JP2011038880A - Method of observing rolling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of observing a rolling device capable of accurately observing a state of lubricant by X-ray tomographic data of the rolling device obtained by applying X rays. <P>SOLUTION: X-ray absorption rate data inside the rolling device are obtained by applying X rays, and X-ray image data indicating shading inside the rolling device by a gray scale are acquired, based on the X-ray absorption rate data. Then, CAD image data indicating shapes of an inner track member, an outer track member, and a rolling element for composing the rolling device are acquired based on the CAD data. Then, differential image data, namely non-common parts of the X-ray image data and the CAD image data, are acquired based on a difference between the X-ray image data and the CAD image data. After that, an internal shape of the rolling device is displayed on an image display device based on the X-ray image data and the differential image data, and a shape change part is observed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for observing an internal state of a rolling device by acquiring image data by X-ray irradiation.

For rolling bearings (rolling devices) filled with grease (lubricant), in order to extend the bearing life by grease lubrication, which part of the raceway surface inside the rolling bearing has grease (grease distribution), It is necessary to inspect the grease condition such as how the grease is attached (grease shape).
Conventionally, at least one of the inner ring (inner race member) and the outer ring (outer race member) is made of a transparent material such as acrylic resin, and grease is seen through the transparent body, so that information on the grease state in the rolling bearing is obtained. There is known a method for obtaining the above (for example, Patent Document 1).

In the method of Patent Document 1, only the surface of the grease seen through the transparent body of at least one of the inner ring and the outer ring is observed, and therefore information on the distribution and shape of the grease cannot be obtained accurately.
Therefore, for example, as shown in Patent Documents 2 and 3, a method of inspecting the inside of a sample by irradiating the inside of the sample with X-rays and performing image processing of an X-ray transmission image based on a difference in the X-ray absorption coefficient inside the sample, Alternatively, as shown in Patent Document 4, X-ray tomograms are taken by irradiating X-rays on rolling bearings filled with grease, and the area change and the position change in the dark color area of the X-ray tomograms are compared to determine the grease. A method for acquiring state information is known.

JP 2005-69288 A JP 2001-201465 A JP 2007-1111525 A JP 2007-155534 A

However, even if the samples of Patent Documents 2 and 3 are applied to a rolling bearing, or just by irradiating the rolling bearing with X-rays as in the method of Patent Document 4, information on the grease state in the rolling bearing can be accurately obtained. It is difficult to get.
That is, the inner ring, the outer ring, the rolling elements, etc., which are components of a rolling bearing, usually use bearing steel having a higher X-ray absorption rate than grease, and photograph the shape of the component made of bearing steel. Therefore, the presence of grease disappears when irradiated with intense X-rays, and when X-rays are irradiated to the extent that the state of the grease can be imaged, the X-rays can pass through the components made of bearing steel, and the shape is imaged. There is a problem that can not be.

  Accordingly, the present invention solves the above-mentioned problems of the prior art, and allows the state of the lubricant to be accurately observed from the X-ray tomographic data of the rolling device obtained by X-ray irradiation. It aims at providing the observation method of an apparatus.

  In order to achieve the above object, an invention according to claim 1 is a method for observing an internal state of a rolling device including an inner race member, an outer race member, a rolling element, and a lubricant, and irradiates X-rays. To obtain X-ray absorptance data inside the rolling device, and based on the X-ray absorptance data, obtain X-ray image data representing the gray inside the rolling device in gray scale, CAD image data indicating the shapes of the inner race member, the outer race member, and the rolling element is acquired based on CAD data at the time of designing a rolling device, and based on a difference between the X-ray image data and the CAD image data. Difference image data that is a non-common part of these data is acquired, and a change portion of the internal shape of the rolling device is displayed on the image display device based on the X-ray image data and the difference image data. Was Unishi.

The invention according to claim 2 is the observation method of the rolling device according to claim 1, wherein the gray scale of the lubricant is different from the gray scale of the inner race member, the outer race member, and the rolling element. The material of the inner race member, the outer race member, the rolling element and the lubricant was selected.
According to a third aspect of the present invention, in the rolling device observation method according to the first aspect, the inner raceway member, the outer raceway member, the rolling element, the lubricant, and the air present inside the rolling device are The materials of the inner race member, the outer race member, the rolling element, and the lubricant were selected so as to have different gray scales.

