JP2004325134A - Rotation support device with state detection device - Google Patents

Rotation support device with state detection device Download PDF

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Publication number
JP2004325134A
JP2004325134A JP2003117351A JP2003117351A JP2004325134A JP 2004325134 A JP2004325134 A JP 2004325134A JP 2003117351 A JP2003117351 A JP 2003117351A JP 2003117351 A JP2003117351 A JP 2003117351A JP 2004325134 A JP2004325134 A JP 2004325134A
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Japan
Prior art keywords
detected
output signal
load
information
sensors
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JP2003117351A
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Japanese (ja)
Inventor
Hiroo Ishikawa
寛朗 石川
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Nsk Ltd
日本精工株式会社
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Priority to JP2003117351A priority Critical patent/JP2004325134A/en
Publication of JP2004325134A publication Critical patent/JP2004325134A/en
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Abstract

<P>PROBLEM TO BE SOLVED: To make detectable the load on a rolling bearing 3 in real time with high accuracy even when a variation is generated in characteristics of a detected part of an encoder 30a due to a manufacturing error or the like. <P>SOLUTION: Information about the characteristics in each phase position of the detected part is previously stored in a controller. The applied load is found by using strength at that moment among output signals of respective sensors 24, 24 in operation, and information about the phase position corresponding to that moment among the information. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The rotation support device with a state detection device according to the present invention rotates a rotating member such as a main shaft of a machine tool or a wheel (or an axle) of an automobile with respect to a fixed portion such as a knuckle constituting a housing or a suspension device. It is freely supported and is used for detecting the rotation speed and the applied load of the rotating member.
[0002]
[Prior art]
For example, in the case of a machine tool, it is important to detect the rotation speed and the applied load of the main spindle in order to perform operation control for improving machining accuracy. In the case of an automobile, it is important to detect the rotational speed and load of wheels (or an axle) in order to control the running stability and confirm the total weight of the vehicle. Conventionally, in such a case, the rotation speed and the applied load of the rotating member such as the main shaft and the wheels are generally detected by separate detection devices. However, if such separate detection devices are provided, it is difficult to reduce the size and cost of the entire mechanical device to which these detection devices are assembled.
[0003]
Therefore, in order to solve such inconvenience, Patent Document 1 discloses a rotation support device with a state detection device in which the rotation speed and the applied load can be detected by one detection device. 12 to 15 show a first example of a rotation support device with a state detection device described in Patent Document 1. A rotating shaft 1 such as a main shaft or an axle is rotatably supported by a rolling bearing 3 inside a fixed and non-rotating housing 2. That is, the outer ring 4, which is a stationary wheel, constituting the rolling bearing 3 has the outer ring raceway 5 on the inner peripheral surface, and is internally fixed to the inner peripheral surface of the housing 2 by interference fit. The inner ring 6, which is a rotating ring, has an inner raceway 7 on the outer peripheral surface, and a step 9 provided on the outer peripheral surface of the rotating shaft 1 at an intermediate portion of the rotating shaft 1 and externally fitted to the rotating shaft 1. It is externally fitted and fixed in a state where positioning in the axial direction is achieved by the fixing ring 10. A plurality of rolling elements 8 are provided between the outer raceway 5 and the inner raceway 7 so as to freely roll, whereby the rotary shaft 1 is rotatably supported inside the housing 2. .
[0004]
In the illustrated example, the outer race 4 is internally fixed to the housing 2 by interference fitting. However, instead of this, a flange is formed on the outer peripheral surface of the outer race 4 and the flange and the housing It is also possible to adopt a structure in which a part of the second member 2 is fixedly connected with bolts. In the illustrated example, balls are used as the rolling elements 8 and 8. However, in the case of a rolling bearing that supports a large load in the radial direction, rollers may be used as the rolling elements. Further, in the case of a rolling bearing that supports a large load in both the radial and thrust directions, tapered rollers may be used as each rolling element.
[0005]
In addition, combined sealing rings 11 are provided at both ends of the space in which the rolling elements 8 are installed, respectively, to seal both the openings. Each of these combined seal rings 11 includes an outer diameter side seal ring 12 and an inner diameter side seal ring 13. The core metal 14 constituting the outer diameter side seal ring 12 is disposed on the inner peripheral surface of the end of the outer ring 4, and the core metal 15 constituting the inner diameter seal ring 13 is disposed on the outer peripheral surface of the end of the inner ring 6. , Respectively, are fitted and fixed by interference fit. At the same time, the distal edges of the elastic members 16 and 17 forming the outer diameter side and the inner diameter side seal rings 12 and 13 are attached to the inner surfaces of the core metals 15 and 14 forming the mating seal rings 13 and 12, respectively. Sliding contact is made over the entire circumference.
[0006]
An encoder 18 is fixedly supported on the outer side surface (the right side surface in FIGS. 12 to 13) of the core metal 15 of the inner diameter side seal ring 13 constituting one of the combined seal rings 12 (right side in FIG. 12). are doing. The whole of the encoder 18 is formed in a ring shape by a magnetic metal plate such as a steel plate. Then, a plurality of slit-shaped through holes 19, 19, each having a radially long shape, are formed radially at an intermediate portion in the radial direction and at equal intervals in the circumferential direction. The magnetic characteristics of the intermediate portion in the diameter direction of the encoder 18 are changed alternately and at equal intervals in the circumferential direction. In order to change the magnetic characteristics of the encoder 18 in this manner, the encoder 18 may be formed with a notch opening at one of the diametrical ends instead of the through holes 19. . The encoder 18 as described above is fixed to the outer surface of the annular portion constituting the metal core 15 by bonding, spot welding, or the like.
[0007]
A support ring 21 for supporting sensors 24, 24 described below is externally fitted and fixed to a small-diameter stepped portion 20 provided at one end (the right end in FIGS. 12 and 13) of the outer race 4. The support ring 21 is formed by bending a metal plate such as a steel plate to form an entire ring having an L-shaped cross section, and includes a cylindrical portion 22 and one end portion of the cylindrical portion 22 (see FIGS. 12 to 13). (Right end portion) and an inward flange-shaped annular portion 23 bent radially inward at a right angle in the radial direction. The other end of the cylindrical portion 22 (the left end in FIGS. 12 and 13) is externally fitted to the small-diameter step portion 19 by tight fitting so that the support ring 21 is supported on one end of the outer ring 4. It is fixed.
[0008]
The support ring 21 supports four sensors 24, 24 (not shown in FIGS. 12 to 13; see FIGS. 14 to 15). These sensors 24, 24 are held at equal intervals in the circumferential direction on the inner diameter side of the cylindrical portion 22 constituting the support ring 21 in a state of being embedded in a synthetic resin 25 functioning as a holder. That is, the respective sensors 24, 24 are arranged on the circumference centered on the center axis of the support ring 21 (the center axis of the outer ring 4) with the phases in the circumferential direction shifted by 90 degrees from each other. I have. Then, in this state, the detection units of the sensors 24, 24 are placed axially (FIGS. 12 to 13) at the diametrically intermediate portion of the outer surface (the right side surface in FIGS. 13 (in the left-right direction) via a minute gap (for example, 0.5 to 1 mm or less). The size of each part is regulated so that the size of the minute gap becomes equal between the sensors 24 when the load applied to the rotating shaft 1 is zero.
