Hub bearing roller large end face and flange contact failure judgment method and device and storage medium

Abstract

The invention discloses a hub bearing roller large end face and flange contact failure judgment method and device and a storage medium, and belongs to the technical field of commercial vehicle hub bearing design, and the method comprises the following steps: obtaining a static balance equation of a roller and a static balance equation of a bearing; solving the static balance equation of the bearing, and substituting into the static balance equation of the roller to obtain the contact force between the large end surface of the roller and the flange; calculating the distance between the intersection point of the flange and the raceway generatrix and the intersection point of the large end face of the roller and the flange, and calculating the half-axis width of a contact ellipse and the relative sliding speed of the large end face of the roller and the flange; judging whether the contact is invalid or not for the first time according to the relationship among the distance, the half-axis width of the contact ellipse and the known oil gallery grinding undercut size; and calculating the product value of the maximum contact stress of the central point of the contact ellipse and the relative sliding speed to judge whether the contact is invalid for the second time. According to the method, the double-row tapered roller bearing flange contact analysis can be effectively carried out, and the judgment of the contact failure of the large end face and the flange is realized.

Description

Technical Field

[0001] The invention relates to a method, a device and a storage medium for judging failure of contact between a large end face of a hub bearing roller and a rib, and belongs to the technical field of commercial vehicle hub bearing design. Background Art

[0002] Commercial vehicle wheel hub bearings mostly use tapered roller bearings. Under heavy loads, sliding friction occurs at the contact point between the roller and the flange, which directly affects the contact stress and friction torque of the wheel hub bearing. Detailed analysis of the flange contact of tapered roller bearings has been conducted at home and abroad, and new products have been developed to meet the requirements of long life and low friction torque of roller bearings under heavy loads. However, current research mainly focuses on the flange contact analysis of single tapered roller bearings, and there is less research on the flange contact analysis of double-row tapered roller bearings, especially failure analysis. Therefore, there is an urgent need in the prior art for a method that can analyze the contact between the large end face and the flange of a double-row tapered roller bearing in many aspects and can determine the failure of the contact between the large end face and the flange. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a method, device and storage medium for judging the contact failure between the large end face of the roller of a hub bearing and the rib, which can effectively analyze the contact between the large end face and the rib of a double-row tapered roller bearing and realize the judgment of the contact failure between the large end face and the rib.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] In a first aspect, the present invention provides a method for judging failure of contact between a large end face of a hub bearing roller and a rib, comprising the following steps:

[0006] When the bearing is subjected to external load, the static balance equation of the roller is established with the roller as the analysis object, and the static balance equation of the bearing is established with the entire bearing as the analysis object;

[0007] Solve the static balance equation of the bearing to obtain the contact force between the roller and the outer raceway, and then substitute the contact force between the roller and the outer raceway into the static balance equation of the roller to obtain the contact force between the large end face of the roller and the rib;

[0008] According to the geometric relationship of the bearing, the intersection point between the flange and the raceway generatrix and the distance between the intersection point between the roller end face and the flange are calculated, and the semi-axis width of the contact ellipse and the relative sliding speed between the roller end face and the flange are calculated according to the Hertz contact theory and the geometric relationship of the bearing;

[0009] The first judgment of whether the contact fails is based on the relationship between the intersection of the rib and the raceway generatrix, the distance between the intersection of the roller large end face and the rib, the semi-axis width of the contact ellipse and the known oil groove overrun groove size.

[0010] According to the contact force between the large end face of the roller and the rib, the maximum contact stress at the center of the contact ellipse is calculated, and then the product of the maximum contact stress at the center of the contact ellipse and the relative sliding speed between the large end face of the roller and the rib is calculated. The product value is used to determine whether the contact fails for the second time;

[0011] If both the first contact judgment and the second contact judgment are satisfied, then the contact between the large end face of the hub bearing roller and the rib is finally judged to be non-failure; otherwise, the contact between the large end face of the hub bearing roller and the rib is finally judged to be failure.

[0012] The static balance equation of the roller established with the roller as the analysis object is specifically:

[0013] (1),

[0014] Represent the contact forces between the roller and the outer raceway, inner raceway and flange respectively, represent The force component in the radial direction, Respectively represent the contact angles between the roller and the outer raceway, inner raceway and rib;

[0015] The normal contact load between the outer raceway and the roller is known. ,get:

[0016] (2).

