JP2003050169A - Real-time bearing load sensing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a system, for measuring load to be applied to a bearing assembly, being complicate and measured result being unable to be obtained in real time. SOLUTION: A method for measuring a load value to be applied to a bearing real time comprises the steps of preparing the bearing, having an inner lace 12, an outer lace 16, and a plurality of rolling elements provided in between the inner lace 12 and the outer lace 16, mounting a plurality of strain gages 20 at the bearing, gathering data of strains measured under the conditions of a plurality of known load states, comparing the strain measured value of each strain gage position with the load at its position for each of the plurality of the load states, forming first equation R/A=4.2242-6.5016(E12 /E3 )+4.6636(E12 / E3 )<2> , where A is an axial, that is, thrust direction load, and R is a radial direction load, representing the load as a function of the measured strain at each strain gage position, mounting the bearing in a machine, operating the machine in a load state, gathering the strain gauge data, converting the measured value of the strain into a load by using the equation, adding the load to be applied to the bearing, thereby obtaining a total load to be applied to the bearing.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates generally to rolling bearing assemblies, and more particularly to rolling bearing assemblies having a sensor which provides an output indicative of the load acting on the bearing.

[0002]

BACKGROUND In the development of mechanical systems, it is often necessary to measure the load on a bearing assembly. The load value allows the proper selection of bearing components for a particular application. Although there are systems that measure the load on bearings, they are often complex systems that do not provide reliable load output. A particular drawback of many existing solutions is their lack of real-time load output capability. Instead, the total load value can only be estimated by examining the part after cyclic loading.

Therefore, in the industry, bearing evaluation, development,
There is a need for a rolling bearing assembly that can be used in component selection to perform load output measurements in real time.

[0004]

SUMMARY OF THE INVENTION According to one aspect of the present invention, a rolling bearing assembly includes an inner race, an outer race, and a plurality of rolling elements provided between the outer race and the inner race and connecting the two. . The assembly further comprises a plurality of strain gauges attached to the bearing assembly and a device for receiving output from the strain measuring device and converting the output into real time load data.

The present invention further provides a method for measuring the load value applied to the rolling bearing in real time. A plurality of strain gauges are mounted on the bearing in a particular orientation, allowing collection of strain data measured under a plurality of known load conditions. By comparing the strain measured at each strain gauge position with the load at this position in each of multiple load conditions, derive an equation for the load as a function of the strain measurement for each strain gauge position. You can By summing the loads on the bearing, measured by the strain gauges, the total load on the bearing is obtained.

[0006]

Detailed Description of the Preferred Embodiments The following description of the preferred embodiments of the invention is not intended to limit the scope of the invention to this particular embodiment, as one of ordinary skill in the art will appreciate. Is to enable.

Referring to FIGS. 1-5, the rolling bearing assembly of the present invention is generally indicated at 10. The bearing assembly includes an inner race 12 having a central shaft 14 and an inner race 1.
2 and is equipped with an outer race 16 adapted to carry a load. The bearing assembly 10 further supports the outer race 16 with the inner race 12 and allows the outer race 16 to rotate about the central axis 14 with respect to the inner race 12 so that the inner race 12 and the inner race 16 rotate together. A plurality of rolling elements 18 are provided between the races 12 and connect them to each other. A plurality of strain gauges 20 are attached to the bearing assembly 10 and are attached to a device that receives the output from the strain gauges 20 and converts the output into real time load data. The strain gauge 20 is preferably a resistance type which is attached to the surface of the bearing 10 by adhesion. The strain is measured by the strain gauge 20 as a resistance change.

In the preferred embodiment, the bearing assembly 10 is
One or both of the races 12, 16 have an unsupported surface 24. The non-supporting surface 24 is a cylindrical inner surface or outer surface that extends in an annular shape along the inner diameter of the inner race 12 or the outer diameter of the outer race 16. The unsupported surface 24 can be formed in a number of ways. In FIG. 2, the outer race 16 may be formed with a groove 26a extending annularly around the outer race 16. When the bearing support portion 28 is attached to the outer diameter of the bearing assembly 10, a gap is created between the bottom of the groove and the bearing support portion 28 attached to the bearing,
The groove bottom becomes the non-supporting surface. When a load is applied to the bearing, the groove bottom, that is, the non-supporting surface 24a can bend outward in the gap. The groove extends annularly around the bearing assembly 10 to allow flexure of the unsupported surface 24. In FIG. 3, an axle 30b to which the bearing assembly 10b is attached is provided with a groove 26b extending annularly around the axle 30b so that the cylindrical portion of the inner race 12b is not supported by the axle 30b. 24b may be formed.

