JP2017096445A - Rolling bearing with sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing with a sensor that can accurately detect flexure generated in an inner race or outer race, has excellent productivity and is excellent in maintainability.SOLUTION: The rolling bearing 10 includes: a flexure sensor 30 capable of detecting flexure; and a sensor holding member 20 to which the flexure sensor 30 is fixedly attached. The sensor holding member 20 is fixed to an axial hole 14 formed in the inner race 11 or outer race 12 while having a tightening allowance.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rolling bearing with a sensor, and more particularly to a rolling bearing with a sensor including a strain sensor capable of detecting a strain generated in the rolling bearing.

  Conventionally, a strain sensor unit is arranged in a notch groove of an inner ring or an outer ring, and an output signal from the strain sensor unit is led to a strain measuring instrument via an optical fiber, and the rolling element passes through the position of the strain sensor unit. 2. Description of the Related Art A method and an apparatus for measuring a load distribution of a rolling bearing that detects a strain are known (see, for example, Patent Documents 1 and 2).

Japanese Patent No. 5638312 Japanese Patent No. 5638313

  By the way, in the load distribution measuring apparatus described in Patent Document 1 or 2, the strain sensor unit is directly bonded to the notch groove of the inner ring or the outer ring with an adhesive. For this reason, it is difficult to replace only the strain sensor portion when the strain sensor portion is damaged or when it is necessary to replace the strain sensor portion with a different sensitivity, for example, and the entire rolling bearing has to be replaced. Further, the adhesion of the strain sensor portion to the notch groove of the inner ring or the outer ring requires a skillful technique, and there is a problem that it is difficult to mass-produce the load distribution measuring device. Further, the durability of the adhesive is directly related to the life of the load distribution measuring device, and there is room for improvement from the viewpoint of the life of the measuring device.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to detect a strain generated in an inner ring or an outer ring with high accuracy, to improve productivity, and to maintain easily. The object is to provide a rolling bearing.

The above object of the present invention can be achieved by the following constitution.
(1) A sensor-equipped rolling bearing comprising: an inner ring; an outer ring; a plurality of rolling elements arranged in a bearing space between the inner ring and the outer ring; and a strain sensor capable of detecting strain. Because
A sensor holding member to which the strain sensor is fixed;
A sensor-equipped rolling bearing, wherein the sensor holding member is fixed to a mounting portion formed on the inner ring or the outer ring with a margin.
(2) The rolling bearing with a sensor according to (1), wherein the strain sensor is fixed to the sensor holding member by adhesion or film formation.
(3) The sensor holding member has a strain sensing part formed with a recess,
(1) or (2), wherein the strain sensor includes a first strain gauge provided in the strain sensitive part and a second strain gauge provided in a place other than the strain sensitive part. Rolling bearing with sensor as described in 1.
(4) The sensor-equipped rolling bearing according to any one of (1) to (3), wherein the sensor holding member is made of the same material as the fixed inner ring or outer ring.

  According to the rolling bearing with a sensor of the present invention, a sensor holding member to which the strain sensor is fixed is separately provided, and the sensor holding member is fixed with a tightening margin to a mounting portion formed on the inner ring or the outer ring. Strain is applied to the sensor holding member and the strain sensor in advance. Thereby, the strain sensor can detect the strain in both directions of loosening and strengthening with high sensitivity with respect to the strain applied at the time of fixation. Therefore, the strain sensor can accurately detect the strain generated in the inner ring or the outer ring. In addition, the present invention has high productivity because it is not necessary to directly bond or form a strain sensor to the rolling bearing, and further, when the strain sensor is damaged or the strain sensor needs to be replaced, The sensor can be easily exchanged together with the sensor holding member, and maintainability is improved.

