Balanced valve core assembly

Abstract

The invention relates to the technical field of balance valves, and discloses a balance valve element assembly which comprises a pressure adjusting screw, the outer arc surface of the pressure adjusting screw is in threaded connection with a thread sleeve, the inner surface of the thread sleeve is sleeved with a pressure spring, and the end, away from the thread sleeve, of the pressure spring is in contact with a balance valve element. An isolation sleeve is embedded in the outer arc face of the balance valve element. The spring cavity oil outlet groove, the spring cavity rapid oil discharging groove and the rapid oil supplementing one-way valve composed of the spring cavity oil inlet one-way valve, the spring cavity oil inlet one-way valve spring, the spring positioning piece and the clamping spring are formed in the balance valve element, so that directional oil supplementing and discharging of the spring cavity are achieved when the balance valve element moves; when the balance valve element is opened, oil can be controlled to be discharged in a staged mode, when the balance valve element is closed, oil is rapidly supplemented through the one-way valve, relative negative pressure is prevented from occurring in a spring cavity, the anti-shaking performance of the balance valve and the dynamic performance at the opening moment are effectively coordinated, the movement stability and response timeliness of the valve element are guaranteed, and the core performance requirement of the balance valve is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of balance valve, in particular to a balance valve core assembly. BACKGROUND

[0002] The balance valve is a key pressure control element in the hydraulic control system, mainly used for regulating the flow direction and pressure stability of the oil in the hydraulic circuit, preventing the load from overspeed descending and impact under the action of gravity or external force, and widely applied in the fields of engineering machinery, mining machinery, hydraulic lifting equipment, etc. The core components usually include valve core, spring, valve sleeve, adjusting screw, etc. Through the balance of spring force and oil pressure, the control of oil on-off and flow is realized, thereby ensuring the smooth operation of the hydraulic cylinder, hydraulic motor and other hydraulic actuators.

[0003] In the prior art, the balance valve relies on the cooperation gap of the valve core and the valve sleeve or a single oil outlet groove to complete the discharge and replenishment of the spring cavity oil, so as to control the opening and closing speed of the valve core. In actual application, the balance valve is often connected in series in the oil return circuit of the hydraulic actuator. When the system needs to drive the load to move, the control oil pushes the valve core to open against the spring force, and the oil is discharged through the cooperation gap or the oil outlet groove to realize the stable movement of the load. When the system stops supplying oil, the spring force pushes the valve core to reset and close, blocking the reverse flow of oil to prevent the load from falling by itself. For example, in the telescopic circuit of the crane's boom, the existing balance valve maintains the position stability during the lifting of the boom by the above structure to prevent the boom from suddenly sinking.

[0004] The balance valve in the prior art has the most critical deficiency, that is, it is difficult to simultaneously consider the anti-shaking performance and the dynamic performance at the opening moment. In order to improve the anti-shaking performance, the existing design often reduces the cooperation gap of the valve core and the valve sleeve or uses a single small-size oil outlet groove to slow down the opening speed of the valve core, which delays the dynamic response at the opening moment and cannot meet the demand of the system for rapid start. If the gap or the size of the oil outlet groove is increased to ensure the dynamic performance at the opening moment, the stability of the valve core during movement will decrease, which is prone to shaking phenomenon, affecting the operation accuracy of the hydraulic system and the stability of the load control. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a balance valve core assembly, which solves the problem that the balance valve in the prior art is difficult to simultaneously consider the anti-shaking and opening dynamic performance.

[0006] In order to achieve the above object, the present application is realized by the following technical scheme: A balance valve core assembly, comprising a pressure adjusting screw, an outer arc surface of the pressure adjusting screw is threadedly connected with a sleeve, an inner surface of the sleeve is sleeved with a pressure spring, one end of the pressure spring away from the sleeve is in contact with a balance valve core, an outer arc surface of the balance valve core is embedded with an isolation sleeve, a right side of the outer arc surface of the balance valve core is sleeved with a one-way valve sleeve, an inner surface of the one-way valve sleeve is fixedly connected with a one-way valve spring on the left side, one end of the one-way valve spring away from the one-way valve sleeve is in contact with a gasket, an inner surface of the balance valve core is fixedly connected with a spring positioning piece on the left side, the spring positioning piece is fixedly connected with a clamping spring on the left side, the spring positioning piece is in contact with a spring cavity oil inlet one-way valve spring on the right side, and the spring cavity oil inlet one-way valve spring is in contact with a spring cavity oil inlet one-way valve on the right side.

