Device for measuring bearing start-up torque and method for measuring same

Abstract

The application relates to the technical field of bearing measurement, in particular to a device for measuring the starting torque of a bearing and a measuring method thereof, which comprises a sliding rail, a lever assembly, a bearing support assembly, a force loading device and an acceleration sensor; the sliding rail is slidably provided with a stand column; the lever assembly comprises a lever rotationally connected with the stand column and a bearing outer ring grab clamp arranged on the lever; the bearing support assembly comprises a bearing support, a bearing inner ring support column arranged on the bearing support and a plurality of bearing inner ring fixing claws telescopically arranged on the bearing inner ring support column; the force loading device comprises a hydraulic cylinder and a support column connected with the driving end of the hydraulic cylinder, the support column is rotationally connected with the side of the lever away from the bearing outer ring grab clamp; and the acceleration sensor is installed on the top of the outer ring of the bearing to be measured. The application breaks the single condition verification, changes the torque combination, measures multiple times and obtains more accurate results.

Description

Technical Field

[0001] This invention relates to the field of bearing measurement technology, specifically to a device and method for measuring bearing starting torque. Background Technology

[0002] Starting torque is an indispensable testing parameter for bearings during manufacturing, selection, installation, and maintenance. Measuring starting torque can identify manufacturing defects such as internal burrs or poor cleanliness. It can verify assembly accuracy, ensure proper lubrication, and guarantee equipment sensitivity. However, existing instruments for measuring bearing starting torque can only measure under single conditions for a given bearing type, and cannot adjust measurement conditions, perform multiple measurements, or verify the results. Summary of the Invention

[0003] In view of the deficiencies of the prior art, the present invention provides a device and method for measuring bearing starting torque, which breaks the single-condition verification, changes the torque combination, and performs multiple measurements to obtain more accurate results.

[0004] To achieve the above objectives, the present invention provides a device for measuring the starting torque of a bearing, comprising a slide rail, a lever assembly, a bearing support assembly, a force loading device, and an acceleration sensor; the slide rail is slidably provided with a column; the lever assembly includes a lever rotatably connected to the column and a bearing outer ring gripper disposed on the lever; the bearing support assembly is disposed at one end of the slide rail, and includes a bearing bracket, a bearing inner ring support column disposed on the bearing bracket, and a plurality of bearing inner ring fixing claws retractably disposed on the bearing inner ring support column; the force loading device is disposed at the other end of the slide rail, and includes a hydraulic cylinder and a support column connected to the drive end of the hydraulic cylinder, the support column being rotatably connected to the side of the lever away from the bearing outer ring gripper; the acceleration sensor is mounted on the top of the outer ring of the bearing to be tested.

[0005] Furthermore, a scale is provided on the slide rail.

[0006] Furthermore, the column has a through hole through which the lever passes.

[0007] The specific steps for measuring bearing starting torque include: Step S100: Determine the type coefficient, size coefficient, and sealing value, and determine the b value based on whether a seal is required; Step S200: Calculate the boom length W using the formula W=akdb. Determine the adjustment range of the boom length W during measurement as W±2d. Where d is the bearing inner diameter, a is the type coefficient, k is the size coefficient, and b is the sealing value; Step S300: The bearing to be tested is mounted on the inner ring fixing claw, and the acceleration sensor is mounted on the top of the outer ring of the bearing to be tested. Step S400: Adjust and determine the position of the column on the slide rail. The distance from the force loading device to the column is the length W of the power arm. Record W. Step S500: Apply force through the hydraulic cylinder to keep the lever balanced, and record the force G applied by the hydraulic cylinder at this time; Step S600: Clamp the bearing outer ring clamp onto the outer ring of the bearing to be tested; Step S700: Apply force through the hydraulic cylinder until the acceleration of the accelerometer is not zero. Record the force value F applied by the hydraulic cylinder at this moment. The starting torque T of the bearing under test can be calculated using the formula: Starting torque T = (FG) × (LW) × 10 -3 Where L is the total length of the lever, 10d≤L≤20d, and L is an integer; Step S800: Within the adjustment range of the power arm length W, change the position of the column on the slide rail, repeat steps S400-S700, and measure multiple times to obtain the bearing starting torque.

[0008] Further, step S100 includes determining the type coefficient, size coefficient, and sealing value by referring to a table based on the bearing type, size, and sealing conditions.

[0009] Furthermore, the type factor a for deep groove ball bearings is 1.2; the type factor a for four-point contact ball bearings is 1.4; the type factor a for needle roller bearings is 1.7; the type factor a for cylindrical roller bearings is 1.8; and the type factor a for full complement cylindrical roller bearings is 2.0.

