JP5254908B2 - How to check the machine - Google Patents

Description

  The present invention relates to a method for inspecting a machine having a gear mechanism coated with grease.

  In a machine having a gear mechanism, since the tooth surfaces of the gears slide, a lubricant is applied to operate the gear mechanism smoothly. As the lubricant, a low-viscosity lubricant (so-called oil) is used when the rotational speed of the machine is fast, and a high-viscosity lubricant (so-called grease) is used when the rotational speed is slow. Various types of lubricants are used depending on the material, load, and usage environment (temperature, etc.) of the gear.

  However, even a gear mechanism coated with a lubricant rubs against each other, so that wear occurs. In particular, a gear mechanism to which a large force is applied has great wear. If the gear teeth are worn, tooth skipping may occur, resulting in malfunctions. Therefore, periodic inspection is required.

  For example, as a machine having a gear mechanism, a sluice door hoisting machine of a hydroelectric power plant will be described as an example. The hoisting machine includes a spindle type, a rack type, and a wire type, all of which are devices that move the sluice door up and down by increasing the torque of the motor driving force with a reduction gear (gear mechanism). As an example, the hoisting machine performs a regular inspection without disassembling the machine once a year, and a precision inspection with disassembling the machine once every three years. In the normal inspection, the appearance inspection, the operation confirmation, and the electrical board check are only performed, but in the precision inspection, the gear mechanism is disassembled and cleaned, and the grease is replaced. In the precise inspection, the degree of wear of the gear teeth is also checked, and if the wear is severe, the gear is replaced.

  The degree of wear of the gear teeth can be measured by the shape of the gear teeth and the concentration of wear particles in the grease. The shape of the gear teeth is for gear teeth that are large to some extent, but the width of the cutting edge is directly measured by calipers or the like. As for the concentration of the wear particles in the grease, the concentration of the metal element in the grease can be analyzed by, for example, plasma emission analysis.

  It is also known that grease deteriorates with time. There are various forms of grease degradation, but mainly due to oxidation, the viscosity decreases or increases, and the polymer breaks down. Also, proper lubrication ability is lost due to contamination of wear particles, dust, and water. Of course, if the grease loses its lubricating ability, the gear teeth wear.

Patent Document 1 describes a method for evaluating the degree of deterioration (oxidation degree) of turbine oil by an infrared absorption spectrum method. Specifically, the turbine oil is irradiated with infrared rays, the change rate from the new oil in the absorbance of the comparative absorption peak in the vicinity of the wave number 720 cm ^{−1 of the} turbine oil is obtained, and the oxide absorption peak (wave number) is calculated based on the change rate. The absorbance at 1710 cm ⁻¹ ) is corrected, and the degree of deterioration of the turbine oil is evaluated from the corrected absorbance of the oxide absorption peak. According to Patent Document 1, the absorbance of the oxide absorption peak can be measured with good measurement accuracy by correcting the difference in the measurement conditions such as the film thickness using the value of the comparative absorption peak that is not affected by deterioration, It is said that the degree of deterioration of turbine oil can be accurately evaluated.

  Patent Document 2 describes a method for estimating the physical properties and performance of an unknown heat medium oil by utilizing the correlation between the near-infrared spectrum of the heat medium oil and the management index value of the heat medium oil. ing. Specifically, the near-infrared spectra of heat medium oils with known properties and performance are measured, and the properties, performance and near-infrared are analyzed by multivariate analysis (amount of decomposition products and polymerization products as examples of control values). The correlation with the spectrum is taken, then the near-infrared spectrum of the unknown heat transfer medium oil is measured, and the performance, life, etc. of the unknown heat transfer medium oil are estimated from the measurement results. According to Patent Document 2, the degree of deterioration of an unknown heat medium oil is evaluated based on this estimation, and an accurate determination can be made in a short time regarding the replacement time, the replenishment time of new oil, and the like.

JP 2003-28793 A JP 2000-105231 A

  As described above, inspection is indispensable in order for a machine having a gear mechanism to continue operating soundly. However, the disassembly work of the gear mechanism requires time for disassembling, assembling, and cleaning the gear, etc., because the large gear is heavy and the mechanism is complicated. Therefore, the inspection and maintenance costs tend to be enormous. The number becomes even more so, even if one unit is subjected to a thorough inspection once every three years, the operator side is constantly inspecting many machines.

  On the other hand, there are many cases where no trouble has occurred during the close inspection (although it is determined at such a frequency), it is considered that there is room for reviewing the frequency of the close inspection. However, if you simply reduce the frequency of close inspections, some individuals may still suffer from time to time. Also, in the example of the hoisting machine, there is a difference in operation frequency depending on the installation location, and there are some that are consumed earlier and those that are hardly consumed, and it is difficult to determine the optimum frequency.