[0007] Preferably, the outer arc surface of the balance valve core is axially provided with a spring cavity oil outlet groove, the spring cavity oil outlet groove penetrates the side wall of the balance valve core, and the spring cavity oil outlet groove is located between the one-way valve sleeve and the isolation sleeve.

[0008] Preferably, the outer arc surface of the balance valve core is provided with a spring cavity rapid oil discharge groove on the side close to the isolation sleeve, the axial length of the spring cavity rapid oil discharge groove is shorter than the axial length of the spring cavity oil outlet groove, and the spring cavity rapid oil discharge groove and the spring cavity oil outlet groove are spaced apart in the circumferential direction of the balance valve core.

[0009] Preferably, the isolation sleeve is in an annular structure, the inner arc surface of the isolation sleeve is tightly fitted with the outer arc surface of the balance valve core, the outer arc surface of the isolation sleeve is in contact with the inner ring of the pressure spring, and the axial two ends of the isolation sleeve are oppositely arranged with the end surface of the pressure spring and the end surface of the one-way valve sleeve, respectively.

[0010] Preferably, the side wall of the balance valve core is radially provided with a spring cavity oil inlet passage hole, the spring cavity oil inlet passage hole is located on the right side of the spring cavity oil inlet one-way valve, the spring cavity oil inlet passage hole penetrates the inner and outer arc surfaces of the balance valve core, and the hole diameter of the spring cavity oil inlet passage hole is smaller than the outer diameter of the spring cavity oil inlet one-way valve.

[0011] Preferably, a gap is left between the inner arc surface of the one-way valve sleeve and the outer arc surface of the balance valve core, the left end surface of the one-way valve sleeve is provided with an annular boss, the inner arc surface of the annular boss is fitted with the outer arc surface of the balance valve core, and the right end surface of the one-way valve sleeve is in a planar structure.

[0012] Preferably, the gasket is in an annular sheet structure, the inner hole of the gasket is sleeved at the outer arc surface of the balance valve core, the left end surface of the gasket is in contact with the right end of the one-way valve spring, and the right end surface of the gasket is fitted with the stepped surface provided on the outer arc surface of the balance valve core.

[0013] Preferably, the spring positioning sheet is annular structure, the outer arc surface of the spring positioning sheet is in interference fit with the inner surface of the balance valve core, the right side end surface of the spring positioning sheet is provided with a circular groove, the inner diameter of the circular groove is adapted to the outer diameter of the spring cavity oil inlet check valve spring, and the left side end surface of the spring positioning sheet is attached to the right side end surface of the snap spring.

[0014] Preferably, the snap spring is clamped in the annular clamping groove formed in the inner surface of the balance valve core, the outer diameter of the snap spring is adapted to the inner diameter of the balance valve core, and the left side end surface of the snap spring does not exceed the left side end surface of the balance valve core.

[0015] Preferably, the spring cavity oil inlet check valve is cylindrical structure, the outer arc surface of the spring cavity oil inlet check valve is in sliding connection with the inner surface of the balance valve core, the left side end surface of the spring cavity oil inlet check valve is in contact with the right end of the spring cavity oil inlet check valve spring, and the right side end surface of the spring cavity oil inlet check valve is provided with a semispherical protrusion.

