A method for adjusting the axial clearance of tapered roller bearings for rail transit

Abstract

A method for adjusting the axial clearance of tapered roller bearings used in rail transit is disclosed, relating to the field of bearing testing technology. This method addresses the problems of inaccurate axial clearance detection due to limitations in the accuracy of measuring equipment, the high precision requirements for machining spacer widths, and the need for bearing users to equip themselves with specialized equipment for spacer machining under existing axial clearance adjustment methods. The method includes: (1) calculating the required width of the assembly spacer; (2) selecting an assembly spacer that meets the width requirements; and (3) assembly. This invention is applicable to axial clearance adjustment when two single-row tapered roller bearings of a rail transit wheel are installed back-to-back. The nominal width of the assembly spacer in this invention is much smaller than that of existing test spacers, making transportation and storage more convenient. The smaller width of the assembly spacer allows for selection of multiple specifications, eliminating the need for bearing users to equip themselves with specialized equipment for spacer machining; they can simply select assembly spacers of different widths to meet the bearing axial clearance adjustment requirements.

Description

Technical Field

[0001] This invention relates to the field of bearing testing technology, specifically a method for adjusting the axial clearance of tapered roller bearings used in rail transit. Background Technology

[0002] Current tapered roller bearings for rail transit consist of two single-row tapered roller bearings mounted back-to-back. The backs of the two outer rings of the bearings are positioned by the steps of the inner bore of the rail transit wheel. The axial clearance of the bearings is adjusted by changing the width of the spacer between the two inner rings. Due to the limitations of the existing rail transit wheel structure, the width of the spacer in tapered roller bearings is relatively large, generally above 30mm, making the transportation and storage of the spacer inconvenient.

[0003] The existing tapered roller bearings did not have their original axial clearance controlled before installation. The method for adjusting the bearing's axial clearance is as follows: install the two bearing outer rings at the step of the wheel's inner bore → install a test spacer between the two bearing inner rings → fix the test spacer and the two bearing inner rings axially → test the bearing axial clearance (most of the tested bearing axial clearance does not meet the design requirements) → calculate the spacer size that meets the bearing axial clearance requirements based on the tested axial clearance → machine the spacer according to the calculated spacer size to meet the designed bearing axial clearance requirements → remove the test spacer → replace with a machined qualified spacer. The above method is limited by the accuracy of the measuring equipment, resulting in inaccurate bearing axial clearance detection. The equipment required for machining the spacer width has high precision requirements, necessitating the bearing user to equip themselves with specialized equipment for machining the spacer or outsource the machining, causing considerable inconvenience. Summary of the Invention

[0004] The purpose of this invention is to provide a method for adjusting the axial clearance of tapered roller bearings for rail transit, which solves the problems of inaccurate axial clearance detection due to limitations in the accuracy of measuring equipment, high precision requirements for the equipment needed to process the spacer width, and the need for bearing users to equip themselves with special equipment to process the spacer under the existing axial clearance adjustment methods.

[0005] The technical solution adopted by this invention to solve its technical problem is: a method for adjusting the axial clearance of a tapered roller bearing for rail transit, comprising the following steps:

[0006] 1. Calculate the required width of the spacer rings;

[0007] 2. Select assembly spacers that meet the width requirements;

[0008] III. Assembly.

[0009] Furthermore, the specific steps for calculating the required width of the assembly spacer include:

[0010] S1.1 Defines the nominal dimension A of the assembly spacer width.

[0011] S1.2 Specify the dimensions of the assembly spacer.

[0012] Set the assembly spacer width dimension to n specifications;

[0013] S1.3 defines the difference in width between adjacent dimensions of the assembly spacer as A. n -A n-1 A n -A n-1 = (Maximum design height of wheel step h) max -Minimum design value h for wheel step height min )÷(n-1);

[0014] S1.4 Specify the dimensions of the assembly spacers, arranged in ascending order, namely A1, A2...A n ;in,

[0015] A1 = Nominal dimension of assembly spacer width A + Minimum design value of wheel step height h min -Nominal dimension h of wheel step height design;

[0016] A2=A1+(A n -A n-1 );

[0017] A3=A2+(A n -A n-1 );

[0018] ...

