A sealing structure under complex working conditions

Abstract

The utility model belongs to sealing system technical field, concretely relates to a sealing structure under complex working condition, wherein including: ice scraper, dustproof ring and reverse installation U -shaped ring, the ice scraper forms annular and the inner circle of ice scraper extends obliquely to the outer end of guide bush, the inner circle of ice scraper is tightly matched with piston rod, the outer circle of ice scraper is gap matched with the groove of guide bush, the orifice of the inner circle of ice scraper to the outer end of guide bush is set up sharply;The inner circle of dustproof ring is tightly matched with piston rod, the outer circle of dustproof ring is tightly matched with the groove of guide bush;The inner circle of reverse installation U -shaped ring is tightly matched with piston rod, the outer circle of reverse installation U -shaped ring is tightly matched with the groove of guide bush, and the first U -shaped groove is equipped on the side of reverse installation U -shaped ring to dustproof ring. The utility model discloses through ice scraper, dustproof ring, reverse installation U -shaped ring setting gradually from the outer end of guide bush to the inner along piston rod axial self -guiding, forms three -step progressive protection structure, can scrape ice, dustproof, waterproof, satisfies the sealing demand of oil cylinder under complex working condition.

Description

Technical Field

[0001] This utility model relates to the field of sealing system technology, and in particular to a sealing structure for complex working conditions. Background Technology

[0002] During the operation of the hydraulic cylinder, the piston rod needs to perform reciprocating linear motion within the cylinder body. To ensure that the hydraulic oil inside the cylinder does not leak and to prevent impurities in the external environment (such as dust, particles, etc.) from entering the cylinder and affecting its normal operating performance, a special sealing structure is usually fitted on the piston rod to achieve the sealing and protection function.

[0003] In relatively mild, conventional production environments such as indoors and at room temperature, the commonly used sealing structure in existing technologies is a combination of a dustproof ring, a U-shaped ring, a guide ring, a buffer ring, and another guide ring, as shown in the attached diagram. Figure 1 As shown in the figure. This type of combined structure, with its simple structure and low cost, can meet the basic requirements for cylinder sealing under normal working conditions, and to a certain extent achieves the effects of preventing hydraulic oil leakage and preventing the entry of external impurities. Therefore, it has been widely used in the above-mentioned conventional scenarios.

[0004] However, the existing structure's skeleton dustproof ring can only provide a certain degree of protection against dust in dry environments, and its waterproof performance is poor. The existing structure's guide ring has low resistance to lateral loads, and if subjected to lateral loads during piston rod movement, it is prone to deformation or wear, which in turn affects the overall stability of the sealing structure. The existing structure's slip ring buffer ring not only has low pressure resistance and cannot withstand the pressure impact of the cylinder under high pressure conditions, but also has poor wear resistance and low resistance to lateral loads, making it prone to damage during long-term use.

[0005] When hydraulic cylinders are used in harsh environments (such as open-air environments, mines, oceans, etc., where there is a lot of dust, water, mud, or hard materials such as sand and metal scraps), the existing sealing structure cannot effectively waterproof or remove external materials, which can easily lead to damage and failure of the sealing ring and oil leakage. Utility Model Content

[0006] The technical problem to be solved by this utility model is that, in order to solve the technical problem that the existing sealing structure cannot effectively waterproof and cannot remove external substances, which easily leads to damage and failure of the sealing ring and oil leakage, this utility model provides a sealing structure for complex working conditions, which can meet the sealing requirements of the oil cylinder under complex working conditions.

[0007] The technical solution adopted by this utility model to solve its technical problem is: a sealing structure for complex working conditions, installed inside a guide sleeve and fitted onto a piston rod, wherein the guide sleeve has an outer end and an inner end, and the sealing structure includes: an ice scraper, a dustproof ring, and a reverse-mounted U-ring, wherein the ice scraper, dustproof ring, and reverse-mounted U-ring are arranged sequentially from the outer end to the inner end of the guide sleeve. The ice scraper is formed in a ring shape and the inner ring of the ice scraper extends obliquely toward the outer end of the guide sleeve. The inner ring of the ice scraper is tightly fitted with the piston rod, and the outer ring of the ice scraper is loosely fitted with the groove of the guide sleeve. The opening of the inner ring of the ice scraper toward the outer end of the guide sleeve is sharply set. The inner ring of the dustproof ring is tightly fitted with the piston rod, and the outer ring of the dustproof ring is tightly fitted with the groove of the guide sleeve; The inner ring of the inverted U-shaped ring is tightly fitted with the piston rod, and the outer ring of the inverted U-shaped ring is tightly fitted with the groove of the guide sleeve. A first U-shaped groove is provided on the side of the inverted U-shaped ring facing the dustproof ring.

