JP7263063B2 - LUBRICANT DISTRIBUTION MEASURING SYSTEM AND LUBRICANT DISTRIBUTION MEASUREMENT METHOD - Google Patents

Description

The present invention relates to a lubricant distribution measuring system and a lubricant distribution measuring method.

In order to reduce the friction loss and oil consumption of a reciprocating internal combustion engine, it is important to understand the behavior of the oil film around the piston during actual operation. As a method for grasping such oil film behavior, there is a laser fluorescence oil film thickness measurement method. The laser fluorescent oil film thickness measurement method utilizes the fact that when a lubricating oil film containing a fluorescent substance is irradiated with a short wavelength laser beam, the intensity of the excited fluorescence is proportional to the oil film thickness ( For example, see Patent Document 1).

In Patent Document 1, a fluorescent substance is mixed in lubricating oil interposed between a cylinder and a piston arranged in the cylinder, and a laser beam is incident on the inside of the cylinder, and fluorescence excited by the laser beam is emitted. An oil film thickness measuring device is disclosed that detects the intensity with an optical sensor and measures the thickness of the lubricating oil at the site where the laser beam is incident based on the detected fluorescence intensity. Moreover, Patent Document 1 discloses that coumarin 6, which is an organic dye compound, is used as a fluorescent substance. When measuring the oil film thickness, Rhodamine B, which is an organic dye compound, is generally used in addition to Coumarin 6.

JP-A-6-174431

By the way, a laser fluorescent oil film thickness measuring method using an organic dye compound such as coumarin 6 or rhodamine B as a fluorescent substance is widely applied.

However, when measuring the thickness of an oil film using an organic dye compound, it is difficult to measure the thickness of a large oil film due to the light shielding effect of the organic dye compound itself. Specifically, when coumarin is used as the organic dye compound, the thickness of the oil film is limited to about 100 μm.
In addition, since the excitation light causes fading of the organic dye compound, continuous or long-term stable measurement is difficult.
In addition, the optical properties of the organic dye compound change greatly with temperature, and it is difficult to accurately measure the oil film thickness under conditions where the temperature changes.
In addition, organic dye compounds have low fluorescence intensity and low solubility in oil. Therefore, when a large amount of organic dye compound is added to the oil in order to obtain sufficient fluorescence intensity, the organic dye compound precipitates, making it difficult to obtain a high S/N ratio (signal-to-noise ratio). Have difficulty.

The present invention has been made in view of the above facts, and provides a lubricant distribution measuring system capable of stably measuring the distribution of lubricant dispersed inside a rolling bearing during rotation, and a lubricant. It is an object of the present invention to provide a distribution state measuring method.

A first aspect of the present disclosure is a rolling bearing portion comprising an inner ring and an outer ring, wherein at least one of the inner ring and the outer ring transmits light, and fluorescent light is emitted between the inner ring and the outer ring by excitation light. A rolling bearing portion having a storage portion for storing a lubricant in which quantum dots are dispersed, an irradiation portion for irradiating the storage portion with the excitation light while rotating the rolling bearing portion, and the storage portion are photographed. A measuring unit that two-dimensionally measures the fluorescence intensity of the quantum dots from the image captured by the imaging unit, and based on the fluorescence intensity measured by the measuring unit, derives the distribution state of the lubricant inside the rotating rolling bearing. and a lead-out part , wherein a lipophilic group is coordinated to the surface of the quantum dot .

A second aspect of the present disclosure is the lubricant distribution measuring system according to the first aspect, wherein a load is applied to at least one of the bearing and the rotating shaft of the rolling bearing portion in a direction intersecting the rotating shaft. It further comprises a part.

A third aspect of the present disclosure is the lubricant distribution measuring system according to the first aspect or the second aspect, wherein the fluorescence emitted by the quantum dots has a wavelength of 450 nm to 680 nm.

A fourth aspect of the present disclosure is the lubricant distribution measuring system according to any one of the first to third aspects, wherein the irradiation unit emits light having a wavelength less than the wavelength of fluorescence emitted by the quantum dots. A band-pass filter having a wavelength equal to or greater than the wavelength of fluorescence emitted by the quantum dots is further provided between the inner and outer rings and the imaging unit.

A fifth aspect of the present disclosure is the lubricant distribution measuring system according to any one of the first to fourth aspects, wherein the irradiation unit emits light with an irradiation time of 1 millisecond or less, Irradiate in synchronization with the rotation cycle of the bearing.

A sixth aspect of the present disclosure is a rolling bearing portion comprising an inner ring and an outer ring, wherein at least one of the inner ring and the outer ring transmits light, and fluorescence is emitted by excitation light between the inner ring and the outer ring A captured image captured by an imaging unit that captures an image of the storage part by irradiating the storage part with the excitation light while rotating the rolling bearing part having the storage part that stores the lubricant in which the quantum dots are dispersed. A method for two-dimensionally measuring the fluorescence intensity of the quantum dots and deriving the distribution state of the lubricant inside the rotating rolling bearing based on the measured fluorescence intensity, wherein the surface of the quantum dots has a lipophilic group This is a method for measuring the distribution state of a lubricant in which is coordinated .

According to the present invention, it is possible to provide a lubricant distribution measuring system and a lubricant distribution measuring method capable of stably measuring the distribution of lubricant dispersed inside a rolling bearing during rotation. can.

