Oil seal lip protecting sleeve with positioning, pressing and self-resetting functions

Abstract

The invention provides an oil seal lip protecting sleeve with a positioning, pressing and self-resetting function, which not only can effectively isolate direct damage of obstacles on a shaft to a lip in the assembly process of an oil seal, but also can have good oil seal positioning performance and operation convenience. The device comprises a rigid guide structure, the rigid guide structure comprises a positioning plate, fixing rods and a guide sleeve, the positioning plate and an installation ring of the guide sleeve are assembled through the multiple fixing rods to form a fixing frame, and the front end of the guide sleeve protrudes forwards to form a guide ring sleeve; the inner diameter of the guide ring sleeve is matched with the outer diameter of a guide shaft position at the tail end of a connecting shaft of the oil seal to be installed in a sleeved mode, and the outer diameter of the guide ring sleeve is matched with the diameter of an inner hole of the oil seal to be installed to form interference fit or transition fit. The push block structure comprises a push block, a push plate, a plurality of push rods and an elastic reset structure, the push block is an annular block, and the push plate is connected with the push block through the push rods.

Description

Technical Field

[0001] This invention relates to the technical field of mechanical seal installation, specifically to an oil seal lip protective sleeve with a positioning, pressing, and self-resetting function. Background Technology

[0002] Oil seals, as a widely used rotating shaft sealing element, rely on a lip made of flexible rubber or polytetrafluoroethylene (PTFE) for their core sealing function. Under preload, this lip forms a narrow line contact band with the rotating shaft surface, achieving a dynamic seal through the surface tension of the oil film. This prevents lubricating oil, grease, and other media from leaking from the equipment, while also preventing the intrusion of external contaminants such as dust and moisture. Due to the soft material and precise structure of the lip, it is extremely fragile during installation.

[0003] In traditional oil seal installation, operators need to push or press the entire oil seal into the mounting hole of the equipment to align it with the shaft. During this process, various features on the shaft, such as keyways, splines, shoulders, chamfers, and unavoidable machining burrs or surface scratches, can become potential "traps." When the oil seal lip comes into contact with these rigid obstacles under axial pressure, it is highly susceptible to scratches, cuts, curling, or even tearing. Even a minor damage is enough to destroy the intact seal formed between the lip and the shaft, causing the oil seal to leak shortly after being put into use, resulting in equipment lubrication failure, environmental pollution, unplanned downtime, and high maintenance costs. Statistics show that premature oil seal failure due to improper installation accounts for a significant proportion of all oil seal failures.

[0004] In existing technologies, several methods are typically used to address this problem: First, a large amount of grease is applied to the lip and shaft before installation, utilizing the filling and lubricating properties of the grease to reduce friction and impact. Second, a guide sleeve or mounting sleeve made of soft material is used, pre-fitted onto the shaft to provide a smooth transition path for the oil seal lip. However, the grease application method has inconsistent protective effects; the grease may be squeezed out or unevenly distributed. Excess or squeezed-out grease adheres to the outer surface of the oil seal. When removing the protective sleeve, the grease's viscosity can cause the already properly positioned oil seal to be pulled out or misaligned. The pulled-out oil seal needs to be inspected for damage, and the misaligned oil seal needs to be realigned, making the installation process time-consuming and labor-intensive. While soft guide sleeves provide a physical barrier, their application varies. In particular, the input shaft and oil seal journal of some new energy vehicle special transmissions are very similar in size, with a radial dimension difference of less than 3mm. These sleeves must protect the oil seal lip while also having suitable rigidity for easy removal. Furthermore, existing protective sleeves have poor durability, resulting in high costs.

[0005] Therefore, there is an urgent need for a new type of oil seal installation protection device that can effectively isolate the direct damage to the lip from obstacles on the shaft, while also having good positioning and ease of operation. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides an oil seal lip protective sleeve with a positioning and pressing self-resetting function. This sleeve effectively isolates the lip from direct damage by obstacles on the shaft during the assembly process, while also providing good oil seal positioning and ease of operation.

[0007] An oil seal lip protective sleeve with positioning and self-resetting function, characterized in that it comprises: A rigid guide structure includes a positioning plate, a fixing rod, and a guide sleeve. The positioning plate and the mounting ring of the guide sleeve are assembled into a fixed frame by several fixing rods. The front end of the guide sleeve protrudes forward to form a guide ring sleeve. The inner diameter of the guide ring sleeve is adapted to the outer diameter of the end guide shaft of the connecting shaft to be installed with the oil seal. The outer diameter of the guide ring sleeve is adapted to the inner diameter of the oil seal to be installed, forming an interference fit or a transition fit. The push block structure includes a push block, a pressure plate, several push rods, and an elastic reset structure. The push block is an annular block, and the pressure plate is connected to the push block through several push rods. The push plate is located at the rear end of the positioning plate. The push block is fitted onto the guide ring of the guide sleeve. The push rod passes through the corresponding clearance holes of the positioning plate and the mounting ring of the guide sleeve and is fixed to the corresponding position of the rear end face of the push block. The push rod is equipped with the elastic reset structure in the axial area between the positioning plate and the push plate. When the push plate is not subjected to forward pushing force, the rear end face of the push block is arranged close to the front end face of the mounting ring.

