JP4951943B2 - Rotating member displacement or load measuring device - Google Patents

Description

The apparatus for measuring displacement or load of a rotating member according to the present invention, for example, supports a vehicle (automobile) wheel rotatably with respect to a suspension device, and measures the magnitude of a load applied to the wheel to stabilize the vehicle. Use to secure operation. Or, it is incorporated in a rolling bearing unit for supporting the spindle of various machine tools, and is used to measure the load applied to the spindle and the displacement due to thermal expansion, etc., and to adjust the feed rate of the tool appropriately. .

  For example, a rolling bearing unit is used to rotatably support a vehicle wheel with respect to a suspension device. In order to ensure the running stability of the vehicle, a running state stabilizing device for the vehicle such as an antilock brake system (ABS) or a traction control system (TCS) is widely used. According to these running state stabilizing devices such as ABS and TCS, the running state of the vehicle at the time of braking or acceleration can be stabilized, but in order to ensure this stability even under more severe conditions, the vehicle It is necessary to control the brakes and the engine by incorporating more information that affects the running stability of the vehicle.

  That is, in the case of the conventional running state stabilizing device such as ABS or TCS, since so-called feedback control is performed to detect the slip between the tire and the road surface and control the brake and the engine, the brake and engine Control is delayed for a moment. In other words, in order to improve performance under severe conditions, the so-called feed-forward control prevents slippage between the tire and the road surface, or the so-called brake one-side effect where the braking forces of the left and right wheels are extremely different. Cannot be prevented. Furthermore, it is impossible to prevent the running stability of a truck or the like from being deteriorated based on the poor loading state.

  In order to cope with such a problem, in order to perform the feedforward control or the like, one of a radial load and an axial load applied to the wheel is applied to the rolling bearing unit for supporting the wheel with respect to the suspension device. Or it is possible to incorporate a load measuring device for measuring both. Conventionally, what was described in patent documents 1-4 is known as a rolling bearing unit for wheel support with a load measuring device which can be used in such a case.

  Of these, Patent Document 1 describes a rolling bearing unit with a load measuring device capable of measuring a radial load. In the case of the first example of the conventional structure, the outer ring and the hub are measured by measuring the radial displacement between the outer ring that does not rotate and the hub that rotates on the inner diameter side of the outer ring by a non-contact displacement sensor. The radial load applied between and is calculated. The obtained radial load is used not only to properly control the ABS but also to inform the driver of a bad loading condition.

  Patent document 2 describes a structure for measuring an axial load applied to a rolling bearing unit. In the case of the second example of the conventional structure described in Patent Document 2, bolts for connecting the fixed side flange to the knuckle are screwed at a plurality of positions on the inner side surface of the fixed side flange provided on the outer peripheral surface of the outer ring. Each load sensor is attached to a portion surrounding the screw hole. Each load sensor is clamped between the outer surface of the knuckle and the inner surface of the fixed flange in a state where the outer ring is supported and fixed to the knuckle. In the case of the load measuring device for the rolling bearing unit of the second example having such a conventional structure, the axial load applied between the wheel and the knuckle is measured by the load sensors.

  Further, in Patent Document 3, the displacement sensor unit supported at four positions in the circumferential direction of the outer ring and the L-shaped detection ring that is externally fitted and fixed to the hub are used to detect the above-described outer ring at the four positions. A structure is described in which the displacement of the hub in the radial direction and the thrust direction is detected, and the direction and magnitude of the load applied to the hub are determined based on the detected values of the respective parts.

  Furthermore, in Patent Document 4, a strain gauge for detecting dynamic strain is provided in a member corresponding to an outer ring whose rigidity is partially reduced, and the revolution speed of the rolling element is determined from the passing frequency of the rolling element detected by the strain gauge. A method for determining the axial load applied to the rolling bearing from the revolution speed is described.

  In the case of the first example of the conventional structure described in Patent Document 1, the load applied to the rolling bearing unit is measured by measuring the displacement in the radial direction between the outer ring and the hub using a displacement sensor. However, since the displacement amount in the radial direction is small, it is necessary to use a highly accurate displacement sensor in order to obtain this load with high accuracy. Since high-precision non-contact sensors are expensive, it is inevitable that the cost of the entire rolling bearing unit with a load measuring device increases.

In the second example of the conventional structure described in Patent Document 2, it is necessary to provide as many load sensors as the bolts for supporting and fixing the outer ring to the knuckle. For this reason, coupled with the fact that the load sensor itself is expensive, it is inevitable that the cost of the entire load measuring device of the rolling bearing unit is considerably increased. In addition, the structure described in Patent Document 3 is more expensive than the structure described in Patent Document 1 because sensors are installed at four positions in the circumferential direction of the outer ring. Furthermore, the method described in Patent Document 4 needs to reduce the rigidity of a part of the outer ring equivalent member, and it may be difficult to ensure the durability of the outer ring equivalent member.
Moreover, the structure and method described in any of Patent Documents 1 to 4 are provided with a dedicated mechanism for measuring the load applied to the rolling bearing unit. For this reason, an increase in cost and weight is inevitable.

  Further, as a technique related to the present invention, Patent Document 5 uses an encoder in which N poles and S poles are alternately arranged on a detection surface, thereby detecting a center runout of an inner ring that supports the encoder. The structure is described. However, Patent Document 5 does not describe a technique for obtaining a load applied to a rolling bearing unit using the encoder, even if a description suggesting such a technique is included.

  On the other hand, the inventors have determined the direction of the load applied to the rolling bearing unit and the direction of the load applied to the rolling bearing unit based on the change pattern of the output signal of the sensor that changes with the rotation of the encoder attached to the hub constituting the rolling bearing unit. It invented about the structure which calculates | requires a magnitude | size (Japanese Patent Application No. 2005-147642). In the case of the rolling bearing unit with a load measuring device according to the present invention, a sensor that supports and fixes an encoder concentrically with a part of a rotating raceway such as a hub and is supported by a non-rotating part. The detecting section is opposed to the detected surface of the encoder. Further, the width direction of the detected surface is made to coincide with the acting direction of the load to be obtained. Furthermore, the characteristics of the detected surface are alternately changed in the circumferential direction, and the pitch or phase at which the characteristics change in the circumferential direction is continuously changed in the width direction of the detected surface. When a load is applied to the rotating raceway, the position in the width direction of the detection surface of the encoder, which is opposed to the detection unit of the sensor, changes, and the pattern in which the output signal of the sensor fluctuates changes. Since there is a correlation between the degree of change of this pattern and the magnitude of the load, the magnitude of the load can be obtained by observing this pattern.

  By the way, for example, in the case of a rolling bearing unit for supporting a wheel, its rigidity is considerably high in order to ensure the running stability of the automobile. Accordingly, the amount of relative displacement between the stationary-side raceway and the rotation-side raceway that is generated based on the load is small regardless of whether the load is a radial load or an axial load. For example, when an axial load of about 10 kN is applied to the wheel support rolling bearing unit, the amount (length) of relative displacement in the axial direction between the stationary side raceway and the rotation side raceway is several tens of μm to It is only a few hundred μm. Further, when a radial load of about 10 kN is applied, the amount of relative displacement of the stationary side raceway and the rotation side raceway in the radial direction is only about several tens of μm.

  As is apparent from the above description, in order to obtain the above-mentioned axial load with practical accuracy for ensuring the running stability of the automobile, several μm to several μm (depending on the rigidity of the rolling bearing unit for supporting the wheel) An axial displacement of about 10 μm must be obtained based on the detection signal of the sensor. Furthermore, regarding the radial load, a radial displacement of about several μm or less (depending on the rigidity of the wheel support rolling bearing unit) must be obtained based on the detection signal of the sensor. In order to obtain such a small amount of displacement, the boundary line where the characteristics of the detection surface of the encoder change (the boundary between the concave and convex portions formed on the detection surface, or the N pole magnetized on the detection surface) And the boundary between the magnetic field and the S magnet) must be manufactured with high accuracy (the position of the boundary line and the inclination angle are as designed). On the other hand, there is a limit to machining accuracy and magnetization accuracy, and it must be considered to some extent that the pattern in which the detection signal of the sensor varies based on the dimensional error of the boundary line changes.

  Even if the accuracy of the boundary line where the characteristics of the detected surface of the encoder changes is satisfactory, the rotation of the rotating side raceway is caused by the assembling error when the encoder is assembled to the rotating side raceway. As a result, the surface to be detected is apparently displaced (vibrates with rotation) regardless of the load. When the load acting between the stationary bearing ring and the rotating bearing ring constituting the rolling bearing unit is obtained by the structure of the prior invention as described above, the above-described sensor output signal is not particularly corrected unless the output signal is corrected. It is important that the geometric center axis of the detected surface of the encoder and the rotation center axis coincide. When these two central axes are inconsistent with each other, that is, when both the central axes are displaced in the radial direction or are inclined with respect to each other, the detection portions of the sensor face each other regardless of the load. The position in the width direction of the detection surface is shifted.

  For example, when the load to be detected is a radial load, the detected surface of the encoder is the side surface in the axial direction, but the radial position between the central axis of the axial side surface and the rotational center axis of the rotating side raceway is shifted. In such a case, the detected surface performs a first-order rotation motion as the rotation-side raceway rotates. Also, when the load to be detected is an axial load, the detected surface of the encoder is often the peripheral surface, but the central axis of this peripheral surface and the rotational central axis of the rotating side raceway are inclined. In this case, the detected surface undergoes a rotation primary axial displacement movement as the rotation-side raceway rotates. In any case, a portion of the detected surface that is opposed to the detection portion of the sensor is shifted with respect to the width direction of the detected surface. As a result, even when the load does not change, the pattern in which the output signal of the sensor fluctuates changes, and the measurement accuracy of the load deteriorates.

JP 2001-21577 A Japanese Patent Laid-Open No. 3-209016 Japanese Patent Laid-Open No. 2004-3918 Japanese Patent Publication No.62-3365 JP 2004-77159 A

In the present invention, in view of the circumstances as described above, due to poor assembly of the encoder with respect to the rotating member such as the rotating side raceway, the detected surface of the encoder is rotated along with the rotation of the rotating member such as the rotating side raceway. Even when it swings in the width direction, the displacement amount of this rotating member or the load applied to this rotating member is applied to the relative displacement amount of the rotating side raceway and the stationary side raceway, or between these two raceways. The invention was invented to realize a displacement or load measuring device for a rotating member that is accurately obtained as a load or the like.

The rotational member displacement or load measuring device according to claim 1 of the rotational member displacement or load measuring device of the present invention includes an encoder, a sensor, a filter circuit, and a computing unit.
Among these members, the rotating member is a member that is coupled and fixed to the rotating side bearing ring of the rolling bearing unit or the rotating side bearing ring and rotates together with the rotating side bearing ring. The rolling bearing unit exists on the circumferential surfaces of the rotating side bearing ring that rotates in the used state, the stationary side bearing ring that does not rotate in the used state, and the rotating side bearing ring and the stationary side bearing ring that face each other. And a plurality of rolling elements provided between the stationary-side track and the rotating-side track.
The encoder is supported by a part of the rotating member concentrically with the rotating member, and alternately changes the characteristics of the surface to be detected in the circumferential direction. The pitch or phase at which the characteristic of the detected surface of the encoder changes in the circumferential direction corresponds to the direction of the displacement to be detected (in the direction in which the detected surface is displaced in accordance with the displacement to be detected). The width of the detected surface is continuously changed. In short, the encoder is assembled to the rotating member in a state where the width direction of the detected surface coincides with the direction in which the encoder is displaced corresponding to the displacement to be detected. Further, a plurality of detection combination portions each consisting of a pair of individualized portions each having different characteristics from the other portions are arranged on the detection surface of the encoder at equal intervals in the circumferential direction. The intervals in the circumferential direction between each pair of individualized portions constituting each detected combination part are continuously in the same direction with respect to the width direction of the detected surface in all the detected combination parts. Change.
The sensor is supported by a portion that does not rotate with the detection portion facing the detection surface, and changes its output signal in response to a change in the characteristics of the detection surface. That is, the sensor changes the phase of the change in the output signal of the sensor in accordance with the position in the width direction of the detection surface of the encoder that the detection unit of the sensor faces.
The filter circuit performs a filtering process on the change phase (a signal representing the change) of the output signal of the sensor or a processing signal obtained based on the output signal. That is, the filter circuit eliminates an error component based on an error related to a change in characteristics of the detected surface in the circumferential direction, among fluctuations in the output signal or the processing signal.
The computing unit is coupled and fixed to the rotating member (the rotating side raceway or the rotating side raceway ) on the basis of the phase of the change (a signal representing) filtered by the filter circuit. The amount of displacement of the member rotating with the rotating side raceway or the load applied to the rotating member is calculated. That is, the computing unit calculates the relative displacement amount or the load between the rotating side raceway and the stationary side raceway based on the pattern in which the output signal or the processing signal changes after passing through the filter circuit. Has a function to calculate.

In addition, among the displacement or load measuring device of the rotating member according to the present invention, the displacement or load measuring device of the rotating member according to claim 2 is similar to the above-described invention according to claim 1 in that the encoder and sensor And a filter circuit and an arithmetic unit.
Among these members, the rotating member is a member that is coupled and fixed to the rotating side bearing ring of the rolling bearing unit or the rotating side bearing ring and rotates together with the rotating side bearing ring. The rolling bearing unit exists on the circumferential surfaces of the rotating side bearing ring that rotates in the used state, the stationary side bearing ring that does not rotate in the used state, and the rotating side bearing ring and the stationary side bearing ring that face each other. And a plurality of rolling elements provided between the stationary-side track and the rotating-side track .
The encoder is supported by a part of the rotating member concentrically with the rotating member, and alternately changes the characteristics of the surface to be detected in the circumferential direction. The pitch or phase at which the characteristic of the detected surface of the encoder changes in the circumferential direction corresponds to the direction of the displacement to be detected (in the direction in which the detected surface is displaced with the displacement to be detected). The width of the detected surface is continuously changed. In short, the encoder is assembled to the rotating member in a state where the width direction of the detected surface coincides with the direction in which the encoder is displaced corresponding to the displacement to be detected. Further, in the detected surface of the encoder, the portion where the detection portion of at least one sensor is opposed inclines the boundary whose characteristics change in the circumferential direction with respect to the width direction.
The sensor is supported by a portion that does not rotate with the detection portion facing the detection surface, and changes the output signal in response to a change in the characteristics of the detection surface. A pair is provided in a state in which the respective detection units are positioned at positions separated in the width direction of the surface to be detected. Then, the phase of the change in the output signal of at least one of the two sensors is changed in accordance with the position in the width direction of the detection surface of the encoder that the detection unit of the sensor faces.
The filter circuit performs a filtering process on the change phase (a signal representing the change) of the output signal of the sensor or a processing signal obtained based on the output signal. That is, the filter circuit eliminates an error component based on an error related to a change in characteristics of the detected surface in the circumferential direction, among fluctuations in the output signal or the processing signal.
The computing unit is coupled and fixed to the rotating member (the rotating side raceway or the rotating side raceway) on the basis of the phase of the change (a signal representing) filtered by the filter circuit. The amount of displacement of the member rotating with the rotating side raceway or the load applied to the rotating member is calculated. That is, the computing unit calculates the relative displacement amount or the load between the rotating side raceway and the stationary side raceway based on the pattern in which the output signal or the processing signal changes after passing through the filter circuit. Has a function to calculate.

Further, among the displacement or load measuring device of the rotating member according to the present invention, the displacement or load measuring device of the rotating member according to claim 3 is similar to the above-described invention according to claim 1 in that the encoder and sensor And a filter circuit and an arithmetic unit.
Among these members, the rotating member is a member that is coupled and fixed to the rotating side bearing ring of the rolling bearing unit or the rotating side bearing ring and rotates together with the rotating side bearing ring. The rolling bearing unit exists on the circumferential surfaces of the rotating side bearing ring that rotates in the used state, the stationary side bearing ring that does not rotate in the used state, and the rotating side bearing ring and the stationary side bearing ring that face each other. And a plurality of rolling elements provided between the stationary-side track and the rotating-side track.
A plurality of the encoders are provided. Each of these encoders is supported by a part of the rotating member concentrically with the rotating member, and alternately changes the characteristics of the detected surface in the circumferential direction. In addition, in each of these encoders, it is assumed that the characteristics of the respective detection surfaces are alternately changed at the same pitch between the encoders in the circumferential direction. Further, the phase in which the characteristic of the detected surface of at least one of these encoders changes in the circumferential direction is continuously changed in the width direction of the detected surface corresponding to the direction of displacement to be detected. Shall.
A plurality of the sensors are provided. Each of these sensors is supported by a portion that does not rotate in a state in which each detection unit faces the detected surface of each encoder, and changes its output signal in response to a change in the characteristics of each detected surface.
The filter circuit performs a filtering process on a signal representing a phase difference existing between the output signals of the plurality of sensors among the output signals of the sensors or a processing signal obtained based on the output signals. Apply. That is, the filter circuit eliminates an error component based on an error related to a change in characteristics of the detected surface in the circumferential direction, among fluctuations in the output signal or the processing signal.
Further, the computing unit is configured to perform the rotation member (the rotation side raceway or the rotation side raceway ring) based on a signal representing a phase difference existing between the output signals of the plurality of sensors subjected to the filtering process by the filter circuit. A displacement amount of a member that is coupled and fixed to the rotation side raceway and rotates together with the rotation side raceway or a load applied to the rotation member is calculated. That is, the arithmetic unit is configured to detect the relative displacement between the rotation side raceway and the stationary side raceway based on a signal representing a phase difference existing between the output signals of the sensors that has passed through the filter circuit. It has a function of calculating the quantity or the load.
In carrying out the invention described in claim 3 as described above, preferably, as described in claim 8, an integrated one is used as the plurality of encoders each having a detection surface. To do.

