Bearing seal and its application

Abstract

Bearing seal (10) comprising an anchoring section (20) that can be attached to a first bearing ring (3) and a sealing section (30) capable of forming a sealing seat with a second bearing ring (2), wherein the sealing section (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 designed to regulate the sealing contact with the second bearing ring (2) by its own deformation under the influence of the pressure differential between the bearing interior and the bearing exterior.Based on the bearing seal (10) described above, the present invention further provides a rolling bearing (1) comprising a first bearing ring (3), a second bearing ring (2), at least a series of rolling elements (4) provided between the first and the second bearing ring (3, 2), and the bearing seal (10) described above.

Description

Technical field of the invention

[0001] The present invention relates to a bearing seal, and in particular to a seal capable of preventing lubricant from escaping the bearing when the internal pressure of the bearing is higher than the external pressure. The invention also relates to rolling bearings that utilize such a bearing seal. State of the art

[0002] The reasons for grease loss from bearings are complex and varied. One important reason is that the internal temperature of the bearings rises during operation, causing the grease to thin and leak out. Furthermore, the temperature increase leads to a rise in the bearing's internal pressure, creating a pressure differential between the inside and outside, which further exacerbates grease loss. In some technical applications, an external vacuum can trigger the development of this pressure differential, accelerating grease loss. Bearings lacking grease wear out quickly, becoming a failure risk and a potential weak point in equipment durability. Even more problematic is the fact that escaping grease can have serious consequences if it enters the mixing material.Especially in industries like medicine, chemicals, and precision manufacturing, such contamination must never occur. The realities demand a bearing seal that effectively prevents lubricant leakage and a rolling bearing that utilizes such a seal. Brief description of the invention

[0003] To solve the technical problems described above, the present invention provides a bearing seal comprising an anchoring section that can be attached to a first bearing ring and a sealing section capable of forming a sealing seat with a second bearing ring. The sealing section includes at least one dynamic sealing lip capable of forming a contact seal with the second bearing ring during operation. The dynamic sealing lip is able to regulate the sealing contact with the second bearing ring by its own deformation under the influence of the pressure differential between the bearing interior and exterior.

[0004] In the seals described above, the dynamic sealing lip is not only able to deform synchronously with the pressure increase inside the bearing, but the extent of the deformation also shows a positive correlation with the magnitude of the pressure difference between the bearing interior and exterior. That is, the greater the pressure difference, the tighter the seal. Consequently, it can dynamically and immediately adapt to changes in the pressure difference between the bearing interior and exterior, preventing grease leakage to the greatest extent possible. Conversely, when the internal and external pressures of the bearing reach equilibrium (i.e., the difference between internal and external pressure is zero), the dynamic sealing lip is in a normal contact state, which does not lead to problems such as premature wear and excessive temperature rise due to excessive contact pressure.Furthermore, the features of the dynamic sealing lip described above do not lead to an increase in the size of the seal, so that versatility and interchangeability with existing seals are maintained and the seal can be applied to a wide variety of existing bearings.

[0005] Based on the aforementioned seal, the present invention also provides a rolling bearing capable of preventing lubricant leakage in the event of an imbalance between internal and external pressure. It is understood that such a bearing is capable of long-term and reliable operation without contamination of the external environment due to escaping lubricant.

[0006] Various embodiments and advantageous technical effects of the present invention are described in detail below in conjunction with the accompanying drawings. Brief description of the characters Fig. Figure 1 shows a schematic cross-sectional view of a rolling bearing comprising the improved seal of the present invention; Fig. Figure 2 shows a schematic representation of an overall cross-section of the improved seal of the present invention; and Fig. Figure 3 shows a partially enlarged view of the in Fig. 2 shown seals. Detailed description of the invention

[0007] In the following description, identical or similar reference symbols are used to denote identical or similar components. Furthermore, terms denoting directions, such as "axial," "radial," and "circumferential," refer to the axial, radial, and circumferential directions of the depicted components, unless otherwise specified.

[0008] Fig. Figure 1 shows a schematic cross-sectional view of a rolling bearing comprising an improved seal of the present invention, wherein the rolling bearing 1 comprises an inner ring 2, an outer ring 3, and at least one series of rolling elements 4 provided between the inner ring and the outer ring. To prevent contaminants from entering the bearing from the outside and lubricating grease from flowing out of the bearing, the bearing 1 is provided with seals 10 on both of its axial sides.

