JP2008002884A - Deterioration detector of lubricant and bearing with detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deterioration detector of a lubricant capable of reducing the cross section of the fine gap between the leading ends of light guide members arranged in opposed relationship to enable stable and accurate detection, and to provide a bearing with the deterioration detector of the lubricant. <P>SOLUTION: The deterioration detector 1 of the lubricant has the light guide member 4 on a light projection side connected to a light emitting element 2 and the light guide member 5 on a light detection side connected to a light detection element 3. The leading ends of both light guide members 4 and 5 are arranged in opposed relationship through the fine gap 10 becoming the arranging space of the lubricant 6. The cross section of the light guide member 4 on the light projection side is made different from that of the light guide member 5 on the light detection side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lubricant deterioration detection device that detects a deterioration state due to a lubricant contamination and the like, and a bearing with a detection device including the lubricant deterioration detection device, for example, for railway vehicles that require safety and maintainability. The present invention relates to a bearing with a lubricant deterioration detection device for a power plant or the like.

  In a bearing in which a lubricant is encapsulated, if the lubricant (grease, oil, etc.) in the bearing deteriorates, a 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 bearings, etc., will be dealt with after an operational abnormality occurs due to the end of its 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.
For detecting the wear state of the bearing, a sensor-equipped bearing in which a sensor such as an electrode or a coil is arranged inside the seal of the bearing and the electrical characteristics of the lubricant mixed with wear powder is detected by the sensor. It 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. 5, each end of the optical fibers 46 and 47 on the light emitting side and the light receiving side is opposed to the detecting unit 48 in which the lubricant 45 to be detected is present to emit light. An optical configuration is considered in which the light emitting element 43 is disposed at the other end of the optical fiber 46 on the side and the light receiving element 44 is disposed at the other end of the optical fiber 47 on the light receiving side.
In the configuration of FIG. 5, the light emitted from the light emitting element 43 passes through the lubricant 45 present in the detection unit 48 via the light emitting side optical fiber 46, and further receives light via the light receiving side optical fiber 47. Detected by element 44. When the amount of foreign matter such as iron powder contained in the lubricant 45 increases, the amount of transmitted light that passes through the lubricant 45 decreases. Therefore, the determination circuit 49 provided at the next stage of the light receiving element 44 is detected by the light receiving element 44. The amount of foreign matter mixed in the lubricant 45 can be estimated based on the transmitted light amount.

However, in the configuration of FIG. 5, when the gap serving as the arrangement space of the lubricant 45 is reduced by being interposed between the tip of the light-emitting side optical fiber 46 and the tip of the light-receiving side optical fiber 47 that face each other, It may be difficult for the lubricant 45 to enter the gap, or the lubricant 45 once entering the gap is difficult to be replaced, making it difficult to detect stable deterioration. That is, in the above optical configuration, in order to be able to measure the amount of foreign matter mixed in the lubricant 45 to a desired value, the transmitted light that can be detected even when the transparency of the lubricant 45 is low is observed. There is a need. As a countermeasure to meet such a demand, for example, as shown in FIG. 6, if the cross-sectional area of both optical fibers 46 and 47 is increased and the gap 50 between the tips of both optical fibers 46 and 47 is narrowed, lubrication with low transparency is achieved. Even the agent 45 can ensure sufficient transmitted light, but in this case, the lubricant 45 hardly enters the gap 50.
On the other hand, as shown in FIG. 7, if the gap 50 is relatively increased by reducing the cross-sectional areas of the optical fibers 46 and 47, the lubricant 45 can easily enter the gap 50. However, in this case, since the cross-sectional areas of the optical fibers 46 and 47 are reduced, a sufficient amount of light cannot be obtained and the intensity of the detection signal may be insufficient.

  An object of the present invention is to provide a lubricant deterioration detection device capable of reducing the cross-sectional area of a minute gap between the tips of light guide members arranged opposite to each other and capable of stable and accurate detection, and the lubricant deterioration detection device. Another object is to provide a bearing with a detection device.

