JP6873870B2 - Lubrication state diagnosis device and lubrication state diagnosis method for bearings in rotary shaft devices - Google Patents

Description

The present invention relates to a diagnostic device and a diagnostic method for diagnosing a lubrication state of a bearing in a rotary shaft device in which a rotary shaft is pivotally supported by a bearing, such as a spindle device of a machine tool.

Bearings are used in many rotary shaft devices such as spindle devices for machine tools. In such bearings, it is desirable to reduce the amount of oil supplied to the bearings as much as possible for the reasons of consideration for the environment, cost reduction, frictional heat generation and suppression of power loss. Oil-air lubrication, in which lubricating oil is conveyed by compressed air, is known as such a trace amount of oil lubrication method, and is used for lubrication of high-speed spindle bearings of machine tools. In a rotary shaft device that employs oil-air lubrication, a technique for grasping the supply state and the lubrication state of the lubricant is required in order to avoid troubles such as seizure due to insufficient lubrication.
Regarding this technique, for example, in Patent Document 1, a lubricant that monitors the flow rate of oil particles in a lubricant supply path by a sensor that can set the monitoring sensitivity according to the oil particles and emits a signal when the flow rate exceeds a predetermined flow rate. The feeder is shown.
Patent Document 2 discloses a bearing lubrication mechanism that avoids bearing damage due to poor lubrication by monitoring the amount of particles of the lubricant flowing through the supply path with a sensor.
Patent Document 3 discloses a flow rate measuring device that calculates a flow rate from the volume and flow rate of passing oil droplets by a spatial filter using a standing wave of microwaves.
Patent Document 4 discloses a method of detecting the flow of lubricating oil by an electromagnetic wave of a specific frequency in a pipeline after a mixing valve.
In Patent Document 5, a representative value is calculated by extracting cycle data for each operation cycle from continuous data including a physical quantity and a measurement time for the lubrication state of a movable member whose mechanical operation is a constant cycle, and when the representative value is used. A device for diagnosing the presence or absence of insufficient lubrication based on the sequence transition is shown.
Patent Document 6 discloses a method of determining the deterioration state of the spindle by comparing the inertial rotation time and the rotational resistance when the machine tool spindle is inertially operated with a preset threshold value.
Patent Document 7 discloses a method of detecting an increase in rotational torque after replenishing grease for a main shaft for grease lubrication to determine whether or not grease has been discharged.

Japanese Unexamined Patent Publication No. 2006-258263 Japanese Unexamined Patent Publication No. 2008-3004036 Japanese Patent No. 4160575 Japanese Patent No. 4920518 Japanese Patent No. 4965261 Japanese Unexamined Patent Publication No. 2016-200523 Japanese Unexamined Patent Publication No. 2005-344784

In the inventions of Patent Documents 1 to 4, it is possible to determine the abnormality of the lubricant supply to the detection position by detecting the passage of the lubricant particles in the flow path to which the lubricant is supplied. There is a problem that it is not possible to determine whether or not the lubricant is supplied to the bearing beyond the detection position. Further, since an additional sensor is required to determine the supply state of the lubricant, there is a problem that the manufacturing cost increases. Furthermore, since the optimum amount of lubricant supplied differs depending on the bearing built-in preload and the spindle speed during machining, it is difficult to judge the quality of the lubrication state by monitoring the flow rate of the lubricant. There is.
In the invention of Patent Document 5, it can be determined that the lubrication state deviates from the initial state with respect to the rotary shaft device that repeats a predetermined operation in a constant cycle such as an injection molding machine, but it is a relative determination. If the lubrication state is not appropriate from the initial state, there is a problem that it may not be detected as an abnormality.
In the invention of Patent Document 6, the deterioration state of the machine tool spindle can be determined by setting the thresholds of the inertial rotation time and the rotational resistance in advance, but in order to determine the thresholds, the variation due to the machine tool difference and the season There is a problem that many experiments are required to consider fluctuations and the like. In addition, if the rotation speed is different, the ease with which the lubricant is discharged and the amount of heat generated are different. Therefore, if the rotation speed changes significantly during inertial operation, even if the value of rotational resistance during inertial operation is calculated, it is constant. Since it does not necessarily reflect the state during normal use when operating at the rotation speed of, there is a problem that proper diagnosis may not be possible.
Since the lubrication state fluctuates periodically in oil-air lubrication, it is possible to detect that oil-air lubrication is functioning by detecting an increase in rotational torque as in the invention of Patent Document 7. However, since the lubrication state fluctuates periodically regardless of the excess or deficiency of the lubricant, there is a problem that it cannot be determined whether or not the lubrication is insufficient even if it is detected that the rotational torque increases.

