Pin shaft dustproof seal with lip compensation function

Abstract

The utility model relates to the technical field of mechanical dust prevention, in particular to a dust seal with lip compensation. A pin shaft dust seal with lip compensation comprises an annular sealing ring body and an annular supporting body connected with the sealing ring body in a sleeved mode, a cavity is reserved between the sealing ring body and the annular supporting body, an elastic body and a sealing body are contained in the cavity, and the sealing body and the annular supporting body are bonded together. The elastic body is embedded in the cavity in an interference fit mode and abuts against the sealing ring body and the sealing body all the time, and the elastic body continuously provides radial force for the sealing body so as to compensate deformation loss of the sealing body. The problems which are not solved by two schemes of VAY and DLI are solved, that is, the problems of poor wear resistance and poor compression permanent deformation of the product are solved at the same time, and a more reliable and lasting dustproof sealing guarantee is provided for engineering machinery.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical dustproofing, in particular to a dustproof seal with lip compensation. Background Art

[0002] Pin dust seals play a vital role in the engineering field and are widely used in the pins and cylinder piston rod bushings of various types of engineering machinery such as excavators and loaders, providing effective dustproof sealing protection for these key parts.

[0003] In practical applications, construction machinery often operates under complex and harsh conditions, placing extremely high demands on the performance of dust seals. This demanding dustproofness necessitates the use of highly wear-resistant materials. Among various materials, polyurethane is widely chosen for its excellent wear resistance. However, polyurethane is not without flaws. It suffers from the significant disadvantage of poor compression set, meaning that after prolonged stress and subsequent release, the material does not fully recover to its original shape. Over time, polyurethane gradually ages. During this aging process, the dust seal's lip size increases, significantly reducing its sealing force. This makes it unable to effectively prevent the intrusion of dust, sand, and other impurities, significantly impacting the proper operation and service life of the construction machinery.

[0004] Currently, pins and hydraulic cylinder bushings used in construction machinery are subject to rocking motion during operation. To reduce wear, they must be lubricated with grease. Furthermore, to prevent grease loss and contamination from external sediment intrusion, it is crucial to add dust seals at both ends of the pins.

[0005] There are two main types of pin-type dust seals: VAY and DLI. The VAY structure uses rubber as the elastomer, making it suitable for relatively clean environments like indoor construction machinery. However, common construction machinery like excavators and loaders often work in environments filled with mud, water, sand, and other impurities. In such harsh environments, the rubber's wear resistance becomes a serious issue, rendering VAY dust seals unsuitable for practical applications.

[0006] The DLI structure's elastomer is made of polyurethane, which offers excellent wear resistance and high hardness in the presence of grease, making it suitable for the harsh environments of construction machinery. However, after a period of use, DLI products experience fatigue and aging at the lip, gradually increasing in size due to the inherent poor compression set of polyurethane. This ultimately leads to a significant decrease in the product's dustproof performance, making it unable to provide reliable dust protection for construction machinery.

[0007] In summary, the purpose of the present invention is to solve the problems that the existing VAY and DLI solutions have not solved, that is, to simultaneously solve the problems of poor wear resistance and compression permanent deformation of the product, and to provide more reliable and long-lasting dustproof sealing protection for engineering machinery. Utility Model Content

[0008] In order to solve the problems of poor wear resistance and compression permanent deformation of products, the utility model provides a pin dust seal with lip compensation.

[0009] The utility model provides a pin shaft dust seal with self-contained lip compensation, comprising an annular sealing ring body and an annular support body sleeved with the sealing ring body, a cavity is left between the sealing ring body and the annular support body, an elastomer and a sealing body are accommodated in the cavity, the sealing body and the annular support body are bonded together, the elastomer is embedded in the cavity with an interference fit and is always in contact with the sealing ring body and the sealing body, the elastomer continuously provides radial force to the sealing body to compensate for the deformation loss of the sealing body.

[0010] Furthermore, the sealing ring body includes a side wall and a top wall, the annular support body includes a support top and a support arm extending in the axial direction, the side wall is provided with a flange, and the sealing ring body and the annular support body are interference fit at the flange.

[0011] Furthermore, a cut corner is provided on the side wall of the sealing ring body.

[0012] Furthermore, a limiting structure is provided on the side of the sealing body in contact with the elastic body. The limiting structure includes an inclined surface approaching and tilting toward the side of the sealing ring body. The inclined surface and the sealing ring body form a cavity for accommodating the elastic body.

[0013] Furthermore, the sealing body includes a groove for accommodating the support arm, the support arm is accommodated in the groove, and the sealing body wraps the support arm.