It is a figure showing an example of a schematic structure of a lubricant distribution state measuring system concerning a 1st embodiment. It is a figure which shows an example of a structure of an image measurement part. It is a figure which shows an example of a structure according to function of an arithmetic control unit. It is a figure which shows an example of the relationship between the fluorescence intensity of a liquid lubricant, and thickness (film thickness). It is a figure which shows an example of the relationship between the fluorescence intensity of a quantum dot, and the thickness of a liquid lubricant. It is a figure which shows an example which implement|achieved the arithmetic control unit by the structure containing a computer. FIG. 7 is a diagram showing an example of the flow of processing of a lubricant distribution calculation program 77P; FIG. 10 is a diagram showing an example of a photographed image of an observation site by irradiation with white light; FIG. 4 is a diagram showing an example of a fluorescent image in a stationary state; FIG. 4 is a diagram showing an example of a fluorescent image in a rotating state; FIG. 10 is a diagram showing an example of a fluorescent image when continuously irradiated with UV light in a rotating state; FIG. 10 is a diagram showing an example of a photographed image of an observation site by irradiation with white light; FIG. 4 is a diagram showing an example of a fluorescence image in a rotating state; It is a figure which shows an example of the rotation mechanism part which can measure the inner ring|wheel side of a ball bearing. It is a figure which shows an example of the rotating-mechanism part which can further measure the inner ring|wheel side of a ball bearing. FIG. 7 is a diagram showing an example of a schematic configuration of a lubricant distribution state measuring system according to a second embodiment; It is a figure which shows an example of the external appearance of a needle bearing. FIG. 4 is a diagram showing an example of a fluorescent image in a stationary state; FIG. 10 is a diagram showing an example of a fluorescence image in a needle bearing in a low rotation state; FIG. 10 is a diagram showing an example of a fluorescence image in a needle bearing in a high rotation state; FIG. 4 is a diagram showing an example of a three-dimensionally displayed image of a fluorescent image of an observation region in a stationary state; FIG. 10 is a diagram showing an example of a three-dimensionally displayed image of a fluorescent image of an observation area in a low rotation state; FIG. 10 is a diagram showing an example of a three-dimensionally displayed image of a fluorescent image of an observation area in a high rotation state;

An example of an embodiment that implements the technology of the present disclosure will be described in detail below with reference to the drawings. In the present disclosure, an example will be described in which the technology of the present disclosure is applied to a lubricant distribution state measuring system that measures the distribution state of lubricant applied inside the rolling bearing while the rolling bearing is rotating.

[Lubricant distribution state measurement system]
A lubricant distribution state measuring system of the present disclosure includes an inner ring and an outer ring, wherein at least one of the inner ring and the outer ring is a rolling bearing portion that transmits light, and fluorescence is generated by excitation light between the inner ring and the outer ring. a rolling bearing unit that stores a lubricant in which quantum dots that emit light are dispersed; an irradiation unit that irradiates the storage unit with the excitation light while rotating the rolling bearing unit; and the storage unit a measurement unit that two-dimensionally measures the fluorescence intensity of the quantum dots from the captured image captured by the imaging unit that captures the distribution of the lubricant inside the rotating rolling bearing based on the fluorescence intensity measured by the measurement unit and a derivation unit for deriving the state.

Quantum dots tend to be less likely to be degraded by excitation light irradiation, have superior fluorescence intensity, and have superior solubility in liquid lubricants, as compared to organic dye compounds. Therefore, the lubricant distribution state measuring system of the present disclosure can stably measure the distribution state of, for example, a liquid lubricant over a long period of time.

In addition, quantum dots can suppress the influence of their own light shielding compared to organic dye compounds, and can measure the thickness of a lubricant having a large film thickness. For example, the lubricant distribution state measuring system of the present disclosure can accurately measure lubricant thickness in a wide range from sub-μm to mm order, for example, lubricant thickness from 0.1 μm to 5 mm order.

In addition, quantum dots exhibit less change in fluorescence wavelength, fluorescence intensity, etc. due to temperature than organic dye compounds, and can accurately measure the thickness of a lubricant even under conditions where temperature changes.

In the present disclosure, a numerical range indicated using "-" indicates a range including the numerical values before and after "-" as the minimum and maximum values, respectively.
In the numerical ranges described step by step in the present disclosure, the upper limit value or lower limit value described in one numerical range may be replaced with the upper limit value or lower limit value of another numerical range described step by step. . Moreover, in the numerical ranges described in the present disclosure, the upper or lower limits of the numerical ranges may be replaced with the values shown in the embodiments.
In the present disclosure, each component may contain multiple types of applicable substances. When there are multiple types of substances corresponding to each component in the lubricant, the content rate or content of each component is the total content rate or content of the multiple types of substances present in the lubricant unless otherwise specified. means quantity.

[First embodiment]
The lubricant distribution measuring system according to the first embodiment uses a ball bearing as an example of the rolling bearing of the present disclosure, and measures the distribution of lubricant provided inside the ball bearing in the rotating state of the rolling bearing. .

FIG. 1 shows an example of a schematic configuration of a lubricant distribution state measuring system 100 according to the first embodiment.
As shown in FIG. 1, the lubricant distribution state measuring system 100 includes irradiation units 1 and 1A, image measurement units 2 and 2A which are examples of the measurement unit of the present disclosure, and ball sensors which are examples of the rolling bearing unit of the present disclosure. It has a rotating mechanism section 3 to which a bearing 3A is rotatably attached. The lubricant distribution state measuring system 100 also includes an arithmetic control unit 7 that is an example of the derivation unit of the present disclosure.

The lubricant distribution measuring system 100 includes an image measuring unit for observing the side portion (left side in FIG. 1) and the radial upper portion (upper side in FIG. 1) of the ball bearing 3A in the rotating mechanism portion 3. 2, 2A (details will be described later) are installed. Henceforth, the case where the upper part (upper side in FIG. 1) of the radial direction of 3 A of ball bearings is observed is mainly demonstrated.
The rotation mechanism section 3 has a rotation section 36 , and the central axis of the rotation section 36 is connected to a rotation drive section 6 such as a motor through an elastic coupling 5 . A shaft load application unit 4 is provided between the rotation mechanism unit 3 and the rotation drive unit 6 to apply a load to the ball bearing 3A by vertically displacing the shaft.

<Rotating mechanism>
A ball bearing 3A, which is an example of the rolling bearing portion of the present disclosure, uses a light-transmissive deep groove ball bearing, includes an inner ring 31 and an outer ring 32, and at least one of the inner ring 31 and the outer ring 32 transmits light. In addition, the ball bearing 3A includes balls 33 between the inner ring 31 and the outer ring 32, and liquid-like quantum dots that emit fluorescence by excitation light are dispersed in the region between the inner ring 31 and the outer ring 32. A storage part 35 for storing lubricant (hereinafter referred to as liquid lubricant) is provided.

Further, the rotating mechanism section 3 is provided with a glass window 37 on the front side to contain the liquid lubricant and to allow observation of the ball bearing 3A. In the cross-sectional view, in addition to the glass window portion, a sealed container portion 38 is provided to allow the liquid lubricant to be supplied to the ball bearing 3A to be circulated or sealed.