[0017] The static equilibrium equation of the bearing established by taking the entire bearing as the analysis object is specifically:

[0018] Assume that the wheel hub bearing is a double-row tapered roller bearing, and the inner and outer rings of the two-row bearings are regarded as a whole, and the outer ring is fixed. The radial displacement of the inner ring relative to the outer ring is defined as , axial displacement and angular displacement ;

[0019] Considering the inner ring and roller as a whole, the first row of bearings is analyzed. Under the action of external force, the normal displacement of the outer ring can be obtained from the geometric relationship. :

[0020] (3),

[0021] According to the geometric relationship, the radial displacement of the outer ring of the bearing at the jth roller is ,in is the azimuth of the roller, the azimuth of the jth roller , Represents the number of rollers, the axial displacement of the jth roller , so the normal displacement between the outer rings of the bearing at the jth roller is for:

[0022] (4),

[0023] Contact force between the jth roller and the outer raceway The components in the radial and axial directions are:

[0024] (5),

[0025] (6),

[0026] in, represents the normal contact force between the jth roller and the outer raceway;

[0027] Assume that the distance from the center of the roller to the center of the paired bearing O is R, and its radial and axial projections are R1 and R2 respectively. Then the relative rotation angle of the inner and outer rings generated at the jth roller is :

[0028] (7),

[0029] Due to angular displacement The radial displacement component and the axial displacement component They are:

[0030] (8),

[0031] in It represents the bearing center pitch diameter;

[0032] So the total radial displacement at the jth roller is:

[0033] (9),

[0034] If an axial preload F0 is applied, the axial predeformation can be calculated according to formula (10).

[0035] (10),

[0036] At this time, the total axial displacement is:

[0037] (11),

[0038] in, represents the stiffness coefficient,

[0039] (12),

[0040] in, is the effective length of the roller, is the average roller diameter;

[0041] The normal displacement at the jth roller is:

[0042] (13),

[0043] Then, by adding the axial force and radial force of each roller, we can get the axial force F of the first row of bearings as a whole. a and radial force F r ,

[0044] (14),

[0045] F a = ∑ j = 1 Z [ Q ej sin α e ] = ∑ j = 1 Z K ne ( δ rj cos α e cos φ j + δ aj sin α e ) 1 . 11 sin α e (15),

[0046] F r = ∑ j = 1 Z [ Q ej cos α e cos φ j ] = ∑ j = 1 Z K ne ( δ rj cos α e cos φ j + δ aj sin α e ) 1 . 11 cos α e cos φ j (16),

[0047] The resisting moment generated by the contact load is partly the moment generated by the axial component of the load about the bearing center O. :

[0048] (17),

[0049] The other part is the moment generated by the radial component of the contact load on the bearing center O. :

[0050] (18),

[0051] In the formula, is the distance between the centers of the two rows of bearings, then the total resisting moment is for:

[0052] (19),

[0053] Superimposing the corresponding loads of the two rows of bearings, the static equilibrium equation of the bearing is obtained:

[0054] (20),

[0055] Wherein, the subscript i is the number of columns of the corresponding bearing.

[0056] The static equilibrium equation of the bearing is solved to obtain the contact force between the roller and the outer raceway as follows: Substitute the known axial load, radial load and moment into the nonlinear equation of equation (20), solve it using the MATLAB program to obtain the normal displacement of each roller, and finally solve for the contact force between the roller and the outer raceway: .

[0057] According to the geometric relationship of the bearing, the distance between the intersection point of the rib and the raceway generatrix and the intersection point of the roller large end face and the rib is calculated as follows:

[0058] (twenty one),

[0059] Among them, C represents the intersection of the rib and the raceway generatrix, D represents the intersection of the roller large end face and the rib, CD represents the distance between the two intersection points, SR is the radius of the roller ball base surface, is the roller large end diameter, is the distance between the two intersection points C, and β is the roller semi-cone angle.

[0060] Inner ring rib length The calculation method is:

[0061] (twenty two),

[0062] in It is the large rib diameter of the bearing inner ring.

[0063] The ratio of CD to L is the contact position ratio The calculation method is:

[0064] (twenty three),

[0065] The value is between 0.33 and 0.5.

[0066] The contact ellipse semi-axis width and the relative sliding speed between the large end face of the roller and the rib are calculated based on the Hertz contact theory and the bearing geometric relationship, and the maximum contact stress at the center point of the contact ellipse is calculated based on the contact force between the large end face of the roller and the rib:

[0067] Maximum contact stress p at the center of the contact ellipse, length of the semi-axis of the contact ellipse , ellipse semi-axis width The calculation formulas are:

[0068] (twenty four),

[0069] (25),

[0070] (26),

[0071] In the formula are the curvatures and, assuming that the roller is contact body 1, the rib is contact body 2, the axial plane of the bearing is principal plane I, the other plane orthogonal to the principal plane is principal plane II, the convex surface is positive, and the concave surface is negative. Related to the second kind of elliptic integral, we can first calculate the curvature difference , and then get it by looking up the table and using the interpolation method;

[0072] (27),

[0073] (28),

[0074] (29),

[0075] (30),

[0076] in are the curvature of the roller on the main plane I, the curvature of the roller on the main plane II, the curvature of the rib on the main plane I, and the curvature of the rib on the main plane II, respectively. 1Ⅱ is the radius of curvature of the roller on the main plane II.

