JP4031745B2 - Gear diagnosis method and gear diagnosis device - Google Patents

Description

  The present invention relates to a gear diagnosis method and a gear diagnosis device for a power transmission mechanism using gears, such as a speed reducer and a speed increaser used in ships and the like.

In a power transmission mechanism using a gear such as a speed reducer, components such as gears are housed in a casing, and the components cannot be visually inspected.
As a device for diagnosing the state of the component parts of such a device, there is a bearing monitor described in Patent Document 1 described later.
This bearing monitor detects the wear state of the bearing that supports the rotor shaft of the motor. The bearing monitor is fixed to the rotor shaft and can be brought into contact with one end of the bearing in the support member. And a rotating member disposed opposite to each other, and a notch is provided in a circumferentially facing portion of the supporting member or the rotating member, and these members come into contact with each other when a bearing is worn, and generate a vibration sound. ing.
When the bearing is worn, the members come into contact with each other to generate a vibration sound to notify that the bearing is worn.

JP 08-285565 A (paragraph [0012])

  However, this bearing monitor is only for diagnosing the state of the bearing, and cannot detect the state of the gears constituting the power transmission mechanism.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a gear diagnosis method and a gear diagnosis device that can easily diagnose the state of a gear constituting a power transmission mechanism. .

Further, the gear diagnosis method according to the present invention is a gear diagnosis for detecting a state of the gear of a power transmission mechanism that transmits the rotation input to the input shaft to the output shaft by increasing or decreasing the speed using a plurality of gears. A method of measuring a vibration of a part of the plurality of gears to obtain a period in which abnormal vibration is detected, and selecting a gear capable of grasping a rotation period among the gears as a reference gear And the rotation period of the reference gear is a reference period, and among the gears, an abnormality occurs in a gear whose ratio of the rotation period to the reference gear is equal to the ratio of the reference period to the abnormal vibration period. It is characterized by identifying the gears.

In this gear diagnosis method, the vibration generated in the gear is measured, and the period in which abnormal vibration is detected is obtained.
Here, all the gears provided in the power transmission mechanism are meshed directly or indirectly via other gears, and vibrations generated in the gears are transmitted to each other. For this reason, the vibration which generate | occur | produces in all the gears is detectable by detecting a vibration about at least any one gear.
On the other hand, among the gears, a gear capable of grasping the rotation cycle is set as a reference gear, and the rotation cycle is set as a reference cycle.
Then, the gear having the abnormality is identified from the ratio between the reference period and the period of the abnormal vibration.
That is, if abnormal vibration is detected periodically, it seems that some abnormality has occurred in the gear that rotates in this cycle, so the gear that rotates in the same cycle as the cycle of abnormal vibration in this way Is identified.

Since the ratio of the reference period and the period of abnormal vibration is the ratio of the rotation period of the reference gear and the gear in which an abnormality has occurred, a gear whose ratio of the rotation period to the reference gear is the same as the above ratio, It is a gear that has an abnormality.
As described above, in the gear diagnosis method according to the present invention, it is possible to specify which gear has an abnormality without disassembling the power transmission mechanism and with the power transmission mechanism operating. Is possible.

Here, the vibration generated in the gear is measured directly, in addition to the vibration generated in the gear rotating shaft supporting the gear and the bearing supporting the gear, or in the casing that houses the gear in the power transmission mechanism. You may measure indirectly by measuring.
In addition to direct measurement, the rotation speed of the reference gear can be indirectly measured by detecting the rotation speed of the gear rotation shaft that supports the reference gear and rotates integrally with the reference gear.

Further, the gear diagnosis method according to the present invention is a gear diagnosis for detecting a state of the gear of a power transmission mechanism that transmits the rotation input to the input shaft to the output shaft by increasing or decreasing the speed using a plurality of gears. A method of measuring the amplitude of vibration of at least one of the gears, obtaining a probability density function of the amplitude, and the value of the probability density function reaching a predetermined reference value. and that an abnormality is occurring when, judged to be normal otherwise, when an abnormality has occurred, the gear there is an abnormality by means of a gear diagnostic method according to claim 1 It is characterized by specifying.