Further, the groove 26b 'may be formed in the bearing support portion 28 attached to the outer race 16b so that the cylindrical portion of the outer race 16b is unsupported and the unsupported surface 24b' is provided.
In FIG. 4, the inner race 12c is provided with a groove 26c extending annularly around the inner race 12c, and the inner race 12c has a cylindrical inner surface 24c.
May be provided. When a load is applied to the bearing assembly 10c,
The surface 24c can flex within a gap formed between the unsupported surface 24c and the axle 30c. Figure 5 shows the inner race 12d
A bearing assembly 10d is shown having a groove 26d formed deeply in the inner race 12d to form an unsupported surface 24d. This may be desirable in reducing the rigidity of the bearing assembly 10d so that the bearing assembly 10d flexes more and increases its sensitivity to applied loads.

The unsupported surface 24 of the bearing assembly 10 is necessary to create the point on the bearing assembly 10 at which bearing deflection occurs. Preferably, the measured strain is due to bending or deflection of the bearing along the unsupported surface of bearing assembly 10. The strain gauge 20 is preferably mounted on the unsupported surface 24 of the bearing assembly 10 to maximize strain gauge measurements. Also, the strain gauge 20 may be mounted to the bearing assembly 10 in any orientation, but in the preferred embodiment, the strain gauge 20 is attached to the central axis 14 of the bearing assembly 10 to measure axial bending strain. It extends in the same axial direction. The load on the bearing 10 having a radial component causes the unsupported surface 24 to flex. This deflection is measured as the tensile strain of the unsupported surface 24 which extends axially in the same direction as the central axis 14 of the bearing, ie parallel thereto.

A first preferred method of measuring the real-time load value on a bearing is the bearing assembly 1 as described above.
0 and mounting a plurality of strain gauges 20 at the positions of the bearing rolling elements 18 of the bearing assembly 10. Preferably, at least two strain gauges 20 are used, one of which is located at the point where the radial load is directly applied and the other strain gauge 20 is connected to the first strain gauge 2.
Index from 0 in the direction of rotation.

In operation, the bearing assembly 10 can be mounted with the axle 30 to which the inner race 12 is attached not rotating and the load on the bearing assembly 10 being transmitted through the axle 30. In this case, since the direction of the load does not change with respect to the bearing assembly 10, the strain gauge 20
Is attached to the inner race 12 with one of the gauges 20 aligned with the point at which the radial load is directly applied.

In another situation, the load is transmitted via points on the outer race 16. In this situation, the point at which the direct load is applied is that the outer gauge 16 moves around the bearing assembly 10 as the outer race 16 rotates about the inner race 12, so the strain gauge 20 is one point where maximum deflection of the outer race 16 occurs. Outer race 1 with one of the gauges 20 aligned
Attach to 6. Each of the above two situations illustrates the concept that the strain gauge 20 is aligned with the point of maximum bending deflection caused by radial loads. If the load does not rotate with respect to the inner race 12 of the bearing assembly 10, the strain gauge 20 is attached to the inner race 12, and if the point where the load is directly rotating around the bearing assembly 10, the strain gauge 20 will Attach to the outer race 16.

Data is then collected from the strain gauges 20 by simulating a known load condition of the bearing assembly 10 and recording the strain at that load condition. Preferably, the data is collected based on a number of known loading situations. The use of multiple load situations results in multiple data points that ultimately provide more accurate load information when the bearing assembly 10 is used in the field.

The data can be collected in one of two ways, based on the known loading situation.
Preferably, the bearing assembly 10 is mounted on a test device,
Operate under different load conditions. While operating the bearing assembly 10 under various conditions, data is recorded from the strain gauges 20 attached to it. However, when the bearing assembly 10 is extremely large, mounting the bearing assembly 10 on a test device is impractical or impossible. Alternatively, a finite element model of the bearing assembly 10 can be created and the expected strain data under known load conditions can be measured by finite element analysis.

When the data from each strain gauge 20 is collected for each of the different known load conditions, the measured strain is compared to the load as a function of the strain measurements applied to the bearing assembly 10. "A" joining the assembly
Several mathematical formulas for obtaining the load in the axial direction, that is, the thrust direction represented by and the load in the radial direction represented by "R" are created. In the preferred embodiment, the different loads are radial loads (R).
Is expressed in the form of a ratio of the load to the load (A) in the axial direction, that is, the thrust direction. The strain gauge ratio is calculated for each combination of load ratio and load. The strain gauge ratio is the ratio of the strain gauge 20 at the maximum load point to the other strain gauges 20. When using two or more strain gauges 20, a more complicated relational expression of the strain gauges 20 is required. Next, the strain gauge ratios for different loading conditions are averaged. Next, a regression analysis is performed on this data to derive a first equation which is an equation for obtaining a load ratio as a function of the relationship of the strain gauge 20.

