JP7024655B2 - Lubricant deterioration detector - Google Patents

Description

The present invention relates to a lubricant deterioration detection device.

A general method for detecting an abnormality in a bearing is to detect a change in vibration, an increase in temperature, or the like (Patent Document 1). Deterioration of bearing balls and rollers, contamination of foreign matter, etc. can be detected by this method, but deterioration of bearing lubricant is difficult to detect by vibration and temperature.

If no abnormal load is applied or foreign matter is not mixed in from the outside, the bearing failure is first the deterioration of the lubricant, and the deterioration of the inner and outer rings, balls and rollers of the bearing, and the foreign matter from there. For example, it leads to the generation of shavings.

If there is a lubricant supply / recovery device, there is a method of measuring the resistance, dielectric constant, capacitance, and light transmission rate in the recovery tank (Patent Document 2, Patent Document 3, Patent Document 4). The equipment is complicated and it is difficult to measure with the lubricant enclosed in the bearing. For example, Patent Document 1 describes a method for detecting deterioration of a lubricant sealed in a bearing, but uses a sensor having a complicated mechanism.

Japanese Unexamined Patent Publication No. 2007-192769 Japanese Unexamined Patent Publication No. 2017-323552 Japanese Unexamined Patent Publication No. 2017-191062 Japanese Unexamined Patent Publication No. 2017-215253

The present invention has been made in view of the above problems, and an object of the present invention is to provide a lubricant deterioration detecting device capable of detecting deterioration of a lubricant without requiring a complicated device, a sensor, or the like. ..

The lubricant deterioration detection device according to one aspect of the present disclosure includes a heat flow sensor 12 that holds the rotating shaft 11 and is provided in the bearing portion 16 in which the lubricant 22 is sealed and can detect the heat flow velocity of the bearing portion. A rotation sensor 14 capable of detecting the rotation speed of the rotation shaft, and a determination unit 10 connected so as to be able to receive a detection signal from the heat flow sensor and the rotation sensor, the determination unit includes the rotation sensor. The acceleration of the rotating shaft is calculated from the rotational speed of the rotating shaft received from, and the amount of change in the thermal flow velocity during acceleration of the rotating shaft is calculated from the heat flow velocity of the bearing portion received from the heat flow sensor. After performing this round, the slope of the straight line approximated by this acceleration-heat flow velocity change plot is obtained by a linear equation, and the degree of deterioration of the lubricant is determined by comparing the judgment reference value prepared in advance with the slope. do.

According to this configuration, it is possible to provide an effective means for detecting the degree of deterioration of the lubricant 22 enclosed in the bearing portion 16 without taking it out to the outside. Further, it is not necessary to determine the deterioration of the lubricant 22 by taking out the lubricant 22 to the outside or using a sensor or an apparatus having a complicated mechanism.

A block diagram showing a schematic configuration of a lubricant deterioration detection device according to an embodiment. Partial perspective plan showing the schematic configuration of the heat flow sensor Vertical cross-sectional view showing the schematic configuration of the heat flow sensor A flow chart showing an outline of the judgment process in the lubricant deterioration detection device. Graph showing the outline of the relationship between the speed of the rotating body and the heat flow velocity The figure which shows the outline of the deterioration determination method of a lubricant.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In the following description, substantially the same components are designated by the same reference numerals, and the description thereof will be omitted. In addition, the drawings referred to are schematic, and the dimensional relationships and ratios of the drawn configurations do not always match the actual ones.

The lubricant deterioration detecting device 1 according to the embodiment uses a heat flow sensor 12 that detects a heat flow velocity, and detects deterioration of the bearing lubricant from the amount of change in the heat flow velocity during rotational acceleration of the rotating shaft 11.

As shown in FIGS. 1 to 3, the lubricant deterioration detection device 1 according to the embodiment includes a determination unit 10, a heat flow sensor 12, and a rotation sensor 14. In addition, in FIG. 1, the rotary shaft 11 and the bearing portion 16 are shown in a cross-sectional view. The determination unit 10, the heat flow sensor 12, and the rotation sensor 14 are connected by a wired or wireless communication means 20. The determination unit 10, the heat flow sensor 12, and the rotation sensor 14 are connected by the communication means 20 so as to be able to receive the detection signals from the heat flow sensor 12 and the rotation sensor 14.

