Elevator hoist, rolling bearing, and diagnostic device for the rolling bearing

Abstract

Provided is an elevator hoist, a rolling bearing, and a diagnostic device for the rolling bearing, capable of diagnosing the degree of damage with high accuracy. The diagnostic device (7) includes a behavior sensor (8), a calculation unit (14), and a diagnosis unit (11). The behavior sensor (8) is provided on the inner ring (2) or the outer ring (3) of the rolling bearing (1), or on a housing (6) that holds the inner ring (2) or the outer ring (3). The behavior sensor (8) measures the behavior of the rolling bearing. The calculation unit (14) calculates an evaluation speed based on information acquired by the behavior sensor (8). The evaluation speed is the maximum speed component in the direction in which a load from a rotating shaft (5) acts within a time period longer than the period of a natural vibration determined by the specifications of the rolling bearing (1) and the relative rotation speed of the inner ring (2) and the outer ring (3). The diagnosing unit (11) diagnoses damage to the rolling bearing (1) using an evaluation index based on the evaluation speed calculated by the calculating unit (14) and the relative rotation speed of the inner ring (2) and the outer ring (3).

Description

[Technical field]

[0001] The present disclosure relates to an elevator hoist, a rolling bearing, and a diagnostic device for the rolling bearing. [Background technology]

[0002] Patent Document 1 discloses an example of a diagnostic device for a rolling bearing. The diagnostic device includes a vibration sensor and a damage / degradation diagnostic unit. The vibration sensor is attached in contact with the inner ring, the outer ring, or a housing that holds the inner ring or the outer ring of the rolling bearing. The damage / degradation diagnostic unit diagnoses damage / degradation of the rolling bearing based on the amplitude of an output signal from the vibration sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 61-61055 Summary of the Invention [Problem to be solved by the invention]

[0004] The diagnostic device of Patent Document 1 diagnoses the impact value measured by the vibration sensor using a converted impact value converted for a specified reference bearing diameter and a specified reference rotation speed. However, since the impact value is strongly affected by the shape of the damaged corner of the rolling bearing, the diagnostic device may not be able to accurately diagnose the extent of the damage itself.

[0005] The present disclosure relates to solving such problems. The present disclosure provides an elevator hoist, a rolling bearing, and a diagnostic device for a rolling bearing that can further improve the accuracy of damage diagnosis. [Means for solving the problem]

[0006] A diagnostic device according to the present disclosure is a diagnostic device that diagnoses a rolling bearing including an inner ring, an outer ring arranged concentrically with the inner ring, and a plurality of rolling elements arranged between a raceway surface of the outer ring and a raceway surface of the inner ring, each of which rolls in association with rotation of the inner ring or the outer ring, and the diagnostic device has a rotation sensor provided in a rotating device including the rolling bearing, a behavior sensor provided in the inner ring, the outer ring, or in a housing that holds the inner ring or the outer ring, and that measures the behavior of the rolling bearing, specifications of the rolling bearing, Prescribed a calculation unit that calculates an evaluated speed, which is a maximum speed component in the direction of a load acting on the rolling bearing from a rotating shaft that rotates integrally with the inner ring or the outer ring, within a time period that is longer than the period, based on information acquired by the behavior sensor; Bishou A diagnosis unit that diagnoses damage to the rolling bearing by using an evaluation index based on the rotation speed. The relative rotation speed is a relative rotation speed between the inner ring and the outer ring obtained based on a measurement value of the rotation sensor, and the predetermined period is a period of a natural vibration determined by the relative rotation speed and the specifications of the rolling bearing. .

[0007] The rolling bearing according to the present disclosure comprises an inner ring, an outer ring arranged concentrically with the inner ring, a plurality of rolling elements arranged between the raceway surfaces of the outer ring and the inner ring, each of which rolls in conjunction with rotation of the inner ring or the outer ring, and the above-mentioned diagnostic device.

[0008] The elevator hoist according to the present disclosure comprises a rolling bearing including an inner ring, an outer ring arranged concentrically with the inner ring, a plurality of rolling elements arranged between the raceway surface of the outer ring and the raceway surface of the inner ring, each of which rolls as the inner ring or the outer ring rotates, and the above-mentioned diagnostic device, a sheave, a rotating shaft that rotates integrally with the sheave and a part of the rolling bearing, and an electric motor that rotates the rotating shaft. Effect of the Invention

[0009] According to the elevator hoist, rolling bearing, or rolling bearing diagnostic device according to the present disclosure, the accuracy of damage diagnosis can be improved. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a configuration diagram of a rolling bearing according to a first embodiment. [Diagram 2] 4A to 4C are diagrams illustrating an example of diagnosis of damage to a rolling bearing by the diagnosis device according to the first embodiment. [Diagram 3] 5A to 5C are diagrams for explaining another example of diagnosis of damage to a rolling bearing by the diagnosis device according to the first embodiment. [Figure 4] FIG. 11 is a configuration diagram of a rolling bearing according to a second embodiment. [Diagram 5] 13A and 13B are diagrams for explaining an example of diagnosis of damage to a rolling bearing by the diagnosis device according to the third embodiment. [Figure 6] FIG. 13 is a configuration diagram of a rolling bearing according to a seventh embodiment. [Figure 7] FIG. 13 is a configuration diagram of a rolling bearing according to a ninth embodiment. [Figure 8] 13 is a diagram for explaining an example of diagnosis of damage to a rolling bearing by the diagnosis device according to the ninth embodiment. FIG. [Figure 9] 13A to 13C are diagrams illustrating an example of the behavior of a rolling element of a rolling bearing according to embodiment 9 when passing through a damaged portion. [Figure 10] 23 is a diagram for explaining an example of diagnosis of damage to a rolling bearing by the diagnosis device according to the sixteenth embodiment. FIG. [Figure 11] FIG. 23 is a configuration diagram of a rolling bearing according to a nineteenth embodiment. [Figure 12] FIG. 26 is a configuration diagram of a rolling bearing according to embodiment 20. [Figure 13] 2 is a diagram illustrating an example of a hardware configuration of a control unit of a diagnostic device according to any one of embodiments 1 to 21. FIG. [Figure 14] FIG. 22 is a schematic diagram of an elevator hoisting machine according to a twenty-second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present disclosure will now be described with reference to the accompanying drawings, in which the same or corresponding parts are designated by the same reference numerals, and duplicated descriptions will be appropriately simplified or omitted.

[0012] Embodiment 1 FIG. 1 is a configuration diagram of a rolling bearing according to a first embodiment.

[0013] The rolling bearing 1 includes an inner ring 2, an outer ring 3, a plurality of rolling elements 4, and a rotating shaft 5. FIG. 1 shows a cross section of the rolling bearing 1 taken along a plane perpendicular to the axis of the rotating shaft 5. The inner ring 2 is cylindrical in shape. The outer ring 3 is cylindrical in shape. The outer ring 3 is arranged concentrically with the inner ring 2 on the outside of the inner ring 2. The plurality of rolling elements 4 are arranged between the inner ring 2 and the outer ring 3. Each rolling element 4 is shaped to be capable of rolling, such as a spherical or cylindrical shape. The rolling elements 4 are arranged between a raceway surface, which is the inner peripheral surface of the outer ring 3, and a raceway surface, which is the outer peripheral surface of the inner ring 2. The rolling elements 4 roll with the rotation of the inner ring 2, the rotation of the outer ring 3, or the rotation of both the inner ring 2 and the outer ring 3. Here, when it is necessary to distinguish between the individual rolling elements 4, any one of the plurality of rolling elements 4 may be referred to as rolling element 4a, rolling element 4b, or the like.

[0014] The rotating shaft 5 rotates integrally with the inner ring 2 or the outer ring 3. In this example, the rotating shaft 5 rotates counterclockwise on the page in FIG. 1. Here, the axial direction along the axis of the rotating shaft 5, i.e., the extension direction of the rotating shaft 5, is sometimes simply referred to as the axial direction. The circumferential direction around the axis of the rotating shaft 5, i.e., the rotation direction of the rotating shaft 5, is sometimes simply referred to as the circumferential direction. The direction from the axis of the rotating shaft 5 toward the outside of the rotating shaft 5 is sometimes simply referred to as the radial direction.

[0015] In the rolling bearing 1 of this example, the inner ring 2 rotates integrally with the rotating shaft 5, and the outer ring 3 is fixed. Note that in the rolling bearing 1, the outer ring 3 may rotate integrally with the rotating shaft 5, and the inner ring 2 may be fixed. Also, the rolling bearing 1 may be configured so that the inner ring 2 and the outer ring 3 rotate together.

[0016] The rolling bearing 1 is held in a housing 6. The housing 6 holds the inner ring 2 or the outer ring 3 of the rolling bearing 1.

[0017] A diagnostic device 7 is applied to the rolling bearing 1. The diagnostic device 7 is equipped with a function for diagnosing the condition of the rolling bearing 1, such as damage. The diagnostic device 7 may be a device included as part of a rotating device, such as an electric motor, in which the rolling bearing 1 is provided, or may be an external device applied from the outside to the rotating device. The diagnostic device 7 may be a device that is permanently installed on the rolling bearing 1 or the rotating device in which the rolling bearing 1 is provided, or may be a device that is temporarily installed as a portable device on the rolling bearing 1 or the rotating device in which the rolling bearing 1 is provided. The diagnostic device 7 includes a behavior sensor 8 and a control unit 9.

[0018] The behavior sensor 8 is attached to the housing 6. The behavior sensor 8 is a sensor that measures the behavior of the housing 6. The behavior sensor 8 is, for example, an acceleration sensor, a displacement sensor, or a speed sensor.

[0019] The control unit 9 is equipped with a function of performing information processing in the diagnosis device 7. The control unit 9 may be composed of one or more independent pieces of hardware, or may be a part of other hardware such as a control device for a rotating device in which the rolling bearing 1 is provided. The control unit 9 includes a first calculation unit 10 and a diagnosis unit 11.

[0020] The first calculation unit 10 is a part that has a function of calculating an evaluation speed used for diagnosing the rolling bearing 1. The evaluation speed is calculated for a time period equal to or longer than the period Tr of the natural vibration determined by the specifications of the rolling bearing 1. The evaluation speed is the sum of the maximum speed component in the direction in which the load from the rotating shaft 5 acts and the maximum speed component in the opposite direction to the direction in which the load from the rotating shaft 5 acts within that time period. The direction in which the load from the rotating shaft 5 acts is, for example, a radially outward direction or a vertically downward direction. In this case, the opposite direction to the direction in which the load from the rotating shaft 5 acts is a radially inward direction or a vertically upward direction. Here, the direction in which the load from the rotating shaft 5 acts may be referred to as the load direction, and the opposite direction to the direction in which the load from the rotating shaft 5 acts may be referred to as the anti-load direction.

[0021] The first calculation unit 10 calculates the evaluated speed by processing the output signal from the behavior sensor 8. For example, when the behavior sensor 8 is a speed sensor, the first calculation unit 10 calculates the evaluated speed using time series data of the speed, which is an output signal from the behavior sensor 8. When the behavior sensor 8 is an acceleration sensor, the first calculation unit 10 calculates the time series data of the speed by time integrating the time series data of the acceleration, which is an output signal from the behavior sensor 8. At this time, the first calculation unit 10 calculates the evaluated speed using the calculated time series data of the speed. When the behavior sensor 8 is a displacement sensor, the first calculation unit 10 calculates the time series data of the speed by time differentiating the time series data of the displacement, which is an output signal from the behavior sensor 8. At this time, the first calculation unit 10 calculates the evaluated speed using the calculated time series data of the speed.

[0022] The first calculation unit 10 calculates the maximum speed component in the direction in which the load from the rotating shaft 5 acts from the time series data of speed for a preset time period equal to or greater than the period Tr. The first calculation unit 10 calculates the maximum speed component in the direction opposite to the direction in which the load from the rotating shaft 5 acts from the time series data of speed for that time. The first calculation unit 10 calculates the evaluated speed by adding up the absolute values ​​of these two maximum speed components.

[0023] The diagnosis unit 11 is a part equipped with a function of diagnosing damage to the rolling bearing 1 using an evaluation index based on the evaluation speed calculated by the first calculation unit 10. In this example, the diagnosis unit 11 diagnoses damage to the rolling bearing 1 using the evaluation speed calculated by the first calculation unit 10 itself as the evaluation index. The diagnosis unit 11 diagnoses that damage has occurred in the rolling bearing 1 when, for example, the evaluation speed exceeds a preset threshold value.

[0024] Next, an example of diagnosis of damage to the rolling bearing 1 by the diagnosis device 7 will be described with reference to FIG. FIG. 2 is a diagram for explaining an example of diagnosis of damage to a rolling bearing by the diagnosis device according to the first embodiment. 2, a damaged portion 100 is shown as an example of damage that can occur in the rolling bearing 1. The damaged portion 100 occurs in the rolling bearing 1, for example, as follows.

[0025] In the rolling bearing 1 of this example, the rotating shaft 5 rotates counterclockwise on the paper together with the inner ring 2. At this time, each rolling element 4 in contact with the raceway surface of the inner ring 2 rotates and moves so as to revolve counterclockwise on the paper around the central axis of the rotating shaft 5 between the inner ring 2 and the outer ring 3 while rolling clockwise on the paper around the center point of the rolling element 4 itself as the inner ring 2 rotates. When a load on the inner ring 2 due to the load of the rotating shaft 5 or the like acts downward on the paper, most of the load from the rotating shaft 5 is transmitted to the raceway surface of the outer ring 3 via the raceway surface of the inner ring 2 and the multiple rolling elements 4 located below the rotating shaft 5. When the rotating shaft 5 is stationary, the position and magnitude of the load generated on each of the inner ring 2, the outer ring 3, and the rolling elements 4 do not change. On the other hand, when the rotating shaft 5 is rotating, the position and magnitude of the load change periodically as the inner ring 2 and the rolling elements 4 rotate and move. This causes repeated stress loads to act on the raceway surfaces of the inner ring 2 and the outer ring 3. This repeated stress load can cause cracks to develop from the inside of the inner ring 2 or the outer ring 3, for example, starting from impurities inside the material, and reach the surface. When this happens, internally originating spalling damage, in which the surface layer peels off in a scale-like pattern, can occur on the raceway surfaces of the inner ring 2 or the outer ring 3.

[0026] Furthermore, insufficient lubrication of the raceway surface due to insufficient supply, deterioration, leakage, or insufficient viscosity of lubricants such as grease, as well as excessive load, may cause abnormal slippage between the rolling elements 4 and the inner ring 2 and outer ring 3. In this case, stress may be easily concentrated on the surface of the raceway surface due to surface roughness and wear, which may accelerate damage to the raceway surface. As an example, surface-originating spalling damage, in which the surface layer of some of the raceway surface peels off in a scaly pattern, and wear damage may occur on the raceway surface.

[0027] For internally initiated spalling damage, there is a life design formula called the L10 life, and since the specifications of the rolling bearing 1 are usually determined based on that life design formula, there are few cases of internally initiated spalling damage. On the other hand, surface initiated spalling damage can occur much earlier than internally initiated spalling damage, so condition diagnosis of the rotating equipment in which the rolling bearing 1 is installed is important to ensure the reliability and long-term operation of the said rotating equipment.

[0028] According to findings obtained from bearing tests, the damaged portion 100 due to spalling damage is often formed on the raceway surface of the rolling bearing 1. The damaged portion 100 is often composed of a recessed portion 101 and a damaged corner portion 102. It is considered that the size and shape of the recessed portion 101 and the damaged corner portion 102 are constantly changing according to the total number of rotations of the rolling bearing 1. It has also been confirmed that as the total number of rotations of the rolling bearing 1 increases, the recessed portion 101 becomes larger, while the damaged corner portion 102 may have a sharp shape in the initial stage of damage occurrence, but may later change to a smooth shape due to wear or the like. When the damaged portion 100 is due to surface-origin spalling damage, the depth of the recessed portion 101 is shallow in the initial stage of damage occurrence, so that as the damage progresses, the recessed portion 101 becomes larger in the axial and circumferential directions and also becomes deeper in the radial direction.

[0029] Although the sharp shape of the damaged corner 102 may lead to a momentary increase in vibration, the impact on the lifespan of the rolling bearing 1 and the rotating equipment in which the rolling bearing 1 is provided is small. On the other hand, the recessed portion 101 grows larger as the total number of rotations of the rolling bearing 1 increases, which may lead to a continuous increase in rattle, vibration, or abnormal noise of the rolling bearing 1 and the entire rotating equipment in which the rolling bearing 1 is provided. For this reason, the size of the recessed portion 101 can have a significant impact on the lifespan of the rolling bearing 1 and the entire rotating equipment in which the rolling bearing 1 is provided.