[0009]
Also, as each of the sensors 24, 24, an active sensor (not shown) including a permanent magnet and a detecting element such as a Hall IC or a magnetoresistive element, or as shown in, for example, FIGS. Such a passive sensor including a permanent magnet 26, a stator 27 made of a magnetic material, and a coil 28 wound around the stator 27 is used. However, the structure of the sensors used is the same for each of the sensors 24, 24 so that the same output change can be obtained for the same displacement. In the case where the passive sensors are used as the sensors 24, 24, the structure shown in FIG. 14A is not used to arrange the stator 27 in the axial direction of the outer ring 4 as shown in FIG. It is preferable to adopt a structure in which the stator 27 is arranged in the circumferential direction of the outer race 4 as shown in FIG. The reason for this is that the dimensions of the sensors 24, 24 in the axial direction of the outer ring 4 are reduced, and the size of the support ring 21 supporting the sensors 24, 24 in the axial direction (the left-right direction in FIGS. 12 to 13) is reduced. In order to achieve However, if there is room in the installation space, the structure shown in FIG. A harness 29 for extracting signals from the sensors 24, 24 is drawn out from the outer side surface (the right side surface in FIGS. 12 and 13) of the support ring 21.
[0010]
The operation of the rotation support device with the state detection device configured as described above is as follows. First, the operation when the rotation speed of the rotation shaft 1 is detected will be described. When the encoder 18 supported by the inner ring 6 rotates with the rotation of the rotating shaft 1, the vicinity of the detection unit of each of the sensors 24, 24 is changed to through holes 21, 21 provided in the encoder 18, The pillars existing between the holes 21 and 21 pass alternately. As a result, the output (voltage value or resistance value) of each of the sensors 24, 24 changes. The frequency at which this output changes is proportional to the rotation speed of the rotating shaft 1. Therefore, if the output of at least one of the sensors 24, 24 is sent to a controller provided on a machine tool or an automobile including the rotating shaft 1, the rotational speed of the rotating shaft 1 is increased. Can be calculated.
[0011]
Next, the operation when the load applied to the rotating shaft 1 is detected will be described with reference to FIG. The load applied to the rotating shaft 1 is detected as a load applied to the rolling bearing 3 that rotatably supports the rotating shaft 1 (relative displacement between the outer ring 4 and the inner ring 6 based on the load). FIG. 15 schematically shows the positional relationship between the encoder 18 and each of the sensors 24, 24. In FIG. 15, a two-dot chain line a indicates the arrangement surface of the detection target portion of the encoder 18 in a state where no load is applied to the rotating shaft 1 (no-load operation state of the rolling bearing 3). Indicates the arrangement surface of the detected portion in a state in which a load is applied to the rotating shaft 1 and the outer ring 4 and the inner ring 6 are relatively displaced (the load operation state of the rolling bearing 3). An arrangement surface of the detection unit of each of the sensors 24 and 24 is indicated by an alternate long and short dash line d, which indicates a central axis of a circumference on which each of the sensors 24 and 24 is arranged.
[0012]
When the rolling bearing 3 shifts from the no-load operation state to the load operation state, the outer ring 4 and the inner ring 6 are relatively displaced. As a result, the arrangement surface of the detected portion of the encoder 18 is changed to the position shown in FIG. Is displaced from the state shown by the two-dot chain line a to the state shown by the solid line b. Then, the displacement amount in the radial direction (vertical direction in FIG. 15) of the arrangement surface of the detected portion at this time is represented by δ. r , The displacement amount in the axial direction (the left-right direction in the left half of FIG. 15) a , The inclination angle with respect to an imaginary plane orthogonal to the central axis (dashed line) d is θ. In this case, the detection unit S of each of the sensors 24 before and after the relative displacement. 1 ~ S 4 Of the distance in the axial direction between the encoder and the detected part of the encoder 18. S1 ~ Δ S4 Is represented by the following equations (1) to (4) due to geometric relationships.
In the above equations (1) to (4), r is the detection unit S of each of the sensors 24, 24. 1 ~ S 4 Is the radius of the circumference (pitch circle) where φ is located, the plane including the two-dot chain line a and the solid line b, the center axis d, and the detection unit S of the first sensor 26 of the sensors 24, 24. 1 Respectively represent angles with respect to the plane including.
[0013]
On the other hand, the values on the left side of the expressions (1) to (4), that is, the detection units S of the sensors 24 before and after the relative displacement. 1 ~ S 4 Of the distance in the axial direction between the encoder and the detected part of the encoder 18. S1 ~ Δ S4 Can be detected by the sensors 24, 24. That is, the detection unit S of each of these sensors 24, 24 1 ~ S 4 There is a fixed distance between the distance in the axial direction between the sensor and the detected part of the encoder 18 (and in the case of a passive sensor, the rotational speed of the encoder 18) and the output intensity of each of the sensors 24, 24. There is a relationship. Therefore, if this relationship is used, the relative intensities of the respective sensors 24, 24 before the relative displacement and after the relative displacement (and the rotational speed of the encoder 18 if necessary) are used to determine the relative displacement. The detection unit S of each of the sensors 24 before and after the relative displacement. 1 ~ S 4 The distance in the axial direction between the encoder and the detected portion of the encoder 18 can be obtained. Further, from the difference between the distance before and after the relative displacement obtained in this way, the above-mentioned change amount δ S1 ~ Δ S4 Can be requested. In order to cause the controller to perform such calculations, the controller previously stores the above relationship and the output intensity of each sensor 24 before the relative displacement (and rotation of the encoder 18 if necessary). (Speed). The two types of information and the output intensity of each of the sensors 24 and 24 after the relative displacement, which is another information different from the two types of information (and the rotation speed of the encoder 18 if necessary). Thus, as described above, each change amount δ S1 ~ Δ S4 Is required.
[0014]
Therefore, each change amount δ obtained as described above S1 ~ Δ S4 Is substituted into the left side of the above equations (1) to (4), and the above equations (1) to (4) are solved as simultaneous equations by the controller, so that the sensors 24 and 24 are arranged. Four values δ that determine the relative displacement between the center axis of the circumference and the center axis of the encoder 18 r , Δ a , Θ, and φ can be obtained. By the way, the central axis of the circumference on which the sensors 24 are arranged coincides with the central axis of the outer ring 4, and the central axis of the encoder 18 coincides with the central axis of the inner ring 6. Therefore, the above four values δ r , Δ a , Θ, and φ are values that determine the relative displacement between the outer ring 4 and the inner ring 6.
[0015]
Once the relative displacement between the center axis of the inner ring 6 and the center axis of the outer ring 4 is determined as described above, the controller then informs the controller of the relative displacement and the known rigidity of the rolling bearing 3. , The load applied to the rolling bearing 3 is calculated. The operation of a machine tool or an automobile having the rotating shaft 1 is controlled using the load.
[0016]
In the case where the first example of the conventional structure described above is implemented, the four sensors 24, 24 are not necessarily placed on the circumference having the center axis of the support ring 21 (the center axis of the outer ring 4) as its center axis. There is no need to place them at intervals. Further, when the machine tool or the like is operated, the direction in which the center axis of the inner ring 6 is inclined with respect to the center axis of the outer ring 4 (the direction of the load applied to the rotating shaft 1) is known in advance (the relative displacement is determined). Four values δ r , Δ a , Θ, φ, when the angle φ is known in advance), it is sufficient to provide a total of three sensors 24, 24. However, in this case, the detection unit S of the first sensor 26 1 At the position of φ = 0. The sensors 24, 24 to be used may be passive sensors as described above. However, the use of an active sensor in which the intensity of the output signal does not change due to the rotation speed of the encoder 18 facilitates signal processing. Is advantageous.