  Therefore, there is a demand for estimating the occurrence and progression of gear wear, that is, the degree of wear without disassembly. But this seems easy and not easy. This is because in order to measure the shape of the gear teeth with a caliper, the grease must be wiped off, and since the internal teeth cannot be caulked against the tooth surface, the measurement is difficult unless disassembled. Also, when trying to measure the concentration of wear particles in the grease, the viscosity of the grease is high and the wear particles do not diffuse, so the concentration of wear particles is significantly uneven depending on the location, and the grease was collected within the reach of the inspection port. There is no guarantee that the concentration can be measured properly.

  In addition, said patent document 1 describes degradation evaluation by the infrared absorption spectrum method of a lubricant. However, it is merely a deterioration of the lubricant, and there is no description on the relationship between the deterioration of the lubricant and the occurrence or progression of gear wear.

  Moreover, in said patent document 2, it is described that the near-infrared spectrum of heat-medium oil has correlation with management values, such as the amount of decomposition products of a heat-medium oil, and the amount of polymerization products. However, it is only a management value (state parameter) of the heat medium oil itself, and there is no place to describe the relationship between the occurrence and progress of gear wear.

  Accordingly, an object of the present invention is to provide a machine inspection method capable of estimating the occurrence and progress of gear wear without disassembling and optimizing the frequency of precision inspection involving disassembly.

  As a result of extensive research by the inventors to solve the above-mentioned problems, there are types of wear particles, which can be broadly classified into corrosive wear particles and adhesive wear particles, and cutting wear particles that occur suddenly due to foreign matter contamination. We focused on the fact that each could be identified by microscopic observation. And it discovered that corrosive wear particles generate | occur | produce with the oxidation of grease among said wear particles, and adhesion wear particles became large with progress of wear degree. From these facts, it was conceived that the degree of wear can be estimated by the size instead of the concentration of the wear particles, and the present invention was completed with further investigation.

  That is, a typical configuration of the present invention is a method for inspecting a machine having a gear mechanism coated with grease, and performing a wear test that reproduces the wear of the gear mechanism using pre-oxidized grease, and wear particles are Set the first control value consisting of the degree of grease oxidation at the beginning of generation, set the second control value for the size of wear particles generated by gear mechanism wear, Collect grease from the vicinity of the gear mechanism and measure the degree of oxidation of the collected grease. If the measured degree of oxidation exceeds the first control value, measure the size of the wear particles contained in the collected grease. And when the size of the measured wear particles exceeds the second control value, a precise inspection accompanied by disassembly of the machine is performed.

  According to the above configuration, the probability of corrosion wear or cohesive wear is first determined based on the oxidation degree of grease, and the size of wear particles is measured only when the probability is high (when the oxidation degree exceeds the first control value). After checking the degree of wear, perform a precise inspection as necessary. Thus, since it is determined primarily by the degree of oxidation that can be easily measured, and the size of the wear particles is less dependent on the sampling location, the necessity for precise inspection can be determined easily and accurately. Therefore, it is possible to estimate the occurrence and progress of gear wear without disassembling, and to optimize the frequency of precision inspection involving disassembly.

  By measuring the size of the wear particles, the first control value may be calibrated according to whether or not the wear particles are measured. Thereby, the optimal first management value can be obtained irrespective of the difference in the type of grease and the operating frequency of the machine.

  A large number of machines to be inspected may be grouped according to the operating frequency, and the first management value may be calibrated for each group. Even if the degree of oxidation of grease is the same, the degree of wear varies depending on the frequency of operation, so it is essentially desirable to calibrate individually. However, if the regular inspection is performed at a frequency of once a year or the like, it will take a considerable amount of time to collect sample data sufficient for calibration, and practically calibration cannot be performed. Therefore, it is possible to calibrate quickly and appropriately by grouping for each operation frequency.

  A large number of machines to be inspected may be grouped according to the operating frequency, a wear test reflecting the operating frequency condition may be performed for each group, and the first management value may be set. If the first management value can be set for each group by performing a wear test in consideration of the operation frequency, a more optimal first management value can be obtained from the beginning.

  The measurement of the size of the wear particles may be performed periodically in addition to the case where the degree of oxidation of the collected grease exceeds the first control value. By periodically measuring the size of the wear particles, it is possible to detect cutting wear that is not related to the degree of grease oxidation.

