JP4899722B2 - Rolling bearing unit with state quantity measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a structure for satisfactory measurement accuracy of a state quantity in which gaps &delta;<SB>0</SB>, &delta;<SB>180</SB>between a surface to be detected of an encoder 4a and detection parts of respective sensors 6a<SB>1</SB>, 6c<SB>2</SB>in a neutral state are not uselessly large, respectively. <P>SOLUTION: The gaps &delta;<SB>0</SB>, &delta;<SB>180</SB>are not made into the same dimension but the gaps &delta;<SB>0</SB>, &delta;<SB>180</SB>are provided with mutual dimensional relationship of &delta;<SB>0</SB>&lt;&delta;<SB>180</SB>corresponding to the amounts of decrease in the gaps &delta;<SB>0</SB>, &delta;<SB>180</SB>during operation. By adopting such a structure, the above problem is solved. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  A rolling bearing unit with a state quantity measuring device according to the present invention supports, for example, a wheel of a vehicle such as an automobile so as to be rotatable with respect to a suspension device, and measures the magnitude of an external force applied to the wheel, Use to ensure stable operation.

  For example, automobile wheels are rotatably supported by a suspension device by a double-row angular type rolling bearing unit. In order to ensure the running stability of the automobile, for example, as described in Non-Patent Document 1, an antilock brake system (ABS), a traction control system (TCS), and an electronically controlled vehicle stability A vehicle travel stabilization device such as a control system (ESC) is used. In order to control such various vehicle running stabilization devices, signals representing the rotational speed of the wheels, acceleration in each direction applied to the vehicle body, and the like are required. In order to perform higher-level control, it may be preferable to know the magnitude of an external force (for example, one or both of a radial load and an axial load) applied to the rolling bearing unit via a wheel.

  In view of such circumstances, Patent Document 1 describes an invention for measuring the magnitude of an external force applied to a rolling bearing unit using a special encoder. FIGS. 6 to 8 are not related to the structure described in Patent Document 1, but are related to a rolling bearing unit with a state quantity measuring device that employs the same external force measurement principle as the structure described in Patent Document 1. 1 shows a first example of the structure of the invention. The first example of the structure of the prior invention is a hub that is a rotating side race ring that rotates together with the wheel while being supported and fixed to the inner diameter side of the outer race 1 that is a stationary side race ring that does not rotate during use. 2 is rotatably supported via a plurality of rolling elements 3 and 3. A preload is applied to each of the rolling elements 3 and 3 together with contact angles that are opposite to each other (in the illustrated case, a rear combination type). In the illustrated example, balls are used as the rolling elements 3 and 3. However, in the case of an automobile bearing unit that is heavy in weight, a tapered roller may be used instead of the ball.

Also, the inner end of the hub 2 ("inner" in the axial direction means the center side in the width direction of the vehicle when assembled to the automobile, and is the right side of FIGS. 6, 9, 15 and 16. On the contrary, to the automobile. 6, 15, 16, which is the outer side in the width direction of the vehicle in the assembled state, is referred to as “outside” with respect to the axial direction. The encoder 4 is supported and fixed concentrically with the hub 2. In addition, a pair of sensors 6a ₁ and 6a ₂ are supported inside the bottomed cylindrical cover 5 that closes the inner end opening of the outer ring 1, and the detection portions of both the sensors 6a ₁ and 6a ₂ are provided as described above. The encoder 4 is placed in close proximity to the outer peripheral surface, which is the detected surface.

  Of these, the encoder 4 is made of a magnetic metal plate. In the first half (axially inner half) of the outer peripheral surface of the encoder 4, which is a detected surface, through holes 7 and 7 (first characteristic part) and column parts 8 and 8 (second characteristic part) Are arranged alternately and at equal intervals in the circumferential direction. The boundaries between the through holes 7 and 7 and the pillars 8 and 8 are inclined at the same angle with respect to the axial direction of the encoder 4, and the inclined direction with respect to the axial direction is set to the intermediate portion in the axial direction of the encoder 4. The directions are opposite to each other. Accordingly, each of the through holes 7 and 7 and each of the column portions 8 and 8 has a “h” shape (or “k” shape) in which an intermediate portion in the axial direction protrudes most in the circumferential direction. Of the two halves in the axial direction of the surface to be detected, the inclination directions of the boundaries are different from each other, the outer half in the axial direction is the first characteristic change portion 9, and the inner half in the axial direction is the second characteristic change. Part 10 is used. Each of the through holes constituting both the characteristic changing portions 9 and 10 may be formed in a continuous state as shown in the figure, or may be formed independently from each other as shown in FIGS. You may do it. Further, although the detection accuracy is inferior, only the boundary of one of the characteristic change parts 9 and 10 is inclined with respect to the axial direction, and the boundary of the other characteristic change part is parallel to the axial direction. You can also do it.

Each of the pair of sensors 6a ₁ and 6a ₂ includes a permanent magnet and a magnetic detection element such as a Hall IC, a Hall element, an MR element, and a GMR element that constitute a detection unit. These two sensors 6a ₁ and 6a ₂ are supported and fixed inside the cover 5, and the detection part of _one sensor 6a ₁ is used as the first characteristic changing part 9 and the detection part of the other sensor 6a ₂ is used. The second characteristic changing section 10 is made to face and face each other. The positions where the detection parts of these sensors 6a ₁ and 6a ₂ face both the characteristic change parts 9 and 10 are the same in the circumferential direction of the encoder 4. Further, in the state where an axial load does not act between the outer ring 1 and the hub 2, the portion that protrudes most in the circumferential direction in the axial direction intermediate portion of each of the through holes 7 and 7 and the column portions 8 and 8 (boundary boundary). The position where each member is installed is regulated so that the portion where the inclination direction changes) is just at the center position between the detection parts of the sensors 6a ₁ and 6a ₂ .

In the case of a rolling bearing unit with a state quantity measuring device configured as described above, when an axial load acts between the outer ring 1 and the hub 2 (the outer ring 1 and the hub 2 are relatively displaced in the axial direction), The phase in which the output signals of the sensors 6a ₁ and 6a ₂ change is shifted. That is, in the neutral state in which an axial load is not applied between the outer ring 1 and the hub 2, the detecting portions of the sensors 6a ₁ and 6a ₂ are shown as solid lines A and B in FIG. That is, it faces a portion that is shifted from the most protruding portion by the same amount in the axial direction. Therefore, the phases of the output signals of the two sensors 6a ₁ and 6a ₂ coincide as shown in FIG.

On the other hand, when a downward axial load acts on the hub 2 to which the encoder 4 is fixed as shown in FIG. 8A, the detecting portions of the sensors 6a ₁ and 6a ₂ are shown in FIG. A) is opposed to the broken lines B and B, that is, the portions that are different from each other in the axial direction from the most protruding portion. In this state, the phases of the output signals of the sensors 6a ₁ and 6a ₂ are shifted as shown in FIG. Further, when an upward axial load is applied to the hub 2 to which the encoder 4 is fixed as shown in FIG. 8A, the detecting portions of the sensors 6a ₁ and 6a ₂ are shown in FIG. Deviations in the axial direction from the chain lines C and C, that is, from the most projecting portion are opposed to different portions in the opposite direction. In this state, the phases of the output signals of the two sensors 6a ₁ and 6a ₂ are shifted as shown in FIG.

