Condition monitoring system and condition monitoring method for rolling bearing

Abstract

To provide a state monitoring system and a state monitoring method capable of detecting a sign of a failure of a rolling bearing.SOLUTION: A condition monitoring system for a roller bearing according to the present invention includes a sensor 18 that monitors a condition of a roller bearing 17b including a roller outer ring 17c1 covered with a fixed member 17b and a rod-shaped member 17c1 that connects the fixed member 17c1 and the roller outer ring 17b to prevent the roller outer ring 17e from rotating with respect to the fixed member 17c, and monitors a physical quantity of the rod-shaped member 17e, and a condition monitoring device 62 that monitors the condition of the roller bearing based on a change in the physical quantity acquired by the sensor 18. 17c.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a condition monitoring system and a condition monitoring method for detecting signs of a malfunction in a rolling bearing. [Background technology]

[0002] BACKGROUND ART Rolling bearings are used in machinery that supports rotating shafts, such as speed increasers for wind power generators and automobile transmissions.

[0003] Take a wind turbine generator as an example. Wind turbine generators are often installed in mountainous or coastal areas, making access for maintenance difficult. Furthermore, because wind turbine generators are large in structure, maintenance requires extensive crane work. For this reason, if a rolling bearing in the speed-increasing gearbox malfunctions, maintenance takes several days, and the wind turbine generator must be shut down for those several days.

[0004] Condition monitoring systems that detect signs of bearing problems are effective in reducing downtime of machinery.

[0005] Examples of problems that can occur in bearings include damage to the bearing, such as wear and flaking of the raceway surface, caused by bending loads that combine loads from multiple directions, excessive loads, and repeated loads. Such damage affects the operating accuracy of the bearing, and depending on the extent of the damage, may require the replacement of the part.

[0006] In order to prevent the above-mentioned situation from occurring, various methods have been devised for monitoring the condition of bearings in order to detect early signs of problems in rolling bearings.

[0007] Patent Document 1 describes a technology for observing the lubricating oil present between the outer ring of a bearing and the rolling elements and the lubrication state by generating ultrasonic waves toward the outer ring of a bearing from an ultrasonic probe attached to the bearing housing and measuring the reflected waves from the boundary between the outer ring of the bearing and the rolling elements.

[0008] Patent document 2 describes a sensor device that detects the load acting on a rolling bearing, and includes an ultrasonic sensor that measures changes in the contact area between a movable body and a fixed body that are in contact with each other using ultrasonic echoes, and processing means that determines the external load from the sensor output by utilizing the correlation between the external load and the contact area.

[0009] Patent Document 3 describes a method for monitoring the condition of a rolling bearing, in which an ultrasonic sensor attached to at least one of the outer ring, housing, inner ring, or shaft on which the inner ring is fitted of the rolling bearing generates ultrasonic waves toward the outer ring or inner ring, receives reflected waves from the boundary between the outer ring and rolling element, the boundary between the outer ring and housing, the boundary between the inner ring and rolling element, or the boundary between the inner ring and shaft, determines the measured number of revolutions of the rolling element based on fluctuations in the echo height of this reflected wave, and compares this measured number of revolutions with the theoretical number of revolutions to monitor orbital slippage of the rolling bearing. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-181237 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-177933 [Patent Document 3] Patent Publication No. 2021-32769 Summary of the Invention [Problem to be solved by the invention]

[0011] A rolling bearing that supports a rotating shaft has a pin between the bearing housing or cover configured to cover the bearing outer ring and the bearing outer ring to prevent the bearing outer ring from rotating relative to the bearing housing or cover, i.e., a pin that has a rotation-preventing function for the bearing outer ring.

[0012] When a bearing is subjected to repeated structural deformation, for example, due to a bending load that combines loads from multiple directions or an unexpected excessive load, the pin will naturally deform as well. If repeated sliding occurs between the pin and the hole in which it is attached due to pin deformation, the pin will gradually wear out, and a gap will form between the pin and the hole. This gap will expand as the sliding between the pin and the hole continues, and eventually the pin's anti-rotation function will be lost. When the pin's anti-rotation function is lost in this way, bearing creep can occur, causing the bearing outer ring to rotate relative to the bearing housing or cover. When bearing creep occurs, wear occurs on the contact surfaces between the bearing housing or cover and the bearing outer ring. If this wear induces misalignment or tilt of the rotating shaft, it can damage the bearing itself.

[0013] For example, a gearbox for a wind turbine generator is configured to change speed in stages, thereby increasing the rotational speed of the main shaft to match the rotational speed of the generator. Such a gearbox is a machine that changes speed using multiple gear trains, and is equipped with rolling bearings on the rotating shaft that supports the gears.

[0014] Generally, multiple bearings support a shaft, each with its own role. For example, a fixed bearing for axial positioning is installed at one end of the supported shaft, and a free bearing is installed at the other end. In the free bearing, for example, the bearing outer ring and housing are loosely fitted, allowing the shaft expansion and contraction to be relieved along with the bearing. Free bearings may also be used separately for supporting radial loads and thrust loads, in which case the bearing for supporting thrust loads is loosely fitted. Bearing creep is naturally more likely to occur when the bearing outer ring and housing are loosely fitted. However, bearing creep can occur in both fixed and free bearings, depending on the bearing load support method and the load distribution within the machine.

[0015] Pin wear can have other effects on bearings as well. In machines where the oil that lubricates the gears and bearings circulates within the machine, a dust-collecting filter is installed in the oil piping system. However, depending on the equipment in which the bearings are installed, the filter may not be able to sufficiently remove the wear debris. For example, the gearboxes for wind turbine generators are approved to allow wear debris less than 10 μm in diameter to pass through the filter, which can result in the wear debris remaining inside the machine.

[0016] Under these conditions, rotating gears and bearings can become entrapped with foreign matter such as wear debris. When foreign matter gets caught on the raceway surface of a bearing, it creates an indentation on the raceway surface, which increases localized stress and shortens the bearing's lifespan. If the bearing continues to operate in this condition, it becomes more susceptible to fatigue damage such as pitting.

[0017] Wear of the pins that prevent the outer ring of a bearing from rotating is considered to be a sign of bearing malfunctions, such as bearing creep, which causes the outer ring to rotate relative to the bearing housing or cover. However, conventional technology does not focus on the pins, making it difficult to prevent the loss of the anti-rotation function due to pin wear and making it difficult to effectively detect signs of bearing malfunctions. For example, in conventional bearings, pin wear is often already advanced by the time bearing creep is noticed. For this reason, there is a demand for devices and methods that can detect signs of rolling bearing malfunctions, particularly those caused by pin wear.