  The degree of oxidation of grease may be measured by an infrared absorption spectrum. In addition, the degradation degree (oxidation degree) of the grease measured by the infrared spectrum may be called IR oxidation degree. This makes it possible to easily measure the degree of oxidation at the site where the machine is installed.

  The size of the wear particles may be measured by a ferrography analyzer for the wear particles contained in the grease. Thereby, the size of the wear particles can be measured easily and accurately.

  The machine may be a sluice door hoist. Since the sluice gate has been used for many years, the number of units is large, and a heavy load is applied to operate the sluice gate, which is a heavy load, so the frequency of close inspection is optimized by applying the present invention. By doing so, the profit can be fully enjoyed.

  According to the present invention, it is possible to estimate the occurrence and progress of gear wear without disassembling, and to optimize the frequency of precision inspection involving disassembly, thereby reducing the burden on inspection of a machine having a gear mechanism. be able to.

It is a figure explaining the hoisting machine of the sluice door used for a hydroelectric power station etc. It is a chart which shows the failure factor of a hoisting machine. It is a figure explaining an abrasion particle. It is a figure explaining the test which investigates the relationship between grease degradation and wear. It is a figure explaining the IR tester which measures IR oxidation degree. It is a figure explaining the ferrography analyzer which can measure the magnitude | size of an abrasion particle. It is a figure explaining the method of extract | collecting grease in a winding machine. It is a flowchart which shows the inspection method of the machine concerning this embodiment. It is a figure explaining calibration of the 1st management value. It is a flowchart which shows the inspection method at the time of using a 3rd management value. It is an example which measures the magnitude | size of a wear particle regularly, Comprising: It is a flowchart which shows the inspection method in the case of also performing a precise check regularly.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  In this embodiment, a sluice door hoisting machine will be described as an example of a machine that is a target of the inspection method according to the present invention. The sluice door has been used for many years, and the number of the sluice gates is large, and a heavy load is applied to the gears in order to operate the sluice gate which is a heavy object. For this reason, by applying the present invention and optimizing the frequency of the precision inspection, the benefits can be fully enjoyed. However, the machine inspection method according to the present invention can be applied to any machine having a gear mechanism coated with grease.

  FIG. 1 is a view for explaining a sluice door hoisting machine used in a hydroelectric power plant or the like. The hoisting machine 100 illustrated in FIG. 1A is a device that adjusts the amount of flowing water by moving the sluice door 150 up and down. As shown in FIG. 1 (a), a gate that adjusts the amount of water flowing from a water source 160 such as a river to a water channel 170 is called a water control gate, although not shown, a gate for discharging sand from a water channel of a hydroelectric power plant or the like. This is called the sand gate.

  FIG. 1B shows an example of a spindle type hoisting machine 100. The driving force of the electric motor 112 controlled by the electrical board 110 is transmitted to the worm gear 116 after the torque is increased by the speed reducer 114. The driving force is converted by 90 degrees in the rotation direction by the worm gear 116 and the female screw 118, whereby the spindle 120 moves in the vertical direction. Since the sluice door 150 is heavy, the gear ratio of the speed reducer 114 is large, and the vertical movement speed of the sluice door 150 is about 0.3 (m / min) on average. The worm gear 116 is also connected with a manual handle 122 for manually moving the sluice door 150 up and down.

  A larger torque (contact stress) acts between the spindle 120 and the female screw 118 than between the gears constituting the speed reducer 114. Therefore, the oil film of grease is likely to be cut between them, and wear is likely to occur. The spindle 120 is a long and large-diameter screw and is expensive to manufacture. For this reason, the female screw 118 combined with the spindle 120 is formed of a softer material than the spindle 120, and the female screw 118 is exclusively worn. Specifically, the spindle 120 is formed of a steel material such as SS (structural steel), SC (carbon steel for mechanical structure), SUS (stainless steel), and the internal thread 118 is softer than that, such as a high-strength brass casting. It is made of brass.

  FIG. 2 is a chart showing failure factors of the hoisting machine 100. As shown in FIG. 2A, the electrical factor due to the failure of the electrical board 110 or the like is 38%, and the mechanical factor is 62%. Among these, regarding electrical factors, the electrical circuit board 110 can be checked by opening the case, and if there is a malfunction somewhere, the malfunction is apparently poor, so inspection and maintenance are relatively easy. Therefore, checking for electrical factors is not a special burden.

  However, regarding mechanical factors, the internal gears etc. are intricately engaged, so the visibility is extremely bad, looseness and damage are extremely difficult to understand from the appearance, and even if a malfunction begins to occur, it is not necessarily malfunctioning. Because it does not become necessary, it is difficult to understand the failure, and overhaul inspection is fundamental. However, since disassembly and maintenance is a large machine, each part is heavy, and since it is a complicated mechanism, it takes time and labor for assembly as well as disassembly. Accordingly, the inspection of mechanical factors (inspection accompanied by disassembly) is a heavy burden on the operator.