In this gear diagnosis method, the amplitude of vibration generated in the gear is measured to obtain a probability density function of the amplitude, and the presence or absence of abnormality is determined based on the magnitude. That is, it is possible to determine whether an abnormality has occurred in the gear without disassembling the power transmission mechanism and with the power transmission mechanism operating.
The probability density function indicates what value the amplitude of one irregular waveform appears at a certain time. In this gear diagnosis method, it indicates the amplitude distribution.
When the power transmission mechanism is normal, the amplitude of vibration generated in the gear changes within a substantially constant range, so that the amplitude distribution is substantially normal.
On the other hand, in the power transmission mechanism, when the gear is scratched or the gear bites foreign matter such as dust, the scratched part or the foreign matter is located at the meshing part of the gears for a very short time. Just fluctuate greatly. For this reason, the amplitude distribution has a shape with a wider base than the normal distribution. That is, the value of the probability density function becomes larger than that in the normal state.
The gear diagnosis method according to the present invention utilizes this fact to determine whether or not an abnormality has occurred in the gear of the power transmission mechanism. In addition, the reference value used for determination of the state of a gear is calculated | required based on the result of experiment, simulation, etc., for example.
Here, all the gears provided in the power transmission mechanism are meshed directly or indirectly via other gears, and vibrations generated in the gears are transmitted to each other. For this reason, in this gear diagnosis method, all gears can be diagnosed by measuring the amplitude of vibration generated in at least one of the gears.
In addition to direct measurement, the vibration generated in the gear is measured directly on the gear rotation shaft that supports the gear and the bearing that supports the gear, and the vibration generated in the casing that houses the gear in the power transmission mechanism. You may measure indirectly by measuring.
In this gear diagnosis method, it is possible to perform from the determination of whether or not an abnormality has occurred in the gear to the identification of the gear in which the abnormality has occurred without disassembling or stopping the power transmission mechanism. it can.

According to a third aspect of the present invention, there is provided a gear diagnosis method comprising: determining a state of the gear of a power transmission mechanism that transmits a rotation input to an input shaft to the output shaft by increasing or decreasing speed using a plurality of gears. A gear diagnosis method to detect, wherein the gear diagnostic method according to claim 1 is used to identify a gear in which an abnormality has occurred, and the vibration amplitude obtained for at least one of the gears is determined. It is characterized in that at least one of judgment elements of the probability density function value and the noise level generated from the gear is individually weighted, and the state of the gear is judged based on each of the weighted judgment elements. And

In this gear diagnosis method, a gear having an abnormality is identified using the gear inspection method according to claim 1, and a probability density function of an amplitude of vibration obtained for at least one of the gears the value of, and weighted separately at least one of the determination factors of the size of the noise generated from the gear, in order to determine the state of the gear based on the determination elements described these weights, the state of the gear excessive or Accurate judgment can be made without underestimation. Moreover, coupled with the fact that the weight assigned to each determination element can be changed according to the use environment, etc., it is possible to accurately and reliably determine the quality of the gear state, and to prevent the occurrence of gear damage. Can do.

According to a fourth aspect of the present invention, there is provided a gear diagnosis method comprising: determining a state of the gear of a power transmission mechanism that transmits a rotation input to an input shaft to the output shaft by increasing or decreasing speed using a plurality of gears. A gear diagnosis method to detect, wherein the gear diagnostic method according to claim 1 is used to identify a gear in which an abnormality has occurred, and the vibration amplitude obtained for at least one of the gears is determined. Observing a temporal change of at least one judgment factor among a value of a probability density function and a noise level generated from the gear, and judging a state of the gear based on a tendency of the temporal change. It is characterized by.

In this gear diagnosis method, a gear having an abnormality is identified using the gear inspection method according to claim 1, and a probability density function of an amplitude of vibration obtained for at least one of the gears In order to determine the state of the gear based on the temporal change of at least one judgment factor of the value of the value and the magnitude of the noise generated from the gear and to determine the state of the gear based on the tendency of the temporal change, the gear is damaged. By detecting the possibility of damage before it occurs, maintenance can be performed early.
It is also possible to predict the life of the gear based on the tendency of the determination element to change with time.