[0018] An object of the present invention is to provide a condition monitoring system and a condition monitoring method that can detect signs of a rolling bearing malfunction. [Means for solving the problem]

[0019] The rolling bearing condition monitoring system according to the present invention monitors the condition of a rolling bearing comprising a bearing outer ring covered by a fixed member and a rod-shaped member that connects the fixed member and the bearing outer ring to prevent the bearing outer ring from rotating relative to the fixed member, and comprises a sensor that monitors the physical quantity of the rod-shaped member, and a condition monitoring device that monitors the condition of the rolling bearing based on changes in the physical quantity acquired by the sensor.

[0020] A method for monitoring the condition of a rolling bearing according to the present invention monitors the condition of a rolling bearing comprising a bearing outer ring covered by a fixed member and a rod-shaped member that connects the fixed member and the bearing outer ring to prevent the bearing outer ring from rotating relative to the fixed member, and includes a measurement step of monitoring the physical quantity of the rod-shaped member with a sensor, and a condition monitoring step of monitoring the condition of the rolling bearing based on changes in the physical quantity acquired by the sensor. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a condition monitoring system and a condition monitoring method that can detect signs of a rolling bearing malfunction. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a side view of the wind turbine generator, showing a cutaway side of the wind turbine generator in a schematic manner. [Figure 2] FIG. 2 is a cross-sectional view of the step-up gear, showing a secondary step-up gear located at the rear upper portion of the step-up gear with a portion cut away. [Figure 3] 3 is a cross-sectional view of the secondary speed-increasing gear shown in FIG. 2, showing a schematic cutaway view of the periphery of the rearmost rolling bearing. [Figure 4] 4 is a front view of the rolling bearing shown in FIG. 3, seen from the direction along the rotation axis. [Figure 5] FIG. 4 is a cross-sectional view of the rolling bearing shown in FIG. 3, viewed from above. [Figure 6] 1 is a diagram showing the configuration of a status monitoring system according to an embodiment of the present invention; [Figure 7]1 is a cross-sectional view of a portion of a rolling bearing, seen from above and rear, of the rolling bearing whose condition is monitored by a condition monitoring system according to an embodiment of the present invention. [Figure 8A] FIG. 10 is a side view of the anti-rotation pin, showing the pin in a state where no bending load is applied. [Figure 8B] FIG. 10 is a side view of the anti-rotation pin, showing the pin undergoing shear deformation due to a bending load being applied. [Figure 8C] FIG. 10 is a side view of the anti-rotation pin, showing that the end portion in the longitudinal direction of the pin has worn down and become thinner. [Figure 8D] FIG. 10 is a side view of the anti-rotation pin, showing the pin with its narrowed end bent and deformed. [Figure 8E] FIG. 10 is a side view of the anti-rotation pin, showing the pin whose end has been worn and whose length has been shortened. [Figure 9] FIG. 8B is an image diagram of time history data of ultrasonic waves propagating through the pin shown in FIGS. 8A, 8B, and 8C. [Figure 10] FIG. 8E is an image diagram of time history data of ultrasonic waves propagating through the pin shown in FIG. 8D. [Figure 11] FIG. 8F is an image diagram of time history data of ultrasonic waves propagating through the pin shown in FIG. 8E. [Figure 12] 8C and 8D. FIG. 8D is a conceptual diagram of time history data of ultrasonic waves propagating through the pin when the pin alternates between the state shown in FIG. 8C and the state shown in FIG. 8D. [Figure 13] FIG. 8B is an image diagram of time history data of ultrasonic waves propagating through the pin when the pin alternates between the state shown in FIG. 8E and the state shown in FIG. 8D. [Figure 14] 1 is a cross-sectional view of a portion of a rolling bearing having a hollow pin, seen from above; [Figure 15] 1 is a cross-sectional view of a portion of a rolling bearing provided with a hollow pin in this embodiment, seen from above. [Figure 16] 1 is a cross-sectional view of a portion of a rolling bearing provided with a hollow pin having a notched end, as viewed from above. [Figure 17] 1 is a cross-sectional view of a portion of a rolling bearing, seen from above, that includes a hollow pin having a notched end in this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] The rolling bearing condition monitoring system and condition monitoring method according to the present invention monitor the condition of a rolling bearing and can detect signs of a rolling bearing malfunction caused by wear of a rod-shaped member (e.g., a pin) that prevents the outer ring of the rolling bearing from rotating. Detecting signs of a rolling bearing malfunction can prevent the pin that prevents the outer ring from rotating from losing its anti-rotation function and bearing creep of the rolling bearing. Therefore, use of the present invention can reduce the downtime of machinery that uses rolling bearings.

[0024] A condition monitoring system and a condition monitoring method for a rolling bearing according to an embodiment of the present invention will be described below with reference to the drawings. Hereinafter, the extension direction of the shaft supported by the rolling bearing will be referred to as the axial direction, the rotation direction of this shaft will be referred to as the circumferential direction, and the radial direction of this shaft will be referred to as the radial direction. In the drawings used in this specification, identical or corresponding components will be designated by the same reference numerals, and repeated explanations of these components may be omitted. [Example]

[0025] <Wind power generation equipment> First, an example of a mechanical device to which the rolling bearing condition monitoring system and condition monitoring method according to this embodiment can be applied will be described. The condition monitoring system and condition monitoring method according to this embodiment can be applied to any device equipped with a rolling bearing. Below, as an example, an example will be described in which the condition monitoring system and condition monitoring method according to this embodiment are applied to a gearbox for a wind turbine generator.

[0026] 1 is a side view of the wind turbine generator 11, showing a cutaway schematic view of the side of the wind turbine generator 11. The up-down direction in FIG. 1 is the up-down direction of the wind turbine generator 11. In FIG. 1, the left side is the front direction of the wind turbine generator 11, and the right side is the rear direction of the wind turbine generator 11.

[0027] The wind turbine generator 11 includes a nacelle 14 that is rotatable in a horizontal plane and is mounted on a support base 12. A main shaft 15 that extends in the front-to-rear direction of the wind turbine generator 11 is provided within the casing of the nacelle 14.

[0028] The main shaft 15 is rotatably supported by a pair of front and rear main shaft bearings 1. One end (front end) of the main shaft 15 protrudes outside the casing of the nacelle 14 and is provided with a blade support base 16a. Blades 16 are rotatably mounted on the blade support base 16a. The other end (rear end) of the main shaft 15 is connected to the gearbox 17 as an input shaft. An output shaft 20 of the gearbox 17 is connected to a generator 19.

