Oil seal structure of cross bearing with plug on outer diameter
By employing a combination design of secondary and primary sealing rings in the oil seal structure of the cross bearing with outer diameter plug, the problem of edge cutting during O-ring installation is solved, achieving highly reliable sealing performance and extending service life.
Patent Information
- Application Number
- CN202520549055.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-26
- Publication Date
- 2026-01-13
- Estimated Expiration
- 2035-03-26
AI Technical Summary
The O-rings of existing cross bearings with plugged outer diameters are easily cut off by sharp corners during installation, resulting in decreased sealing performance, shortened service life, and oil and air leakage.
An oil seal structure with a plugged cross bearing on the outer diameter was designed, which adopts a combination of a secondary seal ring and a primary seal ring. The outer diameter of the secondary seal ring is larger than that of the primary seal ring. During installation, it first enters the plug mounting hole to protect the primary seal ring from being cut off. The integrity of the seal ring is ensured by setting an oil seal mounting groove on the outer periphery of the plug.
It improves the durability of O-rings, significantly enhances sealing performance, reduces air and oil leakage to below 0.1%, and extends service life.
Smart Images
Figure CN223794506U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of bearing technology and relates to an oil seal structure for a cross bearing with a plugged outer diameter. Background Technology
[0002] Currently, due to the relatively mature machining and assembly of the plugged holes in cross roller bearings with plugged outer diameters, they are widely used in spherical plain bearings for industrial robot motor drives. These spherical plain bearings are generally lubricated with gear oil. The plug and plugged hole in cross roller bearings with plugged outer diameters have a small clearance fit, making it easy for gear oil to leak from this point. To avoid this, it is necessary to consider installing an oil seal structure at this location to prevent leakage.
[0003] The commonly used solution in the market is to groove the plug near the raceway and install an O-ring to seal the oil. This solution is simple in structure and effective. However, because the gap between the plug and the hole is very small, and because there is also a tapered pin hole on the plug hole for installing the tapered pin to position the plug, a sharp corner will appear at the junction of the two holes during machining. However, since it is inside, the sharp corner is difficult to remove. Thus, when the O-ring is installed into the hole through the O-ring groove, it is easily cut by the sharp corner formed at the junction of the external plug hole and the internal tapered pin hole. This can shorten the service life of the O-ring or even cause the oil seal to fail. Utility Model Content
[0004] To solve the above-mentioned technical problems, this utility model proposes an oil seal structure with a plugged cross bearing on the outer diameter.
[0005] This utility model is achieved through the following technical solution: an oil seal structure for a cross bearing with a plug on the outer diameter, including a plug, wherein an anti-cutting oil seal structure is provided on the outer periphery of the plug; the anti-cutting oil seal structure includes a secondary sealing ring and a primary sealing ring located above it, wherein the outer diameter of the secondary sealing ring is larger than the outer diameter of the primary sealing ring; during installation, the secondary sealing ring first enters the plug mounting hole of the cross bearing to protect the primary sealing ring located above it.
[0006] According to this utility model, the crossed bearing further includes an inner ring and an outer ring disposed on its outer periphery, with a roller disposed between the two. A plug mounting hole is provided inside the outer ring, and the plug is inserted into the plug mounting hole, with one end tangent to the roller and the other end fixedly connected to the outer ring to achieve positioning of the two.
[0007] According to this utility model, a groove for installing an oil seal is formed on the outer periphery of the blockage, and both the secondary sealing ring and the main sealing ring are installed in the groove for installing an oil seal.
[0008] According to this utility model, both the secondary sealing ring and the main sealing ring are O-rings.
[0009] According to this utility model, the width of the oil seal mounting groove is 1.1-1.3 times the sum of the cross-sectional diameters of the O-ring secondary seal and the O-ring primary seal.
[0010] According to this utility model, the depth of the oil seal mounting groove allows the cross-sectional diameter of the main sealing ring to achieve a compression of 15% to 25%.
[0011] According to this utility model, the cross-sectional diameter of the secondary sealing ring is 10% to 20% smaller than that of the primary sealing ring.
[0012] According to this utility model, the outer diameter of the secondary sealing ring is greater than the depth of the oil seal mounting groove.