A gear diagnosis apparatus according to the present invention is a gear diagnosis apparatus for detecting a state of the gear of a power transmission mechanism that transmits rotation input to an input shaft to an output shaft by increasing or decreasing speed using a plurality of gears. A vibration measuring device that measures vibration of some of the plurality of gears, a reference period that is a rotation period of a reference gear that is one of the gears, and a period of the abnormal vibration And a second arithmetic unit that obtains the ratio of.

In the gear diagnosis device configured as described above, vibration of at least one of the gears of the power transmission mechanism is measured by the vibration measuring device. Based on this measurement result, an abnormal vibration period is obtained.
On the other hand, the reference period which is the rotation period of the reference gear is measured by the reference period measuring device.
Then, the gear having an abnormality can be identified from the ratio between the reference period and the period of abnormal vibration.
Specifically, among the gears, a gear in which the ratio of the rotation period to the reference gear is the same as the ratio of the reference period obtained by the second arithmetic unit and the period of abnormal vibration is a gear in which an abnormality has occurred. It is.
That is, in the gear diagnosis device according to the present invention, the gear diagnosis can be performed using the gear diagnosis method according to the first aspect .

A gear diagnosis apparatus according to a sixth aspect of the present invention is the gear diagnosis apparatus according to the fifth aspect, wherein a storage unit that stores a rotation period ratio between the gears and information stored in the storage unit are used. On the basis of the above, there is provided a discriminating device for identifying a gear having a rotation cycle ratio with the reference gear equal to a ratio between the reference cycle and the abnormal vibration cycle.

  In the gear diagnosis device configured as described above, a gear having an abnormality can be automatically specified from a plurality of gears provided in the driving force transmission device.

A gear diagnosis device according to claim 7 of the present invention is the gear diagnosis device according to claim 5 or 6 , wherein an amplitude measurement device measures the amplitude of vibration of at least one of the gears. The first arithmetic unit that obtains the probability density function of the amplitude of the gear from the measurement value of the amplitude measuring device, and an abnormality occurs when the value of the probability density function reaches a predetermined reference value It is characterized by having a determination device that determines that it is normal and otherwise determines that it is normal

In the gear diagnostic device configured as described above, the amplitude measurement device measures the amplitude of at least one of the gears of the power transmission mechanism, and based on the measurement result, the first arithmetic device calculates the value of the probability density function. Is required.
The value of the probability density function thus obtained is sent to the determination device, and the determination device determines whether an abnormality has occurred based on the value of the probability density function.
Specifically, the determination device determines that an abnormality has occurred if the value of the probability density function is equal to or greater than a predetermined reference value, and is normal if the value is less than the reference value.
In the gear diagnosis device configured as described above, it is possible to determine whether or not an abnormality has occurred in the gear based on the value of the probability density function of the amplitude of vibration obtained for at least one of the gears. it can.
Here, in addition to direct measurement, the measurement of the amplitude of the vibration of the gear occurred in the casing that houses the gear in the power transmission mechanism by measuring the vibration generated in the gear rotating shaft that supports the gear and the bearing that supports the gear. You may measure indirectly by measuring a vibration. And when abnormality has arisen, the gear in which abnormality has arisen can be specified by the gear diagnosis method of Claim 1 .
That is, it is possible to perform from determination of whether or not an abnormality has occurred in the gear to identification of the gear in which the abnormality has occurred without disassembling or stopping the power transmission mechanism.

  According to the gear diagnosis method and the gear diagnosis device of the present invention, it is possible to detect the state of the gear without disassembling the power transmission mechanism and with the power transmission mechanism operating. .

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
The gear diagnosis device 1 according to the present embodiment detects the state of the gear of the power transmission mechanism PT that transmits the rotation input to an input shaft (not shown) to the output shaft by increasing or decreasing the speed using a plurality of gears. To do.
Here, first, the configuration of the power transmission mechanism PT will be described. The power transmission mechanism PT includes a casing K, a plurality of gears provided in the casing K, a gear rotation shaft P that supports the gear K with the gears coaxially and restricts relative rotation around the shaft, and a gear rotation shaft P. A bearing that is rotatably supported around the axis is provided.