Next, a regression analysis is performed on the sum of the radial (R) load and the axial (A) load to obtain the sum of the radial and axial loads as a function of the strain of the strain gauge 20 at the maximum load point. Formula 2 is derived. Preferably, the second equation is a linear equation having a unique slope for each of the different load ratios. A regression analysis is performed to calculate a third equation, which is an equation representing the slope of the second equation, which is a function of the load ratio. Second and third
The equations are combined to form an equation that represents the function of the sum of the radial and axial loads, and the strain measured by strain gauge 20 at the point of maximum load and the ratio of radial load to axial load.

Next, the strain gauge 2 under an unknown load condition
The measured value of the actual strain gauge of 0 is substituted into the first equation to obtain the ratio of radial load to axial load. Substituting the ratio of radial load to axial load into the fourth equation,
Calculate the sum of radial load and axial load. Finally, the ratio of the radial load to the axial load and the sum of the radial load and the axial load are substituted into the following formulas to calculate the axial load and the radial load. In the following equation, A is an axial or thrust load, and R is a radial load.

A = (R + A) / [(R / A) +1] R = (R + A)-[(R + A) / [(R / A) ^ 2]] In the bearing assembly 10. The first preferred method of measuring the applied real-time load value is by the system or bearing assembly 10.
When the axle 30 to which the bearing assembly 10 is attached is sufficiently rigid, it works well. This is because the first preferred method and the equations used in this method are basic and do not take into account the dramatic flexing of the axle 30 and / or bearing assembly 10. is there. Thus, for systems with large deflection of the axle 30 and other components, a different approach is required to associate the strain measurements of the bearing assembly 10 with the load applied to the bearing assembly 10.

Preferably, the bearing assembly 10 receives data from the strain gauges 20 for instant calculation and conversion.
A device (not shown) that outputs the radial load and the axial load applied to the shaft in real time is used. Preferably the device is a computer. However, it should be understood that it is possible for a human to read and analyze the data using any suitable method, including methods of reading strain gage data and making calculations.

A second preferred method for measuring the value of the load applied to the bearing in real time is to provide the bearing assembly 10 as described above, and attach a plurality of strain gauges 20 to the rolling elements 18 of the bearing assembly 10. Including steps. Ideally, if one strain gauge 20 is provided at each position of the rolling element of the bearing assembly 10, the most accurate data can be obtained. However, since such a thing is difficult in reality, the strain gauge 20 is provided only on one side of the bearing assembly 10 in this embodiment. That is, FIG.
Since the bearing assembly 10 is symmetrical, the strain gauges 20 begin on the 0 ° position 32 and extend circumferentially at 30 ° intervals to 180 ° positions 34 on only one side of the bearing assembly 10, as shown in FIG. Seven are provided. When the bearing assembly 10 has an asymmetric structure, the strain gauge 20 needs to be provided over the entire circumference. The present invention is applicable to any suitable number of rolling elements 18 within bearing assembly 10 and any suitable number of strain gauges 20 symmetrically spaced about bearing assembly 10. You should understand that.

The strain gauge 20 is preferably attached to the unsupported surface 24 as described above. Also strain gauge 2
0 may be mounted to bearing assembly 10 in any orientation, but in the preferred embodiment, strain gauge 20 is axially aligned with central axis 14 of bearing assembly 10 to measure axial tensile strain. It extends in the same direction.

Data is then collected from the strain gauge 20 by simulating a known load situation of the bearing assembly 10 and recording the strain under that load situation. Preferably, the data is collected based on a number of known loading situations. The use of multiple load situations results in multiple data points that ultimately provide more accurate load information when the bearing assembly 10 is used in the field.

The data can be collected in one of two ways, based on the known loading situation. Preferably, the bearing assembly 10 is mounted on the test apparatus and operated under various load conditions. While operating the bearing assembly 10, record data from the strain gauges 20 attached to it. However, if the bearing assembly 10 is extremely large, mounting the bearing assembly 10 on a test device is impractical or impossible. Alternatively, a finite element model of the bearing assembly 10 and an axle may be created and the strain data expected under known load conditions may be measured by finite element analysis.