[0017]
Next, FIGS. 16 and 17 show a second example of the conventional structure, which is also described in Patent Document 1. FIG. Under normal load conditions during operation of a machine tool or the like, the phases of the radial load and the moment load applied to the rotating shaft 1 in the circumferential direction coincide with each other. For this reason, in the first example of the conventional structure described above, the radial displacement amount δ of the encoder 18 in the circumferential direction around the center axis d. r And the phase of the surface including the inclination angle θ are also coincident with each other, and the relative displacement is detected. However, when a special load condition is given during the operation of the machine tool or the like or when the vehicle turns sharply, the phase in the circumferential direction of the radial load and the moment load applied to the rotating shaft 1 is It may not match each other. In such a case, the radial displacement amount δ r And the phase of the plane including the inclination angle θ do not coincide with each other. Therefore, in the case of the second example of the conventional structure, the radial displacement amount δ r And the phase of the plane including the tilt angle θ can be separately detected.
[0018]
In the case of the second example of such a conventional structure, the first encoder 30 and the second encoder 31 are supported and fixed to the core metal 15a of the inner diameter side seal ring 13a constituting the combination seal ring 11a. That is, the cored bar 15a is formed by bending a metal plate such as a steel plate to form an entire ring having a crank-shaped cross section, and includes a large-diameter cylindrical portion 32, a small-diameter cylindrical portion 33, and both of these cylindrical portions. And a ring portion 34 that connects the edges of the portions 32 and 33 to each other. The small-diameter cylindrical portion 33 is fixedly fitted to the end of the inner ring 6 and the large-diameter cylindrical portion 32 is fitted to the inner ring 6 so as to project from the end face (the right end face in FIG. 16).
[0019]
The first encoder 30 is formed in a ring shape by a permanent magnet such as a rubber magnet in which powder of a ferromagnetic material such as ferrite is mixed into rubber, and is formed in an axial direction (the left-right direction in FIG. 16). It is magnetized. The directions of magnetization are changed alternately and at equal intervals in the circumferential direction. Therefore, S poles and N poles are alternately arranged at equal intervals on the outer side surface (the right side surface in FIG. 16) of the first encoder 30 which is the detection target. The second encoder 31 is also formed in a cylindrical shape entirely by a permanent magnet such as a rubber magnet in which powder of a ferromagnetic material is mixed in rubber, and is magnetized in a radial direction. The direction of magnetization is changed alternately at regular intervals in the circumferential direction. Therefore, S poles and N poles are alternately arranged at equal intervals on the inner peripheral surface of the second encoder 31 which is the detection target. Then, the first encoder 30 is baked on one surface (the right surface in FIG. 16) of the annular portion 34 constituting the cored bar 15a, and the second encoder 31 is baked on the inner peripheral surface of the large-diameter cylindrical portion 32, respectively. It is attached and fixed by adhesion or the like.
[0020]
On the other hand, a part of the synthetic resin 25a, which is a holder and embeds and supports the plurality of sensors 24, 24a (omitted in FIG. 16, see FIG. 17), is made to enter the inner diameter side of the large-diameter cylindrical portion 32. The sensors 24 and 24a are embedded in and supported by a part of the synthetic resin 25a that has entered the inner diameter side of the large-diameter cylindrical portion 32 in this manner. Further, in the case of the second example of this conventional structure, a total of six sensors 24 and 24a are provided, and the center axis of the support ring 21 (the center axis of the outer ring 4) that supports each of the sensors 24 and 24a is set as the sensor. They are arranged at equal intervals on the circumference as the central axis. That is, the sensors 24 and 24a are arranged so that their phases in the circumferential direction are shifted by 60 degrees. Also, in this state, three of the six sensors 24, 24a are detected by the detecting units S of the sensors 24, 24. A1 ~ S A3 Are opposed to the detected portion of the first encoder 30 via a minute gap in the axial direction (the left-right direction in FIG. 16). The remaining three sensors 24a, 24a of the above-mentioned six sensors 24, 24a are the detection units S of the sensors 24a, 24a. R1 ~ S R3 Are opposed to the detected portion of the second encoder 31 via a minute gap in the radial direction. The sensors 24, 24 facing the first encoder 30 and the sensors 24a, 24a facing the second encoder 31 are alternately arranged in the circumferential direction in which the sensors 24, 24a are arranged. I have.
[0021]
Next, with reference to FIG. 17, the operation when the relative displacement between the outer ring 4 and the inner ring 6 is detected by the rotation support device with the state detection device of the second example of the conventional structure having the above-described structure will be described. I will explain it. When the rolling bearing 3 shifts from the no-load operation state to the load operation state, the outer ring 4 and the inner ring 6 are relatively displaced. As a result, the first and second encoders 30 and 31 are moved to the positions shown in FIG. It is assumed that the state is changed from the state shown by the two-dot chain line a to the state shown by the solid line b. The displacement amount of the first and second encoders 30 and 31 in the radial direction (up and down direction in FIG. 17) at this time is represented by δ. r The displacement amount in the axial direction (the left-right direction in the left half of FIG. 17) is represented by δ a The angle of inclination with respect to an imaginary plane orthogonal to the central axis (dashed line) d is θ. As described above, the radial displacement amount δ in the circumferential direction about the center axis d. r And the phase of the plane including the inclination angle θ do not always coincide with each other (however, in the illustrated example, they are coincident for convenience).
[0022]
In this case, the detection units S of the sensors 24 before and after the relative displacement between the outer ring 4 and the inner ring 6 and after the relative displacement. A1 ~ S A3 Of the distance in the axial direction between the first encoder 30 and the detected part of the first encoder 30 SA1 ~ Δ SA3 Is represented by the following equations (5) to (7) due to geometrical relationships.
In the expressions (5) to (7), r is the detection unit S of each of the sensors 24, 24. A1 ~ S A3 And a detection unit S of each of the sensors 24a, 24a to be described later. R1 ~ S R3 Is the radius of the circumference (pitch circle) where φ is located, φ is the plane including the inclination angle θ, the center axis d and the detection unit S of the first sensor 26 of the sensors 24, 24. A1 Respectively represent angles with respect to the plane including.
[0023]
Further, in the above equations (5) to (7), δ, each of which is a minute amount, r And tanθ, that is, δ r Tan θ is a high-order minute amount and can be ignored. Therefore, the above equations (5) to (7) can be rewritten as the following equations (8) to (10).
[0024]
Also, the detection unit S of each of the sensors 24a, 24a R1 ~ S R3 And the amount of change δ in the radial distance between the detected portion of the second encoder 31 and SR1 ~ Δ SR3 Is represented by the following equations (11) to (13) due to geometric relationships.
In the expressions (11) to (13), α is the radial displacement δ in the circumferential direction about the center axis d. r And the detection part S of the first sensor 24a of the center axis d and the sensors 24a, 24a. R1 Is shown between the plane and the plane including.
[0025]
The values on the left side of the equations (8) to (10) and the equations (11) to (13), that is, the respective detection units S between before the relative displacement and after the relative displacement. A1 ~ S A3 Of the distance in the axial direction between the first encoder 30 and the detected part of the first encoder 30 SA1 ~ Δ SA3 , And each of the detection units S R1 ~ S R3 And the change amount δ in the radial direction between the detected portion of the second encoder 31 and the detected portion of the second encoder 31. SR1 ~ Δ SR3 Is detectable by the sensors 24 and 24a as in the case of the first example of the conventional structure described above. Therefore, also in the case of the second example of the conventional structure, the above-mentioned sensors (8) to (10) and (11) to (13) can be solved by the controller as simultaneous equations, so that the sensors 24, 24 can be used. Five values δ that determine the relative displacement between the central axis of the circumference to be arranged and the central axes of the first and second encoders 30 and 31, that is, the relative displacement between the outer ring 4 and the inner ring 6. r , Δ a , Θ, φ, α can be detected. Note that δ r When each value of α and α is obtained from the simultaneous equations composed of the above equations (11) to (13), only one extra equation is required. That is, in the case of the second example of the conventional structure, it is sufficient to provide two sensors 24a, 24a facing the second encoder 31. However, the above δ r In order to improve the detection accuracy of each value of α and α, it is preferable to provide three sensors 24a, 24a as shown in the example of FIG. The other configuration, the operation when detecting the rotation speed, and the like are the same as those of the above-described first example of the conventional structure.
