Bearing seal and use thereof

Abstract

A bearing seal (10) comprises an anchoring portion (20) capable of being fastened to a first bearing ring (3) and a sealing portion (30) capable of forming a sealing fit with a second bearing ring (2). The sealing part (30) comprises at least one dynamic sealing lip (40) capable of forming a contact seal with the second bearing ring (2) during operation. The dynamic sealing lip (40) is arranged to be capable of being in sealing contact with the second bearing ring (2) through deformation adjustment of the dynamic sealing lip (40) under the action of the internal and external pressure difference of the bearing. On the basis of the sealing element (10), the invention further provides a rolling bearing (1) which comprises a first bearing ring (3), a second bearing ring (2), at least one row of rolling bodies (4) arranged between the first bearing ring (3) and the second bearing ring (2) and the bearing sealing element (10).

Description

Technical Field

[0001] The present invention relates to a bearing seal, and in particular to a seal capable of preventing lubricant from leaking out of a bearing when the internal pressure of the bearing is higher than the external pressure. The present invention also relates to a rolling bearing using the bearing seal. Background Art

[0002] The reasons for bearing grease leakage are complex and varied. One important reason is that the internal temperature of the bearing increases during operation, causing the grease to become thinner and flow out. In addition, the increase in temperature also leads to an increase in the internal pressure of the bearing, thereby forming an internal and external pressure difference, further exacerbating the loss of grease. In some technical fields, external vacuum will exacerbate the formation of internal and external pressure difference of the bearing, thereby accelerating the loss of grease. Bearings lacking grease will wear out quickly, becoming a hidden danger of equipment failure and / or a life bottleneck. What's more serious is that once the leaked grease is mixed with the stirred material, it is very likely to cause serious consequences. Especially in industries such as medical, chemical and precision manufacturing, such contamination is absolutely not allowed. Reality calls for a bearing seal that can effectively prevent lubricant leakage and a rolling bearing using such a seal. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a bearing seal, comprising an anchoring portion capable of being fastened to a first bearing ring and a sealing portion capable of forming a sealing fit with a second bearing ring. The sealing portion comprises at least one dynamic sealing lip capable of forming a contact seal with the second bearing ring during operation. The dynamic sealing lip can adjust the sealing contact with the second bearing ring through its own deformation under the action of the pressure difference between the inside and outside of the bearing.

[0004] In the above-mentioned seal, the dynamic sealing lip can not only deform synchronously with the increase of the internal pressure of the bearing, but also the deformation amplitude is positively correlated with the size of the pressure difference between the inside and outside of the bearing, that is, the greater the pressure difference, the tighter the sealing degree of the sealing lip, so that it can dynamically and timely adapt to the changes in the pressure difference between the inside and outside of the bearing, and prevent the leakage of lubricating grease to the greatest extent. On the contrary, when the internal and external pressures of the bearing reach equilibrium (that is, the internal and external pressure difference is zero), the dynamic sealing lip is in a normal contact state, and will not cause problems such as premature wear and excessive temperature rise due to too tight contact. In addition, the above-mentioned characteristics of the dynamic sealing lip will not cause the size of the seal to increase, so it can maintain the commonality and replaceability with existing seals, and is widely applicable to various types of existing bearings.

[0005] Based on the above seal, the present invention also provides a rolling bearing. The improved bearing can avoid the phenomenon of lubricant leakage when the internal and external pressures are unbalanced. Obviously, such a bearing can operate reliably and permanently, and will not cause external pollution due to lubricant leakage.

[0006] Various embodiments and beneficial technical effects of the present invention are described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 A schematic cross-sectional view of a rolling bearing including an improved seal of the present invention;

[0008] Figure 2 An overall cross-sectional schematic diagram of the improved seal of the present invention; and

[0009] Figure 3 for Figure 2 An enlarged view of a portion of the seal shown in FIG. DETAILED DESCRIPTION

[0010] In the following description, the same or similar reference numerals are always used to indicate the same or similar components. In addition, the terms indicating directions, such as "axial", "radial" and "circumferential direction", refer to the axial, radial and circumferential directions of the components being described unless otherwise limited or specified.

[0011] Figure 1 Schematic diagram of a cross section of a rolling bearing including the improved seal of the present invention. The rolling bearing 1 includes an inner ring 2, an outer ring 3, and at least one row of rolling elements 4 arranged between the inner ring and the outer ring. In order to prevent foreign matter from entering the bearing and grease from flowing out of the bearing, the bearing 1 is provided with seals 10 on both sides of the axial direction.

