JP2002295463A - Rolling bearing unit with sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate setting work of a sensor to detect a state of a rolling bearing unit of a double row tapered roller bearing 3, etc. SOLUTION: The sensor of a rotational speed sensor 27a, etc. is set on an outer ring presser ring 34 to press an outer end surface of an outer ring 4 to constituted the double row tapered roller bearing 3. A signal of each of these sensors is taken out through a cable 42 after processing it by ICs 39a, 39b, 39c. This cable 42 is connected to a connector 46 provided on a bottom plate part 24a of a cover 22a to press an outer end surface of the outer ring presser ring 24. The purpose it attained in these constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A rolling bearing unit with a sensor according to the present invention is a device for fixing a rotating shaft of a wheel of a railway vehicle or a rotating shaft of various industrial machinery such as a rolling mill to a fixed portion such as a vehicle body or a support stand. And used to detect one or more states selected from among the rotational speed, temperature, and vibration of the rolling bearing unit in the operating state.

[0002]

2. Description of the Related Art For example, a rolling bearing unit is used to rotatably support a wheel of a railway vehicle with respect to a bearing box fixed to the railway vehicle. In addition, in order to determine the traveling speed of a railway vehicle or to perform sliding control for preventing uneven wear of the wheels, it is necessary to detect the rotational speed of the wheels. Further, in order to prevent the occurrence of an abnormality in the rolling bearing unit and seizure of the rolling bearing unit, it is necessary to detect the temperature of the rolling bearing unit. Therefore, the wheel is rotatably supported with respect to the bearing box by a rotation support device with a sensor in which a rotation speed sensor and a temperature sensor are incorporated in the rolling bearing unit, and the rotation speed of the wheel and the rolling bearing unit In recent years, detecting the temperature has been performed.

FIGS. 11 to 12 show an example of a conventional structure of a rotation supporting device with a sensor for such a railway vehicle. The axle 1 is a rotating shaft that rotates during use with a wheel (not shown) supported and fixed. The axle 1 is formed into a hollow cylindrical shape for weight reduction, and a rolling bearing is provided on the inner diameter side of the bearing box 2 that does not rotate during use. It is rotatably supported by a certain double row tapered roller bearing 3. The double-row tapered roller bearing 3 includes an outer ring 4 and a pair of inner rings 5 arranged concentrically with each other, and a plurality of tapered rollers 6, 6 each of which is a rolling element. The outer race 4 is formed in a cylindrical shape as a whole, and has a double-row outer raceway 7 on the inner peripheral surface. Each of the outer raceways 7 has a conical concave shape, and is inclined in such a direction that the inner diameter increases toward the axial end of the outer race 4.

Each of the pair of inner races 5 is formed in a substantially short cylindrical shape, and a conical convex inner raceway 8 is formed on each outer peripheral surface. Each of the inner rings 5 is arranged concentrically with the outer ring 4 on the inner diameter side of the outer ring 4 with the end faces on the smaller diameter side facing each other. Further, each of the tapered rollers 6, 6 is provided between the outer raceway 7 and the inner raceway 8 so as to be freely rollable while being held by a retainer 9 in a plural number. Note that, in many cases, a bearing box provided on the suspension device side to support an axle of a railway vehicle is formed in a saddle shape in which a lower portion is opened. Such a saddle-shaped bearing box is placed so as to cover the upper half of the outer ring 4 in an assembled state.

[0005] Of the double row tapered roller bearing 3 as described above,
The outer race 4 is internally fitted and held in the bearing housing 2. In the illustrated example, a step portion 10 is formed near the outer end (left end in FIG. 11) of the inner peripheral surface of the bearing housing 2, and is internally fitted to the inner end (right end in FIG. 11) of the bearing housing 2. The outer race 4 is sandwiched between both sides of the outer race 4 with a fixed retaining ring (not shown). On the other hand, each of the inner races 5 has one end of the axle 1 (FIG. 11) with the spacer 11 sandwiched between the inner races 5.
(Left end) is fitted outside. An annular member 12 called an oil drain is externally fitted to a portion of the end of the axle 1 that protrudes from the inner ring 5 on the outside in the axial direction. Further, the inner end surface of the inner inner ring abuts a step surface formed in the intermediate portion of the axle 1 via another annular member. Therefore, the pair of inner rings 5 is not displaced closer to the center of the axle 1 (rightward in FIG. 11) than in the state of FIG. And
The annular member 12 is pressed toward the outer end surface of the outer inner ring 5 by a nut 14 screwed into a male screw portion 13 formed at the outer end of the axle 1. Furthermore, the nut 1
4 is fixed to the outer end face of the axle 1 by bolts 15 and 15 and is provided on the inner circumference of the detent ring 16 with the groove provided on the outer circumference of the outer end of the axle 1 to engage the nut 14.
To prevent loosening.

