JP2007198767A - Lubricant deterioration detector and bearing with detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing with a detector for preventing lubrication failure in a bearing from occurring by detecting detailed information on deterioration of a lubricant such as the amount of foreign matter having got mixed in the lubricant and also by easily detecting the state of deterioration of the lubricant. <P>SOLUTION: This lubricant deterioration detector 1 is equipped with: an optical system 2 comprising a plurality of light emitting elements 3A and 3B severally differing in wavelengths, and at least one light receiving element 4 entered by light of the plurality of the emitting elements 3A and 3B; and an estimation means 5 for estimating the state of deterioration of the lubricant 6. In the optical system 2, the lubricant 6 is caused to stand in optical paths between the elements 3A and 3B, and the element 4. The estimation means 5 estimates the state of deterioration of the lubricant 6 from wavelength-by-wavelength differences in absorptivity detected in an output of the element 4. Besides, the emitting elements can be of white while a plurality of light receiving elements different in wavelength sensitivity can be used. The deterioration detector 1 of this structure is mounted on a bearing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lubricant deterioration detection device for detecting a deterioration state due to a contaminant of a lubricant, and a bearing with a detection device provided with the lubricant deterioration detection device, for example, for railway vehicles, automobiles, industrial machinery, etc. The present invention relates to a bearing with a lubricant deterioration detection device.

  In a bearing in which a lubricant is enclosed, if the lubricant (grease, oil, etc.) inside the bearing deteriorates, the rolling element will be poorly lubricated and the bearing life will be shortened. Judging the poor lubrication of the rolling elements from the vibration state of the bearing, etc., will be dealt with after an operational abnormality occurs due to the end of the life, so the abnormality of the lubricating state cannot be detected earlier. Therefore, it is desired to observe the state of the lubricant in the bearing periodically or in real time so that the abnormality or the maintenance period can be predicted.

As a major factor in the deterioration of the lubricant, wear powder generated with use of the bearing is mixed into the lubricant.
A sensor-equipped bearing in which a sensor such as an electrode or a coil is arranged inside the seal of the bearing so that the electrical characteristics of the lubricant mixed with wear powder can be detected by the sensor. Has been proposed (for example, Patent Document 1).
JP 2004-293776 A

However, the sensor-equipped bearing of Patent Document 1 is for detecting the electrical characteristics of the lubricant. Therefore, unless a situation occurs such that a large amount of wear powder enters and conduction occurs, it is not detected as a characteristic change. Detection of contaminants may be difficult.
In order to solve such a problem, for example, as shown in FIG. 6, a lubricant 36 to be detected is interposed between the light emitting element 33 and the light receiving element 34, and is emitted from the light emitting element 33 and passes through the lubricant 36. A configuration has been considered in which light is detected by the light receiving element 34 and the deterioration state of the lubricant 36 is estimated from the amount of light detected by the light receiving element 34.

  However, in this configuration, it is not possible to detect optical characteristics such as a difference in absorption rate depending on the wavelength of light only by grasping a simple relationship between the lubricant and the amount of light absorption. Therefore, it is difficult to detect the deterioration of the lubricant with higher accuracy, and detailed information regarding the deterioration of the lubricant such as the type of foreign matter contained in the lubricant cannot be obtained.

An object of the present invention is to provide a lubricant deterioration detection device capable of detecting detailed information related to lubricant deterioration such as the amount of foreign matter mixed in the lubricant.
Another object of the present invention is to provide a bearing with a detecting device that can easily detect the state of deterioration of the lubricant and prevent the bearing from being poorly lubricated.

