JP2008032672A - Abnormality detecting method of rolling device, and abnormality detector for rolling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abnormality detecting method of a rolling device and an abnormality detector for the rolling device capable of detecting whether an abnormality occurs in the rolling device without using a complicated structure for connecting a conducting wire to a rotating component and without removing the rolling device from a machine device. <P>SOLUTION: An electromagnetic induction sensor 14 having a coil for forming an alternating current magnetic field and a coil for detection is used as a sensor for detecting variation of the magnetic field resulting from the variation of metal texture occurring in the rolling device component of the rolling device or the variation of the lubrication state. It is detected whether an abnormality occurs in the rolling device based on the induced electromotive force occurring in the coil for detection of the electromagnetic induction sensor 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for detecting whether or not an abnormality such as poor lubrication or flaking has occurred in a rolling device such as a rolling bearing, a ball screw, or a linear motion guide bearing device.

  In general, when a rolling bearing such as a ball bearing or a roller bearing is used as a main shaft bearing of a machine tool, it is desirable to reduce the rotational resistance due to the lubricant as much as possible. For this reason, measures such as reducing the amount of grease enclosed in the rolling bearing or using lubricating oil instead of grease have been taken, but the grease enclosed in the rolling bearing is depleted. If the oil supply device that supplies the lubricating oil to the rolling bearing in the form of a mist or mist fails, the rolling bearing is poorly lubricated and is likely to cause serious damage such as seizure. Therefore, as a method for judging the quality of a rolling bearing in which a plurality of rolling elements incorporated between the outer race and the inner race are made of insulating ceramics, at least one of the rolling elements is made of conductive ceramics. A method is known in which the quality of the lubrication state between the rolling elements and the outer race and the inner race is determined based on the potential difference between the outer race and the inner race (see Patent Document 1). ).

In addition, as a method of diagnosing the load state of the rolling bearing, an exciting current is passed through the coil to induce an eddy current in the surface layer of the bearing ring or rolling element, and a change in impedance generated in the coil is detected by the eddy current. An eddy current sensor (specifically, as shown in FIG. 7, an alternating magnetic field forming coil 1, an alternating current power source 2 for supplying alternating current to the alternating magnetic field forming coil 1, and an alternating magnetic field formation from the alternating current power source 2 An impedance change detection circuit 3 for detecting an impedance change of the alternating current supplied to the coil 1, a comparator 4 for comparing the impedance change detected by the impedance change detection circuit 3 with a preset threshold value, and this comparison Recording and displaying the comparison result of the device 4 and an eddy current sensor comprising the display 5), and the residual in steel due to rolling bearing fatigue. Measuring the amount of decrease in austenite, a method of diagnosing a load condition of the rolling bearing from the measurement result is known (see Patent Documents 2 and 3).
JP 2003-156038 A JP 2004-198246 A JP-A-5-2082

  However, in the method described in Patent Document 1, it is necessary to measure the potential difference between the outer race and the inner race with a potentiometer. In order to measure the potential difference between the outer race and the inner race with a potentiometer. Since it is necessary to prevent the wire connected to the rotating raceway of the outer raceway and the inner raceway from being entangled by the rotation of the raceway, the structure of the connection portion of the lead becomes complicated There was a problem.

  On the other hand, in order to detect whether or not flaking (early separation) has occurred on the raceway surface of the raceway by the methods described in Patent Documents 2 and 3, a rolling bearing attached to a machine such as a machine tool is used as a machine. After being detached and disassembled, it is necessary to bring the eddy current sensor closer to the raceway surface of the raceway. For this reason, the method described in Patent Document 2 has a problem in that it requires a lot of work because the operation of the machine to which the rolling bearing is attached must be stopped or the rolling bearing must be removed from the mechanical device. .

  The present invention has been made paying attention to the above-mentioned problems, and its purpose is to use a complicated structure for connecting a conducting wire to a rotating component and without removing a rolling bearing from a mechanical device. An object of the present invention is to provide a rolling device abnormality detection method and a rolling device abnormality detection device capable of detecting whether or not an abnormality has occurred in the rolling device.

  According to the first aspect of the present invention, there is provided a rolling device abnormality detection method using an alternating current as a sensor for detecting a change in a magnetic structure caused by a change in a metal structure or a lubrication state generated in a rolling device part of the rolling device. An electromagnetic induction sensor comprising a magnetic field forming coil and a detection coil is used to detect whether an abnormality has occurred in the rolling device from the induced electromotive force generated in the detection coil of the electromagnetic induction sensor. It is characterized by that.

