Rolling bearing arrangement and procedure for producing a rolling bearing arrangement

Abstract

The invention starts from a rolling bearing arrangement with at least a first ring (10) and at least a first component (12), which is rotatable relative to the at least first ring, and with rolling elements (14), which are designed to roll on a raceway (16) of the first ring and on a raceway (18) of the first component, and with a first seal (20) and at least a second seal (22), which together seal a space (24) of the rolling bearing arrangement, in which the rolling elements are located, wherein the first seal is located at a first end (26) of the space and the second seal is located at a second end (28) of the space, which is arranged opposite to the first end of the space. It is suggested that a surface area (30) of the rolling bearing arrangement, which is a boundary area of the space and which is designed to be always on a distance from all of the rolling elements, is made at least partially of potassium and / or calcium and / or sodium and / or magnesium and / or aluminum and / or zinc and / or cadmium and / or iron and / or nickel and / or tin and / or lead and / or copper and / or at least one zeolite and / or zinc phosphate.

Description

[0001] Rolling bearing arrangement and procedure for producing a rolling bearing arrangement

[0002] The invention concerns a rolling bearing arrangement and a procedure for producing a rolling bearing arrangement.

[0003] The document JP 2003287037 A describes a rolling bearing which is sealed by two sealings. An oxygen absorbent is fastened on an inner surface on the side of rolling elements of a sealing. The oxygen absorbent can contain an organic substance.

[0004] The document US 8,313243 B2 discloses a rolling bearing. In at least one of the members constructing the space inside the rolling bearing, an auxiliary agent for the grease is fixed to a surface, of at least one of the members, which is disposed at a side of a space inside the rolling bearing other than a sliding surface, of at least one of the members, on which the rolling elements slide. The auxiliary agent for the grease is fixed to a surface, of the seal, which is disposed at a side of the space inside the bearing. The auxiliary agent for the grease includes an agent whose component melts in the grease (additive), thus assisting the grease directly and an agent which generates a gas or the like and decreases an oxygen concentration in the space within the bearing, thus preventing the oxidation deterioration of the grease and indirectly assisting the grease.

[0005] Moreover, V. Bagotsky, Fundamentals of Electrochemistry. 2nd Edition, New Jersey: John Wiley & Sons, Inc., 2006, teaches about the tendency of materials to be oxidized.

[0006] Furthermore, A. Khan and M. E. Kordesch, "Large-scale fabrication of metallic Zn nanowires by thermal evaporation," Physica E: Low-dimensional Systems and Nanostructures, vol. 33, no. 1 , pp. 88-91 , 2006, describes amongst others the production of nanowires.

[0007] Moreover, E. Perez-Botella, S. Valencia and F. Rey, "Zeolites in Adsorption Processes: State of the Art and Future Prospects," Chemical Reviews, vol. 122, no. 24, pp. 17647-17695, 2022, describes prior art with respect to zeolites.

[0008] Furthermore, J. Sebastian and R. V. Jasra, "Sorption of Nitrogen, Oxygen, and Argon in Silver- Exchanged Zeolites," Industrial Engineering Chemical research, vol. 44, pp. 8014-8024, 2005, informs about the adsorption of oxygen by zeolites.

[0009] Moreover, L. Calabrese, " Anticorrosion Behavior of Zeolite Coatings Obtained by In Situ Crystallization: A Critical Review," Materials (Basel), vol. 12, no. 1 , p. 59, 2018, informs about zeolite coatings. The prevention of grease oxidation can be improved by using an inert grease. However, such a grease is not degradable and therefore harmful for the environment and for the health.

[0010] The problem of the invention is in particular to extend the lubricant lifetime in a rolling bearing arrangement. The problem is solved according to the invention by the features of claim 1 and by the features of claim 10, while advantageous embodiments and further embodiments of the invention can be taken from the subclaims.

[0011] The invention proceeds from a rolling bearing arrangement with at least a first ring and at least a first component, which is rotatable relative to the at least first ring, and with rolling elements, which are designed to roll on a raceway of the first ring and on a raceway of the first component, and with a first seal and at least a second seal, which together seal a space of the rolling bearing arrangement, in which the rolling elements are located, wherein the first seal is located at a first end of the space and the second seal is located at a second end of the space, which is arranged opposite to the first end of the space.