[0030] For example, as shown in FIG. 1, consider a case where a recessed portion 101 is formed on the load side of an outer ring 3 in an inner ring rotating rolling bearing 1 in which an inner ring 2 rotates with a rotating shaft 5. If the recessed portion 101 becomes large, the rolling element 4 sinks into the recessed portion 101 at the timing when the rolling element 4 reaches the recessed portion 101 during the rotation of the rolling bearing 1. At this time, the rolling element 4 falls in the depth direction of the recessed portion 101 together with the inner ring 2 and the rotating shaft 5. Furthermore, at the timing when the rolling element 4 leaves the recessed portion 101, the rolling element 4 rises from the bottom of the recessed portion 101 together with the inner ring 2 and the rotating shaft 5. For this reason, the deeper the recessed portion 101, the greater the rattle, vibration, and abnormal noise of the rolling bearing 1 and the rotating shaft 5. If the recessed portion 101 becomes too deep, the rattle, vibration, and abnormal noise of the rolling bearing 1 and the rotating shaft 5 may become extremely large. In this case, the design upper limit of the rotating device in which the rolling bearing 1 is provided may be exceeded. This may also lead to failures such as cracking or breaking of the rolling bearing 1, failures of peripheral devices of the rolling bearing 1, and failures of the entire rotating device in which the rolling bearing 1 is provided.

[0031] For this reason, it is important to diagnose the condition of the rolling bearing 1 to determine the size or degree of damage, such as the depth of the recessed portion 101. By diagnosing the condition of the rolling bearing 1, it is possible to detect abnormalities in the rolling bearing 1 and estimate the remaining lifespan, and perform maintenance and life extension measures such as replacing the rolling bearing 1 or grease at an appropriate time. This also makes it possible to reduce the maintenance labor required for the rolling bearing 1, the peripheral equipment of the rolling bearing 1, and the entire rotating equipment in which the rolling bearing 1 is installed, and to operate it stably for a long time.

[0032] For example, the diagnostic device 7 performs diagnosis on the damaged portion 100 as shown in Fig. 2 as follows. Note that Fig. 2 shows an example in which the damaged portion 100 occurs on the outer ring 3, but the damaged portion 100 may occur on the inner ring 2 or the rolling element 4.

[0033] The first calculation unit 10 calculates the evaluation speed for a time equal to or longer than the period Tr of the natural vibration determined by the specifications of the rolling bearing 1. The natural vibration here includes not only the vibration generated when the rolling element 4 passes over the damaged portion 100 that has occurred in the outer ring 3 as shown in Fig. 2, but also the vibration generated when the rolling element 4 passes over the damaged portion 100 that has occurred in the inner ring 2, and the vibration generated when the inner ring 2 and the outer ring 3 pass over the damaged portion 100 that has occurred in the rolling element 4. Here, the period Tr of the natural vibration resulting from the damage to the inner ring 2 is defined as Tr i [sec], the period of the natural vibration caused by the damage of the outer ring 3 is Tr o [sec], and the period of the natural vibration resulting from the damage to the rolling element 4 is Tr b When the inner ring 2 is damaged, the period Tr i When the outer ring 3 is damaged, the natural vibration of o When the rolling element 4 is damaged, the natural vibration of the period Tr b For example, when there is a damaged portion 100 on the outer ring 3 as shown in FIG. 2, the period from when the rolling element 4a passes over the damaged portion 100 until when the rolling element 4b passes over the damaged portion 100 is equal to the period Tr. o For example, the diameter of the rolling element 4 is d [mm], the revolution diameter of the rolling element 4 is D [mm], the number of the rolling elements 4 is Z, the contact angle of the rolling element 4 is α [rad], and the rotation frequency of the inner ring 2 is f r [rps], the natural vibration period Tr i is the following formula (1), and the natural vibration period Tr o is the following equation (2), and the natural vibration period Tr b are expressed by the following equation (3), respectively.

[0034]

number

[0035]

number

[0036]

number

[0037] Regardless of whether the damaged portion 100 occurs in the inner ring 2, the outer ring 3, or the rolling element 4, a behavior in which any part sinks into the recessed portion 101 of the damaged portion 100 and falls, and then escapes and rises occurs at least once within the time period Tr. The first calculation unit 10 uses the time series data of the speed based on the output signal from the behavior sensor 8 to calculate the maximum speed component in the direction in which the load from the rotating shaft 5 acts and the maximum speed component in the opposite direction within a time period equal to or longer than the period Tr. The first calculation unit 10 calculates the evaluation speed by adding the absolute values ​​of these two maximum speed components. In this way, the diagnosis unit 11 diagnoses the damage to the rolling bearing 1 based on the evaluation speed calculated by the first calculation unit 10, so that the diagnosis device 7 can diagnose the size or degree of the damaged portion 100 with high accuracy regardless of whether the damaged portion 100 occurs in the inner ring 2, the outer ring 3, or the rolling element 4.

[0038] Furthermore, the diagnosing unit 11 can perform an abnormality diagnosis, for example, when the evaluated speed exceeds a preset threshold value, such as diagnosing that damage has occurred in the rolling bearing 1. Furthermore, the diagnosing unit 11 can also diagnose the size or degree of the damaged part 100, such as the depth of the recessed part 101, with high accuracy by diagnosing based on the evaluated speed.

[0039] As described above, the rolling bearing 1 according to the first embodiment includes the inner ring 2, the outer ring 3, a plurality of rolling elements 4, and the diagnostic device 7. The outer ring 3 is arranged concentrically with the inner ring 2. The plurality of rolling elements 4 are arranged between the raceway surface of the outer ring 3 and the raceway surface of the inner ring 2. Each rolling element 4 rolls with the rotation of the inner ring 2, the rotation of the outer ring 3, or the rotation of both the inner ring 2 and the outer ring 3. In the rolling bearing 1, the rotating shaft 5 rotates integrally with the inner ring 2 or the outer ring 3. The diagnostic device 7 includes a behavior sensor 8, a first calculation unit 10, and a diagnostic unit 11. The behavior sensor 8 is provided in the housing 6 that holds the inner ring 2 or the outer ring 3. The behavior sensor 8 measures the behavior of the housing 6. The first calculation unit 10 calculates the evaluation speed based on the information acquired by the behavior sensor 8. The evaluation speed is the sum of the maximum speed component in the direction in which the load from the rotating shaft 5 acts and the maximum speed component in the opposite direction to the direction in which the load from the rotating shaft 5 acts, within a time period equal to or longer than the period Tr of the natural vibration determined by the specifications of the rolling bearing 1. The diagnosing unit 11 diagnoses damage to the rolling bearing 1 using an evaluation index based on the evaluation speed calculated by the first calculation unit 10.

[0040] As a comparative example, let us consider a case where damage to a rolling bearing is diagnosed based only on the amplitude of vibration of the output signal from the vibration sensor, not on an evaluation index based on the evaluation speed as in the diagnosis device 7. When a rolling element of a rolling bearing passes through a damaged part, fine and small vibrations are often generated in multiple separate instances. For this reason, even if the damaged part becomes larger, the vibration amplitude does not increase, so that the damage may not be accurately diagnosed based only on the vibration amplitude. In addition, when the damaged corner of the damaged part becomes smooth due to wear or the like, the rolling element passes through the damaged part smoothly, so that the influence of the damaged part does not appear in the vibration amplitude and the damage is not detected. In addition, even if the dent shape of the damaged part is small, when the damaged corner shape is sharp, the momentary change in behavior may become large at the timing when the rolling element passes through the damaged corner. At this time, vibrations in which acceleration in the load direction and the counter-load direction, etc., momentarily increase alternately may occur. As a result, the acceleration amplitude, etc. may increase regardless of the size of the dent shape, so that it may be difficult to accurately diagnose the size of the damage itself, such as the size of the dent shape of the damaged part. Furthermore, the vibration of a rolling bearing may also include vibration in the high frequency band caused by frictional sliding, etc. Therefore, the magnitude of the vibration may change depending on the lubrication state of the rolling bearing. For example, if the lubrication state deteriorates due to oxidation degradation, oil separation, leakage, or thickener destruction of the grease that lubricates the rolling bearing, the vibration may become several times larger even if the rolling bearing itself is not damaged. In this way, a diagnosis based only on the magnitude of the vibration amplitude is affected by changes in the lubrication state of the rolling bearing, and the accuracy of the diagnosis of damage to the rolling bearing may decrease.

[0041] On the other hand, the diagnostic device 7 performs diagnosis using an evaluation speed obtained by adding up the maximum speed component in the load direction at the timing when the rolling element 4 sinks into the recessed portion 101 and the maximum speed component in the anti-load direction at the timing when the rolling element 4 escapes from the recessed portion 101. The instantaneous behavior that occurs when the rolling element 4 passes through the damaged corner portion 102 appears as an instantaneous acceleration amplitude. The speed obtained by integrating such instantaneous acceleration amplitude hardly becomes large and is small compared with the speed at the timing when the rolling element 4 sinks into and escapes from the recessed portion 101. Since the diagnostic device 7 performs diagnosis using an evaluation speed obtained by adding up these speeds, the diagnostic device 7 can suppress the influence of the instantaneous behavior of the rolling element 4 due to the shape of the damaged corner portion 102 during diagnosis. In addition, the greater the depth of the recessed portion 101, the greater both the maximum speed component in the load direction and the maximum speed component in the anti-load direction. In this way, the diagnostic device 7 using an evaluation speed that is strongly correlated with the depth of the recessed portion 101 can accurately diagnose the depth of the recessed portion 101. In addition, since the evaluation speed is high due to the geometric shape of the recessed portion 101, unlike devices that perform diagnosis using vibrations including the high frequency band caused by frictional sliding, the diagnostic device 7 can reduce the influence of the lubrication state and more accurately diagnose damage to the rolling bearing 1.

[0042] Generally, rolling bearings are the parts of rotating equipment that are most heavily loaded and are prone to failure first. When damage occurs to a rolling bearing, the stress around the damage increases, and the damage may grow at an accelerated rate. When the damage grows, it may cause the rolling bearing to break, damage or destruction of the equipment around the rolling bearing, and serious failure of the entire rotating equipment in which the rolling bearing is installed.

[0043] In contrast, the diagnostic device 7 can diagnose damage to the rolling bearing 1 with high accuracy, enabling preventive maintenance of the rolling bearing 1. This makes it possible to prevent failures not only in the rolling bearing 1 itself, but also in peripheral equipment of the rolling bearing 1 and the entire rotating equipment in which the rolling bearing 1 is provided.

[0044] FIG. 3 is a diagram for explaining another example of diagnosis of damage to a rolling bearing by the diagnosis device according to the first embodiment. FIG. 3 shows, as another example of damage that can occur in the rolling bearing 1, a damaged portion 100 in which a recessed portion 101 is asymmetric in the circumferential direction.

[0045] In such a damaged portion 100, the maximum speed component in the load direction and the maximum speed component in the counter-load direction may differ depending on the rotation direction of the rotating shaft 5. Even in this case, the diagnostic device 7 can diagnose the damage of the rolling bearing 1 with high accuracy regardless of the rotation direction by diagnosing using the evaluation speed, which is the sum of the maximum speed component in the load direction and the maximum speed component in the counter-load direction. For example, as shown in FIG. 3, in a rolling bearing 1 in which the inner ring 2 rotates counterclockwise on the paper together with the rotating shaft 5, the recessed portion 101 of the damaged portion 100 may be inclined more steeply on the side opposite to the direction of progress of the rotation direction than on the side of the direction of progress of the rotation direction. In this case, for the damaged portion 100 symmetrical in the circumferential direction, the maximum speed component in the load direction may be large at the timing when the rolling element 4 sinks into the recessed portion 101, but the maximum speed component in the counter-load direction may be small at the timing when the rolling element 4 comes out of the recessed portion 101. Also, when the rotating shaft 5 rotates in the reverse direction, the maximum speed component in the load direction becomes small at the timing when the rolling element 4 sinks into the recessed portion 101, but the maximum speed component in the anti-load direction may become large at the timing when the rolling element 4 comes out of the recessed portion 101. That is, for the same recessed portion 101, the maximum speed component in the load direction and the maximum speed component in the anti-load direction may have different magnitudes depending on the rotation direction of the rotating shaft 5. On the other hand, the magnitude of the evaluation speed obtained by adding up the maximum speed component in the load direction and the maximum speed component in the anti-load direction does not change substantially depending on the rotation direction. Since the diagnostic device 7 performs diagnosis using the evaluation speed, it becomes possible to suppress the influence of the rotation direction of the rotating shaft 5 and to more accurately diagnose damage to the rolling bearing 1. In particular, in the rolling bearing 1 applied to rotating equipment whose rotation direction can change, such as elevators, railway cars, and bidirectional rotating generators, the diagnostic device 7 more effectively exhibits the function of being able to diagnose without being influenced by the rotation direction.

[0046] In each of the embodiments described below, differences from the examples disclosed in the other embodiments will be described in detail. For features not described in each of the embodiments below, any feature of the examples disclosed in the other embodiments may be adopted.

[0047] Embodiment 2 FIG. 4 is a configuration diagram of a rolling bearing according to the second embodiment.

[0048] The control unit 9 of the diagnosis device 7 for the rolling bearing 1 comprises a first calculation unit 10, a second calculation unit 12 and a diagnosis unit 11.

[0049] The second calculation unit 12 is a part that has a function of calculating an acceleration frequency spectrum, or an acceleration overall value, or both, based on information acquired by the behavior sensor 8.

[0050] The second calculation unit 12 calculates the acceleration frequency spectrum, the acceleration overall value, or both by processing the output signal from the behavior sensor 8. For example, when the behavior sensor 8 is an acceleration sensor, the second calculation unit 12 calculates the acceleration frequency spectrum, the acceleration overall value, or both by using time series data of acceleration that is an output signal from the behavior sensor 8. When the behavior sensor 8 is a speed sensor, the second calculation unit 12 may calculate the acceleration time series data by time-differentiating the speed time series data that is an output signal from the behavior sensor 8. At this time, the second calculation unit 12 calculates the acceleration frequency spectrum, the acceleration overall value, or both by using the calculated acceleration time series data. When the behavior sensor 8 is a displacement sensor, the second calculation unit 12 may calculate the acceleration time series data by time-differentiating twice the displacement time series data that is an output signal from the behavior sensor 8. At this time, the second calculation unit 12 calculates the acceleration frequency spectrum, the acceleration overall value, or both by using the calculated acceleration time series data. The second calculation unit 12 may calculate, for example, the acceleration frequency spectrum or the acceleration overall value, or both, for a time period equal to or longer than the period Tr that was targeted by the first calculation unit 10 when calculating the evaluation speed, or may calculate the acceleration frequency spectrum or the acceleration overall value, or both, for a longer or shorter time.

[0051] The acceleration frequency spectrum is the magnitude of the acceleration amplitude spectrum obtained for each frequency band by performing calculation processing such as Fourier transform on the time series data of acceleration acquired by the behavior sensor 8.

[0052] Since the evaluation vibration is an evaluation index calculated based on both the evaluation speed and the acceleration frequency spectrum, it may be possible to diagnose the size of the damaged part 100 with high accuracy, and also to determine the location where the damaged part 100 occurs. In particular, by using the acceleration amplitude spectrum in the frequency band of the natural vibration, which is the inverse of the period of the natural vibration of the rolling bearing, it becomes possible to capture the natural vibration caused by the damage in detail according to the location where the damaged part 100 occurs, such as the inner ring 2, the outer ring 3, or the rolling element 4. This allows the diagnosing unit 11 to determine whether the damaged part 100 occurs in the inner ring 2, the outer ring 3, or the rolling element 4 of the rolling bearing 1. In addition, the diagnosing unit 11 can diagnose the size of the damaged part 100 with high accuracy using information related to the magnitude of the acceleration amplitude spectrum in the frequency band of the natural vibration.

[0053] The acceleration overall value is a value obtained by integrating the magnitude of the entire acceleration frequency spectrum for information such as time-series data acquired by the behavior sensor 8, regardless of the frequency band.

