Rolling bearing, state monitoring device, and method for detecting revolution slip of rolling bearing

Abstract

To provide a rolling bearing, a state monitoring device, and a revolution slip detection method of the rolling bearing capable of detecting revolution slip of a rolling element without disassembling a machine device, and capable of maintaining a normal operation state of the bearing by feeding back a revolution slip state to operation control of the machine.SOLUTION: The method includes a measurement step of measuring a signal including rolling element passage vibration when the rolling elements 40 pass through the raceway surfaces 21 and 31 using the rolling bearing 10 in which one of the outer ring raceway surface 21 and the inner ring raceway surface 31 is formed in a non-circular shape, a calculation step of performing frequency analysis on the signal to calculate spectrum data, and a detection step of comparing a frequency at which a peak appears due to the rolling element passage vibration with a theoretical revolution frequency due to revolution of the rolling elements 40 when there is no slip in the rolling elements 40 to detect the presence or absence of revolution slip of the rolling elements 40.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rolling bearing, a condition monitoring device, and a method for detecting orbital slippage of a rolling bearing, and in particular to a rolling bearing, a condition monitoring device, and a method for detecting orbital slippage of a rolling bearing that are capable of accurately detecting orbital slippage of a rolling element without disassembling a mechanical device in which the rolling bearing is incorporated. [Background technology]

[0002] When rolling bearings are used under light loads, high speeds, or excessive lubrication, the rolling elements may not be able to rotate normally and may slip on the raceway, a phenomenon known as orbital slippage. When orbital slippage occurs, each rolling element may lead or lag relative to the number of revolutions, causing excessive loads to be applied to the cage from the rolling elements, and in extreme cases, the cage may be damaged.

[0003] Patent Document 1 discloses a rolling bearing that uses an AE sensor embedded in the fixed ring to enable accurate and early detection of abnormalities such as minute damage to the fixed ring. Patent Document 2 also discloses a bearing condition monitoring device that includes a sensor that detects signals based on vibrations and sound generated by the bearing or strain values ​​of the inner ring, outer ring, shaft, and housing, a waveform processing unit that performs frequency analysis on the signals and calculates spectrum data, and a calculation unit that compares the frequency at which peaks in the spectrum data appear with theoretical frequencies due to the rotation and revolution of the rolling elements when there is no slip between the inner and outer rings of the bearing and the rolling elements, and determines fluctuations in the rotation speed and revolution speed of the rolling elements of the bearing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-7823 [Patent Document 2] WO2019-221251 publication Summary of the Invention [Problem to be solved by the invention]

[0005] However, the rolling bearing described in Patent Document 1 is intended to detect damage to the fixed ring and is unable to detect orbital slippage of the rolling elements. Also, the bearing condition monitoring device described in Patent Document 2 is capable of monitoring fluctuations in the rotation and revolution speeds of the rolling elements, but there is a demand for accurate detection of orbital slippage from vibrations generated by the bearing, and further improvements have been desired.

[0006] The present invention has been made in view of the above-mentioned problems, and its object is to provide a rolling bearing, a condition monitoring device, and a method for detecting orbital slippage of a rolling bearing that are capable of accurately detecting orbital slippage of a rolling element without disassembling a mechanical device in which the rolling bearing is incorporated. [Means for solving the problem]

[0007] Therefore, the above object of the present invention is achieved by the following rolling bearing configuration [1]. [1] A rolling bearing comprising an outer ring having an outer ring raceway surface on its inner peripheral surface, an inner ring having an inner ring raceway surface on its outer peripheral surface, and a plurality of rolling elements arranged to roll freely between the outer ring raceway surface and the inner ring raceway surface, At least one of the outer ring raceway surface and the inner ring raceway surface has a non-circular shape when viewed in the axial direction. Rolling bearing.