[0013] According to this utility model, the cross-sections of the main sealing ring and the secondary sealing ring are polygonal.
[0014] According to this utility model, the main sealing ring and the secondary sealing ring have different cross-sectional shapes.
[0015] The beneficial effects of this utility model are as follows: This utility model can eliminate the edge cutting phenomenon of the O-ring main seal in the prior art, improve its durability, and thus extend its service life;
[0016] This invention has high reliability, reducing air and oil leakage to below 0.1%. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of an oil seal structure for a cross bearing with a plugged outer diameter according to the present invention;
[0018] Figure 2 This is a schematic diagram of the plug with an oil seal structure according to the present invention.
[0019] Among them, 1-outer ring, 2-inner ring, 3-plug, 31-oil seal mounting groove, 4-roller, 5-tapered pin, 6A-O-type secondary seal ring, 6B-O-type main seal ring, 7-skeleton oil seal. Detailed Implementation
[0020] To facilitate understanding of the utility model's objectives and effects, the specific embodiments of the utility model are as follows, in conjunction with the accompanying drawings:
[0021] like Figure 1The diagram illustrates an oil seal structure for a cross-bearing with a plug on its outer diameter. The oil seal structure includes an inner ring 2 and an outer ring 1 disposed on its outer circumference. A roller 4 is positioned between the two rings. The outer ring 1 has a tapered pin mounting hole and a plug mounting hole with their axes perpendicular to each other. A plug 3 is inserted into the plug mounting hole, with one end tangent to the roller 4. A tapered pin 5 is inserted into the tapered pin mounting hole to fix the other end of the plug 3 to the outer ring 1, thus positioning the plug 3 and the outer ring 1. To improve the sealing performance of the plug 3, an anti-cutting oil seal structure is provided on the outer circumference of the plug 3 to prevent the plug 3 from being cut by the sharp corner formed at the junction of the tapered pin mounting hole and the plug mounting hole during installation, thereby improving the overall sealing performance of the bearing.
[0022] Specifically, such as Figure 2 As shown, a schematic diagram of a plug with an oil seal structure is provided. An oil seal mounting groove 31 is formed on the outer periphery of the plug 3. An O-ring secondary seal 6A and an O-ring primary seal 6B located above it are installed in the oil seal mounting groove 31, with the outer diameter of the O-ring secondary seal 6A being larger than that of the O-ring primary seal 6B. During the installation of the plug 3, due to the small gap between the plug hole and the plug, when the plug 3 is pressed into the plug hole and passes through the groove opening of the oil seal mounting groove 31, the O-ring in the oil seal mounting groove 31 is squeezed during installation. Because an O-ring secondary seal 6A is installed on top of the O-ring primary seal 6B, the O-ring secondary seal 6A acts as a retainer, protecting the O-ring primary seal 6B from contacting the groove opening when squeezed, thus ensuring that the O-ring primary seal 6B can completely enter the plug mounting hole. The O-ring secondary seal 6A will experience edge trimming due to the squeezing of the O-ring primary seal 6B. When the oil seal mounting groove 31 passes through the junction of the plug mounting hole and the internal tapered pin mounting hole, the O-ring secondary seal 6A will be subjected to compression and edge trimming. However, it protects the O-ring primary seal 6B from compression and edge trimming, thus ensuring the sealing performance of the O-ring primary seal 6B. Not limited to this, the cross-section of the O-ring can also be square, triangular, or other polygonal; the cross-sections of the two O-rings can also be different shapes.
[0023] In this embodiment, the width of the oil seal mounting groove 31 is 1.1-1.3 times the sum of the cross-sectional diameters of the two O-rings, and the groove depth is based on the cross-sectional diameter of the main O-ring to ensure that the compression is between 15% and 25%.
[0024] In this embodiment, the diameter of the O-ring 6B is installed in the oil seal mounting groove 31, and a compression of 15% to 25% is required to ensure sealing performance. The cross-sectional diameter of the O-ring 6B is 10% to 20% smaller than that of the O-ring 6A, and the outer diameter of the O-ring 6B is greater than the depth of the oil seal mounting groove 31. This ensures that the outer circumferential surface of the O-ring 6B is located outside the plug 3, better protecting the O-ring 6A from being cut off and improving its service life.