[0026]
[Patent Document 1]
JP-A-11-218542
[0027]
[Problems to be solved by the invention]
In order to appropriately control the operation of a machine tool, an automobile, or the like, it is important to detect the load applied to the rolling bearing 3 in real time and to ensure sufficient detection accuracy of the load. However, in the case of the above-described conventional structure, if the characteristics of the detected portion of the encoder 18 (30, 31) do not change with a uniform size in the circumferential direction based on a manufacturing error or an assembly error of each member. In some cases, it may be difficult to ensure sufficient accuracy in detecting the load. Hereinafter, this point will be described.
[0028]
As described above, in the case of the conventional structure described in Patent Document 1, in order to detect the load applied to the rolling bearing 3, before and after the relative displacement between the outer ring 4 and the inner ring 6 constituting the rolling bearing 3, The amount of change δ in the distance between each detecting part and the detected part in S1 ~ Δ S4SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 ). And each of these variations δ S1 ~ Δ S4SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 In order to obtain (2), two types of information stored in the controller in advance are used. As described above, the two types of information are, when one of them is the distance between each of the detecting units and the to-be-detected unit divided by the passive type sensor, the rotational speed of the encoder 18 (30, 31). And the intensity of the output signal of each sensor 24 (24a), and the other is the intensity of the output signal of each sensor 24 (24a) in a no-load operation state. In addition, each of the change amounts δ S1 ~ Δ S4SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 ) Is used together with the above two types of information, and as another type of information other than the two types of information, the intensity of the output signal of each of the sensors 24 (24a) in the load operation state is used. I do. As described above, each of the above-mentioned variations δ S1 ~ Δ S4SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 ) Is related to the intensity of the output signal of each of the sensors 24 (24a).
[0029]
By the way, the intensity of the output signal of each of the sensors 24 (24a) (peak value or integral value of the waveform, etc.) is constant at the distance between each of the detecting sections and the detected section (further, the rotational speed). Is not always uniform at each phase of the output signal. That is, when the distance (and the rotation speed) is constant, and when the characteristic of the detected portion of the encoder 18 (30, 31) changes in a uniform size in the circumferential direction, As shown in FIG. 18A, the intensity of the output signal becomes uniform at each phase of the output signal. On the other hand, if the characteristics of the detected portion do not change in a uniform size in the circumferential direction based on a manufacturing error or the like. For example, the transparent portion formed on the detected portion of the encoder 18 made of a magnetic metal plate. When the shape and size of the holes 19, 19 or the notches are different for each of the through holes 19, 19 or each notch, or when the magnetized magnets provided in the detected parts of the permanent magnet encoders 30, 31 are used. In the case where the magnetization intensity of the regions (S-pole or N-pole) is different for each of these magnetization regions, the intensity of the output signal is increased as shown in FIG. It becomes non-uniform at each phase of the output signal.
[0030]
Among them, when the intensity of the output signal is uniform at each phase of the output signal (in the case of FIG. 18A), the uniform intensity is defined as the intensity of the output signal. There is no particular problem because it can be determined. On the other hand, when the intensity of the output signal is non-uniform at each phase of the output signal (in the case of FIG. 18B), the intensity of each phase is different. The problem is how to determine the strength of the sphere.
[0031]
In such a case, for example, as the strength of the output signal for obtaining two types of information to be stored in the controller in advance, the strength of the output signal shown in FIG. Assume that the strength of the P portion (or Q portion), which is a (small) phase portion, is adopted. However, if the intensity of the output signal is determined in this manner, it becomes impossible to sufficiently ensure the detection accuracy of the load applied to the rolling bearing 3. That is, when the load of the rolling bearing 3 is detected in real time as described above, regardless of the method of determining the intensity of the output signal when obtaining the two types of information as described above, As the strength of the output signal in the load operation state, which is information, the strength of the phase portion corresponding to the current time (the moment) in the output signal shown in FIG. 18B is adopted. That is, the phase position for determining the intensity differs depending on the time of detection.
[0032]
Therefore, when the intensity of the largest P portion (or the smallest Q portion) is adopted as the intensity of the output signal when two types of information are obtained as described above, particularly, the intensity of the other types of information is relatively low. At a time (instantaneous time) at which the intensity of the small (or relatively large) phase portion is adopted, each of the change amounts δ S1 ~ Δ S4SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 ) Will greatly decrease the detection accuracy. As a result, the detection accuracy of the load applied to the rolling bearing 3 cannot be sufficiently secured. Of course, even if an intermediate intensity is adopted, the detection accuracy at the moment corresponding to the above-mentioned P portion or the Q portion deteriorates, and if the intensity of the P portion or the Q portion is adopted, it corresponds to the P portion or the Q portion. Except at the moment, the detection accuracy deteriorates.
Rolling bearing with a state detection device of the present invention, in view of the above-described circumstances, even if the characteristics of the detected portion of the encoder does not change in a uniform size in the circumferential direction based on manufacturing errors and assembly errors, The present invention has been invented so that detection of a load in real time can be accurately performed.
[0033]
[Means for Solving the Problems]
Each of the rolling bearings with a state detection device of the present invention includes a rolling bearing, an encoder, a plurality of sensors, and a controller, similarly to the above-described conventional structure.
Among these, the rolling bearing has a stationary raceway on the stationary peripheral surface, and has a stationary wheel that does not rotate during use, and a rotational raceway on the rotating peripheral surface opposite to the stationary peripheral surface. It comprises a rotating wheel that rotates, and a plurality of rolling elements provided so as to freely roll between the stationary-side track and the rotating-side track.
The encoder has a to-be-detected portion in which characteristics in the circumferential direction are alternately and equally changed, and is fixed to a part of the rotating wheel concentrically with the rotating wheel.
In addition, each of the sensors is supported by a portion that does not rotate during use in a state where the respective detecting portions are opposed to a plurality of circumferential positions of the detected portion. The detection unit changes the output signal in accordance with the change in the characteristic of the opposing portion, and also changes the intensity of the output signal in accordance with the distance between the detected portion and its own detection portion.
Further, the controller obtains a rotation speed of the rotating wheel with respect to the stationary wheel by performing a calculation based on an output signal of at least one of the sensors. Further, the controller is a controller which stores two types of information stored in advance in the controller, that is, the relationship between the distance between the detection section of each sensor and the detected section and the intensity of the output signal of each sensor. And the intensity of the output signal of each sensor in the no-load operation state of the rolling bearing, and the other two types of information, which are other types of information, in the load operation state of the rolling bearing. Utilizing the strength of the output signal of each sensor, the distance between the detection unit of each sensor and the detected part when the rolling bearing shifts from the no-load operation state to the load operation state. By calculating the amount of change in the distance and performing calculations based on the amount of change in each of the distances, the positional relationship between the stationary wheel and the rotating wheel in the no-load operation state is referred to as a reference in the load operation state. Relative displacement between these stationary and rotating wheels It is intended to determine the amount and direction.
[0034]
In particular, in the rotation support device with the state detection device according to claim 1, a plurality of information items, each of which is established for each phase position of the detected portion, as two types of information stored in the controller in advance. Prepare. Then, when calculating the amount of change in the distance between the detection unit of each of the sensors and the detected unit, the other type of information includes the output signal in the load operation state at the current time (the moment). In addition to using the intensity at the corresponding phase location, the two types of information that have the same phase as the other types of information are used.