[0009] Fig. Figure 2 shows a schematic representation of the overall cross-section of the seal, with the seal on the right side of the bearing being taken as an example. As can be seen from the figure, the bearing seal 10 comprises an anchoring section 20, which is able to be reliably fixed to the outer bearing ring 3, and a sealing section 30, which is able to form a sealing seat with the inner bearing ring 2, wherein the sealing section 30 further comprises at least one dynamic sealing lip 40, which projects axially towards the interior of the bearing, and at least one static sealing lip 50, which in a preferred embodiment is arranged axially outside the dynamic sealing lip 40.

[0010] Typically, the dynamic sealing lip 40 and the static sealing lip 50 can be made of elastomeric materials such as rubber and PTFE. The static sealing lip 50 is primarily used to prevent the ingress of contaminants into the bearing from the outside and can form either a contact seal or a non-contact seal with the inner bearing ring 2, as required. In the case of a non-contact seal, the static sealing lip 50 can, for example, form a sealing gap of 0.1 to 0.9 mm with the inner ring 2. Compared to non-contact seals, contact seals provide a better sealing effect, but the friction caused by the contact increases the temperature rise and also reduces the force transmission efficiency of the bearing.

[0011] Fig. 3 is a partially enlarged view of the in Fig. Figure 2 shows the seal and indicates that the dynamic sealing lip 40 comprises a relatively rigid zone (hereinafter referred to as the “rigid zone”) 40A, which begins at its root 42, and a relatively flexible zone (hereinafter referred to as the “flexible zone”) 40B, which ends at its tail 44, where the ratio t / L between the thickness t of the rigid zone 40A and the total length L of the dynamic sealing lip 40 (the section separated from the static sealing lip 50) is between 8% and 16%. The rigid zone 40A, which has the dimensional proportions described above, largely defines the overall flexibility of the dynamic sealing lip 40 and provides the dynamic sealing lip with both the stiffness required to resist the pressure differential between the inside and outside of the bearing and the deformability required to adapt its own position.

[0012] Furthermore, the dynamic sealing lip 40 is also provided with a folding zone 40C between the rigid zone 40A and the flexible zone 40B. In the Fig. In the specific embodiment shown in Figure 3, the thickness of the folding zone 40C is less than that of the main areas of the rigid and flexible zones 40A and 40B, respectively, creating a "bottleneck" with respect to the thickness of the entire dynamic sealing lip 40. This bottleneck can be either progressive, with the thickness of the dynamic sealing lip first gradually decreasing from the rigid to the flexible zone and then gradually increasing, or abrupt, with the thickness of the dynamic sealing lip first rapidly decreasing from the rigid to the flexible zone over a very small area and then rapidly increasing over a very small area. Regardless of the shape of the assumed dimensional change, the folding zone is designed so that the warping and deformation effects of the dynamic sealing lip occur predominantly within the folding zone.

[0013] When installed, the dynamic sealing lip 40 is located in the Fig.The position shown in Figure 3 is located on the inner bearing ring 2. If the internal pressure of the bearing is greater than the external pressure, the difference between the internal and external pressures causes an overall deformation of the dynamic sealing lip 40. The result of the deformation is that the rigid zone 40A approaches the static sealing lip 50, and the angle α between the rigid zone 40A and the radial direction of the bearing decreases, and the flexible zone 40B rests with its rear side against the inner ring 2 of the bearing, and the contact height angle β with the inner ring increases.In other words, the difference between the internal and external pressure changes the position and location of the dynamic sealing lip 40, causing the rigid zone 40A to rotate outwards in the axial direction and be pressed downwards in the radial direction, so that the flexible zone 40B increases the contact height angle β and presses more firmly against the inner ring 2 of the bearing, thereby increasing the sealing effect and preventing the escape of lubricant.

[0014] From the above description, it is evident that the angle α between the rigid zone 40A and the radial direction of the bearing, and the contact height angle β between the flexible zone 40B and the inner ring 2 of the bearing, determine the overall position of the dynamic sealing lip 40. This position largely determines the sealing capacity of the dynamic sealing lip 40 under the influence of the difference between the internal and external pressure. In the assembled state, the following angular ranges for α and β help to optimize the sealing effect of the dynamic sealing lip: the inclination angle α of the rigid zone 40A is between 10 and 30 degrees, preferably between 15 and 25 degrees; the contact height angle β of the flexible zone 40B is between 110 and 130 degrees, preferably between 115 and 125 degrees.