<Reservoir>
The reservoir 35 may transmit light in a wavelength band less than the fluorescence wavelength of the quantum dots at the position where the thickness of the liquid lubricant is measured. Further, the storage part 35 may be in a state in which a liquid lubricant in which quantum dots are dispersed is stored.

The liquid lubricant is not particularly limited as long as it can disperse the quantum dots. Examples of liquid lubricants include water-based lubricants, silicone-based lubricants, and oil-based lubricants, among which oil-based lubricants are preferred. Examples of oil-based lubricants include oils and greases based on hydrocarbon oils, ester oils, etc. More specifically, lubricating oils such as engine oils and automatic transmission fluids may be used. .
The liquid lubricant may be any lubricant that has fluidity under the usage environment, and may not have fluidity at room temperature, for example.

(quantum dot)
Quantum dots are not particularly limited, and include CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe , CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgGaZnSTe, GaN, GasGaPInS, GaN, ZnGaPInS N, AlP, AlAs, AlSb , InN, InP, InAs, InSb, GaNP, GaNAs, GaNAsb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP , GAINNAS, GAINNSB, GAINPAS, GAINPAS, GAINPSB, Inalnp, Inalnasb, Inalnsb, Inalpas, Snsb, Sns, Sns, SNSE, SNTE, PBS, PBS, PBS, PBS, SNSET, SNSET, SNSET, SNSET, SNSET PBSete, PBSTE, Snpbs, SnpbSE, Snpbte, Snpbsses , SnPbSeTe, SnPbSTe, Si, Ge, SiC, SiGe and the like.

Quantum dots may have a core-shell structure. Combinations of core and shell (core/shell) include CdSeS/ZnS, CdS/ZnS, CdSe/ZnS, CdSe/CdS, InP/ZnS, ZnCuInS/ZnS, PbSe/PbS, CdTe/CdS, CdTe/ZnS, and the like. mentioned.
Quantum dots also include carbon quantum dots, carbon quantum dots, graphene quantum dots, and the like.
From the viewpoint of suppressing adverse effects on the human body and the environment, it is preferable not to use quantum dots containing lead (Pb).

It is preferable that the quantum dot has a ligand coordinated to its surface. As a result, the dispersibility of the quantum dots in the liquid lubricant is improved, and the aggregation and precipitation of the quantum dots in the liquid lubricant tends to be suppressed. As a result, the quantum dots can be dispersed in the liquid lubricant with high uniformity for a long period of time, and the thickness of the liquid lubricant tends to be measured with high accuracy.

The ligand is preferably a compound having a hydrocarbon group and at least one substituent selected from among an amino group, a carboxyl group, a mercapto group, a phosphine group and a phosphine oxide group. Compounds having the aforementioned substituents are more preferred.

Specific examples of ligands include hexylamine, decylamine, hexadecylamine, octadecylamine, oleylamine, myristylamine, laurylamine, oleic acid, mercaptopropionic acid, trioctylphosphine and trioctylphosphine oxide.

The fluorescence wavelength (fluorescence peak wavelength) of quantum dots is preferably 450 nm to 680 nm. As the quantum dots, one type of quantum dots having a fluorescence wavelength of 450 nm to 680 nm may be used, or two or more types may be used.

When two or more types of quantum dots are used, the two or more types of quantum dots have a ratio of the overlapping area of the fluorescence intensity of the quantum dot and the other quantum dots to the area of the fluorescence intensity of the quantum dot. Each is 10% or less. Preferably.
Note that the aforementioned ratio is preferably 0%, that is, it is preferable that there is no overlapping region between the fluorescence intensity of a certain quantum dot and the fluorescence intensity of another quantum dot.

When using three types of quantum dots, each of the three types of quantum dots has a ratio of the overlapping area of the fluorescence intensity of the quantum dot and the other quantum dots to the area of the fluorescence intensity of the quantum dot is 10% or less. , and the fluorescence wavelengths of the quantum dots are preferably 400 nm to 500 nm, 500 nm to 570 nm and 570 nm to 680 nm, respectively.

The content of quantum dots in the liquid lubricant is preferably 0.0001% by mass to 0.1% by mass, more preferably 0.0003% by mass to 0.1% by mass, and 0.0005% by mass. % to 0.05% by mass, and particularly preferably 0.001% to 0.01% by mass. The content of quantum dots in the liquid lubricant may be appropriately adjusted according to the expected thickness of the liquid lubricant. For example, if the expected thickness of the liquid lubricant is relatively small, the aforementioned content is increased, and if the expected thickness of the liquid lubricant is relatively large, the aforementioned content is decreased. preferably.

When coumarin 6 is used as the fluorescent substance, the content of coumarin 6 in the liquid lubricant is said to be preferably 0.14 g/L to 0.28 g/L. Here, since the density of the engine liquid lubricant is about 0.85 g/cm ³ , the content is 0.016 mass % to 0.032 mass %. Organic dye compounds have poor solubility in liquid lubricants and are likely to precipitate.

On the other hand, quantum dots tend to be suppressed from being precipitated even when the content in the liquid lubricant is high, and they tend to be stably dispersed in the liquid lubricant. Therefore, when quantum dots are used as a fluorescent substance, there is a tendency to obtain high fluorescence intensity and a high S/N ratio.

When three types of quantum dots are used, the fluorescence wavelengths of the quantum dots are 400 nm to 500 nm, 500 nm to 570 nm and 570 nm to 680 nm, respectively, and the content of the quantum dots is independently 0.0001% by mass to 0.033. % by mass is preferable, 0.0005% by mass to 0.01% by mass is more preferable, and 0.001% by mass to 0.01% by mass is particularly preferable.

The particle size of the quantum dots is preferably 1 nm to 50 nm, more preferably 1 nm to 20 nm, even more preferably 3 nm to 10 nm.

The quantum dots to be used are preferably selected according to the spectral characteristics and wavelength band sensitivity of a light receiver such as a camera. For example, it is preferable to have a light emission characteristic in a wavelength band in which the light receiving sensitivity of a light receiver such as a camera is high. to ±50 nm band, and more preferably have a wavelength band of ±30 nm.

(liquid lubricant)
Next, a specific example of the liquid lubricant will be described. As quantum dots, 1 mg of CdSeS/ZnS alloy quantum dots with a particle size of 6 nm, which are surface-modified with oleic acid groups (18 carbon atoms) and have fluorescence spectrum wavelengths (medians) of 450 nm, 540 nm, 575 nm, 630 nm, and 665 nm. /mL toluene solution (manufactured by Sigma-Aldrich) or a 5 mg/mL toluene solution (manufactured by Sigma-Aldrich) of an InP/ZnS system with a particle size of 5 nm and a fluorescence spectrum wavelength (median value) of 620 nm. .