As the data from each strain gauge 20 at different known load conditions are collected, the strain measurements are contrasted with the load and the axial and axial loads applied to the bearing assembly as a function of the strain measurements applied to the bearing assembly 10. Several equations for the radial load are created. In the preferred embodiment, the strain data for each different load condition at each strain gauge position is individually regression analyzed to derive an equation that describes the load at that strain gauge position as a function of the strain measured at that position. Any suitable type of regression analysis may be used. Depending on the data, linear regression may be the most accurate, and quadratic or cubic regression may be more accurate. The most suitable type of regression for your data is appropriate.

After deriving a load equation relating the load at each strain gauge position to the strain measured at the corresponding position,
Strain data from a known load is substituted into the load equation to calculate the load value. If there is an error between the load value calculated in this way and the known load value, it is analyzed by regression method and the error between the calculated load and the actual load is calculated as the strain at each strain gauge position. A first error equation associated with is obtained.
The first error equation is calculated for each strain gauge position and added to the load equation at the corresponding strain gauge position, or
Then subtract. The error thus obtained in the formula thus obtained is reduced, and the accuracy of the load data is improved. The process of deriving this error formula can be performed any number of times, and the more times it is performed, the more accurate the load formula becomes.

The bearing assembly 10 is then attached to the axle 30 of a machine or vehicle and used in multiple normal load conditions.
During use of the machine, strain gauges output strain data. This data is collected and substituted into the load formula obtained for each strain gauge position to calculate the load at each strain gauge position. Preferably, the data is sent from the strain gauges to the device, where it is instantly calculated and transformed to provide the bearing assembly 1
The load applied to 0 is output in real time. After calculating the load at each strain gauge position, the load at each rolling element position between each strain gauge position is calculated by the extrapolation method to obtain the load applied to each rolling element position of the bearing assembly 10. If the loads at the individual rolling element positions can be calculated, they are summed to determine the total load applied to the bearing assembly 10.

The bearing assembly 10 can be any type of bearing, including cylindrical roller bearings and needle bearings designed to handle radial loads only, but for most applications, such as tapered roller bearings and ball bearings. Other types of bearings that support both axial and radial loads are needed.
When the bearing assembly 10 is a type of bearing that bears both radial and axial loads, it calculates all the loads at each rolling element position and then decomposes it into radial and axial components. . This can be done by a simple calculation based on the shape of the ball or tapered roller bearing. Thereafter, the axial components are summed and the radial components are summed to obtain the total axial load and the total radial load applied to the bearing assembly 10.

[0029]

EXAMPLES The following examples illustrate embodiments and methods of the present invention.
It is to be noted that the methods disclosed in the following examples represent the examples and methods that the inventor believes to work well in carrying out the present invention, and thus constitute a preferred mode for carrying out the invention. The trader will understand. Therefore, the examples should not be construed as limiting the invention to this preferred form. Furthermore, one of ordinary skill in the art appreciates that many modifications can be made to the particular embodiments and methods disclosed and that similar results can be obtained without departing from the spirit and scope of the invention. Should.

Example 1 In FIGS. 1 and 5, the bearing assembly 1 used in Example 1
Reference numeral 0 denotes a tapered roller bearing having 33 rolling elements 18. As shown in FIG. 9, the three strain gauges A1, A2,
A3 was provided inside the inner race. The inner diameter of the bearing is provided with a hollow so that the inner race 12 can be unsupported. All three strain gauges were axially aligned with the bearing assembly. The load was applied at the point P1 of the bearing and held stationary with respect to the inner race, thereby maintaining its position relative to the strain gauge 20. Point P1 is between strain gauges A1 and A2, so the strains measured by these two gauges were averaged to obtain A12. Therefore, two strain gauges A12
The result is similar to that of the experiment using A3 and A3. Sixteen tests were conducted with four different load combinations for the four load ratios. The data gathered from these tests is shown in Table 1.
Shown in. R / A in the table is the ratio of the radial load to the axial load.

[0031]

[Table 1]

The strain gauge ratios for all 16 tests were then calculated, and the average strain gauge ratio for each of the four radial / axial load ratios was calculated. The results are shown in Table 2.

[0033]

[Table 2]

Next, this data was subjected to a quadratic regression analysis to derive an equation expressing the ratio of load to the measured strain ratio. R / A = 4.2242-6.5016 (Ε ₁₂ / Ε ₃ ) +4.6636 (Ε ₁₂ / Ε ₃ ) ² (Formula 1).

