JP2008241555A - Lubricant degradation detector and bearing with detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant degradation detector simply and compactly mountable on a bearing for stably and accurately detecting the state of a degraded lubricant within the bearing, and a bearing with a detector equipped with the degradation detector. <P>SOLUTION: In this lubricant degradation detector, a light emitting element and a light receiving element are oppositely provided on both ends, respectively, of a circular arc-shaped optical fiber 4, and a gap part 7 for measurement is provided in a part of the optical fiber 4 for causing a lubricant to exist therein. This gap part 7 is provided at an inclination angle θ with respect to a direction vertical to an optical path made up of the optical fiber 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lubricant deterioration detection device for detecting a deterioration state due to a lubricant contamination and the like, and a bearing with a detection device provided with the lubricant deterioration detection device, for example, for railway vehicles, automobiles, windmill equipment, factories The present invention relates to a bearing with a lubricant deterioration detection device for equipment.

  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 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.
To detect the wear state of the bearing, an electrode is placed inside the seal member of the bearing, and the electrical characteristics of the lubricant due to the mixing of wear powder can be determined by changes in resistance, capacitance, magnetic resistance, and impedance. A sensor-equipped bearing 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. 7, a split ring-shaped optical fiber 44 is provided at both ends so that the light-emitting element 42 and the light-receiving element 43 face each other. An optical configuration in which a measurement gap portion 47 with a lubricant 45 interposed in a part in the circumferential direction is provided.
In the configuration of FIG. 7, the light emitted from the light emitting element 42 passes through the lubricant 45 existing in the measurement gap 47 via the optical fiber 44 and is detected by the light receiving element 43 via the optical fiber 44. The amount of foreign matter such as iron powder mixed in the lubricant 45 is estimated from the amount of transmitted light detected by the light receiving element 43.

  However, when such an optical sensor is incorporated in a bearing and used to detect deterioration of the lubricant sealed in the bearing, the measurement gap 47 is provided perpendicular to the optical path of the optical fiber 44. Therefore, the lubricant that moves together with the cage in accordance with the rotation of the rolling element in the bearing is difficult to get into the measurement gap 47, and stable and accurate detection cannot be performed.

  An object of the present invention is to provide a lubricant deterioration detection device that can be easily and compactly mounted on a bearing and that can stably and accurately detect a lubricant deterioration state inside the bearing, and a detection device including the lubricant deterioration detection device. Provided bearings.

The lubricant deterioration detecting device of the present invention is provided with a light emitting element and a light receiving element facing each other at both ends of an arc-shaped optical fiber, and a measurement gap portion for interposing the lubricant in a part of the arc-shaped optical fiber. In the lubricant deterioration detection device provided, the measurement gap is provided at an angle inclined with respect to an optical path constituted by the optical fiber.
According to this configuration, for example, when mounting on a rolling bearing to detect deterioration of the lubricant inside the bearing, if the arc-shaped optical fiber is installed so as to be concentric with the bearing, the measurement gap portion is It arrange | positions so that an inclination-angle may be made | formed with respect to radial direction. Therefore, the lubricant that moves in the bearing rotation direction inside the bearing can easily enter the measurement gap, and the lubricant that has entered the measurement gap can be replaced smoothly. As described above, since the lubricant is sequentially replaced in the measurement gap portion, the lubricant that always acts on the lubrication is to be detected, and the deterioration of the lubricant can be detected stably and accurately. it can. Further, since it is mainly composed of the arc-shaped optical fiber and the light emitting element and the light receiving element disposed at both ends thereof, it can be easily and compactly mounted on the bearing.