As shown in FIG. 1, the gear diagnosis apparatus 1 according to the present embodiment includes an acceleration sensor 2 provided in a bearing B that is one of bearings provided in the power transmission mechanism PT, and an output signal V of the acceleration sensor 2. And a CPU unit 4 that performs arithmetic processing on the output signal and the like of the first amplifier 3 and stores processing results and other information.
Further, the gear diagnosis device 1 includes a display device 5 that displays a processing result and other information of the CPU unit 4, a determination device that determines a gear state based on the processing result of the CPU unit 4, and an operator that performs an operation of the CPU unit. And a console C for sending a command signal to the unit. In the present embodiment, the CPU unit 4 also serves as a determination device.
Here, the acceleration sensor 2 is attached to a bearing B provided outside the casing K among the bearings by, for example, bolting or the like. The CPU unit 4 includes a calculation unit (not shown) such as a central processing unit and a storage unit M including a memory. The acceleration sensor 2 and the CPU unit 4 constitute an amplitude measuring device that measures the amplitude of the gear and a vibration measuring device that measures the vibration of the gear. In addition, a value of the ratio of the rotation cycles between the gears is input to the storage unit M in advance. The CPU unit 4 constitutes a determination device that identifies a gear having an abnormality based on information input to the storage unit M.

The output system of the first amplifier 3 is bifurcated, one of which is connected to the CPU unit 4 and the other is a second amplifier 11 that further amplifies the output signal of the first amplifier 3. It is connected.
An audio output device 12 is connected to the second amplifier 11, and the output signal of the second amplifier 11 by the audio output device 12, that is, the acceleration sensor 2 amplified by the first and second amplifiers 3, 11 is used. The output signal can be output as sound.
In the present embodiment, the audio output device 12 is configured by headphones that are detachably connected to the second amplifier 11.

Here, between the first amplifier 3 and the second amplifier 11, a first line L1 consisting only of wiring, a second line L2 having a filter 13 provided in parallel with the first line L1, A switch 14 is provided that can selectively connect only one of the first and second lines L1, L2 to the first amplifier 3.
That is, by operating the switch 14 and connecting the second amplifier 11 and the first amplifier 3 by the first line L1, all frequency components of the output signal of the acceleration sensor 2 are input to the audio output device 12. It is like that. Further, by operating the switch 14 to connect the second amplifier 11 and the first amplifier 3 by the second line L2, the output signal of the acceleration sensor 2 excluding a predetermined frequency component is a sound. It is input to the output device 12.
In the present embodiment, a filter 13 is used that removes frequency components that are not important in diagnosis (here, 100 Hz to 10000 Hz) from the input signal and allows other frequency components to pass therethrough.

  In addition, the gear diagnosis device 1 is provided with a noise measuring device 16 that measures the magnitude of noise generated by the power transmission mechanism PT. The noise measuring device 16 is configured to output a measurement value to the CPU unit 4.

Further, the gear diagnostic device 1 is provided with a reference period measuring device 21 that detects the rotation of one of the gears provided in the power transmission mechanism PT (hereinafter, the reference period measuring device 21 determines the rotation period). The gear to be measured is called “reference gear G”). In the present embodiment, the gear that is the object of vibration detection by the acceleration sensor 2 is the reference gear G. Here, the storage unit M of the CPU unit 4 stores in advance the ratio of the rotation cycles of the reference gear G and all other gears.
The reference period measuring device 21 is provided, for example, at a position facing the index 22 on the peripheral surface of the gear rotation shaft P that supports the reference gear G and the gear rotation shaft P that supports the reference gear G. A non-contact sensor 23 that detects the passage of the index 22 associated with the rotation of the gear rotation shaft P in a non-contact manner, and a rotation detector that detects the rotation of the gear rotation shaft P based on the detection signal D of the non-contact sensor 23. 24.
Here, as the non-contact type sensor 23, for example, an optical sensor is used.