According to a first aspect of the present invention, there is provided a lubricant deterioration detecting device including an optical system having a plurality of light emitting elements having different wavelengths and at least one light receiving element on which light from the plurality of light emitting elements is incident. The optical system includes a lubricant in the optical path between the plurality of light emitting elements and the light receiving element, and estimates the deterioration state of the lubricant from the difference in absorption rate for each wavelength detected from the output of the light receiving element. An estimation means is provided.
In the lubricant deterioration detection apparatus configured as described above, light emitted from a plurality of (for example, two) light emitting elements and transmitted through the lubricant is detected by the light receiving element. In this case, when both the light emitting elements are turned on alternately, the light receiving element measures the light transmittance (or light absorption rate) of each of the wavelengths in the lubricant in a time-sharing manner. The amount of light can be detected. Since the amount of transmitted light decreases as the content of foreign matter such as iron powder contained in the lubricant to be detected increases, the estimation means can estimate the content of foreign matter in the lubricant from the detected amount of transmitted light. it can.
When a lubricant is used in, for example, a bearing, it is a foreign matter mixed in the lubricant because wear powder generated with the use of the bearing is mixed as a major factor in the deterioration of the lubricant. By estimating the wear powder content by the estimating means, the deterioration state of the lubricant can be estimated. In particular, in this lubricant deterioration detection device, the amount of transmitted light of different wavelengths is detected by the optical system. Therefore, due to the difference in the amount of transmitted light according to the wavelength, for example, the contamination condition and color of the lubricant, and foreign matter to be mixed It is possible to obtain detailed information on deterioration such as identification of

A lubricant deterioration detection device according to a second aspect of the present invention includes an optical system having at least one light emitting element and a plurality of light receiving elements each having a different wavelength sensitivity and receiving light from the light emitting element. In this optical system, a lubricant is interposed in the optical path between the light-emitting element and the plurality of light-receiving elements, and the difference in the absorption rate for each wavelength detected by comparing the outputs of the light-receiving elements is used. An estimation means for estimating the deterioration state is provided.
In the lubricant deterioration detection device configured as described above, light emitted from the light emitting element and transmitted through the lubricant is detected by a plurality of light receiving elements having different wavelength sensitivities. The estimation means can estimate the content of foreign matter in the lubricant from the detected transmitted light amount, and can also estimate the deterioration state of the lubricant from the estimated content of foreign matter. In addition, because the transmitted light amount or light absorption rate of different wavelengths is detected by the optical system, from the difference in the transmitted light amount according to the wavelength, the contamination condition and color of the lubricant, the type of foreign matter to be mixed, etc. It becomes possible to obtain detailed information regarding deterioration.

The bearing with the lubricant deterioration detecting device of the present invention is equipped with the lubricant deterioration detecting device of the present invention.
According to this configuration, detailed information regarding deterioration of the lubricant inside the bearing and the amount of foreign matter such as iron powder mixed in the lubricant can be detected accurately and periodically or in real time from the outside of the bearing. As a result, it is possible to determine the necessity of replacement of the lubricant before the operation abnormality occurs in the bearing, and therefore it is possible to prevent damage to the bearing due to poor lubrication. In addition, since the necessity for replacing the lubricant can be determined by the output of the lubricant deterioration detecting device, the amount of lubricant discarded before the expiration date is reduced.

According to a first aspect of the present invention, there is provided a lubricant deterioration detecting device including an optical system having a plurality of light emitting elements having different wavelengths and at least one light receiving element on which light from the plurality of light emitting elements is incident. The optical system has a lubricant interposed in the optical path between the plurality of light emitting elements and the light receiving element, and estimates the deterioration state of the lubricant from the difference in absorption rate for each wavelength detected from the output of the light receiving element. Since the estimation means is provided, it is possible to detect detailed information regarding the deterioration of the lubricant, such as the amount of foreign matter mixed in the lubricant.
A lubricant deterioration detection device according to a second aspect of the present invention includes an optical system having at least one light emitting element and a plurality of light receiving elements each having a different wavelength sensitivity and receiving light from the light emitting element. In this optical system, a lubricant is interposed in the optical path between the light-emitting element and the plurality of light-receiving elements, and the difference in the absorption rate for each wavelength detected by comparing the outputs of the light-receiving elements is used. Since the estimation means for estimating the deterioration state is provided, it is possible to detect detailed information regarding the deterioration of the lubricant, such as the amount of foreign matter mixed in the lubricant.
Since the bearing with the lubricant deterioration detecting device of the present invention is equipped with the lubricant deterioration detecting device of the present invention, it is possible to easily detect the deterioration state of the lubricant and to prevent the bearing from being poorly lubricated. The amount of lubricant that is discarded before the expiration date can be reduced.

