An equal load multi-ball bearing seat and a design method thereof

Abstract

The application discloses a uniformly-loaded multi-ball bearing seat and a design method thereof, relates to the technical field of multi-ball bearing seats, and the multi-ball bearing seat comprises an upper thrust plate, a lower thrust plate, a plurality of steel balls arranged between the upper thrust plate and the lower thrust plate, and a retainer assembly for limiting the steel balls, the plurality of steel balls have the same diameter, and the design method comprises the following steps: establishing a multi-ball bearing seat finite element model in which bearing surfaces of the upper thrust plate, the lower thrust plate and the steel balls are all planes, applying a design load to the finite element model, and obtaining the deformation amount of the steel balls at different radial positions. Through compensation of the loaded deformation of the steel balls at different radial positions, the load distribution state among the plurality of steel balls is improved, the contact stress of the steel balls at different radial positions tends to be balanced, local stress concentration is reduced, and the bearing performance and service life of the multi-ball bearing seat are improved.

Description

Technical Field

[0001] This invention relates to the field of multi-ball bearing housing technology, specifically to a load-balanced multi-ball bearing housing and its design method. Background Technology

[0002] Chinese patent CN107211580B discloses a multi-ball bearing housing, which consists of a housing, top cover, pressure block, retaining ring, upper pressure plate, lower pressure plate, rolling elements, locating pins, locating bolts, fastening pressure block, bolts, and nuts. The key components of the multi-ball bearing housing are the upper thrust plate (also known as the upper pressure plate), the lower thrust plate (also known as the lower pressure plate), the steel balls (as rolling elements), and the cage assembly. During operation, axial load is transmitted to each steel ball via the thrust plate, and then to the other thrust plate via the steel balls.

[0003] In existing multi-ball bearing housings, the bearing surfaces of the upper and lower thrust plates that contact the steel balls typically have a planar structure. When subjected to large axial loads, the load conditions of the steel balls at different radial positions vary due to factors such as thrust plate deformation. This can easily lead to a situation where the steel balls near the center bear a larger load, while the steel balls at the outer edges bear a smaller load, resulting in an uneven distribution of the load among the steel balls.

[0004] The aforementioned uneven load distribution can cause significant contact stress in the contact area between some steel balls and their corresponding thrust plates, easily leading to localized stress peaks. This exacerbates fatigue damage in the contact area between the steel balls and the thrust plates, and affects the load-bearing performance and service life of the multi-ball bearing housing. Therefore, improving the load distribution between steel balls at different radial positions and reducing localized contact stress are problems that need to be addressed in the design of multi-ball bearing housings. Summary of the Invention

[0005] The purpose of this invention is to propose a load-balanced multi-ball bearing housing and its design method. By compensating for the load deformation of steel balls at different radial positions, the load distribution among multiple steel balls is improved, the contact stress of steel balls at different radial positions tends to be balanced, local stress concentration is reduced, and the load-bearing performance and service life of the multi-ball bearing housing are improved.

[0006] The technical solution adopted in this invention is: a design method for a multi-ball bearing housing with equal load, wherein the multi-ball bearing housing includes an upper thrust plate, a lower thrust plate, a plurality of steel balls disposed between the upper thrust plate and the lower thrust plate, and a cage assembly for limiting the position of the steel balls, wherein the plurality of steel balls have the same diameter, and the design method includes the following steps: A finite element model of a multi-ball bearing seat is established, in which the bearing surfaces of the upper thrust plate and the lower thrust plate that are in contact with the steel ball are both planar. A design load is applied to the finite element model to obtain the deformation of the steel ball at different radial positions. The constant coefficients of the micro-concave surface are determined based on the deformation difference of the steel balls at different radial positions and the deformation compensation coefficient, and the surface profile of the micro-concave surface is determined based on the constant coefficients. The bearing surface of one of the upper and lower thrust plates that contacts the steel ball is set as the micro-concave surface, while the bearing surface of the other thrust plate that contacts the steel ball remains flat; wherein, the micro-concave surface is centered on the axis of the thrust plate that forms the micro-concave surface, and its central region near the axis is concave relative to the peripheral region toward the side away from the steel ball. A finite element model with the micro-concave surface is established. A load is applied to the finite element model to obtain the contact stress of the steel balls at different radial positions. The constant coefficient is adjusted according to the distribution of the contact stress so that the contact stress of the steel balls at different radial positions tends to be balanced.