[0016] Working principle: When the device is used, the control oil acts on the check valve sleeve, and the check valve sleeve is pushed to move towards the direction close to the screw sleeve until the size S2 is zero, the check valve sleeve is stopped by the screw sleeve, at this time, the balance valve enters the state of output flow, and the opening process of the balance valve core is divided into two stages, the first stage is in the range of 0 to S2, the spring cavity of the balance valve core is realized by the spring cavity quick oil discharge groove formed therein, the spring cavity is quickly discharged, and the valve core moves quickly, the second stage is in the range of S2 to the maximum stroke, the oil in the spring cavity is discharged through the spring cavity oil outlet groove, if S3 is equal to S2, the oil is directly discharged through the spring cavity oil outlet groove, if S3 is greater than S2, the oil is first discharged through the gap between the balance valve core and the isolation sleeve, and then discharged through the spring cavity oil outlet groove, the oil discharge speed in this stage is determined by the size and shape of the spring cavity oil outlet groove, the valve core is slowly opened, if the spring cavity oil outlet groove is not processed, the oil is discharged through the gap between the balance valve core and the isolation sleeve, and the size of the gap directly controls the opening speed, when the balance valve core moves from left to right, the spring cavity volume increases, the check valve structure composed of the spring cavity oil inlet check valve, the spring cavity oil inlet check valve spring, the spring positioning sheet and the snap spring is opened, the oil enters the spring cavity through the spring cavity oil inlet channel hole and the check valve, and the relative negative pressure in the spring cavity is avoided, when the balance valve core moves from right to left, the check valve structure is closed, and the oil in the spring cavity is prevented from being discharged through the check valve, the oil is only discharged through the spring cavity oil outlet groove or the cooperation gap, if the outer diameter of the pressure spring is small enough, the isolation sleeve can be omitted, at this time, the oil in the spring cavity is discharged through the gap between the balance valve core and the screw sleeve, and the size of the gap also affects the opening speed; when the balance valve core is closed, the spring cavity volume decreases, the above-mentioned check valve structure is quickly opened, the oil is quickly supplemented into the spring cavity, the balance valve core is quickly reset, and the closing action is completed.

[0017] The application provides a balance valve core assembly. 1. The application realizes the directional supplement and discharge of the spring cavity oil when the balance valve core moves, controls the oil discharge in stages when the balance valve core opens, and supplements the oil through the one-way valve when the balance valve core closes, so as to avoid the relative negative pressure in the spring cavity, effectively coordinate the anti-shaking performance and dynamic performance of the balance valve at the opening moment, guarantee the stability and timeliness of the valve core movement, and meet the core performance requirements of the balance valve.

[0018] 2. When the spring cavity oil outlet groove is not set, the oil discharge function is realized by relying on the cooperation gap between the isolation sleeve and the balance valve core, or the gap formed by the valve core and the balance valve core, so as to improve the structural design flexibility. This design can adapt to pressure springs of different outer diameters. When the outer diameter of the pressure spring is small, the isolation sleeve does not need to be assembled, and the oil outlet groove can meet the oil discharge requirements of the spring cavity without additional machining, which simplifies the assembly process while ensuring the stability of the oil discharge path, and is compatible with different specifications of the balance valve design and application scenarios.

[0019] 3. The spring cavity oil outlet groove is set to various shapes and forms including a triangular groove, which expands the structural adaptation range of the oil outlet groove. Different shapes of the oil outlet groove correspond to different oil discharge rates, and the oil outlet groove structure can be adjusted according to the actual working condition of the balance valve to realize precise control of the slow opening time of the balance valve core in the S2 to maximum stroke interval. It does not need to be limited to a single groove design, reduces the structural design limitations of the balance valve in different application scenarios, and improves the working condition adaptability of the assembly. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a front view of the application; Figure 2 It is a schematic diagram of the spring cavity quick oil discharge channel of the application; Figure 3 It is a top view cross-sectional view of the application; Figure 4 It is a schematic diagram of the spring cavity oil outlet groove and oil inlet one-way valve cross-section of the application; Figure 5 It is a schematic diagram of the spring cavity oil outlet groove and oil inlet one-way valve cross-section of the application; Figure 6 It is a schematic diagram of the spring cavity quick oil discharge channel and oil outlet groove on the main valve core of the application; Figure 7 It is a cross-sectional structure schematic diagram of the application without an isolation sleeve.