Next, a linear regression analysis of the sum of the radial load and the axial load was performed, and an equation representing the sum of the radial load and the axial load as a function of the strain E12 at the load point was derived. Where m is the slope of this linear equation, R is the radial load,
A is the axial load. (R + A) = m (Ε ₁₂ ) +1000 (second formula).

The slope m of the second equation differs depending on the load ratio.
The inclinations m with respect to the load ratios 2, 3, 4, 5 are 3 respectively
3, 48, 61 and 64. Then, a linear regression analysis of the slope was performed to derive an equation representing the slope that is a function of the load ratio. m = -18.6 + 31.6 (R / A) -3 (R / A) ² (3rd formula).

The second and third equations were combined to derive a fourth equation which represents the ratio of the radial load to the axial load and the sum of the radial and axial loads as a function of strain at the load point. . (R / A) = 1000 + Ε 12 [-18.6 + 31.6 (R / A) - 3 (R / A) 2] ( 4 type).

There are two equations and two unknowns. To solve this equation, the values of strain gauge values E12 and E3 are substituted into the first equation to obtain (R / A). Then (R /
Substituting the values of A) and E12 into the fourth expression, (R + A) is obtained. Finally, (R + A) and (R / A) can be used to calculate the radial load R and axial load A as shown below. A = (R + A) / [(R / A) +1] (5th formula). R = (R + A)-[(R + A) / (R / A) ² ] (6th formula).

By operating the bearing under the same load conditions, collecting strain data, and using the above method, the calculated load values were within a few percent of the actual load, as shown in Table 3 below. In the table, the units of the radial load R and the axial load A are pounds, and all strains are micro inches per inch.

[0040]

[Table 3]

Example 2 Referring to FIGS. 7 and 8, a double row bearing mechanism used in a very large vehicle used in a considerably large class under a very large load of about one million pounds was analyzed. The device is too large to be tested in the lab. Instead, we made a finite element analysis model of the axle. Strain data on bearing 10 was simulated under four known load conditions using four load scenarios and FEA analysis. The bearing assemblies 10 were both conical rolling element bearings having 36 rolling elements. They were mounted on the axle 30 in a state of being axially opposed to each other with a space therebetween. The inner diameter of the bearing is provided with a hollow so that the inner race 12 can be unsupported. The two bearing assemblies 10 are attached to the inboard side bearing 3
6. Outboard side bearing 38 is used. The load conditions (unit: pound) are shown in Table 4 below.

[0042]

[Table 4]

It was assumed that seven strain gauges were provided for each of the two bearing assemblies 10 of the FEA model. The first strain gauge is attached at the 12 o'clock position, that is, at the 0 ° position, and from there, at 30 ° intervals up to the 180 ° position, 0
°, 30 °, 60 °, 90 ° 120 °, 150 °, 18
It is assumed that seven pieces are provided at the 0 ° position. It was assumed that the strain gauge 20 was provided on the inner diameter of the inner race 12 and was axially aligned with the bearing assembly 10. Strain data by simulation collected in each strain gauge 20 in each load state is shown in Tables 5, 6, 7, and 8 below.

[0044]

[Table 5]

[0045]

[Table 6]

[0046]

[Table 7]

[0047]

[Table 8]

Next, four different load conditions are analyzed by the finite element analysis method, and the inboard-side bearing 36 and the outboard-side bearing 38 are bearings at the same rolling element position with respect to the strain of the bearing measured at the rolling element position. An equation expressing the load applied to is obtained. This formula is shown in Tables 9 and 10 below.

[0049]

[Table 9]

[0050]

[Table 10]

Next, by substituting the measured values of the strain gauges into these expressions, it was examined how close the solution of this expression was to the load applied to the bearing. The calculated load was compared with the actual load to calculate the error at each strain gauge position. If the error is too large, analyze it by regression analysis to create a formula that describes this error as a function of the strain at the rolling element position and add that formula to the first formula for a more accurate calculation. You can get the value. The operation of substituting the actual strain value into the equation updated in this way and comparing the load obtained by the calculation with the actual load may be repeated many times. Once the error is small enough, the formula is complete. Some of the expressions in Tables 9 and 10 have been corrected in this way, and are more complicated than the other expressions because of such operations. The load data obtained by calculation and the actual load data are shown in Tables 11, 12, 13, and 14 below.