The rotating member displacement or load measuring device according to claim 4 of the rotating member displacement or load measuring device of the present invention includes an encoder, a sensor, a filter circuit, and a calculator.
Of these, the encoder is supported by a part of the rotating member concentrically with the rotating member, and the characteristics of the detection surface are alternately changed in the circumferential direction.
The sensor is supported by a portion that does not rotate with the detection portion facing the detection surface, and changes its output signal in response to a change in the characteristics of the detection surface.
The filter circuit performs a filtering process on the output signal of the sensor or a processing signal obtained based on the output signal. That is, the filter circuit eliminates an error component based on an error related to a change in characteristics of the detected surface in the circumferential direction, among fluctuations in the output signal or the processing signal. Such a filter circuit is configured by providing an adaptive filter and at least one of a low-pass filter and a notch filter in series with each other. Further, the adaptive filter is arranged in a stage preceding at least one of the low-pass filter and the notch filter. In this way, by arranging the adaptive filter and at least one of the low-pass filter and the notch filter in series with each other, the error component mixed in with respect to the detection signal of the sensor is good over a wide range. Can be removed. In addition, since the adaptive filter is arranged on the upstream side of the other filter, the time required for the filter coefficient of the adaptive filter to converge is not increased by using this other filter.
The computing unit calculates a displacement amount of the rotating member or a load applied to the rotating member based on the output signal or the processed signal subjected to the filtering process by the filter circuit. That is, the arithmetic unit has a function of calculating the relative displacement amount or the load based on a pattern in which the output signal or the processing signal changes after passing through the filter circuit.

Further, when the invention according to claim 4 of the displacement or load measuring device of the rotating member of the present invention is carried out, for example, as described in claim 5, the rotating member is rotated by a rolling bearing unit. A member that is coupled and fixed to the side raceway or the rotation side raceway and rotates together with the rotation side raceway. The rolling bearing unit exists on the circumferential surfaces of the rotating side bearing ring that rotates in the used state, the stationary side bearing ring that does not rotate in the used state, and the rotating side bearing ring and the stationary side bearing ring that face each other. And a plurality of rolling elements provided between the stationary-side track and the rotating-side track.

Further, when the invention described in claim 4 or 5 as described above is implemented, for example, as described in claim 6, the pitch at which the characteristic of the detected surface of the encoder changes in the circumferential direction. Alternatively, the phase is continuously changed with respect to the width direction of the detected surface corresponding to the direction of the displacement to be detected (in the direction in which the detected surface is displaced with the displacement to be detected). In short, the encoder is assembled to the rotating member in a state where the width direction of the detected surface coincides with the direction in which the encoder is displaced corresponding to the displacement to be detected.

Further, when carrying out the invention described in claim 6, for example, as described in claim 7, the first detected portion and the second detected portion having different characteristics are provided on the detected surface of the encoder. These are arranged alternately and at equal intervals in the circumferential direction. Of the widths of these detected parts in the circumferential direction, the width of the first detected part is wider on one side in the width direction of the detected surface, and the width of the second detected part is the width of the detected surface. Make the other side of the direction wider. Further, the output signal of the sensor is a pulse signal or a sine wave signal that changes a value related to the period or amplitude in accordance with the difference in the width in the circumferential direction between the first detected part and the second detected part. . The filter circuit performs a filtering process on the ratio relating to the period or amplitude. Further, the computing unit obtains a relative displacement amount or a load based on a signal that passes through the filter circuit and represents a ratio relating to the period or amplitude.

Further, when implementing the above-described displacement or load measuring device of the rotating member of the present invention, for example, as described in claim 9, the computing unit is connected to a relative displacement amount between the rotating side raceway and the stationary side raceway. This relative displacement is used to calculate the load acting between the rotating side raceway and the stationary side raceway.
In addition, in order to obtain the load acting between the rotation side raceway and the stationary side raceway, it is not always necessary to obtain the relative displacement amount between the rotation side raceway and the stationary side raceway. That is, the function of directly calculating the load applied to the rotating member (without going through the process of obtaining the relative displacement amount) based on the output signal of the sensor or the processing signal obtained based on the output signal to the computing unit. You can also have it.

The rotating member displacement or load measuring device of the present invention configured as described above is configured so that the displacement of the rotating member or the load applied to the rotating member is, for example, a stationary-side track ring in the same manner as in the above-described previous invention. It is calculated as the displacement between the rotating side raceway and the load applied between these raceways. That is, when a load is applied between the two raceways, the raceways are relatively displaced with the elastic deformation of the stationary side, the rotary side raceways and the rolling elements. As a result, the positional relationship between the detected surface of the encoder supported by the rotation-side raceway and the detection unit of the sensor supported by a part of the stationary-side raceway or the suspension device changes.

Therefore, as in the invention described in claims 1 to 3 and the invention described in claim 6, the load to be detected is the pitch or phase at which the characteristic of the detected surface of the encoder changes in the circumferential direction. If the two raceways are relatively displaced based on this load, the output signal of the sensor changes with the rotation of the rotation-side raceway ( The period or magnitude of change, or phase) changes. Since there is a correlation between the degree of change in the pattern and the magnitude of the load, the magnitude of the load or the relative displacement between the two races can be obtained based on this pattern.

Further, when an encoder having the configuration of the invention described in claim 1 is adopted, the output signal of the sensor having the detection portion opposed to the detection surface of the encoder is instantly opposed to each individualized portion. Although changing, the changing interval (cycle) changes with the change in the position in the width direction of the portion where the detection unit of the sensor faces.

Further, when the configuration as in the invention described in claims 2 and 3 is adopted, the relative displacement between the two race rings based on the load applied between the rotation side race ring and the stationary side race ring, Of the surface to be detected, the position in the width direction of the portion where the detection portions of the two sensors face each other changes. Then, the phase of the output signal of one of these sensors advances. When the boundaries of the portions where the detection portions of both sensors are opposed are inclined in opposite directions, the phase of the output signal of the one sensor advances and the phase of the output signal of the other sensor is delayed. Therefore, if the phase shift between the output signals of the two sensors is obtained, the relative displacement between the two race rings or the magnitude of the load acting between the two race rings can be obtained.

When the configuration as in the invention described in claim 7 is adopted, along with the relative displacement between the two race rings based on the load applied between the rotation side raceway and the stationary side raceway, Among them, the position in the width direction of the part where the detection part of the sensor faces changes. And when the width direction position of the part which the detection part of a sensor opposes in the said to-be-detected surface with the fluctuation | variation of the said load, among the 1st and 2nd to-be-detected parts which the said detection part opposes The circumferential length of one of the detected parts becomes longer, and the circumferential length of the other detected part becomes shorter. The period or magnitude of the change in the output signal of the sensor changes according to the circumferential lengths of the first and second detected parts opposed to the detection part. Therefore, the ratio of the period or magnitude of the change corresponding to the first detected part to the period or magnitude of the change corresponding to the second detected part of the change in the output signal of the sensor can be obtained. For example, the degree of radial eccentricity (or axial load) acting between the two bearing rings is extended to the extent that the central axes of both the bearing rings are eccentric in the radial direction (or the displacement in the axial direction). The size is required.

Further, in the case of the invention described in claim 8, an integrated one is used as the plurality of encoders each having a detected surface. For this reason, the operation | work which adjusts the phase of each of these encoder becomes easy.

The combination of the encoder and the sensor, such as described above is also required for detecting the rotational speed of the rotating side raceway for controlling the ABS and TCS (if performed with respect to the wheel support rolling bearing unit) . Even when it is performed on a machine tool, it is necessary for detecting the rotational speed of the spindle. The rotating member displacement or load measuring device of the present invention can be configured so as to obtain the load or displacement by devising a structure necessary for detecting such a rotational speed, and is newly added to the rolling bearing unit portion. Eliminates the need to install extra parts. For this reason, the structure for calculating | requiring the load or displacement added to this rolling bearing unit can be comprised small and lightweight.

Further, in the case of the present invention, the rotation side raceway is caused by a defective assembly of the encoder with respect to the rotation side raceway or a rotary member that is coupled and fixed to the rotation side raceway and rotates together with the rotation side raceway. Even if the detected surface of this encoder swings in the width direction with the rotation of a rotating member such as a wheel, or there is a pitch error related to a change in the characteristics of the detected surface, A displacement amount of the rotating member such as a relative displacement amount with respect to the stationary side raceway or a load applied to the rotating member can be accurately obtained. That is, in the case of the present invention, the filter circuit performs filtering processing on the output signal of the sensor or a processing signal obtained based on the output signal by the filter circuit, so that the characteristic change over the circumferential direction of the detected surface of the encoder is performed. The error component based on the error is eliminated. For this reason, the amount of displacement of the rotating member which appears as the amount of relative displacement between the two race rings, regardless of the swinging of the surface to be detected due to the poor assembly or the pitch error of the characteristic change of the surface to be detected. Alternatively, the load applied to the rotating member such as the load applied between the two race rings can be accurately obtained.

Moreover, when implementing this invention, Preferably , at least an adaptive filter is used as a filter circuit as described in Claim 10.
If an adaptive filter is used as the filter circuit, signal processing delays associated with eliminating errors related to displacement measurement based on the deflection of the detected surface of the encoder in the width direction can be eliminated, and various controls using this displacement can be performed quickly. It can be done.
That is, the fluctuation displacement generated with the encoder mounting error with respect to the rotating side raceway, such as the inclination and eccentricity, becomes the error of the rotation primary component. For example, the rotational speed of a rotating wheel of a rolling bearing unit for supporting a wheel of an automobile traveling at a vehicle speed of 40 km / h is about 300 min ⁻¹ (5 Hz), and the frequency of the rotation primary component error is a low frequency of about 5 Hz. It becomes. Such a low-frequency error component can be removed by a high-pass filter, but in this case, a response delay becomes large and control based on the obtained displacement (load) cannot be performed quickly. For this reason, for example, there is almost no problem when controlling a machine tool, but it is not preferable when performing control for ensuring the running stability of an automobile. On the other hand, if the low-frequency error component as described above is removed by the adaptive filter, the response delay can be eliminated and the control based on the obtained displacement (load) can be quickly performed.

Preferably, when an adaptive filter is used as in the invention described in claim 10, as described in claim 11, an LMS (least mean square) algorithm (a mean square error is minimized based on the steepest descent method). Digital filters or analog filters that operate according to the calculation rules) are used.
Alternatively, as described in claim 12, an adaptive filter using a synchronous LMS algorithm is used.
With this configuration, the number of calculation processes required for the sensor detection signal is greatly reduced each time the encoder characteristics change (every pulse), and the calculation speed is not particularly high. Processing in the device (CPU) is sufficiently possible.

  The adaptive filter can also remove an error component due to encoder manufacturing error. In other words, the variation in the detection signal of the sensor based on the manufacturing error has periodicity as in the variation based on the encoder assembly error. For example, the error due to the deviation of the circumferential position of the boundary line where the characteristics of the surface to be detected deviates from the design value is the error of the rotation n-order component, which is repeated every time the rotation-side raceway makes one rotation. Become. In this case, such an error component can be effectively removed by using the synchronous LMS adaptive filter. That is, according to the adaptive filter using the synchronous LMS algorithm, it is possible to remove all error components of the rotation n-order component including the rotation first order, and to reduce the calculation amount.

  Further, as described in claim 13, if the step size parameter μ of the LMS adaptive filter is changed and the step size parameter μ is set to a small value after a predetermined time has elapsed, the phase delay can be suppressed to a very small value. In addition, even when the displacement (load) to be detected transiently occurs at the same frequency as the rotation n-order component, which is an error, if the step size parameter μ is reduced, the displacement (load) can be reduced. It is possible to detect fluctuations. The reason is that the adaptive filter is installed in parallel to the main signal path for sending the output signal of the sensor to the arithmetic unit, and the process for removing the error is performed by subtraction. This is because processing can be performed even if the component to be detected has the same frequency.

When carrying out the invention described in claims 11 to 13 as described above, more preferably, as described in claim 14, when the filtering process by the adaptive filter is started, the adaptive filter is first input. The data represented by the output signal or the processed signal is used as the initial value of the filter coefficient of this adaptive filter.
That is, when the correction calculation for removing the rotation n-th order fluctuation component is started by the adaptive filter, the data represented by the output signal or the processing signal first input to the adaptive filter is affected by the fluctuation component. Excluding (noise), it can be assumed that this data (average DC level) is almost equivalent. Of course, since the first input data itself contains the noise, it is not exactly equal to the average DC level, but it is considered to be used for the purpose of improving the convergence of the adaptive filter. There is no particular problem with making the above assumptions. That is, if the first input data is input as initial values to all the filter coefficients, it becomes a value close to the finally converged filter coefficient (the difference from the finally converged filter coefficient is Only the fluctuation component).

  As described above, by adopting a value close to the original (appropriate) filter coefficient as the first input filter coefficient (initial value of the filter coefficient), the adaptive filter is activated (filtering starts). In a short time, the filter coefficient of the adaptive filter converges to an appropriate value. After the filter coefficient has converged to an appropriate value, the relative displacement between the rotation-side raceway and the stationary-side raceway after removing the error component contained in the output signal of the sensor (corrected for the error). Get accurate data on quantity. For this reason, for example, when the load applied between the two race wheels is obtained based on the relative displacement amount, and this load is used for controlling the running stability of the vehicle, this control is performed immediately after starting. Can be performed appropriately to improve the running stability of the automobile.

  The first input filter coefficient can be set only from the first sampled data, but the average value of a plurality of (first to kth) data sampled immediately after startup is The initial value of the filter coefficient can be input to the adaptive filter. However, if the number of data to be averaged (value of k) is increased too much, it takes time to obtain the initial value of the filter coefficient, resulting in a response delay, and the original purpose cannot be achieved. Absent.

When the present invention is implemented, for example, as described in claim 15, at least one of a low-pass filter and a notch filter can be included in the filter circuit.
For example, error components due to disturbances other than errors caused by the rolling bearing unit, such as shape errors, dimensional errors, and assembly errors of the components of the rolling bearing unit, are naturally errors that are asynchronous to the rotation of the rotating raceway. Become an ingredient. For example, electrical noise, magnetic flux noise, sensor vibration due to road surface vibration, and the like correspond to this. Normally, error components asynchronous to these rotations have a relatively high frequency, and therefore, the response delay can be suppressed to a level that does not cause a problem by a low-pass filter. The low-pass filter used in this case may be a rotation order tracking type filter or a fixed frequency type filter.

  On the other hand, when the frequency of the error component is constant, the error component can be removed by the notch filter. For example, the resonance frequency of a portion (so-called unsprung) existing on the road surface side from a spring incorporated in a suspension device of an automobile is about 15 to 25 Hz. When the sensor vibrates due to such unsprung resonance and an error component is mixed in the detection signal of the sensor, the notch frequency of the notch filter is previously adjusted to this resonance frequency. In this case, a fixed frequency filter is used as the notch filter.

On the other hand, there is a possibility that an error component may be mixed in the detection signal of the sensor based on the vibration having a determined rotation order, such as the vibration caused by the shape error of the rolling elements constituting the rolling bearing unit. The number of rolling elements constituting the rolling bearing unit is Z, the contact angle is α, the diameter is d, the pitch circle diameter is D, the revolution speed is ω _c , and the rotation speed ω of the inner ring that is the rotation side raceway ring If the _r, is _{ω c = (1-d ·} cosα / D) · (ω r / 2), the rolling vibration by moving object _{nZω c, 0.5nZω c, nω c} , revolution such 0.5Enuomega _c It becomes the order component. Since the relationship between the rotational speed ω _{r of the} inner ring serving as the rotation-side raceway and the revolution speed ω _c of each rolling element is as shown in the above equation, the vibration frequency of each revolution order is expressed as the rotation order of the rotation-side raceway. Then, the frequency of the error component to be removed by the notch filter is set. In this case, a rotation order tracking type filter is used as the notch filter.