[0008] The above object of the present invention is also achieved by the following configuration [2] relating to the status monitoring device. [2] A condition monitoring device for detecting revolutionary slip of the rolling bearing according to [1], a vibration sensor that detects a signal based on vibration generated from the rolling bearing, including rolling element passing vibration when the rolling element rolls on the raceway surface having the non-circular shape; a rotation sensor for detecting the rotation speed of the rolling bearing; a waveform processing unit that performs frequency analysis on the signal detected by the vibration sensor and calculates spectrum data; a calculation unit that detects the presence or absence of orbital slip of the rolling element by comparing a frequency at which a peak appears due to the rolling element passing vibration in the spectrum data with a theoretical revolution frequency due to the revolution of the rolling element when there is no slip of the rolling element; A condition monitoring device comprising:

[0009] The above object of the present invention is also achieved by the following configuration [3] relating to a method for detecting revolutionary slippage of a rolling bearing. [3] A method for detecting revolutionary slip of a rolling bearing using the rolling bearing according to [1], a measuring step of measuring a signal based on vibration generated from the rolling bearing, the signal including rolling element passing vibration when the rolling element rolls on the raceway surface having the non-circular shape; a calculation step of performing frequency analysis on the signal to calculate spectral data; a detection step of detecting the presence or absence of orbital slip of the rolling element by comparing a frequency at which a peak appears due to the rolling element passing vibration in the spectrum data with a theoretical revolution frequency due to the revolution of the rolling element when there is no slip of the rolling element; A method for detecting revolutionary slippage in a rolling bearing, comprising: [Effects of the Invention]

[0010] According to the rolling bearing and condition monitoring device, and method for detecting orbital slippage of a rolling bearing of the present invention, vibrations are generated when the rolling element passes through a vibration generating section provided on the raceway surface, and by measuring this vibration, orbital slippage of the rolling element, which is the cause of malfunctions in the rolling bearing, can be detected with greater accuracy. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating the configuration of a condition monitoring device that detects whether or not there is orbital slippage in a rolling bearing. [Figure 2] 1 is a schematic diagram of a rolling bearing having an elliptical outer ring raceway surface according to a first embodiment of the present invention; [Figure 3] FIG. 4 is a schematic diagram of a rolling bearing having an elliptical inner ring raceway surface according to a second embodiment of the present invention. [Figure 4] FIG. 10 is a schematic diagram of a rolling bearing having a pentagonal outer ring raceway surface according to a third embodiment of the present invention. [Figure 5] FIG. 10 is a schematic diagram of a rolling bearing having a pentagonal inner ring raceway surface according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] (First embodiment) Hereinafter, a rolling bearing and a revolutionary slip detection method according to the present invention, as well as a condition monitoring device for carrying out the revolutionary slip detection method, will be described. The revolutionary slip of the rolling elements in the rolling bearing can be detected by measuring and analyzing the vibration of the rolling bearing, and in this embodiment, the revolutionary slip is detected using a condition monitoring device 50 described below.

[0013] (Condition monitoring device) 1, the condition monitoring device 50 comprises a vibration sensor 51 that detects vibrations of the rolling bearing 10, a rotation sensor 52 that detects the rotational speed of the rolling bearing 10, an A / D conversion unit 53 that A / D converts the vibration data detected by the vibration sensor 51, a waveform processing unit 54 that performs frequency analysis on the A / D converted vibration data and calculates spectrum data, and a calculation unit 55 that compares the frequency of the spectrum data with the theoretical revolution frequency of the rolling element 40 to detect the presence or absence of revolutionary slippage. The A / D conversion unit 53, waveform processing unit 54 and calculation unit 55 are mainly configured using an information processing device 60 such as a personal computer.

[0014] (Method for detecting revolutionary slippage in rolling bearings) In the method of detecting revolutionary slippage using such a condition monitoring device 50, first, the condition monitoring device 50 is set on the rolling bearing 10 incorporated in a mechanical device, and the rotary shaft 61 of the mechanical device is rotated.

[0015] The vibration sensor 51 detects vibrations, including rolling element passing vibrations, generated from the rolling bearing 10 as electrical signals, and the detected electrical signals are amplified by an amplifier 56 and input to an A / D conversion unit 53. The rotation sensor 52 detects the rotation of the rotating shaft 61, and calculates the rotation speed with a tachometer 57, which is input to a calculation unit 55.

[0016] The vibration data input from the vibration sensor 51 to the A / D conversion unit 53 is converted into a digital signal by the A / D conversion unit 53, and then envelope processing and frequency analysis are performed by the waveform processing unit 54 to calculate spectrum data.