The toluene solution is added to the hydrocarbon base oil YUBASE-8 (manufactured by SK Corporation) or the commercially available automatic transmission fluid Toyota so that the quantum dot content is 0.000010 wt% to 0.10 wt% relative to the oil. A mixed liquid containing each quantum dot in autofluid WS was prepared.

The mixture was then heated at 80° C. for 28 hours to remove toluene to prepare a quantum dot-containing oil.
FIG. 1 shows the appearance of the CdSeS/ZnS alloy-type quantum dot-containing oil (quantum dot concentration: 0.10 wt %) and how it emits light when irradiated with ultraviolet rays. It can be seen that various fluorescence characteristics from blue to red are exhibited depending on the fluorescence spectrum wavelength of the quantum dots. In addition, in the quantum dot-containing oil produced by this method, the quantum dots were stably and uniformly dispersed in the oil, and neither precipitation nor separation occurred even after standing for one month. The InP/ZnS quantum dot-containing oil similarly exhibited stable dispersion properties and fluorescence properties. Compared to the CdSeS/ZnS system, the In/ZnS system is Cd-free, and therefore has better safety handling properties.

<Irradiation unit>
The irradiation unit 1 irradiates the excitation light to the reservoir 35 formed inside the ball bearing while rotating the ball bearing 3A. Specifically, the irradiation unit 1 irradiates excitation light for observing a radially upper portion (upper side in FIG. 1) of the rotation mechanism unit 3 .
The irradiation unit 1 can measure the distribution behavior of the liquid lubricant inside the ball bearing in the rotating state, and the light emission time and light emission period can be set from 1 light emission/μs to 1 light emission/s (continuous light emission), and the light emission period can be set to the maximum. It is controllable up to 1 kHz. This light emission cycle can be arbitrarily controlled by a trigger signal from an external system such as the arithmetic and control unit 7 .

The irradiation unit 1 may irradiate light in a wavelength band shorter than the fluorescence wavelength of the quantum dots, for example, ultraviolet rays. Further, the irradiation unit may irradiate light other than light in a wavelength band less than the fluorescence wavelength of the quantum dots, such as visible light, together with light in the wavelength band less than the fluorescence wavelength of the quantum dots.

The irradiation light wavelength of the irradiation unit 1 is preferably 100 nm or more and less than 450 nm (100≦λ<450). For the irradiation light emitted from the irradiation unit 1, one type of light source having an irradiation light wavelength of 100 nm or more and less than 450 nm may be used, or two or more types may be used.
In particular, it is preferable that the emission intensity ratio of light of 450 nm or more (λ≦450) in the irradiation unit 1 is less than 0.01% of the total light intensity.

More specifically, the irradiation unit 1 includes a light-emitting diode (LED), a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a deep ultraviolet lamp, an ultraviolet laser, a xenon lamp, a metal halide lamp, and the like. Further, when the irradiation section is an ultraviolet laser or the like that emits laser light, a movable mirror that changes the irradiation position of the laser light in the storage section may be arranged between the irradiation section and the storage section.

For example, when the irradiating unit 1 irradiates mixed light of ultraviolet light, which is light in the wavelength band less than the fluorescence wavelength of the quantum dots, and visible light, which is light other than light in the wavelength band less than the fluorescence wavelength of the quantum dots. , it is preferable to dispose an ultraviolet transmission visible absorption filter between the irradiation unit 1 and the storage unit 35 . As a result, the visible light is absorbed by the UV transmissive visible absorption filter, and only the UV light is irradiated to the liquid lubricant containing the quantum dots stored in the storage section.

When liquid lubricant containing quantum dots is stored in the reservoir 35 , light in a wavelength band less than the fluorescence wavelength of the quantum dots passes through the reservoir 35 and irradiates the liquid lubricant. By irradiating the quantum dots contained in the liquid lubricant with light in a wavelength band shorter than the fluorescence wavelength of the quantum dots, the quantum dots are excited, and the quantum dots emit fluorescence of a predetermined wavelength. Next, the fluorescence intensity of the quantum dots is two-dimensionally measured by the image measurement unit 2 .

When the content of quantum dots contained in the liquid lubricant is constant, the fluorescence intensity of the quantum dots is proportional to the thickness of the liquid lubricant. By using this property, the thickness of the liquid lubricant can be measured.
Further, the irradiation unit 1A irradiates excitation light for observing the side portion (the left side in FIG. 1) of the ball bearing 3A. The irradiation unit 1A has the same configuration as that of the irradiation unit 1, so the description thereof is omitted.

<Image measurement part>
The lubricant distribution state measuring system of the present disclosure includes an image measuring section 2 . The image measuring unit 2 is a measuring device that captures fluorescence in order to observe the fluorescence emitted from the quantum dot-containing liquid lubricant sealed inside the ball bearing 3A. That is, the image measurement unit 2 two-dimensionally measures the fluorescence intensity of the quantum dots from the captured image captured by the capturing unit that captures the storage unit 35 . The image measurement unit 2 includes, for example, a CCD camera and 3CCD camera using a CCD (Charge-Coupled Device) image sensor, and a CMOS camera and 3CMOS camera using a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

<Band pass filter>
The lubricant distribution measuring system of the present disclosure includes a band-pass filter with a wavelength greater than λ nm between the storage unit and the image measurement unit when the irradiation unit irradiates light with a wavelength of λ nm (100≦λ≦400). may be For example, when the irradiation unit irradiates light with a wavelength λ nm as light in a wavelength band less than the fluorescence wavelength of the quantum dots, by providing a band-pass filter with a wavelength greater than λ nm, light with a wavelength λ nm (less than the fluorescence wavelength of the quantum dots wavelength band) is suppressed from being irradiated to the image measurement unit, and light having a wavelength greater than λnm (for example, fluorescence of quantum dots) is selectively irradiated to the image measurement unit. Thereby, the fluorescence intensity of the quantum dots can be two-dimensionally measured with high accuracy.