[0015] The effectiveness of a contact seal depends primarily on the pressure of the seal seat, not on the size of the contact area. With a constant contact area, the seal is better the higher the contact pressure. Accordingly, the present invention also incorporates at least one localized rounded profile at the end 44 of the dynamic sealing lip 40, which ensures that the flexible zone 40B is able to contact the inner ring of the bearing regardless of changes in the contact height angle β caused by the rounded profile. Since the contact area of ​​the circular profile with the inner ring of the bearing does not change with the contact height angle β in the flexible zone 40B, the circular profile becomes the structural basis for establishing a positive correlation between the difference between the internal and external pressure and the sealing pressure.In other words, the rounded profile means that the sealing effect is no longer influenced by the contact area of ​​the sealing lip, so that the pressure difference between the inside and outside of the bearing becomes the decisive factor for determining the sealing force of the dynamic sealing lip. In a preferred embodiment, the radius of curvature r of the circular profile can be between 0.10 and 0.25 mm.

[0016] In the description above, the anchoring section 20 of the seal 10 is attached to the outer bearing ring 3, and the sealing section 30 of the seal 10 forms a sealing seat with the inner bearing ring 2. In an alternative embodiment, the anchoring section 20 of the seal 10 can also be attached to the inner bearing ring 2, while the sealing section 30 of the seal 10 forms a sealing seat with the outer bearing ring 3. For the sake of consistency, the bearing ring against which the anchoring section 20 rests is defined in the present invention as the “first bearing ring,” and the bearing ring that forms a sealing seat with the sealing section 30 is defined as the “second bearing ring.”

[0017] It is clear to those skilled in the art that the bearing seal described above and the bearings using the seal are not limited by the specific embodiments and that more general technical solutions are subject to the limitations in the appended claims. Any modifications and improvements to the present invention fall within the scope of protection of the present invention, provided they remain within the limitations of the appended claims.

Claims

[1] Bearing seal (10) comprising an anchoring portion (20) which can be fastened to a first bearing ring (3) and a sealing portion (30) which is capable of forming a sealing seat with a second bearing ring (2), wherein the sealing portion (30) comprises at least one dynamic sealing lip (40) which is capable of forming a contact seal with the second bearing ring (2) during operation, characterized by that the dynamic sealing lip (40) is designed to regulate the sealing contact with the second bearing ring (2) by its own deformation under the effect of the pressure difference between the inside and the outside of the bearing. [2] Bearing seal (10) according to claim 1, characterized byin that the dynamic sealing lip (40) comprises a relatively rigid zone (40A) which begins at its root (42) and a relatively flexible zone (40B) which ends at its end (44), the dynamic sealing lip (40) being designed in such a way that it is able, by its own deformation under the effect of the difference between the internal and external pressure, to reduce the angle (α) between the relatively rigid zone (40A) and the radial direction of the bearing and to increase the contact elevation angle (β) between the relatively flexible zone (40B) and the second bearing ring (2). [3] Bearing seal (10) according to claim 2, characterized by that the ratio t / L between the thickness (t) of the relatively rigid zone (40A) and the total length (L) of the dynamic sealing lip (40) is between 8 and 16%. [4] Bearing seal (10) according to claim 3, characterized bythat the dynamic sealing lip (40) is provided with a folding zone (40C) between the relatively rigid zone (40A) and the relatively flexible zone (40B). [5] Bearing seal (10) according to claim 4, characterized by that in the assembled state the angle (α) between the relatively rigid zone (40A) and the radial direction of the bearing 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] Bearing seal (10) according to claim 5, characterized by that the dynamic sealing lip (40) is formed at its end (44) with an at least partially rounded profile and rests against the second bearing ring (2) via this rounded profile. [7] Bearing seal (10) according to one of claims 1 to 6, characterized bythat the sealing section (30) further comprises at least one static sealing lip (50) arranged axially outwardly of the dynamic sealing lip (40). [8] Bearing seal (10) according to claim 7, characterized by that a contact-free seal is formed between the static sealing lip (50) and the second bearing ring (2). [9] Bearing seal (10) according to claim 7, characterized by that a contact seal is formed between the static sealing lip (50) and the second bearing ring (2). [10] Rolling bearing (1) comprising a first bearing ring (3), a second bearing ring (2) and at least one row of rolling elements (4) provided between the first and second bearing rings (3, 2), characterized by that the bearing (1) comprises a bearing seal (10) according to one of the preceding claims.

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