[0029] In addition to rotational torque, a bending moment due to wind force is generated on the main shaft 15. Although it depends on the structure of the wind power generator 11, the speed increaser 17 shares the reaction force generated on the main shaft 15.

[0030] <Gearbox> The gearbox 17 provided in the wind turbine generator 11 will be described.

[0031] The speed increaser 17 is a device that rotates the generator 19 while gradually increasing the rotational speed of the main shaft 15 therein. The speed increaser 17 has a planetary gear mechanism as a primary speed increaser on the main shaft 15 side, and a secondary speed increaser on the generator 19 side.

[0032] The planetary gear mechanism has a structure in which multiple planetary gears are arranged on a carrier connected to the main shaft 15, and these planetary gears are meshed with an internally toothed ring gear and a sun gear, and the shaft integrated with the sun gear is connected to the secondary speed increaser as the output shaft.

[0033] The secondary speed increaser transmits the rotation of the output shaft of the primary speed increaser to the generator 19 via a plurality of gear trains.

[0034] FIG. 2 is a cross-sectional view of the speed-increasing gear 17, showing a secondary speed-increasing gear located above and behind the speed-increasing gear 17, with a portion thereof cut away.

[0035] The speed increaser 17 includes a rotating shaft 17f and a rolling bearing 17c that supports the rotating shaft 17f.

[0036] The gear of the secondary speed-increasing gear of the speed-increasing gear 17 is supported by a rotating shaft 17f. Both ends of the rotating shaft 17f are supported by a plurality of rolling bearings 17c. The rolling bearing 17c arranged at one end of the rotating shaft 17f is used as a fixed-side bearing, and the rolling bearing 17c arranged at the other end is used as a free-side bearing.

[0037] The speed increaser 17 includes a substantially annular housing 17a configured to cover the rolling bearing 17c. The housing 17a is a bearing housing and includes a front housing 17a1 and a rear housing 17a2. The speed increaser 17 further includes a substantially annular cover 17b configured to cover the rolling bearing 17c. The cover 17b includes a front cover 17b1 and a rear cover 17b2. The housing 17a and the cover 17b are fixing members that cover the rolling bearing 17c and fix the rolling bearing 17c. The housing 17a and the cover 17b have an integrated structure because their respective flange portions are fastened to each other with bolts.

[0038] Of the rolling bearings 17c, the free-side bearing has a clearance fit between the bearing outer ring and housing 17a, and the expansion and contraction of the rotating shaft 17f is relieved together with the bearing. In a configuration in which the free-side bearing is divided into one for supporting radial (radial) loads and one for supporting thrust (axial) loads, it is common for the bearing for supporting thrust loads to have a clearance fit.

[0039] Typically, lubricating oil is supplied to the gears and bearings inside the housing 17a. The lubricating oil is circulated inside the machine by a circulation unit equipped with a pump and piping. If wear debris generated inside the machine for some reason circulates inside the machine along with the lubricating oil, and the gears and bearings become caught in this wear debris as foreign matter, fatigue damage such as pitting becomes more likely to occur on the surfaces of the rolling parts.

[0040] In order to extend the life of the rolling parts and reduce the frequency of maintenance of the wind power generation device 11, an oil filter for collecting dust is arranged in the circulation section, and this oil filter removes wear dust.

[0041] The speed increaser 17 includes an oil seal 17d between the rotary shaft 17f and the cover 17b to prevent the lubricating oil from leaking to the outside.

[0042] <Rolling bearings> Rolling bearings include ball bearings and roller bearings, which differ in the shape of the rolling elements. A rolling bearing comprises a cylindrical inner ring arranged to cover the outer peripheral surface of a rotating shaft, and a cylindrical outer ring that covers the outer peripheral surface of the inner ring. The outer ring is arranged concentrically with the inner ring and is spaced a predetermined distance radially outward from the outer peripheral surface of the inner ring. A plurality of rolling elements are arranged circumferentially between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring. A housing that covers the bearing is usually attached to the outer periphery of the outer ring.

[0043] Deep groove bearings are also used as rolling bearings. Deep groove bearings have a plurality of arc-shaped deep grooves formed at predetermined intervals in the circumferential direction on the outer peripheral surface of the inner ring, and a plurality of arc-shaped deep grooves formed on the inner peripheral surface of the outer ring at positions facing the deep grooves formed on the outer peripheral surface of the inner ring.

[0044] <Pin to prevent rotation of bearing outer ring> Rolling bearing 17c has pin 17e between the outer ring of the bearing and housing 17a or cover 17b to prevent bearing creep, which is rotation of the outer ring of the bearing. Housing 17a and cover 17b are fixing members that cover and fix the outer ring of the bearing. Pin 17e is a rod-shaped member made of metal, for example, to prevent rotation of the outer ring of the bearing relative to housing 17a or cover 17b. Pin 17e connects the outer ring of the bearing and housing 17a or cover 17b and fixes the outer ring of the bearing to housing 17a or cover 17b, thereby preventing bearing creep.

[0045] Figure 3 is a cross-sectional view of the speed increaser 17, showing a schematic cutaway view of the area around the rearmost rolling bearing 17c (the rightmost one in Figure 2) of the rolling bearings 17c of the secondary speed increaser shown in Figure 2.

[0046] Rolling bearing 17c includes outer bearing ring 17c1, inner bearing ring 17c3, and a plurality of rolling elements 17c2 arranged between outer bearing ring 17c1 and inner bearing ring 17c3. In this embodiment, rolling elements 17c2 are spherical elements (balls), but may also be cylindrical elements (rollers).

[0047] Bearing inner ring 17c3 is fixed to rotating shaft 17f. In the example shown in Fig. 3, bearing outer ring 17c1 is fixed to cover 17b (front cover 17b1) of gearbox 17. Cover 17b has a substantially annular shape, is installed concentrically with bearing outer ring 17c1, and covers bearing outer ring 17c1.

[0048] 3, pin 17e for preventing rotation of bearing outer ring 17c1 is installed between bearing outer ring 17c1 and cover 17b (rear cover 17b2) configured to cover bearing outer ring 17c1. As described above, pin 17e is a rod-shaped member for preventing bearing creep, and fixes bearing outer ring 17c1 to cover 17b to prevent bearing outer ring 17c1 from rotating relative to cover 17b.

[0049] Pin 17e is fixedly installed in a hole in cover 17b (or housing 17a) that covers bearing outer ring 17c1, and the part that protrudes from cover 17b (or housing 17a) is inserted into the hole in bearing outer ring 17c1. Pin 17e is positioned in this way to prevent bearing outer ring 17c1 from rotating relative to cover 17b, thereby preventing bearing creep.