[0019] And so on;

[0020] S1.5 determines the dimensional tolerance of the assembly spacer width;

[0021] S1.6 Determine the material of the assembly spacer;

[0022] S1.7 Determine the hardness of the assembly spacer;

[0023] S1.8 Inner Ring Boss Setting

[0024] An inner ring boss is provided on the inner ring end face of the bearing. The depth of the inner ring boss is 0.5 × (the nominal design dimension h of the wheel step height - the nominal dimension A of the assembly spacer width + the average axial clearance of the bearing design). );

[0025] Definition of S1.9 Protrusion

[0026] In each bearing set, the end face of the inner ring boss that faces away from the inner ring of the bearing is called the inner ring boss end face, and the wider end face of the outer ring of the bearing is called the outer ring wide end face. The distance between the inner ring boss end face and the outer ring wide end face is the protrusion amount.

[0027] Measurement of S1.10 protrusion

[0028] The protrusion of each single-row tapered roller bearing is measured and recorded as b1, b2, ..., b x ... b n ;

[0029] S1.11 The original axial clearance of the control bearing before installation is the bearing's design average axial clearance. Select b1+b x = Nominal wheel step height h - Nominal assembly spacer width A + Average axial clearance of bearing design Two sets of bearings are paired together; a test spacer is machined such that the width C of the test spacer is equal to the nominal height h of the wheel step; the two selected sets of bearings, the test spacer, and an assembly spacer with a width of nominal width A are grouped together, and the original axial clearance of this group of bearings before installation is tested to confirm that the original axial clearance of this group of bearings before installation is equal to the bearing's design average axial clearance.

[0030] S1.12 Match and number the bearings that pass the inspection;

[0031] S1.13 Measure the actual dimension h of the vehicle step height for rail transit wheels. c ;

[0032] S1.14 Calculate the width range of the assembly spacer.

[0033]

[0034]

[0035] Furthermore, the calculation method for the specification quantity n in step S1.2 is: n = 2 × (maximum design height of wheel step h) max -Minimum design value h for wheel step height min )÷(Maximum axial clearance Ga of bearing design) max -Minimum axial clearance Ga min )+1.

[0036] Furthermore, in step S1.5, the tolerance of the assembly spacer width is determined to be 0mm to +0.005mm.

[0037] Furthermore, in step S1.6, the material of the spacer is selected as GCr15.

[0038] Furthermore, in step S1.7, the hardness of the assembly spacer is determined to be 59HRC~63HRC.

[0039] Furthermore, in step S1.9, a process for controlling the protrusion of each single-row tapered roller bearing is added to the bearing grinding and assembly process.

[0040] Furthermore, when selecting an assembly spacer that meets the width requirements, the width dimension A of the assembly spacer... x Should satisfy A min ≤A x ≤A max .

[0041] Furthermore, the specific assembly steps are as follows:

[0042] The paired bearing outer ring, the paired bearing inner ring, and the compliant assembly spacer are installed into the same rail vehicle wheel.

[0043] Furthermore, during assembly, the outer ring of the bearing should be installed first, followed by the inner ring and the assembly spacer. The beneficial effects of this invention are: it is applicable to axial clearance adjustment when two single-row tapered roller bearings of a rail transit wheel are installed back-to-back. The nominal width of the assembly spacer of this invention is much smaller than that of existing test spacers, making transportation and storage more convenient; the smaller width of the assembly spacer allows for selection of multiple specifications, eliminating the need for bearing users to equip themselves with specialized equipment for spacer processing, as they can simply select assembly spacers of different widths to meet the bearing axial clearance adjustment requirements. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the assembly of existing rail transit wheels and tapered roller bearings.

[0045] Figure 2 This is a schematic diagram of the assembly of the rail transit wheel and the tapered roller bearing of the present invention.

[0046] Figure 3 This is a schematic diagram showing the protrusion of a tapered roller bearing.

