Control valve group, motor driving system, heat dissipation system and engineering machinery

Abstract

The utility model relates to the technical field of engineering machinery, and discloses a control valve group, a motor driving system, a heat dissipation system and engineering machinery. The control valve set comprises an oil inlet path, an oil return path, a pressure relief path and an oil path control module, the pressure relief path is connected with the oil inlet path and the oil return path, a hydraulic control one-way valve is arranged on the pressure relief path, and the oil inlet path and the oil return path can be selectively communicated through the hydraulic control one-way valve; the oil way control module is connected with the oil inlet way and the control end of the hydraulic control one-way valve and comprises an electromagnetic reversing valve, and the electromagnetic reversing valve is used for controlling opening or closing of the hydraulic control one-way valve through hydraulic oil in the oil inlet way. The control valve group disclosed by the utility model can be opened in time to release pressure when dealing with large flow, is applied to a motor driving system or a heat dissipation system, can normally control the start and stop of the motor through the matching of the electromagnetic directional valve and the hydraulic control one-way valve, and is timely in response, high in switching speed and low in cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of engineering machinery, and particularly relates to a control valve group, a motor driving system, a heat dissipation system and engineering machinery. BACKGROUND

[0002] In large engineering machinery, a large power engine needs to be equipped with an auxiliary heat dissipation system to dissipate heat when working, and different cooling requirements are matched according to the engine water temperature and the intake air temperature. In the auxiliary heat dissipation system, the fan blades are rotated by a hydraulic motor, so the hydraulic motor is required to have a controllable rotating speed according to the temperature. The number of heat dissipation fans varies from one to multiple, so the control valve flow of the hydraulic motor also gradually increases.

[0003] The existing large-flow heat dissipation fan hydraulic control system provides high-pressure oil through a gear pump, and the high-pressure oil enters the motor through a control valve group, so as to drive the fan to rotate through the motor. However, in the large-flow (>120L / min) heat dissipation control valve, an electro-hydraulic reversing valve needs to be used, otherwise the hydraulic force cannot be overcome when the flow is large, so that the electro-hydraulic reversing valve cannot be reversed, resulting in abnormal start and stop of the motor. However, the electro-hydraulic reversing valve has a long reversing time and slow response. CONTENT OF THE INVENTION

[0004] The purpose of the present application is to provide a control valve group, a motor driving system, a heat dissipation system and engineering machinery, which are used to solve the problem of long reversing time and slow response of the electro-hydraulic reversing valve in the existing large-flow heat dissipation control valve group.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present application provides a control valve group, comprising:

[0006] an oil inlet oil path;

[0007] an oil return oil path;

[0008] a pressure relief oil path connected with the oil inlet oil path and the oil return oil path, wherein a hydraulic control check valve is arranged on the pressure relief oil path, and an oil inlet end of the hydraulic control check valve is communicated with the oil inlet oil path; and

[0009] a control oil path module for controlling the pilot hydraulic oil acting on a control end of the hydraulic control check valve to reversely open the hydraulic control check valve.

[0010] As a further improvement of the above-mentioned technical solution:

[0011] In some embodiments, the control oil path module comprises:

[0012] an electromagnetic reversing valve;

[0013] a pilot oil branch connected with the oil inlet oil path and the electromagnetic reversing valve; and

[0014] An oil return branch is connected to the electromagnetic directional valve and used to return to an oil tank.

[0015] The electromagnetic directional valve controls the communication between the control end of the hydraulic control check valve and the pilot oil branch or controls the communication between the control end of the hydraulic control check valve and the oil return branch by valve position switching.

[0016] In some embodiments, a check valve is arranged on the pilot oil branch, and an oil outlet end of the check valve is in communication with the oil inlet line.

[0017] In some embodiments, a damping valve is further arranged on the pilot oil branch, and the damping valve is located between the check valve and the electromagnetic directional valve.

[0018] In some embodiments, the electromagnetic directional valve is a plug-in directional valve.