On the other hand, at both ends of the outer ring 4, a seal case 17 formed by forming a metal plate such as a mild steel plate into a generally cylindrical shape with a crank-shaped cross section is fixedly fitted. A seal ring 18 is provided between the inner peripheral surface of each of the seal cases 17 and the outer peripheral surface of each of the annular members 12.
Is provided to close the openings at both ends of the space in which the plurality of tapered rollers 6, 6 are installed. With this configuration, the inside and outside of this space are shut off, and the lubricating grease sealed in this space is prevented from leaking to the outside, and foreign matters such as rainwater and dust enter the above space from outside. Has been prevented.

On one end surface of the axle 1, an encoder 19 formed of a magnetic metal material such as steel and having an L-shaped cross section in a ring shape as a whole is connected to the axle 1 by a plurality of bolts 20 and 20. Concentrically fixed. Concave portions and convex portions are formed alternately and at regular intervals in the circumferential direction on the outer peripheral edge of the outward flange-shaped annular portion 21 provided on the encoder 19, and the magnetic characteristics of the outer peripheral portion are circular. They are changed alternately and at equal intervals in the circumferential direction.

The one end opening of the bearing housing 2 is closed by a cover 22 fixed to one end of the bearing housing 2.
The cover 22 is formed entirely of a synthetic resin or a metal material into a bottomed cylindrical shape, and has a cylindrical portion 23 and a bottom plate portion 24 that closes an opening of one end (the left end in FIG. 11) of the cylindrical portion 23.
And an outward flange-shaped mounting portion 25 provided on the outer peripheral surface of a portion near the other end (right end in FIG. 11) of the cylindrical portion 23. Such a cover 22 fits the other end of the cylindrical portion 23 inside one end of the bearing housing 2 and the mounting portion 2.
The mounting portion 25 is fixed to the one end surface of the bearing box 2 with a bolt (not shown) in a state in which the one end 5 is abutted against one end surface of the bearing box 2, thereby closing the one end opening of the bearing box 2.

A sensor diametrically penetrating both the inner and outer peripheral surfaces of the cylindrical portion 23 at a portion of the cylindrical portion 23 which is diametrically opposed to the outer peripheral edge of the annular portion 21 of the encoder 19. A mounting hole 26 is formed. Then, a rotation speed sensor 27 is inserted into the sensor mounting hole 26, and a detection unit provided on a tip end surface (a lower end surface in FIG. 11) of the rotation speed sensor 27 is provided on an outer peripheral edge of the circular ring portion 21. The detection unit is opposed to the detection unit via a minute gap. On the other hand, a sensor mounting concave hole 28 is formed in a portion located around the outer ring 4 in an intermediate portion of the bearing housing 2. The temperature sensor 29 is inserted into the sensor mounting recess 28.
Is installed.

In the case of the rotation supporting device with a sensor having the above-described configuration, when the encoder 19 rotates together with the axle 1 supporting and fixing the wheels during operation, the concave portion and the convex portion constituting the detected portion of the encoder 19 are formed. The rotation speed sensor 27
Pass alternately in the vicinity of the detection unit provided on the tip end surface of. As a result, the density of the magnetic flux flowing in the sensor 27 changes,
The output of the sensor 27 changes. The frequency at which the output of the sensor 27 changes in this way is proportional to the rotational speed of the wheel. Therefore, if the output of the sensor 27 is sent to a controller (not shown), the rotation speed of the wheel can be detected, and the sliding control of the railway vehicle can be appropriately performed.

If the rotational resistance of the double-row tapered roller bearing 3 abnormally rises for some reason, such as excessive skew of the tapered rollers 6, 6 and the temperature of the double-row tapered roller 3 rises, The temperature sensor 29 detects this temperature. The temperature signal detected by the temperature sensor 29 in this manner is also sent to a controller (not shown), and the controller issues an alarm such as turning on a warning lamp installed in the driver's seat. When such an alarm is issued, the driver takes measures such as an emergency stop.

Further, although not shown in the drawings,
No. 43723 discloses an attachment hole provided in a cylindrical portion of a seal case in which a base end portion is internally fitted and fixed to an end portion of an outer ring, and a rotation speed sensor, a temperature sensor, and a sensor for detecting vibration are provided in the attachment hole portion. A structure for mounting various sensors such as a vibration sensor is described. In the case of the structure described in this publication, the encoder for detecting the rotational speed is installed on the outer peripheral surface of the rotating shaft at a portion between the seal ring provided at the end of the seal case and the end surface of the inner ring.

[0013]

In the case of the conventional structure shown in FIGS. 11 to 12, the rotational speed sensor 27 and the temperature sensor 2 are used.
9 is supported and fixed to the cover 22 or the bearing box 2 independently of each other, so that the mounting work of each of the sensors 27 and 29 is not only troublesome, but also the signal extraction from each of the sensors 27 and 29 is performed. It becomes troublesome. That is, the rotational speed sensor 27 is fixed to the cover 22 by a plurality of bolts 31a, 31a through which the mounting flange 30a is inserted, and a signal is taken out by a harness 32a. The mounting flange 30b is fixed to the bearing housing 2 by a plurality of bolts 31b, 31b inserted therethrough, and a signal is taken out by a harness 32b.

