Elevator traction machine, rolling bearings, and rolling bearing diagnostic equipment

Abstract

An elevator traction machine capable of diagnosing the degree of damage with high accuracy, a rolling bearing, and a diagnostic device for the rolling bearing are described. The diagnostic device (7) comprises a behavior sensor (8), a processing unit (14), and a diagnostic unit (11). The behavior sensor (8) is arranged on an inner ring (2) or an 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 processing unit (14) calculates an evaluation rate based on information acquired by the behavior sensor (8).The evaluation speed is a maximum velocity component in a direction in which a load acts from a rotating shaft (5) within a period longer than one period of characteristic vibrations determined by the specifications of the rolling bearing (1), and a relative rotational speed of the inner ring (2) and the outer ring (3). The diagnostic unit (11) diagnoses damage to the rolling bearing (1) by using an evaluation index based on the evaluation speed calculated by the computation unit (14) and the relative rotational speed of the inner ring (2) and the outer ring (3).

Description

Technical field

[0001] The present invention relates to an elevator traction machine, a rolling bearing and a diagnostic device for a rolling bearing. State of the art

[0002] PTL 1 discloses an example of a diagnostic device for a rolling bearing. The diagnostic device comprises a vibration sensor and a damage and deterioration diagnostic unit. The vibration sensor is in contact with an inner or outer ring of a rolling bearing or with a housing that holds the inner or outer ring. The damage and deterioration diagnostic unit diagnoses damage or deterioration of the rolling bearing based on the amplitude of an output signal from the vibration sensor. Bibliography Patent literature

[0003] PTL 1: JP S61-61055 A Summary of the invention Problem to be solved by the invention

[0004] The diagnostic device according to PTL 1 performs a diagnosis using converted impact values. These values ​​are obtained by converting an impact value measured at the vibration sensor into a value when the bearing diameter is a predetermined reference bearing diameter, and a value when the rotational speed is a predetermined reference rotational speed. However, the impact value is strongly influenced by the shape of a damaged corner area of ​​the rolling bearing, and consequently, the diagnostic device may not be able to diagnose the extent of the damage with high accuracy.

[0005] The present invention solves such a problem. The present invention provides an elevator traction machine, a rolling bearing, and a diagnostic device for a rolling bearing, which can further improve the diagnostic accuracy of damage. Ways to solve the problem

[0006] A diagnostic device according to the present invention is a diagnostic device that diagnoses or performs a diagnosis on a rolling bearing, wherein the rolling bearing comprises: an inner ring, an outer ring arranged concentrically with the inner ring, and a plurality of rolling elements arranged between a running surface of the outer ring and a running surface of the inner ring, each of which rolls in conjunction with the rotation of the inner ring or the rotation of the outer ring, wherein the diagnostic device comprises: a behavior sensor arranged on the inner ring, on the outer ring, or on a housing holding the inner ring or the outer ring, and which measures the behavior of the rolling bearing;a calculation unit that calculates an evaluation speed based on information acquired by the behavior sensor, wherein the evaluation speed is a maximum velocity component in one direction of the load acting on the rolling bearing from a rotating shaft that rotates in an integrated manner with the inner ring or the outer ring, within a period equal to or longer than a period of characteristic vibrations determined by specifications of the rolling bearing and the relative rotational speed of the inner ring and the outer ring; and a diagnostic unit that diagnoses damage to the rolling bearing by using an evaluation index based on the evaluation speed and the relative rotational speed.

[0007] A rolling bearing according to the present invention comprises: an inner ring, an outer ring arranged concentrically with the inner ring, a plurality of rolling elements arranged between a running surface of the outer ring and a running surface of the inner ring, each of which rolls in conjunction with the rotation of the inner ring or the rotation of the outer ring, and the above diagnostic device.

[0008] An elevator traction machine according to the present invention comprises: a rolling bearing comprising: an inner ring, an outer ring arranged concentrically with the inner ring, a plurality of rolling elements arranged between a running surface of the outer ring and a running surface of the inner ring, each of which rolls in conjunction with the rotation of the inner ring or the rotation of the outer ring, and the above-mentioned diagnostic device, a pulley; a rotating shaft which rotates in an integrated manner with a part of the pulley and the rolling bearing; and a motor which rotates the rotating shaft. Advantageous effects of the invention

[0009] With the elevator traction machine, the rolling bearing or the diagnostic device for a rolling bearing according to the present invention, it is possible to further improve the diagnostic accuracy of damage. Brief description of the drawings Fig. Figure 1 is a configuration diagram of a rolling bearing according to a first embodiment. Fig. Figure 2 is a diagram illustrating an example of the diagnosis of damage to the rolling bearing by a diagnostic device according to the first embodiment. Fig. Figure 3 is a diagram to illustrate another example of the diagnosis of damage to the rolling bearing by the diagnostic device according to the first embodiment. Fig. Figure 4 is a configuration diagram of a rolling bearing according to a second embodiment. Fig. Figure 5 is a diagram illustrating an example of the diagnosis of damage to a rolling bearing by a diagnostic device according to a third embodiment. Fig. Figure 6 is a configuration diagram of a rolling bearing according to a seventh embodiment. Fig. Figure 7 is a configuration diagram of a rolling bearing according to a ninth embodiment. Fig. Figure 8 is a diagram illustrating an example of the diagnosis of damage to the rolling bearing by a diagnostic device according to the ninth embodiment. Fig. Figure 9 is a diagram illustrating an example of the behavior when a rolling element of the rolling bearing according to the ninth embodiment passes a damaged area. Fig. Figure 10 is a diagram illustrating an example of the diagnosis of damage to a rolling bearing by a diagnostic device according to a sixteenth embodiment. Fig. Figure 11 is a configuration diagram of a rolling bearing according to a nineteenth embodiment. Fig. Figure 12 is a configuration diagram of a rolling bearing according to a twentieth embodiment. Fig. Figure 13 is a diagram showing an example of a hardware configuration of a control unit of the diagnostic device according to one of the first to twenty-first embodiments. Fig. Figure 14 is a configuration diagram of an elevator traction machine according to a twenty-second embodiment. Description of embodiments

[0010] Methods for implementing the features of the present invention are described with reference to the accompanying drawings. In the respective drawings, identical or corresponding areas are designated with the same reference numerals, and their repeated description is simplified or omitted where appropriate. First embodiment

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

[0012] A rolling bearing 1 has an inner ring 2, an outer ring 3, a plurality of rolling elements 4 and a rotating shaft 5. In Fig. Figure 1 shows a section of the rolling bearing 1 along a plane perpendicular to the core of the rotating shaft 5. The inner ring 2 has a cylindrical shape. The outer ring 3 also has a cylindrical shape. The outer ring 3 is arranged concentrically with the inner ring 2, positioned outside the inner ring 2. The majority of rolling elements 4 are arranged between the inner ring 2 and the outer ring 3.

[0013] Each of the rolling elements 4 has a rolling shape, such as a spherical or columnar shape. The rolling elements 4 are arranged between a running surface, which is an inner peripheral surface of the outer ring 3, and a running surface, which is an outer peripheral surface of the inner ring 2. The rolling elements 4 roll in conjunction 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 a case where individual rolling elements 4 are distinguished from one another, one of the plurality of rolling elements 4 can be described as a rolling element 4a, a rolling element 4b, or the like.

[0014] The rotating shaft 5 rotates in an integrated manner with the inner ring 2 or the outer ring 3. In this example, the rotating shaft 5 rotates counterclockwise in the plane of the paper. Fig. 1. Here, the wave direction along the core of the rotating shaft 5, i.e., the direction of travel of the rotating shaft 5, can simply be referred to as the wave direction. Furthermore, the circumferential direction around the core of the rotating shaft 5, i.e., the direction of rotation of the rotating shaft 5, can simply be referred to as the circumferential direction. In addition, the direction extending outwards from the core of the rotating shaft 5 can simply be referred to as the radial direction.

[0015] In the rolling bearing 1 in this example, the inner ring 2 rotates in an integrated manner with the rotating shaft 5, and the outer ring 3 is fixed. It should be noted that in the rolling bearing 1, the outer ring 3 can also rotate in an integrated manner with the rotating shaft 5, while the inner ring 2 can be fixed. Furthermore, the rolling bearing 1 can be configured such that both the inner ring 2 and the outer ring 3 rotate.

[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 used in the rolling bearing 1. The diagnostic device 7 diagnoses damage and similar conditions of the rolling bearing 1. The diagnostic device 7 can be an integral part of rotating equipment, such as a motor, in which the rolling bearing 1 is located, or it can be an external device intended for use with rotating equipment. The diagnostic device 7 can be permanently located in the rolling bearing 1 or in the rotating equipment in which the rolling bearing 1 is located, or it can be temporarily located as a portable device in the rolling bearing 1 or in the rotating equipment in which the rolling bearing 1 is located. The diagnostic device 7 comprises 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 accelerometer, a displacement sensor, a velocity sensor, or the like.

[0019] The control unit 9 performs data processing in the diagnostic unit 7. The control unit 9 can comprise one or more independent hardware components or be part of other hardware, such as the control equipment of the rotary equipment in which the rolling bearing 1 is located. The control unit 9 includes a first processing unit 10 and a diagnostic unit 11.

[0020] The first calculation unit 10 is a component whose function is to calculate an evaluation velocity to be used for diagnosing the rolling bearing 1. The evaluation velocity is calculated for a period equal to or longer than a period Tr of characteristic vibrations, which are determined by the specifications of the rolling bearing 1. The evaluation velocity is the sum of a maximum velocity component in the direction in which the load acts from the rotating shaft 5 and a maximum velocity component in the opposite direction to the direction in which the load acts from the rotating shaft 5 within the given period.

[0021] The direction in which the load acts from the rotating shaft 5 is, for example, an outward direction in the radial direction or a downward direction in the vertical direction. In this case, the direction opposite to the direction in which the load acts from the rotating shaft 5 is an inward direction in the radial direction or an upward direction in the vertical direction. Here, the direction in which the load acts from the rotating shaft 5 and the direction opposite to the direction in which the load acts from the rotating shaft 5 can be expressed as a loading direction and an anti-load direction.

[0022] The first processing unit 10 calculates the evaluation speed by processing an output signal from the behavior sensor 8. For example, if the behavior sensor 8 is a velocity sensor, the first processing unit 10 calculates the evaluation speed using time-series data of a velocity, which is the output signal from the behavior sensor 8. Furthermore, if the behavior sensor 8 is an acceleration sensor, the first processing unit 10 performs time integration of the time-series data of an acceleration, which is the output signal from the behavior sensor 8, and thus calculates the time-series data of the velocity. In this case, the first processing unit 10 calculates the evaluation speed using the calculated time-series data of the velocity.

[0023] Furthermore, in a case where the behavior sensor 8 is a displacement sensor, the first processing unit 10 differentiates – with respect to time – time series data of a displacement, which is the output signal from the behavior sensor 8, and thus calculates the time series data of the velocity. In this case, the first processing unit 10 calculates the evaluation velocity using the calculated time series data of the velocity.

[0024] The first calculation unit 10 calculates a maximum velocity component in the direction in which the load acts from the rotating shaft 5, from the time series data of the velocity for a predefined period that is equal to or longer than one period Tr. The first calculation unit 10 calculates a maximum velocity component in the direction opposite to the direction in which the load acts from the rotating shaft 5, from the time series data of the velocity for the period. The first calculation unit 10 calculates the evaluation velocity by adding the absolute values ​​of these two maximum velocity components.

[0025] The diagnostic unit 11 is a component with a function for diagnosing damage to the rolling bearing 1 by using an evaluation index based on the evaluation rate calculated by the first computation unit 10. In this example, the diagnostic unit 11 diagnoses the damage to the rolling bearing 1 using the evaluation rate itself, calculated by the first computation unit 10, as the evaluation index. For example, the diagnostic unit 11 provides a diagnosis that damage to the rolling bearing 1 has occurred if the evaluation rate exceeds a predefined threshold.

[0026] Next, an example of diagnosing damage to rolling bearing 1 using the diagnostic device 7 will be given. Fig. 2 described.

[0027] Fig. Figure 2 is a diagram illustrating an example of the diagnosis of damage to the rolling bearing by the diagnostic device according to the first embodiment.

[0028] In Fig. Figure 2 shows a damaged area 100 as an example of the damage that can occur on the rolling bearing 1. The damaged area 100 occurs in the rolling bearing 1, for example, as follows.

[0029] In the rolling bearing 1 in this example, the rotating shaft 5 rotates counterclockwise in the plane of the paper, in an integrated manner with the inner ring 2. In this case, each rolling element 4 in contact with the running surface of the inner ring 2 rotates such that it revolves counterclockwise in the plane of the paper about a central axis of the rotating shaft 5 between the inner ring 2 and the outer ring 3, while simultaneously rotating clockwise in the plane of the paper about a central point of the rolling element 4 itself, in conjunction with the rotation of the inner ring 2. If a load acts on the inner ring 2 due to a load on the rotating shaft 5 in a lower part in the plane of the paper, most of the load is transferred from the rotating shaft 5 to the running surface of the inner ring 2 and the running surface of the outer ring 3 via the majority of rolling elements 4 located below the rotating shaft 5.

[0030] When the rotating shaft 5 is stationary, the position and magnitude of the load acting on each of the inner ring 2, the outer ring 3, and the rolling elements 4 remain constant. However, when the rotating shaft 5 rotates, the position and magnitude of the load change periodically, in conjunction with the rotational movement of the inner ring 2 and the rolling elements 4. This results in repetitive loads acting on the running surfaces of the inner ring 2 and the outer ring 3. As a consequence of such repetitive loads, a crack originating from impurities within a material, for example, can propagate from the interior of the inner ring 2, the outer ring 3, or the like, and reach a surface. In this case, internally originating flaking damage, characterized by scaly peeling from a surface area, can occur on the running surface of the inner ring 2 or the outer ring 3.

[0031] Furthermore, abnormal slippage or sliding can occur between the rolling element 4 and the inner ring 2 and outer ring 3 due to poor lubrication of the raceway. This can result from insufficient lubrication with a lubricant such as grease, deterioration, leakage or insufficient efflux, insufficient viscosity, excessive load, or similar factors. In this case, loads are likely to concentrate on one surface of the raceway due to a rough surface, wear, or similar condition, and the damage to the raceway can accelerate. For example, surface damage such as flaking of a surface zone on part of the raceway, wear damage, or similar damage may occur on the raceway.

[0032] Regarding internal flaking damage, there is a lifetime design formula called L10 life, and the specifications of the rolling bearing 1 are usually determined based on this lifetime design formula. Consequently, internal flaking damage rarely occurs. On the other hand, surface flaking damage can occur much earlier than internal flaking damage. Therefore, it is important to diagnose the condition of the rotating equipment to ensure reliability and achieve long-term operation of the rolling bearing 1 and the rotating equipment in which the rolling bearing 1 is installed.

[0033] Based on the knowledge obtained from the bearing test, the damaged area 100 is frequently formed on the running surface of the rolling bearing 1 by flaking damage. Furthermore, the damaged area 100 is often composed of a recessed area 101 and a damaged corner area 102. It is assumed that the sizes and shapes of the recessed area 101 and the damaged corner area 102 change according to the total number of rotations of the rolling bearing 1. Moreover, the recessed area 101 becomes larger as the total number of rotations of the rolling bearing 1 increases.

[0034] On the other hand, it was confirmed that the shape of the damaged corner area 102 is sharp in an initial stage of the damage, but can subsequently change to a smooth shape due to wear and tear. In a case where the damaged area 100 is caused by flaking damage originating from the surface, the depth of the recessed area 101 is shallow in an initial stage of the damage, and consequently, the recessed area 101 increases in the wave direction and circumferential direction, and it also becomes deeper in the radial direction as the damage progresses.

[0035] While the instantaneous vibration increases as a result of the damaged corner area 102 becoming sharper, the service life of the rolling bearing 1 and the rotating equipment in which the rolling bearing 1 is located is less affected. On the other hand, the recess area 101 becomes larger as the total number of rotations of the rolling bearing 1 increases, which can lead to a continuous increase in chatter, flutter, or other abnormal disturbances of the rolling bearing 1 and the entire rotating equipment in which the rolling bearing 1 is located. Consequently, the size of the recess area 101 can significantly affect the service life of the rolling bearing 1 and the entire rotating equipment in which the rolling bearing 1 is located.

[0036] As in Fig. Figure 1 illustrates, for example, a case in which, in the inner-ring rotary bearing 1, where the inner ring 2 rotates along with the rotating shaft 5, the recess area 101 is formed on the load side of the outer ring 3. As the recess area 101 enlarges, the rolling element 4 descends within the recess area 101, specifically at the point when the rolling element 4 reaches the recess area 101 in relation to the rotation of the rolling bearing 1. In this case, the rolling element 4 falls in the depth direction of the recess area 101, along with the inner ring 2 and the rotating shaft 5. Furthermore, the rolling element 4 rises from a bottom region of the recess area 101, along with the inner ring 2 and the rotating shaft 5, at the point when the rolling element 4 exits the recess area 101.