In order to achieve the above object, the invention according to claim 1 is in a rotary shaft device having a rotary shaft supported by a bearing that is lubricated by being conveyed by compressed air of a lubricant that is periodically discharged. , A device for diagnosing the lubrication state of bearings
Based on the information acquired at different timings in the lubricant reduction section, which is the section where the amount of lubricant existing on the rolling surface of the bearing decreases , the feature amount representing the magnitude of the rotational resistance of the rotating shaft is obtained. Multiple feature amount calculation means and
Representative time information is a timing obtained the used to calculate each feature quantity, and the lubricating phase calculating means for calculating each feature calculation when lubricating phase indicating which timing the discharge cycle of the lubricant,
It is characterized in that it is provided with a lubrication state determining means for determining the lubrication state of the bearing by a plurality of feature amounts having different lubrication phases at the time of calculating the feature amount.
According to the second aspect of the present invention, in the configuration of the first aspect, the lubrication state determining means calculates an index indicating whether or not the rotational resistance is increased in the lubricant decreasing section from a plurality of feature amounts, and the index is It is characterized in that it is judged that the lubrication is insufficient when the reference value is exceeded.
In order to achieve the above object, the invention according to claim 3 is in a rotary shaft device having a rotary shaft supported by a bearing that is lubricated by being conveyed by compressed air of a lubricant that is periodically discharged. , A device for diagnosing the lubrication state of bearings
Based on the information acquired at different timings in the lubricant reduction section, which is the section where the amount of lubricant existing on the rolling surface of the bearing decreases, the feature amount representing the magnitude of the rotational resistance of the rotating shaft is obtained. Multiple feature amount calculation means and
Lubrication phase calculation means for calculating the lubrication phase at the time of feature amount calculation, which indicates which timing of the discharge cycle of the lubricant is the representative time, which is the timing at which the information used for calculating each feature amount is acquired.
Characterized by comprising a display unit for displaying a graph with the vertical axis of one of either the feature amount and the feature amount calculated during lubrication phase, the other on the horizontal axis, a.
The invention according to claim 4 includes, in any of the configurations of claims 1 to 3 , an inertial operating means for executing inertial operation of the rotating shaft and a rotating speed detecting means for detecting the rotational speed of the rotating shaft. The feature amount calculating means is characterized in that the feature amount is calculated based on the change mode of the rotation speed during inertial operation.
According to the fifth aspect of the present invention, in the configuration of the fourth aspect , the rotational speed range from the start to the end of the inertial operation in the inertial operation is such that the fluctuation of the feature amount in the rotational speed range during the inertial operation is equal to or less than the reference value. It is characterized by determining to.
In order to achieve the above object, the invention according to claim 6 is in a rotary shaft device having a rotary shaft supported by a bearing in which a lubricant periodically discharged is conveyed by compressed air to be lubricated. , A method of diagnosing the lubrication state of bearings,
Based on the information acquired at different timings in the lubricant reduction section, which is the section where the amount of lubricant existing on the rolling surface of the bearing decreases , the feature amount representing the magnitude of the rotational resistance of the rotating shaft is obtained. Multiple feature amount calculation steps and
Representative time information is a timing obtained the used to calculate each feature quantity, and the lubricating phase calculation step of calculating respective characteristic amount calculated during the lubricating phase indicating which timing the discharge cycle of the lubricant,
At the time of calculating the feature amount, the lubrication state determination step of determining the lubrication state of the bearing by a plurality of feature amounts having different lubrication phases is executed.
In order to achieve the above object, the invention according to claim 7 is in a rotary shaft device having a rotary shaft supported by a bearing in which a lubricant periodically discharged is conveyed by compressed air to be lubricated. , A method of diagnosing the lubrication state of bearings,
Based on the information acquired at different timings in the lubricant reduction section, which is the section where the amount of lubricant existing on the rolling surface of the bearing decreases, the feature amount representing the magnitude of the rotational resistance of the rotating shaft is obtained. Multiple feature amount calculation steps and
A lubrication phase calculation step for calculating the lubrication phase at the time of feature calculation, which indicates which timing of the lubricant discharge cycle is the representative time when the information used for calculating each feature is acquired.
It is characterized by executing a display step of displaying a graph having either one of the feature amount and the lubrication phase at the time of feature amount calculation on the vertical axis and the other on the horizontal axis.

