Built-in bidirectional independent flow control valve structure

Abstract

This utility model relates to a built-in bidirectional independent flow control valve structure, belonging to the field of hydraulic transmission technology. It includes a flow valve assembly located within a valve stem hole in a motor cover, first elastic components at both ends of the flow valve assembly, and screw plugs located at both ends of the valve stem hole and respectively abutting against the two first elastic components. The flow valve assembly includes a valve stem, two valve cores symmetrically installed at both ends of the valve stem, central through-holes located on the outer sides of the two valve cores, and a second elastic component located between the valve cores and the central through-holes. The valve stem has a symmetrical structure with an annular groove on its outer wall. An oil passage hole is formed in the annular groove, and a cavity connecting the oil passage hole is provided inside the valve stem. The oil passage hole is interconnected with the valve core hole inside the valve stem and the cavity. The valve stem moves axially within the valve stem hole, and the valve cores open and close independently within the valve stem under hydraulic pressure. This utility model simplifies the structure and reduces costs, providing bidirectional independent control functionality; failure on one side does not affect the operation of the other side.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic transmission technology, and in particular to a hydraulic motor for a closed hydraulic system, specifically a structure with a built-in bidirectional independent flow control valve. Background Technology

[0002] Closed-loop hydraulic systems are widely used in engineering and agricultural machinery. In these systems, hydraulic oil continuously circulates in a closed loop between the pump and motor, which can easily lead to overheating and high temperatures. To address this problem, a common practice is to install a flushing flow valve in the motor circuit. This valve works by diverting some of the high-temperature hydraulic oil from the low-pressure side of the motor to the motor housing or oil tank for cooling, and then replenishing it with a corresponding amount of cooler hydraulic oil from the tank. This achieves the goal of circulating cooling, controlling, and reducing the system temperature.

[0003] Commonly used flushing flow valves include Figure 1 As shown, it is generally a cartridge structure, consisting of numerous components such as valve sleeve 1', flat sealing ring 2', gasket 3', fixing rod 4', second spring 5', spring seat 6', first spring 7', second O-ring seal 8', second retaining ring 9', valve core 10', valve stem 11', first O-ring seal 12', first retaining ring 13', third O-ring seal 14', third retaining ring 15', sealing cap 16', and wire stop 17'.

[0004] This structure has the following drawbacks: In terms of structural design, its complexity results in a large number of parts, leading to extremely stringent requirements for machining precision and ultimately making it difficult to reduce manufacturing costs. Regarding functionality, the valve core and valve stem typically employ a linked design or share a single valve body or sleeve. If any part malfunctions or becomes stuck, the cooling function of both oil ports on the motor often fails simultaneously, significantly reducing system reliability and posing a substantial safety hazard. In terms of maintenance, the use of wire retaining rings and other fixing structures makes disassembly during after-sales repairs difficult, consuming considerable time and manpower.

[0005] Therefore, there is an urgent need in this field for a built-in flow valve that is simple in structure, low in cost, highly reliable, and capable of bidirectional independent operation, that is, when the valve core on one side fails, the other side can still work normally, thereby greatly improving the working reliability and safety of the motor in the closed hydraulic system. Utility Model Content

[0006] The purpose of this invention is to provide a built-in bidirectional independent flow control valve structure to solve the problems of complex structure, poor independence, and difficult maintenance in the prior art.

[0007] To achieve the above objectives, the present invention provides a built-in bidirectional independent flow control valve structure, including a flow valve assembly located in the valve stem hole of the motor cover, first elastic components located at both ends of the flow valve assembly, and screw plugs located at both ends of the valve stem hole and respectively abutting against the two first elastic components. The flow valve assembly includes a valve stem, two valve cores symmetrically installed at both ends of the valve stem, central through screw plugs respectively located on the outer sides of the two valve cores, and a second elastic component located between the valve cores and the central through screw plugs. The valve stem has a symmetrical structure with an annular groove on its outer wall. A third oil passage hole and a fourth oil passage hole are provided on the annular groove. The valve stem has a cavity inside that connects the third oil passage hole and the four fourth oil passage holes at both ends. The third oil passage hole and the fourth oil passage hole are interconnected through the valve core hole and the cavity inside the valve stem. The valve stem moves axially within the valve stem hole, and the valve cores open and close independently within the valve stem under oil pressure, thereby achieving bidirectional independent flushing and cooling of the low-pressure side oil circuit of the motor.