[0037] Consequently, the chatter, flutter, and abnormal disturbances of the rolling bearing 1 and the rotating shaft 5 increase when the recess area 101 is deeper. If the recess area 101 becomes too deep, the chatter, flutter, and abnormal disturbances of the rolling bearing 1 and the rotating shaft 5 can become extremely severe. In this case, a design limit of the rotating equipment in which the rolling bearing 1 is located may be exceeded. Furthermore, this may lead to a malfunction, such as a crack or fracture of the rolling bearing 1, a malfunction of peripheral equipment of the rolling bearing 1, a malfunction of the entire rotating equipment in which the rolling bearing 1 is located, and the like.

[0038] It is therefore important to diagnose the condition, size, or degree of damage of the rolling bearing 1, such as the depth of the recess area 101. By diagnosing the condition of the rolling bearing 1, it is possible to diagnose any anomalies in the rolling bearing 1, estimate its remaining service life, and perform maintenance and service life extension treatments, such as replacing the rolling bearing 1 or lubricating it at an appropriate time. Furthermore, this makes it possible to reduce maintenance costs and achieve stable long-term operation of the rolling bearing 1, its peripheral components, and the entire rotating equipment in which the rolling bearing 1 is located.

[0039] Diagnostic device 7 diagnoses the damaged area 100, as shown in Fig. 2 shown, for example as follows. The following should be noted: In Fig. Figure 2 shows an example of a case where the damaged area 100 occurred in the outer ring 3. However, the damaged area 100 can also occur in the inner ring 2 or in the rolling element 4.

[0040] The first calculation unit 10 calculates an evaluation rate for a period equal to or longer than the period Tr of the characteristic vibrations determined by the specifications of the rolling bearing 1. The characteristic vibrations described here include not only the vibrations that occur when the rolling element 4 passes the damaged area 100 that has occurred in the outer ring 3, as in Fig. 2 shown, but also the vibrations that occur when the rolling element 4 passes the damaged area 100 that has occurred in the inner ring 2, as well as the vibrations that occur when the inner ring 2 and the outer ring 3 pass through the damaged area 100 that has occurred in the rolling element 4.

[0041] The following applies to the period Tr: One period of the characteristic vibrations resulting from the damage to the inner ring 2 is denoted as Tr i [sec] defined. A period of characteristic vibrations resulting from damage to the outer ring 3 is defined as Tr. o [sec] defined. A period of characteristic vibrations resulting from damage to the rolling element 4 is defined as Tr. b [sec] defined.

[0042] In a case where damage occurred on the inner ring 2, the characteristic vibrations of period Tr iParticularly large, in a case where damage occurred on the outer ring 3, are the characteristic vibrations of period Tr. o particularly large, and in one case where damage occurred on rolling element 4, the characteristic vibrations of period Tr b especially large. For example, in a case where the outer ring 3 has the damaged area 100, as in Fig. As shown in Figure 2, the period from the time when rolling element 4a passes the damaged area 100 until the time when rolling element 4b passes the damaged area 100 is called period Tr. o .

[0043] For example, the following applies: The diameter of the rolling element 4 is defined as d [mm]. The rotational diameter of the rolling element 4 is defined as D [mm]. The number of rolling elements 4 is defined as Z. The contact angle of the rolling element 4 is defined as α [rad]. The rotational frequency of the inner ring 2 is defined as fr [rev / sec or rps]. Then the period Tr i the characteristic vibrations resulting from the damage to the inner ring 2, the period Tr o the characteristic vibrations resulting from the damage to the outer ring 3, and the period Tr b the characteristic vibrations resulting from the damage to the rolling element 4, each expressed by the following expression (1), expression (2) and expression (3). Mathematical expression 1 Tri=2frZ(DD+dcosα) Mathematical expression 2 Tro=2frZ(DD−dcosα) Mathematical expression 3 Trb=2dfrD(D2D2−d2cos2α)

[0044] Regardless of the position where the damaged area 100 occurred beneath the inner ring 2, the outer ring 3, and the rolling element 4, the behavior of any part that descends and falls within the recess area 101 of the damaged area 100 and that rises and emerges from the recess area 101 occurs at least twice during the period Tr. The first calculation unit 10 calculates a maximum velocity component in the direction in which the load acts from the rotating shaft 5 and a maximum velocity component in the opposite direction, within a period equal to or longer than the period Tr, using the time-series velocity data based on the output signal from the behavior sensor 8.

[0045] The first calculation unit 10 adds the absolute values ​​of the two maximum velocity components and thus obtains the evaluation velocity. As a result of the diagnostic unit 11 diagnosing the damage to the rolling bearing 1 in this way, based on the evaluation velocity obtained by the first calculation unit 10, the following applies: Regardless of the position where the damaged area 100 occurred under the inner ring 2, the outer ring 3, and the rolling element 4, the diagnostic unit 7 can diagnose the size or extent of the damaged area 100 with high accuracy.

[0046] Furthermore, the diagnostic unit 11 can provide an anomaly diagnosis indicating that damage has occurred to the rolling bearing 1 if the evaluation speed exceeds a predefined threshold. Additionally, the diagnostic unit 11 can diagnose the size or extent of the damaged area 100, such as the depth of the recess 101, with high accuracy through a diagnosis based on the evaluation speed.

[0047] As described above, the rolling bearing 1 according to the first embodiment comprises the inner ring 2, the outer ring 3, the 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 running surface of the outer ring 3 and the running surface of the inner ring 2. Each of the rolling elements 4 rolls in conjunction 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 in an integrated manner with the inner ring 2 or the outer ring 3.

[0048] The diagnostic device 7 comprises the behavior sensor 8, the first processing unit 10, and the diagnostic unit 11. The behavior sensor 8 is located on the housing 6, which holds the inner ring 2 or the outer ring 3. The behavior sensor 8 measures the behavior of the housing 6. The first processing 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 velocity component in the direction in which the load acts from the rotating shaft 5 and the maximum velocity component in the direction opposite to the direction in which the load acts from the rotating shaft 5, within a period equal to or longer than the period Tr of the characteristic vibrations determined by the specifications of the rolling bearing 1.The diagnostic unit 11 diagnoses the damage to the rolling bearing 1 using the evaluation index based on the evaluation speed, calculated by the first calculation unit 10.

[0049] As a comparative example, consider the case where damage to the rolling bearing is diagnosed solely based on the amplitude of the vibrations in the output signal from the vibration sensor, without any dependence on the evaluation index based on the evaluation speed, unlike diagnostic device 7. When the rolling element of the rolling bearing passes through the damaged area, it is common for fine and small vibrations to occur several times. Consequently, even if the damaged area becomes large, the amplitude of the vibrations will not be large, and therefore, there is a case where the damage cannot be diagnosed with high accuracy based solely on the amplitude of the vibrations.

[0050] If the shape of the damaged corner area becomes smooth due to wear and tear, the rolling element passes over it without interference. Consequently, the impact of the damaged area does not appear in the vibration amplitude, and the damage goes undetected. Furthermore, if the shape of the damaged corner area is sharp, even if the recessed area of ​​the damaged section is small, a sudden change in behavior can occur as the rolling element passes over it. In this case, vibrations can occur where the acceleration alternately increases in the direction of loading and unloading.

[0051] This can lead to large acceleration amplitudes, regardless of the size of the recessed area, and consequently, it can be difficult to accurately diagnose the extent of the damage itself, such as the size of the recessed area. Furthermore, the rolling bearing vibrations may include high-frequency vibrations caused by sliding friction and similar factors. Therefore, the intensity of the vibrations can vary depending on the lubrication condition of the rolling bearing.

[0052] For example, if the lubrication condition deteriorates due to oxidation of the lubricant lubricating the rolling bearing, oil separation, leakage, degradation of a thickening agent, or similar factors, then vibrations may increase several times, even if no damage is present in the rolling bearing itself. In this way, the diagnosis, which is based solely on the amplitude of the vibrations, is affected by a change in the lubrication condition of the rolling bearing, and consequently, the diagnostic accuracy of the rolling bearing damage may be reduced.

[0053] On the other hand, the diagnostic device 7 performs a diagnosis using the evaluation velocity, which is the sum of the maximum velocity component in the loading direction at the time when the rolling element 4 descends in the recess area 101 and the maximum velocity component in the anti-load direction at the time when the rolling element 4 exits the recess area 101. The instantaneous behavior that occurs when the rolling element 4 passes through the damaged corner area 102 manifests as an instantaneous acceleration amplitude.

[0054] The velocity obtained by integrating such an instantaneous acceleration amplitude is hardly large and is relatively smaller than the velocities at the time when the rolling element 4 is sinking in the recess area 101 and at the time when the rolling element 4 is moving out of the recess area 101. The diagnosis is performed using the evaluation velocity, which is the sum of these velocities, and consequently the diagnostic device 7 can suppress the influence of the instantaneous behavior of the rolling element 4 by the shape of the damaged corner area 102 on the diagnosis.

[0055] Furthermore, both the maximum velocity component in the loading direction and the maximum velocity component in the anti-load direction increase as the depth of the recess area 101 increases. The diagnostic device 7, which uses the evaluation speed with a strong correlation to the depth of the recess area 101, can diagnose the depth of the recess area 101 with high accuracy. Furthermore, the evaluation speed is increased by the geometric shape of the recess area 101, and the following applies: In contrast to a device that performs a diagnosis based on vibrations containing a high-frequency band caused by sliding friction, the diagnostic device 7 can diagnose damage to the rolling bearing 1 with high accuracy while suppressing the influence of the lubrication condition.

[0056] Furthermore, the rolling bearing is typically the area subjected to the greatest load in the rotating equipment and is therefore likely to be the first to be damaged. If damage occurs to the rolling bearing, it can worsen at an accelerated rate as a result of the increasing loads in the area of ​​the damage. As the damage becomes extensive, there is a possibility of bearing failure, damage or failure of the peripheral components of the rolling bearing, serious malfunction of the entire rotating equipment in which the rolling bearing is located, and so on.

[0057] In light of this, the diagnostic device 7 can diagnose damage to the rolling bearing 1 with high accuracy, thus enabling preventive maintenance of the rolling bearing 1. This makes it possible to prevent malfunctions 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 located.

[0058] Fig. Figure 3 is a diagram to illustrate another example of the diagnosis of damage to the rolling bearing by the diagnostic device according to the first embodiment.

[0059] Fig. Figure 3 illustrates the damaged area 100, which has the recess area 101 that is asymmetrical in the circumferential direction, as another example of damage that can occur on the rolling bearing 1.

[0060] There is a case where, in such a damaged area 100, the maximum velocity component in the loading direction and the maximum velocity component in the anti-load direction differ, depending on the direction of rotation of the rotating shaft 5. Even in this case, the diagnostic device 7 can diagnose the damage to the rolling bearing 1 with high accuracy, regardless of the direction of rotation, by performing a diagnosis using the evaluation velocity, which is the sum of the maximum velocity component in the loading direction and the maximum velocity component in the anti-load direction.

[0061] For example, in Fig. As shown in Figure 3, in the rolling bearing 1, where the inner ring 2 rotates counterclockwise in the plane of the paper in conjunction with the rotating shaft 5, there is a case where the side of the damaged area 100 opposite the direction of rotation of the recess 101 is more steeply inclined than the side of the direction of rotation. Compared to the damaged area 100, which is symmetrical in the circumferential direction, the maximum velocity component in the loading direction can become large at the time when the rolling element 4 descends in the recess 101, and the maximum velocity component in the unloading direction can become small at the time when the rolling element 4 moves out of the recess 101.

[0062] Furthermore, in a case where the rotating shaft 5 rotates backwards, the maximum velocity component in the loading direction can become small at the time when the rolling element 4 descends in the recess area 101, and the maximum velocity component in the reversing direction can become large at the time when the rolling element 4 moves out of the recess area 101. In other words, there is a case in which the maximum velocity component in the loading direction and the maximum velocity component in the reversing direction can differ in magnitude depending on the direction of rotation of the rotating shaft 5, and this occurs for the same recess area 101.

[0063] On the other hand, the magnitude of the evaluation speed, which is the total value of the maximum speed component in the loading direction, and the maximum speed component in the unloading direction do not change significantly depending on the direction of rotation. The diagnostic device 7 performs a diagnosis using the evaluation speed, and consequently, it can diagnose damage to the rolling bearing 1 with higher accuracy, while suppressing the influence of the rotation direction of the rotating shaft 5. In particular, for the rolling bearing 1 intended for use with rotating equipment, such as an elevator, a rail vehicle, and a generator, which rotate in both directions and where the direction of rotation can change, the diagnostic device 7 performs a function capable of carrying out the diagnosis more effectively and without being influenced by the direction of rotation.

[0064] In each of the embodiments described below, the differences from the examples in the other embodiments are described in detail. With regard to any features not described in each of the embodiments below, any features in the examples described in the other embodiments may be used. Second embodiment

[0065] Fig. Figure 4 is a configuration diagram of a rolling bearing according to a second embodiment.

[0066] The control unit 9 of the diagnostic device 7 of the rolling bearing 1 has the first calculation unit 10, a second calculation unit 12 and the diagnostic unit 11.

[0067] The second calculation unit 12 is a part with a function for calculating an acceleration frequency spectrum, a total acceleration value or both, based on the information acquired by the behavior sensor 8.

[0068] The second processing unit 12 calculates the acceleration frequency spectrum, the total acceleration value, or both, by processing the output signal from the behavior sensor 8. For example, if the behavior sensor 8 is an acceleration sensor, the second processing unit 12 calculates the acceleration frequency spectrum, the total acceleration value, or both, using time-series acceleration data that is the output signal from the behavior sensor 8. Furthermore, if the behavior sensor 8 is a velocity sensor, the second processing unit 12 can differentiate time-series velocity data that is the output signal from the behavior sensor 8 and thus calculate time-series acceleration data.In this case, the second calculation unit 12 calculates the acceleration frequency spectrum, the total acceleration value, or both, using the calculated time series data of the acceleration.

[0069] Furthermore, in a case where the behavior sensor 8 is a displacement sensor, the second processing unit 12 can differentiate twice with respect to time: firstly, the time-series data of the displacement, which is the output signal from the behavior sensor 8, and secondly, the time-series data of the acceleration. In this case, the second processing unit 12 calculates the acceleration frequency spectrum, the total acceleration value, or both, using the calculated time-series data of the acceleration. The second processing unit 12 can calculate the acceleration frequency spectrum, the total acceleration value, or both, for example, for a period equal to or longer than the period Tr for which the evaluation speed is calculated by the first processing unit 10, or it can calculate the acceleration frequency spectrum, the total acceleration value, or both for a longer or shorter period.

[0070] The acceleration frequency spectrum is the strength of an acceleration amplitude spectrum obtained for each frequency by performing a calculation, such as a Fourier transform, on the time series data of the acceleration acquired using the behavior sensor 8.

[0071] The evaluation vibration is an evaluation index calculated based on both the evaluation speed and the acceleration frequency spectrum. Consequently, the location of the damaged area 100 can be determined, and its size can be diagnosed with higher accuracy. In particular, using the acceleration amplitude spectrum in the frequency band of the characteristic vibrations, which is the inverse of the period of the characteristic vibrations of the rolling bearing, allows for the detection of characteristic vibrations originating from the damage, and in detail for each location of the damaged area 100, such as the inner ring 2, the outer ring 3, or the rolling element 4.

[0072] This enables the diagnostic unit 11 to determine the position under the inner ring 2, the outer ring 3, or the rolling element 4 of the rolling bearing 1 where the damaged area 100 has occurred. Furthermore, the diagnostic unit 11 can diagnose the size of the damaged area 100 with high accuracy using information regarding the strength of the acceleration amplitude spectrum in the frequency band of the characteristic vibrations.

[0073] The total acceleration value is an integrated value of the strengths of the entire acceleration frequency spectra, regardless of the frequency band for the information, such as time series data and the like, which is captured by the behavior sensor 8.

[0074] In a case where minor damage, such as wear or a rough surface on the running surface or the like, has occurred on which the rolling element 4 rolls, then the rolling element 4 barely sinks downwards into or barely moves out of the recess area 101. In this case, the rise range of the evaluation speed becomes small. On the other hand, the total acceleration value is the integrated value of the magnitudes of the entire acceleration frequency spectra, regardless of the frequency band, and consequently, it also increases significantly due to minor wear, rough surfaces, or the like. The evaluation vibration is an evaluation index that is calculated based on both the evaluation speed and the total acceleration value, and consequently, the diagnostic device 7 can also diagnose minor damage, such as wear or a rough surface, with high accuracy.

[0075] As described above, the diagnostic unit 11 calculates the evaluation vibration as the evaluation index using the evaluation speed calculated by the first computation unit 10 and the acceleration frequency spectrum calculated by the second computation unit 12, the total acceleration value, or both. Furthermore, the diagnostic unit 11 calculates the evaluation vibration, for example, by multiplying each of the evaluation speed and the acceleration frequency spectrum, the total acceleration value, or both by a weighting coefficient and summing the results. The diagnostic unit 11 can also calculate the evaluation vibration, for example, by using an arithmetic mean, a geometric mean, or other functions of the evaluation speed and the acceleration frequency spectrum, the total acceleration value, or both.