  According to a fourth aspect of the present invention, in the rolling device observation method according to any one of the first to third aspects, the rolling element is guided and held between the tracks of the inner track member and the outer track member. A CAD image data indicating the shape of the cage together with the inner race member, the outer race member and the rolling element based on CAD data, and obtaining the X-ray image data and the CAD image. Difference image data that is a non-common part of these data is acquired based on the difference in data, and a change portion of the internal shape of the rolling device is transferred to the image display device based on the X-ray image data and the difference image data. Displayed.

  According to the observation method for a rolling device according to the present invention, X-ray absorption rate data inside the rolling device is obtained by irradiating X-rays, and the inside of the rolling device is obtained based on the X-ray absorption rate data. X-ray image data representing the shade of the image in gray scale is acquired, CAD image data indicating the shapes of the inner track member, the outer track member and the rolling element is acquired based on the CAD data at the time of designing the rolling device, and the X-ray Based on the difference between the image data and the CAD image data, differential image data which is a non-common part of these data is obtained, and the internal shape of the rolling device is displayed on the image display device based on the X-ray image data and the differential image data. Therefore, it is possible to accurately grasp the shape of each constituent member (inner ring, outer ring, ball) that has a relatively small shape change but relatively moves. As a result, it is possible to accurately acquire a relatively large change in the distribution and shape of the lubricant enclosed in the rolling device.

It is a figure which shows the axial direction cross section of the rolling device of 1st Embodiment for inside observation. It is an AA arrow line view of FIG. It is a figure which shows the structure of the observation apparatus which performs the internal observation of the rolling device of 1st Embodiment. It is a figure which shows the rolling device of 2nd Embodiment for internal observation. It is a figure which shows the rolling device of 3rd Embodiment for internal observation. It is a figure which shows the rolling device of 4th Embodiment for internal observation. It is a figure which shows the rolling device of 5th Embodiment for internal observation.

Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
(Configuration of rolling bearing)
FIG. 1 is an axial sectional view showing a rolling bearing 1 according to the present invention, and FIG. 2 is an AA cross section of FIG.

As shown in FIG. 1, the rolling bearing 1 includes an outer ring 2, an inner ring 3, a plurality of balls 4 incorporated between the outer ring 2 and the inner ring 3, and a crown for guiding and arranging a plurality of balls 4. And a cage 5 having a shape.
An arc groove-shaped outer ring raceway surface 2a is formed at the axial center of the inner peripheral surface of the outer ring 2, and an arc groove shape facing the outer ring raceway surface 2a is formed at the axial central portion of the outer peripheral surface of the inner ring 3. The inner ring raceway surface 3a is formed.

  As shown in FIG. 2, grease 6 is sealed in a predetermined distribution and shape in the internal space of the rolling bearing 1 surrounded by the outer ring raceway surface 2 a, the inner ring raceway surface 3 a, and the cage 5. Air (bubbles) 7 is present in an internal region different from that in FIG.

  The outer ring 2 and the inner ring 3 are formed of a composite material of fluorine-based resin and carbon fiber, or a composite material of heat-resistant resin and carbon fiber. Specific examples of the composite material of the fluororesin and the carbon fiber include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-ethylene copolymer (ETFE), and polyvinylidene fluoride ( PVDF), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyether nitrile (PEN), polyether ether ketone (PEEK), copolymer of polyetheretherketone and polybenzimidazole (PEEK-PBI), thermoplastic polyimide (TPI), aluminum borate whisker, potassium titanate whisker, carbon Fibrous fillers such as isker, aramid fiber, aromatic polyimide fiber, liquid crystal polyester fiber, graphite whisker, glass fiber, carbon fiber, boron fiber, silicon carbide whisker, silicon nitride whisker, alumina whisker, aluminum nitride whisker, wollastonite The material which mix | blended is mentioned.

The balls 4 are made of ceramic or glass. Specific ceramic materials include silicon nitride (Si ₃ N ₄ ), silicon carbide (SiC), sialon, and partially stabilized zirconia (ZrO ₂ ). , Hard carbon, and alumina (Al ₂ O ₃ ).
The cage 5 is made of fluororesin or heat-resistant resin, and specific materials include PFA, ETFE, PVDF, FEP, PCTFE, ECTFE, PEN, PEEK, PEEK-PBI, TPI, etc. Can be mentioned.