[0054] When minor damage such as wear or surface roughness occurs on the raceway surface on which the rolling element 4 rolls, the rolling element 4 hardly sinks into or comes out of the recessed portion 101. At this time, the increase in the evaluated speed is small. On the other hand, since the acceleration overall value is a value obtained by integrating the magnitude of the entire acceleration frequency spectrum regardless of the frequency band, it increases significantly even due to minor wear and surface roughness. Since the evaluated vibration is an evaluation index calculated based on both the evaluated speed and the acceleration overall value, the diagnostic device 7 can diagnose minor damage such as wear and surface roughness with high accuracy.

[0055] As described above, the diagnosing unit 11 calculates the evaluation vibration as an evaluation index using the evaluation speed calculated by the first calculation unit 10 and the acceleration frequency spectrum or the acceleration overall value or both calculated by the second calculation unit 12. The diagnosing unit 11 also calculates the evaluation vibration by, for example, multiplying the evaluation speed and the acceleration frequency spectrum or the acceleration overall value or both by a weighting coefficient and adding them together. The diagnosing unit 11 may also calculate the evaluation vibration by, for example, the arithmetic mean, geometric mean, or other function of the evaluation speed and the acceleration frequency spectrum or the acceleration overall value or both. For example, when the evaluation vibration exceeds a preset threshold value, the diagnosing unit 11 diagnoses that damage has occurred in the rolling bearing 1. Here, the weighting coefficient and the function are, for example, determined in advance by a data analysis method such as regression analysis or a machine learning method using data calculated from the evaluation speed and the acceleration frequency spectrum or the acceleration overall value or both for a plurality of rolling bearings 1 whose damage magnitude is known. By determining the weighting coefficients and functions using information on the rolling bearing 1 with known damage magnitude, the correlation between the evaluation vibration and the damage magnitude and occurrence location becomes stronger, which further improves the accuracy of the diagnosis of damage in the rolling bearing 1 using the evaluation vibration as an evaluation index.

[0056] Embodiment 3 FIG. 5 is a diagram for explaining an example of diagnosis of damage to a rolling bearing by the diagnosis device according to the third embodiment. 5, the horizontal axis represents the passage of time. The vertical axis represents the speed acquired by the behavior sensor 8. The upper side of the vertical axis represents the magnitude of the speed in the load direction. On the other hand, the lower side of the vertical axis represents the magnitude of the speed in the anti-load direction.

[0057] For example, when an acceleration sensor is used as the behavior sensor 8 and acceleration time series data is integrated over time to calculate speed time series data, the speed may become extremely large in the load direction for a period of time equal to or longer than the period Tr, as shown by the dashed line in Fig. 5. This occurs when the acceleration time series data (output signal) is shifted overall in the load direction when the behavior sensor 8 (accelerometer) is poorly attached or when noise such as other disturbance vibrations is significantly reflected. For the same reason, the speed may become large in the anti-load direction for a period of time equal to or longer than the period Tr.

[0058] On the other hand, even if minute vibrations occur in the rolling bearing 1 and the housing 6, the installation positions of the rolling bearing 1 and the housing 6 usually do not change significantly. For this reason, it is not the reality that the speed continues to increase over a long period of time as shown by the dashed line in Figure 5, and if such time-series data is used as is, the evaluated speed Vp will be calculated as an excessively large value. For this reason, the diagnosis device 7 performs a slope correction on the time-series data of the speed.

[0059] The first calculation unit 10 of the diagnosis device 7 performs a slope correction process on the time series data of speed based on the information acquired by the behavior sensor 8. The slope correction process is performed, for example, by determining a slope component of the time series data of speed over a time period equal to or longer than the cycle Tr by linear regression or other methods, and subtracting the determined slope component from the time series data of speed. The first calculation unit 10 calculates an evaluation speed Vp' for a time period equal to or longer than the cycle Tr using the time series data of speed after the slope correction process.

[0060] By using the evaluation speed Vp' calculated in this manner, the diagnosing device 7 can diagnose damage to the rolling bearing 1 without being affected by the mounting state of the behavior sensor 8 or noise such as external vibration.

[0061] Embodiment 4 The first calculation unit 10 of the diagnostic device 7 performs frequency filtering on time series data based on information acquired by the behavior sensor 8. The first calculation unit 10 performs frequency filtering on, for example, time series data of acceleration, speed, or displacement acquired by the behavior sensor 8. The first calculation unit 10 may perform frequency filtering on time series data of speed derived from time series data of acceleration or displacement acquired by the behavior sensor 8. The first calculation unit 10 may also perform frequency filtering on both the time series data acquired by the behavior sensor 8 and the time series data of speed derived from the time series data. The frequency filtering is, for example, a high-pass filter, a low-pass filter, a band-pass filter, or other filtering. The first calculation unit 10 calculates an evaluation speed for a time period equal to or longer than the period Tr using the time series data of speed after frequency filtering.

[0062] By using the evaluation speed calculated in this manner, the diagnostic device 7 can diagnose damage to the rolling bearing 1 without being affected by low-frequency vibrations caused by humming, high-frequency vibrations caused by friction, noise, and external vibrations.

[0063] Embodiment 5. The diagnosis unit 11 of the diagnosis device 7 diagnoses damage to the rolling bearing 1 using an evaluation index statistical value obtained by statistically processing a data group of evaluation indexes such as evaluation speed or evaluation vibration calculated multiple times. The evaluation index statistical value is, for example, the average value, median value, effective value, or maximum value of the data group of the evaluation index. The diagnosis unit 11 diagnoses that damage has occurred in the rolling bearing 1 when, for example, the evaluation index statistical value exceeds a preset threshold value.

[0064] The individual values ​​of the evaluation indexes, such as the evaluation speed or evaluation vibration for each time calculated by the first calculation unit 10 or the like, may take extremely large values, for example, when the behavior sensor 8 detects sudden disturbance vibrations that are not related to damage to the rolling bearing 1. In contrast, the diagnosis unit 11 performs diagnosis using evaluation index statistics, such as the average, median, or effective value obtained by statistically processing a data group of the evaluation indexes, so that the diagnosis device 7 can perform diagnosis without being affected by sudden events that are not related to damage to the rolling bearing 1.

[0065] Also, for example, when the damage to the rolling bearing 1 is at a small stage, the evaluation indexes such as the evaluation speed and evaluation vibration may become large at a low frequency. In response to this, the diagnosing unit 11 performs diagnosis using evaluation index statistics such as maximum values ​​obtained by statistically processing a data group of the evaluation index, so that the diagnosing device 7 can diagnose the occurrence of damage at an earlier stage, even when the damage is at a small stage.

[0066] Furthermore, for example, in a state where damage to the rolling bearing 1 is progressing rapidly, evaluation indices such as the evaluation speed and evaluation vibration may change rapidly. In response to this, the diagnosing unit 11 performs diagnosis using evaluation index statistics such as standard deviation or variance obtained by statistically processing a data group of the evaluation index, so that the diagnosing device 7 can perform a better diagnosis of the progress state of the damage.

[0067] Embodiment 6 The diagnosing unit 11 of the diagnosing device 7 diagnoses damage to the rolling bearing 1 based on periodic changes in an evaluation index such as an evaluation speed or evaluation vibration that is calculated continuously and continuously over time.

[0068] For example, in time-series data of the evaluation index calculated by the diagnosing unit 11 or the like, the evaluation index increases at the timing when the rolling element 4 passes through the damaged part 100, and roughly coincides with the period Tr of the natural vibration determined by the specifications of the rolling bearing 1. Meanwhile, the period when the rolling element 4 passes through the damaged part 100 is determined by formulas (1) to (3) using the occurrence position of the damaged part 100, the dimensions of the rolling bearing 1, the rotation speed of the rotating shaft 5, and the like. Therefore, from the period or frequency at which the evaluation index increases, based on the dimensions and rotation speed of the rolling bearing 1, the diagnosing unit 11 can determine whether the damaged part 100 occurs on the inner ring 2, the outer ring 3, or the rolling element 4 of the rolling bearing 1.

[0069] Furthermore, the diagnosis unit 11 may diagnose the size of the damaged part 100 based on the evaluation index in a cycle in which the evaluation index becomes large. This allows the diagnosis unit 11 to accurately diagnose the size of the damaged part 100 without being affected by noise such as disturbance vibration. For example, the diagnosis unit 11 may diagnose the occurrence position of the damaged part 100 from a frequency band having a large spectrum for frequency analysis data obtained by frequency analyzing the time series data of the evaluation index. For example, the diagnosis unit 11 can accurately diagnose the size of the damaged part 100 without being affected by noise such as disturbance vibration by diagnosing the size of the damaged part 100 from the magnitude of the spectrum of a specific frequency band.

[0070] Embodiment 7 FIG. 6 is a configuration diagram of a rolling bearing according to the seventh embodiment.

[0071] The control unit 9 of the diagnosis device 7 for the rolling bearing 1 includes a first calculation unit 10 , a storage unit 13 , and a diagnosis unit 11 .

[0072] The storage unit 13 is a part that has a function of storing information. The storage unit 13 accumulates and stores the calculated evaluation index. The storage unit 13 stores the evaluation index, for example, as time series data. The storage unit 13 stores, for example, time series data of the evaluation speed as the evaluation index. When the diagnostic device 7 calculates the evaluation vibration as the evaluation index, the storage unit 13 may store time series data of one or both of the evaluation speed and the evaluation vibration as the evaluation index. The storage unit 13 stores the change in the evaluation index over time by storing the evaluation index as time series data. The storage unit 13 may also store the amount of change, such as the time derivative of the evaluation index calculated by, for example, the diagnostic unit 11.

[0073] In a rotating device provided with multiple rolling bearings 1 with different specifications such as size and rotation speed, the evaluation indices such as the evaluation speed and evaluation vibration may have different values ​​depending on the usage conditions, even if the damage caused to each rolling bearing 1 is the same. For example, the evaluation speed and evaluation vibration for the same degree of damage tend to be larger as the size and rotation speed of the rolling bearing 1 increase.

[0074] The diagnosis unit 11 diagnoses damage to the rolling bearing 1 based on the information stored in the memory unit 13. The diagnosis unit 11 calculates, for example, a first-order differential value of the evaluation index, which is the rate of change of the evaluation index over time, and diagnoses the damage state from the first-order differential value of the evaluation index. As a result, the diagnosis unit 11 diagnoses the damage state based on the rate of change of the evaluation index, and can more accurately diagnose damage to rolling bearings 1 with different specification conditions.

[0075] Furthermore, the diagnosis unit 11 may estimate the remaining life until the evaluation index reaches a threshold value that is the life of the rolling bearing 1, based on time-series data of the evaluation index stored in the storage unit 13, etc. This allows the diagnosis device 7 to determine the appropriate replacement timing or maintenance inspection timing for the rolling bearing 1. In this way, the diagnosis device 7 can contribute to reducing the maintenance labor and ensuring long-term stable operation of the rolling bearing 1, peripheral devices of the rolling bearing 1, and the entire rotating equipment in which the rolling bearing 1 is provided.

[0076] Embodiment 8 The rolling bearing 1 includes an inner ring 2, an outer ring 3, a plurality of rolling elements 4, a rotating shaft 5, and a diagnostic device 7.

[0077] Generally, rolling bearings are the parts of rotating equipment that are most heavily loaded and are prone to failure first. When damage occurs to a rolling bearing, the stress around the damage increases, and the damage may grow at an accelerated rate. When the damage grows, the behavior of the entire rotating equipment, including the rotating shaft, becomes unstable, which may lead to damage to peripheral equipment of the rolling bearing, the rotating shaft, gears and couplings, stators, housings, frames, etc.

[0078] In contrast, the rolling bearing 1 can use the diagnostic device 7 to diagnose with high accuracy damage to the rolling bearing 1 and the rotating equipment in which the rolling bearing 1 is provided. This makes it possible to prevent failures not only in the rolling bearing 1 itself, but also in the peripheral equipment of the rolling bearing 1 and the entire rotating equipment in which the rolling bearing 1 is provided.

[0079] In the rolling bearing 1 according to any one of the first to eighth embodiments, the rolling bearing 1 may be configured such that, for example, the inner ring 2 and the outer ring 3 both rotate integrally with separate rotating shafts 5 .

[0080] Embodiment 9 FIG. 7 is a configuration diagram of a rolling bearing 1 according to a ninth embodiment.

[0081] The rolling bearing 1 includes an inner ring 2, an outer ring 3, a plurality of rolling elements 4, and a rotating shaft 5. FIG. 1 shows a cross section of the rolling bearing 1 taken along a plane perpendicular to the axis of the rotating shaft 5. The inner ring 2 is cylindrical in shape. The outer ring 3 is cylindrical in shape. The outer ring 3 is arranged concentrically with the inner ring 2 on the outside of the inner ring 2. The plurality of rolling elements 4 are arranged between the inner ring 2 and the outer ring 3. Each rolling element 4 is shaped to be capable of rolling, such as a spherical or cylindrical shape. The rolling elements 4 are arranged between a raceway surface, which is the inner peripheral surface of the outer ring 3, and a raceway surface, which is the outer peripheral surface of the inner ring 2. The rolling elements 4 roll in accordance with the rotation of the inner ring 2 or the rotation of the outer ring 3. Here, when distinguishing between the individual rolling elements 4, one of the plurality of rolling elements 4 may be referred to as a rolling element 4a or a rolling element 4b.

[0082] The rotating shaft 5 rotates integrally with the inner ring 2 or the outer ring 3. In this example, the rotating shaft 5 rotates counterclockwise on the page in FIG. 1. Here, the axial direction along the axis of the rotating shaft 5, i.e., the extension direction of the rotating shaft 5, is sometimes simply referred to as the axial direction. The circumferential direction around the axis of the rotating shaft 5, i.e., the rotation direction of the rotating shaft 5, is sometimes simply referred to as the circumferential direction. The direction from the axis of the rotating shaft 5 toward the outside of the rotating shaft 5 is sometimes simply referred to as the radial direction.

[0083] In the rolling bearing 1 of this example, the inner ring 2 rotates integrally with the rotating shaft 5, and the outer ring 3 is held and fixed in the housing 6. Note that in the rolling bearing 1, the inner ring 2 may be held and fixed in the housing 6, and the outer ring 3 may rotate integrally with the rotating shaft 5 provided on the outside thereof.

[0084] The rolling bearing 1 is held in a housing 6. The housing 6 holds the inner ring 2 or the outer ring 3 of the rolling bearing 1.

[0085] A diagnostic device 7 is applied to the rolling bearing 1. The diagnostic device 7 is equipped with a function for diagnosing the condition of the rolling bearing 1, such as damage. The diagnostic device 7 may be a device included as part of a rotating device, such as an electric motor, in which the rolling bearing 1 is provided, or may be an external device applied from the outside to the rotating device. The diagnostic device 7 may be a device that is permanently installed on the rolling bearing 1 or the rotating device in which the rolling bearing 1 is provided, or may be a device that is temporarily installed as a portable device on the rolling bearing 1 or the rotating device in which the rolling bearing 1 is provided. The diagnostic device 7 includes a behavior sensor 8 and a control unit 9.

[0086] The behavior sensor 8 is attached to the inner ring 2, the outer ring 3, or the housing 6 that holds the inner ring 2 or the outer ring 3. The behavior sensor 8 is a sensor that measures the behavior of the rolling bearing 1, such as the inner ring 2, the outer ring 3, or the housing 6. The behavior sensor 8 is, for example, an acceleration sensor, a displacement sensor, or a speed sensor.

[0087] The control unit 9 is equipped with a function of performing information processing in the diagnostic device 7. The control unit 9 may be composed of one or more independent pieces of hardware, or may be a part of other hardware such as a control device for a rotating device in which the rolling bearing 1 is provided. The control unit 9 includes a calculation unit 14 and a diagnosis unit 11.

[0088] The calculation unit 14 is a part that includes a function of calculating an evaluation speed used for diagnosing the rolling bearing 1. The evaluation speed is calculated for a time longer than the period Tr of the natural vibration determined by the specifications of the rolling bearing 1. The evaluation speed is the maximum speed component in the direction in which the load from the rotating shaft 5 acts within that time. The direction in which the load from the rotating shaft 5 acts is, for example, a radially outward direction or a vertically downward direction. In this case, the opposite direction to the direction in which the load from the rotating shaft 5 acts is a radially inward direction or a vertically upward direction. Here, the direction in which the load from the rotating shaft 5 acts may be referred to as the load direction, and the opposite direction to the direction in which the load from the rotating shaft 5 acts may be referred to as the counter load direction. The calculation unit 14 may include some or all of the functions of the first calculation unit 10 and the second calculation unit 12 in the diagnosis device 7 according to other embodiments.