[0077] Relative sliding speed The calculation method is:

[0078] (31)

[0079] in is the inner ring speed, The average roller diameter

[0080] The first determination of whether the contact fails is specifically based on the relationship between the distance between the intersection point of the rib and the raceway generatrix and the intersection point of the roller large end face and the rib, the contact ellipse semi-axis width and the known oil groove overrun groove size:

[0081] When the length of the contact ellipse does not exceed the oil groove, it is judged that the contact between the large end face of the roller and the rib is not ineffective, and the formula (32) must be satisfied:

[0082] (32)

[0083] Point M is the edge point of the oil groove, and CM is the overrun groove size of the oil groove, that is, the distance between the intersection point C of the rib and the raceway generatrix and the edge point M of the oil groove.

[0084] The method of calculating the product value of the maximum contact stress at the center point of the contact ellipse and the relative sliding speed between the large end face of the roller and the rib and using the product value to determine whether the contact fails for the second time is as follows:

[0085] When the maximum contact stress and the relative sliding velocity are multiplied to satisfy formula (33), it is judged that the contact between the large end face of the roller and the rib is not failed.

[0086] (33).

[0087] In a second aspect, the present invention provides a device for judging failure of contact between a large end face of a hub bearing roller and a rib, comprising:

[0088] The static balance equation establishment module is used to establish the static balance equation of the roller with the roller as the analysis object when the bearing is subjected to external load, and to establish the static balance equation of the bearing with the entire bearing as the analysis object;

[0089] The contact force calculation module is used to solve the static balance equation of the bearing to obtain the contact force between the roller and the outer raceway, and then substitute the contact force between the roller and the outer raceway into the static balance equation of the roller to obtain the contact force between the large end face of the roller and the rib;

[0090] The contact failure parameter calculation module is used to calculate the intersection point between the flange and the raceway generatrix and the distance between the intersection point between the roller end face and the flange according to the bearing geometry, and to calculate the contact ellipse semi-axis width and the relative sliding speed between the roller end face and the flange according to the Hertz contact theory and the bearing geometry;

[0091] The first contact failure judgment module is used to judge whether the contact fails for the first time based on the relationship between the intersection point between the rib and the raceway generatrix and the distance between the intersection point between the roller large end face and the rib, the contact ellipse semi-axis width and the known oil groove overrun groove size;

[0092] The second contact failure judgment module is used to calculate the maximum contact stress at the center point of the contact ellipse according to the contact force between the large end face of the roller and the rib, and then calculate the product value of the maximum contact stress at the center point of the contact ellipse and the relative sliding speed between the large end face of the roller and the rib, and use the product value to judge whether the contact fails for the second time;

[0093] The final contact failure judgment module is used to finally judge that the contact between the large end face of the wheel hub bearing roller and the rib is not failed if both the first judgment that the contact is not failed and the second judgment that the contact is not failed are satisfied; otherwise, it is finally judged that the contact between the large end face of the wheel hub bearing roller and the rib is failed.

[0094] In a third aspect, the present invention provides a computer-readable storage medium having a computer program / instruction stored thereon. When the computer program / instruction is executed by a processor, the steps of the method for determining failure of contact between the large end face of the roller of the hub bearing and the rib are implemented.

[0095] Beneficial effects of the present invention: The present invention provides a method, device and storage medium for judging the contact failure between the large end face of a hub bearing roller and the rib. The method first judges whether the contact has failed based on the relationship between the distance between the intersection of the rib and the raceway generatrix and the intersection of the large end face of the roller and the rib, the semi-axis width of the contact ellipse and the known oil groove overrun groove size. The maximum contact stress at the center point of the contact ellipse is calculated based on the contact force between the large end face of the roller and the rib. The product value of the maximum contact stress at the center point of the contact ellipse and the relative sliding speed between the large end face of the roller and the rib is then calculated. The product value is used to judge whether the contact has failed for the second time. If both the first judgment that the contact has not failed and the second judgment that the contact has not failed are satisfied, then it is finally judged that the contact between the large end face of the hub bearing roller and the rib has not failed. Otherwise, it is finally judged that the contact between the large end face of the hub bearing roller and the rib has failed. Through the two contact judgments, the rib contact of the double-row tapered roller bearing can be effectively analyzed to realize the judgment of the contact failure between the large end face and the rib. BRIEF DESCRIPTION OF THE DRAWINGS

[0096] Figure 1 It is the force analysis diagram of the tapered roller in the present invention;

[0097] Figure 2 The figure is a contact geometry analysis diagram of the tapered roller rib in the present invention;

[0098] Figure 3 It is a schematic diagram of the structure of the 363020X1C bearing in the present invention. DETAILED DESCRIPTION

[0099] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the protection scope of the present invention.