[0076] For example, diagnostic unit 11 provides a diagnosis indicating that damage has occurred to rolling bearing 1 when the evaluation vibration exceeds a predefined threshold. Here, the weighting coefficient and function are determined in advance, for example, using a data analysis method such as regression analysis or machine learning, which takes as input data the evaluation speed and acceleration frequency spectrum, the total acceleration value, or both, calculated for a plurality of rolling bearings 1 for which the extent of the damage is known.As a result of the weighting coefficient and the function determined using information about rolling bearing 1, for which the damage size is known, the correlation between the evaluation vibration and the size and location of the damage becomes strong. This further improves the diagnostic accuracy of the damage to rolling bearing 1 using the evaluation vibration as the evaluation index. Third embodiment

[0077] Fig. Figure 5 is a diagram illustrating an example of the diagnosis of damage to a rolling bearing by a diagnostic device according to a third embodiment.

[0078] Fig. 5 indicates the course of time on the horizontal axis. Fig. Figure 5 indicates the velocity detected by the behavior sensor 8 on the vertical axis. The upper side of the vertical axis indicates the velocity magnitude in the direction of load. The lower side of the vertical axis, in turn, indicates the velocity magnitude in the direction of rebound.

[0079] For example, in a case where the velocity time series data are calculated by performing a time integration of the acceleration time series data using the accelerometer as a behavior sensor 8, as shown by the dashed line in Fig. As indicated in 5, the velocity in the loading direction can increase dramatically over a period equal to or longer than the period Tr. This occurs as a result of poor acceleration time series data, which constitute the output signal and is shifted overall in the loading direction, in a case where the behavior sensor 8, which is the accelerometer, is in an optimal mounting condition, in a case where disturbances, such as other turbulence vibrations, are strongly reflected, or the like. For a similar reason, the velocity in the anti-load direction can increase over a period equal to or longer than the period Tr.

[0080] On the other hand, the following applies: Even if there is a case in which minor vibrations can occur in the rolling bearing 1 and the housing 6, the mounting locations of the rolling bearing 1 and the housing 6 do not normally change much. Consequently, the condition in which the speed increases over a long period of time is as shown by the dashed line in Fig. Figure 5 shows a different state than the actual state, and if such time series data are used as is, an evaluation velocity Vp is calculated as an excessive value. Consequently, the diagnostic device 7 performs a slope correction of the velocity time series data.

[0081] The first processing unit 10 of the diagnostic device 7 performs slope correction processing on the time-series velocity data based on information acquired by the behavior sensor 8. This slope correction processing is carried out, for example, by obtaining a slope component from the time-series velocity data using linear regression or other methods over a period equal to or longer than the period Tr, and then subtracting this slope component from the time-series velocity data. The first processing unit 10 then calculates an evaluation velocity Vp' for the period equal to or longer than the period Tr, using the time-series velocity data that has undergone slope correction processing.

[0082] The diagnostic device 7 can diagnose damage to the rolling bearing 1 without being affected by the mounting condition of the behavior sensor 8 and disturbances such as turbulence vibration by using the evaluation speed Vp' calculated in this way. Fourth embodiment

[0083] The first processing unit 10 of the diagnostic device 7 performs frequency filter processing of the time series data based on the information acquired by the behavior sensor 8. The first processing unit 10 performs frequency filter processing of the time series data of, for example, acceleration, velocity, or displacement acquired by the behavior sensor 8. The first processing unit 10 can perform frequency filter processing of the velocity time series data derived from the acceleration or displacement time series data acquired by the behavior sensor 8.

[0084] Furthermore, the first processing unit 10 can perform frequency filter processing on both the time series data acquired by the behavior sensor 8 and the time series velocity data derived from the time series data. Frequency filter processing includes, for example, high-pass, low-pass, band-pass, or other types of filter processing. The first processing unit 10 calculates the evaluation velocity for the period equal to or longer than the period Tr, using the velocity time series data that has undergone frequency filter processing.

[0085] The use of the evaluation speed calculated in this way enables the diagnostic device 7 to diagnose the damage to the rolling bearing 1 without being affected by low-frequency vibrations caused by impacts and the like, high-frequency vibrations caused by friction and the like, disturbances, turbulence vibrations, and the like. Fifth embodiment

[0086] Diagnostic Unit 11 of Diagnostic Unit 7 diagnoses damage to rolling bearing 1 by using an evaluation index statistic obtained by statistically processing a data set of evaluation indices, such as evaluation velocities or evaluation vibration, which is calculated multiple times. The evaluation index statistic is, for example, the mean, median, RMS, or maximum value for the data set of evaluation indices. Diagnostic Unit 11 provides a diagnosis indicating that damage to rolling bearing 1 has occurred, for example, if the evaluation index statistic exceeds a predefined threshold.

[0087] Each evaluation index, such as an evaluation rate or evaluation vibration at any given time, calculated by the first processing unit 10, and the like, can assume an extremely large value, for example, as a result of the behavior sensor 8 detecting an unexpected turbulence vibration or the like, which is irrelevant to the damage of the rolling bearing 1. In light of this, the diagnostic unit 11 performs the diagnosis using the evaluation index statistics, such as the mean value, the median value, the RMS value, and the like, which are obtained by statistically processing the data set of evaluation indices. Consequently, the diagnostic unit 7 can perform the diagnosis without being affected by an unexpected event that is irrelevant to the damage of the rolling bearing 1.

[0088] Furthermore, for example, the evaluation index, such as the evaluation speed and the evaluation vibration, can become large at a low frequency in a stage where the damage to the rolling bearing 1 is small. In light of this, the diagnostic unit 11 performs the diagnosis using the evaluation index statistics, such as the maximum value obtained by statistically processing the evaluation index data set. Consequently, the diagnostic unit 7 can diagnose the occurrence of damage at a small stage earlier.

[0089] Furthermore, the evaluation index, such as the evaluation speed and evaluation vibration, can change rapidly, specifically in a state where the damage to the rolling bearing 1 is progressing rapidly. In light of this, the diagnostic unit 11 performs the diagnosis using evaluation index statistics, such as a standard deviation value or a variance value, obtained by statistically processing the evaluation index data set. Consequently, the diagnostic unit 7 can further diagnose a progressive state of damage. Sixth embodiment

[0090] The diagnostic unit 11 of the diagnostic device 7 diagnoses damage to the rolling bearing 1 on the basis of a cyclic change in the evaluation index, such as the evaluation speed or the evaluation vibration, which is continuously calculated so that temporarily successive evaluation speeds or evaluation vibrations are obtained.

[0091] For example, in the time series data of the evaluation index, calculated by the diagnostic unit 11, and the like, the evaluation index becomes large at a time when the rolling element 4 passes through the damaged area 100, and essentially corresponds to the period Tr of the characteristic vibrations determined by the specifications of the rolling bearing 1. On the other hand, the period of the rolling element 4 passing through the damaged area 100 is determined by expressions (1) to (3), using the position where the damaged area 100 occurred, the dimensions of the rolling bearing 1, the rotational speed of the rotating shaft 5, and the like.Consequently, the diagnostic unit 11 can determine a position under the inner ring 2, the outer ring 3 or the rolling element 4 of the rolling bearing 1 where the damaged area 100 has occurred, based on the period, frequency or the like at which the evaluation index becomes large, on the basis of the dimensions and the rotational speed of the rolling bearing 1.

[0092] Furthermore, the diagnostic unit 11 can diagnose the size of the damaged area 100 based on the evaluation index during the period in which the evaluation index becomes large. This allows the diagnostic unit 11 to diagnose the size of the damaged area 100 with high accuracy, unaffected by disturbances such as turbulence, vibrations, and the like. For example, the diagnostic unit 11 can diagnose the location where the damaged area 100 occurred from a frequency band with a large spectrum, using frequency analysis data obtained by performing a frequency analysis of the time series data of the evaluation index. The diagnostic unit 11 can diagnose the size of the damaged area 100 with high accuracy, unaffected by disturbances such as...Turbulence vibrations are influenced, for example by diagnosing the size of the damaged area 100 from the strength of the spectrum in a specific frequency band. Seventh embodiment

[0093] Fig. Figure 6 is a configuration diagram of a rolling bearing according to a seventh embodiment.

[0094] The control unit 9 of the diagnostic device 7 of the rolling bearing 1 has the first calculation unit 10, a storage unit 13 and the diagnostic unit 11.

[0095] Storage unit 13 is a unit whose function is to store information. Storage unit 13 accumulates and stores the calculated evaluation index. Storage unit 13 stores the evaluation indices, for example, as time series data. For instance, storage unit 13 stores the time series data of the evaluation speed as the evaluation index. In a case where diagnostic unit 7 calculates the evaluation vibration as the evaluation index, storage unit 13 can store time series data of one or both the evaluation speed and the evaluation vibration as the evaluation index. Storage unit 13 stores a change in the evaluation index over time by storing the evaluation index as time series data. Furthermore, storage unit 13 can, for example, store a change value, such as a time difference value of the evaluation index calculated by diagnostic unit 11, and the like.

[0096] In rotary equipment where multiple rolling bearings 1 with different specification conditions, such as size and speed, are arranged, the following applies: Even if the magnitude of the damage occurring in the respective rolling bearings 1 is the same, the evaluation index, such as the evaluation rate and evaluation vibration, can assume different values ​​depending on the differences in the operating conditions. For example, the evaluation rate and evaluation vibration for damage of the same degree tend to increase as the size and speed of the rolling bearing 1 increase.

[0097] The diagnostic unit 11 diagnoses damage to the rolling bearing 1 based on information stored in the storage unit 13. For example, the diagnostic unit 11 calculates a first-order differential value of the evaluation index, which is the rate of change of the evaluation index over time, and diagnoses a damage condition from this first-order differential value. Thus, the diagnostic unit 11 diagnoses the damage condition based on the rate of change of the evaluation index, making it possible to diagnose damage to the rolling bearing 1 with higher accuracy under different description conditions.

[0098] Furthermore, the diagnostic unit 11 can estimate the remaining service life until the evaluation index reaches a threshold value that represents the service life of the rolling bearing 1, based on the time series data of the evaluation index and the like, which are stored in the storage unit 13. This enables the diagnostic device 7 to determine a suitable replacement or maintenance inspection time for the rolling bearing 1. In this way, the diagnostic device 7 can contribute to labor savings during maintenance and to the stable long-term operation of the rolling bearing 1, the peripheral equipment of the rolling bearing 1, and the entire rotating equipment in which the rolling bearing 1 is located. Eighth embodiment

[0099] The rolling bearing 1 has the inner ring 2, the outer ring 3, the plurality of rolling elements 4, the rotating shaft 5 and the diagnostic device 7.

[0100] Typically, the rolling bearing is the area subjected to the greatest load in rotating equipment and is therefore likely to be the first to be damaged. When damage occurs to the rolling bearing, it can sometimes worsen rapidly as a result of increased stresses in the area of ​​damage. As the damage becomes extensive, the behavior of the entire rotating equipment, including the rotating shaft, becomes unstable, potentially leading to damage to peripheral components such as the bearing's drive shaft, gearbox and coupling, stator, housing, frame, or similar parts.

[0101] In view of this, the rolling bearing 1 can diagnose damage to the rolling bearing 1 and the rotating equipment in which the rolling bearing 1 is located with high accuracy by means of the attached diagnostic device 7. This makes it possible to prevent in advance a malfunction of the peripheral equipment of the rolling bearing 1 and the entire rotating equipment in which the rolling bearing 1 is located, as well as of the rolling bearing 1 itself.

[0102] In the rolling bearing 1 according to one of the first to eighth embodiments, the rolling bearing 1 can, for example, use a configuration in which both the inner ring 2 and the outer ring 3 rotate in an integrated manner with different rotating shafts 5. Ninth embodiment

[0103] Fig. Figure 7 is a configuration diagram of the rolling bearing 1 according to a ninth embodiment.

[0104] A rolling bearing 1 comprises the inner ring 2, the outer ring 3, the plurality of rolling elements 4, and the rotating shaft 5. Fig. Figure 1 illustrates a section of the rolling bearing 1 along a plane perpendicular to the core of the rotating shaft 5. The inner ring 2 and the outer ring 3 are cylindrical. The outer ring 3 is arranged concentrically with the inner ring 2, outside the inner ring 2. The majority of rolling elements 4 are arranged between the inner ring 2 and the outer ring 3. Each of the rolling elements 4 has a rolling shape, such as a spherical or columnar shape. The rolling elements 4 are arranged between a raceway that is an inner peripheral face of the outer ring 3 and a raceway that is an outer peripheral face of the inner ring 2. The rolling elements 4 roll in sync with the rotation of the inner ring 2 and the rotation of the outer ring 3.In a case where individual rolling elements 4 are distinguished from one another, one of the plurality of rolling elements 4 can be described as a rolling element 4a, a rolling element 4b or the like.

[0105] The rotating shaft 5 rotates in an integrated manner with the inner ring 2 or the outer ring 3. In this example, the rotating shaft 5 rotates counterclockwise in the plane of the paper. Fig. 1. Here, the wave direction along the core of the rotating shaft 5, i.e., the direction of travel of the rotating shaft 5, can simply be referred to as the wave direction. Furthermore, the circumferential direction around the core of the rotating shaft 5, i.e., the direction of rotation of the rotating shaft 5, can simply be referred to as the circumferential direction. In addition, the outward direction from the core of the rotating shaft 5 can simply be referred to as the radial direction.

[0106] In the rolling bearing 1 in this example, the inner ring 2 rotates in an integrated manner with the rotating shaft 5, and the outer ring 3 is held and fixed in the housing 6. It should be noted that in the rolling bearing 1, the outer ring 2 can also be held and fixed in the housing 6, and the outer ring 3 can rotate in an integrated manner with the rotating shaft 5, which is located outside the outer ring 3.

[0107] The rolling bearing 1 is held in the housing 6. The housing 6 holds the inner ring 2 or the outer ring 3 of the rolling bearing 1.

[0108] The diagnostic device 7 is used in the rolling bearing 1. The diagnostic device 7 diagnoses damage and similar conditions of the rolling bearing 1. The diagnostic device 7 can be integrated as part of a rotating device, such as a motor, in which the rolling bearing 1 is located, or it can be an external device intended for use with the rotating device. The diagnostic device 7 can be permanently located within the rolling bearing 1 or the rotating device in which the rolling bearing 1 is located, or it can be temporarily located as a portable device within the rolling bearing 1 or the rotating device in which the rolling bearing 1 is located. The diagnostic device 7 includes the behavior sensor 8 and the control unit 9.

[0109] 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 behavior of the inner ring 2, the outer ring 3, or the housing 6. The behavior sensor 8 is, for example, an accelerometer, a displacement sensor, or a velocity sensor.

[0110] The control unit 9 performs data processing in the diagnostic unit 7. The control unit 9 can contain one or more independent hardware components or be part of other hardware, such as the control equipment of the rotary equipment in which the rolling bearing 1 is located. The control unit 9 includes a processing unit 14 and a diagnostic unit 11.

[0111] The calculation unit 14 is a component whose function is to calculate an evaluation velocity used for diagnosing the rolling bearing 1. The evaluation velocity is calculated for a period equal to or longer than the period Tr of the characteristic vibrations, which are determined by the specifications of the rolling bearing 1. The evaluation velocity is a maximum velocity component in a direction in which the load acts from the rotating shaft 5 within this period. The direction in which the load acts from the rotating shaft 5 is, for example, an outward direction in the radial direction or a downward direction in the vertical direction.

[0112] In this case, the direction opposite to the direction in which the load acts from the rotating shaft 5 is an inward direction in the radial direction or an upward direction in the vertical direction. Here, the direction in which the load acts from the rotating shaft 5 and the direction opposite to the direction in which the load acts from the rotating shaft 5 can be expressed as a loading direction and an anti-load direction. The calculation unit 14 can have some or all of the functions of the first calculation unit 10, the second calculation unit 12, and the like in the diagnostic device 7 according to other embodiments.

[0113] The processing unit 14 calculates the evaluation speed by processing the output signal from the behavior sensor 8. For example, if the behavior sensor 8 is a velocity sensor, the processing unit 14 calculates the evaluation speed using time-series data of a velocity, which is the output signal from the behavior sensor 8. Furthermore, if the behavior sensor 8 is an acceleration sensor, the processing unit 14 performs time integration of the time-series data of an acceleration, which is the output signal from the behavior sensor 8, and thus calculates the time-series data of the velocity. In this case, the processing unit 14 calculates the evaluation speed using the calculated time-series data of the velocity.

[0114] Furthermore, in a case where the behavior sensor 8 is a displacement sensor, the computation unit 14 differentiates – with respect to time – time series data of a displacement, which is the output signal from the behavior sensor 8, and thus calculates the time series data of the velocity. In this case, the computation unit 14 calculates the evaluation velocity using the calculated time series data of the velocity.

[0115] The calculation unit 14 calculates - as evaluation speed - a maximum velocity component in the direction in which the load acts from the rotating shaft 5, from time series data of the velocity for a period equal to or longer than the period Tr, which is predetermined.

[0116] The diagnostic unit 11 is a component with a function for diagnosing damage to the rolling bearing 1 by using an evaluation index based on the evaluation speed calculated by the computation unit 14. In this example, the diagnostic unit 11 diagnoses the damage to the rolling bearing 1 using the evaluation index based on the evaluation speed calculated by the computation unit 14 and the relative rotational speed of the inner ring 2 and the outer ring 3.