For this reason, the mounting space for the sensors 27 and 29 is increased, the mounting work is complicated, and the handling of the harnesses 32a and 32b is also troublesome. The rotation support sensor for a railway vehicle includes the rotation speed sensor 27.
In addition to the temperature sensor 29 and a vibration sensor for detecting vibration, it is considered to be assembled, and the number of sensors to be incorporated in the rotation support device tends to increase. As the number of sensors increases, the above-mentioned problem becomes more prominent.

On the other hand, Japanese Patent Application Laid-Open No. 2000-43723
In the case of the structure described in Japanese Patent Application Laid-Open No. H10-270, a sensor is provided in a seal case exposed to the outside air. Therefore, when the sensor is a temperature sensor, the temperature of the rolling bearing unit cannot always be measured accurately. Further, since the vibration transmitted from the outer race to the seal case is attenuated by the seal ring held at the tip of the seal case, when the sensor is a vibration sensor, the vibration cannot be measured accurately. The rolling bearing unit with a sensor of the present invention has been invented in view of such circumstances.

[0016]

A rolling bearing unit with a sensor according to the present invention comprises a rolling bearing unit and at least one sensor for detecting the state of the rolling bearing unit. Of these rolling bearing units,
An outer ring that does not rotate while being held in the bearing housing, an inner ring that rotates with the rotating shaft while supporting the rotating shaft, an outer ring raceway formed on the inner peripheral surface of these outer rings, and an outer ring formed on the outer peripheral surface of the inner ring. And a plurality of rolling elements provided rotatably between the inner ring raceway. The sensor is supported by a portion that does not rotate. In particular, the sensor-equipped rolling bearing unit of the present invention is provided with a restraining member which is fixed to the end of the bearing box and whose front end surface is abutted against the outer end surface of the outer race. The sensor is installed on a part of the holding member, and a harness for extracting the output of the sensor is provided on the holding member.

[0017]

In the case of the rolling bearing unit with a sensor according to the present invention configured as described above, the state of the rolling bearing unit is detected by installing a holding member for supporting the outer ring in the bearing housing. A sensor and a harness for extracting an output of the sensor can be installed. For this reason, there is no increase in the mounting space for this sensor and no troublesome mounting work. Further, when the sensor is a temperature sensor, the temperature sensor can be brought into contact with or close to the outer ring of the rolling bearing unit, so that the temperature of the rolling bearing unit can be accurately detected. Further, since the vibration transmitted from the outer race to the suppressing member is hardly attenuated, when the sensor is a vibration sensor, the vibration sensor can accurately detect the vibration of the rolling bearing unit.

[0018]

1 to 3 show a first embodiment of the present invention corresponding to claims 1 to 5. FIG. still,
This embodiment is characterized in that a rotation speed sensor 27a for detecting the rotation speed of the axle 1, which is the rotation shaft described in the claims, and a double-row tapered roller bearing that is a rolling bearing unit that rotatably supports the axle 1. An outer ring restraining ring, which is a restraining member, comprising: a temperature sensor 29a for detecting the temperature of the roller 3; and a vibration sensor 33 such as an acceleration sensor for detecting the vibration of the double row tapered roller bearing 3. 34 is to solve the above-mentioned problem of the conventional structure. The structure and operation of the other parts are as described in FIGS.
2 is the same as that of the conventional structure shown in FIG. 2, the same reference numerals are given to the same parts, and the description of the overlapping parts will be omitted or simplified, and the following description will focus on the characteristic parts of the present invention.

In the case of this embodiment, the stepped portion 10 for abutting the outer end surface of the outer ring 4 as shown in FIGS. 11 to 12 is not formed on the inner peripheral surface of the outer end portion of the bearing housing 2a. With the face. Instead, in the case of this example, the outer ring holding ring 34 is connected to the outer end of the bearing housing 2a (the left end in FIGS. 1 and 2).
And the inner end face of the outer ring restraining ring 34 (FIGS.
2 (right end face of FIG. 1) against the outer end face of the outer ring 4 (left end face in FIGS. 1 and 2), and the outer end face of the outer ring holding ring 34 is held down by the inner end face of the cylindrical portion 23a constituting the cover 22a. ing. In a state where the rolling bearing unit with the sensor according to the present embodiment is assembled, the cover 22a is firmly connected to the bearing box 2a by bolts, so that the outer ring pressing ring 34 has a pressing strength of the outer end face of the outer ring 4 that is: We can secure enough. The rotation speed sensor 27a and the temperature sensor 29
a and the vibration sensor 33 are installed.

The outer ring restraining ring 34 is made of a material such as a metal such as steel, which has a small internal loss and hardly dampens vibration, and is formed in an annular shape with an L-shaped cross section. The dimension in the direction is large, and the dimension in the axial direction of the radially inner half is small. In order to install the rotation speed sensor 27a on such an outer ring holding ring 34, a holding recess is formed on a part of the inner peripheral surface of the outer ring holding ring 34 in the axial outer half (left half in FIGS. 1 and 2). A hole 35 is formed. The rotation speed sensor 27a fits inside the holding recess 35 without rattling,
It is fixed with an adhesive as needed. In this state, the detection unit of the rotational speed sensor 27a faces radially inward of the outer ring restraining ring 34.