It is a principal part exploded perspective view of the rolling bearing with a sensor of a 1st embodiment concerning the present invention. (A) is a top view of the sensor holding member to which the strain sensor of FIG. 1 is fixed, (b) is a front view, (c) is a side view, and (d) is a back view. (A) is an exploded perspective view of an essential part of a rolling bearing with a sensor according to a second embodiment of the present invention, (b) is a plan view of a sensor holding member to which a strain sensor is fixed, and (c) is a strain sensor being fixed. FIG. (A) is a principal part disassembled perspective view of the rolling bearing with a sensor of 3rd Embodiment which concerns on this invention, (b) is a front view of a rolling bearing. (A) is a principal part disassembled perspective view of the rolling bearing with a sensor of 4th Embodiment which concerns on this invention, (b) is a front view of a rolling bearing.

  Hereinafter, each embodiment of a rolling bearing with a sensor concerning the present invention is described in detail based on a drawing.

(First embodiment)
First, with reference to FIG.1 and FIG.2, the rolling bearing with a sensor of 1st Embodiment which concerns on this invention is demonstrated.
The sensor-equipped rolling bearing 10 according to the present embodiment includes an inner ring 11, an outer ring 12, and a plurality of rollers 13 that are rolling elements disposed in a bearing space S between the inner ring 11 and the outer ring 12. It is a cylindrical roller bearing provided with a cage (not shown) that holds a plurality of rollers 13 in the circumferential direction at a predetermined interval. The sensor-equipped rolling bearing 10 further includes a strain sensor 30 that can detect strain and a sensor holding member 20 to which the strain sensor 30 is fixed.

  The outer ring 12 is provided with an axial hole (attachment portion) 14 drilled along the axial direction on the side surface thereof, and the sensor holding member 20 is press-fitted into the axial hole 14 with a tightening margin. It is fixed.

  The sensor holding member 20 has an outer peripheral surface having a diameter slightly larger than the diameter of the axial hole 14 of the outer ring 12 and is formed in a rod shape. Further, as shown in FIG. 2, the sensor holding member 20 is formed with a flat portion 21 extending along the axial direction, and the thick portions 26 on both sides in the axial direction are formed on the back surface side of the flat portion 21. A substantially U-shaped concave portion 22 is formed. The portion of the sensor holding member 20 in which the concave portion 22 is located on the back side is a thin-walled portion 24 that has a large strain when stress is applied, and serves as a strain-sensitive portion 25 for detecting the strain.

  As the material of the sensor holding member 20, it is preferable to use the same steel material as that of the outer ring 12 so that the linear expansion coefficient is the same.

A strain sensor 30 that is a strain resistance film made of metal or a conductive resin material is fixed to the flat surface portion 21 of the sensor holding member 20. When the strain sensor 30 is formed of a metal film, for example, a Cr (chromium) -N (nitrogen) thin film can be formed by reactive sputtering as the metal film. The Cr—N-based strain resistance film also has good strain sensitivity.
The strain sensor 30 may be another type of strain sensor. Furthermore, the single strain sensor 30 may be fixed to the flat surface portion 21 of the sensor holding member 20 by adhesion or welding without using film formation.

  The strain sensors 30 are two active gauges 31 that are first strain gauges that are orthogonally arranged in the axial direction and the circumferential direction, respectively, and second strain gauges that are respectively oriented in the axial direction. Two dummy gauges 32. The active gauge 31 is provided on the plane of the strain sensing part 25, and the dummy gauge 32 is provided on the plane of the thick part 26.

  The active gauge 31 disposed on the plane of the strain sensing unit 25 detects the strain (true strain and apparent strain) of the strain sensing unit 25 when a load is applied to the outer ring 12. The sensitivity of the active gauge 31 can be changed by adjusting the thickness of the strain sensing part 25 (thin wall part 24).

  The dummy gauge 32 arranged on the plane of the thick portion 26 detects the strain of the sensor holding member 20 itself, that is, the apparent strain (disturbance). By obtaining the difference between the detection value of the active gauge 31 and the detection value of the dummy gauge 32, the influence of the deformation (disturbance) of the sensor holding member 20 itself can be eliminated, and the detection accuracy of the strain sensor 30 is improved. .

