Pressure-regulating sealing structure

Abstract

The utility model discloses a pressure-regulating sealing structure, and relates to the technical field of sealing. A main sealing groove and floating sealing grooves are formed in the peripheral side of the heavy hammer piston, and the floating sealing grooves are formed in the two sides of the main sealing groove in the axis direction of the heavy hammer piston correspondingly; a liquid storage chamber is arranged in the heavy hammer piston; a pressure regulating piston is arranged at the bottom of the liquid storage chamber; the sealing structure comprises a first sealing assembly and a second guiding sealing assembly. The first sealing assembly is arranged in the main sealing groove and comprises a sealing tire and a sealing sliding ring. The second guide sealing assemblies are symmetrically arranged in the floating sealing grooves in the two sides of the main sealing groove, and each second guide sealing assembly comprises a supporting tire and a floating sealing guide ring; the heavy hammer piston moves downwards under the action of gravity to cause the pressure regulating piston to relatively move upwards, so that the amount of oil liquid pressed into the sealing tire and the supporting tire in the liquid storage chamber is increased, the sealing slip ring and the floating sealing guide ring are pushed to move towards the cylinder wall, and a sealing gap between the heavy hammer piston and the cylinder wall is dynamically reduced; therefore, the dynamic sealing structure of the heavy hammer piston with large cylinder diameter and large pressure is provided.

Description

Technical Field

[0001] This utility model belongs to the field of sealing technology, specifically relating to a pressure regulating sealing structure. Background Technology

[0002] Hydraulic systems are widely used in various industries due to their high power density and large output force, but they also face the problem of low energy efficiency. Gravity-based accumulators offer energy savings by automatically performing work using gravity, and their energy supply efficiency is superior to that of a constant pressure supply system using a fixed displacement pump and relief valve. They have broad application prospects for energy saving in constant pressure supply for factory hydraulic equipment. Conventional gravity-based accumulators store and release energy through the positional changes of a gravity weight; pressure is generated when the gravity weight applies force to the hydraulic oil through a piston. While this type of accumulator has a simple structure, the piston is difficult to seal reliably, resulting in an insufficient piston size and consequently, insufficient capacity and pressure of the gravity piston accumulator. Furthermore, the large inertia of the gravity piston inherently leads to a lack of responsiveness in the accumulator itself. Using existing sealing structures reduces the sealing gap δ, further increasing friction between the piston and cylinder wall. Increased friction causes premature seal failure due to overheating or twisting, and reduces the force of the gravity weight, leading to unstable pressure. This further reduces the piston's responsiveness and trouble-free operating time, ultimately increasing maintenance costs.

[0003] High pressure places higher demands on the seals of hydraulic systems. Traditional sealing materials and structures may not withstand deformation and wear under high pressure, leading to leakage problems. Therefore, seals need to have better elasticity, wear resistance, and high-pressure resistance to ensure the sealing performance of the hydraulic system. In the prior art, publication number CN114056192A, entitled "A Pneumatic-Hydraulic Tension Compensation Device and Implementation Method," provides a tire seal structure that can be inflated with air or liquid, and where the internal air or hydraulic pressure is constant pressure using high-pressure gas as the energy storage medium, forming a leak-proof seal between the tire-shaped piston seal ring and the cylinder wall. This overcomes the low-temperature load leakage problem commonly found in existing compensation devices, achieving reliable sealing at all ambient temperatures. However, if this sealing structure is used in a hammer-type piston accumulator, it suffers from high frictional resistance, slow hammer piston response, and high return resistance. Furthermore, due to its use of a car vacuum tire structure, the size is difficult to economically increase to several meters or more, making it difficult to meet the piston seal requirements of large-size, high-capacity, and high-pressure hammer-type piston accumulator pumps needed in the future market.

[0004] Therefore, there is an urgent need for a piston seal structure for a weighted accumulator pump that is used to increase the diameter of the piston and cylinder wall to place more weights to build up higher pressure, and also for large-diameter seals that need to float to ensure pressure stability by changing pressure. Utility Model Content

[0005] This utility model provides a pressure regulating sealing structure to solve the piston sealing problem of a heavy-duty accumulator pump that can provide stable high-flow-rate pressure for the future market, reducing leakage and high return resistance caused by the increase in structural size; it positively utilizes the characteristics of the heavy-duty piston, which has a slow response but stable output, to solve the problem of the difficulty in establishing a large and stable oil source pressure.

[0006] The technical solution adopted in this utility model is as follows:

[0007] A pressure-regulating sealing structure includes a main sealing groove and a floating sealing groove formed around the periphery of a counterweight piston. The floating sealing grooves are respectively arranged on both sides of the main sealing groove along the axial direction of the counterweight piston. The counterweight piston contains a liquid storage chamber. A pressure-regulating piston is installed at the bottom of the liquid storage chamber, and a sealing cover is provided at the top of the liquid storage chamber. A safety valve is provided on the cover. The sealing structure includes:

[0008] The first sealing assembly, disposed within the main sealing groove, includes an upper support ring, a sealing element, a sealing slip ring, and a lower support ring; the upper support ring is connected to the upper wall of the main sealing groove, and the lower support ring is connected to the lower wall of the main sealing groove; the sealing element is disposed between the upper and lower support rings, and the sealing slip ring is disposed between the sealing element and the cylinder wall.

[0009] The second guide sealing assembly is symmetrically arranged in floating sealing grooves on both sides of the main sealing groove. It includes a limiting ring, a support ring, an inner support ring, and a floating sealing guide ring. The limiting ring is connected to the groove wall of the floating sealing groove on the side closest to the main sealing groove. The inner support ring is connected to the bottom of the floating sealing groove. The support ring is arranged in the groove outside the inner support ring and is adjacent to the limiting ring. The floating sealing guide ring is arranged between the support ring and the cylinder wall. The sealing section of the floating sealing guide ring is adjacent to the limiting ring. The guiding section of the floating sealing guide ring is in elastic contact with the inner support ring.

[0010] The heavy hammer piston has a first filling channel, a second filling channel and a third filling channel; the first filling channel connects the liquid storage chamber to the sealing tire through a first quick connector; the second filling channel connects the liquid storage chamber to the support tire above the main sealing groove through a second quick connector; the third filling channel connects the liquid storage chamber to the support tire below the main sealing groove through a third quick connector.

[0011] The sealing slip ring is located between the upper support ring and the lower support ring, and is connected between the inner side of the sealing tire and the cylinder wall in the radial direction of the hammer piston. When the sealing tire is filled with liquid, the sealing slip ring can contact and connect with the cylinder wall, so that a sealing connection is formed between the hammer piston and the cylinder wall.

[0012] The sealing slip ring has at least three pressure equalizing grooves on its circumferential side where it contacts the cylinder wall, and two O-rings for fastening are installed in the upper and lower grooves respectively.

[0013] The sealing slip ring can extend beyond the main sealing groove by a predetermined distance, and the sealing slip ring protrudes along the axis perpendicular to the hammer piston and is set on the upper support ring or the lower support ring to prevent the upper support ring or the lower support ring from rubbing against the cylinder wall.

[0014] At least three pressure equalization grooves are provided on the circumferential side of the sealing slip ring that contacts the cylinder wall. The multiple pressure equalization grooves are evenly distributed along the piston axis to facilitate the uniform distribution of contact pressure between the sealing slip ring and the cylinder wall.

[0015] The groove depth of the two O-rings for installation and fastening on the upper and lower sides shall not exceed 90% of the O-ring diameter, and the groove width shall not exceed 110% of the O-ring diameter, so as to ensure that the contact area between the O-ring and the cylinder wall is small and to reduce torsional damage.

[0016] The pressure regulating sealing structure also includes an inner liner, which is set at the bottom of the main sealing groove. The inner liner is used to protect or position the sealing tire, preventing the sealing tire from coming into contact with the uneven metal contact surface at the bottom of the groove, which could lead to a puncture and tire blowout.

[0017] The floating seal guide ring has a conical structure and is set in the floating seal grooves on both sides of the main seal groove. The floating seal guide ring has oblique or staggered concave-convex connecting grooves, and the staggered oblique or concave-convex connecting grooves form a closed connection along the circumference. Furthermore, the outer conical surface of the floating seal guide ring faces the top or bottom of the piston and does not contact the cylinder wall.

[0018] An arc-shaped inner groove is provided on the inner side of the floating seal guide ring at the position where it contacts the support tire, so as to ensure that the expansion force of the support tire presses the outer side of the floating seal guide ring against the cylinder wall through the arc-shaped inner groove; the floating seal guide ring has an L-shaped structure and elastically contacts the inner support ring, and is surrounded by the limiting ring on the outer periphery of the support tire.

[0019] The first, second, and third filling channels are arranged in a ring array on the projection surface along the axis of the hammer piston, so as to balance the weight of the piston and ensure that the center of gravity of the piston is on the axis.