[0047] In the diagram: 1 Rail transit wheel, 2 Wheel step, 3 Bearing outer ring, 4 Bearing inner ring, 5 Test spacer, 6 Inner ring boss, 7 Assembly spacer, 8 Outer ring wide end face, 9 Inner ring boss end face. Detailed Implementation

[0048] like Figure 1 As shown, the existing tapered roller bearing for rail transit includes an outer ring 3, an inner ring 4, and rollers. The outer ring 3 is fixed within the inner bore of the rail transit wheel 1, and its end face contacts the wheel step 2 of the rail transit wheel 1 to position the tapered roller bearing. The axial clearance adjustment method for the tapered roller bearing for rail transit according to the present invention is described below with reference to the accompanying drawings:

[0049] 1. Calculate the required width of the assembly spacer 7.

[0050] (1) Define the nominal dimension A of the assembly spacer 7 width.

[0051] The nominal dimension A of the width of the assembly spacer 7 is controlled to be around 1.6mm.

[0052] (2) Develop the specifications for the size of the assembly spacer 7.

[0053] The width dimension of the assembly spacer 7 is set to n specifications, and the number of specifications n is:

[0054] n = 2 × (maximum design height of wheel step 2 h) max -Minimum design value h for wheel step height 2 min )÷(Maximum axial clearance Ga of bearing design) max -Minimum axial clearance Ga min )+1.

[0055] (3) Define the difference between the width dimensions of adjacent specifications of assembly spacer 7 as:

[0056] A n -A n-1 = (Maximum design height h of wheel step 2) max -Minimum design value h for wheel step height 2 min )÷(n-1).

[0057] (4) Define the specifications and dimensions of the assembly spacer 7. The width dimensions are arranged in ascending order, namely A1, A2...A n .

[0058] Where A1 = nominal width of assembly spacer 7 A + minimum design height of wheel step 2 h min - The nominal dimension h of the wheel step height design;

[0059] A2=A1+(A n -A n-1 );

[0060] A3=A2+(A n -A n-1 );

[0061] ...

[0062] And so on.

[0063] (5) Determine the width tolerance of the assembly spacer 7

[0064] The width tolerance of the assembly spacer 7 is set to 0mm to +0.005mm.

[0065] (6) Determine the material of assembly spacer 7

[0066] The assembly spacer 7 is made of GCr15 material.

[0067] (7) Determine the hardness of the assembly spacer 7

[0068] The hardness of the assembly spacer 7 is determined to be 59HRC~63HRC.

[0069] (8) Setting of inner ring boss 6

[0070] like Figure 2 As shown, an inner ring boss 6 is provided on the end face of the inner ring 4 of the bearing. The depth of the inner ring boss 6 is 0.5 × (the nominal design dimension h of the wheel step 2 - the nominal dimension A of the assembly spacer width 7 + the average axial clearance of the bearing design). ).

[0071] (9) Definition of convexity b

[0072] like Figure 3 As shown, in each bearing set, the end face of the inner ring boss 6 facing away from the inner ring 4 is called the inner ring boss end face 9, and the wider end face of the outer ring 3 is called the outer ring wide end face 8. The distance between the inner ring boss end face 9 and the outer ring wide end face 8 is referred to as the protrusion amount b. In the bearing grinding and assembly process, a control process for the protrusion amount b of each single-row tapered roller bearing is added.

[0073] (10) Measurement of protrusion b

[0074] The protrusion amount b of each single-row tapered roller bearing is measured and recorded as b1, b2, ..., b x ... b n .

[0075] (11) Control the original axial clearance of the bearing before installation to be the bearing design average axial clearance. Select b1+b x = Wheel step height 2 (nominal dimension h) - Assembly spacer width 7 (nominal dimension A) + Bearing design average axial clearance Two sets of bearings are paired together. A test spacer 5 is machined, with a width C equal to the nominal height h of the wheel step 2. The selected two sets of bearings are then paired with the test spacer 5 and an assembly spacer 7 with a width A equal to the nominal width. The original axial clearance of this bearing set before installation is checked to confirm that the original axial clearance of this bearing set before installation is equal to the bearing's design average axial clearance.

[0076] (12) Pair and number the bearings that pass the inspection.

[0077] (13) Measure the actual height h of the vehicle step 2 of the rail transit wheel 1. c .