The bandpass filter preferably transmits 90% or more of light with wavelengths of 450 nm to 470 nm, 520 nm to 570 nm and 600 nm to 680 nm. As a result, blue, green, and red light is selectively irradiated to the image measurement unit, and thereby, particularly when three types of quantum dots are used, the fluorescence intensity of each quantum dot can be accurately two-dimensionally measured. , the thickness of the liquid lubricant can be calculated two-dimensionally with higher accuracy.

FIG. 2 shows an example of the configuration of the image measuring section 2. As shown in FIG. The image measurement unit 2 shown in FIG. 2 is configured to multiplex the excitation light emitted from the irradiation unit 1 onto the imaging optical axis.
The image measurement unit 2 includes an objective lens 22 and a camera 23, and photographs excited fluorescence, that is, performs two-dimensional measurement in order to measure the distribution behavior of the liquid lubricant inside the ball bearing in a rotating state. . The image measurement unit 2 incorporates a beam splitter 15 , and the excitation light from the light source 11 guided by the light guide 14 is guided coaxially with the optical axis of the camera 23 . The image measuring section 2 also has a UV cut filter between the camera 23 and the objective lens 22 . Therefore, the excitation light emitted from the light source 11 is applied through the beam splitter 15 to the reservoir above the ball bearing, which is the object of measurement. In the reservoir above the ball bearing, the quantum dots are excited by the excitation light and emit fluorescence. A camera 23 photographs the fluorescence.

As the light source 11, an LED light source with a wavelength of 405 nm (manufactured by Leistungselektronik JENA GmbH) can be used. The light source 11 can measure the distribution behavior of the liquid lubricant inside the ball bearing in the rotating state, and the light emission time and light emission period are each from 1 light emission/μs to 1 light emission/s (continuous light emission), and the maximum light emission period is 1 kHz. controlled up to This light emission cycle is arbitrarily controlled by a trigger signal from the arithmetic control unit 7, which will be described later. As the filter 13, an ultraviolet transmission visible absorption filter (manufactured by Sigma Koki Co., Ltd.) can be used, and as the light guide 14, a UV transmission type light guide (manufactured by Lumatec Co., Ltd.) can be used. A plate-type beam splitter (manufactured by Edmund Corporation) can be used as the beam splitter 15 . As the adapter 21, an adapter (manufactured by Edmond) having a built-in long-pass filter (manufactured by Edmond) having a transmission band wavelength of 508 to 1650 nm can be used. An object telecentric lens (manufactured by Optoart Co., Ltd.) can be used for the objective lens 22 . A 3CMOS camera (manufactured by JAI Corporation) can be used as the camera 23 . A single-chip camera may be used as the 3CMOS camera.
The image measuring unit 2 having such a configuration is an example set to be suitable for measuring a lubricant containing quantum dots with a fluorescence wavelength of 540 nm, and the present disclosure is not limited to this configuration.

Note that FIG. 2 shows, as an example, the image measurement unit 2 for observing the radially upper portion (upper side in FIG. 1) of the rotation mechanism unit 3 . The image measuring section 2A for observing the side portion (the left side in FIG. 1) of the ball bearing 3A has the same configuration as the image measuring section 2, so the description thereof is omitted.

<Arithmetic control unit>
Based on the fluorescence intensity two-dimensionally measured by the image measurement unit 2, the arithmetic control unit 7 two-dimensionally derives the distribution state (thickness) of the liquid lubricant inside the rotating ball bearing 3A. For example, the fluorescence irradiated to the image measurement unit 2 is converted into an electric signal corresponding to its intensity, the converted electric signal is transmitted to the arithmetic control unit 7, and the thickness distribution of the liquid lubricant is derived.

FIG. 3 shows an example of the functional configuration of the arithmetic and control unit 7 .
The arithmetic control device 7 includes an image processing section 71 having a thickness distribution calculation section 72 , a synchronous drive control section 73 , a state control section 74 , a display section 75 and an operation input section 76 . The state control unit 74 controls the axial load applying unit 4 so that the load input by the operation input unit 76 is applied to the ball bearing 3A. The synchronous drive control unit 73 controls the light source of the irradiation unit 1 according to the light emission time and the light emission period input by the operation input unit 76 in order to measure the distribution behavior of the liquid lubricant inside the ball bearing 3A in the rotating state. emits light, and the rotary drive unit 6 is controlled so that the ball bearing 3A is in a rotating state. Based on the fluorescence image measured by the image measurement unit 2, the image processing unit 71 uses the thickness distribution calculation unit 72 to derive the distribution state of the liquid lubricant applied inside the ball bearing 3A.

In the example shown in FIG. 3, the state control unit 74 of the arithmetic control unit 7 controls the axial load applying unit 4 so as to apply a load to the ball bearing 3A. , and the axial load applying unit 4 may autonomously or mechanically apply the load to the ball bearing 3A. In this case, the state control section 74 is unnecessary, and the connection of the axial load applying section 4 to the arithmetic control device 7 is also unnecessary. When using the value of the load applied to the ball bearing 3A, the applied load is detected by a sensor such as a load cell, and the detected sensor value is manually or automatically input to the arithmetic control device 7. good.

In the example shown in FIG. 3, the synchronous drive control unit 73 controls the light emission time and light emission cycle of the light source of the irradiation unit 1, and controls the rotation drive unit 6 so as to rotate the ball bearing 3A. Although a case is shown, the technology of the present disclosure is not limited to this. That is, the light may be emitted autonomously or mechanically according to the light emission time and light emission period set in the irradiation unit 1 . Moreover, the rotation drive part 6 may use the independent rotation drive device which rotates 3 A of ball bearings autonomously or mechanically so that 3 A of ball bearings may be in a rotating state. In this case, the synchronous drive control section 73 is unnecessary, and the connection of the irradiation section 1 and the rotation drive section 6 to the arithmetic control device 7 is also unnecessary. When using the light emission time and light emission period of the light source and the rotation speed, each set value or the sensor value detected by the sensor may be manually or automatically input to the arithmetic and control unit 7 .

Here, when the content of quantum dots contained in the liquid lubricant is constant, the fluorescence intensity of the quantum dots is proportional to the thickness of the liquid lubricant. Therefore, when the content of quantum dots contained in the liquid lubricant is a specific value, a correspondence relationship (for example, a calibration curve) between the fluorescence intensity of the quantum dots and the thickness of the liquid lubricant is prepared in advance, By using the calibration curve data, the thickness of the liquid lubricant can be derived two-dimensionally based on the fluorescence intensity two-dimensionally measured by the image measurement unit 2 .