[0052]

[Table 11]

[0053]

[Table 12]

[0054]

[Table 13]

[0055]

[Table 14]

Next, the load at the rolling element position where the strain gauge 20 was not mounted nearby was determined by the linear extrapolation method. The load was then decomposed into radial and axial components using the contact angle of the tapered roller bearing. Then, this is the last, but for each of the four load conditions, the radial load and the axial load were summed to determine the total load applied to the bearing in each load condition. The bearing was symmetrical, so 0
While the load at the ° and 180 ° positions was counted only once,
The load at the position of 10 ° to 170 ° was counted twice in order to count the corresponding rolling elements on the opposite side. The final results are shown in Tables 15-18 below. All units are pounds.

[0057]

[Table 15]

[0058]

[Table 16]

[0059]

[Table 17]

[0060]

[Table 18]

As mentioned above, radial and axial loads at the 0 ° and 180 ° positions are counted only once and from 10 ° to
At the position of 170 °, the load in the radial direction and the load in the axial direction were summed twice. Table 19 shows the total loads on the bearings obtained using the method of the present invention.

[0062]

[Table 19]

The final step of this method is to establish a reference for selecting a bearing suitable for practical use by using the same or similar axle 30 under the same or similar load conditions as in the experiment. .

The foregoing discussion discloses and describes a preferred embodiment of the present invention. From this description and the accompanying drawings and claims, those skilled in the art will readily recognize that changes can be made without departing from the spirit and scope of the invention as defined by the above claims. The above description is intended to be an understanding of the invention and is not intended to be limiting.

[Brief description of drawings]

FIG. 1 is a perspective view of a bearing assembly of the present invention.

FIG. 2 is a vertical sectional side view of a bearing of the present invention in which a groove is formed in an outer race.

[FIG. 3] A groove is formed in a support portion to which a bearing is attached,
Vertical side view of the bearing of the present invention

FIG. 4 is a vertical sectional side view of the bearing of the present invention in which a groove is formed in the inner race.

FIG. 5 is a vertical sectional side view of a bearing of the present invention in which a deep groove is formed in an inner race.

FIG. 6 is a longitudinal sectional view of an end portion of a bearing of the present invention in which a groove is formed on an axle.

FIG. 7 is a vertical sectional side view of an axle having two bearing assemblies attached.

FIG. 8 is a longitudinal sectional view of an end portion of a bearing assembly provided with seven strain gauges.

FIG. 9 is a longitudinal sectional view of an end portion of a bearing assembly provided with three strain gauges.

[Explanation of symbols]

10 bearing 12 inner race 16 outer race 20 strain gauges 24, 24a, 24b, 24b ', 24c, 24d
Unsupported cylindrical surface 26a, 26b, 26b ', 26c, 26d Annular groove

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Peter M. Eich             United States 60067 Illinois Para             Tyne Dorset Avenue 776 F-term (reference) 2F051 AB09 BA07                 3J101 AA16 AA25 AA32 AA42 AA54                       AA62 BA77 FA25 GA02

Claims (27)