[0017] The calculation unit 55 further calculates the theoretical revolution frequency of the rolling element 40 when there is no revolutionary slip of the rolling element 40, based on the rotation speed of the rotating shaft 61 detected by the rotation sensor 52, and compares this theoretical revolution frequency with the frequency at which the peak of the spectrum data obtained by the waveform processing unit 54 appears, to detect whether or not there is revolutionary slip of the rolling element 40.

[0018] In this embodiment, in order to more accurately detect whether or not the rolling elements are orbitally sliding, the raceway surface of the bearing ring is made non-circular, and rolling element passing vibration that occurs when the rolling elements pass over the non-circular raceway surface is promoted. Hereinafter, the rolling bearing will be described in detail with reference to the drawings.

[0019] (rolling bearings) As shown in Figure 2, the rolling bearing 10 of this embodiment comprises an outer ring 20 having an outer ring raceway surface 21 on its inner peripheral surface, an inner ring 30 having an inner ring raceway surface 31 on its outer peripheral surface, a plurality of rolling elements 40 arranged so as to be freely rollable between the outer ring raceway surface 21 and the inner ring raceway surface 31, and a retainer 45 that holds the plurality of rolling elements 40 so as to be freely rotatable.

[0020] The outer ring raceway surface 21 of the outer ring 20 is formed in a non-circular shape, specifically an ellipse, when viewed from the side. Note that the ellipse is exaggerated in Fig. 2 for ease of understanding. When such a rolling bearing 10 having an elliptical outer ring raceway surface 21 is rotated, the rolling elements 40 move radially along the outer ring raceway surface 21, generating vibrations including rolling element passing vibrations.

[0021] This vibration is measured by the condition monitoring device 50 described above, and analyzed in accordance with the method for detecting revolutionary slippage of a rolling bearing, thereby making it possible to detect whether or not revolutionary slippage of the rolling element 40 is occurring.

[0022] When detecting vibrations of a stationary wheel, the vibration sensor 51 is preferably installed in the load zone phase, and more preferably in a position radially opposite the stationary wheel. Furthermore, when detecting vibrations of the rotating ring, the vibration sensor 51 is preferably installed when assembling the rolling bearing 11. Furthermore, it is more preferable to install the vibration sensor 51 at a position radially opposite the rotating ring. In addition, if the vibration sensor 51 cannot be installed in a position radially opposite the stationary ring or the rotating ring, it is preferable to install it in a position axially opposite the stationary ring or the rotating ring at the position where the rolling bearing 11 is assembled.

[0023] As described above, according to the rolling bearing 10 and the method for detecting orbital slippage of a rolling bearing of this embodiment, vibrations are generated that are enhanced by the rolling element passing over a non-circular raceway surface, and by measuring these vibrations, orbital slippage of the rolling element 40 can be detected without disassembling the mechanical device in which the rolling bearing 10 is incorporated. Furthermore, by feeding back the detected revolutionary slip state to the operation control of the machine, it is possible to control the load, rotation speed, and amount of lubricant to maintain the normal operating state of the rolling bearing 10. Specifically, when revolutionary slip occurs, the load can be increased, the rotation speed can be reduced, and the amount of lubricant can be reduced.

[0024] (Second embodiment) As shown in Figure 3, the inner ring 30 of the rolling bearing 10 of this embodiment has a non-circular, specifically elliptical, inner ring raceway surface 31 in side view. Note that the ellipse is exaggerated in Figure 3 for ease of understanding. When such a rolling bearing 10 with an elliptical inner ring raceway surface 31 is rotated, the rolling elements 40 move radially along the inner ring raceway surface 31, generating vibrations including rolling element passing vibrations.

[0025] As described in the first embodiment, the vibrations including the rolling element passing vibration are measured by the condition monitoring device 50 and analyzed according to the method for detecting orbital slippage of a rolling bearing, thereby making it possible to detect whether or not the rolling element 40 is orbital slippage.