The determination unit 10 is a processor configured to include, for example, a CPU, RAM, ROM, I / O, and the like. The determination unit 10 processes, for example, the heat flow velocity and rotation speed data acquired from the heat flow sensor 12 and the rotation sensor 14 by executing the program stored in the ROM, and whether or not the lubricant is deteriorated. Judgment is carried out.

The bearing portion 16 is, for example, a ball rolling bearing composed of a spherical ball 16a, an outer bearing portion 16b that movably sandwiches the ball 16a, and an inner bearing portion 16c. A liquid or gel-like lubricant 22 is sealed between the ball 16a and the outer bearing portion 16b and the inner bearing portion 16c, that is, inside the bearing portion 16.

In the embodiment, the bearing portion 16 has been described by way of exemplifying a ball bearing, but there is no intention of limiting the bearing portion 16. The bearing portion 16 can be applied to any bearing as long as the lubricant 22 is used. As the bearing, various bearings such as rolling bearings such as ball bearings and cylindrical roller bearings, and sliding bearings called metal and spur bearings can be used.

The heat flow sensor 12 is installed in a bearing portion 16 that rotatably holds the rotating shaft 11. The heat flow sensor 12 electrically detects the heat transfer of the bearing portion 16 and measures the heat flow velocity. The heat flow velocity measured by the heat flow sensor 12 is transmitted to the determination unit 10 in chronological order.

A rotation sensor 14 is installed on the rotation shaft 11. The rotation sensor 14 measures the rotation speed of the rotation shaft 11. The rotation speed signal of the rotation shaft 11 detected by the rotation sensor 14 is transmitted to the determination unit 10 in chronological order. The determination unit 10 that has received the rotation speed signal stores the rotation speed signal in chronological order. The determination unit 10 calculates the acceleration of rotation of the rotation shaft 11 by calculating the rotation speed signal.

An amplifier 18 that amplifies the detected heat flow velocity signal may be arranged between the heat flow sensor 12, the rotation sensor 14, and the determination unit 10. Since the signal detected by the heat flow sensor 12 and the rotation sensor 14 is amplified by the amplifier 18 and transmitted to the determination unit 10, it is possible to improve the detection sensitivity of deterioration of the lubricant 22, which will be described later.

The determination unit 10 that has received the heat flow velocity and the rotation speed stores the heat flow velocity and the rotation speed in chronological order as described above. Further, the determination unit 10 calculates the heat flow velocity and the rotation speed stored in chronological order, detects the maximum value of the heat flow velocity during acceleration of the rotation shaft 11, and obtains the maximum value as shown in FIG. Is the measurement point M.

The determination unit 10 calculates the amount of change in the heat flow velocity by calculating the difference between the heat flow velocity immediately before acceleration and the maximum heat flow velocity at the measurement point M. The determination unit 10 stores the acceleration at the measurement point M and the amount of change in the heat flow velocity. In FIG. 5, the correspondence between the measurement point M and the acceleration at the measurement point M is shown by a broken line, and the amount of change in heat flux at the measurement point M is shown as ΔQ.

When the rotation of the rotating shaft 11 is accelerated, the energy required for accelerating the rotation of the rotating shaft 11 increases, so that the amount of heat increases. It is difficult due to the influence. However, since the amount of change in the heat flow velocity is not related to the ambient temperature, the increase in the amount of heat in the bearing portion 16 can be detected as the heat flow velocity by using the heat flow sensor 12.

Here, the configuration of the heat flow sensor 12 will be described with reference to FIGS. 2 and 3. In FIG. 3, the upper side is the front side and the lower side is the back side. FIG. 2 is a plan view seen from the direction of arrow B in FIG. 3, and FIG. 3 is a vertical cross-sectional view of a portion along the line AA in FIG.

As shown in FIG. 3, the heat flow sensor 12 includes an insulating base material 40, a back surface protecting member 42 arranged on the back surface side of the insulating base material 40, and a surface protecting member 44 arranged on the front surface side of the insulating base material 40. I have. The insulating base material 40 is made of, for example, a film made of a thermoplastic resin, and has flexibility and flexibility.