  A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a lubricant deterioration detection device according to this embodiment. This lubricant deterioration detection device 1 is an optical device having a plurality (two in this case) of light emitting elements 3A and 3B having different wavelengths and one light receiving element 4 on which the light of the plurality of light emitting elements 3A and 3B is incident. The system 2 and the estimation means 5 are provided. As the light emitting elements 3A and 3B, light emitting diodes such as red LEDs and blue LEDs are used. As the light receiving element 4, one having sensitivity to the wavelength of light of both the light emitting elements 3A and 3B is selected. In the optical system 2, a lubricant 6 to be detected is interposed in the optical path between the light emitting elements 3 </ b> A and 3 </ b> B and the light receiving element 4. The light emitting elements 3A and 3B, the light receiving element 4, and the circuit to be the estimating means 5 are mounted on a circuit board 7 and the circuit board 7 is installed in the housing 8. The housing 8 has a gap 9 such as a recess capable of accommodating the lubricant 6 to be detected, and the light emitting elements 3A and 3B and the light receiving element 4 are arranged to face each other with the gap 9 interposed therebetween. The estimation means 5 estimates the deterioration state of the lubricant 6 according to setting criteria from the difference in absorption rate for each wavelength detected from the output of the light receiving element 4. The detection signal of the estimation means 5 is output from the wiring cable 10 to the outside. Further, power is supplied to the lubricant deterioration detection device 1 from the outside via the wiring cable 10.

  As the light emitting elements 3A and 3B, in addition to LEDs, incandescent bulbs, semiconductor laser diodes, EL, organic EL, fluorescent tubes, and the like can be used. The light receiving element 4 may be a photodiode, phototransistor, CDS, solar cell, photomultiplier tube, or the like.

  According to the lubricant deterioration detection device 1 having this configuration, the light emitted from the plurality of light emitting elements 3A and 3B and transmitted through the lubricant 6 is detected by one light receiving element 4. In this case, the light emitting elements 3A and 3B are alternately turned on. Thereby, the light receiving element 4 has a predetermined wavelength which is emitted from one light emitting element 3A and transmitted through the lubricant 6, and a predetermined wavelength which is different from the wavelength emitted from the other light emitting element 3B and transmitted through the lubricant 6. Detect light and light alternately. That is, the light receiving element 4 measures the light transmittance (or light absorption rate) for each wavelength in the lubricant 6 in a time-sharing manner, and can detect the transmitted light amount for each wavelength. Since the amount of transmitted light decreases as the content of foreign matter such as iron powder contained in the lubricant 6 to be detected increases, the estimation means 5 estimates the content of foreign matter in the lubricant 6 from the detected amount of transmitted light. can do.

  When the lubricant 6 is used in, for example, a bearing, a main factor of deterioration of the lubricant 6 is that wear powder generated with the use of the bearing is mixed into the lubricant 6. Therefore, by estimating the content of abrasion powder, which is a foreign matter mixed in the lubricant 6, by the estimating means 5, the deterioration state of the lubricant 6 can be estimated. In particular, in the lubricant deterioration detection device 1, the transmitted light amounts of the different wavelengths are detected by the optical system 2, and therefore, for example, due to the difference in the transmitted light amount depending on the wavelength, for example, the degree of dirt and the hue of the lubricant 6, It is possible to obtain detailed information regarding deterioration, such as specifying the type of foreign matter to be mixed.

  FIG. 2 shows a schematic configuration diagram of another embodiment of the present invention. The lubricant deterioration detection device 1 according to this embodiment includes a single light emitting element 3 and a plurality (two in this case) of light receiving elements 4A and 4B that have different wavelength sensitivities and receive light from the single light emitting element 3. And an estimation unit 5. One of the light receiving elements 4A has sensitivity to red, for example, and the other light receiving element 4B has sensitivity to blue, for example. The light emitting element 3 is selected to emit, for example, white light including red and blue wavelengths. In the optical system 2A, a lubricant 6 to be detected is interposed in the optical path between the light emitting element 3 and the plurality of light receiving elements 4A and 4B. The light-emitting element 3, the light-receiving elements 4A and 4B, and the circuit serving as the estimating means 5 are mounted on the circuit board 7, and the circuit board 7 is installed in the housing 8, and the lubricant in which the housing 8 is a detection target. 6 and the light emitting element 3 and the light receiving elements 4A and 4B are arranged opposite to each other with the gap 9 interposed therebetween, as in the first embodiment. The estimation means 5 compares the outputs of the light receiving elements 4A and 4B, and estimates the deterioration state of the lubricant 6 according to the setting criteria from the difference in the light transmittance (or light absorption rate) for each detected wavelength. Is. The detection signal of the estimation means 5 is output to the outside from the wiring cable 10 and the power is supplied to the lubricant deterioration detection device 1 from the outside via the wiring cable 10 as in the case of the first embodiment.