In order to achieve the above object, the invention according to claim 1 is in a rotary shaft device having a rotary shaft supported by a bearing that is lubricated by being conveyed by compressed air of a lubricant that is periodically discharged. , A device for diagnosing the lubrication state of bearings
A feature amount calculation means that calculates a plurality of feature amounts representing the magnitude of the rotational resistance of the rotating shaft at different timings, and
It is characterized by including a lubrication phase calculating means for calculating the lubrication phase at the time of calculating the feature amount, which indicates which timing of the discharge cycle of the lubricant is the representative time when calculating the feature amount.
According to the second aspect of the present invention, in the configuration of the first aspect, the feature amount calculating means uses a plurality of feature amounts as a lubricant reduction section, which is a section in which the amount of the lubricant present on the rolling surface of the bearing is reduced. It is characterized in that it is calculated in.
The invention according to claim 3 is characterized in that, in the configuration of claim 1 or 2, a lubrication state determining means for determining the lubrication state of the bearing by a plurality of feature amounts having different lubrication phases at the time of calculating the feature amount is provided. To do.
According to the fourth aspect of the present invention, in the configuration of the third aspect, the lubrication state determining means calculates an index indicating whether or not the rotational resistance is increased in the lubricant decreasing section from a plurality of feature amounts, and the index is It is characterized in that it is judged that the lubrication is insufficient when the reference value is exceeded.
The invention according to claim 5 includes, in any of the configurations of claims 1 to 4, an inertial operating means for executing inertial operation of the rotating shaft and a rotating speed detecting means for detecting the rotational speed of the rotating shaft. The feature amount calculating means is characterized in that the feature amount is calculated based on the change mode of the rotation speed during inertial operation.
According to the sixth aspect of the present invention, in the configuration of the fifth aspect, the rotational speed range from the start to the end of the inertial operation in the inertial operation is such that the fluctuation of the feature amount in the rotational speed range during the inertial operation is equal to or less than the reference value. It is characterized by determining to.
The invention according to claim 7 displays a graph in which one of the feature amount and the lubrication phase at the time of calculating the feature amount is on the vertical axis and the other is on the horizontal axis in any of the configurations of claims 1 to 6. It is characterized by having a display unit.
In order to achieve the above object, the invention according to claim 8 is in a rotary shaft device having a rotary shaft supported by a bearing in which a lubricant periodically discharged is conveyed by compressed air to be lubricated. , A method of diagnosing the lubrication state of bearings,
A feature amount calculation step that calculates a plurality of feature amounts that represent the magnitude of the rotational resistance of the rotating shaft at different timings, and
A lubrication phase calculation step for calculating the lubrication phase at the time of feature calculation, which indicates which timing of the lubricant discharge cycle the representative time for calculating the feature amount is.
At the time of calculating the feature amount, the lubrication state determination step of determining the lubrication state of the bearing by a plurality of feature amounts having different lubrication phases is executed.

According to the present invention, the bearing rolling surface has a characteristic amount representing the magnitude of rotational resistance, which has a characteristic of increasing when the amount of lubricant present in the bearing is excessive and excessive and decreasing when approaching an appropriate amount. It is necessary to carry out an experiment to set a threshold in order to determine whether or not lubrication is insufficient by calculating multiple times at the timing when the amount of lubricant present in the vehicle decreases and checking whether or not the characteristic amount is increasing. Absent. Further, if the control device and the speed detector provided in the general rotary shaft device are used, an additional sensor is not required, and it is possible to appropriately grasp and diagnose the lubrication state of the bearing at low cost. Furthermore, since the rotation speed range from the start to the end of the inertial operation is determined so that the rotational resistance does not fluctuate significantly during the inertial operation, the change in the rotational speed is too large and the diagnosis is made in a state significantly different from that during normal use. You can prevent that.
Then, by displaying the transition of the rotational resistance, it becomes possible to visually grasp the fluctuation of the lubrication state.