The axle 1 is made to be able to detect the rotational speed of the axle 1 by the rotational speed sensor 27a.
Annular member 12a called an oil drain, sandwiched between an inner end surface of a nut 14 screwed to an outer end portion of the inner ring 5 and an outer end surface of the inner ring 5.
An outward flange-shaped flange portion 36 is formed on the outer peripheral surface of the outer end portion over the entire circumference. A concave portion and a convex portion are formed on the outer peripheral edge of the flange portion 36 alternately and at equal intervals in the circumferential direction, and the magnetic properties of the outer peripheral edge are alternately and equally spaced on the circumferential direction. Is changing. The flange 36 has a function as an encoder for detecting the rotational speed, and the detecting portion of the rotational speed sensor 27a is opposed to the outer peripheral edge of the flange 36.

On the other hand, in order to install the temperature sensor 29a and the vibration sensor 33 on the outer ring restraining ring 34, a part of the inner end face of the outer diameter side half of the outer ring restraining ring 34 has a phase in the circumferential direction. Is formed in a portion corresponding to the holding recess 35 with an arc-shaped recess 37 as shown in FIG.
The temperature sensor 29a and the vibration sensor 33 are fixedly installed in the recess 37 by bonding or the like, with the respective detection portions facing inward in the axial direction. Both sensors 29
Since the thicknesses of a and 33 are equal to or less than the depth of the concave portion 37,
A part of each of the sensors 29a and 33 does not protrude beyond the inner end surface of the outer diameter half of the outer ring holding ring 34. With the sensor-equipped rolling bearing unit of the present example assembled, the inner end face of the outer diameter side half of the outer ring restraining ring 34 is:
Since the sensor is abutted against the outer end surface of the outer ring 4, the detecting portions of the sensors 29 a and 33 abut or approach the outer end surface of the outer ring 4.

Further, a flat surface portion 38 is located radially outside of the holding recess 35 on the outer peripheral surface of the outer half portion of the outer ring holding ring 34, and a flat surface portion 38 is provided on the outer side of the concave portion 37 in the axial direction. Are formed so as to be recessed radially inward from the portion. Each of the sensors 2 is placed on the flat surface portion 38.
ICs 39a, 39b, and 39c constituting a signal processing circuit for processing the detection signals of 7a, 29a, and 33 are installed by bonding or the like. These ICs 39a, 39b, 3
9c includes a plurality of resistors, capacitors, etc.,
It incorporates an amplifier circuit, a filter circuit, a waveform shaping circuit, and the like, and has a function of processing signals output from the sensors 27a, 29a, and 33, and then sending the processed signals to a controller (not shown).

The flat surface 38 and the holding recess 3 as described above
The harnesses 41a and 41b for transmitting signals output from the sensors 27a, 29a and 33 are arranged in the through holes 40a and 40b, respectively. Has been established. The other end of each of the harnesses 41a, 41b whose one end is connected to the output of each of the sensors 27a, 29a, 33 is connected to the input of each of the ICs 39a, 39b, 39c. Further, the harnesses each connected to one end of each of the ICs 39a, 39b, 39c are bundled into one cable 42 and taken out of the cover 22a through a through hole 43 formed in the bottom plate 24a of the cover 22a. .

In order to guide the cable 42 from the flat surface portion 38 to the through hole 43, in the case of the present embodiment, a portion of the outer end face of the outer ring restraining ring 34 whose circumferential phase coincides with the flat surface portion 38. A concave groove 44 is formed in the groove.
A protection tube 45 is provided between the inner end of the concave groove 44 and the through hole 43. The above cable 42
Through the concave groove 44 and the protective tube 45,
It is connected to the inner end of a connector 46 provided in the through hole 43. In order to dispose the cable 42 in this manner, the cable 42 is strongly clamped between the cylindrical portion 23a of the cover 22a and the outer end surface of the outer ring 4, or the outer periphery of the nut 14 that rotates with the axle 1. Damage caused by contact with a surface or the like can be reliably prevented. In use, a plug provided at an end of another cable for transmitting a signal to a controller (not shown) is connected to the outer end of the connector 46.

As described above, in the case of the rotation supporting device with a sensor according to the present invention, the above-mentioned sensors 27a, 29a, 33 and these sensors 27a, 33a are attached to the outer ring holding ring 34 for holding the outer end surface of the outer ring 4. Since the ICs 39a, 39b, and 39c for processing the detection signals of the sensors 29a and 33 are provided, the mounting space for the sensors 27a, 29a, and 33 is reduced, and at the same time, the sensors 27a,
29a and 33 can be easily attached. Also, since the harnesses 41a, 41b for extracting the output signals of the sensors 27a, 29a, 33 are bundled together to form a single cable 42, the above-mentioned sensors 27a, 29a, 3
It is easy to handle the harness for extracting the signal of No. 3.