[0012] Figure 2 Taking the seal on the right side of the bearing as an example, the overall cross-sectional schematic diagram of the seal is shown. As can be seen from the figure, the bearing seal 10 includes an anchoring portion 20 that can be reliably fixed on the bearing outer ring 3 and a sealing portion 30 that can form a sealing fit with the bearing inner ring 2. Among them, the sealing portion 30 further includes at least one dynamic sealing lip 40 extending axially toward the inside of the bearing and at least one static sealing lip 50 located axially outside the dynamic sealing ring 40 in a preferred case.

[0013] In a typical case, the dynamic sealing lip 40 and the static sealing lip 50 can be made of elastic materials such as rubber and PTFE. Among them, the static sealing lip 50 is mainly used to prevent external foreign matter from entering the interior of the bearing, and can form a contact or non-contact seal with the bearing inner ring 2 as required. In the case of non-contact sealing, the static sealing lip 50 can form a sealing gap of, for example, 0.1 to 0.9 mm with the inner ring 2. Compared with non-contact sealing, contact sealing has a better sealing effect, but the friction caused by contact will aggravate the temperature rise effect and reduce the transmission efficiency of the bearing.

[0014] Figure 3 for Figure 2The partial enlarged view of the seal shown in FIG. 4 shows that the dynamic sealing lip 40 includes a relatively rigid area (hereinafter referred to as the "rigid area") 40A starting from its root 42 and a relatively flexible area (hereinafter referred to as the "flexible area") 40B ending at its tip 44. Among them, the ratio t / L between the thickness t of the rigid area 40A and the overall length L of the dynamic sealing lip 40 (the part separated from the static sealing lip 50) is between 8% and 16%. The rigid area 40A with the above-mentioned size ratio roughly determines the overall flexibility of the dynamic sealing lip 40, so that the dynamic sealing lip has both the rigidity required to withstand the pressure difference between the inside and outside of the bearing and the deformation ability required to adjust its own posture.

[0015] In addition, the dynamic sealing lip 40 is provided with a folding area 40C between the rigid area 40A and the flexible area 40B. Figure 3 In the specific embodiment shown, the thickness of the turning area 40C is smaller than the main area of ​​the rigid area 40A and the flexible area 40B, thereby forming a "bottleneck" in thickness of the entire dynamic sealing lip 40. This bottleneck can be gradual, that is, the thickness of the dynamic sealing lip gradually decreases from the rigid area to the flexible area, and then gradually increases; or it can be sudden, that is, the thickness of the dynamic sealing lip first decreases rapidly in a very small range from the rigid area to the flexible area, and then rapidly increases in a very small range. Regardless of the form of dimensional change, the setting of the turning area is intended to make the warping deformation action of the dynamic sealing lip mainly occur in the turning area.

[0016] In the assembled state, the dynamic sealing lip 40 will Figure 3 The posture shown is against the bearing inner ring 2. When the internal pressure of the bearing is greater than the external pressure, the internal and external pressure difference will cause the dynamic sealing lip 40 to deform as a whole. As a result of the deformation, the rigid area 40A is close to the static sealing lip 50, and the angle α between it and the radial direction of the bearing becomes smaller, and the flexible area 40B leans against the bearing inner ring 2, and the contact elevation angle β with the inner ring increases. In other words, the internal and external pressure difference will change the posture and position of the dynamic sealing lip 40, causing the rigid area 40A to rotate outward in the axial direction and press up and down in the radial direction, so that the flexible area 40B expands the contact elevation angle β and more closely fits against the bearing inner ring 2, thereby strengthening the seal and preventing the leakage of lubricant.

[0017] It can be seen from the above description that the angle α between the rigid zone 40A and the radial direction of the bearing and the contact elevation angle β between the flexible zone 40B and the inner ring 2 of the bearing determine the overall posture of the dynamic sealing lip 40, and this posture largely determines the sealing ability of the dynamic sealing lip 40 under the action of the internal and external pressure difference. In the assembled state, the following angle ranges of α and β help the dynamic sealing lip to obtain the best sealing effect: the inclination angle α of the rigid zone 40A is between 10 and 30 degrees, preferably between 15 and 25 degrees; the contact elevation angle β of the flexible zone 40B is between 110 and 130 degrees, preferably between 115 and 125 degrees.

