A type of overflow valve for a walking motor

Abstract

This utility model belongs to the technical field of hydraulic components and discloses a relief valve for a walking motor, including a valve body and a plug fixedly connected to the end of the valve body. A sealing groove is formed between the outer peripheral wall of the plug and the inner peripheral wall of the valve body, and a sealing ring is installed in the sealing groove. The inner peripheral wall of the valve body includes a first wall and a second wall. The sealing ring abuts against the first wall, and the plug is fixedly connected to the second wall. The first wall has a first end away from the second wall and a second end close to the second wall along the axial direction. The vertical distance from the first end to the axis is denoted as L1, and the vertical distance from the second end to the axis is denoted as L2, where L1 is greater than L2. Under the same compression, the sealing ring of the relief valve of this utility model has a smaller effective contact area on the side of the sealing ring closer to the second end, which reduces the risk of the sealing ring detaching away from the second end due to the force. At the same time, it can also improve the sealing performance after the sealing ring is matched with the valve body and the plug to a certain extent.

Description

Technical Field

[0001] This utility model relates to the technical field of hydraulic components, and in particular to a relief valve for a walking motor. Background Technology

[0002] The relief valve is a key pressure control component in a hydraulic system. Its function is to limit system pressure and ensure the safe and stable operation of the system. A relief valve typically consists of a valve body, valve core, spring, and plug. The valve core closes the oil port under the preload of the spring, and the plug is usually used to seal the end of the valve body. When the system pressure increases, the hydraulic oil acts on the end face of the valve core and overcomes the spring preload to open the oil port, thus achieving the pressure relief process.

[0003] When relief valves are used in high-pressure applications such as excavator travel motor systems, the hydraulic pressure in the hydraulic system is usually high. After long-term action of high-pressure hydraulic oil on the relief valve, leakage may occur at the connection between the plug and the valve body.

[0004] Therefore, a walking motor overflow valve is needed to solve the above problems. Utility Model Content

[0005] The purpose of this utility model is to provide a travel motor relief valve. Through the design of the plug and valve body structure, combined with the sealing fit between the sealing ring and the sealing groove, the travel motor relief valve can still have good sealing performance under long-term high pressure environment, and minimize the possibility of hydraulic oil leakage from the connection between the plug and the valve body.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A travel motor overflow valve includes a valve body and a plug fixedly connected to the end of the valve body. A sealing groove is formed between the outer peripheral wall of the plug and the inner peripheral wall of the valve body. A sealing ring is installed in the sealing groove. The inner peripheral wall of the valve body includes a first wall and a second wall. The sealing ring abuts against the first wall, and the plug is fixedly connected to the second wall. The first wall has a first end away from the second wall and a second end close to the second wall along the axial direction. The vertical distance from the first end to the axis of the valve body is denoted as L1, and the vertical distance from the second end to the axis is denoted as L2, where L1 is greater than L2.

[0008] Preferably, the inner peripheral wall of the valve body further includes a third wall for connecting the first wall and the second wall. The plug includes a small diameter section, a transition connecting section and a large diameter section. The sealing ring abuts against the small diameter section, the transition connecting section abuts against the third wall, and the transition connecting section and the third wall form a buffer space. The large diameter section is fixedly connected to the second wall.

[0009] Preferably, the angle between the first wall and the axis of the valve body is denoted as α, and the angle between the third wall and the axis of the valve body is denoted as β, where α is less than β.

[0010] Preferably, the outer diameter of the smaller diameter segment is less than or equal to the inner diameter of the second wall.

[0011] Preferably, the plug further includes an end cap, which abuts against the end face of the valve body to seal the sealing groove, and the sealing ring abuts against the end cap.

[0012] Preferably, the overflow valve further includes a valve core assembly, which includes a conical valve core, a return spring, and a retaining ring. The valve body has an oil inlet and an oil return port. The conical valve core is guided and slidably disposed in the valve body to open or close the oil passage between the oil inlet and the oil return port. The retaining ring is installed in the valve body. The two ends of the return spring abut against the retaining ring and the conical valve core respectively, so that the conical valve core closes the oil passage between the oil inlet and the oil return port.