[0012] It is proposed that a surface area of the rolling bearing arrangement, which is a boundary area of the space and which is designed to be always on a distance from all of the rolling elements, is made at least partially of potassium and / or calcium and / or sodium and / or magnesium and / or aluminum and / or zinc and / or cadmium and / or iron and / or nickel and / or tin and / or lead and / or copper and / or at least one zeolite and / or zinc phosphate. Through this an extension of the lifetime of the lubricant of the bearing can be achieved. In particular, an oxidation of at least parts of the surface area can be achieved before grease of the bearing is getting oxidized.

[0013] With advantage the surface area is a surface region of a coating of the rolling bearing arrangement. Thereby the surface area can be manufactured easily and efficiently.

[0014] Furthermore, it is suggested that a thickness of the coating is between 50 pm and 800 pm, preferably between 250 pm and 650 pm and more preferably between 350 pm and 570 pm. Thereby the coating can deoxidize a big part of the oxygen which occurs in the space and at the same time it is avoided that the coating cracks or peels from a substrate due to the presence of internal stresses.

[0015] Advantageously the coating comprises nanowires, which comprise potassium and / or calcium and / or sodium and / or magnesium and / or aluminum and / or zinc and / or cadmium and / or iron and / or nickel and / or tin and / or lead and / or copper and / or at least one zeolite and / or zinc phosphate. Through this a large ratio between the contact area, in which a contact between the coating and the oxygen can occur, and the volume of the coating can be achieved.

[0016] Moreover, it is suggested that the surface area is a part of a cage of the rolling bearing arrangement or a part of a shoulder of a rolling bearing ring of the rolling bearing arrangement. Thereby an efficient usage of a surface of the rolling bearing arrangement is reached.

[0017] Furthermore, it is proposed that the first seal and the second seal seal the space in an airtight manner. Through this it is avoided that oxygen from outside of the space invades the space and oxidizes lubricant of the rolling bearing arrangement.

[0018] Advantageously the surface area comprises at least one Linde Type A zeolite. Thereby it can be achieved that at least a part of the surface area adsorbs oxygen and can be regenerated such that it can be used many times as oxygen adsorber.

[0019] With advantage the surface area comprises at least one Linde Type A zeolite, which has been modified by at least one chemical treatment. Through this it can be achieved that at least a part of the surface area adsorbs a relatively large amount of oxygen and can be regenerated such that it can be used many times as oxygen adsorber.

[0020] Moreover, it is suggested that all surface regions of the rolling bearing arrangement, which are a boundary region of the space and which are designed to be always on a distance from all of the rolling elements, are made of potassium and / or calcium and / or sodium and / or magnesium and / or aluminum and / or zinc and / or cadmium and / or iron and / or nickel and / or tin and / or lead and / or copper and / or at least one zeolite and / or zinc phosphate. Through this a big capacity for deoxidizing oxygen can be reached.

[0021] Advantageously the rolling bearing arrangement contains grease as a lubricant, wherein the grease contains at least one antioxidant additive. Thereby a long lifetime of the lubricant can be achieved.

[0022] Furthermore, a procedure for producing a rolling bearing arrangement, in particular as described above, is proposed, wherein the rolling bearing arrangement comprises at least a first ring and at least a first component, which is rotatable relative to the at least first ring, and rolling elements, which are designed to roll on a raceway of the first ring and on a raceway of the first component, and a first seal and at least a second seal, which together seal a space of the rolling bearing arrangement, in which the rolling elements are located, wherein the first seal is located at a first end of the space and the second seal is located at a second end of the space, which is arranged opposite to the first end of the space, wherein a surface area of the rolling bearing arrangement, which is a boundary area of the space and which is designed to be always on a distance from all of the rolling elements and which is made at least partially of potassium and / or calcium and / or sodium and / or magnesium and / or aluminum and / or zinc and / or cadmium and / or iron and / or nickel and / or tin and / or lead and / or copper and / or at least one zeolite and / or zinc phosphate, is created by chemical solution deposition and / or electrodeposition and / or spray deposition and / or physical vapor deposition. Through this the lubricant lifetime in the rolling bearing arrangement can be extended.

[0023] Further advantages can be seen in the following description of the drawing. An example of an embodiment of the invention is shown in the drawing. The drawing, the description and the claims contain numerous features in combination. The skilled person will expediently also consider the features individually and combine them to form useful further combinations.

[0024] Fig. 1 shows a schematic axial half section through a rolling bearing arrangement according to the invention.