[0008] Preferably, the valve core has an axial valve core throttling hole at the center of its left end face, a sixth oil passage hole communicating with the valve core throttling hole is radially opened at one end of the valve core, a seventh oil passage hole is radially opened on the side wall of the other end of the valve core, and an axial eighth oil passage hole is provided at the center of the right end face of the valve core, with the seventh oil passage hole communicating with the eighth oil passage hole.

[0009] Preferably, the inner wall of the valve stem hole is provided with five sequentially arranged first annular cylindrical surfaces, second annular cylindrical surfaces, third annular cylindrical surfaces, fourth annular cylindrical surfaces and fifth annular cylindrical surfaces. A first oil passage hole is radially opened on the first annular cylindrical surface, and a second oil passage hole is radially opened on the fifth annular cylindrical surface.

[0010] Preferably, the center of the through-hole plug has a ninth oil passage hole, the through-hole plug is connected to the end of the valve stem by a thread, and the second spring is placed between the through-hole plug and the valve core. Under the preload of the second spring, the valve core abuts against the end face of the valve stem to achieve a sealing fit.

[0011] Preferably, a spring seat and a first spring are sequentially provided on the inner sides of both ends of the valve stem hole. One end of the first spring acts on the screw plug, and the other end acts on the spring seat. The spring seat then acts on the valve stem end of the flow valve assembly, so that the flow valve assembly is in the center position.

[0012] Preferably, the spring seat has a damping hole.

[0013] Preferably, the valve stem hole has a first threaded hole and a second threaded hole at both ends for connecting the screw plug.

[0014] Preferably, the O-ring is disposed between the screw plug and the motor cover.

[0015] In summary, this utility model has the following beneficial technical effects: This invention achieves a high degree of integration and structural simplification by embedding the flow valve within the motor cover, significantly reducing the number of external connections and parts. This design not only lowers production costs but also improves the reliability and stability of the system. Compared to traditional cartridge valves, this invention solves problems such as complex structure, high processing costs, and poor independence, providing a more efficient and economical solution for hydraulic systems.

[0016] The bidirectional independent control function is another significant advantage of this invention. The valve core units on both sides are completely independent; even if one side fails, it will not affect the normal operation of the other side, thus greatly improving the system's reliability. In practical applications, this design ensures stable operation of the hydraulic system under complex working conditions, avoids system downtime due to single-point failures, and greatly enhances the system's safety and availability.

[0017] In terms of maintenance, this invention is designed for ease of use, allowing for easy internal repairs and replacements simply by removing the screw plug. This convenient operation significantly reduces maintenance time and costs, improving the maintainability of the equipment. Furthermore, the compact built-in structure of this invention, through the coordinated movement of the valve stem and the opening of the valve core, precisely controls the flushing flow from the low-pressure side to the motor housing, ensuring stable heat dissipation and further extending the equipment's service life.

[0018] This invention has a wide range of applications, including closed-loop hydraulic systems in engineering machinery, agricultural machinery, and other applications. Its unique bidirectional independent flow control function provides strong technical support for the efficient and stable operation of hydraulic motors under various working conditions. By precisely controlling the movement of the valve stem and the opening process of the valve core, this invention achieves bidirectional independent flushing and cooling of the low-pressure side oil circuit of the motor, effectively improving the operating efficiency and reliability of the hydraulic system. It possesses significant innovation and practicality, providing a strong guarantee for the efficient operation of hydraulic equipment. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a cartridge-type flushing flow valve in the prior art; Figure 2 This is a schematic cross-sectional view of the overall structure of this utility model; Figure 3 for Figure 2 Enlarged structural schematic diagram of the medium flow valve assembly; Figure 4 This is a cross-sectional structural diagram of the motor cover in this utility model; Figure 5 for Figure 3 Schematic diagram of the middle valve stem; Figure 6 for Figure 3 Schematic diagram of the middle valve core; Figure 7 for Figure 3 A schematic diagram of the structure of the through-hole plug.