  Here, among mechanical factors, there are a part that is likely to fail and a part that is not so. As shown in FIG. 2B, where there are various failure factors, damage (wear) of the internal thread 118 and deterioration of the grease are dominant. This is because in the hoisting machine 100, the largest torque is applied between the spindle 120 and the female screw 118. However, other machines may have a gear mechanism coated with grease. In the same way, it is considered that there is a place where the force concentrates and it is easy to break down.

  FIG. 2C is a diagram showing the relationship between the operation frequency of the machine and the amount of wear. Among the mechanical factors described above, the deterioration of grease is mainly a change with time (assuming that the casing of the same type of machine has the same degree of sealing), but the damage (wear) of the female screw 118 is different for each machine. Varies greatly depending on the operation frequency. That is, even a machine that has run out of oil film will not wear unless it is operated. Referring to FIG. 2 (c), it can be seen that the wear is small when the operation frequency is low, but there is a large variation between the high wear frequency and the low wear frequency when the operation frequency is high. In other words, it can be seen that wear is not necessarily high just because the operation frequency is high.

  Therefore, when the wear particles are observed using an SEM (Scanning Electron Microscope), there are various types of wear particles. Corrosion wear particles, adhesive wear particles, and cutting wear particles that are suddenly generated due to foreign matter contamination. Can be broadly divided. Each can be identified by observing under a microscope.

  FIG. 3 is a diagram illustrating wear particles. FIG. 3A is an SEM photograph of corrosive wear particles, which is generated when a metal surface is corroded by an organic acid. FIG. 3B is an SEM photograph of the adhesive wear particles, which is produced by rubbing the metals with each other due to oil film breakage. FIG. 3C is an SEM photograph of cutting wear particles, which is produced by cutting with foreign matter such as mixed sand.

  Among the above wear particles, the corrosion wear particles have an irregular shape and do not become very large. Adhesive wear particles are thin, have a surface texture that is relatively organized, and look as if they are sliced off. The cutting wear particles have a thin and sharp shape, and have a linear (rod-like) shape. In this way, it is possible to roughly determine which type of wear particles is by looking at the shape. Note that the shape of the wear particles can be similarly observed by using a TEM (Transmission Electron Microscope) or an optical microscope instead of the SEM.

  Therefore, the relationship between the deterioration degree (oxidation degree) of the lubricant and the occurrence of corrosion wear particles was investigated. FIG. 4 is a diagram for explaining a test for investigating the relationship between grease degradation and wear.

  FIG. 4A is a diagram illustrating the configuration of the tester 200. The tester 200 is a device that slides two test pieces. The upper test piece 204 is fixed to the tip of the drive shaft 202, the lower test piece 208 is fixed on the stage 206, and the upper test piece 204 is used as an insulator. The lower test piece 208 is pressurized by 210 and the weight 212. Then, the upper test piece 204 is rotated in the thrust direction with respect to the lower test piece 208 by rotating the drive shaft 202. The stage 206 is configured to be rotatable, and an arm 214 provided so as to protrude from the stage 206 is pressed against the torque detector 216 so that a friction coefficient can be calculated. The room temperature and the temperature of the lower test piece 208 were measured using a thermocouple 218.

The upper test piece 204 was made of the same stainless steel (SUS304) as the spindle 120. The lower test piece 208 was made of the same high-strength brass as the female screw 118. As test conditions, the surface pressure was 3.36 N / mm ² , the number of revolutions was 68 rpm, and the test time was 90 seconds. The test was conducted while supplying grease to the sliding surfaces of the upper test piece 204 and the lower test piece 208. Here, the degree of oxidation of grease was changed by accelerated deterioration treatment, and the generation of wear particles according to the degree of oxidation was measured. As for the degree of oxidation, the IR oxidation degree (abs / cm) for irradiating infrared rays and identifying the acid component from the absorption spectrum was measured.

  Five types of grease were prepared: new, early deterioration, middle deterioration I, middle deterioration II, and last deterioration. “Degradation end stage” grease was accelerated and deteriorated to a considerable extent after about 16 years. The initial deterioration, middle deterioration I, and deterioration middle II greases are a mixture of new grease and end-of-degradation grease in ratios of 75:25, 50:50, and 25:75, respectively (approximately 4 years each). It is considered to be a considerable grease after about 12 years.