[0100] Example 1

[0101] The present invention discloses a method for judging failure of contact between a large end face of a hub bearing roller and a rib, comprising the following steps:

[0102] Step 1: When the bearing is subjected to an external load, a static equilibrium equation of the roller is established with the roller as the analysis object, and a static equilibrium equation of the bearing is established with the entire bearing as the analysis object.

[0103] Step 2: Solve the static balance equation of the bearing to obtain the contact force between the roller and the outer raceway, and then substitute the contact force between the roller and the outer raceway into the static balance equation of the roller to obtain the contact force between the large end face of the roller and the rib.

[0104] Step three, according to the geometric relationship of the bearing, calculate the distance between the intersection of the rib and the raceway generatrix and the intersection of the large end face of the roller and the rib, and calculate the semi-axis width of the contact ellipse and the relative sliding speed between the large end face of the roller and the rib according to the Hertz contact theory and the geometric relationship of the bearing.

[0105] Step 4: Determine for the first time whether the contact has failed based on the relationship between the distance between the intersection of the rib and the raceway generatrix, the distance between the intersection of the roller large end face and the rib, the semi-axis width of the contact ellipse and the known oil groove overrun groove size.

[0106] Step 5: Calculate the maximum contact stress at the center of the contact ellipse based on the contact force between the large end face of the roller and the rib, then calculate the product of the maximum contact stress at the center of the contact ellipse and the relative sliding speed between the large end face of the roller and the rib, and use the product value to determine whether the contact has failed for the second time.

[0107] Step six, if both the first judgment that the contact is not failed and the second judgment that the contact is not failed are satisfied, then it is finally judged that the contact between the large end face of the hub bearing roller and the rib is not failed, otherwise it is finally judged that the contact between the large end face of the hub bearing roller and the rib is failed.

[0108] The present invention can effectively analyze the contact of the rib of a double-row tapered roller bearing through two contact judgments, and realizes the judgment of the contact failure between the large end face and the rib, which has important practical significance and application value for the design and manufacture of bearings.

[0109] Example 2

[0110] The present invention discloses a method for judging failure of contact between a large end face of a hub bearing roller and a rib, comprising the following steps:

[0111] The first step is to establish the static equilibrium equation of the double-row tapered roller.

[0112] Figure 1 This is the force analysis diagram of the tapered roller under the action of external load. Represent the contact forces between the roller and the outer raceway, inner raceway and flange respectively, Respectively represent the contact angles between the roller and the outer raceway, inner raceway and rib. Taking roller contact as the analysis object, the static equilibrium equation is satisfied:

[0113] (1)

[0114] in, Represents the radial component of the normal contact force of the inner raceway;

[0115] The normal contact load between the outer raceway and the roller is known. ,get:

[0116] (2)

[0117] Commercial vehicle wheel hub bearings generally use double-row tapered roller bearings, which are grease lubricated and subject to axial loads, radial loads, and moment loads. In the analysis, the inner and outer rings of the two-row bearings are considered as a whole, and the outer ring is fixed. In this way, the overall displacement of the inner ring relative to the outer ring is defined as the radial displacement. , axial displacement and angular displacement .

[0118] The inner ring and rollers are considered as a whole and the first row of bearings are analyzed. Under the action of external force, the axial displacement between the inner ring and the outer ring of the bearing is and radial displacement From the geometric relationship, the normal displacement of the outer ring can be obtained .

[0119] (3)

[0120] is the azimuth of the roller, the azimuth of the jth roller , Z represents the number of rollers. According to the geometric relationship, the radial displacement of the outer ring of the bearing at the jth roller is , axial displacement , so the normal displacement between the outer rings of the bearing at the jth roller is:

[0121] (4)

[0122] Normal contact force between the jth roller and the outer raceway The components in the radial and axial directions are:

[0123] (5)

[0124] (6)

[0125] Assume that the distance from the center of the roller to the center of the paired bearing O is R, and its radial and axial projections are R1 and R2 respectively. Since the relative rotation angle of the inner and outer rings generated at the jth roller is

[0126] (7)

[0127] because The resulting radial and axial displacement components are:

[0128] (8)

[0129] in It represents the bearing center pitch diameter;

[0130] So the total radial displacement at the jth roller is:

[0131] (9)

[0132] If an axial preload F0 is applied, the number of rollers is Z, and the stiffness coefficient is , then the axial pre-deformation can be calculated according to formula (10).

