JP2022030011A - Load estimation method, estimation device, and computer program - Google Patents

Abstract

To provide a technique that can accurately determine an estimated value of radial load.SOLUTION: The present invention is a load estimation method for determining an estimated value of radial load acting on a rolling bearing 4 that supports a rotation shaft. The rolling bearing 4 has an inner ring 10, an outer ring 12, and a plurality of rolling elements 14 interposed between the inner ring and the outer ring. The load estimation method includes: an estimated value acquisition step of determining the estimated value of the radial load based on output from a distortion sensor 22 provided on the outer ring 12; a centrifugal force acquisition step of determining the value of a centrifugal force acting on the plurality of rolling elements 14 based on the revolution speed of the plurality of rolling elements 14; and a correction step of correcting the estimated value by using the value of the centrifugal force.SELECTED DRAWING: Figure 4

Description

The present invention relates to a rolling bearing load estimation method, an estimation device, and a computer program.

Patent Document 1 discloses a rolling bearing with a sensor in which a strain sensor is attached to an outer ring and the strain of the outer ring is detected in an actual operating state (see, for example, Patent Document 1).
For example, when the rolling bearing with a sensor is used to support the rotating shaft, the strain sensor can detect the strain generated in the outer ring by the input from the rotating shaft, and can monitor the state of the rolling bearing during rotation. can.

Japanese Unexamined Patent Publication No. 2017-44312

For example, the radial load acting on the rolling bearing that rotatably supports the rotating shaft of the motor has a correlation with the rotational force output by the rotating shaft. Therefore, if the radial load acting on the rolling bearing can be estimated by using the rolling bearing with a sensor, the rotational force output by the rotating shaft can be estimated based on the estimated radial load.

Here, the rolling bearing has a plurality of rolling elements interposed between the inner and outer rings. The plurality of rolling elements revolve between the inner and outer rings due to the relative rotation between the inner ring and the outer ring. Therefore, centrifugal force due to revolution acts on the plurality of rolling elements.
The centrifugal force acting on the plurality of rolling elements acts to move the plurality of rolling elements outward in the radial direction. Therefore, the radial load of the rolling bearing is superposed with the load based on the centrifugal force acting on the plurality of rolling elements.

The centrifugal force acting on the plurality of rolling elements fluctuates due to the fluctuation of the revolution speed of the plurality of rolling elements.
When estimating the rotational force output by the rotating shaft based on the radial load, the load based on the centrifugal force of a plurality of fluctuating rolling elements becomes noise for the radial load depending on the rotating shaft, and the rotational force of the rotating shaft is estimated. Decrease accuracy.
When estimating the rotational force of the rotating shaft based on the radial load, it is important to accurately grasp the radial load due to the rotation of the rotating shaft, and it is not preferable that such noise is superimposed.

(1) The load estimation method according to the present invention is
It is a load estimation method that obtains an estimated value of the radial load acting on the rolling bearing that supports the rotating shaft.
The rolling bearing has an inner ring, an outer ring, and a plurality of rolling elements interposed between the inner and outer rings.
An estimated value acquisition process for obtaining an estimated value of the radial load based on the output of the strain sensor provided on the outer ring, and
A centrifugal force acquisition step of obtaining the value of the centrifugal force acting on the plurality of rolling elements based on the revolution speeds of the plurality of rolling elements, and
A correction step of correcting the estimated value using the value of the centrifugal force is included.

According to the load estimation method having the above configuration, it is possible to correct the estimated value of the radial load based on the output of the strain sensor by excluding the value of the centrifugal force acting on the plurality of rolling elements that becomes noise. As a result, the estimated value of the radial load depending on the rotation of the rotating shaft can be accurately obtained.

(2) In the above load estimation method,
A step of acquiring the revolution speed of the plurality of rolling elements based on the output by the revolution speed detection sensor that detects the revolution speed of the plurality of rolling elements may be further included.
In this case, by directly measuring the revolution speeds of the plurality of rolling elements by the revolution speed detection sensor, the revolution speeds of the plurality of rolling elements can be accurately obtained, and the estimated value of the radial load can be obtained with higher accuracy. Can be done.