  Grease 6 has no particular restrictions on the type and blending ratio of base oil, thickener, additive, and mineral oil, ester-based synthetic oil, ether-based synthetic oil, hydrocarbon-based synthetic oil, etc. are used as the base oil. As soaps, metal soaps such as lithium soap, urea compounds, and the like are used.

(Rolling bearing observation device)
Next, an embodiment of a rolling bearing observation apparatus that observes the rolling bearing 1 having the above-described configuration will be described with reference to FIG.
The rolling bearing observation apparatus 10 according to the present embodiment irradiates the rolling bearing 1 with X-rays from a predetermined position orthogonal to the axial direction to obtain a CT value (for example, 0 for water and −1000 for air in the case of medical use). X-ray CT11 that measures data, a CT data storage unit 12 that stores CT value data measured by the X-ray CT11, and a CT image creation calculation unit 13 that creates a CT image based on the CT value data A gray scale processing calculation unit 14 that performs gray scale processing on the CT image generated by the CT image generation calculation unit 13 and data (X-ray image data) subjected to gray scale processing by the gray scale processing calculation unit 14 are used. Based on the X-ray image data storage unit 24 to be stored and the CAD (Computer Aided Design) data of the rolling bearing 1 to be observed, the outer ring 2, the inner ring 3, the ball 4, and the three-dimensional shape The CT image analysis data is displayed based on the data of the CAD image data storage unit 25 storing the image data (CAD image data) of the holder 5 and the X-ray image data storage unit 24 and the CAD image data storage unit 25. MPU that controls the display device (image display device: color display) 16 and the X-ray CT 11, CT data storage unit 12, image creation calculation unit 13, grayscale processing calculation unit 14, CT image analysis processing unit 15, and display device 16 A (microprocessing unit) 17 and an operation unit 18 for operating the MPU 17 are provided.

  The X-ray CT 11 is in relation to the sample mounting table 20 on which the rolling bearing 1 is mounted such that the axial direction is in the vertical direction (the direction of gravity) and is rotatable about the axis, and the rolling bearing 1. An X-ray irradiation unit 21 that emits X-rays from a direction orthogonal to the axial direction, a moving unit 22 that moves the X-ray irradiation unit 21 in the vertical direction, and an X-ray measurement unit 23 that measures the CT value of the rolling bearing 1 It has. The sample mounting table 20 has a function of rotating the rolling bearing 1 around its axis.

Based on the CT image created by the image creation computation unit 13, the gray scale processing computation unit 14 stores, for example, a CT value as a 14-bit numerical value and uses a gray scale in the range of −8192 to 8192 with 2 ¹⁴ = 16384 gradations. And highlighted for each gradation in a predetermined range.
The CT image analysis processing unit 15 creates data that can grasp the shape of each component of the rolling bearing 1 and finally data that can grasp the distribution and shape of the grease 6.

  Here, the rolling bearing observation apparatus 10 having the above configuration rotates the sample mounting table 20 of the X-ray CT 11 to rotate the rolling bearing 1 to a predetermined angle around the axis, and drives the moving unit 22 to drive the rolling bearing 1. It is assumed that CT image analysis data is displayed on the display device 16 while the irradiation direction of the rolling bearing 1 irradiated with X-rays from the X-ray irradiation unit 21 is appropriately changed by changing the vertical position.

  Therefore, in the observation method of the rolling bearing 1 of the present embodiment, CT value data inside the rolling bearing 1 is obtained by irradiating the rolling bearing 1 with X-rays, and the inside of the rolling bearing 1 is obtained based on this CT value data. X-ray image data representing gray scale in gray scale is acquired, and CAD image data indicating the shapes of the outer ring 2, inner ring 3, ball 4 and cage 5 of the rolling bearing 1 is acquired based on CAD data stored in advance. Based on the difference between the X-ray image data and the CAD image data, difference image data which is a non-common part of these data is acquired, and the shape change portion can be observed based on the difference image data. Further, even if there is no difference in the gray scale values of the constituent members (the inner ring 3, the outer ring 2, the ball 4, the cage 5, and the grease 6) in the X-ray image data, it is based on the difference between the X-ray image data and the CAD image data. The difference image data which is a non-common part of these data is acquired, and the shape of each constituent member (the inner ring 3, the outer ring 2, the ball 4, the cage 5) and the other part can be distinguished, thereby rolling. Since the shape of the grease 6 and the like existing inside the bearing 1 can be reliably grasped and the grease 6 and other parts can be clearly separated, the distribution and shape of the grease 6 inside the bearing 1 can be obtained accurately. it can.