[0018] The effect of contact sealing mainly depends on the pressure of the sealing fit, rather than the size of the contact area. When the contact area is constant, the greater the contact pressure, the better the sealing effect. Therefore, the present invention also forms at least a partial curved profile at the tip 44 of the dynamic sealing lip 40 to ensure that the flexible area 40B can contact the inner ring of the bearing through the curved profile regardless of how the contact elevation angle β changes. Since the contact area between the curved profile and the inner ring of the bearing does not change with the contact elevation angle β of the flexible area 40B, the curved profile becomes the structural basis for constructing a positive correlation between the internal and external pressure difference and the sealing pressure. In other words, the curved profile makes the sealing effect no longer affected by the contact area of ​​the sealing lip, so that the internal and external pressure difference of the bearing becomes the decisive factor in determining the sealing strength of the dynamic sealing lip. As a preferred embodiment, the radius of curvature r of the curved profile may be between 0.10 and 0.25 mm.

[0019] In the above description, the anchoring portion 20 of the seal 10 is fixed on the bearing outer ring 3, and the sealing portion 30 of the seal 10 forms a sealing fit with the bearing inner ring 2. In another case, the anchoring portion 20 of the seal 10 can also be fixed on the bearing inner ring 2, and the sealing portion 30 of the seal 10 forms a sealing fit with the bearing outer ring 3. For the sake of uniformity, the bearing ring equipped with the anchoring portion 20 is defined as the "first bearing ring" in the present invention, and the bearing ring that forms a sealing fit with the sealing portion 30 is defined as the "second bearing ring".

[0020] Those skilled in the art should understand that the above bearing seal and the bearing using the seal are not limited by the specific implementation method, and the more general technical solution shall be subject to the definition in the attached claims. Any changes and improvements to the present invention, as long as they comply with the definition in the attached claims, shall fall within the protection scope of the present invention.

Claims

1. A bearing seal (10), comprising an anchoring portion (20) capable of being fastened to a first bearing ring (3) and a sealing portion (30) capable of forming a sealing fit with a second bearing ring (2), wherein the sealing portion (30) comprises at least one dynamic sealing lip (40) capable of forming a contact seal with the second bearing ring (2) during operation, characterized in that: The dynamic sealing lip (40) is configured to be able to adjust the sealing contact with the second bearing ring (2) through its own deformation under the action of the pressure difference between the inside and outside of the bearing.

2. The bearing seal (10) according to claim 1, characterized in that: The dynamic sealing lip (40) comprises a relatively rigid area (40A) starting from a root (42) and a relatively flexible area (40B) ending at a tip (44). Under the action of the internal and external pressure difference, the dynamic sealing lip (40) is configured to be able to reduce the angle (α) between the relatively rigid area (40A) and the radial direction of the bearing through its own deformation, and to increase the contact elevation angle (β) between the relatively flexible area (40B) and the second bearing ring (2).

3. The bearing seal (10) according to claim 2, characterized in that: The ratio t / L between the thickness (t) of the relatively rigid zone (40A) and the overall length (L) of the dynamic sealing lip (40) is between 8% and 16%.

4. The bearing seal (10) according to claim 3, characterized in that: The dynamic sealing lip (40) is provided with a folding area (40C) between a relatively rigid area (40A) and a relatively flexible area (40B).

5. The bearing seal (10) according to claim 4, characterized in that: In the assembled state, the clamping angle (α) between the relatively rigid zone (40A) and the bearing radial direction is between 10° and 30°, preferably between 15° and 25°, and the contact elevation angle (β) between the relatively flexible zone (40B) and the second bearing ring (2) is between 110° and 130°, preferably between 115° and 125°.

6. The bearing seal (10) according to claim 5, characterized in that: The dynamic sealing lip (40) is formed with an at least partially curved profile at its tip (44), and abuts against the second bearing ring (2) via the curved profile.

7. The bearing seal (10) according to any one of claims 1 to 6, characterized in that: The sealing portion (30) further includes at least one static sealing lip (50) located axially outside the dynamic sealing lip (40).

8. The bearing seal (10) according to claim 7, characterized in that: A non-contact seal is formed between the static sealing lip (50) and the second bearing ring (2).

9. The bearing seal (10) according to claim 7, characterized in that: A contact seal is formed between the static sealing lip (50) and the second bearing ring (2).

10. A rolling bearing (1), comprising a first bearing ring (3), a second bearing ring (2) and at least one row of rolling elements (4) arranged between the first and second bearing rings (3, 2), characterized in that: The bearing (1) comprises a bearing seal (10) as claimed in any one of the preceding claims.

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