JP7017094B2 - A ball screw device and mechanical equipment equipped with the ball screw device. - Google Patents

Description

The present invention relates to a ball screw device and mechanical equipment provided with the ball screw device. In particular, the present invention relates to a technique for detecting the presence or absence of a peeling phenomenon occurring on a ball screw shaft.

Machine tool equipment such as machining centers are equipped with a ball screw device. The ball screw device includes a ball screw shaft and a nut assembled to the ball screw shaft. A ball circulation path is formed on the outer peripheral surface of the ball screw shaft and the inner peripheral surface of the nut, and the ball is arranged in the circulation path. The rotation of the ball screw shaft causes the ball to circulate in the circulation path, and the nut moves axially on the ball screw shaft. As a result, moving objects such as saddles, columns, and tables of machine tools that are integrated with the nut move.

As described above, the ball screw device used for the linear moving element in the machine tool equipment is a mechanical element that changes the rotational motion into a linear motion. In this ball screw device, peeling occurs due to fatigue life or intrusion of foreign matter at the contact portion between the ball screw shaft and the nut raceway surface where the ball contacts. In particular, there is a strong tendency for peeling to occur on the ball screw shaft. The peeling phenomenon is generally called pitting in the initial state of peeling, and is called fretting in the advanced state of peeling.

In the ball screw device, since the relative positions of the ball screw shaft and the nut constantly change, it is difficult to detect the peeling that occurs in the ball screw shaft in the initial state of occurrence. For this reason, there has been a problem that the ball screw device must be replaced urgently at the stage when it is confirmed that the processing accuracy is poor or abnormal noise is generated in the machine tool equipment due to the peeling phenomenon.

Therefore, conventionally, there is a proposal as shown in the following patent document as a method for detecting an abnormality such as peeling that occurs in a ball screw shaft in a ball screw device. For example, there is a method of directly measuring and detecting the displacement of the surface of the contact portion of the ball screw shaft with which the ball comes into contact with a detection sensor (see Patent Documents 1 and 2 below). Further, there is a method of detecting the vibration of the nut, extracting a frequency component in a certain range, and determining the presence or absence of an abnormality based on the standard deviation of the ball passing cycle (see Patent Document 3 below).

Japanese Unexamined Patent Publication No. 2004-12209 Japanese Unexamined Patent Publication No. 2007-333195 Japanese Unexamined Patent Publication No. 2009-257806

By the way, since the peeling phenomenon does not appear as an abnormal noise or a conspicuous poor processing accuracy at the initial stage of the peeling, it is difficult to notice the occurrence and progress of the peeling. The peeling phenomenon spreads around the place where it occurs, and by the time it appears as abnormal noise or obvious poor processing accuracy, the peeling often spreads.

Therefore, the present inventors focused on evaluating the peeling phenomenon in a range, and considered to predict the life of the ball screw shaft and grasp the replacement timing by detecting the spread / progress of the peeling. ..

Therefore, the present invention was invented in view of the above points, and the problem to be solved by the present invention is the progress of the peeling in order to grasp the progress of the peeling occurring in the ball screw shaft. The purpose is to capture the state from the phenomenon that occurs in the nut and to evaluate the peeled state of the ball screw shaft.

In order to solve the above problems, the present invention takes the following means.

A first aspect of the present invention is a machine on a ball screw shaft of a nut assembled to the ball screw shaft in a ball screw device having a ball screw shaft and a nut assembled to the ball screw shaft. The coordinate acquisition means for acquiring the coordinate position, the nut information detecting means attached to the nut and capturing the peeling state generated in the ball screw shaft as a phenomenon occurring in the nut at the peeling position, and the nut information detecting means detect the peeling state. A peeling state detector that determines the presence or absence and degree of peeling based on the phenomenon that occurs in the nut, and a ball screw shaft state that records information on the peeling state for each axial position of the ball screw shaft as the entire ball screw shaft. It is a ball screw device including a recording unit and a peeling evaluation unit that evaluates a peeling state of the ball screw shaft based on the information of the ball screw shaft state recording unit.