The bearing with a lubricant deterioration detecting device according to the present invention is the same as the above-described lubricant deterioration detecting device according to the present invention except that the measuring gap is positioned between the fixed ring and the rotating ring in the rolling bearing. It is attached.
In this case, when the lubricant deterioration detecting device is mounted concentrically with the rolling bearing, the measurement gap portion of the optical fiber is arranged at an inclination angle with respect to the radial direction of the rolling bearing. Lubricant that moves in the rotation direction can easily enter the gap portion for measurement, and the deterioration of the lubricant inside the bearing can be detected stably and accurately by the lubricant deterioration detection device.
As a result, the deterioration state of the lubricant enclosed 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, 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 detecting device of the present invention is provided with a light emitting element and a light receiving element facing each other at both ends of an arc-shaped optical fiber, and a measurement gap portion for interposing the lubricant in a part of the arc-shaped optical fiber. An apparatus for detecting deterioration of lubricant, wherein the measuring gap is provided at an inclination angle with respect to the optical path constituted by the optical fiber, so that the bearing can be easily and compactly mounted. The internal lubricant deterioration state can be detected stably and accurately.
The bearing with a lubricant deterioration detecting device according to the present invention is the same as the above-described lubricant deterioration detecting device according to the present invention except that the measuring gap is positioned between the fixed ring and the rotating ring in the rolling bearing. As a result, the lubricant stably enters the measurement gap portion of the optical fiber, and the lubricant deterioration detection device can detect the deterioration of the lubricant inside the bearing stably and accurately. As a result, the deterioration state of the lubricant enclosed 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, and it is possible to prevent the bearing from being damaged due to poor lubrication. Further, since the necessity for replacing the lubricant can be determined based on the output to the lubricant deterioration detecting device, the amount of lubricant discarded before the expiration date is reduced.

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a lubricant deterioration detection device according to this embodiment. The lubricant deterioration detection device 1 is mounted on a bearing and detects deterioration of the lubricant enclosed in the bearing, and includes a light emitting element 2 and a light receiving element 3, an arcuate optical fiber 4, and the light receiving element. And a determination means 6 for determining deterioration of the lubricant based on the output of 3. One end of the optical fiber 4 is disposed to face the light emitting surface of the light emitting element 2, and the other end is disposed to face the light receiving surface of the light receiving element 3. In addition, a measurement gap portion 7 in which the lubricant 5 is interposed is provided in a part of the optical fiber 4 in the circumferential direction.
In this way, by providing the gap portion for measurement 7 in which the lubricant 5 to be detected is interposed in a part of the circular optical fiber 4 in the circumferential direction, the light emitted from the light emitting element 2 passes through the optical fiber 4. Through the lubricant 5, the transmitted light is further incident on the light receiving element 3 through the optical fiber 4.

  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 8. 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 9 that receives the output.

  The optical fiber 4 is attached to an arc-shaped cover 12 having substantially the same diameter as the optical fiber 4 via two fixtures 10 and 11. The arc-shaped cover 12 is a member that covers the portion of the optical fiber 4 except for the vicinity of the measurement gap portion 7 and protects the optical fiber 4 from the load caused by the flow of the lubricant 5 to be detected. As shown in FIG. 2B showing a cross-sectional view taken along the line B-B, the cross-sectional outline is made of a rigid material having an S-shape, for example, a synthetic resin material or a metal material. Specifically, the arc-shaped cover 12 covers at least one side (right side in FIG. 2B) of the arc-shaped optical fiber 4 in the arc central axis direction. When the lubricant deterioration detecting device 1 is installed in the bearing, the surface side of the arc-shaped cover 12 (the right side surface in FIG. 2B) is disposed so as to be exposed to the lubricant sealed in the bearing.

  One fixture 10 for fixing the optical fiber 4 is an arc-shaped member joined to the lower half of the back surface of the cover 12 (the left side surface in FIG. 2B). Both ends are fixed, and the light emitting element 2 and the light receiving element 3 are also fixed to the fixture 10. Another fixing tool 11 that fixes the optical fiber 4 is fixed to the front surface side of another fixing tool 10 as shown in FIG. 11, the vicinity of the measurement gap 7 of the optical fiber 4 is fixed and positioned. As described above, by fixing the vicinity of the measurement gap 7 with the fixture 11 that is different from the fixture 10 that fixes both ends of the optical fiber 4, the positioning of the measurement gap 7 can be facilitated. This makes it easy to assemble the lubricant deterioration detection device 1. Note that the fixture 11 may be directly fixed to the arcuate cover 12 instead of being fixed to the other fixture 10. Further, these two fixtures 10 and 11 may be an integral member.