[0020] The pressure regulating piston is a cylindrical structure with different upper and lower cross sections concentric with the counterweight piston, and / or, the pressure regulating piston is a concentric cylindrical structure with two different upper and lower cross sections symmetrical with the axis of the counterweight piston; a movable gap is formed between the upper outer cylindrical surface or the lower outer cylindrical surface of the pressure regulating piston and the counterweight piston, so that the pressure regulating piston can move relative to the counterweight piston; when the pressure regulating piston and the counterweight piston move downward by gravity, the small piston at the bottom of the pressure regulating piston is subjected to the high pressure oil at the bottom of the counterweight piston and transmits the force to the oil in the reservoir chamber acted upon by the large piston at the top of the pressure regulating piston.

[0021] The upper support ring and / or the lower support ring have a first opening inclined to the axial direction for installation in the main sealing groove; the limiting ring has a second opening inclined to the axial direction for installation in the floating sealing groove.

[0022] Due to the adoption of the above technical solution, the beneficial effects achieved by this utility model are as follows:

[0023] 1. This application utilizes a large-capacity internal chamber of the sealing tire or support tire to connect with the liquid reservoir in the piston. Taking advantage of the large elastic deformation of the sealing tire or support tire's skin, a pressure-regulating piston establishes a connection between the liquid reservoir and the oil pressure at the bottom of the hammer piston. This establishes a relationship between the elasticity of the sealing tire or support tire's skin and the oil pressure at the bottom of the hammer piston. Thus, when the piston is first placed into the cylinder wall, the bottom of the hammer piston experiences a relatively small pressure value. As the hammer piston moves down to its working position within the cylinder wall, the pressure value gradually increases. When the oil pressure increases, the oil pressure in the liquid reservoir, after being reduced by the pressure-regulating piston, also increases, thereby increasing the oil pressure in the internal chamber of the sealing tire or support tire. This, in turn, increases the contact pressure between the sealing slip ring and the inner wall of the cylinder. The increased pressure in the sealing tire causes it to expand further, causing the sealing slip ring to move towards the cylinder wall. Similarly, the increased pressure in the support tire causes it to expand further, causing the floating sealing guide ring to move towards the cylinder wall. During the downward movement of the hammer piston under gravity, the bottom of the pressure-regulating piston... The small piston, under the pressure of the high-pressure oil at the bottom of the counterweight piston, transmits the force to the oil in the reservoir at the top of the pressure regulating piston. This pressurizes the oil, causing the sealing element in the main sealing groove or the supporting element in the floating sealing groove around the counterweight piston to expand further. This prevents the oil at the bottom of the counterweight piston from leaking through gaps, thereby reducing the sealing gap δ between the piston and the cylinder wall in the radial direction. The pressure of the sealed oil increases, further reducing the sealing gap δ and significantly enhancing the sealing performance between the piston and the cylinder wall. This further reduces oil leakage and improves the sealing effect. This floating adjustment sealing scheme, which is related to the oil pressure at the bottom of the counterweight piston, ensures that even with a large piston diameter, the sealing gap δ will not increase due to an excessively large piston diameter or excessively long gap, thus preventing leakage and pressure relief. This achieves a pressure self-compensating sealing effect. This structure can solve the piston sealing problem of counterweight accumulator pumps with stable high-flow-rate pressure in the future market, reducing leakage problems caused by increased structural size.

[0024] 2. When the counterweight piston moves upward via the drive mechanism, the bottom of the pressure regulating piston is no longer affected by the high-pressure oil below the counterweight piston and falls. This causes a decrease in the oil pressure in the oil reservoir above the pressure regulating piston, which in turn causes the sealing or support at the counterweight piston seal to contract. This reduces the sealing pressure between the main piston and the cylinder wall, allowing more oil above the main piston to wet the cylinder wall contact surface. This reduces the frictional resistance of the cylinder wall against the main piston when it rises, facilitating rapid upward movement of the main piston. It also allows the oil in the tank to lubricate and remove frictional heat through the gap between the main piston and the cylinder wall. This ensures sufficient sealing between the counterweight piston and the cylinder wall during operation while preventing increased friction that could lead to insufficient piston movement. It also solves the problem of high return resistance of the counterweight piston. This positive utilization of the slow response but stable output characteristics of the counterweight piston provides an energy-saving new sealing structure for establishing a large and stable high-pressure oil source piston pump.

[0025] 3. When the sealing or supporting tire operates under high pressure, the pressure regulating piston adjusts the internal pressure of the sealing or supporting tire to help the sealing slip ring or floating sealing guide ring withstand deformation under high pressure. During the rapid lifting of the counterweight piston, without increasing the wear of the sealing slip ring or floating sealing guide ring, gravity causes the pressure regulating piston to move downward, thus reducing the internal pressure of the sealing or supporting tire. This reduces the contact pressure between the sealing slip ring or floating sealing guide ring and the cylinder wall, reducing wear and extending the seal life. This method of adjusting the internal pressure of the sealing or supporting tire gives this new sealing structure a greater elastic deformation capacity than conventional sealing materials. Combined with automatic pressure adjustment based on gravity according to different operating conditions, the sealing surface has stronger wear resistance and high-pressure resistance, thereby extending the seal life and improving its reliability. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0027] Figure 1 This is a schematic diagram of a pressure regulating and sealing structure according to one embodiment of the present invention;

[0028] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0029] in,

[0030] 1. Counterweight piston; 2. Liquid reservoir; 3. Pressure regulating piston; 4. Sealing cover; 5. Safety valve; 6. First sealing assembly; 61. Upper support ring; 62. Sealing tire; 63. Sealing slip ring; 64. Lower support ring; 7. Second guide sealing assembly; 71. Limiting ring; 72. Support tire; 73. Inner support ring; 74. Floating sealing guide ring; 8. First filling channel; 9. Second filling channel; 10. Third filling channel; 11. Liner; 12. Female head; 13. Male head. Detailed Implementation

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0032] Furthermore, it should be understood in the description of this utility model that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, 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.

[0033] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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, an electrical connection, or a communication 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 according to the specific circumstances.

[0034] In this invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "implementation," "example," "aspect," or "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0035] To more clearly illustrate the overall concept of this utility model, a detailed description will be provided below with reference to the accompanying drawings.

[0036] The formula for correcting the leakage flow of the gap for the misalignment ε between the piston and the cylinder wall is: From the above formula, the leakage Q is proportional to the gap contact width πd, the cube of the gap gap δ, and the pressure difference ΔP, respectively. μ is the dynamic viscosity of the oil, and L is the plunger length. For a heavy-duty piston accumulator, increasing pressure will increase ΔP. Increasing the oil storage capacity requires increasing the piston size, which will lead to an increase in the gap contact width πd. Either of these two situations, or both simultaneously, will cause an increase in leakage Q. An increase in leakage Q not only leads to energy loss but also makes it difficult to build up pressure inside the piston. Even if you want to increase ΔP, it is difficult to achieve the expected ΔP. In particular, it is generally difficult to guarantee the roundness or ellipticity of the piston and cylinder wall in terms of machining accuracy. That is, there is a positive correlation between the gap contact width πd and the gap clearance δ. Thus, while increasing the size d of the heavy-duty piston accumulator to increase the oil storage capacity, it also leads to an increase in the gap clearance δ between the piston and the cylinder wall, resulting in more oil leakage and difficulty in building up ΔP. Conventional seals are difficult to solve this large amount of leakage caused by size issues, which is a major reason why the pressure of conventional heavy-duty accumulators is difficult to increase. Therefore, in traditional accumulator pumps, the accumulator piston not only needs to pressurize the oil in the lower part of the accumulator piston by its own weight and prevent leakage of the sealing gap, but also needs to ensure that the accumulator piston moves up quickly to pump oil. At this time, the small sealing gap δ increases friction, which leads to increased friction between the piston and the cylinder wall. Increased friction will also cause the sealing ring to fail prematurely due to heat or twisting. This not only reduces the sensitivity of the piston response, but also shortens the fault-free working time due to seal damage, thus increasing maintenance costs.

[0037] Traditional sealing methods use O-rings and other sealing structures. This type of sealing structure is only suitable for pistons with a small diameter d. Because d is small, the gap δ is also small. Thus, the elastic deformation range of a sealing ring such as an O-ring can effectively seal small gaps δ. However, for larger gaps δ, the elastic deformation range of a Glyd ring or a Step seal is difficult to reach, or even if it does reach, it is difficult to form a compressed sealing ring surface, leading to leakage. Therefore, conventional O-ring sealing structures are ineffective for pistons with larger diameters (d). The main reason is that while O-rings have good ductility, even when using silicone rubber (VMQ) or fluororubber (FKM) with low plastic deformation, their compression rebound elastic deformation exceeds 40% of the O-ring's cross-sectional diameter. (The compression set of O-ring materials is temperature-dependent. Leakage occurs when the deformation rate is 40% or higher.) Therefore, the heat resistance limits for several rubber materials are: nitrile rubber 70℃, EPDM rubber 100℃, and fluororubber 140℃. Consequently, various countries have established regulations regarding the permanent deformation of O-rings. The loss of rebound force in O-rings is due to the fact that the synthetic rubber material used in O-ring seals is viscoelastic. Therefore, the initial compression and rebound blocking capacity will gradually be lost through permanent deformation after prolonged use, eventually leading to leakage. Permanent deformation and loss of elasticity are the main reasons why O-rings lose their sealing performance, thus compromising sealing effectiveness.