[0007] As a preferred embodiment, the deformation difference is the difference between the maximum deformation of the steel ball at the middle position and the minimum deformation of the steel ball at the outer position.

[0008] As a preferred embodiment, the micro-concave surface, centered on the axis of the thrust plate forming the micro-concave surface, has its profile extending radially outward from the axis satisfying the following curve equation:

[0009] In the formula, This represents the radial distance of a point on the curved surface profile from the axis. This represents the axial coordinate corresponding to that point; These are constant coefficients; The maximum radial distance from the center of the plurality of steel balls to the axis is given. ; This is a tiny offset.

[0010] As a preferred option, the deformation difference and the deformation compensation coefficient are determined. time value, and will and corresponding Substituting the value into the curve equation, the constant coefficient is obtained. .

[0011] As a preferred approach, the determined constant coefficients are substituted into the curve equation, and the coordinate points on the surface profile are obtained by changing the value of x. Then, a three-dimensional coordinate point set of the micro-concave surface is generated based on the coordinate points.

[0012] As a preferred approach, the contact stress of the steel balls at different radial positions is obtained through finite element analysis, and the constant coefficient is adjusted accordingly. The contact stress difference between steel balls at different radial positions is not greater than the preset value until the stress difference is not greater than the preset value.

[0013] A load-balanced multi-ball bearing housing includes an upper thrust plate, a lower thrust plate, a plurality of equal-diameter steel balls disposed between the upper and lower thrust plates, and a cage assembly for limiting the position of the steel balls. The surface profile of the micro-concave surface of the load-balanced multi-ball bearing housing is determined using the aforementioned design method. The bearing surface of one of the upper and lower thrust plates that contacts the steel balls is a micro-concave surface, while the bearing surface of the other thrust plate that contacts the steel balls is a plane. The micro-concave surface is centered on the axis of the thrust plate that forms the micro-concave surface, and its central region near the axis is concave towards the side away from the steel balls relative to the peripheral region.

[0014] As a preferred embodiment, the thrust plate forming the micro-concave surface adopts a circular arc transition on the radially outer side of the bearing area where the plurality of steel balls are located.

[0015] As a preferred embodiment, the thrust plate forming the micro-concave surface is provided with a damping material coating.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention provides targeted compensation based on the deformation differences of steel balls at different radial positions under load, which can improve the situation where the central steel ball is subjected to a larger load and the outer steel ball is subjected to a smaller load, so that the axial load is more evenly distributed to multiple steel balls, thereby improving the load-sharing performance of the multi-ball bearing housing.

[0017] 2. This invention obtains the deformation of steel balls at different radial positions through finite element analysis, and determines the surface profile of the micro-concave surface accordingly, so that the surface shape is adapted to the actual load deformation state of the multi-ball bearing seat. Compared with empirically setting the bearing surface shape, it can improve the pertinence and rationality of the surface compensation design.

[0018] 3. By adjusting the constant coefficient of the micro-concave curved surface and using the contact stress distribution of steel balls at different radial positions as the optimization basis, this invention can reduce the difference in contact stress between steel balls and reduce the peak value of local contact stress, thereby reducing fatigue damage in the contact area between the steel balls and the thrust plate.

[0019] 4. This invention achieves load compensation for steel balls at different radial positions while maintaining multiple steel balls of equal diameter. It eliminates the need to adjust the load by changing the diameter of steel balls at different positions, which helps maintain the consistency of steel ball specifications and improves the load-bearing stability and service life of multi-ball bearing housings under large axial loads. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the evenly loaded multi-ball bearing housing in this invention; Figure 2 This is an axial cross-sectional view of the upper thrust plate in this invention; Figure 3 This is a schematic diagram of the curved surface profile in this invention.