As described above, in the case of the first example of the structure of the prior invention, the phases of the output signals of the sensors 6a ₁ and 6a ₂ are in the direction of the action of the axial load applied between the outer ring 1 and the hub 2. The direction is shifted. Further, the degree to which the phase of the output signals of the two sensors 6a ₁ and 6a ₂ is shifted due to the axial load increases as the axial load increases. Therefore, the axial acting between the outer ring 1 and the hub 2 based on the presence and absence of the phase shift of the output signals of the sensors 6a ₁ and 6a ₂ and the direction and magnitude of the shift, if any. The direction and magnitude of the load can be determined. The processing for calculating the axial load based on the phase difference between the output signals of the two sensors 6a ₁ and 6a ₂ is performed by a calculator (not shown). For this reason, in this computing unit, the relationship between the phase difference and the axial load, which have been examined in advance by theoretical calculation or experiment, is incorporated in the form of a calculation formula or a map.

Next, FIGS. 9 to 10 show a second example of the structure of the prior invention relating to a rolling bearing unit with a state quantity measuring device disclosed in Japanese Patent Application No. 2005-267552. Also in the case of the second example of the structure of the prior invention, the through holes 7a and 7a and the column portion 8a are formed on the outer peripheral surface (detected surface) of the encoder 4a made of a magnetic metal plate, which is fitted and fixed to the inner end portion of the hub 2. , 8a are alternately arranged at equal intervals in the circumferential direction. However, the boundary between each of the through holes 7a and 7a and each of the column portions 8a and 8a is a straight line inclined at the same angle in the same direction with respect to the axial direction. In addition, when the position of the lower end portion of the detected surface in use is a position of θ = 0 degrees with respect to the circumferential direction of the detected surface, a position of θ = 0 degrees on the detected surface ( The detection portions of the pair of sensors 6a ₁ and 6a ₂ are placed in close proximity to each other at the lower end portion and a position at θ = 180 degrees (upper end portion). In this state, the sensors 6a ₁ and 6a ₂ are supported and fixed on the inner peripheral surface of the cover 5 that is coupled and fixed to the inner end of the outer ring 1.

In the case of a rolling bearing unit for supporting a wheel of an automobile, the axial load Fy applied between the outer ring 1 and the hub 2 is input from the ground contact surface between the outer peripheral surface of the wheel (tire) coupled and fixed to the hub 2 and the road surface. The Since this ground contact surface exists radially outward from the rotation center of the outer ring 1 and the hub 2, the axial load Fy is not between the outer ring 1 and the hub 2 but as a pure axial load. 1 and the center axis of the hub 2 and the center of the grounding surface are applied with a moment in a virtual plane (in the vertical direction). The magnitude of this moment is proportional to the magnitude of the axial load Fy input from the ground plane. Therefore, if this moment is obtained, this axial load Fy can be obtained. On the other hand, when a moment is applied to the hub 2, the upper end portion of the encoder 4a is displaced in any direction with respect to the axial direction, and the lower end portion is similarly displaced in the opposite direction. As a result, the phases of the detection signals of the sensors 6a ₁ and 6a ₂ in which the respective detection units are closely opposed to the upper and lower ends of the outer peripheral surface of the encoder 4a are shifted in opposite directions with respect to the neutral positions. . Therefore, the direction and magnitude of the axial load Fy can be obtained based on the direction and magnitude of the phase shift of the detection signals of both the sensors 6a ₁ and 6a ₂ .

Next, FIGS. 11 to 14 show third to fourth examples of the structure of the prior invention relating to a rolling bearing unit with a state quantity measuring device disclosed in Japanese Patent Application No. 2005-125029. The encoders 4b used in the third to fourth examples of the structure of the prior invention also have axial halves on the outer peripheral surface that is the detected surface, as in the case of the encoder 4 used in the first example of the structure of the previous invention. This section includes first and second characteristic change sections 9 and 10. However, in the case of the encoder 4b used in the third to fourth examples of the structure of the previous invention, the through holes 7a and 7a constituting the first characteristic changing unit 9 and the second characteristic changing unit 10 are provided. The through-holes 7b and 7b to be formed are formed independently of each other. In any of the third to fourth examples of the structure of the prior invention, the position of the lower end portion of the detected surface of the encoder 4b at the time of use is expressed as θ = circumferential direction of the detected surface. When the position is 0 degree, the first and second sensors 6a ₁ and 6a ₂ are placed at the position of θ = 0 degrees of the first and second characteristic changing parts 9 and 10, and the first and second sensors 6a ₁ and 6a ₂ are At the position of θ = 270 degrees (θ = −90 degrees) of the second characteristic change section 10, the detection sections of the third sensor 6 a ₃ are respectively placed close to each other. Further, in the case of the fourth example of the structure of the prior invention shown in FIGS. 13 to 14, the detection part of the fourth sensor 6a ₄ is brought close to the position of θ = 90 degrees of the second characteristic change part 10. They are facing each other. Although detailed description is omitted, according to the third to fourth examples of the structure of the prior invention, the outer ring 1 (see FIG. 6) supporting the sensors 6a _{1 to} 6a ₄ and the encoder 4b are supported. Based on the phase difference between the output signals of the sensors 6a _{1 to} 6a ₄ caused by the relative displacement with the hub 2 (see FIG. 6), not only the axial displacement and the load Fy, but also the radial displacement. And the load Fz are also obtained.

Next, FIGS. 15 to 17 show a fifth example of the structure of the prior invention relating to the rolling bearing unit with a state quantity measuring device disclosed in Japanese Patent Application No. 2006-214194. In the case of the fifth example of the present invention, when the position of the lower end portion of the detected surface of the encoder 4 at the time of use is set to a position of θ = 0 degrees with respect to the circumferential direction of the detected surface, The first and second characteristic changing portions 9 and 10 provided on both axial halves of the detected surface are positioned at θ = 0 °, at θ = 120 °, and at θ = 240 °. The detection units of a total of six sensors (6a ₁ , 6a ₂ ), (6a ₃ , 6a ₄ ), (6a ₅ , 6a ₆ ) are placed in close proximity to each other. Although detailed explanation is omitted, according to the fifth example of the structure of the prior invention, the output signals of the _six sensors 6a _{1 to} 6a 6 generated by the relative displacement between the outer ring 1 and the hub 2 are not detected. In addition to displacement and load in the axial direction (y direction) and displacement and load in the radial direction (x direction, z direction, etc.), tilt angle (φ _x , φ _z etc.) and moment ( _Mx , _Mz, etc.) are also required.