  In this embodiment, the rolling bearing 1 is used as a rolling device for observation. However, the linear guide device 26 shown in FIG. 4, the ball screw 27 shown in FIG. 5, the rack and pinion 28 shown in FIG. 6, or FIG. Even if the worm gear 29 shown in FIG. 2 is used as a rolling device for observation, the distribution and shape of the grease sealed in the device can be accurately acquired. In these figures, the cross section for obtaining the CT value by irradiating X-rays is a cross section D1 orthogonal to the axial direction of the rail portion 26a in which the bearing portion 26b is movably arranged in the linear guide device 26 of FIG. In the ball screw 27 of FIG. 5, a cross section D2 perpendicular to the axial direction of the screw portion 27b in which the nut portion 27a is movably disposed, and in the rack and pinion 28 of FIG. 6, the meshing cross section D3 of the rack portion 28a and the pinion 28b, The worm gear 29 has a meshing section D4 between the worm 29a and the worm wheel 29b.

  DESCRIPTION OF SYMBOLS 1 ... Rolling bearing (rolling device), 2 ... Outer ring (outer raceway member), 2a ... Outer ring raceway surface, 3 ... Inner ring (inner raceway member), 3a ... Inner ring raceway surface, 4 ... Ball (rolling element), 5 ... Cage, 6 ... Grease (lubricant), 7 ... Air, 10 ... Bearing observation device, 11 ... X-ray CT, 12 ... Data storage unit, 13 ... Image creation calculation unit, 14 ... Grayscale processing calculation unit, 15 ... CT image analysis processing unit, 16 ... display device (image display device), 17 ... MPU, 18 ... operation unit, 20 ... sample mounting table, 21 ... X-ray irradiation unit, 22 ... moving unit, 23 ... X-ray measurement unit, 24 ... X-ray image data storage unit, 25 ... CAD image data storage unit, 26 ... Linear guide device (rolling device), 27 ... Ball screw (rolling device), 28 ... Rack and pinion (rolling device), 29 ... Worm gear (rolling device)

Claims (4)

A method of observing the internal state of a rolling device provided with an inner race member, an outer race member, rolling elements and a lubricant,
X-ray image data representing X-ray absorptance data inside the rolling device by irradiating X-rays, and representing the shade inside the rolling device in gray scale based on the X-ray absorptance data Get
CAD image data indicating the shape of the inner race member, the outer race member and the rolling element is obtained based on CAD data;
Based on the difference between the X-ray image data and the CAD image data at the time of designing the rolling device, obtaining difference image data that is a non-common part of these data,
A method for observing a rolling device, wherein a change portion of the internal shape of the rolling device is displayed on an image display device based on the X-ray image data and the difference image data.   The material of the inner race member, the outer race member, the rolling element and the lubricant so that the gray scale of the lubricant is in a different range from the gray scale of the inner race member, the outer race member and the rolling element. The method for observing a rolling device according to claim 1, wherein:   The inner track member, the outer track member, the rolling element so that the air present in the inner track member, the outer track member, the rolling element, the lubricant, and the rolling device have different gray scales. The rolling device observation method according to claim 1, wherein a material of the lubricant is selected. A cage for guiding and holding the rolling elements between the tracks of the inner track member and the outer track member;
CAD image data indicating the shape of the cage together with the inner race member, the outer race member and the rolling element is obtained based on CAD data;
Based on the difference between the X-ray image data and the CAD image data, obtain differential image data that is a non-common part of these data;
The change part of the internal shape of the said rolling device is displayed on an image display apparatus based on the said X-ray image data and the said difference image data, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. Observation method of the rolling device.

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