[0038] Furthermore, due to factors such as uneven O-ring cross-sectional diameter, material hardness, lubricating oil film thickness, and surface roughness of the sealing shaft, part of the O-ring slides along the workpiece surface while the other part rolls, causing O-ring distortion. Typically, O-rings with smaller cross-sectional dimensions are prone to uneven friction. Moving O-rings have larger cross-sectional diameters than fixed O-rings, making them more susceptible to distortion and damage during movement. This is a significant cause of sealing device damage and leakage. Moreover, at pressures greater than 20 MPa, the increase in the contact area between the O-ring and the metal surface gradually slows down with increasing pressure, and the increase in friction also slows down accordingly. Under normal circumstances, the service life of an O-ring decreases approximately quadratically with increasing liquid pressure. Therefore, the limited elastic recovery of O-rings, the increased friction with increasing pressure, and the distortion damage in dynamic seals result in poor sealing performance of conventional O-ring and other sealing structures for pistons with larger dimensions (d). This is typically determined after 72 hours of measurement at 25% compression. Therefore, there is an urgent need for a piston sealing structure for increasing the diameter of the piston and cylinder wall to place more weights to build up higher pressure, and also for a weighted accumulator piston sealing structure that needs to float and seal with pressure changes to ensure pressure stability in large-diameter seals. Based on the above technical background, this application designs a pressure regulating sealing structure.

[0039] This utility model relates to a pressure regulating and sealing structure, such as Figure 1-2 As shown, a main sealing groove and a floating sealing groove are formed around the periphery of the hammer piston 1. The floating sealing grooves are respectively arranged on both sides of the main sealing groove along the axial direction of the hammer piston 1. The hammer piston 1 has a liquid storage chamber 2. A pressure regulating piston 3 is set at the bottom of the liquid storage chamber 2, and a sealing cover plate 4 is set at the top of the liquid storage chamber 2. A safety valve 5 is opened on the cover plate. The sealing structure includes:

[0040] The first sealing assembly 6 is disposed in the main sealing groove and includes an upper support ring 61, a sealing element 62, a sealing slip ring 63, and a lower support ring 64. The upper support ring 61 is connected to the upper wall of the main sealing groove, and the lower support ring 64 is connected to the lower wall of the main sealing groove. The sealing element 62 is disposed between the upper support ring 61 and the lower support ring 64, and the sealing slip ring 63 is disposed between the sealing element 62 and the cylinder wall.

[0041] The second guide sealing assembly 7 is symmetrically arranged in the floating sealing grooves on both sides of the main sealing groove, including a limiting ring 71, a support 72, an inner support ring 73, and a floating sealing guide ring 74; the limiting ring 71 is connected to the groove wall of the floating sealing groove on the side closer to the main sealing groove, the inner support ring 73 is connected to the bottom of the floating sealing groove, the support 72 is arranged in the groove outside the inner support ring 73 and is adjacent to the limiting ring 71; the floating sealing guide ring 74 is arranged between the support 72 and the cylinder wall, and the sealing section of the floating sealing guide ring 74 is adjacent to the limiting ring 71, and the guiding section of the floating sealing guide ring 74 is in elastic contact with the inner support ring 73;

[0042] The heavy hammer piston 1 has a first filling channel 8, a second filling channel 9, and a third filling channel 10. The first filling channel 8 connects the liquid storage chamber 2 to the sealing tire 62 through a first quick connector. The second filling channel 9 connects the liquid storage chamber 2 to the support tire 72 above the main sealing groove through a second quick connector. The third filling channel 10 connects the liquid storage chamber 2 to the support tire 72 below the main sealing groove through a third quick connector.

[0043] Furthermore, a quick-connect connector is provided between the liquid storage chamber 2 connecting channel and the sealing tire 62. The quick-connect connector on the sealing tire 62 is a male head 13, and the sealing tire 62 end of the liquid storage chamber 2 connecting channel on the piston is provided with a female head 12 of the quick-connect connector. A seal is provided between the female head 12 and the liquid storage chamber 2 connecting channel, and a threaded connection is used so that it can be set in advance before the sealing tire 62 is installed, so as to facilitate quick connection when the sealing tire 62 is installed. The piston sealing groove is provided with a quick-connect operating space, and a seal adapted to the space is provided around the operating space for static sealing between the sealing tire 62 and the piston sealing groove.

[0044] It should be noted that a safety valve 5 is provided in the cover plate to prevent the sealing tire 62 or the support tire 72 from exploding due to excessive oil pressure in the reservoir 2. The sealing tire 62 or the support tire 72 is confined by the surrounding space, limiting its expansion. Therefore, the volume of oil in the reservoir 2 remains essentially unchanged, and the pressure regulating piston 3 does not move significantly. Oil is incompressible; the upper part of the piston is filled with liquid first, and its pressure is supplied by the lower part of the piston, but the displacement is minimal.

[0045] A gap seal is used between the pressure regulating piston 3 and the counterweight piston 1 to ensure a smooth movement of the pistons. Alternatively, if the pressure at the bottom of the counterweight piston 1 is too high or the manufacturing error of the gap between the pressure regulating piston 3 and the counterweight piston 1 is large, an O-ring seal can be installed in the pressure equalization groove of the piston. However, the compression ratio of the O-ring caused by the clearance of the moving fit should not exceed 10% of the O-ring wire diameter to facilitate installation and flexible movement between the pistons. The wetting or flow of oil in the upper and lower parts of the counterweight piston 1 reduces the friction between the sealing slip ring 63 or the O-ring and the cylinder wall. The frictional heat is also easily carried away by the flowing oil, preventing the O-ring from overheating, aging, or twisting and breaking. This also overcomes the problems of unreliable piston seals and short seal life in current counterweight cylinders.

[0046] When the counterweight piston 1 moves upward, the pressure regulating piston 3 slides down by its weight. Because the elastic modulus of the oil is high, even a small expansion of space can cause the oil pressure in the reservoir 2 to decrease, thereby causing the sealing tire 62 or the support tire 72 to contract, reducing the contact force and contact area between the seal and the cylinder wall, which is conducive to the rapid lifting and return of the counterweight piston 1.

[0047] For example, a cylinder with a diameter of 10mm has a cross-sectional area of ​​π / 4 × 100 = 78.5mm². Because the circumference πd of a 10mm diameter cylinder is small, the clearance can easily be within 10μm. Therefore, a pressure equalization and load reduction groove is sufficient to prevent high-pressure oil from communicating with the low-pressure area in the reservoir and forming a communicating vessel. Furthermore, the pressure equalization and load reduction groove does not require an O-ring, allowing the Φ10 pressure regulating piston to move more flexibly up and down, quickly responding to the high pressure below the hammer piston. When the hammer piston moves downwards under gravity, the piston, subjected to the high-pressure oil P (30MPa) below the hammer piston, quickly transmits the force to the oil in the reservoir, where the large-area piston A2 acts, with little or no contact friction. This maintains the oil pressure in the reservoir at a low pressure of A1 / A2 × P = 1MPa (where P = 30MPa), resulting in A2 = 30 × 78.5mm² = π / 4 × D × D, where the large piston diameter D = The diameter is 54.7mm, rounded to Φ55. The fit clearance can easily be achieved within 10μm. Correspondingly, only the pressure equalization and unloading groove is needed to ensure that the high-pressure oil does not connect to the low-pressure area in the reservoir and form a communicating vessel. For the Φ55 large piston, an O-ring can also be set in the pressure equalization and unloading groove to slow down the up and down movement of the large piston column and stabilize the oil pressure in the reservoir. Due to the rigid connection, it does not affect the small piston's ability to quickly provide pressure to the large piston to respond to the high pressure changes at the bottom of the hammer piston. This meets the pressure bearing requirements of the easily manufactured inner tube. If the hammer piston suddenly sinks during installation, or if the air bubbles below the hammer piston suddenly explode and dissolve, the pressure will suddenly rise to 30MPa. At this time, the oil pressure A1 / A2×P in the reservoir will also suddenly rise. When it exceeds 10×1.1MPa, the oil will be unloaded through the safety valve set on the upper cover of the reservoir to ensure that the oil pressure in the reservoir does not exceed 1MPa.

[0048] Under the action of the sealing ring or support ring, the sealing gap δ between the sealing ring and the cylinder wall is reduced. The amount of gap reduction is positively correlated with P in A1 / A2×P. With A1 / A2 constant, P can be adjusted by adjusting the weight of the counterweight, and the sealing gap δ can be adjusted by A1 / A2×P. Due to the existence of three seals, the pressure difference ΔP2 above and below the main seal can reach 2 / 3P (ignoring atmospheric pressure P0=0, ΔP=ΔP1+ΔP2+ΔP3=P-P0=P). The influence of the eccentricity ε can be ignored. By ensuring that the leakage flow of the gap is not greater than 1% to 10% of the output flow, the volumetric efficiency of the counterweight piston seal can reach 99% to 90% or more. The correction formula with eccentricity ε is: In the formula, the pressure difference ΔP reaches P (ignoring atmospheric pressure P0=0, ΔP=P-P0=P).

