A forklift tilt cylinder piston seal system

Abstract

The application relates to a forklift tilting oil cylinder piston sealing system, which comprises a lip-shaped seal embedded on the outer side wall of a piston close to a rod cavity side and a piston ring embedded on the outer side wall of the piston close to a rodless cavity side, the lip of the lip-shaped seal is arranged to face the rod cavity, and a guide ring is embedded between the lip-shaped seal and the piston ring on the outer side wall of the piston. The application has the effect of reducing the probability of seal failure caused by the lip-shaped seal.

Description

Technical Field

[0001] This application relates to the field of hydraulic cylinder sealing, and more particularly to a piston sealing system for a forklift tilting cylinder. Background Technology

[0002] The forklift tilt cylinder is the core hydraulic component for tilt control of the forklift mast. Its main function is to control the mast to tilt forward or backward through hydraulic drive, which facilitates loading, unloading and handling of goods.

[0003] Existing forklift tilting cylinder piston sealing systems (such as...) Figure 1 As shown, the piston 0 includes two lip seals 1 embedded on the outer walls of both ends of the piston 0 along its length. The lips of the two lip seals 1 are arranged opposite each other. A guide ring 2 is embedded between the two lip seals 1 on the outer wall of the piston 0. A sealing full retaining ring 3 is provided on the side of the lip seal 1 near the rod chamber that is away from the lip 6. The sealing full retaining ring 3 is embedded in the piston 0. The existing forklift tilting cylinder piston sealing system adopts a back-to-back installation method for the lip seals 1. Considering that the rod chamber pressure of the forklift tilting cylinder is relatively high, a sealing full retaining ring 3 filled with PTFE material is added to the root of the lip seal 1 near the rod chamber.

[0004] However, when double-lip seals are installed back-to-back, the large interference fit of the lip seal design results in high frictional resistance, leading to significant frictional heat generation and high oil temperature during the reciprocating motion of the hydraulic cylinder. Especially in summer, the lip seals, typically made of polyurethane, are subject to accelerated deterioration due to the high oil temperature, exacerbating wear and ultimately causing seal failure. Utility Model Content

[0005] To reduce the probability of seal failure caused by lip seals, this application provides a piston sealing system for a forklift tilting cylinder.

[0006] The forklift tilting cylinder piston sealing system provided in this application adopts the following technical solution: A forklift tilting cylinder piston sealing system includes a lip seal embedded in the outer wall of the piston near the rod chamber and a piston ring embedded in the outer wall of the piston near the rodless chamber. The lip of the lip seal faces the rod chamber, and a guide ring is embedded between the lip seal and the piston ring on the outer wall of the piston.

[0007] By adopting the above technical solution, the pressure on the rodless chamber side of the forklift tilting cylinder is low, and the sealing requirements on the rodless chamber side are not high. Replacing the lip seal on the rodless chamber side with a piston ring reduces the sealing friction resistance and the heat generated by friction, thereby reducing the oil temperature in the cylinder. This slows down the deterioration rate of the lip seal and reduces the probability of seal failure caused by the lip seal.

[0008] Optionally, a sealing half-ring is provided on the side of the lip seal away from the lip opening.

[0009] By adopting the above technical solution, the full retaining ring must be designed as an open structure, while the half retaining ring has no installation restrictions and can be designed as a complete ring; as a whole, the half retaining ring will not move or misalign after installation, and its reliability is extremely high.

[0010] Optionally, multiple piston rings are evenly arranged along the length of the piston.

[0011] By adopting the above technical solution, multiple piston rings can improve the sealing effect, thereby improving the sealing effect of the piston on the rodless chamber side.

[0012] Optionally, all of the piston rings are open structures.

[0013] By adopting the above technical solution, the piston ring with the open structure can be easily installed, and it can also allow extremely small amounts of oil to flow from the high-pressure side to the low-pressure side through this gap, so that the trapped pressure generated between the lip seal and the piston ring can be discharged from the opening.

[0014] Optionally, the opening structures of adjacent piston rings are offset by 180°.

[0015] By adopting the above technical solution, the staggered setting of the opening structure can improve the sealing effect.

[0016] In summary, this application includes at least one of the following beneficial technical effects: The rodless chamber side of the forklift tilting cylinder has low pressure and low sealing requirements. Replacing the lip seal on the rodless chamber side with piston rings reduces sealing friction resistance and heat generated by friction, thereby lowering the oil temperature in the cylinder. This slows down the deterioration rate of the lip seal and reduces the probability of seal failure caused by the lip seal. Full retaining rings must be designed as open structures, while half retaining rings have no installation restrictions and can be designed as a complete ring; as a whole, half retaining rings will not move or misalign after installation, and have extremely high reliability; The open-type piston rings are easy to install and allow extremely small amounts of oil to flow from the high-pressure side to the low-pressure side through this gap, so that the trapped pressure between the lip seal and the piston ring can be discharged from the opening. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the piston and cylinder wall in the prior art.

[0018] Figure 2 This is a schematic diagram of the piston and cylinder wall in an embodiment of this application.

[0019] Explanation of reference numerals in the attached diagram: 0, piston; 1, lip seal; 2, guide ring; 3, full sealing ring; 4, piston ring; 5, half sealing ring; 6, lip. Detailed Implementation

[0020] The following is in conjunction with the appendix Figure 2 This application will be described in further detail.