  Since the sensor holding member 20 to which the strain sensor 30 is fixed is press-fitted into the axial hole 14 of the outer ring 12 with a tightening margin, a strain in the compression direction is preliminarily applied to the sensor holding member 20 and the strain sensor 30. Is done. In this state, when a deformation (strain) of the sensor holding member 20 generated by a load applied to the outer ring 12 is detected, the strain is loosened (elongation direction) or strengthened with respect to the strain previously applied in the compression direction ( Compression direction), and the strain can be detected with high sensitivity. Moreover, since the active gauge 31 is provided on the flat surface portion 21 of the strain sensing unit 25, the strain can be detected with high accuracy.

And based on the distortion | strain detected by the strain sensor 30, the radial load distribution of the rolling bearing 10 is calculated | required by an external diagnostic apparatus, the state of the rolling bearing 10 is monitored, and generation | occurrence | production of wear and abnormality is diagnosed. Further, it is possible to check the state of the rolling bearing 10 during actual operation.
Note that the detection signal from the strain sensor 30 may be sent to the diagnostic apparatus by either wired or wireless methods.

Further, the outer ring 12 to which the sensor holding member 20 is fixed may be either a fixed ring or a rotating ring.
Specifically, when the outer ring 12 is a rotating wheel, the strain sensor 30 rotates with the outer ring 12 and can be measured in all phases. Therefore, one strain sensor 30 may be disposed on the outer ring 12. The measurement waveform of the strain sensor 30 is a continuous waveform having a substantially sinusoidal shape with small amplitude and small amplitude after passing through the position of each roller 13. The average value of the sinusoidal continuous waveform increases when the strain sensor 30 is located on the load bearing side of the rolling bearing 10, and decreases when the strain sensor 30 is located on the no-load bearing side. It becomes a substantially sinusoidal waveform with a large amplitude of one cycle.

  Further, when the outer ring 12 is a fixed ring, the position (phase) that can be measured by the strain sensor 30 is constant. For example, by arranging three strain sensors 30 on the outer ring 12, the strain at each phase can be reduced. You may make it estimate from the measured value in three places.

  As described above, the sensor-equipped rolling bearing 10 according to the present embodiment includes the strain sensor 30 capable of detecting strain and the sensor holding member 20 to which the strain sensor 30 is fixed. The shaft is fixed to the axial hole 14 formed in the outer ring 12 with a tightening margin. Thereby, the strain sensor 30 can detect the strain in both directions of loosening and strengthening with high sensitivity with respect to the strain applied at the time of fixing. Therefore, the strain sensor 30 can accurately detect the strain generated in the outer ring 12. Further, since it is not necessary to directly bond or form the strain sensor 30 to the rolling bearing 10, the productivity is good. Further, when the strain sensor 30 is damaged or the strain sensor 30 needs to be replaced, the strain sensor 30 is strained. The sensor 30 can be easily replaced together with the sensor holding member 20 and the maintainability is improved.

  In particular, the strain sensor 30 is formed by directly forming the strain resistance film on the flat surface portion 21 of the sensor holding member 20, so that an adhesive for bonding the strain sensor 30 to the sensor holding member 20 becomes unnecessary. The problem of the sensor life due to the durability of the adhesive and the difficult sensor bonding process can be omitted. In addition, since the strain sensor 30 is provided on the sensor holding member 20, which is a member different from the outer ring 12, it is difficult to form a film on the outer ring 12, and it is possible to employ the strain sensor 30 that is also formed on a large bearing. it can.

  Even when the strain sensor 30 is bonded to the sensor holding member 20, since the sensor holding member 20 is a separate part from the outer ring 12, the shape design has a high degree of freedom and the shape considering the bonding work of the strain sensor 30. can do. Therefore, the bonding work is greatly facilitated as compared with the conventional work requiring the skill of bonding the strain sensor in the small groove formed in the bearing inner ring or the outer ring.

  In addition, since the sensor holding member 20 is composed of a separate part different from the outer ring 12, the same sensor holding member 20 (strain sensor 30) can be used regardless of the molding method (film formation, adhesion) of the strain sensor 30. The present invention can be applied to various types and sizes of bearings and various measurement sites, and the strain sensor 30 can be shared, thereby reducing the cost.