When carrying out the invention described in claims 10 to 15, as described in claim 16, the adaptive filter and at least one of the low-pass filter and the notch filter are connected in series with each other. It can also be provided. In this case, the adaptive filter is arranged in a stage preceding at least one of the low-pass filter and the notch filter.
In this way, by arranging the adaptive filter and at least one of the low-pass filter and the notch filter in series with each other, the error component mixed in with respect to the detection signal of the sensor is good over a wide range. Can be removed. In addition, since the adaptive filter is arranged on the upstream side of the other filter, the time required for the filter coefficient of the adaptive filter to converge is not increased by using this other filter.

The filtering processing by each filter described above may be performed on data relating to the duty ratio of the sensor output signal or data relating to the phase difference, or data relating to the period and frequency (speed) of the output signal. May be subjected to a series of filtering processes, and the duty ratio or phase difference may be extracted from the filtered result.
In any case, the relative displacement between the stationary and rotating side raceways, and the distance between these raceways, regardless of the shake of the detected surface of the encoder or the vibration of the sensor due to improper assembly, etc. The load applied to can be accurately determined.

Moreover, when implementing the invention described in claims 15 to 16, preferably, as described in claim 17, the cutoff frequency of at least one of the low-pass filter and the notch filter is set as follows. It is changed according to the rotational speed of the rotating member, such as a rotating side raceway or a member that is coupled and fixed to the rotating side raceway and rotates together with the rotating side raceway.
With this configuration, regardless of the change in the rotation speed of the rotating member, the rotation of the surface to be detected regardless of the swinging of the surface to be detected due to the poor assembly of the encoder, the pitch error of the characteristic change of the surface to be detected, etc. The amount of displacement of the member and thus the load applied to the rotating member can be accurately obtained.

Further , when the invention described in claims 1 to 3 and 5 is carried out, preferably, as described in claim 18, the rolling bearing unit is arranged so that the stationary side raceway and the rotation side raceway face each other. A double-row rolling bearing unit is provided in which a pair of circumferential surfaces are provided with a double-row stationary-side raceway surface and a rotary-side raceway surface, respectively.
Such a double row rolling bearing unit can obtain sufficient rigidity by giving a contact angle in the opposite direction (rear combination type or front combination type) to the rolling elements arranged in the double row, and can also be stationary. The side raceway and the rotation side raceway are displaced in the direction of the load acting between the two raceways by an amount corresponding to the magnitude of the load. Therefore, if the invention described in claims 1 to 5 is carried out for the double row rolling bearing unit, the direction and size of the load can be appropriately measured.

When carrying out the invention described in claim 18 as described above, for example, as described in claim 19, the rolling bearing unit is a wheel bearing rolling bearing unit. Then, in use, the outer ring, which is a stationary side race ring, is supported and fixed to the suspension device, and the hub, which is a rotation side race ring, is supported and fixed to a wheel and rotated together with the wheel. In addition, between the double row outer ring raceway that exists on the inner peripheral surface of the outer ring and each of which is a stationary side track, and the double row inner ring raceway that exists on the outer peripheral surface of the hub and that is each a rotary side raceway. A plurality of rolling elements are provided for each row. Further, a flange for supporting and fixing the wheel is provided at the outer end of the hub in the axial direction.
If comprised as mentioned above, the load added to a wheel can be calculated and it can utilize for the control for ensuring running stability.

Further, when carrying out the inventions described in the above-mentioned claims 18 to 19, for example, as described in claim 20, the encoder is arranged between a plurality of rotation-side raceway surfaces in a part of the rotation-side raceway. The part is supported and fixed concentrically with the rotating raceway.
Alternatively, as described in claim 21, the encoder is supported and fixed concentrically with the rotating raceway at the end of the rotating raceway.
Which structure is adopted is determined by design in consideration of the internal space of the double row rolling bearing unit.

When carrying out the invention described in claim 19, for example, as described in claim 22, a disk rotor that constitutes a disk brake with a member that rotates together with the rotating side race ring being coupled and fixed to a hub. And The outer peripheral surface of this disk rotor is used as the detected surface. In this case, the outer peripheral surface of the disk rotor itself may be used as the detected surface, or the encoder may be fitted and fixed to the outer peripheral surface of the disk rotor.
Alternatively, as described in claim 23, the member that rotates together with the rotating side raceway is a constant velocity joint that is coupled and fixed to the hub. And let the one part outer peripheral surface of this constant velocity joint be a to-be-detected surface. Also in this case, the outer peripheral surface of the constant velocity joint itself may be used as the detected surface, or the encoder may be fitted and fixed to the outer peripheral surface of the constant velocity joint.
In any case, the detected surface and the sensor facing the detected surface can be installed in a wide space outside the double row rolling bearing unit. For this reason, even when a small double row rolling bearing unit does not have a space in which the detected surface and the sensor can be installed, the load applied to the double row rolling bearing unit can be measured.

When carrying out the invention described in claims 1 to 3, for example, as described in claim 24, the rolling bearing unit is for rotatably supporting the spindle of the machine tool on the housing. In the state of use, the outer ring, which is a stationary side race ring, is fitted and fixed to the housing or a part fixed to the housing, and the inner ring, which is a rotation side race ring, is fitted to the main shaft or a part that rotates together with the main shaft. You can also do it.
If comprised in this way, the load added to the said spindle can be measured, and the feed rate of the tool supported by this spindle can be controlled appropriately.

1-7 has shown Example 1 of this invention corresponding to Claims 4-7 , 9-10 , 12-13 , 18-19 , 21. FIG. The rolling bearing unit with a displacement measuring device (or with a load measuring device) of the present embodiment is a displacement measuring device 2 (or a load measuring device) having a function as a wheel bearing rolling bearing unit 1 and a rotational speed detecting device. ).
Of these, the wheel support rolling bearing unit 1 includes an outer ring 3, a hub 4, and a plurality of rolling elements 5, 5 as shown in FIG. 1. Of these, the outer ring 3 is a stationary-side bearing ring that is supported and fixed to the suspension device in use. The outer ring 3 has double-row outer ring raceways 6 and 6 connected to the suspension surface on the outer peripheral surface. Each has an outward flange-shaped attachment portion 7. The hub 4 is a rotating raceway that supports and fixes a wheel in use and rotates together with the wheel. The hub body 8 and the inner ring 9 are combined and fixed. Such a hub 4 includes a flange 10 for supporting and fixing a wheel to an outer peripheral end portion in the axial direction of the outer peripheral surface (an end portion on the outer side in the width direction of the vehicle body when assembled to the suspension device). Double-row inner ring raceways 11 are provided on the outer circumferential surface of the inner ring 9. Each of the rolling elements 5, 5 is provided between the inner ring raceways 11, 11 and the outer ring raceways 6, 6 so as to be freely rollable in a state where a preload is applied. On the inner diameter side, the hub 4 is rotatably supported concentrically with the outer ring 3. In the illustrated example, a ball is used as the rolling element, but in the case of a rolling bearing unit for supporting a wheel of a heavy vehicle, a tapered roller may be used as each rolling element. The structure using balls as rolling elements can increase the amount of displacement between the outer ring and the hub compared to the structure using tapered rollers, but the amount of displacement can also be achieved in the structure using tapered rollers as rolling elements. Since they are small, they are displaced, and can be the subject of the present invention.

On the other hand, the displacement measuring apparatus 2 includes an encoder 12, a sensor 13, and an arithmetic unit (not shown) as shown in FIG.
Of these, the encoder 12 includes a support plate 14 and an encoder body 15. Of these, the support plate 14 is formed by bending a magnetic metal plate such as a mild steel plate so that the annular portion 16 and the cylindrical portion 17 are continuous by an inclined portion. Is an annular shape. The encoder body 15 is made of a permanent magnet such as a rubber magnet or a plastic magnet, and has an annular shape as a whole. The encoder body 15 is attached and fixed concentrically with the cylindrical portion 17 on the inner surface in the axial direction of the annular portion 16. Yes.

  The permanent magnets constituting the encoder body 15 are magnetized in the axial direction, and the magnetization direction is changed alternately and at equal intervals over the circumferential direction. Therefore, N poles and S poles are alternately arranged at equal intervals on the inner side surface in the axial direction of the encoder body 15 which is a detected surface. In the case of the present embodiment, the first detected portion in which the portion magnetized in the N pole and the portion magnetized in the S pole exist on the detection surface of the encoder 12 and have different characteristics from each other. And the second detected part. As shown in FIG. 2, the width of the portion magnetized in the N pole is the radial direction of the width in the circumferential direction between the portion magnetized in the N pole and the portion magnetized in the S pole. The outer side is wider and the width of the portion magnetized in the S pole is wider toward the inner side in the radial direction.

  The encoder 12 configured as described above is fitted on the inner end of the hub 4 in the axial direction by fitting the cylindrical portion 17 of the support plate 14 to the inner end of the inner ring 9 with an interference fit. The hub 4 is connected and fixed concentrically. In this state, the inner surface in the axial direction of the encoder body 15 is located on a virtual plane orthogonal to the central axis of the hub 4.

  On the other hand, the sensor 13 is supported and fixed to the inner end of the outer ring 3 in the axial direction via a cover 18. The cover 18 is formed into a bottomed cylindrical shape by injection molding a synthetic resin or by drawing a metal plate, and in a state of closing the inner end opening of the outer ring 3, It is fitted and fixed to the inner end of the outer ring 3. A mounting hole 20 is formed in a portion of the bottom plate portion 19 of the cover 18 that is close to the outer diameter of the bottom plate portion 19 and opposed to the detection surface of the encoder 12 so as to penetrate the bottom plate portion 19 in the axial direction. ing.

  The sensor 13 is supported and fixed to the bottom plate portion 19 in a state in which the mounting hole 20 is inserted from the inside in the axial direction to the outside. And the detection part provided in the front end surface (left-end surface of FIG. 1) of the said sensor 13 is made to oppose and adjoin with the to-be-detected surface of the said encoder 12 through the measurement clearance gap of about 0.5-2 mm. In addition, a magnetic detecting element such as a Hall element or a magnetoresistive element is provided in the detecting portion of the sensor 13 which is an active magnetic sensor. The characteristics of such a magnetic detection element change between a state facing the N pole and a state facing the S pole. Therefore, when the encoder 12 rotates together with the hub 4, the characteristics of the magnetic detection element change, and the output signal of the sensor 13 changes.

In this way, the cycle (frequency) at which the output signal of the sensor 13 changes varies according to the rotational speed of the hub 4. Specifically, the faster the rotation speed, the shorter the cycle of changing the output signal, and the higher the changing frequency. For this reason, if this output signal is sent to a controller (not shown) provided on the vehicle body side or the like, the rotational speed of the wheel rotating together with the encoder 12 can be obtained to control the ABS and TCS. This point is the same as a conventionally known technique.
In particular, in the case of the present embodiment, a pattern in which the output signal changes due to a radial displacement between the hub 4 and the outer ring 3 based on a radial load acting between the hub 4 and the outer ring 3. Therefore, by observing this pattern, the relative displacement amount in the radial direction between the hub 4 and the outer ring 3 and further the radial load can be obtained. This point will be described with reference to FIGS.

  First, the premise for obtaining the radial load will be described. As described in Patent Document 1 described above, the relative position in the radial direction between the outer ring 3 and the hub 4 changes according to the magnitude of the radial load applied between the outer ring 3 and the hub 4. . The reason for this is that, based on the radial load, the rolling elements 5, 5 and the rolling surfaces of the rolling elements 5, 5 are in rolling contact with the outer ring raceways 6, 6 and the inner ring raceways 11, respectively. This is because the amount of elastic deformation 11 changes. In the case of the prior art described in Patent Document 1, the displacement amount in the radial direction between the outer ring and the hub is directly measured by a displacement sensor, and further, based on this displacement amount, between the outer ring and the hub. The radial load applied to is determined. On the other hand, in this embodiment, based on the relative displacement between the encoder 12 and the sensor 13, the relative displacement between the outer ring 3 and the hub 4, and further, the outer ring 3 and the hub 4 The magnitude of the radial load applied during the period is determined. This point will be described below.

When a standard radial load (standard value) is applied between the outer ring 3 and the hub 4, the detection portion of the sensor 13 faces the center portion in the radial direction of the detection surface of the encoder 12. Assuming that In this case, the detection unit of the sensor 13 scans the central portion in the radial direction of the detection surface, which is indicated by a chain line α in FIG. In this radial central portion, the width in the circumferential direction of the portion magnetized in the N pole and the width in the circumferential direction of the portion magnetized in the S pole are equal to each other. As shown in FIG. 4A, the same voltage is swung on both sides around the reference voltage (for example, 0 V). That is, the period T _H when the voltage of the output signal is higher than the reference voltage and the period T _{L when} it is lower are equal to each other (T _H = T _L ). The difference ΔV _H between the maximum value of the output signal voltage and the reference voltage and the difference ΔV _L between the minimum value and the reference voltage are also equal to each other (ΔV _H = ΔV _L ).

On the other hand, when the radial load applied between the outer ring 3 and the hub 4 becomes larger than a standard value, the position of the outer ring 3 with respect to the hub 4 is shifted downward, and the detection unit of the sensor 13 Opposite to the radially inner portion of the detection surface of the encoder 12. In this case, the detection unit of the sensor 13 scans a radially inward portion of the detected surface indicated by a chain line β in FIG. In the radially inward portion, the width in the circumferential direction of the portion magnetized in the N pole is narrower than the width in the circumferential direction of the portion magnetized in the S pole. As shown in FIG. 4B, the reference voltage (for example, 0 V) is largely shifted toward the lower side. That is, the voltage of the output signal is greater than the period T _H the period T _L becomes lower than the reference voltage becomes higher (T H _{<T L).} Further, the difference ΔV _L between the minimum value of the output signal voltage and the reference voltage is also larger than the difference ΔV _H between the maximum value and the reference voltage (ΔV _L > ΔV _H ).

Further, contrary to the case described above, when the radial load applied between the outer ring 3 and the hub 4 becomes smaller than the standard value, the position of the outer ring 3 with respect to the hub 4 shifts upward, and the sensor 13 The detecting portion of the encoder 12 is opposed to a radially outward portion of the detected surface of the encoder 12. In this case, the detection unit of the sensor 13 scans a radially outward portion of the detected surface indicated by a chain line γ in FIG. In the radially outer portion, the width in the circumferential direction of the portion magnetized in the N pole is wider than the width in the circumferential direction of the portion magnetized in the S pole. As shown in (C) of FIG. 4, the reference voltage (for example, 0V) is largely swung to the higher side. That is, the voltage of the output signal is greater than the period T _L which becomes higher period T _H than the reference voltage is lower (T _{H> T L).} The difference ΔV _H between the maximum value of the voltage of the output signal and the reference voltage is also larger than the difference ΔV _L between the minimum value and the reference voltage (ΔV _H > ΔV _L ).

Therefore, by looking at the pattern of the output signal of the sensor 13, it is possible to determine the degree of deviation (radial displacement) between the central axis of the outer ring 3 and the central axis of the hub 4. Specifically, by looking at the ratio "T _{H /} T _L" in the period T _L of the potential of the output signal becomes lower as the higher becomes the period T _H than the reference voltage, the central shaft and the hub of the outer ring 3 It is possible to determine the degree of deviation from the central axis of 4 (the amount of radial displacement). Or, observe the ratio “ΔV _H / ΔV _L ” between the difference ΔV _H between the maximum value of the voltage of the output signal and the reference voltage and the difference ΔV _L between the minimum value and the reference voltage. The above-described radial displacement amount can also be obtained. The relationship between these ratios “T _H / T _L ”, “ΔV _H / ΔV _L ” and the amount of radial displacement can be easily obtained because any ratio is almost linear. And the calculated | required relationship is integrated in the software installed in the calculator (microcomputer) which is not shown in figure for calculating the said radial load. In some cases, a waveform shaping circuit is incorporated in the sensor 13 so that the output signal of the sensor 13 is a pulse-changing rectangular wave. In this case, the radial displacement cannot be obtained based on the voltage ratio “ΔV _H / ΔV _L ”. However, the radial displacement is determined by the cycle ratio “T _H / T _L ”. Can be obtained as in the case where the output signal is a sine wave.