[0049] For example, the diameter of the counterweight piston 1 is d = 2m, the cylinder depth is 1.5m, and 1 / 3 of the oil in the accumulator of the counterweight piston 1 is used for operation. The oil volume is approximately 150 liters. Assuming a supply rate of 60 liters per minute for 5 pieces of equipment, and assuming a design ΔP = 20MPa, the dynamic viscosity of No. 46 hydraulic oil is 0.039m. 2 / s, allowable leakage flow rate Q = 1% × 60 L / min = 0.60 L / min, sealing length between sealing slip ring 63 and cylinder wall L = 100 mm, then choose C = 1, clearance δ = Q × 12 × μ × L × C / (πdΔP) = 0.60 L / min × 12 × = 0.015 mm. Therefore, at the main seal with L = 100 mm, under the condition of allowable leakage of 0.60 L / min, the sealing clearance needs to be less than 0.015 mm. Therefore, sealing slip ring 63 can be made into a split part for convenient installation of large size. Because the pressure is above 20MPa, the leakage of gaps is relatively large, which can easily lead to the instability of pressure establishment. Therefore, a fine-diameter O-ring that can be bonded is used to bind the split sealing slip ring 63. Taking advantage of the large shrinkage elasticity, non-deformation and long service life of the O-ring, the split sealing slip ring 63 can be tightly connected. It can also ensure that the sliding gap between the sealing slip ring 63 and the cylinder wall is 0.015mm when the sealing length between the sealing slip ring 63 and the cylinder wall is not greater than 100mm. It can also form an oil film thickness of 0.01-0.03mm commonly used in general industrial machinery equipment.

[0050] As those skilled in the art will know, the minimum oil film thickness for precision machinery (such as aircraft and automotive bearings) is typically 0.001-0.004 mm; the oil film thickness for general industrial equipment (such as electric motors and generators) is approximately 0.01-0.03 mm; and the oil film thickness for large machinery (such as water turbines and turbomachinery) can reach 0.05-0.1 mm to support high loads. Ideally, the oil film thickness for most high-speed machinery should be maintained at 5-10 μm; excessively thin or thick oil film can lead to increased friction or component damage.

[0051] Furthermore, the sealing tire 62 or the support tire 72 adopts the structure of a bicycle inner tube, with its rubber ring's annular cross-section supporting the middle of the sealing slip ring 63. Therefore, the force exerted by the sealing tire 62 on both sides of the sealing slip ring 63 will be less than that on the middle of the sealing slip ring 63, because even if it is the same material, the elastic deformation and reaction force are different in different parts. Taking advantage of the small force and small deformation on both sides of the sealing slip ring 63, O-rings are set in the pressure equalization grooves on both sides of the sealing slip ring 63 to tighten the separate sealing slip ring 63. At the same time, the groove depth for placing the O-rings is set so that the protrusion of the O-rings is about 10% of the cross-sectional diameter of the O-ring rubber ring. Thus, the O-rings installed on both sides of the sealing slip ring 63, because the amount protruding from the outer O-ring groove of the sealing slip ring 63 is only 10% or less, will basically not suffer torsional damage during the piston's up and down movement. Moreover, even though the compression is less than 10%, it can effectively compensate for the gap caused by the uneven force on both sides of the sealing slip ring 63, and provide auxiliary sealing for the establishment of high pressure. This can fill the gap unevenness caused by the increased diameter of the hydraulic cylinder of the hammer piston 1 and the increased machining error, which is currently the difficulty in establishing the pressure of the hammer cylinder.

[0052] When the piston diameter is large, the circumferential contact length between the piston and the cylinder wall will increase. Due to machining errors such as ellipticity, the circumferential contact gap will also increase. The contact width of the gap between the piston and the cylinder wall refers to the arc length πd formed by the gap between the outer circumferential surface of the piston and the inner circumferential surface of the cylinder wall. From the above formula, the leakage amount Q is proportional to the contact width of the gap πd, the cube of the gap gap δ, and the pressure difference ΔP.

[0053] For the accumulator 1 with a heavy hammer piston, if a higher pressure P is required, the sealing area for oil pressure buildup must be increased by ΔP = P - P0. Increasing the oil storage capacity requires a larger piston size, which leads to a larger gap contact width πd. Either of these conditions, or both simultaneously, will result in increased leakage Q. Increased leakage Q not only leads to energy loss but also makes it difficult to build up pressure within the piston. Even if ΔP is to be increased, it is difficult to achieve the desired result. In particular, the machining accuracy of pistons and cylinder walls is generally difficult to guarantee roundness or ellipticity. That is, there is a positive correlation between the gap contact width πd and the gap clearance δ. This means that while increasing the size d of the heavy hammer piston 1 accumulator to increase the oil storage capacity, it also increases the gap clearance δ between the piston and cylinder wall, resulting in significant oil leakage. ΔP is difficult to establish a conventional seal, making it difficult to solve this large leakage caused by machining size issues. This is a major reason why conventional heavy hammer accumulators are difficult to increase pressure.

[0054] Traditional sealing methods employ O-rings or piston seals such as Step seals or Glyd rings. These sealing structures are only suitable for small pistons, i.e., small diameters (d). Because of the small diameter (d), the gap (δ) is also small. Thus, a typical seal like an O-ring can effectively seal small gaps (δ) within its elastic deformation range. However, for larger gaps (δ), the elastic deformation range of the O-ring in Step seals or Glyd rings is insufficient to reach them, or even if it does, it is difficult to form a compressed sealing ring, leading to leakage. Therefore, conventional O-ring and other sealing structures are ineffective for pistons with larger diameters (d), and thus cannot guarantee a proper seal. This application uses a tire-type seal with a large elastic deformation range to replace the O-ring in Step seals or Glyd rings, thereby enhancing the dynamic sealing effect, especially for large-diameter pistons moving within the cylinder wall. This application utilizes the large-capacity internal chamber of the sealing tire 62 or the supporting tire 72, which is connected to the liquid reservoir 2 in the piston. Taking advantage of the large elastic deformation of the tire skin of the sealing tire 62 or the supporting tire 72, the liquid reservoir 2 contacts the oil at the bottom of the piston via the pressure regulating piston 3 or directly with the oil at the bottom of the piston. Thus, when the piston is first placed into the cylinder wall, it experiences a relatively small pressure value. As the piston moves down to its working position within the cylinder wall, the pressure gradually increases. When the oil pressure increases, the pressure in the liquid reservoir 2 also increases through the pressure regulating piston 3 or direct contact, thereby increasing the pressure of the oil in the internal chamber of the sealing tire 62 or the supporting tire 72. This, in turn, increases the contact pressure between the sealing slip ring 63 and the inner wall of the cylinder, thus achieving sealing. The increased pressure on tire 62 causes the sealing tire 62 to expand further, which in turn causes the sealing slip ring 63 to move toward the cylinder wall. The increased pressure on support tire 72 causes the support tire 72 to expand further, which in turn causes the floating sealing guide ring 74 to move toward the cylinder wall. This reduces the sealing gap δ between the piston and the cylinder wall in the radial direction, causing the pressure of the sealed oil to rise. The reduced sealing gap δ significantly enhances the sealing performance between the piston and the cylinder wall, further reducing oil leakage and improving the sealing effect. Therefore, even with a large piston diameter, the sealing gap δ will not increase due to the large piston diameter and long gap, thus preventing leakage and pressure relief. This achieves a pressure self-compensating sealing effect.

[0055] The smaller the sealing gap δ, the higher the pressure P that can be built up inside the piston. The sealing ring is used to limit the amount of oil leakage between the piston and the accumulator cylinder. Because the rubber used in the tire has great extensibility, the oil inside is continuously supplied from the reservoir 2 as the piston moves down, so that the sealing tire 62 or the supporting tire 72 has a larger floating sealing margin, which can continuously reduce the sealing gap δ as the pressure increases. Due to this sufficiently large adjustment size margin, the fitting clearance or positional accuracy between the piston accumulator cylinder and the piston can be widened, thereby reducing the machining difficulty of the fitting size between the cylinder and the piston, which is beneficial to the pressure increase or capacity increase of the accumulator of the counterweight piston 1.

[0056] The sealing ring can ensure sufficient sealing gap δ between the piston body and the accumulator cylinder body according to the tire expansion amount and expansion pressure. According to the principle that the pressure difference P-P0=ΔP at both ends of the seal is inversely proportional to the cube of δ when the leakage amount Q at both ends of the seal is constant, it can be seen that the pressure P can be significantly adjusted by the tire expansion amount, which is beneficial to further increase the pressure of the accumulator.

[0057] Taking advantage of the fact that gas tends to flow upwards, resulting in a gas-liquid mixture in the upper part of the liquid storage chamber 2, a cover plate is installed on the upper part of the liquid storage chamber 2. A one-way valve or a straight-through overflow valve is installed inside the cover plate. This not only ensures that when the pressure in the liquid storage chamber 2 rises too high, the one-way valve or the straight-through overflow valve acts as a safety valve 5 to release pressure outwards, preventing the tire rubber from expanding outwards beyond its sufficient extensibility and bursting, but also utilizes the fact that the compressibility of gas and liquid is higher than that of liquid, causing bubbles to concentrate at the cover plate at the upper part of the liquid storage chamber 2. The low viscosity of the gas makes it easy to seep out through the safety valve 5, and the oil also easily overflows outwards through the safety valve 5 first, thus having a venting function.