The lubricant deterioration detection device of the present invention has a light-projecting-side light guide member connected to the light-emitting element, and a light-receiving-side light guide member connected to the light-receiving element. Lubricant deterioration detection device arranged opposite to each other through a minute gap serving as a lubricant placement space, wherein the cross-sectional area of the light-guiding member on the light-transmitting side and the cross-sectional area of the light-guiding member on the light-receiving side are different from each other It is characterized by that. The light guide member is, for example, an optical fiber.
According to this configuration, since the cross-sectional area of the light guide member on the light projecting side and the cross-sectional area of the light guide member on the light receiving side are made different from each other, the cross-sectional area of the micro gap can be reduced, and the lubricant can easily enter the micro gap. Therefore, stable and accurate deterioration detection becomes possible. In addition, since the influence when the optical axes of the light guide members deviate from each other is reduced, simple assembly is possible. In addition, since the leading ends of both light guide members are opposed to each other through the minute gap as the detection unit, for example, in the installation in the bearing in which the lubricant to be detected is sealed, the lubricant inside the bearing The detection unit can be arranged without hindering the circular movement.

In the present invention, the cross-sectional area of the light guide member on the light projecting side may be smaller than the cross-sectional area of the light guide member on the light receiving side.
Thus, if the cross-sectional area of the light-guiding member on the light-emitting side that does not significantly affect the sensing sensitivity is made smaller than the cross-sectional area of the light-guiding member on the light-receiving side, The cross-sectional area of the light guide member on the side can be reduced to a cross-sectional area that can secure a minimum necessary light amount, and the cross-sectional area of the minute gap can be further reduced. In addition, since the cross-sectional area of the light-receiving side light guide member is larger than the cross-sectional area of the light-projecting side light guide member, even if the projected light spreads and scatters, the light-receiving side light guide member reliably receives light. As a result, the received light intensity does not weaken.

The bearing with a detecting device of the present invention is a bearing in which the lubricant deterioration detecting device having any one of the above configurations of the present invention is mounted on a bearing.
The lubricant deterioration detection device according to the present invention can reduce the cross-sectional area of the detection unit gap, which is the lubricant placement space, and enables stable and accurate detection of deterioration. The detection part gap can be disposed at the position, and the deterioration of the lubricant in the bearing can be detected stably and accurately.
As a result, it is possible to accurately detect the deterioration of the lubricant sealed in the bearing in real time. As a result, it is possible to determine the necessity of replacement of the lubricant before the operation abnormality occurs in the bearing, and it is possible to prevent the bearing from being damaged 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.

The lubricant deterioration detection device of the present invention has a light-projecting-side light guide member connected to the light-emitting element, and a light-receiving-side light guide member connected to the light-receiving element. Lubricant deterioration detecting device arranged opposite to each other through a minute gap serving as a lubricant arrangement space, because the cross-sectional area of the light guide member on the light projecting side and the cross sectional area of the light guide member on the light receiving side are made different from each other The cross-sectional area of the minute gap between the tips of the light guide members disposed opposite to each other can be reduced, and stable and accurate detection is possible.
Since the bearing with the lubricant deterioration detecting device of the present invention is mounted on the bearing, the bearing with the detecting device of the present invention can reduce the cross-sectional area of the minute gap, which is the lubricant placement space in the lubricant deterioration detecting device, and can be stably and accurately deteriorated. Detection is possible, a minute gap as a detection unit can be arranged at an observation position in the bearing, and deterioration detection of the lubricant in the bearing can be detected stably and accurately. As a result, it is possible to accurately detect the deterioration of the lubricant sealed in the bearing in real time. As a result, it is possible to determine the necessity of replacement of the lubricant before the operation abnormality occurs in the bearing, and it is possible to prevent the bearing from being damaged 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.