(calibration curve)
Next, a calibration curve showing the correspondence relationship between the fluorescence intensity of the quantum dots and the thickness of the liquid lubricant will be described.
FIG. 4 shows an example of the relationship between the fluorescence intensity and the thickness (film thickness) of the liquid lubricant with respect to the position of the thickness (film thickness) of the liquid lubricant that changes continuously.
FIG. 4 shows the measurement results of the fluorescence intensity of the liquid lubricant when it is irradiated with excitation light when the thickness (film thickness) of the liquid lubricant is continuously changed using a jig. In the example shown in FIG. 4, the fluorescence intensity is set to 0 at the portion where the thickness (film thickness) of the liquid lubricant is the smallest (for example, the vertex portion of the test piece).

In this measurement, a planar non-fluorescent quartz was placed on the surface of a test piece having a spherical surface with a radius of curvature of 50 mm, and a jig was used in which a liquid lubricant was filled between the surface of the test piece and the non-fluorescent quartz. A state in which the thickness of the agent changes spherically was prepared. As the liquid lubricant, an oil containing 0.1 mass % of quantum dots emitting fluorescence wavelength of 540 nm in a base oil (YUBASE4, manufactured by SK Corporation) was prepared and used. In this measurement, the image measurement unit 2 described above is used. The two-dimensional measurement was performed with an image of 8 bits, the number of pixels of 2064×1544, and a frame rate of 20 fps.

As shown in FIG. 4, the fluorescence intensity increases as the thickness of the liquid lubricant increases, corresponding to the spherical shape. FIG. 5 shows the result of deriving the correspondence relationship between the fluorescence intensity of the quantum dots and the thickness of the liquid lubricant based on the measurement results shown in FIG. As shown in FIG. 5, the correspondence relationship between the fluorescence intensity of the quantum dots and the thickness of the liquid lubricant is a good linear relationship, and the thickness of the liquid lubricant can be derived from the measured fluorescence intensity.

The thickness distribution calculation unit 72 stores in advance the correspondence relationship between the fluorescence intensity of the quantum dots and the thickness of the liquid lubricant (for example, the calibration curve shown in FIG. 5), and two-dimensionally measured by the image measurement unit 2. By deriving the thickness of the liquid lubricant corresponding to the fluorescence intensity for each pixel, the thickness of the liquid lubricant can be two-dimensionally derived.

(computer configuration)
The arithmetic and control unit 7 described above can be realized by a configuration including a computer as an execution device that executes processing for realizing the functions described above.
FIG. 6 shows an example in which the arithmetic and control unit 7 is implemented by a configuration including a computer.
The arithmetic control unit 7 has a computer main body 77 . The computer main body 77 has a CPU 77A, a RAM 77B, a ROM 77C, and an input/output interface (I/O) 77D. These CPU 77A, RAM 77B, ROM 77C, and input/output I/O 77D are connected via a bus 77E so as to exchange data and commands with each other. Further, the irradiation unit 1, the image measurement unit 2, the axial load applying unit 4, the rotation driving unit 6, the display unit 75, and the operation input unit 76 are connected to the I/O 77D.

As described above, the connection of the axial load applying section 4 is not necessary when the axial load applying section 4 autonomously or mechanically applies a load to the ball bearing 3A. In addition, when the irradiation unit 1 is configured to autonomously or mechanically emit light, and when the ball bearing 3A is configured to rotate autonomously or mechanically, the connection between the irradiation unit 1 and the rotation driving unit 6 is also possible. No need.

The ROM 77C stores a lubricant distribution calculation program 77P for causing the computer to function as the arithmetic control device 7. FIG. The CPU 77A reads the lubricant distribution calculation program 77P from the ROM 77C, develops it in the RAM 77B, and executes processing. As a result, the computer executing the lubricant distribution calculation program 77P operates as an image measuring device. The ROM 77C stores information indicating the correspondence relationship (calibration curve) between the fluorescence intensity of the quantum dots and the thickness of the liquid lubricant as a table. The lubricant distribution calculation program 77P and the table may be provided by a recording medium such as a CD-ROM.

FIG. 7 shows an example of the processing flow of the lubricant distribution calculation program 77P. The lubricant distribution calculation program 77P is an example of the lubricant distribution state measuring method of the present disclosure.

First, in step S100, initial setting is performed for measuring the distribution behavior of the liquid lubricant inside the ball bearing in the rotating state. An example of initial settings includes a calibration curve corresponding to the number of pixels, the frame rate, the light emission time in the irradiation unit 1, the period, and the liquid lubricant.
In the next step S102, by controlling the rotation drive unit 6, the ball bearing 3A is shifted to a rotating state. Synchronized irradiation. In the next step S106, the fluorescence intensity is two-dimensionally measured by photographing the fluorescence due to the irradiation of the excitation light of the irradiation unit 1. In the next step S108, the distribution state of the liquid lubricant is derived. indicate. In the next step S112, it is determined whether or not to end the lubricant distribution calculation process. If the answer is NO, the process returns to step S12.

FIGS. 8 to 11 show examples of observation images obtained by observing the radial upper portion (upper side in FIG. 1) of the ball bearing 3A as an observation portion using the lubricant distribution state measuring system of the present disclosure.
FIG. 8 shows a photographed image obtained by photographing an observation site irradiated with white light. FIG. 9 shows a photographed image of a fluorescence image from the liquid lubricant when irradiated with UV light in a stationary state. FIG. 10 shows a photographed image of a fluorescent image from the liquid lubricant when a portion to be observed of the ball bearing 3A in the rotating state is flash-irradiated with UV light. FIG. 11 shows a photographed image obtained by photographing a fluorescent image from the liquid lubricant when the observed portion of the ball bearing 3A in the rotating state is continuously irradiated with UV light. The periodic short-time UV light irradiation was performed with light having a wavelength of 405 nm at a frequency of 20 Hz and an irradiation time of 500 μs/shot. A rotation test was performed in a state in which the liquid lubricant was immersed up to half the height of the shaft center.