[0008] The specific technical effects are as follows: A three-tiered progressive protection structure is formed by sequentially installing an ice scraper, a dustproof ring, and a reverse-mounted U-ring along the piston rod axially from the outer end of the guide sleeve inwards. The first-tier ice scraper removes dirt from the external environment. Its inner ring fits tightly with the piston rod, and its sharp inner edge removes dirt adhering to the piston rod surface. The second-tier dustproof ring, with its inner ring also fitting tightly with the piston rod, removes heavy contaminants such as mud. Its outer ring fits tightly with the groove of the guide sleeve, preventing moisture from entering. The third-tier reverse-mounted U-ring, with the first U-shaped groove facing the dustproof ring, provides a second layer of protection in case of damage to the ice scraper or dustproof ring, preventing the entry of foreign objects. The gap between the outer ring of the ice scraper and the groove of the guide sleeve compensates for piston rod bending, ensuring the ice scraper's responsiveness to the piston rod. This prevents damage to the ice scraper when the piston rod is subjected to lateral loads and facilitates maintenance and replacement.

[0009] Furthermore, the dustproof ring includes a dustproof body, a first dustproof lip, and a second dustproof lip. The dustproof body is formed in an annular shape with a rectangular cross-sectional shape. The first dustproof lip is formed in an annular shape and is disposed on the side of the dustproof body facing the ice scraper. The first dustproof lip is elastic and extends inward at an angle toward the ice scraper. The second dustproof lip is formed in an annular shape with a triangular cross-sectional shape and is located on the outer edge of the dustproof body near the ice scraper. The inner rings of the dustproof body and the first dustproof lip are both in close contact with the piston rod, and the outer rings of the dustproof body and the second dustproof lip are both in close contact with the groove of the guide sleeve.

[0010] The specific technical effects are as follows: by setting an inclined first dustproof lip, when the dustproof ring is fitted on the piston rod, the first dustproof lip will be subjected to force and undergo elastic deformation. The inner ring of the first dustproof lip changes from an inclined surface to a straight surface and is tightly attached to the piston rod, which can scrape off heavy contaminants such as mud and ice. The second dustproof lip is tightly attached to the groove of the guide sleeve to prevent moisture from entering the groove.

[0011] Furthermore, the dustproof ring is a one-piece molded polyurethane dustproof ring. Specifically, the dustproof ring is a one-piece design and made of polyurethane material, offering high wear resistance.

[0012] Furthermore, the ice scraper includes an ice scraper body and an ice scraper part. The ice scraper body is formed in an annular shape with a rectangular cross-section. The ice scraper part is formed in an annular shape and is disposed in the inner ring of the ice scraper body. The outer ring of the ice scraper part is connected to the inner ring of the ice scraper body. The ice scraper part extends inward at an angle toward the outer end of the guide sleeve. The opening of the inner ring of the ice scraper part toward the outer end of the guide sleeve is sharply set. The inner ring of the ice scraper part is tightly fitted with the piston rod. The outer ring of the ice scraper body is loosely fitted with the groove of the guide sleeve.

[0013] Furthermore, the ice scraper is a one-piece molded metal ice scraper, and the hardness of the piston rod is greater than that of the ice scraper. The specific technical effect is: to prevent the ice scraper from damaging the piston rod surface during extension and retraction, and the use of metal materials in the ice scraper facilitates the removal of stubborn dirt adhering to the piston rod.

[0014] Furthermore, the sealing structure also includes a first retaining ring, which is located on the outer side of the ice scraper facing the outer end of the guide sleeve. The specific technical effect is that the first retaining ring on the outer side of the ice scraper creates a limiting effect, preventing the ice scraper from moving axially along with the piston rod and affecting the scraping effect.

[0015] Furthermore, the sealing structure also includes a guide ring for supporting the guide sleeve. The guide ring is sleeved on the piston rod and accommodated within the groove of the guide sleeve. The guide ring is located on the side of the reverse-mounted U-shaped ring opposite to the dustproof ring. Specifically, the guide ring can support the guide sleeve and prevent the guide sleeve from contacting the piston rod and damaging it.

[0016] Furthermore, the gap H1 between the outer ring of the ice scraper and the groove of the guide sleeve is ≥0.5mm.