A first embodiment of the present invention will be described with reference to FIG. FIG. 1A shows a schematic configuration diagram of the lubricant deterioration detection device of this embodiment. The lubricant deterioration detection device 1 includes a light-emitting element 2 and a light-receiving element 3, a pair of light guide members 4, 5 having their tips opposed to each other through a minute gap 10 serving as an arrangement space for the lubricant 6, And determination means 7 for detecting the amount of foreign matter mixed in the lubricant 6 from the output of the light receiving element 3. The pair of light guide members 4 and 5 are made of optical fibers. Of the pair of light guide members 4 and 5, one light guide member 4 is a light guide member on the light projecting side whose base end is connected to the light emitting surface of the light emitting element 2. The other light guide member 5 is a light guide member on the light receiving side whose base end is connected to the light receiving surface of the light receiving element 3. The cross sectional area of the light guide member 4 on the light projecting side and the cross sectional area of the light guide member 5 on the light receiving side are different from each other. Specifically, in this embodiment, as shown in an enlarged view in FIG. 1B, the cross-sectional area of the light guide member 4 on the light projecting side is made smaller than the cross sectional area of the light guide member 5 on the light receiving side. It is.
By arranging the light projecting side light guide member 4 and the light receiving side light guide member 5 in this manner, the light emitted from the light emitting element 2 passes through the lubricant 6 via the light projecting side light guide member 4. The transmitted light is incident on the light receiving element 3 through the light guide member 5 on the light receiving side.

  As the light emitting element 2, an LED, an EL, an organic EL, or the like can be used and driven by the light emitting circuit 11. As the light receiving element 3, a photodiode, a phototransistor, or the like can be used, and the amount of light received by the light receiving element 3 is detected by the light receiving circuit 12 that receives the output.

  When the lubricant 6 is new, it is nearly transparent, and the intensity of transmitted light that is projected from the light guide member 4 on the light projecting side and transmitted through the lubricant 6 is high. However, as the amount of foreign matter mixed in the lubricant 6 increases, the intensity of transmitted light gradually decreases. Therefore, the determination unit 7 detects the amount of foreign matter mixed in the lubricant 6 from the output of the light receiving element 3 corresponding to the intensity of transmitted light. Since the increase in the amount of foreign matter mixed in the lubricant 6 means the progress of deterioration of the lubricant 6, the deterioration degree of the lubricant 6 can be estimated from the detected amount of foreign matter.

As described above, in the lubricant deterioration detection device 1, the tip of the light guide member 4 on the light projecting side and the tip of the light guide member 5 on the light receiver side are arranged to face each other through the minute gap 10 serving as a space for arranging the lubricant 6. In addition, since the sectional area of the light guide member 4 on the light emitting side and the sectional area of the light guide member 5 on the light receiving side are made different from each other, the sectional area of the minute gap 10 can be reduced, and the lubricant 6 enters the minute gap 10. It becomes easy and stable and accurate deterioration detection becomes possible. In addition, since the influence when the optical axes of the light guide members 4 and 5 are shifted is reduced, simple assembly is possible. Further, since the ends of the light guide members 4 and 5 are opposed to each other through the minute gap 10 as the detection unit, for example, in the installation in the bearing in which the lubricant 6 to be detected is sealed, the bearing It is possible to arrange the detection unit without hindering the circulating movement of the internal lubricant 6.
In particular, in this embodiment, the cross-sectional area of the light-guiding member 4 on the light-projecting side that does not significantly affect the sensing sensitivity is made smaller than the cross-sectional area of the light-guiding member 5 on the light-receiving side. Therefore, the cross-sectional area of the light guide member 4 on the light projecting side can be reduced to a cross-sectional area that can secure a minimum necessary light amount, and the cross-sectional area of the minute gap 10 can be further reduced. Further, since the cross-sectional area of the light-receiving side light-guiding member 5 is larger than the cross-sectional area of the light-projecting-side light guiding member 4, even if the projected light spreads and scatters, The light is surely received, and the received light intensity does not weaken.