As shown in FIG. 9, the fluorescent image of the liquid lubricant at rest was distributed in an oval shape in the vertical direction of the screen (the width direction of the bearing) similar to the boundary of the liquid lubricant in the white light image shown in FIG. The state of existence of the liquid lubricant is clear. That is, the difference in the thickness of the liquid lubricant corresponds to the difference in fluorescence intensity. By deriving the thickness of the liquid lubricant corresponding to the fluorescence intensity, the thickness of the liquid lubricant can be two-dimensionally calculated. can be derived. In addition, as shown in FIG. 10, it is clear that the distribution of the liquid lubricant changes with the rotation in the periodic short-time irradiation of the UV light in the rotating state. On the other hand, as shown in FIG. 11, when the image was taken by continuously irradiating UV light, the fluorescent image was flowing, and it was difficult to accurately capture the distribution of the liquid lubricant. Thus, it is understood that periodic short-time irradiation of UV light is effective when measuring the distribution of liquid lubricant in a rotating state.

12 and 13 show an example of an observation image obtained by observing the side portion (the left side in FIG. 1) of the ball bearing 3A in the rotation mechanism 3 using the lubricant distribution state measuring system of the present disclosure. .
FIG. 12 shows a photographed image obtained by photographing an observation site irradiated with white light. FIG. 13 shows a photographed image of fluorescence from the liquid lubricant under periodic short-duration irradiation of UV light in a rotating state. Here, in order to enable detailed measurement of the distribution behavior of the liquid lubricant from the side surface of the ball bearing 3A, a fixed focus machine vision lens ( Optart Co.) and an ultraviolet achromatic condensing lens (Sigma Koki Co.) were used in combination.
As shown in FIG. 13, the spherical portion of the ball bearing 3A is bright, and even when the supply amount of the liquid lubricant is small, the liquid lubricant adheres to the spherical surface of the ball bearing 3A and rotates. could be measured.

The lubricant distribution state measuring system 100 includes an image measuring unit 2 and an image measuring unit 2A, and the upper part (the upper side in FIG. 1) and the side part (the left side in FIG. 1) in the radial direction of the rotation mechanism part 3. ), the technique of the present disclosure is not limited to this. For example, either one of the image measuring section 2 and the image measuring section 2A may be provided, and either the upper portion or the side portion in the radial direction of the rotating mechanism portion 3 may be observed.

<Modification>
The lubricant distribution state measuring system 100 described above includes an image measuring section 2 that measures the distribution of the liquid lubricant on the rolling surface of the outer ring side using the radially upper portion (upper side in FIG. 1) as an observation portion. explained the case. The technology of the present disclosure is not limited to this, and may measure the distribution of the liquid lubricant on the inner ring side rolling surface, and further measure the distribution of the liquid lubricant on the inner ring side rolling surface. may

FIG. 14 shows an example of the rotation mechanism 3 capable of measuring the distribution of the liquid lubricant on the inner ring side rolling surface 31A of the ball bearing 3A.
As shown in FIG. 14, a mirror 39 inclined at a predetermined angle (for example, 45 degrees) is installed at the central portion of the axis. By using the image measuring unit 2A to measure the distribution of the liquid lubricant on the inner ring side rolling surface 31A, the inner ring side rolling surface 31A of the ball bearing 3A can be observed (measured).

FIG. 15 shows an example of the rotating mechanism 3 capable of further measuring the distribution of the liquid lubricant on the rolling contact surface of the inner ring.
As shown in FIG. 15, the lubricant distribution measuring system 100 shown in FIG. 1 is provided with a mirror 39 inclined at a predetermined angle (for example, 45 degrees) at the center of the axis. By measuring the distribution of the liquid lubricant on the inner ring side rolling surface 31A with the image measuring unit 2A, the outer ring side rolling surface 32A and the inner ring side rolling surface 31A of the ball bearing 3A are measured. Both can be observed (measured).

Thus, according to the present embodiment, by measuring the fluorescence intensity of the fluorescence excited by the quantum dots and measuring the thickness distribution of the liquid lubricant, the The distribution of the liquid lubricant can be measured, and the behavior of the liquid lubricant can be measured from the distribution of the liquid lubricant measured in chronological order.

[Second embodiment]
Next, a second embodiment will be described.
The lubricant distribution measuring system according to the second embodiment uses a needle bearing, that is, a needle roller bearing as an example of the rolling bearing of the present disclosure, and measures the lubrication applied inside the needle bearing in the rotating state of the rolling bearing. Measure the distribution of the agent. In addition, since the second embodiment has the same configuration as the first embodiment, the same parts are denoted by the same reference numerals and detailed description thereof is omitted.

FIG. 16 shows an example of a schematic configuration of a lubricant distribution state measuring system 200 according to the second embodiment.
As shown in FIG. 16, the lubricant distribution state measuring system 200 includes a rotating mechanism section 3 to which a needle bearing 3B, which is an example of the rolling bearing section of the present disclosure, is rotatably attached. In addition, the lubricant distribution state measuring system 200 is provided with a supply unit 8 that supplies oil to the shaft center in order to reproduce the lubricant supply state of a transmission or the like in which oil is supplied to the shaft center as a needle bearing. there is In the second embodiment, by providing the supply unit 8, the rotation mechanism unit 3 is configured to exclude the side glass window 37 and the image measurement unit 2A. It is the same as the distribution state measuring system 100, and is a mechanism capable of rotating the shaft while applying a load to the bearing portion of the needle bearing.

17 to 23 show examples of images related to observation images in the needle bearing 3B using the lubricant distribution state measuring system according to the second embodiment. In this embodiment, a case of observing the rolling surfaces of the bearing outer ring and the needle will be described as an example.
In addition, in the second embodiment, the irradiation conditions of the UV light are 20 Hz and 500 μs/shot as in the first embodiment. Also, the case where oil is supplied from the axial center at 5 mL/min will be described.

FIG. 17 shows the appearance of the needle bearing 3B, and a part of the area (in FIG. 17, the area surrounded by a square near the center) is shown as an observation area for observing the fluorescence caused by the quantum dots. FIG. 18 shows a photographed image of a fluorescent image from the liquid lubricant in the observed area when irradiated with UV light in a stationary state.
As shown in FIG. 18, at the needle portion near the center in the rotational direction (near the center in the vertical direction in FIG. 18), the space between the needle portion and the outer ring is small, and the oil film is thin. , the liquid lubricant is thickened. In this state, it is considered that the liquid lubricant is thickly present in the recessed portion of the retainer that holds the needle so as to correspond to the shape of the recessed portion.