Further, a period adjusting device 26 that adjusts the frequency of the detection signal D is provided at the subsequent stage of the reference period measuring device 21. Specifically, although not shown, the cycle adjusting device 26 reduces the cycle of the detection signal D of the reference cycle measuring device 21 to an arbitrary ratio (makes the frequency an arbitrary multiple), and the cycle of the detection signal D. And a frequency divider (reducing the frequency to an arbitrary ratio).
The cycle adjusting device 26 sends the simulation detection signal Da to the CPU unit 4, while the CPU unit 4 receives a command designating a frequency magnification or reduction ratio as a signal.

Hereinafter, a gear diagnosis method by the gear diagnosis device 1 configured as described above will be described with reference to a flowchart of FIG.
First, in a state where the power transmission mechanism PT is operated, the output signal V of the acceleration sensor 2 is taken into the CPU unit 4 (step S1). Here, although the acceleration sensor 2 is provided in the bearing B, the vibration of the reference gear G is transmitted to the bearing B through the gear rotation shaft P supported by the bearing B. That is, the output signal V of the acceleration sensor 2 includes information on the vibration of the reference gear G.
In addition, the gears provided in the power transmission mechanism PT are meshed directly or indirectly via other gears, and the generated vibrations are transmitted to each other. For this reason, the vibration of the reference gear G includes information on the vibrations of other gears.
Then, the CPU unit 4 detects the vibration level of the reference gear G, that is, the acceleration (m / s ² ) and the amplitude (m), from the output signal V of the acceleration sensor 2, and based on this information, the reference gear The state of G is detected (step S2).

The CPU unit 4 obtains the value of the probability density function of the amplitude of the reference gear G from the amplitude information of the reference gear G obtained from the acceleration sensor 2 (step S3).
Here, the probability density function (amplitude distribution) of the amplitude of the reference gear G means that the amplitude value is x and x + Δx in the waveform x (t) of the output signal V of the acceleration sensor 2 as shown in the graph of FIG. Is the ratio of the sum Δt ₁ + Δt ₂ +... + Δtn to the total observation time T, that is, the probability.
The storage unit M of the CPU unit 4 has a memory, and the memory has an address corresponding to each section divided in units of width Δx in the amplitude direction in FIG. At each address, the number of times that the waveform of the output signal has entered the corresponding section is stored.
Then, the CPU unit 4 holds a total value of values obtained by multiplying each address value by a corresponding amplitude value as a value of the probability density function.

Here, when the power transmission mechanism PT is normal, the amplitude of vibration generated in the reference gear G changes within a substantially constant range, so that the amplitude distribution is almost as shown in FIG. The shape is close to a normal distribution.
On the other hand, in the power transmission mechanism PT, when there is a scratch on the gear, or when the gear bites foreign matter such as dust, as shown in FIG. Compared with the normal time, the amplitude of the vibration generated in the reference gear G greatly fluctuates only for a very short period of time located at the meshing portion. For this reason, the amplitude distribution has a shape with a wider base than the normal distribution. That is, the value of the probability density function becomes larger than that in the normal state.
In FIG. 4A and FIG. 4B, the order of the vertical axis of the graph is different by one digit. For comparison of the size and shape of these probability density functions, the probability density function graph shown in FIG. 4A is shown by a broken line in FIG. 4B.

In the gear diagnostic apparatus 1, as described above, it is determined whether or not an abnormality has occurred in the gear of the power transmission mechanism PT by utilizing the influence of the state of the gear on the magnitude of the probability density function of the amplitude. . More specifically, the determination device provided in the CPU unit 4 compares the probability density function value with a predetermined reference value, and if the probability density function value reaches the reference value, an abnormality is detected. It determines with having arisen, and when that is not right, it judges that it is normal (step S4). The determination result is displayed on the display device 5 and is transmitted to the operator.
In addition, the reference value used for determination of the state of a gear is calculated | required based on the result of experiment, simulation, etc., for example.
Here, all the gears provided in the power transmission mechanism PT are meshed directly or indirectly via other gears, and vibrations generated in the gears are transmitted to each other. For this reason, in this gear diagnosis method, all gears can be diagnosed by measuring the amplitude of vibration generated in the reference gear G.