Next, FIGS. 18 to 19 show a sixth example of the structure of the prior invention relating to the rolling bearing unit with a state quantity measuring device disclosed in Japanese Patent Application No. 2006-017091. In the case of the sixth example of the structure of the prior invention, the boundary between each through hole 7c, 7c and each column portion 8c, 8c provided on the outer peripheral surface, which is a detection surface, as the encoder 4c made of a magnetic metal plate is in the axial direction. The one that is parallel to is used. When the position of the lower end portion of the detected surface of the encoder 4c at the time of use is set to θ = 0 degrees with respect to the circumferential direction of the detected surface, θ = 0 degrees of the detected surface , The position of θ = 90 degrees, the position of θ = 180 degrees, and the position of θ = 270 degrees, respectively, and the detection units of _four sensors 6a _{1 to} 6a 4 in total face each other. I am letting. According to the sixth example of the structure of the prior invention, the outer ring 1 (see FIG. 6) supporting the sensors 6a _{1 to} 6a ₄ and the hub 2 (see FIG. 6) supporting the encoder 4c. The phase difference between the output signals of the pair of sensors 6a ₁ and 6a ₃ arranged at the position of θ = 0 ° and the position of θ = 180 °, which is caused by relative displacement, and the θ = 90 ° Based on the position and the phase difference between the output signals of the pair of sensors 6a ₂ and 6a ₄ arranged at the position of θ = 270 °, the direction and magnitude of the radial displacement and the radial load can be obtained.

In the case of the structure of each of the above-described prior inventions, an external force acts between the outer ring 1 and the hub 2 during driving of the automobile (the outer ring 1 and the hub 2 are relatively displaced by elastic deformation of each part). Accordingly, the detected surface of the encoder 4 (4a, 4b, 4c) and the detecting portion of the sensor 6a ₁ (6a _{2 to} 6a ₆ ) are displaced relative to each other in the width direction of the detected surface, and the directions of moving relative to each other. Also relative displacement. For this reason, even when such relative displacement in the direction of moving in the direction of each other occurs, an external force is applied between the outer ring 1 and the hub 2 so that the detection surface and the detection unit do not interfere with each other. It is necessary to leave a sufficient space between the detected surface and the detection unit in a neutral state where the sensor is not acting. However, in the case of the structure of each of the above-described prior inventions, the above-described covering in the neutral state is performed in order to prevent the measurement accuracy of the state quantity (displacement, load, etc.) from being deteriorated at the same time as satisfying such a request. It is necessary to narrow the distance between the detection surface and the detection unit as much as possible. The reason for this will be described with reference to FIGS.

The solid line α ₁ (and the chain line β ₁ ) in FIGS. 20 to 21 passes through the detection unit of the sensor 6a ₁ (6a _{2 to} 6a ₆ ) when the encoder 4 (4a, 4b, 4c) rotates. The magnetic flux density (magnetic flux density) is shown. The amplitude of the magnetic flux density α ₁ (and β ₁ ) increases as the distance between the detected surface and the detection unit becomes narrower as shown in FIG. 20A. It becomes smaller as shown in FIG. On the other hand, a solid line α ₂ (and a chain line β ₂ ) in FIGS. 20 to 21 indicates the output signal of the sensor 6a ₁ (6a _{2 to} 6a ₆ ). The output signal α ₂ (and β ₂ ) is converted from the magnetic flux density α ₁ (and β ₁ ) to a binary signal having a high potential and a low potential by a Schmitt trigger circuit having a predetermined hysteresis width W in the threshold level S. It is formed by converting into The hysteresis width W is provided to prevent erroneous detection of the magnetic flux density α ₁ (and β ₁ ).

Further, in the case of the structure of each of the above-described prior inventions, as shown in FIGS. 20 to 21, as the detected surface and the detecting unit are relatively displaced in the direction of moving relative to each other during driving of the automobile, as shown in FIGS. density amplitude in alpha ₁ → beta ₁ (or the β ₁ → α ₁₎ changes (or the beta ₂ → alpha ₂₎ the _second output signal is alpha ₂ → beta Along with this change. At this time, in the case of FIG. 20 described above, there is almost no phase shift between the output signals α ₂ and β ₂ . The reason for this is that, in the case of FIG. 20 described above, the amplitudes of both the magnetic flux densities α ₁ and β ₁ are large, so even if there is a slight amplitude difference between the two magnetic flux densities α ₁ and β ₁ , This is because the curves representing the magnetic flux densities α ₁ and β ₁ are almost coincident with each other in the hysteresis width W portion (the angle at which the curve crosses the hysteresis width W portion is close to a right angle). On the other hand, in the case of FIG. 21 described above, a slight phase shift (error) occurs between the output signals α ₂ and β ₂ . The reason for this is that, in the case of FIG. 21 described above, since the amplitudes of both the magnetic flux densities α ₁ and β ₁ are small, if there is a slight amplitude difference between the two magnetic flux densities α ₁ and β ₁ , This is because a slight shift occurs in the hysteresis width W portion between the curves representing the densities α ₁ and β ₁ .

Further, in the case of the structure of each of the above-described prior inventions, the sensor 6a ₁ (6a _{2 to} 6a ₆ ) is used only when the detected surface and the detecting portion are relatively displaced in the width direction of the detected surface. The state quantity is calculated on the assumption that the phase of the output signal is shifted. For this reason, even when the detected surface and the detection unit are relatively displaced in the direction in which they move relative to each other, if a phase shift (error) of the output signal occurs as shown in FIG. Measurement accuracy of the state quantity is deteriorated. Therefore, in order to prevent the measurement accuracy of the state quantity from deteriorating due to such a reason, even when the detected surface and the detection unit are relatively displaced in the direction in which they move relative to each other, FIG. As shown in the figure, in order to prevent the output signal from shifting in phase, the distance between the detected surface and the detecting portion in the neutral state (the range where the detecting portion of each sensor and the detected surface of the encoder do not interfere) It is necessary to make it as small as possible.

On the other hand, in the case of a structure in which the detection portions of the plurality of sensors 6a _{1 to} 6a ₆ are opposed to the detection surface of the encoder 4 (4a, 4b, 4c) as in the structure of each of the above-described prior inventions, In the neutral state, these detection units are arranged on a circumference concentric with the detected surface. That is, each of these detection units is made to face the detected surface at equal intervals. However, when such a configuration is adopted, the following problems to be improved arise.

That is, in the case of a rolling bearing unit for supporting a wheel of an automobile that constitutes the structure of each of the above-described prior inventions, the magnitude of an external force acting between the outer ring 1 and the hub 2 during operation of the automobile (the outer ring 1 and the hub). 2) is not uniform in all directions but varies. Therefore, the displacement amount in the radial direction of the encoder 4 (4a, 4b, 4c) supported and fixed to the inner end portion of the hub 2 {the detected surface of the encoder 4 (4a, 4b, 4c) and each sensor 6a ₁ The amount of decrease in the interval with the detection unit of ˜6a ₆ is not uniform in all directions (in all these intervals) but varies. Therefore, when the detection units are opposed to the detection surface at equal intervals in the neutral state, the intervals are wasted (in order to prevent interference between the sensor and the encoder) in the sensor portion where the decrease in the interval is small. Therefore, the measurement accuracy of the state quantity is lowered accordingly.

