阅读说明：本技术 滚动轴承单元 (Rolling bearing unit ) 是由 蔡福强 吴丽娟 刘志恒 贾宪林 于 2021-09-03 设计创作，主要内容包括：本发明涉及一种滚动轴承单元,其包括滚动轴承和保持架状态监测组件(60,70)。滚动轴承包括外圈(10)、保持架(40)和至少一列滚动体(20),其中,外圈的内周表面构造有挡边部,其中,保持架同心地布置在外圈的径向内侧并且在正常运行时相对挡边部形成径向间隙。保持架状态监测组件(60,70)包括：不透光涂层(62,72),其局部地设置在挡边部的内周表面处并且能够因保持架在非正常运行时的接触而磨损；光学传感器(61,71),其设置在位于外圈处的容纳孔(11)中,其中,光学传感器能够朝向不透光涂层发射出发射光并且检测发射光在不透光涂层处反射的反射光,其中,在反射光的减少量随不透光涂层的磨损达到阈值时能够判定保持架失效。(The invention relates to a rolling bearing unit comprising a rolling bearing and a cage condition monitoring assembly (60, 70). The rolling bearing comprises an outer ring (10), a cage (40) and at least one row of rolling bodies (20), wherein the inner circumferential surface of the outer ring is configured with a rim portion, wherein the cage is concentrically arranged radially inside the outer ring and forms a radial gap with respect to the rim portion during normal operation. The cage condition monitoring assembly (60, 70) includes: an opaque coating (62, 72) which is partially provided at an inner peripheral surface of the flange portion and which can be worn by contact due to abnormal operation of the holder; an optical sensor (61, 71) which is arranged in the receiving opening (11) at the outer ring, wherein the optical sensor is capable of emitting a radiation towards the light-impermeable coating and detecting a reflected radiation of the radiation reflected at the light-impermeable coating, wherein a cage failure can be determined when the reduction of the reflected radiation reaches a threshold value as the light-impermeable coating wears.)

1. A rolling bearing unit including:

a rolling bearing comprising an outer ring (10), a cage (40) and at least one row of rolling bodies (20), wherein an inner circumferential surface of the outer ring (10) is configured with a rim for axially stopping the rolling bodies (20), wherein the cage (40) is concentrically arranged radially inside the outer ring (10) and forms a radial gap with respect to the rim during normal operation; and

a cage condition monitoring assembly (60, 70),

characterized in that the cage condition monitoring assembly (60, 70) comprises:

an opaque coating (62, 72) which is partially provided at an inner peripheral surface of the collar portion and which can be worn by contact of the cage (40) during abnormal operation,

an optical sensor (61, 71) which is arranged in a receiving opening (11) at the outer ring (10), wherein the optical sensor (61, 71) is capable of emitting a radiation in the direction of the light-impermeable coating (62, 72) and of detecting a reflected radiation of the radiation reflected at the light-impermeable coating (62, 72), wherein a failure of the cage (40) can be determined when a reduction in the reflected radiation reaches a threshold value as a result of wear of the light-impermeable coating (61, 71).

2. Rolling bearing unit according to claim 1, wherein the light-tight coating (62, 72) is configured as an ink coating.

3. Rolling bearing unit according to claim 1 or 2, wherein the coating material of the light-tight coating (62, 72) is configured such that the reflectivity of the coating material is different from the reflectivity of the material of which the cage (40) is made for the wavelength band of the emitted light of the optical sensor (61, 71).

4. Rolling bearing unit according to claim 1, wherein the receiving hole (11) communicates from an outer peripheral surface of the outer ring (10) to an inner peripheral surface of the collar portion, wherein the opaque coating (62, 72) covers an opening of the receiving hole (11) on a radially inner side.

5. The rolling bearing unit according to claim 1, wherein the accommodation hole communicates from an axial end face of the outer ring (10) to an inner peripheral surface of the collar portion, wherein the opaque coating (62, 72) covers an opening of the accommodation hole on a radially inner side.

6. Rolling bearing unit according to claim 1, wherein the cage condition monitoring assembly (60, 70) further comprises a bracket (63, 73) fixed in the receiving bore (11), wherein the bracket (63, 73) is configured with a support section made of a light-transmitting material, wherein the support section is arranged between the optical sensor (61, 71) and the light-impermeable coating (62, 72).

7. Rolling bearing unit according to claim 6, wherein the carrier (63) is further configured with a sensor receiving section having a groove, wherein the optical sensor (61) is arranged in the groove.