[0021] Wherein, 1, pressure adjusting screw; 2, screw sleeve; 3, pressure spring; 4, isolation sleeve; 5, balance valve core; 6, one-way valve sleeve; 7, one-way valve spring; 8, gasket; 9, spring cavity oil inlet one-way valve; 10, spring cavity oil inlet one-way valve spring; 11, spring positioning piece; 12, clamping spring; 13, spring cavity oil inlet one-way valve; 14, spring cavity oil outlet groove; 15, spring cavity oil inlet passage hole; 16, spring cavity rapid oil discharge groove. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the specification of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0023] Embodiment: Please refer to the drawings in the specification of the present application Figure 1The embodiment of the present application provides a balance valve core assembly, which comprises a pressure adjusting screw 1, a sleeve 2 is threadedly connected to the outer arc surface of the pressure adjusting screw 1, the axial position of the sleeve 2 can be adjusted by rotating the pressure adjusting screw 1, thereby changing the pre-compression amount of a pressure spring 3, so that the initial opening pressure of the balance valve is set, the inner surface of the sleeve 2 is sleeved with the pressure spring 3, the pressure spring 3 provides an axial reset elastic force for a balance valve core 5, the balance valve core 5 is kept in a closed state when there is no control oil effect, and the reverse flow of oil is blocked, one end, away from the sleeve 2, of the pressure spring 3 is in contact with the balance valve core 5, the balance valve core 5 is a core moving part of the balance valve, and the balance valve core 5 realizes the opening and closing of an oil passage and flow control through axial movement, an isolation sleeve 4 is embedded in the outer arc surface of the balance valve core 5, the isolation sleeve 4 is used for isolating a spring cavity and an oil inlet, limiting the discharge path of oil in the spring cavity, avoiding the influence of oil cross flow on the stability of the valve core movement, a one-way valve sleeve 6 is sleeved with the right side of the outer arc surface of the balance valve core 5, the one-way valve sleeve 6 is used for cooperating with control oil to drive the balance valve core 5 to move, and the one-way valve sleeve 6 is limited by the sleeve 2, the movement of the one-way valve sleeve 6 is stopped when the size S2 is zero, so that the balance valve enters a state capable of outputting flow, a one-way valve spring 7 is fixedly connected to the inner surface of the one-way valve sleeve 6 on the left side, the one-way valve spring 7 provides an axial reset force for the one-way valve sleeve 6, and the one-way valve sleeve 6 is driven to reset to an initial position when control oil is depressurized, one end, away from the one-way valve sleeve 6, of the one-way valve spring 7 is in contact with a gasket 8, the one-way valve spring 7 is prevented from being in direct contact with the stepped surface of the outer arc surface of the balance valve core 5, and the wear between the spring end surface and the valve core is reduced, a spring positioning sheet 11 is fixedly connected to the inner surface of the balance valve core 5 on the left side, the spring positioning sheet 11 is used for positioning a spring cavity oil inlet one-way valve spring 10 and preventing the spring cavity oil inlet one-way valve spring 10 from being radially deviated in the working process, a clamping spring 12 is fixedly connected to the left side of the spring positioning sheet 11, the axial displacement of the spring positioning sheet 11 is limited, and the spring positioning sheet 11 is prevented from being separated from the inner hole of the balance valve core 5, the right side of the spring positioning sheet 11 is in contact with the spring cavity oil inlet one-way valve spring 10, the spring cavity oil inlet one-way valve spring 10 provides a normally closed elastic force for a spring cavity oil inlet one-way valve 13, and the spring cavity oil inlet one-way valve 13 is allowed to be opened only when the spring cavity appears relative negative pressure, the right side of the spring cavity oil inlet one-way valve spring 10 is in contact with the spring cavity oil inlet one-way valve 13, control oil can only flow into the spring cavity in one direction, and the oil in the spring cavity is prevented from flowing back through the spring cavity oil inlet one-way valve 13, the spring positioning sheet 11 is in an annular structure, the outer arc surface of the spring positioning sheet 11 is in interference fit with the inner surface of the balance valve core 5, the connection between the spring positioning sheet 11 and the balance valve core 5 is reliable, and axial movement of the spring positioning sheet 11 in the working process is avoided, a circular groove is formed in the right side end surface of the spring positioning sheet 11, the inner diameter of the circular groove is matched with the outer diameter of the spring cavity oil inlet one-way valve spring 10, the radial position of the spring cavity oil inlet one-way valve spring 10 is further limited, the inner diameter of the circular groove is matched with the outer diameter of the spring cavity oil inlet one-way valve spring 10, the left side end surface of the spring positioning sheet 11 is attached to the right side end surface of the clamping spring 12, the spring positioning sheet 11 is kept in a fixed position through the axial limiting action of the clamping spring 12, and the clamping spring 12 is clamped in the annular clamping groove formed in the inner surface of the balance valve core 5.The quick assembly and fixation of the snap spring 12 are realized, and the later maintenance and disassembly are facilitated. The outer diameter of the snap spring 12 is matched with the inner diameter of the balance valve core 5, so that the gap between the snap spring 12 and the inner hole of the balance valve core 5 is avoided to cause radial shaking. The left end surface of the snap spring 12 does not exceed the left end surface of the balance valve core 5.