[0089] The calculation unit 14 calculates the evaluated speed by processing the output signal from the behavior sensor 8. For example, when the behavior sensor 8 is a speed sensor, the calculation unit 14 calculates the evaluated speed using time series data of the speed, which is an output signal from the behavior sensor 8. When the behavior sensor 8 is an acceleration sensor, the calculation unit 14 calculates the time series data of the speed by time integrating the time series data of the acceleration, which is an output signal from the behavior sensor 8. At this time, the calculation unit 14 calculates the evaluated speed using the calculated time series data of the speed. When the behavior sensor 8 is a displacement sensor, the calculation unit 14 calculates the time series data of the speed by time differentiating the time series data of the displacement, which is an output signal from the behavior sensor 8. At this time, the calculation unit 14 calculates the evaluated speed using the calculated time series data of the speed.

[0090] The calculation unit 14 calculates, as an evaluation speed, a maximum speed component in a direction in which the load from the rotating shaft 5 acts, from the time series data of the speed for a time period longer than a preset cycle Tr.

[0091] The diagnosis unit 11 is a part equipped with a function of diagnosing damage to the rolling bearing 1, using an evaluation index based on the evaluation speed calculated by the calculation unit 14. In this example, the diagnosis unit 11 diagnoses damage to the rolling bearing 1, using an evaluation index based on the evaluation speed calculated by the calculation unit 14 and the relative rotation speed between the inner ring 2 and the outer ring 3.

[0092] Next, an example of diagnosis of damage to the rolling bearing 1 by the diagnosis device 7 will be described with reference to Fig. 8. Fig. 8 is a diagram for explaining an example of diagnosis of damage to the rolling bearing 1 by the diagnosis device according to embodiment 9. In Fig. 8, a damaged part 100 is shown as an example of damage that can occur in the rolling bearing 1. The damaged part 100 occurs in the rolling bearing 1, for example, as follows.

[0093] In the rolling bearing 1 of this example, the rotating shaft 5 rotates counterclockwise on the paper together with the inner ring 2. At this time, each rolling element 4 in contact with the raceway surface of the inner ring 2 rotates and moves so as to revolve counterclockwise on the paper around the central axis of the rotating shaft 5 between the inner ring 2 and the outer ring 3 while rolling clockwise on the paper around the center point of the rolling element 4 itself as the inner ring 2 rotates. In other words, as the inner ring 2 rotates, the multiple rolling elements 4 between the inner ring 2 and the outer ring 3 rotate and move in the circumferential direction so as to revolve between the inner ring 2 and the outer ring 3 while rolling. Here, an example is shown in which the inner ring 2 rotates, but if the outer ring 3 is also rotating, as the outer ring 3 rotates or as both the inner ring 2 and the outer ring 3 rotate, the multiple rolling elements 4 between the inner ring 2 and the outer ring 3 rotate and move in the circumferential direction so as to revolve between the inner ring 2 and the outer ring 3 while rolling. The rolling speed of the rolling element 4 around its own center point is proportional to the relative rotation speed between the inner ring 2 and the outer ring 3. The circumferential rotational movement speed of the rolling element 4 around the central axis of the rotating shaft 5 is proportional to the relative rotation speed between the inner ring 2 and the outer ring 3 and to the diameter of the central locus of the rolling element 4 when it rotates in the circumferential direction so as to revolve around the central axis of the rotating shaft 5.

[0094] When the load on the inner ring 2 due to the load of the rotating shaft 5 acts downward on the paper, most of the load from the rotating shaft 5 is transmitted to the raceway surface of the outer ring 3 via the raceway surface of the inner ring 2 and the multiple rolling elements 4 located below the rotating shaft 5. When the rotating shaft 5 is stationary, the position and magnitude of the load generated on each of the inner ring 2, the outer ring 3, and the rolling elements 4 do not change. On the other hand, when the rotating shaft 5 is rotating, the position and magnitude of the load change periodically with the rotational movement of the inner ring 2 and the rolling elements 4. This causes repeated stress loads to act on the raceway surfaces of the inner ring 2, the outer ring 3, and the rolling elements 4. Such repeated stress loads may cause, for example, impurities inside the material to start as a crack, which may progress from the inside of the inner ring 2, the outer ring 3, or the rolling elements 4, and reach the surface. At this time, internally originating spalling damage, in which the surface layer peels off in a scale-like manner, may occur on the raceway surfaces of the inner ring 2, the outer ring 3, or the rolling elements 4.

[0095] Furthermore, insufficient lubrication of the raceway surface due to insufficient supply, deterioration, leakage, or insufficient viscosity of lubricants such as grease, as well as excessive load, may cause abnormal slippage between the rolling elements 4 and the inner ring 2 and the outer ring 3. In this case, stress may be easily concentrated on the surface of the raceway surface due to surface roughness and wear, which may accelerate damage to the raceway surface. As an example, surface-originating peeling damage, wear damage, or seizure damage, in which the surface layer of a portion of the raceway surface peels off in a scale-like pattern, may occur on the raceway surface.

[0096] For internally initiated spalling damage, there is a life design formula called the L10 life, and since the specifications of the rolling bearing 1 are usually determined based on that life design formula, there are few cases of internally initiated spalling damage. On the other hand, damage such as surface initiated spalling damage can occur much earlier than internally initiated spalling damage, so condition diagnosis of the rotating equipment in which the rolling bearing 1 is installed is important to ensure the reliability and long-term operation of the said rotating equipment.

[0097] According to findings obtained from bearing tests, the damaged portion 100 due to spalling damage is often formed on the raceway surface of the rolling bearing 1. The damaged portion 100 is often composed of a recessed portion 101 and a damaged corner portion 102. It is considered that the size and shape of the recessed portion 101 and the damaged corner portion 102 are constantly changing according to the total number of rotations, which is the cumulative number of relative rotations between the inner ring 2 and the outer ring 3 of the rolling bearing 1. It has also been confirmed that as the total number of rotations of the rolling bearing 1 increases, the recessed portion 101 becomes larger, while the damaged corner portion 102 may have a sharp shape in the early stage of damage occurrence, but may later change to a smooth shape due to wear or the like. When the damaged portion 100 is due to damage such as surface-originating spalling damage, the depth of the recessed portion 101 is shallow in the early stage of damage occurrence, so that as the damage progresses, the recessed portion 101 becomes larger in the axial and circumferential directions and also becomes deeper in the radial direction.

[0098] Although the sharp shape of the damaged corner 102 may lead to a momentary increase in vibration or impact, it does not lead to a large rattle of the entire rotating device, so the impact of the damaged corner 102 on the life of the rolling bearing 1 and the rotating device in which the rolling bearing 1 is provided is small. In addition, the shape of the damaged corner 102 changes sensitively due to wear and tear, so it is not suitable for use in diagnosis. On the other hand, the recessed portion 101 becomes larger as the total number of rotations of the rolling bearing 1 increases, which may lead to a continuous increase in rattle, vibration, or abnormal noise of the rolling bearing 1 and the peripheral devices of the rolling bearing 1, and the entire rotating device in which the rolling bearing 1 is provided. For this reason, the size of the recessed portion 101 has a significant impact on the life of the rolling bearing 1 and the entire rotating device in which the rolling bearing 1 is provided, so diagnosing the size of the recessed portion 101 also leads to diagnosing the life of the entire rotating device.

[0099] For example, as shown in FIG. 1, consider a case where a recessed portion 101 is formed on the load side of an outer ring 3 in an inner ring rotating rolling bearing 1 in which an inner ring 2 rotates with a rotating shaft 5. If the recessed portion 101 becomes large, the rolling element 4 sinks into the recessed portion 101 at the timing when the rolling element 4 reaches the recessed portion 101 during the rotation of the rolling bearing 1. At this time, the rolling element 4 falls in the depth direction of the recessed portion 101 together with the inner ring 2 and the rotating shaft 5. Furthermore, at the timing when the rolling element 4 leaves the recessed portion 101, the rolling element 4 rises from the bottom of the recessed portion 101 together with the inner ring 2 and the rotating shaft 5. For this reason, the deeper the recessed portion 101, the greater the rattle, vibration, and abnormal noise of the rolling bearing 1 and the rotating shaft 5. If the recessed portion 101 becomes too deep, the rattle, vibration, and abnormal noise of the rolling bearing 1 and the rotating shaft 5 may become extremely large. In this case, the design upper limit of the rotating device in which the rolling bearing 1 is provided may be exceeded. This may also lead to failures such as cracking or breaking of the rolling bearing 1, failures of peripheral devices of the rolling bearing 1, and failures of the entire rotating device in which the rolling bearing 1 is provided.

[0100] For this reason, diagnosing the size or extent of damage to the rolling bearing 1, such as the depth of the recessed portion 101, is important in diagnosing the condition, damage state, and lifespan of the rotating equipment. Diagnosing the condition of the rolling bearing 1 makes it possible to detect abnormalities in the rolling bearing 1 and estimate the remaining lifespan, and perform maintenance and life extension measures such as replacing the rolling bearing 1 or grease at an appropriate time. This also makes it possible to reduce the maintenance effort and operate the rolling bearing 1, the peripheral equipment of the rolling bearing 1, and the entire rotating equipment in which the rolling bearing 1 is installed, stably for a long time.

[0101] For example, the diagnostic device 7 performs diagnosis on the damaged part 100 as shown in Fig. 8 as follows. Note that Fig. 8 shows an example in which the damaged part 100 occurs on the outer ring 3, but the damaged part 100 may occur on the inner ring 2 or the rolling element 4.

[0102] The calculation unit 14 calculates the evaluation speed for a time longer than the period Tr of the natural vibration determined by the specifications of the rolling bearing 1. The natural vibration here includes not only the vibration generated when the rolling element 4 passes over the damaged portion 100 that has occurred in the outer ring 3 as shown in Fig. 2, but also the vibration generated when the rolling element 4 passes over the damaged portion 100 that has occurred in the inner ring 2, and the vibration generated when the inner ring 2 and the outer ring 3 pass over the damaged portion 100 that has occurred in the rolling element 4. Here, the period Tr of the natural vibration resulting from the damage to the inner ring 2 is defined as Tr i [sec], the period of the natural vibration caused by the damage of the outer ring 3 is Tr o [sec], and the period of the natural vibration resulting from the damage to the rolling element 4 is Tr b When the inner ring 2 is damaged, the period Tr i When the outer ring 3 is damaged, the natural vibration of o When the rolling element 4 is damaged, the natural vibration of the period Tr b For example, when there is a damaged portion 100 on the outer ring 3 as shown in FIG. 8, the period from when the rolling element 4a passes over the damaged portion 100 until when the rolling element 4b passes over the damaged portion 100 is equal to the period Tr. o For example, the diameter of the rolling element 4 is d [mm], the diameter of the central locus of the rolling element 4 is D [mm], the number of rolling elements 4 is Z, the contact angle of the rolling element 4 is α [rad], and the relative rotation speed between the inner ring 2 and the outer ring 3 is f s [rps], the natural vibration period Tr i is the following equation (4), and the natural vibration period Tr o is the following equation (5), and the natural vibration period Tr b are expressed by the following formula (6): Here, the contact angle α of the rolling element 4 is the angle between a line connecting the contact point of the inner ring 2 and the rolling element 4 and the contact point of the rolling element 4 and the outer ring 3 on a cross section along the axial direction of the rotating shaft 5, and a line perpendicular to the central axis of the rotating shaft 5 on the same cross section.

[0103]

number

[0104]

number

[0105]

number

[0106] In this way, the natural vibration period Tr determined by the specifications of the rolling bearing 1 and the relative rotation speed of the inner ring 2 and the outer ring 3 is Tr in equation (4) when the inner ring 2 is damaged. i If the outer ring 3 is damaged, Tr in formula (5) o If the rolling element 4 is damaged, Tr b Regardless of whether any of the rings is damaged, the natural vibration period Tr can be calculated as the period of the relative rotational speed f s It can be determined using the diameter d of the rolling element 4, the diameter D of the central locus of the rolling element 4, and the contact angle α of the rolling element 4.

[0107] From the relationship between the numerator and denominator of each equation, for example, the natural vibration period Tr when the inner ring 2 is damaged is i The following can be seen for the period Tr i is the relative rotation speed f s As the period Tr increases, it becomes shorter in inverse proportion to the period Tr. i The period Tr becomes shorter in inverse proportion to the number Z of rolling elements 4. i The period Tr becomes longer as the diameter D of the central path of the rolling element 4 becomes larger. i The period Tr becomes shorter as the diameter d of the rolling element 4 becomes larger. i The larger the contact angle α, the longer the natural vibration period Tr o The following can be seen for the period Tr o is the relative rotation speed f s As the period Tr increases, it becomes shorter in inverse proportion to the period Tr. o The period Tr becomes shorter in inverse proportion to the number Z of rolling elements 4.o The period Tr becomes shorter as the diameter D of the central locus of the rolling element 4 becomes larger. o The period Tr becomes longer as the diameter d of the rolling element increases. o The larger the contact angle α, the shorter the natural vibration period Tr b The following can be seen for the period Tr b is the relative rotation speed f s As the period Tr increases, it becomes shorter in inverse proportion to the period Tr. b The larger the contact angle α, the shorter the period Tr. In addition, the diameter D of the central path of the rolling element 4 and the diameter d of the rolling element appear in both the numerator and the denominator of the formula (6). If we consider that the influence of the squared term in the denominator is greater than the influence of the cross term in the numerator, b In many cases, the greater the diameter D of the central locus of the rolling element 4, the shorter the length becomes, and the greater the diameter d of the rolling element 4, the longer the length becomes.

[0108] In addition, the relative rotation speed f s can be given in various ways depending on the rotation pattern of the rolling bearing 1. For example, as shown in FIG. 7, when the outer ring 3 is fixed and the inner ring 2 rotates integrally with the rotating shaft 5, the relative rotation speed f s can be given as the rotation speed of the inner ring 2 or the rotation speed of the rotating shaft 5. In addition, when the inner ring 2 is fixed and the outer ring 3 rotates integrally with the rotating shaft, the relative rotation speed f s can be given as the rotation speed of the outer ring 3 or the rotation speed of the rotating shaft. In addition, when the inner ring 2 and the outer ring 3 are integral with different rotating shafts and rotate in the same direction, the relative rotation speed f s can be given as the absolute value of the difference between the rotation speed of the inner ring 2 and the rotation speed of the outer ring 3. In addition, when the inner ring 2 and the outer ring 3 are integral with different rotating shafts and rotate in opposite directions, the relative rotation speed f s can be given as the sum of the rotation speed of the inner ring 2 and the rotation speed of the outer ring 3.

[0109] Next, an example of diagnosis based on the equation of motion when the rolling element 4 sinks into the recessed portion 101 will be shown.

[0110] 9, the equation of motion when the rolling element 4 sinks into the recessed portion 101 is solved to calculate the depth h [mm] of the recessed portion 101. FIG. 9 is a diagram for explaining an example of the behavior of the rolling element 4 of the rolling bearing 1 when it passes through the damaged portion 100.

[0111] Here, the diameter of the rolling element 4 is d, the diameter of the center path of the rolling element 4 when the rolling element 4 rotates and moves around the central axis of the rotating shaft 5 between the inner ring 2 and the outer ring 3 in a counterclockwise direction on the paper surface is D [mm], and the number of rotations of the rolling element 4 in the revolution direction is f o The time from when the rolling element 4 starts to sink into the recess 101 until it collides with the surface of the recess 101 is t [sec], the average speed of the rolling element 4 within the time t is V [mm / sec], and the average speed in the radial direction of the rolling element 4 within the time t is V r [mm / sec], and the average circumferential speed of the rolling element 4 during the time t is V θ [mm / sec], the circumferential movement distance of the rolling element 4 during that time t is s [mm], and the angle that the central locus line of the rolling element 4 during that time t makes with the radial line connecting the center of the rotating shaft 5 and the center of the rolling element 4 is β [rad].

[0112] The depth h [mm] of the recessed portion 101 is calculated by the following formula (7) based on the trigonometric function, and is expressed as the circumferential velocity V of the rolling element 4. θ is expressed by the following equation (8).