[0010] Furthermore, when 5≤d≤10, the size factor k is 0.5; when 10≤d<20, the size factor k is 0.6; when 20≤d<30, the size factor k is 0.8; when 30≤d<40, the size factor k is 0.9; and when 40≤d≤50, the size factor k is 1.0.

[0011] Furthermore, the sealing value for non-sealed bearings is 2; the sealing value for sealed bearings is 4.

[0012] Furthermore, the total length of the lever is equal to 10d.

[0013] The beneficial effects of this invention are: This method considers the main factors affecting bearing starting torque, such as bearing type, size, and seal, and assigns weights to calculate them, thus limiting the length of the bearing starting torque power arm and clarifying the range of measurement length.

[0014] This device has the ability to eliminate errors caused by interference factors such as internal frictional resistance of the measuring mechanism. It uses the lever principle to accurately measure the starting torque of the bearing body and can be measured multiple times to reduce random errors. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a device for measuring bearing starting torque according to an embodiment of the present invention; Figure 2 This is a top view of a device for measuring bearing starting torque according to an embodiment of the present invention; Figure 3 A structural diagram showing the connection point between the column and the lever; Figure 4 This is a structural diagram showing the connection point between the lever and the support column; Figure 5 This is a magnified view of the location of the bearing support assembly; Figure 6 This is a schematic diagram of the bearing support assembly. In the picture: 100. Slide rail; 110. Column; 111. Through hole; 112. Limit pin; 120. Scale. 200. Lever assembly; 210. Lever; 220. Bearing outer ring clamp. 300. Bearing support assembly; 310. Bearing bracket; 320. Bearing inner ring support column; 330. Bearing inner ring retaining claw; 331. Adjusting screw; 332. Tightening block. 400. Force loading device; 410. Hydraulic cylinder; 411. Display; 420. Support column. 500. Accelerometer sensor 10. Bearing to be tested; 11. Outer ring. Detailed Implementation

[0016] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0017] See Figures 1-4A device for measuring bearing starting torque includes a slide rail 100, a lever assembly 200, a bearing support assembly 300, a force loading device 400, and an acceleration sensor 500. A column 110 is slidably mounted on the slide rail 100. The lever assembly 200 includes a lever 210 rotatably connected to the column 110 and a bearing outer ring gripper 220 mounted on the lever 210. The bearing outer ring gripper 220 can be an elastic gripper as used in the prior art, and is used to fix the outer ring 11 of the bearing 10 to be tested. The bearing support assembly 300 is located at one end of the slide rail 100. The bearing support assembly 300 includes a bearing bracket 310, a bearing inner ring support column 320 disposed on the bearing bracket 310, and a plurality of bearing inner ring fixing claws 330 retractably disposed on the bearing inner ring support column 320. As an example, the bearing inner ring fixing claw 330 includes an adjusting screw 331 threadedly connected to the bearing inner ring support column 320 and a clamping block 332 rotatably connected to the end of the adjusting screw 331. When fixing the bearing 10 to be tested, the adjusting screw 331 is rotated sequentially, so that the clamping block 332 at the end of the adjusting screw 331 clamps the inner ring of the bearing 10 to be tested. The force loading device 400 is disposed at the other end of the slide rail 100. The force loading device 400 includes a hydraulic cylinder 410 and a support column 420 connected to the drive end of the hydraulic cylinder 410. The support column 420 is rotatably connected to the side of the lever 210 away from the bearing outer ring gripper 220. An acceleration sensor 500 is mounted on the top of the outer ring 11 of the bearing 10 to be tested.

[0018] In one embodiment, a scale 120 with a range of 0~400mm is provided on the slide rail 100. It should be noted that, in actual setting, the scale range of the scale 120 is determined according to the total length of the lever. In this embodiment, L is 400mm.

[0019] In one embodiment, the column 110 has a through hole 111 through which the lever 210 passes. The column 110 provides a fulcrum for the lever 210. Specifically, a limiting pin 112 is screwed into the column 110 at the location where the through hole 111 is opened, so as to limit the lever 210 and prevent unnecessary movement between the lever 210 and the column 110 in the axial direction of the through hole 111 during the measurement process, which would affect the measurement results.

[0020] In one embodiment, a display 411 is provided on the hydraulic cylinder 410 to display the instant when the acceleration of the bearing 10 under test is not zero and the force value acting on the bearing under test. The display 411 has a built-in calculation device to display the force value at the end of the bearing under test. The calculation device calculates the force value at the end of the bearing under test using the lever principle. The force applied by the hydraulic cylinder N × the length of the power arm (mm) = the force on the bearing under test N × (L - the length of the power arm (mm)).