  FIG. 4B is a diagram showing the relationship between the degree of grease degradation and the presence or absence of corrosion wear. For brand A, corrosion wear particles were generated with grease in the middle stage of deterioration I, and for brand B, corrosion wear particles were generated with grease at the end of deterioration.

  From this result, it was found that the corrosive wear particles started to be generated at a certain stage where the deterioration (degree of oxidation) progressed. The abrasion is caused by the oil film breakage, and the oil film breakage is easily caused by the deterioration (oxidation) of the grease. As a result, the IR oxidation degree can be used as one management value of the wear degree. For example, the control value can be set using the IR oxidation degree at the stage where corrosion wear begins to occur in FIG. 4B (IR oxidation degree of medium-term deterioration I in the brand A) (IR oxidation degree at this time) Is X (abs / cm)). Corrosion wear particles are one of the indicators of adhesion wear particles. After corrosion wear particles are generated, the wear progresses at an accelerated rate, so the degree of oxidation when the corrosion wear particles are generated is controlled. A value is appropriate.

  Moreover, it was found by detailed observation that the number of adhered wear particles increased with the progress of the degree of wear, and the particles tended to increase. Here, the degree of wear is conventionally measured by the concentration of wear particles in the grease, but the viscosity of the grease is so high that the wear particle concentration is significantly biased. Could not be measured. However, if the determination is based on the size, the wear degree can be easily determined because it can be observed if any wear particles are mixed. That is, instead of the concentration of wear particles, the size of the adhesive wear particles can be used as one management value for the degree of wear.

  In the present embodiment, the primary determination is made with the IR oxidation degree at the stage where the corrosive wear particles are generated as the first management value, and the secondary determination is made with the size of the predetermined adhesive wear particles as the second management value. In other words, in principle, the size of the wear particles is measured only when the IR oxidation degree exceeds the first control value, and the precise inspection is performed only when the size of the wear particles exceeds the second control value. This is because when the following measuring device is used, the IR oxidation degree can be measured more easily.

FIG. 5 is a diagram for explaining an IR tester for measuring the IR oxidation degree. FIG. 5A is an external view of the IR tester 230, and includes a sample application unit 232, a light shielding plate 234, a display unit 236, and an operation unit 238. The IR oxidation degree is measured by applying grease to the sample application part 232, closing the light shielding plate 234, and irradiating infrared rays from the inside to measure the absorption peak. Specifically, the IR oxidation degree (abs / cm) can be measured by measuring an absorption peak (caused by a CO group of carboxylic acid) appearing in the vicinity of a wave number of 1710 cm ⁻¹ . In addition, since the absorption peak appearing near the wave number of 720 cm ⁻¹ (due to the CH group of the hydrocarbon) does not change even when the oil is oxidized, a more accurate evaluation can be performed by correcting using the peak value. can do. Thus, the IR tester 230 using the infrared absorption spectrum can be miniaturized and has portability, so that the degree of oxidation can be easily measured at the site where the hoisting machine 100 is installed. It becomes possible.

  The evaluation (measurement result) can be displayed on the display unit 236. On the display unit 236, the first management value (IR oxidation degree) is set to 100%, and the evaluation is displayed as a percentage. Note that the IR oxidation degree itself as a measurement result may be displayed together. The first management value can be set by performing a preliminary test in advance using the tester 200 shown in FIG. In addition, the first management value can be stored for each of a plurality of types of grease in a built-in storage unit (not shown), and measurement (evaluation) can be performed by switching using the operation unit 238.

  FIG. 6 is a diagram illustrating a ferrography analyzer that can measure the size of wear particles. The ferrography analysis device 240 shown in FIG. 6A is a device that performs ferrograph analysis in which the wear particles contained in the grease are arranged and observed by magnetic force. In particular, the ferrography analyzer 240 according to the present embodiment is a rotary ferrography analyzer that rotates a plate in a magnetic field and captures wear particles in grease on the plate in an annular shape by centrifugal force and magnetic force. Thus, analysis can be performed in a short time. The ferrography analyzer 240 shown in FIG. 6A supplies a sample containing wear particles from the storage container 242 onto the plate 244, and the plate is rotated on the magnetic field generating means 248 (magnet) by the plate holding and rotating means 246. 244 is rotated. The plate 244 supplemented with the wear particles can be observed with an optical microscope (not shown). Thereby, the size of the wear particles can be measured easily and accurately.