(3) Further, the estimation device according to the present invention is
It is an estimation device that obtains an estimated value of the radial load acting on the rolling bearing that supports the rotating shaft.
The rolling bearing has an inner ring, an outer ring, and a plurality of rolling elements interposed between the inner and outer rings.
The strain sensor provided on the outer ring and
A processing unit for obtaining an estimated value of the radial load is provided.
The processing unit
Estimated value acquisition processing to obtain the estimated value of the radial load based on the output of the strain sensor, and
Centrifugal force acquisition processing for obtaining the value of the centrifugal force acting on the plurality of rolling elements based on the revolution speeds of the plurality of rolling elements, and
A correction process for correcting the estimated value using the value of the centrifugal force is executed.
According to the estimation device having the above configuration, it is possible to accurately obtain the estimated value of the radial load depending on the rotation of the rotating shaft.

(4) In the above estimation device
The revolution speed detection sensor for detecting the revolution speed of the plurality of rolling elements may be further provided. In this case, the revolution speeds of the plurality of rolling elements can be accurately measured by directly measuring the revolution speeds of the plurality of rolling elements. You can ask.

(5) Further, the computer program according to the present invention is
It is a computer program for causing a computer to execute a load estimation process for obtaining an estimated value of a radial load acting on a rolling bearing that supports a rotating shaft.
The rolling bearing has an inner ring, an outer ring, and a plurality of rolling elements interposed between the inner and outer rings.
An estimated value acquisition step for obtaining an estimated value of the radial load based on the output of the strain sensor provided on the outer ring of the computer, and
A centrifugal force acquisition step for obtaining the value of the centrifugal force acting on the plurality of rolling elements based on the revolution speeds of the plurality of rolling elements.
It is a computer program for executing a correction step of correcting the estimated value using the value of the centrifugal force.

According to the present invention, the estimated value of the radial load can be obtained with high accuracy.

FIG. 1 is a partial cross-sectional view of an electric motor provided with an estimation device according to an embodiment. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is an enlarged view of the strain sensor in FIG. FIG. 4 is a flowchart showing an example of a method of estimating a radial load acting on a rolling bearing. FIG. 5 is a graph showing an example of the output of the strain sensor acquired by the processing unit. FIG. 6 is a diagram showing an example of a radial load database. FIG. 7 is a graph showing an example of the result of obtaining an estimated value of the radial load based on the peak value acquired in FIG. FIG. 8 is a diagram when the rolling bearing is viewed from the axial direction, and is a diagram showing the relationship between the estimated value of the radial load and the value of the centrifugal force. FIG. 9 is a block diagram showing a configuration example of the processing unit. FIG. 10 is a cross-sectional view of a rolling bearing that supports an output shaft, and shows a case where the rolling bearing is an angular contact ball bearing.

Hereinafter, preferred embodiments will be described with reference to the drawings.
FIG. 1 is a partial cross-sectional view of an electric motor provided with an estimation device according to an embodiment.
The electric motor 1 includes an output shaft 2 (rotary shaft) for outputting a rotational force and a rolling bearing 4 that supports the output shaft 2. Rolling bearings 4 are provided at both ends of the output shaft 2 and rotatably support the output shaft 2. Note that FIG. 1 shows only the rolling bearing 4 on one side.
In FIG. 1, the rolling bearing 4 that rotatably supports the output shaft 2 is fixed to the housing 6 of the motor 1.
In this specification, as shown by the arrow in FIG. 1, the direction along the central axis S of the output shaft 2 is defined as the “axial direction”. Further, the "axial direction" includes a direction parallel to the central axis S.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
As shown in FIGS. 1 and 2, the rolling bearing 4 includes an inner ring 10, an outer ring 12, a plurality of rolling elements 14, and a cage 16 for holding the plurality of rolling elements 14. The plurality of rolling elements 14 are balls, and the rolling bearing 4 of the present embodiment is a deep groove ball bearing.
An inner ring track 10a on which a plurality of rolling elements 14 roll is provided on the outer peripheral surface of the inner ring 10. An outer ring track 12a on which a plurality of rolling elements 14 roll is provided on the inner peripheral surface of the outer ring 12.
The plurality of rolling elements 14 are rotatably interposed between the inner ring track 10a and the outer ring track 12a.
The cage 16 is an annular member made of metal, resin, or the like, and is provided with a plurality of pockets 16a for holding the plurality of rolling elements 14. The pockets 16a are provided at equal intervals in the circumferential direction, and hold the plurality of rolling elements 14 so that the plurality of rolling elements 14 are evenly spaced in the circumferential direction.