[0133] (10)

[0134] At this time, the total axial displacement is:

[0135] (11),

[0136] in, represents the stiffness coefficient,

[0137] (12),

[0138] in, is the effective length of the roller, is the average roller diameter;

[0139] The normal displacement at the jth roller is:

[0140] (13)

[0141] Then, by adding the axial force and radial force of each roller, we can get the axial force F of the first row of bearings as a whole. a and radial force F r .

[0142] (14)

[0143] F a = ∑ j = 1 Z [ Q ej sin α e ] = ∑ j = 1 Z K ne ( δ rj cos α e cos φ j + δ aj sin α e ) 1 . 11 sin α e (15)

[0144] F r = ∑ j = 1 Z [ Q ej cos α e cos φ j ] = ∑ j = 1 Z K ne ( δ rj cos α e cos φ j + δ aj sin α e ) 1 . 11 cos α e cos φ j (16)

[0145] The resisting moment generated by the contact load is partly the moment generated by the axial component of the load about the bearing center O:

[0146] (17)

[0147] The other part is the moment generated by the radial component of the contact load on the bearing center O:

[0148] (18)

[0149] In the formula, is the distance between the centers of the two rows of bearings. The total resisting moment is:

[0150] (19)

[0151] Tapered roller bearings are generally symmetrically distributed in two rows. The absolute values ​​of the displacement and corresponding load (including moment) of the second row of bearings are the same as those of the first row, and their positive and negative signs are shown in Table 1.

[0152] Table 1 Displacement and corresponding load symbols

[0153]

[0154] By superimposing the corresponding loads of the two rows of bearings, the static equilibrium equation of the bearing pair can be obtained:

[0155] (20)

[0156] In the formula, the subscript i is the number of columns of the corresponding bearing, and j is the number of the corresponding rollers. Generally speaking, given the known axial load, radial load and moment, equation (20) is a nonlinear equation to be solved. During the solution process, it is necessary to satisfy that the normal displacement is greater than 0 and the roller is in contact with the raceway. The MATLAB program can be used to solve the displacement and finally obtain , and then the flange contact load is obtained by formula (2): .

[0157] Step 2: Calculate the rib contact ellipse and the tapered roller rib contact geometry analysis diagram as shown below: Figure 2 shown.

[0158] Figure 2 The figure is the contact geometry analysis of the tapered roller rib. Point D is the contact tangent point, point C is the intersection of the rib and the raceway generatrix, the oil groove overrun groove size is CM, O1 is the center of the roller ball base surface, O is the end face vertex of the inner and outer rings of the bearing, β is the roller semi-cone angle, O1D is perpendicular to CD, SR is the roller ball base radius, is the roller large end diameter, is the diameter of the inner ring large rib. According to the geometric relationship, the contact point position can be obtained:

[0159] (twenty one)

[0160] Inner ring rib length:

[0161] (twenty two)

[0162] The ratio of CD to L is the contact position ratio:

[0163] (twenty three)

[0164] Generally speaking, The safe distance is between 0.33 and 0.5, and 0.5 is taken as the optimal position in this study.

[0165] The contact between the roller ball base surface and the rib is the Hertz point contact between the spherical surface and the inner cone surface, and the bearing material is GCr15. According to the Hertz point contact theory, the maximum contact stress P at the center of the contact ellipse and the half length of the ellipse are , ellipse half width The calculation formula is:

[0166] (twenty four)

[0167] (25)

[0168] (26)

[0169] In the formula are the curvatures and, assuming that the roller is contact body 1, the rib is contact body 2, the axial plane of the bearing is principal plane I, the other plane orthogonal to the principal plane is principal plane II, the convex surface is positive, and the concave surface is negative. Related to the second kind of elliptic integral, we can first calculate the curvature difference , and then get it by looking up the table and using the interpolation method;

[0170] (27),

[0171] (28),

[0172] (29),

[0173] (30),

[0174] in are the curvature of the roller on the main plane I, the curvature of the roller on the main plane II, the curvature of the rib on the main plane I, and the curvature of the rib on the main plane II, respectively. 1Ⅱ is the radius of curvature of the roller on the main plane II.

[0175] At this point, we can derive the first condition for judging the failure of the contact between the roller end face and the rib, that is, the length of the contact ellipse does not exceed the oil groove, and formula (31) must be satisfied:

[0176] (31)

[0177] The third step is to calculate the PV value of the guard contact.