FIG. 19 shows a photographed image of a fluorescence image in an observation area when the needle bearing 3B in a low rotation state (for example, 295 rpm) is flash-irradiated with UV light. FIG. 20 shows a photographed image obtained by photographing a fluorescence image of the observation area of the needle bearing 3B in a high rotation state (for example, 1480 rpm) higher than the rotation state shown in FIG.
As shown in FIG. 19, the distribution state of the liquid lubricant in the low rotation state is substantially the same distribution state as in the stationary state shown in FIG. 18, and sufficient liquid lubricant is provided to the needle bearing 3B in the low rotation state. and the liquid lubricant is flowing. On the other hand, as shown in FIG. 20, in the distribution state of the liquid lubricant in the high rotation state, vertical streak-like bright and dark areas are observed in the longitudinal direction of the screen on the needle exit side in the rotation direction, and the streak-like liquid lubricant is small. parts are occurring. This is considered to be a cavitation phenomenon caused by negative pressure generated at the outlet of the needle rotating at high speed.

In this embodiment, from the fluorescence intensity distribution two-dimensionally measured by the image measurement unit 2, the distribution state of the liquid lubricant, that is, the thickness distribution, can be derived in the arithmetic and control unit 7. FIG. The arithmetic and control unit 7 can three-dimensionally display the distribution state of the liquid lubricant according to the derived fluorescence intensity.

FIGS. 21 to 23 show examples of images in which the fluorescence intensity in the observation region is three-dimensionally displayed.
FIG. 21 shows a three-dimensional representation of the distribution of the liquid lubricant based on the fluorescence image (fluorescence intensity) of the observation area in the stationary state shown in FIG. FIG. 22 corresponds to FIG. 19 and shows a three-dimensional image of the distribution of the liquid lubricant in the low rotation state. FIG. 23 corresponds to FIG. 19 and shows a three-dimensional image of the distribution of the liquid lubricant in the high rotation state. 21 to 23 show that the thickness of the liquid lubricant increases downward (z-axis direction, 0-z direction in the figure). In addition, the distribution of the liquid lubricant changes cylindrically in the vicinity of the center of the Y axis so as to correspond to the shape of the needle, and the liquid lubricant exists thickly corresponding to the recessed portion of the cage before and after the needle. understood. Thus, in this lubricant distribution state measuring system, it is possible to confirm the distribution of the liquid lubricant as a shape image.

As described above, according to the present embodiment, by measuring the fluorescence intensity of the fluorescence excited by the quantum dots and measuring the thickness distribution of the liquid lubricant, the rolling surface of the ball bearing in the rotating state can be obtained. The distribution of the liquid lubricant in the vicinity can be measured, and the behavior of the liquid lubricant can be measured from the distribution of the liquid lubricant measured in time series. Also, the distribution of the liquid lubricant can be confirmed as a shape image.

Although each embodiment has been described above, the technical scope of the disclosed technology is not limited to the scope described in the above embodiments. Various changes or improvements can be made to the above-described embodiments without departing from the scope of the invention, and forms with such changes or improvements are also included in the technical scope of the technology disclosed herein.

Further, in the above-described embodiment, a case has been described in which the processing is implemented by a software configuration using a flowchart, but the present invention is not limited to this, and may be implemented by a hardware configuration.

1 Irradiation section 2, 2A Image measurement section 3 Rotation mechanism section 3A Ball bearing 3B Needle bearing 4 Axial load applying section 5 Elastic coupling 6 Rotary drive section 7 Arithmetic control device 8 Supply section 11 Light source 13 Filter 14 Light guide 15 Beam splitter 21 Adapter 22 Objective lens 23 Camera 31 Inner ring 31A Rolling surface 32 Outer ring 32A Rolling surface 33 Ball 35 Storage section 36 Rotating section 37 Glass window 38 Sealed container section 39 Mirror 71 Image processing section 72 Thickness distribution calculation section 73 Synchronous drive control section 74 State control unit 75 Display unit 76 Operation input unit 77P Lubricant distribution calculation program 100 Lubricant distribution state measuring system 200 Lubricant distribution state measuring system

Claims (6)

A lubricant comprising an inner ring and an outer ring, wherein at least one of the inner ring and the outer ring transmits light, wherein quantum dots that emit fluorescence by excitation light are dispersed between the inner ring and the outer ring. a rolling bearing portion having a storage portion for storing the
an irradiation unit that irradiates the storage unit with the excitation light while rotating the rolling bearing;
a measurement unit that two-dimensionally measures the fluorescence intensity of the quantum dots from an image captured by an imaging unit that captures the storage unit;
a derivation unit that derives the distribution state of the lubricant inside the rotating rolling bearing based on the fluorescence intensity measured by the measurement unit;
with
A lipophilic group is coordinated to the surface of the quantum dot
Lubricant distribution measurement system. 2. The lubricant distribution measuring system according to claim 1, further comprising an applying unit that applies a load to at least one of the bearing of the rolling bearing unit and the rotating shaft in a direction that intersects the rotating shaft. The lubricant distribution measuring system according to claim 1 or 2 , wherein the wavelength of fluorescence emitted by the quantum dots is from 450 nm to 680 nm. The irradiation unit irradiates light having a wavelength less than the wavelength of fluorescence emitted by the quantum dots,
The lubricant distribution according to any one of claims 1 to 3 , further comprising a band-pass filter having a wavelength of fluorescence emitted by the quantum dots or more between the inner ring and the outer ring and the imaging unit. Condition measurement system. The lubricant distribution measuring system according to any one of claims 1 to 4 , wherein the irradiation unit irradiates light with an irradiation time of 1 millisecond or less in synchronization with a rotation cycle of the rolling bearing. . A lubricant comprising an inner ring and an outer ring, wherein at least one of the inner ring and the outer ring transmits light, wherein quantum dots that emit fluorescence by excitation light are dispersed between the inner ring and the outer ring. irradiating the excitation light to the storage portion while rotating the rolling bearing portion having the storage portion for storing the
two-dimensionally measuring the fluorescence intensity of the quantum dots from a captured image captured by an imaging unit that captures the storage part;
A method for deriving the distribution state of lubricant inside the rotating rolling bearing based on the measured fluorescence intensity,
A lipophilic group is coordinated to the surface of the quantum dot,
Method for measuring lubricant distribution.

Images