The inner ring 10 is externally fitted and fixed to the output shaft 2. Further, the outer ring 12 is fitted and fixed to the annular inner peripheral surface 6a provided in the housing 6. As a result, the rolling bearing 4 rotatably supports the output shaft 2.

As shown in FIG. 1, the estimation device 20 includes a strain sensor 22, a revolution speed detection sensor 24, and a processing unit 26 to which outputs of both sensors 22 and 24 are given. The estimation device 20 is a device for obtaining an estimated value of the radial load acting on the rolling bearing 4.
The strain sensor 22 is provided on the outer peripheral surface 12b of the outer ring 12. The strain sensor 22 is accommodated in the space between the groove portion 6b recessed radially outward from the annular inner peripheral surface 6a of the housing 6 and the outer peripheral surface 12b of the outer ring 12.
As shown in FIG. 1, the strain sensor 22 is provided at a position corresponding to the axial center of the outer ring track 12a of the outer ring 12 in the cross section including the central axis S.

The revolution speed detection sensor 24 is a sensor for detecting the revolution speed of a plurality of rolling elements 14. The revolution speed detection sensor 24 is a proximity sensor and is provided at the end of the inner peripheral surface 12c of the outer ring 12. The detection unit 24a provided at the tip of the revolution speed detection sensor 24 for detecting an approaching metal is arranged at a predetermined distance in the axial direction with respect to the rolling element 14.
The plurality of rolling elements 14 revolve by the relative rotation between the outer ring 12 and the inner ring 10. Therefore, the plurality of rolling elements 14 repeatedly approach and pass the detection unit 24a in order.
The revolution speed detection sensor 24 detects the timing when a plurality of rolling elements 14 approach each other and gives the timing to the processing unit 26. The processing unit 26 obtains the revolution speed of the plurality of rolling elements 14 based on the time interval of the approach timing of each of the plurality of rolling elements 14.

The processing unit 26 is, for example, a computer including a CPU, a storage unit, and the like, and has a function of obtaining an estimated value of the radial load acting on the rolling bearing 4 based on the outputs given by the strain sensor 22 and the revolution speed detection sensor 24. Have.

FIG. 3 is an enlarged view of the strain sensor 22 in FIG.
As described above, the strain sensor 22 is provided on the outer peripheral surface 12b of the outer ring 12, and is housed in a space surrounded by the groove portion 6b provided on the annular inner peripheral surface 6a of the housing 6 and the outer peripheral surface 12b. ing.

The strain sensor 22 includes a rectangular plate-shaped member 22a, a joining member 22b for joining the plate-shaped member 22a to the outer peripheral surface 12b, and a strain gauge 22c provided on the plate-shaped member 22a.
The plate-shaped member 22a is a thin metal plate such as a steel plate or a copper plate. The joining members 22b are provided at the four corners of the plate-shaped member 22a, and the plate-shaped member 22a is joined to the outer peripheral surface 12b.
The plate-shaped member 22a and the joining member 22b transmit the strain generated on the outer peripheral surface 12b of the outer ring 12 to the strain gauge 22c.
The strain gauge 22c is connected to the processing unit 26, and gives an output indicating the result of detecting the strain on the outer peripheral surface 12b to the processing unit 26. The strain gauge 22c is provided on the outer peripheral surface 12b so as to detect the strain in the circumferential direction, for example.