[0017] Furthermore, the sealing structure also includes a positive main sealing ring, the inner ring of which is tightly fitted with the piston rod, the outer ring of which is tightly fitted with the groove of the guide sleeve, the positive main sealing ring being located on the side of the reverse U-shaped ring opposite to the dustproof ring, and a second U-shaped groove for blocking oil being provided on the side of the positive main sealing ring opposite to the reverse U-shaped ring.

[0018] The specific technical effect is as follows: the positive main sealing ring is the main sealing ring used to prevent oil leakage. Therefore, it is set on the side opposite to the reverse U-shaped ring in the second U-shaped groove, that is, facing the inside of the oil cylinder to block oil.

[0019] Furthermore, the sealing structure also includes a buffer ring, which is located on the side of the positive main sealing ring opposite to the reverse U-shaped ring. The inner ring of the buffer ring is tightly fitted with the piston rod, and the outer ring of the buffer ring is tightly fitted with the groove of the guide sleeve. A third U-shaped groove for blocking oil is provided on the side of the buffer ring opposite to the positive main sealing ring, and a notch for relieving pressure is provided on the side of the buffer ring facing the positive main sealing ring.

[0020] The specific technical effects are as follows: the buffer ring is located on the side opposite to the reverse U-shaped ring of the main sealing ring, which effectively reduces the pressure on the main sealing ring and extends its service life. By setting a third U-shaped groove on the side of the buffer ring facing the inside of the cylinder, the buffer ring becomes more resistant to high pressure. The notch groove is designed to eliminate pressure accumulation between the main sealing ring and the buffer ring, thus extending the service life of both the main sealing ring and the buffer ring.

[0021] Furthermore, the sealing structure also includes a wire retaining ring for the bore and a sliding bushing, which are sequentially arranged along the axial direction of the piston rod from the inner end to the outer end of the guide sleeve. Specifically, the wire retaining ring and the sliding bushing support the guide sleeve and guide the piston rod.

[0022] Furthermore, a zinc-nickel protective layer is provided on the inner wall of the guide sleeve. Specifically, the inner hole of the guide sleeve is plated with zinc-nickel, increasing its corrosion resistance.

[0023] Furthermore, the outer ring of the guide sleeve is at least fitted with a set of O-ring assemblies for sealing the hydraulic cylinder. Each set of O-ring assemblies includes an O-ring and a second retaining ring, with the second retaining ring positioned closer to the outer end of the guide sleeve than the O-ring. The specific technical effect is that the O-ring and the second retaining ring form a static sealing structure, which, when fitted onto the outer ring of the guide sleeve, seals the guide sleeve and the hydraulic cylinder, preventing oil leakage.

[0024] Compared with the prior art, the beneficial effects of this utility model are: (1) This utility model forms a three-stage progressive protection structure by sequentially arranging an ice scraper, a dustproof ring, and a reverse-installed U-shaped ring along the piston rod axis from the outer end of the guide sleeve inward. The first-stage ice scraper can scrape off dirt from the external environment. The inner ring of the ice scraper is tightly fitted with the piston rod, and the sharp inner edge of the ice scraper can scrape off dirt adhering to the surface of the piston rod. The second-stage dustproof ring has an inner ring that is tightly fitted with the piston rod, which can scrape off heavy pollutants such as mud. The outer ring of the dustproof ring is tightly fitted with the groove of the guide sleeve, which can prevent moisture from entering the groove. The third-stage reverse-installed U-shaped ring, that is, the first U-shaped groove is opened on the side facing the dustproof ring, can serve as a second layer of protection in case the ice scraper or dustproof ring is damaged, preventing foreign objects from entering. (2) The present invention uses the groove gap between the outer ring of the ice scraper and the guide sleeve to compensate for the bending of the piston rod, ensuring the following of the ice scraper and the piston rod. When the piston rod is subjected to lateral load, the ice scraper can be prevented from being damaged, and it is convenient to repair and replace. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Figure 1 This is a schematic diagram of a sealing structure in the prior art; Figure 2 This is a schematic diagram of the installation of the sealing structure of this utility model; Figure 3 This is a partial structural diagram of the sealing structure in Example 1; Figure 4 for Figure 3 Enlarged schematic diagram of a local structure at point A; Figure 5 This is a schematic diagram of the ice scraper in Example 1; Figure 6 This is a partial structural schematic diagram of the dustproof ring in Example 1; Figure 7 for Figure 3 Enlarged schematic diagram of the local structure at point B; Figure 8 This is a schematic diagram of the internal structure of the guide sleeve in Example 1; Figure 9 This is a schematic diagram of the reverse-mounted U-shaped ring in Example 1; Figure 10 This is a partial structural diagram of the sealing structure in Example 2; Figure 11 for Figure 10 Enlarged schematic diagram of the local structure at point C; Figure 12 This is a partial structural diagram of the sealing structure in Example 3; Figure 13 for Figure 12 Enlarged schematic diagram of the local structure at point D; Figure 14 This is a schematic diagram of the main sealing ring in Example 3; Figure 15 This is a schematic diagram of the buffer ring structure in Example 3; Figure 16 for Figure 12 Enlarged schematic diagram of the local structure at point E in the middle.