[0113]

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[0114]

number

[0115] When the radial load acting on the rolling element 4 is sufficiently large, the time t from when the rolling element 4 starts to sink into the recessed portion 101 to when it collides with the surface of the recessed portion 101 is equal to or greater than the radial velocity V rThe time required for the rolling element 4 to travel the depth h of the recessed portion 101 and the rolling element 4 to travel at a circumferential speed V θ This coincides with the time required for the rolling element 4 to travel the circumferential distance s. Therefore, by using equations (7) and (8), the radial velocity V r is expressed by the following equation (9).

[0116]

number

[0117] Further rearrangement of equation (9) gives the following equation (10).

[0118]

number

[0119] Here, the restitution coefficient when the rolling element 4 sinks into the recessed portion 101 and collides with it is e, and the radial velocity of the structure moving in conjunction with the recessed portion 101 before the collision is Vo. r [mm / sec], and the radial velocity of the structure moving in conjunction with the recessed portion 101 immediately after the collision is Vo r ´ [mm / sec], the radial velocity of the rolling element 4 after the collision is V r ´ [mm / sec], the relationship between each velocity during rebound is expressed by the following equation (11).

[0120]

number

[0121] In addition, the mass of all the structures including the rolling element 4, the inner ring 2, and the rotating shaft 5 that apply a load to the recessed portion 101 via the rolling element 4 is m [kg], and the mass of the structure that moves in conjunction with the recessed portion 101 is m o [kg], according to the law of conservation of momentum, the relationship between each speed can also be expressed as the following equation (12).

[0122]

number

[0123] Here, the radial velocity Vo of the recessed portion 101 before the collision r Using equations (11) and (12), V r Vo r Calculate the relational expression expressed by ´ and V in equation (10) r Substituting this into the equation, we obtain the following equation (13).

[0124]

number

[0125] Here, by substituting formula (13) into formula (7), the depth h of the recessed portion 101 is expressed by the following formula (14).

[0126]

number

[0127] Here, the relative rotation speed between the inner ring 2 and the outer ring 3 is f s [rps], the contact angle of the rolling element 4 is α [rad], the rotational speed of the rolling element 4 in the revolution direction is f o [rps] is expressed by the following equation (15).

[0128]

number

[0129] The number of revolutions of the rolling element 4 in the revolution direction when there is little slippage, f o The result is generally the same as that obtained by equation (15). By substituting equation (15) into equation (14) and substituting a constant determined by each mass and the shape and dimensions of rolling bearing 1 as coefficient A, the depth h of recessed portion 101 is expressed by the following equation (16).

[0130]

number

[0131] Here, while the rolling element 4 moves a distance h in the radial direction, the rolling element 4 moves a distance s in the circumferential direction. Therefore, the circumferential movement distance s can be expressed by the following equation (17) from Pythagoras' theorem.

[0132]

number

[0133] Furthermore, sin β used in equation (16) is expressed by the following equation (18) from a trigonometric formula using the circumferential movement distance s.

[0134]

number

[0135] By substituting equation (18) into equation (16) and rearranging, the depth h of the recessed portion 101 is expressed by the following equation (19).

[0136]

number

[0137] The radial velocity Vo of the outer ring 3 or the housing 6 that holds the outer ring 3, which is one of the structures that moves in conjunction with the recessed portion 101 r ' becomes maximum immediately after the collision between the rolling element 4 and the recessed portion 101. Therefore, the radial velocity Vo r ' corresponds to the evaluated speed, which is the maximum speed component in the direction of the load acting on the rolling bearing 1 from the rotating shaft 5 that rotates integrally with the inner ring 2 or outer ring 3. From equation (19), the diameter d of the rolling element 4, the diameter D of the central locus of the rolling element 4, the mass of the entire structure including the rolling element 4, the inner ring 2, and the rotating shaft 5 that applies a load to the recessed portion 101 via the rolling element 4 is m, the corresponding load acting on the rolling bearing 1 from the rotating shaft 5, and the mass of the structure that moves in conjunction with the recessed portion 101 is m o And so on, the evaluation speed Vo r ´ is the relative rotation speed f sRelative evaluation speed (Vo r ´ / f s ) the depth h of the recessed portion 101 can be calculated.

[0138] In addition, from equation (19), the relative evaluation speed (Vo r ´ / f s The greater the relative evaluation velocity (Vo r ´ / f s ) is the same, the mass m of the structure that moves in conjunction with the recessed portion 101 o The greater the value obtained by dividing by the mass m, the greater the depth h of the recessed portion 101 can be diagnosed. Here, mass m is the mass of all structures including the rolling elements 4, the inner ring 2, and the rotating shaft 5, which are structures that apply a load to the recessed portion 101 via the rolling elements 4. In addition, from the relationship between the numerator and denominator of formula (19), the relative evaluation speed (Vo r ´ / f s When the relative evaluation speed (Vo r ´ / f s ) is the same, it can be determined that the smaller the restitution coefficient e when the rolling element 4 sinks into the recessed portion 101 and collides, the greater the depth h of the recessed portion 101.

[0139] The restitution coefficient e is related to the hardness of the material, and when two materials with high hardness collide with each other, the restitution coefficient e often becomes large. For this reason, the relative evaluation speed (Vo r ´ / f s), the lower the hardness of the rolling element 4 and the outer ring 3 having the recessed portion 101, the greater the depth h of the recessed portion 101. In addition, since the logarithm of the material hardness and the restitution coefficient are often proportional to each other, the restitution coefficient can be calculated based on the logarithm of the material hardness, and the depth h of the recessed portion 101 can be diagnosed using formula (19). In addition, bearing steel is often used as the material of the rolling element 4 and the outer ring 3 having the recessed portion 101, and the depth h of the recessed portion 101 can be diagnosed based on the restitution coefficient e between the bearing steels or the hardness of the bearing steel. On the other hand, there are also cases where a material such as ceramic is used for the rolling element 4 in the rolling bearing 1. For this reason, it is necessary to consider the effect of differences in materials on vibration in damage diagnosis using vibration information. According to the configuration of the ninth embodiment, even if the material of the rolling bearing 1 is changed, damage can be diagnosed with high accuracy based on the restitution coefficient e or hardness of the changed material.

[0140] Here, the structure that moves in conjunction with the recessed portion 101 is, for example, the outer ring 3 and the housing 6 that holds the outer ring 3. The speed of the outer ring 3 and the housing 6 is small before the rolling element 4 collides with the recessed portion 101, and immediately after the collision, the speed of the outer ring 3 and the housing 6 increases to a speed Vo in the load direction. r According to the configuration of the ninth embodiment, the behavior sensor 8 and the calculation unit 14 provided on the outer ring 3 or the housing 6 holding the outer ring 3 calculate the velocity Vo in the load direction immediately after the rolling element 4 collides with the recessed portion 101. r ' is calculated as the evaluation speed. For this purpose, for example, the diagnosis unit 11 of the control unit 9 calculates the evaluation speed and the relative rotation speed f s The depth h of the recessed portion 101 of the rolling bearing 1 can be diagnosed with high accuracy by using an evaluation index based on the above.

[0141] Furthermore, regardless of whether the damaged portion 100 occurs on the inner ring 2, the outer ring 3, or the rolling element 4, the behavior of the rolling element 4 sinking into the recessed portion 101 of the damaged portion 100 occurs at least once within a time period longer than the period Tr of each natural vibration. The period Tr of each natural vibration can be calculated in advance using equations (4) to (6). Therefore, the period Tr of the natural vibration when damage occurs on the inner ring 2 can be calculated by i and the natural vibration period Tr when damage occurs to the outer ring 3. o and the natural vibration period Tr when damage occurs to the rolling element 4. b Among these, the longest period can be determined and adopted. The control unit 9 acquires an evaluation speed, which is the maximum speed component in the direction of the load acting on the rolling bearing 1 from the rotating shaft 5 rotating integrally with the inner ring 2 or the outer ring 3, within a time period longer than the longest period adopted, by a behavior sensor 8 attached to the inner ring 2, the outer ring 3, or the housing 6. The diagnosis unit 11 of the control unit 9 diagnoses damage to the rolling bearing 1 using an evaluation index based on the evaluation speed and the relative rotation speeds of the inner ring 2 and the outer ring 3, thereby making it possible to accurately diagnose the damage even when it is unclear in which position the damage will occur.

[0142] The revolution period To of the rolling element 4 when the rolling element 4 rotates so as to revolve around the central axis of the rotation shaft 5 in the circumferential direction is expressed by the following equation (20).

[0143]

number

[0144] The revolution period To of the rolling element 4 is the relative rotation speed f s The revolution period To can be determined by the diameter d of the rolling element 4, the diameter D of the central locus of the rolling element 4, and the contact angle α of the rolling element 4. The revolution period To is the natural vibration period Tr when the outer ring 3 is damaged. o is the same as the value obtained by multiplying the number of rolling elements 4, Z, by the number of rolling elements 4. In addition, the following can be seen regarding the revolution period To of the rolling elements 4. The revolution period To is calculated by multiplying the relative rotation speed f sThe orbital period To becomes shorter in inverse proportion to the contact angle α. The orbital period To becomes shorter as the diameter D of the central locus of the rolling elements 4 becomes larger. The orbital period To becomes longer as the diameter d of the rolling elements 4 becomes larger. The orbital period To becomes shorter as the contact angle α becomes larger. In addition, the rotation period of the cage that rotates together with the rolling elements 4 while maintaining the spacing between the multiple rolling elements 4 that rotate and move so as to revolve around the central axis of the rotating shaft 5 between the inner ring 2 and the outer ring 3 is also almost the same as the orbital period To of the rolling elements 4 shown in equation (20).

[0145] The rolling element 4, which rotates in the circumferential direction so as to revolve between the inner ring 2 and the outer ring 3, receives a load from the rotating shaft 5 in a circumferential region defined as a loaded region, and the other region defined as a non-loaded region. In this case, if a damaged portion 100 occurs in the inner ring 2 or the rolling element 4, the rolling element 4 sinks into the recessed portion 101 only when the damaged portion 100 is in the loaded region, and the evaluation index increases. In other words, if the damaged portion 100 occurs in the inner ring 2, the rotational speed f of the rotating shaft 5, which rotates integrally with the inner ring 2, s The rotation period (1 / f s ) during the time when the damaged part 100 is in the load zone, the natural vibration period Tr, which can be calculated using equation (4), i On the other hand, when the damaged part 100 occurs in the rolling element 4, the evaluation index becomes large at the timing of the natural vibration period Tr, which can be calculated by the formula (4), during the time when the damaged part 100 is in the load range in the revolution period To of the rolling element 4. i The evaluation index becomes larger at the timing. The contact angle α takes values ​​in the range from 0 to 90 deg, and the diameter d of the rolling element 4 never becomes larger than the diameter D of the central locus of the rolling element 4. For this reason, the factor in the parentheses on the right-hand side of equation (20) is always 1 or greater. Therefore, from equation (20), the revolution period To of the rolling element 4 is calculated as the rotation period of the rotating shaft 5 (1 / f s) is always longer than the orbital period To of the rolling element 4. In other words, the evaluation index becomes large at least once within a time longer than the orbital period To of the rolling element 4. The control unit 9 acquires the evaluation speed from the measurement results of the behavior sensor 8 within a time longer than the orbital period To of the rolling element 4. For this reason, by diagnosing damage to the rolling bearing 1 using an evaluation index based on the evaluation speed and the relative rotational speeds of the inner ring 2 and the outer ring 3, the control unit 9 including the diagnoser 11 can accurately diagnose damage even when it is unclear at which position the damage will occur.

[0146] Also, for example, when the relative rotational speed of the inner ring 2 and the outer ring 3 is accelerating or decelerating, the control unit 9 may obtain the evaluated speed from the measurement results of the behavior sensor 8 attached to the housing 6 within a time longer than the period Tr of the natural vibration and within a time in which the maximum value of the relative rotational speed of the inner ring 2 and the outer ring 3 is within a range of 1.2 times the minimum value. s The time change of is kept small, and the relative rotation speed f is constant. s Equation (19) approximately holds true from equation (7) which assumes that. Therefore, by diagnosing damage to the rolling bearing 1 using an evaluation index based on the evaluation speed and the relative rotational speed of the inner ring 2 and the outer ring 3, the control unit 9 including the diagnosing unit 11 can accurately diagnose damage even when the relative rotational speed of the inner ring 2 and the outer ring 3 is accelerating or decelerating.

[0147] In addition, the depression 101 often expands in the axial and circumferential directions as its radial depth increases. Therefore, the diagnostic device 7 can diagnose the depth of the depression 101, thereby diagnosing the extent of damage, such as the size and volume of the depression 101.

[0148] Generally, rolling bearings are the parts of rotating equipment that are most heavily loaded and are prone to failure first. When damage occurs to a rolling bearing, the stress around the damage may increase, causing the damage to grow at an accelerated rate. When the damage grows, it may result in the destruction of the rolling bearing, damage or destruction of the equipment surrounding the rolling bearing, and serious failure of the entire rotating equipment in which the rolling bearing is installed.

[0149] In contrast, the diagnostic device 7 can diagnose damage to the rolling bearing 1 with high accuracy, enabling preventive maintenance of the rolling bearing 1. This makes it possible to prevent failures not only in the rolling bearing 1 itself, but also in peripheral equipment of the rolling bearing 1 and the entire rotating equipment in which the rolling bearing 1 is provided.

[0150] Furthermore, the diagnosis unit 11 can, for example, diagnose that damage has occurred in the rolling bearing 1 when the evaluated speed exceeds a preset threshold value, and diagnose that severe damage has occurred when the evaluated speed exceeds an even higher threshold value. The diagnosis unit 11 can also diagnose the extent of damage, such as the depth, size, and volume of the damaged part 100, according to the value of the evaluated speed.

[0151] The rolling bearing 1 according to the ninth embodiment has been described by taking as an example a configuration in which the inner ring 2 rotates integrally with the rotating shaft 5, and the outer ring 3 is held and fixed to the housing 6. On the other hand, even in a configuration in which the inner ring 2 is held and fixed to the housing 6, and the outer ring 3 rotates integrally with the rotating shaft 5 provided on the outside thereof, the equations of motion when the rolling element 4 sinks into the recessed portion 101, equations (7) to (19), hold true at least relatively. For this reason, the diagnosis device 7 uses the behavior sensor 8 provided on the inner ring 2 or the housing 6 that holds the inner ring 2 to calculate an evaluation speed that is the maximum speed component in the direction of the load acting on the rolling bearing 1 from the rotating shaft 5 that rotates integrally with the outer ring 3, and can diagnose damage to the rolling bearing 1 using an evaluation index based on the evaluation speed and the relative rotation speeds of the inner ring 2 and the outer ring 3.

[0152] As described above, the rolling bearing 1 according to the ninth embodiment includes the inner ring 2, the outer ring 3, a plurality of rolling elements 4, and the diagnostic device 7. The outer ring 3 is arranged concentrically with the inner ring 2. The plurality of rolling elements 4 are arranged between the raceway surface of the outer ring 3 and the raceway surface of the inner ring 2. Each rolling element 4 rolls with the rotation of the inner ring 2 or the rotation of the outer ring 3. In the rolling bearing 1, the rotating shaft 5 rotates integrally with the inner ring 2 or the outer ring 3. The diagnostic device 7 includes a behavior sensor 8, a calculation unit 14, and a diagnosis unit 11. The behavior sensor 8 is provided in the housing 6 that holds the outer ring 3 or the outer ring 3, and measures the behavior of the outer ring 3 or the housing 6. The calculation unit 14 calculates the evaluated speed based on the information acquired by the behavior sensor 8. The evaluation speed is the maximum speed component in the direction in which the load from the rotating shaft 5 acts within a time period longer than or equal to the period Tr of the natural vibration determined by the specifications of the rolling bearing 1. The diagnosing unit 11 diagnoses damage to the rolling bearing 1 by using an evaluation index based on the evaluation speed and the relative rotation speed calculated by the calculating unit 14.

[0153] As a comparative example, let us consider a case where diagnosis is made based on the impact value from the vibration sensor, the size of the rolling bearing, and the relative rotation speed, without depending on the evaluation speed as in the diagnosis device 7. The impact value is expressed in the same unit [mm / sec 2 ].

[0154] In the comparative example, although the relationship between the velocities during rebound can be obtained as in Equation (11), the relationship between the impact values ​​cannot be obtained. The radial velocity Vo of the outer ring or housing that is maximum immediately after the collision between the rolling element and the recessed portion is r However, it is not possible to obtain a relational expression based on the physical phenomenon between the impact value and the depth h of the dent shape using the impact value from the vibration sensor, the rolling bearing size, and the relative rotation speed, so it is difficult to diagnose the damage with high accuracy.