[0021] First, it should be noted that in the description of this application, the use of directional terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" indicates the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for descriptive purposes and do not indicate or imply that the device or component 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 application. Furthermore, the use of numerical quantifiers such as "first," "second," and "third" is for descriptive purposes only and should not be construed as indicating or implying relative importance. Additionally, in this application, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, interference fits, transition fits, or integral connections; they can refer to direct connections or indirect connections through an intermediate medium. Therefore, those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0022] This application discloses a piston sealing system for a forklift tilting cylinder, referring to... Figure 2 The piston cylinder comprises a lip seal 1 embedded in the outer wall of the piston 0 near the rod chamber and a piston ring 4 embedded in the outer wall of the piston 0 near the rodless chamber. The lip seal 1 is made of polyurethane material and is circular in shape. The lip 6 of the lip seal 1 faces the rod chamber. A guide ring 2 is embedded between the lip seal 1 and the piston ring 4 on the outer wall of the piston 0. The guide ring 2 of the piston 0, also known as the support ring, is a key component in the moving mechanism of hydraulic cylinders, pneumatic cylinders, etc. It has the functions of supporting, guiding, reducing friction, assisting sealing, and cleaning the cylinder wall. The pressure on the rodless chamber side of the forklift tilting cylinder is low, and the sealing requirements on the rodless chamber side are not high. Replacing the lip seal 1 on the rodless chamber side with the piston ring 4 reduces the sealing friction resistance, reduces the heat generated by friction, thereby reducing the oil temperature in the cylinder, thus slowing down the deterioration rate of the lip seal 1 and reducing the probability of the lip seal 1 causing sealing failure.

[0023] Reference Figure 2A sealing half-retaining ring 5 is provided on the side of the lip seal 1 away from the lip opening 6. The full retaining ring must be designed as an open structure, while the half-retaining ring has no installation restrictions and can be designed as a complete ring. As a whole, the half-retaining ring will not move or misalign after installation, and its reliability is extremely high. The sealing half-retaining ring 5 is sleeved on the outer side of the end of the lip seal 1. When the lip seal 1 is deformed by force, the end of the lip seal 1 will deform due to the extrusion force and extend out of the piston 0 to abut against the cylinder wall. During the repeated movement of the piston 0, the lip seal 1 will wear out severely and lose its sealing effect. The sealing half-retaining ring 5, sleeved on the end of the lip seal 1, can replace the lip seal 1 in rubbing against the cylinder wall, thereby reducing the friction loss of the lip seal 1 and improving the service life of the lip seal 1. In order to improve the service life of the sealing system, the sealing half-retaining ring 5 is made of high wear-resistant engineering plastic material.

[0024] Reference Figure 2 Multiple piston rings 4 are evenly arranged along the length of piston 0. In this embodiment, two piston rings 4 are provided. Multiple piston rings 4 can improve the sealing effect, thereby improving the sealing effect of piston 0 on the rodless cavity side. Although the sealing effect of piston ring 4 is not as good as lip seal 1, the sealing effect of piston 0 on the rodless cavity side can still be achieved by setting multiple piston rings 4. Both piston rings 4 are open structures. Pressure trapping is easy to be generated between the sealing structures on both sides of piston 0. The pressure trapping is much greater than the normal oil pressure. The presence of pressure trapping can easily cause lip seal 1 to be deformed by reverse compression, resulting in sealing failure. The open structure of piston ring 4 can be easily installed and can also allow a very small amount of oil to flow from the high pressure side to the low pressure side through this gap, so that the pressure trapping generated between lip seal 1 and piston ring 4 can be discharged from the opening, thereby reducing the probability of high pressure being generated between lip seal 1 and piston ring 4 and reducing the probability of reverse deformation of lip seal 1 leading to sealing failure. The open structure positions of adjacent piston rings 4 are staggered by 180°. The staggered position of the open structure positions can improve the sealing effect.

[0025] The implementation principle of this application embodiment is as follows: the guide ring 2 is installed on the piston 0, then the lip seal 1 is installed on the piston 0 and a sealing half-retaining ring 5 is sleeved on the end of the lip seal 1, then the two piston rings 4 are installed on the piston 0 and the opening structure position of the two piston rings 4 is adjusted to complete the assembly of the piston 0. After connecting the piston 0 with the piston rod, it is installed into the cylinder body of the cylinder. When the piston 0 is connected to the piston rod, the piston rod is installed on the end of the piston 0 where the lip seal 1 is embedded.

[0026] It should be noted that the above embodiments are only used to illustrate this application and are not intended to limit the technical solutions described in this application. Although this specification has described this application in detail with reference to the above embodiments, those skilled in the art should understand that they can still make modifications or equivalent substitutions to this application. All technical solutions and improvements that do not depart from the spirit and scope of this application should be covered within the scope of the claims of this application.

Claims

1. A piston sealing system for a forklift tilting cylinder, characterized in that: It includes a lip seal (1) embedded in the outer wall of the piston (0) near the rod chamber and a piston ring (4) embedded in the outer wall of the piston (0) near the rodless chamber. The lip (6) of the lip seal (1) is arranged facing the rod chamber. A guide ring (2) is embedded between the lip seal (1) and the piston ring (4) on the outer wall of the piston (0).

2. The forklift tilting cylinder piston sealing system according to claim 1, characterized in that: The lip seal (1) has a sealing half-ring (5) on the side away from the lip opening (6).

3. The forklift tilting cylinder piston sealing system according to claim 1, characterized in that: The piston rings (4) are evenly arranged in multiples along the length of the piston (0).

4. The forklift tilting cylinder piston sealing system according to claim 3, characterized in that: All of the piston rings (4) are open structures.

5. A forklift tilting cylinder piston sealing system according to claim 4, characterized in that: The opening structures of adjacent piston rings (4) are offset by 180°.

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