It is the schematic of the lubrication state diagnostic apparatus. It is a flowchart of the lubrication state diagnosis method. It is a graph which shows the measurement example of the rotation resistance. It is a graph which shows the rotation speed waveform at the time of a diagnosis operation.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration of a lubrication state diagnostic device provided in a spindle device of a machine tool as a rotary shaft device, and will be specifically described with reference to this figure.
The spindle 1 is rotatably attached to the spindle housing 2 via bearings 2a and 2a which are rolling bearings, and a tool 3 for processing is fixed to the spindle housing 2. The motor 4 drives the spindle 1. At the time of processing, the control device 6 controls the current supplied to the motor 4 so as to keep the rotation speed of the motor 4 measured by the speed detector 5 as the rotation speed detection means at the command rotation speed. The lubricant device 7 discharges a fixed amount of lubricant at a set time interval (hereinafter referred to as a lubricant discharge cycle), mixes it with compressed air, passes through a pipe (not shown), and supplies the lubricant to bearings 2a and 2a. To do.

Since the lubrication state of the bearing 2a fluctuates with the lubricant discharge cycle, the lubrication state of the bearing 2a can be regarded as the same even at different times if the elapsed time from the latest lubricant discharge is the same. In addition, in order to discuss the timing when the lubrication state is generally the same regardless of the lubricant discharge cycle, a dimensionless value obtained by dividing the elapsed time from the latest lubricant discharge by the lubricant discharge cycle is defined as the lubrication phase. .. The lubrication phase takes a value of 0 or more and less than 1, and the lubricant is discharged at the timing when the lubrication phase becomes 0.

Reference numeral 100 denotes a lubrication state diagnostic device for the bearing 2a, which includes a storage unit 8, a calculation unit 9, and a display unit 10. During the diagnosis operation by the lubrication state diagnosis device 100, the control device 6 controls not only to keep the rotation speed of the motor 4 at the command rotation speed but also to stop the power supply to the motor 4 to enter the inertial operation state. That is, the control device 6 also functions as an inertial driving means.
The storage unit 8 has a moment of inertia of the rotating body, a lubricant discharge cycle, the latest lubricant discharge time, a scheduled inertial operation start time, a preset diagnostic rotation speed, a preset inertial operation start speed, and a preset inertial operation end. Time-series data of speed and rotation speed during inertial operation, whether or not inertial operation has been performed in the lubrication phase at the start of each inertial operation, lubrication phase at the time of feature calculation described later, and rotational resistance at the diagnostic rotation speed arrival time described later. , The date of diagnosis, the rate of increase in rotational resistance, and the judgment result of the lubrication state are stored.

The calculation unit 9 calculates the scheduled inertial operation start time from the current time, the lubricant discharge cycle, the latest lubricant discharge time, whether or not the inertial operation has been performed in the lubrication phase at the start of each inertial operation. Further, the time when the diagnostic rotation speed is reached is calculated from the time series data of the rotation speed during the inertial operation and the time series data of the diagnosis rotation speed and the rotation speed during the inertial operation. Further, the lubrication phase at the time of feature calculation is calculated from the lubricant discharge cycle, the latest lubricant discharge time, and the diagnostic rotation speed arrival time. In addition, the rotational resistance at the time when the diagnostic rotational speed is reached is calculated from the moment of inertia of the rotating body, the time-series data of the rotational speed during inertial operation, and the diagnostic rotational speed. Then, the increase rate of the rotational resistance is calculated from the lubrication phase at the time of calculating the feature amount and the rotational resistance at the time when the diagnostic rotation speed is reached, and the determination result of the lubrication state is calculated from the increase rate of the rotational resistance. That is, it functions as a feature amount calculation means, a lubrication phase calculation means, and a lubrication state determination means of the present invention.
The display unit 10 displays a determination result of the lubrication state and a two-dimensional graph in which the lubrication phase is on the horizontal axis and the rotational resistance is on the vertical axis.

The amount of the lubricant supplied to the bearing 2a becomes maximum at the timing delayed by the time when the lubricant is conveyed by the compressed air and reaches the bearing 2a from the timing when the lubricant is discharged in a fixed amount (the lubrication phase is 0). , Decreases over time. Therefore, the amount of the lubricant present on the bearing rolling surface changes from the timing of the lubrication phase 0 to the timing of the next 0 in the order of decrease → increase → decrease.
On the other hand, the value of rotational resistance decreases as the amount of lubricant present on the bearing rolling surface approaches an appropriate state from an excessive state, and the amount of lubricant present on the bearing rolling surface decreases from an appropriate state. It has the property of increasing as it approaches the shortage state.
From the above, when the rotational resistance is regarded as a function of the lubrication phase, as shown in FIG. 3, the lubricant is discharged from the timing when the inclination of the rotational resistance becomes a different sign immediately before the lubricant is discharged (near 1/4 of the phase in the figure). Immediately after that, at the timing when the inclination of the rotational resistance becomes a different sign (around 3/8 of the phase in the figure), the amount of lubricant existing on the bearing rolling surface is decreasing, so this section or this If the value of the rotational resistance increases in a narrower section (“lubricant reduction section” shown in FIG. 3), it is possible to determine that the lubrication is insufficient.