  When the CPU unit 4 determines that an abnormality has occurred in the gear, the CPU 4 proceeds to the next stage, and specifically checks which gear has an abnormality. Even if it is determined that there is no abnormality in the gear, by continuing the diagnosis of the gear using the probability density function, the temporal change of the state can be observed, and this information is included in this information. Based on this, it is possible to detect the possibility of an abnormality or to predict the life of the gear.

Hereinafter, the second stage of gear diagnosis by the gear diagnosis apparatus 1 according to the present embodiment will be described with reference to FIG. At this stage, the gear is diagnosed based on the period of vibration generated in the reference gear G.
Specifically, first, the reference period measuring device 21 detects the rotation of the reference gear G. Here, the rotation detector 24 of the reference period measuring device 21 outputs a detection signal D in which a pulse appears at the same period as the rotation period of the reference gear G, as shown in FIGS.
This detection signal D is input to the cycle adjusting device 26, and is sent to the CPU unit 4 and the display device 5 as a simulated detection signal Da whose rotation cycle is adjusted (step S5). And in the display apparatus 5, as shown in FIG.1 and FIG.5, the waveform of the simulation detection signal Da is displayed.

  The CPU unit 4 controls the operation of the cycle adjusting device 26 so that, for example, at the start of diagnosis, the cycle of the simulation detection signal Da is set to be longer than the rotation cycle of all gears, and the cycle is gradually set. Control to shorten. On the contrary, the cycle of the simulated detection signal Da may be lengthened at the start of diagnosis. In other words, as long as the period of the simulation detection signal Da is configured to sweep the band including all the gear periods, the direction of sweeping may be either.

As shown in FIGS. 1 and 5, the output signal V of the acceleration sensor 2, that is, the gear vibration pattern detected using the acceleration sensor 2 is also displayed on the display device 5.
Then, the CPU 4 causes the generation period T1 (sec) of abnormal vibration in the output signal V of the acceleration sensor 2 to be the same as the generation period Tp (sec) of pulses in the detection signal Da of the period adjustment device 26. Thus, the operation of the period adjusting device 26 is controlled. This operation may be performed visually by the operator based on the display on the display device 5.

  In this manner, the simulated detection signal Da by the period adjusting device 26 in a state where the generation period T1 of the abnormal vibration in the output signal V and the generation period Tp of the pulse in the detection signal D of the period adjusting device 26 are substantially the same. The amount of change in the period is confirmed (step S7). This value is represented by a ratio Tp / Tb between the period Tb and the period Ta of the simulated detection signal Da, where the period of the detection signal D immediately after being output from the reference period measurement device 21 is the reference period Tb.

The fact that abnormal vibrations are detected periodically is considered to have caused some abnormality in the gear rotating at this period T1.
Since the ratio of the reference period Tb to the abnormal vibration period T1 is the ratio of the rotation period of the reference gear G to the abnormal gear, the ratio of the rotation period to the reference gear G is the same as the ratio. Is a gear in which an abnormality has occurred.
That is, it is determined that some abnormality has occurred in the gear constituting the power transmission mechanism PT, the gear having the rotation period ratio of Tp / Tb with respect to the reference gear G.

  In the gear inspection device 1, the discrimination device provided in the CPU unit 4 rotates the reference gear G from the gears based on the value of the ratio of the rotation periods of the gears stored in the storage unit M in advance. A gear having a cycle ratio of Tp / Tb is specified (step S8). The determination result is recorded in the CPU unit 4 and displayed on the display device 5.

In this way, the gear in which an abnormality has occurred is identified, and maintenance of the power transmission device T is performed at an appropriate time as necessary.
Here, the gear diagnosis using the ratio of the rotation cycles may be performed in parallel with the first stage diagnosis. Then, by continuously diagnosing the gear using the ratio of the rotation cycles, it is possible to observe the temporal change of the state of each gear, and based on this information, individually for each of the gears. It is possible to detect the possibility of occurrence of abnormality and to predict the life of the gear.