FIG. 2 is a cross-sectional view showing a schematic configuration of an optical system in a lubricant deterioration detection device according to another embodiment of the present invention. The configuration of the parts other than the optical system is the same as that of the embodiment of FIG. 1, and the redundant description thereof is omitted here. In this embodiment, in the lubricant deterioration detection device 1 of the embodiment of FIG. 1, each of the light guide member 4 on the light projecting side and the light guide member 5 on the light receiver side is bent into an approximate L shape. The optical path of the entire optical system is U-shaped.
In this way, if the optical path of the entire optical system is made U-shaped, the optical system can be made compact. For example, in installation in a bearing in which the lubricant 6 to be detected is enclosed, the lubricant deterioration detection device 1 The degree of freedom of arrangement can be increased.

FIG. 3 is a cross-sectional view showing a schematic configuration of an optical system in a lubricant deterioration detecting apparatus according to still another embodiment of the present invention. The configuration of parts other than the optical system is the same as that in the embodiment of FIG. 1, and is omitted here. In this embodiment, in the lubricant deterioration detecting device 1 of the embodiment of FIG. 1, only the light guide member 5 on the light receiving side of the light guide member 4 on the light projecting side and the light guide member 5 on the light receiving side is schematically shaped L. By bending into a letter shape, the optical path of the entire optical system is L-shaped. Instead of the light guide member 5 on the light receiving side, only the light guide member 4 on the light projecting side may be bent into an approximate L shape.
When one of the light guide members 4 and 5 is bent into an L shape in this way, the optical path of the entire optical system can be made an L shape, and both the light guide members 4 and 5 are formed in an L shape as in the embodiment of FIG. Since the optical path of the entire optical system can be made U-shaped when bent into, for example, when installed in a bearing or the like in which the lubricant 6 to be detected is enclosed, it can be easily processed and arranged according to the situation of the installation location. it can.

  In each of the above embodiments, the cross-sectional area of the light guide member 4 on the light projecting side is made smaller than the cross sectional area of the light guide member 5 on the light receiving side. The cross-sectional area of the light guide member 5 on the light receiving side may be larger. In this case, since only a part of the light emitted from the light guide member 4 on the light emitting side is received by the light guide member 5 on the light receiving side, the light receiving intensity is weaker than in the case of each of the above embodiments. When the light intensity projected through 4 is sufficiently strong, the present invention can be applied without reducing the effect of the present invention.

FIG. 4 is a cross-sectional view of an example in which a bearing with a detection device on which the above-described lubricant deterioration detection device 1 is mounted is used in a railway vehicle bearing unit. The railcar bearing unit in this case includes a bearing 21 with a detection device and an oil drain 22 and a rear lid 23 which are accessory parts provided on 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 20 on the center side of the bearing 21 and has an oil seal 28 slidably contacted on the outer periphery. The oil drain 22 is attached to the axle 20 and has an oil seal 29 slidably contacted on the outer periphery. The two oil seals 28 and 29 disposed at both ends of the bearing 21 seal the lubricant inside the bearing 21 and ensure dustproof and water resistance.