JP 2006-1113017 A Motoo Aoyama, “Red Badge Super Illustrated Series / A book that shows the latest mechanics of cars”, p. 138-139, p. 146-149, Sangensha Co., Ltd./Kodansha Co., Ltd., December 20, 2001

  The rolling bearing unit with a state quantity measuring device according to the present invention is in a state where a detection unit of a plurality of sensors is opposed to different portions of a detection surface of an encoder in view of the above-described circumstances. It was invented to realize a structure capable of improving the measurement accuracy of quantity.

The rolling bearing unit with a state quantity measuring device of the present invention includes a rolling bearing unit and a state quantity measuring device.
Of these, the rolling bearing unit has a stationary side raceway on the stationary side circumferential surface and does not rotate even in use, and a stationary side raceway that has a rotation side raceway on the rotation side circumferential surface and rotates in the usage state. A track ring, and a plurality of rolling elements provided so as to be freely rollable between the stationary side track and the rotation side track.
The state quantity measuring device includes an encoder, a sensor device, and a calculator.
Among these, the encoder is supported and fixed directly on a part of the rotation side raceway or through another member, and has a detection surface concentric with the rotation side raceway on the peripheral surface. The surface characteristics are alternately changed in the circumferential direction.
The sensor device is supported by a portion that does not rotate during use, and includes a plurality of sensors. Each of these sensors has a detection unit opposed to a different portion of the detected surface, and changes an output signal in response to a change in characteristics of the detected surface.
Further, the arithmetic unit has a function of calculating a state quantity of the rolling bearing unit based on information relating to output signals of the sensors.
In particular, in the rolling bearing unit with a state quantity measuring device of the present invention, no load is applied between the stationary bearing ring and the rotating bearing ring (the two bearing rings are not relatively displaced). ) In a neutral state, without making the distance between the detected surface and each detection unit uniform, a size relationship corresponding to the reduction amount of each distance during use is given between these intervals. ing. By setting this magnitude relationship, the distance between the detection units of the sensors and the detected surface of the encoder closest to each other is made to substantially match each sensor.

  When implementing such a rolling bearing unit with a state quantity measuring device of the present invention, for example, the configuration described in claim 2 can be adopted. In the case of adopting the configuration described in claim 2, as an encoder, the characteristics of the detected surface are alternately changed with respect to the circumferential direction, and the phase or pitch at which the characteristics of the detected surface changes with respect to the circumferential direction. At least part of the detected surface in the width direction is used which is continuously changed in the width direction. At the same time, as a computing unit, based on the information about the output signal of each sensor constituting the sensor device, the relative displacement amount between the stationary side raceway and the rotation side raceway, and the stationary side raceway and the rotation side raceway, Among these, an external force acting between the two has a function of calculating at least one state quantity.

  Further, when the invention described in claim 2 is implemented, for example, the configuration described in claim 3 can be adopted. When the configuration described in claim 3 is adopted, the encoder has first and second characteristic change portions at two positions out of the detected surface with respect to the width direction of the detected surface. Then, the characteristics of these two characteristic changing portions are alternately changed at the same pitch with respect to the circumferential direction, and the phase of the characteristic change of at least one of the two characteristic changing portions is related to the width direction. What is gradually changed in a state different from the other characteristic changing portion is used. Further, as the sensor device, at least one having a pair of sensors in which the respective detection units are opposed to the both characteristic change units is used. Further, as the computing unit, information that calculates a state quantity using at least the phase difference between the output signals of the pair of sensors is used as information about the output signals of the sensors constituting the sensor device.

  Further, when carrying out the invention described in claim 2 as described above, for example, the configuration described in claim 4 can be adopted. When implementing the configuration described in claim 4, as an encoder, the characteristics of the surface to be detected are alternately changed in the circumferential direction, and the pitch at which the characteristics of the surface to be detected changes in the circumferential direction is What is continuously changed in the width direction of the detected surface is used. Further, as the computing unit, information that calculates the state quantity using the duty ratio of the output signal of at least one sensor is used as information regarding the output signal of each sensor constituting the sensor device.

Moreover, when the invention described in claims 1 to 4 as described above is carried out, the configuration described in claims 5 to 9 is preferably adopted. When the configurations described in claims 5 to 9 are employed, the detected surface of the encoder is provided on the outer peripheral surface of the encoder. An angle about the central axis of the detected surface is defined as θ, and the position of the lower end portion of the detected surface at the time of use is defined as θ = 0 degrees.
When the configuration described in claim 5 is adopted among the above claims 5 to 9, the sensor device has a position of θ = 0 degrees and a position of θ = 180 degrees of the detected surface. Each of the detection parts of at least one sensor is opposed to each other. Then, when the distance between the detected surface and each detection unit in the neutral state is δ ₀ at the position θ = 0 ° and δ ₁₈₀ at the position θ = 180 degrees, δ ₀ <Δ ₁₈₀ .

Similarly, when the configuration described in claim 6 is adopted, the sensor device has a position of θ = 0 degrees, a position of θ = 90 degrees, a position of θ = 270 degrees, The detection part of at least one sensor is opposed to at least one of the positions. Then, the distance between the detected surface and each detection unit in the neutral state is δ ₀ at the position of θ = 0 degrees, δ ₉₀ at the position of θ = 90 degrees, and θ = 270 degrees. Where δ ₂₇₀ at the position of δ ₉₀ = δ ₂₇₀ <δ ₀ .
Similarly, when the configuration described in claim 7 is adopted, the sensor device has a position of θ = 0 degrees, a position of θ = 120 degrees, a position of θ = 240 degrees on the detected surface. In addition, the detection units of at least one sensor are opposed to each other. Then, the distance between the detected surface and the detection units in the neutral state is δ ₀ at the position of θ = 0 degrees, δ ₁₂₀ at the position of θ = 120 degrees, and θ = 240 degrees. When δ ₂₄₀ is set at the position δ ₀ <δ ₁₂₀ = δ ₂₄₀ .

Similarly, when the configuration described in claim 8 is employed, the sensor device has a position of θ = 60 degrees, a position of θ = 180 degrees, a position of θ = 300 degrees, In addition, the detection units of at least one sensor are opposed to each other. Then, the distance between the detected surface and each of the detection units in a neutral state where no external force is acting between the stationary side raceway and the rotation side raceway is expressed as δ ₆₀ at the position of θ = 60 degrees. And δ ₁₈₀ at the position of θ = 180 degrees and δ ₃₀₀ at the position of θ = 300 degrees, δ ₆₀ = δ ₃₀₀ <δ ₁₈₀ .
Similarly, when the configuration described in claim 9 is adopted, the sensor device has a position of θ = 0 degrees, a position of θ = 90 degrees, a position of θ = 180 degrees on the detected surface. , Θ = 270 degrees, and the detection unit of at least one sensor is made to face each other. Then, in the neutral state where no external force is applied between the stationary-side raceway and the rotation-side raceway, the distance between the detected surface and each of the detection units is δ ₀ at the position of θ = 0 °. And δ ₉₀ at the position of θ = 90 degrees, δ ₁₈₀ at the position of θ = 180 degrees, and δ ₂₇₀ at the position of θ = 270 degrees, δ ₉₀ = δ ₂₇₀ <δ ₀ < Let δ ₁₈₀ .