  Further, the relationship between the radial displacement and the radial load can be obtained by calculation or experiment. When obtaining by calculation, the specifications of the rolling bearing unit 1, that is, the radius of curvature of the cross sections of the outer ring raceways 6 and 6 and the inner ring raceways 11 and 11, the number and diameter of the rolling elements 5 and 5, respectively. In addition, based on the material of the outer ring 3 and the hub 4, it is obtained based on the theory widely known in the technical field of rolling bearing units. Further, in the case of obtaining by experiment, a relative displacement amount in the radial direction between the outer ring 3 and the hub 4 is applied between the outer ring 3 and the hub 4 while applying different known radial loads. Measure. In any case, a relationship as shown in FIG. 5 is obtained with respect to the radial displacement amount and the radial load, and incorporated in the software. It is also possible to directly obtain the relationship between the radial load and any of the above ratios and incorporate this relationship into the software.

As described above, in the case of the present embodiment, based on any one of the above ratios “T _H / T _L ” and “ΔV _H / ΔV _L ”, the center axis of the outer ring 3 and the hub 4 The amount of displacement (or radial load) in the radial direction with respect to the central axis is obtained. In order to accurately obtain this amount of displacement, the accuracy of the detected surface of the encoder 12 needs to be good as described above. . On the other hand, the accuracy regarding the position of the boundary portion where the characteristics of the surface to be detected change may not always be sufficient due to the assembly error of the encoder 12 with respect to the hub 4 as described above. Therefore in the case of this embodiment, any of the above ratio "T _{H /} T _L", the data on the "△ V _{H /} △ V _L", by processing by the adaptive filter 32 such as shown in FIG. 6, An error related to the position of the boundary portion is removed. The adaptive filter 32 uses an LMS algorithm. Hereinafter, the operation of the adaptive filter 32 will be described with a focus on the case where the error of the rotation first-order component due to the shake due to the assembly error of the encoder 12 with respect to the hub 4 is removed.

The width of the boundary between the S pole and the N pole existing on the detected surface of the encoder 12 at the portion where the detection portion of the sensor 13 is opposed is actually displaced in the radial direction with respect to the sensor 13. and minutes d _d which change with it to become what the error component d _n of rotational primary component by the whirling like are superimposed _(d d ₊ d _n). That is, the signal d based on the output signal of the sensor 13 is a signal d (= d _d + d _n ) obtained by adding the signal d _d representing the actual radial displacement and the error component d _n . Therefore, by subtracting the variation amount d _n from the output signal d by the adaptive filter 32 (Genzure In) will be asked to the actual displacement amount d _d.

On the other hand, in order to operate the adaptive filter 32, a reference signal x having a correlation with the variation d _n based on the whirling is required. If obtain this reference signal x, the adaptive filter 32 by the self-learning, with the same characteristics as the transmission characteristics of the actual signal flow "d _n → d ', FIR (finite impulse response) filter (impulse response time A finite filter = a filter whose impulse response becomes 0 within a finite time). Then, by subtracting a cancel signal y {= y (k) to be described later] obtained as a result of calculation by the adaptive filter 32 from the output signal d of the sensor 13, the wobbling from the output signal d of the sensor 13 become variation _{d n} removal of the _{(d-d n)} that is equivalent to by. When in this manner removes the variation d _n, the adaptive filter 32, instead of filtering the output signal d to be sent to the main root of the signal (upper half portion in FIG. 6), sub-route ( based on the reference signal x is fed to the lower half portion) of FIG. 6 calculates the cancellation signal y for removing the variation amount d _n. Since the cancel signal y is simply subtracted from the output signal d that is the main route, a response delay of the output signal d is not caused.

  In the case of this embodiment, the reference signal x is applied to the output signal processing circuit of the sensor 13 facing the encoder 12 based on the number of characteristic changes during one rotation of the encoder 12, or to this output signal. On the basis of this, a processing circuit for obtaining a displacement amount in the radial direction between the central axis of the outer ring 3 and the central axis of the hub 4 (and a radial load from this displacement amount) is self-generated. Therefore, the cost required for generating the reference signal x can be reduced. That is, when the structure of active noise control, which has been generally known as an application of an adaptive filter, is applied as it is to the structure for accurately obtaining the amount of displacement as it is, the whirling of the encoder 12 can be changed to a displacement sensor or rotational speed. Detection is performed by a sensor provided separately, such as a sensor, and the detection signal of this sensor is used as the reference signal x of the adaptive filter 32. Of course, it is possible to implement the present invention with such a structure, but the cost and the installation space are required as much as a separate sensor is provided.

On the other hand, in the case of the present embodiment, the reference signal x is obtained without using the detection signal of such a separately provided sensor, and based on the swing of the encoder 12 by the adaptive filter 32. reduces variation d _n of the output signal d of the sensor 13. That is, the number of characteristic changes during one rotation of the encoder 12 (the number of S poles and N poles) is known in advance. Therefore, this By observing the number of pulses for one revolution of the encoder 12, without particularly providing a separate sensor such as a displacement sensor or a speed sensor, generates the reference signal x having a correlation with the variation amount d _n it can. Specifically, the influence of the swing of the encoder 12 is a waveform whose main component is the rotation primary. For example, if the encoder 12 has 60 pulses per rotation, one cycle is 60 data. Can be self-generated as a sine wave, triangle wave, sawtooth wave, rectangular wave, pulse wave, etc.

Such a waveform of the reference signal x is generated by a processing circuit (CPU) for calculating a displacement amount (and radial load) in the radial direction between the central axis of the outer ring 3 and the central axis of the hub 4. It can also be generated by an electronic circuit unit (IC) attached to the sensor 13. Anyway, the resulting canceled signal y calculated based on the reference signal x, is subtracted from the output signal d of the sensor 13 modifies the signal e {= below representing the actual displacement amount d _d e (K)} is obtained. The correction signal e obtained in this way is sent to a processing circuit for calculating the displacement (radial load) and used to determine the displacement (radial load), and the adaptive filter 32 is self-learning. Also used as information to do.

The processing for obtaining the correction signal e by obtaining the cancellation signal y in the adaptive filter 32 and further subtracting the cancellation signal y from the output signal d of the sensor 13 is as follows. (3) Perform based on the equation.

In the above equations (1), (2), and (3), k is a data number in time series, and N is the number of taps of the FIR filter used as the adaptive filter 32. Further, w represents a filter coefficient of the FIR filter, w _k is a filter coefficient used when the k-th data processing is performed, and w _{k + 1} is a filter coefficient used when the next data series (k + 1-th) is processed. Respectively. That is, in the case of the present embodiment, the FIR filter is an adaptive filter in which the filter coefficient is updated appropriately and sequentially according to the above equation (3).

The reference signal x input to the adaptive filter 32 is a signal that is correlated with the rotation n-th order (n is a positive integer) component of the encoder 12 typified by the swing of the encoder 12 and the like. Since it is good, one impulse signal per one rotation of the encoder 12 may be used. Therefore, it is assumed that the reference signal x is an impulse signal and the number N of taps of the adaptive filter 32 is equal to the number of pulses per rotation of the encoder 12. In this case, the reference signal x used for calculation at the instant of time series k is expressed by the following equation (4).

In this equation (4), the position j at which the reference signal x becomes an impulse having the value 1 is shifted one by one to the right as the time series k advances to the rightmost “N−1” th. If shifted, a new impulse value appears at the leftmost 0th in the next time series. That is, the reference signal x is a data string obtained by circulating the position of the impulse having the value 1 from the 0th to the (N-1) th. When this equation (4) is applied to the aforementioned equations (1) and (3), the following equations (5) and (6) can be obtained.

  When the adaptive filter is operated by a normal LMS algorithm that is not synchronous, the calculations shown in the equations (1), (2), and (3) must be repeated as described above, whereas the synchronous filter is synchronous. When the adaptive filter is operated by the LMS algorithm, it is only necessary to perform the calculations shown in the equations (5), (6) and (2). For example, when the number of taps N of the adaptive filter 32 is set to 60, when the adaptive filter 32 is operated by a normal LMS algorithm, the total number of calculations for each pitch of the encoder 12 is multiplied by the above equation (1). 60 times, subtraction with the above equation (2) once, 120 multiplications with the above equation (3) and 180 additions with 60 times, a total of 241 times. On the other hand, when the adaptive filter 32 is operated by the synchronous LMS algorithm, the above equation (5) is not calculated only by data replacement, is subtracted once by the above equation (2), and is multiplied by the above equation (6). What is necessary is just to perform four arithmetic operations of 1 time and 1 time of addition, a total of 3 times for every pulse of the encoder 12. In other words, by adopting a synchronous method as the LMS algorithm, the number of operations can be reduced to approximately 1/80 compared to a case where the LMS algorithm is not employed.

  However, when the synchronous LMS algorithm is employed to operate the adaptive filter 32, in order to prevent even the DC component which is a signal representing the actual displacement amount from being canceled, It is necessary to correct the zero point. That is, when a synchronous system is adopted as the LMS algorithm for operating the adaptive filter 32 and no particular countermeasure is taken, not only the fluctuation component based on the swing of the encoder 12 but also the DC representing the displacement amount of the encoder 12 is used. Even components are canceled and the output value becomes zero. This is a phenomenon that occurs because the filter coefficient W of the adaptive filter 32 has a DC level due to the adaptive operation, and as a result, the output signal y of the adaptive filter 32 has a DC level. In order to solve this problem, the DC level is calculated from the average value of the filter coefficient w expressed by the above equation (6), and a DC signal obtained by multiplying the DC level by the impulse value of the reference signal x is calculated. (If the impulse value is 1, multiplication is not necessary). Then, by adding the DC signal calculated as described above to the signal e whose error has been canceled by the adaptive filter 32, a DC level representing an accurate displacement amount can be obtained.

It should be noted that the filter coefficient w _k used at the start of the calculation may be self-adapted if it starts to move even if zero is substituted. However, a desired filter characteristic is obtained in advance and its value is set. It may be substituted. Alternatively, the filter coefficient last used in the previous process may be stored in a storage unit such as an EEPROM and used at the time of restart. Furthermore, as in the invention described in claim 14, the data represented by the first input signal can be used as the initial value of the filter coefficient.

尚、この（７）式中のαも、フィルタ係数を自己適正化させていく為の更新量を決定するパラメータとなるが、０＜α＜１の範囲であれば良く、上記μよりも設定が容易である。又、本実施例の場合には、前記参照信号ｘを自己生成するので、上記（７）式中の分母の値は既知であり、μの最適値を事前に算出しておく事もできる。計算量削減の観点からは、予め（７）式でこのμを算出しておき、このμを定数として上記（３）式でフィルタ係数を自己適正化させるのが望ましい。 Also, μ in the above equation (3) is a value called a step size parameter that determines the update amount when the filter coefficient is self-optimized, and is usually a value of about 0.01 to 0.001. Actually, however, the validity of the adaptive operation can be examined and set in advance, or it can be updated sequentially using the following equation (7).

Note that α in the equation (7) is also a parameter for determining the update amount for self-optimizing the filter coefficient, but it may be in the range of 0 <α <1, and is set more than the above μ. Is easy. In the case of this embodiment, the reference signal x is self-generated, so that the value of the denominator in the equation (7) is known, and the optimum value of μ can be calculated in advance. From the viewpoint of reducing the amount of calculation, it is desirable to calculate μ in advance using equation (7), and to self-optimize the filter coefficient using equation (3), with μ being a constant.

As described above, the output signal d of the sensor 13, by subtracting the cancellation signal y, wherein the adaptive filter 32 has been calculated, is determined a correction signal e representative of the actual displacement amount d _d. Then, based on the correction signal e obtained in this way, the amount of displacement in the radial direction between the central axis of the outer ring 3 and the central axis of the hub 4, and further, there is an action between the outer ring 3 and the hub 4. The radial load to be accurately determined. In the actual case, the output signal d of the sensor 13 includes a second variation having a shorter cycle than the variation based on the swing of the sensor 13 based on the pitch error. Therefore, a low-pass filter such as an averaging filter for averaging the second variation is provided before or after the adaptive filter 32 (preferably after the invention described in claims 4 and 16). Regardless of the second variation, the displacement amount and further the radial load can be accurately obtained. Since the structure and operation of a low-pass filter such as an averaging filter for suppressing high-frequency fluctuations are well known in the art, detailed description thereof is omitted.

  Since the present embodiment is configured as described above, it is possible to obtain the radial load without having to incorporate new parts such as a displacement sensor in the rolling bearing unit portion. That is, the combination of the encoder 12 and the sensor 13 is also necessary for detecting the rotational speed of the hub 4 so as to control the ABS and TCS. The rolling bearing unit with a displacement measuring device of this embodiment is a structure for obtaining the above radial load by devising a structure necessary for detecting such a rotational speed. Therefore, the radial load applied to the rolling bearing unit is determined. The required structure can be made small and lightweight.

Incidentally, as is clear from FIG. 4, in the present embodiment, the magnitude of the radial load, the period T _L of the voltage of the output signal becomes lower as the higher becomes the period T _H than the reference voltage of the sensor 13 changes . Therefore, in order to accurately obtain the rotational speed of the hub 4 regardless of the change in the radial load, the rotational speed is calculated based on the sum of the both periods “ _TH + _TL ”. This sum “T _H + T _L ” is obtained even when the part magnetized in the N pole and the part magnetized in the S pole are fan-shaped or reverse fan-shaped as shown in FIGS. Since the rotation speed is almost constant regardless of the direction displacement, the rotation speed can be accurately obtained.

(A) of FIG. 7 has shown Example 2 of this invention corresponding to Claims 4-7 , 9-10 , 12-13 , 18-19 , 21. FIG. In the case of the present embodiment, the through holes 21 and 21 are formed at equal intervals in the circumferential direction in the intermediate portion in the radial direction of the annular encoder 12a. In the case of the present embodiment, each of the through holes 21 and 21 has an inverted fan shape (or an inverted trapezoidal shape) whose width in the circumferential direction becomes narrower toward the radially outer side of the encoder 12a. The portions 22 and 22 between the through holes 21 adjacent to each other in the circumferential direction are formed in a sector shape (or a trapezoidal shape) whose width in the circumferential direction increases toward the outer side in the radial direction. Therefore, in the case of the present embodiment, the above-described inter-portions 22 and 22 become the first detected portions described in claim 7 , and the respective through-holes 21 and 21 become the second detected portions as well. Contrary to the above case, as shown in FIG. 7B, the width of the through holes 21a, 21a is increased toward the outer side in the radial direction, and the width of the intermediate portions 22a, 22a is increased outward in the radial direction. You can make it smaller as you go.

In any case, by combining with an appropriate sensor, the center axis of the stationary side race ring such as an outer ring supporting this sensor and the encoder 12a are supported and fixed in the same manner as in the case of the first embodiment. The amount of displacement in the radial direction with respect to the central axis of the rotating raceway such as a hub can be obtained. And the radial load which acts between these stationary side races and rotation side races is calculated. As in the case of the first embodiment, the process of obtaining the displacement amount may be omitted and the radial load may be obtained directly. The material constituting the encoder 12a is selected according to the type of sensor.
For example, when the sensor is an active magnetic sensor including a permanent magnet and a magnetic detection element such as a Hall element or a magnetoresistive element, the encoder 12a is made of a magnetic metal such as a steel plate. . The same applies to the case where the sensor is a passive magnetic sensor including a permanent magnet, a pole piece, and a coil. Even in such a structure, in the same manner as in the first embodiment, the output signal of the sensor is detected in accordance with the change in the radial position of the portion of the detection surface of the encoder 12a facing the detection portion of the sensor. Changes. When a magnetic sensor is used, a fan-shaped or inverted fan-shaped concave portion or convex portion can be formed on the detection surface of the encoder instead of the through hole. In the case of an encoder made of a permanent magnet having N poles and S poles arranged on the surface to be detected, the load detection accuracy may deteriorate as the magnetic flux intensity becomes non-uniform. If an encoder having a through-hole, or a concave or convex portion is used on the plate, such a problem does not occur, and it is easy to ensure the load detection accuracy.

On the other hand, when the sensor is an optical sensor, one structure of the first detected part or the second detected part formed on the detected surface of the encoder 12a is limited to a through hole. In this case, the material constituting the encoder 12a may be any material that blocks light. When an optical sensor is used, a cycle in which the output signal of the sensor changes in accordance with a change in the radial position of a portion of the detection surface of the encoder 12a that faces the detection unit of the sensor. Change (the magnitude of change does not change).
Since the structure and operation of the parts other than the encoder 12a are the same as those in the first embodiment described above, the illustration and description regarding the equivalent parts are omitted.

