JP2010286069A - Rolling bearing observation method - Google Patents

Abstract

The present invention provides a rolling bearing observation method capable of observing a grease state and the inside of a cage with high accuracy from X-ray tomographic data of the rolling bearing obtained by X-ray irradiation.
The material of the inner ring, outer ring, rolling element and grease is selected so that the gray scale of grease is different from the gray scale of the inner ring, outer ring and rolling element. A mixed material of reinforcing fibers or a mixed material of heat resistant resin and reinforcing fibers is selected, and a material having a different gray scale is selected for the resin portion of the fluorine-based resin or the heat resistant resin and the reinforcing fibers. Based on the X-ray absorptance data, image data representing the gray scale of the rolling bearing cross section is acquired and displayed on the image display device. In addition, the state of the inner ring, outer ring, rolling elements and grease is observed with an image display device. Moreover, the fiber flow direction of a reinforced fiber is observed with an image display apparatus by performing the density | concentration process which isolate | separates the resin part and reinforcing fiber of a cage | basket.
[Selection] Figure 6

Description

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

In rolling bearings filled with grease, in order to extend the life of the bearing by grease lubrication, which part of the raceway surface inside the rolling bearing has grease (grease distribution) and how the grease is attached It is necessary to check the grease condition (grease shape).
Conventionally, a method is known in which at least one of an inner ring and an outer ring is made of a transparent body such as an acrylic resin, and grease is seen through the transparent body to obtain information on the grease state in the rolling bearing ( For example, Patent Document 1).

In the method of Patent Document 1, since 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, 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.

  Therefore, the present invention solves the problems of the prior art as described above, and a rolling bearing observation method capable of accurately inspecting the grease state based on X-ray tomographic data of the rolling bearing obtained by X-ray irradiation. The purpose is to provide.

  In order to achieve the above object, an observation method for a rolling bearing according to claim 1 includes an inner ring, an outer ring, a rolling element, a cage and a grease for guiding and holding the rolling element between the races of the inner ring and the outer ring. X-ray absorptivity data of the cross section of the rolling bearing is obtained by irradiating the provided rolling bearing with X-rays, and based on the X-ray absorptivity data, image data representing the gray level of the transverse cross section is obtained. A method of observing an internal state of the rolling bearing by acquiring and displaying the image on an image display device, wherein the gray scale of the grease is in a range different from the gray scale of the inner ring, the outer ring, and the rolling element. The inner ring, the outer ring, the rolling element and the grease material are selected, and the cage is a mixed material of fluorine-based resin and reinforcing fiber, or heat-resistant resin and reinforced A material having a gray scale different from that of the fluororesin of the cage or the resin portion of the heat-resistant resin and the reinforcing fiber is selected as a fiber mixed material, and the inner ring and the outer ring inside the rolling bearing are selected. In addition to observing the state of the rolling elements and the grease with the image display device, based on the gray scale of the image data, performing a density process for separating the resin portion and the reinforcing fiber of the cage The fiber flow direction of the reinforcing fibers of the cage is observed with the image display device.

  According to a second aspect of the present invention, there is provided an observation method for a rolling bearing comprising: an inner ring, an outer ring, a rolling element, a rolling bearing provided with a retainer and grease for guiding and holding the rolling element between the races of the inner ring and the outer ring; X-ray absorptance data of the cross section of the rolling bearing is obtained by irradiating a line, and based on this X-ray absorptivity data, image data representing the gray level of the cross section in gray scale is obtained to obtain an image display device In the method of observing the internal state of the rolling bearing, the inner ring, the outer ring, the rolling element, the grease and the air present in the bearing have different gray scales, respectively. The material of the inner ring, the outer ring, the rolling element and the grease is selected, and the cage is a mixed material of fluorine resin and reinforcing fiber, or a mixture of heat resistant resin and reinforcing fiber. A material having a different gray scale is selected for the fluororesin of the cage or the resin portion of the heat resistant resin and the reinforcing fiber, and the inner ring, the outer ring, and the rolling ring inside the rolling bearing. While observing the state of the moving body, the grease and the air with the image display device, based on the gray scale of the image data, by performing a light and shade process to separate the resin portion and the reinforcing fiber of the cage, The fiber flow direction of the reinforcing fibers of the cage is observed with the image display device.

  According to the method for observing a rolling bearing according to the present invention, it is possible to accurately acquire the distribution and shape of the grease, and to observe the resin and the reinforcing fiber forming the cage with high accuracy.

It is a figure which shows the axial direction cross section of the rolling bearing of 1st Embodiment for internal observations. It is an AA arrow line view of FIG. It is a figure which shows the structure of the bearing observation apparatus which observes a rolling bearing. It is the figure which displayed the air which exists in a rolling bearing image. It is the figure which displayed the image of the holder | retainer and rolling element inside a rolling bearing. It is the figure which image-displayed the fluororesin and reinforced fiber which comprise the cage | basket inside a rolling bearing. It is the figure which displayed the image of the inner ring | wheel and outer ring | wheel of a rolling bearing. It is the figure which displayed the grease enclosed with the rolling bearing as an image.