  A slit-like opening 13 extending in the circumferential direction is provided in the circumferential intermediate portion of the arc-shaped cover 12 at a position corresponding to the measurement gap portion 7 of the optical fiber 4 as shown in a front view in FIG. As a result, the measurement gap 7 is exposed to the lubricant 5 inside the bearing. As shown in a plan view in FIG. 3, the fixture 11 has a forked portion in the vicinity of the measurement gap portion 7 of the optical fiber 4 from the opening 13 of the arc-shaped cover 12 toward the surface of the cover 12. It is set as the protrusion part 11a which protruded in the shape. As a result, the vicinity of the measurement gap 7 of the optical fiber 4 is projected from the arc-shaped cover 12 to the outside of the cover.

  With the above configuration, both ends of the optical fiber 4, the surface side of the fixture 10 that fixes the light emitting element 2 and the light receiving element 3 are covered with the cover 12. Further, as shown in FIG. 2B, a portion other than the measurement gap portion 7 of the optical fiber 4 is formed in an arcuate space 14 formed by being sandwiched between the cover 12 on the front surface side and the fixture 10 on the back surface side. Be placed. Thereby, the optical fiber 4, the light emitting element 2, and the light receiving element 3 are protected from the load by the flow of the lubricant 5.

  Fixing of the fixtures 10 and 11 to the arc-shaped cover 12 or fixing of the other fixtures 11 to the fixture 10 is performed by one or more coupling processes of screw, press-fitting, adhesion, and welding. Thereby, this lubricant deterioration device 1 can be easily incorporated into the bearing.

  The measurement gap portion 7 of the optical fiber 4 is provided so as to form a predetermined inclination angle θ with respect to the vertical direction of the optical path formed by the optical fiber 4 as shown in an enlarged front view in FIG. . That is, the gap constituting end surfaces 4 a and 4 a on both sides constituting the measurement gap portion 7 of the optical fiber 4 are parallel to each other and inclined with respect to the axis of the optical fiber 4. Note that the inclination angle θ is an angle in a range in which light in the optical fiber 4 can enter and exit through the measurement gap portion 7. Moreover, in the fixture 11 that supports the vicinity of the measurement gap 7 in the optical fiber 4, the inner surfaces 11aa and 11aa of the bifurcated protrusions 11a and 11a that face each other are also adjusted to the inclination angle θ. It is an inclined surface.

  The operation of the above configuration will be described. When the lubricant 5 is new, it is nearly transparent, and the intensity of transmitted light that is projected from the light emitting element 2 via the optical fiber 4 and transmitted through the lubricant 5 is high. However, as the amount of foreign matter such as iron powder (wear powder) mixed in the lubricant 5 increases, the intensity of transmitted light gradually decreases. Therefore, the determination unit 6 detects the amount of foreign matter mixed in the lubricant 5 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 5 means the progress of deterioration of the lubricant 5, the degree of deterioration of the lubricant 5 can be estimated from the detected amount of foreign matter.

  As described above, in this lubricant deterioration detection device 1, the light emitting element 2 and the light receiving element 3 are provided opposite to each other at both ends of the arcuate optical fiber 4, and the lubricant 5 is interposed in a part of the optical fiber 4. A measurement gap portion 7 is provided, and the measurement gap portion 7 is provided with an inclination angle θ with respect to the vertical direction of the optical path formed by the optical fiber 4. When the deterioration of the lubricant 5 is detected, if the arcuate optical fiber 4 is installed so as to be concentric with the bearing, the measurement gap portion 7 forms an inclination angle θ with respect to the radial direction of the bearing. Will be placed. As a result, the lubricant 5 that moves in the bearing rotation direction inside the bearing can easily enter the measurement gap portion 7, and the lubricant 5 that has entered the measurement gap portion 7 can be replaced smoothly. In this way, since the lubricant 5 is sequentially replaced in the measurement gap portion 7, the lubricant 5 that always acts on the lubrication is to be detected, and can be easily and compactly mounted on the bearing and is stable. In addition, the deterioration of the lubricant can be detected with high accuracy.