According to the first invention, the machine coordinate position on the ball screw shaft of the nut assembled to the ball screw shaft is acquired by the coordinate acquisition means. That is, the position of the nut fitted to the ball screw shaft is grasped. Then, the nut information detecting means attached to the nut captures the peeled state generated in the ball screw shaft as a phenomenon occurring in the nut at the peeled position. Then, the presence / absence and degree of the peeled state are determined based on the phenomenon that occurs in the nut detected by the nut information detecting means by the peeled state detecting unit. Then, the information on the peeled state for each axial position of the ball screw shaft is recorded by the ball screw shaft state recording unit as the entire ball screw shaft. Then, the peeling state of the ball screw shaft is evaluated based on the information between the peeling state detecting unit and the ball screw shaft state recording unit, which determines the presence / absence and degree of the peeling state by the peeling evaluation unit. As a result, information on the peeling state for each axial position can be grasped, so that the spread of the peeling phenomenon that has occurred on the surface of the ball screw shaft can be grasped, and replacement can be determined at a more appropriate timing and the life of the ball screw shaft can be predicted. Will be easier to do.

The second invention of the present invention is the ball screw device of the first invention described above, and further, the influence or the peeling state on the phenomenon occurring in the nut in the nut information detecting means due to the operating state of the ball screw shaft. It is a ball screw device having an information storage device for storing in advance the relationship of influence on the peeling state detection information by the detection unit.

According to the second invention, further, the information storage device is provided, and the relationship between the phenomenon generated in the nut by the nut information detecting means or the peeling state detection information by the peeling state detecting unit and the operating state of the ball screw shaft is obtained. Remember it in advance. As a result, the peeling state can be evaluated in consideration of the influence on the phenomenon occurring in the nut or the peeling state detection information due to the operating state of the ball screw shaft, so that the presence or absence and the degree of the peeling state can be more accurately performed. Can be judged.

The third invention of the present invention is the ball screw device of the first invention or the second invention described above, and further, an alarm is given based on the evaluation information of the peeling state of the ball screw shaft in the peeling evaluation unit. It is a ball screw device having an alarm unit and a ball screw device.

According to the third invention, an alarm unit is further provided, and an alarm is issued based on the evaluation information of the peeling state of the ball screw shaft in the peeling evaluation unit described above. As a result, it is possible to know that the evaluation of the peeled state of the ball screw shaft is in an abnormal state indicating that the ball screw device is in a state to be repaired or replaced.

The fourth invention of the present invention is the ball screw device of the third invention described above, and the evaluation information of the peeling state is the range amount of the peeling occurrence point or the change amount of the peeling, and the alarm unit is described by the alarm unit. A ball screw device that issues an alarm when the range amount or the change amount exceeds a predetermined threshold value.

According to the fourth invention, the alarm is evaluated by at least one of the range amount of the axial peeling of the ball screw shaft and the change amount of the peeling, and these numerical values exceed a predetermined threshold value. If you are alerted. This ensures that an alarm is given. The range amount of peeling is the size of the area where peeling is determined to occur, that is, the length in the axial direction, and the amount of change means the progress speed of the peeling phenomenon.

A fifth aspect of the present invention is the ball screw device according to any one of the first to fourth inventions described above, wherein the nut information detecting means is a nut sensor that acquires nut vibration information. , A ball screw device.

According to the fifth aspect of the invention, the nut sensor that acquires the vibration information of the nut detects the peeled state of the ball screw shaft as a phenomenon that occurs in the nut. As a result, it is possible to reliably grasp whether or not the ball screw shaft is in a peeled state.

The sixth invention of the present invention is the ball screw device of the fifth invention described above, wherein the vibration information of the nut is the magnitude of the vibration.

According to the sixth invention, since the peeled state appears as the magnitude of the vibration of the vibration information of the nut, the presence or absence of the peeled state can be grasped by the difference in the magnitude of the vibration.