[0020] Figure label: 1. Motor cover; 101. First working oil passage; 102. Second working oil passage; 103. First threaded hole; 104. First annular cylindrical surface; 105. First oil passage hole; 106. Third annular cylindrical surface; 107. Second oil passage hole; 108. Fifth annular cylindrical surface; 109. Second threaded hole; 2. Plug; 3. O-ring; 4. First spring; 5. Spring seat; 6. Flow valve assembly; 7. Through plug; 701. Ninth oil passage hole; 8. Second spring; 9. Valve core; 901. Valve core throttling hole; 902. Sixth oil passage hole; 903. Seventh oil passage hole; 904. Eighth oil passage hole; 10. Valve stem; 1001. Annular groove; 1002. Third oil passage hole; 1003. Valve core hole; 1004. Fourth oil passage hole; 1005. Fifth oil passage hole; 1' Valve sleeve; 2' Flat sealing ring; 3' Gasket; 4' Fixing rod; 5' Second spring; 6' Spring seat; 7' First spring; 8' Second O-ring seal; 9' Second retaining ring; 10' Valve core; 11' Valve stem; 12' First O-ring seal; 13' First retaining ring; 14' Third O-ring seal; 15' Third retaining ring; 16' Sealing cap; 17' Wire stop. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Example 1: This utility model discloses a built-in bidirectional independent flow control valve structure, including a motor cover 1, a screw plug 2, an O-ring 3, a first spring 4, a spring seat 5, a flow valve assembly 6, a central screw plug 7, a second spring 8, a valve core 9, a valve stem 10, and other components. The components cooperate with each other to realize the bidirectional independent flushing and cooling function of the low-pressure side oil circuit of the motor.

[0023] The motor cover 1 is the basic component of this structure, and a horizontal valve stem hole is machined inside it, within which the flow valve assembly 6 is disposed. The inner wall of the valve stem hole has five sequentially arranged annular cylindrical surfaces, from left to right: a first annular cylindrical surface 104, a second annular cylindrical surface 106, a fourth annular cylindrical surface 108, and a fifth annular cylindrical surface 105. The first annular cylindrical surface 104 has a first oil passage hole 105 radially formed, and the fifth annular cylindrical surface 108 has a second oil passage hole 107 radially formed. Both oil passage holes lead to the motor housing cavity, which is connected to the oil tank, thus providing a path for oil return. The third annular cylindrical surface 106 isolates the first working oil passage 101 and the second working oil passage 102, forming two independent working chambers, ensuring independent flow and control of oil between the different oil passages.

[0024] The valve stem hole of the motor cover 1 is provided with a first threaded hole 103 and a second threaded hole 109 at both ends. The screw plug 2 is screwed into these two threaded holes, and an O-ring 3 is provided between the screw plug 2 and the motor cover 1. The O-ring 3 can effectively prevent oil leakage and ensure the sealing of the valve hole.

[0025] The flow valve assembly 6 is the core component for realizing flow control and cooling functions. It includes a valve stem 10 and two valve cores 9 symmetrically installed at both ends of the valve stem 10. Through the axial movement of the valve stem 10 in the hole of the motor cover 1 and the independent opening and closing of the valve cores 9 under oil pressure, bidirectional independent flushing and cooling of the low-pressure side oil circuit of the motor can be achieved.

[0026] The valve stem 10 has a symmetrical structure. Its outer wall has an annular groove 1001, on which a third oil passage 1002 and a fourth oil passage 1004 are formed. The fourth oil passage 1004 is located to the left of the third oil passage 1002. The valve stem 10 has an internal cavity connecting the third oil passage 1002 and the two fourth oil passages 1004. Both the third and fourth oil passages are interconnected through a valve core hole 1003 and the cavity inside the valve stem 10. Additionally, a fifth oil passage 1005, symmetrical to the third oil passage 1002, is located at the left end of the valve stem 10. The valve stem 10 has a valve core hole 1003 inside, and the internal cavity connects to the oil passages at both ends, allowing oil to flow within the valve stem 10. Each valve stem 10 has the same structure, including a central plug 7, a second spring 8, and a valve core 9. The through-hole plug 7 is connected to the end of the valve stem 10 via a thread. The second spring 8 is placed between the through-hole plug 7 and the valve core 9. Under the preload of the second spring 8, the valve core 9 abuts against the end face of the valve stem 10, thereby achieving a sealing fit.

[0027] The valve core 9 has an axial throttling orifice 901 at its center on the left end face. One end of the valve core 9 has a radially opening sixth oil passage 902 communicating with the throttling orifice 901. The other end of the valve core 9 has a radially opening seventh oil passage 903 on its side wall. The right end face of the valve core 9 has an axial eighth oil passage 904 at its center, with the seventh and eighth oil passages communicating with each other. These oil passages, in conjunction with the throttling orifice 901, enable the throttling and reversing functions of the oil. The center of the through-hole plug 7 has a ninth oil passage 701 for oil flow and pressure balance, ensuring smooth oil flow and stable pressure within the valve core 9. The spring seat 5 has a damping orifice, which can be used to adjust the dynamic response characteristics of the system, allowing for smoother flow control and switching during operation. The valve core 9 units at both ends have identical structures, allowing for bidirectional installation and independent operation, achieving bidirectional flow.