[0022] Reference numerals: 1. Upper thrust plate, 2. Steel ball, 3. Cage assembly, 4. Lower thrust plate, 5. Curved surface profile, 6. Arc. Detailed Implementation

[0023] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0024] It should be noted that, unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "a," "an," or "the," etc., used in the specification and claims of this patent application do not express a limitation on quantity, but rather indicate the presence of at least one; the terms "first," "second," and "third," as used herein, should not be considered as a limitation on the order of components, but are merely for distinguishing different components; the terms "comprising," "including," etc., indicate that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects having the same function.

[0025] To more clearly describe this load-sharing multi-ball bearing housing and its design method, in conjunction with the attached... Figure 1-3 Description of the embodiment: like Figure 1 As shown, the load-balanced multi-ball bearing housing includes an upper thrust plate 1, a lower thrust plate 4, a plurality of steel balls 2 disposed between the upper thrust plate 1 and the lower thrust plate 4, and a cage assembly 3 for limiting and guiding the steel balls 2. The plurality of steel balls 2 have the same diameter, and the cage assembly 3 separates the steel balls 2 from each other and limits and guides the steel balls 2.

[0026] Example 1

[0027] In this embodiment, the bearing surface of the upper thrust plate 1 in contact with the steel ball 2 is set as a slightly concave curved surface, and the bearing surface of the lower thrust plate 4 in contact with the steel ball 2 is a flat surface. The slightly concave curved surface covers at least a plurality of bearing areas where the steel balls 2 are located, and with the axis of the upper thrust plate 1 (hereinafter referred to as the axis) as the center, its central area near the axis is concave towards the side away from the steel ball 2 relative to the outer area.

[0028] like Figure 2 and Figure 3 As shown, any plane passing through the axis of the upper thrust plate 1 intersects with the micro-concave surface to form a curved surface profile 5. The curved surface profile 5 is symmetrical about the axis of the upper thrust plate 1. One side of the curved surface profile 5 extending radially outward from the axis is determined according to the above-mentioned curve equation, and the micro-concave surface is formed by rotating the curve on this side around the axis. By analyzing the deformation differences of the steel balls 2 at different radial positions under planar load conditions, the curve parameters of the curved surface profile 5 are determined, and the micro-concave surface of the upper thrust plate 1 is formed accordingly.

[0029] The specific design process is as follows.

[0030] Step 1: Establish an initial model and perform finite element analysis.

[0031] Based on the actual application requirements of the load-sharing multi-ball bearing housing, the basic structural parameters of the upper thrust plate 1, lower thrust plate 4, steel balls 2, and cage assembly 3 are determined, including the dimensions of the upper thrust plate 1 and lower thrust plate 4, the number of steel balls 2, the diameter of the steel balls 2, and the distribution range of the steel balls 2 on the thrust plates. Multiple steel balls 2 use the same diameter.

[0032] A three-dimensional model is created where the bearing surfaces of the upper thrust plate 1 and lower thrust plate 4 in contact with the steel ball 2 are both planar. The three-dimensional model is then imported into finite element analysis software to create a finite element model. Design loads are applied to the finite element model, and the lower thrust plate 4 is constrained. Static analysis is then performed to obtain the deformation of each steel ball 2 under the load.

[0033] Due to the uneven load distribution in planar load-bearing structures, the load on the middle steel ball 2 is typically larger, while the load on the outer steel balls 2 is smaller. The maximum deformation of the middle steel ball 2 is extracted from the finite element analysis results. and the minimum deformation of the outer steel ball 2 And calculate the difference in deformation between the two. :

[0034] in, This indicates the maximum deformation of steel ball 2 at the middle position; This represents the minimum deformation of the outer steel ball 2; This indicates the difference in deformation between the middle steel ball 2 and the outer steel ball 2.

[0035] The aforementioned deformation of steel ball 2 is the compressive deformation of steel ball 2 under load, that is, the reduction in diameter of steel ball 2 along the load direction. The difference in deformation can reflect the load difference between the middle region and the outer region under planar load conditions.

[0036] Step 2: Determine the curve parameters of the micro-concave surface based on the deformation difference.