FIG. 4 is a flowchart showing an example of a method of estimating the radial load acting on the rolling bearing 4.
First, the electric motor 1 is operated to rotate the output shaft 2, and during that time, the outputs of the strain sensor 22 and the revolution speed detection sensor 24 are acquired over time (step S1 in FIG. 4).
FIG. 5 is a graph showing an example of the output of the strain sensor 22 acquired by the processing unit 26. In FIG. 5, the horizontal axis is time, and the vertical axis is the strain value obtained from the output of the strain sensor 22.
As shown in FIG. 5, the processing unit 26 acquires the output of the strain sensor 22 over time for a certain period of time.

As shown in FIG. 5, a plurality of peaks appear in the output of the strain sensor 22.
The strain generated in the outer ring 12 is generated when a load generated due to the rotational force of the output shaft 2 or the like acts on the outer ring 12 via the inner ring 10 and the rolling element 14.
The plurality of rolling elements 14 are revolving, and the plurality of rolling elements 14 sequentially pass through the positions of the outer ring 12 in the circumferential direction in which the strain sensor 22 is provided. The strain at the position in the circumferential direction where the strain sensor 22 is provided on the outer ring 12 becomes maximum at the timing when the rolling element 14 is located. That is, the timing at which the peak appears indicates the timing at which the plurality of rolling elements 14 are located at the positions in the circumferential direction in which the strain sensor 22 is provided.
As described above, the plurality of peaks appearing in the output of the strain sensor 22 appear when each of the plurality of rolling elements 14 sequentially passes the position in the circumferential direction in which the strain sensor 22 is provided in the outer ring 12.

Further, in parallel with the acquisition of the output of the strain sensor 22, the processing unit 26 also acquires the output of the revolution speed detection sensor 24 over time for a certain period of time.
The processing unit 26 acquires the outputs of the strain sensor 22 and the revolution speed detection sensor 24 at any time with the fixed period as one unit.

As shown in FIG. 4, when the outputs of both sensors 22 and 24 are acquired, the processing unit 26 obtains an estimated value of the radial load acting on the rolling bearing 4 based on the outputs of the strain sensor 22 (step in FIG. 4). S2: Estimated value acquisition process).
The processing unit 26 acquires the strain value (peak value) of the peak appearing at the output of the strain sensor 22 during a certain period of time, and obtains an estimated value of the radial load acting on the rolling bearing 4.

The peak value of the output of the strain sensor 22 indicates the strain of the outer ring 12 caused by the load generated by the rotational force of the output shaft 2 transmitted to the outer ring 12 via the inner ring 10 and the rolling element 14. There is. That is, in the deep groove ball bearing, the strain of the outer ring 12 indicated by the peak value of the output of the strain sensor 22 has a correlation with the rolling element load acting on the rolling element 14.
Further, in deep groove ball bearings, the rolling element load has a correlation with the radial load acting on the rolling bearing 4. Therefore, there is a correlation between the peak value of the output of the strain sensor 22 and the radial load acting on the rolling bearing 4.
Therefore, the processing unit 26 obtains the value of the radial load acting on the rolling bearing 4 from the peak value of the output of the strain sensor 22.
For example, the storage unit of the processing unit 26 stores a radial load database showing the relationship between the output of the strain sensor 22 and the radial load.
The processing unit 26 refers to this radial load database and obtains an estimated value of the radial load based on the peak value.

FIG. 6 is a diagram showing an example of a radial load database. In FIG. 6, the radial load database is shown as a graph.
In the radial load database 40 shown in FIG. 6, the horizontal axis indicates the radial load. Further, the vertical axis shows the strain value corresponding to the peak value of the output of the strain sensor 22.
Therefore, the diagram L10 in FIG. 6 shows the relationship between the strain value corresponding to the peak value and the radial load.
The radial load database 40 is obtained by obtaining the strain generated in the outer ring 12 of the rolling bearing 4 when the output shaft 2 is rotated and the corresponding radial load by stress analysis using CAE (Computer Aided Engineering) or the like. ..

As shown in FIG. 6, there is a certain correlation between the strain value corresponding to the peak value and the radial load. Therefore, if the peak value is acquired, the radial load corresponding to the acquired peak value can be acquired as an estimated value.