[0028] To ensure the flow valve assembly 6 is centered under no-pressure conditions, spring seats 5 and first springs 4 are sequentially installed on the inner sides of both ends of the valve stem hole. One end of the first spring 4 acts on the plug 2, and the other end acts on the spring seat 5, which in turn acts on the end of the valve stem 10 of the flow valve assembly 6. Under the action of the first springs 4 at both ends, the flow valve assembly 6 can be maintained in the centered position of the valve stem hole, ensuring a sealing fit between the valve core 9 and the end face of the valve stem 10, and also providing a basis for flow regulation under different operating conditions.

[0029] During assembly, the O-ring 3, the first spring 4, and the spring seat 5 are first placed into the valve stem holes at both ends of the motor cover 1 in sequence. Then, the assembled flow valve assembly 6 is installed, and finally, the screw plug 2 is used to seal and tighten it. Under the action of the first spring 4 at both ends, the flow valve assembly 6 is in the center position, thus completing the assembly of the entire built-in bidirectional independent flow control valve structure.

[0030] The working principle of this utility model structure (taking the high-pressure oil inlet of the first working oil circuit 101 as an example) is as follows: When high-pressure oil enters from the first working oil passage 101, the oil enters the sealing chamber a through the fourth oil passage 1004 on the left side of the valve stem 10. The oil pressure pushes the entire flow valve assembly 6 to move to the right, overcoming the force of the first spring 4 on the right. At the same time, the second working oil passage 102, as a low-pressure return oil passage, exerts its oil pressure on the right valve core 9. After overcoming the force of the second spring 8, it pushes the right valve core 9 to move to the right, causing it to separate from the end face of the valve stem 10 and form a gap.

[0031] At this time, the low-pressure return oil flows sequentially through the fourth oil passage 1004 on the right, the valve core throttling orifice 901, the sixth oil passage 902, the inner cavity of the valve stem 10, the third oil passage 1002, the annular groove 1001, and the second oil passage 107, finally flowing into the inner cavity of the motor housing and returning to the oil tank, thus completing the flushing and cooling of the low-pressure side oil. During this process, the first oil passage 105 on the left is blocked and sealed by the cylindrical surface of the valve stem 10, ensuring that the high-pressure oil inlet circuit is not directly connected to the motor housing cavity.

[0032] When the system reverses direction, the operation is reversed. When hydraulic oil enters from the second working oil circuit 102 on the right, the flow valve assembly 6 moves to the left, and the valve core 9 unit on the left opens independently, realizing the reverse flushing and cooling function. The flow control in the two directions is completely independent and does not interfere with each other. In this way, the built-in bidirectional independent flow control valve structure can effectively perform bidirectional independent flushing and cooling of the low-pressure side oil circuit of the motor, ensuring the reliability and service life of the motor during operation.

[0033] The built-in bidirectional independent flow control valve structure disclosed in this utility model embodiment, through reasonable design and close cooperation between various components, realizes the bidirectional independent flushing and cooling function of the low-pressure side oil circuit of the motor. It has the advantages of compact structure, reliable operation and convenient assembly, and can be widely used in hydraulic motor systems, providing a strong guarantee for the efficient operation of hydraulic equipment.

[0034] Example 2: Based on Embodiment 1, this embodiment also discloses a control method for the aforementioned built-in bidirectional independent flow control valve structure. This method, by precisely controlling the movement of the valve stem 10 and the opening process of the valve core 9, achieves bidirectional independent flushing and cooling of the low-pressure side oil circuit of the motor, effectively improving the operating efficiency and reliability of the hydraulic system. It includes the following steps: When the first working oil passage 101 is used as a high-pressure oil inlet, high-pressure hydraulic oil enters the system and pushes the flow valve assembly 6 to move toward the second working oil passage 102, thereby compressing the first spring 4 on that side. The low-pressure oil in the second working oil circuit 102, under the action of pressure difference, pushes the valve core 9 on this side to overcome the elastic force of the second spring 8 and open the oil circuit passage. Low-pressure oil flows into the motor housing cavity through the flow channel inside the valve stem 10, the annular groove 1001, and the second oil passage 107, thereby effectively cooling the low-pressure side oil circuit of the motor and ensuring the stability and safety of the hydraulic system under high load operation. When the second working oil circuit 102 is converted to a high-pressure oil inlet circuit, the flow valve assembly 6 moves in the opposite direction under the push of hydraulic oil, and the valve core 9 unit on the other side opens independently under the action of pressure difference, realizing the reverse flushing and cooling function.