  Furthermore, since the strain sensor 30 has an active gauge 31 provided in the strain sensitive part 25 formed with the recess 22 in the sensor holding member 20 and a dummy gauge 32 provided in addition to the strain sensitive part 25. Even when there is a disturbance such as deformation of the sensor holding member 20 itself, the strain can be detected with high accuracy.

(Second Embodiment)
Next, with reference to FIG. 3, the rolling bearing with a sensor of 2nd Embodiment which concerns on this invention is demonstrated. Note that portions that are the same as or equivalent to those of the first embodiment are denoted by the same reference numerals in the drawings, and description thereof is omitted or simplified.

  In the outer ring 12 of the rolling bearing with sensor 10A of the present embodiment, a bottomed hole (attachment portion) 15 is formed along the radial direction substantially at the center in the axial direction of the outer peripheral surface 12a. A sensor holding member 40 to which the strain sensor 30 is fixed is fixed to the bottomed hole 15 by press-fitting with a tightening margin.

  The sensor holding member 40 includes an outer peripheral surface having a diameter slightly larger than the diameter of the bottomed hole 15 of the outer ring 12, and has two planes parallel to the outer peripheral surface. The sensor holding member 40 has a flat surface portion 41 on the upper surface (axial end surface), and a substantially U-shaped concave portion 42 is formed on the back surface side of the flat surface portion 41. That is, the portion corresponding to the concave portion 42 is the thin-walled portion 44 and serves as a strain sensing portion 45 for detecting strain. Further, portions other than the recess 42 (both ends in the longitudinal direction) are thick portions 46.

Two active gauges 31 are formed on the strain sensitive portion 45 (thin wall portion 44) of the sensor holding member 40, and two dummy sheets are formed on the upper surface of the thick portion 46 other than the strain sensitive portion 45. A gauge 32 is formed. Then, when the sensor holding member 40 is press-fitted into the bottomed hole 15, the strain sensor 30 is fixed to the outer ring 12 in a state where compressive stress is applied. The sensor holding member 40 is fixed to the bottomed hole 15 of the outer ring 12 so that two planes are oriented in the circumferential direction of the rolling bearing in consideration of the direction of the strain sensor 30.
Other configurations and operational effects are the same as those in the first embodiment, and a description thereof will be omitted.

(Third embodiment)
Next, a sensor-equipped rolling bearing according to a third embodiment of the present invention will be described with reference to FIG.
In the rolling bearing with sensor 10B of this embodiment, a U-shaped groove (attachment portion) 16 is formed on the outer peripheral surface 12a of the outer ring 12 over the entire length in the axial direction. A sensor holding member 50 to which the strain sensor 30 is fixed is fixed (press-fitted) with a tightening margin in the U-shaped groove 16.

  The sensor holding member 50 is formed in a substantially rectangular shape having a width slightly larger than the width of the U-shaped groove 16 of the outer ring 12, and a flat portion 51 is formed on the upper surface, and on the back side of the flat portion 51. Is formed with a substantially U-shaped recess 52. That is, the thin-walled portion 54 corresponding to the concave portion 52 becomes the strain sensing portion 55. Further, portions other than the recess 52 (both ends in the width direction) are thick portions 56.

Two active gauges 31 are formed on the plane of the strain sensitive portion 55 (thin portion 54) of the sensor holding member 50, and on the plane of the thick portion 56 other than the strain sensitive portion 55, Two dummy gauges 32 are formed. When the sensor holding member 50 is press-fitted into the U-shaped groove 16, the strain sensor 30 is fixed to the outer ring 12 in a state where compressive stress is applied.
Other configurations and operational effects are the same as those in the first embodiment, and a description thereof will be omitted.

(Fourth embodiment)
Next, a rolling bearing with a sensor according to a fourth embodiment of the present invention will be described with reference to FIG.
In the rolling bearing with sensor 10C of the present embodiment, a pair of grooves 17 and 17 spaced in the circumferential direction are provided on the outer peripheral surface 12a of the outer ring 12 via a convex portion 18 having a flat surface portion 18a lower than the outer peripheral surface 12a. A mounting portion 19 formed along the direction is formed. A sensor holding member 60 to which the strain sensor 30 is fixed is fixed to the attachment portion 19 by press-fitting with a tightening margin.