The insulating base material 40 includes a plurality of first holes 401 and second holes 402 provided so as to penetrate the front and back surfaces of the insulating base material 40. In the first hole 401, the first thermoelectric conversion member 46 is embedded so as to cross the front and back of the insulating base material 40. A second thermoelectric conversion member 48 is embedded in the second hole 402 so as to cross the front and back of the insulating base material 40. On the remote base material 40, the first thermoelectric conversion member 46 and the second thermoelectric conversion member 48 are arranged alternately adjacent to each other along the line L shown in FIG.

The back surface protective member 42 is made of, for example, a film made of a thermoplastic resin, and has flexibility and flexibility. The back surface protective member 42 is provided on the back surface 403 of the insulating base material 40. A first wiring 405 formed of a patterned copper thin film is provided between the back surface 403 of the insulating base material 40 and the surface 421 of the back surface protecting member 42 on the insulating base material 40 side. The adjacent first thermoelectric conversion member 46 and the second thermoelectric conversion member 48 are electrically connected by the first wiring 405 on the back surface 403 side of the insulating base material 40.

The surface protection member 44 is made of, for example, a film made of a thermoplastic resin, and has flexibility and flexibility. The surface protection member 44 has substantially the same size as the insulating base material 40. The surface protection member 44 is provided on the surface 404 of the insulating base material 40. A plurality of second wirings 406 formed of a patterned copper thin film are provided between the surface 404 of the insulating base material 40 and the base material surface 441 on the insulating base material 40 side of the surface protection member 44. The adjacent first thermoelectric conversion member 46 and the second thermoelectric conversion member 48 are electrically connected by a second wiring 406 on the surface 404 side of the insulating base material 40.

The first thermoelectric conversion member 46 and the second thermoelectric conversion member 48 are formed of, for example, a thermoelectric material made of a semiconductor or metal. In the embodiment, the first thermoelectric conversion member 46 is made of, for example, a Bi-Sb-Te-based metal compound which is a p-type thermoelectric material, and the second thermoelectric conversion member 48 is made of, for example, an n-type thermoelectric material. It is composed of a certain Bi-Te metal compound. The first thermoelectric conversion member 46 and the second thermoelectric conversion member 48 are alternately and continuously connected on the front and back sides by the first wiring 405 and the second wiring 406, thereby forming the thermoelectric module unit 12a.

As described above, the thermoelectric module portion 12a of the heat flow sensor 12 is composed of thermoelectric conversion members 46 and 48 made of n-type and p-type thermoelectric materials connected in series alternately. The n-type thermoelectric material exhibits a negative Seebeck coefficient with electrons as charge charia. The p-type thermoelectric material has a positive Seebeck coefficient with holes as charge carriers. When there is a temperature gradient that traverses the front and back of the heat flow sensor 12, the carriers generated on the high temperature side of the first thermoelectric conversion member 46 and the second thermoelectric conversion member 48 diffuse to the low temperature side, so that a thermal potential difference is generated. .. The heat flow sensor 12 detects the heat flow velocity by measuring the thermoelectromotive force generated in this way.

As shown in FIGS. 2 and 3, in one heat flow sensor 12, a plurality of alternately arranged first thermoelectric conversion members 46 and second thermoelectric conversion members 48 are connected in series by the first wiring 405 and the second wiring 406. As shown by the line L shown in FIG. 2, it is formed to meander as a whole, and terminals 461 and 481 are connected to both ends thereof.

As shown in FIG. 3, the first thermoelectric conversion member 460 located at the end of the plurality of first thermoelectric conversion members 46 is electrically connected to the terminal 461. Further, the second thermoelectric conversion member 48 located at the end of the plurality of second thermoelectric conversion members 48 is electrically connected to the terminal 481. The terminals 461 and 481 are exposed to the outside through the opening 442 provided in the surface protection member 44.

The terminal 461 is electrically connected to the output line 463 via the connection bump 462. The terminal 481 is electrically connected to the output line 483 via the connection bump 482. The output lines 463 and 483 are electrically connected to the determination unit 10. The heat flow sensor 12 is configured as described above.

In the heat flow sensor 12, when the magnitude of the amount of heat flowing in the thickness direction of the heat flow sensor 12, that is, the direction from the back surface protection member 42 to the surface protection member 44 in FIG. 3, that is, the heat flow velocity changes, the first heat flow sensors are alternately connected in series. The electromotive voltage generated in the thermoelectric conversion member 46 and the second thermoelectric conversion member 48 changes. In the heat flow sensor 12, this voltage is output to the determination unit 10 as a detection signal via the output lines 463 and 483, and is detected as a heat flow velocity.