[0058] The sealing tire 62 and the support tire 72 can be made of materials with different hardness and thickness. The tire pressure should not exceed 8.9 bar ≈ 1 MPa. The sealing tire 62 in the main sealing groove is made of thin and soft rubber with a large cross-sectional diameter, fast response, and large force to assist the main sealing slip ring 63 in adhering tightly to the cylinder wall and establishing pressure. The support tire 72 is made of thick and hard rubber and serves as the movable support point for the floating sealing guide ring 74, emphasizing stability and adjustability. It has a small wire diameter and a slow response to assist in guiding the sealing slip ring 63 according to the cylinder wall. The dimensional changes rely on the pressure of the oil inside the cylinder to create a floating guiding effect on the conical guide ring. The floating sealing guide ring 74 has not only circumferential pressure-equalizing grooves (at least three in total) on its sealing contact surface, but also small through grooves in the axial direction to allow and ensure leakage. This allows the leaked oil to lubricate its own sealing ring surface and also assists in the lubrication between the main sealing slip ring 63 and the cylinder wall, without causing a sudden increase in the amount or pressure of oil between the sealing tire 62 and the support tire 72. The sealing tire 62 and the support tire 72 can be bicycle inner tubes. The pressure of bicycle inner tubes is usually measured in psi (pounds per square inch) or bar, not MPa (megapascals). Recommended tire pressure ranges vary depending on the type and purpose of the bicycle. Recommended tire pressure values ​​for different types of bicycles are as follows:

[0059] Road bikes: Tire pressure is typically between 80-130 psi (approximately 5.5-8.9 bar). Higher pressure reduces rolling resistance and improves riding efficiency. Mountain bikes: Tire pressure is between 30-65 psi (approximately 2.1-4.6 bar). Lower pressure provides better grip and comfort but increases rolling resistance. City / commuter bikes: Tire pressure is typically between 40-60 psi (approximately 2.8-4.1 bar), providing a comfortable ride while maintaining good rolling efficiency. Mixed-surface / recreational bikes: Tire pressure may be between 50-70 psi (approximately 3.5-4.8 bar), depending on tire type and rider weight.

[0060] In a preferred embodiment, the sealing slip ring 63 is disposed between the upper support ring 61 and the lower support ring 64, and is connected in the radial direction of the counterweight piston 1 between the sealing tire 62 and the inner side of the cylinder wall. When the sealing tire 62 is filled with liquid, the sealing slip ring 63 can contact and connect with the cylinder wall, so that a sealed connection is formed between the counterweight piston 1 and the cylinder wall. At least three pressure equalizing grooves are opened on the circumferential side of the sealing slip ring 63 that contacts the cylinder wall, and fastening O-rings are installed in the upper and lower two grooves respectively.

[0061] The sealing or supporting element acts on the sealing slip ring, reducing the sealing gap δ between the sealing slip ring and the cylinder wall. The amount of gap reduction is positively correlated with the pressure P in A1 / A2×P. With A1 / A2 constant, P can be adjusted by adjusting the weight of the counterweight, and the sealing gap δ can be adjusted by A1 / A2×P, as long as... When the pressure difference ΔP reaches P (ignoring atmospheric pressure p0=0, ΔP=P-P0=P), leakage is permissible. Therefore, the sealing slip ring can be made into a split form to facilitate large-size installation. Since the leakage of gaps is relatively large above 30MPA, a fine-diameter O-ring that can be glued is used to bind the split sealing slip ring. Taking advantage of the O-ring's large shrinkage elasticity, resistance to deformation, and long service life, the split sealing slip ring can be tightly connected.

[0062] By wetting the upper and lower parts of the heavy hammer piston 1 with oil, the friction between the sealing slip ring 63 or O-ring and the cylinder wall is reduced, preventing the O-ring from twisting and breaking. This also overcomes the current problems of unreliable piston sealing and short sealing life in heavy hammer cylinders. When the piston diameter is large, the circumferential contact length between the heavy hammer piston 1 and the cylinder wall will increase. Due to machining errors such as ellipticity, the circumferential contact gap will also increase. The gap contact width between the heavy hammer piston 1 and the cylinder wall refers to the arc length πd dimension formed by the gap between the outer circumferential surface of the piston and the inner circumferential surface of the cylinder wall. From the above formula, the leakage amount Q is proportional to the contact width of the gap πd, the cube of the gap gap δ, and the pressure difference ΔP.

[0063] For the accumulator of the heavy hammer piston 1, increasing pressure will increase ΔP. Increasing the oil storage capacity requires increasing the piston size, which will lead to an increase in the gap contact width πd. Either of these conditions, or both simultaneously, will result in an increase in leakage Q. Increased leakage Q not only leads to energy loss but also makes it difficult to build up pressure within the piston. Even if ΔP is to be increased, it is difficult to achieve the expected ΔP, especially since the machining accuracy of the piston and cylinder wall is generally difficult to guarantee roundness or ellipticity. There is a positive correlation between the gap contact width πd and the gap clearance δ. This means that while increasing the size d of the heavy hammer piston 1 accumulator to increase the oil storage capacity, it also leads to an increase in the gap clearance δ between the piston and cylinder wall, resulting in significant oil leakage and making it difficult to build up ΔP. Conventional seals are insufficient to address this large leakage caused by size issues, thus making it difficult to increase the pressure of conventional heavy hammer accumulators.

[0064] Traditional sealing methods employ O-rings and similar sealing structures. These structures are only suitable for pistons with small diameters (d). Because of the small diameter (d), the resulting gap (δ) is also small. Generally, the elastic deformation range of an O-ring can effectively seal small gaps (δ). However, for larger gaps (δ), the elastic deformation range of the O-ring is insufficient to reach them, or even if it does, it is difficult to form a compressed sealing ring, leading to leakage. Therefore, conventional O-rings and similar sealing structures are ineffective for pistons with larger diameters (d), and thus cannot guarantee a proper seal.

[0065] Preferably, the O-rings are respectively disposed in the two grooves at the top or bottom. The O-rings have the characteristics of small wire diameter and strong self-adaptability, which can compensate for the problem of large contact area and poor adaptability of the sealing slip ring 63. This application adopts a unique sealing structure to enhance the dynamic sealing effect, especially when a large-diameter piston moves within the cylinder wall. This application utilizes the large-capacity internal chamber of the sealing tire 62 or support tire 72 to connect with the liquid reservoir 2 in the piston. Utilizing the large elastic deformation of the tire skin of the sealing tire 62 or support tire 72, the liquid reservoir 2 contacts the oil at the bottom of the piston through the pressure regulating piston 3 or directly. When the piston is first placed inside the cylinder wall, the piston experiences a small pressure value. As the piston moves down to its working position within the cylinder wall, the pressure value gradually increases. When the oil pressure increases, the pressure in the liquid reservoir 2 also increases through the pressure regulating piston 3 or direct contact, thereby increasing the pressure of the oil in the large-capacity internal chamber of the sealing tire 62 or support tire 72, and further enhancing the dynamic sealing effect of the sealing slip ring 63 in contact with the cylinder wall. The increased contact pressure on the cylinder wall causes the sealing ring 63 to move towards the cylinder wall, further expanding due to the increased pressure on the sealing ring 62. The increased pressure on the supporting ring 72 further expands the supporting ring 72, causing the floating sealing guide ring 74 to move towards the cylinder wall. This reduces the radial gap δ between the piston and the cylinder wall, causing the pressure of the sealed oil to rise. The reduced gap δ significantly enhances the sealing performance between the piston and the cylinder wall, further reducing oil leakage and improving the sealing effect. Even with a large piston diameter, the increased gap δ prevents leakage and pressure relief, achieving a pressure self-compensating sealing effect.

[0066] The smaller δ is, the higher the pressure P inside the piston. The sealing ring is used to limit the amount of oil leakage between the piston and the accumulator cylinder. Because the rubber used in the tire has great extensibility, the oil inside is continuously supplied from the reservoir 2 through the downward movement of the piston, so that the sealing tire 62 or the supporting tire 72 has a larger floating sealing margin. As the pressure increases, the sealing gap δ continuously shrinks. Because the adjustment size margin is large enough, the fitting clearance or positional accuracy between the piston accumulator cylinder and the piston is widened, thereby reducing the machining difficulty of the fitting size between the cylinder and the piston, which is beneficial to the pressure increase or capacity increase of the accumulator of the counterweight piston 1.

[0067] The sealing ring can ensure a sufficient sealing gap δ between the piston body and the accumulator cylinder based on the tire expansion amount and expansion pressure. According to the fact that the leakage amount Q at both ends of the seal is constant, the pressure difference P-P0=ΔP at both ends of the seal is inversely proportional to the cube of δ. It can be seen that the pressure P can be significantly adjusted by the tire expansion amount, which is beneficial to further increase the pressure of the accumulator.

[0068] Furthermore, the thickness of the liner 11 is smaller than the thickness of the sealing slip ring 63.