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 the rolling bearing of the first embodiment)
FIG. 1 is an axial sectional view showing a rolling bearing 1 according to an embodiment of 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, and 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 a mixed material of fluorine-based resin and reinforcing fiber, or a mixed material of heat-resistant resin and reinforcing fiber. Specific examples of the fluorine-based resin or heat-resistant resin include PFA, ETFE, PVDF, FEP, PCTFE, ECTFE, PEN, PEEK, PEEK-PBI, TPI and the like can be mentioned. Specific materials for the reinforcing fiber include carbon fiber and glass fiber.

Next, an embodiment of a rolling bearing observation apparatus for observing 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, thereby obtaining a CT value (for example, X-ray absorption rate for medical use: water X An X-ray CT apparatus 11 for measuring data), and a CT data storage unit 12 for storing CT value data measured by the X-ray CT apparatus 10; The CT image creation calculation unit 13 that creates a CT image (image data) based on the CT value data, the gray scale processing calculation unit 14 that performs gray scale processing on the created CT image, and the gray scale processing calculation unit 14 A CT image analysis processing unit 15 that creates CT image analysis data based on the scale-processed data (grayscale processing data), and a CT image analysis created by the CT image analysis processing unit 15 A display device (image display device: color display) 16 for displaying data, an X-ray CT apparatus 11, a CT data storage unit 12, an image creation calculation unit 13, a gray scale processing calculation unit 14, a CT image analysis processing unit 15, and An MPU (microprocessing unit) 17 that controls the display device 16 and an operation unit 18 that operates the MPU 17 are provided.

  The X-ray CT apparatus 11 includes a sample mounting table 20 on which the rolling bearing 1 is mounted so that the axial direction is in the vertical direction (the direction of gravity) and is rotatable about the axis, and the rolling bearing 1. On the other hand, an X-ray irradiation unit 21 that irradiates 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 that measures the CT value of the rolling bearing 1. 23. 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. The tone is emphasized and held for each predetermined gradation range.
The CT image analysis processing unit 15 creates data that can grasp the shape of each component of the rolling bearing 1, data that can finally grasp the distribution and shape of the grease 6, and data that can grasp the state of the reinforcing fiber of the cage 5. To do.

Next, a procedure for observing the rolling bearing 1 using the rolling bearing observation apparatus 10 having the above configuration will be described with reference to FIGS.
First, when the rolling bearing 1 is placed on the sample mounting table 20 of the X-ray CT apparatus 11 and irradiated with X-rays from the X-ray irradiating unit 21, the cross section (axial direction) of the rolling bearing 1 measured by the X-ray measuring unit 23. The CT value is stored as a ¹⁴ -bit numerical value on the basis of the CT data of the cross section orthogonal to (2 cross section), and is represented by a gray scale in the range of −8192 to 8192 with 2 ¹⁴ = 16384 gradations. Process data is created.

  First, information indicating the position of the air (symbol 7 in FIG. 2) in the rolling bearing 1 is displayed on the display device 16. That is, as shown in FIG. 4, the display device 16 displays CT image analysis data obtained by converting the gray scale indicating the air region into blue.

  Next, information indicating the positions of the cage 5 and the balls 4 is displayed on the display device 16. That is, on the display device 16, as shown in FIG. 5, the gray scale of the area excluding the cage 5 and the ball 4 is converted to black, and the gray scale of the area showing the cage 5 and the ball 4 is converted to yellow. The CT image analysis data obtained is displayed.

  Next, linear information indicating the fiber flow of the reinforcing fibers contained in the cage 5 is displayed on the display device 16. That is, as shown in FIG. 6, the display device 16 converts the gray scale indicating the region of the reinforcing fiber of the cage 5 to black, and the region of the fluororesin of the cage 5 or the resin portion of the heat resistant resin. The CT image analysis data obtained by converting the gray scale indicating yellow into yellow is displayed.

Next, information indicating the positions of the inner ring 3 and the outer ring 2 is displayed on the display device 16. That is, as shown in FIG. 7, the display device 16 converts the gray scale of the area excluding the inner ring 3 and the outer ring 2 into black, and converts the gray scale indicating the inner ring 3 and the outer ring 2 into red. Data is displayed.
Next, information indicating the position of the grease (reference numeral 6 in FIG. 2) is displayed on the display device 16. That is, as shown in FIG. 8, the display device 16 displays CT image analysis data in which the gray scale indicating the grease region is displayed in gray and the gray scale indicating the other region is converted to white.