[0019] In some embodiments, the control valve group further comprises a pressure regulating oil line connected to the oil inlet line and the oil return line.

[0020] In some embodiments, a proportional overflow valve is arranged on the pressure regulating oil line.

[0021] In some embodiments, the proportional overflow valve is a reverse proportional overflow valve.

[0022] The second aspect of the present application provides a motor driving system, comprising an oil tank, an oil pump, a motor, and a control valve group according to the first aspect described above, the oil pump is connected to the oil tank and used to deliver hydraulic oil to the oil inlet line in the control valve group.

[0023] The oil inlet line and the oil return line are respectively connected to two oil ports of the motor, and the oil return line is connected to the oil tank.

[0024] The third aspect of the present application provides a heat dissipation system, comprising an oil tank, an oil pump, a motor, a heat dissipation fan, and a control valve group according to the first aspect described above, the oil pump is connected to the oil tank and used to deliver hydraulic oil to the oil inlet line in the control valve group.

[0025] The oil inlet line and the oil return line are respectively connected to two oil ports of the motor, and the oil return line is connected to the oil tank, and the motor is drivingly connected to the heat dissipation fan.

[0026] The fourth aspect of the present application provides an engineering machine, comprising a motor driving system according to the second aspect described above, or comprising a heat dissipation system according to the third aspect described above.

[0027] Compared with the prior art, the control valve group, the motor driving system, the heat dissipation system, and the engineering machine provided by the present application at least have the following technical effects:

[0028] The control valve group provided by the application is connected with the oil inlet oil path and the oil return oil path through a pressure relief oil path, a hydraulic control check valve is arranged on the pressure relief oil path, an oil inlet end of the hydraulic control check valve is communicated with the oil inlet oil path, and the hydraulic control check valve is in a forward blocking state at the beginning, at which time the pressure relief oil path is not conducted, and the oil inlet oil path can normally supply oil without returning to the oil return oil path through the pressure relief oil path. When the control oil path module acts on the control end of the hydraulic control check valve through pilot hydraulic oil, the hydraulic control check valve is switched from the forward blocking state to the forward conduction, so as to reversely open the hydraulic control check valve, at which time the hydraulic oil of the oil inlet oil path enters the oil return oil path through the pressure relief oil path to return and relieve pressure. In this way, when a large flow is responded to, the pressure relief can be opened in time, and the control valve group is applied to a motor driving system or a heat dissipation system. Through cooperation of the control oil path module and the hydraulic control check valve, the motor can be normally controlled to start and stop, and the response is timely and the switching speed is fast. In addition, the cost is lower than that of an electro-hydraulic directional valve.

[0029] Other features and advantages of the embodiments of the application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings are included to provide a further understanding of the embodiments of the application, and constitute a part of the specification, and are used together with the following specific embodiments to explain the embodiments of the application, but do not constitute a limitation on the embodiments of the application. For those skilled in the art, other drawings can be obtained from the structures shown in the drawings without creative labor. In the drawings:

[0031] Figure 1 A structural schematic diagram of a control valve group provided by the embodiments of the application;

[0032] Figure 2 An oil path schematic diagram of a motor driving system provided by the embodiments of the application;

[0033] Figure 3 An oil path schematic diagram of a heat dissipation system provided by the embodiments of the application.

[0034] EXPLANATION OF REFERENCE NUMERALS

[0035] 100, control valve group; 110, oil inlet oil path; 120, oil return oil path; 130, pressure relief oil path; 131, hydraulic control check valve; 140, control oil path module; 141, electromagnetic directional valve; 142, pilot oil branch; 143, oil return branch; 144, check valve; 145, damping valve; 150, pressure regulating oil path; 151, proportional overflow valve;

[0036] 200, oil tank;

[0037] 300, oil pump;

[0038] 400. Motor;

[0039] 500. Cooling fan. Detailed Implementation

[0040] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0041] The present application will now be described in detail with reference to the accompanying drawings and exemplary embodiments.