[0014] Furthermore, a compensation structure is provided on the side of the elastic body in contact with the sealing body, and the compensation structure includes a gap for accommodating the sealing body.

[0015] Furthermore, the sealing body forms a first lip in the axial direction, the first lip extends close to one side of the top wall of the sealing ring body, and a waterproof groove is formed between the first lip and the sealing ring body.

[0016] Furthermore, the sealing body forms a second lip in the axial direction, the second lip is arranged on a side of the support arm close to the annular support body, and a dirt storage tank is formed between the second lip and the first lip.

[0017] Furthermore, the first lip and the second lip form a sealing angle toward the shaft diameter side, and the sealing angle is squeezed by the pin and is in close contact with the pin.

[0018] Furthermore, the material of the elastomer is rubber, and the material of the sealing body is polyurethane.

[0019] In summary, the present invention has the following beneficial technical effects:

[0020] 1. The utility model proposes a pin dust seal with built-in lip compensation, which uses polyurethane as the seal body. With its excellent wear resistance and hardness, it provides reliable dust protection for key parts such as the pin and cylinder piston rod bushing of engineering machinery. The rubber elastomer has excellent compression permanent deformation properties and can continuously compensate for the fatigue aging loss of the TPU elastomer. When the lip size of the polyurethane elastomer increases and the sealing force decreases due to aging during use, the radial force provided by the rubber elastomer can promptly compensate for this deformation loss, ensuring that the sealing performance is always maintained at a high level, effectively preventing the intrusion of impurities such as dust, mud and sand, and extending the service life of the engineering machinery.

[0021] 2. This utility model proposes a pin dust seal with built-in lip compensation. Through rational design, it reduces the use of polyurethane material. Since polyurethane is generally expensive, reducing its use while maintaining product performance can significantly reduce production costs. The flanged sidewall of the seal ring body creates an interference fit with the annular support, enhancing the product's connection strength and preventing loosening or separation under harsh operating conditions.

[0022] 3. The utility model proposes a pin dust seal with built-in lip compensation. The limiting structure on the sealing body and the compensation structure on the elastic body cooperate with each other to form a cavity and gap to accommodate the elastomer, so that the elastomer can play a compensating role more stably. At the same time, it also ensures the stability of the position of the sealing body and improves the compensation effect of the elastomer on the sealing body.

[0023] 4. The utility model proposes a pin dust seal with built-in lip compensation. The first lip and second lip formed by the sealing body in the direction of the shaft diameter, as well as the waterproof groove and dirt storage groove formed between them, can effectively block moisture and store pollutants, further improving the dust and water resistance of the product. The sealing angle formed by the first lip and the second lip toward the shaft diameter side is in close contact with the pin after being squeezed by the pin, ensuring the tightness of the seal and preventing grease loss and intrusion of external impurities. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is an exploded view of a pin dust seal with lip compensation according to an embodiment of the present invention.

[0025] Figure 2 It is a side sectional view of a pin dust seal with lip compensation according to an embodiment of the present invention.

[0026] Figure 3 This utility model Figure 2 A partial enlarged view of .

[0027] Figure 4 It is a cross-sectional view of the cooperation between the sealing ring body and the annular support body according to an embodiment of the present utility model.

[0028] Figure 5 It is a cross-sectional view of the sealing ring body, the annular support body and the sealing body in an embodiment of the present utility model.

[0029] Figure 6 It is a cross-sectional view of the sealing ring body, the annular support body and the elastic body in the embodiment of the present utility model.

[0030] Figure 7 This is an embodiment of the utility model Figure 3 A partial enlarged view of the combination.

[0031] Among them, 1. Sealing ring body; 101. Side wall; 102. Top wall; 103. Flanged edge; 104. Cut corner; 2. Annular support body; 201. Support top; 202. Support arm; 3. Chamber; 301. Cavity; 302. Gap; 4. Elastomer; 401. Compensating structure; 5. Sealing body; 501. Groove; 502. Inclined surface; 503. Limiting structure; 6. First lip; 7. Waterproof groove; 8. Second lip; 9. Sewage storage tank; 10. Sealing corner. DETAILED DESCRIPTION

[0032] The present invention will be described in further detail below with reference to the accompanying drawings.