[0037] Using the section passing through the axis of the upper thrust plate 1 as the design section of the curved surface profile 5, the initial curve equation of the micro-concave surface is established for the side of the curved surface profile 5 extending radially outward from the axis:

[0038] In the formula, The radial distance from a point on the curved surface profile 5 to the axis of the upper thrust plate 1 is denoted as . This is the axial coordinate corresponding to that point. These are constant coefficients. Let be the maximum radial distance from the center of the multiple steel balls 2 to the axis. It is a positive number.

[0039] Based on the deformation difference obtained in step one And combined with deformation compensation coefficient Determine the y value corresponding to x = r:

[0040] In the formula, This represents the y value corresponding to x = r; This represents the deformation compensation coefficient. It is used to adjust the degree of compensation for the micro-concave surface based on the deformation difference obtained from finite element analysis. Its value is generally 1 to 2, and in this embodiment it is 1.5. Indicates the difference in deformation. .

[0041] In practical applications, the initial curve equation described above needs to cover the radial range of 0 ≤ x ≤ r. However, the curve has a singularity at x = r, making it impossible to obtain a valid y-value using this equation, nor can the constant coefficients applicable to practical surface design be derived from the compensation amount at x = r. Therefore, while maintaining the original curve's variation law, the radial parameters in the curve equation are modified by introducing a small offset. And order:

[0042] because Greater than This is to avoid a singularity at x = r.

[0043] The corrected surface profile 5 satisfies:

[0044] That is:

[0045] Therefore, the constant coefficients can be determined. :

[0046] When x = r (Right now Substituting the values, we get:

[0047] In this embodiment, the minute offset 1mm is acceptable. It can also be selected according to the specific dimensions of the multi-ball bearing housing. Its function is to avoid the logarithmic function singularity at x=r, while keeping the change law of the modified curve basically consistent with that of the initial curve.

[0048] After determining the constant coefficient k, the value of x is changed within the range of 0 ≤ x ≤ r, and the corresponding y value is calculated according to the modified curve equation, thereby obtaining a series of coordinate points on the surface profile 5. A three-dimensional coordinate point set of the micro-concave surface is formed based on the coordinates of the surface profile 5, and the micro-concave surface model of the upper thrust plate 1 is established accordingly.

[0049] Since the central region of the curved profile 5 is recessed away from the outer region relative to the outer region, the central steel ball 2 receives corresponding geometric compensation compared to the original planar bearing surface, while the outer steel ball 2 participates in the bearing capacity to a corresponding degree, thereby improving the state in the planar structure where the central steel ball 2 is subjected to a larger load and the outer steel ball 2 is subjected to a smaller load.

[0050] Step 3: Machining the micro-concave surface.

[0051] The coordinate points of the surface profile 5 are calculated based on the corrected curve equation, and a three-dimensional coordinate point set of the micro-concave surface of the upper thrust plate 1 is generated based on these coordinate points.

[0052] When machining the micro-concave surface of the upper thrust plate 1 using a CNC grinding machine, the grinding wheel is dressed according to the coordinate point, and the machining trajectory is programmed based on the surface coordinates to ensure that the machined micro-concave surface corresponds to the designed surface contour 5. In this embodiment, the machining accuracy of the micro-concave surface is controlled within 0.002mm.

[0053] After processing, a coordinate measuring machine can be used to inspect the actual surface profile of the micro-concave surface, so that the profile error between the actual processed surface and the designed surface is controlled within ±0.002mm.

[0054] like Figure 2 As shown, an arc 6 is also provided on the radially outer side of the bearing area where the multiple steel balls 2 are located. Specifically, the portion of the upper thrust plate 1 located on the radially outer side of the bearing area where the multiple steel balls 2 are located uses an arc 6 for transition, so that the outer side of the slightly concave curved surface smoothly transitions with the rest of the surface of the upper thrust plate 1.

[0055] Step four: Perform finite element simulation optimization.

[0056] A finite element model of a multi-ball bearing housing with the aforementioned micro-concave surface is established, and the same loads and constraints as in step one are applied to obtain the contact stress of the steel balls 2 at different radial positions.

[0057] Compare the contact stress distribution of each steel ball 2. When the contact stress difference between steel balls 2 at different radial positions is greater than the preset value, adjust the constant coefficient k, and regenerate the surface profile 5 based on the adjusted constant coefficient k, establish a new finite element model and calculate again.