[0042] Example 1

[0043] Please see Figure 1 and Figure 2 This embodiment provides a control valve assembly 100, and more particularly relates to a high-flow control valve assembly 100 that can be used in a high-flow hydraulic drive system.

[0044] In this embodiment, the control valve assembly 100 includes an oil inlet passage 110, an oil return passage 120, a pressure relief passage 130, and a control passage module 140. One end of the oil inlet passage 110 is connected to an oil supply device (e.g., an oil pump 300), and the other end is connected to a drive device (e.g., a hydraulic motor, hereinafter referred to as motor 400).

[0045] The pressure relief oil circuit 130 is connected to the oil inlet circuit 110 and the oil return circuit 120. The pressure relief oil circuit 130 is equipped with a hydraulic control check valve 131, and the oil inlet end of the hydraulic control check valve 131 is connected to the oil inlet circuit 110.

[0046] The control oil circuit module 140 is used to control the pilot hydraulic oil to act on the control terminal of the hydraulic control check valve 131 to open the hydraulic control check valve 131 in reverse.

[0047] It should be noted that both the pilot-operated check valve 131 and the check valve component 144 (described below) have an inlet end and an outlet end. In the initial state, the section from the inlet end to the outlet end is in a forward-closing state, and the section from the outlet end to the inlet end is in a reverse-flowing state. The pilot-operated check valve 131 also has a control end. When pilot hydraulic oil is introduced into the control end of the pilot-operated check valve 131, the valve core of the pilot-operated check valve 131 opens in the reverse direction, thereby switching the pilot-operated check valve 131 from forward-closing to forward-flowing.

[0048] It can be understood that in the embodiment, in the initial state, the hydraulic control check valve 131 is in the forward blocking state, at this time, the pressure relief oil way 130 is not conducted, the oil inlet oil way 110 can normally supply oil to the driving device, and the oil return oil way 120 is not returned through the pressure relief oil way 130. When the driving device stops working, the control oil way module 140 controls the pilot hydraulic oil acting on the control end of the hydraulic control check valve 131 to reversely open the hydraulic control check valve 131, at this time, the hydraulic control check valve 131 is switched to the forward conduction, and the oil inlet oil way 110 returns to the oil return oil way 120 through the pressure relief oil way 130.

[0049] Therefore, when a large flow is responded to, the pressure relief can be opened in time, and the motor 400 driving system or the heat dissipation system is applied, the cooperation of the control oil way module 140 and the hydraulic control check valve 131 can normally control the start and stop of the motor 400, and the response is timely, the switching speed is fast, and the cost is lower than that of using an electro-hydraulic reversing valve.

[0050] Further, the hydraulic control check valve 131 can also supplement the oil when the oil supply of the oil inlet oil way 110 is insufficient. Taking the driving device as the motor 400 as an example, it should be noted that when the oil pump 300 stops working, the oil inlet oil way 110 on the oil inlet side of the hydraulic motor 400 will appear negative pressure under the action of the inertia rotation of the motor 400. The hydraulic control check valve 131 can make the hydraulic oil in the oil return oil way 120 connected with the oil return side of the motor 400 enter the oil inlet oil way 110 in reverse along the pressure relief oil way 130 through the hydraulic control check valve 131 (the hydraulic control check valve 131 is reversely conducted), thereby supplementing the oil for the oil inlet side of the motor 400.

[0051] The control oil way module 140 described above further includes an electromagnetic reversing valve 141, a pilot oil branch 142 and an oil return branch 143. The pilot oil branch 142 is connected with the oil inlet oil way 110 and the electromagnetic reversing valve 141, so that the oil inlet oil way 110 can provide the pilot hydraulic oil for the pilot oil branch 142; the oil return branch 143 is connected with the electromagnetic reversing valve 141 and is used for returning to the oil tank 200.

[0052] The electromagnetic reversing valve 141 controls the control end of the hydraulic control check valve 131 to communicate with the pilot oil branch 142 or the control end of the hydraulic control check valve 131 to communicate with the oil return branch 143 through valve position switching.