[0035]
On the other hand, in the rotation support device with the state detection device according to the second aspect, the two types of information stored in advance in the controller are respectively the intensity of the output signal of each sensor and the intensity of this output signal. A device using an average value of the intensities of all the phase portions for at least one cycle is prepared. Then, when calculating the amount of change in the distance between the detection unit of each of the sensors and the detected unit, the other type of information includes the output signal in the load operation state at the current time (the moment). The two types of information based on the average value are used while using the intensity of the corresponding phase portion.
[0036]
[Action]
In the case of the rotation support device with the state detection device of the present invention configured as described above, when the characteristic of the detected portion of the encoder does not change with a uniform size in the circumferential direction based on a manufacturing error, an assembly error, or the like. However, the amount of change in the distance between the detection section of each sensor and the detected section of the encoder can be accurately detected in real time. For this reason, the load applied to the rolling bearing can be accurately detected in real time based on these amounts of change.
[0037]
BEST MODE FOR CARRYING OUT THE INVENTION
1 to 4 show a first example of an embodiment of the present invention corresponding to claim 1. The feature of the present embodiment is that when the load of the rolling bearing 3 is detected in real time, the detection accuracy of the load can be sufficiently ensured irrespective of the manufacturing error of the detected portion of the encoder 30a. On the point. For this purpose, specifically, the structure of the encoder 30a to be used, the number of sensors, the number of information related to the output signals of these sensors, and the processing method are devised. The configuration and operation of the other parts are the same as those of the first example of the conventional structure shown in FIGS. 12 to 15 described above. Hereinafter, the description will focus on the characteristic portions of this example.
[0038]
In the case of the present example, an encoder as shown in detail in FIG. 2 is used as an encoder 30a attached and fixed to the outer surface of the cored bar 15 of the inner diameter side seal ring 13 constituting the combined seal ring 11. The encoder 30a is formed as a whole in a ring shape by a permanent magnet such as a rubber magnet in which powder of ferromagnetic material such as ferrite is mixed into rubber, and is formed in an axial direction (horizontal direction in FIG. 1 and vertical direction in FIG. 2). ) Is magnetized. In the case of the present example, the magnetization patterns in the circumferential direction of the encoder 30a are different between the radial inner half part and the radial outer half part of the encoder 30a. That is, in the radial inner half of the encoder 30a, the direction of magnetization in the axial direction is changed alternately and at equal intervals in the circumferential direction, so that one side of the radial inner half (FIG. On the right side (upper side in FIG. 2), S poles and N poles are alternately arranged at regular intervals in the circumferential direction. On the other hand, in the radial outer half of the encoder 30a, the direction of magnetization in the axial direction is reversed only at one place in the circumferential direction with respect to the other places, so that the radial outer half is An N pole is arranged at one location in the circumferential direction on one side, and an S pole is arranged at the remaining location. Then, one side surface of the encoder 30a, in which the S pole and the N pole are arranged as described above, is used as a detected portion. Such an encoder 30a is attached and fixed to the outer surface of the cored bar 15 by baking, bonding, or the like.
[0039]
In the case of the present example, the detection units of the four sensors 24, 24 (see FIG. 15) embedded and supported at equal circumferential positions of the synthetic resin 25, which is a holder, are respectively the detection target units of the encoder 30a. Are opposed to each other through a minute gap in the axial direction (the left-right direction in FIG. 1). Also in the case of this example, the size of each part is regulated so that the size of the minute gap becomes equal to each other between the sensors 24 when the load applied to the rolling bearing 3 is zero. In the case of this example, the same type of structure as each of the sensors 24, 24 is provided in a part of the synthetic resin 25 in the circumferential direction, in a radially outer part than a part in which the four sensors 24, 24 are arranged. Is embedded and supported. The detection unit of this one sensor 24b is opposed to the radially outer half of the detected portion of the encoder 30a via a minute axial gap.
[0040]
In this state, when the encoder 30a rotates with respect to each of the sensors 24 and 24b, four of the sensors 24 and 24 rotate the diameter of the detected portion as shown in the lower half of FIG. A sinusoidal output signal corresponding to the change in the characteristic of the inner half part in the direction is obtained. On the other hand, an output signal of one pulse is obtained for each rotation as shown in the upper half of FIG. In the case of this example, the output signal of this one sensor 24b is used as a trigger for specifying the phase position of the output signal of the four sensors 24, 24.
[0041]
In the case of the rolling bearing with the state detecting device of the present embodiment configured as described above, similarly to the case of the above-described first example of the conventional structure, two types of information stored in the controller in advance and the load of the rolling bearing 3 are set. Utilizing another type of information other than the above two types of information obtained during operation, the above-mentioned 4 types before and after the relative displacement between the outer ring 4 and the inner ring 6 constituting the rolling bearing 3. Change amount δ between the detection units of the sensors 24, 24 and the detection target unit of the encoder 30a. S1 ~ Δ S4 Ask for. And each of these variations δ S1 ~ Δ S4 , The relative displacement between the inner race 6 and the outer race 4 is determined, and the load applied to the rolling bearing 3 is further determined. The two types of information stored in advance in the controller are, as shown in FIG. 4, one of the distances between the detection units of the four sensors 24 and 24 and the detection target. In the case of a passive type sensor, the relationship between the rotational speed of the encoder 30a) and the intensity of the output signal of each of the sensors 24, 24 is another. The intensity of the output signal of each sensor 24, 24. On the other hand, the other type of information is the strength of the output signal of each of the sensors 24, 24 in the load operation state of the rolling bearing 3.
[0042]
In particular, in the case of this example, in order to detect the load applied to the rolling bearing 3 in real time, and to ensure sufficient detection accuracy of the load, two types of data stored in the controller in advance are used. A plurality of pieces of information (the same number as the number of periods during one rotation) that are established for each phase location (each S-pole and N-pole in each magnetized region) of the detected portion are prepared as the information. That is, each of the two types of information is related to the intensity of the output signal of each of the sensors 24, 24. Therefore, in order to obtain these two types of information, it is necessary to determine the intensity of the output signal of each of the sensors 24, 24. Therefore, in the case of this example, the intensity (peak value, integral value, etc. of the waveform) of each phase of the output signal of each of the sensors 24, 24, which corresponds to each phase of the detected part, These are adopted as the intensities of the output signals of the sensors 24, 24, respectively. Then, the above two types of information are obtained for each of the intensities of these phase portions, and these are stored in the controller in advance. The intensity of each phase portion of the output signal of each of the sensors 24, 24 is determined by, for example, using an electric motor or the like to rotate the encoder 30a supported on the inner ring 6 at a constant rotation speed (when the sensors 24, 24 are of an active type). In this case, the speed does not need to be constant), but can be obtained by performing at least one rotation. However, if the average value or the median value for each phase location is obtained by rotating a plurality of times, the intensity at each phase location can be obtained more accurately. In the case of the present example, in order to detect the load applied to the rolling bearing 3 in real time, the other types of information include, among the output signals of the sensors 24, 24 in the load operation state, the current signals. The intensity at the phase corresponding to the time (the moment) is used.
[0043]
In the case of this example, when the load of the rolling bearing 3 is detected in real time, the other type of information is used, and among the two types of information stored in advance in the controller, The above-mentioned other types of information and the phase of the output signal coincide with each other, so that each of the displacement amounts δ S1 ~ Δ S4 Ask for. At this time, the phase adjustment of the information is performed accurately by using the output signal of one sensor 24b as a trigger. Then, each of the change amounts δ S1 ~ Δ S4 , The relative displacement between the outer ring 4 and the inner ring 6 constituting the rolling bearing 3 is determined, and the load applied to the rolling bearing 3 is further determined.