[0026] (Third embodiment) As shown in Figure 4, the outer ring 20 of the rolling bearing 10 of this embodiment has a non-circular, specifically pentagonal, outer ring raceway surface 21 in side view. The vertices of the pentagonal outer ring raceway surface 21 are connected by smooth curves 22. Note that the pentagonal shape is exaggerated in Figure 4 for ease of understanding. When such a rolling bearing 10 with a pentagonal outer ring raceway surface 21 is rotated, the rolling elements 40 move radially along the outer ring raceway surface 21, generating vibrations including rolling element passing vibrations.

[0027] As described in the first embodiment, the vibrations including the rolling element passing vibration are measured by the condition monitoring device 50 and analyzed according to the method for detecting orbital slippage of a rolling bearing, thereby making it possible to detect whether or not the rolling element 40 is orbital slippage.

[0028] (Fourth embodiment) As shown in Figure 5, the inner ring 30 of the rolling bearing 10 of this embodiment has a non-circular, specifically pentagonal, inner ring raceway surface 31 in side view. The vertices of the pentagonal inner ring raceway surface 31 are connected by smooth curves 32. Note that the pentagonal shape is exaggerated in Figure 5 for ease of understanding. When such a rolling bearing 10 with a pentagonal inner ring raceway surface 31 is rotated, the rolling elements 40 move radially along the inner ring raceway surface 31, generating vibrations including rolling element passing vibrations.

[0029] As described in the first embodiment, the vibrations including the rolling element passing vibration are measured by the condition monitoring device 50 and analyzed according to the method for detecting orbital slippage of a rolling bearing, thereby making it possible to detect whether or not the rolling element 40 is orbital slippage.

[0030] The present invention is not limited to the above-described embodiment, and modifications and improvements are possible as appropriate. For example, in the above embodiment, the non-circular shape has been described as an elliptical shape or a pentagonal shape (polygonal shape), but the shape is not limited to this as long as it can generate rolling element passing vibration. In the first to third embodiments, when the raceway surface on which the rolling elements pass is non-circular, the circumferential surface of the bearing ring opposite the raceway surface is also formed non-circular. However, as shown in the fourth embodiment, when the raceway surface on which the rolling elements pass is non-circular, the circumferential surface of the bearing ring opposite the raceway surface may be formed circular.

[0031] The variation in radius of the non-circular raceway surface from the central axis CL of the outer ring 20 or the inner ring 30 is set to a range that allows the rolling element passing vibration to be reliably measured and that prevents the vibration generating part 12 from becoming a starting point for flaking during normal bearing operation.

[0032] Furthermore, the type of rolling bearing is not limited, and the present invention can be applied to any type of rolling bearing, such as a ball bearing, a cylindrical roller bearing, a tapered roller bearing, or a needle roller bearing, and the same effects can be achieved.

[0033] Furthermore, in the case of a rolling bearing with two rows of raceway surfaces, by providing the above-mentioned non-circular raceway surface on the outer ring of one row and on the inner ring of the other row, it is possible to isolate the vibration frequency of each row and detect the orbital slip state of both rows simultaneously.

[0034] As described above, the present specification discloses the following: (1) A rolling bearing comprising an outer ring having an outer ring raceway surface on its inner peripheral surface, an inner ring having an inner ring raceway surface on its outer peripheral surface, and a plurality of rolling elements disposed so as to roll freely between the outer ring raceway surface and the inner ring raceway surface, At least one of the outer ring raceway surface and the inner ring raceway surface has a non-circular shape when viewed in the axial direction. Rolling bearing. This configuration enhances the vibration of the rolling bearing when the rolling element passes, making it possible to more accurately detect the orbital slip of the rolling element without disassembling the mechanical device in which the rolling element is incorporated.

[0035] (2) The non-circular shape is an elliptical shape. (1) The rolling bearing according to (1). According to this configuration, the revolutionary slip of the rolling element can be detected with higher accuracy.

[0036] (3) The non-circular shape is a polygonal shape whose vertices are connected by smooth curves. (1) The rolling bearing according to (1). According to this configuration, the revolutionary slip of the rolling element can be detected with higher accuracy.