[0050] Fig. 4 is a front view of rolling bearing 17c shown in Fig. 3, seen from the direction along rotating shaft 17f. Rolling bearing 17c includes outer bearing ring 17c1, inner bearing ring 17c3, and a plurality of rolling elements 17c2.

[0051] Figure 4 shows an example of pin 17e that is cylindrical, i.e., has a circular cross section perpendicular to the length direction and is solid. The cross section of pin 17e may also have other shapes, such as a rectangle. Figure 4 also shows two pins 17e attached to bearing outer ring 17c1. To ensure the anti-rotation function of bearing outer ring 17c1 and to ensure the strength of pins 17e, multiple pins 17e are usually attached to bearing outer ring 17c1.

[0052] The pin 17e is also attached to the cover 17b (or the housing 17a). The hole in the cover 17b (or the housing 17a) for attaching the pin 17e can have any cross-sectional shape as long as the pin 17e can have a rotation-preventing function. For example, the cross-sectional shape of this hole can be circular or rectangular. In the example shown in FIG. 4, the cover 17b has a circular hole, and the pin 17e, which has a circular cross-sectional shape, is firmly fixed in this hole by interference fitting, press fitting, or the like.

[0053] 4, a bearing outer ring 17c1 fixed to the cover 17b of the gearbox 17 has a rectangular hole on its outer periphery. This hole is formed, for example, by cutting out the outer periphery of the bearing outer ring 17c1.

[0054] As shown in Figure 3, when the flange surface of rear cover 17b2 is aligned with front cover 17b1 and bearing outer ring 17c1, pin 17e fixed to rear cover 17b2 is inserted into a hole provided in bearing outer ring 17c1, and cover 17b and bearing outer ring 17c1 form an integrated structure.

[0055] The hole in bearing outer ring 17c1 can have any cross-sectional shape, such as rectangular or circular, as long as pin 17e can be inserted therein. Pin 17e is preferably firmly fixed to the hole in bearing outer ring 17c1. However, from the perspective of assembly, pin 17e tends to be more loosely fixed to the hole in bearing outer ring 17c1 than to the hole in cover 17b (or housing 17a). Whether pin 17e is more firmly fixed to the hole in bearing outer ring 17c1 or the hole in cover 17b (or housing 17a) can be determined based on, for example, whether rolling bearing 17c is used as a fixed bearing or a free bearing, and the load support method of rolling bearing 17c.

[0056] Figure 5 is a cross-sectional view of rolling bearing 17c shown in Figure 3, viewed from above. Rolling bearing 17c includes bearing outer ring 17c1, a plurality of rolling elements 17c2, and bearing inner ring 17c3 (not shown in Figure 5). Bearing outer ring 17c1 is fixed to cover 17b of gearbox 17. Figure 5 shows an end face of rolling bearing 17c, an end face of cover 17b (rear cover 17b2), and the mating surfaces of cover 17b (rear cover 17b2) and bearing outer ring 17c1 (see Figure 3).

[0057] 5, in hole 17e1 of bearing outer ring 17c1 in which pin 17e is installed, there is an axial gap 17e2 between pin 17e and bearing outer ring 17c1. Also, in hole 17b3 of cover 17b in which pin 17e is installed, there is an axial gap 17e3 between pin 17e and cover 17b.

[0058] 5 shows an example in which both gap 17e2 and gap 17e3 are present, but only one of gap 17e2 and gap 17e3 may be present, or neither may be present. From the viewpoint of firmly fixing pin 17e to hole 17e1 and hole 17b3 so as not to loosen, it is preferable that gap 17e2 and gap 17e3 are absent.

[0059] In this embodiment, an example will be described in which the pin 17e is arranged along the axial direction of the bearing outer ring 17c1, but the pin 17e may also be arranged along the radial direction of the bearing outer ring 17c1.

[0060] <Example of embodiment of the present invention> A condition monitoring system and a condition monitoring method for a rolling bearing according to an embodiment of the present invention will now be described in detail.

[0061] Fig. 6 is a diagram showing the configuration of the condition monitoring system according to this embodiment. Fig. 6 also shows a cross-sectional view of a portion of the rolling bearing 17c, viewed from above, of the rolling bearing 17c whose condition is monitored by the condition monitoring system according to this embodiment. Fig. 7 is a cross-sectional view of a portion of the rolling bearing 17c, viewed from above and rearward, of the rolling bearing 17c whose condition is monitored by the condition monitoring system according to this embodiment.

[0062] The condition monitoring system according to this embodiment includes a sensor 18, a condition monitoring device 62, and a pin condition database 63, and monitors the condition of the rolling bearing 17c to detect signs of a malfunction of the rolling bearing 17c. The condition of the rolling bearing 17c refers to the presence or absence of a behavior in which the outer ring 17c1 of the rolling bearing 17c rotates relative to the housing 17a or cover 17b configured to cover the outer ring 17c1, i.e., the presence or absence of bearing creep. In this embodiment, the sensor 18 is an ultrasonic sensor and includes an ultrasonic device 61.

[0063] A pin 17e for preventing rotation of the outer ring 17c1 of the rolling bearing 17c is attached between the outer ring 17c1 of the rolling bearing 17c and the housing 17a or the cover 17b configured to cover the outer ring 17c1.

[0064] The sensor 18 is installed on one end surface of the pin 17e, which is a rod-shaped member, and monitors the physical quantity of the pin 17e. In this embodiment, the sensor 18 is an ultrasonic sensor that is installed in contact with one end surface of the pin 17e, emits ultrasonic waves from one end surface of the pin 17e toward the other end surface, and receives the ultrasonic waves reflected by the other end surface and returning. The physical quantity of the pin 17e is, for example, the length of the pin 17e. That is, in this embodiment, the sensor 18 measures and monitors the length of the pin 17e as the physical quantity of the pin 17e. The sensor 18 is rod-shaped (for example, approximately cylindrical) like the pin 17e. The diameter of the sensor 18 may be larger or smaller than the diameter of the pin 17e, or may be the same as the diameter of the pin 17e.

[0065] When multiple pins 17e are attached to the bearing outer ring 17c1, sensors 18 may be installed on all or some of the pins 17e. For example, sensors 18 may be installed on only those pins 17e that are located in positions where symptoms of bearing creep can be easily detected. A position where symptoms of bearing creep can easily be detected is, for example, a position where the length of the pin 17e is likely to change.

[0066] Housing 17a and cover 17b are provided with hole 18b for installing sensor 18 on one end surface of pin 17e from the outside. Hole 18b opens to the outside of housing 17a and cover 17b. Sensor 18 is installed in hole 18b and attached to pin 17e. When multiple pins 17e are attached to bearing outer ring 17c1, it is preferable that multiple holes 18b corresponding to the multiple pins 17e are provided in housing 17a and cover 17b.