[0044]
As described above, in the case of this example, each of the displacement amounts δ S1 ~ Δ S4 In order to obtain the above, the other types of information and the two types of information stored in advance in the controller are used for the same phase of the output signals of the sensors 24 and 24, respectively. For this reason, the characteristics of the detected portion of the encoder 30a do not change uniformly in the circumferential direction based on a manufacturing error, an assembly error, or the like, and the intensity of the output signal of each of the sensors 24, 24 is reduced as shown in FIG. As shown in (B), even when the phase becomes non-uniform at each phase, each of the displacement amounts δ S1 ~ Δ S4 Detection accuracy can be improved. As a result, the detection accuracy of the rolling bearing 3 can be sufficiently ensured.
[0045]
Next, FIGS. 5 and 6 show a second example of the embodiment of the present invention, which also corresponds to claim 1. The feature of this example is that, when the load of the rolling bearing 3 is detected in real time, the detection accuracy of the load is detected regardless of the manufacturing error of the detected part of each of the first and second encoders 30a and 31. The point is that it was able to secure enough. For this purpose, specifically, the structure of the first encoder 30a to be used, the number of sensors, the number of information related to the output signals of these sensors, and the processing method are devised. Since the configuration and operation of the other parts are the same as those of the second example of the conventional structure shown in FIGS. 16 and 17 described above, the same reference numerals are given to the same parts, and the duplicate description is omitted or simplified. Hereinafter, the description will focus on the characteristic portions of this example.
[0046]
In the case of this example, among the first and second encoders 30a and 31 that are supported and fixed to the core metal 15a of the inner diameter side seal ring 13a that configures the combined seal ring 11a, the circular ring portion 34 that configures the core metal 15a. The above-described first encoder 30a shown in FIG. On the other hand, the second encoder 31 attached and fixed to the inner peripheral surface of the large-diameter cylindrical portion 32 constituting the cored bar 15a is the same as that of the second example of the above-described conventional structure as shown in FIG. , That is, those in which S poles and N poles are alternately arranged at equal intervals in the circumferential direction on the inner peripheral surface that is the portion to be detected.
[0047]
In the case of the present example, three of the six sensors 24, 24a embedded and supported on the synthetic resin 25a as a holder at circumferentially equally spaced positions as shown in FIG. Each of the detecting portions is opposed to the radially inner half of the detected portion of the first encoder 30a via a minute gap in the axial direction. On the other hand, the detection units of the remaining three sensors 24a are respectively opposed to the detection units of the second encoder 31 via a minute gap in the radial direction. Also in the case of this example, the dimensions of the respective parts are set such that the size of each of the minute gaps is equal to each other between the sensors 24 and each of the sensors 24a when the load applied to the rolling bearing 3 is zero. Regulating. In the case of the present example, a part of the synthetic resin 25a in a circumferential direction, a part radially outside of the part where the three sensors 24 are arranged, is provided with the same type of the sensors 24 and the sensors 24a. One sensor 24b having a structure is embedded and supported. The detection unit of this one sensor 24b is opposed to the outer half in the radial direction of the detected portion of the first encoder 30a via a minute gap in the axial direction.
[0048]
In this state, when the first and second encoders 30a, 31 rotate with respect to the sensors 24, 24a, 24b, the lower half of FIG. As a result, a sinusoidal output signal corresponding to the change in the characteristic of each of the detected parts is obtained. On the other hand, an output signal of one pulse is obtained for each rotation as shown in the upper half of FIG. In the case of this example, the output signal of the single sensor 24b is used as a trigger for specifying the phase position of the output signal of the six sensors 24, 24a.
[0049]
Also in the case of the rolling bearing with the state detecting device of the present embodiment configured as described above, two kinds of information (for each of the first and second encoders 30a and 31) previously stored in the controller and the rolling bearing 3 Using the other types of information (for each of the first and second encoders 30a and 31) obtained at the time of the load operation, before and after relative displacement between the outer ring 4 and the inner ring 6 constituting the rolling bearing 3 Detection unit S of the three sensors 24, 24 A1 ~ S A3 Of the distance in the axial direction between the first encoder 30a and the detected part of the first encoder 30a. SA1 ~ Δ SA3 , And the detection units S of the three sensors 24a, 24a R1 ~ S R3 And the change amount δ in the radial direction between the detected portion of the second encoder 31 and the detected portion of the second encoder 31. SR1 ~ Δ SR3 Ask for. And each of these variations δ S1 ~ Δ S4 , The relative displacement between the inner race 6 and the outer race 4 is determined, and the load applied to the rolling bearing 3 is further determined.
[0050]
The two types of information (for each of the first and second encoders 30a and 31) stored in the controller in advance include one of the three sensors 24 or 24 as shown in FIG. The distance between the detection unit of the three sensors 24a and the detection target unit of the first encoder 30a or the second encoder 31 (in the case of a passive sensor, the first and second encoders 30a, 31 And the intensity of the output signal of the three sensors 24 or the three sensors 24a. The other is the intensity of the output signal of each of the sensors 24 and 24a when the rolling bearing 3 is in a no-load operation state. On the other hand, another type of information different from the above two types of information is the intensity of the output signal of each of the sensors 24 and 24a in the load operating state of the rolling bearing 3.
[0051]
In particular, also in the case of the present example, the load of the rolling bearing 3 is detected in real time, and the controller is stored in advance in order to ensure sufficient detection accuracy of the load (first, The two types of information (for each of the second encoders 30a and 31) are respectively established for each phase position (each magnetized region S pole and N pole) of the detected part of the first encoder 30a or the second encoder 31. (The same number as the number of cycles during one rotation). At the same time, in the case of this example, in order to be able to detect the load applied to the rolling bearing 3 in real time, the other types of information (for each of the first and second encoders 30a and 31) include the load operation state. Of the output signals of the sensors 24 and 24a, the intensity at the phase corresponding to the current time is used.
[0052]
In the case of this example, when the load of the rolling bearing 3 is detected in real time, the other types of information (for each of the first and second encoders 30a and 31) and the controller are previously stored in the controller. Of the two types of stored information (for each of the first and second encoders 30a and 31), the other types of information (for each of the first and second encoders 30a and 31) and the phase of the output signal, respectively. Are used, and each of the change amounts δ SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 Ask for. At this time, the phase adjustment of the information is performed accurately using the output signal of one sensor 24b as a trigger. Then, each of the change amounts δ S1 ~ Δ S4 , The relative displacement between the outer ring 4 and the inner ring 6 constituting the rolling bearing 3 is determined, and the load applied to the rolling bearing 3 is further determined.
[0053]
As described above, also in the case of the present example, each of the above-mentioned change amounts δ SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 In order to obtain the above, other types of information (for each of the first and second encoders 30a and 31) and 2 (for each of the first and second encoders 30a and 31) previously stored in the controller. As the type information, those relating to the same phase of the output signals of the sensors 24 and 24a are used. Therefore, the characteristics of the detected parts of the first and second encoders 30a and 31 do not change uniformly in the circumferential direction based on a manufacturing error, an assembly error, and the like, and the output signals of the sensors 24 and 24a do not change. 18B, even if the intensity becomes uneven at each phase, as shown in FIG. SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 Detection accuracy can be improved. As a result, the detection accuracy of the rolling bearing 3 can be sufficiently ensured.
[0054]
In the above-described second example, three sensors 24 each facing the radially inner half of the detected portion of the first encoder 30a and three sensors 24a each facing the detected portion of the second encoder 31 are provided. And However, when the present invention is implemented, the number of the sensors 24 and 24a may be four, for example. If the number is four, the detection accuracy can be improved as compared with the case where the number is three.