  In carrying out the inventions described in the first to ninth aspects, preferably, as described in the tenth aspect, the rolling bearing unit is a hub unit for supporting a wheel of an automobile. Then, in use, the stationary side race is supported by the suspension device of the automobile, and the wheel is coupled and fixed to the hub that is the rotation side race. Further, the encoder is supported and fixed to the inner end of the hub in the axial direction.

  In the case of the rolling bearing unit with a state quantity measuring device of the present invention configured as described above, the distance between the detected surface of the encoder and the detecting portion of each sensor in the neutral state is excessively wide. Can be prevented. That is, each of these intervals can be sufficiently narrowed. For this reason, the amplitude of the output signal of each sensor can be sufficiently increased. Accordingly, it is possible to effectively prevent the phase of the output signals of the sensors from being shifted even when the intervals change slightly due to relative displacement between the stationary side raceway and the rotation side raceway during operation. As a result, it is possible to prevent the state quantity measurement accuracy from deteriorating.

[First example of embodiment]
FIG. 1 shows a first example of an embodiment of the present invention corresponding to claims 1, 2, 3, 5 and 10. The feature of this example is that the distance between the detected surface (outer peripheral surface) of the encoder 4a and the detecting portions of the sensors 6a ₁ and 6a _{2 in} the neutral state is regulated based on predetermined conditions. is there. Since the structure and operation of the other parts are the same as in the case of the second example of the structure of the prior invention shown in FIG. 9 described above, overlapping illustrations and explanations are omitted or simplified. The explanation will be focused on.

この表１に示す様に、自動車の運転時に、上記エンコーダ４ａの上下方向変位ｚは、−０．０６３mm〜＋０．２０９mmの範囲で変化し、同じく前後方向変位ｘは、−０．０２０mm〜＋０．０２０mmの範囲で変化する。 As described above, in the case of the rolling bearing unit for supporting a wheel of an automobile that constitutes the rolling bearing unit with a state quantity measuring device of this example, during the operation of the automobile, the outer ring 1 and the hub 2 (see FIG. 9) The extent to which an external force acts (the relative displacement between the outer ring 1 and the hub 2) is not uniform in all directions but varies (the magnitude of the external force varies depending on the direction of the external force). For this reason, the radial displacement amount of the encoder 4a supported and fixed to the inner end portion of the hub 2 is not uniform in all directions but varies (the maximum displacement amount in the radial direction differs in the circumferential direction). Table 1 below shows the results of a simulation performed by the present inventor on a general rolling bearing unit for supporting a wheel for a passenger car in order to examine the tendency of variation. In Table 1, Fy is an axial load (y-axis direction load) acting on the hub 1, Fz is also a vertical radial load (z-axis direction load), and Fx is also a front-rear direction. Radial load (x-axis direction load), z indicates the vertical displacement of the encoder 4a with respect to the position in the neutral state, and x similarly indicates the longitudinal displacement.

As shown in Table 1, during the driving of the automobile, the vertical displacement z of the encoder 4a varies in the range of -0.063 mm to +0.209 mm. Similarly, the longitudinal displacement x is -0.020 mm to +0. .Varies within the range of 020 mm.

  Analyzing these results, first, the vertical displacement z (−0.063 mm to +0.209 mm) varies in a wider range than the longitudinal displacement x (−0.020 mm to +0.020 mm). To do. The reason for this is as follows. That is, during operation of the automobile, a moment Mx around the x axis due to the axial load Fy and the radial load Fz acts on the hub 2. The moment Mx causes the central axis of the hub 2 to be inclined with respect to the central axis of the outer ring 1 in a direction that causes the vertical displacement z. Further, during operation of the automobile, a moment Mz around the z-axis caused by the radial load Fx also acts on the hub 2. The moment Mz causes the central axis of the hub 2 to be inclined with respect to the central axis of the outer ring 1 in a direction that causes the longitudinal displacement x. On the other hand, the moment Mx causing the vertical displacement z during driving of the automobile is larger than the moment Mz causing the longitudinal displacement x. For this reason, the vertical displacement z (−0.063 mm to +0.209 mm) varies in a wider range than the longitudinal displacement x (−0.020 mm to +0.020 mm).

  Further analysis of the above results shows that the vertical displacement z (−0.063 mm to +0.209 mm) is upward (+ z direction) and the vertical displacement z (0.209 mm) is downward (−z direction). ) In the vertical direction displacement z (0.063 mm). The reason for this is as follows. That is, the direction and magnitude of the vertical displacement z changes under the influence of the direction and magnitude of the moment Mx, and the direction and magnitude of the moment Mx depends on the direction and magnitude of the axial load Fy. Changes under the influence of. For this reason, the direction and magnitude of the vertical displacement z changes under the influence of the direction and magnitude of the axial load Fy. Specifically, the + y-direction axial load Fy acts to generate an upward vertical displacement z, and the -y-direction axial load Fy acts to generate a downward vertical displacement z. Further, the axial load Fy in the + y direction acts on the hub 2 that supports the turning outer wheel when the vehicle is turning, and the axial load Fy in the −y direction similarly acts on the hub 2 that supports the turning inner wheel. . However, in this case, since the road surface reaction force (axial load Fy in the ∝ + y direction) of the turning outer wheel becomes larger than the road surface reaction force (axial load Fy in the 方向 -y direction) of the turning inner wheel, the + y direction The axial load Fy is larger than the axial load Fy in the -y direction. Accordingly, the vertical displacement z (−0.063 mm to +0.209 mm) is larger in the upward vertical displacement z (0.209 mm) than in the downward vertical displacement z (0.063 mm).

In the case of this example, if the distance between the detected surface of the encoder 4a and the detecting portion of the sensor 6a _{1 at} the position of θ = 0 ° is δ _{0 in} the neutral state, the downward vertical displacement z ( 0.063 mm) is a reduction amount of the interval δ ₀ during operation. When the distance between the detected surface and the detecting portion of the sensor 6a _{2 at} the position θ = 180 degrees in the neutral state is δ ₁₈₀ , the upward vertical displacement z (0.209 mm) is In this case, the amount of decrease is the interval δ ₁₈₀ . Therefore, in this example, the reduction amount (0.209 mm) of the interval δ ₁₈₀ during operation is larger than the reduction amount (0.063 mm) of the interval δ ₀ . Therefore, in the case of this example, each of these intervals [delta] _0, between [delta] ₁₈₀ between, reduction of the distance _{δ 0, δ 180 (0.063mm,} 0.209mm) size relationship [delta] ₀ corresponding to < δ ₁₈₀ is given. The distance between the detection units of the sensors 6a ₁ and 6a _{2 and} the detected surface of the encoder 4a is the same between the sensors 6a ₁ and 6a ₂ . .