[0027] In the diagram: 001, guide sleeve; 002, piston rod; 003, oil cylinder; 1, ice scraper; 101, ice scraper body; 102, ice scraper part; 2, dustproof ring; 201, dustproof body; 202, first dustproof lip; 203, second dustproof lip; 3, reverse-mounted U-ring; 301, first U-shaped groove; 4, guide ring; 5, upright-mounted main sealing ring; 501, second U-shaped groove; 6, buffer ring; 601, third U-shaped groove; 602, notch groove; 7, sliding bushing; 8, wire retaining ring for the hole; 9, O-ring; 10, second retaining ring; 11, first retaining ring. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0029] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, 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, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] Example 1 like Figures 2 to 9 As shown, this embodiment provides a sealing structure for complex working conditions. Installed inside the guide sleeve 001 and fitted onto the piston rod 002, it can meet the sealing requirements under complex working conditions (such as open-air environments, mines, oceans, etc., where there is a large amount of dust, water, mud, or the environment contains hard substances such as sand, gravel, and metal fragments). The guide sleeve 001 has an outer end and an inner end. The inner end of the guide sleeve 001 guides the end of the guide sleeve 001 towards the inside of the cylinder 003, and the outer end of the guide sleeve 001 guides the end of the guide sleeve 001 towards the outside of the cylinder 003. The sealing structure includes: an ice scraper 1, a dustproof ring 2, and a reverse-mounted U-shaped ring 3. The ice scraper 1, dustproof ring 2, and reverse-mounted U-shaped ring 3 are self-guiding. The outer end of the sleeve 001 is arranged sequentially towards the inner end. The ice scraper 1 is formed into a ring, and the inner ring of the ice scraper 1 extends obliquely towards the outer end of the guide sleeve 001. The inner ring of the ice scraper 1 is tightly fitted with the piston rod 002, and the outer ring of the ice scraper 1 is loosely fitted with the groove of the guide sleeve 001. The opening of the inner ring of the ice scraper 1 towards the outer end of the guide sleeve 001 is sharply set. The inner ring of the dustproof ring 2 is tightly fitted with the piston rod 002, and the outer ring of the dustproof ring 2 is tightly fitted with the groove of the guide sleeve 001. The inner ring of the reverse U-shaped ring 3 is tightly fitted with the piston rod 002, and the outer ring of the reverse U-shaped ring 3 is tightly fitted with the groove of the guide sleeve 001. A first U-shaped groove 301 is provided on the side of the reverse U-shaped ring 3 facing the dustproof ring 2.

[0032] Specifically, the guide sleeve 001 has an opening through which the piston rod 002 passes. The piston rod 002 can move axially along the opening. The inner wall of the opening has a groove, and the sealing structure is installed in the groove and sleeved on the piston rod 002. By sequentially installing the ice scraper 1, dustproof ring 2, and reverse-mounted U-ring 3 along the axial direction of the piston rod 002 from the outer end of the guide sleeve 001 inward, a three-stage progressive protection structure is formed. This protection structure can scrape ice, prevent dust, and prevent water, thus meeting the sealing requirements of the hydraulic cylinder 003 under complex working conditions.

[0033] Therefore, the first-stage ice scraper 1 is designed as a ring. The inner ring of the ice scraper 1 extends obliquely towards the outer end of the guide sleeve 001, and the orifice of the inner ring towards the outer end of the guide sleeve 001 is sharply set. At the same time, the inner ring of the ice scraper 1 is tightly fitted with the piston rod 002. This structure allows the sharp inner ring orifice to closely fit the surface of the piston rod 002 when the piston rod 002 makes reciprocating linear motion. It can effectively scrape off various external substances adhering to the surface of the piston rod 002, including dust, mud, water, ice, snow, sand, metal fragments and other hard substances, blocking external pollutants from entering the sealed structure from the source. There is a gap H1 between the outer ring of the ice scraper 1 and the groove of the guide sleeve 001. The range of H1 is ≥0.5mm. This gap H1 can compensate for displacement when the piston rod 002 bends due to working conditions, ensuring that the inner ring of the ice scraper 1 always maintains a good fit with the piston rod 002, avoiding deformation or damage to the ice scraper 1 due to bending of the piston rod 002, and improving the structural resistance to lateral loads.