[0021] Table 1 Parameter Comparison Table

[0022] As shown in Table 1, the type coefficient a for deep groove ball bearings is 1.2; the type coefficient a for four-point contact ball bearings is 1.4; the type coefficient a for needle roller bearings is 1.7; the type coefficient a for cylindrical roller bearings is 1.8; and the type coefficient a for full complement cylindrical roller bearings is 2.0.

[0023] When 5 ≤ d ≤ 10, the size factor k is 0.5; when 10 ≤ d < 20, the size factor k is 0.6; when 20 ≤ d < 30, the size factor k is 0.8; when 30 ≤ d < 40, the size factor k is 0.9; when 40 ≤ d ≤ 50, the size factor k is 1.0.

[0024] The sealing value for non-sealed bearings is 2; the sealing value for sealed bearings is 4.

[0025] In one embodiment, the method for measuring bearing starting torque is used to measure the starting torque of a NU306EM (72×30×19), i.e., a non-sealed cylindrical roller bearing with an outer diameter of 72mm, an inner diameter of 30mm, and a bearing width of 19mm. The NU306EM (72×30×19) bearing has an outer diameter less than 130mm and a bearing width less than 40mm. The specific steps include: Step S100: Based on the type, size, and sealing conditions of the bearing NU306EM (72×30×19), determine the type coefficient a of NU306EM (72×30×19) as 1.8, the size coefficient k as 0.9, and the sealing value b as 2. Determine L as the total length of the lever, 10d≤L≤20d, and L as an integer; d as the inner diameter of the bearing, 300mm≤L≤600mm; in this embodiment, L is taken as 400mm.

[0026] Step S200: Calculate the boom length W using the formula W=akdb. Determine the adjustment range of boom length W during measurement as W±2dmm and W±60mm.

[0027] Where d is the bearing inner diameter, a is the type coefficient, k is the size coefficient, and b is the sealing value; As an example, in step S200, the length of the power arm W is calculated as follows: W = akdb = 1.8 × 0.9 × 30 × 2 = 97.2 mm. The adjustment range of the power arm length W during measurement is determined to be W ± 60 mm, that is, the adjustment range of the power arm length W is 37 mm to 157 mm.

[0028] In step S300, the bearing to be tested, NU306EM (72×30×19), is installed on the inner ring support column 320, and the acceleration sensor 500 is installed on the top of the outer ring 11 of the bearing to be tested, NU306EM (72×30×19).

[0029] Step S400: Adjust and determine the position of the column 110 on the slide rail 100. The distance from the force loading device 400 to the column 110 is the length W of the power arm. Record W. In this embodiment, W=60mm.

[0030] Step S500: To eliminate the influence of the lever 210's own weight on the measurement results, a force is applied by the hydraulic cylinder 410 to keep the lever 210 in balance, and the force value G applied by the hydraulic cylinder 410 at this time is recorded; in this embodiment, G=16N.

[0031] Step S600: Clamp the bearing outer ring gripper 220 onto the outer ring 11 of the bearing to be tested, NU306EM (72×30×19).

[0032] Step S700: Apply force through hydraulic cylinder 410 until the acceleration of acceleration sensor 500 is not zero. Specifically, for easy observation of acceleration values, display 411 is mounted on hydraulic cylinder 410 and connected to the acceleration sensor 500 signal. It receives and displays the signal from acceleration sensor 500 and records the force F applied by hydraulic cylinder 410 at this time. In this embodiment, F = 44.27 N. The starting torque T of the bearing NU306EM (72×30×19) under test can be calculated as: Starting torque T = (FG) × (LW) × 10. -3 =(44.27N-16N)×(400mm-60mm)×10 -3 =9.612 Nm.

[0033] Step S800: Within the adjustment range of the power arm length W, change the position of the column 110 on the slide rail 100, repeat steps S400-S700, take multiple measurements, eliminate errors, and obtain accurate results.

[0034] In this embodiment, the position of the column 110 on the slide rail 100 is changed so that W=80mm. When the bearing outer ring clamp 220 is not connected to the outer ring 11 of the bearing 10 under test, the force applied by the hydraulic cylinder 410 is G=7N. The bearing outer ring clamp 220 clamps the outer ring 11 of NU306EM (72×30×19). The force is applied by the hydraulic cylinder 410 until the acceleration in the acceleration sensor 500 is not zero. The force applied by the hydraulic cylinder 410 at this time is recorded as F=37.04N. The starting torque of this bearing is calculated as T=(FG)×(LW)×10. -3 =(37.04N-7N)×(400mm-80mm)×10 -3 =9.612 Nm.