FIG. 2 shows a flowchart for diagnosing the lubrication state of the bearing 2a in the lubrication state diagnosis device 100, and FIG. 4 shows a change in the rotation speed during the diagnosis operation, an inertial operation start speed, and a diagnosis rotation. The relationship between the speed, the inertial operation end speed, the inertial operation start time, and the diagnostic rotation speed arrival time is shown. A specific description will be given based on this flowchart and FIG.
First, in S1, the spindle 1 is rotated at the diagnostic rotation speed (here, 4000 min ^-1 ) via the control device 6 and waits for the inertial operation start time (S2). When the inertial operation start time is reached in the determination of S2 (Y: YES in S2), the inertial operation is started by controlling ^{the rotation speed to the inertial operation start speed (here, 4100 min -1) in S3.} During the inertial operation, the rotation speed is recorded in chronological order (S4), and the inertial operation end speed (here, 3900 min ^-1 ) is waited for to be reached (S5).

When the inertial operation end speed or less is reached in the determination of S5 (Y: YES in S5), the rotation speed is controlled to the diagnostic rotation speed in S6. Then, in S7, from the recorded rotation speed time-series data and the value of the moment of inertia of the rotating body, the time when the diagnostic rotation speed is reached during the inertial operation used as the feature amount in this diagnostic device (hereinafter, the time when the diagnostic rotation speed is reached). The value of the rotational resistance in (referred to as) is calculated according to the following formula (1), and the lubrication phase (lubricating phase at the time of calculating the feature amount) at the representative time is calculated according to the following formula (2) (feature amount calculation). Step and lubrication phase calculation step). In this diagnostic device, the diagnostic rotation speed arrival time is used as the representative time. Angular acceleration is the derivative of rotational speed.

Rotational resistance = -1 x moment of inertia x angular acceleration ... Equation (1)
Lubrication phase at the time of feature calculation = (Diagnosis rotation speed arrival time-Latest lubricant discharge time at diagnosis rotation speed arrival time) ÷ Lubricant discharge cycle ・ ・ Equation (2)

However, in S7, the ratio of the difference between the maximum value and the minimum value of the rotational resistance between the inertial operation start speed and the inertial operation end speed of one inertial operation to the average of the rotational resistance exceeds the reference value (for example, 15%). In that case, it is judged that the rotation resistance during normal use when operating at a constant rotation speed cannot be estimated because the change in rotation speed is too large, and the difference between the inertial operation start speed and the inertial operation end speed is made small. Then make a diagnosis from the beginning again.

Next, in S8, the rotation resistance at the time when the diagnostic rotation speed is reached and the lubrication phase at the time of calculating the feature amount are recorded, and it is recorded that the inertial operation at the lubrication phase at the start of the inertial operation this time has been performed.
In S9, it is determined whether or not the inertial operation in all the lubrication phases at the start of the inertial operation has been performed, that is, whether or not the diagnosis is possible, and if the lubrication phase that has not been performed remains (N: in S9: NO), the inertial operation start time is calculated, and the process returns to S2. If it has already been carried out (Y: YES in S9), in S10, the rate of increase in rotational resistance used as a diagnostic index in this diagnostic device is calculated from the lubrication phase at the time of feature quantity calculation and the rotational resistance at the time when the diagnostic rotation speed is reached. Calculate according to equation (3).

Increase rate of rotational resistance = average slope of rotational resistance in the lubricant decrease section ÷ average rotational resistance in the lubricant decrease section ・ ・ Equation (3)

Then, the lubrication state is determined in S11 (lubrication state determination step). Here, when the rate of increase in rotational resistance is greater than the reference value of 0%, it can be determined that the rotational resistance is increasing in the lubricant decreasing section, and thus it is determined that the lubrication is insufficient.
In S12, a two-dimensional graph in which the lubrication phase indicating the transition of the lubrication state is plotted on the horizontal axis and the rotational resistance is plotted on the vertical axis, and the diagnosis result of the lubrication state are displayed on the display unit 10.