  As shown in FIG. 6B, the evaluation (determination) of the size of the wear particles can be made based on whether or not the size measured by the microscope exceeds the second management value. The relationship between the size of the wear particles and the degree of wear can be classified as a little wear when the size is less than 15 μm, a transition region between 15 μm and less than 40 μm, and a wear state requiring treatment over 40 μm. . In the present embodiment, since only the wear state needs to be determined, 40 μm is set as the second management value. The numerical value of the second management value is an example, and is determined as appropriate according to the combination of materials.

  It is sufficient that a small amount of grease can be collected for the above-described IR oxidation degree measurement and ferrography analysis. In particular, when determining the size of the wear particles in the ferrography analysis, it is sufficient that the wear particles are mixed even if it is a little without paying attention to the concentration distribution of the wear particles. A small amount of grease may be collected from the vicinity of the contact point.

  FIG. 7 is a view for explaining a method of collecting grease in the hoisting machine 100. In the hoisting machine 100, it is considered that wear particles are mainly generated in the meshing portion of the spindle 120 and the female screw 118, and the meshing portion of the female screw 118 and the worm gear 116. FIG. 7A shows a tool for collecting from the thread valley of the spindle 120, FIG. 7B shows a tool for collecting grease from the vicinity of the worm gear 116, and FIG. 7C shows an inspection port of the hoisting machine 100. Is shown.

  Since the spindle 120 is inserted into the internal part of the internal thread 118, the meshing part of the spindle 120 and the internal thread 118 cannot collect grease from the gap without being disassembled. Therefore, sampling is performed from the vicinity of the female screw 118 of the spindle 120. Therefore, as shown in FIG. 7A, a vinyl tube 264 is attached to the tip of a wire 262 that can be bent freely, and the upper inspection port 124 (above the female screw 118) and the lower inspection port 126 ( It is collected by inserting a vinyl tube 264 from below the female screw 118 and scraping off grease from the thread valley of the spindle 120.

  The meshing portion between the female screw 118 and the worm gear 116 collects grease from a nearby greasing port 128. However, since the worm gear 116 is below the greasing port 128 and cannot work linearly and is filled with a relatively large amount of grease, it is difficult to reach the periphery of the worm gear 116 with a wire. Therefore, as shown in FIG. 7B, a syringe-like cylinder 268 is attached to the rear end of the flexible tube 266 (silicon tube or Teflon (registered trademark) tube), and the tube is fed from the greasing port 128. Grease is collected by inserting the tip of 266 and sucking with a cylinder 268.

  In this way, it is possible to collect grease from a place where wear particles are considered to be mainly generated without being decomposed. In other words, a sufficiently useful test can be performed with grease that can be collected without being decomposed.

  Next, the flow of the machine inspection method according to the present embodiment will be described. FIG. 8 is a flowchart showing a machine inspection method according to this embodiment.

  First, a preliminary test is performed using the tester 200 shown in FIG. 4 (S102), and the degree of IR oxidation at the time when corrosive wear particles are generated is obtained, and this is set as the first control value. This is a preliminary preparation and is performed only once for one hoisting machine 100 in principle. The second management value is determined in advance.

  Next, a normal inspection is performed at a predetermined time (for example, once a year) (S104). The normal inspection is an inspection that does not involve disassembly inspection, including operation confirmation, appearance inspection, and electrical board check. In this normal inspection, grease is collected from the vicinity of the gear mechanism as shown in FIG. 6 (S106). The collected grease is measured for the degree of IR oxidation by the IR tester 230 shown in FIG.

  The IR tester 230 compares the measured IR oxidation degree with the first management value (S110), and displays the evaluation on the display unit 236 (percent display). If it is equal to or higher than the first control value (when the evaluation exceeds 100%), ferrography analysis is performed using the apparatus shown in FIG. 6, and wear particles (adhesion wear) contained in the collected grease are analyzed. The size of the particles is measured (S112). It is determined whether or not the size of the measured wear particles exceeds the second control value (S114). If it exceeds, the possibility that wear has occurred is very high. It performs (S116). The precision inspection is inspection accompanied by disassembly of the machine, and includes disassembly and assembly of the gear mechanism, grease replacement, and replacement of parts as necessary.

  If the close inspection in S116 is completed, if the IR oxidation degree is less than the first control value in S110, and if the size of the wear particles is less than the second control value in S114, the equipment of the hoisting machine 100 Comprehensive judgment on soundness is made to determine whether maintenance (replacement) is necessary (S118). If it is determined that maintenance (replacement) is necessary, maintenance (replacement) is performed (S120). Otherwise, the next normal inspection (S102) is waited.