[0024] Please refer to the accompanying drawings Figure 1 and the accompanying drawings Figure 7 The inner arc surface of the isolation sleeve 4 is tightly fitted with the outer arc surface of the balance valve core 5, so that the coaxiality of the isolation sleeve 4 and the balance valve core 5 is ensured, the oil leakage from the gap between the two is prevented, the isolation effect of the spring cavity and the oil inlet is ensured, the outer arc surface of the isolation sleeve 4 is in contact with the inner ring of the pressure spring 3, the radial positioning of the pressure spring 3 is provided, the radial deviation of the pressure spring 3 during compression or reset is avoided, the elastic force is ensured to be transmitted to the balance valve core 5 along the axial direction, the axial both ends of the isolation sleeve 4 are oppositely arranged with the end surface of the pressure spring 3 and the end surface of the one-way valve sleeve 6, so that the axial installation position of the isolation sleeve 4 is limited, the pressure spring 3 and the one-way valve sleeve 6 are separated, and direct contact between the two is avoided to cause abrasion. There is a gap between the inner arc surface of the one-way valve sleeve 6 and the outer arc surface of the balance valve core 5, so that the axial movement space of the one-way valve sleeve 6 is provided, and the flexible movement of the one-way valve sleeve 6 along with the change of the control oil pressure is ensured. The left end surface of the one-way valve sleeve 6 is provided with an annular boss, the inner arc surface of the annular boss is fitted with the outer arc surface of the balance valve core 5, the fitting gap between the one-way valve sleeve 6 and the balance valve core 5 is reduced, and the control oil leakage from the gap is prevented. The inner arc surface of the annular boss is fitted with the outer arc surface of the balance valve core 5, the right end surface of the one-way valve sleeve 6 is a plane structure, the sealing performance of the oil circuit is ensured by facilitating the cooperation between the one-way valve sleeve 6 and the sealing element in the oil circuit of the hydraulic system, the gasket 8 is an annular sheet structure, the inner hole of the gasket 8 is sleeved at the outer arc surface of the balance valve core 5, so that the coaxiality of the gasket 8 and the balance valve core 5 is ensured, and the uneven force of the one-way valve spring 7 caused by the deflection of the gasket 8 is avoided. The left end surface of the gasket 8 is in contact with the right end of the one-way valve spring 7, the force of the one-way valve spring 7 is buffered, and the spring directly impacts the balance valve core 5 is avoided. The right end surface of the gasket 8 is fitted with the stepped surface formed in the outer arc surface of the balance valve core 5, the axial position of the gasket 8 is limited, and the axial movement of the gasket 8 along with the compression and reset of the one-way valve spring 7 is prevented.

