Rolling bearing cage
Patent Information
- Application Number
- JP2023577265
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2021-07-05
- Filing Date
- 2022-06-09
- Publication Date
- 2025-06-02
- Estimated Expiration
- 2042-06-09
AI Technical Summary
Existing rolling bearing cages face challenges with lubricity at high speeds, limited lubrication options, and costly manufacturing processes, particularly in cylindrical roller bearings.
The cage design features angled slopes on the inner and outer sides of the side rings and webs, allowing for improved lubrication and injection points, and is manufactured via injection molding using PEEK material.
Enhances lubrication flexibility, supports high rotational speeds, and reduces manufacturing costs by up to 20% compared to traditional methods, ensuring high precision and robustness.
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Abstract
Description
[Technical field]
[0001] The present invention relates to a rolling bearing cage comprising a first side ring and a second side ring, the two side rings being arranged spaced apart from each other in the axial direction, and a number of webs extending between the two side rings thereby forming a number of storage pockets for the rolling elements, the number of which corresponds to the number of webs. [Background technology]
[0002] Cages of the above mentioned type are well known, for example from DE 10 2010009331 A1, which shows a cage for a cylindrical roller bearing, which consists of two side rings arranged axially spaced apart, which are connected to one another via a web.
[0003] Especially in applications where the bearings have to rotate at very high speeds, the aforementioned cages still have disadvantages in terms of good lubrication. Furthermore, there are limited options as to where oil can be injected into the inside of the bearing, i.e. in the area of the rolling elements. In part, this is only possible between the outer ring and the cage.
[0004] Moreover, in part, the manufacturing process of the cage is laborious and expensive, especially when the cage has to be machined from the ring components. Summary of the Invention [Problem to be solved by the invention]
[0005] The object of the present invention is therefore to provide a cage for rolling bearings, in particular cylindrical roller bearings, which is particularly suitable for use at high rotational speeds. Lubrication of the bearings may be promoted by the shape of the cage. It may then also be possible to have a wider range of options as to where oil is injected into the interior of the bearing. In addition, a convenient and inexpensive method for producing the cage is sought. [Means for solving the problem]
[0006] The solution according to the invention to this problem comprises that on the surface located radially inside of the cage, in the axial region of the two side rings, a first and a second slope are formed which extend at an angle to the axial direction towards the side ring and / or the web, the radius of the surfaces of the slopes decreasing towards the axial center of the cage, and that on the surface located radially outside of the cage, in the axial region of one of the two side rings, a third slope is formed which extends at an angle to the axial direction towards the side ring and / or the web.
[0007] The last mentioned specification regarding the first and second inclinations provides that these inclinations are directed in opposite directions in the region of the two side rings and decrease in diameter towards the bearing center.
[0008] The first inclination in the region of the first side ring preferably extends at an angle between 8° and 20°. The second inclination in the region of the second side ring preferably extends at an angle between 35° and 55°. The first side ring then preferably has a smaller radial extension than the second side ring.
[0009] The inclination preferably has an axial extension which is between 10% and 20%, in particular between 12% and 16%, of the width of the cage.
[0010] The cage is particularly preferably formed as an injection-molded part and in that case preferably consists of polyetheretherketone (PEEK).
[0011] Furthermore, the surface located radially outward of the cage is provided with a further fourth inclination in the axial region of one of the two side rings, which extends towards the side ring and / or the web at an angle to the axial direction.
[0012] All the above mentioned inclinations are preferably formed as flats on the side rings, more particularly on the webs, which extend at an angle to the axial direction of the cage in radial cross section.
[0013] The third and fourth slopes are preferably arranged in the same direction on the side ring and / or web, in contrast to the first and second slopes.
[0014] As previously mentioned, the shaping contemplates that the first side ring has a smaller radial extension than the second side ring.
[0015] The cage is preferably a component part of a cylindrical roller bearing.