[0117] Next, an example of diagnosing damage to rolling bearing 1 using the diagnostic device 7 will be given. Fig. 8 described. Fig. Figure 8 is a diagram illustrating an example of the diagnosis of damage to the rolling bearing 1 by the diagnostic device according to the ninth embodiment. Fig. Figure 8 illustrates the damaged area 100 as an example of the damage that can occur on the rolling bearing 1. The damaged area 100 occurs in the rolling bearing 1, for example, as follows.

[0118] In the rolling bearing 1 in this example, the rotating shaft 5 rotates counterclockwise in the plane of the paper, in an integrated manner with the inner ring 2. In this case, each rolling element 4 in contact with the running surface of the inner ring 2 rotates such that it orbits counterclockwise in the plane of the paper about a central axis of the rotating shaft 5 between the inner ring 2 and the outer ring 3, while rotating clockwise in the plane of the paper about a central point of the rolling element 4 itself, in conjunction with the rotation of the inner ring 2. In other words, the majority of rolling elements 4 located between the inner ring 2 and the outer ring 3 rotate circumferentially, so that they orbit between the inner ring 2 and the outer ring 3, rolling in conjunction with the rotation of the inner ring 2.

[0119] While an example is described in which the inner ring 2 rotates, in a case where the outer ring 3 also rotates, the majority of rolling elements 4 located between the inner ring 2 and the outer ring 3 rotate circumferentially, so that they orbit between the inner ring 2 and the outer ring 3, rolling in sync with the rotation of the outer ring 3 or the rotation of both the inner ring 2 and the outer ring 3. The rolling speed of the rolling element 4 around its central point is proportional to the relative rotational speed of the inner ring 2 and the outer ring 3.The rotational speed of the rolling element 4 in the circumferential direction around the central axis of the rotating shaft 5 is proportional to the relative rotational speed of the inner ring 2 and the outer ring 3, and to the diameter of the trajectory of the center of the rolling element 4 when the rolling element 4 moves rotationally in the circumferential direction so that it revolves around the central axis of the rotating shaft 5.

[0120] In a case where the load on the inner ring 2 is exerted downwards in the plane of the paper by the load of the rotating shaft 5 and the like, most of the load is transferred from the rotating shaft 5 to the running surface of the inner ring 2 and the running surface of the outer ring 3 via the majority of rolling elements 4 and the like located below the rotating shaft 5. When the rotating shaft 5 is stationary, the position and magnitude of the load acting on each of the inner ring 2, the outer ring 3, and the rolling element 4 do not change significantly. However, when the rotating shaft 5 is rotating, the position and magnitude of the load change periodically, in conjunction with the rotational movement of the inner ring 2 and the rolling element 4. This results in repetitive loads acting on the running surfaces of the inner ring 2 and the outer ring 3, as well as on the rolling element 4.As a result of such repetitive stresses, for example, a crack originating from impurities within a material can propagate from the interior of the inner ring 2, the outer ring 3, the rolling element 4, or the like, and reach a surface. In this case, flaking damage originating from the inside, which is a scale-like flaking from a surface zone, can occur on the running surface or the like of the inner ring 2, the outer ring 3, or the rolling element 4.

[0121] Furthermore, abnormal slippage or sliding can occur between the rolling element 4, the inner ring 2, and the outer ring 3 due to poor lubrication of the running surface. This can result from insufficient lubrication with a lubricant such as grease, deterioration, leakage or insufficient efflux, insufficient viscosity, excessive load, or similar factors. In this case, loads are likely to concentrate on one surface of the running surface due to a rough surface, wear, or similar defects, and the damage to the running surface can be further accelerated. For example, surface damage such as flaking of a surface zone of part of the running surface, wear damage, seizing damage, or similar defects may occur on the running surface.

[0122] Regarding internal flaking damage, there is a lifetime design formula called L10 life, and the specifications of the rolling bearing 1 are usually determined based on this lifetime design formula. Consequently, internal flaking damage rarely occurs. On the other hand, surface flaking damage can occur much earlier than internal flaking damage. Therefore, it is important to diagnose the condition of the rotating equipment to ensure reliability and achieve long-term operation of the rolling bearing 1 and the rotating equipment in which the rolling bearing 1 is installed.

[0123] Based on the knowledge obtained from the bearing test, the damaged area 100 is frequently formed on the running surface of the rolling bearing 1 by flaking damage. Furthermore, the damaged area 100 is often formed from the recessed area 101 and the damaged corner area 102. It is assumed that the sizes and shapes of the recessed area 101 and the damaged corner area 102 change according to the total number of rotations of the rolling bearing 1, which is the cumulative number of relative rotations of the inner ring 2 and the outer ring 3 of the rolling bearing 1. Furthermore, the recessed area 101 becomes larger as the total number of rotations of the rolling bearing 1 increases.

[0124] On the other hand, it was confirmed that the shape of the damaged corner area 102 is sharp in an initial stage of the damage, but can subsequently change to a smooth shape due to wear and tear. In a case where the damaged area 100 is caused by flaking damage originating from the surface, the depth of the recessed area 101 is shallow in an initial stage of the damage, and consequently, the recessed area 101 increases in the wave direction and circumferential direction, and it also becomes deeper in the radial direction as the damage progresses.

[0125] While the sharpening of the damaged corner area 102 may increase instantaneous vibrations or impacts, it does not lead to significant chatter in the entire rotating assembly. Consequently, the service life of the rolling bearing 1 and the rotating assembly in which the rolling bearing 1 is located is less affected by the damaged corner area 102. Furthermore, the shape of the damaged corner area 102 is easily altered by wear and tear, and therefore it is unsuitable for diagnostic use. On the other hand, the recess area 101 becomes larger as the total number of revolutions of the rolling bearing 1 increases, which can lead to a continuous increase in chatter, flutter, or other abnormal disturbances of the rolling bearing 1, its peripheral components, and the entire rotating assembly in which the rolling bearing 1 is located.Consequently, the size of the recess area 101 strongly influences the service life of the rolling bearing 1 and the entire rotating equipment in which the rolling bearing 1 is arranged, and consequently, a diagnosis of the size of the recess area 101 leads to a diagnosis of the service life of the entire rotating equipment.

[0126] As in Fig. Figure 1 illustrates, for example, a case in which, in the inner-ring rotary bearing 1, where the inner ring 2 rotates along with the rotating shaft 5, the recess area 101 is formed on the load side of the outer ring 3. As the recess area 101 enlarges, the rolling element 4 descends within the recess area 101, specifically at the point when the rolling element 4 reaches the recess area 101 in relation to the rotation of the rolling bearing 1. In this case, the rolling element 4 falls in the depth direction of the recess area 101, along with the inner ring 2 and the rotating shaft 5.

[0127] Furthermore, the rolling element 4 rises from a bottom area of ​​the recess 101, accompanied by the inner ring 2 and the rotating shaft 5, at the point when the rolling element 4 exits the recess 101. Consequently, the chatter, flutter, and abnormal disturbances of the rolling bearing 1 and the rotating shaft 5 increase as the recess 101 deepens. If the recess 101 becomes too deep, the chatter, flutter, and abnormal disturbances of the rolling bearing 1 and the rotating shaft 5 can become extremely severe. In this case, a design limit of the rotating equipment in which the rolling bearing 1 is located may be exceeded. Furthermore, this may lead to a malfunction, such as... B. a crack or fracture of the rolling bearing 1, a malfunction of peripheral equipment of the rolling bearing 1, a malfunction of the entire rotating equipment in which the rolling bearing 1 is arranged, and the like.

[0128] It is therefore important to diagnose the condition, size, or degree of damage of the rolling bearing 1, such as the depth of the recess area 101, in order to diagnose the condition, damage status, service life, and the like of the rotating equipment. By diagnosing the condition of the rolling bearing 1, it is possible to diagnose an anomaly in the rolling bearing 1, estimate its remaining service life, and perform maintenance and service life extension treatments, such as replacing the rolling bearing 1 or lubricating it at an appropriate time. Furthermore, this makes it possible to save on maintenance costs and achieve stable long-term operation of the rolling bearing 1, its peripheral components, and the entire rotating equipment in which the rolling bearing 1 is located.

[0129] Diagnostic device 7 diagnoses the damaged area 100, as shown in Fig. 8 shown, for example, as follows. The following should be noted: In Fig. Figure 8 shows an example of a case where the damaged area 100 occurred in the outer ring 3. However, the damaged area 100 can also occur in the inner ring 2 or in the rolling element 4.

[0130] The calculation unit 14 calculates the evaluation speed for a period equal to or longer than the period Tr of the characteristic vibrations determined by the specifications of the rolling bearing 1. The characteristic vibrations described here include not only the vibrations that occur when the rolling element 4 passes the damaged area 100 that has occurred in the outer ring 3, as in Fig. 2 shown, but also the vibrations that occur when the rolling element 4 passes the damaged area 100 that has occurred in the inner ring 2, as well as the vibrations that occur when the inner ring 2 and the outer ring 3 pass through the damaged area 100 that has occurred in the rolling element 4.

[0131] The following applies to the period Tr: One period of the characteristic vibrations resulting from the damage to the inner ring 2 is denoted as Tr i [sec] defined. A period of characteristic vibrations resulting from damage to the outer ring 3 is defined as Tr. o [sec] defined. A period of characteristic vibrations resulting from damage to the rolling element 4 is defined as Tr. b [sec] defined. In a case where damage has occurred on the inner ring 2, the characteristic vibrations of period Tr are iParticularly large, in a case where damage occurred on the outer ring 3, are the characteristic vibrations of period Tr. o particularly large, and in one case where damage occurred on rolling element 4, the characteristic vibrations of period Tr b especially large.

[0132] For example, in a case where the outer ring 3 has the damaged area 100, as in Fig. As shown in Figure 8, the period from the time when rolling element 4a passes the damaged area 100 until the time when rolling element 4b passes the damaged area 100 is called period Tr. oFor example, the following case is assumed: The diameter of the rolling element 4 is defined as d [mm], the diameter of the trajectory of the center of the rolling element 4 is defined as D [mm], the number of rolling elements 4 is defined as Z, the contact angle of the rolling element 4 is defined as α [rad], and the relative rotational speed of the inner ring 2 and the outer ring 3 is defined as f s [U / sec or rps].

[0133] Then the following applies: The period Tr i the characteristic vibrations resulting from damage to the inner ring 2, the period Tr o the characteristic vibrations resulting from the damage to the outer ring 3, and the period Tr bThe characteristic vibrations resulting from the damage to the rolling element 4 are expressed by the following expressions (4), (5), and (6), respectively. Here, the contact angle α of the rolling element 4 is the angle formed by a line connecting a contact point of the inner ring 2 and the rolling element 4 and a contact point of the rolling element 4 and the outer ring 3 in a section along the shaft direction of the rotating shaft 5, and a line perpendicular to the central axis of the rotating shaft 5 in the same section. Mathematical expression 4 Tri=2fsZ(11+dDcosα) Mathematical expression 5 Tro=2fsZ(11−dDcosα) Mathematical expression 6 Trb=2fs(Dd(D2−d2)cos2α)

[0134] In this way, the period Tr of the characteristic vibrations, which is determined by the specifications of the rolling bearing 1 and the relative rotational speed of the inner ring 2 and the outer ring 3, can be expressed as Tr i in expression (4) in a case where damage has occurred on the inner ring 2, it can be obtained as Tr o in expression (5) in a case where damage has occurred on the outer ring 3, and it can be considered as Tr b in expression (6) in a case where damage has occurred on the rolling element 4. At any position where the damage has occurred, the period Tr of the characteristic vibrations can be determined using the relative rotational speed f. sof the inner ring 2 and the outer ring 3, the diameter d of the rolling element 4, the diameter D of the trajectory of the center of the rolling element 4 and the contact angle or touch angle α of the rolling element 4 can be obtained.

[0135] Regarding the Tr period i Regarding the characteristic vibrations in a case where damage has occurred on the inner ring 2, the following, for example, can be derived from the relationship between the numerator and denominator of each expression. The period Tr i becomes inversely proportional to the relative rotational speed f. s increases. The period Tr i The period Tr becomes inversely proportional to its length as the number Z of rolling elements increases. i The period Tr increases as the diameter D of the trajectory of the center of the rolling element 4 increases. i The period Tr becomes shorter when the diameter d of the rolling elements 4 increases. iIt becomes longer when the contact angle α increases. Furthermore, for example, the period Tr can be... o The following can be derived from the characteristic vibrations in a case where damage has occurred on the outer ring 3.

[0136] The period Tr o becomes inversely proportional to the relative rotational speed f. s increases. The period Tr o The period Tr becomes inversely proportional to its length as the number Z of rolling elements increases. o The period Tr becomes shorter as the diameter D of the trajectory of the center of the rolling element 4 increases. o The period Tr increases as the diameter d of the rolling element increases. o It becomes shorter when the contact angle α increases. Furthermore, for example, with regard to the period Tr bThe characteristic vibrations in a case where damage has occurred on rolling element 4 are evident from the following.

[0137] The period Tr b becomes inversely proportional to the relative rotational speed f. s increases. The period Tr b becomes shorter as the contact angle α increases. Furthermore, the following applies: While the diameter D of the trajectory of the center of the rolling element 4 and the diameter d of the rolling element are included in both the numerator and the denominator of expression (6), the period Tr is calculated – taking into account that the influence of a quadratic term in the denominator is greater than the influence of a cross term in the numerator. b The trajectory is often shorter when the diameter D of the center of the rolling element 4 increases, and it becomes longer when the diameter d of the rolling element 4 increases.

[0138] It should be noted that there are different ways to measure the relative rotational speed f. s to specify according to a rotation pattern of the rolling bearing 1, and for example - as in Fig. Figure 7 illustrates that in a case where the outer ring 3 is fixed and the inner ring 2 rotates in an integrated manner with the rotating shaft 5, the relative rotational speed f s The rotational speed of the inner ring 2 or the rotational speed of the rotating shaft 5 can be specified. Furthermore, in a case where the inner ring 2 is fixed and the outer ring 3 rotates in an integrated manner with the rotating shaft, the relative rotational speed f can be specified. s as the rotational speed of the outer ring 3 or the rotational speed of the rotating shaft.

[0139] Furthermore, in a case where the inner ring 2 and the outer ring 3 rotate in the same direction in an integrated manner with different rotating shafts, the relative rotational speed f sThe absolute value of the difference between the rotational speed of the inner ring 2 and the rotational speed of the outer ring 3 can be expressed. Furthermore, in a case where the inner ring 2 and the outer ring 3 rotate in opposite directions with different rotating shafts, the relative rotational speed f can be determined. s The total rotational speed of the inner ring 2 and the rotational speed of the outer ring 3 are given as the sum of these values.

[0140] The following is an example of a diagnosis based on an equation of motion when the rolling element 4 sinks in the recess area 101.

[0141] The equation of motion when the rolling element 4 sinks in the recess area 101 is solved, and the depth h [mm] of the recess area 101 is determined using Fig. 9 calculated. Fig. Figure 9 is a diagram to illustrate an example of the behavior when the rolling element 4 of the rolling bearing 1 passes the damaged area 100.

[0142] Here, the diameter of the rolling element 4 is defined as d, the diameter of the trajectory of the center of the rolling element 4 when the rolling element 4 rotates so that it revolves counterclockwise around the central axis of the rotating shaft 5 between the inner ring 2 and the outer ring 3 in the plane of the paper is defined as D [mm], and the rotational speed in the direction of rotation of the rolling element 4 is defined as f o [rps]. Furthermore, the following applies: The period from the time when the rolling element 4 begins to descend in the recess area 101 until the time when the rolling element 4 collides with a surface of the recess area 101 is defined as t [sec], the average velocity of the rolling element 4 within the period t is defined as V [mm / sec], the average velocity in the radial direction of the rolling element 4 within the period t is defined as V r[mm / sec], the average speed in the circumferential direction of the rolling element 4 within the time period t is defined as V θ [mm / sec], the distance of movement in the circumferential direction of the rolling element 4 within the period t is defined as s [mm], and the angle formed by a line of the trajectory of the center of the rolling element 4 and a line in the radial direction connecting the center of the rotating shaft 5 and the center of the rolling element 4 within the period t is defined as β [rad].