[0067] Sensor 18, which is an ultrasonic sensor, includes an ultrasonic device 61 and can measure and monitor the physical quantity, such as the length, of pin 17e installed in bearing outer ring 17c1. For example, sensor 18, which is an ultrasonic sensor, can measure the physical quantity of pin 17e installed in bearing outer ring 17c1 while rolling bearing 17c is in operation. The physical quantity of pin 17e measured and acquired by sensor 18 is transmitted to condition monitoring device 62.

[0068] The ultrasonic device 61 determines the propagation time from when the ultrasonic waves are incident on the pin 17e from the sensor 18 until they are reflected and return to the sensor 18, and determines the physical quantity of the pin 17e from this propagation time of the ultrasonic waves. Because the speed of sound of the ultrasonic waves propagating inside the pin 17e is constant and can be determined in advance, the ultrasonic device 61 can determine the length of the pin 17e, which is the physical quantity of the pin 17e, from the propagation time and speed of sound of the ultrasonic waves.

[0069] The condition monitoring device 62 monitors and diagnoses the condition of the rolling bearing 17c based on changes in the physical quantity of the pin 17e acquired by the sensor 18, and detects signs of malfunction of the rolling bearing 17c. The condition monitoring device 62 can be configured, for example, by a computer. In this embodiment, the condition monitoring device 62 determines the condition of the pin 17e from the propagation time of ultrasonic waves. For example, the condition monitoring device 62 can determine changes in the length of the pin 17e from changes in the propagation time of ultrasonic waves.

[0070] The pin status database 63 is a database that stores information about the relationship between the length of the pin 17e, the propagation time of ultrasonic waves, and the reception intensity (degree of ultrasonic wave attenuation). The pin status database 63 stores the relationship between the length of the pin 17e, the propagation time of ultrasonic waves, and the reception intensity in a normal state where no bearing creep is occurring. This relationship can be obtained in advance by conducting experiments or the like.

[0071] In this embodiment, by focusing on the physical quantity (length) of pin 17e, it is possible to detect signs of bearing creep, in which bearing outer ring 17c1 rotates relative to housing 17a or cover 17b, and to detect signs of a malfunction in rolling bearing 17c. Specifically, condition monitoring device 62 determines a change in the length of pin 17e by comparing the propagation time of ultrasonic waves in a normal state stored in pin condition database 63 with the propagation time of measured ultrasonic waves, thereby detecting signs of a malfunction in rolling bearing 17c. Condition monitoring device 62 may determine the change in the length of pin 17e by comparing the length of pin 17e determined from the propagation time of ultrasonic waves in a normal state with the length of pin 17e determined from the propagation time of measured ultrasonic waves.

[0072] In the wind turbine generator 11, when the gearbox 17 is configured to share the bending moment acting on the main shaft 15, the gearbox 17 shares not only the rotational torque but also the bending moment due to structural irregularities such as mounting errors, shape errors, excessive loads, eccentricity, etc. This bending moment acts as a bending load on the bearing of the gearbox 17. This bending load is also transmitted to the rear of the gearbox 17, and is also applied to the anti-rotation pin 17e of the bearing outer ring 17c1.

[0073] The pin 17e may be deformed by this bending load.

[0074] 8A to 8E are side views of anti-rotation pin 17e and illustrate modified examples of pin 17e. 8A to 8E also show sensor 18 installed on one end face of pin 17e, and the ultrasonic waves that are incident on pin 17e from sensor 18 (ultrasonic sensor), reflected, and returned to sensor 18 are shown by dashed lines.

[0075] Fig. 8A is a diagram showing pin 17e in a state where no bending load is applied, and shows pin 17e in a normal state where no bearing creep has occurred.

[0076] 8B is a diagram showing pin 17e that has undergone shear deformation due to the application of a bending load. When a small bending load is applied, pin 17e undergoes shear deformation while remaining integrated with bearing outer ring 17c1 and cover 17b (or housing 17a). When a large bending load is applied, pin 17e may move relative to hole 17e1 in bearing outer ring 17c1.

[0077] When a bending load is applied to pin 17e, pin 17e undergoes shear deformation and repeatedly moves relative to hole 17e1 of bearing outer ring 17c1, causing the longitudinal ends to gradually wear due to sliding against hole 17e1 of bearing outer ring 17c1.

[0078] Fig. 8C shows pin 17e whose longitudinal end has worn away and become thinner, in a state where no bending load is applied (no bending deformation has occurred).

[0079] When the end of the pin 17e in the length direction wears down to a certain extent and becomes thinner, a gap is formed between the end and the hole 17e1 of the bearing outer ring 17c1, and this end undergoes bending deformation due to the bending load.

[0080] Depending on the mounting conditions of the bearing outer ring 17c1 and the cover 17b (or the housing 17a), the end of the pin 17e on the bearing outer ring 17c1 side (the end inserted into the bearing outer ring 17c1) or the end on the cover 17b (or the housing 17a) side may wear.

[0081] Fig. 8D shows pin 17e whose narrowed end has undergone bending deformation. Fig. 8D shows pin 17e whose end on the bearing outer ring 17c1 side has worn away and undergone bending deformation, causing the end surface that reflects ultrasonic waves to be tilted at an angle θ.

[0082] If the wear at the end of the pin 17e continues to progress, the length of the pin 17e will become shorter, and eventually the function of the pin 17e to prevent rotation with respect to the bearing outer ring 17c1 will be lost.

[0083] Figure 8E shows pin 17e whose end has worn away and become shorter. For comparison, pin 17e (Figure 8A) in its normal state, where its length has not yet shortened, is shown in dashed lines in Figure 8E. Before bearing creep occurs, the length of pin 17e, which is a rod-shaped member, changes, as shown in Figure 8E.

[0084] The ultrasonic device 61 determines the length of the pin 17e, which is a physical quantity of the pin 17e, from the propagation time and sound speed of the ultrasonic waves.

[0085] 8A is the pin 17e in a state where no bending load is applied and no deformation is occurring, that is, in a normal state. The length of this pin 17e is defined as the reference length.

[0086] The pin 17e shown in Figure 8B, which has been subjected to a bending load and has undergone shear deformation, has not changed in length.The pin 17e shown in Figure 8C, which has been worn down and thinned at its end, also has not changed in length.

[0087] 8D, the length of pin 17e, whose narrowed end is bent, changes. For example, if pin 17e is bent while expanding, the length of pin 17e increases, and if pin 17e is bent while contracting, the length of pin 17e decreases. In this embodiment, the length of pin 17e is increased from the reference length due to bending deformation.

