A skeleton oil seal for large interference press fitting

Abstract

This invention provides a skeleton oil seal for large interference fit. The outer periphery of its rubber layer has radially protruding first, second, and third stepped sections from top to bottom. The bottom end of the third stepped section has an auxiliary chamfer. The interference fit of the three stepped sections is different, with the second stepped section having the largest interference fit. This simplifies the interference fit installation of the skeleton oil seal and optimizes stress distribution, reducing the maximum shear force. The auxiliary chamfer helps reduce the interference fit during initial press fit, facilitating smooth alignment of the bottom end of the skeleton oil seal and its forward insertion into the bearing. Multiple annular protrusions are provided on the outer sides of the three stepped sections, forming a wavy, concave-convex structure. This reduces the rebound of the skeleton oil seal after assembly, ensuring it is in the correct assembly position. While maintaining sealing performance, this reduces rubber compression, thus preserving rubber elasticity and extending the service life of the skeleton oil seal.

Description

Technical Field

[0001] This utility model relates to the field of oil seal production, and in particular to a skeleton oil seal for large interference fit. Background Technology

[0002] Oil seals with skeletons are commonly used components in modern industrial production, used to prevent fluids such as lubricating oil from leaking out from the joint between the oil seal and fixed components such as shafts. For example, the oil seal rings used in cross roller bearings have extremely high requirements for sealing performance, which necessitates a large interference fit to ensure the reliability of the seal. However, when pressing the oil seal skeleton with a large interference fit, the rubber at the contact point between the outer periphery of the skeleton oil seal and the bearing is squeezed and sheared, causing damage and potentially leading to seal ring failure. This also results in low pressing efficiency and makes it easy for misalignment to occur during initial pressing, leading to improper installation and substandard sealing performance. Summary of the Invention

[0003] This invention addresses the problem of low pressing efficiency and unsatisfactory sealing effect caused by compression shearing and pressing misalignment during large interference fit of oil seal skeletons. It proposes a skeleton oil seal for large interference fit.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A skeleton oil seal for large interference fit includes an L-shaped skeleton and a rubber layer wrapped around the L-shaped skeleton. The L-shape includes an axially extending first skeleton side and a radially extending second skeleton side. The first skeleton side is close to the outer periphery of the skeleton oil seal, and the tail end of the second skeleton side is close to the inner periphery of the skeleton oil seal. The portion of the rubber layer near the tail end of the second skeleton extends to form a dust lip and a sealing lip. A self-tightening spring is installed on the side of the sealing lip near the first skeleton side.

[0006] The outer periphery of the rubber layer is provided with a first step, a second step, and a third step that are radially raised from top to bottom. The bottom end of the third step is provided with an auxiliary chamfer. The radial protrusion lengths of the third step, the first step, and the second step are arranged from small to large. The first step, the second step, and the third step are all provided with circumferentially circumferential convex strips.

[0007] Preferably, the angle range of the auxiliary chamfer is 30°-60°, and the chamfer height is 1-2mm.

[0008] Preferably, the interference fit of the first step is 0.3 mm.

[0009] Preferably, the interference fit of the second step is 0.5 mm.

[0010] Preferably, the interference fit of the third step is 0.2 mm.

[0011] Preferably, the outer periphery of the first step portion, the second step portion, and the third step portion are all integrally provided with at least one protruding strip.

[0012] Preferably, each convex strip has at least two fracture gaps, which divide the convex strip into several arc segments along the circumference.

[0013] Preferably, the fracture cracks on the convex rib are staggered and arranged in a staggered manner with the fracture cracks on other convex ribs.

[0014] Preferably, the convex strip is a triangular convex strip.

[0015] Preferably, each corner of the rubber layer has a rounded transition structure.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] The outer periphery of the rubber layer of the skeleton oil seal is designed as a three-layer stepped structure, changing the traditional uniform interference to a stepped interference. The interference amounts of the three steps are different, with the second step having the largest interference amount. This makes the interference installation of the skeleton oil seal relatively simpler, while optimizing the stress distribution and reducing the maximum shear force.

[0018] An auxiliary chamfer is provided at the bottom of the third step. When the skeleton oil seal is press-fitted, the third step, which is located at the lowest end, is pressed into the bearing first. The auxiliary chamfer helps to reduce the interference during the initial press-fitting, and facilitates the bottom end of the skeleton oil seal to be smoothly aligned and enter the bearing in the forward direction.