[0055]
In the above-described second example, a trigger (a signal of one pulse per rotation) used to specify the phase position of the output signal of each sensor 24, 24a is used for the structure of the detected part of the first encoder. It was generated by devising. However, when implementing the present invention, the trigger can be generated by devising the structure of the detected part of the second encoder. In this case, for example, an encoder as shown in FIG. 7 can be used as the second encoder 31a. This second encoder 31a arranges S poles and N poles alternately and at equal intervals in the circumferential direction on one half in the axial direction (the front half in FIG. 7) of the inner peripheral surface that is the part to be detected. are doing. On the other hand, in the other half of the inner peripheral surface in the axial direction (the rear half in FIG. 7), an N pole is arranged at one location in the circumferential direction, and an S pole is arranged at the remaining location. . When such a second encoder 31a is used, the sensor 24b for generating a trigger is opposed to the other half of the detected portion of the second encoder 31a in the axial direction via a minute gap in the radial direction. Let it. When such a second encoder 31a is used, the first encoder 30 is the same as the second example of the above-described conventional structure as shown in FIG. S poles and N poles are alternately arranged at equal intervals on the side surface in the circumferential direction.
[0056]
The above-mentioned trigger is generated by encoders 30 and 31 as shown in FIG. 6 or FIG. 8, that is, encoders 30 in which S poles and N poles are alternately arranged at equal intervals in the circumferential direction in the detected part. , 31, the magnetization strength of one of the poles is made sufficiently larger than the magnetization strength of the other pole (sufficiently larger than the variation of the magnetization strength caused due to a manufacturing error or the like). You can get. That is, as shown in FIG. 9, the output signal of the sensor opposed to the detected portion of such an encoder has a phase position corresponding to the pole having the increased magnetization strength, and has a higher intensity than the other phase portions. Obviously it will be larger (as different from non-uniformity due to manufacturing errors) Therefore, the portion where the strength is clearly increased can be used as a trigger. Such a trigger can also be obtained, for example, by changing the height of one tooth in the circumferential direction as shown in the upper center of the figure with a gear-shaped encoder 35 as shown in FIG. it can. When these encoders are used, it is not necessary to separately provide a trigger detection sensor, so that space and cost can be saved.
[0057]
Next, the invention described in claim 2 will be described. When the invention described in claim 2 is carried out, the two types of information stored in the controller in advance are respectively the intensity of the output signal of each sensor, and the total phase position for at least one cycle of this output signal Prepare the one using the average value of the intensities. That is, as described above, each of the two types of information is related to the intensity of the output signal of each of the sensors. Therefore, in order to obtain these two types of information, it is necessary to determine the intensity of the output signal of each sensor. Therefore, when the invention described in claim 2 is carried out, in order to obtain the above two types of information, the intensity of the output signal of each of the sensors is calculated as the intensity of each phase portion for at least one cycle of the output signal. Intensities (peak values, integrated values, etc.) are added to each other, and the added values are divided by the number of the above-described phase portions (the number of periods per rotation) to obtain an averaged value. Then, based on the intensity adopted in this way, the above two types of information are obtained and stored in the controller in advance. On the other hand, in order to be able to detect the load of the rolling bearing in real time, other types of information obtained during the load operation include the current time (the instant ) Is used.
[0058]
According to the second aspect of the present invention, when the load of the rolling bearing is detected in real time, the rolling bearing is configured by utilizing the other type of information and the two types of information. The amount of change δ in the distance between the detection unit of each sensor and the detection target unit of the encoder before and after the relative displacement between the inner ring and the outer ring. S1 ~ Δ S4SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 ). And each of these variations δ S1 ~ Δ S4SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 ), The relative displacement between the inner ring and the outer ring is determined, and the load applied to the rolling bearing is determined.
[0059]
As described above, in the case of the invention described in claim 2, the intensity of the output signal of each sensor when obtaining the two types of information is an average of the intensity of all the phase portions for at least one cycle of the output signal. Adopt the value. Therefore, the characteristics of the detected portion of the encoder do not change uniformly in the circumferential direction based on a manufacturing error, an assembly error, or the like, and the output signal of each of the above-described sensors becomes different from each other as shown in FIG. Even in the case of non-uniformity at each location, the applied load can be accurately detected in real time. That is, as described above, the intensity of the output signal of each sensor when obtaining the two types of information is the intensity of the largest P portion (or the smallest Q portion) of the output signals shown in FIG. When the intensity is adopted, the change amount δ at the moment when the intensity of the phase portion having relatively small intensity (or relatively large intensity) is adopted as the other type of information. S1 ~ Δ S4SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 ) Will greatly decrease the detection accuracy. On the other hand, as described above, when the average value of the intensities of all the phase portions for at least one cycle of the output signal is adopted as the intensity of the output signal of each sensor when the two types of information are obtained, Even at the moment when the intensity of a phase portion having a relatively small intensity (or a relatively large intensity) is adopted as the other type of information, each of the change amounts S1 ~ Δ S4SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 ) Can be prevented from significantly lowering the detection accuracy. Therefore, each of these variations δ S1 ~ Δ S4SA1 ~ Δ SA3 , Δ SR1 ~ Δ SR3 ), The load can be detected in real time while ensuring sufficient practical accuracy.
[0060]
When the present invention is implemented, when the rolling bearing rotates only in one direction, such as a rolling bearing for supporting a main shaft of a machine tool, two types of information stored in the controller in advance are: What is necessary is just to prepare what is related to this one-way rotation. On the other hand, when the rolling bearing rotates in both directions, such as a rolling bearing for supporting a wheel or an axle of an automobile, the above two types of information are prepared for each of these rotating directions. Is preferred. That is, in this case, of the two types of information prepared for each rotation direction, two types of information corresponding to the rotation direction during operation are used. Further, in order to be able to use such information corresponding to the rotation direction, it is necessary to detect the rotation direction during operation. In such a case, for example, by devising the arrangement phase of the plurality of sensors to be used in the circumferential direction, the mutual phase is different from 180 degrees as shown in FIG. 11 (for example, 90 degrees). It is sufficient to obtain two shifted output waveforms. That is, if such two output waveforms are obtained, the rotation direction can be detected by examining the direction in which the phases of these two output waveforms are shifted. When the phase of the arrangement of the sensors in the circumferential direction is devised as described above, in accordance with this, each of the equations (1) to (13), Correct the phase angle of the sensor.
[0061]
In each of the above-described embodiments, the structure in which the stationary wheel is the outer wheel and the rotating wheel is the inner wheel has been described. However, the present invention is also applicable to a structure in which the stationary wheel is the inner wheel and the rotating wheel is the outer wheel. is there.
[0062]
【The invention's effect】
Since the rotation support device with the state detection device of the present invention is configured and operates as described above, the characteristic of the detected portion of the encoder has a uniform size in the circumferential direction based on a manufacturing error or an assembly error. Even if it has not changed, it is possible to detect the applied load in real time with high accuracy. For this reason, operation control of a machine tool, an automobile, or the like can be appropriately performed, and reliability of the operation control can be improved.
[Brief description of the drawings]
FIG. 1 is a view similar to FIG. 13, showing a first example of an embodiment of the present invention;
FIG. 2 is a partial perspective view of a ring-shaped encoder for generating a trigger.
FIG. 3 is a diagram showing an output signal of a sensor.
FIG. 4 is a diagram illustrating a relationship between a distance between a detection unit and a detection target and an output intensity of a sensor.
FIG. 5 is a view similar to FIG. 16, showing a second example of the embodiment of the present invention.
FIG. 6 is a partial perspective view showing a cylindrical encoder when viewed from the inner diameter side.
FIG. 7 is a partial perspective view showing a cylindrical encoder for generating a trigger when viewed from the inner diameter side.
FIG. 8 is a partial perspective view of an encoder configured in a ring shape.
FIG. 9 is a diagram showing an output signal of a sensor.
FIG. 10 is a side view of an encoder configured as a gear.
FIG. 11 is a diagram showing a pair of output signals whose phases are shifted by 90 degrees.