[0013] Preferably, the valve core assembly further includes a spool valve core and a limiting piston. The limiting piston is fixedly installed in the valve body, and the spool valve core slides and engages with the limiting piston. One end of the spool valve core extends out of the limiting piston and abuts against the plug. A first chamber is formed inside the spool valve core, and a conical valve core extends into the spool valve core and slides and engages with the spool valve core. The conical valve core has a first damping channel communicating with the first chamber, and the spool valve core has a second damping channel communicating with the first chamber. A force-receiving groove communicating with the second damping channel is formed on the end face of the spool valve core that abuts against the plug.

[0014] Preferably, the first damping channel includes a first damping hole, a second damping hole, a third damping hole, and a fourth damping hole. The first damping hole is arranged axially along the cone valve core and communicates with the oil inlet. The second damping hole is arranged circumferentially along the cone valve core. The first damping hole and the second damping hole are connected through a radial channel. The fourth damping hole is arranged axially and communicates with the first chamber. The second damping hole and the fourth damping hole are connected through the radially arranged third damping hole.

[0015] Preferably, the valve core has an annular step, and the retaining ring is disposed outside the valve core and is axially limited by the action of the annular step.

[0016] Preferably, the end face of the plug away from the valve body has a tool groove.

[0017] The beneficial effects of this utility model are:

[0018] The vertical distance between the first end of the relief valve and the central axis of the valve body is denoted as L1, and the vertical distance between the second end and the central axis of the valve body is denoted as L2. The setting that L1 is greater than L2 is so that when the relief valve is applied in the field of engineering machinery, such as the high-pressure environment of the excavator travel motor system, the hydraulic oil acts on one side of the plug for a long time. This causes the sealing ring to have a smaller effective contact area on the side closer to the second end under the same compression. As a result, the force on the side of the sealing ring closer to the second end is reduced, thereby reducing the risk of the sealing ring detaching away from the second end due to the force. At the same time, it can also improve the sealing performance after the sealing ring is matched with the valve body and the plug to a certain extent.

[0019] The angle between the first wall of the overflow valve and the central axis of the valve body is denoted as α, and the angle between the third wall and the central axis of the valve body is denoted as β. With α being greater than β, compared to other schemes, the sealing ring has less room for movement on the side near the end cover. At the same time, under the same compression, the contact area between the sealing ring and the first wall, the end face of the end cover, and the small diameter section is greater, which can improve the sealing performance of the sealing ring to a certain extent. Attached Figure Description

[0020] Figure 1 This is a cross-sectional structural schematic diagram of the overflow valve provided by this utility model;

[0021] Figure 2 This is a cross-sectional structural schematic diagram of the slide valve core and cone valve core provided by this utility model;

[0022] Figure 3 This is an exploded structural diagram of the connection between the plug and the valve body provided by this utility model.

[0023] In the picture:

[0024] 1. Valve body; 11. Oil inlet; 12. Oil return port; 13. Stepped groove; 14. First wall; 141. First end; 142. Second end; 15. Second wall; 16. Third wall; 17. Buffer space;

[0025] 2. End cap; 21. End cap; 22. Small diameter section; 23. Transition connection section; 24. Large diameter section;

[0026] 3. Valve core assembly; 31. Cone valve core; 311. First damping channel; 3111. First damping orifice; 3112. Second damping orifice; 3113. Third damping orifice; 3114. Fourth damping orifice; 3115. Flow channel; 312. Limiting part; 32. Return spring; 33. Retaining ring; 34. Slide valve core; 341. Annular step; 342. First chamber; 343. Force groove; 344. Second damping channel; 35. Limiting piston;

[0027] 4. Valve seat; 5. Sealing ring; 6. Tool groove; 7. Sealing groove. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0029] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] In the description of this embodiment, the terms "upper," "lower," "left," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0032] A relief valve typically consists of a valve body, valve core, spring, and plug. The valve body has an inlet and an outlet. The valve core slides within the valve body and opens or closes the oil passage between the inlet and outlet. The plug is usually fixed to the end of the valve body furthest from the inlet to seal the valve body end. The spring is installed within the valve body and ensures that the valve core initially closes the oil passage between the inlet and outlet. However, when this type of relief valve is used in construction machinery, such as in high-pressure environments like excavator travel motor systems, where oil pressure can typically reach 420 bar, higher requirements are placed on the sealing performance at the connection between the plug and the valve body. Prolonged use in such scenarios may lead to hydraulic oil leakage at this connection.