[0037] (4) A condition monitoring device for detecting revolutionary slip of the rolling bearing according to (1), a vibration sensor that detects a signal based on vibration generated from the rolling bearing, including rolling element passing vibration when the rolling element rolls on the raceway surface having the non-circular shape; a rotation sensor for detecting the rotation speed of the rolling bearing; a waveform processing unit that performs frequency analysis on the signal detected by the vibration sensor and calculates spectrum data; a calculation unit that detects the presence or absence of orbital slip of the rolling element by comparing a frequency at which a peak appears due to the rolling element passing vibration in the spectrum data with a theoretical revolution frequency due to the revolution of the rolling element when there is no slip of the rolling element; A condition monitoring device comprising: According to this configuration, the revolutionary slip of the rolling elements can be detected with higher accuracy without being affected by the operating state of the rolling bearing.

[0038] (5) A condition monitoring device as described in (4), wherein when the vibration sensor detects a stationary ring that is the outer ring or the inner ring having the non-circular shaped raceway surface, the vibration sensor is installed in the load zone phase of the stationary ring. With this configuration, vibrations of the stationary wheel can be detected with high accuracy.

[0039] (6) A method for detecting revolutionary slip of a rolling bearing using the rolling bearing according to (1), comprising: a measuring step of measuring a signal based on vibration generated from the rolling bearing, the signal including rolling element passing vibration when the rolling element rolls on the raceway surface having the non-circular shape; a calculation step of performing frequency analysis on the signal to calculate spectral data; a detection step of detecting the presence or absence of orbital slip of the rolling element by comparing a frequency at which a peak appears due to the rolling element passing vibration in the spectrum data with a theoretical revolution frequency due to the revolution of the rolling element when there is no slip of the rolling element; A method for detecting revolutionary slippage in a rolling bearing, comprising: According to this configuration, the revolutionary slip of the rolling elements can be detected with higher accuracy without being affected by the operating state of the rolling bearing. [Explanation of symbols]

[0040] 10. Rolling bearings 20 outer ring 21 Outer ring raceway 22, 32 Smooth curves 30 Inner Circle 31 Inner ring raceway surface 40 rolling elements

Claims

1. A rolling bearing comprising an outer ring having an outer ring raceway surface on its inner peripheral surface, an inner ring having an inner ring raceway surface on its outer peripheral surface, and a plurality of rolling elements arranged to roll freely between the outer ring raceway surface and the inner ring raceway surface, At least one of the outer ring raceway surface and the inner ring raceway surface has a non-circular shape when viewed in the axial direction. Rolling bearing.

2. The non-circular shape is an elliptical shape.

2. The rolling bearing according to claim 1.

3. The non-circular shape is a polygonal shape whose vertices are connected by smooth curves.

2. The rolling bearing according to claim 1.

4. 2. A condition monitoring device for detecting revolutionary slip of a rolling bearing according to claim 1, a vibration sensor that detects a signal based on vibration generated from the rolling bearing, including rolling element passing vibration when the rolling element rolls on the raceway surface having the non-circular shape; a rotation sensor for detecting the rotation speed of the rolling bearing; a waveform processing unit that performs frequency analysis on the signal detected by the vibration sensor and calculates spectrum data; a calculation unit that detects the presence or absence of orbital slip of the rolling element by comparing a frequency at which a peak appears due to the rolling element passing vibration in the spectrum data with a theoretical revolution frequency due to the revolution of the rolling element when there is no slip of the rolling element; A condition monitoring device comprising:

5. 5. The condition monitoring device according to claim 4, wherein when the vibration sensor detects a stationary ring that is the outer ring or the inner ring having the raceway surface of the non-circular shape, the vibration sensor is installed in a load zone phase of the stationary ring.

6. A method for detecting revolutionary slip of a rolling bearing using the rolling bearing according to claim 1, comprising: a measuring step of measuring a signal based on vibration generated from the rolling bearing, the signal including rolling element passing vibration when the rolling element rolls on the raceway surface having the non-circular shape; a calculation step of performing frequency analysis on the signal to calculate spectral data; a detection step of detecting the presence or absence of orbital slip of the rolling element by comparing a frequency at which a peak appears due to the rolling element passing vibration in the spectrum data with a theoretical revolution frequency due to the revolution of the rolling element when there is no slip of the rolling element; A method for detecting revolutionary slippage in a rolling bearing, comprising:

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