[0034] Therefore, through the second-stage dustproof ring 2, the inner ring of the dustproof ring 2 is tightly fitted with the piston rod 002, which can perform secondary scraping to remove heavy contaminants (such as viscous mud) that remain after the initial scraping by the ice scraper 1, further purifying the surface of the piston rod 002 and preventing a small amount of residual contaminants from entering the subsequent sealing process with the movement of the piston rod 002. The outer ring of the dustproof ring 2 is tightly fitted with the groove of the guide sleeve 001, which can form a sealing barrier between the groove of the guide sleeve 001 and the outer ring of the dustproof ring 2, effectively preventing moisture in the external environment from entering the groove of the guide sleeve 001, preventing moisture from contacting the subsequent sealing components, and avoiding aging or damage to the sealing components due to moisture.

[0035] Therefore, by using the third-stage reverse-installed U-ring 3, in the event of damage to the ice scraper 1 or the dustproof ring 2, the reverse-installed U-ring 3 can serve as a second layer of protection to prevent the entry of external foreign objects. The first U-shaped groove 301 is opened on the side facing the dustproof ring 2, which is the reverse-installed design. The first U-shaped groove 301 can form a dirt-holding space. In the event of damage to the ice scraper 1 or the dustproof ring 2, dirt can be temporarily stored in the groove and will not directly enter the inner and outer rings of the reverse-installed U-ring 3, further improving the sealing stability.

[0036] In this embodiment, see Figures 4 to 5 As shown, the ice scraper 1 includes an ice scraper body 101 and an ice scraper 102. The ice scraper body 101 is formed in an annular shape with a rectangular cross-section. The ice scraper 102 is formed in an annular shape and is disposed in the inner ring of the ice scraper body 101. The outer ring of the ice scraper 102 is connected to the inner ring of the ice scraper body 101. The ice scraper 102 extends inward at an angle toward the outer end of the guide sleeve 001. The opening of the inner ring of the ice scraper 102 toward the outer end of the guide sleeve 001 is sharply set. The inner ring of the ice scraper 102 is tightly fitted with the piston rod 002. The outer ring of the ice scraper body 101 is loosely fitted with the groove of the guide sleeve 001.

[0037] In this embodiment, the ice scraper 1 is a one-piece molded metal ice scraper 1, and the hardness of the piston rod 002 is greater than the hardness of the ice scraper 1. Therefore, the ice scraper 1 prevents damage to the surface of the piston rod 002 during extension and retraction. The metal design of the ice scraper 1 facilitates the removal of stubborn dirt adhering to the piston rod 002. Specifically, the ice scraper 1 can be made of copper, or more specifically, QAL9-4 material.

[0038] In this embodiment, the sealing structure further includes a first retaining ring 11, which is located on the outer side of the ice scraper 1 facing the outer end of the guide sleeve 001. Thus, the first retaining ring 11 on the outer side of the ice scraper 1 forms a limit, preventing the ice scraper 1 from moving axially along with the piston rod 002 and affecting the scraping effect.

[0039] In this embodiment, see Figures 6 to 7 As shown, the dustproof ring 2 includes a dustproof body 201, a first dustproof lip 202, and a second dustproof lip 203. The dustproof body 201 is annular, and its cross-sectional shape is rectangular. The rectangular cross-section prevents the dustproof ring 2 from twisting or deforming due to uneven force during installation. The first dustproof lip 202 is annular and is located on the side of the dustproof body 201 facing the ice scraper 1. The first dustproof lip 202 is elastic and extends inward at an angle towards the ice scraper 1. When the dustproof ring 2 is fitted onto the piston rod 002, the first dustproof lip 202 will elastically deform due to the contact pressure with the piston rod 002, changing from an initial inclined state to an inner ring that is straight and tightly attached to the piston rod 002. 2. It can scrape off heavy contaminants such as mud and ice. After the inclined structure is deformed into a straight surface, the contact area is increased and the scraping effect is improved. The second dustproof lip 203 is formed into a ring and the cross-sectional shape is triangular. The second dustproof lip 203 is located on the outer edge of the dustproof body 201 near the ice scraper 1. The inner rings of the dustproof body 201 and the first dustproof lip 202 are tightly attached to the piston rod 002. The outer rings of the dustproof body 201 and the second dustproof lip 203 are tightly attached to the groove of the guide sleeve 001. The second dustproof lip 203 tightly attached to the groove of the guide sleeve 001 can prevent moisture from entering the groove. The slightly raised triangular cross-section is thinner than the rectangular cross-section and is easier to deform and adapt to the groove during assembly, avoiding assembly difficulties caused by excessive lip thickness.

