oil path L5, and the second path is the handle oil path L6 flowing through the hydraulic control handle 4, and is branched into the first handle oil path L61 and the second handle oil path L62 through the two outlet ends of the hydraulic control handle 4. By operating the hydraulic control handle 4, the pilot oil in the second path can be alternatively directed to the first handle oil path L61 or the second handle oil path L62, that is, alternatively enters the a port or b port of the swing buffer valve group 5; at this time, since the electromagnets Y2a and Y2b of the first remote control reversing valve 53 and the second remote control reversing valve 54 are both de-energized, both are in Figure 2 the upper valve position. After the pilot oil at the a port or b port passes through the first remote control reversing valve 53 and the second remote control reversing valve 54, it is divided into two paths again, that is, one path makes the second brake reversing valve 52 act through the hydraulic control pilot oil path L7, conducting the oil path from the P1 port to the k port of the swing buffer valve group 5, so that the brake pilot oil path L5 is conducted and the swing brake 7 is opened; the other path makes the spool of the main valve 8 act through the spool pilot oil path L8, connecting the swing working oil path from the P port to the A port or B port of the swing buffer valve group 5, thereby driving the swing motor 6 to rotate left or right, and further realizing the left swing or right swing of the crane.

[0080] When using remote control to operate the left swing or right swing, the electromagnets Y2a and Y2b of the first remote control reversing valve 53 and the second remote control reversing valve 54 are both energized, and their lower valve positions are conducted. After the pilot oil enters the P1 port of the swing buffer valve group 5, it is divided into two paths after passing through the first remote control reversing valve 53 or the second remote control reversing valve 54: one path makes the second brake reversing valve 52 act through the hydraulic control pilot oil path L7, conducting the oil path from the P1 port to the k port of the swing buffer valve group 5, so that the brake pilot oil path L5 is conducted and the swing brake 7 is opened; the other path makes the spool of the main valve 8 act through the spool pilot oil path L8, connecting the swing working oil path from the P port to the A port or B port of the swing buffer valve group 5, thereby driving the swing motor 6 to rotate left or right, and further realizing the left swing or right swing of the crane.

[0081] When the electromagnet of the free rotation change-over valve 56 is energized, the first rotation working oil circuit L1 of port A of the slewing motor 6 and the second rotation working oil circuit L2 of port B will be conducted. When the first brake change-over valve 51 is energized, the oil circuit from port P1 to port k of the slewing buffer valve group 5 will be connected, thereby opening the slewing brake 7. When both are energized, the free slewing function of the crane can be realized.

[0082] In summary, the present invention provides an integrated slewing hydraulic circuit of a crane with a remote control slewing function, which integrates and optimizes multiple valve groups such as a slewing buffer valve, a slewing brake valve, an electromagnetic change-over valve, and a shuttle valve group. Through the internal oil passages of the valve body being interconnected, both manual operation and remote control operation can be achieved, reducing the number of hydraulic pipelines and oil leakage points, improving the simplicity and aesthetics of the product. At the same time, the use of control pipelines is greatly reduced, improving the action response. Moreover, when remotely controlled, the slewing speed can be controlled by changing the current value of the electro-hydraulic proportional relief valve.

[0083] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0084] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0085] In the description of this specification, the descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0086] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. Rotary hydraulic system, characterized in that, The swing hydraulic system includes: A swing working oil circuit (L1, L2) connected between the swing motor (6) and the main valve (8); A pilot control oil circuit (L5, L6) including a handle oil circuit (L6) provided with a hydraulic control handle (4) and a brake pilot oil circuit (L5) connected to the swing brake (7); Brake changeover valves (51, 52) for conducting or blocking the brake pilot oil circuit (L5); Remote control changeover valves (53, 54) for selectively guiding the hydraulic oil of the handle oil circuit (L6) or the brake pilot oil circuit (L5) to the hydraulic control end of the main valve (8); Among them, the brake changeover valves (51, 52) include a first brake changeover valve (51) and a second brake changeover valve (52) for independently controlling the conduction or blocking of the brake pilot oil circuit (L5), and the first brake changeover valve (51) is an electromagnetic changeover valve; The second brake changeover valve (52) is a hydraulic control changeover valve, and the hydraulic control pilot oil circuit (L7) of the second brake changeover valve (52) is connected to the outlet end of the remote control changeover valves (53, 54) to selectively communicate with the handle oil circuit (L6) or the brake pilot oil circuit (L5); The handle oil circuit (L6) includes a first handle oil circuit (L61) and a second handle oil circuit (L62) independently branched from two outlet ends of the hydraulic control handle (4), the remote control changeover valves (53, 54) include a first remote control changeover valve (53) connected to the first handle oil circuit (L61) and a second remote control changeover valve (54) connected to the second handle oil circuit (L62), and both the first remote control changeover valve (53) and the second remote control changeover valve (54) are electromagnetic changeover valves; A shuttle valve (9) is provided in the hydraulic control pilot oil circuit (L7) of the second brake changeover valve (52), and two comparison ends of the shuttle valve (9) are respectively connected to the first remote control changeover valve (53) and the second remote control changeover valve (54), and the other end is connected to the hydraulic control end of the second brake changeover valve (52).

2. The rotary hydraulic system according to claim 1, characterized in that, Throttle check valve groups (10) are respectively provided in the first handle oil circuit (L61), the second handle oil circuit (L62) and the brake pilot oil circuit (L5), and the throttle check valve groups (10) include a check valve and a throttle element arranged in parallel.

3. The rotary hydraulic system according to claim 1, wherein, The swing working oil circuit (L1, L2) includes a first swing working oil circuit (L1) and a second swing working oil circuit (L2) respectively connected to two ends of the swing motor (6), and the swing hydraulic system further includes a free return changeover valve (56) for conducting or blocking the first swing working oil circuit (L1) and the second swing working oil circuit (L2).

4. The rotary hydraulic system according to claim 3, characterized in that, The swing hydraulic system includes: A main pump oil circuit (L3) and a main oil return circuit (L4) respectively connected to the inlet port and the return port of the main valve (8); A safety overflow valve (55) is arranged between the main pump oil circuit (L3) and the main oil return circuit (L4).

5. The rotary hydraulic system according to claim 4, characterized in that, The braking and reversing valves (51, 52), the remote control reversing valves (53, 54), the safety overflow valve (55), and the free return reversing valve (56) are integrated into a swing buffer valve group (5).

6. The rotary hydraulic system according to claim 4, wherein The swing hydraulic system includes: A common hydraulic pump (2), and the main pump oil supply line (L3) and the pilot control oil supply lines (L5, L6) are connected in parallel to the oil outlet of the common hydraulic pump (2).

7. The rotary hydraulic system according to claim 4, wherein The swing hydraulic system includes: A first hydraulic pump (21) for pumping hydraulic oil to the main pump oil supply line (L3); A second hydraulic pump (22) for pumping hydraulic oil to the pilot control oil supply lines (L5, L6); wherein, the first hydraulic pump (21) and the second hydraulic pump (22) are single pumps independently driven respectively, or the first hydraulic pump (21) and the second hydraulic pump (22) form a double pump.

8. The rotary hydraulic system according to any one of claims 1 to 7, characterized in that The swing hydraulic system includes: An electro-hydraulic proportional pressure reducing valve (3) provided at the front end of the pilot control oil supply lines (L5, L6).

9. A crane, characterized in that, The crane includes the swing hydraulic system according to any one of claims 1 to 8.

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