FIG. 7 is a graph showing an example of the result of obtaining an estimated value of the radial load based on the peak value acquired in FIG. In FIG. 7, the horizontal axis shows time, and the vertical axis shows an estimated value of the radial load acting on the rolling bearing 4.
In FIG. 7, a plurality of points 44 are plotted. These points 44 indicate the estimated value of the radial load obtained based on each peak value (see FIG. 5) included in the output of the strain sensor 22. That is, each point 44 plotted in FIG. 7 corresponds to each peak value.

In this way, the processing unit 26 can obtain an estimated value of the radial load based on the acquired sensor output (peak value).
In the following description, processing for the estimated value of the radial load obtained from one peak value will be described.

As shown in FIG. 4, when the estimated value of the radial load is acquired, the processing unit 26 next obtains the value of the centrifugal force acting on the plurality of rolling elements 14 (in FIG. 4, step S3: centrifugal force acquisition step). ).
The value of the centrifugal force of the plurality of rolling elements 14 can be calculated by the following formula.
Centrifugal force value d = a × c × ((b / 60) × 2 × π) ²

In the above formula, a is the mass (kg) of the rolling element 14, and b is the rotation speed (rotation / minute) of the rolling element 14. Further, as shown in FIG. 8, c is the radius (m) of the pitch circle P where the positions of the centers of gravity of the plurality of rolling elements 14 when the rolling bearing 4 is viewed from the axial direction are located.
Of the above values, the mass a and the radius c are stored in advance in the storage unit of the processing unit 26.
The rotation speed b of the rolling element 14 is a variable and is obtained by the output of the revolution speed detection sensor 24.

Therefore, the processing unit 26 can obtain the value d of the centrifugal force acting on the rolling bearing 4 by using the rotation speed of the rolling element 14 obtained from the output of the revolving speed detection sensor 24 acquired together with the output of the strain sensor 22. can.
At this time, the processing unit 26 acquires the rotational speed of the rolling element 14 at the timing corresponding to the peak value used for obtaining the estimated value of the radial load, and obtains the centrifugal force value d using this.
The processing unit 26 may obtain the centrifugal force value d by performing calculation at any time from the rotational speed of the rolling element 14, or stores a table in which the rotational speed and the centrifugal force value d are associated with each other. This table may be used to obtain the centrifugal force value d.

When the processing unit 26 obtains the centrifugal force value d of the plurality of rolling elements 14, the processing unit 26 corrects the estimated value of the radial load by using the centrifugal force value d (step S4: correction step in FIG. 4).
The processing unit 26 corrects the estimated value of the radial load obtained in step S2 in FIG. 4 by using the values of the centrifugal forces of the plurality of rolling elements 14.

FIG. 8 is a diagram when the rolling bearing 4 is viewed from the axial direction, and is a diagram showing the relationship between the estimated value of the radial load and the value d of the centrifugal force.
Since the centrifugal force is generated in the same direction as the radial load, the centrifugal force acting on the rolling element 14 is superimposed on the radial load.

In FIG. 8, the estimated value of the radial load is estimated based on the output from the strain sensor 22. Therefore, the estimated value of the radial load can be expressed on the straight line L1 orthogonal to the central axis S and passing through the strain sensor 22.
Further, the centrifugal force acting on the rolling element 14 is also generated in the direction along the straight line L1. Therefore, the value d of the centrifugal force can also be expressed on the straight line L1.
Centrifugal force acting on the rolling element 14 is superimposed on the estimated value of the radial load shown in FIG.
Therefore, the processing unit 26 corrects the estimated value of the radial load by subtracting the value d of the centrifugal force from the estimated value of the radial load, and obtains the corrected estimated value.
When the correction estimated value is obtained, the processing unit 26 outputs the corrected estimated value as an estimated value of the radial load (step S5 in FIG. 4), and returns to step S1 in FIG. 4 again.

According to the above configuration, it is possible to correct the estimated value of the radial load based on the output of the strain sensor 22 by excluding the value d of the centrifugal force acting on the plurality of rolling elements 14 which becomes noise. As a result, the estimated value of the radial load depending on the rotation of the output shaft 2 can be accurately obtained.
Further, in the present embodiment, since the revolution speeds of the plurality of rolling elements are directly measured by the revolution speed detection sensor, the revolution speeds of the plurality of rolling elements can be accurately obtained.