[0008] Its further features are: The positioning plate and the guide sleeve are fixed together by a number of evenly arranged ring-shaped fixing rods to form a fixed frame. The push block and the push plate are fixed together by a number of push rods that are evenly arranged in a ring to form an integral frame structure. Each of the push rods is equipped with the elastic reset structure in the axial region between the positioning plate and the push plate. This ensures that the reset force of the push block is uniform along the circumference and that the front end face of the push block does not experience axial lag at individual radial positions when it resets and retracts, thereby ensuring that the oil seal is assembled stably and reliably. The inner diameter of the push block is 0.1mm to 0.2mm larger than the outer diameter of the oil seal mounting shaft section of the connecting shaft to which the oil seal is to be installed. The inner diameter of the oil seal is adapted to the outer diameter of the oil seal mounting shaft end, which facilitates the insertion and removal of the push block. As a result, when the push block is reset under the drive of the elastic reset structure, it will not rub against the connecting shaft, ensuring the stable and reliable assembly of the oil seal. The elastic reset structure is specifically a long strip spring. The long strip springs are all the same long strip springs. The long strip springs are fitted onto the push rod in the axial region between the positioning plate and the push plate. The two ends of each long strip spring are respectively mounted on the corresponding end faces of the positioning plate and the push plate. The front end of the guide ring sleeve of the guide sleeve is provided with a smooth, trumpet-shaped or arc-shaped guide surface with a forward-protruding outer wall that tapers towards the center. In the natural state without external force, the lip of the oil seal can be fitted into the guide ring sleeve without contacting the front end face of the guide ring sleeve, and the guide ring sleeve becomes the front end protection mechanism of the oil seal. The positioning plate has a positioning hole at its center, which is used to align the central shaft head of the connecting shaft. The inner diameter of the positioning hole is 0.1 to 0.15 mm larger than the diameter of the central shaft head. In the oil seal assembly state, the rear end of the central shaft head is inserted into the positioning hole, and there is a gap of 0.1-0.15 mm between the outer circumference of the central shaft head and the inner wall of the positioning hole, and they are arranged in a centered manner.

[0009] With the above technical solution, during oil seal assembly, the oil seal is fitted onto the guide ring sleeve, and a push block is arranged at the rear end of the oil seal. The entire mechanism is mounted on the oil seal mounting shaft via the guide ring sleeve, and the guide ring sleeve is fitted onto the end guide shaft of the connecting shaft to be installed to complete radial centering. The guide sleeve is installed together with the oil seal. After the guide sleeve passes over positions such as keyways, splines, shaft shoulders, and chamfers, the front end of the guide ring sleeve is mounted on the transition between the oil seal journal and the connecting shaft. Then, a forward or downward pushing force is applied to the push plate, and the pushing force is transmitted to the push block through the push rod. The oil seal installed on the guide ring sleeve is pushed out. After the pushing force of the push plate is released, the elastic force of the elastic reset structure resets the push plate to its initial position. Then, the push plate is pressed twice to guide the oil seal, so that the front end guide of the oil seal is in complete contact with the housing guide. This process is the "press-self-reset" cycle, which enables the oil seal to effectively isolate the direct damage to the lip from obstacles on the shaft during assembly, and also has good oil seal positioning and convenient operation. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the main view structure of the present invention; Figure 2 This is a three-dimensional structural schematic diagram of the present invention; Figure 3 for Figure 1 A schematic diagram of the AA cross-section structure; Figure 4 This is a three-dimensional schematic diagram of the oil seal assembly according to the present invention; Figure 5 This is a partial cross-sectional schematic diagram of the oil seal assembly of the present invention; The names corresponding to the serial numbers in the diagram are as follows: Oil seal 100, connecting shaft 200, end guide shaft 201, spline 202, oil seal mounting shaft section 203, oil seal journal 204, center shaft head 205, housing 300; Rigid guide structure 10, positioning plate 11, positioning hole 111, fixing rod 12, guide sleeve 13, mounting ring 131, guide ring sleeve 132, guide surface 1321, push block structure 20, push block 21, push plate 22, push rod 23, elastic reset structure 24. Detailed Implementation