[0058] Through the aforementioned finite element analysis and adjustment of the constant coefficient k, the contact stress of the steel ball 2 at the middle position is gradually reduced, while the contact stress of the outer steel ball 2 is correspondingly increased, until the contact stress difference between steel balls 2 at different radial positions is no greater than a preset value. In this embodiment, an optimization target of no more than 10% contact stress difference between steel balls 2 can be used.

[0059] In one specific embodiment, the radius R of the upper thrust plate 1 is 415 mm, and the radius of the lower thrust plate 4 is... The diameter of the steel balls is 510mm, the number of equal-diameter steel balls 2 is 348, the diameter d of the steel balls 2 is 20mm, and the maximum radial distance r from the center of the multiple steel balls 2 to the axis of the thrust plate is 360mm.

[0060] Under a design load of F = 2000 kN, the initial finite element model with a planar bearing surface is analyzed to obtain the maximum deformation of the steel ball 2 at the middle position. The minimum deformation of the outer steel ball 2 is 0.15mm. Since it is 0.05mm, therefore:

[0061] Deformation compensation coefficient Take 1.5, a small offset. Taking 1 mm, the constant coefficient k is determined based on the above deformation difference and the corrected curve equation. In this embodiment, the final constant coefficient k is -0.029.

[0062] Substitute the determined constant coefficient k into the modified curve equation, obtain the coordinates of the surface profile 5 according to different x values, and form the micro-concave surface of the upper thrust plate 1.

[0063] The finite element model with the micro-concave surface was analyzed under the same 2000kN load condition. The results showed that the contact stress of the steel ball 2 at the middle position was reduced from about 1800MPa when using a planar bearing surface to about 1100MPa, while the contact stress of the outer steel ball 2 was increased from about 600MPa to about 1050MPa. The contact stress difference between the steel balls 2 at different radial positions could be controlled within 5%.

[0064] Therefore, by first analyzing the deformation differences of each steel ball 2 in the planar structure, the initial surface parameters of the micro-concave surface are determined based on the deformation difference, and then a small offset is used. Eliminating the logarithmic singularity of the curve and further adjusting the constant coefficient k through finite element analysis can make the load distribution among multiple equal-diameter steel balls 2 tend to be balanced, reducing the peak value of local contact stress.

[0065] Under impact load conditions, a damping material coating can be applied to the upper thrust plate 1, which forms a micro-concave curved surface, to further reduce the stress peak under impact load.

[0066] Example 2

[0067] This embodiment shares the same basic structure and design method as Embodiment 1, the difference being that a slightly concave curved surface is placed on the bearing surface where the lower thrust plate 4 contacts the steel ball 2, while the bearing surface where the upper thrust plate 1 contacts the steel ball 2 remains planar. The finite element analysis of the initial planar model, extraction of the deformation of the steel ball 2, calculation of the deformation difference, establishment of the initial curve equation, and small offset are also discussed. The introduction of the curve equation, the correction of the curve equation, and the finite element optimization process of the constant coefficient k can all be referred to in Example 1, and will not be repeated here.

[0068] In this embodiment, any plane passing through the axis of the lower thrust plate 4 intersects with the micro-concave surface to form a curved surface profile 5. The curved surface profile 5 is symmetrical about the axis of the lower thrust plate 4. The side of the curved surface profile 5 extending radially outward from the axis is determined according to the above-mentioned curve equation, and the curve on this side rotates around the axis to form a micro-concave surface.

[0069] The side of the curved profile 5 extending radially outward from the axis of the lower thrust plate 4 satisfies the following:

[0070] Where x is the radial distance from a point on the curved profile 5 to the axis of the lower thrust plate 4, y is the axial coordinate of the corresponding point, k is a constant coefficient, and r is the maximum radial distance from the center of the multiple steel balls 2 to the axis of the lower thrust plate 4. , This is a tiny offset.

[0071] By adjusting the constant coefficient k through finite element analysis, the contact stress difference of the steel balls 2 at different radial positions is ensured to be no greater than a preset value. The portion of the lower thrust plate 4 located radially outside the bearing area where multiple steel balls 2 are located can also be transitioned using an arc 6. Under impact load conditions, a damping material coating can also be applied to the lower thrust plate 4, which forms a slightly concave curved surface.