[0143] The depth h [mm] of the recess area 101 can be expressed using the following expression (7) from a formula of a trigonometric function, and the velocity V θ in the circumferential direction of the rolling element 4 can be expressed by the following expression (8). Mathematical expression 7 h=(d2)(1−cosβ) Mathematical expression 8 Vθ=Dπfo

[0144] In a case where the load in the radial direction acting on the rolling element 4 is sufficiently large, the period t from the time when the rolling element 4 begins to sink in the recess area 101 until the time when the rolling element 4 collides with the surface of the recess area 101 is equal to the period required for the rolling element 4 to advance by the depth h of the recess area 101 at the radial direction velocity V r does, and the time required for the rolling element 4 to make a progress by the circumferential distance s at the circumferential speed V θ does. Consequently, the radial direction velocity V can r The rolling element 4 can be expressed using the following expression (9) with expression (7) and expression (8). Mathematical expression 9 Vr=ht=hsVθ=h(d2)sinβVθ=(d2)(1−cosβ)Dπfo(d2)sinβ

[0145] The following expression (10) can be obtained by further rearranging expression (9). Mathematical expression 10 (1−cosβ)=VrsinβDπfo

[0146] The following case applies here: If the restitution coefficient or the collision number, when the rolling element 4 sinks in and collides with the recess area 101, is defined as e, and the radial direction velocity of a structure that moves in coordination with the recess area 101 before the collision is defined as Vo r [mm / sec] is defined as the radial direction velocity of the structure, which moves in coordination with the recess area 101 immediately after the collision, as Vo r ' [mm / sec] is defined, and the radial direction velocity of the rolling element 4 after the collision is defined as V r' [mm / sec] is defined, then a relational expression of the respective velocities towards the restitution can be expressed by the following expression (11). Mathematical expression 11 e(Vr−Vor)=Vor'−Vr'

[0147] Furthermore, the following applies in one case: If the mass of all structures including the rolling element 4, the inner ring 2 and the rotating shaft 5, which exert a load on the recess area 101 via the rolling element 4, is defined as m [kg], and the mass of the structure that moves in coordination with the recess area 101 is defined as m o [kg] is defined, a relational expression of the respective velocities can also be expressed by the following expression (12), according to the law of conservation of momentum. Mathematical expression 12 mVr+moVor=mVr'+moVor'

[0148] Assume that the radial direction velocity Vo rSince the area of ​​the recess 101 before the collision is 0, a relational expression is used here, which V r with Vo r 'expresses, obtained using expression (11) and expression (12), and in V r is substituted into expression (10), and the following expression (13) is obtained. Mathematical expression 13 (1−cosβ)=(m+mo)Vor'sinβ(1+e)mDπfo(∵Vor=0)

[0149] When expression (13) is substituted into expression (7), the depth h of the recess area 101 can be expressed by the following expression (14). Mathematical expression 14 h=(d2)(1−cosβ)=sinβ(1+mom)2π(1+e)Dd⋅Vor'fo

[0150] If the relative rotational speed of the inner ring 2 and the outer ring 3 is given by f s If the rotational speed is defined as [U / sec or rps] and the contact angle of the rolling element 4 is defined as α [rad], the rotational speed f can be determined. o[U / sec or rps] in the direction of rotation of the rolling element 4 can be expressed by the following expression (15). Mathematical expression 15 fo=fs2(D−dcosαD)

[0151] The rotational speed f o The result in the direction of rotation of the rolling element 4 in a case where there is less slippage is also essentially the same as the result expressed by expression (15). If expression (15) is substituted into expression (14) and a constant determined by each mass and the shape and dimensions of the rolling bearing 1 is replaced as a coefficient A, the depth h of the recess area 101 can be expressed by the following expression (16). Mathematical expression 16 h=AsinβVor'fs,A=(1+mom)π(1+e)(Dd−cosα)

[0152] Here, the rolling element 4 moves in the circumferential direction by the distance s, while the rolling element 4 moves in the radial direction by the distance h, and consequently the distance of movement s in the circumferential direction can be expressed by the following expression (17), from the Pythagorean theorem. Mathematical expression 17 s=(d2)2−((d2)−h)2=dh−h2

[0153] Furthermore, sinβ, used in expression (16), can be expressed by the following expression (18), from a formula of a trigonometric function which uses the distance of movement s in the circumferential direction. Mathematical expression 18 sinβ=s(d2)=2dh−h2d

[0154] If expression (16) is substituted into expression (18) and rearranged, the depth h of the recess area 101 can be expressed by the following expression (19). Mathematical expression 19 h=d1+(d2A)21(Vor'fs)2,A=(1+mom)π(1+e)(Dd−cosα)

[0155] The radial direction velocity Vo r The velocity of the outer ring 3 or of the housing 6 that holds the outer ring 3, which is one of the structures that moves in coordination with the recess area 101, is maximized immediately after the rolling element 4 collides with the recess area 101. Consequently, the radial direction velocity Vo corresponds to r ' the 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, which rotates in an integrated manner with the inner ring 2 or the outer ring 3.

[0156] Expression (19) yields the following: Using the diameter d of the rolling element 4, the diameter D of the trajectory of the center of the rolling element 4, the mass m of all structures that exert the load on the recess area 101 via the rolling element 4 and that comprise the rolling element 4, the inner ring 2 and the rotating shaft 5, the load acting on the rolling bearing 1 from the rotating shaft 5 accordingly, and the mass m o the structure, which moves in a coordinated manner with the recess area 101 and the like, and a relative evaluation speed (Vo r ' / f s ), obtained by dividing the evaluation speed Vo r ' by the relative rotational speed f s , the depth h of the recess area 101 can be calculated.

[0157] Furthermore, it can be diagnosed from expression (19) that the depth h of the recessed area 101 is larger when the relative evaluation speed (Vo)r ' / f s ) is higher. Furthermore, a relation and the like of the numerator and denominator in expression (19) can be used in a case where the relative evaluation speed (Vo) r ' / f s ) the same, it can be diagnosed that the depth h of the recess area 101 is greater when the value obtained by dividing the mass m o the structure, which moves in coordination with the recess area 101, through which the mass m is obtained, is larger.

[0158] Here, the mass m is the mass of all structures that exert the load on the recess area 101 via the rolling element 4 and that comprise the rolling element 4, the inner ring 2, and the rotating shaft 5. Furthermore, from the relation and the like of the numerator and denominator in expression (19), in a case where the relative evaluation speed (Vo) r ' / f s) is the same, it can be diagnosed that the depth h of the recess area 101 is larger when the diameter D of the trajectory of the center of the rolling element 4 is smaller. Furthermore, from the relation and the like of the numerator and denominator in expression (19) in a case where the relative evaluation speed (Vo) r ' / f s ) the same, be diagnosed that the depth h of the recess area 101 is larger when the coefficient of restitution e is smaller when the rolling element 4 sinks downwards and collides with the recess area 101.

[0159] It should be noted that the restitution coefficient e is related to the hardness of a material, and when objects made of materials with high hardness are brought into collision with each other, the restitution coefficient e often becomes large. From the relation and the like of the numerator and denominator in expression (19) in a case where the relative evaluation speed (Vo r ' / f s ) is the same, it can therefore be diagnosed that the depth h of the recess area 101 is greater if the hardness of the rolling element 4 and the outer ring 3 with the recess area 101 is lower.

[0160] Furthermore, the logarithmic value of the material's hardness and the coefficient of restitution often have a proportional relationship, and consequently, it is possible to obtain the coefficient of restitution based on the logarithmic value of the material's hardness and to determine the depth h of the recess area 101 using expression (19). Additionally, bearing steel is frequently used as the material for the rolling element 4 and the outer ring 3 with the recess area 101, and consequently, the depth h of the recess area 101 can be determined based on the coefficient of restitution e between the bearing steel, the hardness of the bearing steel, and the like.

[0161] On the other hand, there is also the case where a material such as ceramic is used for the rolling element 4 and the like in the rolling bearing 1. It is therefore necessary to consider the influence that vibrations are expected to have on damage diagnosis, specifically through a difference in material, using vibration information. According to the configuration of the ninth embodiment, the following applies: Even if the material of the rolling bearing 1 changes, damage can be diagnosed with high accuracy based on the coefficient of restitution e or the hardness of the changed material.

[0162] Here is the structure that moves in coordination with the recess area 101, for example, the outer ring 3, the housing 6 that holds the outer ring 3, or the like. The speed of the outer ring 3 and the housing 6 is low before the rolling element 4 collides with the recess area 101; the speed Vo r The velocity in the direction of the load reaches a maximum value immediately after the collision, and is then gradually dampened and decreases. According to the configuration of the ninth embodiment, the behavior sensor 8, which is arranged on the outer ring 3 or on the housing 6 that holds the outer ring 3, and the calculation unit 14 calculate the velocity Vo. r' in the direction of load, immediately after the rolling element 4 collides with the recess area 101, as the evaluation speed. Consequently, for example, the diagnostic unit 11 of the control unit 9 can diagnose the depth h of the recess area 101 of the rolling bearing 1 with high accuracy, using the evaluation index based on the evaluation speed and the relative rotational speed f. s .

[0163] Even if the damaged area 100 has occurred at any position of the inner ring 2, the outer ring 3, and the rolling element 4, the behavior of the rolling element 4, which sinks in the recess area 101 of the damaged area 100, occurs at least once within a period equal to or longer than the period Tr of the characteristic vibrations. The period Tr of the characteristic vibrations can be calculated in advance from expressions (4) to (6). Under the period Tri the characteristic vibrations when damage has occurred on the inner ring 2, the period Tr o the characteristic vibrations when damage has occurred on the outer ring 3, and the period Tr b The longest period of the characteristic vibrations when damage has occurred on the rolling element 4 can therefore be assessed and used.

[0164] The control unit 9 detects the 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, which rotates in an integrated manner with the inner ring 2 or the outer ring 3 within a period equal to or longer than the longest period used, by means of the behavior sensor 8, which is attached to the inner ring 2, the outer ring 3, or the housing 6. The diagnostic unit 11 of the control unit 9 can diagnose damage with high accuracy by diagnosing the damage to the rolling bearing 1 using the evaluation index based on the evaluation speed and the relative rotational speed of the inner ring 2 and the outer ring 3, even in cases where the position at which the damage occurred is unknown.

[0165] The period of rotation To of the rolling element 4 when the rolling element 4 moves rotationally so that it rotates around the central axis of the rotating shaft 5 in the circumferential direction can be expressed by the following expression (20). Mathematical expression 20 =2fs(11−dDcosα)

[0166] It should be noted that the rotation period To of the rolling element 4 is determined using the relative rotational speed f. sThe rotation period To can be determined from the inner ring 2 and the outer ring 3, the diameter d of the rolling element 4, the diameter D of the trajectory of the center of the rolling element 4, and the contact angle α of the rolling element 4. The rotation period To is equal to the value obtained by multiplying the period Tro of the characteristic vibrations in a case where damage has occurred to the outer ring 3 by the number Z of rolling elements 4. The following is also evident with regard to the rotation period To of the rolling element 4.

[0167] The rotation period To becomes inversely proportional to the shorter relative rotational speed f. sThe rotation period To becomes shorter when the diameter D of the trajectory of the center of the rolling element 4 increases. The rotation period To becomes longer when the diameter d of the rolling element 4 increases. The rotation period To becomes shorter when the contact angle α increases. Furthermore, the rotation period of a holder that rotates in sync with the rolling element 4 while maintaining a distance is, among the majority of rolling elements 4 rotating so that they revolve around the central axis of the rotating shaft 5 between the inner ring 2 and the outer ring 3, essentially the same as the rotation period To of the rolling element 4, as given in expression (20).

[0168] The area in the circumferential direction where the rolling element 4, which rotates circumferentially between the inner ring 2 and the outer ring 3, receives a load from the rotating shaft 5, is considered the loaded zone, and the remaining area is considered the unloaded zone. In this case, the following applies: If the damaged area 100 has occurred in the inner ring 2 or on the rolling element 4, the rolling element 4 sinks into the recessed area 101, and the evaluation index only becomes large when the damaged area 100 is located in the loaded zone.

[0169] In other words, in a case where the damaged area 100 occurred on the inner ring 2, the evaluation index will be set at a time point in period Tr. ithe characteristic vibrations are large, which can be calculated by expression (4), within a period during which the damaged area is 100 in the loaded zone, with a rotation period (1 / f s ), which is the inverse of the rotational speed f s the rotating shaft 5, which rotates in an integrated manner with the inner ring 2. On the other hand, in a case where the damaged area 100 has occurred in the rolling element 4, the evaluation index at a time point of the period Tr i the characteristic vibrations are large, which can be calculated using expression (4), within the period during which the damaged area 100 is in the loaded zone, with the rotation period To of the rolling element 4.

[0170] The contact angle α assumes a value in the range of 0° to 90°, and the diameter d of the rolling element 4 is not larger than the diameter D of the trajectory of the center of the rolling element 4. Consequently, the factor in parentheses on the right-hand side of expression (20) always assumes a value equal to or greater than 1. It is therefore evident from expression (20) that the rotation period To of the rolling element 4 is always longer than the rotation period (1 / f). s ) of the rotating shaft 5. In other words: The evaluation index becomes large at least once within the period that is equal to or longer than the rotation period To of the rolling element 4.

[0171] The control unit 9 detects the evaluation speed from the measurement result of the behavior sensor 8 within a period equal to or longer than the rotation period To of the rolling element 4. By diagnosing the damage to the rolling bearing 1 using the 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, which includes the diagnostic unit 11, can diagnose the damage with high accuracy, even in cases where the location of the damage is unknown.

[0172] Furthermore, for example, in a case where the relative rotational speed of the inner ring 2 and the outer ring 3 increases or decreases, the following applies: The control unit 9 can determine the evaluation speed from the measurement result of the behavior sensor 8, which is attached to the housing 6, within the period that is equal to or longer than the period Tr of the characteristic vibrations and in which the maximum value of the relative rotational speed of the inner ring 2 and the outer ring 3 falls within the range of 1.2 times the minimum value. Within such a period, the temporal change of the relative rotational speed f s so suppressed that it is small, and expression (19) holds approximately, from expression (7), which specifies a certain relative rotational speed f s assumes.

[0173] By diagnosing damage to the rolling bearing 1 using the 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, which has the diagnostic unit 11, can diagnose the damage with high accuracy, even in a case where the relative rotational speed of the inner ring 2 and the outer ring 3 increases or decreases.

[0174] Furthermore, the recessed area 101 often expands in the wave direction and circumferential direction as the depth increases in the radial direction. Consequently, the diagnostic device 7 can diagnose the degree of damage, such as the size and volume of the recessed area 101, by measuring its depth.

[0175] Typically, the rolling bearing is an area that receives the greatest load in the rotating equipment and is likely to be the first to be damaged.

[0176] If damage occurs to a rolling bearing, it can sometimes worsen rapidly as a result of increased stress in the area of ​​damage. Extensive damage can lead to failure of the rolling bearing itself, damage to or failure of its peripheral components, serious malfunction of the entire rotating assembly in which the rolling bearing is mounted, and so on.

[0177] In light of this, the diagnostic device 7 can diagnose damage to the rolling bearing 1 with high accuracy, thus enabling preventive maintenance of the rolling bearing 1. This makes it possible to prevent malfunctions 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 located.

[0178] Furthermore, the diagnostic unit 11 can, for example, provide a diagnosis indicating that damage has occurred to the rolling bearing 1 if the evaluation speed exceeds a predefined threshold; it can provide a diagnosis indicating that severe damage has occurred if the evaluation speed exceeds an even higher threshold. Furthermore, the diagnostic unit 11 can also diagnose the degree of damage, such as the depth, size, and volume of the damaged area 100, according to a value of the evaluation speed.

[0179] With regard to the rolling bearing 1 according to the ninth embodiment, a configuration is described as an example in which the inner ring 2 rotates in an integrated manner with the rotating shaft 5 and the outer ring 3 is held and fixed in the housing 6. On the other hand, even in a configuration in which the inner ring 2 is held and fixed in the housing 6 and the outer ring 3 rotates in an integrated manner with the rotating shaft 5, which is arranged outside the outer ring 3, expressions (7) to (19) apply, at least relatively, when the rolling element 4 sinks into the recess area 101.Consequently, the diagnostic device 7 can calculate the 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, which rotates in an integrated manner with the outer ring 3, using the behavior sensor 8, which is attached to the inner ring 2 or to the housing 6, which holds the inner ring 2, and diagnose the damage to the rolling bearing 1 using the evaluation index based on the evaluation speed and the relative rotational speed of the inner ring 2 and the outer ring 3.

[0180] As described above, the rolling bearing 1 according to the ninth embodiment comprises the inner ring 2, the outer ring 3, the 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 running surface of the outer ring 3 and the running surface of the inner ring 2. Each rolling element 4 rolls in sync 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 in an integrated manner with the inner ring 2 or the outer ring 3. The diagnostic device 7 comprises the behavior sensor 8, the calculation unit 14, and the diagnostic unit 11.

[0181] The behavior sensor 8 is located on the outer ring 3 or on the housing 6 that holds the outer ring 3 and measures the behavior of the outer ring 3 or the housing 6. The processing unit 14 calculates the evaluation 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 acts from the rotating shaft 5 within a period equal to or longer than the period Tr of the characteristic vibrations determined by the specifications of the rolling bearing 1. The diagnostic unit 11 diagnoses damage to the rolling bearing 1 using the evaluation index based on the evaluation speed calculated by the processing unit 14 and the relative rotational speed.

[0182] As a comparative example, consider the case where the diagnosis is performed based on an impact value from the vibration sensor, the size of the rolling bearing, and the relative rotational speed, without depending on the evaluation speed, in contrast to diagnostic device 7. It should be noted that the unit of the impact value is the same as [mm / sec]. 2 ] of acceleration.

[0183] In the comparative example, the following applies: Even if the relation of each velocity to a recoil can be obtained as in expression (11), a relation expression of each impact value cannot be obtained. While the depth h of the recess area can be determined using the radial direction velocity Vo rSince the impact force of the outer ring or housing, which is at its maximum immediately after the rolling element collides with the recess area, cannot be calculated, a relational expression based on a physical phenomenon between the impact value and the depth h of the recess area cannot be obtained. Therefore, it is difficult to diagnose damage with high accuracy, even when the diagnosis is based on the impact value from the vibration sensor, the size of the rolling bearing, and the relative rotational speed.

