Rolling bearing and diagnostic device for rolling bearing

Abstract

A rolling bearing and a rolling bearing diagnostic device that can improve the accuracy of damage diagnosis are provided. The diagnostic device (7) includes a behavior sensor (8), a first calculation unit (10), and a diagnosis unit (11). The behavior sensor (8) is provided in a housing (6) that holds an inner ring (2) or an outer ring (3) of a rolling bearing (1). The behavior sensor (8) measures the behavior of the housing (6). The first calculation unit (10) calculates an evaluation speed based on information acquired by the behavior sensor (8). The evaluation speed is the sum of a maximum speed component in a direction in which a load from a rotating shaft (5) acts and a maximum speed component in a direction opposite to the direction in which the load from the rotating shaft (5) acts within a time period equal to or longer than a period Tr of a natural vibration determined by the specifications of the rolling bearing (1). The diagnosis 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).

Description

[Technical field]

[0001] The present disclosure relates to 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 a housing 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] Japan Practical Fair Trade Commission Publication No. 6-45215 Summary of the Invention [Problem to be solved by the invention]

[0004] The diagnostic device in Patent Document 1 diagnoses the extent of damage by capturing vibrations that occur when the rolling elements of the rolling bearing pass through a damaged part, based on the amplitude of the output signal from a vibration sensor. However, since the vibration amplitude 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 is directed to solving such problems. The present disclosure provides a rolling bearing and a diagnosis 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 that is arranged concentrically with the inner ring, and a plurality of rolling elements that are arranged between a raceway surface of the outer ring and a raceway surface of the inner ring and that each roll with the rotation of the inner ring, the rotation of the outer ring, or the rotation of both the inner ring and the outer ring. The diagnostic device includes a behavior sensor that is provided in a housing that holds the inner ring or the outer ring and that measures the behavior of the housing, and a behavior sensor that measures the specifications of the rolling bearing and , the number of revolutions of a rotating shaft that rotates integrally with the inner ring or the outer ring The sum of the maximum speed component in the direction in which the load from the rotating shaft that rotates integrally with the inner ring or the outer ring acts, and the maximum speed component in the opposite direction to the direction in which the load from the rotating shaft acts, within a time period equal to or greater than the natural vibration period determined by and not the velocity amplitude. The vehicle speed monitoring system includes a first calculation unit that calculates an evaluation speed based on information acquired by the behavior sensor, and a diagnosis unit that diagnoses damage to the rolling bearing by using an evaluation index based on the evaluation speed. The 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 the rotation of the inner ring, the rotation of the outer ring, or the rotation of both the inner ring and the outer ring, and is equipped with: a behavior sensor provided in a housing that holds the inner ring or the outer ring and measures the behavior of the housing; a first calculation unit that calculates, from information acquired by the behavior sensor within a time period equal to or greater than a period of a natural vibration determined by the specifications of the rolling bearing and the rotation speed of a rotating shaft that rotates integrally with the inner ring or the outer ring, an evaluation speed that is the sum of a maximum speed component in a direction in which a load from the rotating shaft acts and a maximum speed component in a direction opposite to the direction in which the load from the rotating shaft acts, of vibrations that are not of a single vibration amplitude, based on information acquired by the behavior sensor; and a diagnostic unit that diagnoses damage to the rolling bearing using an evaluation index based on the evaluation speed.

[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 surface of the outer ring and the raceway surface of the inner ring, each of which rolls in conjunction with rotation of the inner ring, rotation of the outer ring, or rotation of both the inner ring and the outer ring, and the above-mentioned diagnostic device. Effect of the Invention

[0008] According to the 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]

[0009] [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] 1 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 eighth embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] 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.

[0011] Embodiment 1 FIG. 1 is a configuration diagram of a rolling bearing according to a first embodiment.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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 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 evaluation speed by adding up the absolute values ​​of these two maximum speed components.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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 [sec -1 ], the natural vibration period Tr caused by damage to the inner ring 2 is 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.

[0033]

number

[0034]

number

[0035]

number

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] Embodiment 2 FIG. 4 is a configuration diagram of a rolling bearing according to the second embodiment.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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, the outer ring, or the rolling element, and the diagnosing unit 11 can 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 by using information related to the magnitude of the acceleration amplitude spectrum in the frequency band of the natural vibration.

[0052] 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.

[0053] 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.

[0054] 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 increases the accuracy of the diagnosis of damage in the rolling bearing 1 using the evaluation vibration as an evaluation index.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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 dividing the time series data of speed by a period equal to or greater than the cycle Tr, determining a slope component of the time series data of speed 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 period equal to or greater than the cycle Tr using the time series data of speed after the slope correction process.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] Furthermore, for example, in a state where damage to the rolling bearing 1 is progressing rapidly, evaluation indexes such as the evaluation speed and evaluation vibration may change rapidly. In response to this, the diagnostic unit 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 diagnostic device 7 can perform a better diagnosis of the progress state of the damage.

[0066] 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 continuously calculated so as to be continuous over time.

[0067] 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.

[0068] 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.

[0069] Embodiment 7 FIG. 6 is a configuration diagram of a rolling bearing according to the seventh embodiment.

[0070] 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 .

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] FIG. 7 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 eighth embodiments. In FIG.

[0079] The functions of the control unit 9 can be realized by a control circuit 200 shown in Fig. 7, 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.

[0080] 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 that stores the control program. In addition, it can be said that this control program causes a 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 that modularizes, for example, a process for calculating an evaluation speed based on a signal obtained from the behavior sensor 8, 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. These modules are loaded onto the main storage device and generated on the main storage device.