[0040] Specifically, the thickness of the dustproof body 201 along the axial direction is L2, and the thickness of the groove in the guide sleeve 001 for installing the dustproof body 201 along the axial direction is L1, where L1 > L2.

[0041] In this embodiment, the dust ring 2 is a one-piece molded polyurethane dust ring. Therefore, the dust ring 2 is a one-piece design and made of polyurethane material, which has high wear resistance. The highly wear-resistant polyester material allows the dust ring to operate in extremely harsh environments.

[0042] Specifically, the dust ring 2 uses a British Hellett T38 dust ring, ensuring that the inner surface of the dust ring 2 fits tightly against the piston rod 002, and can scrape off heavy contaminants such as mud and ice. The outer surface of the dust ring 2 fits tightly against the groove of the guide sleeve 001, preventing moisture from entering the groove. Compared with the skeleton dust ring, this structure of the dust ring 2 can better prevent moisture from entering and requires less installation space.

[0043] Example 2 like Figures 10 to 11 As shown, to ensure sealing protection in situations where the small cavity lacks hydraulic pressure, this embodiment, compared to Embodiment 1, adds a guide ring 4 to the sealing structure to support the guide sleeve 001. The guide ring 4 is fitted onto the piston rod 002 and accommodated within the groove of the guide sleeve 001. The guide ring 4 is located on the side opposite to the dustproof ring 2 of the reverse-mounted U-shaped ring 3. Therefore, the guide ring 4 can support the guide sleeve 001 and prevent the guide sleeve 001 from contacting and damaging the piston rod 002.

[0044] In this embodiment, the guide ring 4 is a self-lubricating guide ring. Therefore, the guide ring 4 is made of a self-lubricating material, specifically, a polyester-reinforced fabric PC71. No additional grease or lubricating oil is needed. Under complex working conditions, grease easily attracts dust and mud, forming a paste, which will instead aggravate the wear between the guide ring 4 and the piston rod 002.

[0045] Therefore, the sealing structure consisting of the ice scraper 1, dustproof ring 2, reverse U-shaped ring 3, and guide ring 4 can be used for sealing protection in small cavities without oil pressure.

[0046] Example 3 See Figures 12 to 16As shown, in order to be suitable for sealing protection under hydraulic conditions, compared with Embodiment 2, the sealing structure of this embodiment also adds a positive main sealing ring 5 and a buffer ring 6. The inner ring of the positive main sealing ring 5 is tightly fitted with the piston rod 002, and the outer ring of the positive main sealing ring 5 is tightly fitted with the groove of the guide sleeve 001. The positive main sealing ring 5 is located on the side of the guide ring 4 opposite to the dustproof ring 2. A second U-shaped groove 501 for blocking oil is provided on the side of the positive main sealing ring 5 opposite to the reverse U-shaped ring 3. The buffer ring 6 is located on the side of the positive main sealing ring 5 opposite to the reverse U-shaped ring 3. The inner ring of the buffer ring 6 is tightly fitted with the piston rod 002, and the outer ring of the buffer ring 6 is tightly fitted with the groove of the guide sleeve 001. A third U-shaped groove 601 for blocking oil is provided on the side of the buffer ring 6 opposite to the positive main sealing ring 5. A notch 602 for relieving pressure is provided on the side of the buffer ring 6 facing the positive main sealing ring 5. The notch 602 is designed to be annular.

[0047] Therefore: the main sealing ring 5 is the primary sealing ring used to prevent oil leakage. The second U-shaped groove 501 is located on the side of the main sealing ring 5 opposite to the reverse U-shaped ring 3, facing inwards towards the cylinder 003, to block oil. The buffer ring 6 is located on the side of the main sealing ring 5 opposite to the reverse U-shaped ring 3, effectively reducing the pressure on the main sealing ring 5 and extending its service life. By providing a third U-shaped groove 601 on the side of the buffer ring 6 facing inwards towards the cylinder 003, the buffer ring 6 becomes more resistant to high pressure. The notch 602 is designed to eliminate pressure buildup between the main sealing ring 5 and the buffer ring 6, extending the service life of both.