[0069] In a preferred embodiment, the sealing slip ring 63 extends beyond the main sealing groove by a predetermined distance, and the sealing slip ring 63 protrudes along the direction perpendicular to the axis of the hammer piston 1 and is disposed on the upper support ring 61 or the lower support ring 64 to prevent the upper support ring 61 or the lower support ring 64 from rubbing against the cylinder wall.

[0070] In a preferred embodiment, the sealing slip ring 63 has at least three pressure equalizing grooves on its circumferential side in contact with the cylinder wall. These grooves are evenly distributed along the piston axis to ensure uniform pressure distribution between the sealing slip ring 63 and the cylinder wall. The grooves on the upper and lower sides for mounting and fastening O-rings have a depth not exceeding 90% of the O-ring diameter and a width not exceeding 110% of the O-ring diameter to ensure a small contact area between the O-ring and the cylinder wall and reduce torsional damage.

[0071] The shrinkage rate of O-rings is typically 15%-30% for static seals and 10%-20% for dynamic seals. The compression must match the flatness to avoid leakage due to insufficient deformation. After the O-ring is installed in the shaft, it generally experiences some stretching. If there is no stretching, it may easily come loose during assembly. Excessive stretching will cause the cross-sectional area of ​​the O-ring to decrease too much, resulting in leakage. Generally, the stretching is 1%-5%.

[0072] The purpose of setting at least three pressure equalization grooves is to balance the uneven force caused by the excessive size of the annular seal in contact with the cylinder wall, thereby balancing the pressure around the circumference and helping to correct piston eccentricity and misalignment. They are also used to store oil to reduce friction and to increase the energy loss caused by the fluctuating diameter space between the sealing contact gaps, thus slowing down oil leakage along the axial gap.

[0073] As a preferred embodiment, the pressure regulating sealing structure also includes an inner liner 11, which is disposed at the bottom of the main sealing groove. The inner liner 11 is used to protect or position the sealing tire 62, and to prevent the sealing tire 62 from contacting the uneven metal contact surface at the bottom of the groove, which could lead to a puncture and tire blowout.

[0074] The inner liner 11 is bonded to the bottom of the main sealing groove with an elastic bandage to protect or position the sealing tire 62, preventing the sealing tire 62 from coming into contact with the uneven metal contact surface of the groove bottom, which could lead to a puncture and tire blowout.

[0075] In a preferred embodiment, the floating sealing guide ring 74 has a conical barrel structure and is arranged in a ring in the floating sealing grooves on both sides of the main sealing groove. The floating sealing guide ring 74 has oblique or staggered concave-convex connecting grooves, and the staggered oblique or concave-convex connecting grooves form a closed connection along the circumference. Furthermore, the outer conical surface of the floating sealing guide ring 74 faces the top or bottom of the piston and does not contact the cylinder wall.

[0076] To facilitate the installation of seals or sealing guide rings on large pistons, the annular ring has beveled openings or staggered convex and concave grooves along the axial direction, and the staggered bevels or convex and concave grooves can be closely connected along the circumferential direction.

[0077] In a preferred embodiment, an arc-shaped inner groove is provided on the inner side of the floating sealing guide ring 74 at the position where it contacts the support tire 72, so as to ensure that the expansion force of the support tire 72 presses the outer side of the floating sealing guide ring 74 against the cylinder wall through the arc-shaped inner groove; the floating sealing guide ring 74 has an L-shaped structure and elastically contacts the inner support ring 73, and is surrounded by the limiting ring 71 on the outer periphery of the support tire 72.

[0078] The elastic contact length and compression amount are preset according to the accumulator pressure to ensure that the guiding part has a margin for inward contraction towards the piston axis without causing the support tire 72 to be subjected to a hydraulic pressure exceeding 1 MPa. Let the contact area between the arc-shaped inner groove and the support tire 72 be A1, and the contact area between the sealing guide ring and the cylinder wall be A2. Then the pressure F exerted by the support tire 72 under a hydraulic pressure of 1 MPa on the sealing guide ring is F = 1 MPa × A1. The pressure (pressure intensity) P1 exerted by the outer side of the floating sealing guide ring 74 pressing against the cylinder wall is P1 = F / A2 = 1 MPa × A1 / A2. If A1 < A2, then P1 < 1 MPa < the hydraulic pressure P at the bottom of the weight piston 1. The hydraulic pressure at the bottom of the weight piston 1 causes the raised part on the inner side of the floating sealing guide ring 74 corresponding to the outer peripheral conical surface of the floating sealing guide ring 74 to be in elastic contact with the inner support ring 73 and enclose the other side of the support tire 72, further strengthening the guiding effect of the piston's downward movement and also preventing the support tire 72 from being subjected to a hydraulic pressure exceeding 1 MPa.

[0079] As a preferred embodiment, the first liquid filling channel 8, the second liquid filling channel 9, and the third liquid filling channel 10 are arranged in a circular array on the projection plane along the axis direction of the weight piston 1, so as to balance the piston weight and ensure that the piston's center of gravity is on the axis line.

[0080] The pressure regulating piston 3 has a cylindrical structure with different cross-sections at the upper and lower parts and is concentric with the weight piston 1, and / or, the pressure regulating piston 3 has two concentric cylindrical structures with different cross-sections at the upper and lower parts and is axisymmetric with the weight piston 1; there is a movable gap formed between the upper outer cylindrical surface or the lower outer cylindrical surface of the pressure regulating piston 3 and the weight piston 1, so that the pressure regulating piston 3 can move relative to the weight piston 1; when the pressure regulating piston 3 and the weight piston 1 descend by gravity, the small piston at the bottom of the pressure regulating piston 3 transmits the acting force to the oil in the liquid storage chamber 2 acting on the large piston at the top of the pressure regulating piston 3 after being affected by the high-pressure oil at the lower part of the weight piston 1.

[0081] The high-pressure oil at the lower part of the weight piston 1 is proportionally decompressed by the pressure regulating piston 3 to the oil in the liquid storage chamber 2, and by utilizing the characteristic that the compression deformation amount of the oil is extremely small, the pressure regulating piston 3 only needs a small margin of movement up and down to overcome the problem that a conventional pressure reducing valve cannot be reliably decompressed when it reaches the limit position.

[0082] This application achieves this by arranging the pressure regulating piston 3 into a cylindrical structure concentric with the counterweight piston 1 and fitting it inside the inner hole of the counterweight piston 1. This creates a movable gap between the outer cylindrical surface of the pressure regulating piston 3 and the inner wall of the counterweight piston 1, allowing the pressure regulating piston 3 to move relative to the counterweight piston 1. The pressure regulating piston 3 is configured as a concentric cylindrical structure with a smaller lower section and a larger upper section. A pressure equalization groove is formed on either the lower or upper cylindrical surface of the pressure regulating piston 3; or the cylinder of the pressure regulating piston 3 has a movable gap with the contacting cylindrical surface of the inner hole of the counterweight piston 1. In addition to the gap, contact length, and pressure equalization groove, an O-ring can also be set in the pressure equalization groove of the pressure regulating piston 3. The pressure equalization groove set on the pressure regulating piston 3 serves as a gap seal and can also ensure that the stored oil is used for lubrication. When the pressure at the bottom of the counterweight piston 1 is too high or the manufacturing error of the gap between the pressure regulating piston 3 and the counterweight piston 1 is large, an O-ring can be set in the pressure equalization groove of the pressure regulating piston 3. However, the compression rate of the O-ring caused by the moving fit gap should not be greater than 10% of the O-ring wire diameter, so as to facilitate installation and flexible movement between pistons.

[0083] When the counterweight piston moves upward via the drive mechanism, the bottom of the pressure regulating piston is no longer affected by the high-pressure oil below the counterweight piston and falls. This causes a decrease in the oil pressure in the oil reservoir above the pressure regulating piston, which in turn causes the sealing or support at the counterweight piston seal to contract. This reduces the sealing pressure between the main piston and the cylinder wall, allowing the oil above the main piston to wet more of the cylinder wall contact surface. This reduces the frictional resistance of the cylinder wall against the main piston when it rises, facilitating rapid upward movement of the main piston. It also allows the oil in the tank to lubricate and remove the frictional heat between the main piston and the cylinder wall in a timely manner. This ensures sufficient sealing between the counterweight piston and the cylinder wall during operation while preventing increased friction that could lead to insufficient piston movement. It also solves the problem of high return resistance of the counterweight piston. This positive utilization of the slow response but stable output characteristics of the counterweight piston provides an energy-saving new sealing structure for establishing a large and stable high-pressure oil source piston pump.

[0084] When the pressure regulating piston 3 and the counterweight piston 1 descend under gravity, the bottom of the pressure regulating piston 3 is subjected to the high-pressure oil at the bottom of the counterweight piston 1, and the force is transmitted to the oil in the reservoir 2 at the top of the pressure regulating piston 3. A gap seal is used between the pressure regulating piston 3 and the counterweight piston 1 to ensure an oil film exists between them for flexible movement. Alternatively, if the pressure at the bottom of the counterweight piston 1 is too high or the manufacturing error of the gap between the pressure regulating piston 3 and the counterweight piston 1 is large, an O-ring seal can be installed in the pressure equalization groove of the piston. However, the compression rate of the O-ring caused by the moving fit clearance should not exceed 10% of the O-ring wire diameter, etc., to facilitate installation and flexible movement between the pistons.