[0016] The proposed cage is suitable in a particularly advantageous manner for cylindrical roller bearings which rotate at very high speeds in operation. A particularly preferred application is spindle bearings in which a cylindrical roller bearing equipped with the above-mentioned cage is used.
[0017] In that case, an oil lubrication device is preferably provided in the region of the rolling elements to maintain optimal operating conditions.
[0018] A cylindrical roller bearing provided with the above-described cage can operate at high rotational speeds while ensuring high precision and robustness.
[0019] The cage, preferably when manufactured by injection molding, as contemplated, can be rapidly and cost-effectively manufactured. The above-mentioned inclinations expedite the manufacturing process.
[0020] As already mentioned above, up to now, cages of the above kind are often manufactured from ring-shaped blanks made of PEEK by machining (turning and milling). This machining process requires high cycle times and is therefore expensive. Injection molding eliminates these disadvantages, in which case the provided inclination contributes in particular to an advantageous release of the cage from the injection mold.
[0021] With the proposed concept, rotation speeds can be increased by up to 20% compared to previously known solutions.
[0022] Furthermore, in an advantageous manner, more freedom can be made available when applying the lubricant. Whereas previously it was often possible to apply the lubricant only between the inner ring and the cage or only between the outer ring and the cage, now, thanks to the embodiment according to the invention, it is possible to apply the lubricant not only in the area of the outer ring but also in the area of the inner ring by means of the above-mentioned tilt. In that case, tilted lubrication is also possible, in particular at the inner ring. The tilt is used as a reflecting or sliding surface and makes it possible to supply the lubricant (oil) to the inside of the bearing, i.e. up to the rolling elements.
[0023] The cycle time for lubrication changes accordingly compared to the initially mentioned solution. In particular, tilted lubrication is possible if the axial travel path is relatively large. The tilt provided according to the invention thereby ensures a higher degree of freedom when dosing with lubricant (oil).
[0024] Preferred embodiments of a rolling bearing cage formed according to the present invention will now be described in detail with reference to the accompanying drawings. [Brief description of the drawings]
[0025] [Figure 1] 1 is a radial cross-sectional view of a cylindrical roller bearing including a cage formed according to the present invention; [Diagram 2] 2 is a radial section through the cage according to FIG. 1, showing a cross section in the region of the storage pocket; [Diagram 3] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] In Fig. 1 a cylindrical roller bearing 11 is shown in radial section with an inner ring 12 and an outer ring 13, between which cylindrical rollers 6 are arranged. The cylindrical rollers 6 are guided by a cage 1. The cage 1 has a special embodiment, as can be seen in the further Figs. 2 and 3.
[0027] In a known manner, the cage 1 has a first side ring 2 and a second side ring 3 arranged spaced apart from one another in the axial direction a. The connection between the two side rings 2 and 3 is achieved by webs 4. The side rings 2 and 3 as well as the two adjacent webs 4 then define storage pockets 5 for cylindrical rollers 6.
[0028] As can be further seen from the figure, the surface located radially inside the cage 1, more particularly in the axial region of the two side rings 2 or 3, is provided with inclines, more particularly a first incline 7 and a second incline 8, on the side rings 2, 3 or on the web 4. The first incline 7 is then arranged on the first side ring 2 and extends over the entire circumference of the side ring 2. The second inclines 8 are respectively arranged on the webs 4. The first incline 7 and the second incline 8 are then oriented opposite to one another, i.e. the surface radius of the respective incline decreases towards the axial center M of the cage 1.
[0029] 2, the radial extension (radial direction r) of the first side ring 2 is then smaller than the radial extension of the second side ring 3, which, in combination with the above-mentioned first and second inclinations 7 and 8, allows an advantageous application of lubricating oil in the region of the storage pockets 5.
[0030] In the embodiment, the angle α of the first slope 7 is about 13°. The angle β of the second slope 8 is about 45°.
[0031] The extensions of the first inclination 7 and the second inclination 8 in the axial direction a are approximately 12% to 15% of the width B of the cage 1 in this embodiment.