8. Rolling bearing unit according to claim 7, wherein the support section and the sensor housing section are of one-piece construction.

9. Rolling bearing unit according to any of claims 6 to 8, wherein the carrier (63, 73) is made of plastic or glass.

10. Rolling bearing unit according to claim 1, wherein the rolling bearing unit further comprises a sealing member (50) arranged at an axial end side of the rolling bearing, wherein the sealing member (50) is configured with a through hole through which a wire of the optical sensor (61, 71) passes.

Technical Field

The invention relates to the technical field of bearings. The invention relates in particular to a rolling bearing unit with a cage condition monitoring assembly.

Background

The rolling bearing is effectively monitored in state and diagnosed in fault, and the rolling bearing monitoring system has important significance for guaranteeing the safe operation of machinery and saving the expenditure. Currently, in one type of bearing condition monitoring system, early failure of a bearing can be detected by finding bearing fatigue. In another type of bearing condition monitoring system, which is relatively common, the raceway wear of the bearing can be monitored by vibration measurement, but in such monitoring schemes the operation is complicated and the overall cost of the monitoring system is high.

However, the above-described bearing condition monitoring system cannot effectively monitor the condition of the cage. Therefore, even if the cage is severely worn or broken, abnormality of the cage may not be detected. In this case, especially for wheel set bearings of rail transportation vehicles such as subway trains, once the retainer is broken, the running safety of the transportation vehicles is seriously affected. For this reason, it is often desirable to add bearing noise detection when a train returns to the factory.

There are also a few bearing condition monitoring solutions for cages. For example, patent document CN105570320B discloses a bearing system with a holder state monitoring system, wherein the holder state monitoring system includes an RFID chip, a printed circuit line and an RFID reader, wherein the RFID chip is fixed on the holder, the RFID chip is electrically connected with the printed circuit line, the printed circuit line is arranged along the whole body of the holder and is kept conducted under the condition that the part of the holder covered by the printed circuit line is kept complete, and the RFID reader can communicate with the RFID chip through a radio frequency signal to monitor the state of the holder. However, the bearing condition monitoring system for the cage is complex and costly.

Disclosure of Invention

It is therefore an object of the present invention to provide a rolling bearing unit which enables effective monitoring of the cage operating state at low cost.

According to the invention, the above object is solved by a rolling bearing unit comprising a rolling bearing and a cage condition monitoring assembly. The rolling bearing comprises an outer ring, a cage and at least one row of rolling bodies, wherein the inner circumferential surface of the outer ring is provided with a flange part for stopping the rolling bodies in the axial direction, wherein the cage is concentrically arranged on the radial inner side of the outer ring and forms a radial gap relative to the flange part in normal operation. The holder condition monitoring assembly includes an opaque coating and an optical sensor, wherein the opaque coating is partially disposed at an inner peripheral surface of the collar portion and can be worn due to contact during abnormal operation of the holder, wherein the optical sensor is disposed in the receiving hole at the outer ring, wherein the optical sensor can emit the emitted light toward the opaque coating and detect reflected light of the emitted light reflected at the opaque coating, and wherein the holder can be determined to be failed when a decrease in the reflected light reaches a threshold value as the opaque coating wears.

In the description herein, it is to be noted that, unless otherwise explicitly specified and defined, the terms "axial", "radial" and "circumferential" are based on the axis of rotation of the rolling bearing.

Within the scope of the present description, the rolling bearing in the rolling bearing unit can be implemented substantially according to the existing design. It is conceivable that the rolling bearing comprises an inner ring in addition to the above-mentioned outer ring, cage and at least one row of rolling elements, so that the rotation support function of the rolling bearing can be achieved.

Here, raceways on which the rolling bodies roll and collar portions formed on both axial sides of the raceways are formed on the inner circumferential surface of the outer ring, wherein the collar portions preferably project from the raceways toward the radial inside so as to be able to be stopped in the axial direction at the axial end faces of the respective rolling bodies. It is to be understood that, in the embodiment of the single row bearing, two flange portions are formed at the inner peripheral surface of the outer ring, wherein the two flange portions are formed at both axial ends of the outer ring, respectively. It will also be understood that in the embodiment of the double row bearing, three stop portions are formed at the inner circumferential surface of the outer ring, distributed in the axial direction, wherein every two adjacent stop portions serve to stop one row of rolling elements in the axial direction.