Since the insulating base material 40, the back surface protection member 42, the front surface protection member 44, and the like of the heat flow sensor 12 described above are made of a film made of resin, they have flexibility and flexibility as a whole. As a result, the heat flow sensor 12 can be curved and wound along the outer shape of the bearing portion 16. If the heat flow sensor 12 is wound around the bearing portion 16 and installed, the bearing portion 16 and the heat flow sensor 12 can be arranged with good adhesion, the contact area is increased, and the heat flow velocity of the bearing portion 16 is efficiently detected. It becomes possible.

Here, when the lubricant 22 of the bearing portion 16 deteriorates, the energy required for accelerating the rotation of the rotating shaft 11 increases, and the amount of heat flowing out from the bearing portion 16 increases. Therefore, if the increase in the amount of heat in the bearing portion 16 is monitored as the heat flow velocity by using the heat flow sensor 12, the deterioration of the lubricant 22 can be detected by the increase in the heat flow velocity.
Next, the process of determining the deterioration of the lubricant 22 in the lubricant deterioration detection device 1 will be described.

First, the determination unit 10 detects whether or not the rotation shaft 11 is accelerating (S1). Whether or not the rotary shaft 11 is accelerating is determined by the change in the speed of the rotary shaft 11 transmitted from the rotary sensor 14. If the rotating shaft 11 is not accelerating (S1: NO), the process returns to the determination of whether or not the rotating shaft 11 is accelerating (S1). If the rotating shaft 11 is accelerating (S1: YES), the determination unit 10 calculates the acceleration from the speed signal of the rotating shaft 11 transmitted from the rotating sensor 14 (S2).

Next, the determination unit 10 detects the amount of change in the heat flow velocity in the bearing unit 16 by monitoring the heat flow velocity received from the heat flow sensor 12 (S3). Then, as shown in FIG. 5, the difference between the heat flow velocity before the rotation acceleration of the rotating shaft 11 and the maximum value of the heat flow velocity at the time of acceleration is detected as the heat flow velocity change amount, and the acceleration and the heat flow velocity change amount at this time are detected. Is memorized (S4). This process is performed multiple times at various accelerations, and the multiple accelerations and the amount of change in heat flow velocity are stored.

If the number of data does not reach n (S5: NO), the process returns to the determination of whether or not the rotating shaft 11 is accelerating (S1). When the number of data reaches n (S5: YES), as shown in FIG. 6, the acceleration-heat flow velocity change amount plot of the rotation of the rotation axis 11 is performed, and the slope of a straight line approximated by a linear equation is obtained. Calculate (S6). The larger the inclination, the larger the heat flow velocity in the bearing portion 16 with respect to the acceleration, and therefore, the larger the deterioration of the lubricant 22 is. n is preset as a sufficient number to perform a linear approximation for this plot of acceleration-heat flow velocity change.

Next, the deterioration of the lubricant 22 is determined by comparing the obtained inclination with the determination reference value prepared in advance. Here, when the slope ≤ the determination reference value (S7: NO), the process ends with no abnormality. If the inclination> the determination reference value (S7: YES), it is determined that there is an abnormality, that is, the lubricant 22 has deteriorated, and a measure for the abnormality is taken (S8). In this way, the determination of deterioration of the lubricant 22 is carried out. This determination process is performed by the determination unit 10.

As an abnormal measure in S8, for example, when the deterioration state of the lubricant 22 is slight, a "warning" is displayed, and when the degree of deterioration of the lubricant 22 is large, for example, "equipment stop" is taken. implement.

The degree of deterioration of the lubricant 22 can be determined, for example, as follows. As shown in FIG. 6, the judgment reference value having a small slope is set as the first judgment reference value and is set as the judgment reference value corresponding to the slight deterioration, and when the plotted slope> the first judgment reference value, It is judged that there is slight deterioration. In this case, take abnormal measures such as displaying a "warning" corresponding to the case of slight deterioration. The first determination reference value and the second determination reference value are set in advance according to the degree of deterioration of the lubricant 22.