For this purpose, specifically, the intervals δ ₀ and δ ₁₈₀ are set to values that are larger by the same amount (Xmm) than the reduction amounts (0.063 mm and 0.209 mm) of the intervals δ ₀ and δ ₁₈₀ { δ ₀ = (0.063 + X) mm, δ ₁₈₀ = (0.209 + X) mm}. Alternatively, the results are the same, but first, based on the experimental results described above, after obtaining the radial displacement range of the detected surface of the encoder 4a during operation, it is more than the outer periphery of this displacement range. A similar closed curve C is set that is slightly larger (the width of the outer peripheral edge in the normal direction is larger by the above-mentioned X mm), and the detection units of the sensors 6a ₁ and 6a ₂ are arranged on the closed curve C, respectively. ing. In the case of carrying out this example, Xmm is as small as possible (for example, from several millimeters to several millimeters) while taking into consideration the prevention of interference (safety aspect) between the detected surface and each of the detection units during operation. A few mm).

In the case of the rolling bearing unit with the state quantity measuring device of the present example configured as described above, the distance δ ₀ between the detected surface of the encoder 4a and the detecting portions of the sensors 6a ₁ and 6a _{2 in} the neutral state, It is possible to prevent δ _{180 from} becoming unnecessarily wide (unnecessary for preventing interference between the detected surface and the detection unit). That is, the intervals δ ₀ and δ ₁₈₀ can be sufficiently narrowed. For this reason, the amplitudes of the output signals of these sensors 6a ₁ and 6a ₂ can be sufficiently increased. Accordingly, the phase of the output signals of the sensors 6a ₁ and 6a ₂ is shifted even when the distances δ ₀ and δ ₁₈₀ change as the outer ring 1 and the hub 2 are relatively displaced during operation. It can be effectively prevented. As a result, it is possible to prevent the state quantity measurement accuracy from deteriorating.

[Second Example of Embodiment]
Next, FIG. 2 shows a second example of an embodiment of the present invention corresponding to claims 1, 2, 3, 6, and 10. The feature of this example is that the distance between the detected surface (outer peripheral surface) of the encoder 4b and the detection portions of the sensors 6a _{1 to} 6a _{4 in} the neutral state is regulated based on predetermined conditions. is there. Since the structure and operation of the other parts are the same as in the case of the fourth example of the structure of the prior invention shown in FIG. 13 described above, overlapping illustrations and explanations are omitted or simplified. The explanation will be focused on.

Also in the case of this example, the sensors 6a ₁ and 6a ₂ existing at the position of θ = 0 degrees with respect to the detected surface in the neutral state in the same manner as in the case of the first example of the embodiment described above. An interval δ _{0 from} the detection unit, an interval δ ₉₀ between the detection surface and the detection unit of the sensor 6a ₄ existing at a position of θ = 90 degrees, and a position of θ = 270 degrees from the detection surface. The magnitude relationship δ ₉₀ = δ ₂₇₀ <δ ₀ corresponding to the reduction amount of each of these intervals δ ₀ , δ ₉₀ , δ ₂₇₀ during operation is between the interval δ ₂₇₀ and the detection unit of the sensor 6a _3. (Each of the detection units is arranged on a closed curve C).

Also in this embodiment the state quantity measuring rolling bearing unit of constituting in this way, in the neutral state, the interval [delta] ₀ of the detection portion of the detection surface and the sensors 6a ₁ ~6a ₄ encoder 4b, [delta] ₉₀ , Δ ₂₇₀ can be prevented from becoming unnecessarily wide. That is, these intervals δ ₀ , δ ₉₀ and δ ₂₇₀ can be sufficiently narrowed. For this reason, the amplitude of the output signals of these sensors 6a _{1 to} 6a ₄ can be sufficiently increased. Accordingly, even when the intervals δ ₀ , δ ₉₀ , δ ₂₇₀ change as the outer ring 1 and the hub 2 are relatively displaced during operation, the phases of the output signals of the sensors 6a _{1 to} 6a ₄ change. It is possible to effectively prevent the shift. As a result, it is possible to prevent the state quantity measurement accuracy from deteriorating.

[Third example of embodiment]
Next, FIG. 3 shows a third example of an embodiment of the present invention corresponding to claims 1, 2, 3, 7, and 10. The feature of this example is that the distance between the detected surface (outer peripheral surface) of the encoder 4 and the detection portions of the sensors 6a _{1 to} 6a _{6 in} the neutral state is regulated based on predetermined conditions. is there. Since the structure and operation of the other parts are the same as in the case of the fifth example of the structure of the prior invention shown in FIGS. 15 to 16, the overlapping illustrations and explanations are omitted or simplified. The description will focus on the characteristic part.

Also in the case of this example, each sensor 6a existing at a position of θ = 0 degrees with respect to the detected surface in the neutral state by the same method as in the case of the first example of the embodiment shown in FIG. ₁ , 6a ₂ , the distance δ ₀ between the detection part, the distance δ ₁₂₀ between the detected surface and the detection part of each sensor 6a ₃ , 6a ₄ at a position of θ = 120 degrees, and the detected surface Corresponding to the reduction amount of each of these intervals δ ₀ , δ ₁₂₀ , and δ ₂₄₀ during operation between the sensors 6a ₅ and 6a ₆ at the position θ = 240 degrees and the interval δ ₂₄₀ between the sensors 6a ₅ and 6a _6. The magnitude relation δ ₀ <δ ₁₂₀ = δ ₂₄₀ is given (each of the detection units is arranged on the closed curve C).

Also in the case of the rolling bearing unit with the state quantity measuring device of this example configured in this way, the distances δ ₀ , δ ₁₂₀ between the detected surface of the encoder 4 and the detecting portions of the sensors 6a _{1 to} 6a _{6 in} the neutral state. , Δ ₂₄₀ can be prevented from becoming unnecessarily wide. That is, the intervals δ ₀ , δ ₁₂₀ , and δ ₂₄₀ can be sufficiently narrowed. For this reason, the amplitudes of the output signals of these sensors 6a _{1 to} 6a ₆ can be sufficiently increased. Thus, with the possible and the outer ring 1 and the hub 2 are relatively displaced during operation, each interval [delta] _0, [delta] _120, even when [delta] ₂₄₀ is changed, the output signals of the sensors 6a ₁ ~6a ₆ phase It is possible to effectively prevent the shift. As a result, it is possible to prevent the state quantity measurement accuracy from deteriorating.

[Fourth Example of Embodiment]
Next, FIG. 4 shows a fourth example of an embodiment of the present invention corresponding to claims 1, 2, 3, 8, and 10. The feature of this example is that the distance between the detected surface (outer peripheral surface) of the encoder 4 and the detection portions of the sensors 6a _{1 to} 6a _{6 in} the neutral state is regulated based on predetermined conditions. is there. The structure and operation of the other parts are as follows in the state of use of the three sensor sets, each consisting of a pair of sensors (6a ₁ , 6a ₂ ), (6a ₁ , 6a ₂ ), (6a ₁ , 6a ₂ ). Except for the fact that the arrangement location is changed to three locations of θ = 60 degrees, 180 degrees, and 300 degrees, it is the same as in the case of the fifth example of the structure of the prior invention shown in FIGS. For this reason, overlapping illustrations and descriptions will be omitted or simplified, and the following description will focus on the features of this example.