  According to the above configuration, the probability of corrosion wear or cohesive wear is first determined based on the oxidation degree of grease, and the size of wear particles is measured only when the probability is high (when the oxidation degree exceeds the first control value). After checking the degree of wear, perform a precise inspection as necessary. Thus, since it is determined primarily by the degree of oxidation that can be easily measured, and the size of the wear particles is less dependent on the sampling location, the necessity for precise inspection can be determined easily and accurately. Therefore, it is possible to estimate the occurrence and progress of gear wear without disassembling, and to optimize the frequency of precision inspection involving disassembly.

  Here, as described above, the first management value is set in advance in the preliminary test. However, depending on the sealing degree of the hoisting machine 100 and the environment of the installation location, there is a possibility that the relationship between the IR oxidation degree and the time of occurrence of corrosion wear does not match (or does not match) with the laboratory. Therefore, the first control value may be calibrated according to whether or not the wear particles (corrosion wear particles) are measured by measuring the size of the wear particles in the ferrography analysis. Thereby, the optimal first management value can be obtained irrespective of the difference in the type of grease and the operating frequency of the machine.

  FIG. 9 is a diagram for explaining calibration of the first management value. Whether or not corrosive wear particles have been detected during the measurement of wear particle size in the ferrography analysis shown in the flowchart of FIG. 8 (S112) is determined (S124). If the corrosive wear particles are generated, it means that the deterioration is progressing earlier than the current first control value, and therefore the first control value is calibrated in the direction of decreasing (S126). . If corrosive wear particles are not generated, it means that there is still a margin for deterioration at the current first management value, and therefore the first management value is calibrated in the direction of increasing (S128).

  Since the regular inspection (S104) is performed at a frequency of about once a year, there is a possibility that the degree of IR oxidation greatly passes near the first control value between the previous measurement and the current measurement. In such a case, the range of calibration can be adjusted in consideration of the difference between the measured IR oxidation degree and the first control value. In addition, the degree to which the IR oxidation degree should be calibrated can be set to an appropriate minute width, and asymptotically approached as the calibration is repeated.

  In addition, since the regular inspection (S104) is performed at a frequency of about once a year, it may take a considerable amount of time to collect sample data for calibration. However, as described with reference to FIG. 2 (c), even if the oxidation degree of grease is the same, the wear degree also changes if the operation frequency is different. It is desirable that data of other hoisting machines 100 cannot be used unnecessarily.

  Therefore, a large number of hoisting machines 100 to be inspected may be grouped according to the operating frequency, and the first management value may be calibrated for each group. The operating frequency is generally consistent with the classification by role. For example, as shown in Fig. 2 (c), intake control gates are frequently operated, and dam drainage gates are frequently used. Since it is not operating, it is infrequent. Thus, by calibrating the first management value for each group, it is possible to perform calibration promptly (early) and appropriately.

  Further, in the setting of the first management value in the first preliminary test, a wear test reflecting the operating frequency condition may be performed for each group. That is, the number of preliminary tests (different conditions) corresponding to the number of groups may be performed. The operating frequency condition can be reflected, for example, by changing the number of rotations, intermittently rotating, or changing the test time. If the wear test in consideration of the operation frequency is performed in this way and the first management value can be set for each group, a more optimal first management value can be obtained from the beginning.

  The second management value may be calibrated according to whether or not the wear degree of the gear mechanism is determined in the close inspection and the wear degree is within an allowable range. As a result, the optimal second control value can be obtained regardless of the difference in the material of the gear and the load applied to the gear, and the frequency of the precise inspection can be optimized.

  Further, for the IR oxidation degree, a third management value lower than the first management value is further set, and if it is equal to or higher than the third management value and lower than the first management value, for example, the frequency of normal inspection is increased. Can do. The third management value itself has no physical meaning, and can be set as a predetermined ratio (for example, 50%) with respect to the first management value, as shown in FIG.

  FIG. 10 is a flowchart showing an inspection method when the third management value is used. The IR oxidation degree measured by the IR tester 230 is compared with the first management value (S110). If the IR oxidation degree is less than the first management value, the IR oxidation degree is equal to or greater than the third management value. Whether or not (S130). If it is greater than or equal to the third management value and less than the first management value, the inspection frequency of the next normal inspection is set short (for example, six months later or three months later) (S132).

  The inspection performed at a short frequency may be simpler than a normal ordinary inspection, for example, only the measurement of the IR oxidation degree of grease. Thereby, it becomes possible to detect without oxidation of grease. Since the IR oxidation degree can be measured easily, the burden does not increase even if the inspection frequency is increased. On the other hand, if the first management value is not reached by a simple inspection with a short frequency, the frequency of the normal inspection can be reduced.

  In addition, when the 1st management value is calibrated, you may calibrate a 3rd management value as a ratio with respect to this. Thereby, optimization can be achieved similarly to the first management value.