FIG. 8 shows Embodiment 3 of the present invention corresponding to claims 4 to 7, 9 to 10 , 12 to 13, and 18 to 20. In the case of the present embodiment, the encoder 12b is externally fitted and fixed between the rolling elements 5 and 5 arranged in a double row at the axially intermediate portion of the hub 4a. The encoder 12b includes a support plate 14a that is L-shaped in cross section and formed in an annular shape as a whole. Then, the permanent magnet encoder body 15 as shown in FIGS. 2 and 3 is attached to one side surface in the axial direction of the annular portion 23 of the support plate 14a, or the annular portion 23 shown in FIG. By forming the through-holes 21 and 21a or the concave holes as shown in FIG. 5, the ring portion 23 itself has a function as an encoder.

The sensor 13a combined with such an encoder 12b is inserted into a mounting hole 20a formed in a portion between the double-row outer ring raceways 6 and 6 at an intermediate portion in the axial direction of the outer ring 3 from the radially outer side of the outer ring 3. It is inserted toward the direction. The detector provided on the side surface in the axial direction at the front end of the sensor 13a is close to the detected surface of the encoder body 15 attached to the axial side surface of the annular portion 23 or the side surface of the annular portion 23 itself. I am letting.
Based on the output signal pattern of the sensor 13a, a deviation (a radial displacement amount) between the central axis of the hub 4a and the central axis of the outer ring 3 is obtained, and from this deviation (or directly from the output signal pattern) Regarding the point of obtaining the radial load acting between the hub 4a and the outer ring 3, and the point of eliminating the fluctuation of the output signal of the sensor 13a due to the mounting error etc. by the adaptive filter, the first embodiment or the first embodiment described above. Since it is the same as 2, overlapping description is omitted.

9 to 11 show a fourth embodiment of the present invention corresponding to claims 1 and 9 . In the case of the present embodiment, a plurality of detection combination portions 24, 24 are arranged at equal intervals in the circumferential direction on the side surface in the axial direction of the encoder 12c, which is the detection surface. Each of these combination parts for detection 24, 24 is composed of a pair of individualized portions 25, 25 each having a different characteristic from the other portions. Such individualized portions 25, 25 include slit-like long holes as shown in FIG. 9A, concave holes as shown in FIG. 9B, and bank-like shapes as shown in FIG. Can be used. Regardless of the individualization portions 25, 25, the distance between the pair of individualization portions 25, 25 constituting the detected combination portions 24, 24 in the circumferential direction is the total. The detected combination parts 24 and 24 are continuously changed in the same direction with respect to the radial direction. In the illustrated example, the interval in the circumferential direction between the pair of individualized portions 25, 25 constituting each detected combination portion 24, 24 increases toward the outer side in the radial direction of the encoder 12c. The intervals in the circumferential direction between the individualized portions 25, 25 constituting each of the detected combination portions 24, 24 that are adjacent to each other are inclined so as to become smaller toward the outside in the radial direction of the encoder 12c.

The output signal of the sensor having the detection portion opposed to the detection surface of the encoder 12c as described above changes at the moment of facing the individualization portions 25, 25 as shown in FIG. The changing interval (cycle) changes with the change in the radial position of the portion of the sensor facing the detecting portion.
For example, when a standard radial load (standard value) is applied between a stationary-side raceway such as an outer ring and a rotation-side raceway such as a hub, the detection unit of the sensor is shown in FIG. The center portion in the radial direction of the detected surface shown in FIG. In this case, the output signal of the sensor changes as shown in FIG.
On the other hand, when the radial load applied between the stationary side raceway and the rotation side raceway becomes larger than the standard value, the detection unit of the sensor is indicated by a chain line β in FIGS. Then, the radially inward portion of the detected surface is scanned. In this case, the output signal of the sensor changes as shown in FIG.
Further, when the radial load applied between the stationary side raceway and the rotation side raceway becomes smaller than the standard value, the detection unit of the sensor, for example, the above-mentioned covered portion indicated by a chain line γ in FIGS. Scan a radially outward portion of the detection surface. In this case, the output signal of the sensor changes as shown in FIG.
Therefore, also in the case of the present embodiment, if the output signal pattern (change interval) of the sensor is viewed, the center axis of the stationary side raceway and the center axis of the rotation side raceway are shifted (diameter). (Direction displacement amount) can be obtained, and from this degree of deviation (or directly from the pattern of the output signal), the radial load applied between the two race rings can be obtained.

12-14 shows Example 5 of this invention corresponding to Claims 4-7 , 9-10 , 12-13 , 18-20 . In the case of the present embodiment, an encoder 12d is externally fitted and fixed to a portion between the rolling elements 5 and 5 arranged in a double row at the intermediate portion in the axial direction of the hub 4a. This encoder 12d is configured as shown in FIG. 13B by rounding a strip-shaped material as shown in FIG. 13A, and is similarly cylindrical on the outer peripheral surface of the cylindrical support plate 14b. An encoder main body 15a is attached and fixed over the entire circumference.

  The encoder body 15a is made of a permanent magnet such as a rubber magnet or a plastic magnet, and is magnetized in the radial direction. The magnetization direction is changed alternately and at equal intervals over the circumferential direction. Therefore, N poles and S poles are alternately arranged at equal intervals on the outer peripheral surface of the encoder body 15a, which is the detection surface. Among these, the width in the circumferential direction of the portion magnetized to the N pole that is the first detected portion is wide at one end in the axial direction of the encoder body 15a and narrow at the other end. On the other hand, the width in the circumferential direction of the portion magnetized by the S pole as the second detected portion is narrow at one end in the axial direction of the encoder body 15a and wide at the other end.

  The sensor 13b combined with such an encoder 12d is inserted into a mounting hole 20a formed in a portion between the double-row outer ring raceways 6 and 6 at an intermediate portion in the axial direction of the outer ring 3 from the radially outer side of the outer ring 3. It is inserted toward the direction. And the detection part provided in the front end surface of the said sensor 13b is made to adjoin and oppose the outer peripheral surface of the said encoder main body 15a.

  In the case of the present embodiment having the above-described configuration, if the relative position between the outer ring 3 and the hub 4a is shifted in the axial direction due to the variation of the axial load applied between the outer ring 3 and the hub 4a, The axial position of the portion of the outer peripheral surface of the encoder main body 15a facing the detection portion of the sensor 13b changes. As a result, as in the case of the first embodiment described above, the pattern in which the output signal of the sensor 13b changes as shown in FIG. The pattern in which the output signal of the sensor 13b changes as shown in FIG. 14, the amount of axial displacement between the outer ring 3 and the hub 4a, and the magnitude of the axial load applied between the outer ring 3 and the hub 4a Similarly to the relationship between the radial displacement amount and radial load and the change pattern of the output signal in the first embodiment, the relationship is obtained by calculation or experiment. Accordingly, by observing the change pattern of the output signal, the axial displacement amount and the magnitude of the axial load can be obtained. The point that the fluctuation of the output signal of the sensor 13b due to the mounting error or the like is removed by the adaptive filter is the same as in the first to fourth embodiments.

FIG. 15 shows Embodiment 6 of the present invention corresponding to claims 4 to 7, 9 to 10 , 12 to 13 , 18 to 19, and 21 . In the case of the present embodiment, the encoder 12e is fitted and fixed to the inner end of the hub 4a in the axial direction. The encoder 12e includes a support plate 14c. And the permanent magnet encoder which alternately arrange | positioned the north-pole and the south pole on the inner peripheral surface of the cylindrical part 26 of this support plate 14c in the state magnetized in the fan-shaped or trapezoid range, respectively. By attaching a main body or forming a fan-shaped or trapezoidal through hole in the cylindrical portion 26, the cylindrical portion 26 itself has a function as an encoder. And the detection part of the sensor 13c supported and fixed to the cover 18a fixed to the inner end opening part of the outer ring 3 is made to face the inner peripheral surface of the encoder 12e that is the detection surface.
Also in this embodiment, by observing the change pattern of the output signal of the sensor 13c, the amount of axial displacement between the outer ring 3 and the hub 4a and the relationship between the outer ring 3 and the hub 4a The magnitude of the axial load acting between them can be determined. The point that the fluctuation of the output signal of the sensor 13c due to the attachment error or the like is removed by the adaptive filter is the same as in the first to fourth embodiments.

FIG. 16 shows a seventh embodiment of the present invention corresponding to claims 1 and 9 . In the present embodiment, the structure of the fourth embodiment shown in FIGS. 9 to 11 is applied to determine the magnitude of the axial load. That is, in the case of the present embodiment, a plurality of detection combination parts 24, 24 are wound in the circumferential direction at equal intervals on the outer peripheral surface (or inner peripheral surface) of the cylindrical encoder 12f that is the detection surface. It is arranged with. Each of these combination parts for detection 24, 24 is composed of a pair of individualized portions 25, 25 each having a different characteristic from the other portions. In the case of the present embodiment, slit-like long holes are employed as such individualized portions 25 and 25.

  The encoder 12f having such individualized portions 25 and 25 has a belt-like magnetic metal plate in which the long holes are punched and formed in advance as shown in FIG. It is made by rounding into two and butt welding the circumferential edges. In addition, as each said individualization part 25 and 25, the above-mentioned concave hole as shown to (B) of FIG. 9 and the bank-like convex part as similarly shown to (C) are also employable. Also in the case of the present embodiment, as in the case of the above-described embodiment 4, the distance in the circumferential direction between the pair of individualized portions 25 and 25 that constitute each of the detected combination portions 24 and 24 is the total. The detected combination parts 24 and 24 are continuously changed in the same direction with respect to the axial direction. That is, the interval in the circumferential direction between the pair of individualized portions 25, 25 constituting each detected combination portion 24, 24 becomes smaller at one end in the axial direction of the encoder 12f (lower right end in FIG. 16). The interval in the circumferential direction between the individualized portions 25, 25 constituting each of the combination parts for detection 24, 24 adjacent in the circumferential direction is the other axial end of the encoder 12f (the upper left end in FIG. 16). It is inclined in the direction of decreasing.

  As shown in FIG. 11, the output signal of the sensor having the detection portion opposed to the outer peripheral surface (or inner peripheral surface) that is the detection surface of the encoder 12f as described above is as shown in FIG. , And changes at the moment of facing the individualized portions 25, 25. The changing interval (cycle) changes with the change in the axial position of the portion of the sensor facing the detecting portion. Therefore, in the case of this embodiment as well, by looking at the output signal pattern of the sensor, the degree to which the stationary side raceway and the rotational side raceway are displaced in the axial direction (axial displacement amount) is obtained. From this level (or directly from the pattern of the output signal), the axial load applied between the two race rings can be obtained. Regarding the method for obtaining the relative displacement amount and the load from the pattern of the output signal of the sensor, the above implementation is performed except that the direction of the relative displacement to be obtained is changed from the radial direction to the axial direction and the load is changed from the radial load to the axial load. The same as in the case of Example 4. The point that the fluctuation of the output signal of the sensor due to the mounting error or the like is removed by the adaptive filter is the same as in the fourth embodiment.

FIGS. 17-19 shows Example 8 of this invention corresponding to Claims 4-7 , 9-10 , 12-13 , 18-20 . The present embodiment shows a case where the present invention is implemented with a wheel support rolling bearing unit 1a for driving wheels. In consideration of incorporation into a heavy vehicle, tapered rollers are used as the rolling elements 5a and 5a. In the case of this embodiment, an encoder 12g as shown in FIG. 18 is externally fixed to a portion between the double-row inner ring raceways 11a, 11a at the intermediate portion in the axial direction of the hub 4b. The encoder 12g is made of a magnetic metal material in an annular shape, and has convex portions 27 and 27 as first detected portions and concave portions 28 and 28 as second detected portions on an outer peripheral surface. These are formed alternately at equal intervals in the circumferential direction.

In the case of the present embodiment having the above-described configuration, these outer rings 3a are accompanied by fluctuations in the axial load applied between the outer ring 3a having double-row outer ring raceways 6a, 6a formed on the inner peripheral surface and the hub 4b. When the relative position between the hub 4b and the hub 4b deviates in the axial direction, the position in the axial direction of the portion of the outer peripheral surface of the encoder 12g facing the detection portion of the sensor 13d supported on the intermediate portion in the axial direction of the outer ring 3a changes. . As a result, the pattern (duty ratio) in which the output signal of the sensor 13d changes as shown in FIG. The pattern in which the output signal of the sensor 13d changes as shown in FIG. 19, the amount of relative displacement in the axial direction between the outer ring 3a and the hub 4b, and the axial load applied between the outer ring 3a and the hub 4b. The relationship with the size can also be obtained by calculation or experiment in the same manner as in Example 5 described above. Therefore, by observing the change pattern of the output signal, the relative displacement amount and the magnitude of the axial load can be obtained. In terms of eliminating the fluctuation of the output signal of the sensor due to the mounting error, etc. by the adaptive filter, the direction of the relative displacement to be obtained changes from the radial direction to the axial direction, and the load to be obtained changes from the radial load to the axial load. Except for these points, the second embodiment is the same as the fifth embodiment.
In addition, as in this embodiment, a structure in which trapezoidal or inverted trapezoidal concave and convex portions are alternately arranged in the circumferential direction is applied to an encoder in which the detected surface is formed on the side surface in the axial direction, and is used in a rolling bearing unit. It can also be used to measure the applied radial load.

20 to 24 show a ninth embodiment of the present invention corresponding to claims 2-3 , 8-10 , 12 , 16 , 18-20 . In the case of the present embodiment, as in the fifth embodiment shown in FIGS. 12 to 14, the encoder 12h made of a permanent magnet is externally fitted and fixed to the intermediate portion of the hub 4a. On the outer peripheral surface of the encoder 12h, which is a detected surface, there are a portion magnetized in the N pole corresponding to the first detected portion and a portion magnetized in the S pole corresponding to the second detected portion. They are arranged alternately and at equal intervals in the circumferential direction. In particular, in the case of the present embodiment, the boundary between the part magnetized in the N pole and the part magnetized in the S pole corresponding to the first and second detected parts is defined by the encoder 12h. Inclined by the same angle with respect to the axial direction, and the inclined directions with respect to the axial direction are opposite to each other with the intermediate portion in the axial direction of the encoder 12h as a boundary. Therefore, the portion magnetized in the N pole and the portion magnetized in the S pole have a “<” shape with the axially middle portion protruding (or recessed) most in the circumferential direction.

  On the other hand, a pair of sensors 13e and 13e are installed in the middle part between the rolling elements 5 and 5 arranged in a double row in the axial direction intermediate part of the outer ring 3, and the detection parts of these sensors 13e and 13e are connected to the encoder. The outer peripheral surface of 12h is closely opposed. The positions where the detection parts of both the sensors 13e and 13e face the outer peripheral surface of the encoder 12h are the same with respect to the circumferential direction of the encoder 12h. In other words, the detection parts of both the sensors 13e and 13e are arranged on a virtual straight line parallel to the central axis of the outer ring 3. Further, in the state where the axial load is not applied between the outer ring 3 and the hub 4a, the axially intermediate portion between the portion magnetized in the N pole and the portion magnetized in the S pole is the most in the circumferential direction. The installation position of each member 12h, 13e, 13e is regulated so that the protruding part (the part where the inclination direction of the boundary changes) exists at the center position between the detection parts of the sensors 13e, 13e. ing.

  In the case of the present embodiment configured as described above, when an axial load is applied between the outer ring 3 and the hub 4a, the phase in which the output signals of the sensors 13e and 13e change is shifted. That is, in a state where an axial load is not applied between the outer ring 3 and the hub 4a, the detection portions of the sensors 13e and 13e are on the solid lines A and B in FIG. It faces a portion that is shifted in the axial direction by the same amount. Therefore, the phases of the output signals of both the sensors 13e and 13e coincide with each other as shown in FIG. On the other hand, when a downward axial load acts on the hub 4a to which the encoder 12h is fixed as shown in FIG. 23A, the detecting portions of the sensors 13e and 13e are shown in FIG. , Opposite to the portions where the deviations in the axial direction from the most protruding portion are different from each other. In this state, the phases of the output signals of the sensors 13e and 13e are shifted as shown in FIG. Further, when an upward axial load is applied to the hub 4a to which the encoder 12h is fixed as shown in FIG. 23A, the detecting portions of both the sensors 13e and 13e are connected to the chain line hub shown in FIG. , C, that is, the deviation in the axial direction from the most projecting portion opposes different portions in the opposite direction. In this state, the phases of the output signals of the sensors 13e and 13e are shifted as shown in FIG.

  As described above, in the case of this embodiment, the phases of the output signals of the sensors 13e and 13e are shifted in a direction corresponding to the direction of the axial load applied between the outer ring 3 and the hub 4a. Further, the degree to which the phase of the output signals of the sensors 13e and 13e is shifted by this axial load increases as the axial load increases. Therefore, in the case of the present embodiment, the presence or absence of a phase shift between the output signals of both the sensors 13e and 13e, and if there is a shift, between the outer ring 3 and the hub 4a based on the direction and magnitude. The relative displacement amount in the axial direction and the direction and magnitude of the axial load acting between the outer ring 3 and the hub 4a can be obtained.