[Claims] 1. An inner race having a central axis attached to an axle, an outer race attached to the inner race for supporting a bearing supporting portion, wherein an annular groove forming an unsupported cylindrical surface is the inner race, An unsupported cylindrical surface of an inner race or an outer race that extends around the bearing assembly is formed on any of the outer race, the axle, and the bearing support portion, and a plurality of rolling elements form the outer race. The rolling elements are provided between the inner races, and the outer races are supported by the inner races so as to be rotatable about the central axis with respect to the inner races. A plurality of strain gauges are provided in the inner races of the bearing assembly. Alternatively, a rolling bearing assembly mounted on the cylindrical surface of the outer race and measuring the axial strain caused by the load being applied to the bearing and one of the races flexing. 2. The annular groove is formed in the inner race,
The rolling bearing of claim 1, extending in the circumferential direction of the inner race, the inner diameter of the groove forming the unsupported surface, and the plurality of strain gauges being attached to the unsupported surface of the inner race. Assembly. 3. The inner race is attached to the axle so as not to rotate relative to the axle and a load applied to the axle, and the strain gauge is attached to a point of the inner race to which a radial load is directly applied. Claim 2
Rolling bearing assembly. 4. The annular groove is formed in the axle, extends in the circumferential direction of the axle, the inner race has an inner diameter surface that straddles the groove, and the unsupported surface has the inner diameter of the inner race. 2. The rolling bearing assembly of claim 1, which is a portion of a surface, just above the groove, wherein the plurality of strain gauges are attached to the unsupported surface of the inner race. 5. The inner race is attached to the axle so as not to rotate relative to the axle and a load applied to the axle, and the strain gauge is attached to a point of the inner race to which a radial load is directly applied. Claim 4
Rolling bearing assembly. 6. The annular groove is formed in the bearing support portion, extends in the circumferential direction of the bearing support portion, the outer race has an outer diameter surface that straddles the groove, and the non-support surface is the 2. The rolling bearing assembly of claim 1, which is a portion of the outer diameter surface of the outer race that is in line with the groove and wherein the plurality of strain gauges are attached to the unsupported surface of the outer race. 7. The inner race is attached to the axle so as not to rotate relative to the axle, a load applied to the bearing rotates about the axle, and the strain gauge is in a radial direction of the outer race. The rolling bearing assembly of claim 6 mounted at a point where a load is directly applied. 8. The annular groove is formed in the outer race,
The rolling of claim 1, extending in the circumferential direction of the outer race, the groove having an outer diameter that provides the unsupported surface, and the plurality of strain gauges being attached to the unsupported surface of the outer race. Bearing assembly. 9. The inner race is attached to the axle so as not to rotate relative to the axle, a load applied to the bearing rotates about the axle, and the strain gauge is in a radial direction of the outer race. The rolling bearing assembly of claim 8 mounted at a point where the load is directly applied. 10. The rolling bearing assembly of claim 1, wherein the axle is an axle of an automobile that supports wheels. 11. The bearing assembly is connected to a device that receives data from the strain gauges, instantaneously performs the necessary calculations and conversions, and outputs the radial and axial loads on the bearings in real time. The rolling bearing assembly according to claim 1. 12. One of the plurality of strain gauges is attached to the inner race or the outer race at a point where a radial load is directly applied, and the remaining strain gauges are circumferentially separated from the one strain gauge. The rolling bearing assembly according to claim 1. 13. A strain gauge comprising two strain gauges, wherein a first gauge of the strain gauges is provided at a point where a radial load is directly applied, and the other of the strain gauges is surrounded by the first strain gauge. 13. The rolling bearing assembly of claim 12, spaced apart in the direction. 14. The rolling bearing assembly according to claim 12, further comprising a plurality of strain gauges arranged at equal intervals in the circumferential direction on the non-supporting surface and arranged in the same direction as the rolling element position in the bearing. . 15. The plurality of strain gauges are provided one at each rolling element position of the bearing, and each strain gauge is attached to the unsupported surface in a state of being aligned with one of the rolling elements. The rolling bearing assembly according to claim 12. 16. An inner race mounted on an axle, an outer race supporting a bearing support portion, and a plurality of rolling elements provided between them, and the bearing is mounted on any one of the inner race, the outer race, the axle and the bearing support portion. Providing a bearing with an annular groove extending in the circumferential direction of the bearing, the annular groove forming an unsupported cylindrical surface that allows axial bending flexure of the bearing, the inner race or outer race of the bearing Installing multiple strain gauges in the rolling element position on the unsupported surface of the bearing in axial alignment with the bearing, collecting strain data measured by each strain gauge under multiple known load conditions, Comparing the measured values to the axial and radial loads on the bearing, creating multiple equations for the axial and radial loads on the bearing, corresponding to the measured strain on the bearing, and mounting the bearing on the machine. With , Operating the machine under load, collecting strain gauge data when the load applied to the machine is changing, and using the above equations to convert strain measurements into real-time radial and axial loads. A method of measuring the value of the load applied to the bearing in real time, including converting. 17. The operation of collecting strain data measured by each strain gauge under a plurality of known load conditions,
Attach the bearing with the strain gauge to the test fixture,
17. By collecting data from strain gauges while operating the bearing under a plurality of known load conditions.
the method of. 18. The operation of collecting strain data measured by each strain gauge under a plurality of known load conditions,