[0033] like Figures 1-3 As shown, this embodiment provides a travel motor overflow valve, including a valve body 1, a plug 2, and a valve core assembly 3. The valve body 1 has a through-hole along its axial direction. The plug 2 is fixedly connected to one end of the valve body 1 to close the valve body 1. The fixed connection can be a threaded connection or an interference fit between the plug and the valve body. A valve seat 4 is fixedly connected to the other end of the valve body 1. The valve seat 4 has an oil inlet 11 communicating with the through-hole along its axial direction. Multiple return ports 12 communicating with the through-hole are circumferentially formed on the side wall of the valve body 1 near the oil inlet 11. The valve core assembly 3 is installed within the through-hole and is used to open or close the oil passage between the oil inlet 11 and the return ports 12. In other embodiments, the other end of the valve body 1 may also have a direct oil inlet 11.

[0034] Reference Figures 1-3 The valve core assembly 3 includes a cone valve core 31, a return spring 32, a retaining ring 33, a spool valve core 34, and a limiting piston 35. A stepped groove 13 is formed at the end of the channel within the valve body 1 near the plug 2. The limiting piston 35 is fixedly connected to the stepped groove 13 and has a hollow tubular structure. The spool valve core 34 is slidably connected to the limiting piston 35. One end of the spool valve core 34 near the plug 2 extends out of the limiting piston 35 and abuts against the plug 2, and the diameter of this end is larger than the inner diameter of the limiting piston 35 (the inner diameter refers to the diameter of the hollow channel of the limiting piston 35). The other end of the spool valve core 34 extends out of the limiting piston 35 and forms an annular step 341. The retaining ring 33 is fixedly connected to the annular step 341 and abuts against the annular step 341 to achieve axial limiting of the retaining ring 33. The spool valve core 34 has a first chamber 342. One end of the cone valve core 31 extends into the first chamber 342 and slides in cooperation with the spool valve core 34. The other end of the cone valve core 31 slides in cooperation with the valve body 1 and abuts against the valve seat 4. The end of the cone valve core 31 near the oil inlet 11 is integrally formed with a limiting part 312. The two ends of the return spring 32 abut against the retaining ring 33 and the limiting part 312 respectively, so that the cone valve core 31 presses against the valve seat 4 in the initial state and closes the oil passage between the oil inlet 11 and the oil return port 12.

[0035] The cone valve core 31 has a first damping channel 311 connected to the first chamber 342. The first damping channel 311 includes a first damping hole 3111, a second damping hole 3112, a third damping hole 3113, and a fourth damping hole 3114. The first damping hole 3111 is opened axially along the cone valve core 31 and is connected to the oil inlet 11. The second damping hole 3112 is opened circumferentially along the cone valve core 31 and is located on the side of the first damping hole 3111 away from the oil inlet 11. The second damping hole 3112 and the first damping hole 3111 are connected by a flow channel 3115 arranged radially along the cone valve core 31 and an axially arranged flow channel 3115. The third damping hole 3113 is arranged radially along the cone valve core 31 and is connected to the second damping hole 3112. The fourth damping hole 3114 is opened axially along the cone valve core 31 and connects the third damping hole 3113 and the first chamber 342. A force-receiving groove 343 is provided on the end face of the spool valve core 34 that abuts against the plug 2. A second damping channel 344 is provided along the axial direction of the spool valve core 344. The second damping channel 344 connects the force-receiving groove 343 and the first chamber 342. The cross-sectional area of ​​the force-receiving groove 343 is much larger than the cross-sectional area of ​​the second damping channel 344, so as to provide the working area of ​​the hydraulic oil and give the cone valve core 31 the force to press against and close the oil passage between the oil inlet 11 and the oil return port 12.

[0036] Initially, the return spring 32 is compressed. The force generated at one end of the return spring 32 acts on the retaining ring 33. Due to the axial limiting fit between the annular step 341 and the retaining ring 33, the retaining ring 33 applies force to the spool valve core 34, causing the spool valve core 34 to abut against the plug 2. The force generated at the other end of the return spring 32 acts on the limiting part 312 of the cone valve core 31, causing the cone valve core 31 to abut against the valve seat 4 and close the oil passage between the inlet port 11 and the return port 12. When oil enters from the inlet port 11, the oil accumulates at the inlet port 11 due to the action of the cone valve core 31. The oil enters the cone valve core 31 through the first damping hole 3111 and then passes through the second damping hole 3112, the third damping hole 3113 and the fourth damping hole 3114 to reach the first chamber 342. After entering the first chamber 342, the oil acts on the force groove 343 of the slide valve core 34 through the second damping channel 344 and gives the slide valve core 34 a force. The slide valve core 34 moves axially and abuts against the limit piston 35, while driving the retaining ring 33 to further compress the return spring 32, thereby increasing the force of the cone valve core 31 to close the oil passage between the oil inlet 11 and the oil return port 12.