[0184] Furthermore, the surface of the damaged area of ​​the rolling bearing is often rough, and consequently, when the rolling element passes over the damaged area, a fine, minor impact occurs several times. Even if the damaged area becomes large, the impact value will therefore not be significant, and consequently, there is a situation where damage cannot be diagnosed with high accuracy by comparison using only the impact value.

[0185] Furthermore, the impact value becomes large due to an instantaneous change in behavior, and consequently, the impact value is not always large as a result of the behavior of the rolling element sinking into the recess area, but often becomes significantly large due to a minor change in shape, such as a rough surface or the damaged corner area. Therefore, while a continuous increase in chatter, flutter, or abnormal disturbances of the rolling bearing, the peripheral equipment of the rolling bearing, or the entire rotating equipment in which the rolling bearing is located, and a minor change in shape that does not directly affect the remaining service life of the rolling bearing and the entire rotating equipment, and the like, can be diagnosed, the comparative example is unsuitable for diagnosing the size of the recess area that directly affects the remaining service life.

[0186] For example, if the shape of the damaged corner becomes smooth due to wear and tear, the rolling element passes smoothly through the damaged area, and consequently the influence of the damaged area does not appear in the impact value, and the damage is not detected. Furthermore, for example, in a case where the shape of the damaged corner is sharp, even if the recessed area of ​​the damaged region is small, the impact value may become large at the time the rolling element passes through the damaged corner.

[0187] In this case, vibrations can occur in such a way that the acceleration in the loading direction and the acceleration in the anti-load direction, and so on, alternately become instantaneously large. This can cause the acceleration amplitude, the impact value, and the like to increase, regardless of the size of the recessed area, and consequently, it can be difficult to diagnose the degree of damage itself, specifically as a measure of the recessed area of ​​the damaged region, with high accuracy compared to the reference example.

[0188] Furthermore, the impact of the rolling bearing can contain vibrations in a high-frequency band caused by sliding friction and the like. Consequently, the impact intensity can vary depending on the lubrication condition of the rolling bearing. For example, if the lubrication deteriorates due to oxidation of the lubricant, oil separation, leakage, degradation of a thickening agent, or similar factors, the impact may be significantly higher, even if no damage is present in the rolling bearing itself. Thus, a diagnosis based solely on the impact value is affected by changes in the lubrication condition of the rolling bearing, and consequently, the diagnostic accuracy of the rolling bearing damage may decrease.

[0189] On the other hand, the diagnostic device 7 performs the diagnosis using the evaluation index based on the evaluation velocity, which is the maximum velocity component in the load direction, at the time when the rolling element 4 sinks into the recess area 101, and the relative rotational speed. The instantaneous behavior that occurs when the rolling element 4 passes through the damaged corner area 102 appears as an instantaneous acceleration amplitude. If such an instantaneous change in acceleration is integrated with respect to time, the acceleration, whose positive / negative direction is instantaneously reversed, is canceled out by the integration, and consequently, the velocity does not become large when the rolling element 4 passes through the damaged corner area 102.

[0190] On the other hand, the direction of acceleration continuously becomes the load direction at a point in time when the rolling element 4 descends in the recess area 101, and consequently the evaluation velocity, which is the maximum velocity 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 the diagnosis using the evaluation velocity, can diagnose the size of the recess area 101 with high accuracy, while the influence of the instantaneous behavior of the rolling element 4 by the shape of the damaged corner area 102 is suppressed. Furthermore, the maximum velocity component in the load direction becomes deeper when the depth of the recess area 101 is greater.

[0191] The diagnostic device 7, which uses an evaluation speed that is strongly correlated with the depth of the recess area 101, can thus diagnose the degree of depth of the recess area 101. Furthermore, the recess area 101 often expands in the wave direction and circumferential direction as the depth increases in the radial direction. Consequently, the diagnostic device 7 can diagnose the degree of damage, such as the size and volume of the recess area 101, by diagnosing its depth.

[0192] Furthermore, the evaluation speed is increased by the geometric shape of the recess area 101. In contrast to a device that performs a diagnosis using vibrations containing a high frequency band caused by sliding friction, the diagnostic device 7 can consequently diagnose the damage to the rolling bearing 1 with high accuracy, while suppressing the influence of the lubrication condition and turbulence, such as turbulence vibration. Tenth embodiment

[0193] An example of a diagnosis of damage to the rolling bearing 1 by the diagnostic device 7 according to a tenth embodiment is described. In the diagnostic device 7 according to the tenth embodiment, the diagnostic unit 11 diagnoses the damage to the rolling bearing 1 using a relative evaluation speed, which is obtained by dividing the evaluation speed by the relative rotational speed, as an evaluation index.

[0194] The inventors worked intensively, using data from numerous actual products and test data, and deduced that the evaluation speed increases proportionally to the relative rotational speed, even under identical damage conditions. In other words, to evaluate and compare the damage levels of the rolling bearing 1 under varying relative rotational speeds, it is necessary to perform the diagnosis while taking into account the influence of both the relative rotational speed and the evaluation speed. With the diagnostic device 7 according to the tenth embodiment, it is possible to diagnose the damage level of the rolling bearing 1 regardless of the relative rotational speed by using the relative evaluation speed, obtained by dividing the evaluation speed by the relative rotational speed, as the evaluation index.

[0195] An example of the diagnosis using the equation of motion is described when the rolling element 4 descends in the recess area 101. If the relative evaluation speed (Vo) r ' / f s ), obtained by dividing the evaluation speed Vo r ' by the relative rotational speed f s The rotational shaft 5 on the right-hand side in expression (19), considered as an evaluation index, allows the depth h of the recess area 101 to be calculated using a constant determined by each mass, the shape and dimensions of the rolling bearing 1, and the evaluation index, which represents the relative evaluation speed (Vo). r ' / f s ) is.

[0196] In other words, by using the evaluation index, which determines the relative evaluation speed (Vo r ' / f sGiven that the depth h of the recess area 101 for the rolling bearing 1 is determined, the diagnostic device 7 can obtain this depth. Furthermore, the recess area 101 often expands in the shaft direction and circumferential direction as the depth increases in the radial direction. Consequently, the diagnostic device 7 can diagnose the degree of damage to the recess area 101 by determining its depth h. In other words, it is possible to diagnose the degree of damage to the rolling bearing using the evaluation index, which determines the relative evaluation speed (Vo). r ' / f s ) is.

[0197] Even if the relative rotational speed of the inner ring 2 and the outer ring 3 is not measured during a time interval in which the evaluation speed to be used for diagnosis is measured, there is a case in which this can be anticipated as a design consideration. In this case, the diagnostic device 7 can diagnose the damage to the rolling bearing 1 using the evaluation speed in that time interval and the evaluation index based on the known relative rotational speed.

[0198] Furthermore, even in a case where the absolute value of the relative rotational speed is not recorded in advance, in a case where the multiplication of factors of the relative rotational speeds in two or more time periods can be recorded, the diagnostic device 7 can diagnose the damage of the rolling bearing 1 on the basis of the evaluation index obtained by dividing the evaluation speeds in the respective time periods by the respective multiplication factors.

[0199] For example, the evaluation speed in a time interval A, during which the total number of revolutions of rolling bearing 1 is small, is defined as Va, and the evaluation speed in a time interval B, during which the total number of revolutions of rolling bearing 1 is large, is defined as Vb. In a case where the relative rotational speed in time interval A is known to be twice the relative rotational speed in time interval B, the diagnostic device 7 can diagnose damage to rolling bearing 1 while specifying the evaluation index in time interval A as Va and the evaluation index in time interval B as Vb / 2.

[0200] For example, if the difference between Vb / 2 and Va is smaller than a predefined range, the diagnostic device 7 can provide a diagnosis indicating that the damage will not increase significantly with an increase in the total number of revolutions of the rolling bearing 1. Conversely, if Vb / 2 is greater than Va, the diagnostic device 7 can provide a diagnosis indicating that the damage will increase significantly with an increase in the total number of revolutions of the rolling bearing 1. Furthermore, for example, if it is known that there is a small difference between the relative rotational speed in time period A and the relative rotational speed in time period B, the diagnostic device 7 can diagnose damage to the rolling bearing 1 by specifying the evaluation index as Va in time period A and as Vb in time period B.

[0201] For example, if the difference between Vb and Va is less than a predefined range, the diagnostic device 7 can provide a diagnosis indicating that the damage will not increase significantly with an increase in the total number of revolutions of the rolling bearing 1. Conversely, if Vb is greater than Va, the diagnostic device 7 can provide a diagnosis indicating that the damage will increase significantly with an increase in the total number of revolutions of the rolling bearing 1. Eleventh embodiment

[0202] An example of a diagnosis of damage to the rolling bearing 1 by the diagnostic device 7 according to an eleventh embodiment is described. In the diagnostic device according to the eleventh embodiment, the diagnostic unit 11 diagnoses the extent of the damage to the rolling bearing 1 based on the evaluation index and a specific coefficient of the rolling bearing 1.

[0203] The inventors worked intensively, using data from numerous actual products and test data, and deduced that when the specific coefficient of the rolling bearing 1 changes according to its type, operating conditions, and other factors, the evaluation index also changes, even for the same degree of damage. In other words, to evaluate and compare the degree of damage to the rolling bearing 1 in conditions where its specific coefficient varies, it is necessary to perform a diagnosis that also takes into account the influence of the specific coefficient. The diagnostic device 7 according to the eleventh embodiment can diagnose the extent of damage to the rolling bearing 1 with high accuracy by using the evaluation index and the specific coefficient of the rolling bearing 1.

[0204] The inventors worked intensively, using data from numerous actual products and test data, and deduced that even if the extent of the damage to the rolling bearing 1 does not change, the evaluation index increases depending on the shape or size of the dimensions of the rolling bearing 1. In other words, to evaluate and compare the degree of damage to the rolling bearing 1 in a condition where the shape or size of the dimensions of the rolling bearing 1 differs, it is necessary to perform a diagnosis while also taking into account the influence of the shape or size of the dimensions of the rolling bearing 1.With the diagnostic device according to the eleventh embodiment, it is possible to diagnose the extent of the damage to the rolling bearing 1 with high accuracy by using the evaluation index and the specific coefficient, which are determined on the basis of the shape or dimensions of the rolling bearing 1.

[0205] An example of a diagnosis using the equation of motion is described when the rolling element 4 sinks in the recess area 101. The computation unit 14 can calculate the depth h of the recess area 101 from expression (19) and the like, using the specific coefficient of the rolling bearing 1 and the relative evaluation rate (Vo). r ' / f s), which is obtained by dividing the evaluation speed by the relative rotational speed. Here, the specific coefficient of the rolling bearing 1 has various types of values, such as the diameter d of the rolling element 4, the diameter D of the trajectory of the center of the rolling element 4, the mass m of all structures that apply a load to the recess area 101 via the rolling element 4 and that comprise the rolling element 4, the inner ring 2 and the rotating shaft 5, the load that acts on the rolling bearing 1 from the rotating shaft 5 accordingly, and the mass m o the structure which moves in coordination with the recess area 101, specified on the right side of expression (19), and a coefficient A calculated from these, and the like.

[0206] For example, the diagnostic unit 11 of the diagnostic device 7 can provide a diagnosis indicating that the depth h of the recess area 101 is greater when the evaluation index, which determines the relative evaluation speed (Vo r ' / f s ) is larger. Furthermore, the diagnostic device 7 can, for example, calculate from expression (19) that the evaluation index becomes larger when the specific coefficient A is smaller, even if the depth h of the recess area 101 is the same. In this way, the diagnostic device 7 can diagnose the depth h of the recess area 101, the size of the damage to the recess area 101, and the like with high accuracy by using the evaluation index and the specific coefficient based on the shape, dimensions, and the like of the rolling bearing 1. Twelfth embodiment

[0207] An example of a diagnosis of damage to the rolling bearing 1 by the diagnostic device 7 according to a twelfth embodiment is described. In the diagnostic device 7 according to the twelfth embodiment, the diagnostic unit 11 diagnoses the extent of the damage to the rolling bearing 1 based on the evaluation index and one of the diameter D of the trajectory of the center of the rolling element 4.

[0208] The inventors worked intensively, using data from numerous actual products and test data, and deduced that even if the extent of the damage to the rolling bearing 1 does not change, the evaluation index increases when the diameter D of the trajectory of the center of the rolling element 4 increases. In other words, to evaluate and compare the degree of damage to the rolling bearing 1 in a state where the diameter D of the trajectory of the center of the rolling element 4 varies, it is necessary to perform a diagnosis that also takes into account the influence of the size of the diameter D of the trajectory of the center of the rolling element 4. The diagnostic device 7 according to the twelfth embodiment can diagnose the extent of the damage to the rolling bearing 1 with high accuracy based on the evaluation index and the diameter D of the trajectory of the center of the rolling element 4.

[0209] An example of a diagnosis using the equation of motion is described when the rolling element 4 descends in the recess area 101. From expression (19), it is evident that the specific coefficient A decreases as the diameter D of the trajectory of the center of the rolling element 4 increases. In other words, it can also be calculated from expression (19) that even if the depth h of the recess area 101 remains constant, the evaluation index can increase as the diameter D of the trajectory of the center of the rolling element 4 increases. In other words, the diagnostic device 7 can diagnose the depth h of the recess area 101 and the extent of the damage to the recess area 101 with high accuracy by using the evaluation index and the diameter D of the trajectory of the center of the rolling element 4. Thirteenth embodiment

[0210] An example of a diagnosis of damage to the rolling bearing 1 by the diagnostic device 7 according to a thirteenth embodiment is described. In the diagnostic device according to the thirteenth embodiment, the diagnostic unit 11 diagnoses the extent of the damage to the rolling bearing 1 based on the evaluation index and the load acting on the rolling bearing 1 from the rotating shaft 5.

[0211] The inventors worked intensively, using data from numerous actual products and test data, and deduced that even if the extent of the damage to the rolling bearing 1 does not change, the evaluation index increases when the load acting on the rolling bearing 1 increases. In other words, to evaluate and compare the degree of damage to the rolling bearing 1 under varying load conditions, it is necessary to perform the diagnosis while also taking into account the influence of the load acting on the rolling bearing 1. The diagnostic device 7 according to the twelfth embodiment can diagnose the extent of the damage to the rolling bearing 1 with high accuracy, based on the evaluation index and the load acting on the rolling bearing 1.

[0212] An example of a diagnosis using the equation of motion is described when the rolling element 4 sinks in the recess area 101. The specific coefficient A on the right-hand side of expression (19) is a coefficient based on the mass ratio (m). o / m) of mass m o The structure that moves in coordination with the recess area 101 is related to the mass m of all structures that exert the load on the recess area 101 via the rolling element 4 and that comprise the rolling element 4, the inner ring 2, and the rotating shaft 5. In other words, the diagnostic device 7 can diagnose the depth h of the recess area 101 with high accuracy by using the evaluation index and the specific coefficient based on this mass ratio. Furthermore, the diagnostic device 7 can diagnose the extent of the damage to the rolling bearing 1 with high accuracy.

[0213] Here, the mass m has a proportional relationship to the load acting on the rolling bearing 1 from the rotating shaft 5, and m o often corresponds to the mass of a structure that holds the rolling bearing 1. If the mass ratio (m o If the mass ratio (m) is too small, there is concern that the strength of the structure holding the rolling bearing 1 may decrease. Conversely, if the mass ratio (m) is too high, there is a risk that the strength of the structure holding the rolling bearing 1 may decrease. o If / m) is too large, the weight and size of the rotating equipment containing this rolling bearing 1 will be large, making the design difficult with respect to the migration efficiency of the rotating equipment and due to space constraints where the rotating equipment is located.

[0214] In other words: The mass ratio (m oThe specific coefficient A ( / m) is essentially uniquely determined according to the load acting on the rolling bearing 1, specifically by the strength, migration efficiency, space constraints where the rotating equipment is located, and the like. Consequently, the specific coefficient A can be considered a coefficient based on the load acting on the rolling bearing 1. In other words, the diagnostic device 7 can diagnose the depth h of the recess area 101 with high accuracy by using the evaluation index and the specific coefficient A based on the load acting on the rolling bearing 1. Furthermore, the diagnostic device 7 can diagnose the extent of the damage to the rolling bearing 1 with high accuracy. Fourteenth embodiment

[0215] An example of a diagnosis of damage to the rolling bearing 1 by the diagnostic device 7 according to a fourteenth embodiment is described. In the diagnostic device 7 according to the fourteenth embodiment, the diagnostic unit 11 diagnoses the extent of the damage to the rolling bearing 1 based on the evaluation index, a maximum displacement of the outer ring 3 or the housing 6 that holds the outer ring 3, and the load acting on the rolling bearing 1 from the rotating shaft 5. Here, the maximum displacement of the outer ring 3 or the housing 6 is a maximum displacement in a direction in which the load acts from the rotating shaft 5 within a period that is equal to or longer than the period of the characteristic vibrations determined by the specifications of the rolling bearing 1.