  The sensor holding member 60 has a flat surface portion 61 on the upper surface, and a substantially U-shaped concave portion 62 is formed on the back surface side of the flat surface portion 61. That is, the portion corresponding to the concave portion 62 is the thin portion 64 and serves as a strain sensing portion 65 for detecting strain. Further, portions other than the recess 62 (both ends in the width direction) become thick portions 66.

  The width W1 between the pair of thick portions 66 is slightly narrower than the circumferential width W2 of the convex portion 18. Further, two active gauges 31 are formed on the strain sensing part 65, and two dummy gauges 32 are formed on the upper surface of the thick part 66.

The sensor holding member 60 is press-fitted into the mounting portion 19 and fixed to the outer ring 12 so that the convex portion 18 is sandwiched between the pair of thick portions 66. At this time, a gap is secured between the width direction end surface of the sensor holding member 60 and the outer surfaces of the pair of grooves 17 and 17. Thereby, a tensile force acts on the strain sensing part 65 of the sensor holding member 60. That is, the strain sensor 30 of the present embodiment is fixed to the outer ring 12 in a state in which a tensile stress is applied in advance, contrary to the strain sensor 30 of the first to third embodiments. Therefore, even in the strain sensor 30 of the present embodiment, strains in both directions of loosening (compression direction) and strengthening direction (extension direction) with respect to the strain applied at the time of fixation can be detected with high sensitivity.
Other configurations and operational effects are the same as those in the first embodiment, and a description thereof will be omitted.

In addition, this invention is not limited to each embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
For example, in each of the above-described embodiments, the example in which the strain sensor 30 is provided in the cylindrical roller bearing 10 has been described. However, the present invention is not limited thereto, and other types of rolling bearings may be used.
Moreover, in each said embodiment, although the strain sensor 30 is arrange | positioned at the attaching part of the outer ring | wheel 12, you may arrange | position at the attaching part of the inner ring | wheel 11, In this case, this inner ring 11 is a fixed ring. Alternatively, it may be a rotating wheel.
Moreover, the attachment part formed in an inner ring | wheel or an outer ring | wheel will not be limited to the thing of embodiment mentioned above, if it is a shape fixed with a margin in addition to the shape of a sensor holding member.
Furthermore, the configuration of the strain sensor 30 is not limited to that of the present embodiment, and may be other configurations.

10, 10A, 10B, 10C Rolling bearing with sensor 11 Inner ring 12 Outer ring 13 Roller (rolling element)
14 Axial hole (mounting part)
15 Bottomed hole (mounting part)
16 U-shaped groove (mounting part)
19 Mounting portion 20, 40, 50, 60 Sensor holding member 22, 42, 52, 62 Recessed portion 25, 45, 55, 65 Strain sensitive portion 30 Strain sensor 31 Active gauge (first strain gauge)
32 Dummy gauge (second strain gauge)
S Bearing space

Claims (4)

A sensor-equipped rolling bearing comprising: an inner ring; an outer ring; a plurality of rolling elements arranged in a bearing space between the inner ring and the outer ring; and a strain sensor capable of detecting strain. ,
A sensor holding member to which the strain sensor is fixed;
A sensor-equipped rolling bearing, wherein the sensor holding member is fixed to a mounting portion formed on the inner ring or the outer ring with a margin.   The rolling bearing with a sensor according to claim 1, wherein the strain sensor is fixed to the sensor holding member by adhesion or film formation. The sensor holding member has a strain sensing part formed with a recess,
The said strain sensor has the 1st strain gauge provided in the said strain sensitive part, and the 2nd strain gauge provided in other than the said strain sensitive part, The Claim 1 or 2 characterized by the above-mentioned. Roller bearing with sensor.   The rolling bearing with a sensor according to claim 1, wherein the sensor holding member is made of the same material as the inner ring or the outer ring to be fixed.

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