[0085] For example, a cylinder with a diameter of 10mm has a cross-sectional area of ​​π / 4×100=78.5^2mm. Since the circumference πd of a cylinder with a diameter of 10mm is small, the fitting clearance can easily reach within 10μm. Therefore, the pressure equalization and load reduction groove is sufficient to ensure that the high-pressure oil does not connect to the low-pressure reservoir and form a communicating vessel. Moreover, the pressure equalization and load reduction groove does not have an O-ring, and the Φ10 pressure regulating piston can move up and down more flexibly, which can quickly respond to the high pressure at the bottom of the hammer piston. When the hammer piston moves down by gravity, the piston is subjected to the high-pressure oil P of 30MPa at the bottom of the hammer piston. The force is quickly transmitted to the oil in the reservoir where the upper cylindrical end face area A2 of the pressure regulating piston is acted upon, with little or no contact friction. This keeps the oil pressure in the reservoir at a low pressure of P2≤1MPa. If the pressure at the bottom of the counterweight piston is P1 = 30 MPa, P1 × A1 = P2 × A2, and the contact area between the pressure regulating piston and the oil is A1 = πr^2, where r is the radius of the lower cylinder of the pressure regulating piston, and r is preferably 10 mm; then we can obtain:

[0086]

[0087] Since P2 ≤ 1 MPa, we can obtain Therefore, A2 = πR^2 ≥ 30 × πr^2 = 30 × A1, so we choose A2 = 30 × A1. That is, the need can be met.

[0088] It is known that the radius of the circle where the cylinder on the pressure regulating piston contacts the oil is R = 55mm, which ensures that the pressure P in the oil reservoir 15 is ≤ 1MPa. Since the radius r of the lower cylinder of the pressure regulating piston is preferably 10mm, the circumference of the gap 2πr is smaller, making it less likely to leak and cause the pressure in the oil reservoir 15 to exceed 1MPa, thus opening the safety valve. The fitting clearance can also be easily achieved within 10μm. Correspondingly, only the pressure equalization and load reduction groove is needed to ensure that the high-pressure oil does not communicate with the low-pressure area in the reservoir, thus preventing the formation of a communicating vessel. For the Φ55 large piston, an O-ring can also be set in the pressure equalization and load reduction groove to slow down the up and down movement of the large piston column, which can stabilize the oil pressure in the reservoir. Due to the rigid connection, it does not affect the small piston's ability to quickly provide pressure to the large piston to respond to the high-pressure changes at the bottom of the counterweight piston.

[0089] When the counterweight piston 1 moves upward, the pressure regulating piston 3 slides down by its own weight. Due to the high elastic modulus of the oil, even a small expansion of space can reduce the oil pressure in the reservoir 2, causing the sealing tire 62 or the support tire 72 to contract. This reduces the contact force and contact area between the sealing tire 62 or the support tire 72 and the cylinder wall, thus facilitating the rapid return of the counterweight piston 1 to its original position. When the counterweight piston 1 moves downward by gravity, the small area A1 of the bottom surface of the pressure regulating piston 3 is affected by the high-pressure oil P (30MPA) below the counterweight piston 1. The force is then quickly transmitted to the large area A2 of the top surface of the pressure regulating piston 3 with little or no contact friction. The pressure regulating piston 3 acts on the oil in the reservoir 2, thereby maintaining the oil pressure in the reservoir 2 at a low pressure A1 / A2×P(30MPa)=1MPa to meet the pressure bearing capacity of the easily manufactured sealing tire 62 or support tire 72. If the counterweight piston 1 suddenly sinks during installation, or if the air bubble below the counterweight piston 1 suddenly explodes and dissolves, the pressure P(30MPa) will suddenly increase. At this time, the oil pressure A1 / A2×P in the reservoir 2 will also suddenly increase. When it exceeds 10×1.1MPa, the oil will be unloaded by opening the safety valve 5 set on the upper cover plate of the reservoir 2 to ensure that the oil pressure in the reservoir 2 does not exceed 1MPa.

[0090] After the bottom of the pressure regulating piston is subjected to the high-pressure oil P (30MPA) from the lower part of the counterweight piston, the force is quickly transmitted to the oil in the reservoir chamber where the large-area piston A2 acts, with little or no contact friction. This reduces the oil pressure in the reservoir chamber to A1 / A2×P (30MPA) = 1MPA, ensuring that the easily manufactured sealing or supporting tires do not rupture under the pressure of the counterweight piston. The sealing or supporting tires act on the sealing slip ring, reducing the sealing gap δ between the sealing slip ring and the cylinder wall. The amount of gap reduction is positively correlated with P in A1 / A2×P. With a fixed A1 / A2, P can be adjusted by adjusting the weight of the counterweight, and the sealing gap δ can be adjusted by A1 / A2×P, as long as... When the pressure difference ΔP reaches P (ignoring atmospheric pressure P0=0, ΔP=P-P0=P), leakage is allowed; the sealing slip ring can be made into a split form for easy installation of large sizes. Because the leakage of gaps is large above 30MPA, a fine-diameter O-ring that can be glued is used to bind the split sealing slip ring. Taking advantage of the O-ring's large shrinkage elasticity, resistance to deformation, and long service life, the split sealing slip ring can be tightly connected.

[0091] By wetting the upper and lower parts of the heavy hammer piston 1 with oil, the friction between the sealing slip ring 63 or O-ring and the cylinder wall is reduced, preventing the O-ring from twisting and breaking. This also overcomes the current problems of unreliable sealing and short sealing life of the heavy hammer piston 1.

[0092] The sealing tire 62 or support tire 72 adopts the structure of a bicycle inner tube. Its annular cross-section is supported in the middle of the sealing slip ring 63. The force exerted by the sealing tire 62 on both sides of the sealing slip ring 63 will be less than that on the middle of the sealing slip ring 63. Even if the same material is used, the elastic deformation of different parts is different, and the reaction force is also different. In this way, the O-rings installed on both sides of the sealing slip ring 63 will not be torsional damage because the amount of protrusion of the O-ring groove on the outer side of the sealing slip ring 63 is only 10% or less. Moreover, even with less than 10% compression, it can effectively fill the uneven gap caused by the increased diameter of the hydraulic cylinder of the counterweight piston 1 and the increased machining error.

[0093] In a preferred embodiment, the upper support ring 61 and / or the lower support ring 64 have a first opening inclined to the axial direction for installation in the main sealing groove; the limiting ring 71 has a second opening inclined to the axial direction for installation in the floating sealing groove.

[0094] The upper support ring 61 and the lower support ring 64 can extend beyond the main sealing groove by a predetermined distance; there is a moving gap between the upper support ring 61, the lower support ring 64 and the cylinder wall.

[0095] Both the limiting ring 71 and the support ring have openings, which can lead to significant leakage under high pressure. The impact and extrusion of the leakage can easily cause the temperature of the leaking oil to rise. Therefore, it is necessary for oil to be present or filled in the direction of the leakage, similar to a river flowing into the sea. Through the self-damping effect of the oil, the oil temperature becomes uniform, and the leakage flow is reduced. Due to the back pressure flowing into the sea, ΔP decreases, thus reducing leakage. Through the three layers of oil (lower, middle, and upper) and the seal, the oil pressure at the bottom of the piston is established as P = ΔP1 + ΔP2 + ΔP3.

[0096] The limiting ring 71 and the support ring can be made of rubber. The compression set of rubber, expressed as a percentage, reflects the characteristic that rubber cannot fully recover its original dimensions after the compression stress is removed. A higher value indicates more significant permanent deformation of the material, thus affecting its performance. The following are the compression set ranges for different rubber materials: Natural rubber (NR) has a deformation range of 10% to 25% at room temperature, while at high temperatures this value may rise to 30% to 50%; Nitrile rubber (NBR) has a deformation range of 15% to 30% at room temperature, reaching 35% to 50% at high temperatures, and may even exceed 40% at extremely high temperatures; Silicone rubber (VMQ) has a smaller deformation at room temperature, only 5% to 10%, but at high temperatures (200℃), this value can increase to 15% to 30%. 0%; Fluororubber (FKM) has a deformation rate of 5% to 15% at room temperature, which increases slightly to 20% to 40% at high temperatures; Ethylene propylene rubber (EPDM) has a deformation rate of 10% to 20% at room temperature, which increases to 20% to 30% at high temperatures; Chloroprene rubber (CR) has a deformation rate of 15% to 25% at room temperature, which further increases to 30% to 45% at high temperatures; Polyurethane rubber (PU) has a relatively small deformation rate of 5% to 10% at room temperature, but this value can rise to 20% to 35% at high temperatures.