[0216] The mass of the structure, which moves in coordination with the recess area 101, is defined as m o[kg], maximum radial direction velocity of the structure within the period equal to or longer than the period of the characteristic vibrations determined by the specifications of rolling bearing 1, is defined as Vo r ' [mm / sec], the maximum radial direction displacement of the structure is defined as X max [mm], and the spring stiffness of the structure with respect to displacement is defined as k [N / mm]. The radial velocity of the structure, moving in coordination with the recess area 101, is maximized immediately after the rolling element 4 sinks downwards and collides with the recess area 101, and the structure has kinetic energy [N·mm]. Then, kinetic energy is converted into elastic energy [N·mm] of the structure, and the velocity of the structure becomes zero at a time when the structure has moved by the maximum displacement X. maxis shifted. The law of conservation of energy can be expressed in this case by the following expression (21). Mathematical expression 21 12moVor'2=12kXmax2

[0217] The spring stiffness k with respect to the displacement of the structure moving in coordination with the recess area 101 can be obtained as a value by dividing a test load by a measured displacement, specifically by measuring the displacement when a load is applied beforehand to a test base. Alternatively, the spring stiffness k can also be obtained as a value by dividing an assumed load by an assumed displacement obtained with respect to the assumed load, either by manual calculation or using an analysis tool such as CAD, from the material of the structure, the structure itself, a constraint, and the like. In other words, if the maximum radial direction velocity Vo r ' and the maximum displacement X max The structure can be measured to determine the mass m ofrom expression (21). By using this, the diagnostic device 7 can diagnose the depth h of the recess area 101 with higher accuracy from expression (19).

[0218] Among the structures moving in coordination with the recess area 101, the velocity and displacement tend to be greatest in the outer ring 3 and the housing 6, which holds the outer ring 3, of the rolling bearing 1, which bear the load from the rotating shaft 5 at the nearest position. The outer ring 3 and the housing 6 move essentially in an integrated manner, and consequently the maximum radial direction velocity Vo can be r ' and the maximum displacement X max the structure is defined as the maximum radial direction velocity and the maximum displacement of the outer ring 3 or the housing 6.

[0219] In a case where the behavior sensor 8 is an accelerometer, the computation unit 14 can calculate time series displacement data by performing second-order time integration on the acceleration time series data, which is the output signal from the behavior sensor 8. The computation unit 14 can then calculate the maximum displacement X. max of the outer ring 3 or the housing 6 can be obtained from these time series data. Furthermore, in a case where the behavior sensor 8 is a velocity sensor, the computation unit 14 can calculate time series displacement data by performing a time integration of the velocity time series data, which is the output signal from the behavior sensor 8.

[0220] The calculation unit 14 can handle the maximum displacement X maxof the outer ring 3 or the housing 6 from these time series data. Furthermore, in a case where the behavior sensor 8 is a displacement sensor, the computation unit 14 can determine the maximum displacement X. max from time series data of the displacement, which is the output signal from behavior sensor 8. In other words, the calculation unit 14 can determine the maximum radial direction velocity Vo. r ' and the maximum displacement X max of the outer ring 3 or the housing 6 based on the output signal from the behavior sensor 8. Furthermore, the diagnostic device 7 can calculate the mass m othe structure which moves in coordination with the recess area 101, namely from expression (21). The diagnostic device 7 can diagnose the depth h of the recess area 101 with higher accuracy from expression (19) and the like. Furthermore, the diagnostic device 7 can diagnose the size of the damage to the rolling bearing 1 with high accuracy. Fifteenth embodiment

[0221] An example of a diagnosis of damage to the rolling bearing 1 by the diagnostic device 7 according to a fifteenth embodiment is described. In the diagnostic device 7 according to the fifteenth embodiment, the diagnostic device 11 diagnoses the extent of the damage to the rolling bearing 1 based on the evaluation index, actually measured data indicating the extent of the damage to the rolling bearing 1, and data of the evaluation index in that state.

[0222] An example of the diagnosis using the equation of motion is described when the rolling element 4 sinks in the recess area 101. By using expression (19), the depth h of the recess area 101 can be calculated using the relative evaluation rate (Vo). r ' / f s ), which is obtained by dividing the evaluation speed by the relative rotational speed, and the specific coefficient of the rolling bearing 1. By preparing, for example, at least one of the actually measured data indicating the size of the damage, such as the depth h of the recess area 101, and data of the evaluation index in the state, the specific coefficient can consequently be obtained from expression (19).

[0223] In this way, by using the specific coefficient obtained from the actual measured data and the evaluation index, even in cases where there is no design data necessary to obtain the specific coefficient, the diagnostic device 7 can diagnose the depth h of the recess area 101 with high accuracy. Furthermore, the diagnostic device 7 can diagnose the extent of the damage to the rolling bearing 1 with high accuracy. Sixteenth embodiment

[0224] Fig. Figure 10 is a diagram illustrating an example of the diagnosis of damage to the rolling bearing 1 by the diagnostic device 7 according to a sixteenth embodiment. Fig. 10 indicates the course of time on the horizontal axis. Fig. Figure 10 indicates the speed detected by the behavior sensor 8 on the vertical axis. The upper side of the vertical axis indicates the speed in the direction of load. The lower side of the vertical axis, in turn, indicates the speed in the direction of rebound.

[0225] For example, in a case where the velocity time series data are calculated by performing a time integration of the acceleration time series data using the accelerometer as a behavior sensor 8, as shown by the dashed line in Fig. As specified in 10, the velocity in the loading direction can become extremely large for a period equal to or longer than the period Tr. This occurs as a result of the fact that—in a case where the mounting condition of the behavior sensor 8, which is the accelerometer, is poor, in a case where disturbances, such as other turbulence vibrations, are strongly reflected, or the like—the time series acceleration data, which represent the output signal, are shifted overall in the loading direction. For a similar reason, the velocity in the anti-load direction can become large for a period longer than the period Tr.

[0226] On the other hand, the following applies: Even if slight vibrations can occur in the rolling bearing 1 and the housing 6, the positions in which the rolling bearing 1 and the housing 6 are arranged do not normally change much. Consequently, the continuous increase in speed over a period of time, as shown by the dashed line in Fig. Figure 10 shows a different state than the actual state, and if such time series data are used as is, the evaluation speed Vp is calculated as an excessive value. Therefore, the diagnostic device 7 performs a slope correction of the time series speed data.

[0227] The processing unit 14 of the diagnostic device 7 performs slope correction processing on the velocity time series data based on information acquired by the behavior sensor 8. This slope correction processing is carried out, for example, by obtaining a slope component from the velocity time series data over the period longer than period Tr using linear regression or other methods, and then subtracting this slope component from the velocity time series data. The processing unit 14 then calculates the evaluation velocity Vp' for the period longer than period Tr using the velocity time series data that has undergone slope correction processing.

[0228] The diagnostic device 7 can diagnose the degree and size of damage to the rolling bearing without being affected by the mounting condition of the behavior sensor 8 and disturbances such as turbulence vibrations, by using the evaluation speed Vp' calculated in this way. Seventeenth embodiment

[0229] An example of a diagnosis of rolling bearing damage by the diagnostic device 7 according to a seventeenth embodiment is described. The diagnostic unit 11 of the diagnostic device 7 diagnoses the damage of the rolling bearing 1 by using an evaluation index statistic. The evaluation index statistic is calculated for time periods obtained by decomposing a period longer than one rotational period of the rolling element 4, when the rolling element 4 rotates circumferentially about the central axis of the rotating shaft 5, into a plurality of time periods, each equal to or longer than the period of the characteristic vibrations. The evaluation index statistic can be obtained by performing statistical processing on a data set of a plurality of evaluation indices within the decomposed plurality of time periods.

[0230] The rotation period To of the rolling element 4, when the rolling element 4 rotates so that it revolves circumferentially around the central axis of the rotating shaft 5, is expressed in expression (20). It should be noted that the rotation period To of the rolling element 2 is determined using the relative rotational speed f. s The rotation period To is the same value as the value obtained by determining the period Tr. o The characteristic vibrations in a case where damage has occurred to the outer ring 3 are multiplied by the number Z of rolling elements 4. Furthermore, the following is evident for the rotation period To of the rolling element 4.

[0231] The rotation period To of the rolling element 4 is inversely proportional to an increase in the relative rotational speed f. s The rotation period To of the rolling element 4 becomes shorter when the diameter D of the trajectory of the center of the rolling element 4 increases. The rotation period To of the rolling element 4 becomes longer when the diameter d of the rolling element 4 increases. The rotation period To of the rolling element 4 becomes shorter when the contact angle α increases. Furthermore, the rotation period of a holder that rotates in sync with the rolling element 4 while maintaining a distance is also essentially equal to the rotation period To of the rolling element 4 among the majority of rolling elements 4 rotating so that they revolve around the central axis of the rotating shaft 5 between the inner ring 2 and the outer ring 3, as specified in expression (20).

[0232] The holder and the rolling element 4 move freely within a clearance area within the rolling bearing 1, depending on a constraint. In a case where the spacing among the majority of rolling elements 4 is not uniform, in a case where the center of the holder is displaced from the central axis of the rotating shaft 5, and in a case where damage, such as wear or scarring, has occurred on a part of the holder and the rolling element 4, and the symmetry of the shape is lost, the vibrations that occur when each rolling element 4 passes through the damaged area 100 can exhibit a periodicity with the rotation period To of the rolling element 4.

[0233] This is because when the rolling element 4 passes the damaged area 100 at a specific position in the circumferential direction of the holder in which the above-described non-uniformity, displacement, damage or the like has occurred, or when a specific rolling element 4 in which the above-described non-uniformity, displacement, damage or the like has occurred passes the damaged area 100, the values ​​of the shape and dimensions of the rolling bearing 1, the mass, the load, the speed and the like, which are to be used from expression (7) to expression (19), and the like, change.

[0234] To measure periodic vibrations at least once per rotation period To of the rolling element 4, the period longer than the rotation period To of the rolling element 4 is divided into a plurality of time periods, each equal to or longer than the period Tr of the characteristic vibrations determined by the specifications of the rolling bearing 1 and the relative rotational speed of the inner ring 2 and the outer ring 3. By using the evaluation index statistics, obtained by calculating the evaluation index within each of the divided time periods, and by performing statistical processing on a data set of a plurality of evaluation indices obtained in equal numbers to the divided time periods, the diagnostic device 7 can diagnose the degree of damage to the rolling bearing 1 with high accuracy.

[0235] The evaluation index statistic is, for example, the average value, the median value, the effective value, the maximum value, or the like for the data group of evaluation indices. For example, diagnostic unit 11 provides a diagnosis indicating that damage has occurred to rolling bearing 1 if the evaluation index statistic exceeds a predefined threshold.

[0236] Furthermore, for example, each value of the evaluation index for any given time, calculated by the computation unit 14, can assume an extremely large value as a result of, for example, the behavior sensor 8 detecting a sudden turbulence vibration, or the like, which is irrelevant to the damage of the rolling bearing 1. According to the configuration of the seventeenth embodiment, the diagnostic unit 11 performs a diagnosis using the evaluation index statistics, such as the mean value, the median value, the RMS value, or the like, which are obtained by performing statistical processing of the evaluation index data set. Consequently, the diagnostic unit 7 can perform the diagnosis with high accuracy without being affected by a sudden event that is irrelevant to the damage of the rolling bearing 1.

[0237] Furthermore, there is, for example, the case where the evaluation index can become large with a low frequency, even at a stage where the damage to the rolling bearing 1 is small. In light of this, the diagnostic unit 11 performs the diagnosis using the evaluation index statistics, such as the maximum value obtained by statistically processing the evaluation index data set, so that the diagnostic unit 7 can diagnose the damage even at a stage where the damage is small.

[0238] Furthermore, the following applies, for example: While there is a case in which the average value or similar of the evaluation indices can change rapidly, specifically in a state where the damage to rolling bearing 1 is progressing rapidly, the time series fluctuation of the evaluation indices is often large in the preceding stage, as a harbinger of such a rapid change in the state. By using the evaluation index statistic, which indicates a time series fluctuation, such as a standard deviation value or a variance value, obtained by performing statistical processing of the evaluation index data set, the diagnostic device 7 can diagnose the progression of the damage early on with high accuracy. Eighteenth embodiment

[0239] An example of a diagnosis of damage to the rolling bearing 1 by the diagnostic device 7 according to an eighteenth embodiment is described. The diagnostic unit 11 of the diagnostic device 7 diagnoses the damage to the rolling bearing 1 based on a periodic change in the evaluation index, which is continuously calculated so that it receives successive evaluation indices over time.

[0240] For example, the evaluation index becomes large at a time when the rolling element 4 passes through the damaged area 100, as shown in the time series data of the evaluation index calculated by the diagnostic unit 11, and this period essentially corresponds to the period Tr of the characteristic vibrations determined by the specifications of the rolling bearing 1. On the other hand, the period of the rolling element 4 passing through the damaged area 100 is determined by expression (4) to expression (6), using the position where the damaged area 100 occurred, the dimensions of the rolling bearing 1, the relative rotational speed, and the like.Consequently, the diagnostic unit 11 can determine whether the damaged area 100 has occurred at any position of the inner ring 2, the outer ring 3 or the rolling element 4 of the rolling bearing 1, based on the dimensions of the rolling bearing 1 and the relative rotational speed from the period, frequency or the like, at which the evaluation index becomes large.

[0241] While Fig. Figure 8 illustrates an example in which the damaged area 100 occurred in the outer ring 3. The following applies: Even if the damaged area 100 occurred in the inner ring 2 or in the rolling element 4, expressions (7) to (19), the equations of motion, apply when the rolling element 4 descends in the recess area 101, at least relatively. Consequently, in a similar manner to the case where the damaged area 100 occurred in the outer ring 3, the diagnostic device 7 can calculate the depth h of the recess area 101.

[0242] The area in the circumferential direction where the rolling element 4, which rotates circumferentially between the inner ring 2 and the outer ring 3, receives a load from the rotating shaft 5, is considered the loaded zone, and the remaining area is considered the unloaded zone. In this case, the following applies: If the damaged area 100 has occurred in the inner ring 2 or on the rolling element 4, the rolling element 4 sinks into the recessed area 101, and the evaluation index only becomes large when the damaged area 100 is located in the loaded zone.

[0243] In other words, if the damaged area occurred on inner ring 2, the evaluation index will be at a time point in period Tr. ithe characteristic vibrations are large, which can be calculated by expression (4), within a period during which the damaged area is 100 in the loaded zone, with a rotation period (1 / f s ), which is the inverse of the rotational speed f s the rotating shaft, which rotates in an integrated manner with the inner ring 2. On the other hand, in a case where the damaged area 100 has occurred in the rolling element 4, the evaluation index at a time point of period Tr i the characteristic vibrations are large, which is calculated using expression (4), within the period during which the damaged area 100 is in the loaded zone, with the rotation period To of the rolling element 4.

[0244] Consequently, the diagnostic unit 11 can diagnose the position under the inner ring 2, the rolling element 4, and the outer ring 3 where the damaged area 100 occurred by obtaining a time period during which the damaged area 100 was located in the loaded zone, specifically from the period during which the evaluation index increases. Even if the damaged area 100 occurred at multiple positions, the diagnostic unit 11 can also determine at how many positions the damaged area 100 occurred. Furthermore, the diagnostic unit 11 can determine the position under the inner ring 2, the outer ring 3, and the rolling element 4 of the rolling bearing 1 where each of the multiple damaged areas 100 occurred.

[0245] Furthermore, the diagnostic unit 11 can diagnose the size of the damaged area 100 based on the evaluation index during the period in which the evaluation index becomes large. This allows the diagnostic unit 11 to diagnose the depth of the recessed area 101 or the size of the damaged area 100 with high accuracy, without being affected by disturbances such as turbulence vibrations. For example, the diagnostic unit 11 can diagnose the location where the damaged area 100 occurred from a frequency band in which the spectral intensity is high, using frequency analysis data obtained by performing a frequency analysis of the time series data of the evaluation index.

[0246] For example, diagnostic unit 11 can diagnose a location where the damaged area 100 occurred by comparing the spectral intensity in specific frequency bands that are the inverses of the periods Tr defined from expression (4) to expression (6). Diagnostic unit 11 provides a diagnosis indicating that the damaged area 100 occurred in inner ring 2, in a case where the frequency band with high spectral intensity is closest to the inverse of period Tri from expression (4), among the inverses of periods Tr from expression (4) to expression (6). Diagnostic unit 11 provides a diagnosis indicating that the damaged area 100 occurred in outer ring 3, in a case where the frequency band with high spectral intensity is closest to the inverse of period Tr. ofrom expression (5), specifically among the inverses of the periods Tr from expression (4) to expression (6). The diagnostic unit 11 provides a diagnosis indicating that the damaged area 100 occurred in the inner ring 2, in a case where the frequency band with high spectral intensity is closest to the inverse of the period Tr. b from expression (6), namely among the inverses of the periods Tr from expression (4) to expression (6).