As described above, according to the lubrication state diagnosis device 100 of the above-described embodiment, the calculation unit 9 calculates a plurality of feature amounts representing the magnitude of the rotational resistance of the spindle 1 at different timings, and calculates the feature amounts. The lubrication phase at the time of feature amount calculation, which indicates which timing of the discharge cycle of the lubricant is the representative time, is calculated, and the lubrication state of the bearing 2a is determined by a plurality of feature amounts having different lubrication phases at the time of feature amount calculation. .. That is, the timing at which the lubricant present on the bearing rolling surface decreases is the value of the rotational resistance, which has the characteristic of increasing when the amount of lubricant present in the bearing 2a is excessive or too small and decreasing when approaching an appropriate amount. Since it is determined whether or not the lubrication is insufficient by calculating multiple times and checking whether or not the rotational resistance is increasing, it is not necessary to carry out an experiment to set the threshold value. Further, since the control device 6 and the speed detector 5 provided in the spindle device are used, no additional sensor is required, and it is possible to appropriately grasp and diagnose the lubrication state of the bearing 2a at low cost. Furthermore, since the rotation speed range from the start to the end of the inertial operation is determined so that the rotational resistance does not fluctuate significantly during the inertial operation, the change in the rotational speed is too large and the diagnosis is made in a state significantly different from that during normal use. You can prevent that.
In particular, here, since the transition of the rotational resistance is displayed on the display unit 10, it is possible to visually grasp the fluctuation of the lubrication state.

In the above embodiment, the value of the rotational resistance during inertial operation, which is directly related to the lubrication state of the bearing, is used as the feature quantity representing the magnitude of the rotational resistance, but the change in the moment of inertia at the time of diagnosis is used. If it can be ignored, the absolute value of the angular acceleration during inertial operation may be used.
In addition, as an example of calculating the feature amount, the rotational resistance is calculated from the values of the angular acceleration and the moment of inertia during inertial operation. However, if sufficient measurement accuracy can be obtained to capture the fluctuation of the rotational resistance, The rotation resistance may be calculated from the magnitude of the power supplied to the motor and the value of the rotation speed to keep the rotation speed at a constant command rotation speed, or flow to the motor to keep the rotation speed at a constant command rotation speed. The magnitude of the current may be used as a feature quantity. In this case, the feature amount can be measured continuously rather than discretely with respect to the lubrication phase. The representative time when calculating the feature amount may be the time when the magnitude of the electric power or current supplied to the motor is measured or commanded.

Further, although an example of 0% is shown as a reference value for the rate of increase in rotational resistance, it may be set to a value larger than 0% to avoid erroneous judgment due to measurement variation, or 0% to surely avoid insufficient lubrication. It may be smaller than the value.
On the other hand, an example is shown in which the rate of increase in rotational resistance is used as an index for classifying the lubrication state, but any index that expresses the increase or decrease in rotational resistance in the lubricant decrease section may be used, and the rotational resistance may be used in the lubricant decrease section. May be replaced with the ratio of the phase in which is increased.
If the ratio of the difference between the inertial operation start time and the diagnostic rotation speed arrival time to the lubricant discharge cycle is smaller than the interval between the lubrication phases at which the inertial operation starts, it represents the inertial operation start time instead of the diagnostic rotation speed arrival time. It may be the time.
Furthermore, an example was shown in which the judgment result of the lubrication state was calculated from the increase rate of the rotational resistance and the judgment result was displayed, but the increase rate of the rotational resistance and the display of the two-dimensional graph were limited, and the operator judged from the displayed contents. You may try to do it.

In addition, the bearing diagnostic device and method of the present invention can be applied not only to the spindle device of a machine tool but also to the rotary shaft device of other mechanical equipment such as an automobile, a railroad vehicle, and a ship.

1 ... Spindle, 2 ... Main shaft housing, 2a ... Bearing, 3 ... Tool, 4 ... Motor, 5 ... Speed detector, 6 ... Control device, 7 ... Lubrication device, 8 ... Storage unit , 9 ... Calculation unit, 100 ... Lubrication condition diagnostic device.