Further, as shown in FIG. 6, the judgment reference value having a larger inclination is set as the second judgment reference value, and is set as the judgment standard corresponding to the large deterioration, that is, the severe deterioration, and the plotted inclination> the second judgment standard. If it is a value, it is determined that there is severe deterioration. In this case, take abnormal measures such as implementing "equipment shutdown" in case of severe deterioration. As described above, the content of the abnormal treatment in S8 may be different depending on the degree of deterioration of the lubricant 22.

In the above description, the two abnormal treatments of "warning" display and "equipment stop" have been illustrated and described according to the degree of deterioration of the lubricant 22, but the present invention is not limited to this. Further, in the above description, the two determination reference values, the first determination reference value and the second determination reference value, have been illustrated and described, but the present invention is not limited thereto. It is also possible to determine the degree of deterioration of the lubricant 22 by using a plurality of determination reference values according to the degree of deterioration of the lubricant 22. Further, the above treatment is carried out once a day, once a week, once a month, for example, although it depends on the frequency of use of the apparatus and the durability of the lubricant 22.

The judgment reference value is, for example, based on the acceleration-heat flow velocity change plot immediately after the start of use or replacement of the bearing, x times the first judgment reference value and y times the second judgment reference value (x <y). ) And so on.

According to the lubricant deterioration detection device 1 described above, the following effects are obtained.
According to the lubricant deterioration detecting device 1 according to the embodiment, the heat flow sensor 12 arranged by winding around the bearing portion 16 monitors the heat flow velocity of the bearing portion 16, and thus is enclosed in the bearing portion 16. It is possible to provide an effective means for detecting the degree of deterioration of the lubricant 22 without taking it out to the outside. Further, according to the lubricant deterioration detecting device 1 according to the embodiment, it is not necessary to determine the deterioration of the lubricant 22 by taking out the lubricant 22 to the outside or using a sensor or an apparatus having a complicated mechanism. Therefore, the device configuration can be relatively simple, and the cost can be reduced.

The present disclosure has been described in accordance with the examples, but it is understood that the present disclosure is not limited to the examples and structures. The present disclosure also includes various variations and variations within a uniform range. In addition, various combinations and forms, as well as other combinations and forms that include only one element, more, or less, are within the scope and scope of the present disclosure.

1 ... Lubricant deterioration detector, 10 ... Control unit, 11 ... Rotating shaft, 12 ... Heat flow sensor, 14 ... Rotation sensor, 16 ... Bearing unit, 22 ... Lubricant

Claims (6)

A heat flow sensor (12) provided in a bearing portion (16) holding a rotating shaft (11) and having a lubricant (22) sealed therein, and capable of detecting the heat flow velocity of the bearing portion.
A rotation sensor (14) capable of detecting the rotation speed of the rotation axis, and
A determination unit (10) connected so as to be able to receive a detection signal from the heat flow sensor and the rotation sensor is provided.
The determination unit calculates the acceleration of the rotation shaft from the rotation speed of the rotation shaft received from the rotation sensor, and changes the heat flow velocity during acceleration of the rotation shaft from the heat flow velocity of the bearing portion received from the heat flow sensor. After calculating the amount and performing this multiple times, the slope of the straight line approximated by this acceleration-heat flow velocity change amount plot is obtained by a linear equation, and the preset judgment reference value is compared with the slope. A lubricant deterioration detection device that determines the degree of deterioration of the lubricant. The lubricant deterioration detection device according to claim 1, wherein the determination reference value is a plurality of determination reference values according to the degree of deterioration of the lubricant. The determination reference value is the first determination reference value corresponding to the case where the deterioration of the lubricant is slight, and the second determination reference value corresponding to the case where the degree of deterioration of the lubricant is severe according to claim 1. The described lubricant deterioration detector. The lubricant deterioration detection device according to claim 1, wherein the determination reference value in the previous term is calculated based on an acceleration-heat flow velocity change amount plot immediately after the start of use or replacement of the bearing. The lubricant deterioration detection device according to any one of claims 2 to 4, wherein different measures are taken depending on the degree of deterioration of the lubricant. The lubricant deterioration detecting device according to any one of claims 1 to 5, wherein the heat flow sensor has flexibility and can be wound around the bearing portion and installed.

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