[0097] Furthermore, it should be noted that O-rings or O-ring rubber seals bonded with sealing strips must not be stretched at the joint. Since the synthetic rubber material used in O-ring seals is a viscoelastic material, the initial set compression and rebound sealing capacity will gradually be lost due to permanent deformation after prolonged use, eventually leading to leakage. Permanent deformation and loss of elasticity are the main reasons why O-rings lose their sealing performance. The main causes of permanent deformation are as follows: (1) the relationship between compression ratio and elongation and permanent deformation; (2) the relationship between temperature and the O-ring relaxation process; (3) the working pressure of the medium and permanent deformation; (4) the relationship between the compression permanent deformation rate of the O-ring material and temperature. When the deformation rate is 40% or higher, leakage will occur. Therefore, the heat resistance limits for several rubber materials are: nitrile rubber 70℃, EPDM rubber 100℃, and fluororubber 140℃. Therefore, various countries have made regulations regarding the permanent deformation of O-rings.

[0098] Many factors can cause O-ring seals to twist and become damaged. The most common are uneven clearances between the piston, piston rod, and cylinder; excessive eccentricity; and uneven O-ring cross-sectional diameter. These uneven frictional forces cause some parts of the O-ring to experience excessive friction, leading to twisting. Generally, O-rings with smaller cross-sectional dimensions are more prone to uneven friction. Therefore, to avoid twisting, moving O-rings have larger cross-sectional diameters than stationary O-rings. Furthermore, issues such as coaxiality deviations in the sealing groove, unequal sealing heights, and uneven O-ring cross-sectional diameters can cause some parts of the O-ring to be over-compressed while others are under-compressed or uncompressed. When the groove eccentricity (coaxial deviation) exceeds the O-ring's compression, the seal will completely fail. Another harmful effect of large coaxiality deviations in the sealing groove is uneven compression of the O-ring along its circumference. Furthermore, factors such as uneven O-ring cross-sectional diameter, material hardness, lubricating oil film thickness, and surface roughness of the sealing shaft can cause part of the O-ring to slide along the workpiece surface while the other part rolls, resulting in O-ring twisting. This movement makes the ring easily damaged by twisting, a significant cause of sealing device damage and leakage. Therefore, improving the machining precision of the sealing groove and reducing eccentricity are crucial factors in ensuring reliable sealing and longevity of the O-ring. The sealing ring should not be installed in a twisted state. If it is twisted during installation, twisting damage will occur quickly. During operation, twisting can cut the O-ring, causing significant oil leakage, and the cut O-ring can mix with other parts of the hydraulic system, leading to serious accidents.

[0099] To prevent O-rings from being twisted and damaged, the following points should be considered during the design process:

[0100] (1) The concentricity of the O-ring mounting groove should be considered from two aspects: ease of processing and prevention of twisting.

[0101] (2) The cross-sectional dimensions of the O-ring should be uniform, and lubricating oil or grease should be applied to the sealing area each time it is installed. Sometimes a felt ring lubrication device that is soaked in lubricating oil can also be used.

[0102] (3) Increase the cross-sectional diameter of the O-ring. The cross-sectional diameter of the O-ring used for dynamic sealing should generally be larger than that used for static sealing. In addition, O-rings should be avoided as seals for large-diameter pistons.

[0103] (4) When torsion damage occurs even under low pressure, a sealing ring can be used to protect the retaining ring.

[0104] (5) Reduce the surface roughness of the cylinder and piston rod.

[0105] (6) Use materials with low coefficient of friction to make O-ring seals.

[0106] (7) O-rings can be replaced with sealing rings that are less prone to twisting.

[0107] For any parts not mentioned in this utility model, existing technologies can be used or referenced.

[0108] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0109] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. A pressure-regulating sealing structure, characterized in that, The main sealing groove and the floating sealing groove are arranged on the circumference of the weight piston, and the floating sealing grooves are respectively arranged on the two sides of the main sealing groove along the axial direction of the weight piston; the weight piston has a liquid storage chamber; a pressure regulating piston is arranged at the bottom of the liquid storage chamber, and a sealing cover plate is arranged at the top of the liquid storage chamber, and a safety valve is arranged on the cover plate; The sealing structure comprises: The first sealing assembly is arranged in the main sealing groove and comprises an upper support ring, a sealing bladder, a sealing sliding ring and a lower support ring; The upper support ring is connected to the upper wall of the main sealing groove, and the lower support ring is connected to the lower wall of the main sealing groove; the sealing bladder is arranged between the upper support ring and the lower support ring, and the sealing sliding ring is arranged between the sealing bladder and the cylinder wall; The second guide sealing assembly is symmetrically arranged in the floating sealing grooves on the two sides of the main sealing groove and comprises a limiting ring, a support bladder, an inner support ring and a floating sealing guide ring; the limiting ring is connected to the groove wall of the floating sealing groove close to the main sealing groove, the inner support ring is connected to the groove bottom of the floating sealing groove, and the support bladder is arranged in the groove outside the inner support ring and is adjacent to the limiting ring; the floating sealing guide ring is arranged between the support bladder and the cylinder wall, and the sealing section of the floating sealing guide ring is arranged adjacent to the limiting ring, and the guide section of the floating sealing guide ring is in elastic contact with the inner support ring; The weight piston is provided with a first liquid filling channel, a second liquid filling channel and a third liquid filling channel; the first liquid filling channel is connected in communication between the liquid storage chamber and the sealing bladder through a first quick connector; the second liquid filling channel is connected in communication between the liquid storage chamber and the support bladder above the main sealing groove through a second quick connector; and the third liquid filling channel is connected in communication between the liquid storage chamber and the support bladder below the main sealing groove through a third quick connector.

2. A pressure regulating seal as claimed in claim 1, wherein The sealing sliding ring is arranged between the upper support ring and the lower support ring and is connected between the sealing bladder and the inner side of the cylinder wall in the radial direction of the weight piston, so that the sealing sliding ring can contact the cylinder wall when the sealing bladder is filled with liquid, and a sealed connection is formed between the weight piston and the cylinder wall; At least three pressure equalizing grooves are arranged on the circumference of the sealing sliding ring in contact with the cylinder wall, and two grooves on the upper side and the lower side are respectively provided with fastening O-shaped sealing rings.

3. A pressure regulating seal as claimed in claim 2, wherein The sealing sliding ring can extend out of the main sealing groove by a predetermined distance, and the sealing sliding ring is protrudingly arranged on the upper support ring or the lower support ring in the direction perpendicular to the axis of the weight piston, so as to prevent the upper support ring or the lower support ring from being in frictional contact with the cylinder wall.

4. A pressure regulating seal as defined in claim 2, wherein, At least three pressure equalizing grooves are arranged on the circumference of the sealing sliding ring in contact with the cylinder wall, and the plurality of pressure equalizing grooves are uniformly distributed in the axial direction of the piston, so as to facilitate uniform distribution of the contact pressure between the sealing sliding ring and the cylinder wall. The depth of the two grooves in which the upper side and the lower side of the fastening O-shaped sealing ring are installed is not greater than 90% of the line diameter of the O-shaped sealing ring, and the width of the groove is not greater than 110% of the line diameter of the O-shaped sealing ring, so as to ensure that the contact area between the O-shaped sealing ring and the cylinder wall is small and the damage caused by twisting is reduced.

5. The pressure regulating seal of claim 1, wherein The inner liner is arranged at the groove bottom of the main sealing groove and is used for protecting or positioning the sealing bladder, so as to avoid the contact between the sealing bladder and the uneven groove bottom metal contact surface and the resulting pinhole blowout.

6. A pressure regulating seal as claimed in claim 5, wherein The floating seal guide ring is in a conical barrel structure, is arranged annularly in the floating seal groove on both sides of the main seal groove, is provided with inclined openings or staggered concave-convex connecting grooves, the staggered inclined openings or concave-convex connecting grooves are connected in a closed manner in the circumferential direction, and the outer peripheral conical surface of the floating seal guide ring faces upward or downward relative to the piston and does not contact the cylinder wall.

7. A pressure regulating seal as claimed in claim 6, wherein An arc-shaped inner groove is arranged at the position where the inner side of the floating seal guide ring contacts the support tire, so as to ensure that the inflation force of the support tire is transmitted to the cylinder wall through the arc-shaped inner groove; the floating seal guide ring is in an L-shaped structure and elastically contacts the inner support ring, and is arranged at the outer periphery of the support tire together with the limiting ring.

8. The pressure regulating seal of claim 1, wherein, The first, second and third liquid filling channels are arranged in a ring array on the projection plane in the direction of the axis of the weight piston, so as to balance the weight of the piston and ensure that the center of gravity of the piston is on the axis.

9. The pressure regulating seal of claim 1, wherein, The pressure regulating piston is in a cylindrical structure with different upper and lower sections and is concentric with the weight piston, and / or the pressure regulating piston is in a concentric cylindrical structure with two upper and lower sections and is symmetric to the axis of the weight piston; an active gap is formed between the upper or lower outer cylindrical surface of the pressure regulating piston and the weight piston, so that the pressure regulating piston can move relative to the weight piston; when the pressure regulating piston and the weight piston move downward under the action of gravity, the small piston at the bottom of the pressure regulating piston transmits the force to the oil in the liquid storage chamber of the large piston at the top of the pressure regulating piston under the action of the high-pressure oil at the lower part of the weight piston.

10. The pressure regulating seal of claim 1, wherein, The upper support ring and / or the lower support ring has a first opening inclined to the axis direction, so as to be installed in the main seal groove; the limiting ring has a second opening inclined to the axis direction, so as to be installed in the floating seal groove.

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