[0048] Specifically, when the hydraulic cylinder 003 is working, the internal hydraulic oil will generate continuous high pressure (the pressure fluctuation is more intense under complex working conditions). If this high pressure acts directly on the main sealing ring 5, it will cause the main sealing ring 5 to be subjected to excessive compressive stress for a long time, which will accelerate the aging, deformation or wear of its sealing lip and shorten its service life. By having the buffer ring 6 contact the main sealing ring 5 first and bear part of the high pressure of the hydraulic oil, the working pressure of the main sealing ring is effectively relieved and the service life of the main sealing ring 5 is extended. In actual operation, a small amount of hydraulic oil may break through the initial seal of the buffer ring 6 and enter the tiny gap between the buffer ring 6 and the main sealing ring 5. Without the notch groove 602, this oil will accumulate in the gap. As the working pressure of the cylinder 003 increases, the oil pressure in the gap will continue to accumulate, which is called pressure accumulation, forming a bidirectional squeeze on the buffer ring 6 and the main sealing ring 5. The presence of the notch groove 602 provides a pressure relief channel for the pressure accumulating oil in the gap. The accumulated oil can flow back into the cylinder 003 through the notch groove 602, completely eliminating the pressure accumulation phenomenon and avoiding damage to both components due to excessive squeezing.

[0049] In this embodiment, the sealing structure further includes a wire retaining ring 8 and a sliding bushing 7, which are sequentially arranged along the axial direction of the piston rod 002 from the inner end to the outer end of the guide sleeve 001. Thus, the wire retaining ring 8 and the sliding bushing 7 serve to support the guide sleeve 001 and guide the piston rod 002.

[0050] Specifically, the sliding bushing 7 is made of PTFE (polytetrafluoroethylene) with added copper powder, which has a lower coefficient of friction, better wear resistance, and higher resistance to lateral loads.

[0051] In this embodiment, a zinc-nickel protective layer is provided on the inner wall of the guide sleeve 001. Therefore, the inner hole of the guide sleeve 001 is plated with zinc-nickel, increasing its corrosion resistance.

[0052] In this embodiment, the outer ring of the guide sleeve 001 is fitted with two sets of O-ring assemblies for sealing the hydraulic cylinder. Each set of O-ring assemblies includes an O-ring 9 and a second retaining ring 10, with the second retaining ring 10 closer to the outer end of the guide sleeve 001 than the O-ring 9. Thus, the O-ring 9 and the second retaining ring 10 form a static sealing structure, which, when fitted onto the outer ring of the guide sleeve 001, seals the guide sleeve 001 between the guide sleeve 001 and the hydraulic cylinder 003, preventing oil leakage.

[0053] The above description is based on the preferred embodiments of this utility model. Through the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined by the scope of the claims.

Claims

1. A sealing structure for complex operating conditions, installed inside a guide sleeve (001) and fitted onto a piston rod (002), wherein the guide sleeve (001) has an outer end and an inner end, characterized in that, The sealing structure includes: an ice scraper (1), a dustproof ring (2), and a reverse U-shaped ring (3), wherein the ice scraper (1), the dustproof ring (2), and the reverse U-shaped ring (3) are arranged sequentially from the outer end to the inner end of the guide sleeve (001); The ice scraper (1) is formed in a ring shape and the inner ring of the ice scraper (1) extends obliquely toward the outer end of the guide sleeve (001). The inner ring of the ice scraper (1) is tightly fitted with the piston rod (002). The outer ring of the ice scraper (1) is loosely fitted with the groove of the guide sleeve (001). The opening of the inner ring of the ice scraper (1) toward the outer end of the guide sleeve (001) is sharp. The inner ring of the dustproof ring (2) is tightly fitted with the piston rod (002), and the outer ring of the dustproof ring (2) is tightly fitted with the groove of the guide sleeve (001); The inner ring of the reverse-mounted U-ring (3) is tightly fitted with the piston rod (002), and the outer ring of the reverse-mounted U-ring (3) is tightly fitted with the groove of the guide sleeve (001). A first U-shaped groove (301) is provided on the side of the reverse-mounted U-ring (3) facing the dustproof ring (2).