The abnormality detection method for a rolling device according to a second aspect of the present invention is the abnormality detection method for a rolling device according to the first aspect, wherein the abnormality is deterioration of a lubricant.
The abnormality detection method for a rolling device according to a third aspect of the invention is the abnormality detection method for a rolling device according to the first aspect, wherein the abnormality is a surface damage that has occurred in the rolling device component. To do.

The abnormality detection method for a rolling device according to a fourth aspect of the present invention is the abnormality detection method for a rolling device according to the first aspect, wherein the abnormality is surface fatigue or internal fatigue occurring in the rolling device component. It is characterized by.
An abnormality detection device for a rolling device according to a fifth aspect of the present invention is an abnormality detection device for a rolling device that detects whether or not an abnormality has occurred in the rolling device, and includes an AC magnetic field forming coil and a detection device. An electromagnetic induction sensor having a coil, an amplifier for amplifying a signal output from the electromagnetic induction sensor, and processing the output signal of the electromagnetic induction sensor amplified by the amplifier to cause an abnormality in the rolling device And determining means for determining whether or not the above has occurred.

The abnormality detecting device for a rolling device according to a sixth aspect of the present invention is the abnormality detecting device for a rolling device according to the fifth aspect, wherein the determination means is a microcomputer.
The abnormality detecting device for a rolling device according to a seventh aspect of the invention is the abnormality detecting device for a rolling device according to the fifth or sixth aspect, wherein at least one of the electromagnetic induction sensor, the amplifier, and the determination means is the rolling device. It is attached to a machine equipped with a moving device or the rolling device.

  The abnormality detecting device for a rolling device according to an invention of claim 8 is the abnormality detecting device for a rolling device according to any one of claims 5 to 7, wherein the AC magnetic field forming coil and the detection coil are It is characterized by being housed in one housing.

  According to the present invention, since the measurement target of the electromagnetic induction sensor is a magnetic field that transmits air, an abnormality has occurred in the rolling device without using a complicated structure for connecting the lead wire to the rotating component. Whether or not can be detected. In addition, unlike the case of using an eddy current sensor, it is not necessary to remove and disassemble the rolling device attached to a machine such as a machine tool. The presence or absence can be inspected even when the rolling device is operated or stopped.

  In FIG. 1, schematic structure of the abnormality detection apparatus for rolling devices which concerns on the 1st Embodiment of this invention is shown. In the figure, reference numeral 10 is a bearing housing, 11 is a ball bearing as a rolling bearing accommodated in the bearing housing 10, 12 is a rotating shaft supported by the ball bearing 11, and 13 is poorly lubricated in a rolling device such as a rolling bearing. An abnormality detection device for a rolling device that detects whether or not an abnormality such as the above has occurred, the abnormality detection device for rolling device 13 is a change in metal structure (for example, residual austenite in steel) ) Or an electromagnetic induction sensor 14 that amplifies the signal output from the electromagnetic induction sensor 14, and the electromagnetic induction sensor 14 that is amplified by the amplifier 15. And a microcomputer 16 as a judging means for judging whether or not an abnormality has occurred in the rolling device (ball bearing 11).

  As shown in FIG. 2, the electromagnetic induction sensor 14 includes an alternating magnetic field forming coil 14 a that forms an alternating magnetic field in a space including the inspection site of the rolling device component (for example, the outer race 11 b of the ball bearing 11), The AC magnetic field forming coil 14a includes a detection coil 14b that detects a change in the AC magnetic field by an electromagnetic induction phenomenon. In the AC magnetic field forming coil 14a, an AC current is supplied as an exciting current to an AC power source 19 (FIG. 1). See). The detection coil 14b is wound coaxially with the AC magnetic field forming coil 14a with a part in contact with the AC magnetic field forming coil 14a. The AC magnetic field forming coil 14a and the detection coil 14b are housed in one casing.

The detection coil 14b of the electromagnetic induction sensor 14 is connected to an amplifier 15 (see FIG. 1), and the induced electromotive force generated in the detection coil 14b is amplified by the amplifier 15, and then a rolling device such as a ball bearing. Is supplied to a microcomputer 16 as a determination means for determining whether or not an abnormality has occurred.
The microcomputer 16 has a signal processing unit 16a that processes the output signal of the electromagnetic induction sensor 14 (the induced electromotive force of the detection coil 14b) amplified by the amplifier 15, and the output of the signal processing unit 16a is set in advance. And a comparison determination unit 16b that determines that an abnormality such as poor lubrication has occurred in the rolling device when the output of the signal processing unit 16a is greater than the threshold. The determination result is output to a display device 17 such as a CRT and also to a recording device 18 such as a printer.