[0072] It should be noted that although the present invention has been described through the above embodiments, the present invention may have many other embodiments. Without departing from the spirit and scope of the present invention, those skilled in the art can obviously make various corresponding changes and modifications to the present invention, but all such changes and modifications should fall within the scope of protection of the appended claims and their equivalents.

Claims

1. A design method for a load-balanced multi-ball bearing housing, the multi-ball bearing housing comprising an upper thrust plate, a lower thrust plate, a plurality of steel balls disposed between the upper thrust plate and the lower thrust plate, and a cage assembly for limiting the position of the steel balls, wherein the plurality of steel balls have the same diameter, characterized in that, The design method includes the following steps: A finite element model of a multi-ball bearing seat is established, in which the bearing surfaces of the upper thrust plate and the lower thrust plate that are in contact with the steel ball are both planar. A design load is applied to the finite element model to obtain the deformation of the steel ball at different radial positions. The constant coefficients of the micro-concave surface are determined based on the deformation difference of the steel balls at different radial positions and the deformation compensation coefficient, and the surface profile of the micro-concave surface is determined based on the constant coefficients. The bearing surface of one of the upper and lower thrust plates that contacts the steel ball is set as the micro-concave surface, while the bearing surface of the other thrust plate that contacts the steel ball remains flat; wherein, the micro-concave surface is centered on the axis of the thrust plate that forms the micro-concave surface, and its central region near the axis is concave relative to the peripheral region toward the side away from the steel ball. A finite element model with the micro-concave surface is established. A load is applied to the finite element model to obtain the contact stress of the steel balls at different radial positions. The constant coefficient is adjusted according to the distribution of the contact stress so that the contact stress of the steel balls at different radial positions tends to be balanced.

2. The design method according to claim 1, characterized in that: The deformation difference is the difference between the maximum deformation of the steel ball in the middle position and the minimum deformation of the steel ball on the outer side.

3. The design method according to claim 1, characterized in that, With the axis of the thrust plate forming the micro-concave surface as the center, the side of the surface profile extending radially outward from the axis satisfies the following curve equation: In the formula, This represents the radial distance of a point on the curved surface profile from the axis. This represents the axial coordinate corresponding to that point; These are constant coefficients; The maximum radial distance from the center of the plurality of steel balls to the axis is given. ; This is a tiny offset.

4. The design method according to claim 3, characterized in that, Determined based on the deformation difference and deformation compensation coefficient time value, and will and corresponding Substituting the value into the curve equation, the constant coefficient is obtained. .

5. The design method according to claim 4, characterized in that: Substitute the determined constant coefficients into the curve equation, obtain the coordinate points on the surface profile by changing the value of x, and generate the three-dimensional coordinate point set of the micro-concave surface based on the coordinate points.

6. The design method according to claim 3, characterized in that: The contact stress of the steel ball at different radial positions was obtained through finite element analysis, and the constant coefficient was adjusted accordingly. The contact stress difference between steel balls at different radial positions is not greater than the preset value until the stress difference is not greater than the preset value.

7. A load-balanced multi-ball bearing housing, comprising an upper thrust plate, a lower thrust plate, a plurality of equal-diameter steel balls disposed between the upper thrust plate and the lower thrust plate, and a cage assembly for limiting the position of the steel balls, characterized in that, The surface profile of the micro-concave surface of the load-sharing multi-ball bearing housing is determined by the design method described in any one of claims 1-6. The bearing surface of one of the upper and lower thrust plates that contacts the steel ball is a micro-concave surface, and the bearing surface of the other thrust plate that contacts the steel ball is a plane. The micro-concave surface is centered on the axis of the thrust plate that forms the micro-concave surface, and its central region near the axis is concave towards the side away from the steel ball relative to the peripheral region.

8. The load-balanced multi-ball bearing housing according to claim 7, characterized in that: The thrust plate forming the micro-concave surface adopts a circular arc transition on the radially outer side of the bearing area where the multiple steel balls are located.

9. The load-balanced multi-ball bearing housing according to claim 7, characterized in that: The thrust plate forming the micro-concave surface is coated with a damping material.

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