[0025] Please refer to the accompanying drawings Figure 3, and FIG. 6, the outer arc surface of the balance spool 5 is provided with a spring cavity oil outlet groove 14 in the axial direction, which provides an outlet channel for the oil in the spring cavity, adapts to the slow oil discharge requirement of the later opening stage of the balance spool 5, and penetrates the side wall of the balance spool 5. The spring cavity oil outlet groove 14 is located between the one-way valve sleeve 6 and the isolation sleeve 4, which defines the action area of the spring cavity oil outlet groove 14 and ensures that the oil is discharged through the groove only when the spool is opened to the corresponding position. The side of the outer arc surface of the balance spool 5 close to the isolation sleeve 4 is provided with a spring cavity rapid oil discharge groove 16, which provides a large-flow oil discharge channel for the initial opening stage of the balance spool 5. The axial length of the spring cavity rapid oil discharge groove 16 is shorter than the axial length of the spring cavity oil outlet groove 14, which adapts to the short-stroke rapid oil discharge requirement of the initial opening stage of the balance spool 5. The spring cavity rapid oil discharge groove 16 and the spring cavity oil outlet groove 14 are spaced apart in the circumferential direction of the balance spool 5, which avoids the circumferential overlap of the two grooves affecting the oil discharge efficiency and the structural strength of the spool. The side wall of the balance spool 5 is provided with a spring cavity oil inlet passage hole 15 in the radial direction, which provides a channel for the oil to enter the spring cavity. The spring cavity oil inlet passage hole 15 is located to the right of the spring cavity oil inlet one-way valve 13, which ensures that the oil needs to pass through the spring cavity oil inlet one-way valve 13 before entering the spring cavity, realizing one-way control. The spring cavity oil inlet passage hole 15 penetrates the inner and outer arc surfaces of the balance spool 5, so that the external oil can enter the interior of the balance spool 5 through the hole and flow to the spring cavity. The hole diameter of the spring cavity oil inlet passage hole 15 is smaller than the outer diameter of the spring cavity oil inlet one-way valve 13, which prevents the spring cavity oil inlet one-way valve 13 from being pulled out of the spring cavity oil inlet passage hole 15 and ensures the structural integrity of the one-way valve. The spring cavity oil inlet one-way valve 13 is a cylindrical structure, the outer arc surface of the spring cavity oil inlet one-way valve 13 is in sliding connection with the inner surface of the balance spool 5, the left side end surface of the spring cavity oil inlet one-way valve 13 is in contact with the right end of the spring cavity oil inlet one-way valve spring 10, and the spring cavity oil inlet one-way valve 13 is kept in a normally closed state by the elastic force of the spring cavity oil inlet one-way valve spring 10. The right side end surface of the spring cavity oil inlet one-way valve 13 is provided with a hemispherical protrusion, which reduces the resistance when the oil pushes the spring cavity oil inlet one-way valve 13 to open, and improves the response speed of the one-way valve to the pressure change in the spring cavity.

[0026] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A balanced spool assembly comprising a pressure regulating screw (1), characterized in that, The outer arc surface of the pressure regulating screw (1) is threadedly connected with a sleeve (2), the inner surface of the sleeve (2) is sleeved with a pressure spring (3), one end of the pressure spring (3) away from the sleeve (2) is in contact with a balance valve core (5), the outer arc surface of the balance valve core (5) is embedded with an isolation sleeve (4), the outer arc surface of the balance valve core (5) is sleeved with a one-way valve sleeve (6) on the right side, the inner surface of the one-way valve sleeve (6) is fixedly connected with a one-way valve spring (7) on the left side, one end of the one-way valve spring (7) away from the one-way valve sleeve (6) is in contact with a gasket (8), the inner surface of the balance valve core (5) is fixedly connected with a spring positioning piece (11) on the left side, the left side of the spring positioning piece (11) is fixedly connected with a clamping spring (12), the right side of the spring positioning piece (11) is in contact with a spring cavity oil inlet one-way valve spring (10), the right side of the spring cavity oil inlet one-way valve spring (10) is in contact with a spring cavity oil inlet one-way valve (13).