The electromagnetic induction sensor 14 may be fixed integrally with the outer race 11b of the ball bearing 11 or the bearing housing 10, or may be fixed detachably. Further, part or all of the electromagnetic induction sensor 14, the AC power source 19, the amplifier 15, and the microcomputer 16 may be integrated with a rolling device or a machine to which the rolling device is attached.
When determining the quality of the lubrication state of the rolling device such as the ball bearing 11 using the rolling device abnormality detecting device 13 configured as described above, as shown in FIG. 1, the axial direction of the electromagnetic induction sensor 14 The electromagnetic induction sensor 14 is brought close to the outer peripheral surface of the outer raceway ring 11b so that it is perpendicular to the contact surface between the rolling element 11a of the ball bearing 11 and the outer raceway ring 11b. An alternating current is supplied to the 14 alternating current magnetic field forming coils 14a. Then, the alternating current magnetic field forming coil 14a of the electromagnetic induction sensor 14 is excited by the alternating current supplied from the alternating current power source 19, and the alternating magnetic field 20 as shown in FIG. 3 is generated by exciting the alternating magnetic field forming coil 14a. Note that it is desirable to use an AC power supply 19 that can adjust the frequency of the supplied AC current.

  When the AC magnetic field 20 is generated from the AC magnetic field forming coil 14a of the electromagnetic induction sensor 14 in this way, an induced electromotive force is generated in the detection coil 14b of the electromagnetic induction sensor 14. At this time, the induced electromotive force generated in the detection coil 14b is a change in the magnetic field generated in the rolling device due to a change in the lubrication state due to deterioration of the lubricant or a change in retained austenite in the steel of the outer race 11b due to fatigue. Therefore, the quality of the lubrication state of the ball bearing 11 can be determined by comparing the induced electromotive force generated in the detection coil 14b with a preset threshold value.

Therefore, in the above-described first embodiment of the present invention, it is necessary to connect a member electrically connected to the rotating raceway and the potentiometer with a conducting wire when determining the quality of the lubrication state of the rolling bearing. Therefore, the quality of the lubrication state of the rolling bearing can be determined with high accuracy without using a complicated structure for connecting the conducting wire to the rotating component.
In addition, when inspecting whether abnormalities such as premature peeling have occurred, it is not necessary to remove the rolling device attached to the machine such as a machine tool from the machine and disassemble it. The presence or absence of abnormalities such as early peeling can be inspected even when the rolling device is operating or stopped.

Furthermore, the inspection result obtained by the microcomputer 16 can be used for controlling the rotation of the rotary shaft 12.
In the first embodiment described above, the ball bearing is exemplified as the inspection object. However, the present invention is not limited to this. For example, the present invention can be applied to a roller bearing, a ball screw, and a linear motion guide bearing device. it can. Further, the bearing may be a thrust bearing or a radial bearing, and can be applied when one or both of the inner ring and the outer ring rotate. Further, signal transmission from the electromagnetic induction sensor 14 to the amplifier 15 and from the amplifier 15 to the microcomputer 16 may be wired or wireless.

  Next, FIG. 4 shows a schematic configuration of the abnormality detecting device for a rolling device according to the second embodiment of the present invention. The abnormality detecting device for a rolling device shown in the figure stops the operation of the machine to determine whether or not an abnormality such as a defect or damage has occurred in the machined cage 21a of the cylindrical roller bearing, and removes the rolling bearing from the machine. A turntable 22 for mounting a semi-assembled roller bearing, an electromagnetic induction sensor 14 disposed above the turntable 22, and the electromagnetic induction sensor. A sensor swing mechanism 23 that swings 14 around the X axis (in the direction of the arrow θx in the figure), and a sensor lift mechanism that drives the electromagnetic induction sensor 14 up and down in the Z axis direction in the figure via the sensor swing mechanism 23. 24, a sensor positioning mechanism 25 for positioning the sensor by moving the electromagnetic induction sensor 14 in the X-axis direction and the Y-axis direction in the figure, and holding the punching table even if the turntable 22 is moved in the X-axis direction in the figure It is constituted by a rolling device component positioning mechanism 26 for positioning the rolling device parts such as 21a.