[0035] When the position of the column 110 on the slide rail 100 is changed so that W=120mm and the bearing outer ring clamp 220 is not connected to the outer ring 11 of the bearing 10 under test, the force applied by the hydraulic cylinder 410 is G=5N. The bearing outer ring clamp 220 clamps the outer ring 11 of NU306EM (72×30×19) and applies force through the hydraulic cylinder 5.3 until the acceleration in the acceleration sensor 500 is not zero. Record the force applied by the hydraulic cylinder 410 at this time as F=39.33N. Calculate the starting torque of this bearing as T=(FG)×(LW)×10. -3 =(39.33N-5N)×(400mm-120mm)×10 -3 =9.612 Nm.

[0036] The starting torque of NU306EM (72×30×19) was 9.612 Nm after three repeated measurements. After eliminating errors, this value is valid.

[0037] In another embodiment, the method for measuring the bearing starting torque is used to measure the starting torque of a 6208-2RS (80×40×18), i.e., a sealed deep groove ball bearing with an outer diameter of 80mm, an inner diameter of 40mm, and a bearing width of 18mm. For the 6208-2RS (80×40×18) bearing, the outer diameter is less than 130mm and the bearing width is less than 40mm. The specific steps include: Step S100: Based on the type, size, and sealing conditions of bearing 6208-2RS (80×40×18), determine the type coefficient a of 6208-2RS (80×40×18) to be 1.2, the size coefficient k to be 1.0, and the sealing value b to be 4. Determine L as the total length of the lever, 10d≤L≤20d, and L is an integer; d is the inner diameter of the bearing, 400mm≤L≤800mm; in this embodiment, L is taken as 400mm.

[0038] Step S200: Calculate the boom length W using the formula W=akdb. Determine the adjustment range of boom length W during measurement as W±2dmm and W±80mm.

[0039] Where d is the bearing inner diameter, a is the type coefficient, k is the size coefficient, and b is the sealing value; As an example, in step S200, the length of the power arm W is calculated as follows: W = akdb = 1.2 × 1.0 × 40 × 4 = 192 mm. The adjustment range of the length of the power arm W during measurement is determined to be W ± 80 mm, that is, the adjustment range of the length of the power arm W is 112 mm ~ 272 mm.

[0040] In step S300, the bearing to be tested 6208-2RS (80×40×18) is installed on the inner ring support column 320, and the acceleration sensor 500 is installed on the top of the outer ring 11 of the bearing to be tested 6208-2RS (80×40×18).

[0041] Step S400: Adjust and determine the position of the column 110 on the slide rail 100. The distance from the force loading device 400 to the column 110 is the length W of the power arm. Record W. In this embodiment, W=160mm.

[0042] Step S500: To eliminate the influence of the lever 210's own weight on the measurement results, a force is applied by the hydraulic cylinder 410 to keep the lever 210 in balance, and the force value G applied by the hydraulic cylinder 410 at this time is recorded; in this embodiment, G=9N.

[0043] Step S600: Clamp the bearing outer ring clamp 220 onto the outer ring 11 of the bearing to be tested 6208-2RS (80×40×18).

[0044] Step S700: Apply force through hydraulic cylinder 410 until the acceleration of acceleration sensor 500 is not zero, and record the force value F applied by hydraulic cylinder 410 at this time. In this embodiment, F=63N. The starting torque T of the bearing 10 under test can be calculated as follows: Starting torque T=(FG)×(LW)×10 -3 =(63N-9N)×(400mm-160mm)×10 -3 =12.96Nm.

[0045] Step S800: Within the adjustment range of the power arm length W, change the position of the column 110 on the slide rail 100, repeat steps S400-S700, take multiple measurements, eliminate errors, and obtain accurate results.

[0046] In this embodiment, when the position of the column 110 on the slide rail 100 is changed so that W=200mm and the bearing outer ring clamp 220 is not connected to the outer ring 11 of the bearing 10 under test, the force applied by the hydraulic cylinder 410 is G=6N. The bearing outer ring clamp 220 clamps the outer ring 11 of 6208-2RS (80×40×18). The force is applied by the hydraulic cylinder 410 until the acceleration in the acceleration sensor 500 is not zero. The force applied by the hydraulic cylinder 410 at this time is recorded as F=70.8N. The starting torque of this bearing is calculated as T=(FG)×(LW)×10. -3 =(70.8N-6N)×(400mm-200mm)×10 -3 =12.96Nm.