[0053] Specifically, in the embodiment, the electromagnetic reversing valve 141 includes a switchable first valve position and a second valve position. When the electromagnetic reversing valve 141 switches to the first valve position, the control end of the hydraulic control check valve 131 is in communication with the pilot oil branch 142, and since the pilot oil branch 142 is connected to the oil inlet oil line 110, when the oil inlet oil line 110 provides pilot hydraulic oil to the pilot oil branch 142, the pilot hydraulic oil directly acts on the control end of the hydraulic control check valve 131 through the electromagnetic reversing valve 141, and the hydraulic control check valve 131 is opened in reverse, at this time, the oil inlet oil line 110 and the oil return oil line 120 are communicated through the pressure relief oil line 130, and the hydraulic oil in the oil inlet oil line 110 enters the oil return oil line 120 through the pressure relief oil line 130, thereby achieving oil return and pressure relief.

[0054] When the electromagnetic reversing valve 141 switches to the second valve position, the control end of the hydraulic control check valve 131 is in communication with the oil return branch 143, at this time, the oil return branch 143 directly guides the hydraulic oil at the control end of the hydraulic control check valve 131 to the oil tank 200, so that the control oil of the hydraulic control check valve 131 is relieved, and the hydraulic control check valve 131 is closed under the pressure of the oil inlet oil line 110 (the pressure at the oil inlet end is greater than the pressure at the oil outlet end). It should be noted that the oil return branch 143 is designed to return to the oil tank 200, which can effectively avoid the problem that the hydraulic control check valve 131 cannot be closed due to back pressure, thereby ensuring the normal and stable operation of the control valve group 100.

[0055] Optionally, the electromagnetic reversing valve 141 is a plug-in reversing valve. Specifically, it can be a two-position three-way electromagnetic valve.

[0056] In the embodiment, the pilot oil branch 142 is provided with a check valve 144, the oil outlet end of the check valve 144 is in communication with the oil inlet oil line 110, and the oil inlet end of the check valve 144 is in communication with the electromagnetic reversing valve 141, specifically the oil port of the first valve position. In this way, when the pressure at the oil inlet end of the check valve 144 is greater than the pressure at the oil outlet end, the check valve 144 switches to the closed state, at this time, it can be ensured that the oil pressure between the check valve 144 and the hydraulic control check valve 131 is locked in the pipeline, so that the hydraulic control check valve 131 can always be kept in an open state (the electromagnetic reversing valve 141 is kept in the first valve position), that is, the pressure relief oil line 130 is kept in communication.

[0057] Further, the pilot oil branch 142 is also provided with a damping valve 145, and the damping valve 145 is located between the check valve 144 and the electromagnetic reversing valve 141. The arrangement of the damping valve 145 can stabilize the oil pressure of the pilot oil branch 142, avoid the pressure change of the oil inlet oil line 110, and cause the oil pressure of the pilot oil branch 142 to fluctuate greatly.

[0058] In the embodiment, the control valve group 100 further comprises a pressure regulating oil path 150 connected to the oil inlet path 110 and the oil return path 120, wherein the pressure regulating oil path 150 is provided with a proportional relief valve 151. In this way, the relief pressure of the pressure regulating oil path 150 can be controlled by the proportional relief valve 151, so as to control the oil return amount of the oil inlet path 110 through the pressure regulating oil path 150, control the flow into the driving device, and achieve the control of the working pressure or speed of the driving device.

[0059] Further, the proportional relief valve 151 is a reverse proportional relief valve 151. The input current value of the reverse proportional relief valve 151 is inversely proportional to the relief pressure. The greater the current, the smaller the relief pressure. The smaller the current, the greater the relief pressure value. In this way, the reverse proportional relief valve 151 is adopted, so that the relief valve is in a small current state for a long time during operation, avoiding damage to the relief valve by large current.

[0060] It should be noted that when the oil inlet path 110 is depressurized to 0 and the one-way valve member 144 is closed, the control current of the reverse proportional relief valve 151 becomes zero, preventing damage caused by long-time power supply.

