Method for mounting a rolling bearing

Abstract

This invention relates to the installation of a rolling bearing (1) by eccentrically arranging two bearing rings (2, 3) between each other, filling the space between the eccentrically positioned bearing rings (2, 3) with a rolling element (4), and deforming at least one of the bearing rings (2, 3). Here, the bearing rings (2, 3) are plastically deformed, thereby changing their roundness.

Description

Technical Field

[0001] This invention relates to a method for installing rolling bearings, which is configured as an eccentric installation method. Background Technology

[0002] For example, this eccentric mounting method is known from DE 10 2014 223 708 A1. Typically, in an eccentric mounting method, the inner bearing ring is positioned eccentrically relative to the outer bearing ring to allow for the filling of rolling elements, such as balls. To increase the number of balls that can be filled, one of the bearing rings can be elastically deformed. In the case of DE 10 2014 223 708 A1, the deformation of both bearing rings is proposed.

[0003] The method for installing rolling bearings described in GB 190811353 A proposes that the outer ring of the bearing be positioned in an approximately triangular shape during installation.

[0004] An eccentric mounting method is also described in DE 2 137 979 A. In this case, the balls are also filled into the sickle-shaped space between the eccentrically positioned bearing rings. During the subsequent centering process of the bearing rings, small elastic deformation occurs in either the outer or inner ring.

[0005] In principle, it is also feasible to fill the space between the two bearing rings with rolling elements through a filling port located in the bearing rings. In the case of bearing devices known from EP 2 143 835 B1, the net width of the rolling element filling recess in the bearing ring is slightly smaller than the diameter of the rolling element. Filling the rolling elements should be possible only through the elastic deformation of the bearing rings. Summary of the Invention

[0006] The object of this invention is to improve the eccentric mounting of rolling bearings compared to existing technologies, so that, given bearing size and high process reliability—even under mass production conditions—the largest possible number and size of rolling elements can be rationally mounted.

[0007] According to the invention, this objective is achieved by a method for installing a rolling bearing. The rolling bearing to be installed is, in particular, a deep groove ball bearing. The rolling bearing comprises two bearing rings, which are eccentrically positioned relative to each other during installation. To enable filling of the rolling elements, at least one bearing ring is elastically deformed in a manner known in principle.

[0008] According to the present invention, the bearing ring is plastically deformed during installation, thereby changing its roundness. Roundness indicates the extent to which the circumferential line of the workpiece, i.e., the annular line located on the outer circumferential surface of the bearing ring or in the bottom of the raceway, deviates from an ideal reference circle, the circumferential line of the workpiece lying in a plane normal to the central axis of the bearing ring. For a general understanding of the concept of "roundness," refer to the standard DIN EN ISO 1101 "Geometrical Specifications for Products."

[0009] Unlike typical eccentric mounting methods, at least one of the bearing rings, typically the outer ring, undergoes not only elastic deformation during bearing installation but also deformation extending into the plastic range. This means that the bearing ring, after deformation without external force, has a different shape than it would have before deformation without any external force. Theoretically, in addition to the deformation of the outer bearing ring, the inner bearing ring can also be deformed during installation. In any case, a near-ideal circular shape can be achieved through the deformation of the bearing ring during the filling of rolling elements—based on the non-circular shape present before filling.

[0010] In contrast, the mounting method can also be configured such that the plastic deformation of the bearing ring during the filling of the rolling elements, based on the at least near-ideal circular shape existing before filling, is transformed into a near-less-ideal non-circular shape. This is considered in the case that, although deviating from the ideal circular shape, the roundness of the bearing ring remains within a defined tolerance. The advantage of plastic deformation during the filling of the rolling elements in this case lies in the significantly increased deformation path during mounting compared to conventional methods.

[0011] By eccentrically mounting the bearing ring with an approximate ideal circular shape, according to the first feasible method embodiment, a non-circular, typically elliptical shape existing before the rolling elements are filled is intentionally produced through plastic deformation of the bearing ring, wherein deformation occurs after heat treatment of the bearing ring. Through plastic deformation performed prior to mounting, the ratio between the maximum and minimum diameters of the bearing ring, respectively measured on the outer circumference, is preferably set to at least 1.000012 and a maximum of 1.0004. This diameter ratio can also relate to the raceway of the bearing ring, measured at the raceway center.