  As shown in FIG. 2, the electromagnetic induction sensor 14 includes an alternating magnetic field forming coil 14a and a detecting coil 14b, and an alternating current is supplied to the alternating magnetic field forming coil 14a from an alternating current power source. ing. The detection coil 14b is wound coaxially with the AC magnetic field forming coil 14a with a part in contact with the AC magnetic field forming coil 14a. The AC magnetic field forming coil 14a and the detection coil 14b are housed in one casing. In FIG. 4, 21b represents a cylindrical roller of a cylindrical roller bearing, and 21c represents an outer race of the cylindrical roller bearing.

  As a procedure for detecting whether or not an abnormality such as a defect or damage has occurred in the machined cage 21a using such a rolling device abnormality detection device, first, as shown in FIG. A cylindrical roller bearing with a machined cage from which (not shown) has been removed is placed on the turntable 22. Next, after the turntable 22, the sensor swing mechanism 23, the sensor lifting mechanism 24, the sensor positioning mechanism 25, and the rolling device component positioning mechanism 26 are driven to bring the electromagnetic induction sensor 14 closer to the end surface of the machined cage 21a. When an AC voltage is applied to the AC magnetic field forming coil 14a of the electromagnetic induction sensor 14, an AC magnetic field is generated from the AC magnetic field forming coil 14a.

  When an AC magnetic field is generated from the AC magnetic field forming coil 14a of the electromagnetic induction sensor 14 in this way, an induced electromotive force is generated in the detection coil 14b of the electromagnetic induction sensor 14. At this time, since the induced electromotive force generated in the detection coil 14b changes in proportion to the defect or damage generated in the machined cage 21a, the induced electromotive force generated in the detection coil 14b is set to a preset threshold value. It is possible to detect whether or not an abnormality such as a defect or damage has occurred in the machined cage 21a.

  Next, FIG. 5 shows a schematic configuration of the abnormality detecting device for a rolling device according to the third embodiment of the present invention. The abnormality detecting device for a rolling device shown in FIG. 1 is arranged above a turntable 22 on which a rolling bearing component is placed as a single component or a rolling bearing, or placed in a semi-assembled state. The electromagnetic induction sensor 14, the sensor oscillation mechanism 27 that drives the electromagnetic induction sensor 14 to swing around the Z axis (in the direction of the arrow θz in the figure), and the electromagnetic induction sensor 14 via the sensor oscillation mechanism 27. A sensor elevating mechanism 24 that moves up and down in the Z-axis direction in the figure, a sensor positioning mechanism 25 that positions the sensor by moving the electromagnetic induction sensor 14 in the X-axis direction and the Y-axis direction in the figure, and a turntable 22 in the X-axis direction in the figure. And a rolling device component positioning mechanism 26 that moves in the direction to position the rolling device component.

  As shown in FIG. 2, the electromagnetic induction sensor 14 includes an AC magnetic field forming coil 14a and a detection coil 14b, and an alternating current is supplied to the AC magnetic field forming coil 14a from an AC power source. Yes. The detection coil 14b is wound coaxially with the AC magnetic field forming coil 14a with a part in contact with the AC magnetic field forming coil 14a. The AC magnetic field forming coil 14a and the detection coil 14b are housed in one casing.

  As a procedure for detecting whether or not an abnormality such as a defect or damage has occurred in the pillar portion of the machined cage 21a using such a rolling device abnormality detection device, first, the operation of the machine is stopped. Then, with the rolling bearing removed from the machine, as shown in FIG. 5, the cylindrical roller bearing with a machined cage from which the inner ring (not shown) has been removed is placed on the turntable 22. Next, the turntable 22, the sensor swing mechanism 27, the sensor elevating mechanism 24, the sensor positioning mechanism 25, and the rolling device component positioning mechanism 26 are driven to bring the electromagnetic induction sensor 14 closer to the pillar portion of the machined cage 21a. Thereafter, when an AC voltage is applied to the AC magnetic field forming coil 14a of the electromagnetic induction sensor 14, an AC magnetic field is generated from the AC magnetic field forming coil 14a.

  When an AC magnetic field is generated from the AC magnetic field forming coil 14a of the electromagnetic induction sensor 14 in this way, an induced electromotive force is generated in the detection coil 14b of the electromagnetic induction sensor 14. At this time, the induced electromotive force generated in the detection coil 14b changes in proportion to the defect or damage generated in the pillar portion of the machined cage 21a, so the induced electromotive force generated in the detection coil 14b is set in advance. By comparing with the threshold value, it is possible to detect whether or not an abnormality such as a defect or damage has occurred in the pillar portion of the machined cage 21a.