In the illustrated example, the annular member 12a and the encoder are integrated with each other by forming the outer peripheral edge of the flange 36 integrally formed with the annular member 12a into an uneven shape. On the other hand, an independently annular encoder is sandwiched between the annular member and the nut 14, or an outward flange-shaped flange formed integrally with the inner peripheral surface of the inner end of the nut 14. Of the nut 14
And the encoder can be integrated. Further, as an encoder, a magnetic metal plate is formed by bending and a plurality of through holes are formed in a part thereof in the circumferential direction in an annular shape, or S poles and N poles are alternately arranged in the circumferential direction. An annular permanent magnet can also be used.

The structure of the rolling bearing unit with a sensor of this embodiment is as described above. By combining such a rolling bearing unit with a sensor with a comparator and a threshold value setting circuit, the operating speed is frequently changed from a low speed to a high speed. Detecting anomalies of the changing double-row tapered roller bearing 3 can be performed with high reliability. That is, in the case of a rolling bearing unit whose rotation speed changes frequently from a high speed to a low speed, such as a double-row tapered roller bearing 3 for supporting the axle 1 of a railway vehicle, it is determined whether there is an abnormality according to the rotation speed. Changing the threshold value for determination is preferable for performing highly reliable determination. The reason for this is that if a fixed threshold value is used, it must be based on the high-speed rotation at which the temperature rise and vibration are most remarkable, and it becomes difficult to detect the abnormality that occurred during the low-speed operation. Next, five examples of a determination circuit for determining the presence / absence of abnormality detection in consideration of such circumstances will be described.

First, in the first example shown in FIG. 4, the rotational speed of the axle 1 supported by the double-row tapered roller bearing 3 and the temperature sensor 2 are obtained by the detection signal of the rotational speed sensor 27a.
The presence or absence of an abnormality in the double-row tapered roller bearing 3 is determined based on the temperature of the double-row tapered roller bearing 3 obtained from the detection signal 9a. In the first example, a threshold value setting circuit 48 uses a speed signal representing a value related to the rotation speed of the axle 1 obtained by a rotation speed detection circuit 47 that processes a detection signal of the rotation speed sensor 27a to detect an abnormality. Determine the threshold. The threshold value is compared with a temperature signal sent from the temperature sensor 29a by a comparator 49, and a signal indicating the result of the comparison is determined by a bearing abnormality determination circuit 50, and the double row tapered roller bearing 3 is determined. The presence or absence of abnormality is determined. When there is an abnormality, a signal is sent to an alarm device 51 such as a buzzer or a warning light,
By operating the alarm 51, an alarm is issued to notify the driver or worker of the occurrence of an abnormality. In the processing apparatus of the present embodiment as described above, the temperature threshold for abnormality detection is sequentially changed in accordance with the change in the rotation speed of the double-row tapered roller bearing 3 obtained by the detection signal of the rotation speed sensor 27a. It is possible to detect an abnormality of the rolling bearing unit which occurs not only at the time of high-speed rotation but also at the time of low-speed rotation.

Next, in the second example shown in FIG. 5, the rotational speed of the axle 1 supported by the double-row tapered roller bearing 3 obtained from the detection signal of the rotational speed sensor 27a and the vibration sensor 3
Double-row tapered roller bearing 3 obtained by the detection signal
The presence or absence of an abnormality in the double-row tapered roller bearing 3 is determined from the above vibration. In the case of this example, a threshold for detecting an abnormality related to the vibration is set according to a speed signal obtained based on a detection signal of the rotation speed sensor 27a,
The threshold value and a signal from the vibration sensor 33 are compared by a comparator 49a to determine whether or not the double-row tapered roller bearing 3 is abnormal. In the case of such a processing apparatus of the present embodiment, the threshold value of the abnormality detection relating to the vibration is sequentially changed in accordance with a change in the rotation speed of the double-row tapered roller bearing 3, whereby the double-row tapered roller bearing 3 is rotated at a low speed. It is possible to detect abnormal vibration of the row tapered roller bearing 3,
Even a slight peeling occurring on the rolling contact surface inside the double row tapered roller bearing 3 can be detected at an early stage.

That is, in general, the magnitude of the vibration generated during operation of the rolling bearing unit including the double-row tapered roller bearing 3 increases as the rotation speed increases. For this reason, when it is attempted to determine whether or not there is an abnormality in the rolling bearing unit such as the double-row tapered roller bearing 3 based on only the detection signal of the vibration sensor 33, the vibration value generated at the expected maximum rotational speed is adjusted. It is necessary to set a threshold value for abnormality detection. For this reason, it was difficult to detect the abnormality of the rolling bearing unit such as the double-row tapered roller bearing 3 at the time of low-speed rotation. On the other hand, if the processing apparatus of this example is used, the threshold value for abnormality detection can be sequentially changed in accordance with the rotation speed at that time, so that abnormality detection such as peeling can be increased based on the magnitude of vibration. Can be done with reliability.