[0012] According to an alternative method implementation, the non-circular state of the bearing ring, as determined by manufacturing techniques, is determined before the rolling elements are filled. This means that the manufacturing of the bearing ring is intentionally designed to avoid deviations from the desired circular shape. Instead, it is assumed that such deviations are unavoidable due to manufacturing conditions. After determining the deviation of the bearing ring from the desired circle by measurement techniques, markings indicating the location and extent of the deviation can be applied to the bearing ring.

[0013] Within a batch of heat-treated bearing rings, the heat treatment may lead to different results in the bearing rings. Therefore, it is feasible for each bearing ring to have more austenite than others. Each bearing ring has a more or less clearly indicated deviation from the ideal circular shape. If bearing rings with different austenite content are subjected to stresses that would lead to plastic deformation before installation, then this stress, achieved through a controlled path, can lead to different results: ideally heat-treated bearing rings with virtually no austenite do not undergo residual deformation under controlled mechanical stress, while such plastic deformation occurs completely at bearing rings with higher austenite content. In the last case, plastic deformation is at least partially compensated for during installation. In the first case, i.e., with less austenite content, especially when austenite is lacking, stronger elastic deformation is always feasible. In general, the method according to the invention is designed to allow for deviations in the heat treatment of bearing rings and to achieve high installation deformation despite the resulting differences between the bearing rings. This also applies in cases where no improvement in the circularity of the bearing rings is achieved during installation.

[0014] Regardless of whether a deviation from the ideal circle has been intentionally induced or whether this deviation is an unintended consequence of manufacturing conditions, the subsequent conversion of the bearing ring into a shape approaching the ideal circle for bearing mounting is carried out in a controlled manner. Here, the force vector pointing towards the bearing ring, causing plastic deformation, forms an angle of 90° ± 20°, particularly 90° ± 10°, with respect to the minor axis of the previously given non-circular, at least elliptical shape of the bearing ring.

[0015] The rolling elements filling the space between the bearing rings are preferably balls. These balls can be made of metallic or ceramic materials. Generally, rolling bearings are preferably configured as deep groove ball bearings. After the balls are evenly distributed between the bearing rings, a rolling bearing cage can be installed, for example, in the form of a plate-riveted cage. Optionally, the rolling bearing is sealed on one or both sides. Attached Figure Description

[0016] Two embodiments of the present invention are described in detail below with reference to the accompanying drawings. The drawings show:

[0017] Figure 1 A schematic, ultra-high-resolution view shows a bearing ring, which is designed to be used as a component in a rolling bearing, and is capable of elastic deformation.

[0018] Figures 2 to 4 Shown in use according to Figure 1 The installation steps for manufacturing rolling bearings in the case of bearing rings.

[0019] Figure 5This shows a bearing ring deformed compared to its geometrically ideal shape.

[0020] Figure 6 The flowchart illustrates the mass production of rolling bearing rings when using bearing rings with non-precise, uniform shapes.

[0021] Unless otherwise stated, the following explanation involves not only... Figures 1 to 5 The embodiments, and also relating to, according to Figure 6 Examples of embodiments. Parts that correspond to each other or serve the same function in principle are denoted by the same reference numerals throughout the figures. The corresponding terms apply to characterizing geometric parameters or other parameters. Detailed Implementation

[0022] The rolling bearing, generally indicated by reference numeral 1 in the attached drawing, namely a deep groove ball bearing, comprises an inner ring 2 and an outer ring 3 as bearing rings 2 and 3, with balls 4 as rolling elements rolling between the bearing rings. In an eccentric mounting method, the balls 4 are positioned in their predetermined positions between the bearing rings 2 and 3. The inner ring 2, like the outer ring 3, is configured as a single-piece bearing ring without a filler. Within the mounted rolling bearing 1, the balls 4 roll in the grooved raceways of the bearing rings 2 and 3 in a known manner, such that not only radial forces but also, secondarily, axial forces can be transmitted between the bearing rings 2 and 3.