A seventh aspect of the present invention is the ball screw device according to any one of the third to sixth inventions, which is subordinate to the second invention described above, and the operating state of the ball screw shaft is a ball. A ball screw device that is the rotational speed of a screw shaft.

According to the seventh invention, the operating state of the ball screw shaft is the rotation speed of the ball screw shaft, and the nut moves on the ball screw shaft under the control of the rotation speed. Then, the peeling phenomenon that occurs in the ball screw shaft is detected as a vibration amplitude according to the rotation speed. That is, the vibration of the nut changes not only due to the peeled state but also due to the rotation speed. Therefore, a more accurate peeling state can be determined by considering the influence of the rotation speed when determining the presence / absence and degree of peeling.

The eighth invention of the present invention is the ball screw device of any one of the above-mentioned first to seventh inventions, and the evaluation by the peeling evaluation unit for evaluating the peeling state of the ball screw shaft is described above. In the case of an evaluation showing a peeling phenomenon over the entire length of the ball screw shaft, the ball screw device evaluates that the nut has a peeling phenomenon by the peeling evaluation unit.

According to the eighth invention, in the case of the evaluation showing the peeling phenomenon over the entire length of the ball screw shaft, it is evaluated that the nut has the peeling phenomenon, and the peeling state generated in the nut is grasped. That is, when the vibration factor of the nut is caused by the peeling on the ball screw side, the presence or absence of the peeling and the degree of the peeling differ depending on the axial position. Therefore, if the axial position changes, the presence or absence of vibration appears. If the nut side is peeled or damaged, it becomes a vibration factor regardless of the axial position and vibration continues to occur, so it can be inferred that the nut side is peeled off.

The ninth invention of the present invention is the mechanical equipment provided with the ball screw device of the first invention described above, and for each position of the ball screw shaft recorded in the ball screw shaft state recording unit in the ball screw device described above. It is a mechanical equipment having a monitor in which information on the peeling state of the ball screw is visually displayed as a whole ball screw shaft.

According to the ninth aspect of the invention, since the mechanical equipment provided with the ball screw device has a monitor visually displayed by a figure or the like, the peeling state of each position of the ball screw shaft can be visually confirmed.

A tenth aspect of the present invention is the mechanical equipment of the ninth invention described above, and the monitor visually displays information when an alarm is given by the alarm unit of the third invention described above. Is.

According to the tenth invention, the information when the alarm unit in the third invention gives an alarm is also displayed by the monitor in the eighth invention, so that the alarm state is surely notified.

According to the present invention, in order to grasp the progress state of the peeling of the ball screw shaft, the progress state of the peeling can be captured from the phenomenon occurring in the nut and the peeling state of the ball screw shaft can be evaluated.

It is a schematic whole block diagram which shows the ball screw apparatus of this embodiment. It is sectional drawing which shows the combination structure of a ball screw shaft and a nut. It is a waveform diagram which shows the vibration information detected by the nut sensor when the ball screw shaft is peeled off. It is a peeling situation map visually displayed on the monitor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present embodiment is a case of a ball screw device provided in machine tool equipment such as a machining center.

FIG. 1 shows a schematic overall configuration diagram of a ball screw device 10 provided in a machine tool equipment 12 such as a machining center. The ball screw device 10 is provided as a device for moving the moving body 14 in the machine tool equipment 12. The moving body 14 of the machine tool equipment 12 is a table, a column, a saddle, or the like. A plurality of ball screw devices 10 are provided as operating mechanisms for each axis such as the X-axis, Y-axis, and Z-axis in machine tool equipment.

The ball screw device 10 includes a ball screw shaft 16 and a nut 18 as mechanical elements that change the rotary motion into a linear motion, and the nut 18 moves axially on the ball screw shaft 16 due to the rotation of the ball screw shaft 16. In this embodiment, the range of movement of the nut 18 is shown in FIG. 1 as the range of L. The positional state of the nuts 18 at the left and right ends in the moving range is shown by a virtual line.