2. The sealing structure under complex working conditions as described in claim 1, characterized in that, The dustproof ring (2) includes a dustproof body (201), a first dustproof lip (202), and a second dustproof lip (203). The dustproof body (201) is formed in an annular shape, and the cross-sectional shape of the dustproof body (201) is rectangular. The first dustproof lip (202) is formed in an annular shape and is disposed on the side of the dustproof body (201) facing the ice scraper (1). The first dustproof lip (202) is elastic and faces the ice scraper. (1) extends inward at an angle, the second dustproof lip (203) is formed in an annular shape and has a triangular cross-sectional shape, the second dustproof lip (203) is located on the outer edge of the dustproof body (201) near the ice scraper (1), the inner rings of the dustproof body (201) and the first dustproof lip (202) are both in close contact with the piston rod (002), and the outer rings of the dustproof body (201) and the second dustproof lip (203) are both in close contact with the groove of the guide sleeve (001).

3. The sealing structure under complex working conditions as described in claim 1, characterized in that, The dustproof ring (2) is an integrally molded polyurethane dustproof ring.

4. The sealing structure under complex working conditions as described in claim 1, characterized in that, The ice scraper (1) includes an ice scraper body (101) and an ice scraper (102). The ice scraper body (101) is formed in an annular shape and has a rectangular cross-section. The ice scraper (102) is formed in an annular shape and is disposed in the inner ring of the ice scraper body (101). The outer ring of the ice scraper (102) is connected to the inner ring of the ice scraper body (101). The ice scraper (102) extends inward at an angle toward the outer end of the guide sleeve (001). The opening of the inner ring of the ice scraper (102) toward the outer end of the guide sleeve (001) is sharply set. The inner ring of the ice scraper (102) is tightly fitted with the piston rod (002). The outer ring of the ice scraper body (101) is loosely fitted with the groove of the guide sleeve (001).

5. The sealing structure under complex working conditions as described in claim 1, characterized in that, The ice scraper (1) is a one-piece molded metal ice scraper, and the hardness of the piston rod (002) is greater than that of the ice scraper (1).

6. The sealing structure under complex working conditions as described in claim 1, characterized in that, The sealing structure also includes a first retaining ring (11), which is located on the outside of the ice scraper (1) facing the outer end of the guide sleeve (001).

7. The sealing structure under complex working conditions as described in claim 1, characterized in that, The sealing structure also includes a guide ring (4) for supporting the guide sleeve (001). The guide ring (4) is sleeved on the piston rod (002) and accommodated in the groove of the guide sleeve (001). The guide ring (4) is located on the side of the reverse U-shaped ring (3) opposite to the dustproof ring (2).

8. The sealing structure under complex working conditions as described in claim 1, characterized in that, The gap H1 between the outer ring of the ice scraper (1) and the groove of the guide sleeve (001) is ≥0.5mm.

9. The sealing structure under complex working conditions as described in claim 1, characterized in that, The sealing structure also includes a positive main sealing ring (5), the inner ring of which is tightly fitted with the piston rod (002), the outer ring of which is tightly fitted with the groove of the guide sleeve (001), the positive main sealing ring (5) is located on the side of the reverse U-shaped ring (3) opposite to the dustproof ring (2), and a second U-shaped groove (501) for blocking oil is provided on the side of the positive main sealing ring (5) opposite to the reverse U-shaped ring (3).

10. A sealing structure for complex working conditions as described in claim 9, characterized in that, The sealing structure also includes a buffer ring (6), which is located on the side of the positive main sealing ring (5) opposite to the reverse U-shaped ring (3). The inner ring of the buffer ring (6) is tightly fitted with the piston rod (002), and the outer ring of the buffer ring (6) is tightly fitted with the groove of the guide sleeve (001). A third U-shaped groove (601) for blocking oil is provided on the side of the buffer ring (6) opposite to the positive main sealing ring (5), and a notch (602) for relieving pressure is provided on the side of the buffer ring (6) facing the positive main sealing ring (5).

11. The sealing structure under complex working conditions as described in claim 1, characterized in that, The sealing structure also includes a wire retaining ring (8) for the hole and a sliding bushing (7), which are arranged sequentially from the inner end of the guide sleeve (001) to the outer end along the axial direction of the piston rod (002).

12. The sealing structure under complex working conditions as described in claim 1, characterized in that, A zinc-nickel protective layer is provided on the inner wall of the guide sleeve (001).

13. The sealing structure under complex working conditions as described in claim 1, characterized in that, The outer ring of the guide sleeve (001) is fitted with at least one set of O-ring assemblies for sealing the oil cylinder. Each set of O-ring assemblies includes an O-ring (9) and a second retaining ring (10). The second retaining ring (10) is closer to the outer end of the guide sleeve (001) than the O-ring (9).

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