Here, in the present embodiment, an example is shown in which the frequency of the reference rotation period is changed by the period adjusting device 26 so that the acceleration sensor detects the abnormal value once per reference rotation period. Without being limited thereto, for example, when the number of times the acceleration sensor 2 detects an abnormal value per reference rotation cycle is N times, the gear having the abnormality is N times faster than the reference gear G. It may be determined that the gear is rotating. In this case, the period adjusting device 26 is not necessary, and the configuration can be further simplified.
In the gear inspection device 1, the output signal of the acceleration sensor 2 can be output as a sound from the sound output device 12. As a result, the generation period T1 of the abnormal amplitude value in the output signal of the acceleration sensor 2 can be detected based on the sound output from the sound output device 12 without using various devices as described above. . Then, by comparing the generation period T1 of the abnormal amplitude thus obtained with the rotation period of each gear, it is possible to identify the gear in which the abnormality has occurred.

The gear diagnosis apparatus 1 according to the present embodiment can further perform diagnosis by the noise measurement device 16 in addition to the first and second stage diagnosis.
Specifically, the measurement signal of the noise measurement device 16 is input to the CPU unit 4, and the CPU unit 4 determines that the noise level (dBA) measured by the noise measurement device 16 is a predetermined reference value. If it exceeds, it is determined that an abnormality has occurred, and that effect is displayed on the display device 5.

The gear diagnostic device 1 individually weights at least two judgment elements of the results of the first and second stage diagnoses and the result of the diagnosis based on the noise level. It has the structure which judges the state of a gear based on it.
Specifically, as shown in FIG. 2, the determination unit provided in the CPU unit 4 determines the level of the probability density function, the vibration level, and the noise level, and digitizes them. (Steps S9, S10, S11). Here, an example of this criterion is shown in FIG.
For example, when the value of the probability density function is 10, the determination result is 0.1. When the vibration level is 8G, the determination result is 0.5. When the noise level is 80 dBa, the determination result is 0.1.
The determination results digitized in this way are input to an adder provided in the CPU unit 4 and added (step S12). In the above example, the sum of the determination results is 0.1 + 0.5 + 0.1 = 0.7.

The output of the adder is input to an evaluator provided in the CPU unit 4. As the evaluator, the first evaluator that evaluates normal when the input value is within the setting range, the second evaluator that evaluates as caution when the input value is within the setting range, and the input When the value is within the set range, a third evaluator that evaluates that an abnormality has occurred is provided, and the evaluation is returned for each input value (steps S13, S14, and S15).
Here, an example of the set values of the first to third evaluators is shown in FIG. In the above example, since the total of the determination results is 0.7, it is evaluated as “normal” by the first evaluator.
These evaluation results are stored together with time information in the storage unit M of the CPU unit 4 and also displayed on the display device 5.

  Thus, by weighting and evaluating each diagnosis result, it is possible to accurately determine the state of the gear without being overestimated or underestimated. Moreover, coupled with the fact that the weight assigned to each determination element can be changed according to the use environment, etc., it is possible to accurately and reliably determine the quality of the gear state, and to prevent the occurrence of gear damage. Can do.

  As described above, the gear diagnostic apparatus 1 according to the present embodiment can measure the state of vibration of the gear and determine whether or not an abnormality has occurred in the gear from the information obtained thereby. Furthermore, when an abnormality has occurred in the gear, it is possible to detect which gear has an abnormality without further disassembling the power transmission device, so that the power transmission mechanism can be detected. The state of the gears can be easily diagnosed.

  Then, the gear diagnosis by the gear diagnosis device 1 is performed continuously or periodically, so that the possibility of abnormality in the gears and the life of the gears are predicted from the transition of the diagnosis results. be able to.

  Here, in the present embodiment, since the acceleration sensor 2 is provided in the bearing B that is a member closer to the gear as means for detecting the vibration of the gear, the vibration of the gear can be detected more accurately. Further, the acceleration sensor 2 may be simply fixed to the bearing B, and work such as fine adjustment of the mounting position is not necessary. In particular, in the present embodiment, since the acceleration sensor 2 is provided on the bearing B provided outside the casing K, the acceleration sensor 2 is easy to install, and there is no fear that it will fall off and be caught in the gear.