FIG. 9 is a block diagram showing a configuration example of the processing unit 26.
The processing unit 26 shown in FIG. 9 is a computer including a calculation unit including a CPU (Central Processing Unit), a storage unit including a memory and a hard disk, an input / output unit, and the like. In the processing unit 26. As described above, the strain sensor 22 and the revolution speed detection sensor 24 are connected.

A computer program or the like for execution by the arithmetic unit is stored in the storage unit of the processing unit 26. When the calculation unit executes the computer program recorded in the storage unit, each functional unit described later described in the processing unit 26 is realized.

The processing unit 26 has a functional unit that executes an estimated value acquisition unit 26a, a centrifugal force acquisition unit 26b, and a correction processing unit 26c.
Further, the processing unit 26 stores the above-mentioned radial load database 40 in the storage unit.
The estimated value acquisition unit 26a has a function of executing a process (step S2 in FIG. 4) of obtaining an estimated value of the radial load acting on the rolling bearing 4 based on the output of the strain sensor 22 provided on the outer ring 12.

Further, the centrifugal force acquisition unit 26b has a function of executing a process (step S3 in FIG. 4) of obtaining the value of the centrifugal force acting on the plurality of rolling elements 14 based on the revolution speeds of the plurality of rolling elements 14. ..
The correction processing unit 26c has a function of executing a process (step S4 in FIG. 4) of correcting the estimated value of the radial load acquired by the estimated value acquisition unit 26a using the centrifugal force value obtained by the centrifugal force acquisition unit 26b. Has.
When the processing unit 26 obtains the corrected estimated value (corrected estimated value), the processing unit 26 outputs the corrected estimated value as an estimated value of the radial load from the input / output unit (step S5 in FIG. 4).

FIG. 10 is a cross-sectional view of a rolling bearing 4 that supports the output shaft 2, and shows a case where the rolling bearing 4 is an angular contact ball bearing.
In FIG. 10, since the rolling bearing 4 is an angular contact ball bearing, the contact point K1 between the inner ring track 10a of the inner ring 10 and the rolling element 14 and the contact point K2 between the outer ring track 12a of the outer ring 12 and the rolling element 14 are formed. The straight line L12 passing through is inclined at a predetermined contact angle with respect to the radial direction.

In the present embodiment, the strain sensor 22 is provided on the straight line L12 in the cross section including the central axis S of the rolling bearing 4. Further, the rolling element load acting on the rolling element 14 also acts along the straight line L12.
By providing the strain sensor 22 on the straight line L12, the strain sensor 22 can detect the strain at the position along the direction of the rolling element load.
As a result, the strain detected by the strain sensor 22 can have a correlation with the rolling element load.

As shown in FIG. 10, the rolling element load of the rolling bearing 4 of the present embodiment includes a load component in the radial direction and a load component in the axial direction.
Therefore, the output from the strain sensor 22 of the present embodiment has a correlation with both the radial load component in the rolling element load and the axial load component in the rolling element load.
Therefore, the processing unit 26 can obtain an estimated value of the radial load based on the output (peak value) of the strain sensor 22 as in the first embodiment.
As the radial load database 40 included in the processing unit 26 of the present embodiment, the one created corresponding to the rolling bearing 4 which is an angular contact ball bearing is used.

Further, the processing unit 26 of the present embodiment corrects the obtained estimated value of the radial load excluding the value d of the centrifugal force acting on the rolling element 14.
As a result, even in the angular contact ball bearing, the estimated value of the radial load depending on the rotation of the output shaft 2 can be accurately obtained.

The embodiments disclosed this time are exemplary in all respects and are not restrictive.
For example, in the above embodiment, a case where a proximity sensor is used as the revolution speed detection sensor 24 for obtaining the revolution speed of the rolling element 14 has been exemplified, but the present invention is not limited to this.
For example, the rotation speed of a plurality of rolling elements 14 may be obtained by imparting a function as an encoder to the cage 16 and detecting the rotation speed of the cage 16.