[0155] In addition, the surface of the damaged part of the rolling bearing is often rough, so when the rolling element passes through the damaged part, small impacts are often generated in multiple steps. Therefore, even if the damaged part becomes larger, the impact value does not increase, so that the damage cannot be accurately diagnosed by the comparative example that uses only the impact value.

[0156] In addition, since the impact value increases due to an instantaneous change in behavior, it is not necessarily the case that the behavior of the rolling element sinking into the recessed portion of the damaged portion that increases the impact value, but it often increases significantly due to minor shape changes such as surface roughness or damaged corners. Therefore, even if the comparative example can diagnose a continuous increase in rattle, vibration, or abnormal noise of the rolling bearing, peripheral equipment of the rolling bearing, or the entire rotating equipment in which the rolling bearing is provided, and minor shape changes that are not directly related to the remaining life of the rolling bearing and the entire rotating equipment, it is not suitable for diagnosing the size of the recessed portion that is directly related to the remaining life.

[0157] For example, when the damaged corner of the damaged part becomes smooth due to wear, the rolling element passes through the damaged part smoothly, so that the effect of the damaged part does not appear in the impact value and the damage is not detected. In addition, for example, even if the dent shape of the damaged part is small, the impact value may become large when the rolling element passes through the damaged corner, for example, when the dent shape of the damaged part is sharp. At this time, vibrations may occur in which the acceleration in the load direction and the anti-load direction, etc., momentarily increase alternately. As a result, the acceleration amplitude and the impact value may increase regardless of the size of the dent shape, so that it may be difficult in the comparative example to accurately diagnose the degree of the damage itself, such as the size of the dent shape of the damaged part.

[0158] The impact of the rolling bearing may also include vibrations in the high frequency band caused by frictional sliding. Therefore, the magnitude of the impact may change depending on the lubrication state of the rolling bearing. For example, if the lubrication state deteriorates due to oxidation degradation, oil separation, leakage, or thickener destruction of the grease lubricating the rolling bearing, the impact may become several times larger even if the rolling bearing itself is not damaged. In this way, a diagnosis based only on the impact value is affected by changes in the lubrication state of the rolling bearing, and the accuracy of the diagnosis of damage to the rolling bearing may decrease in the comparative example.

[0159] On the other hand, the diagnostic device 7 performs diagnosis using an evaluation index based on the evaluated speed, which is the maximum speed component in the load direction at the timing when the rolling element 4 sinks into the recessed portion 101, and the relative rotation speed. The instantaneous behavior that occurs when the rolling element 4 passes through the damaged corner 102 appears as an instantaneous acceleration amplitude. When such an instantaneous acceleration change is integrated over time, the acceleration that momentarily reverses its direction from positive to negative is offset by the integration, so the speed that occurs when the rolling element 4 passes through the damaged corner 102 does not increase. On the other hand, at the timing when the rolling element 4 sinks into the recessed portion 101, the direction of the acceleration continues to face the load direction, so the evaluated speed, which is the maximum speed component in the load direction obtained by integration, becomes sufficiently large. In other words, the diagnostic device 7 according to the ninth embodiment, which performs diagnosis using the evaluated speed, can diagnose the size of the recessed portion 101 with high accuracy by suppressing the influence of the instantaneous behavior of the rolling element 4 due to the shape of the damaged corner 102. Also, the greater the depth of the recessed portion 101, the greater the maximum speed component in the load direction. In this way, the diagnostic device 7 using the evaluation speed that is highly correlated with the depth of the indentation shape 101 can diagnose the extent of the depth of the indentation shape 101. Furthermore, as the indentation shape 101 becomes deeper in the radial direction, it often also expands in the axial and circumferential directions. Therefore, by diagnosing the depth of the indentation shape 101, the diagnostic device 7 can diagnose the extent of damage, such as the size and volume of the indentation shape 101.

[0160] In addition, the evaluation speed is high due to the geometric shape of the recessed portion 101. Therefore, unlike devices that perform diagnosis using vibrations including high frequency bands caused by frictional sliding, the diagnosis device 7 can diagnose damage to the rolling bearing 1 with high accuracy by suppressing the influence of disturbances such as lubrication state and disturbance vibration.

[0161] Embodiment 10 An example of diagnosing damage to a rolling bearing 1 by a diagnosing device 7 according to embodiment 10 will be described. In the diagnosing device 7 according to embodiment 10, a diagnosing unit 11 diagnoses damage to the rolling bearing 1 by using a relative evaluation speed obtained by dividing an evaluation speed by a relative rotation speed as an evaluation index.

[0162] The inventors conducted extensive research using data from multiple actual products and test data, and came to the conclusion that even in the same damaged state, the evaluation speed increases in proportion to the relative rotation speed. In other words, in order to evaluate and compare the extent of damage to the rolling bearing 1 under conditions of different relative rotation speeds, it is necessary to make a diagnosis taking into account the influence of the relative rotation speed as well as the evaluation speed. In the diagnosis device 7 according to the tenth embodiment, by using the relative evaluation speed obtained by dividing the evaluation speed by the relative rotation speed as an evaluation index, it becomes possible to accurately diagnose the extent of damage to the rolling bearing 1 regardless of the relative rotation speed.

[0163] An example of diagnosis using the equation of motion when the rolling element 4 sinks into the recessed portion 101 is shown below. The evaluation speed Vo on the right side of the equation (19) is r ´ is the relative rotation speed f of the rotating shaft 5 s Relative evaluation speed (Vo r ´ / f s ) is used as an evaluation index, the depth h of the recessed portion 101 is determined by a constant determined by the masses and the shape and dimensions of the rolling bearing 1, and a relative evaluation speed (Vo r ´ / f s ) can be calculated using the evaluation index. In other words, the relative evaluation speed (Vo r ´ / f s), the diagnostic device 7 is able to determine the depth h of the recessed portion 101 for the rolling bearing 1. Furthermore, as the radial depth of the recessed portion 101 increases, the recessed portion 101 often also expands in the axial and circumferential directions. For this reason, the diagnostic device 7 can diagnose the degree of damage to the recessed portion 101 by diagnosing the depth h of the recessed portion 101. In other words, the relative evaluation speed (Vo r ´ / f s ) can be used to diagnose the extent of damage to rolling bearings.

[0164] There are cases where the relative rotation speed between the inner ring 2 and the outer ring 3 during the time interval in which the evaluation speed used for diagnosis is measured can be known in advance as a design item without measuring it. In this case, the diagnosis device 7 can diagnose damage to the rolling bearing 1 using the evaluation speed during that time interval and an evaluation index based on the known relative rotation speed.

[0165] Furthermore, even if the absolute value of the relative rotation speed is not known in advance, if the magnification of each relative rotation speed in two or more time intervals is known, the diagnostic device 7 can diagnose damage to the rolling bearing 1 based on an evaluation index obtained by dividing the evaluated speed in each time interval by the corresponding magnification. For example, the evaluated speed in time interval A in which the total rotation speed of the rolling bearing 1 is small is Va, and the evaluated speed in time interval B in which the total rotation speed of the rolling bearing 1 is large is Vb. If it is known that the relative rotation speed in time interval A is twice as large as the relative rotation speed in time interval B, the diagnostic device 7 can diagnose damage to the rolling bearing 1 by setting the evaluation index in time interval A to Va and the evaluation index in time interval B to Vb / 2. For example, if the difference between Vb / 2 and Va is smaller than a preset range, the diagnostic device 7 can diagnose that the damage is not increasing with an increase in the total rotation speed of the rolling bearing 1. On the other hand, if Vb / 2 is larger than Va, the diagnostic device 7 can diagnose that the damage is increasing with an increase in the total rotation speed of the rolling bearing 1. Furthermore, for example, when it is known that there is almost no difference between the relative rotation speed in time interval A and the relative rotation speed in time interval B, the diagnostic device 7 can diagnose damage to the rolling bearing 1 by setting the evaluation index in time interval A to Va and the evaluation index in time interval B to Vb. For example, when the difference between Vb and Va is smaller than a preset range, the diagnostic device 7 can diagnose that the damage is not increasing with an increase in the total rotation speed of the rolling bearing 1. On the other hand, when Vb is larger than Va, the diagnostic device 7 can diagnose that the damage is increasing with an increase in the total rotation speed of the rolling bearing 1.

[0166] Embodiment 11 An example of diagnosing damage to a rolling bearing 1 by a diagnosing device 7 according to embodiment 11 will be described. In the diagnosing device according to embodiment 11, a diagnosing unit 11 diagnoses the extent of damage to the rolling bearing 1 based on an evaluation index and an inherent coefficient of the rolling bearing 1.

[0167] The inventors conducted extensive research using data from multiple actual products and test data, and came to the deduction that even in the same damaged state, the evaluation index changes when the intrinsic coefficient of the rolling bearing 1 changes depending on the type of the rolling bearing 1 or the conditions of use. In other words, in order to evaluate and compare the extent of damage to the rolling bearing 1 under conditions where the intrinsic coefficients of the rolling bearing 1 are different, it is necessary to make a diagnosis taking into account the influence of the intrinsic coefficient of the rolling bearing 1. The diagnosis device 7 according to the eleventh embodiment can accurately diagnose the extent of damage to the rolling bearing 1 by using the evaluation index and the intrinsic coefficient of the rolling bearing 1.

[0168] Furthermore, the inventors have conducted extensive studies using data from multiple actual products and test data, and have come to the deduction that even if the extent of damage to the rolling bearing 1 does not change, the evaluation index increases according to the shape or size of the rolling bearing 1. In other words, in order to evaluate and compare the extent of damage to the rolling bearing 1 under conditions in which the shape or size of the rolling bearing 1 differs, it is necessary to make a diagnosis taking into consideration the influence of the shape or size of the rolling bearing 1. In the diagnosis device according to the eleventh embodiment, by using the evaluation index and a characteristic coefficient determined based on the shape or size of the rolling bearing 1, it becomes possible to accurately diagnose the extent of damage to the rolling bearing 1.

[0169] An example of diagnosis using the equation of motion when the rolling element 4 sinks into the recessed portion 101 is shown. The calculation unit 14 calculates the characteristic coefficient of the rolling bearing 1 and the relative evaluation speed (Vo r ´ / f s ), the depth h of the recessed portion 101 can be calculated using equation (19) or the like. The specific coefficients of the rolling bearing 1 are, for example, the diameter d of the rolling element 4, the diameter D of the central locus of the rolling element 4, the mass m of the entire structure including the rolling element 4, the inner ring 2, and the rotating shaft 5 which are structures that apply a load to the recessed portion 101 via the rolling element 4, the corresponding load acting on the rolling bearing 1 from the rotating shaft 5, and the mass m of the structure that moves in conjunction with the recessed portion 101, which appear on the right side of equation (19). oThe diagnostic unit 11 of the diagnostic device 7 includes, for example, a relative evaluation speed (Vo r ´ / f s ), the greater the evaluation index, the greater the depth h of the recessed portion 101. Furthermore, from equation (19), the diagnostic device 7 can calculate that, for example, even if the depth h of the recessed portion 101 is the same, the smaller the characteristic coefficient A, the greater the evaluation index. In this way, by using the evaluation index and the characteristic coefficient based on the shape or dimensions of the rolling bearing 1, the diagnostic device 7 can accurately diagnose the depth h of the recessed portion 101 and the extent of damage to the recessed portion 101.

[0170] Embodiment 12 An example of diagnosing damage to a rolling bearing 1 by a diagnosing device 7 according to embodiment 12 will be described. In the diagnosing device 7 according to embodiment 12, a diagnosing unit 11 diagnoses the extent of damage to the rolling bearing 1 based on an evaluation index and a diameter D of the central locus of a rolling element 4.

[0171] The inventors conducted extensive research using data from multiple actual products and test data, and came to the deduction that the evaluation index increases as the diameter D of the central locus of the rolling element 4 increases, even if the degree of damage to the rolling bearing 1 does not change. In other words, in order to evaluate and compare the degree of damage to the rolling bearing 1 under conditions where the diameter D of the central locus of the rolling element 4 is different, it is necessary to make a diagnosis taking into consideration the influence of the diameter D of the central locus of the rolling element 4. The diagnosis device 7 according to the twelfth embodiment can accurately diagnose the degree of damage to the rolling bearing 1 based on the evaluation index and the diameter D of the central locus of the rolling element 4.

[0172] An example of diagnosis using the equation of motion when the rolling element 4 sinks into the recessed portion 101 is shown below. It can be seen from equation (19) that the larger the diameter D of the central locus of the rolling element 4, the smaller the characteristic coefficient A. In other words, even if the depth h of the recessed portion 101 is the same, it can also be calculated from equation (19) that the larger the diameter D of the central locus of the rolling element 4, the larger the evaluation index can be. In other words, by using the evaluation index and the diameter D of the central locus of the rolling element 4, the diagnosis device 7 can accurately diagnose the depth h of the recessed portion 101 and the extent of damage to the recessed portion 101.

[0173] Embodiment 13 An example of diagnosing damage to a rolling bearing 1 by a diagnosing device 7 according to embodiment 13 will be described. In the diagnosing device according to embodiment 13, a diagnosing unit 11 diagnoses the extent of damage to the rolling bearing 1 based on an evaluation index and a load acting on the rolling bearing 1 from a rotating shaft 5.

[0174] The inventors have conducted extensive studies using data from multiple actual products and test data, and have come to the deduction that, even if the degree of damage to the rolling bearing 1 does not change, the evaluation index increases as the load acting on the rolling bearing 1 increases. In other words, in order to evaluate and compare the degree of damage to the rolling bearing 1 under conditions in which the load acting on the rolling bearing 1 is different, it is necessary to make a diagnosis taking into consideration the influence of the load acting on the rolling bearing 1. The diagnosis device 7 according to the thirteenth embodiment can accurately diagnose the degree of damage to the rolling bearing 1, etc., based on the evaluation index and the load acting on the rolling bearing 1.

[0175] An example of diagnosis using the equation of motion when the rolling element 4 sinks into the recessed portion 101 is shown below. The characteristic coefficient A on the right side of equation (19) is the mass m of all the structures including the rolling element 4, the inner ring 2, and the rotating shaft 5, which are structures that apply a load to the recessed portion 101 via the rolling element 4, and the mass m of the structure that moves in conjunction with the recessed portion 101. o Mass ratio (m o / m). In other words, by using the evaluation index and the characteristic coefficient based on this mass ratio, the diagnostic device 7 can diagnose the depth h of the recessed portion 101 with high accuracy. Also, the diagnostic device 7 can diagnose the extent of damage to the rolling bearing 1 with high accuracy.

[0176] Here, the mass m is proportional to the load acting on the rolling bearing 1 from the rotating shaft 5, and m o In many cases, the mass ratio (m o If the mass ratio (m o If the mass ratio (m / m) is too large, the weight and size of the rotating equipment equipped with the rolling bearing 1 will increase, making the design difficult due to restrictions on the movement efficiency and installation space of the rotating equipment. o / m) is almost uniquely determined by the load acting on the rolling bearing 1, subject to constraints such as strength, movement efficiency, and installation space. For this reason, the characteristic coefficient A can be considered as a coefficient based on the load acting on the rolling bearing 1. In other words, by using the evaluation index and the characteristic coefficient A based on the load acting on the rolling bearing 1, the diagnostic device 7 can diagnose the depth h of the recessed portion 101 with high accuracy. In addition, the diagnostic device 7 can diagnose the extent of damage to the rolling bearing 1 with high accuracy.

[0177] Embodiment 14 An example of diagnosis of damage to a rolling bearing 1 by a diagnosis device 7 according to embodiment 14 will be described. In the diagnosis device 7 according to embodiment 14, a diagnosis unit 11 diagnoses the extent of damage to the rolling bearing 1 based on an evaluation index, a maximum displacement of the outer ring 3 or a housing 6 that holds the outer ring 3, and a load acting on the rolling bearing 1 from a rotating shaft 5. Here, the maximum displacement of the outer ring 3 or the housing 6 is the maximum displacement in the direction in which the load from the rotating shaft 5 acts within a time period longer than or equal to the period of the natural vibration determined by the specifications of the rolling bearing 1.