[0088] Pin 17e, shown in Figure 8E, has a shortened, worn end, reducing its length.

[0089] Fig. 9 is an image diagram of the time history data of ultrasonic waves propagating through pin 17e shown in Fig. 8A, Fig. 8B, and Fig. 8C. As an example, Fig. 9 shows an example in which ultrasonic waves are emitted three times from sensor 18, and three pairs of incident waves and reflected waves are shown.

[0090] 8A, 8B, and 8C, the ultrasonic wave propagation time from incidence to reflection is the same for all three times. Furthermore, since the ultrasonic wave propagation times are the same for these pins 17e, it can be seen that the length has not changed from the reference length.

[0091] The propagation time of the ultrasonic waves in the pin 17e increases or decreases depending on the change in the length of the pin 17e due to bending or wear.

[0092] Fig. 10 is an image diagram of the time history data of ultrasonic waves propagating through pin 17e shown in Fig. 8D. As an example, Fig. 10 shows an example in which ultrasonic waves are emitted three times from sensor 18, and three pairs of incident waves and reflected waves are shown. Fig. 10 also shows the time history data of the reflected waves for pin 17e shown in Fig. 8A (i.e., the waveform of the reflected wave shown in Fig. 9) as data of the original shape.

[0093] In the example shown in Fig. 10, the propagation time from incidence to reflection of the ultrasonic waves is the same for all three times, but is longer than the example shown in Fig. 9. In the pin 17e with a bent end shown in Fig. 8D, the end surface from which the ultrasonic waves are reflected is tilted by an angle θ due to bending deformation, and the ultrasonic waves are refracted and reflected at this end surface, lengthening the propagation time by the amount of refraction. The longer propagation time of the ultrasonic waves indicates that the length of pin 17e has changed and increased from the reference length.

[0094] Fig. 11 is an image diagram of the time history data of ultrasonic waves propagating through pin 17e shown in Fig. 8E. As an example, Fig. 11 shows an example in which ultrasonic waves are emitted three times from sensor 18, and three pairs of incident waves and reflected waves are shown. Fig. 11 also shows the time history data of the reflected waves for pin 17e shown in Fig. 8A (i.e., the waveform of the reflected wave shown in Fig. 9) as data of the original shape.

[0095] In the example shown in Figure 11, the propagation time from the incidence of the ultrasonic wave to its reflection is the same for all three times, but is shorter than the example shown in Figure 9. The propagation time of the ultrasonic wave is shorter for pin 17e, whose end has become shorter due to wear, as shown in Figure 8E. The shorter propagation time of the ultrasonic wave indicates that the length of pin 17e has changed and decreased from the reference length.

[0096] The condition monitoring device 62 can detect a change in the length of the pin 17e by using the relationship between the length of the pin 17e in a normal state and the propagation time of ultrasonic waves, which is stored in the pin condition database 63, and the propagation time of ultrasonic waves emitted from the sensor 18. If the length of the pin 17e has changed (particularly if the length of the pin 17e has decreased), the condition monitoring device 62 can detect this as a sign of a malfunction in the rolling bearing 17c.

[0097] Next, a description will be given of an example of a method for monitoring the state of the pin 17e by the state monitoring device 62. The state monitoring device 62 can monitor the state of the pin 17e by, for example, comparing the pin 17e in a loaded state, such as when the rolling bearing 17c is in operation, with the pin 17e in an unloaded state, such as when the rolling bearing 17c is not in operation.

[0098] Figure 12 is an image diagram of time history data of ultrasonic waves propagating through pin 17e when pin 17e alternates between the state shown in Figure 8C and the state shown in Figure 8D. In the state shown in Figure 8C, the worn, thinned end of pin 17e does not undergo bending deformation, but in the state shown in Figure 8D, the worn, thinned end undergoes bending deformation. Figure 12 also shows data of the original shape shown in Figures 10 and 11.

[0099] In Fig. 12, during time periods A and C, no bending load is applied to pin 17e, and pin 17e is in an unloaded state and not bent, as shown in Fig. 8C. During time period B, a bending load is applied to pin 17e, and pin 17e is in a loaded state and bent, as shown in Fig. 8D. As shown in Fig. 12, pin 17e alternates between an unloaded state in which no bending load is applied and a loaded state in which a bending load is applied.

[0100] The propagation time of the ultrasonic waves is longer for the pin 17e (the pin 17e in a loaded state) in time period B than for the pin 17e (the pin 17e in an unloaded state) in time period A. The propagation times of the ultrasonic waves for the pin 17e (the pin 17e in an unloaded state) in time period A and time period C are equal to each other.

[0101] The state monitor 62 can distinguish between the loaded and unloaded states of the pin 17e from each other based on the difference in propagation time of the ultrasonic waves.

[0102] Fig. 13 is an image diagram of time history data of ultrasonic waves propagating through pin 17e when pin 17e alternates between the state shown in Fig. 8E and the state shown in Fig. 8D. In the state shown in Fig. 8E, the end of pin 17e, which has become worn and shortened in length, does not undergo bending deformation, while in the state shown in Fig. 8D, the end undergoes bending deformation. However, in the explanation here, it is assumed that in the state shown in Fig. 8D, the end of pin 17e has become worn and shortened in length (i.e., it is assumed that pin 17e shown in Fig. 8E undergoes bending deformation). Fig. 13 also shows data of the original shape shown in Figs. 10 and 11.

[0103] In Fig. 13, during time periods D and F, no bending load is applied to pin 17e, and pin 17e is in an unloaded state and not bent, as shown in Fig. 8E. During time period E, a bending load is applied to pin 17e, and pin 17e is in a loaded state and bent, as shown in Fig. 8D. As shown in Fig. 13, pin 17e alternates between an unloaded state in which no bending load is applied and a loaded state in which a bending load is applied.

[0104] The ultrasonic wave propagation time for pin 17e (pin 17e in a loaded state) in time period E is longer than that for pin 17e (pin 17e in an unloaded state) in time period D. The ultrasonic wave propagation times for pin 17e (pin 17e in an unloaded state) in time periods D and F are equal to each other and shorter than the ultrasonic wave propagation time in the original shape data.

[0105] The state monitor 62 can distinguish between the loaded and unloaded states of the pin 17e from each other based on the difference in propagation time of the ultrasonic waves.

[0106] Furthermore, the state monitoring device 62 can determine which of the states shown in Figures 8C to 8E the pin 17e is in based on the difference in propagation time of the ultrasonic waves as shown in Figures 12 and 13.