Also in the case of this example, each sensor 6a existing at a position of θ = 60 degrees with respect to the detected surface in the neutral state in the same manner as in the case of the first example of the embodiment shown in FIG. ₁ , 6a ₂ , the interval δ ₆₀ with respect to the detection unit, the interval δ ₁₈₀ between the detection surface and the detection unit of each sensor 6a ₃ , 6a ₄ at the position of θ = 180 degrees, and the detection surface Corresponding to the reduction amount of each of these intervals δ ₆₀ , δ ₁₈₀ , and δ ₃₀₀ during operation between the interval δ ₃₀₀ and the detection unit of each sensor 6a ₅ , 6a ₆ existing at a position of θ = 300 degrees. The magnitude relation δ ₆₀ = δ ₃₀₀ <δ ₁₈₀ is given (each of the detection units is arranged on the closed curve C).

Also in the case of the rolling bearing unit with the state quantity measuring device of this example configured as described above, the distances δ ₆₀ , δ ₁₈₀ between the detected surface of the encoder 4 and the detecting portions of the sensors 6a _{1 to} 6a _{6 in} the neutral state _. , Δ ₃₀₀ can be prevented from becoming unnecessarily wide. That is, the intervals δ ₆₀ , δ ₁₈₀ , and δ ₃₀₀ can be sufficiently narrowed. For this reason, the amplitudes of the output signals of these sensors 6a _{1 to} 6a ₆ can be sufficiently increased. Thus, with the possible and the outer ring 1 and the hub 2 are relatively displaced during operation, each interval [delta] _60, [delta] _180, even when [delta] ₃₀₀ is changed, the output signals of the sensors 6a ₁ ~6a ₆ phase It is possible to effectively prevent the shift. As a result, it is possible to prevent the state quantity measurement accuracy from deteriorating.

[Fifth Example of Embodiment]
Next, FIG. 5 shows a fifth example of an embodiment of the present invention corresponding to claims 1, 2, 3, 9 and 10. The feature of this example is that the distance between the detected surface (outer peripheral surface) of the encoder 4c and the detection portions of the sensors 6a _{1 to} 6a _{4 in} the neutral state is regulated based on predetermined conditions. is there. Since the structure and operation of other parts are the same as in the case of the sixth example of the structure of the prior invention shown in FIG. 18 described above, overlapping illustrations and explanations are omitted or simplified. The explanation will be focused on.

Also in the case of this example, the sensor 6a ₁ existing at a position of θ = 0 degrees with respect to the detected surface in the neutral state by the same method as in the case of the first example of the embodiment shown in FIG. The distance δ ₀ between the detection surface and the detection surface of each sensor 6a ₂ existing at a position of θ = 90 degrees and the detection surface δ _90, and the position of the detection surface with θ = 180 degrees. an interval [delta] ₁₈₀ and the detection portion of the sensor 6a ₃ present, between the interval [delta] ₂₇₀ and the detection portion of the sensor 6a ₄ at the position of the detected face and theta = 270 degrees, at the time of operation The magnitude relation δ ₉₀ = δ ₂₇₀ <δ ₀ <δ ₁₈₀ corresponding to the amount of decrease in each of these intervals δ ₀ , δ ₉₀ , δ ₁₈₀ , δ ₂₇₀ is given (each of the detection units is a closed curve C, respectively). Placed on top).

Also in this embodiment the state quantity measuring rolling bearing unit of constituting in this way, in the neutral state, the interval [delta] ₀ of the detection portion of the detection surface and the sensors 6a ₁ ~6a ₄ encoder 4, [delta] ₉₀ , Δ ₁₈₀ , and δ ₂₇₀ can be prevented from becoming unnecessarily wide. That is, these intervals δ ₀ , δ ₉₀ , δ ₁₈₀ , δ ₂₇₀ can be sufficiently narrowed. For this reason, the amplitude of the output signals of these sensors 6a _{1 to} 6a ₄ can be sufficiently increased. Accordingly, even when the intervals δ ₀ , δ ₉₀ , δ ₁₈₀ , and δ ₂₇₀ change as the outer ring 1 and the hub 2 are relatively displaced during operation, the output signals of the sensors 6a _{1 to} 6a ₄ are also changed. It can be effectively prevented that the phase of the phase shifts. As a result, it is possible to prevent the state quantity measurement accuracy from deteriorating.

  In the present invention, the number of sensors included in the target structure and the locations of these sensors can be determined if the amount of decrease in the distance between the detected surface of the encoder and the detecting portion of each sensor can be grasped during operation. Even if θ is different from the case of each of the above-described embodiments, it can be appropriately implemented.

The schematic diagram which shows the positional relationship of the encoder and sensor in a neutral state which shows the 1st example of embodiment of this invention. The figure similar to FIG. 1 which shows the 2nd example. The figure similar to FIG. 1 which shows the 3rd example. The figure similar to FIG. 1 which shows the 4th example. The figure similar to FIG. 1 which shows the same 5th example. Sectional drawing which shows the 1st example of the structure of a prior invention. The figure which looked at a part of to-be-detected surface of the encoder incorporated in this 1st example from the radial direction outer side. The diagram for demonstrating the state from which the output signal of a pair of sensor changes based on an axial load. Sectional drawing which shows the 2nd example of the structure of a prior invention. The schematic diagram which shows the positional relationship of the encoder and sensor in a neutral state of this 2nd example. The perspective view of the encoder and sensor which shows the 3rd example of the structure of a prior invention. The schematic diagram which shows the positional relationship of the encoder and sensor in a neutral state of this 3rd example. The perspective view of the encoder and sensor which shows the 4th example of the structure of a prior invention. The schematic diagram which shows the positional relationship of the encoder and sensor in a neutral state of this 4th example. Sectional drawing which shows the 5th example of the structure of a prior invention. The schematic diagram which shows this 5th example. The schematic diagram which shows the positional relationship of the encoder and sensor in a neutral state of this 5th example. The fragmentary sectional view of an encoder and a sensor which shows the 6th example of the structure of a prior invention. The schematic diagram which shows the positional relationship of the encoder and sensor in a neutral state of this 6th example. The figure which shows the relationship between the density (magnetic flux density) of the magnetic flux which passes the detection part of this sensor, and the output signal of this sensor when the space | interval of the to-be-detected surface of an encoder and the detection part of a sensor is comparatively narrow . The figure which shows the relationship between the density (magnetic flux density) of the magnetic flux which passes the detection part of this sensor, and the output signal of this sensor when the space | interval of the to-be-detected surface of an encoder and the detection part of a sensor is comparatively wide .