[0025] In this embodiment, the outer ring 1 is provided with a skeleton oil seal 7.
[0026] The working principle of this utility model is as follows: A plug installation hole is opened on the outer diameter of the outer ring 1 of the bearing. A plug 3 is installed inside with a clearance fit of 0.02-0.04. A tapered pin 5 is attached to the end face to restrict the radial displacement and axial rotation of the plug. Before assembling the roller 4, the tapered pin 5 on the end face of the outer ring 1 is knocked out and the plug 3 is removed. An inner ring 2 that matches the raceway size of the outer ring and a set of corresponding rollers 4 are found. The raceway positions of the inner and outer rings are aligned, and the roller 4 can be installed through the plug installation hole. After the roller 4 fills the raceway, the main and auxiliary O-ring seals are installed in the oil seal mounting groove 31 on the plug 3 in the correct order. When the plug 3 is installed in the plug installation hole, the auxiliary O-ring seal 6A can protect the main O-ring seal 6B when the seal is installed under pressure, thereby ensuring the integrity of the main O-ring seal 6B when it is installed in place and improving its service life.
[0027] The above description is merely a preferred embodiment of this utility model and is not intended to limit this utility model in any form or substance. It should be noted that those skilled in the art can make several improvements and additions without departing from this utility model, and these improvements and additions should also be considered within the protection scope of this utility model. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of this utility model are equivalent embodiments of this utility model. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of this utility model still fall within the scope of the technical solution of this utility model.
Claims
1. An oil seal structure for a cross bearing with a plug on its outer diameter, comprising a plug, characterized in that, The outer periphery of the plug is provided with an anti-cutting oil seal structure; the anti-cutting oil seal structure includes a secondary sealing ring and a primary sealing ring located above it, the outer diameter of the secondary sealing ring being larger than the outer diameter of the primary sealing ring; during installation, the secondary sealing ring first enters the plug mounting hole of the cross bearing to protect the primary sealing ring located above it.
2. The oil seal structure with a plugged cross bearing on the outer diameter as described in claim 1, characterized in that, The crossed bearing includes an inner ring and an outer ring disposed on its outer periphery, with rollers disposed between the two. A plug mounting hole is provided inside the outer ring, and the plug is inserted into the plug mounting hole, with one end tangent to the roller and the other end fixedly connected to the outer ring to achieve positioning of the two.
3. The oil seal structure with a plugged cross bearing on the outer diameter as described in claim 1, characterized in that, An oil seal mounting groove is formed on the outer periphery of the blockage, and both the secondary sealing ring and the main sealing ring are installed in the oil seal mounting groove.
4. The oil seal structure with a plugged cross bearing on the outer diameter as described in claim 3, characterized in that, Both the secondary and primary sealing rings are O-rings.
5. The oil seal structure with a plugged cross bearing on the outer diameter as described in claim 4, characterized in that, The width of the oil seal mounting groove is 1.1-1.3 times the sum of the cross-sectional diameters of the secondary sealing ring and the main sealing ring.
6. The oil seal structure with a plugged cross bearing on the outer diameter as described in claim 3, characterized in that, The depth of the oil seal mounting groove allows the cross-sectional diameter of the main sealing ring to achieve a compression of 15% to 25%.
7. The oil seal structure with a plugged cross bearing as described in claim 1, characterized in that, The cross-sectional diameter of the secondary sealing ring is 10% to 20% smaller than that of the primary sealing ring.
8. The oil seal structure with a plugged cross bearing on the outer diameter as described in claim 3, characterized in that, The outer diameter of the secondary sealing ring is greater than the depth of the oil seal mounting groove.
9. The oil seal structure with a plugged cross bearing on the outer diameter as described in claim 1, characterized in that, The cross-sections of the main sealing ring and the secondary sealing ring are polygonal.
10. The oil seal structure with a plugged cross bearing on the outer diameter as described in claim 9, characterized in that, The main sealing ring and the secondary sealing ring have different cross-sectional shapes.