In the 2nd and 3rd embodiment mentioned above, although the machined cage was illustrated as rolling device components, it is not restricted to this. For example, as shown in FIG. 6, the inner bearing ring 21d of the rolling bearing as a rolling device part is placed on the turntable 22 to detect whether an abnormality such as a defect or damage has occurred in the inner bearing ring 21d. You may make it do.
The roller bearings that can be separated from the inner ring and the outer ring in the assembled state are not limited to the cylindrical roller bearings of the embodiment, and tapered roller bearings and self-aligning roller bearings can be disassembled and assembled by hand. The present invention can be applied if no damage or the like affecting the performance occurs due to repeated assembly.

It is a figure which shows schematic structure of the abnormality detection apparatus for rolling devices which concerns on the 1st Embodiment of this invention. It is a perspective view which shows schematic structure of the electromagnetic induction sensor which detects the change of the magnetic field resulting from the change of the metal structure which arises in the rolling device components of the rolling device, or the change of the lubrication state. It is a figure which shows the alternating current magnetic field generate | occur | produced from the coil for alternating current magnetic field formation of an electromagnetic induction sensor. It is a perspective view which shows schematic structure of the abnormality detection apparatus for rolling devices which concerns on the 2nd Embodiment of this invention. It is a perspective view which shows schematic structure of the abnormality detection apparatus for rolling devices which concerns on the 3rd Embodiment of this invention. It is a perspective view which shows schematic structure of the abnormality detection apparatus for rolling devices which concerns on the 4th Embodiment of this invention. It is a figure which shows schematic structure of an eddy current sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Bearing housing 11 Ball bearing 11a Rolling element 11b Outer raceway ring 11c Inner raceway ring 12 Rotating shaft 13 Rolling device abnormality detection device 14 Electromagnetic induction sensor 14a AC magnetic field forming coil 14b Detection coil 15 Amplifier 16 Microcomputer 16a Signal processing Section 16b Comparison judgment section 17 Indicator 18 Recording device 19 AC power supply 20 AC magnetic field 21a Cylindrical roller bearing milling cage 21b Cylindrical roller bearing cylindrical roller 21c Cylindrical roller bearing outer race ring 21d Cylindrical roller bearing inner race ring 22 Turntable 23, 27 Sensor swing mechanism 24 Sensor lifting mechanism 25 Sensor positioning mechanism 26 Rolling device component positioning mechanism

Claims (8)

  An alternating magnetic field is formed in a space including an inspection site of the rolling device part as a sensor for detecting a change in magnetic structure caused by a change in a metal structure or a lubrication state generated in the rolling device part of the rolling device. Using an electromagnetic induction sensor comprising an alternating magnetic field forming coil and a detection coil for detecting a change in the alternating magnetic field formed by the alternating magnetic field forming coil by an electromagnetic induction phenomenon, the alternating magnetic field of the electromagnetic induction sensor An abnormality detection method for a rolling device, comprising: detecting whether or not an abnormality has occurred in the rolling device from an induced electromotive force generated in a detection coil disposed inside the rolling device.   The abnormality detection method for a rolling device according to claim 1, wherein the abnormality is deterioration of a lubricant.   2. The method for detecting an abnormality of a rolling device according to claim 1, wherein the abnormality is a surface damage occurring in the rolling device component.   The abnormality detection method for a rolling device according to claim 1, wherein the abnormality is surface fatigue or internal fatigue generated in the rolling device component.   An abnormality detection device for a rolling device for detecting whether or not an abnormality has occurred in the rolling device, comprising an electromagnetic induction sensor having an AC magnetic field forming coil and a detection coil, and from this electromagnetic induction sensor An amplifier that amplifies the output signal, and a determination unit that processes the output signal of the electromagnetic induction sensor amplified by the amplifier and determines whether or not an abnormality has occurred in the rolling device. An abnormality detection device for a rolling device.   6. The abnormality detecting device for a rolling device according to claim 5, wherein the determining means is a microcomputer.   The abnormality detection device for a rolling device according to claim 5 or 6, wherein at least one of the electromagnetic induction sensor, the amplifier, and the determination unit is attached to the rolling device or a machine including the rolling device. An abnormality detection device for a rolling device.   The rolling device abnormality detection device according to any one of claims 5 to 7, wherein the alternating-current magnetic field forming coil and the detection coil are accommodated in a single casing. Anomaly detector.

Images