[0037] When the oil level at the inlet 11 increases and exceeds the force of the return spring 32, the oil pushes the cone valve core 31 away from the valve seat 4, thereby opening the oil passage between the inlet 11 and the return port 12. The oil flows from the inlet 11 to the return port 12 and returns to the oil tank from the return port 12, realizing the overflow function and achieving the pressure relief of the oil.

[0038] To minimize the risk of hydraulic oil leakage when the relief valve is used in high-pressure environments such as the travel motor system of an excavator, where the oil pressure can typically reach 420 bar, the hydraulic oil may leak from the connection between the plug 2 and the valve body 1.

[0039] This application solves the above-mentioned problems through a sealing fit between the plug 2 and the valve body 1, specifically, as follows: Figures 1-3 As shown, the plug 2 includes an integrally formed end cap 21, a small-diameter section 22, a transition connecting section 23, and a large-diameter section 24. The end cap 21 is located on the end side of the valve body 1, and the end face of the end cap 21 near the valve body 1 abuts against and fits against the end face of the valve body 1. The end face of the end cap 21 away from the valve body 1 has a tool groove 6 for tool insertion and mating during installation. The outer diameter of the small-diameter section 22 is smaller than the outer diameter of the large-diameter section 24. The transition connecting section 23 is used to accommodate the change in the outer diameter of the small-diameter section 22 and the large-diameter section 24. The inner peripheral wall of the valve body 1 that mates with the plug 2 includes a first wall 14, a second wall 15, and a third wall 16. The second wall 15 and the large-diameter section 24 are threaded together. The transition connecting section 23 abuts against the third wall 16 and forms a buffer space 17. A sealing groove 7 is formed between the end cap 21, the small-diameter section 22, the transition connecting section 23, and the first wall 14 and the third wall 16 of the valve body 1 of the plug 2. A sealing ring 5 is installed in the sealing groove 7, and the sealing ring 5 abuts and seals against the end face of the first wall 14, the end cap 21, and the small-diameter section 22. When the second wall 15 is interference-fitted with the large-diameter section 24, the outer diameter of the small-diameter section 22 is less than or equal to the inner diameter of the second wall 15. Compared with other settings, this is more conducive to the installation of the plug 2, and at the same time minimizes the damage to the sealing ring 5 caused by the size of the small-diameter section 22 during installation.

[0040] The first wall 14 has a first end 141 near the end cover 21 and a second end 142 away from the end cover 21 along the axial direction. Taking a cross-sectional view as an example, the vertical distance between the first end 141 and the central axis of the valve body 1 is denoted as L1, and the vertical distance between the second end 142 and the central axis of the valve body 1 is denoted as L2. L1 is greater than L2, so that when the relief valve is applied in the field of engineering machinery, such as the high-pressure environment of the excavator travel motor system, after the hydraulic oil acts on one side of the plug 2 for a long time, the setting of L1 being greater than L2 makes the sealing ring 5 under the same compression amount less effective contact area on the side of the sealing ring 5 near the second end 142, thus reducing the force on the side of the sealing ring 5 near the second end 142. This reduces the risk of the sealing ring 5 detaching in the direction away from the second end 142 due to the force, and also improves the sealing performance of the sealing ring 5 after it is matched with the valve body 1 and the plug 2 to a certain extent.

[0041] In addition, in order to minimize the wear of the sealing ring 5 after it is installed in the sealing groove, thereby affecting the sealing performance of the sealing ring 5, a buffer space 17 is formed between the transition connection section 23 and the third wall 16 to prevent the sealing ring 5 from contacting the threaded section after it is installed in the sealing groove 7, thus effectively reducing the wear of the sealing ring 5 during the long-term use of the overflow valve.

[0042] Specifically, the angle between the first wall 14 and the central axis of the valve body 1 is denoted as α, and the angle between the third wall 16 and the central axis of the valve body 1 is denoted as β. α is greater than β. Compared with other schemes, the sealing ring 5 has a smaller movement space on the side near the end cover 21. At the same time, under the same compression, the sealing ring 5 has a larger contact area with the first wall 14, the end face of the end cover 21, and the small diameter section 22, which can improve the sealing performance of the sealing ring 5 to a certain extent.