FIG. 5 and FIG. 6 show an example of a bearing with a lubricant deterioration detection device in which the lubricant deterioration detection device 1 of the above embodiment is incorporated in a railway vehicle bearing. As shown in FIG. 5, the bearing 20 with the lubricant deterioration detecting device constitutes a railway vehicle bearing unit with an oil drain 25 and a rear lid 26 which are accessories provided in contact with both sides of the inner ring 21. . The bearing 20 is composed of a roller bearing, specifically, a double row tapered roller bearing, and is divided into inner rings 21 and 21 that are rotating wheels provided for the rollers 23 and 23 in each row, and an integral type that is a fixed ring. An outer ring 22, the rollers 23 and 23, and a cage 24 are provided.
The rear lid 26 is attached to the axle 30 on the center side of the bearing 20 and has a bearing seal 31A in sliding contact with the outer periphery. The oil drainer 25 is attached to the axle 30 and has a bearing seal 31 in sliding contact with its outer periphery. For example, grease, which is a lubricant, is sealed inside the bearing 20 by both bearing seals 31, 31 </ b> A disposed at both ends of the bearing 20, and dust and water resistance are ensured.

In this case, sensor portions (light emitting element 2, light receiving element 3, optical fiber 4, arc-shaped cover 12, etc.) excluding the circuit portions (determining means 6, light emitting circuit 8, light receiving circuit 9) in lubricant deterioration detecting device 1 are It is integrated in a seal unit 27 having the bearing seal 31. FIG. 6 shows an enlarged cross-sectional view of an installation part (A part) of the seal unit 27 in FIG.
The seal unit 27 in this case includes an annular seal case 28 attached to the end of the bearing outer ring 22, a ring member 29 press-fitted into the inner diameter surface of the seal case 28, and an inner peripheral surface of the ring member 29. And a bearing seal 31 that is press-fitted into the bearing. The seal case 28 is an annular member that covers the bearing seal 31 and has a cross-sectional shape in which a plurality of steps are arranged stepwise in the axial direction. One end of the seal case 28 is press-fitted into the inner diameter surface of the bearing outer ring 22 serving as a fixed ring. It is attached to the bearing outer ring 22 by fitting. Furthermore, the small diameter step portion at the other end of the seal case 28 is loosely fitted into a ring-shaped groove 38 formed on the inwardly-width surface of the flange portion 25a of the oil drain 25, so that the small diameter of the groove 38 and the seal case 28 is reduced. A labyrinth gap is formed between the stepped portion and the other end of the seal case 28 is thereby sealed.
The ring member 29 having an L-shaped cross section is attached to the inner diameter surface of the intermediate step portion of the seal case 28 by press-fitting the cylindrical portion 29a. The standing plate portion 29 b extending to the inner diameter side of the ring member 29 is disposed so as to form a predetermined labyrinth gap with respect to the outer diameter surface of the oil drain 25. The bearing seal 31 includes an annular cored bar 32 having an L-shaped cross section and an elastic member 33 fixed to a standing plate part of the annular cored bar 32, and the cylindrical part of the annular cored bar 32 is a cylinder of the ring member 29. It is fixed to the seal case 28 via the ring member 29 by being press-fitted into the inner peripheral surface of the portion 29a. The elastic member 33 is formed with a radial lip that is in sliding contact with the outer diameter surface of the oil drain 25.

  The lubricant deterioration detection device 1 is concentrically attached to the seal unit 27. Specifically, the large-diameter step portion of the seal case 28 is inserted into the inner diameter surface of the large-diameter step portion of the seal case 28 by the press-fitting ring 34 into which the arc-shaped cover 12 of the lubricant deterioration detection device 1 is fitted. The lubricant deterioration detection device 1 is pressed against the end surface and the upright plate portion 29b of the ring member 29 to be positioned and fixed in the axial direction. When the lubricant deterioration detecting device 1 is positioned and fixed in this way, the measurement gap portion 7 of the optical fiber 4 is near the large end surface of the roller 23 on the inner diameter side of the cage 24 of the bearing space between the inner and outer rings 21 and 22. Placed in. By arranging in this way, it is possible to avoid the loss of the fluidity of the lubricant in the bearing by the arc-shaped cover 12 of the lubricant deterioration detecting device 1.