[0178] The PV value of the bearing is the product of the contact stress between the roller and the rib and the relative sliding velocity, which can be used to measure the internal heat generation and friction torque of the bearing. Here P is the maximum contact stress, which can be obtained by formula (24). The relative sliding velocity is:

[0179] (32)

[0180] After the rollers have been processed and the pure rolling of the rollers and raceways is guaranteed, adjusting the CD value becomes the only parameter for adjusting the relative sliding speed. It can be obtained that the relative sliding speed is proportional to the CD length, and according to the characteristics of the PV value, the smaller the CD value, the better. However, according to formula (23), if the CD value is too small, it will exceed the design requirement of 0.33-0.5. According to many years of design of tapered rollers and domestic and foreign main engine matching experience, when the contact position between the large rib and the tapered roller is located at 1 / 3 and close to the root, the relative speed between the roller and the rib can be reduced, but the contact point is easy to fall into the edge of the oil groove, and the roller forms an edge effect. When the contact point is in the middle 1 / 2 of the large rib, it is more conducive to bearing lubrication. In the design of the present invention, the contact point position is controlled at 1 / 2 of the length of the large rib as the optimal point, and the limit point is at 1 / 3.

[0181] For roller bearings, the PV value is an indicator of the risk of adhesion between the ribs and the roller end faces of the roller bearings. The limit PV value is greatly affected by factors such as load, rotation conditions, lubrication method, and heat dissipation conditions, so it is very difficult to determine the limit PV value. According to test results and customer feedback, the constraints of the grease lubrication PV value are:

[0182] (33)

[0183] When the PV value is at the upper limit of the index, it means that the contact between the large end face of the roller and the rib is in a failure state, and it is necessary to consider the selection of lubricants, maintenance, and bearing selection.

[0184] The above calculation process will be implemented using MATLAB programming.

[0185] In order to more specifically illustrate the effectiveness of the method, the present invention provides a calculation example to determine the failure of the contact between the roller end face and the rib of a 363020X1C bearing. The structure of the 363020X1C bearing is as follows: Figure 3 shown.

[0186] Table 2 Main parameters and loads of 363020X1C bearing

[0187] According to the above formula, a MATLAB program was written to calculate, and the results obtained after calculation are shown in Table 3.

[0188] Table 3 MATLAB program calculation results

[0189] The calculated PV value is 119 MPa·m / s, which is less than , meeting the PV value constraint condition required by grease lubrication. In addition, the minimum distance (i.e. CD-CM-b) is 1.62mm, which meets the condition greater than 0, indicating that the contact stress ellipse does not truncate the oil groove, the size of the oil groove is reasonable, and the large end face of the roller is in effective contact with the rib. Combining the above two contact failure judgment methods, since both the first judgment that the contact does not fail and the second judgment that the contact does not fail are met at the same time, it is finally judged that the large end face of the hub bearing roller and the rib are in contact without failure.

[0190] Example 3

[0191] This embodiment discloses a device for judging failure of contact between the large end face of a hub bearing roller and a rib, comprising:

[0192] The static balance equation establishment module is used to establish the static balance equation of the roller with the roller as the analysis object when the bearing is subjected to external load, and to establish the static balance equation of the bearing with the entire bearing as the analysis object;

[0193] The contact force calculation module is used to solve the static balance equation of the bearing to obtain the contact force between the roller and the outer raceway, and then substitute the contact force between the roller and the outer raceway into the static balance equation of the roller to obtain the contact force between the large end face of the roller and the rib;

[0194] The contact failure parameter calculation module is used to calculate the intersection point between the flange and the raceway generatrix and the distance between the intersection point between the roller end face and the flange according to the bearing geometry, and to calculate the contact ellipse semi-axis width and the relative sliding speed between the roller end face and the flange according to the Hertz contact theory and the bearing geometry;

[0195] The first contact failure judgment module is used to judge whether the contact fails for the first time based on the relationship between the intersection point between the rib and the raceway generatrix and the distance between the intersection point between the roller large end face and the rib, the contact ellipse semi-axis width and the known oil groove overrun groove size;

[0196] The second contact failure judgment module is used to calculate the maximum contact stress at the center point of the contact ellipse according to the contact force between the large end face of the roller and the rib, and then calculate the product value of the maximum contact stress at the center point of the contact ellipse and the relative sliding speed between the large end face of the roller and the rib, and use the product value to judge whether the contact fails for the second time;

[0197] The final contact failure judgment module is used to finally judge that the contact between the large end face of the wheel hub bearing roller and the rib is not failed if both the first judgment that the contact is not failed and the second judgment that the contact is not failed are satisfied; otherwise, it is finally judged that the contact between the large end face of the wheel hub bearing roller and the rib is failed.

[0198] Example 4

[0199] This embodiment discloses a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the method described in Embodiment 1 or Embodiment 2 are executed.