[0081] The memory 202 is used as a temporary memory when the processor 201 executes various processes. In the seventh embodiment, the memory 202 is used as the storage unit 13 that stores evaluation indices such as the evaluation speed or the evaluation vibration as time-series data.

[0082] 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.

[0083] 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.

[0084] The rolling bearing 1 according to any of the above embodiments 1 to 8 has been described with an example configuration in which the inner ring 2 rotates together with the rotating shaft 5, but the shaft integral with the inner ring 2 may be fixed in rotation. Also, the example configuration in which the outer ring 3 is fixed to the housing 6 has been described with an example configuration in which the outer ring 3 rotates integrally with the rotating shaft 5 provided on the outside thereof. Furthermore, the rolling bearing 1 may be configured with the inner ring 2 and the outer ring 3 both rotating integrally with separate rotating shafts 5.

[0085] In the rolling bearing 1 according to any one of the above-mentioned first to eighth embodiments, the number and arrangement of the rolling elements 4 are not limited to the number and arrangement exemplified in FIG.

[0086] The rolling bearing 1 or diagnosis device 7 according to any of the above embodiments 1 to 8 has been described taking as an example a state in which there is one damaged portion 100, but the number of damaged portions 100 may be two or more. Also, while the example has been described in which the damaged portion 100 occurs in the outer ring 3, the damaged portion 100 may occur in the inner ring 2 or the rolling elements 4.

[0087] Although the rolling bearing 1 or diagnosis device 7 according to any one of the above embodiments 1 to 8 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. Furthermore, the position and shape of the behavior sensor 8 are not limited to the examples described above.

[0088] The diagnostic device 7 according to any of the above embodiments 1 to 8 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 rotational operation, and a rolling bearing 1 at a standstill.

[0089] 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", "includes", and "have" do not mean exclusive expressions that exclude the presence of other components.

[0090] 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]

[0091] 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]

[0092] 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 storage unit, 100 damaged portion, 101 recessed portion, 102 damaged corner portion, 200 control circuit, 201 processor, 202 memory

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 a rotation of the inner ring, a rotation of the outer ring, or a rotation of both the inner ring and the outer ring; A diagnostic device for diagnosing a rolling bearing, comprising: a behavior sensor provided in a housing that holds the inner ring or the outer ring and that measures a behavior of the housing; a first calculation unit that calculates, based on information acquired by the behavior sensor, an evaluated speed that is the sum of a maximum speed component in a direction in which a load from a rotating shaft that rotates integrally with the inner ring or the outer ring acts, and a maximum speed component in a direction opposite to the direction in which the load from the rotating shaft acts, within a time period equal to or greater than a period of a natural vibration determined by the specifications of the rolling bearing and a rotational frequency of the inner ring; a diagnosis unit that diagnoses damage to the rolling bearing by using an evaluation index based on the evaluation speed; A diagnostic device comprising:

2. A diagnostic device as described in claim 1, characterized in that the period of the natural vibration is determined by the specifications of the rolling bearing, including the diameter of the rolling element and the orbital diameter of the rolling element, and the rotational frequency of the inner ring.

3. A diagnostic device as described in claim 1, characterized in that the period of the natural vibration is determined by the specifications of the rolling bearing, including the diameter of the rolling body, the orbital diameter of the rolling body, and the contact angle of the rolling body, and the rotational frequency of the inner ring.

4. the behavior sensor is an acceleration sensor, The first calculation unit calculates the evaluated speed using time series data of a speed obtained by time-integrating time series data of acceleration, which is an output signal from the behavior sensor. The diagnostic device of claim 1 .

5. the behavior sensor is a displacement sensor, The first calculation unit calculates the evaluated speed using time series data of a speed obtained by time-differentiating time series data of a displacement, which is an output signal from the behavior sensor. The diagnostic device of claim 1 .

6. the behavior sensor is a speed sensor, The first calculation unit calculates the evaluation speed by using time series data of speed which is an output signal from the behavior sensor. The diagnostic device of claim 1 .

7. The first calculation unit calculates the evaluated speed using time series data obtained by performing a slope correction on the time series data of the speed. A diagnostic device according to any one of claims 4 to 6.

8. The first calculation unit calculates the evaluated speed using time series data obtained by performing frequency filtering on one or both of time series data that is an output signal from the behavior sensor and time series data of the speed. A diagnostic device according to any one of claims 4 to 6.

9. the diagnosing unit diagnoses damage to the rolling bearing by using an evaluation index statistical value obtained by statistically processing a data group of the evaluation index calculated multiple times. A diagnostic device according to claim 1 or any one of claims 4 to 6.

10. The diagnosing unit diagnoses damage to the rolling bearing based on a periodic change in the continuously calculated evaluation index. A diagnostic device according to claim 1 or any one of claims 4 to 6.

11. The diagnosing unit diagnoses damage to the rolling bearing by using frequency analysis data of the time series data of the evaluation index continuously calculated. The diagnostic device of claim 10.

12. A storage unit that accumulates and stores the evaluation index or the amount of change in the evaluation index. Equipped with The diagnosis unit calculates a maintenance and inspection timing for the rolling bearing based on the information stored in the storage unit. A diagnostic device according to claim 1 or any one of claims 4 to 6.

13. 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 a rotation of the inner ring, a rotation of the outer ring, or a rotation of both the inner ring and the outer ring; A diagnostic device according to claim 1 or any one of claims 4 to 6; A rolling bearing comprising:

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