[0078] (14) Calculate the width range of the assembly spacer 7.

[0079]

[0080]

[0081] II. Select assembly spacers 7 that meet the width requirements.

[0082] The selection of spacer 7 ensures that A min ≤A x ≤A max A x The width dimension for assembling spacer 7.

[0083] III. Assembly

[0084] The paired bearing outer ring 3, the paired bearing inner ring 4, and the compliant assembly spacer 7 are installed into the same rail vehicle wheel 1. During assembly, the bearing outer ring 3 should be installed first, followed by the bearing inner ring 4 and the assembly spacer 7.

[0085] The invention will now be described in detail with reference to specific examples.

[0086] The height dimension of the wheel step 2 of the rail transit wheel 1 is 390. +0.2 Taking a nominal dimension h = 39 mm, a nominal dimension of 39 mm for the width of the test spacer 5, and a bearing design axial clearance Ga of 0.01 mm to 0.15 mm as an example, the specific embodiments of the present invention are described as follows:

[0087] 1. Calculate the width dimension of assembly spacer 7.

[0088] 1) The nominal width A of the assembly spacer 7 is designed to be 1.6mm.

[0089] 2) The specification quantity n of assembly spacer 7 is determined as follows:

[0090] n = 2 × (maximum design height of wheel step 2 h) max -Minimum design value h for wheel step height 2 min )÷(Maximum axial clearance Ga of bearing design) max -Minimum axial clearance Ga min )+1

[0091] =2×(39.2-39.0)÷(0.15-0.01)+1=3.857≈4.

[0092] 3) Define the difference in width between adjacent dimensions of assembly spacer 7 as:

[0093] A4-A3=(Design maximum height of wheel step 2 h) max -Minimum design value h for wheel step height 2 min )÷(n-1)

[0094] = (39.2-39.0)mm÷(4-1)

[0095] ≈0.07mm.

[0096] 4) Depending on the width, the spacer ring 7 comes in several sizes, ordered from smallest to largest as follows:

[0097] A1 = Assembly spacer width 7 (nominal dimension) A + Wheel step height 2 (minimum design value h) min - The nominal design dimension of the wheel step height is h = 1.6 + 39.0 - 39 = 1.6 (mm).

[0098] A2 = A1 + 0.07 = 1.67 mm.

[0099] And so on: A3 = 1.74 mm, A4 = 1.81 mm.

[0100] 5) The width tolerance of the assembly spacer 7 is determined to be: 0mm~+0.005mm.

[0101] 6) The material of the assembly spacer 7 is determined to be GCr15.

[0102] 7) Determine the hardness of the assembly spacer 7 to be 59HRC~63HRC.

[0103] 8) such as Figure 2 As shown, an inner ring boss 6 structure is added to the inner ring 4 of the bearing. The inner ring boss 6 is located on one end face of the inner ring 4 of the bearing.

[0104]

[0105] 9) such as Figure 3 As shown, in each bearing set, the distance from the inner ring boss end face 9 to the outer ring wide end face 8 is referred to as the protrusion amount b.

[0106] 10) Measure the protrusion b of each single-row tapered roller bearing, and record them as b1, b2, ..., b x ...

[0107] b n Assume: b1 = 18.62 mm, b2 = 18.66 mm, b3 = 18.74 mm, b4 = 18.82 mm.

[0108] b5 = 18.86 mm, ...

[0109] 11) The original axial clearance of the bearing before installation is the bearing's design average axial clearance.

[0110] Select the protrusions b as b1 and b x The two sets of bearings make:

[0111]

[0112] Therefore, two sets of bearings with b1 = 18.62 mm and b5 = 18.86 mm were selected and paired together.

[0113] A test spacer 5 is machined, with a width C equal to the nominal height h of the wheel step 2, i.e., C = 39 mm. A selected set of bearings is then grouped with the 39 mm wide test spacer 5 and the 1.6 mm wide assembly spacer 7. The original axial clearance of this bearing group before installation is checked to confirm that the original axial clearance of this bearing group before installation is equal to the bearing's design average axial clearance.

[0114] 12) Pair and number the bearings that pass the inspection.