2. A balanced spool assembly according to claim 1, wherein, The outer arc surface of the balance valve core (5) is axially provided with a spring cavity oil outlet groove (14), the spring cavity oil outlet groove (14) penetrates the side wall of the balance valve core (5), and the spring cavity oil outlet groove (14) is located between the one-way valve sleeve (6) and the isolation sleeve (4).

3. A balanced spool assembly according to claim 1, wherein, The outer arc surface of the balance valve core (5) is provided with a spring cavity rapid oil discharge groove (16) on the side close to the isolation sleeve (4), the axial length of the spring cavity rapid oil discharge groove (16) is shorter than the axial length of the spring cavity oil outlet groove (14), and the spring cavity rapid oil discharge groove (16) and the spring cavity oil outlet groove (14) are spaced apart in the circumferential direction of the balance valve core (5).

4. A balanced spool assembly according to claim 1, wherein, The isolation sleeve (4) has an annular structure, the inner arc surface of the isolation sleeve (4) is closely attached to the outer arc surface of the balance valve core (5), the outer arc surface of the isolation sleeve (4) is in contact with the inner ring of the pressure spring (3), and the axial ends of the isolation sleeve (4) are oppositely arranged with the end surface of the pressure spring (3) and the end surface of the one-way valve sleeve (6) respectively.

5. A balanced spool assembly according to claim 1, wherein, The side wall of the balance valve core (5) is radially provided with a spring cavity oil inlet passage hole (15), the spring cavity oil inlet passage hole (15) is located on the right side of the spring cavity oil inlet one-way valve (13), the spring cavity oil inlet passage hole (15) penetrates the inner and outer arc surfaces of the balance valve core (5), and the hole diameter of the spring cavity oil inlet passage hole (15) is smaller than the outer diameter of the spring cavity oil inlet one-way valve (13).

6. A balanced spool assembly according to claim 1, wherein, The inner arc surface of the one-way valve sleeve (6) and the outer arc surface of the balance valve core (5) are left with a gap, the left end surface of the one-way valve sleeve (6) is provided with an annular boss, the inner arc surface of the annular boss is attached to the outer arc surface of the balance valve core (5), and the right end surface of the one-way valve sleeve (6) is a plane structure.

7. A balanced spool assembly according to claim 1 wherein, The gasket (8) has an annular sheet structure, the inner hole of the gasket (8) is sleeved at the outer arc surface of the balance valve core (5), the left end surface of the gasket (8) is in contact with the right end of the one-way valve spring (7), and the right end surface of the gasket (8) is attached to the stepped surface provided on the outer arc surface of the balance valve core (5).

8. A balanced spool assembly according to claim 1, wherein, The spring positioning sheet (11) is annular structure, the outer arc surface of the spring positioning sheet (11) is interference fit with the inner surface of the balance valve core (5), the right side end surface of the spring positioning sheet (11) is provided with circular recess, the inner diameter of the circular recess is adapted with the outer diameter of the spring cavity oil inlet one-way valve spring (10), the left side end surface of the spring positioning sheet (11) is attached with the right side end surface of the snap spring (12).

9. A balanced spool assembly according to claim 1 wherein, The snap spring (12) is clamped in the annular clamping groove in the inner surface of the balance valve core (5), the outer diameter of the snap spring (12) is adapted with the inner diameter of the balance valve core (5), the left side end surface of the snap spring (12) does not exceed the left side end surface of the balance valve core (5).

10. A balanced spool assembly according to claim 1, wherein, The spring cavity oil inlet one-way valve (13) is cylindrical structure, the outer arc surface of the spring cavity oil inlet one-way valve (13) is slidingly connected with the inner surface of the balance valve core (5), the left side end surface of the spring cavity oil inlet one-way valve (13) is in contact with the right end of the spring cavity oil inlet one-way valve spring (10), the right side end surface of the spring cavity oil inlet one-way valve (13) is provided with semispherical convex.

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