JP2018145998A - Device for monitoring state of rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for monitoring a state of a rolling bearing that can monitor an operational state of a rolling bearing for finding a plurality of pieces of information from a datum that is monitored by a sensor.SOLUTION: A device for monitoring a state of a rolling bearing includes: a strain gauge 30 disposed in an outer ring 21 to detect strain of the outer ring 21 caused by passage of a roller 23; and a calculation part 40 for monitoring a state of a rolling bearing 20 from a strain observation waveform of the outer ring 21 that is monitored by the strain gauge 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rolling bearing state monitoring device, and more particularly, to a rolling bearing state monitoring device that monitors an operational state of a rolling bearing from a strain waveform of a fixed ring observed as a rolling element passes.

  Patent Document 1 discloses a rolling bearing in which the magnetostriction of a rolling element is measured by a magnetic sensor to detect the load, rotation speed, and rotation speed of the bearing. In Patent Document 2, the amount of strain of a member deformed by the torque acting on the rotating body is detected as an electric signal by a strain gauge, and the torque acting on the rotating body is calculated from the amplitude of the electric signal. A rotational state detection device is disclosed in which both the torque and the rotational speed are detected from the electrical signal of one strain gauge by calculating the rotational speed of the rotating body based on the fluctuation period.

JP 2004-84737 A JP 2012-202791 A

  In the rolling bearing described in Patent Document 1, a pulsar ring is mounted by forming a rolling element by dispersing a metal having a magnetostriction constant greater than a predetermined value in ceramics and measuring the magnetostriction of the rolling element with a magnetic sensor. The configuration of the rolling bearing can be greatly simplified and miniaturized by making it possible to detect the load, rotation speed, and rotation speed of the bearing without any problems. However, since a rolling element is formed by dispersing a metal having a magnetostriction constant in ceramic as a base material, it cannot be applied to a general rolling bearing. In addition, there are problems such as an increase in cost and inability to use the part where there is an impact, and there is room for improvement.

  Moreover, in patent document 2, although the rotation speed (revolution number) of a roller is calculated | required from the passage period of a roller, the driving | running state of a rolling bearing is not monitored.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to determine the state of a rolling bearing capable of monitoring the operating state of the rolling bearing by obtaining a plurality of information from one data observed by a sensor. It is to provide a monitoring device.

ただし、ｎｃ：転動体の公転数、Ｄｗ：転動体直径、α：接触角、Ｄｐｗ：転動体ピッチ径、ｎｉ：回転輪の回転数
（３） 前記演算部は、前記ひずみ観測波形の振幅から前記転がり軸受に作用するラジアル荷重を算出することを特徴とする（１）又は（２）に記載の転がり軸受の状態監視装置。
（４） 前記転がり軸受は、玉軸受であり、
前記演算部は、前記ひずみ観測波形の周期から求められた前記転動体の公転数に基づいて、前記玉軸受に作用するアキシャル荷重を算出することを特徴とする（１）〜（３）のいずれかに記載の転がり軸受の状態監視装置。 The above object of the present invention can be achieved by the following constitution.
(1) A state monitoring device for a rolling bearing having a fixed wheel, a rotating wheel, and a plurality of rolling elements that are rotatably arranged between the fixed wheel and the rotating wheel,
A strain gauge disposed on the fixed ring for detecting strain of the fixed ring due to passage of the rolling elements;
An arithmetic unit that monitors the state of the rolling bearing from a strain observation waveform of the fixed ring observed by the strain gauge;
A state monitoring device for a rolling bearing, comprising:
(2) The calculation unit obtains the revolution number of the rolling element from the period of the strain observation waveform, and further calculates the rotation number of the rotating wheel from the equation (1). Rolling bearing condition monitoring device.

However, nc: revolution number of rolling element, Dw: rolling element diameter, α: contact angle, Dpw: rolling element pitch diameter, ni: rotation speed of rotating wheel (3) The calculation unit calculates from the amplitude of the strain observation waveform. The state monitoring device for a rolling bearing according to (1) or (2), wherein a radial load acting on the rolling bearing is calculated.
(4) The rolling bearing is a ball bearing,
The calculation unit calculates an axial load acting on the ball bearing based on the number of revolutions of the rolling element obtained from the period of the strain observation waveform. Any of (1) to (3) The rolling bearing state monitoring device according to claim 1.

  According to the rolling bearing state monitoring apparatus of the present invention, a rolling gauge is installed from a strain gauge that is disposed on a fixed ring and detects strain of the fixed ring due to the passage of rolling elements, and a fixed wheel strain observation waveform that is observed by the strain gauge. And a calculation unit that monitors the state of the bearing. Therefore, the state of the rolling bearing can be monitored without increasing the number of parts.

(A) is a perspective view which shows the structure of the state monitoring apparatus of the rolling bearing which concerns on one Embodiment of this invention, (b) is the I section enlarged side view of Fig.1 (a). (A) is a graph of a strain observation waveform observed by passing through the rolling element, and (b) is a rolling showing a state in which a pair of rolling elements are located across the strain gauge, corresponding to II in FIG. The principal part side view of a bearing, (c) is the principal part side view of a rolling bearing which shows the state through which the rolling element passes the position of a strain gauge corresponding to II 'of FIG. 2 (a).