Explanation of symbols

1 the outer ring 2 hub 3 rolling element 4,4a~4c encoder 5 cover 6a ₁ ~6a ₆ sensor 7,7a~7c hole 8,8a~8c pillar portion 9 first characteristic change portion 10 second characteristic change portion

Claims (10)

A rolling bearing unit and a state quantity measuring device;
Of these, the rolling bearing unit has a stationary side raceway on the stationary side circumferential surface and does not rotate even in use, and a stationary side raceway that has a rotation side raceway on the rotation side circumferential surface and rotates in the usage state. A bearing ring, and a plurality of rolling elements provided between the stationary side raceway and the rotation side raceway so as to roll freely,
The state quantity measuring device includes an encoder, a sensor device, and a calculator.
Among these, the encoder is supported and fixed directly on a part of the rotation side raceway or through another member, and has a detection surface concentric with the rotation side raceway on the peripheral surface. The surface characteristics are alternately changed in the circumferential direction.
The sensor device is supported by a portion that does not rotate during use, and includes a plurality of sensors, each of which has a detection portion facing a different portion of the detected surface, and The output signal is changed in response to the change in the characteristics of the detected surface,
The arithmetic unit has a function of calculating a state quantity of the rolling bearing unit based on information on output signals of the sensors.
In rolling bearing unit with state quantity measuring device,
Without neutralizing the distance between the detected surface and each of the detection sections in a neutral state where no external force is acting between the stationary side ring and the rotation side ring, A rolling bearing unit with a state quantity measuring device characterized in that a magnitude relation corresponding to the amount of decrease in each interval during use is given. The encoder alternately changes the characteristics of the detected surface with respect to the circumferential direction, and sets the phase or pitch at which the characteristics of the detected surface change with respect to the circumferential direction to at least a part of the width of the detected surface in the width direction. Is a continuous change in direction,
Based on the information about the output signal of each sensor that constitutes the sensor device, the calculator calculates the relative displacement between the stationary side raceway and the rotation side raceway and between the stationary side raceway and the rotation side raceway. The rolling bearing unit with a state quantity measuring device according to claim 1, which has a function of calculating at least one of the acting external forces. The encoder has first and second characteristic changing portions at two positions out of the detected surface with respect to the width direction of the detected surface, and the characteristics of these two characteristic changing portions are alternately set in the circumferential direction. And the phase of the characteristic change of at least one of these characteristic change parts is gradually changed in a state different from the other characteristic change part with respect to the width direction. Yes,
The sensor device includes at least a pair of sensors in which the respective detection units are opposed to the both characteristic change units,
The computing unit calculates a state quantity using at least a phase difference between the output signals of the pair of sensors as information on the output signals of the sensors constituting the sensor device. Rolling bearing unit with state quantity measuring device. The encoder alternately changes the characteristics of the surface to be detected in the circumferential direction, and the pitch at which the characteristics of the surface to be detected changes in the circumferential direction is continuously changed in the width direction of the surface to be detected. And
The state quantity measuring device according to claim 2, wherein the computing unit calculates a state quantity by using a duty ratio of an output signal of at least one sensor as information on an output signal of each sensor constituting the sensor device. Rolling bearing unit. The detected surface of the encoder is provided on the outer peripheral surface of the encoder. The angle about the central axis of the detected surface is θ, and the position of the lower end portion of the detected surface in use is θ = In the case of the 0 degree position, the sensor device has at least one sensor detection portion facing the θ = 0 degree position and the θ = 180 degree position of the detected surface. In addition, the distance between the detected surface and each of the detection units in a neutral state where no external force is applied between the stationary side raceway and the rotation side raceway is expressed as δ ₀ at the position of θ = 0 °. The rolling bearing unit with a state quantity measuring device according to any one of claims 1 to 4, wherein δ ₀ <δ ₁₈₀ when δ ₁₈₀ at the position of θ = 180 degrees. The detected surface of the encoder is provided on the outer peripheral surface of the encoder. The angle about the central axis of the detected surface is θ, and the position of the lower end portion of the detected surface in use is θ = In the case of the 0 degree position, the sensor device has a position of θ = 0 degrees on the detected surface, and at least one of the position of θ = 90 degrees and the position of θ = 270 degrees. The detection surface and each of the detections in a neutral state where the detection portions of at least one sensor are opposed to each other and no external force is applied between the stationary-side raceway and the rotation-side raceway. When the distance from the portion is δ ₀ at the position of θ = 0 degrees, δ ₉₀ at the position of θ = 90 degrees, and δ ₂₇₀ at the position of θ = 270 degrees, δ ₉₀ = δ ₂₇₀ <[delta] ₀ and to have, a rolling bearing with a state quantity measuring device according to any one of claims 1 to 4 Uni Door. The detected surface of the encoder is provided on the outer peripheral surface of the encoder. The angle about the central axis of the detected surface is θ, and the position of the lower end portion of the detected surface in use is θ = When the position is 0 degree, the sensor device has at least one sensor at the position of θ = 0 degrees, the position of θ = 120 degrees, and the position of θ = 240 degrees on the detected surface. The distance between the detected surface and each of the detection units in a neutral state where the detection units are opposed to each other and no external force is applied between the stationary-side raceway and the rotation-side raceway is defined as θ Δ ₀ at a position of 0 degrees, δ ₁₂₀ at a position of θ = 120 degrees, and δ ₂₄₀ at a position of θ = 240 degrees, δ ₀ <δ ₁₂₀ = δ ₂₄₀ The rolling bearing unit with a state quantity measuring device described in any one of 1-4. The detected surface of the encoder is provided on the outer peripheral surface of the encoder. The angle about the central axis of the detected surface is θ, and the position of the lower end portion of the detected surface in use is θ = In the case of the 0 degree position, the sensor device has at least one sensor at a position of θ = 60 degrees, a position of θ = 180 degrees, and a position of θ = 300 degrees on the detected surface. The distance between the detected surface and each of the detection units in a neutral state where the detection units are opposed to each other and no external force is applied between the stationary-side raceway and the rotation-side raceway is defined as θ Δ ₆₀ at the position of 60 degrees, δ ₁₈₀ at the position of θ = 180 degrees, and δ ₃₀₀ at the position of θ = 300 degrees, δ ₆₀ = δ ₃₀₀ <δ ₁₈₀ The rolling bearing unit with a state quantity measuring device described in any one of 1-4. The detected surface of the encoder is provided on the outer peripheral surface of the encoder. The angle about the central axis of the detected surface is θ, and the position of the lower end portion of the detected surface in use is θ = In the case of the 0 degree position, the sensor device has a position of θ = 0 degrees, a position of θ = 90 degrees, a position of θ = 180 degrees, and a position of θ = 270 degrees on the detected surface. The detection surface and each of the detections in a neutral state where the detection portions of at least one sensor are opposed to each other and no external force is applied between the stationary-side raceway and the rotation-side raceway. The distance from the portion is δ ₀ at the position of θ = 0 degrees, δ ₉₀ at the position of θ = 90 degrees, δ ₁₈₀ at the position of θ = 180 degrees, and the position of θ = 270 degrees. when the [delta] _270, is set to _{δ 90 = δ 270 <δ 0} <δ 180, like that described in any one of claims 1 to 4 Rolling bearing unit with amount measurement device.   The rolling bearing unit is a hub unit for supporting a wheel of an automobile, and the stationary side bearing ring is supported by the suspension system of the automobile in use, and the wheel is coupled and fixed to the hub that is the rotating side bearing ring. The rolling bearing unit with a state quantity measuring device according to any one of claims 1 to 9, wherein an encoder is supported and fixed to an inner end portion in the axial direction of the hub.

Images