  The point that the fluctuation of the output signals of both the sensors 13e and 13e due to the mounting error or the like is removed by the adaptive filter is basically the same as in the first to eighth embodiments. In particular, in the case of this embodiment, based on the phase difference between the output signals of the pair of sensors 13e, 13e, the axial displacement between the outer ring 3 and the hub 4a, and further, the relationship between the outer ring 3 and the hub 4a. Since the axial load applied between them is obtained, a filtering process is applied to the phase difference (a signal representing the above). The basic concept is the same when a waveform shaping circuit is incorporated in both the sensors 13e and 13e and the output signals of both the sensors 13e and 13e are changed to pulse-shaped rectangular waves.

  FIG. 24 shows the result of a computer simulation performed to confirm the effect of this embodiment in which such filtering processing is performed. 24 is the phase difference, that is, the phase difference between the output signals of the sensors 13e and 13e accompanying the axial displacement of the encoder 12h, that is, (B) to (D) of FIG. ) Is a value (phase difference ratio) obtained by dividing the time lag amount between the output signals of both the sensors 13e and 13e by the period of the output signals of both the sensors 13e and 13e. FIG. 24 shows the case where the amount of time deviation is large and the fluctuation of the output signals of the sensors 13e and 13e due to the mounting error is extremely large.

  FIG. 24A shows a case where the phase difference ratio is obtained by directly comparing the output signals of both the sensors 13e and 13e without performing the filtering process. In FIG. 24A, a rotation first-order fluctuation component (error) based on the assembly error of the encoder 12h appears greatly. On the other hand, FIG. 24B shows a signal obtained as a result of performing a filtering process using a synchronous LMS adaptive filter on the signal representing the phase difference ratio. As is apparent from FIG. 24B, this filtering process can reduce the rotational first-order fluctuation component (error) that becomes a problem when the axial load is obtained. Although some high-frequency noise remains in the signal after filtering processing, this high-frequency noise can be easily reduced by a low-pass filter and without causing a response delay that causes a practical problem. It doesn't matter.

25 to 28 show a tenth embodiment of the present invention corresponding to claims 2-3 , 8-10 , 12 , 16 , 18-20 . In the case of the present embodiment, an encoder 12i made of a magnetic metal plate is externally fitted and fixed to an intermediate portion of the hub 4a. On the outer peripheral surface of the encoder 12i, which is a detected surface, slit-shaped through holes 29a and 29b corresponding to the first detected portion and column portions 30a and 30b corresponding to the second detected portion are circular. They are arranged alternately and at equal intervals in the circumferential direction. The pitches of the through holes 29a, 29b adjacent to each other in the circumferential direction or the pitches of the column parts 30a, 30b are equal to each other. However, the width of each through hole 29a, 29b in the circumferential direction and the column parts 30a, 30b The widths in the circumferential direction need not be equal. In particular, in the case of the present embodiment, the through holes 29a and 29b corresponding to the first detected portion and the pillar portions 30a and 30b corresponding to the second detected portion are connected to the encoder 12i. Inclined by the same angle with respect to the axial direction, and the inclined directions with respect to the axial direction are opposite to each other with the intermediate portion in the axial direction of the encoder 12i as a boundary. That is, the encoder 12i according to the present embodiment forms the through holes 29a and 29a inclined in the predetermined direction with respect to the axial direction in one half of the axial direction, and the predetermined direction in the other half of the axial direction. Through holes 29b and 29b are formed which are inclined in the opposite direction by the same angle.

  On the other hand, a pair of sensors 13f and 13f are installed between the rolling elements 5 and 5 arranged in a double row at the intermediate portion in the axial direction of the outer ring 3, and the detecting portions of both the sensors 13f and 13f are connected to the encoder. The outer peripheral surface of 12i is closely opposed. The positions where the detection parts of these sensors 13f and 13f face the outer peripheral surface of the encoder 12i are the same with respect to the circumferential direction of the encoder 12i. Further, in the state where an axial load is not applied between the outer ring 3 and the hub 4a, a rim portion 31 that is located between the through holes 29a and 29b and continues to the entire circumference is provided with the sensors 13f and 13f. The installation positions of the members 12i, 13f, and 13f are restricted so that they exist at exactly the center position between the detection units.

  In the case of the present embodiment configured as described above, when an axial load is applied between the outer ring 3 and the hub 4a, the output signals of the sensors 13f and 13f change as in the case of the ninth embodiment. Out of phase. That is, in the state where an axial load is not acting between the outer ring 3 and the hub 4a, the detection parts of the sensors 13f and 13f are on the solid lines A and B in FIG. It faces a portion that is shifted from the portion 31 by the same amount in the axial direction. Therefore, the phases of the output signals of both the sensors 13f and 13f coincide with each other as shown in FIG. On the other hand, when a downward axial load acts on the hub 4a to which the encoder 12i is fixed as shown in FIG. 28A, the detecting portions of the sensors 13f and 13f are shown in FIG. The broken lines B and B, that is, the portions that are different from each other in the axial direction from the rim portion 31 face each other. In this state, the phases of the output signals of the sensors 13f and 13f are shifted as shown in FIG. Further, when an upward axial load is applied to the hub 4a to which the encoder 12i is fixed as shown in FIG. 28A, the detecting portions of the sensors 13f and 13f are connected to the chain line H shown in FIG. The vertical displacement from the rim portion 31 opposes different portions in the opposite direction. In this state, the phases of the output signals of the sensors 13f and 13f are shifted as shown in FIG.

  As described above, also in the case of the present embodiment, the direction of the axial load applied between the outer ring 3 and the hub 4a by the phase of the output signals of both the sensors 13f and 13f is the same as in the case of the ninth embodiment described above. It shifts in the direction according to. Further, the degree to which the phase of the output signals of the sensors 13f and 13f is shifted by this axial load increases as the axial load increases. Accordingly, also in the present embodiment, the shaft between the outer ring 3 and the hub 4a is based on the presence and absence of the phase shift of the output signals of both the sensors 13f and 13f, and if there is a shift, the direction and magnitude thereof. The amount of displacement with respect to the direction and the direction and magnitude of the axial load acting between the outer ring 3 and the hub 4a can be obtained. The point that the fluctuation of the output signals of both the sensors 13f and 13f due to the mounting error or the like is removed by the adaptive filter is the same as in the ninth embodiment.

  In any of the embodiments, it is preferable that the area (spot diameter) of the detection portion of the sensor is small. The reason for this is to obtain a pattern change of the characteristic change of the detected surface of the encoder in accordance with the load fluctuation so that the pattern change can be read with high accuracy. The structure of the sensor is not particularly limited, such as a magnetic type or an optical type, but a magnetic type is preferable because it is easy to obtain a sensor having the required accuracy at a low cost. In addition, when using a magnetic sensor, either passive type or active type can be used, but the spot diameter can be reduced and accurate measurement can be performed. Since a measurement can be performed, an active type sensor can be preferably used. Furthermore, if it is an active type sensor, magnetic sensors of various structures can be used including a unipolar type that switches output (ON / OFF) in response to a change in the density of magnetic flux passing through the detection element.

FIG. 29 shows Embodiment 11 of the present invention corresponding to claims 2 to 7, 9 to 10 , 12, and 16 . In the case of the present embodiment, the case where the present invention is implemented with respect to a structure for obtaining both displacement in the axial direction and displacement in the radial direction (both axial load and radial load) is shown. . In the case of the present embodiment in order to obtain both of the above-mentioned displacements, each of the radial detection directions of the encoder 12j is provided on an annular detection surface on one side surface of the encoder 12j in order to obtain the displacement in the radial direction. Are provided with detection characteristic portions 33, 33 such as ridges, through holes, concave holes, magnetic poles, etc., which are inclined in one direction. In addition, in the axial half of the cylindrical detection surface (left half of FIG. 29B) in the outer circumferential surface of the encoder 12k for measuring the displacement in the axial direction, Inclined second characteristic portions for detection 34 and 34 are provided. On the other hand, each of the other half portions in the axial direction of the surface to be detected of the encoder 12k {the right half portion in FIG. 29B) is parallel to the axial direction of the encoder 12k. Characteristic portions 35 and 35 are provided. The pitches of the detected characteristic portions 33 to 35 are equal to each other.

  In the case of such a structure incorporating encoders 12j and 12k, the detection portions of a total of three sensors are formed on the detection surfaces of both encoders 12j and 12k, and the above-described detection characteristic portions 33, 34 and 35 are formed. Oppose to the part. Then, the phase shift of the output signals of the remaining two sensors with reference to the moment when the output signals of the sensors facing the third detected characteristic portions 35 and 35 parallel to the axial direction of the encoder 12k change. Determine the direction and size of. Further, the displacement in the axial direction and the radial direction (or the axial load and the radial load) are obtained based on the direction and magnitude of the phase shift.

  According to the structure of the present embodiment, it can be configured to be relatively small, and both the displacement in the axial direction and the displacement in the radial direction (or axial load and radial load) can be obtained. If the filter processing as described in the first embodiment is performed with respect to the direction and magnitude of the phase shift of the output signals of the two sensors with such a structure, the encoders 12j and 12k are covered. The displacement in the axial direction and the radial direction (or the axial load and the radial load) can be obtained with high precision regardless of the swing of the detection surface.

FIG. 30 shows Embodiment 12 of the present invention corresponding to claims 2 to 7, 9 to 10 , 12, and 16. In the case of this embodiment, not only the displacement (load) in the axial direction but also the detection portions of the three sensors 13g to 13i are opposed to the outer peripheral surface of the encoder 12i made of a magnetic metal plate in the radial direction, The displacement (load) in the radial direction is also required. That is, by adding one sensor to the structure of the tenth embodiment shown in FIGS. 25 to 28, the outer ring 3 that is the stationary side race ring and the hub 4a that is the rotation side race ring (see FIG. 25). In addition to the displacement (load) in the axial direction, the displacement (load) in the radial direction can be measured. Since the configuration and operation other than the point that can measure the displacement (load) in the radial direction are the same as in the case of the tenth embodiment, the illustration and description regarding the equivalent parts are omitted or simplified. The description will focus on the features of the example. Of the three sensors 13g to 13i, two sensors 13g and 13h correspond to a pair of sensors 13f and 13f incorporated in the structure of the tenth embodiment. Further, the structure of the encoder 12i is the same as that of the tenth embodiment.

  Among the three sensors 13g to 13i, the detectors of the two sensors 13g and 13h are distributed to both sides in the axial direction of the outer peripheral surface of the encoder 12i, and are located at the same position in the circumferential direction of the encoder 12i. They are facing each other. As in the case of the tenth embodiment, the outer ring 3 and the hub 4a (see FIG. 25) are in a neutral state and are located between the through holes 29a and 29b formed in the encoder 12i. A rim portion 31 that is continuous in the circumference is located at a central position between the detection portions of the sensors 13g and 13h.

  On the other hand, the detection part of the remaining one sensor 13i out of the three sensors 13g to 13i is opposed to a portion closer to one axial side of the outer peripheral surface of the encoder 12i. The position where the detection part of the one sensor 13i faces the outer peripheral surface of the encoder 12i is in a neutral state between the outer ring 3 and the hub 4a, and the sensor 13g faces the rotation direction of the encoder 12i. The position is shifted by 90 degrees from the portion of the image. The axial direction of the encoder 12i is the same position as the portion facing the sensor 13g.

  According to the structure of the present embodiment configured as described above, based on the phase difference between the output signals of the three sensors 13g to 13i caused by the relative displacement between the outer ring 3 and the hub 4a, Not only the displacement (load) in the axial direction but also the displacement (load) in the radial direction is required. Regarding this point, the displacement in each of the x, y, and z directions and the presence / absence of a phase difference between the output signals of the three sensors 13g to 13i will be described. The x, y, and z directions mean the radial direction in the longitudinal direction and the y direction in the axial direction in the case where the present embodiment is applied to a rolling bearing unit for supporting a wheel of an automobile. , And the z direction represents the radial direction with respect to the vertical direction.

(1) When displacement in the x direction occurs (the outer ring 3 and the hub 4a are displaced in the front-rear direction).
In this case, no phase difference occurs between the output signals of the two sensors 13g and 13h provided on the lower side.
In contrast, between the output signal of the one sensor 13i provided in the horizontal direction and facing the first detection surface, and the output signals of the two sensors 13g and 13h provided on the lower side. A phase difference of a direction and a magnitude corresponding to the displacement (direction and magnitude) in the x direction is generated.
(2) When displacement in the y direction occurs {the outer ring 3 and the hub 4a are relatively displaced in the width direction (axial direction)}.
In this case, a phase difference occurs between the output signals of the two sensors 13g and 13h provided on the lower side.
Similarly, a phase difference also occurs between the output signal of one sensor 13i provided in the horizontal direction and the output signal of the sensor 13h provided on the lower side.
On the other hand, there is no phase difference between the output signal of the sensor 13g provided on the lower side and facing the first detection surface and the output signal of one sensor 13i provided in the horizontal direction. .
(3) When displacement in the z direction occurs (the outer ring 3 and the hub 4a are displaced in the vertical direction).
In this case, no phase difference occurs between the output signals of the two sensors 13g and 13h provided on the lower side.
On the other hand, the displacement in the z direction (direction and direction) between the output signal of one sensor 13i provided in the horizontal direction and the output signals of the two sensors 13g and 13h provided on the lower side. A phase difference of a direction and a size according to (size) occurs.

  As is apparent from the appearance of the phase difference between the output signals of the sensors 13g to 13i in the state where the displacements in the x, y, and z directions are generated, Not only the displacement (load) in the direction but also the displacement (load) in the radial direction is required. However, the radial displacement in both the x and z directions cannot be distinguished. Therefore, the structure of the present embodiment is effective for obtaining any one radial displacement (radial load) in addition to the axial displacement (axial load). In other words, if the application or structure is such that the displacement occurs only in one direction of the x direction or the z direction and does not occur in the other direction (a constant value), the above axial, Radial and displacement (load) in both directions can be obtained.

  For example, when the rolling bearing unit is a rolling bearing unit for supporting a driven wheel of an automobile (a rear wheel of an FR vehicle, an FF vehicle, an RR vehicle, or an MR vehicle), the load acting during traveling is Except during braking, only the axial load and the radial load in the vertical direction are available, and the radial load in the front-rear direction may be almost negligible. Therefore, assuming that the radial displacement in the x direction is 0, and processing the phase difference between the output signals of the sensors 13g to 13i, the remaining two directions, that is, the y direction, which is the width direction of the vehicle, are processed. An axial displacement (axial load) and a radial displacement (radial load) with respect to the z direction, which is also the vertical direction, can be obtained. That is, the displacement in the y direction is obtained from the phase difference between the output signals of the sensors 13g and 13h, and the displacement in the z direction is obtained from the phase difference between the output signals of the sensors 13i and 13g (13h). The method of obtaining the displacement in both the y and z directions based on the phase difference between the output signals of the sensors 13g to 13i is basically the case of the tenth embodiment shown in FIGS. Detailed explanation is omitted.

  As described above, if the displacement in both the y and z directions can be obtained, the load applied in both the y and z directions can be obtained. If the filter processing as described in the first embodiment is performed with respect to the direction and magnitude of the phase shift of the output signals of the sensors 13g to 13i with such a structure, the detected surface of the encoder 12i The displacement in the axial direction and the radial direction (axial load and radial load) can be obtained with high accuracy regardless of the swing of the lens.

FIG. 31 shows Embodiment 13 of the present invention corresponding to claims 2 to 7, 9 , 10 , 12, and 16 . In the present embodiment, in addition to the structure of the twelfth embodiment described above, a sensor 13j as a fourth sensor is provided. And the detection part of this sensor 13j is the part which provided the through-holes 29a and 29a and the pillar parts 30a and 30a alternately in the encoder 12i similarly to the detection part of the sensor 13i which is a 3rd sensor. They are facing each other. The position where the detection portion of the sensor 13j as the fourth sensor faces the outer peripheral surface of the encoder 12i is in a neutral state between the outer ring 3 and the hub 4a (see FIG. 25), and the rotational direction of the encoder 12i is as follows. The position is shifted by 90 degrees from the portion where the sensor 13g is opposed to the sensor 13i, which is the third sensor, to the opposite side by 180 degrees. Further, the axial direction of the encoder 12i is set to the same position as the portion where the sensors 13g and 13i are opposed to each other. In the case of the present embodiment, by adopting such a configuration, the displacement in the three directions x, y, and z is obtained, and further, the load applied in these three directions can be obtained from the displacement in these three directions. .