17. The method of claim 16 including creating a finite element model of a bearing and using finite element analysis methods to calculate strain at strain gauge locations under the plurality of known load conditions. 19. A step of comparing a strain measurement value with an axial load and a radial load applied to a bearing, and creating a plurality of formulas for obtaining the axial load and the radial load applied to the bearing corresponding to the measured value of the bearing strain. , Collect strain data from each of multiple strain gauges under each load ratio and load condition, calculate strain gauge ratio for each combination of load ratio and load, average strain gauge ratio for each of multiple load ratios The value is calculated, the regression analysis is carried out to calculate the first formula, the quadratic formula for obtaining the load ratio as a function of the strain gauge ratio is derived, and the regression analysis is carried out to calculate the second formula. Make a formula to find the sum of radial and axial loads as a function of strain on the strain gauge being applied. This formula has a unique slope for each load ratio. Perform regression analysis to calculate the third formula. And load ratio A formula for obtaining the slope of the second formula as a function of is derived, the fourth formula is calculated by combining the second formula and the third formula, and the sum of the radial load and the axial load, which is a function of strain, and the axial direction are calculated. Create a formula to calculate the ratio of radial load to load, substitute the strain gauge value obtained in an unknown load state into the first formula, and calculate the ratio of actual radial load to actual axial load. Substituting the ratio of the actual radial load to the axial load into the fourth formula, the sum of the actual axial load and the actual radial load is obtained, and the sum of the actual axial load and the actual radial load is calculated. , Using the ratio of the actual radial load to the actual axial load,
17. The method of claim 16 comprising the step of calculating the actual radial and axial loads on the bearing. 20. Gathering strain gauge data under varying machine loads and converting strain measurements into real-time radial and axial loads using the above equations. Prepares a device that receives the data from the strain gauge, instantaneously performs necessary calculations and conversions, and outputs the radial and axial loads applied to the bearing in real time, attaches the strain gauge to the device, 17. The method of claim 16 including collecting output data using and converting strain measurements in real time to radial and axial loads. 21. One of an inner race, an outer race, an axle, and a bearing support portion, comprising an inner race attached to an axle, an outer race attached to a bearing support portion, and a plurality of rolling elements provided therebetween. Prepare a bearing in which an annular groove extending in the circumferential direction of the bearing is formed, and the annular groove forms an unsupported cylindrical surface that allows bending of the bearing in the axial direction. At the rolling element position on the unsupported surface of the, the strain gauges that are lined up in the axial direction with the bearing are installed so as to form a line in the axial direction with the bearing, and the strain measured by each strain gauge under multiple known load conditions. For each of several load conditions, the strain measurement value at each strain gauge position is compared with the load at that position, and the strain measured at each strain gauge position is measured for each strain gauge position. Function, at that position Create the first formula to calculate the load, attach the bearing to the machine, operate the machine under the load condition, collect the strain gauge data under the condition that the load applied to the machine changes, and calculate the above formula for each strain gauge position. The strain measurement value at each strain gauge position is converted to the load at that position by extrapolating between the strain gauges, and the load at the rolling element position where the strain gauge is not attached is calculated. A method of measuring the load value applied to a bearing in real time by adding the load applied to the bearing at the position to obtain the total load applied to the bearing. 22. Collecting strain data measured by each strain gauge under a plurality of known loading conditions,
Attach the bearing with the strain gauge to the test equipment,
22. The method of claim 21 including the step of collecting data from the strain gauge while operating the bearing under a plurality of known load conditions. 23. Collecting strain data measured by each strain gauge under a plurality of known loading conditions,
22. The method of claim 21 including the step of creating a finite element model of the bearing and using finite element analysis methods to calculate strain at strain gauge locations under the plurality of known load conditions. 24. In each of a plurality of load states,
The first expression at each strain gauge position is obtained by comparing the strain measurement value at each strain gauge position with the load at the same position to obtain the load at the same position that is a function of the strain measurement value at each strain gauge position. 22. Creating comprises using regression analysis of the strain data at each of the different loading conditions to calculate an equation for the load at this position that is a function of the strain measurement at each strain gauge position. the method of. 25. In each of a plurality of load states,
The first expression at each strain gauge position is obtained by comparing the strain measurement value at each strain gauge position with the load at the same position to obtain the load at the same position that is a function of the strain measurement value at each strain gauge position. The first step is to calculate an error between the measured strain value and the value obtained by the first equation, and perform the regression of this error to obtain the above-mentioned error that is a function of the strain measurement value at each strain gauge position. Forming an error equation and combining the first equation and the first error equation to produce a second equation that more accurately represents the load at the same position, which is a function of the strain measurement at each strain gauge position. Item 24. The method according to Item 24. 26. Collecting strain gauge data in a state where the load applied to the machine is changing, and using the above formula for each strain gauge position, the strain measurement value at each strain gauge position is obtained. The load at the rolling element position where the strain gauge is not attached, and the load applied to the bearing at each rolling element position is added to add to the bearing. The process of obtaining the total load receives the data from the strain gauge, instantaneously performs the necessary calculations and conversions, and prepares a device that outputs the radial and axial loads applied to the bearing in real time. 22. Mounting, collecting output data using a device and converting strain measurements in real time to radial and axial loads.
the method of. 27. The step of adding the loads applied to the bearings at each rolling element position to obtain the total load applied to the bearings decomposes the load at each bearing rolling element position into axial and radial components, Bearing component and radial component are added separately,
22. The method of claim 21, comprising calculating a total radial force and a total axial force on the bearing.