FIG. 12 is a sectional view showing a first example of a conventional structure.
FIG. 13 is an enlarged view of a portion A in FIG. 12;
FIG. 14 is a schematic perspective view showing two examples of the structure of a passive sensor.
FIG. 15 is a schematic diagram showing a positional relationship between each sensor and an encoder before and after relative displacement.
FIG. 16 is a view similar to FIG. 13, showing a second example of the conventional structure.
FIG. 17 is a view similar to FIG. 15;
18A and 18B are diagrams showing output signals of a sensor, in which FIG. 18A shows a case where the characteristic of a detected portion of the encoder changes with a uniform magnitude in the circumferential direction, and FIG. The cases where the size does not change are shown.
[Explanation of symbols]
1 Rotary axis
2 Housing
3 Rolling bearing
4 Outer ring
5 Outer ring track
6 Inner ring
7 Inner ring track
8 rolling elements
9 steps
10 Fixing ring
11, 11a Combination seal ring
12 Outer diameter side seal ring
13, 13a Inner diameter side seal ring
14 core metal
15, 15a Core
16 Elastic material
17 Elastic material
18 Encoder
19 through hole
20 small diameter step
21 Support ring
22 cylindrical part
23 Circle part
24, 24a, 24b sensors
25, 25a synthetic resin
26 permanent magnet
27 Stator
28 coils
29 harness
30, 30a First encoder
31, 31a Second encoder
32 Large diameter cylinder
33 Small diameter cylinder
34 Circle part
35 Encoder

Claims (2)

  1. Including a rolling bearing, an encoder, a plurality of sensors, and a controller,
    Of these, the rolling bearing has a stationary raceway on the stationary peripheral surface, and has a stationary wheel that does not rotate during use, and a rotating raceway on the rotating peripheral surface opposite to the stationary peripheral surface. A rotating wheel that rotates, and a plurality of rolling elements provided rotatably between the stationary track and the rotating track,
    The encoder has an annular to-be-detected portion in which characteristics in the circumferential direction are alternately and equally changed, and is fixed to a part of the rotating wheel concentrically with the rotating wheel,
    Each of the sensors is supported by a portion that does not rotate during use in a state where the respective detecting portions are opposed to a plurality of circumferential positions of the detected portion, and the own detecting portion of the detected portions. Changes the output signal corresponding to the change in the characteristic of the opposing portion, and changes the intensity of the output signal corresponding to the distance between the detected portion and its own detection portion,
    The controller obtains a rotation speed of the rotating wheel with respect to the stationary wheel by performing a calculation based on an output signal of at least one of the sensors, and stores the rotation speed in advance in the controller. The relationship between the distance between the detection section of each sensor and the detected section, which is the two types of information, and the strength of the output signal of each sensor, and the rolling bearing in the no-load operation state. Utilizing the strength of the output signal of each sensor and the strength of the output signal of each sensor in a load operating state of the rolling bearing, which is another type of information different from the two types of information. When the rolling bearing shifts from the no-load operation state to the load operation state, the amount of change in the distance between the detection unit of each sensor and the detected part is determined, and the amount of change in each of these distances is determined. Perform operations based on Thus, based on the mutual positional relationship between the stationary wheel and the rotating wheel in the no-load operation state, the amount and direction of the relative displacement between the stationary wheel and the rotating wheel in the load operation state are determined. is there,
    In the rotation support device with the state detection device,
    As the two types of information stored in advance in the controller, a plurality of information that are established for each phase location of the detected part are prepared, and the distance between the detecting part of each sensor and the detected part is prepared. When determining the amount of change in the output signal in the load operating state, the intensity of the phase portion corresponding to the current time is used as the other type of information, and the other type of information is used as the two types of information. A rotation support device with a state detection device, characterized in that a rotation support device having a phase coincident with information is used.
  2. Including a rolling bearing, an encoder, a plurality of sensors, and a controller,
    Of these, the rolling bearing has a stationary raceway on the stationary peripheral surface, and has a stationary wheel that does not rotate during use, and a rotating raceway on the rotating peripheral surface opposite to the stationary peripheral surface. A rotating wheel that rotates, and a plurality of rolling elements provided rotatably between the stationary track and the rotating track,
    The encoder has an annular to-be-detected portion in which characteristics in the circumferential direction are alternately and equally changed, and is fixed to a part of the rotating wheel concentrically with the rotating wheel,
    Each of the sensors is supported by a portion that does not rotate during use in a state where the respective detecting portions are opposed to a plurality of circumferential positions of the detected portion, and the own detecting portion of the detected portions. Changes the output signal corresponding to the change in the characteristic of the opposing portion, and changes the intensity of the output signal corresponding to the distance between the detected portion and its own detection portion,
    The controller obtains a rotation speed of the rotating wheel with respect to the stationary wheel by performing a calculation based on an output signal of at least one of the sensors, and stores the rotation speed in advance in the controller. The relationship between the distance between the detection section of each sensor and the detected section, which is the two types of information, and the strength of the output signal of each sensor, and the rolling bearing in the no-load operation state. Utilizing the strength of the output signal of each sensor and the strength of the output signal of each sensor in a load operating state of the rolling bearing, which is another type of information different from the two types of information. When the rolling bearing shifts from the no-load operation state to the load operation state, the amount of change in the distance between the detection unit of each sensor and the detected part is determined, and the amount of change in each of these distances is determined. Perform operations based on Thus, based on the mutual positional relationship between the stationary wheel and the rotating wheel in the no-load operation state, the amount and direction of the relative displacement between the stationary wheel and the rotating wheel in the load operation state are determined. is there,
    In the rotation support device with the state detection device,
    As the two types of information stored in advance in the controller, those using the average value of the intensities of all the phase portions for at least one cycle of the output signal as the intensity of the output signal of each sensor are prepared. When calculating the amount of change in the distance between the detection unit of each sensor and the detected portion, the intensity of the phase portion corresponding to the current time in the output signal in the load operation state is used as the other type of information. And a rotation support device with a state detection device, wherein the two types of information are used.
JP2003117351A 2003-04-22 2003-04-22 Rotation support device with state detection device Pending JP2004325134A (en)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006226999A (en) * 2005-01-24 2006-08-31 Nsk Ltd Displacement measuring device and load measurement device for rolling bearing unit
JP2006275251A (en) * 2005-03-30 2006-10-12 Jtekt Corp Rolling bearing device with sensor
JP2007071641A (en) * 2005-09-06 2007-03-22 Nsk Ltd State quantity measuring apparatus
JP2007198992A (en) * 2006-01-30 2007-08-09 Nsk Ltd Load measurement device of rolling bearing unit
JP2012163412A (en) * 2011-02-04 2012-08-30 Nsk Ltd Physical quantity measurement instrument for rotating member
JP2013127390A (en) * 2011-12-19 2013-06-27 Nsk Ltd Rotary machine having physical quantity measurement function

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006226999A (en) * 2005-01-24 2006-08-31 Nsk Ltd Displacement measuring device and load measurement device for rolling bearing unit
JP2006275251A (en) * 2005-03-30 2006-10-12 Jtekt Corp Rolling bearing device with sensor
JP4525423B2 (en) * 2005-03-30 2010-08-18 株式会社ジェイテクト Rolling bearing device with sensor
JP2007071641A (en) * 2005-09-06 2007-03-22 Nsk Ltd State quantity measuring apparatus
JP2007198992A (en) * 2006-01-30 2007-08-09 Nsk Ltd Load measurement device of rolling bearing unit
JP2012163412A (en) * 2011-02-04 2012-08-30 Nsk Ltd Physical quantity measurement instrument for rotating member
JP2013127390A (en) * 2011-12-19 2013-06-27 Nsk Ltd Rotary machine having physical quantity measurement function

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