Claims (7)

A device for diagnosing the lubrication state of a bearing in a rotary shaft device having a rotary shaft supported by a bearing that is lubricated by being conveyed by compressed air of a lubricant that is periodically discharged.
The feature amount representing the magnitude of the rotational resistance of the rotating shaft is added to the information acquired at different timings in the lubricant reducing section, which is the section in which the amount of the lubricant existing on the rolling surface of the bearing is reduced. A feature amount calculation means that calculates multiple features based on
Representative time the a timing acquired the information used in calculating each said feature amount, lubricating phase calculation means for calculating each feature calculation when lubricating phase indicating which timing the discharge cycle of the lubricant When,
Lubrication state determining means for determining the lubrication state of the bearing by a plurality of the feature amounts having different lubrication phases at the time of calculating the feature amount.
A device for diagnosing the lubrication state of bearings in a rotary shaft device. The lubrication state determining means calculates an index indicating whether or not the rotational resistance is increased in the lubricant decreasing section from the plurality of feature amounts, and if the index exceeds the reference value, it is determined that the lubrication is insufficient. The device for diagnosing the lubrication state of a bearing in the rotary shaft device according to claim 1. A device for diagnosing the lubrication state of a bearing in a rotary shaft device having a rotary shaft supported by a bearing that is lubricated by being conveyed by compressed air of a lubricant that is periodically discharged.
The feature amount representing the magnitude of the rotational resistance of the rotating shaft is added to the information acquired at different timings in the lubricant reducing section, which is the section in which the amount of the lubricant existing on the rolling surface of the bearing is reduced. A feature amount calculation means that calculates multiple features based on
Lubrication phase calculation means for calculating the lubrication phase at the time of feature amount calculation, which indicates which timing of the discharge cycle of the lubricant is the representative time, which is the timing at which the information used for calculating each feature amount is acquired. When,
A display unit that displays a graph having either one of the feature amount and the lubrication phase at the time of calculating the feature amount on the vertical axis and the other on the horizontal axis .
A device for diagnosing the lubrication state of bearings in a rotary shaft device. An inertial operation means for executing the inertial operation of the rotating shaft, and
A rotation speed detecting means for detecting the rotation speed of the rotation shaft is provided.
The lubrication state of the bearing in the rotary shaft device according to any one of claims 1 to 3 , wherein the feature amount calculation means calculates the feature amount based on the change mode of the rotation speed during the inertial operation. Diagnostic device. The fourth aspect of claim 4, wherein the rotation speed range from the start to the end of the inertial operation in the inertial operation is determined so that the fluctuation of the feature amount in the rotation speed range during the inertial operation is equal to or less than a reference value. Bearing lubrication condition diagnostic device in the rotary shaft device. A method of diagnosing the lubrication state of a bearing in a rotary shaft device having a rotary shaft supported by a bearing that is lubricated by being conveyed by compressed air of a lubricant that is periodically discharged.
The feature amount representing the magnitude of the rotational resistance of the rotating shaft is added to the information acquired at different timings in the lubricant reducing section, which is the section in which the amount of the lubricant existing on the rolling surface of the bearing is reduced. Feature calculation steps to calculate multiple features based on
Lubricating phase calculation step representative time said a timing acquired the information, to calculate each feature calculation when lubricating phase indicating which timing the discharge cycle of the lubricant to be used for calculating each said feature quantity When,
A lubrication state determination step for determining the lubrication state of the bearing based on a plurality of the feature amounts having different lubrication phases at the time of calculating the feature amount, and a lubrication state determination step.
A method for diagnosing the lubrication state of bearings in a rotary shaft device, which comprises performing. A method of diagnosing the lubrication state of a bearing in a rotary shaft device having a rotary shaft supported by a bearing that is lubricated by being conveyed by compressed air of a lubricant that is periodically discharged.
The feature amount representing the magnitude of the rotational resistance of the rotating shaft is added to the information acquired at different timings in the lubricant reducing section, which is the section in which the amount of the lubricant existing on the rolling surface of the bearing is reduced. Feature calculation steps to calculate multiple features based on
Lubrication phase calculation step for calculating the lubrication phase at the time of feature amount calculation, which indicates which timing of the discharge cycle of the lubricant is the representative time, which is the timing at which the information used for calculating each feature amount is acquired. When,
A display step for displaying a graph having either one of the feature amount and the lubrication phase at the time of calculating the feature amount on the vertical axis and the other on the horizontal axis.
A method for diagnosing the lubrication state of bearings in a rotary shaft device, which comprises performing.

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