[0178] The mass of the structure that moves in conjunction with the recessed portion 101 is m o[kg], the maximum radial velocity of the structure in question within a time period longer than the natural vibration period determined by the specifications of rolling bearing 1 is Vo r ´ [mm / sec], the maximum radial displacement of the structure is X max [mm], and the spring stiffness of the structure against the displacement is k [N / mm]. Immediately after the rolling element 4 sinks into the recessed portion 101 and collides, the radial velocity of the structure moving in conjunction with the recessed portion 101 becomes maximum, and the structure has kinetic energy [N mm]. After that, the kinetic energy is converted into the elastic energy of the structure [N mm], and the structure reaches the maximum displacement X max The velocity of the structure becomes zero when the structure is displaced by the distance θ. The law of conservation of energy at this time is expressed by the following equation (21).

[0179]

number

[0180] The spring stiffness k against the displacement of the structure that moves in conjunction with the recessed portion 101 can be obtained by measuring the displacement when a test load is applied in advance, and dividing the test load by the measured displacement. Alternatively, the spring stiffness k can be obtained by calculating an estimated displacement against an estimated load using hand calculations or an analysis tool such as CAD from the material, structure, and constraints of the structure, and dividing the estimated load by the estimated displacement. In other words, the maximum radial velocity Vo of the structure is r ´ and maximum displacement X max If we measure the mass m o Using this, the diagnostic device 7 can diagnose the depth h of the recessed portion 101 with higher accuracy according to equation (19).

[0181] Among the structures that move in conjunction with the recessed portion 101, the outer ring 3 of the rolling bearing 1 and the housing 6 that holds the outer ring 3, which are closest to the load from the rotating shaft 5, tend to experience the largest speed and displacement. Since the outer ring 3 and the housing 6 move almost as one unit, the maximum radial speed Vo of the structure r´ and maximum displacement X max can be regarded as the maximum radial velocity and maximum displacement of the outer ring 3 or the housing 6. Here, when the behavior sensor 8 is an acceleration sensor, the calculation unit 14 can calculate the time series data of the displacement by performing a second-order time integration on the time series data of the acceleration, which is the output signal from the behavior sensor 8. The calculation unit 14 calculates the maximum displacement X max In addition, when the behavior sensor 8 is a speed sensor, the calculation unit 14 can time-integrate the time-series data of the speed, which is the output signal from the behavior sensor 8, to calculate the time-series data of the displacement. The calculation unit 14 can obtain the maximum displacement X max In addition, when the behavior sensor 8 is a displacement sensor, the calculation unit 14 can obtain the maximum displacement X from the time series data of the displacement, which is the output signal from the behavior sensor 8. max In other words, without providing an additional sensor, the calculation unit 14 can obtain the maximum radial velocity Vo of the outer ring 3 or the housing 6 based on the output signal from the behavior sensor 8. r ´ and maximum displacement X max In addition, the diagnostic device 7 can calculate the mass m of the structure that moves in conjunction with the recessed portion 101 by using the formula (21). o The diagnostic device 7 can diagnose the depth h of the recessed portion 101 with high accuracy using equation (19) etc. Furthermore, the diagnostic device 7 can diagnose the extent of damage to the rolling bearing 1 with high accuracy.

[0182] Embodiment 15 An example of diagnosis of damage to a rolling bearing 1 by a diagnosis device 7 according to embodiment 15 will be described. In the diagnosis device 7 according to embodiment 15, a diagnosis unit 11 diagnoses the extent of damage to the rolling bearing 1 based on an evaluation index, actual measurement data showing the extent of damage to the rolling bearing 1, and data on the evaluation index in that state.

[0183] An example of diagnosis using the equation of motion when the rolling element 4 sinks into the recessed portion 101 will be described. Using equation (19), the relative evaluation speed (Vor ´ / f s ) and the characteristic coefficient of the rolling bearing 1. For this reason, for example, by preparing at least one piece of actual measurement data indicating the magnitude of damage, such as the depth h of the recessed portion 101, and data on the evaluation index in that state, the characteristic coefficient can be found from equation (19). In this way, by using the characteristic coefficient found based on the actual measurement data and the evaluation index, the diagnostic device 7 can diagnose the depth h of the recessed portion 101 with high accuracy even if there is no design data required to find the characteristic coefficient. Furthermore, the diagnostic device 7 can diagnose the magnitude of damage to the rolling bearing 1 with high accuracy.

[0184] Embodiment 16 Fig. 10 is a diagram for explaining an example of diagnosis of damage to a rolling bearing 1 by a diagnosis device 7 according to embodiment 16. In Fig. 10, the horizontal axis represents the passage of time. The vertical axis represents the speed acquired by the behavior sensor 8. The upper side of the vertical axis represents the magnitude of the speed in the load direction. Meanwhile, the lower side of the vertical axis represents the magnitude of the speed in the anti-load direction.

[0185] For example, when an acceleration sensor is used as the behavior sensor 8 and acceleration time series data is integrated over time to calculate speed time series data, the speed may become extremely large in the load direction for a time longer than the period Tr, as shown by the dashed line in Fig. 10. This occurs when the acceleration time series data, which is the output signal, is shifted overall in the load direction when the behavior sensor 8, which is an acceleration sensor, is poorly attached or when noise such as other disturbance vibrations is significantly reflected. For the same reason, the speed may become large in the anti-load direction for a time longer than the period Tr.

[0186] On the other hand, even if minute vibrations occur in the rolling bearing 1 and the housing 6, the installation positions of the rolling bearing 1 and the housing 6 usually do not change significantly. For this reason, it is not the reality that the speed continues to increase over a long period of time as shown by the dashed line in Figure 10, and if such time-series data is used as is, the evaluated speed Vp will be calculated as an excessively large value. For this reason, the diagnosis device 7 performs a slope correction on the time-series data of the speed.

[0187] The calculation unit 14 of the diagnosis device 7 performs a slope correction process on the time series data of the speed based on the information acquired by the behavior sensor 8. The slope correction process is performed, for example, by determining a slope component of the time series data of the speed over a time longer than the period Tr by linear regression or other methods, and subtracting the determined slope component from the time series data of the speed. The calculation unit 14 calculates an evaluation speed Vp' for a time longer than the period Tr using the time series data of the speed after the slope correction process.

[0188] By using the evaluation speed Vp' calculated in this manner, the diagnosing device 7 can diagnose the degree and magnitude of damage to the rolling bearing without being affected by the mounting state of the behavior sensor 8 or noise such as external vibration.

[0189] Embodiment 17 An example of diagnosis of damage to a rolling bearing by a diagnostic device 7 according to a seventeenth embodiment will be described. A diagnostic unit 11 of the diagnostic device 7 diagnoses damage to a rolling bearing 1 by using evaluation index statistics. The evaluation index statistics are calculated for a period of time longer than the revolution period of the rolling element 4 when the rolling element 4 rotates in the circumferential direction around the central axis of the rotating shaft 5, the period being divided into multiple periods of time longer than the period of the natural vibration. The evaluation index statistics are found by statistically processing a data group of multiple evaluation indexes calculated within each of the multiple divided periods.

[0190] The revolution period To of the rolling element 4 when the rolling element 4 rotates around the central axis of the rotating shaft 5 in the circumferential direction is expressed by the formula (20). The revolution period To of the rolling element is calculated by multiplying the relative rotation speed f s The revolution period To can be determined by the diameter d of the rolling element 4, the diameter D of the central locus of the rolling element 4, and the contact angle α of the rolling element 4. The revolution period To is the natural vibration period Tr when the outer ring 3 is damaged. o is the same as the value obtained by multiplying the number of rolling elements 4, Z, by the number of rolling elements 4. In addition, the following can be seen regarding the revolution period To of the rolling elements 4. The revolution period To of the rolling elements 4 is s The orbital period To of the rolling elements 4 becomes shorter in inverse proportion to the contact angle α. The orbital period To of the rolling elements 4 becomes shorter as the diameter D of the central locus of the rolling elements 4 becomes larger. The orbital period To of the rolling elements 4 becomes longer as the diameter d of the rolling elements 4 becomes larger. The orbital period To of the rolling elements 4 becomes shorter as the contact angle α becomes larger. In addition, the rotation period of the cage that rotates together with the rolling elements 4 while maintaining the intervals between the multiple rolling elements 4 that rotate and move so as to revolve around the central axis of the rotating shaft 5 between the inner ring 2 and the outer ring 3 is also almost the same as the orbital period To of the rolling elements 4 shown in formula (20).

[0191] The cage and rolling elements 4 move freely within the gap inside the rolling bearing 1 depending on the constraint conditions. When the intervals between the multiple rolling elements 4 are not uniform, when the center of the cage is offset from the central axis of the rotating shaft 5, and when damage such as wear or scratches occurs in parts of the cage and the rolling elements 4 and the symmetry of the shape is lost, the vibration generated when each rolling element 4 passes through the damaged part 100 may have periodicity with the revolution period To of the rolling element 4. This is because when the rolling element 4 passes through the damaged part 100 at a specific circumferential position of the cage where the above-mentioned unevenness, deviation, or damage occurs, or when a specific rolling element 4 where the above-mentioned unevenness, deviation, or damage occurs passes through the damaged part 100, the values ​​of the shape and dimensions, mass, load, speed, and the like of the rolling bearing 1 used in formulas (7) to (19) change.

[0192] Therefore, in order to measure the periodic vibration during the revolution period To of the rolling element 4 at least once, a time longer than the revolution period To of the rolling element 4 is divided into multiple periods that are longer than the period Tr of the natural vibration determined by the specifications of the rolling bearing 1 and the relative rotation speed between the inner ring 2 and the outer ring 3. The diagnostic device 7 can accurately diagnose the extent of damage to the rolling bearing 1 by calculating an evaluation index within each divided period and using evaluation index statistics obtained by statistically processing the data groups of the multiple evaluation indexes obtained for the number of periods.

[0193] The evaluation index statistical value is, for example, an average value, a median value, an effective value, or a maximum value of a data group of the evaluation index. The diagnosing unit 11 diagnoses that damage has occurred in the rolling bearing 1 when, for example, the evaluation index statistical value exceeds a preset threshold value.

[0194] Furthermore, for example, the individual values ​​of the evaluation indexes calculated for each time by the calculation unit 14 or the like may take extremely large values ​​when the behavior sensor 8 detects, for example, sudden disturbance vibrations unrelated to damage to the rolling bearing 1. According to the configuration of the seventeenth embodiment, the diagnosing unit 11 performs diagnosis using evaluation index statistics such as the average, median, or effective value obtained by statistically processing a data group of the evaluation indexes. This allows the diagnosing device 7 to perform diagnosis with high accuracy without being affected by sudden events unrelated to damage to the rolling bearing 1.

[0195] Also, for example, the evaluation index may become large at a low frequency when the damage to the rolling bearing 1 is still small. In response to this, the diagnosing unit 11 performs diagnosis using evaluation index statistics such as maximum values ​​obtained by statistically processing a group of evaluation index data, so that the diagnosing device 7 can diagnose the damage at an early stage, even when the damage is still small.

[0196] Furthermore, for example, when damage to the rolling bearing 1 progresses rapidly, the average value of the evaluation index may change rapidly, and as a sign of such a rapid change in state, the variation in the time series of the evaluation index often increases in the previous stage.By using evaluation index statistics that indicate the variation in the time series, such as the standard deviation or variance obtained by statistically processing the data group of the evaluation index, the diagnostic device 7 can accurately diagnose the progress of the damage at an early stage.

[0197] Embodiment 18 An example of diagnosing damage to a rolling bearing 1 by a diagnosing device 7 according to embodiment 18 will be described. A diagnosing unit 11 of the diagnosing device 7 diagnoses damage to the rolling bearing 1 based on periodic changes in the evaluation indexes that are continuously calculated so as to be continuous over time.

[0198] For example, in time-series data of the evaluation index calculated by the diagnosing unit 11 or the like, the evaluation index becomes large at the timing when the rolling element 4 passes through the damaged portion 100, and this period roughly coincides with the period Tr of the natural vibration determined by the specifications of the rolling bearing 1. Meanwhile, the period when the rolling element 4 passes through the damaged portion 100 is determined by, for example, equations (4) to (6) using the occurrence position of the damaged portion 100, the dimensions of the rolling bearing 1, and the relative rotation speed. Therefore, from the period or frequency at which the evaluation index becomes large, based on the dimensions and relative rotation speed of the rolling bearing 1, the diagnosing unit 11 can determine whether the damaged portion 100 occurs on the inner ring 2, the outer ring 3, or the rolling element 4 of the rolling bearing 1. 8 shows an example in which the damaged portion 100 occurs on the outer ring 3, but even if the damaged portion 100 occurs on the inner ring 2 or the rolling element 4, the equations of motion when the rolling element 4 sinks into the recessed portion 101, that is, equations (7) to (19), hold at least relatively well. Therefore, similarly to the case in which the damaged portion 100 occurs on the outer ring 3, the diagnostic device 7 can calculate the depth h of the recessed portion 101.

[0199] The rolling element 4, which rotates in the circumferential direction so as to revolve between the inner ring 2 and the outer ring 3, receives a load from the rotating shaft 5 in a circumferential region defined as a loaded region, and the other region defined as a non-loaded region. In this case, if a damaged portion 100 occurs in the inner ring 2 or the rolling element 4, the rolling element 4 sinks into the recessed portion 101 only when the damaged portion 100 is in the loaded region, and the evaluation index becomes large. In other words, if a damaged portion occurs in the inner ring 2, the rotational speed f of the rotating shaft which rotates integrally with the inner ring 2 becomes larger than the rotational speed f of the rotating shaft which rotates integrally with the inner ring 2. s The rotation period (1 / f s ) during the time when the damaged part 100 is in the load zone, the natural vibration period Tr, which can be calculated using equation (4), i On the other hand, when the damaged part 100 occurs in the rolling element 4, the evaluation index becomes large at the timing of the natural vibration period Tr, which can be calculated by the formula (4), during the time when the damaged part 100 is in the load range in the revolution period To of the rolling element 4. i The evaluation index becomes large at this timing. Therefore, the diagnosis unit 11 can determine the time period during which the damaged portion 100 is in the load zone from the period during which the evaluation index becomes large, and diagnose whether the damaged portion 100 occurs on the inner ring 2, the rolling element 4, or the outer ring 3. Even if the damaged portion 100 occurs at multiple positions, the diagnosis unit 11 can determine how many positions the damaged portion 100 occurs at. Furthermore, the diagnosis unit 11 can determine whether each of the multiple damaged portions 100 occurs on the inner ring 2, the outer ring 3, or the rolling element 4 of the rolling bearing 1.

[0200] Furthermore, the diagnostic unit 11 may diagnose the size of the damaged part 100 based on the evaluation index in the cycle in which the evaluation index is large. This allows the diagnostic unit 11 to accurately diagnose the depth of the recessed portion 101 or the size of the damaged part 100 without being affected by noise such as external vibration. The diagnostic unit 11 may diagnose the occurrence position of the damaged part 100 from a frequency band with high spectral intensity for frequency analysis data obtained by frequency analyzing time-series data of the evaluation index. For example, the diagnostic unit 11 may diagnose the occurrence position of the damaged part 100 as follows by comparing the spectral intensity of a specific frequency band that is the reciprocal of the period Tr defined by equations (4) to (6). The diagnostic unit 11 may diagnose the occurrence position of the damaged part 100 from the frequency band with high spectral intensity among the reciprocals of the period Tr of equation (4) among the reciprocals of the period Tr of equation (4) to equation (6). i When the frequency band where the spectrum intensity is high is closest to the reciprocal of the period Tr in the formula (5) among the reciprocals of the period Tr in the formulas (4) to (6), the diagnosis unit 11 diagnoses that the damaged portion 100 has occurred in the inner ring 2. o When the frequency band where the spectrum intensity is high is closest to the reciprocal of the period Tr in the formula (6) among the reciprocals of the period Tr in the formulas (4) to (6), the diagnosis unit 11 diagnoses that the damaged portion 100 has occurred in the outer ring 3. b If the calculated value is closest to the reciprocal of the calculated value, it is determined that a damaged portion 100 has occurred in the inner ring 2.

[0201] Moreover, the evaluation index increases when the rolling element 4 periodically passes through the damaged portion 100, but may also increase at other times due to the influence of disturbance vibrations, etc. The diagnosis unit 11 diagnoses the depth of the recessed portion 101 or the size of the damaged portion 100 based on the spectrum intensity of a specific frequency band when the rolling element 4 passes through the damaged portion 100, thereby enabling highly accurate diagnosis with the influence of noise such as disturbance vibrations suppressed.

[0202] Embodiment 19 FIG. 11 is a configuration diagram of a rolling bearing 1 according to a nineteenth embodiment.