[0061] Embodiment Two

[0062] Please refer to Figure 1 and Figure 2 , the embodiment provides a motor 400 driving system. The motor 400 driving system comprises an oil tank 200, an oil pump 300, a motor 400 and a control valve group 100 provided according to the above-mentioned embodiment one.

[0063] The oil pump 300 is connected to the oil tank 200 and is used to deliver hydraulic oil to the oil inlet path 110 in the control valve group 100; the oil inlet path 110 and the oil return path 120 are respectively connected to two oil ports (one is an oil inlet port and the other is an oil outlet port) of the motor 400, and the oil return path 120 is further connected to the oil tank 200.

[0064] Through the control valve group 100 and the control mode provided by the above-mentioned embodiment one, the main unloading and oil supplement functions of the motor 400 driving system are completed by the hydraulic control one-way valve 131, and the flow rate in the control valve group 100 is determined by the size of the hydraulic control one-way valve 131. When the motor 400 is working, the speed can be controlled by the reverse proportional relief valve 151, and when the motor 400 is not working, the high-pressure oil flows to the oil tank 200 through the oil return path 120 via the hydraulic control one-way valve 131, thereby achieving unloading. The problem of large flow hydraulic power of the electric-hydraulic reversing valve is solved by the low-cost hydraulic control one-way valve 131 + ordinary cartridge-type electromagnetic valve + one-way valve member 144 + damping valve 145, which is lower in cost and lighter in weight than the existing technology using the electric-hydraulic reversing valve.

[0065] Further, the embodiment also provides an engineering machine comprising the motor 400 driving system provided according to the above-mentioned embodiment two.

[0066] Embodiment Three

[0067] Please refer to Figure 1 and Figure 3 The embodiment provides a heat dissipation system. The heat dissipation system comprises an oil tank 200, an oil pump 300, a motor 400, a heat dissipation fan 500 and the control valve group 100 provided in the above embodiment one.

[0068] The oil pump 300 is connected to the oil tank 200 and used for delivering hydraulic oil to an oil inlet oil passage 110 in the control valve group 100; the oil inlet oil passage 110 and an oil return oil passage 120 are respectively connected to two oil ports of the motor 400, the oil return oil passage 120 is connected to the oil tank 200, and the motor 400 is in driving connection with the heat dissipation fan 500.

[0069] Through the control valve group 100 and the control mode provided in the above embodiment one, the main unloading and oil supplement functions of the motor 400 driving system are completed by the hydraulic control check valve 131, and the flow rate in the control valve group 100 is determined by the size of the hydraulic control check valve 131. When the motor 400 works, the rotating speed can be controlled through the inverse proportional overflow valve 151, and when the motor 400 does not work, the high-pressure oil flows to the oil tank 200 through the oil return oil passage 120 and the hydraulic control check valve 131, so that unloading is realized. Through the hydraulic control check valve 131+ordinary cartridge type electromagnetic valve+one-way valve 144+damping valve 145 with low cost, the problem of large flow electro-hydraulic reversing valve reversing hydraulic power is solved, and the cost is lower and the weight is lighter than those of the prior art.

[0070] Further, the embodiment also provides an engineering machinery comprising the heat dissipation system provided in the embodiment three.

[0071] The unloading and oil supplement functions of the heat dissipation system are integrated, the hydraulic control check valve 131+ordinary cartridge type electromagnetic valve+one-way valve+damping valve 145 are used to replace the electro-hydraulic reversing valve+one-way valve, the cost can be greatly reduced, the weight is reduced, the valve body is smaller in size and lighter in mass, and the reversing time is also reduced. For example, when the control valve flow rate is greater than or equal to 160L / min, a larger specification electro-hydraulic reversing valve needs to be selected. However, according to the scheme, the specification of the hydraulic control check valve 131 only needs to be changed to meet the design flow rate, the total cost of the hydraulic control check valve 131+ordinary cartridge type electromagnetic valve+one-way valve+damping valve 145 is reduced by more than half, and the advantages of light weight and short reversing time are more obvious.