[0032] As can be further seen, further inclinations, namely the third inclination 9 and the fourth inclination 10, are also arranged in the region located radially outward of the side rings 2, 3 or the webs 4. The third inclination 9 then preferably extends at an angle γ of 15° to 25° to the axial direction a. The fourth inclination 10, on the other hand, preferably extends at an angle δ of 35° to 55° to the axial direction a. As is also evident from FIG. 2, the first inclination 7 and the third inclination 9 are oriented in such a way that, in a radial cross-section of the cage, the axial end region of the side ring 2, as shown in FIG. 2, is formed pointed, in particular arrow-shaped.
[0033] The cage described above is preferably used in a cylindrical roller bearing, the cylindrical roller bearing being designed for use at high speeds in a spindle.
[0034] The above-mentioned inclination arrangement allows for flexible application of lubricant to the interior of the bearing, i.e. to the receiving pockets 5 or to the area of the rolling elements 6 . [Explanation of symbols]
[0035] 1. Rolling bearing cage (cylindrical roller bearing cage) 2. First Side Ring 3 Second Side Ring 4. Web 5 Storage Pockets 6 Rolling elements (cylindrical rollers) 7 First Slope 8 Second Slope 9. The Third Slope 10 Fourth Slope 11 Rolling bearings (cylindrical roller bearings) 12 Inner Ring 13 Outer Ring a Axial direction r Radial direction M Axial center of cage B Cage width α angle of first inclination 7 β Angle of the second inclination 8 γ Third tilt angle δ Fourth tilt angle
Claims
1. A rolling bearing cage (1) comprising a first side ring (2) and a second side ring (3), the two side rings (2, 3) being arranged spaced apart from each other in an axial direction (a), and a number of webs (4) extending between the two side rings (2, 3) form a number of storage pockets (5) for rolling elements (6) corresponding to the number of the webs (4), 1. A rolling bearing cage (1), characterized in that a surface located radially on the inside of the cage (1) is formed in the axial region of the two side rings (2, 3) with a first slope (7) and a second slope (8) which extend towards the side rings (2, 3) and / or the web (4) at angles (α, β) to the axial direction (a), the radius (r) of the surfaces of the slopes (7, 8) decreasing towards the axial center (M) of the cage (1), and a surface located radially on the outside of the cage (1) is formed in the axial region of one of the two side rings (2, 3) with a third slope (9) which extends towards the side rings (2, 3) and / or the web (4) at an angle (γ) to the axial direction (a).
2. 2. The cage according to claim 1, characterized in that the first inclination (7) extends at an angle (α) of 8° to 20° in the region of the first side ring (2).
3. 3. The cage according to claim 1 or 2, characterized in that the second inclination (8) extends at an angle (β) of 35° to 55° in the region of the second side ring (3).
4. A cage according to any one of claims 1 to 3, characterized in that the inclinations (7, 8) have an extension in the axial direction (a), the extension being 10% to 20%, preferably 12% to 16%, of the width (B) of the cage (1).
5. 5. The cage according to claim 1, wherein the cage (1) is formed as an injection molded part.
6. 6. The cage according to claim 1, wherein the cage (1) is made of polyetheretherketone (PEEK).
7. 7. The cage according to claim 1, characterized in that the surface located radially outward of the cage (1) is formed with a further fourth inclination (10) in the axial region of one of the two side rings (2, 3), which extends towards the side rings (2, 3) and / or towards the web (4) at an angle (δ) to the axial direction (a).
8. 8. The cage according to claim 7, characterized in that the third slope (9) and the fourth slope (10) are arranged in the same direction on the side rings (2, 3) and / or on the webs (4).
9. 9. A cage according to any one of the preceding claims, characterized in that the first side ring (2) has a smaller radial extension than the second side ring (3).
10. 10. The cage according to any one of the preceding claims, characterized in that the cage (1) is a cylindrical roller bearing cage.