Further, assuming that the rolling element 14 does not slip between the inner ring 10 and the outer ring 12, the plurality of rolling elements 14 are based on the rotation speed of the output shaft 2 (relative rotation speed of the inner ring 10 and the outer ring 12). The revolution speed can be calculated.
In this case, it is not necessary to provide the revolution speed detection sensor 24.
Further, the rotation speeds of the plurality of rolling elements 14 may be obtained based on the output of the strain sensor 22. That is, as shown in FIG. 5, a plurality of peaks appear in the output of the strain sensor 22. As described above, the plurality of peaks appear when each of the plurality of rolling elements 14 sequentially passes through the position in the circumferential direction in which the strain sensor 22 is provided in the outer ring 12.
Therefore, the rotation speeds of the plurality of rolling elements 14 can be obtained from the timings of the plurality of peaks appearing in the output of the strain sensor 22.
In this case, since the strain sensor 22 can function as the revolution speed detection sensor, it is not necessary to provide an independent sensor like the revolution speed detection sensor 24 (FIG. 1) in addition to the strain sensor 22.

Further, in the above embodiment, the strain sensor 22 is provided so as to detect the strain in the circumferential direction, but it may be provided so as to detect the strain in the axial direction, or the strain in the direction intersecting the circumferential direction and the axial direction. May be provided to detect.

The scope of rights of the present invention is not limited to the above-described embodiment, but includes all modifications within the scope equivalent to the configuration described in the claims.

2 Output shaft (rotary shaft) 4 Rolling bearing 10 Inner ring 12 Outer ring 14 Rolling element 20 Estimator 22 Strain sensor 24 Revolution speed detection sensor 26 Processing unit 26a Estimated value acquisition unit 26b Centrifugal force acquisition unit 26c Correction processing unit 40 Radial load database

Claims (5)

It is a load estimation method that obtains an estimated value of the radial load acting on the rolling bearing that supports the rotating shaft.
The rolling bearing has an inner ring, an outer ring, and a plurality of rolling elements interposed between the inner and outer rings.
An estimated value acquisition process for obtaining an estimated value of the radial load based on the output of the strain sensor provided on the outer ring, and
A centrifugal force acquisition step of obtaining the value of the centrifugal force acting on the plurality of rolling elements based on the revolution speeds of the plurality of rolling elements, and
A load estimation method including a correction step of correcting the estimated value using the centrifugal force value. Further including a step of acquiring the revolution speed of the plurality of rolling elements based on the output by the revolution speed detection sensor that detects the revolution speed of the plurality of rolling elements.
The load estimation method according to claim 1. It is an estimation device that obtains an estimated value of the radial load acting on the rolling bearing that supports the rotating shaft.
The rolling bearing has an inner ring, an outer ring, and a plurality of rolling elements interposed between the inner and outer rings.
The strain sensor provided on the outer ring and
A processing unit for obtaining an estimated value of the radial load is provided.
The processing unit
Estimated value acquisition processing to obtain the estimated value of the radial load based on the output of the strain sensor, and
Centrifugal force acquisition processing for obtaining the value of the centrifugal force acting on the plurality of rolling elements based on the revolution speeds of the plurality of rolling elements, and
An estimation device that executes a correction process that corrects the estimated value using the value of the centrifugal force. The estimation device according to claim 3, further comprising a revolution speed detection sensor that detects the revolution speed of the plurality of rolling elements. It is a computer program for causing a computer to execute a load estimation process for obtaining an estimated value of a radial load acting on a rolling bearing that supports a rotating shaft.
The rolling bearing has an inner ring, an outer ring, and a plurality of rolling elements interposed between the inner and outer rings.
An estimated value acquisition step for obtaining an estimated value of the radial load based on the output of the strain sensor provided on the outer ring of the computer, and
A centrifugal force acquisition step for obtaining the value of the centrifugal force acting on the plurality of rolling elements based on the revolution speeds of the plurality of rolling elements.
A computer program for executing a correction step of correcting the estimated value using the value of the centrifugal force.

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