Seal cases 30 and 31 are attached to both ends of the outer ring 25 of the bearing 21, and the oil seals 28 and 29 are provided on the seal cases 30 and 31, respectively. One seal case 31 is an annular member having a cross-sectional shape in which a plurality of step portions are arranged stepwise in the axial direction. One end portion of the seal case 31 is press-fitted into the inner diameter surface of the bearing outer ring 25, whereby the outer ring 25. Mounted on. A ring member 32 having an L-shaped cross section is attached to the inner diameter surface of the intermediate step portion of the seal case 31 by press-fitting the cylindrical portion thereof. Inside the seal case 31, the electric circuit unit 13 including the light emitting element 2 and the light receiving element 3 of the lubricant deterioration detecting device 1 and the pair of light guide members 4 and 5 are provided. The minute gap 10 is disposed on the side of the rolling surface on the inner diameter surface of the outer ring 25 that is an observation point of the lubricant.
In this case, if the lubricant deterioration detection device 1 is of the embodiment shown in FIGS. 2 and 3, for example, the optical system including the pair of light guide members 4 and 5 can be configured in a compact manner, and the arrangement is free. Since the degree is high, the arrangement at such a position can be easily performed.
Further, since the lubricant deterioration detecting device 1 can reduce the minute gap 10 and can detect stable and accurate deterioration, the deterioration detection of the lubricant beside the rolling contact surface that contributes to the lubrication of the bearing 21 is possible. Can be performed stably and accurately. Specifically, the electric circuit portion 13 of the lubricant deterioration detection device 1 is fixed to the axially inner surface of the upright plate portion extending toward the inner diameter side of the ring member 32, and the wiring cable 14 penetrates the seal case 31. And pulled out of the bearing. Through the wiring cable 14, power is supplied from the outside of the bearing to the lubricant deterioration detecting device 1 and a detection signal is taken out of the bearing. The penetration part of the wiring cable 14 in the seal case 31 is subjected to waterproofing / oilproofing treatment. This prevents moisture, dust and the like from entering the bearing from the mounting portion of the lubricant deterioration detection device 1.

  For example, the manufacturing process of the outer ring 25 of the bearing 21 is complicated, and there are strict requirements in terms of strength. Therefore, when the lubricant deterioration detection device 1 is mounted, it is not preferable due to an increase in the process. However, when the lubricant deterioration detection device 1 is arranged in the seal case 31 that is a simple part, the attachment process is easy. In addition, when the lubricant deterioration detection device 1 is arranged in the seal case 31, the other bearing components can be shared with a general bearing that does not include the lubricant deterioration detection device 1, and the manufacturing process is the same. And excellent productivity.

  In this bearing 21 with a detecting device equipped with the lubricant deterioration detecting device 1, the deterioration of the lubricant sealed in the bearing can be accurately detected in real time. As a result, it is possible to determine the necessity of replacement of the lubricant before the operation abnormality occurs in the bearing 21, and to prevent damage to the bearing 21 due to poor lubrication. 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.

(A) is a schematic block diagram of the lubricant deterioration detection apparatus according to the first embodiment of the present invention, and (B) is an enlarged view of a minute gap in the lubricant deterioration detection apparatus. It is sectional drawing which shows schematic structure of the optical system in the lubricant deterioration detection apparatus concerning the other implementation state of this invention. It is sectional drawing which shows schematic structure of the optical system in the lubricant deterioration detection apparatus concerning further another embodiment of this invention. It is sectional drawing of an example of the bearing with a detection apparatus carrying the said lubricant deterioration detection apparatus. It is a schematic block diagram of the proposal example of a lubricant deterioration detection apparatus. It is an enlarged view which shows an example of the gap in the same lubricant deterioration detection apparatus. It is an enlarged view which shows the other example of the gap in the same lubricant degradation detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lubricant degradation detection apparatus 2 ... Light emitting element 3 ... Light receiving element 4 ... Light guide side light guide member 5 ... Light guide side light guide member 6 ... Lubricant 10 ... Micro gap 21 ... Bearing with detector

Claims (4)

  A light guide member on the light projecting side connected to the light emitting element and a light guide member on the light receiving side connected to the light receiving element. The tip of both light guide members has a small gap serving as a lubricant arrangement space. A lubricant deterioration detecting device, wherein the cross-sectional area of the light guide member on the light projecting side and the cross sectional area of the light guide member on the light receiving side are made different from each other. .   2. The lubricant deterioration detecting device according to claim 1, wherein a cross sectional area of the light guide member on the light projecting side is smaller than a cross sectional area of the light guide member on the light receiving side.   3. The lubricant deterioration detection device according to claim 1, wherein the light guide member is an optical fiber.   The bearing with a detection apparatus which mounted the lubricant deterioration detection apparatus of any one of Claim 1 thru | or 3 in the bearing.

Images