Next, in the third example shown in FIG. 6, the rotational speed of the axle 1 supported by the double-row tapered roller bearing 3 and the vibration sensor 3 obtained by the detection signal of the rotational speed sensor 27a
Double-row tapered roller bearing 3 obtained by the detection signal
The presence or absence of an abnormality in the double-row tapered roller bearing 3 is determined from the above vibration. In particular, in the case of this example, the double-row tapered roller bearing 3 sent out from the vibration sensor 33.
Is passed through the variable filter 52. The variable filter 52 changes the frequency to be removed or attenuated based on a signal representing the rotation speed of the double row tapered roller bearing 3 obtained from the detection signal of the rotation speed sensor 27a. And, by this variable filter 52,
The vibration value after removing or attenuating the rotational speed component of the double-row tapered roller bearing 3 is compared with a threshold value for abnormality detection obtained in the same manner as in the second example by the comparator 49a. The presence or absence of an abnormality in the double-row tapered roller bearing 3 is determined.

The vibration generated when the rolling bearing unit such as the double-row tapered roller bearing 3 rotates generally has the largest value of the vibration of the rotation speed component synchronized with the rotation speed. In the event that damage such as separation occurs inside the rolling bearing unit, the vibration value of the frequency component not synchronized with the rotation speed increases. Therefore, in the case of this example, the vibration value of the frequency corresponding to the rotation speed component is removed or attenuated by passing through the variable filter 52 that changes the frequency to be removed or attenuated based on the signal of the rotation speed sensor 27a. Let it. Therefore, the vibration represented by the signal after passing through the variable filter 52 has no or little frequency component that appears even in the normal state, and the component of the vibration generated due to the abnormality becomes apparent to that extent. Therefore, it is possible to enhance the detection accuracy regarding the presence or absence of an abnormality in the rolling bearing unit such as the double-row tapered roller bearing 3 or the like. For this reason, at the initial stage when the separation starts to occur in the rolling contact portion inside the double-row tapered roller bearing 3, an abnormality of the double-row tapered roller bearing 3 can be detected. It is possible to prevent serious damage such as burn-in from occurring.

Next, also in the fourth example shown in FIG. 7, the rotational speed of the axle 1 supported by the double-row tapered roller bearing 3 and the vibration sensor 3 obtained by the detection signal of the rotational speed sensor 27a.
Double-row tapered roller bearing 3 obtained by the detection signal
The presence or absence of an abnormality in the double-row tapered roller bearing 3 is determined from the above vibration. In particular, in the case of this example, the waveform of the vibration detected by the vibration sensor
After the analysis in step 3, it is determined whether or not the double-row tapered roller bearing 3 is abnormal. For this reason, in the case of the present embodiment, the rotation speed sensor 27a is used in the bearing abnormality determination circuit 50a.
Double-row tapered roller bearing 3 obtained from the detection signal of
Cycles T ₁ , T 2 of various vibrations generated from the double-row tapered roller bearing 3 based on a rotation speed signal indicating the rotation speed of
_2, the calculation of T _3, and subjected to the determination of the presence or absence of abnormality of the double row tapered roller bearing 3. Each of these periods T ₁ ,
T ₂ and T ₃ are cases where the double-row tapered roller bearing 3 rotates the inner ring, and T ₁ is an outer ring raceway 7 formed on the inner peripheral surface of the outer ring 4.
The period of oscillation when the peeling occurs in, T ₂ is the period of oscillation when peeling the inner ring raceway 8 formed on the outer peripheral surface of the inner ring 5 has occurred, T ₃ is tapered roller 6 is rolling elements , 6 indicate the cycle of vibration when separation occurs on the rolling surfaces. By analyzing the period of the signal from the vibration sensor 33 using the rotation speed signal, it is possible to determine only whether or not the double-row tapered roller bearing 3 has been damaged due to peeling. Instead, it is also possible to specify which portion of the double-row tapered roller bearing 3 has peeled off.

For example, when the outer raceway 7 formed on the inner peripheral surface of the outer race 4 on the stationary side in the double-row tapered roller bearing 3 used for rotation of the inner race is peeled off, the following formula is used. Oscillation of frequency occurs. f ₁ = z · fc where z is the number of rolling elements, fc is the rotation frequency of the cage, and the cycle T _{1 of} this vibration is expressed by the following equation. T ₁ = 1 / f ₁ = 1 / z · fc On the other hand, when separation occurs on the inner raceway 8 formed on the outer peripheral surface of the inner race 5 which is the rotating side, the frequency represented by the following equation is obtained. Vibration occurs. f ₂ = z · (fr−f
c) where z: number of rolling elements, fr: inner ring rotation frequency, f
c: Cage rotation frequency And the cycle T _{2 of} this vibration is
It is expressed by the following equation. T ₂ = 1 / f ₂ = 1 / {z · (fr−fc)} Further, when peeling occurs on the rolling surfaces of the tapered rollers 6, 6 which are the rolling elements, the following expression is used. Oscillation of frequency occurs. f ₃ = 2 · fb where fb is the rotation frequency of the rolling element. The cycle T _{3 of} this vibration is expressed by the following equation. T ₃ = 1 / f ₃ = 1/2 · fb The frequencies of the above fc, fr, fb, etc. can be calculated by knowing the specifications of the double-row tapered roller bearing 3 and the number of revolutions thereof. By analyzing the above, it is possible to identify at which part of the double-row tapered roller bearing 3 the separation has occurred.