Hereinafter, a rolling bearing monitoring device according to an embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the rolling bearing monitoring device 10 according to the present embodiment includes a strain gauge 30 disposed on an outer ring 21 of the rolling bearing 20 and a calculation unit 40.

  The rolling bearing monitoring device 10 according to the present embodiment obtains a plurality of pieces of information from the single strain observation waveform observed by the strain gauge 30, and monitors the operating state of the rolling bearing 20 based on the pieces of information. The main purpose is to make it possible.

In the present embodiment, the plurality of pieces of information obtained from the observed waveform of the strain gauge 30 and monitoring the operating state of the rolling bearing 20 include the revolution number of the rolling element, the rolling confirmation of the rolling element, the rotation number of the rotating wheel, Radial load, abnormal vibration waveform, etc. When the rolling bearing is a ball bearing, the axial load is also targeted.
In the following description, the outer ring 21 is described as a fixed wheel and the inner ring 22 is a rotating wheel. However, the outer ring 21 may be a rotating wheel and the inner ring 22 may be a fixed wheel.

  Specifically, the rolling bearing 20 includes an outer ring 21 that is a fixed ring with an outer ring raceway surface 21a formed on the inner peripheral surface, and an inner ring that is a rotating ring with an inner ring raceway surface 22a (see FIG. 2) formed on the outer peripheral surface. 22 and a plurality of rollers 23 that are disposed between the outer ring raceway surface 21a and the inner ring raceway surface 22a so as to be freely rollable. The presence or absence of the cage is not particularly limited. The material of the rolling bearing 20 can be bearing steel, carburized steel, or the like, but is not particularly limited as long as it can be quenched.

  A cutout 25 having a substantially U-shaped cross section extending in the axial direction is formed on the outer peripheral surface 21 b of the outer ring 21. A strain gauge 30 is fixed to the bottom surface of the notch 25 by adhesion or the like. When the outer ring 21 is elastically deformed by the stress acting on the outer ring 21, the strain gauge 30 electrically detects the strain amount and sends an electric signal proportional to the strain amount to the calculation unit 40.

  Although the attachment position of the strain gauge 30 is not particularly limited, the strain detection sensitivity is improved by disposing the strain gauge 30 in the notch 25 whose mechanical strength is weaker than other portions. For the same reason, the strain gauge 30 is preferably disposed in the load zone of the rolling bearing 20. The strain gauge 30 may be directly bonded to the outer ring 21, or a base material (not shown) to which the strain gauge 30 is fixed may be fixed to the outer ring 21.

  When the outer ring 21 of the thus configured rolling bearing 20 is fixed and the inner ring 22 is rotated, the plurality of rollers 23 revolve while rotating between the outer ring raceway surface 21a and the inner ring raceway surface 22a. A tensile force acts on the outer ring 21 in the circumferential direction with the passage of the rollers 23, and distortion occurs. The strain gauge 30 detects the strain of the outer ring 21 and converts it into an electrical signal proportional to the amount of strain.

  FIG. 2A is a graph of a strain observation waveform observed as the roller 23 passes, and when the two rollers 23 are positioned across the strain gauge 30 as shown in FIG. The amount of strain observed with the strain gauge 30 is reduced, and a valley V is formed in the graph of the strain observation waveform.

  Further, as shown in FIG. 2C, when the roller 23 passes near the position where the strain gauge 30 is disposed, a large strain is observed by the strain gauge 30, and a peak P is shown in the graph of the strain observation waveform. It is formed.

  The computing unit 40 is an information processing unit configured by, for example, a microcomputer and obtains a plurality of information from the strain observation waveform observed by the strain gauge 30. Specifically, the passing period and passing state of the roller 23 can be known from the period T between the peaks P appearing in the strain observation waveform every time the roller 23 passes near the strain gauge 30.

  Also, by checking for irregular fluctuations or noise occurring in the period and amplitude of the strain observation waveform, it is possible to detect abnormalities in the rolling bearing 20 such as peeling of the rollers 23 or breakage of the cage, and abnormalities are detected. Is likely to be found at an early stage.

  Since the number of the rollers 23 of the rolling bearing 20 is known from the design specifications of the rolling bearing 20, the revolution number nc of the roller 23 is obtained by the period T between the peaks P.

  Furthermore, the obtained revolution number nc of the roller 23 and other design specifications of the rolling bearing 20 (the diameter Dw of the roller 23, the pitch circle diameter Dpw of the roller 23, and the contact angle α) are input to the equation (1). Thus, the rotational speed ni of the inner ring 22 can be calculated.

ただし、ｎｃ：転動体の公転数、Ｄｗ：転動体直径、α：接触角、Ｄｐｗ：転動体ピッチ径、ｎｉ：回転輪の回転数

Where nc: revolution number of rolling element, Dw: rolling element diameter, α: contact angle, Dpw: rolling element pitch diameter, ni: rotation number of rotating wheel

  Therefore, the operation state of the rolling bearing 20 can be monitored from the revolution number nc of the roller 23 and the rotation number ni of the inner ring 22.