A moving body 14 is connected to the nut 18 via a connecting member 15, and moves with the axial movement of the nut 18. The ball screw shaft 16 is rotatably supported by support bearings 20 and 22 installed at both ends thereof. The support bearings 20 and 22 are installed on the base 24 of the machine tool equipment 12.

A servomotor 26 is disposed on the support bearing 22 on the right side as seen in FIG. 1, and rotationally drives the ball screw shaft 16. By controlling the rotation speed of the servomotor 26, the axial movement speed of the nut 18 that moves the ball screw shaft 16 is controlled. The rotation speed of the servomotor 26 is controlled by a command from the NC device 38.

FIG. 2 shows the details of the combination configuration of the ball screw shaft 16 and the nut 18. A ball trajectory V groove 28 is spirally formed on the outer peripheral surface of the ball screw shaft 16. Correspondingly, a ball track V groove 30 is spirally formed on the inner peripheral surface of the nut 18. A plurality of balls 32 are interposed between the ball track V-groove 28 of the ball screw shaft 16 and the ball track V-groove 30 of the nut 18. Then, the nut 18 moves in the axial direction as the ball 32 circulates due to the rotation of the ball screw shaft 16. The range of the ball track V groove 28 formed on the outer peripheral surface of the ball screw shaft 16 is the movement range of the nut 18 shown by L in FIG. 1, but it may be formed over the entire length of the ball screw shaft 16. good. In this embodiment, it is formed over the entire length. Further, the cross-sectional V-shape of the ball track V-grooves 28 and 30 may be a half-round cross-section.

In the ball screw device 10 configured as described above, due to the fatigue life of the ball screw shaft 16 due to the circulation of the ball 32 and the intrusion of foreign matter between the ball screw shaft 16 and the nut 18, the ball trajectory V groove 28 of the ball screw shaft 16 is formed. A peeling phenomenon occurs. The peeling phenomenon is generally called pitting or fretting, as described in the background art. Although the peeling phenomenon may occur in the ball trajectory V groove 30 of the nut 18, it tends to occur remarkably on the ball screw shaft 16 side on the side where torque is applied to the ball 32.

In this embodiment, the state of occurrence of peeling occurring in the ball screw device 10 is monitored as follows to evaluate the peeling state, and a replacement alarm (replacement warning) is given before the product is inaccurate or the production is stopped due to the machine stop. , Replacement instructions) are shown accurately.

First, as shown in FIG. 1, the nut 18 is provided with a nut information detecting means 34. The nut information detecting means 34 is a detecting means for capturing the peeling state generated in the ball screw shaft 16 as a phenomenon occurring in the nut 18 fitted at the position where the peeling occurs. In the present embodiment, the nut sensor 36 captures the peeled state generated in the ball screw shaft 16 as a vibration phenomenon generated in the nut 18. The nut sensor 36 is, for example, a displacement sensor attached to the nut 18 and measuring the distance of the ball screw shaft 16 from the surface. Since the nut 18 moves in the movement range L of the ball screw shaft 16, it always passes through the peeling portion generated in the ball trajectory V groove 28 of the ball screw shaft 16 and detects the peeling as the magnitude of the vibration amplitude.

Based on the vibration information detected by the nut sensor 36 which is the nut information detecting means 34, the peeling state detecting unit 35 determines the presence / absence and degree (level) of the peeling state.

As shown by D in FIG. 3, the nut sensor 36 has a larger vibration amplitude at the position of the ball screw shaft 16 where the peeling phenomenon has occurred than at the position of the ball screw shaft 16 where the peeling phenomenon has not occurred as shown by N in FIG. It becomes the vibration amplitude. This makes it possible to detect the presence or absence of a peeling phenomenon. That is, when the magnitude of the vibration amplitude exceeds the threshold value K at which the peeling phenomenon is considered to have occurred, it is determined that the peeling state has occurred. As will be described later, the magnitude of the vibration amplitude fluctuates depending on the rotation speed of the ball screw shaft 16, and the threshold value K also fluctuates accordingly.