Here, in the above observation, the sample mounting table 20 of the X-ray CT apparatus 11 is rotationally driven to rotate the rolling bearing 1 to a predetermined angle around the axis, and the moving unit 22 is driven to move the rolling bearing 1 in the vertical direction. 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 position.
Next, the effect of observation of the rolling bearing 1 using the rolling bearing observation apparatus 10 having the above configuration will be described.

  The rolling bearing 1 for observation of this embodiment has an inner ring 3, an outer ring 2, a ball 4, and a cage made of a material having a CT value (X-ray absorption rate) different from that of the grease 6 and a CT value close to that of the grease 6. 5, each component (inner ring 3, outer ring 2, ball 4, cage 5) and the shape of the air present inside the bearing are reliably grasped, and each component, air, and grease 6 Can be clearly separated, so that the distribution and shape of the grease 6 can be obtained accurately.

In addition, the present embodiment reliably grasps the shape of each component (inner ring 3, outer ring 2, ball 4, cage 25) and air 7 existing inside the bearing, and each component and air 7 and grease 6 Can be clearly separated, so that the distribution and shape of the grease 6 can be obtained accurately.
And in this embodiment, the fiber flow of the reinforced fiber which comprises the holder | retainer 25 is correctly acquired by confirming the area | region of the reinforced fiber displayed in black and linear on CT image analysis data. Can do.

Furthermore, in the method for observing the rolling bearing 1 of the present embodiment, the CT value of the CT image is stored as a ¹⁴ -bit numerical value and expressed by a gray scale in the range of −8192 to 8192 with 2 ¹⁴ = 16384 gradations. Since the rolling bearing observation device 10 that creates gray scale processing data for each gradation range is used, the display device 16 can clearly display the inside of the rolling bearing 1.

  In each of the above-described embodiments, the observation rolling bearings 1 and 24 are used. However, the same operation and effect can be achieved even if the rolling bearing has another configuration in which grease is sealed.

  DESCRIPTION OF SYMBOLS 1 ... Rolling bearing, 2 ... Outer ring, 2a ... Outer ring raceway surface, 3 ... Inner ring, 3a ... Inner ring raceway surface, 4 ... Ball (rolling element), 5 ... Cage (cage of 1st Embodiment), 6 ... Grease , 7 ... Air, 10 ... Bearing observation device, 11 ... X-ray CT device, 12 ... Data storage unit, 13 ... Image creation calculation unit, 14 ... Gray scale processing calculation unit, 15 ... CT image analysis processing unit, 16 ... Display Device (image display device), 17 ... MPU, 18 ... operating unit, 20 ... sample mounting table, 21 ... X-ray irradiation unit, 22 ... moving unit, 23 ... X-ray measuring unit

Claims (2)

X-ray absorptance of the cross section of the rolling bearing by irradiating the rolling bearing with an inner ring, an outer ring, a rolling element, a cage that guides and holds the rolling element between the races of the inner ring and the outer ring, and grease. A method for observing the internal state of the rolling bearing by obtaining data and obtaining image data representing the gray level of the cross section in gray scale based on the X-ray absorptance data and displaying it on an image display device Because
The material of the inner ring, the outer ring, the rolling element, and the grease is selected so that the gray scale of the grease is in a range different from the gray scale of the inner ring, the outer ring, and the rolling element. A mixed material of fluorine resin and reinforcing fiber, or a mixed material of heat resistant resin and reinforcing fiber, and the fluorine resin or resin portion of the heat resistant resin and the reinforcing fiber are selected from materials having different gray scales. ,
While observing the state of the inner ring, the outer ring, the rolling element and the grease inside the rolling bearing with the image display device,
Based on the gray scale of the image data, the fiber flow direction of the reinforcing fibers of the cage is observed with the image display device by performing a density process for separating the resin portion of the cage and the reinforcing fibers. A method of observing a rolling bearing, characterized in that X-ray absorptance of the cross section of the rolling bearing by irradiating the rolling bearing with an inner ring, an outer ring, a rolling element, a cage that guides and holds the rolling element between the races of the inner ring and the outer ring, and grease. A method for observing the internal state of the rolling bearing by obtaining data and obtaining image data representing the gray level of the cross section in gray scale based on the X-ray absorptance data and displaying it on an image display device Because
The inner ring, the outer ring, the rolling elements, the grease, and the air existing in the bearings have different gray scales, and the materials for the inner ring, the outer ring, the rolling elements, and the grease are selected and held. The container is a mixed material of fluorine-based resin and reinforcing fiber, or a mixed material of heat-resistant resin and reinforcing fiber, and the fluorine-based resin or the resin portion of the heat-resistant resin and the reinforcing fiber are materials having different gray scales. Select
While observing the state of the inner ring, the outer ring, the rolling element, the grease and air inside the rolling bearing with the image display device,
Based on the gray scale of the image data, the fiber flow direction of the reinforcing fibers of the cage is observed with the image display device by performing a density process for separating the resin portion of the cage and the reinforcing fibers. A method of observing a rolling bearing, characterized in that

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