[0203] In the nineteenth embodiment, the diagnosis device 7 for the rolling bearing 1 comprises a rotation sensor 15 .

[0204] The rotation sensor 15 may directly measure the rotation speed or rotation angular velocity of the inner ring 2, the outer ring 3, the rotating shaft 5 integrated with the inner ring 2 or the outer ring 3, the rolling elements 4, or the cage, etc., using a laser, light, microwave, or ultrasonic wave, or a magnetic sensor, etc. The rotation sensor 15 may be a sensor integrated with a rotating device such as a motor. The rotation sensor 15 integrated with the rotating device measures an output value such as a current value of the motor, for example, and calculates the number of rotations of the rotating shaft 5 from the output value.

[0205] According to the configuration of the nineteenth embodiment, the diagnostic device 7 can diagnose damage to the rolling bearing 1 with high accuracy by measuring the relative rotation speed using the rotation sensor 15. For example, even when the rotation speed of the rotating shaft 5 is changing, the diagnostic device 7 can always diagnose damage to the rolling bearing 1 with high accuracy by measuring the relative rotation speed of the inner ring 2 and the outer ring 3 in the time interval in which the evaluation speed used for diagnosis is measured.

[0206] Embodiment 20. FIG. 12 is a configuration diagram of a rolling bearing 1 according to a twentieth embodiment.

[0207] In the twentieth embodiment, the control unit 9 of the diagnosing device 7 for the rolling bearing 1 comprises a calculation unit 14 , a storage unit 13 and a diagnosing unit 11 .

[0208] The storage unit 13 is a part equipped with a function for storing information. The storage unit 13 accumulates and stores the calculated evaluation index. The storage unit 13 stores, for example, time series data of the evaluation index. The storage unit 13 may store time series data of the evaluation speed used in calculating the evaluation index. The storage unit 13 stores the evaluation index as time series data, thereby storing changes in the evaluation index over time. The storage unit 13 may also store the amount of change from the evaluation index calculated last time.

[0209] In a rotating device provided with multiple rolling bearings 1 with different specification conditions such as characteristic coefficient, shape, size, relative rotation speed, and load acting on the rolling bearing 1 from the rotating shaft 5, the evaluation index may have different values ​​depending on the usage conditions, even if the damage occurring to each rolling bearing 1 is the same. For example, the evaluation index tends to be larger for the same degree of damage as the diameter of the central locus of the rolling elements 4, the relative rotation speed, or the load acting on the rolling bearing 1 from the rotating shaft 5 is larger.

[0210] On the other hand, even for rolling bearings 1 with different specification conditions such as characteristic coefficients, shapes, dimensions, relative rotational speeds, and loads acting on the rolling bearing 1 from the rotating shaft 5, the time differential value of the evaluation index, which is the rate of change of the evaluation index over time, often has a one-to-one correlation with the degree of damage to the rolling bearing 1. In other words, even if the rolling bearings 1 have different specification conditions, if the time differential values ​​of the evaluation index are approximately the same, the diagnostic device 7 can diagnose the same degree of damage. Alternatively, when the time differential value of the evaluation index exceeds a certain value, the diagnostic device 7 can diagnose this as a sign of a malfunction that will lead to a functional loss of the rolling bearing 1 or the entire rotating device having the rolling bearing 1, such as a crack or breakage of the rolling bearing 1, or a malfunction of a peripheral device of the rolling bearing 1. In other words, the diagnostic unit 11 can calculate the time until the damage that will lead to a functional loss of the rolling bearing 1 or the entire rotating device having the rolling bearing 1 occurs, based on the time rate of change of the evaluation index that can be calculated from the information stored in the storage unit 13. This enables the diagnosing unit 11 to calculate the appropriate timing for maintenance and inspection, and replacement, of the rolling bearing 1 in order to prevent damage that could lead to loss of function. In this way, the diagnosing device 7 can contribute to reducing the maintenance work required for the rolling bearing 1, the peripheral devices of the rolling bearing 1, and the entire rotating equipment in which the rolling bearing 1 is provided, and to long-term stable operation.

[0211] Embodiment 21. The rolling bearing 1 includes an inner ring 2, an outer ring 3, a plurality of rolling elements 4, a rotating shaft 5, and a diagnostic device 7.

[0212] Generally, rolling bearings are the parts of rotating equipment that are most heavily loaded and are prone to failure first. When damage occurs to a rolling bearing, the stress around the damage increases, and the damage may grow at an accelerated rate. When the damage grows, the behavior of the entire rotating equipment, including the rotating shaft, becomes unstable, which may lead to damage to peripheral equipment of the rolling bearing, the rotating shaft, gears and couplings, stators, housings, frames, etc.

[0213] In contrast, the rolling bearing 1 can use the diagnostic device 7 to diagnose with high accuracy the degree and magnitude of damage to the rolling bearing 1 and the rotating equipment in which the rolling bearing 1 is mounted. This makes it possible to prevent failures not only of the rolling bearing 1 itself, but also of peripheral equipment of the rolling bearing 1 and the entire rotating equipment in which the rolling bearing 1 is mounted.

[0214] FIG. 13 is a diagram illustrating an example of a hardware configuration of a control unit of a diagnostic device according to any one of the first to twenty-first embodiments. In FIG.

[0215] The functions of the control unit 9 can be realized by a control circuit 200 shown in Fig. 13, that is, a processor 201 and a memory 202. Examples of the processor 201 include a CPU (also called a central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, processor, or DSP (Digital Signal Processor)) or a system LSI (Large Scale Integration), etc. Examples of the memory 202 include a RAM (Random Access Memory) or a ROM (Read Only Memory), etc.

[0216] The functions of the control unit 9 are realized by the processor 201 reading out and executing a control program, which is a program for causing the control unit 9 to execute processing, from the memory 202 storing the control program. In addition, it can be said that this control program causes the computer to execute a control method for the diagnosis device 7 in the control unit 9. The control program executed by the control unit 9 has a modular configuration in which various processes, such as a process for calculating an evaluation speed, a characteristic coefficient, an evaluation index, or an evaluation index statistic value based on a signal obtained from the behavior sensor 8 or the rotation sensor 15, a process for calculating an acceleration overall value, a process for determining the presence or absence of damage, and a process for diagnosing a damaged state, are modularized. These modules are loaded onto the main storage device and generated on the main storage device.

[0217] The memory 202 is used as a temporary memory when the processor 201 executes various processes. In the seventh and twentieth embodiments, the memory 202 is used as the storage unit 13 that stores evaluation indices such as the evaluation speed or evaluation vibration as time-series data.

[0218] The control program executed by the processor 201 may be provided as a computer program product stored in a computer-readable storage medium in the form of an installable or executable file. The control program executed by the processor 201 may also be provided to the control unit 9 of the diagnostic device 7 via a network such as the Internet.

[0219] The control unit 9 may be realized by dedicated hardware. Alternatively, some of the functions of the control unit 9 may be realized by dedicated hardware, and the other parts may be realized by software or firmware.

[0220] Embodiment 22. FIG. 14 is a configuration diagram of an elevator hoisting machine 300 according to the twenty-second embodiment.

[0221] In this embodiment, an elevator hoisting machine 300 includes a rolling bearing 1, a rotating shaft 5, a sheave 301, and an electric motor 302.

[0222] Sheave 301 can be moved by a rope that moves the elevator car. Electric motor 302 rotates sheave 301 by driving rotation shaft 5 supported by, for example, two rolling bearings 1, thereby moving the elevator car while winding up the rope.

[0223] Generally, among the drive components of an elevator, the rolling bearing 1 of the hoist 300, which generates a large load and friction, is prone to failure. According to the configuration of this embodiment, damage to the rolling bearing 1 of the hoist 300 for an elevator can be accurately diagnosed, and preventive maintenance of the rolling bearing 1 can be performed. In addition, preventive maintenance can be performed on the hoist 300 and peripheral devices of the hoist 300, such as the electric motor 302 and the sheave 301, which are damaged secondarily as a result of damage to the rolling bearing 1.

[0224] The rolling bearing 1 according to any of the above embodiments 1 to 22 has been described with an example configuration in which the inner ring 2 rotates integrally with the rotating shaft 5, but the inner ring 2 may be held and fixed to the housing 6. Also, the outer ring 3 has been described with an example configuration in which the outer ring 3 is held and fixed to the housing 6, but the outer ring 3 may be configured to rotate integrally with the rotating shaft 5 provided outside thereof.

[0225] In the rolling bearing 1 according to any one of the above-mentioned embodiments 1 to 22, the number and arrangement of the rolling elements 4 are not limited to those exemplified in FIG. 1 or FIG.

[0226] The rolling bearing 1 or diagnosis device 7 according to any of the above embodiments 1 to 22 has been described using an example in which there is one damaged portion 100, but the number of damaged portions 100 may be two or more. Also, although an example in which the damaged portion 100 occurs on the outer ring 3 has been described, the damaged portion 100 may occur on the inner ring 2 or the rolling elements 4. Also, the damaged portion 100 may occur in a plurality of positions.

[0227] Although the rolling bearing 1 or diagnosis device 7 according to any one of the above-mentioned embodiments 1 to 22 has been described as an example of a configuration in which the number of behavior sensors 8 is one, the number of behavior sensors 8 may be two or more. In addition, the position and shape of the behavior sensor 8 are not limited to the examples described above.

[0228] The diagnostic device 7 according to any of the above embodiments 1 to 22 can be applied to a rolling bearing 1 to which a lubricant such as grease is supplied, a rolling bearing 1 to which a lubricant such as grease is not supplied, a rolling bearing 1 in rotating operation, and a rolling bearing 1 at a standstill.

[0229] In this specification, expressions expressing directions such as "axial direction", "radial direction", "circumferential direction", "rotational direction", "load direction", and "counter-load direction" not only include those directions strictly, but also include directions in which substantially the same function is obtained. Furthermore, in this specification, the expressions "include", "provide", "include" and "have" do not mean exclusive expressions that exclude the presence of other components.

[0230] In this disclosure, various exemplary embodiments and examples are described, but the various features, aspects and functions described in one or more embodiments are not limited to the application of a particular embodiment, but can be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are envisioned within the scope of the technology of this disclosure. In one example, this includes a case where at least one component is modified, added or omitted, and even a case where at least one component is extracted and combined with a component of another embodiment. In addition, the configurations shown in the above embodiments can be combined with other known technologies. In other words, the configurations shown in the above embodiments can be partially omitted or modified without departing from the gist of the invention. [Industrial Applicability]

[0231] The diagnostic device according to the present disclosure can be applied to a rolling bearing. The rolling bearing according to the present disclosure can be applied to a rotating device. [Explanation of symbols]

[0232] REFERENCE SIGNS LIST 1 rolling bearing, 2 inner ring, 3 outer ring, 4, 4a, 4b rolling elements, 5 rotating shaft, 6 housing, 7 diagnosis device, 8 behavior sensor, 9 control unit, 10 first calculation unit, 11 diagnosis unit, 12 second calculation unit, 13 memory unit, 14 calculation unit, 15 rotation sensor, 100 damaged portion, 101 recessed portion, 102 damaged corner portion, 200 control circuit, 201 processor, 202 memory, 300 hoist, 301 sheave, 302 electric motor

Claims

1. With the inner circle, an outer ring arranged concentrically with the inner ring; a plurality of rolling elements disposed between a raceway surface of the outer ring and a raceway surface of the inner ring, each of which rolls in association with rotation of the inner ring or the outer ring; A diagnostic device for diagnosing a rolling bearing, comprising: a rotation sensor provided in a rotating device including the rolling bearing; a behavior sensor provided on the inner ring, the outer ring, or a housing that holds the inner ring or the outer ring, the behavior sensor measuring a behavior of the rolling bearing; a calculation unit that calculates, based on information acquired by the behavior sensor, a relative rotation speed between the inner ring and the outer ring obtained based on a measurement value of the rotation sensor, and an evaluation speed that is a maximum speed component in the direction of a load acting on the rolling bearing from a rotating shaft that rotates integrally with the inner ring or the outer ring within a time period that is longer than or equal to a period of a natural vibration determined by the specifications of the rolling bearing; and a diagnosis unit that diagnoses damage to the rolling bearing by using an evaluation index based on the evaluation speed and the relative rotation speed; A diagnostic device comprising:

2. the period of the natural vibration is determined by the specifications of the rolling bearing, including the diameter of the rolling element and the diameter of a central locus of the rolling element when the rolling element rotates and moves in a circumferential direction around the central axis of the rotation shaft, and the relative rotation speed; The diagnostic device of claim 1 .

3. the period of the natural vibration is determined by the specifications of the rolling bearing, including the diameter of the rolling element, the diameter of the central locus of the rolling element, and the contact angle of the rolling element, and the relative rotation speed; The diagnostic device of claim 1 .

4. Diagnosing damage to the rolling bearing by using a relative evaluation speed obtained by dividing the evaluation speed by the relative rotation speed as the evaluation index. A diagnostic device according to any one of claims 1 to 3.

5. diagnosing the extent of damage to the rolling bearing based on the evaluation index and an inherent coefficient of the rolling bearing; A diagnostic device according to any one of claims 1 to 3.

6. The specific coefficient is determined based on a shape or a dimension of the rolling bearing. The diagnostic device of claim 5.

7. the characteristic coefficient is determined based on a diameter of a center locus of the rolling element when the rolling element rotates and moves in a circumferential direction around a central axis of the rotation shaft, The diagnostic device of claim 6.

8. The characteristic coefficient is determined based on a load acting on the rolling bearing from the rotating shaft. The diagnostic device of claim 5.

9. The characteristic coefficient is determined based on a maximum displacement of the inner ring, the outer ring, or the housing in a direction in which a load from the rotating shaft acts, within a time period that is longer than or equal to a period of a natural vibration determined by the specifications of the rolling bearing, and based on the load acting on the rolling bearing from the rotating shaft. The diagnostic device of claim 8.

10. The characteristic coefficient is calculated based on actual measurement data indicating the extent of damage to the rolling bearing and data on the evaluation index in the state of the rolling bearing. The diagnostic device of claim 5.

11. the diagnosing unit divides a time longer than the revolution period of the rolling element when the rolling element rotates and moves in a circumferential direction around the central axis of the rotation shaft into a plurality of periods each longer than the period of the natural vibration, and diagnoses damage to the rolling bearing using evaluation index statistics obtained by statistically processing a data group of the plurality of evaluation indexes calculated within each of the plurality of divided periods. A diagnostic device according to any one of claims 1 to 3.

12. The diagnosing unit diagnoses the degree of damage or the location of damage, or both, of the rolling bearing based on a periodic change in the continuously calculated evaluation index. A diagnostic device according to any one of claims 1 to 3.

13. The diagnosing unit diagnoses the degree of damage or the location of damage, or both, of the rolling bearing by using frequency analysis data of the time-series data of the evaluation index that is continuously calculated. The diagnostic device of claim 12.

14. The rotation sensor measures the relative rotation speed. A diagnostic device according to any one of claims 1 to 3.

15. A storage unit that accumulates and stores the evaluation index or the amount of change in the evaluation index. Equipped with the diagnosing unit diagnoses damage to the rolling bearing based on a time differential value of the evaluation index that can be calculated using the information stored in the storage unit. A diagnostic device according to any one of claims 1 to 3.

16. the diagnosis unit calculates a time until damage occurs that will lead to a functional loss of the rolling bearing or a functional loss of an entire rotating device having the rolling bearing, based on the evaluation index stored in the storage unit or a time rate of change of the evaluation index that can be calculated from information stored in the evaluation index, and calculates an appropriate maintenance and inspection timing for the rolling bearing to prevent damage that will lead to the functional loss. The diagnostic device of claim 15.

17. With the inner circle, an outer ring arranged concentrically with the inner ring; a plurality of rolling elements disposed between a raceway surface of the outer ring and a raceway surface of the inner ring, each of which rolls in association with rotation of the inner ring or the outer ring; A diagnostic device according to any one of claims 1 to 3, A rolling bearing comprising:

18. Inner circle, an outer ring arranged concentrically with the inner ring; a plurality of rolling elements disposed between a raceway surface of the outer ring and a raceway surface of the inner ring, each of which rolls in association with rotation of the inner ring or the outer ring; and The diagnostic device according to any one of claims 1 to 3. A rolling bearing comprising: Sheave and A rotating shaft that rotates integrally with the sheave and a part of the rolling bearing; an electric motor that rotates the rotary shaft; An elevator hoisting machine comprising:

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