The monitoring of the cage by the cage condition monitoring assembly herein takes advantage of the fact that the cage has different positional relationships with respect to the outer ring under different operating conditions, i.e., the axial end portions of the cage are able to maintain radial clearance with respect to the rim portion of the outer ring during normal operation and contact and rub against the inner circumferential surface of the rim portion when the cage fails or is about to fail. Here, the opaque coating can be provided at the inner circumferential surface of any, a part of, or all of the stopper portions of the outer ring as needed, and the axial position of the cage state monitoring assembly can be adjusted accordingly.

The cage condition monitoring assembly may operate as follows: during normal operation of the holder, the opaque coating can be held substantially intact at the inner peripheral surface of the rib portion, with the optical sensor emitting emission light toward the opaque coating that can be reflected back to the optical sensor at the opaque coating with a greater reflectivity; when the retainer fails or is about to fail, the opaque coating is abraded or scratched due to the contact between the retainer and the edge blocking part, the light transmittance at the coating is increased, and the emitted light emitted by the optical sensor towards the opaque coating is less reflected back to the optical sensor. The degree of reflection of the light-impermeable coating from the emitted light can be determined in particular in real time by the reception and detection of the reflected light by the optical sensor. If the reflected light received by the optical sensor is reduced by a predetermined amount, in particular compared to when the opaque coating is intact, it can be concluded that the wear of the opaque coating has reached a severe level and a cage failure can be determined therefrom. Therefore, by means of the retainer state monitoring assembly, the operation state of the retainer can be monitored in real time, and the operation reliability of the rolling bearing is guaranteed.

Furthermore, the cage condition monitoring scheme provided herein can be implemented at low cost. On the one hand, the existing rolling bearing does not need to be modified, and only the accommodating hole for the cage state monitoring assembly needs to be additionally arranged at the outer ring. On the other hand, the algorithm for judging whether the retainer fails is very simple, and a large amount of calculation cost can be saved.

Here, it should be noted that the type of the optical sensor of the cage state monitoring assembly is not limited herein, and a skilled person may adopt a known optical sensor according to the cage state monitoring assembly or more specifically according to the specific situation of the rolling bearing unit. Preferably, the optical sensor can be connected with a power supply line and/or a signal transmission line. In this case, the optical sensor itself has a low cost. Furthermore, the wiring design of the optical sensor can be realized simply, especially considering that the optical sensor is mounted on the outer ring and that the outer ring is usually fixed in a mechanical device. Alternatively, the optical sensor may be powered and transmit signals wirelessly. In this case, wiring of the optical sensor does not need to be considered, and the design can be simplified.

Note that the calculation of the reflected light reduction amount and/or the determination of whether or not the holder is defective may be performed by the signal processing unit. Alternatively, the signal processing unit can be integrated into the cage condition monitoring assembly, i.e. into the rolling bearing unit. Alternatively, the signal processing unit may be integrated into a mechanical device provided with a rolling bearing unit.

In a preferred embodiment, the opaque coating is configured as an ink coating. Thus, the opacifying coatings are easy to apply and are low cost. In addition, the ink coating also has the characteristics of good light shielding property and easy abrasion, and is particularly suitable for the retainer state monitoring assembly provided by the paper.

In this case, the coating material of the opaque coating is preferably configured such that the reflectivity of the coating material differs from the reflectivity of the material from which the holder is made for the wavelength band of the emitted light of the optical sensor. In this way, disturbances due to reflection of the emitted light at the holder can be excluded, in particular if the opaque coating has worn off partially or completely.

In an advantageous embodiment, the receiving opening communicates from the outer circumferential surface of the outer ring to the inner circumferential surface of the skirt portion, wherein the opaque coating covers an opening of the receiving opening on a radially inner side. Particularly preferably, the receiving hole is configured as a through hole penetrating the outer circumferential surface and the inner circumferential surface of the outer ring in the radial direction. The receiving bore can be produced in a simple and inexpensive manner and the cage condition monitoring assembly can be easily inserted into the receiving bore.

In a further advantageous embodiment, the receiving bore communicates from an axial end face of the outer ring to an inner circumferential surface of the collar portion, wherein the light-impermeable coating covers an opening of the receiving bore on a radially inner side. In this case, the accommodation hole is preferably L-shaped as a whole. In this case, depending on the specific design of the rolling bearing unit, for example, the design in terms of sealing or sensor wiring, more receiving-bore configurations can be provided for adapting the cage condition monitoring assembly, in particular the optical sensor.