It is a figure which shows the structure of the gear diagnosis apparatus concerning one Embodiment of this invention. It is a flowchart which shows the flow of a process of the gear diagnosis apparatus shown in FIG. It is a figure which shows the principle of the gear diagnosis by the gear diagnosis apparatus shown in FIG. It is a figure which shows the principle of the gear diagnosis by the gear diagnosis apparatus shown in FIG. It is a figure which shows an example of the display by the display part of the gear diagnosis apparatus shown in FIG. It is a figure which shows the reference | standard of the gear diagnosis by the gear diagnostic apparatus shown in FIG.

Explanation of symbols

1 gear diagnosis device 2 acceleration sensor (amplitude measurement device, vibration measurement device)
4 CPU section (amplitude measuring device, vibration measuring device, first and second arithmetic device, determination device, discrimination device)
12 Audio Output Device 21 Reference Period Measuring Device G Reference Gear M Storage Unit T Power Transmission Mechanism

Claims (7)

A gear diagnosis method for detecting a state of the gear of a power transmission mechanism for transmitting the rotation input to the input shaft to the output shaft by increasing or decreasing the speed using a plurality of gears,
Measuring the vibration of some of the plurality of gears to determine the period in which abnormal vibration is detected;
Among the gears, a gear capable of grasping the rotation period is a reference gear and the rotation period of the reference gear is a reference period.
Of the gears, a gear diagnosis method is characterized in that a gear having a ratio of a rotation cycle to the reference gear equal to a ratio of the reference cycle to the abnormal vibration cycle is identified as a gear having an abnormality. . A gear diagnosis method for detecting a state of the gear of a power transmission mechanism for transmitting the rotation input to the input shaft to the output shaft by increasing or decreasing the speed using a plurality of gears,
Measuring the amplitude of vibration of at least one of the gears;
Find the probability density function of the amplitude,
When the value of the probability density function reaches a predetermined reference value, it is assumed that an abnormality has occurred; otherwise, it is determined to be normal.
A gear diagnosis method, wherein when a malfunction has occurred, a gear having a malfunction is identified by the gear diagnosis method according to claim 1. A gear diagnosis method for detecting a state of the gear of a power transmission mechanism for transmitting the rotation input to the input shaft to the output shaft by increasing or decreasing the speed using a plurality of gears,
The gear diagnostic method according to claim 1 is used to identify a gear having an abnormality, a value of a probability density function of an amplitude of vibration obtained for at least one of the gears, and the gear A method of gear diagnosis, comprising: individually weighting at least one of the determination elements of noise generated from the sound and determining the state of the gear based on each of the weighted determination elements. A gear diagnosis method for detecting a state of the gear of a power transmission mechanism for transmitting the rotation input to the input shaft to the output shaft by increasing or decreasing the speed using a plurality of gears,
The gear diagnostic method according to claim 1 is used to identify a gear having an abnormality, a value of a probability density function of an amplitude of vibration obtained for at least one of the gears, and the gear A method for diagnosing gears, comprising: observing a temporal change of at least one judgment element of the noise level generated from the noise and judging a state of the gear based on a tendency of the temporal change. A gear diagnosis device for detecting a state of the gear of a power transmission mechanism for transmitting the rotation input to the input shaft to the output shaft by increasing or decreasing the speed using a plurality of gears,
A vibration measuring device for measuring vibration of some of the plurality of gears;
A gear diagnostic apparatus, comprising: a second arithmetic unit that obtains a ratio between a reference period that is a rotation period of a reference gear that is one of the gears and a period of the abnormal vibration. In the gear diagnosis apparatus according to claim 5,
A storage unit for storing a ratio of rotation periods of the gears;
Based on the information stored in the storage unit, among the gears, a determination device that identifies a gear whose rotation period ratio to the reference gear is equal to the ratio of the reference period to the abnormal vibration period; A gear diagnosis device characterized by comprising: In the gear diagnosis apparatus according to claim 5 or 6,
An amplitude measuring device for measuring the amplitude of vibration of at least one of the gears;
A first arithmetic unit for obtaining a probability density function of the amplitude of the gear from the measurement value of the amplitude measuring device;
A determination device is provided that determines that an abnormality has occurred when the value of the probability density function reaches a predetermined reference value, and otherwise determines that it is normal. Gear diagnosis device.

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