For example, when the vibration component having a period other than the above periods T ₁ , T ₂ , and T ₃ is increasing, an abnormality occurs in a portion other than the rolling contact surface of the double row tapered roller bearing 3. Will be. Therefore, when the period analysis of the detection signal of the vibration sensor 33 is performed by the period analysis circuit 53 as in the present embodiment, the rotation supporting portion and its peripheral portion including the double-row tapered roller bearing 3 and its peripheral portion are used. It is possible to detect the abnormality of the part including. In this case, for example, when the vibration corresponding to the primary component of the rotational speed is particularly large, it is estimated that uneven wear due to sliding has occurred at one portion of the wheel.

Next, in the fifth example shown in FIG. 8, the rotational speed of the axle 1 supported by the double-row tapered roller bearing 3 and the vibration sensor 3 are also obtained by the detection signal of the rotational speed sensor 27a.
Double-row tapered roller bearing 3 obtained by the detection signal
The presence or absence of an abnormality in the double-row tapered roller bearing 3 is determined from the above vibration. In particular, in the case of this example, the vibration signal is passed through an envelope processing circuit 54 for performing envelope processing,
The frequency analysis is performed using the waveform after the envelope processing. As in the fourth example shown in FIG.
If the frequency of the vibration waveform itself (raw waveform) detected by this method is directly analyzed, it is impossible to analyze the bearing abnormality. However, the raw waveform of this vibration is subjected to envelope processing, and the frequency analysis circuit 57 uses the processed waveform to perform frequency analysis. Is performed, it is possible to analyze the abnormality of the rolling bearing unit such as the double-row tapered roller bearing 3 and the like. Then, it is possible to detect the frequencies f ₁ , f ₂ and f ₃ of the vibration generated based on the separation of the rolling contact portion.

In any case, the processing circuits whose five examples are shown in FIGS. 4 to 8 set the threshold value for detecting the abnormality of the rolling bearing unit portion such as the double-row tapered roller bearing 3 in accordance with the change of the rotation speed. In this case, the optimum threshold value can be set according to the state of the rolling bearing unit such as the double-row tapered roller bearing 3 which changes every moment. Further, the accuracy of determining whether or not there is an abnormality in the rolling bearing unit such as the double-row tapered roller bearing 3 can be drastically improved.

Incidentally, in a configuration in which a vibration sensor and a temperature sensor are combined in addition to the rotation speed sensor, an abnormality of the double row tapered roller bearing 3 can be detected from both the vibration and temperature signals, and the grease is detected. It is possible to detect a wide range of abnormalities such as poor lubrication due to deterioration of the roller and peeling of the rolling contact surface due to foreign matter being caught in the roller. According to the abnormality detecting device for the double-row tapered roller bearing 3 as described above, it is possible to detect an abnormality of the rolling bearing unit of the double-row tapered roller bearing 3 and the like at an early stage. It is possible to effectively prevent serious damage such as seizure from occurring in the rolling bearing unit such as the bearing 3.

Next, FIG. 9 shows a second example of the embodiment of the present invention, which also corresponds to claims 1 to 5. In the case of this example, the outer diameter of the outer ring holding ring 34a is
The outer ring holding ring 34a is fixed to the outer end face (the left end face in FIG. 9) of the bearing housing 2b and the cover 22a.
Are sandwiched between the inner end surface (the left end surface in FIG. 9) of the cylindrical portion 23a. The cover 22a is attached to the cylindrical portion 2
A bolt inserted through a plurality of through-holes formed in a portion where the mounting portion 25 formed on the outer peripheral surface of the outer ring 3a and the outer ring holding ring 34a are aligned with each other is screwed into a screw hole formed on the outer end surface of the bearing box 2b. By further tightening, the outer ring holding ring 34a and the bearing ring 2b are connected and fixed together.

As described above, the outer ring restraining ring 34a is
With the structure installed between the bearing housing 2b and the cylindrical portion 23a, a connector 46 for taking out the output of each sensor 27a, 29a, 33 is installed on the outer peripheral surface of the outer ring restraining ring 34a. ing. Also, each of the sensors 27
a, IC 39 for processing output signals of 29a, 33
a, 39c are installed at the bottom of a concave hole 55 formed in the outer ring restraining ring 34a. The other configurations and operations are the same as those of the first example described above, and therefore, duplicated illustration and description will be omitted.