[0033] Example 1

[0034] Reference Figure 1 、 Figure 2 、 Figure 3 and Figure 7 , this embodiment provides a pin shaft dust seal with self-lip compensation, including an annular sealing ring body 1, an annular support body 2 sleeved with the sealing ring body 1, a chamber 3 is left between the sealing ring body 1 and the annular support body 2, the chamber 3 contains an elastomer 4 and a sealing body 5, the sealing body 5 is bonded to the annular support body 2, the elastomer 4 is interference fit in the chamber 3 and is always in contact with the sealing ring body 1 and the sealing body 5, the elastomer 4 continuously provides radial force to the sealing body 5 to compensate for the deformation loss of the sealing body 5.

[0035] Reference Figure 7The elastomer 4 is interference fit in the chamber 3 and is not bonded to the sealing ring body 1, the annular support body 2 and the sealing body 5, but is only in contact with it. When the sealing body 5 is worn out, the elastomer 4 can apply radial force to the sealing body 5 in all directions along the contact surface outward to compensate for the loss.

[0036] Figure 2 A in the figure represents a partial cross-sectional view of the side view of the sealing ring body. Figure 3 A in the figure is the corresponding local enlarged image; Figure 2 B in FIG. 1 represents a partial cross-sectional view of a side view of the annular support body, Figure 3 B in the figure is the corresponding local enlarged view; Figure 2 C in the figure represents a partial cross-sectional view of the side view of the elastic body. Figure 3 A in the figure is the corresponding local enlarged image; Figure 2 D in the figure represents a partial cross-sectional view of the side view of the sealing body. Figure 3 A in FIG is the corresponding local enlarged view.

[0037] Reference Figure 4 The sealing ring body 1 includes a side wall 101 and a top wall 102, the annular support body 2 includes a support top 201 and a support arm 202 extending in the axial direction, and a flange 103 is provided on the side wall 101. The sealing ring body 1 and the annular support body 2 are interference fit at the flange 103.

[0038] The cavity 3 between the sealing ring body 1 and the annular support body 2 provides a stable installation space for the elastomer 4 and the sealing body 5. The elastomer 4 is inserted into the cavity 3 with an interference fit and maintains contact with the sealing ring body 1 and the sealing body 5, ensuring a tight connection between the components and improving the overall structural stability of the product. The flange 103 of the side wall 101 of the sealing ring body 1 and the annular support body 2 form an interference fit, further enhancing the product's connection strength and preventing loosening or separation under harsh operating conditions.

[0039] The side wall 101 of the sealing ring body 1 is provided with a cut corner 104 , and the cut corner 104 enables the sealing ring to be more smoothly embedded in the bushing.

[0040] Reference Figure 5 A limiting structure 503 is provided on the side of the sealing body 5 that contacts the elastic body 4. The limiting structure 503 includes an inclined surface 502 that is close to and inclined toward the side of the sealing ring body 1. The inclined surface 502 and the sealing ring body 1 form a cavity 301 for accommodating the elastic body 4.

[0041] The sealing body 5 includes a groove 501 for accommodating the support arm 202 . The support arm 202 is accommodated in the groove 501 , and the sealing body 5 wraps the support arm 202 .

[0042] Reference Figure 6 A compensation structure 401 is provided on the side of the elastic body 4 that contacts the sealing body 5 , and the compensation structure includes a gap 302 for accommodating the sealing body 5 .

[0043] The limiting structure 503 on the sealing body 5 and the compensation structure 401 on the elastomer 4 cooperate with each other to form a cavity 301 and a gap 302 for accommodating the elastomer 4, so that the elastomer 4 can play a more stable compensation role. At the same time, the inclined surface 502 of the limiting structure 503 also ensures that the position of the elastomer 4 is stable and will not slip out, and the elastomer 4 applies pressure to the inclined surface 502 of the sealing body 5. The compensation structure 401 increases the contact area between the elastomer 4 and the sealing body 5. The elastomer 4 also applies pressure to the sealing body 5, thereby improving the sealing of the product and the reliability of compensation for the sealing body 5.

[0044] Reference Figure 7 The sealing body 5 forms a first lip 6 in the axial direction. The first lip 6 extends close to the top wall 102 of the sealing ring body 1. A waterproof groove 7 is formed between the first lip 6 and the sealing ring body 1.

[0045] Reference Figure 7 The sealing body 5 forms a second lip 8 in the axial direction. The second lip 8 is arranged on the side of the support arm 202 close to the annular support body 2. A dirt storage tank 9 is formed between the second lip 8 and the first lip 6.

[0046] Reference Figure 7 The first lip 6 and the second lip 8 form a sealing angle 10 toward the shaft diameter side, and the sealing angle 10 is squeezed by the pin and is in close contact with the pin.