  Conventionally, in order to know the rotational speed ni of the inner ring 22, dedicated members such as multipolar magnets and slit plates have been required. However, according to the rolling bearing state monitoring device 10 of this embodiment, these dedicated members are The rotational speed ni of the inner ring 22 can be known without providing it.

  Furthermore, since the amplitude W of the strain observation waveform is proportional to the radial load acting on the outer ring 21, if the relationship between the amplitude W and the radial load is obtained in advance, the magnitude of the amplitude W of the strain observation waveform is observed. Thus, the magnitude of the radial load acting on the rolling bearing 20 can be estimated.

  Further, when the rolling bearing 20 is a ball bearing, when an axial load is applied to the ball bearing, the contact angle α of the roller 23 changes, and as a result, the revolution number nc of the roller 23 changes. By observing nc, the axial load of the ball bearing can be estimated.

  Specifically, the relationship between the axial load and the difference between the revolution number nc of the roller 23 in the unloaded state of the axial load and the revolution number nc of the roller 23 in the loaded state is determined by rotating the ball bearing at a constant rotational speed. By obtaining in advance, the axial load can be estimated from the difference between the revolution number nc of the roller 23 observed when the axial load is applied and the revolution number nc of the roller 23 in an unloaded state.

  As described above, according to the rolling bearing state monitoring device 10 of the present embodiment, the strain gauge 30 disposed on the outer ring 21 and detecting strain of the outer ring 21 due to the passage of the rollers 23 is observed by the strain gauge 30. Since the operation unit 40 that monitors the state of the rolling bearing 20 from the observed distortion waveform of the outer ring 21 is provided, the state of the rolling bearing 20 can be monitored without increasing the number of parts.

  Moreover, since the calculating part 40 calculates | requires the revolution number nc of the roller 23 from the period T of a strain observation waveform, and also calculates the rotation speed ni of the inner ring | wheel 22, the rolling bearing 20 by the several information obtained from one strain observation waveform. Can be monitored.

  Moreover, since the calculating part 40 calculates the radial load which acts on the rolling bearing 20 from the amplitude W of the strain observation waveform, the state of the rolling bearing 20 is monitored by a plurality of pieces of information including the radial load acting on the rolling bearing 20. Can do.

  In addition, when the rolling bearing 20 is a ball bearing, the calculation unit 40 calculates the axial load acting on the ball bearing based on the revolution number nc of the roller 23 obtained from the period T of the strain observation waveform. Furthermore, the state of the rolling bearing 20 can be monitored with high accuracy.

  In this manner, the rolling bearing 20 is further in contact with the ball bearing 20 such as the revolution number nc of the roller 23, the rolling confirmation of the roller 23, the rotational speed ni of the inner ring 22, the magnitude of the radial load, the abnormal vibration waveform, etc. from the observed waveform of one strain gauge 30. In the case of a bearing, a lot of information such as the magnitude of the axial load can be obtained, and the operating state of the rolling bearing 20 can be monitored without increasing the number of parts.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. For example, in the above description, the strain of the outer ring 21 is detected by the strain gauge 30, but an optical fiber sensor or the like may be used regardless of the strain detection method as long as the strain of the outer ring 21 can be detected. Further, the arithmetic unit 40 may include a bearing abnormality detection unit, and an alarm may be issued when the bearing abnormality detection unit detects an abnormality.

10 Rolling bearing condition monitoring device 20 Rolling bearing (ball bearing)
21 Outer ring (fixed ring)
22 Inner ring (rotating wheel)
23 Roller (rolling element)
30 Strain gauge 40 Calculation unit Dpw Pitch circle diameter Dw Rolling element diameter nc Number of revolutions of rolling element ni Number of rotations of rotating wheel T Period W Amplitude α Contact angle

Claims (4)

A rolling bearing state monitoring device having a fixed wheel, a rotating wheel, and a plurality of rolling elements that are rotatably arranged between the fixed wheel and the rotating wheel,
A strain gauge disposed on the fixed ring for detecting strain of the fixed ring due to passage of the rolling elements;
An arithmetic unit that monitors the state of the rolling bearing from a strain observation waveform of the fixed ring observed by the strain gauge;
A state monitoring device for a rolling bearing, comprising: 2. The rolling bearing according to claim 1, wherein the calculation unit calculates a revolution number of the rolling element from a period of the strain observation waveform, and further calculates a rotation number of the rotating wheel from the equation (1). Condition monitoring device.

Where nc: revolution number of rolling element, Dw: rolling element diameter, α: contact angle, Dpw: rolling element pitch diameter, ni: rotation number of rotating wheel   The rolling bearing state monitoring device according to claim 1, wherein the calculation unit calculates a radial load acting on the rolling bearing from an amplitude of the strain observation waveform. The rolling bearing is a ball bearing,
The said calculating part calculates the axial load which acts on the said ball bearing based on the revolution number of the said rolling element calculated | required from the period of the said strain observation waveform, The any one of Claims 1-3 characterized by the above-mentioned. The rolling bearing state monitoring device described in the paragraph.

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