[0019] The outer sides of the three stepped sections are provided with raised strips. The multiple annular raised strips form a wavy concave-convex structure. After assembly, the inner wall of the bearing fits tightly together, providing a good sealing effect. The annular grooves formed between the raised strips can accommodate the excess material of the rubber deformation during the interference fit of the skeleton oil seal, thereby reducing the rebound of the skeleton oil seal after assembly. This ensures that the skeleton oil seal is in the correct assembly position, reducing the amount of rubber compression while ensuring sealing performance, thus maintaining the elasticity of the rubber and extending the service life of the skeleton oil seal. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the axial cross-sectional structure of a skeleton oil seal used for large interference fit.

[0022] Figure 2 This is a schematic diagram of the outer peripheral structure of a skeleton oil seal used for large interference fit.

[0023] Among them, L-shaped frame 1, first frame side 11, second frame side 12, rubber layer 2, dustproof lip 201, sealing lip 202, self-tightening spring 3, first step part 21, second step part 22, third step part 23, protrusion 24, fracture gap 241. Detailed Implementation

[0024] To provide a better understanding of the purpose, structure, features, and functions of this utility model, detailed descriptions are provided below with reference to specific embodiments.

[0025] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0026] Please refer to the reference. Figure 1 and Figure 2 A skeleton oil seal for large interference fit includes an L-shaped skeleton 1 and a rubber layer 2 wrapped around the L-shaped skeleton 1. The L-shape includes an axially extending first skeleton side 11 and a radially extending second skeleton side 12. The first skeleton side 11 is close to the outer periphery of the skeleton oil seal, and the tail end of the second skeleton side 12 is close to the inner periphery of the skeleton oil seal. The portion of the rubber layer 2 near the tail end of the second skeleton extends to form a dustproof lip 201 and a sealing lip 202. A self-tightening spring 3 is installed on the side of the sealing lip 202 near the first skeleton side 11.

[0027] The outer periphery of the rubber layer 2 is provided with a first step 21, a second step 22 and a third step 23 that are radially raised from top to bottom. The bottom end of the third step 23 is provided with an auxiliary chamfer a. The radial protrusion lengths of the third step 23, the first step 21 and the second step 22 are arranged from small to large. The first step 21, the second step 22 and the third step 23 are all provided with circumferentially encircling convex strips 24.

[0028] The skeleton oil seal of this utility model is used for large interference fit. It mainly improves the outer peripheral surface structure of the rubber layer 2 that directly abuts the roller bearing during interference fit. The traditional outer peripheral surface is changed to a three-stage stepped structure, thereby changing the traditional uniform interference fit to a stepped interference fit. During assembly, the third step 23, which enters the roller bearing first, has the smallest interference fit. The second step 22, which is located in the middle, has the largest interference fit. The first step 21, which is located at the top and is the last to be assembled into the roller bearing, has an interference fit greater than that of the third step 23 and less than that of the second step 22. When the skeleton oil seal is assembled, the third step 23 has the smallest interference fit, so it can be assembled into the roller bearing more smoothly. The interference fit is relatively smaller than the expected interference fit, and the rebound of the skeleton oil seal during assembly is relatively small, thus reducing the probability of oil seal misalignment and effectively keeping the skeleton oil seal aligned and installed in the correct position. The interference fit of the second step 22 is equal to the expected interference fit. At this time, with the assistance of the third step 23, the oil seal is guided to be aligned during the assembly process from the third step 23 to the second step 22, and the interference fit gradually increases, effectively reducing the assembly difficulty and improving the assembly efficiency. The interference fit of the first step 21 is smaller than that of the second step 22, which can further improve the assembly efficiency. Moreover, the height difference between the first step 21 and the second step 22 effectively optimizes the stress distribution and reduces the maximum shear force.

[0029] The skeleton oil seal of this utility model has an auxiliary chamfer a at the bottom end of the third step 23, which helps to reduce the interference during the initial press-fitting and facilitates the smooth alignment of the skeleton oil seal in the bearing during the initial assembly.

[0030] The skeleton oil seal of this utility model has raised strips 24 on the outer side of each of the three stepped sections. The multiple annular raised strips 24 form a wavy concave-convex structure. After assembly, the inner wall of the bearing fits tightly together, providing a good sealing effect. The annular grooves formed between the raised strips 24 can accommodate the excess material of the rubber during interference fit of the skeleton oil seal, thereby reducing the rebound of the skeleton oil seal after assembly. This ensures that the skeleton oil seal is in the correct assembly position, reducing the amount of rubber compression while ensuring sealing performance, thus maintaining the elasticity of the rubber and extending the service life of the skeleton oil seal.