[0025] Figure 1 shows an axial half section through a rolling bearing arrangement, which consists of a ball bearing. The rolling bearing arrangement comprises a first ring 10, a first component 12 and rolling elements 14, which are designed to roll on a raceway 16 of the first ring and on a raceway 18 of the first component. The first ring is an outer ring of the ball bearing and the first component is an inner ring of the ball bearing. Moreover, the rolling bearing arrangement comprises a first seal 20 and at least a second seal 22. The first seal and the second seal seal a space 24 of the rolling bearing arrangement, in which the rolling elements are located, in an airtight manner. The seals can be made of polymers, rubber and / or metal. In particular, the seals can be made of non-conductive polymers. The first seal is located at a first end 26 of the space and the second seal is located at a second end 28 of the space, which is arranged axially opposite to the first end of the space. All surface regions of the rolling bearing arrangement, which are a boundary region of the space and which are designed to be always on a distance from all of the rolling elements, are made of potassium and / or calcium and / or sodium and / or magnesium and / or aluminum and / or zinc and / or cadmium and / or iron and / or nickel and / or tin and / or lead and / or copper and / or at least one zeolite and / or zinc phosphate. A first one of the surface regions is a surface area 30, which is the surface of a shoulder 36 of the outer ring. Further ones of these surface regions are a surface part of a shoulder 38 of the outer ring, surface parts of shoulders of the inner ring, surface parts of the seals 20, 22 and a part of a surface of a cage 34 of the rolling bearing arrangement. The surfaces of the seals, which are in contact with the inner ring, are not coated in order to achieve a good sealing function. Alternatively, the surfaces of the seals leave only a very thin gap with the inner ring.

[0026] All of the surface regions are surface regions of a coating 32 of the rolling bearing arrangement. A thickness of the coating is between a few nanometers or 50 pm and 800 pm, preferably between 250 pm and 650 pm and more preferably between 350 pm and 570 pm. The thicker the coating is the more oxygen can be deoxidized. The coating can but doesn’t need to comprise or consist of nanowires, which comprise or consist of potassium and / or calcium and / or sodium and / or magnesium and / or aluminum and / or zinc and / or cadmium and / or iron and / or nickel and / or tin and / or lead and / or copper and / or at least one zeolite and / or zinc phosphate. The nanowires can have diameters with the order of a nanometer. Furthermore, the coating can be grown in the form of these nanowires. Moreover, all the surface regions can comprise or consist of at least one Linde Type A zeolite or at least one Linde Type A zeolite, which has been modified by at least one chemical treatment. The chemical treatment can change the Si / AI ratio of the zeolite, which changes the oxygen adsorption significantly.

[0027] The rolling bearing arrangement contains grease (not shown) as a lubricant, wherein the grease contains at least one antioxidant additive. The grease lubricates a movement of the rolling elements relative to the outer ring and the inner ring.

[0028] The coating is created by chemical solution deposition and / or electrodeposition and / or spray deposition and / or physical vapor deposition. By changing the deposition parameters (e. g. increasing the speed, with which the coating is grown) it is possible to increase the coating roughness and therefore increase the surface which is available for oxidation.

[0029] The rolling bearing arrangement can be used in a high temperature range, for example up to 300°C, because the grease of the bearing arrangement is not oxidized quickly.

[0030] By adding more antioxidants to the grease the lifetime of the grease can be extended further.

[0031] Oxidation of the lubricant does not happen before an induction time, i.e., the time when the antioxidant additives, that are dissolved in the lubricant, have been consumed. During this time the coating will oxidize though, consuming the oxygen in the air that fills the interior of the bearing. This results in a reduction of the oxygen concentration and will therefore reduce the reaction rate of the oxidation process after the antioxidants have been consumed and will therefore increase the lifetime of the lubricant. The oxidation rate of the coating will also decrease with a decrease of oxygen in the air. This means that the coating does not need to be very thick. The thickness of the coating depends on the quality of the seals, i.e. the ability of the seals to prevent fresh air to enter the bearing.

[0032] Oxidation of the functional surfaces of the bearing particularly happens in the case of mixed lubrication where (soft) oxide layers wear off, continuously creating fresh surfaces which are exposed to oxygen and will therefore oxidize again. This process is called corrosive mild wear and generates iron containing particles that act as a catalyst for lubricant oxidation. In addition to the above-mentioned direct prevention of lubricant oxidation, the coating will also prevent acceleration of oxidation by catalytic metal particles of the functional surfaces and therefore further reduce the reaction rate of the lubricant oxidation process.