  Moreover, in the said embodiment, it demonstrated so that the magnitude | size of a wear particle might be measured only when IR oxidation degree exceeded the 1st management value. However, the size of the wear particles may be measured periodically in addition to the case where the degree of oxidation of the collected grease exceeds the first control value.

  FIG. 11 is an example of periodically measuring the size of the wear particles, and is a flowchart showing an inspection method in the case where a precise inspection is also periodically performed. The IR oxidation degree measured by the IR tester 230 is compared with the first management value (S110), and even when the IR oxidation degree is less than the first management value, the wear particle size is measured. It is determined whether it is time (S140). If it is a specific time, the size of wear particles (adhesion wear particles) contained in the collected grease is measured (S112). The specific time can be set to a period longer than the normal inspection, for example, once every three years. In this way, by periodically measuring the size of the wear particles, it is possible to detect cutting wear that is not related to the degree of grease oxidation.

  Furthermore, although it was explained that the precise inspection is performed only when the size of the wear particles exceeds the second control value, the case where the size of the measured wear particles does not exceed the second control value is also described. (S114) It may be determined whether or not it is time for a close inspection (S142), and a close inspection (S116) may be performed periodically. Similar to the above specific period, the close inspection period can be set to a longer period than the normal inspection, for example, once every six years. In this way, by performing a regular check regularly, it is possible to check a failure that does not depend on the oxidation of grease without overlooking it.

  As described above, according to the machine inspection method according to the present embodiment, it is possible to estimate the occurrence and progress of gear wear without disassembling, and to optimize the frequency of precision inspection involving disassembly, It is possible to reduce a burden on inspection of a machine having a gear mechanism.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be used as a method for inspecting a machine having a gear mechanism coated with grease.

DESCRIPTION OF SYMBOLS 100 ... Hoisting machine, 110 ... Electrical board, 112 ... Electric motor, 114 ... Reduction gear, 116 ... Worm gear, 118 ... Female screw, 120 ... Spindle, 122 ... Manual handle, 124 ... Upper inspection port, 126 ... Lower inspection port 128 ... Grease port, 150 ... Sluice door, 160 ... Water source, 170 ... Water channel, 200 ... Tester, 202 ... Drive shaft, 204 ... Upper test piece, 206 ... Stage, 208 ... Lower test piece, 210 ... Insulator, 212 ... Weight, 214 ... Arm, 216 ... Torque detector, 218 ... Thermocouple, 230 ... IR tester, 232 ... Sample application part, 234 ... Light shielding plate, 236 ... Display part, 238 ... Operating part, 240 ... Ferro GRAPHIC ANALYZER, 242 ... Storage container, 244 ... Plate, 246 ... Plate holding / rotating means, 248 ... Magnetic field generating means, 262 ... Wire, 264 ... Vinyl tube 266 ... tube, 268 ... cylinder

Claims (8)

A method for inspecting a machine having a gear mechanism coated with grease,
A wear test that reproduces the wear of the gear mechanism using pre-oxidized grease is performed, and a first control value that is composed of the degree of oxidation of the grease at the stage where wear particles start to be generated is set.
A second control value is set for the size of wear particles generated by wear of the gear mechanism;
In a normal inspection without disassembly of the machine,
Collect grease from the vicinity of the gear mechanism,
Measure the degree of oxidation of the collected grease,
If the measured degree of oxidation exceeds the first control value, measure the size of the wear particles contained in the collected grease,
A machine inspection method, comprising: performing a precise inspection accompanied by disassembly of the machine when the size of the measured wear particles exceeds the second control value.   The machine inspection method according to claim 1, wherein the first control value is calibrated according to whether or not wear particles are measured by measuring the size of the wear particles. Group a large number of machines to be inspected according to the operating frequency,
The machine inspection method according to claim 2, wherein the first management value is calibrated for each group. Group a large number of machines to be inspected according to the operating frequency,
2. The machine inspection method according to claim 1, wherein the wear test reflecting an operation frequency condition is performed for each group, and the first management value is set. 3.   The machine according to claim 1, wherein the measurement of the size of the wear particles is performed periodically in addition to the case where the degree of oxidation of the collected grease exceeds the first control value. Inspection method.   The machine inspection method according to claim 1, wherein the oxidation degree of the grease is measured by an infrared absorption spectrum.   The machine inspection method according to claim 1, wherein the size of the wear particles is determined by measuring the wear particles contained in the grease with a ferrography analyzer.   The machine inspection method according to claim 1, wherein the machine is a sluice door hoisting machine.