[0107] In this embodiment, as described above, the condition monitoring device 62 can detect signs of bearing creep occurring in the rolling bearing 17c before it occurs from changes in the length and shape of the pin 17e. By using an ultrasonic sensor as the sensor 18, changes in the length and shape of the pin 17e can be detected from changes in the propagation time of ultrasonic waves in the pin 17e.

[0108] In this embodiment, the condition monitoring device 62 not only detects signs of bearing creep, but also determines the condition of the pin 17e when or after the pin 17e is attached to the housing 17a or the cover 17b. For example, it is possible to determine whether the pin 17e is inserted straight into the hole 17e1 of the bearing outer ring 17c1 or whether it is inserted bent, based on the condition of the pin 17e as shown in Figures 8A to 8E.

[0109] For example, if pin 17e is inserted into hole 17e1 with its end bent as shown in Fig. 8D, depending on the angle θ at which the end face is tilted due to the bend, sensor 18 may not be able to properly receive the ultrasonic waves reflected from the end face, or the intensity of the ultrasonic waves received by sensor 18 may be weak. Also, for example, if the end of pin 17e inserted into hole 17e1 is worn, as shown in Fig. 8C or 8E, if the end of pin 17e is worn and the flat surface is lost, sensor 18 may not be able to properly receive the ultrasonic waves reflected from the end face, or the intensity of the ultrasonic waves received by sensor 18 may be weak.

[0110] In such a case, the state monitor 62 can determine the state of the pin 17e by referring to the data on the pin 17e in a normal state stored in the pin state database 63.

[0111] The pin condition database 63 can store information about the relationship between the length of the pin 17e, the propagation time of the ultrasonic waves, and the reception strength (degree of attenuation of the ultrasonic waves) even for pins 17e with bent ends or pins 17e with worn ends. The pin condition database 63 can also store this information in association with the operating time of the rolling bearing 17c.

[0112] Furthermore, by periodically removing the pin 17e from the rolling bearing 17c and inspecting it, and comparing the ultrasonic propagation time and reception strength with the data stored in the pin condition database 63 and the measured data, it is possible to determine whether the end of the pin 17e is bent, whether the end of the pin 17e is worn, whether the pin 17e is shortened, or a combination of these conditions.

[0113] In this embodiment, an example has been described in which the sensor 18 that monitors the physical quantity of the pin 17e is an ultrasonic sensor. The sensor 18 does not have to be an ultrasonic sensor, and may be, for example, a strain gauge or an FBG (Fiber Bragg Grating) sensor. Unlike an ultrasonic sensor, a strain gauge or an FBG sensor must be installed on the pin 17e by processing the pin 17e, such as by cutting or drilling a notch. An ultrasonic sensor can be installed on the pin 17e without such processing, so that the pin 17e on which the ultrasonic sensor is installed does not lose its rigidity against deformation and is less likely to lose its anti-rotation function with respect to the bearing outer ring 17c1.

[0114] When installing a strain gauge or FBG sensor on pin 17e, it is necessary to temporarily stop the operation of rolling bearing 17c. Furthermore, strain gauges are more susceptible to deterioration due to environmental conditions than ultrasonic sensors, and are relatively prone to deterioration over time. Once installed on rolling bearing 17c, they are difficult to attach and detach from rolling bearing 17c.

[0115] When installing the ultrasonic sensor on the pin 17e, it is preferable to apply liquid couplant to the end face of the pin 17e to promote the propagation of ultrasonic waves. After the rolling bearing 17c is put into operation, there is no need to temporarily stop the operation of the rolling bearing 17c when reapplying liquid couplant to the end face of the pin 17e.

[0116] Furthermore, when installing the ultrasonic sensor on pin 17e, it is sufficient to simply press the ultrasonic sensor lightly against the end face of pin 17e while fixing it in place. The ultrasonic sensor may remain fixed on pin 17e for an extended period of time, or may be removed from pin 17e after any predetermined period of time has elapsed. When an ultrasonic sensor is used for sensor 18, the length of pin 17e can be easily determined from the propagation time of the ultrasonic waves, and changes in the length of pin 17e can be determined from changes in the propagation time.

[0117] The ultrasonic sensor is detachable from the rolling bearing 17c, and may be installed on the rolling bearing 17c at all times, or may be installed on the rolling bearing 17c only when necessary.

[0118] In the above description, the pin 17e is a solid cylindrical rod-shaped member, but the pin 17e may be a hollow rod-shaped member.

[0119] FIG. 14 is a cross-sectional view of a part of the rolling bearing 17c, which includes a hollow pin 17e, seen from above.

[0120] Pin 17e is a hollow rod-shaped member and has a hollow portion 17e4 extending in the longitudinal direction at the center of a cross section perpendicular to the longitudinal direction. Hollow portion 17e4 penetrates pin 17e in the longitudinal direction. Sensor 18, which monitors the physical quantity of pin 17e, is an ultrasonic sensor. If pin 17e is hollow and has hollow portion 17e4, it is difficult to install an ultrasonic sensor on one end face of pin 17e, and it is difficult to determine the change in the length of pin 17e from the change in the propagation time of ultrasonic waves.

[0121] In this embodiment, the hollow pin 17e has a solid rod-shaped member in the hollow portion 17e4, so that an ultrasonic sensor can be installed on one end surface of the pin 17e.

[0122] FIG. 15 is a cross-sectional view of a part of the rolling bearing 17c, which is provided with a hollow pin 17e in this embodiment, as seen from above.

[0123] The hollow pin 17e includes a solid rod-shaped member 17e5 in the hollow portion 17e4. The solid rod-shaped member 17e5 has substantially the same shape as the hollow portion 17e4 of the hollow pin 17e and is large enough to be installed in the hollow portion 17e4. The solid rod-shaped member 17e5 is preferably installed without any gaps in the hollow portion 17e4. The solid rod-shaped member 17e5 is made of, for example, metal and fixed in the hollow portion 17e4 by clearance fit, press fitting, adhesive, or welding. A sensor 18 (ultrasonic sensor) is installed on one end surface of the hollow pin 17e and the solid rod-shaped member 17e5, mainly on one end surface of the solid rod-shaped member 17e5.

[0124] In this embodiment, even though pin 17e is hollow, an ultrasonic sensor can be installed on one end face of pin 17e (particularly, one end face of rod-shaped member 17e5), so that the change in length of pin 17e can be determined from the change in the propagation time of ultrasonic waves. Furthermore, hollow pin 17e, which has rod-shaped member 17e5 in hollow portion 17e4, has a double cylindrical structure, so that not only can an ultrasonic sensor be installed on one end face, but also rigidity is improved, strengthening the anti-rotation function with respect to bearing outer ring 17c1.