[0023] According to Figures 1 to 5 In one embodiment, the outer ring 3 is first placed into a non-circular elliptical shape by a controlled pressure applied along a path, the shape being in Figure 1 It is exaggeratedly shown in the text. Figure 1 The deformation path S marked in the middle D1 The dimensions are determined in such a way that they cause plastic deformation of the bearing ring 3. This means that the bearing ring 3 does not return to its initial circular shape after it is no longer subjected to pressure. Instead, it retains a significant elliptical deformation.

[0024] exist Figure 2 The diagram shows the initial installation of the rolling bearing 1 using an eccentric mounting method. Bearing rings 2 and 3 are eccentrically positioned to accommodate the filling of the rolling elements 4. Subsequently, as in... Figure 3 As shown, the bearing ring 3 undergoes plastic back deformation, wherein, due to the elasticity of the bearing ring 3, an ellipse is first drawn through the bearing ring 3, the major axis of which is orthogonal to the point where, according to... Figure 1 The orientation of the major axis a is given in the state.

[0025] The deformation path that appears on the bearing ring 3 during the filling of the rolling element 4 is represented by S. D2 This indicates that, compared to the usual eccentric installation method, the deformation path S... D2This results in a particularly large elliptical deformation of the bearing ring 3, which enables it to be filled with a particularly large number of rolling elements 4, i.e., balls, and / or particularly large-sized rolling elements 4.

[0026] exist Figure 4 In the roughly illustrated installation steps, the rolling elements 4 are evenly distributed around the circumference of the bearing rings 2 and 3. The rolling bearing cage can then be installed in a manner known per se, such as a riveted cage made of sheet metal. Similarly, a seal that acts between the bearing rings 2 and 3 can be installed.

[0027] exist Figure 5 The shape of the outer ring 3 after its first plastic deformation is compared with the geometrically ideal shape. (According to...) Figure 1 The settings, in Figure 5 The outer ring 3 is shown rotated 90°. Figure 5 China and foreign circles K a The outer circumferential surface of bearing ring 3, indicated by 5, surrounds the bearing ring 3. The inner circumferential surface of bearing ring 3, indicated by 6, is similarly connected to the inner circle K. i Tangent. Standard circle K n Located in outer circle K a and inner circle K i Between these, the standard circle represents an ideal circle, which is equidistant from the outer ring circumferential surface 5 and the inner ring circumferential surface 6 in the initial undeformed state of the bearing ring 3.

[0028] In standard circle K n radius and inner circle K i The difference between the radii is called the internal radius difference d. i In a similar manner, in the standard circle K... n radius and outer circle K a The difference between the radii is called the outer radius difference d. a Use d ges Indicates that on the outer circle K a and inner circle K i The total radius difference between them. After the outer ring 3 elastically deforms back, as in Figure 2 As shown, the radius difference d ges It also remains greater than zero. As the pressure F... D2 The resulting second plastic deformation approximates the radius difference d very well. ges Set it back to zero.

[0029] according to Figure 6 Implementation examples and according to Figures 1 to 5The difference in this embodiment is that the initial plastic deformation of the bearing ring 3 is eliminated. Instead, the mass-produced bearing rings 3 are made possible by the fact that they inherently possess a deviation from the ideal circular shape that can be measured using measurement techniques. Manufacturing equipment 7 can provide mass-produced bearing rings 3. A total of n produced bearing rings 3 are each precisely measured. The measurement results are... Figure 6 Denoted as ME1 to MEn. Each measurement result, ME1 to MEn, specifically includes K. a K i and d ges And a precise description of the position of the major semi-axis for the second-grade roundness. Thus, each measurement ME1 to MEn describes a bearing ring 3, as it is located in... Figure 5 Ideally, this is shown. The shape of bearing ring 3 is evaluated using Fourier analysis, especially fast Fourier analysis.