[0200] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0201] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0202] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0203] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0204] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for judging failure of contact between the large end face of a hub bearing roller and a rib, characterized in that: The following steps are involved: Obtaining a static balance equation of the roller and a static balance equation of the bearing, wherein the static balance equation of the roller is established with the roller as the analysis object when the bearing is subjected to an external load, and the static balance equation of the bearing is established with the entire bearing as the analysis object; Solve the static balance equation of the bearing to obtain the contact force between the roller and the outer raceway, and then substitute the contact force between the roller and the outer raceway into the static balance equation of the roller to obtain the contact force between the large end face of the roller and the rib; According to the geometric relationship of the bearing, the intersection point between the flange and the raceway generatrix and the distance between the intersection point between the roller end face and the flange are calculated, and the semi-axis width of the contact ellipse and the relative sliding speed between the roller end face and the flange are calculated according to the Hertz contact theory and the geometric relationship of the bearing; The first judgment of whether the contact fails is based on the relationship between the intersection of the rib and the raceway generatrix, the distance between the intersection of the roller large end face and the rib, the semi-axis width of the contact ellipse and the known oil groove overrun groove size. According to the contact force between the large end face of the roller and the rib, the maximum contact stress at the center of the contact ellipse is calculated, and then the product of the maximum contact stress at the center of the contact ellipse and the relative sliding speed between the large end face of the roller and the rib is calculated. The product value is used to determine whether the contact fails for the second time; If both the first contact judgment and the second contact judgment are satisfied, then the contact between the large end face of the hub bearing roller and the rib is finally judged to be non-failure; otherwise, the contact between the large end face of the hub bearing roller and the rib is finally judged to be failure.

2. The method for judging failure of contact between the large end face of the roller of the hub bearing and the rib according to claim 1, characterized in that: The static equilibrium equation of the roller is specifically: （1）， Represent the contact forces between the roller and the outer raceway, inner raceway and flange respectively, represent The force component in the radial direction, Respectively represent the contact angles between the roller and the outer raceway, inner raceway and rib; The normal contact load between the outer raceway and the roller is known. ,get: （2）。 3. The method for judging failure of contact between the large end face of the roller of the hub bearing and the rib according to claim 2, characterized in that: The static equilibrium equation of the bearing is established by the following steps: Assume that the wheel hub bearing is a double-row tapered roller bearing, and the inner and outer rings of the two-row bearings are regarded as a whole, and the outer ring is fixed. The radial displacement of the inner ring relative to the outer ring is defined as , axial displacement and angular displacement ; Considering the inner ring and roller as a whole, the first row of bearings is analyzed. Under the action of external force, the normal displacement of the outer ring can be obtained from the geometric relationship. : （3）， According to the geometric relationship, the radial displacement of the outer ring of the bearing at the jth roller is ,in is the azimuth of the roller, the azimuth of the jth roller , Represents the number of rollers, the axial displacement of the jth roller , so the normal displacement between the outer rings of the bearing at the jth roller is for: （4）， Contact force between the jth roller and the outer raceway The components in the radial and axial directions are: （5）， （6）， in, represents the normal contact force between the jth roller and the outer raceway; Assume that the distance from the center of the roller to the center of the paired bearing O is R, and its radial and axial projections are R1 and R2 respectively. Then the relative rotation angle of the inner and outer rings generated at the jth roller is : （7）， Due to angular displacement The radial displacement component and the axial displacement component They are: （8）， in It represents the bearing center pitch diameter; So the total radial displacement at the jth roller is: （9）， If an axial preload F0 is applied, the axial predeformation can be calculated according to formula (10): （10）， At this time, the total axial displacement is: （11）， in, represents the stiffness coefficient, （12）， in, is the effective length of the roller, is the average roller diameter; The normal displacement at the jth roller is: （13）， Then, by adding the axial force and radial force of each roller, we can get the axial force F of the first row of bearings as a whole. a and radial force F r , （14）， （15）， （16）， The resisting moment generated by the contact load is partly the moment generated by the axial component of the load about the bearing center O. : （17）， The other part is the moment generated by the radial component of the contact load on the bearing center O. : （18）， In the formula, is the distance between the centers of the two rows of bearings, then the total resisting moment is for: （19）， Superimposing the corresponding loads of the two rows of bearings, the static equilibrium equation of the bearing is obtained: （20）， Wherein, the subscript i is the number of columns of the corresponding bearing.

4. The method for judging failure of contact between the large end face of the roller of the hub bearing and the rib according to claim 3, characterized in that: The static equilibrium equation of the bearing is solved to obtain the contact force between the roller and the outer raceway as follows: Substitute the known axial load, radial load and moment into the nonlinear equation of equation (20), solve it using the MATLAB program to obtain the normal displacement of each roller, and finally solve for the contact force between the roller and the outer raceway: .