[0033] Nowadays, some sealings are coated with low friction coatings (like DLC or Teflon-like). Because of this there is knowledge about how to coat them in the prior art.

[0034] A further embodiment of the invention differs from the first embodiment of the invention, which was described so far, only through the feature, that the seals are uncoated.A further embodiment of the invention differs from the first embodiment of the invention only through the feature, that the first ring and the first component are uncoated.

[0035] Moreover, in all of the embodiments it is an option to leave the cage uncoated.

[0036] List of reference numerals:

Claims

Claims:1 . Rolling bearing arrangement with at least a first ring (10) and at least a first component (12), which is rotatable relative to the at least first ring, and with rolling elements (14), which are designed to roll on a raceway (16) of the first ring and on a raceway (18) of the first component, and with a first seal (20) and at least a second seal (22), which together seal a space (24) of the rolling bearing arrangement, in which the rolling elements are located, wherein the first seal is located at a first end (26) of the space and the second seal is located at a second end (28) of the space, which is arranged opposite to the first end of the space, characterized in that a surface area (30) of the rolling bearing arrangement, which is a boundary area of the space and which is designed to be always on a distance from all of the rolling elements, is made at least partially of potassium and / or calcium and / or sodium and / or magnesium and / or aluminum and / or zinc and / or cadmium and / or iron and / or nickel and / or tin and / or lead and / or copper and / or at least one zeolite and / or zinc phosphate.

2. Rolling bearing arrangement according to claim 1 , characterized in that the surface area (30) is a surface region of a coating (32) of the rolling bearing arrangement.

3. Rolling bearing arrangement according to claim 2, characterized in that a thickness of the coating (32) is between 50 pm and 800 pm.

4. Rolling bearing arrangement according to at least one of the claims 2 or 3, characterized in that the coating (32) comprises nanowires, which comprise potassium and / or calcium and / or sodium and / or magnesium and / or aluminum and / or zinc and / or cadmium and / or iron and / or nickel and / or tin and / or lead and / or copper and / or at least one zeolite and / or zinc phosphate.

5. Rolling bearing arrangement according to at least one of the preceding claims, characterized in thatthe surface area is a part of a cage (34) of the rolling bearing arrangement or a part of a shoulder (36) of a rolling bearing ring of the rolling bearing arrangement.

6. Rolling bearing arrangement according to at least one of the preceding claims, characterized in that the first seal (20) and the second seal (22) seal the space (24) in an airtight manner.

7. Rolling bearing arrangement according to at least one of the preceding claims, characterized in that the surface area (30) comprises at least one Linde Type A zeolite or at least one Linde Type A zeolite, which has been modified by at least one chemical treatment.

8. Rolling bearing arrangement according to at least one of the preceding claims, characterized in that all surface regions of the rolling bearing arrangement, which are a boundary region of the space and which are designed to be always on a distance from all of the rolling elements, are made of potassium and / or calcium and / or sodium and / or magnesium and / or aluminum and / or zinc and / or cadmium and / or iron and / or nickel and / or tin and / or lead and / or copper and / or at least one zeolite and / or zinc phosphate.

9. Rolling bearing arrangement according to at least one of the preceding claims, characterized in that the rolling bearing arrangement contains grease as a lubricant, wherein the grease contains at least one antioxidant additive.

10. Procedure for producing a rolling bearing arrangement, in particular according to at least one of the preceding claims, wherein the rolling bearing arrangement comprises at least a first ring (10) and at least a first component (12), which is rotatable relative to the at least first ring (10), and rolling elements (14), which are designed to roll on a raceway (16) of the first ring and on a raceway (18) of the first component, and a first seal (20) and at least a second seal (22), which together seal a space (24) of the rolling bearing arrangement, in which the rolling elements are located, wherein the first seal is located at a first end (26) of the space and the second seal is located at a second end (28) of the space, which is arranged opposite to the first end of the space, characterized in that a surface area (30) of the rolling bearing arrangement, which is a boundary area of thespace and which is designed to be always on a distance from all of the rolling elements and which is made at least partially of potassium and / or calcium and / or sodium and / or magnesium and / or aluminum and / or zinc and / or cadmium and / or iron and / or nickel and / or tin and / or lead and / or copper and / or at least one zeolite and / or zinc phosphate, is created by chemical solution deposition and / or electrodeposition and / or spray deposition and / or physical vapor deposition.

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