[0011] A protective sleeve for an oil seal lip with a positioning and self-resetting function, see Figures 1-5 It includes a rigid guide structure 10 and a push block structure 20; The rigid guide structure 10 includes a positioning plate 11, several fixing rods 12, and a guide sleeve 13. The guide sleeve 13 includes a rear mounting ring 131 and a forward-protruding guide ring sleeve 132. The positioning plate 11 and the mounting ring 131 of the guide sleeve 13 are assembled to form a fixed frame through several fixing rods 12. The front end of the guide sleeve 13 protrudes to form the guide ring sleeve 132. The inner diameter of the guide ring sleeve 132 is adapted to the outer diameter of the end guide shaft 201 of the connecting shaft 200 of the oil seal 100 to be installed. The outer diameter of the guide ring sleeve 132 is adapted to the inner diameter of the oil seal 100 to be installed, forming an interference fit or a transition fit. The push block structure 20 includes a push block 21, a push plate 22, a plurality of push rods 23, and an elastic reset structure 24. The push block 21 is an annular block, and the push plate 22 is connected to the push block 21 through a plurality of push rods 23. The push plate 22 is located at the rear end of the positioning plate 11. The push block 21 is fitted onto the guide ring 132 of the guide sleeve 13. The push rod 23 passes through the corresponding clearance holes of the mounting ring 131 of the positioning plate 11 and the guide sleeve 13 and is fixed to the corresponding position of the rear end face of the push block 21. The push rod 23 is equipped with an elastic reset structure 24 in the axial area between the positioning plate 11 and the push plate 22. When the push plate 22 is not subjected to forward pushing force, the rear end face of the push block 21 is arranged close to the front end face of the mounting ring 131.

[0012] In specific implementation, the oil seal 100, housing 300, and connecting shaft 200 used for assembly are shown below. Figure 4 , Figure 5 The output end of the connecting shaft 200 is provided with a spline 202. The axial region of the connecting shaft 200 includes an oil seal mounting shaft section 203, an end guide shaft 201, and an oil seal journal 204. The rear end of the connecting shaft 200 is also provided with a centrally protruding central shaft head 205.

[0013] In a specific embodiment, the positioning plate 11 and the guide sleeve 13 are fixedly connected to form a fixed frame by three evenly arranged ring-shaped fixing rods 12; The push block 21 and the push plate 22 are fixed together by three evenly arranged push rods 23 to form an integral frame structure; Each push rod 23 is equipped with an elastic reset structure 24 in the axial region between the positioning plate 11 and the push plate 22. This ensures that the reset force of the push block 21 is uniform along the circumference and that the front end face of the push block 21 will not experience axial lag at individual radial positions when it resets and retracts, thereby ensuring that the oil seal 100 is assembled stably and reliably.

[0014] In a specific embodiment, the inner diameter of the push block 21 is 0.1mm to 0.2mm larger than the outer diameter of the oil seal mounting shaft section 203 of the connecting shaft 200 to which the oil seal is to be installed. The inner diameter of the oil seal 100 is adapted to the outer diameter of the oil seal mounting shaft section 203, which facilitates the insertion and removal of the push block 21. As a result, when the push block 21 is reset under the drive of the elastic reset structure 24, it will not rub against the connecting shaft 200, thus ensuring the stable and reliable assembly of the oil seal 100.

[0015] In a specific embodiment, the elastic reset structure 24 is a long bar spring. The long bar springs are identical and are fitted onto the push rod 23 in the axial region between the positioning plate 11 and the push plate 22. The two ends of each long bar spring are respectively mounted on the corresponding end faces of the positioning plate 11 and the push plate 22.

[0016] In a specific embodiment, the front end of the guide ring sleeve 132 of the guide sleeve 13 is provided with a smooth, trumpet-shaped or arc-shaped guide surface 1321 with a forward-protruding outer wall that tapers towards the center. When the oil seal 100 is in a natural state without external force, the lip can be fitted into the guide ring sleeve 132 without contacting the front end face of the guide ring sleeve 132. The guide ring sleeve 132 becomes the front end protection mechanism of the oil seal. The positioning plate 11 has a positioning hole 111 at its center. The positioning hole 111 is used to align the central shaft head 205 of the connecting shaft 200. The inner diameter of the positioning hole 111 is 0.1-0.15mm larger than the diameter of the central shaft head 205. When the oil seal 100 is assembled, the rear end of the central shaft head 205 is inserted into the positioning hole 111, and there is a gap of 0.1-0.15mm between the outer circumference of the central shaft head 205 and the inner wall of the positioning hole 111, and they are centered.

[0017] In a specific embodiment, the elastic reset structure 24 uses a highly elastic spring with sufficient resilience to achieve rapid self-reset, and it is connected by a nut and a push rod 23.