Next, speed information is also acquired based on the speed (rotational speed) command from the NC device 38 to the servomotor 26. Further, the coordinate acquisition means 40 acquires the mechanical coordinate position of the nut 18 assembled to the ball screw shaft 16 on the ball screw shaft 16. That is, by obtaining the position of the nut 18 from the mechanical coordinates of the NC device 38, the position of the peeling generated in the ball trajectory V groove 28 of the ball screw shaft 16 is obtained, and the position of the nut 18 with respect to the ball screw shaft 16 is detected. In addition, speed information is also acquired based on the information from the NC device 38.

It should be noted that the relationship between the nut sensor 36, which is the nut information detecting means 34, and the rotation speed of the ball screw shaft 16, which is the operating state of the ball screw shaft 16, is stored in advance by the information storage device from the information acquired in advance. Since the magnitude of the vibration amplitude when the peeling detected by the nut sensor 36 occurs depends on the rotation speed of the ball screw shaft 16 (the shaft movement speed of the nut 18), the relationship is stored from the information acquired in advance. Keep it. Then, when evaluating the peeling state in the peeling evaluation unit 46, which will be described later, the reference value (threshold value) for evaluating the alarm is determined by varying according to the rotation speed of the ball screw shaft 16.

The relationship between the nut sensor 36 and the rotation speed of the ball screw shaft 16 in the operating state of the ball screw shaft 16 is, for example, how much the nut vibrates when the rotation speed and the degree of peeling are changed. It is determined in advance by an experiment whether it will change, and the experimental data is used as a database showing the relationship. Further, it may be based on a logical formula or a simulation result.

Next, the ball screw shaft state recording unit 44 records the information on the peeled state for each position of the ball screw shaft 16 as the entire ball screw shaft. That is, the state of FIG. 3 is recorded as data in the ball screw shaft state recording unit 44.

Then, the peeling evaluation unit 46 evaluates the peeling state of the ball screw shaft 16 based on the information between the information storage device 42 and the ball screw shaft state recording unit 44. The peeling evaluation unit 46 evaluates the level of the abnormal state of the peeling phenomenon that has occurred in the ball screw shaft 16 and the nut 18. The evaluation by the peeling evaluation unit 46 is performed in consideration of the size of the peeling occurrence range, the amount of change in the peeling range per hour, the size of the vibration amplitude, and the like.

In the evaluation of the peeling evaluation unit 46 described above, in the case of the evaluation showing the peeling phenomenon over the entire length of the ball screw shaft 16, the peeling phenomenon is not evaluated as having occurred in the ball screw shaft 16. It is evaluated that the peeling evaluation unit 46 has caused the peeling phenomenon in the nut 18. As a result, the peeled state generated in the nut 18 can also be detected.

This is because when the vibration factor of the nut is caused by the peeling on the ball screw side, the presence or absence of peeling and the degree of peeling differ depending on the axial position, and therefore, if the axial position changes, the presence or absence of vibration appears. However, if the nut side is peeled or damaged, it becomes a vibration factor regardless of the axial position, and the vibration continues to occur, so that it can be inferred that the nut side is peeled off.

Next, an alarm is issued by the alarm unit 48 based on the evaluation by the peeling evaluation unit 46. The alarm is issued when the ball screw device needs to be replaced in the evaluation of the peeling state by the peeling evaluation unit 46. There are two types of alarms: voice alarm methods and visual display alarm methods. From these alarms, it can be known that the evaluation of the peeled state of the ball screw shaft 16 is in an abnormal state. The alarm is evaluated by comprehensively evaluating the size of the peeling occurrence range, the amount of change in the peeling range per hour, the size of the vibration amplitude, etc. in the evaluation of the peeling evaluation unit 46 described above, and a predetermined reference value. Issued when (threshold) is exceeded.