[0247] Furthermore, the following applies: While the evaluation index becomes large at a time when the rolling element 4 periodically passes the damaged area 100, the evaluation index can also become large at other times influenced by turbulence vibrations. The diagnostic unit 11 can perform the diagnosis with high accuracy while suppressing the influence of disturbances, such as turbulence vibrations, by diagnosing the depth of the recessed area 101 or the size of the damaged area 100 from the spectral intensity in a specific frequency band in which the rolling element 4 passes the damaged area 100. Nineteenth version

[0248] Fig. Figure 11 is a configuration diagram of the rolling bearing 1 according to a nineteenth embodiment.

[0249] In the nineteenth embodiment, the diagnostic device 7 of the rolling bearing 1 has a speed sensor 15.

[0250] The speed sensor 15 can be a sensor that directly measures rotational speeds, angular velocities, and the like 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 element 4, the holder, and the like, using lasers, light, microwaves, ultrasonic waves, a magnetic sensor, and the like. The speed sensor 15 can also be a sensor integrated with rotating equipment, such as a motor. For example, the speed sensor 15 integrated with the rotating equipment measures an output value, such as a current value, from the motor and calculates the rotational speed of the rotating shaft 5 from the output value.

[0251] 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 rotational speed using the speed sensor 15. For example, even in a case where the rotational speed of the rotating shaft 5 changes, by measuring the relative rotational speed of the inner ring 2 and the outer ring 3 during a time interval during which the evaluation speed used for diagnosis has been measured, the diagnostic device 7 can always diagnose damage to the rolling bearing 1 with high accuracy. twentieth embodiment

[0252] Fig. Figure 12 is a configuration diagram of the rolling bearing 1 according to a twentieth embodiment.

[0253] In the twentieth embodiment, the control unit 9 of the diagnostic device 7 of the rolling bearing 1 comprises the calculation unit 14, the storage unit 13 and the diagnostic unit 11.

[0254] Storage unit 13 is a unit whose function is to store information. Storage unit 13 accumulates and stores the calculated evaluation index. For example, storage unit 13 stores time series data of the evaluation index. Storage unit 13 can store time series data of the evaluation rate, which is to be used to calculate the evaluation index. Storage unit 13 stores changes in the evaluation index over time by storing the evaluation index as time series data. Furthermore, storage unit 13 can store the change value of the evaluation index that was last calculated.

[0255] For a rotating apparatus in which a plurality of rolling bearings 1 with different specification conditions are arranged, such as the specific coefficient, the shape, the dimensions, the relative rotational speed, and the load exerted on the rolling bearing 1 by the rotating shaft 5, the following applies: Even if the magnitudes of the damage occurring on the respective rolling bearings 1 are the same, the evaluation index can assume different values ​​depending on the differences in the operating conditions. For example, if the diameter of the trajectory of the center of the rolling element 4, the relative rotational speed, the load exerted on the rolling bearing 1 by the rotating shaft 5, and the like are larger, the evaluation index tends to be larger for damage of the same degree.

[0256] On the other hand, a time difference value or 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 of the rolling bearing 1, even for rolling bearings 1 with different specification conditions, such as the specific coefficient, the shape, the dimensions, the relative rotational speed, and the load acting on the rolling bearing 1 from the rotating shaft 5. In other words, even in rolling bearings 1 with different specification conditions, if the time difference or differential values ​​of the evaluation indices are of the same degree, the diagnostic device 7 can provide a diagnosis indicating that the damage is of the same degree.

[0257] Alternatively, if the time difference value or time differential value of the evaluation index exceeds a stable value, the diagnostic unit 7 can diagnose this as a warning sign that will lead to the loss of function of the rolling bearing 1 or the entire rotating equipment including the rolling bearing 1, such as a malfunction like a crack or fracture of the rolling bearing 1, and a malfunction of the peripheral equipment of the rolling bearing 1. In other words, the diagnostic unit 11 can calculate a time period until the occurrence of damage that leads to the loss of function of the rolling bearing 1 or the entire rotating equipment including the rolling bearing 1, based on the evaluation index stored in the storage unit 13, or the rate of change of the evaluation index calculated from the information stored in the storage unit 13.

[0258] This enables the diagnostic unit 11 to calculate an appropriate maintenance, testing, and replacement time for the rolling bearing 1 in order to prevent damage that could lead to a loss of function. In this way, the diagnostic unit 7 can contribute to labor savings and stable long-term operation of the rolling bearing 1, its peripheral equipment, and the entire rotating equipment in which the rolling bearing 1 is located. Twenty-first embodiment

[0259] The rolling bearing 1 has the inner ring 2, the outer ring 3, the plurality of rolling elements 4, the rotating shaft 5 and the diagnostic device 7.

[0260] Typically, the rolling bearing is the area subjected to the greatest load in rotating equipment and is therefore likely to be the first to be damaged. If damage occurs to the rolling bearing, it can accelerate and become severe as a result of increased stresses in the area surrounding the damage. As the damage becomes severe, the behavior of the entire rotating equipment, including the rotating shaft, becomes unstable, potentially leading to damage to peripheral components such as the bearing's drive shaft, gearbox and coupling, stator, housing, frame, or similar parts.

[0261] In light of this, the rolling bearing 1 can diagnose the degree and extent of damage to the rolling bearing 1 and the rotating equipment in which the rolling bearing 1 is located with high accuracy using the attached diagnostic device 7. This makes it possible to prevent malfunctions of the peripheral equipment of the rolling bearing 1 and the entire rotating equipment in which the rolling bearing 1 is located, as well as of the rolling bearing 1 itself, in advance.

[0262] Fig. Figure 13 is a diagram showing an example of a hardware configuration of the control unit of the diagnostic device according to any one of the first to twenty-first embodiments.

[0263] The function of the control unit 9 can be implemented by means of a control circuit 200, which is located in Fig. Figure 13 illustrates this, i.e., a processor 201 and a memory 202. Examples of the processor 201 may include: a CPU (also called a central processing unit, processing unit, arithmetic operating unit, microprocessor, microcomputer, processor, or digital signal processor (DSP)), a system of large-scale integration (LSI), and the like. Examples of the memory 202 may include random-access memory (RAM), read-only memory (ROM), and the like.

[0264] The function of the control unit 9 can be implemented by the processor 201, which reads a control program that causes the control unit 9 to perform processing from memory 202, which stores the control program, and executes the control program. Furthermore, the control program can be considered a program that causes a computer to execute a control procedure of the diagnostic device 7 in the control unit 9.

[0265] The control program, to be executed by the control unit 9, has a modular configuration in which various types of processing are modularized. These different types of processing include, for example: processing to calculate the evaluation speed, specific coefficient, evaluation index, evaluation index statistics, or the like, based on the signal acquired by the behavior sensor 8 or the speed sensor 15, and the like; processing to calculate the total acceleration value; processing to assess whether or not damage has occurred; processing to diagnose the damage state; and the like. These modules are loaded into and generated within a main memory device.

[0266] Memory 202 is used as temporary storage when processor 201 performs various types of processing. Furthermore, in the seventh and twentieth embodiments, memory 202 is used as memory unit 13, which stores the evaluation speed or evaluation index, such as the evaluation vibration, as time-series data.

[0267] The control program to be executed by processor 201 can be stored on a computer-readable storage medium as a file in an installable or executable format and provided as a computer program product. Furthermore, the control program to be executed by processor 201 can be provided to the control unit 9 of the diagnostic device 7 via a network, such as the Internet.

[0268] Furthermore, the control unit 9 can be implemented with dedicated hardware. In addition, some of the functions of the control unit 9 can be implemented by dedicated hardware, and the remaining functions can be implemented by software or firmware. Twenty-second embodiment

[0269] Fig. Figure 14 is a configuration diagram of an elevator traction machine 300 according to a twenty-second embodiment.

[0270] In the present embodiment, the elevator traction machine 300 comprises the rolling bearing 1, the rotating shaft 5, a pulley 301 and a motor 302.

[0271] A rope that moves an elevator car can be suspended from the pulley 301. The motor 302 can move the elevator car while moving the rope up and down, for example by rotating the rotating shaft 5, which is held by two roller bearings 1, so that the pulley 301 rotates.

[0272] Typically, a malfunction likely occurs in the rolling bearing 1 of the traction machine 300, where a high load and friction occur in the parts that drive the elevator. According to the configuration of the present embodiment, damage to the rolling bearing 1 of the elevator traction machine 300 is diagnosed with high accuracy, making it possible to perform preventive maintenance on the rolling bearing 1. Furthermore, it is also possible to perform preventive maintenance on the peripheral equipment of the traction machine 300, such as the motor 302 and the pulley 301, as well as on the traction machine 300 itself, in cases where damage occurs secondarily as a result of damage to the rolling bearing 1.

[0273] While an example of a configuration in which the inner ring 2 rotates in an integrated manner with the rotating shaft 5 has been described for the rolling bearing 1 according to any one of the first to twenty-second embodiments, it is also possible to use a configuration in which the inner ring 2 is held and fixed in the housing 6. Furthermore, while an example of a configuration in which the outer ring 3 is held and fixed in the housing 6 has been described, it is also possible to use a configuration in which the outer ring 3 rotates in an integrated manner with the rotating shaft 5, which is arranged outside the outer ring 3.

[0274] For the rolling bearing 1 according to one of the first to twenty-second embodiments, the number and arrangement of the rolling elements 4 are not limited to the number and arrangement described in Fig. 1, Fig. 7 or similar are shown.

[0275] While an example of a condition in which there is a single damaged area 100 is described for the rolling bearing 1 or the diagnostic device 7 according to any one of the first to twenty-second embodiments, there may also be two or more damaged areas 100. While furthermore an example of a case has been described in which the damaged area 100 has occurred in the outer ring 3, the damaged area 100 may also occur in the inner ring 2 or in the rolling element 4. Furthermore, the damaged area 100 may occur at a plurality of positions.

[0276] While an example of a configuration with a single behavior sensor 8 has been described for the rolling bearing 1 or the diagnostic device 7 according to any of the first to twenty-second embodiments, there can also be two or more behavior sensors 8. Furthermore, the position and shape of the behavior sensor 8 are not limited to the examples described above.

[0277] The diagnostic device 7 according to one of the first to twenty-second embodiments described above can also be used with any of the following: 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 that is in rotational operation; and a rolling bearing 1 that has ceased to rotate.

[0278] It should be noted that in the present description, expressions indicating directions, such as "wave direction," "radial direction," "circumferential direction," "rotational direction," "loading direction," and "anti-loading direction," do not merely include the strictly specified directions, but also directions in which essentially the same functions can be achieved. Furthermore, in the present description, expressions such as "exhibit," "provide," "contain," and "have" do not denote exclusive expressions that preclude the presence of other components.

[0279] While various illustrative embodiments and examples are described in the present invention, the various features, aspects, and functions described in one or more embodiments are not limited to application in a specific embodiment, but can be applied—alone or in various combinations—to different embodiments. Consequently, an unlimited number of modifications not described are considered to be within the scope of the present invention. In one example, it is assumed that the modifications include a modification, an addition, or an omission of at least one component, and furthermore, the extraction of at least one component and the combination of the component with components in other embodiments.Furthermore, the configurations described above in the embodiments can be combined with other publicly known techniques. In other words, some of the configurations described above in the embodiments can be omitted or modified, within a scope that does not deviate from the essence of the invention. Commercial applicability

[0280] The diagnostic device according to the present invention can be used with a rolling bearing. The rolling bearing according to the present invention can be used with a rotary device. Reference symbol list 1 rolling bearing 2 inner ring 3 outer ring 4, 4a, 4b rolling elements 5 Rotary shaft 6 cases 7 Diagnostic device 8 Behavior sensor 9 Control unit 10 first calculation unit 11 Diagnostic Unit 12 second calculation unit 13 storage units 14 Calculation unit 15 Speed ​​sensor 100 damaged area 101 Recess area 102 damaged corner area 200 control circuit 201 processor 202 storage 300 traction machine 301 Pulley 302 engine QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP S61-61055 A

[0003]

Claims

[1] Diagnostic device that diagnoses a rolling bearing which has the following characteristics: an inner ring; an outer ring arranged concentrically with the inner ring; and a plurality of rolling elements arranged between a running surface of the outer ring and a running surface of the inner ring, each rolling in conjunction with the rotation of the inner ring or the rotation of the outer ring, the diagnostic device has the following features: a behavior sensor located on the inner ring, the outer ring or on a housing holding the inner ring or the outer ring, and measuring the behavior of the rolling bearing; a computation unit that calculates an evaluation speed based on information acquired by the behavior sensor, wherein the evaluation speed is a maximum velocity component in one direction of the load acting on the rolling bearing from a rotating shaft that rotates in an integrated manner with the inner ring or the outer ring, within a period equal to or longer than a period of characteristic vibrations determined by the rolling bearing specifications and the relative rotational speed of the inner ring and the outer ring; and a diagnostic unit that diagnoses damage to the rolling bearing by using an evaluation index based on the evaluation speed and the relative rotational speed. [2] Diagnostic device according to claim 1, wherein the period of the characteristic vibrations is determined by the specifications of the rolling bearing and the relative rotational speed, wherein the specifications include the diameter of each rolling element and the diameter of the trajectory of the center of the rolling element when the rolling element rotates circumferentially about a central axis of the rotating shaft. [3] Diagnostic device according to claim 1, wherein the period of the characteristic vibrations is determined by the specifications of the rolling bearing and the relative rotational speed, wherein the specifications include the diameter of each rolling element, the diameter of the trajectory of the center of the rolling element and the contact angle of the rolling element. [4] Diagnostic device according to one of claims 1 to 3, wherein the damage to the rolling bearing is diagnosed by using - as an evaluation index - a relative evaluation speed which is obtained by dividing the evaluation speed by the relative rotational speed. [5] Diagnostic device according to one of claims 1 to 4, wherein the extent of damage to the rolling bearing is diagnosed on the basis of the evaluation index and a specific coefficient of the rolling bearing. [6] Diagnostic device according to claim 5, wherein the specific coefficient is determined on the basis of the shape or dimensions of the rolling bearing. [7] Diagnostic device according to claim 6, wherein the specific coefficient is determined on the basis of the diameter of the trajectory of the center of the rolling element when the rolling element rotates circumferentially about a central axis of the rotating shaft. [8] Diagnostic device according to claim 5, wherein the specific coefficient is determined on the basis of a load acting on the rolling bearing from the rotating shaft. [9] Diagnostic device according to claim 8, wherein the specific coefficient is determined on the basis of a maximum displacement of the inner ring, the outer ring or the housing in a direction in which a load acts from the rotating shaft within the period which is equal to or longer than the period of the characteristic vibrations determined by the specifications of the rolling bearing and the load acting on the rolling bearing from the rotating shaft. [10] Diagnostic device according to one of claims 5 to 9, wherein the specific coefficient is obtained on the basis of actually measured data indicating the size of the damage to the rolling bearing, and data of the evaluation index in a condition of the rolling bearing. [11] Diagnostic device according to any one of claims 1 to 10, wherein the diagnostic unit diagnoses the damage to the rolling bearing by using an evaluation index statistic obtained by dividing a period longer than one rotation period of each rolling element, when the rolling element rotates circumferentially about a central axis of the rotating shaft, into a plurality of time periods, each equal to or longer than the period of the characteristic vibrations, and performing statistical processing of a data set of a plurality of evaluation indices, each calculated within the decomposed plurality of time periods. [12] Diagnostic device according to any one of claims 1 to 11, wherein the diagnostic unit diagnoses both the degree of damage and the position of damage of the rolling bearing on the basis of a cyclic change of the evaluation index which is continuously calculated. [13] Diagnostic device according to claim 12, wherein the diagnostic unit diagnoses the degree of damage or the damage position or both the degree of damage and the damage position of the rolling bearing using frequency analysis data of the time series data of the evaluation index, which are continuously calculated. [14] Diagnostic device according to any one of claims 1 to 13, comprising a speed sensor which measures the relative speed. [15] Diagnostic device according to any one of claims 1 to 14, comprising the following: a storage unit that accumulates and stores the evaluation index or a change value of the evaluation index, the diagnostic unit calculates the damage to the rolling bearing based on a time difference value of the evaluation index, which can be calculated from information stored in the storage unit. [16] Diagnostic device according to claim 15, wherein the diagnostic unit calculates a period until the occurrence of damage that leads to the loss of function of the rolling bearing or loss of function of the entire rotating equipment including the rolling bearing, on the basis of the evaluation index stored in the storage unit or a rate of change of the evaluation index which can be calculated from the information stored in the evaluation index, and calculates a suitable maintenance and inspection time of the rolling bearing, so that damage that leads to loss of function is prevented in advance. [17] Rolling bearing which has the following features: an inner ring; an outer ring arranged concentrically with the inner ring; a plurality of rolling elements arranged between a running surface of the outer ring and a running surface of the inner ring, each rolling in conjunction with the rotation of the inner ring or the rotation of the outer ring; and the diagnostic device according to any one of claims 1 to 16. [18] Elevator traction machine comprising the following: a rolling bearing that has the following features: an inner ring; an outer ring arranged concentrically with the inner ring; a plurality of rolling elements arranged between a running surface of the outer ring and a running surface of the inner ring, each rolling in conjunction with the rotation of the inner ring or the rotation of the outer ring; and the diagnostic device according to any one of claims 1 to 16; a pulley; a rotating shaft that rotates in an integrated manner with part of the pulley and the roller bearing; and a motor that rotates the shaft.

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