[0115] 13) Measure the actual height h of the wheel step 2 of the rail transit wheel 1. c Assume h c =39.16mm. 14) Calculate the required width of the assembly spacer 7.

[0116]

[0117]

[0118] II. Select assembly spacers 7 that meet the width requirements.

[0119] The width dimension of the assembly spacer 7 is A. x It should be ensured that: A min ≤A x ≤A max Therefore, either A3 = 1.74mm or A4 = 1.81mm for the assembly spacer 7 can meet the above requirements.

[0120] III. Assembly

[0121] Two sets of single-row tapered roller bearings with protrusions b of b1 = 18.62 mm and b5 = 18.86 mm respectively, along with a mounting spacer 7 of size A3 = 1.74 mm or A4 = 1.81 mm, are installed into the same rail vehicle wheel 1. During installation, the outer bearing ring 3 is installed first, followed by the inner bearing ring 4 and the mounting spacer 7. The axial clearance of the bearing after installation is:

[0122] b1 + b5 + A3 - h = (18.62 + 18.86 + 1.74 - 39.16) mm = 0.06 mm or

[0123] b1+b5+A4-h=(18.62+18.86+1.81-39.16)mm=0.13mm

[0124] It meets the bearing design requirement of axial clearance Ga of 0.01mm to 0.15mm.

[0125] The present invention has the following advantages:

[0126] (1) This invention is particularly applicable to the adjustment of axial clearance when two single-row tapered roller bearings of a rail transit wheel 1 are installed back to back.

[0127] (2) The present invention controls the nominal width A of the assembly spacer 7 to about 1.6mm, which is convenient for transportation and storage. The assembly spacer 7 has a small width and multiple specifications to choose from. The bearing user does not need to equip special equipment to process the spacer. The bearing axial clearance adjustment requirements can be met by simply selecting assembly spacers 7 with different width specifications.

[0128] (3) The assembly spacer 7 of this invention is made of GCr15, which is the same material as the inner ring 4 of the bearing, ensuring that the thermal expansion and contraction and wear resistance are consistent with the bearing; the hardness of the assembly spacer 7 is 59HRC~63HRC, which improves the wear resistance.

[0129] (4) The present invention can achieve the goal of controlling the width dimension A of the assembly spacer 7 to about 1.6mm by adding an inner ring boss 6 to the inner ring 4 of the bearing.

[0130] (5) This invention ensures that the original axial clearance before bearing installation can be achieved by controlling the protrusion of a single bearing set. By matching the protrusions of two single bearing sets, the original axial clearance before bearing installation can be ensured. By controlling the original axial clearance before bearing installation at the bearing manufacturer, the axial clearance detection of the bearing is more accurate, and the method of adjusting the axial clearance during bearing installation is simplified.

[0131] (6) This invention provides the following formulas for calculating the depth of the inner ring boss 6 of the tapered roller bearing, the size range of the assembly spacer 7, the specifications and quantity of the assembly spacer 7, the difference between adjacent specifications of the assembly spacer 7, the tolerance of the assembly spacer 7, the selection of matching bearings when controlling the original axial clearance before installation, and the required width of the assembly spacer 7 during installation, which facilitates its promotion and application.

Claims

1. A method for adjusting the axial clearance of a tapered roller bearing used in rail transit, characterized in that, Includes the following steps:

1. Measure the wheel step height of the rail transit wheels and calculate the required width of the mounting spacer.

2. Select assembly spacers that meet the width requirements; III. Assembly; During assembly, the outer ring of the bearing is first installed in the inner hole of the rail transit wheel, and then the inner ring of the bearing and the assembly spacer are installed. The specific steps for calculating the required width of the assembly spacer include: S1.1 defines the nominal dimension A of the assembly spacer width; S1.2 Specify the dimensions of the assembly spacer. Set the assembly spacer width dimension to n specifications; S1.3 defines the difference in width between adjacent dimensions of the assembly spacer as A. n -A n-1 A n -A n-1 = (Design maximum height of wheel step h) max -Minimum design value h for wheel step height min )÷(n-1); S1.4 Specify the dimensions of the assembly spacers, arranged in ascending order, namely A1, A2...A n Where, A1 = nominal width of the assembly spacer A + minimum design height of the wheel step h min -Nominal dimension h of wheel step height design; A2 = A1 + (A n - A n-1 (); A3 = A2 + (A n - A n-1 (); …… And so on; S1.5 determines the dimensional tolerance of the assembly spacer width; S1.6 Determine the material of the assembly spacer; S1.7 Determine the hardness of the assembly spacer; S1.8 Inner Ring Boss Setting An inner ring boss is provided on the inner ring end face of the bearing. The depth of the inner ring boss is 0.5 × (the nominal design dimension h of the wheel step height - the nominal dimension A of the assembly spacer width + the average axial clearance of the bearing design). ); Definition of S1.9 Protrusion In each bearing set, the end face of the inner ring boss that faces away from the inner ring of the bearing is called the inner ring boss end face, and the wider end face of the outer ring of the bearing is called the outer ring wide end face. The distance between the inner ring boss end face and the outer ring wide end face is the protrusion amount. Measurement of S1.10 protrusion The protrusion of each single-row tapered roller bearing is measured and recorded as b1, b2, ..., b x ... b n Where x is a positive integer from 1 to n; S1.11 The original axial clearance of the control bearing before installation is the bearing's design average axial clearance. ; Select b1+b x =Nominal wheel step height h - Nominal assembly spacer width A + Average axial clearance of bearing design Two sets of bearings are paired together; a test spacer is machined such that the width C of the test spacer is equal to the nominal height h of the wheel step; the two selected sets of bearings, the test spacer, and an assembly spacer with a width of nominal width A are grouped together, and the original axial clearance of this group of bearings before installation is tested to confirm that the original axial clearance of this group of bearings before installation is equal to the bearing's design average axial clearance. ; S1.12 Match and number the bearings that pass the inspection; S1.13 Measure the actual dimension h of the wheel step height of rail transit wheels. c ; S1.14 Calculate the width range of the assembly spacer. Maximum width dimension A of the assembly spacer max = Nominal dimension A of assembly spacer width + (Ga max - ) + (actual wheel step height h) c -Nominal wheel step height (h); minimum assembly spacer width (A) min = Nominal dimension A of assembly spacer width + (Ga min - ) + (actual wheel step height h) c - The nominal dimension h of the wheel step height, where Ga max For the maximum axial clearance of the bearing design, Ga min Minimum axial clearance for bearing design.

2. The method for adjusting the axial clearance of a tapered roller bearing for rail transit according to claim 1, characterized in that, The calculation method for the specification quantity n in step S1.2 is: n = 2 × (maximum design height of wheel step h) max -Minimum design value h for wheel step height min ) ÷ (Maximum axial clearance Ga of bearing design) max -Minimum axial clearance Ga min )+1.

3. The method for adjusting the axial clearance of a tapered roller bearing for rail transit according to claim 1, characterized in that, In step S1.5, the tolerance of the assembly spacer width is determined to be 0mm to +0.005mm.

4. The method for adjusting the axial clearance of a tapered roller bearing for rail transit according to claim 1, characterized in that, In step S1.6, the spacer material is GCr15.

5. The method for adjusting the axial clearance of a tapered roller bearing for rail transit according to claim 1, characterized in that, In step S1.7, the hardness of the assembly spacer is determined to be 59 HRC to 63 HRC.

6. The method for adjusting the axial clearance of a tapered roller bearing for rail transit according to claim 1, characterized in that, In step S1.9, a process for controlling the amount of protrusion of each single-row tapered roller bearing is added to the bearing grinding and assembly process.

7. The method for adjusting the axial clearance of a tapered roller bearing for rail transit according to claim 1, characterized in that, When selecting a mounting spacer that meets the width requirements, the width dimension A of the mounting spacer is... x Should satisfy A min ≤A x ≤A max .

8. The method for adjusting the axial clearance of a tapered roller bearing for rail transit according to claim 1, characterized in that, The specific assembly steps are as follows: the paired bearing outer ring, the paired bearing inner ring, and the compliant assembly spacer are installed into the same rail transit wheel.

Images