[0072] In the above embodiments, the connection refers to connection through a pipeline unless otherwise specified.

[0073] It should be noted that in the present application, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0074] Electro-hydraulic reversing valve: the pressure oil is used to control the reversing of the main valve core, so as to overcome the hydraulic force during reversing. Hydraulic control check valve 131: normally only forward flow, good sealing when reversed, the valve can be opened in reverse flow when the control path has pressure.

[0075] Thus, the structure of the electro-hydraulic reversing valve and the hydraulic control check valve 131 is well known to those skilled in the art, and does not belong to the core improvement part of the present application, so it will not be described here.

[0076] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0077] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or communicate with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0078] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0079] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A control valve assembly, characterized in that, include: Oil inlet line (110); Return oil line (120); A pressure relief oil circuit (130) connects the inlet oil circuit (110) and the return oil circuit (120). A hydraulically controlled check valve (131) is installed on the pressure relief oil circuit (130), and the inlet end of the hydraulically controlled check valve (131) is connected to the inlet oil circuit (110). The control oil circuit module (140) is used to control the pilot hydraulic oil to act on the control end of the hydraulic control check valve (131) to open the hydraulic control check valve (131) in reverse.

2. The control valve assembly according to claim 1, characterized in that, The control oil circuit module (140) includes: Electromagnetic directional valve (141); A pilot oil branch (142) connects the oil inlet circuit (110) and the solenoid directional valve (141); and The return oil branch (143) is connected to the solenoid directional valve (141) and is used to return the oil to the oil tank (200); The electromagnetic reversing valve (141) controls the control end of the hydraulic control check valve (131) to connect with the pilot oil branch (142) or controls the control end of the hydraulic control check valve (131) to connect with the return oil branch (143) by switching the valve position.

3. The control valve assembly according to claim 2, characterized in that, The pilot oil branch (142) is provided with a one-way valve (144), and the oil outlet end of the one-way valve (144) is connected to the oil inlet (110).

4. The control valve assembly according to claim 3, characterized in that, The pilot oil branch (142) is also provided with a damping valve (145), which is located between the one-way valve (144) and the solenoid directional valve (141).

5. The control valve assembly according to claim 2, characterized in that, The electromagnetic directional valve (141) is a cartridge-type directional valve.

6. The control valve assembly according to any one of claims 1-5, characterized in that, The control valve assembly (100) further includes a pressure regulating oil circuit (150), which is connected to the oil inlet circuit (110) and the oil return circuit (120); The pressure regulating oil circuit (150) is equipped with a proportional relief valve (151).

7. The control valve assembly according to claim 6, characterized in that, The proportional relief valve (151) is an inverse proportional relief valve (151).

8. A motor drive system, characterized in that, The system includes an oil tank (200), an oil pump (300), a motor (400), and a control valve assembly (100) according to any one of claims 1-7, wherein the oil pump (300) is connected to the oil tank (200) and is used to supply hydraulic oil to the oil inlet passage (110) in the control valve assembly (100); The oil inlet passage (110) and the oil return passage (120) are respectively connected to the two oil ports of the motor (400), and the oil return passage (120) is connected to the oil tank (200).

9. A heat dissipation system, characterized in that, The system includes an oil tank (200), an oil pump (300), a motor (400), a cooling fan (500), and a control valve assembly (100) according to any one of claims 1-7, wherein the oil pump (300) is connected to the oil tank (200) and is used to supply hydraulic oil to the oil inlet passage (110) in the control valve assembly (100); The oil inlet passage (110) and the oil return passage (120) are respectively connected to the two oil ports of the motor (400), the oil return passage (120) is connected to the oil tank (200), and the motor (400) is connected to the cooling fan (500) in a drive connection.

10. An engineering machinery, characterized in that, Includes the motor (400) drive system according to claim 8, or includes the heat dissipation system according to claim 9.

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