According to the structure of the present embodiment configured as described above, the axial is based on the phase difference between the output signals of the four sensors 13g to 13j caused by the relative displacement between the outer ring 3 and the hub 4a. Not only the displacement (load) in the direction but also the displacement (load) in the radial direction in two directions is obtained. Regarding this point, the displacement in the x, y, and z directions and the presence or absence of a phase difference between the output signals of the four sensors 13g to 13j will be described.
(1) When displacement in the x direction occurs (the outer ring 3 and the hub 4a are displaced in the front-rear direction).
In this case, no phase difference occurs between the output signals of the two sensors 13g and 13h provided on the lower side.
On the other hand, the displacement (direction and size) in the x direction is between the output signal of the sensor 13h provided on the lower side and the output signals of the two sensors 13i and 13j provided in the horizontal direction. A phase difference corresponding to the direction and size is generated.
Also, according to the displacement (direction and size) in the x direction between the output signal of the sensor 13g provided on the lower side and the output signals of the two sensors 13i and 13j provided in the horizontal direction. A phase difference in the direction and size occurs.
There is no phase difference between the output signals of the two sensors 13i and 13j provided in the horizontal direction.
(2) When displacement in the y direction occurs {the outer ring 3 and the hub 4a are relatively displaced in the width direction (axial direction)}. In this case, a phase difference occurs between the output signals of the two sensors 13g and 13h provided on the lower side.
Similarly, a phase difference also occurs between the output signals of the two sensors 13i and 13j provided in the horizontal direction and the output signal of the sensor 13h provided on the lower side.
On the other hand, no phase difference occurs between the output signal of the sensor 13g provided on the lower side and the output signals of the two sensors 13i and 13j provided in the horizontal direction.
Further, no phase difference is generated between the output signals of the two sensors 13i and 13j provided in the horizontal direction.
(3) When displacement in the z direction occurs (the outer ring 3 and the hub 4a are displaced in the vertical direction).
In this case, no phase difference occurs between the output signals of the two sensors 13g and 13h provided on the lower side.
On the other hand, a phase difference occurs between the output signal of the sensor 13g provided on the lower side and the output signals of the two sensors 13i and 13j provided in the horizontal direction.
A phase difference also occurs between the output signal of the sensor 13h provided on the lower side and the output signals of the two sensors 13i and 13j provided in the horizontal direction.
Further, a phase difference is also generated between the output signals of the two sensors 13i and 13j provided in the horizontal direction.

In short, the phase between the output signals of the two sensors 13g and 13h provided on the lower side changes only by displacement in the y direction (phase difference occurs) and does not change by displacement in the x and z directions. Therefore, the displacement in the y direction can be obtained by measuring the presence / absence, direction and size of the phase difference between the output signals of the two sensors 13g and 13h provided on the lower side.
In addition, the phase between the output signals of the two sensors 13i and 13j provided in the horizontal direction changes only with displacement in the z direction, and does not change with displacement in the x and y directions. Therefore, if the presence / absence, direction and size of the phase difference between the output signals of the two sensors 13i and 13j provided in the horizontal direction are measured, the displacement in the z direction can be obtained.
Furthermore, the phase between the output signals of the sensors 13g and 13i, which are respectively provided in the lower or horizontal direction, varies with the displacement in the x direction, but also varies with the displacement in the z direction. However, since the displacement in the z direction is obtained from the phase difference between the output signals of the two sensors 13i and 13j provided in the horizontal direction, the displacement between the output signals of both the sensors 13i and 13j. If the correction calculation that excludes the influence of the displacement in the z direction is performed from the phase difference, only the displacement in the x direction can be obtained. The displacement in the x direction is also corrected by removing the influence of the displacement in the z direction from the phase difference between the output signals of the sensors 13g and 13j provided in the lower and horizontal directions. Required by doing. That is, only the displacement in the x direction can be obtained from the phase difference between the output signals of the sensors 13g and 13i, the phase difference between the output signals of the sensors 13g and 13j, or the average of both phase differences. .

  Note that the phase difference between the output signals of the sensors 13h and 13i and the phase difference between the output signals of the sensors 13h and 13j also change due to the displacement in the x direction. It also changes depending on the displacement. Since these displacements in the y and z directions are obtained as described above, these y and z directions are calculated based on the phase difference between the output signals of the sensors 13h and 13i and the phase difference between the output signals of the sensors 13h and 13j. In addition, only the displacement in the x direction can be obtained by a correction operation for removing the influence of the displacement in the z direction. However, it is not preferable because the calculation amount increases and not only the time required to obtain the displacement in the x direction is increased, but also errors are easily introduced.

  As described above, if the displacements in both the x, y, and z directions can be obtained, the loads applied in the x, y, and z directions can be obtained. If the filter processing as described in the first embodiment is performed with respect to the direction and magnitude of the phase shift of the output signals of the sensors 13g to 13j with such a structure, the surface to be detected of the encoder 12i is detected. The displacement in the axial direction and the radial direction (axial load and radial load) can be obtained with high accuracy regardless of the swing of the lens.

32 to 33 show a fourteenth embodiment of the present invention corresponding to claims 4 to 7, 9 to 10 , 12 to 13 , 18 to 19, and 21 . The feature of this embodiment is that the shape of the through holes 29c and 29c formed in the encoder 12m is devised, and a pair of sensors 13k and 13m are provided at two positions opposite to the diametrical direction of the encoder 12m. It is in. The structure of the wheel-supporting rolling bearing unit 1 incorporating the displacement measuring device is the same as in the case of the sixth embodiment shown in FIG. 15, for example. Therefore, the redundant description is omitted or simplified. The description will focus on the features of

  Slit-like through holes 29c and 29c are formed at equal intervals in the circumferential direction in the cylindrical portion 36 provided in the front half of the encoder 12m made of a magnetic metal plate. Each of these through-holes 29c and 29c is a straight line inclined with respect to the axial direction of the cylindrical portion 36. Further, a pair of sensors 13k and 13m are supported at two positions on the opposite side in the diameter direction on a part of the inner peripheral surface of the bottomed cylindrical cover 18b fitted and fixed to the inner end portion of the outer ring 3. Yes. In the case of the present embodiment, since it is intended to obtain the axial load applied in the width direction of the vehicle to the contact portion (the contact surface portion) between the tire 38 constituting the wheel 37 and the road surface 39, one of the sensors 13k. Is fixed to the inner peripheral surface of the upper end of the cover 18b, and the other sensor 13m is supported and fixed to the inner peripheral surface of the lower end of the cover 18b.

  In addition, in a state where the central axis of the outer ring 3 and the central axis of the hub 4a (the encoder 12m fitted and fixed to the inner end of the hub 4a) coincide with each other, the detecting portions of the sensors 13k and 13m are connected to the encoder 12m. The positions facing the outer peripheral surface are the same positions with respect to the axial direction of the encoder 12m. Therefore, in the neutral state in which the central axis of the outer ring 3 and the central axis of the hub 4a coincide, the phases of the detection signals of the sensors 13k and 13m coincide with each other (no phase difference occurs). Further, even when the axial dimension of the hub 4a or the encoder 12m changes with temperature change and the cylindrical portion 36 moves in the axial direction, the phases of the detection signals of the sensors 13k and 13m are mutually different. There will be no shift (they will remain consistent).

  On the other hand, when a moment is applied between the outer ring 3 and the hub 4a and the central axes of the outer ring 3 and the hub 4a are not matched, the phases of the detection signals of the sensors 13k and 13m are shifted from each other. (Phase difference occurs). For example, when a counterclockwise moment as indicated by an arrow in FIG. 32 is applied to the hub 4a, the phase of the detection signal of the one sensor 13k is advanced (or delayed) from the neutral state, and the other The phase of the detection signal of the sensor 13m is delayed (or advanced) from the neutral state. As a result, a phase difference is generated between the detection signals of both the sensors 13k and 13m.

  Between the phase difference between the detection signals of these sensors 13k and 13m and the inclination angle between the central axis of the outer ring 3 and the central axis of the hub 4a, which is generated in this manner, A predetermined relationship (first relationship) determined by geometric factors such as the inclination angle θ of 29c, 29c, the pitch P of the rolling elements 5 and 5 arranged in double rows, the diameter of the cylindrical portion 36, and the like. is there. Therefore, if an equation or map representing the first relationship is stored in a memory in a calculator (not shown) that processes the detection signals of the sensors 13k and 13m, the tilt angle is calculated based on the phase difference. Is required. In addition, there is a certain relationship (second relationship) between the magnitude of the inclination angle and the magnitude of the moment, which is determined by the moment stiffness of the wheel support rolling bearing unit 1. This second relationship is obtained not only by calculation based on the elastic contact theory widely known in the field of rolling bearing units, but also by experiments. Accordingly, if an equation or a map representing the second relationship is stored in the computing unit, the moment can be obtained based on the tilt angle.

  Further, between the magnitude of this moment and the axial load applied in the width direction of the vehicle to the contact portion (ground contact surface portion) between the tire 38 constituting the wheel 37 and the road surface 39, the rotation radius of the wheel 37, etc. There is a certain relationship (third relationship) that is geometrically determined by. Therefore, if the formula or map representing the third relationship is stored in the memory in the arithmetic unit, the axial load can be obtained based on the moment. The axial load thus obtained is equivalent to the load generated on the contact surface between the road surface 39 and the wheel 37 (tire 38). Therefore, if the control for stabilizing the running state of the vehicle is performed based on the obtained axial load, the feed forward control for preventing the posture of the vehicle from becoming unstable becomes possible. Advanced control to ensure running stability is possible. In addition, in the case of the present embodiment, the error based on the temperature change does not enter the value of the obtained axial load. If the filter processing as described in the first embodiment is performed with respect to the direction and magnitude of the phase shift of the output signals of the sensors 13k and 13m with the above-described structure, the encoder 12m is detected. The displacement in the axial direction can be obtained with high precision regardless of the surface swing. The axial load may be obtained directly based on the phase shift and magnitude of the output signal, as in the above-described embodiments.

34 to 35 show a fifteenth embodiment of the present invention corresponding to claims 18 , 19 and 22 . Also in the case of this embodiment, for example, as shown in FIGS. 1, 8, 12, 15, 17, 20, 25, 32, and 33 showing the respective embodiments described above, a rolling bearing unit for incorporating a load measuring device is provided. It is a rolling bearing unit for wheel support. The outer ring, which is a stationary side race ring, is supported and fixed to the suspension device in use, and the rotation side race ring is a hub that supports and fixes the wheel and rotates together with the wheel. In particular, in the case of the present embodiment, the encoder 12n is provided on the outer peripheral edge portion of the disk rotor 40, which is a member that rotates together with the hub that is the rotating raceway.

  As is well known, as shown in FIG. 33, the disk rotor 40 is coupled and fixed to the flange 10 provided on the outer peripheral surface of the outer end portion of the hub 4a, which is a rotating member and a rotating raceway, and this hub 4a. Rotate with. Further, since the disk rotor 40 is firmly coupled and fixed to the hub 4a, the disk rotor 40 and the hub 4a are displaced synchronously (integrally). Therefore, if the encoder 12n is provided on the outer peripheral edge of the disk rotor 40 and the detection part of the sensor 13n is opposed to the outer peripheral edge, the hub 4a and the outer ring 3 that is a stationary side raceway are interposed between the hub 4a and the outer ring 3. The applied axial load is required.

  The structure for providing the encoder 12n on the outer peripheral edge of the disk rotor 40 is not particularly limited. In the case of a disk rotor 40 made of a magnetic material such as cast iron, irregularities or holes (concave holes or radial through holes) as shown in FIGS. 34A to 34C are formed directly on the outer peripheral edge. Thus, the magnetic characteristics of the outer peripheral edge of the disk rotor 40 can be changed. In this case, when the disk rotor 40 is a solid type, irregularities having shapes as shown in FIGS. 34A to 34C are formed on the outer peripheral surface of the disk rotor 40. On the other hand, when the disc rotor 40 is a ventilated type, the disc rotor 40 has a cross-sectional shape as shown in FIGS. 34 (A) to (C). A through hole penetrating in the radial direction is formed. On the other hand, when the disk rotor 40 is made of a non-magnetic material such as an aluminum alloy or aluminum composite, the encoder 12n is separately formed in an annular shape with a magnetic material on the outer peripheral edge of the disk rotor 40. Fix externally. Even in this case, when the disk rotor 40 is a solid type, an unevenness is formed on the outer peripheral surface of the encoder 12n, and when it is a ventilated type, a through hole is formed. In the above description, the combination of the encoder 12n and the sensor 13n is a magnetic detection type. In the case of an optical type or the like, even if the disk rotor 40 is made of a non-magnetic material, the irregularities or holes are formed directly on the outer peripheral surface of the disk rotor 40, and this outer peripheral surface is used as a detected surface. Can do.

  On the other hand, the sensor 13n is supported at a portion that is not displaced regardless of the load applied to the wheel supporting rolling bearing unit. As such a part, a knuckle 41 (see FIG. 33) constituting a suspension device and a braking member 42 (see FIG. 35) constituting a disc brake together with the disc rotor 40 can be considered. As the braking member 42, a caliper can be employed when the disc brake is an opposed piston type, and a support can be employed when the disc brake is a floating caliper type. In the case of the illustrated embodiment, the sensor 13 n is supported by the braking member 42 via a support arm 43. According to such a structure of the present embodiment, a rolling bearing unit with a load measuring device can be realized even when the wheel-supporting rolling bearing unit has no space for installing the encoder 12n and the sensor 13n. . Contrary to the case shown in the figure, an encoder may be provided on the inner peripheral edge of the annular friction plate for pressing the pad in the disk rotor 40. In this case, the sensor is installed on a stationary member such as an outer ring of a wheel bearing rolling bearing unit. In any case, even in the structure of this embodiment, if the output signal of the sensor 13n is subjected to the filtering process as described in the first embodiment, the above-described operation is performed regardless of the swinging of the outer peripheral surface of the disk rotor 40. Axial displacement (axial load) can be obtained with high accuracy.

FIG. 36 shows Embodiment 16 of the present invention corresponding to claims 18 , 19, and 23 . Also in the case of the present embodiment, the rolling bearing unit for incorporating the load measuring device is a wheel bearing rolling bearing unit. The outer ring 3a, which is a stationary side race ring, is supported and fixed to the suspension device in use, and the rotation side race ring is a hub 4b that supports and fixes the wheel and rotates together with the wheel. In particular, in the case of the present embodiment, the outer peripheral surface of the intermediate portion of the constant velocity joint 44 that is coupled and fixed to the hub 4b, which is a member that rotates together with the rotating side raceway, is used as the detected surface.

  As is well known, the constant velocity joint 44 is for rotating the hub 4b, and rotates together with the hub 4b. Since the constant velocity joint 44 is firmly coupled and fixed to the hub 4b, the constant velocity joint 44 and the hub 4b are displaced synchronously (integrally). Therefore, if the encoder 12p is provided on the outer peripheral surface of the constant velocity joint 44 and the detection portions of the sensors 13p and 13p are opposed to the outer peripheral surface of the encoder 12p, the axial load applied between the hub 4b and the outer ring 3a is increased. Desired. Therefore, in the case of the present embodiment, a cylindrical encoder 12p is externally fitted and fixed to the intermediate portion of the constant velocity joint 44. And the detection part of both said sensors 13p and 13p supported by the knuckle 41 is made to adjoin and oppose the two positions of the outer peripheral surface of the said encoder 12p.

  Even with this structure of the present embodiment, as in the case of the fifteenth embodiment described above, even when the space for mounting the encoder and sensor cannot be secured in the wheel bearing rolling bearing unit side portion, this wheel support rolling is performed. A structure capable of measuring the load applied to the bearing unit can be realized. Even in the structure of the present embodiment, if the output signal of both the sensors 13p and 13p is subjected to the filter processing as described in the first embodiment, the axial movement is performed regardless of the swinging of the outer peripheral surface of the encoder 12p. The displacement in the direction can be obtained with high accuracy.

Each of the embodiments described above has been described mainly with respect to the case where the relative displacement between the outer ring and the hub is obtained, and then the load applied between the outer ring and the hub is obtained. However, as is apparent from the description of the final stage of paragraph [0028] , there is a correlation between the pattern in which the output signal of the sensor changes and the load. Accordingly, the load can be directly obtained based on the output signal or a processing signal obtained by processing the output signal without obtaining the relative displacement amount. Even in this case, the processing of each of the above embodiments is effective in terms of obtaining this load with high accuracy.