The peeling that occurs in the ball screw shaft 16 usually occurs in a narrow range, and grows and spreads as the operation is continued. In practice, an alarm is issued in consideration of the progress of the spread of this peeling. Repairs such as replacement of the ball screw device 10 in the machine tool equipment 12 usually take several days due to the number of days required for obtaining and procuring replacement parts and the working time required for the replacement work. The timing to issue an alarm is to consider the number of days required to obtain and procure replacement parts and the work time required for replacement work, and to set the timing of replacement work to be a non-working day of the factory. Is preferable because it can reduce the influence on the production plan. In this way, predictive management is also performed as necessary.

The alarm of the present embodiment is visually displayed as shown in FIG. 4, and is displayed on the monitor 50 of the NC device 38 provided in the machine tool equipment 12 of FIG. In the present embodiment, as shown in FIG. 4, the display of the "replacement warning" or / and the "replacement instruction" of the ball screw shaft device 10 is turned on.

In the present embodiment, the monitor 50 visually displays the information on the peeling state of the ball screw shaft 16 for each axial position recorded in the ball screw shaft state recording unit 44 as a figure or the like as the entire ball screw shaft. .. That is, the evaluation state of the peeled state of the ball screw shaft 16 is visually displayed. The visual display of FIG. 4 shows a peeling situation map of the ball screw shaft 16. In the map, the total length of the ball screw shaft 16 is shown, and the points corresponding to the positions where the peeling occurs are shown as a diagram. This makes it possible to know the position and range of the peeling (the axial length of the peeling that occurred on the ball screw shaft) and the progressing speed (change amount) of the peeling.

Further, the monitor 50 displays the observation process of the peeled state. The observation process is sequentially displayed as observation 1, observation 2, and observation 3. For example, Observation 1 shows the state 6 months after the installation of the machine tool equipment, Observation 2 shows the state one year later, and Observation 3 shows the state one and a half years later. Observation 3 also shows that a new exfoliation occurred. From this observation process, it is possible to know the size of the peeling range and the progress speed (change amount) at each time. Then, when the size (range area) of the peeling exceeds a predetermined area (threshold value) in the observation 3, an alarm is issued. In addition, an alarm is issued when it is determined that the progress speed (change amount) that causes peeling up to observation 3 exceeds the threshold value before the next factory vacation.

It should be noted that not only the presence or absence of peeling for each axial portion but also the progress of peeling for each axial portion may be indicated by the shade of color. For example, minor peeling that does not significantly affect the machine operation at the initial stage of peeling is displayed in light color, and large peeling that is concerned about the progress of peeling and may affect machine operation or when considering ball screw replacement is displayed in dark color. .. Further, the degree of peeling may be displayed by a numerical display instead of the figure display.

Although the present invention has been described above with respect to specific embodiments, the present invention can also be implemented in various other embodiments.

For example, in the above-described embodiment, the nut information detecting means 34 is a nut sensor 36 that detects vibration information of the nut 18, but means that can capture the peeling phenomenon that occurs in the ball screw shaft 16 as a phenomenon that occurs in the nut 18. It should be. For example, it may be a load from a ball applied to the nut.

Further, in the above-described embodiment, the case where the ball screw device is applied to the machine tool equipment 12 such as a machining center has been described, but the case may be applied to equipment other than the machine tool.

Further, in the above-described embodiment, the relationship with the operating state of the ball screw shaft 16 in the information storage device 42 is not always necessary. That is, if the rotation speed (rotation speed) of the ball screw shaft 16 is constant, the peeling state can be estimated from the vibration information detected by the nut sensor 36 without being affected by the rotation speed.