[0018] Its working principle is as follows: When assembling the oil seal 100, the oil seal sleeve 100 is installed on the guide ring sleeve 132, and a push block 21 is arranged at the rear end of the oil seal 100. The entire mechanism is set on the mounting shaft (connecting shaft 200) of the oil seal 100 through the guide ring sleeve 132, and the guide ring sleeve 132 is fitted onto the end guide shaft 201 of the connecting shaft 200 to be installed with the oil seal to complete the radial centering arrangement. The guide sleeve 13 is installed together with the oil seal 100. After the guide sleeve 13 passes through positions such as keyway, spline, shaft shoulder, and chamfer, the front end of its guide ring sleeve 132 is abutted at the transition between the oil seal journal 204 and the end guide shaft 201. The positioning hole 111 on the positioning plate 11 is aligned with the center shaft head. 205 performs precise positioning, and then applies a forward or downward pushing force to the push plate 22. The pushing force is transmitted to the push block 21 through the push rod 23, and the oil seal 100 installed on the guide ring sleeve 132 is pushed out. After the pushing force of the push plate 22 is released, the elastic force of the elastic reset structure 24 resets the push plate 22 back to the initial position. Then, the push plate 22 is pressed twice to guide the oil seal 100 so that the front end guide of the oil seal 100 is in complete contact with the guide of the housing 300. This process is the "press-self reset" cycle, which enables the oil seal 100 to effectively isolate the direct damage of the lip to the shaft obstacle during the assembly process, and also has good oil seal positioning and convenient operation.

[0019] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0020] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A protective sleeve for an oil seal lip with a positioning and pressing self-resetting function, characterized in that, It includes: A rigid guide structure includes a positioning plate, a fixing rod, and a guide sleeve. The positioning plate and the mounting ring of the guide sleeve are assembled into a fixed frame by several fixing rods. The front end of the guide sleeve protrudes forward to form a guide ring sleeve. The inner diameter of the guide ring sleeve is adapted to the outer diameter of the end guide shaft of the connecting shaft to be installed with the oil seal. The outer diameter of the guide ring sleeve is adapted to the inner diameter of the oil seal to be installed, forming an interference fit or a transition fit. The push block structure includes a push block, a pressure plate, several push rods, and an elastic reset structure. The push block is an annular block, and the pressure plate is connected to the push block through several push rods. The push plate is located at the rear end of the positioning plate. The push block is fitted onto the guide ring of the guide sleeve. The push rod passes through the corresponding clearance holes of the positioning plate and the mounting ring of the guide sleeve and is fixed to the corresponding position of the rear end face of the push block. The push rod is equipped with the elastic reset structure in the axial area between the positioning plate and the push plate. When the push plate is not subjected to forward pushing force, the rear end face of the push block is arranged close to the front end face of the mounting ring.

2. The oil seal lip protective sleeve with positioning and pressing self-resetting function according to claim 1, characterized in that: The positioning plate and guide sleeve are fixed together by a number of evenly arranged fixing rods to form a fixed frame.

3. The oil seal lip protective sleeve with positioning and pressing self-resetting function according to claim 2, characterized in that: The push block and the push plate are fixed together by a number of push rods evenly arranged in a ring to form an integral frame structure.

4. The oil seal lip protective sleeve with positioning and pressing self-resetting function according to claim 3, characterized in that: Each of the push rods is equipped with the elastic reset structure corresponding to the axial region between the positioning plate and the push plate.

5. The oil seal lip protective sleeve with positioning and pressing self-resetting function according to claim 1, characterized in that: The inner diameter of the push block is 0.1mm to 0.2mm larger than the outer diameter of the oil seal mounting shaft section of the connecting shaft to which the oil seal is to be installed, and the inner diameter of the oil seal is adapted to the outer diameter of the oil seal mounting shaft end.

6. The oil seal lip protective sleeve with positioning and pressing self-resetting function according to claim 4, characterized in that: The elastic reset structure is specifically a long bar spring. All the long bar springs are identical long bar springs. The long bar springs are fitted onto the push rod in the axial region between the positioning plate and the push plate. The two ends of each long bar spring are respectively mounted on the corresponding end faces of the positioning plate and the push plate.

7. A protective sleeve for an oil seal lip with a positioning and pressing self-resetting function according to claim 1, characterized in that: The front end of the guide ring of the guide sleeve is provided with a smooth, trumpet-shaped or arc-shaped guide surface with a forward-protruding outer wall that tapers towards the center.

8. The oil seal lip protective sleeve with positioning and pressing self-resetting function according to claim 1, characterized in that: The positioning plate has a positioning hole at its center, which is used to align the central shaft head of the connecting shaft. The inner diameter of the positioning hole is 0.1 to 0.15 mm larger than the diameter of the central shaft head. In the oil seal assembly state, the rear end of the central shaft head is inserted into the positioning hole, and there is a gap of 0.1-0.15 mm between the outer circumference of the central shaft head and the inner wall of the positioning hole, and they are arranged in a centered manner.

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