[0035] This process not only ensures the cooling requirements of the motor under different operating conditions, but also achieves bidirectional independent flow control through the non-interference design of the 9 valve core units on both sides. This avoids the problem of oil cross-interference that exists in traditional unidirectional flow control valves in bidirectional systems, and significantly improves the control accuracy and response speed of the hydraulic system.

[0036] The control method of this utility model cleverly utilizes the pressure change of hydraulic oil to drive the coordinated action of valve stem 10 and valve core 9, realizing bidirectional independent flushing and cooling of the low-pressure side oil circuit of the motor. This provides strong technical support for the efficient and stable operation of hydraulic motors under complex working conditions, and has significant innovation and practicality.

[0037] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A built-in bidirectional independent flow control valve structure, characterized in that: The flow valve assembly (6) includes a flow valve assembly (6) located in the valve stem hole of the motor cover (1), first elastic components located at both ends of the flow valve assembly (6), and screw plugs (2) located at both ends of the valve stem hole and respectively abutting against the two first elastic components. The flow valve assembly (6) includes a valve stem (10), two valve cores (9) symmetrically installed at both ends of the valve stem (10), through screw plugs (7) respectively located on the outside of the two valve cores (9), and a second elastic component located between the valve cores (9) and the through screw plugs (7). The valve stem (10) has a symmetrical structure and its outer wall is provided with an annular groove (1001). The annular groove (1001) is provided with a third oil passage hole (1002) and a fourth oil passage hole (1004). The valve stem (10) is provided with a cavity that connects the third oil passage hole (1002) and the fourth oil passage holes (1004) at both ends. The third oil passage hole (1002) and the fourth oil passage hole (1004) are connected to each other through the valve core hole (1003) inside the valve stem (10) and the cavity. The valve stem (10) moves axially in the valve stem hole. The valve core (9) is opened and closed independently in the valve stem (10) under the action of oil pressure, so as to realize bidirectional independent flushing and cooling of the low-pressure side oil circuit of the motor.

2. The built-in bidirectional independent flow control valve structure according to claim 1, characterized in that, The valve core (9) has an axial valve core throttling hole (901) at the center of its left end face. One end of the valve core (9) has a sixth oil passage hole (902) that communicates with the valve core throttling hole (901) in a radial direction. The other end of the valve core (9) has a seventh oil passage hole (903) in a radial direction on its side wall. The right end face of the valve core (9) has an axial eighth oil passage hole (904) at the center. The seventh oil passage hole (903) communicates with the eighth oil passage hole (904).

3. The built-in bidirectional independent flow control valve structure according to claim 2, characterized in that, The inner wall of the valve stem hole is provided with five sequentially arranged first annular cylindrical surfaces (104), second annular cylindrical surfaces (106), third annular cylindrical surfaces (107), fourth annular cylindrical surfaces (108), and fifth annular cylindrical surfaces (108). The first annular cylindrical surface (104) is provided with a first oil passage hole (105) in the radial direction, and the fifth annular cylindrical surface (108) is provided with a second oil passage hole (107) in the radial direction.

4. The built-in bidirectional independent flow control valve structure according to claim 3, characterized in that, The center of the through-hole plug (7) is provided with a ninth oil passage hole (701). The through-hole plug (7) is connected to the end of the valve stem (10) by a thread. The second spring (8) is placed between the through-hole plug (7) and the valve core (9). Under the preload of the second spring (8), the valve core (9) abuts against the end face of the valve stem (10) to achieve a sealing fit.

5. The built-in bidirectional independent flow control valve structure according to claim 4, characterized in that, A spring seat (5) and a first spring (4) are sequentially arranged on the inner side of both ends of the valve stem hole. One end of the first spring (4) acts on the screw plug (2) and the other end acts on the spring seat (5). The spring seat (5) then acts on the end of the valve stem (10) of the flow valve assembly (6), so that the flow valve assembly (6) is in the center position.

6. The built-in bidirectional independent flow control valve structure according to claim 5, characterized in that, The spring seat (5) has a damping hole.

7. The built-in bidirectional independent flow control valve structure according to claim 4, characterized in that, The valve stem hole is provided with a first threaded hole (103) and a second threaded hole (109) at both ends for connecting the screw plug (2).

8. The built-in bidirectional independent flow control valve structure according to claim 4, characterized in that, An O-ring (3) is disposed between the plug (2) and the motor cover (1).

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