In a preferred embodiment, the cage condition monitoring assembly further comprises a support secured in the receiving opening, wherein the support is formed with a support section made of a light-transmitting material, wherein the support section is arranged between the optical sensor and the light-impermeable coating. Preferably, the support section is preferably fixed in the receiving bore. The support section can be fixed in the receiving opening by means of a press fit, form fit or by means of an adhesive, for example. The support section can thus not only support the optical sensor by its one end, but can also close the opening of the receiving opening radially on the inside by its other end, so that the light-impermeable coating can be applied easily.

In addition and preferably, the holder is also designed with a sensor receiving section having a recess, wherein the optical sensor is arranged in the recess. The optical sensor can thereby be fixed in the receiving opening by means of the receiving section, and the receiving section can also provide protection for the optical sensor. In this case, the recess of the groove preferably opens out radially outward of the receiving bore, for example, toward the outer circumferential surface or the axial end face of the outer ring, so that the mounting of the optical sensor is simplified.

In this case, it is particularly preferred if the support section and the sensor receiving section are of one-piece design. In this case, the holder can be made entirely of a light-transmitting material, which is generally less expensive and facilitates simplified mounting of the holder itself or a holder already provided with an optical sensor in the receiving opening.

In this case, the carrier is particularly preferably made of plastic or glass. In this case, a carrier with light-transmitting support sections can be produced at low cost.

In an advantageous embodiment, the rolling bearing unit further comprises a sealing component arranged at an axial end of the rolling bearing, wherein the sealing component is configured with a through-hole for the lead wire of the optical sensor to pass through.

Drawings

Preferred embodiments of the present invention are schematically illustrated in the following with reference to the accompanying drawings. The attached drawings are as follows:

fig. 1 is a partial cross-sectional view of a rolling bearing unit according to a preferred embodiment;

fig. 2 is a partial enlarged view of the rolling bearing unit according to fig. 1 at the cage condition monitoring assembly; and

fig. 3 is a partially enlarged view of a rolling bearing unit according to another preferred embodiment at the cage condition monitoring assembly.

Detailed Description

Fig. 1 shows a detail of a sectional view of a rolling bearing unit according to a preferred embodiment. The rolling bearing unit according to the present embodiment can be used for a rail transportation vehicle such as a subway train. As shown in fig. 1, the rolling bearing unit includes a rolling bearing, a cage condition monitoring assembly 60, and a seal member 50.

The rolling bearing serves here as a wheel set bearing and is in the present exemplary embodiment designed in particular as a double-row cylindrical roller bearing. The seal member 50 is provided at an axial end side of the rolling bearing. The rolling bearing comprises an outer ring 10, an inner ring 30, rolling bodies 20 in the form of two rows of cylindrical rollers, and two cages 40.

The rolling elements 20 and the cage 40 are arranged radially between the outer ring 10 and the inner ring 30. Each row of rolling elements 20 is associated with a cage 40, and the individual rolling elements 20 in each row of rolling elements 20 are distributed uniformly in the circumferential direction by means of the cages 40. Two rows of raceways are formed at the inner circumferential surface of the outer ring 10 and two rows of raceways are formed at the outer circumferential surface of the inner ring 30, so that the rolling bodies 20 can roll at the raceways of the outer ring 10 and the raceways of the inner ring 30, thereby performing a rotation supporting function of the rolling bearing.

Here, the inner circumferential surface of the outer ring 10 is configured with rim portions for stopping the rolling elements 20 in the axial direction, wherein the rim portions are formed on both sides of each raceway of the outer ring 10 in the axial direction. In the present embodiment, three rib portions are formed on the inner peripheral surface of the outer ring 10 so as to be distributed in the axial direction, and the rib portions protrude from the raceway in the radially inward direction so as to be capable of being stopped at the axial end surfaces of the respective rolling elements 20 in the axial direction. Fig. 1 shows only one of the two collar portions at the axial ends and one collar portion in the middle, which is additionally provided with an oil filling opening.

Fig. 2 shows a detail of the rolling bearing unit according to fig. 1 on a cage condition monitoring assembly 60. As shown in fig. 2, the holder state monitoring assembly 60 includes an optical sensor 61, a holder 63, and an opaque coating 62.

The optical sensor 61 and the bracket 63 are disposed in the accommodation hole 11 at the outer ring 10. The receiving hole 11 is configured as a stepped through hole in the present embodiment, communicating from the outer peripheral surface of the outer ring 10 to the inner peripheral surface of the skirt portion in the radial direction.