In the lubricant deterioration detection device 1 having this configuration, light emitted from one light emitting element 3 and transmitted through the lubricant 6 is detected by a plurality of light receiving elements 4A and 4B having different wavelength sensitivities. That is, each of the light receiving elements 4A and 4B individually detects the amount of light transmitted from the light emitting element 3 and transmitted through the lubricant 6 and having different wavelengths. The estimation means 5 can estimate the content of foreign matter in the lubricant 6 from the detected transmitted light amount.
Also in the case of the lubricant deterioration detection device 1, the deterioration state of the lubricant 6 can be estimated by estimating the content of foreign matters mixed in the lubricant 6 by the estimation means 5. Further, since the amount of transmitted light (or light absorptance) of different wavelengths is detected by the optical system 2A, due to the difference in the amount of transmitted light according to the wavelength, the contamination condition and color of the lubricant 6, and the type of foreign matter to be mixed It is possible to obtain detailed information on deterioration such as identification of

  FIG. 3 shows a schematic configuration diagram of still another embodiment of the present invention. In the embodiment shown in FIG. 2, the lubricant deterioration detection device 1 of this embodiment uses a plurality of common light receiving elements 4 having a wide range of wavelength sensitivities instead of the light receiving elements 4A and 4B having different wavelength sensitivities. Filters 11A and 11B having different transmission wavelengths are arranged on the front side of each light receiving element 4. For example, a filter that transmits red light is used as one filter 11A, and a filter that transmits blue light is used as the other filter 11B. Thus, the combination of the filter 11A and the light receiving element 4 has a function equivalent to that of the light receiving element 4A in FIG. 2, and the combination of the filter 11B and the light receiving element 4 has a function equivalent to that of the light receiving element 4B in FIG. Other configurations are the same as those in the embodiment of FIG.

  In the lubricant deterioration detection device 1 configured as described above, light emitted from one light emitting element 3 and transmitted through the lubricant 6 is transmitted through the filters 11A and 11B having different transmission wavelengths, and a plurality of individual light receiving elements 4 are transmitted. Detect with. As a result, each light receiving element 4 individually detects the amount of light transmitted through the lubricant 6 emitted from the light emitting element 3 and having a different wavelength. The estimation means 5 can estimate the content of foreign matter in the lubricant 6 from the detected transmitted light amount. Further, the deterioration state of the lubricant 6 can be estimated by estimating the content of the foreign matter mixed in the lubricant 6 by the estimation means 5. Also in this case, since the transmitted light amount (or light absorption rate) of different wavelengths is detected by the optical system 2A, from the difference in transmitted light amount according to the wavelength, the contamination condition and color of the lubricant 6, the identification of foreign matter to be mixed, etc. It becomes possible to obtain detailed information regarding deterioration.

  In the case of this embodiment, the filters 11A and 11B having different transmission wavelengths are used to detect the transmitted light amounts having different wavelengths by the individual light receiving elements 4, so that it matches the characteristics of the lubricant 6 to be detected. The combination of the wavelength light to be detected can be easily changed, and it is also possible to use long wavelength infrared rays that are particularly excellent in transparency.