  The lubricant 5 enclosed between the rolling surfaces of both rows inside the bearing moves toward the bearing seals 31 and 31A while moving in the bearing rotating direction by the rotation of the bearing inner ring 21, the roller 23 and the cage 24. Extruded. The extruded lubricant 5 moves in the rotational direction along the outer peripheral surface of the bearing inner ring 21, the large end surface of the roller 23, and the inner and outer peripheral surfaces of the cage 24. On the side of the bearing seal 31 that is the installation side of the lubricant deterioration detection device 1, the lubricant 5 that moves in the bearing rotation direction if moved to the bearing seal 31 side is the measurement gap portion of the optical fiber 4 in the lubricant deterioration detection device 1. 7, the deterioration state of the lubricant 5 is detected by the lubricant deterioration detection device 1. Since the measurement gap portion 7 is provided with an inclination angle θ with respect to the vertical direction of the optical path formed by the optical fiber 4, that is, with respect to the radial direction of the bearing, the lubricant 5 enters the measurement gap portion 7. This facilitates the replacement of the lubricant 5 that has entered the measurement gap 7. Thereby, the deterioration detection of the lubricant 5 inside the bearing by the lubricant deterioration detection device 1 can be stably and accurately performed.

  Further, if the arcuate cover 12 is arranged concentrically with the seal case 28 in this manner and the lubricant deterioration detecting device 1 is attached, the lubricant deterioration detecting device 1 can be easily positioned in the bearing 20 and can be easily assembled. Become. The attachment of the lubricant deterioration detecting device 1 in this case is not limited to the press-fitting, and one or more joining processes such as screws and adhesion may be employed.

The wiring 35 connecting the light emitting element 2 and the light emitting circuit 8 and the light receiving element 3 and the light receiving circuit 9 in the lubricant deterioration detecting device 1 passes through the hole 36 provided in the seal case 28 from the inside of the lubricant deterioration detecting device 1. Then, it is drawn out of the bearing 20, and the wiring 35 is connected to the light emitting circuit 8 and the light receiving circuit 9. The hole 36 of the seal case 28 is covered with the arc-shaped cover 12 of the lubricant deterioration detection device 1 from the inside, and further sealed with an elastic body 37 to be waterproofed.
The other bearing seal 31A is also attached to the bearing outer ring 22 by the seal unit 27A. The seal unit 27A has the same structure as the seal unit 27 except that the lubricant deterioration detection device 1 is not attached.

  The light emitting circuit 8 and the light receiving circuit 9 may be installed inside the bearing 20. When there is no space for installing a circuit outside the bearing 20, the arc-shaped cover 12 of the lubricant deterioration detection device 1 is extended in the circumferential direction, and the light emitting circuit 8 and the light receiving circuit 9 are arranged on the cover 12. Thus, these circuits can be easily installed in the bearing 20.

  According to this bearing 20 with a detecting device, the deterioration state of the lubricant sealed in the bearing can be accurately detected in real time. Thereby, it is possible to determine the necessity of replacement of the lubricant before the operation abnormality occurs in the bearing 20, and it is possible to prevent the bearing 20 from being damaged 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.

1 is a schematic configuration diagram of a lubricant deterioration detection device according to an embodiment of the present invention. 1A is a cross-sectional view taken along the line AA in FIG. 1, FIG. 1B is a cross-sectional view taken along the line BB in FIG. 1, and FIG. It is a partial top view of a lubricant deterioration detection apparatus. It is an enlarged plan view of the vicinity of the gap portion for measurement of the optical fiber. It is sectional drawing which shows one structural example of the bearing with a lubricant deterioration detection apparatus carrying the lubricant deterioration detection apparatus of this invention. It is an expanded sectional view of the part of the seal unit of the bearing with the same lubricant deterioration detection device. It is a schematic block diagram of the prior art example of a lubricant deterioration detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lubricant deterioration detection apparatus 2 ... Light emitting element 3 ... Light receiving element 4 ... Optical fiber 5 ... Lubricant 7 ... Measurement gap part 20 ... Bearing 21 with lubricant deterioration detection apparatus ... Inner ring (rotating ring)
22 ... Outer ring (fixed ring)

Claims (2)

A lubricant deterioration detecting device in which a light emitting element and a light receiving element are provided opposite to each other on both ends of an arc-shaped optical fiber, and a measurement gap portion is provided in which a lubricant is interposed in a part of the arc-shaped optical fiber. ,
The lubricant deterioration detecting device, wherein the measurement gap is installed at an angle inclined with respect to an optical path constituted by the optical fiber. A bearing with a lubricant deterioration detecting device, wherein the lubricant deterioration detecting device according to claim 1 is attached to the rolling bearing with the measurement gap portion positioned between a fixed ring and a rotating ring in the rolling bearing.

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