The carrier 63 is made of a light-transmitting, preferably completely transparent plastic or glass. The bracket 63 includes a sensor accommodating section and a supporting section integrally formed. The bracket 63 is fixed in the receiving bore 11 of the outer ring 10 by a press fit. Specifically, the sensor receiving section is fixed by press-fitting in a large-diameter section of the receiving hole 11 in the form of a stepped through hole, and the support section is fixed by press-fitting in a small-diameter section of the receiving hole 11 in the form of a stepped through hole. The sensor receiving section is configured with a groove which opens toward the outer circumferential surface of the outer ring 10 and in which the optical sensor 61 is arranged, so that the mounting of the optical sensor 61 is facilitated and the supply lines and the signal transmission lines of the optical sensor 61 can also be guided out of the rolling bearing by means of the notches and the through-holes configured at the sealing component 50. The support section is generally cylindrical, supports the optical sensor 61 by one longitudinal end thereof and closes the opening of the accommodation hole 11 on the radially inner side by the other longitudinal end thereof. Here, preferably, the radially inner longitudinal end of the support section is preferably flush with the inner circumferential surface of the stop.

The opaque coating 62 is applied here at the inner circumferential surface of the stop and completely covers the longitudinal end faces of the support sections of the carrier 63. The opaque coating 62 is here an ink coating.

The monitoring of the cage 40 by the cage condition monitoring assembly 60 takes advantage of the fact that the cage 40 has different positional relationships with respect to the outer ring 10 under different operating conditions, i.e., the axial end portions of the cage 40 are able to maintain radial clearance with respect to the flange portions of the outer ring 10 during normal operation and contact and rub against the inner peripheral surface of the flange portions when the cage 40 fails or is about to fail.

The cage condition monitoring assembly 60 may operate as follows: in normal operation of the holder 40, the opaque coating 62 may be substantially perfectly maintained at the inner peripheral surface of the rib portion, with the optical sensor 61 emitting emission light toward the opaque coating 62 that can be reflected back to the optical sensor 61 at the opaque coating 62 with a greater reflectivity; when the retainer 40 fails or is about to fail, the opaque coating 62 may be worn or scratched by the contact between the retainer 40 and the rib, and the light transmittance at the coating 62 is increased, so that the light emitted by the optical sensor 61 toward the opaque coating is less reflected back to the optical sensor 61. The degree of reflection of the emitted light by the opaque coating 62 can be known in real time by the reception and detection of the reflected light by the optical sensor 61. When the reflected light received by the optical sensor 61 is reduced by a preset amount compared to the initial time, i.e., when the opaque coating 62 is intact, it can be concluded that the wear of the opaque coating 62 is severe and thus a failure of the cage 40 is determined. Here, the preset amount may be flexibly set according to a specific working condition, for example, the threshold of the decrease amount may be set to 50%. Thus, the cage state monitoring unit 60 according to the present embodiment can monitor the operating state of the cage 40 in real time, thereby ensuring the operational reliability of the rolling bearing. Furthermore, the cage monitoring solution provided herein can be implemented at low cost. On the one hand, it is not necessary to modify the existing rolling bearing, but only to add the receiving hole 11 for the cage state monitoring unit 60 at the outer ring 10. On the other hand, the algorithm for determining whether the retainer 40 is failed is very simple, and a large amount of calculation cost can be saved.

Fig. 3 shows a partial enlarged view of a rolling bearing unit according to another preferred embodiment at the cage condition monitoring assembly 70. The rolling bearing unit according to the present embodiment is configured similarly to the rolling bearing unit shown in fig. 1 and 2, the main difference between which lies in the structure of the bracket 63, 73 in the cage state monitoring assembly 60, 70. In the present embodiment, as shown in fig. 3, the cradle 73 includes only a support section configured as a light-transmitting cylinder. Here, the optical sensor 71 is directly mounted in the receiving hole 11 of the outer ring 10. The cage condition monitoring assembly 70 functions in the same manner as the above-described embodiment, and the optical sensor 71 is capable of emitting the emission light toward the opaque coating 72 and detecting the reflected light of the emission light reflected at the opaque coating 72, wherein a failure of the cage 40 can be determined when the amount of decrease in the reflected light reaches a threshold value as the opaque coating 72 wears.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

List of reference numerals

10 outer ring

11 receiving hole

20 rolling element

30 inner ring

40 holding rack

50 sealing member

60 cage condition monitoring assembly

61 optical sensor

62 light-opaque coating

63 support

70 cage condition monitoring assembly

71 optical sensor

72 light-opaque coating

73 support