10 Ball screw device 12 Machinery equipment 14 Moving body 15 Connecting member 16 Ball screw shaft 18 Nut 20 Support bearing 22 Support bearing 24 Base 26 Servo motor 28 (Ball screw shaft side) Ball track V groove 30 (Nut side) Ball Track V-groove 32 Ball 34 Nut information detection means 35 Peeling state detection unit 36 Nut sensor 38 NC device 40 Coordinate acquisition means 42 Information storage device 44 Ball screw shaft state recording unit 46 Peeling evaluation unit 48 Alarm unit 50 Monitor

Claims (9)

In a ball screw device having a ball screw shaft and a nut assembled to the ball screw shaft.
A coordinate acquisition means for acquiring the mechanical coordinate position of the nut assembled to the ball screw shaft on the ball screw shaft, and
A nut information detecting means attached to the nut and capturing the peeled state generated in the ball screw shaft as a phenomenon occurring in the nut at the peeled position.
A peeling state detection unit that determines the presence or absence and degree of a peeling state based on the phenomenon that occurs in the nut detected by the nut information detecting means.
A ball screw shaft state recording unit that records information on the peeled state of each axial position of the ball screw shaft as the entire ball screw shaft, and a ball screw shaft state recording unit.
A peeling evaluation unit that evaluates the peeling state of the ball screw shaft based on the information of the ball screw shaft state recording unit, and a peeling evaluation unit.
An information storage device that previously stores the relationship between the effect on the phenomenon that occurs in the nut in the nut information detecting means due to the operating state of the ball screw shaft or the effect on the peeling state detection information by the peeling state detecting unit. ,
It has an alarm unit that issues an alarm based on the evaluation information of the peeling state of the ball screw shaft in the peeling evaluation unit.
The operating state of the ball screw shaft is the rotation speed of the ball screw shaft, which is a ball screw device. The ball screw device according to claim 1.
The evaluation information of the peeling state is a range amount of a peeling occurrence point or a change amount of peeling, and the alarm unit issues an alarm when the range amount or the change amount exceeds a predetermined threshold value . The ball screw device according to claim 1 or 2.
The nut information detecting means is a ball screw device, which is a nut sensor that acquires nut vibration information . The ball screw device according to claim 3.
The vibration information of the nut is the magnitude of the vibration, which is a ball screw device. In a ball screw device having a ball screw shaft and a nut assembled to the ball screw shaft.
A coordinate acquisition means for acquiring the mechanical coordinate position of the nut assembled to the ball screw shaft on the ball screw shaft, and
A nut information detecting means attached to the nut and capturing the peeled state generated in the ball screw shaft as a phenomenon occurring in the nut at the peeled position.
A peeling state detection unit that determines the presence or absence and degree of a peeling state based on the phenomenon that occurs in the nut detected by the nut information detecting means.
A ball screw shaft state recording unit that records information on the peeled state of each axial position of the ball screw shaft as the entire ball screw shaft, and a ball screw shaft state recording unit.
A peeling evaluation unit that evaluates the peeling state of the ball screw shaft based on the information of the ball screw shaft state recording unit, and a peeling evaluation unit.
An information storage device that previously stores the relationship between the effect on the phenomenon that occurs in the nut in the nut information detecting means due to the operating state of the ball screw shaft or the effect on the peeling state detection information by the peeling state detecting unit. Have,
The nut information detecting means is a nut sensor that acquires vibration information of a nut.
The operating state of the ball screw shaft is the rotation speed of the ball screw shaft, which is a ball screw device. The ball screw device according to claim 5.
The vibration information of the nut is the magnitude of the vibration, which is a ball screw device. The ball screw device according to any one of claims 1 to 6 .
When the evaluation by the peeling evaluation unit for evaluating the peeling state of the ball screw shaft shows the peeling phenomenon over the entire length of the ball screw shaft, it is said that the nut has the peeling phenomenon caused by the peeling evaluation unit. Ball screw device to evaluate . The mechanical equipment provided with the ball screw device according to claim 1.
A mechanical device having a monitor in which information on a peeling state for each position of the ball screw shaft recorded in the ball screw shaft state recording unit in the ball screw device according to claim 1 is visually displayed graphically as the entire ball screw shaft. The mechanical equipment according to claim 8.
Mechanical equipment that visually displays information on the monitor when an alarm is given by the alarm unit according to claim 1.

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