[0047] The first lip 6 and the second lip 8 formed on the sealing body 5 in the axial direction, as well as the waterproof groove 7 and the dirt storage groove 9 formed therebetween, can effectively block moisture and store pollutants, further improving the dustproof and waterproof performance of the product.

[0048] The sealing angle 10 formed by the first lip 6 and the second lip 8 toward the shaft diameter side is in close contact with the pin after being squeezed by the pin, ensuring the tightness of the seal and preventing grease loss and foreign matter from intruding.

[0049] In this embodiment, the sealing ring body 1, the annular support body 2, the elastomer 4 and the sealing body 5 are all integrally formed. The annular support body and the sealing body are bonded together through an injection molding process, and the elastomer is embedded inside. After the sealing ring body is installed in place by extrusion, it is interference fit with the annular support body through a flanging process.

[0050] In this embodiment, the material of the elastic body 4 is rubber, and the material of the sealing body 5 is polyurethane (TPU).

[0051] The TPU elastic element used as the seal 5, with its excellent wear resistance and hardness, effectively prevents the intrusion of external mud and sand, providing reliable dust protection for key parts of construction machinery, such as the pin shaft and cylinder piston rod bushing. This is especially true in harsh working environments such as excavators and loaders, which are filled with mud, water, and gravel. This can greatly reduce damage to key parts caused by impurities, ensuring the normal operation of the construction machinery.

[0052] The rubber elastic element 4 exhibits excellent compression set properties, continuously compensating for any loss in the TPU elastic element due to fatigue and aging. When the TPU elastic element ages and its lip enlarges, reducing its sealing force, the radial force provided by the rubber elastic element 4 promptly compensates for this loss, ensuring a consistently high level of sealing performance. This effectively prevents the intrusion of impurities such as dust and sand, extending the service life of the construction machinery.

[0053] The above are all preferred embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A pin dust seal with lip compensation, characterized in that: The invention comprises an annular sealing ring body (1), an annular support body (2) sleeved with the sealing ring body (1), a chamber (3) being reserved between the sealing ring body (1) and the annular support body (2), an elastic body (4) and a sealing body (5) being accommodated in the chamber (3), the sealing body (5) being bonded to the annular support body (2), the elastic body (4) being embedded in the chamber (3) with an interference fit and always in contact with the sealing ring body (1) and the sealing body (5), and the elastic body (4) continuously providing radial force to the sealing body (5) to compensate for deformation loss of the sealing body (5).

2. A pin dust seal with lip compensation according to claim 1, characterized in that: The sealing ring body (1) comprises a side wall (101) and a top wall (102); the annular support body (2) comprises a support top (201) and a support arm (202) extending in the axial direction; a flange (103) is provided on the side wall (101); and the sealing ring body (1) and the annular support body (2) are interference-fitted at the flange (103).

3. A pin dust seal with lip compensation according to claim 2, characterized in that: A cut corner (104) is provided on the side wall (101) of the sealing ring body (1).

4. A pin dust seal with lip compensation according to claim 3, characterized in that: A limiting structure (503) is provided on the side of the sealing body (5) in contact with the elastic body (4); the limiting structure (503) comprises an inclined surface (502) that approaches and tilts toward one side of the sealing ring body (1); the inclined surface (502) and the sealing ring body (1) form a cavity (301) for accommodating the elastic body (4).

5. A pin dust seal with lip compensation according to claim 4, characterized in that: The sealing body (5) comprises a groove (501) for accommodating the support arm (202); the support arm (202) is accommodated in the groove (501), and the sealing body (5) wraps the support arm (202).

6. A pin dust seal with lip compensation according to claim 5, characterized in that: A compensation structure (401) is provided on the side of the elastic body (4) in contact with the sealing body (5), and the compensation structure includes a gap (302) for accommodating the sealing body (5).

7. A pin dust seal with lip compensation according to claim 6, characterized in that: The sealing body (5) forms a first lip (6) in the axial direction, the first lip (6) extending close to the top wall (102) of the sealing ring body (1), and a waterproof groove (7) is formed between the first lip (6) and the sealing ring body (1).

8. The pin dust seal with lip compensation according to claim 7, characterized in that: The sealing body (5) forms a second lip (8) in the axial direction, the second lip (8) is arranged on a side of the support arm (202) close to the annular support body (2), and a dirt storage tank (9) is formed between the second lip (8) and the first lip (6).

9. A pin dust seal with lip compensation according to claim 8, characterized in that: The first lip (6) and the second lip (8) form a sealing angle (10) toward the shaft diameter side, and the sealing angle (10) is squeezed by the pin shaft and is in close contact with the pin shaft.

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