FIG. 4 is a cross-sectional view in which a bearing with a detection device on which the above-described lubricant deterioration detection device 1 is mounted is used for a railway vehicle bearing unit. The railcar bearing unit in this case includes a bearing 21 with a lubricant deterioration detecting device and an oil drainer 22 and a rear lid 23 which are accessory parts provided in contact with both sides of the inner ring 24 respectively. The bearing 21 is a roller bearing, more specifically, a double row tapered roller bearing. The split type inner rings 24 and 24 provided for the rollers 26 and 26 in each row, the integral type outer ring 25, the rollers 26 and 26, respectively. 26 and a retainer 27.
The rear lid 23 is attached to the axle 30 on the center side with respect to the bearing 21 and is in sliding contact with the outer peripheral oil seal 28. The oil drain 22 is attached to the axle 30 and has an oil seal 29 in sliding contact with the outer periphery. A lubricant is sealed inside the bearing 21 by the oil seals 28 and 29 disposed at both ends of the bearing 21, and dust and water resistance are ensured.

The outer ring 25 of the bearing 21 is attached with a lubricant deterioration detection device 1 that detects the deterioration of the lubricant enclosed in the bearing. The lubricant deterioration detection device 1 is inserted into a detection device insertion hole 25a provided between the raceways of both rows in the outer ring 25, protrudes into the bearing space, and is fixed to the outer ring 25 with bolts or the like. The lubricant deterioration detection device 1 and its wiring cable 10 are subjected to waterproofing / oilproofing treatment. The mounting portion of the lubricant deterioration detection device 1 is also sealed with an oil resistant material. For example, the lubricant deterioration detection device 1 is inserted into the detection device insertion hole 25a of the outer ring 25 through the sealing seal 32, and an O-ring is used as the sealing seal 32, for example. As described above, the lubricant deterioration detecting device 1 is fixed to the outer ring 25 through the hermetic seal 32, so that moisture, dust and the like can be prevented from entering the bearing from the mounting portion of the lubricant deterioration detecting device 1. .
In this bearing 21 with a detecting device equipped with the lubricant deterioration detecting device 1, it is possible to accurately detect deterioration of the lubricant sealed inside the bearing periodically or in real time from the outside of the bearing. As a result, it is possible to determine the necessity of replacement of the lubricant before the operation abnormality occurs in the bearing 21, so that damage to the bearing 21 due to poor lubrication can be prevented. Further, since the necessity of replacing the lubricant can be determined by the output of the lubricant deterioration detecting device 1, the amount of lubricant discarded before the expiration date is reduced.

  FIG. 5 shows another example of the bearing with the lubricant deterioration detecting device. This bearing 21A with a lubricant deterioration detecting device is the same as the bearing 21 with a lubricant deterioration detecting device 21 shown in FIG. Other configurations are the same as those in the example of FIG.

1 is a schematic configuration diagram of a lubricant deterioration detection device according to a first embodiment of the present invention. It is a schematic block diagram of the lubricant deterioration detection apparatus which concerns on other embodiment of this invention. It is a schematic block diagram of the lubricant deterioration detection apparatus which concerns on other embodiment of this invention. It is sectional drawing which shows an example of the bearing with a detection apparatus carrying the said lubricant deterioration detection apparatus. It is sectional drawing of the other example of the bearing with a detection apparatus which mounts the said lubricant deterioration detection apparatus. It is a schematic block diagram of the proposal example of a lubricant deterioration detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lubricant deterioration detection apparatus 2, 2A ... Optical system 3, 3A, 3B ... Light emitting element 4, 4A, 4B ... Light receiving element 5 ... Estimation means 6 ... Lubricant 21,21A ... Bearing with lubricant deterioration detection apparatus

Claims (3)

  An optical system having a plurality of light emitting elements having different wavelengths and a light receiving element on which light of the plurality of light emitting elements is incident is provided, and the optical system includes a lubricant in an optical path between the plurality of light emitting elements and the light receiving element. A lubricant deterioration detection apparatus provided with estimation means for estimating the deterioration state of the lubricant from the difference in absorption rate for each wavelength detected from the output of the light receiving element.   An optical system having at least one light emitting element and a plurality of light receiving elements each having different wavelength sensitivity and receiving the light of the light emitting element is provided, and the optical system has an optical path between the light emitting element and the plurality of light receiving elements. A lubricant deterioration detecting apparatus provided with an estimation means for estimating a lubricant deterioration state from a difference in absorption rate for each wavelength detected by comparing the outputs of the respective light receiving elements. A bearing with a lubricant deterioration detecting device, wherein the lubricant deterioration detecting device according to claim 1 or 2 is mounted on the bearing.

Images