Sectional drawing which shows Example 1 of this invention. The figure which took out the encoder main body and was seen from the right side of FIG. The figure similar to FIG. 2 which shows the scanning part of the to-be-detected surface of the encoder by the detection part of a sensor. The diagram which shows the output signal of the sensor which changes with the fluctuation | variation of radial load. The diagram which shows one example of the relationship between radial displacement of an outer ring | wheel and a hub, and radial load. The block diagram of the adaptive filter which filters the data based on the output signal of a sensor. The perspective view and front view which show two examples of the encoder integrated in Example 2 of this invention. Sectional drawing which shows the same Example 3. FIG. The principal part perspective view which shows three examples of the encoder integrated in the Example 4. FIG. The figure which looked at the to-be-detected surface of the encoder from the axial direction which shows the scanning part of the to-be-detected surface of the encoder by the detection part of a sensor. The diagram which shows the output signal of the sensor which changes with the fluctuation | variation of radial load. Sectional drawing which shows Example 5 of this invention. FIG. 9 is a perspective view showing a material and an assembled state of an encoder incorporated in a fifth embodiment. The diagram which shows the output signal of the sensor which changes with the fluctuation | variation of an axial load. Sectional drawing which shows Example 6 of this invention. The perspective view which shows the raw material and assembly state of the encoder which are integrated in the Example 7. FIG. Sectional drawing which shows the same Example 8. FIG. FIG. 10 is a partial perspective view of an encoder incorporated in an eighth embodiment. The diagram which shows the output signal of the sensor which changes with the fluctuation | variation of an axial load. Sectional drawing which shows Example 9 of this invention. FIG. 10 is a perspective view of an encoder incorporated in a ninth embodiment. Similarly development. The diagram which shows the output signal of the sensor which changes with the fluctuation | variation of an axial load. FIG. 10 is a diagram showing the results of computer simulation performed to confirm the effect of Example 9; Sectional drawing which shows Example 10 of this invention. FIG. 20 is a perspective view of an encoder incorporated in Example 10. Similarly development. The diagram which shows the output signal of the sensor which changes with the fluctuation | variation of an axial load. The side view and top view of an encoder which show Example 11 of this invention. The perspective view of the encoder and sensor which shows the same Example 12. FIG. The perspective view of the encoder and sensor which shows the same Example 13. FIG. Sectional drawing which shows the same Example 14. FIG. The schematic sectional drawing which shows the assembly | attachment state to a suspension apparatus. FIG. 18 is a schematic side view showing three examples of the shape of the detection surface provided on the outer peripheral edge portion of the disk rotor, showing Example 15 of the present invention. The front view and side view which show an example of the attachment state of a sensor. Sectional drawing which shows Example 16 of this invention.

DESCRIPTION OF SYMBOLS 1, 1a Rolling bearing unit for wheel support 2 Displacement measuring device 3, 3a Outer ring 4, 4a, 4b Hub 5, 5a Rolling element 6, 6a Outer ring raceway 7 Mounting part 8 Hub body 9 Inner ring 10 Flange 11, 11a Inner ring raceway 12, 12a to 12p Encoder 13, 13a to 13p Sensor 14, 14a, 14b, 14c Support plate 15, 15a Encoder body 16 Annular part 17 Cylindrical part 18, 18a, 18b Cover 19 Bottom plate part 20, 20a Mounting hole 21, 21a Through hole 22 and 22a part 23 ring part 24 combination part for detection 25 individualization part 26 cylindrical part 27 convex part 28 concave part 29a, 29b, 29c through hole 30a, 30b pillar part 31 rim part 32 adaptive filter 33 characteristic to be detected Part 34 Characteristic part for second detection 35 Characteristic part for third detection 36 Cylindrical part 37 Wheel 8 tire 39 road 40 disc rotor 41 knuckle 42 braking member 43 supporting arm 44 the constant velocity joint

Claims (24)

An encoder that is supported concentrically with the rotating member on a part of the rotating member, and alternately changes the characteristics of the detected surface in the circumferential direction;
A sensor that is supported by a portion that does not rotate in a state where the detection unit faces the detection surface, and that changes an output signal in response to a change in characteristics of the detection surface;
A filter circuit that performs a filtering process on an output signal of the sensor or a processing signal obtained based on the output signal;
On the basis of the filter circuit to the output signal or the processed signal has been subjected to the filtering process, the amount of displacement of the rotating member, or displacement or load of the rotating member and a calculator for calculating a load applied to the rotary member In the measuring device,
The rotating member is a member that is coupled and fixed to the rotation side raceway of the rolling bearing unit or the rotation side raceway and rotates together with the rotation side raceway,
The rolling bearing unit includes the rotating-side bearing ring that rotates in a used state, the stationary-side bearing ring that does not rotate even in a used state, and stationary surfaces that exist on the mutually opposing peripheral surfaces of the rotating-side bearing ring and the stationary-side bearing ring. A plurality of rolling elements provided between the side track and the rotation side track,
In the encoder, the pitch or phase at which the characteristic of the detected surface of the encoder changes in the circumferential direction continuously changes in the width direction of the detected surface corresponding to the direction of displacement to be detected. There are a plurality of combination parts for detection, each consisting of a pair of individualized parts, each having different characteristics from the other parts, arranged at equal intervals in the circumferential direction. The intervals in the circumferential direction between the individualized portions of each pair constituting the combination part for detection vary continuously in the same direction with respect to the width direction of the detection surface in all the combination parts for detection. And
In the sensor, the phase of the change in the output signal of the sensor changes in accordance with the position in the width direction of the detection surface of the encoder that the detection unit of the sensor faces, and the filter circuit Among the fluctuations of the signal or the processed signal, a filtering process is performed on the phase of the change in order to eliminate an error component based on an error related to a characteristic change in the circumferential direction of the detected surface.
The arithmetic unit has a function of calculating a relative displacement amount or the load between the rotation side raceway and the stationary side raceway based on a signal representing the phase of the change that has passed through the filter circuit. A device for measuring displacement or load of a rotating member. An encoder that is supported concentrically with the rotating member on a part of the rotating member, and alternately changes the characteristics of the detected surface in the circumferential direction;
A sensor that is supported by a portion that does not rotate in a state where the detection unit faces the detection surface, and that changes an output signal in response to a change in characteristics of the detection surface;
A filter circuit that performs a filtering process on an output signal of the sensor or a processing signal obtained based on the output signal ;
Based on the output signal or the processed signal subjected to the filtering process by the filter circuit, the displacement or load of the rotating member provided with an arithmetic unit for calculating the displacement amount of the rotating member or the load applied to the rotating member. In the measuring device,
The rotating member is a member that is coupled and fixed to the rotation side raceway of the rolling bearing unit or the rotation side raceway and rotates together with the rotation side raceway,
The rolling bearing unit includes the rotating-side bearing ring that rotates in a used state, the stationary-side bearing ring that does not rotate even in a used state, and stationary surfaces that exist on the mutually opposing peripheral surfaces of the rotating-side bearing ring and the stationary-side bearing ring. A plurality of rolling elements provided between the side track and the rotation side track,
A pair of the sensors are provided in a state in which the respective detection units are positioned at positions separated in the width direction of the detected surface of the encoder,
In the encoder, the pitch or phase at which the characteristic of the detected surface of the encoder changes in the circumferential direction continuously changes in the width direction of the detected surface corresponding to the direction of displacement to be detected. Yes, in this detected surface, at the part where the detection part of at least one of the two sensors is opposed, the boundary whose characteristics change in the circumferential direction is inclined with respect to the width direction, The phase of the change in the output signal of the at least one sensor changes in accordance with the position in the width direction of the detected surface of the encoder that the detection unit of the sensor faces.
The filter circuit performs a filtering process on the phase of the change in order to eliminate an error component based on an error related to a change in characteristics of the detected surface in a circumferential direction among fluctuations of the output signal or the processing signal. Is given,
The arithmetic unit has a function of calculating a relative displacement amount or the load between the rotation side raceway and the stationary side raceway based on a signal representing the phase of the change that has passed through the filter circuit. A device for measuring displacement or load of a rotating member. An encoder that is supported concentrically with the rotating member on a part of the rotating member, and alternately changes the characteristics of the detected surface in the circumferential direction;
A sensor that is supported by a portion that does not rotate in a state in which the detection unit faces the detection surface of the encoder, and that changes an output signal in response to a change in characteristics of each detection surface,
A filter circuit that performs a filtering process on an output signal of the sensor or a processing signal obtained based on the output signal;
Based on the output signal or the processed signal subjected to the filtering process by the filter circuit, the displacement or load of the rotating member provided with an arithmetic unit for calculating the displacement amount of the rotating member or the load applied to the rotating member. In the measuring device,
The rotating member is a member that is coupled and fixed to the rotation side raceway of the rolling bearing unit or the rotation side raceway and rotates together with the rotation side raceway,
The rolling bearing unit includes the rotating-side bearing ring that rotates in a used state, the stationary-side bearing ring that does not rotate even in a used state, and stationary surfaces that exist on the mutually opposing peripheral surfaces of the rotating-side bearing ring and the stationary-side bearing ring. A plurality of rolling elements provided between the side track and the rotation side track,
A plurality of the encoders are provided, and the characteristics of the detected surface of each of the encoders are alternately changed with respect to the circumferential direction at the same pitch between the encoders, and at least one of these encoders The phase in which the characteristics of the detected surface change in the circumferential direction continuously changes in the width direction of the detected surface, corresponding to the direction of displacement to be detected,
A plurality of the sensors are provided in a state where the respective detection units are opposed to the detection surfaces of the encoders,
The filter circuit includes a plurality of output signals of the plurality of sensors in order to eliminate an error component based on an error related to a characteristic change in the circumferential direction of the detected surface among fluctuations of the output signal or the processing signal. Filtering the signal representing the phase difference existing between
The arithmetic unit is based on a signal representing a phase difference existing between the output signals of the sensors that have passed through the filter circuit, and a relative displacement amount between the rotation side raceway and the stationary side raceway, Or the displacement or load measuring device of the rotating member which has a function which calculates the said load. An encoder that is supported on a part of the rotating member concentrically with the rotating member and whose characteristics of the surface to be detected are alternately changed in the circumferential direction, and that the detecting portion does not rotate in a state of facing the surface to be detected. A sensor that is supported by the part and changes its output signal in response to a change in the characteristics of the surface to be detected; a filter circuit that filters the output signal of this sensor or a processing signal obtained based on this output signal; Based on the output signal or the processed signal subjected to the filtering process by the filter circuit, the displacement or load of the rotating member provided with an arithmetic unit for calculating the displacement amount of the rotating member or the load applied to the rotating member. In the measuring device,
The filter circuit includes an adaptive filter and at least one of a low-pass filter and a notch filter in series with each other, and the adaptive filter is connected to at least one of the low-pass filter and the notch filter. Provided in a state where it is placed before the filter, and eliminates the error component based on the error related to the characteristic change in the circumferential direction of the detected surface among the fluctuations of the output signal or the processing signal. And
The computing unit has a function of calculating the relative displacement amount or the load based on a pattern in which the output signal or the processing signal changes after passing through the filter circuit. measuring device. The rotating member is a member that is coupled and fixed to the rotating side bearing ring of the rolling bearing unit or the rotating side bearing ring and rotates together with the rotating side bearing ring,
The rolling bearing unit includes the rotating-side bearing ring that rotates in a used state, the stationary-side bearing ring that does not rotate even in a used state, and stationary surfaces that exist on the mutually opposing peripheral surfaces of the rotating-side bearing ring and the stationary-side bearing ring. A plurality of rolling elements provided between the side raceway and the rotation side raceway, and the computing unit is a relative displacement amount between the rotation side raceway and the stationary side raceway or the rotation The displacement or load measuring device for a rotating member according to claim 4, wherein a load applied to the side bearing ring or a member rotating together with the rotating side bearing ring is calculated. Pitch or phase characteristic of the sensed surface of the encoder is changed in the circumferential direction, corresponding to the direction to be detected displacement, continuously changes with respect to the width direction of the sensed surface, according to claim 4 The displacement or load measuring device for a rotating member according to any one of 5. On the detection surface of the encoder, the first detection portion and the second detection portion having different characteristics are alternately arranged at equal intervals in the circumferential direction, and the circumferential direction of these detection portions is related to the circumferential direction. Of the widths, the width of the first detected portion is wider on one side in the width direction of the detected surface, the width of the second detected portion is wider on the other side in the width direction of the detected surface, and the output signal of the sensor is , A pulse-like signal or a sine wave-like signal that changes a value related to the period or amplitude corresponding to the difference in width in the circumferential direction between the first detected part and the second detected part, and the filter circuit Alternatively, a filtering process is performed on a ratio relating to amplitude, and the arithmetic unit obtains a relative displacement amount or a load based on a signal that passes through the filter circuit and represents the ratio relating to the period or amplitude . Change of rotating member Or load measuring device. The apparatus for measuring displacement or load of a rotating member according to claim 3, wherein a plurality of encoders each having a detected surface are integrated . An arithmetic unit calculates a relative displacement amount between the stationary side race ring and the rotation side race ring, and obtains a load acting between the stationary side race ring and the rotation side race ring based on the relative displacement amount. The displacement or load measuring device for a rotating member according to any one of claims 1 to 8, which is used for the purpose . The displacement or load measuring device for a rotating member according to any one of claims 1 to 9, wherein the filter circuit includes at least an adaptive filter. The apparatus for measuring displacement or load of a rotating member according to claim 10, wherein the adaptive filter is an adaptive filter using an LMS algorithm. The apparatus for measuring displacement or load of a rotating member according to claim 10, wherein the adaptive filter is an adaptive filter using a synchronous LMS algorithm. The displacement or load of the rotating member according to any one of claims 11 to 12, wherein the adaptive filter is operated by an LMS algorithm or a synchronous LMS algorithm and changes a step size parameter of the adaptive filter. Measuring device . The data represented by the output signal or the processed signal that is first input to the adaptive filter when starting the filtering process by the adaptive filter is used as the initial value of the filter coefficient of the adaptive filter. The displacement or load measuring apparatus of the rotating member described in any one of them. The displacement or load measuring device for a rotating member according to any one of claims 1 to 14, wherein the filter circuit includes at least one of a low-pass filter and a notch filter. An adaptive filter and at least one of a low-pass filter and a notch filter are connected in series with each other, and the adaptive filter is placed in front of at least one of the low-pass filter and the notch filter. The displacement or load measuring device for a rotating member according to any one of claims 10 to 15, which is provided in an arranged state. The displacement of the rotating member according to any one of claims 15 to 16, wherein the cut-off frequency of at least one of the low-pass filter and the notch filter changes according to the rotation speed of the rotating member. Or load measuring device . The rolling bearing unit is a double row rolling bearing unit in which a pair of circumferential surfaces of a stationary side raceway and a rotary side raceway are provided with a double row stationary raceway surface and a rotational side raceway surface, respectively. The displacement or load measuring device for a rotating member according to any one of claims 1 to 3 and 5 . The rolling bearing unit is a rolling bearing unit for supporting wheels, and in use, the outer ring, which is a stationary side bearing ring, is supported and fixed to the suspension device, and the hub, which is a rotating side bearing ring, supports and fixes the wheel together with this wheel. A double row outer ring raceway that exists on the inner peripheral surface of the outer ring and that is a stationary side raceway and a double row inner ring race that exists on the outer peripheral surface of the hub and that is a rotary side raceway. 19. A plurality of rolling elements are provided for each row between the raceway and a flange for supporting and fixing a wheel at an axially outer end of the hub. A device for measuring displacement or load of a rotating member. 20. The encoder according to claim 18, wherein the encoder is supported and fixed concentrically with the rotation-side raceway in a portion between the rotation-side raceways in a part of the rotation-side raceway. The displacement or load measuring device of the rotating member described in 1. The displacement or load measuring device for a rotating member according to any one of claims 18 to 19, wherein an encoder is supported and fixed concentrically with the rotating raceway at an end of the rotating raceway. The rotating member according to claim 19, wherein the member rotating together with the rotating side raceway is a disk rotor constituting a disk brake in a state of being coupled and fixed to the hub, and an outer peripheral surface of the disk rotor is a detected surface. Displacement or load measuring device . The member that rotates together with the rotating side raceway is a constant velocity joint that is coupled and fixed to the hub, and the displacement of the rotating member according to claim 19, wherein a part of the outer peripheral surface of the constant velocity joint is a detected surface. Load measuring device . The rolling bearing unit is for rotatably supporting the spindle of the machine tool on the housing, and in use, the outer ring which is a stationary side race ring is fitted and fixed to the housing or a part fixed to the housing. The displacement or load measuring device for a rotating member according to any one of claims 1 to 5 , wherein an inner ring which is a rotating side race ring is externally fitted and fixed to the main shaft or a portion rotating with the main shaft.

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