[0125] The hollow pin 17e may have a notched end.

[0126] FIG. 16 is a cross-sectional view of a part of a rolling bearing 17c, seen from above, that includes a hollow pin 17e with a notched end.

[0127] The hollow pin 17e has a hollow portion 17e4 and a shape in which a surface perpendicular to the longitudinal direction is cut out at the end where ultrasonic waves are reflected. The sensor 18 that monitors the physical quantity of the pin 17e is an ultrasonic sensor. A hollow pin 17e with such a shape requires a surface that is parallel to the ultrasonic wave incident surface as the ultrasonic wave reflecting surface. Furthermore, as with the pin 17e shown in FIG. 14, it is difficult to install an ultrasonic sensor on one end surface of the pin 17e, and it is difficult to determine the change in the length of the pin 17e from the change in the ultrasonic wave propagation time.

[0128] FIG. 17 is a cross-sectional view of a part of a rolling bearing 17c, seen from above, which includes a hollow pin 17e having a notched end in this embodiment.

[0129] Hollow pin 17e, which has a notched end, includes solid rod-shaped member 17e5 in hollow portion 17e4. Solid rod-shaped member 17e5 has substantially the same shape as hollow portion 17e4 of hollow pin 17e, is made of metal, for example, and is fixed to hollow portion 17e4 by clearance fit, press fitting, adhesive, or welding. Sensor 18 (ultrasonic sensor) is installed on one end surface of hollow pin 17e and solid rod-shaped member 17e5, mainly on one end surface of solid rod-shaped member 17e5.

[0130] In this embodiment, even though pin 17e is hollow and has a notched end, an ultrasonic sensor can be attached to one end face of pin 17e (particularly, one end face of rod-shaped member 17e5), so that the change in length of pin 17e can be determined from the change in the propagation time of the ultrasonic waves. Furthermore, hollow pin 17e having rod-shaped member 17e5 in hollow portion 17e4 has a double cylindrical structure, so that not only can an ultrasonic sensor be attached to one end face, but also rigidity is improved, strengthening the anti-rotation function with respect to bearing outer ring 17c1.

[0131] As described above, the condition monitoring system and the condition monitoring method according to this embodiment can detect signs of a malfunction in the rolling bearing 17c.

[0132] <Other Examples of Embodiments of the Present Invention> In the embodiment described above, the rolling bearing 17c located at the rearmost position (the rightmost position in FIG. 2) among the rolling bearings 17c of the secondary gearbox shown in FIG. 2 has been described. This embodiment can also be applied to other rolling bearings provided in the wind turbine generator 11. Furthermore, the rolling elements 17c2 (FIG. 3) provided in the rolling bearing 17c do not have to be spherical members (balls) and may be, for example, cylindrical members (rollers).

[0133] In the condition monitoring system and condition monitoring method according to this embodiment, the ultrasonic device 61 shown in Fig. 6 may be always connected to the sensor 18, or may be connected to the sensor 18 only when monitoring the condition of the rolling bearing 17c. The ultrasonic device 61 is portable, and may be carried and connected to the sensor 18.

[0134] In the embodiment described above, the pin 17e is inserted into the bearing outer ring 17c1 along the axial direction, but the pin 17e may be inserted into the bearing outer ring 17c1 along the radial direction.

[0135] In the above embodiment, an example has been described in which the condition monitoring system and condition monitoring method according to this embodiment are applied to a gearbox of a wind turbine generator. This embodiment can be applied to condition monitoring of any rolling bearing 17c that has a pin 17e for preventing rotation of the bearing outer ring 17c1. For example, this embodiment can also be applied to rolling bearings provided in transmissions of construction machinery and ships, and rolling bearings provided in large machinery such as gas turbines and mixers.

[0136] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to embodiments including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete part of the configuration of each embodiment, or to add or replace other configurations. [Explanation of symbols]

[0137] 1...main shaft bearing, 11...wind turbine generator, 12...support base, 14...nacelle, 15...main shaft, 16...blade, 16a...blade support base, 17...speed increaser, 17a...housing, 17a1...front housing, 17a2...rear housing, 17b...cover, 17b1...front cover, 17b2...rear cover, 17b3...cover hole, 17c...rolling bearing, 17c1...bearing Outer ring, 17c2...rolling element, 17c3...bearing inner ring, 17d...oil seal, 17e...pin, 17e1...hole in bearing outer ring, 17e2...gap, 17e3...gap, 17e4...hollow portion, 17e5...solid rod-shaped member, 17f...rotating shaft, 18...sensor, 18b...hole portion, 19...generator, 20...output shaft, 61...ultrasonic device, 62...condition monitoring device, 63...pin condition database.

Claims

1. monitoring a state of a rolling bearing including a bearing outer ring covered with a fixing member and a rod-shaped member connecting the fixing member and the bearing outer ring to prevent the bearing outer ring from rotating relative to the fixing member; a sensor for monitoring a physical quantity of the rod-shaped member; a condition monitoring device that monitors a condition of the rolling bearing based on a change in the physical quantity acquired by the sensor; Equipped with A rolling bearing condition monitoring system comprising:

2. The sensor measures the length of the rod-shaped member as the physical quantity. The rolling bearing condition monitoring system according to claim 1 .

3. The sensor is installed on the rod-shaped member. The rolling bearing condition monitoring system according to claim 1 .

4. the sensor measures the physical quantity of the rod-shaped member in a state where the rod-shaped member is installed on the bearing outer ring; The rolling bearing condition monitoring system according to claim 1 .

5. the fixing member has a hole portion that opens to the outside of the fixing member, The sensor is installed in the hole and is installed on the rod-shaped member. The rolling bearing condition monitoring system according to claim 1 .

6. The sensor is an ultrasonic sensor. The rolling bearing condition monitoring system according to claim 1 .

7. the rod-shaped member has a hollow portion extending in a longitudinal direction, and the hollow portion has a solid rod-shaped member; The sensor is installed on the solid rod-shaped member. The rolling bearing condition monitoring system according to claim 1 .

8. The condition monitoring device monitors the condition of the rolling bearing provided in the gearbox of the wind turbine generator. The rolling bearing condition monitoring system according to claim 1 .

9. monitoring a state of a rolling bearing including a bearing outer ring covered with a fixing member and a rod-shaped member connecting the fixing member and the bearing outer ring to prevent the bearing outer ring from rotating relative to the fixing member; a measuring step of monitoring a physical quantity of the rod-shaped member with a sensor; a condition monitoring step of monitoring a condition of the rolling bearing based on a change in the physical quantity acquired by the sensor; having A method for monitoring the condition of a rolling bearing, comprising:

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