Next, FIG. 10 shows a third example of the embodiment of the present invention, which also corresponds to claims 1 to 5. In the case of this example, the outer ring holding ring 34b is attached to the cover 22b.
Are formed integrally with the cylindrical portion 23b. With the outer ring restraining ring 34b integrated with the cylindrical portion 23b in this manner, a through hole 56 for arranging the cable 42 for extracting the output of each sensor 27a, 29a, 33 is formed in the cylindrical portion 23b. Is provided. The other configurations and operations are the same as those of the first example described above, and therefore, duplicated illustration and description will be omitted.

[0043]

Since the rolling bearing unit with sensor of the present invention is constructed and operates as described above, not only can the mounting space for the sensor such as the rotational speed sensor be reduced, but also the mounting work becomes easy. The handling of the harness for extracting the signal of each sensor is also facilitated.
For this reason, it is possible to reduce the size and cost of the rotary support portions of various mechanical devices, such as the rotary support portion of the axle of the railway vehicle, and to improve the design flexibility.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a diagram of the outer ring holding ring on which the sensors and ICs are installed, as viewed from the right side of FIG. 2;

FIG. 4 is a block diagram showing a first example of a circuit for detecting an abnormality of a rolling bearing unit.

FIG. 5 is a block diagram showing the second example.

FIG. 6 is a block diagram showing a third example.

FIG. 7 is a block diagram showing a fourth example.

FIG. 8 is a block diagram showing a fifth example.

FIG. 9 is a view similar to FIG. 2, showing a second example of the embodiment of the present invention;

FIG. 10 is a view similar to FIG. 2, showing the third example.

11 shows an example of a conventional structure, BOC of FIG.
Sectional view.

FIG. 12 is a half end view as viewed from the left side of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Axle 2, 2a, 2b Bearing box 3 Double row tapered roller bearing 4 Outer ring 5 Inner ring 6 Tapered roller 7 Outer ring track 8 Inner ring track 9 Cage 10 Step 11 Spacer 12, 12a Annular member 13 Male thread 14 Nut 15 Bolt 16 Non-rotating ring 17 Seal case 18 Seal ring 19 Encoder 20 Bolt 21 Ring part 22, 22a, 22b Cover 23, 23a, 23b Cylindrical part 24, 24a Bottom plate part 25 Mounting part 26 Sensor mounting hole 27, 27a Rotation speed sensor 28 Sensor Mounting recesses 29, 29a Temperature sensors 30a, 30b Mounting flanges 31a, 31b Bolts 32a, 32b Harness 33 Vibration sensors 34, 34a, 34b Outer ring holding ring 35 Holding recess 36 Flange 37 Recess 38 Flat surface 39a, 39b, 39c IC 40a, 40b Through holes 41a, 41b Harness 42 Cable 43 Through hole 44 Groove 45 Protective tube 46 Connector 47 Rotational speed detection circuit 48 Threshold setting circuit 49, 49a Comparator 50, 50a Bearing abnormality judgment circuit 51 Alarm 52 Variable filter 53, 53a Frequency analysis Circuit 54 Envelope processing circuit 55 Concave hole 56 Through hole 57 Frequency analysis circuit

Claims (5)

[Claims] 1. A rolling bearing unit comprising at least one sensor for detecting the state of the rolling bearing unit, wherein the rolling bearing unit does not rotate while being held in a bearing box. And an inner ring that rotates together with the rotating shaft while supporting the rotating shaft, and an outer raceway formed on the inner peripheral surface of the outer race and an inner raceway formed on the outer peripheral surface of the inner race. A plurality of rolling elements provided, wherein the sensor is a sensor-equipped rolling bearing unit supported on a non-rotating portion, and is fixed to an end of the bearing box and has a tip end surface thereof. A special feature is that a restraining member is provided to abut against the outer end surface of the outer race, the sensor is installed on a part of the restraining member, and a harness for extracting the output of the sensor is arranged on the restraining member. Rolling bearing unit with sensor. 2. A rotation speed sensor for detecting a change in magnetic characteristics and detecting a rotation speed of a rotation shaft, wherein the rotation speed sensor is provided in a part of a holding member. Part of the annular member is installed so as to be exposed on the inner peripheral surface of the holding member, and is externally fitted and fixed to a portion protruding from the inner ring at the end of the rotating shaft so as to abut against the outer end surface of the inner ring. The rolling bearing unit with a sensor according to claim 1, wherein the detection unit of the rotation speed sensor is opposed to an encoder unit provided on an outer peripheral surface and having magnetic characteristics that change alternately and at regular intervals in a circumferential direction. 3. The at least one sensor is a temperature sensor, and a detection unit of the temperature sensor installed on the tip end surface of the holding member is in contact with or close to the outer end surface of the outer ring.
The sensor-equipped rolling bearing unit according to claim 1. 4. The rolling bearing unit with a sensor according to claim 1, wherein at least one sensor is a vibration sensor for detecting vibration of the rolling bearing unit. 5. A rotation speed sensor, comprising:
The sensor-equipped rolling bearing unit according to any one of claims 1 to 4, wherein at least two types of sensors including at least one of a temperature sensor and a vibration sensor are installed.