5. The method for judging failure of contact between the large end face of the roller of the hub bearing and the rib according to claim 4, characterized in that: According to the geometric relationship of the bearing, the distance between the intersection point of the rib and the raceway generatrix and the intersection point of the roller large end face and the rib is calculated as follows: （21）， Among them, C represents the intersection of the rib and the raceway generatrix, D represents the intersection of the roller large end face and the rib, CD represents the distance between the two intersection points, SR is the radius of the roller ball base surface, is the roller large end diameter, is the distance between the two intersection points C, β is the roller semi-cone angle, Inner ring rib length The calculation method is: （22）， in is the large rib diameter of the bearing inner ring, The ratio of CD to L is the contact position ratio The calculation method is: （23）， The value is between 0.33 and 0.

5.

6. The method for judging failure of contact between the large end face of the roller of the hub bearing and the rib according to claim 5, characterized in that: The contact ellipse semi-axis width and the relative sliding speed between the large end face of the roller and the rib are calculated based on the Hertz contact theory and the bearing geometric relationship, and the maximum contact stress at the center point of the contact ellipse is calculated based on the contact force between the large end face of the roller and the rib as follows: Maximum contact stress p at the center of the contact ellipse, length of the semi-axis of the contact ellipse , ellipse semi-axis width The calculation formulas are: （24）， （25）， （26）， In the formula Assume that the roller is contact body 1, the flange is contact body 2, the axial plane of the bearing is principal plane I, the other plane orthogonal to the principal plane is principal plane II, the convex surface is positive, and the concave surface is negative. Related to the second kind of elliptic integral, we can first calculate the curvature difference , and then get it by looking up the table and using the interpolation method; （27）， （28）， （29）， （30）， in are the curvature of the roller on the main plane I, the curvature of the roller on the main plane II, the curvature of the rib on the main plane I, and the curvature of the rib on the main plane II, respectively. 1Ⅱ is the radius of curvature of the roller on the main plane II, Relative sliding speed The calculation method is: （31） in is the inner ring speed, is the average roller diameter.

7. The method for judging failure of contact between the large end face of the roller of the hub bearing and the rib according to claim 6, characterized in that: The first determination of whether the contact fails is specifically based on the relationship between the distance between the intersection of the rib and the raceway generatrix and the intersection of the roller large end face and the rib, the contact ellipse semi-axis width and the known oil groove overrun groove size: When the length of the contact ellipse does not exceed the oil groove, it is judged that the contact between the large end face of the roller and the rib is not ineffective, and the formula (32) must be satisfied: （32） Point M is the edge point of the oil groove, and CM is the overrun groove size of the oil groove, that is, the distance between the intersection point C of the rib and the raceway generatrix and the edge point M of the oil groove.

8. The method for judging failure of contact between the large end face of the roller of the hub bearing and the rib according to claim 7, characterized in that: The method of calculating the product value of the maximum contact stress at the center point of the contact ellipse and the relative sliding speed between the large end face of the roller and the rib and using the product value to determine whether the contact fails for the second time is as follows: When the maximum contact stress and the relative sliding velocity are multiplied to satisfy formula (33), it is judged that the contact between the large end face of the roller and the rib is not failed. （33）。 9. A device for judging failure of contact between the large end face of a hub bearing roller and a rib, characterized in that: include; The static balance equation establishment module is used to establish the static balance equation of the roller with the roller as the analysis object when the bearing is subjected to external load, and to establish the static balance equation of the bearing with the entire bearing as the analysis object; The contact force calculation module is used to solve the static balance equation of the bearing to obtain the contact force between the roller and the outer raceway, and then substitute the contact force between the roller and the outer raceway into the static balance equation of the roller to obtain the contact force between the large end face of the roller and the rib; The contact failure parameter calculation module is used to calculate the intersection point between the flange and the raceway generatrix and the distance between the intersection point between the roller end face and the flange according to the bearing geometry, and to calculate the contact ellipse semi-axis width and the relative sliding speed between the roller end face and the flange according to the Hertz contact theory and the bearing geometry; The first contact failure judgment module is used to judge whether the contact fails for the first time based on the relationship between the intersection point between the rib and the raceway generatrix and the distance between the intersection point between the roller large end face and the rib, the contact ellipse semi-axis width and the known oil groove overrun groove size; The second contact failure judgment module is used to calculate the maximum contact stress at the center point of the contact ellipse according to the contact force between the large end face of the roller and the rib, and then calculate the product value of the maximum contact stress at the center point of the contact ellipse and the relative sliding speed between the large end face of the roller and the rib, and use the product value to judge whether the contact fails for the second time; The final contact failure judgment module is used to finally judge that the contact between the large end face of the wheel hub bearing roller and the rib is not failed if both the first judgment that the contact is not failed and the second judgment that the contact is not failed are satisfied; otherwise, it is finally judged that the contact between the large end face of the wheel hub bearing roller and the rib is failed.

10. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instruction is executed by a processor, the steps of the method for judging failure of contact between the large end face of the roller of a hub bearing and the rib as described in any one of claims 1-8 are implemented.

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