[0047] When the position of the column 110 on the slide rail 100 is changed so that W=220mm, and the bearing outer ring clamp 220 is not connected to the outer ring 11 of the bearing 10 under test, the force applied by the hydraulic cylinder 410 is G=5N. The bearing outer ring clamp 220 clamps the outer ring 11 of 6208-2RS (80×40×18), and the hydraulic cylinder 5.3 applies force until the acceleration in the acceleration sensor 500 is not zero. Record the force applied by the hydraulic cylinder 410 at this time as F=77N. Calculate the starting torque of this bearing as T=(FG)×(LW)×10. -3 =(77N-5N)×(400mm-220mm)×10 -3 =12.96Nm.

[0048] The starting torque of NU306EM (72×30×19) was 12.96 Nm after three repeated measurements. After eliminating errors, this value is valid.

[0049] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0051] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] In this invention, unless otherwise explicitly specified and limited, "above" or "below" a second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of a second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" a second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature. It should be noted that when an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or there may be an intermediate element present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element present. The terms "vertical," "horizontal," "above," "below," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

Claims

1. A method for measuring bearing starting torque, comprising a device for measuring bearing starting torque, wherein the device for measuring bearing starting torque includes... The slide rail has columns that can be slidably mounted on it. A lever assembly includes a lever rotatably connected to the column and a bearing outer ring clamp disposed on the lever; A bearing support assembly is disposed at one end of the slide rail, including a bearing bracket, a bearing inner ring support column disposed on the bearing bracket, and a plurality of bearing inner ring fixing claws retractably disposed on the bearing inner ring support column; A force loading device is provided at the other end of the slide rail, including a hydraulic cylinder and a support column connected to the drive end of the hydraulic cylinder. The support column is rotatably connected to the side of the lever away from the outer ring of the bearing gripper. An accelerometer is mounted on the top of the outer ring of the bearing to be tested. Its features are: The specific steps of the method for measuring the bearing starting torque include: Step S100: Determine the type factor, size factor, and sealing value; Step S200: Calculate the boom length W using the formula W=akdb. Determine the adjustment range of the boom length W during measurement as W±2d. Where d is the bearing inner diameter, a is the type coefficient, k is the size coefficient, and b is the sealing value; Step S300: The bearing to be tested is mounted on the inner ring fixing claw, and the acceleration sensor is mounted on the top of the outer ring of the bearing to be tested. Step S400: Adjust and determine the position of the column on the slide rail. The distance from the force loading device to the column is the length W of the power arm. Record W. Step S500: Apply force through the hydraulic cylinder to keep the lever balanced, and record the force G applied by the hydraulic cylinder at this time; Step S600: Clamp the bearing outer ring clamp onto the outer ring of the bearing to be tested; Step S700: Apply force through the hydraulic cylinder until the acceleration of the accelerometer is not zero. Record the force value F applied by the hydraulic cylinder at this moment. The starting torque T of the bearing under test can be calculated using the formula: Starting torque T = (FG) × (LW) × 10 -3 Where L is the total length of the lever, 10d≤L≤20d, and L is an integer; Step S800: Within the adjustment range of the power arm length W, change the position of the column on the slide rail, repeat steps S400-S700, and measure multiple times to obtain the bearing starting torque.

2. The method for measuring bearing starting torque according to claim 1, characterized in that: Step S100 includes determining the type coefficient, size coefficient, and sealing value by referring to a table based on the bearing type, size, and sealing conditions.

3. The method for measuring bearing starting torque according to claim 1, characterized in that: The type factor a for deep groove ball bearings is 1.2; the type factor a for four-point contact ball bearings is 1.4; the type factor a for needle roller bearings is 1.7; the type factor a for cylindrical roller bearings is 1.8; and the type factor a for full complement cylindrical roller bearings is 2.

0.

4. The method for measuring bearing starting torque according to claim 1, characterized in that: When 5 ≤ d ≤ 10, the size factor k is 0.5; When 10 ≤ d < 20, the size factor k is 0.6; When 20 ≤ d < 30, the size factor k is 0.8; When 30 ≤ d < 40, the size factor k is 0.9; When 40≤d≤50, the size factor k is 1.

0.

5. The method for measuring bearing starting torque according to claim 1, characterized in that: The sealing value for non-sealed bearings is 2; the sealing value for sealed bearings is 4.

6. The method for measuring bearing starting torque according to claim 1, characterized in that: The total length of the lever is equal to 10d.

7. A device for measuring the starting torque of a bearing, characterized in that: The bearing starting torque measurement method as described in claim 1 is used, wherein a scale is provided on the slide rail.

8. The device for measuring bearing starting torque according to claim 7, characterized in that: The column has a through hole, and the lever passes through the through hole.

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