[0043] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A walking motor overflow valve, comprising a valve body (1) and a plug (2) fixedly connected to the end of the valve body (1), characterized in that: A sealing groove (7) is formed between the outer peripheral wall of the plug (2) and the inner peripheral wall of the valve body (1). A sealing ring (5) is installed in the sealing groove (7). The inner peripheral wall of the valve body (1) includes a first wall (14) and a second wall (15). The sealing ring (5) abuts against the first wall (14). The plug (2) is fixedly connected to the second wall (15). The first wall (14) has a first end (141) away from the second wall (15) and a second end (142) close to the second wall (15) along the axial direction. The vertical distance from the first end (141) to the axis of the valve body (1) is denoted as L1, and the vertical distance from the second end (142) to the axis of the valve body (1) is denoted as L2, where L1 is greater than L2.

2. The overflow valve for a walking motor according to claim 1, characterized in that, The inner peripheral wall of the valve body (1) also includes a third wall (16) for connecting the first wall (14) and the second wall (15). The plug (2) includes a small diameter section (22), a transition connecting section (23) and a large diameter section (24). The sealing ring (5) abuts against the small diameter section (22), the transition connecting section (23) abuts against the third wall (16), and the transition connecting section (23) and the third wall (16) form a buffer space (17). The large diameter section (24) is fixedly connected to the second wall (15).

3. The overflow valve for a walking motor according to claim 2, characterized in that, The angle between the first wall (14) and the axis of the valve body is denoted as α, and the angle between the third wall (16) and the axis of the valve body is denoted as β, where α is less than β.

4. The overflow valve for a walking motor according to claim 2, characterized in that, The outer diameter of the small diameter segment (22) is less than or equal to the inner diameter of the second wall (15).

5. A walking motor overflow valve according to claim 1, characterized in that, The plug (2) also includes an end cap (21), which abuts against the end face of the valve body (1) to seal the sealing groove (7), and the sealing ring (5) abuts against the end cap (21).

6. A walking motor overflow valve according to claim 1, characterized in that, The overflow valve also includes a valve core assembly (3), which includes a cone valve core (31), a return spring (32), and a retaining ring (33). The valve body (1) has an oil inlet (11) and an oil return port (12). The cone valve core (31) is guided and slidably disposed in the valve body (1) to open or close the oil passage between the oil inlet (11) and the oil return port (12). The retaining ring (33) is installed in the valve body (1). The two ends of the return spring (32) abut against the retaining ring (33) and the cone valve core (31) respectively, so that the cone valve core (31) closes the oil passage between the oil inlet (11) and the oil return port (12).

7. A walking motor overflow valve according to claim 6, characterized in that, The valve core assembly (3) further includes a sliding valve core (34) and a limiting piston (35). The limiting piston (35) is fixedly installed in the valve body (1). The sliding valve core (34) slides and cooperates with the limiting piston (35). One end of the sliding valve core (34) extends out of the limiting piston (35) and abuts against the plug (2). A first chamber (342) is provided in the sliding valve core (34). The cone valve core (31) extends into the sliding valve core (34) and slides and cooperates with the sliding valve core (34). The cone valve core (31) is provided with a first damping channel (311) communicating with the first chamber (342). The sliding valve core (34) is provided with a second damping channel (344) communicating with the first chamber (342). The end face of the sliding valve core (34) that abuts against the plug (2) is provided with a force groove (343) communicating with the second damping channel (344).

8. A walking motor overflow valve according to claim 7, characterized in that, The first damping channel (311) includes a first damping hole (3111), a second damping hole (3112), a third damping hole (3113), and a fourth damping hole (3114). The first damping hole (3111) is axially arranged along the cone valve core (31) and communicates with the oil inlet (11). The second damping hole (3112) is circumferentially arranged along the cone valve core (31). The first damping hole (3111) and the second damping hole (3112) are connected through a radial channel. The fourth damping hole (3114) is axially arranged and communicates with the first chamber (342). The second damping hole (3112) and the fourth damping hole (3114) are connected through the radially arranged third damping hole (3113).

9. A walking motor overflow valve according to claim 7, characterized in that, The valve core (34) has an annular step (341), and the retaining ring (33) is disposed outside the valve core (34) and is axially limited by the annular step (341).

10. A walking motor overflow valve according to claim 1, characterized in that, The end face of the plug (2) away from the valve body (1) is provided with a tool groove (6).

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