[0031] In some embodiments, the angle range of the auxiliary chamfer a is 30°-60°, and the chamfer height is 1-2mm. At the beginning of the assembly, this facilitates the rapid and positive alignment of the bottom end of the skeleton oil seal with the assembly groove of the roller bearing and its gradual pressing into the roller bearing, thereby reducing assembly difficulty and improving assembly efficiency.

[0032] In some preferred embodiments, the interference of the first step portion 21 is 0.3 mm; the interference of the second step portion 22 is 0.5 mm; and the interference of the third step portion 23 is 0.2 mm.

[0033] In some embodiments, at least one protrusion 24 is integrally provided on the outer periphery of the first step portion 21, the second step portion 22 and the third step portion 23. The protrusion 24 is integrally injection molded with the rubber outer layer, and the width of the protrusion 24 can be set according to the actual size of each step portion of the skeleton oil seal.

[0034] In some embodiments, each protrusion 24 is provided with at least two fracture gaps 241, which divide the protrusion 24 into several arc segments along the circumference. When some arc segments of the protrusion 24 are cut off during assembly, while some arc segments are not cut off, the cut arc segments can be filled into the circumferential groove, avoiding large-area damage to the outer circular wall caused by tearing along with the uncut arc segments.

[0035] In some preferred embodiments, the fracture gaps 241 on the protrusion 24 are staggered with the fracture gaps 241 on other protrusions 24; this avoids the partial arc segment on a certain protrusion 24 being cut and filled into the adjacent groove, which would also cause the arc segments of the adjacent protrusions 24 to be skewed and torn, thus better dispersing stress.

[0036] In some embodiments, the ridge 24 is a triangular ridge 24 with a pointed angular shape on the outermost side, which makes the installation of the skeleton oil seal with a large interference fit smoother and produces less debris when sheared.

[0037] In some embodiments, each corner of the rubber layer 2 is a rounded transition structure to reduce the cutting of the rubber layer 2 during assembly.

[0038] In summary, the skeleton oil seal protected by this utility model for large interference fit reduces the shear force during large interference fit by improving the structure of the outer periphery of the rubber layer, optimizes the stress distribution, reduces the assembly difficulty, and improves the assembly efficiency and quality.

[0039] This utility model has been described by the above-described embodiments; however, these embodiments are merely examples for implementing this utility model. It must be noted that the disclosed embodiments do not limit the scope of this utility model. Conversely, any modifications and refinements made without departing from the spirit and scope of this utility model are within the scope of patent protection of this utility model.

Claims

1. A skeleton oil seal for large interference fit, characterized in that: It includes an L-shaped skeleton and a rubber layer wrapped around the L-shaped skeleton. The L-shape includes an axially extending first skeleton side and a radially extending second skeleton side. The first skeleton side is close to the outer periphery of the skeleton oil seal, and the tail end of the second skeleton side is close to the inner periphery of the skeleton oil seal. The portion of the rubber layer near the tail end of the second skeleton extends to form a dustproof lip and a sealing lip. A self-tightening spring is installed on the side of the sealing lip near the first skeleton side. The outer periphery of the rubber layer is provided with a first step, a second step, and a third step that are radially raised from top to bottom. The bottom end of the third step is provided with an auxiliary chamfer. The radial protrusion lengths of the third step, the first step, and the second step are arranged from small to large. The first step, the second step, and the third step are all provided with circumferentially circumferential convex strips.

2. The skeleton oil seal for large interference fit as described in claim 1, characterized in that: The auxiliary chamfer has an angle range of 30°-60° and a chamfer height of 1-2mm.

3. The skeleton oil seal for large interference fit as described in claim 1, characterized in that: The interference fit of the first step is 0.3 mm.

4. The skeleton oil seal for large interference fit as described in claim 3, characterized in that: The interference fit of the second step is 0.5 mm.

5. The skeleton oil seal for large interference fit as described in claim 4, characterized in that: The interference fit of the third step is 0.2 mm.

6. The skeleton oil seal for large interference fit as described in claim 1, characterized in that: The outer periphery of the first step, the second step, and the third step is integrally provided with at least one protruding strip.

7. The skeleton oil seal for large interference fit as described in claim 6, characterized in that: Each convex rib has at least two fracture gaps, which divide the convex rib into several arc segments along the circumference.

8. The skeleton oil seal for large interference fit as described in claim 7, characterized in that: The fracture cracks on the convex ribs are arranged in staggered and alternating positions with the fracture cracks on the other convex ribs.

9. The skeleton oil seal for large interference fit as described in claim 1, characterized in that: The convex strip is a triangular convex strip.

10. The skeleton oil seal for large interference fit as described in claim 1, characterized in that: Every corner on the rubber layer has a rounded transition structure.

Images