[0030] After obtaining the measurement results ME1 to MEn, the measured bearing ring 3, in the example n pieces, is determined according to the mentioned geometric features, especially according to the total radius difference d. ges The bearings are classified. Product groups P1 and P2 are the result of this classification, and each bearing 3 is assigned to a product group. The number of product groups is not theoretically limited. The "ideal shape" of a product group can also be defined according to production conditions. In the bearing rings 3 assigned to the product group, plastic deformation during installation can mean a deterioration in roundness, which never deviates from the defined tolerance range for the roundness of the manufactured rolling bearing 1.

[0031] As long as the bearing ring 3 produced by manufacturing equipment 7 has a shape that significantly deviates from the ideal circle and is suitable for further processing, then the shape of each bearing ring 3 is denoted by the major axis 'a' and the minor axis 'b'. Figure 1 An ellipse, in which deviations from the elliptical shape can actually exist. Markings are applied to determine the positions of the major axis a and minor axis b. Major axis a and minor axis b are the principal axes of the second-order roundness. In any case, based on... Figures 2 to 4 The steps described involve installing each rolling bearing 1 in a tiered manner, immediately following the bearing ring 3.

[0032] List of reference numerals

[0033] 1 Rolling bearing

[0034] 2 Inner Ring

[0035] 3 Outer Ring

[0036] 4 Rolling elements

[0037] 5. Outer ring circumference

[0038] 6. Inner ring circumference

[0039] 7. Production Equipment

[0040] a long axis

[0041] b Short axis

[0042] d a External radius difference

[0043] d i Internal radius difference

[0044] d ges Total radius difference

[0045] S D1 Deformation path

[0046] S D2 Deformation path

[0047] K a outer circle

[0048] K i Inner circle

[0049] K n Standard circle

[0050] ME1 to MEn Measurement Results

[0051] P1, P2 product groups

Claims

1. A method for mounting a rolling bearing (1), wherein two bearing rings (2, 3) are eccentrically positioned relative to each other, a rolling element (4) is filled between the eccentrically positioned bearing rings (2, 3), and at least one of the bearing rings (2, 3) is deformed. Its features are, The bearing rings (2, 3) are plastically deformed, thereby changing their roundness.

2. The method according to claim 1, characterized in that, The bearing rings (2, 3) are transformed from a near-ideal circular shape that existed before the filling to a less ideal non-circular shape through plastic deformation during the filling process.

3. The method according to claim 1, characterized in that, Through plastic deformation during the filling of the rolling element (4), the bearing ring (2, 3) approaches an ideal circular shape from a non-circular shape that existed before the filling.

4. The method according to claim 3, characterized in that, Before filling the rolling element (4), the bearing ring (2, 3) is plastically deformed to produce a non-circular state.

5. The method according to claim 4, characterized in that, By performing plastic deformation prior to filling the rolling element (4), the ratio between the maximum and minimum diameters of the bearing rings (2, 3) that can be measured on the outer circumference is set to at least 1.000012 and at most 1.0004.

6. The method according to claim 4 or 5, characterized in that, By performing plastic deformation before filling the rolling element (4), the ratio between the maximum and minimum raceway diameters of the bearing rings (2, 3) that can be measured at the raceway center is set to at least 1.000012 and at most 1.0004.

7. The method according to any one of claims 1 to 3, characterized in that, Before filling the rolling element (4), the non-circular state of the bearing ring (2, 3) given by the manufacturing technology is determined by measurement techniques.

8. The method according to claim 7, characterized in that, The bearing rings (2, 3) are transformed into a near-ideal circular shape through plastic deformation by applying pressure, wherein the corresponding deformation path S D2 It forms an angle of 90° ± 20° with the previously given non-circular short axis of the bearing ring (2, 3).

9. The method according to claim 1, characterized in that, Ball bearings (4) are filled between the bearing rings (2, 3) as rolling elements.

10. The method according to claim 9, characterized in that, After the balls (4) are evenly distributed between the bearing rings (2, 3), the rolling bearing cage is installed.

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