JP6728793B2 - Bearing device with sensor - Google Patents

Description

The present invention relates to a bearing with a sensor having a sensor for detecting an operating state of a rolling bearing device, a mechanical device, a spindle of a machine tool, or the like, and particularly, without providing a sensor dedicated to load detection, the number of rotations of a shaft or an axial The present invention relates to a bearing device with a sensor and a bearing system capable of detecting a load.

2. Description of the Related Art Conventionally, as a sensor-equipped bearing for detecting the rotation speed of a rotating member integrated with an inner ring or an outer ring, there is, for example, one disclosed in Patent Document 1.

The sensor-equipped bearing disclosed in Patent Document 1 is arranged so as to be rotatable between a stationary wheel, a rotating wheel, and both, and is a ball (plurality) that is maintained at a certain distance by a cage. Row, a sensor for measuring rotational movement, and a phonic wheel (for example, a multi-pole magnet) fixed to the rotating wheel by a holding member. The measurement sensor is a sensor for measuring the mutual movement of the stationary wheel and the rotating wheel, and is housed in the annular sensor carrier and held by the holding device 124.

As described above, in the sensor-equipped bearing for measuring the mutual movement of the two relatively rotating bearing rings, the detection sensor is attached to the outer ring, which is a stationary wheel, via the holding member, and the detected member is attached to the inner ring, which is the rotating wheel. As a multi-pole magnet. The detection sensor is generally housed in a sensor housing (annular sensor carrier in Patent Document 1) and held by a cover.

However, in the case of the conventional structure disclosed in Patent Document 1, when it is attempted to measure an axial load (also referred to as a thrust load) applied in the direction parallel to the axis, a separate load sensor needs to be provided. Therefore, a new space for installing the load sensor is required. Moreover, since the load sensor is very expensive, it is inevitable that the cost of the entire system will increase. As described above, the conventional bearing requires a load sensor for measuring the axial load, and thus has a problem that the installation space of the sensor device is increased and the cost is increased.

Therefore, as a means for solving these problems, there is a bearing device with a sensor disclosed in Patent Document 2, for example.

A bearing device with a sensor disclosed in Patent Document 2 relates to a bearing device with a sensor capable of measuring an axial load. One of the inner and outer rings is a rotating wheel and the other is a stationary wheel, and A bearing device with a sensor, comprising a bearing portion having rolling elements interposed between the two, wherein an axial load applied between the rotating wheel and the stationary wheel is measured at the same time as measuring the rotational speed of a detected object. The first and second sensors include a first sensor that detects an orbital speed of the rolling element or a retainer thereof and a second sensor that detects a rotational speed of the rotating wheel as a sensor for A signal processing unit that calculates the axial load based on a detection signal from the sensor, and the signal processing unit includes the revolution speed and the rotating wheel obtained based on the detection signals from the first and second sensors. The axial load is calculated from the ratio of the rotational speed of the outer ring to the inner peripheral surface of the outer ring, the outer peripheral surface of the inner ring, and the upper and lower surfaces of the rolling element in the axial direction. It is arranged in one of the two annular gaps formed between them.

JP, 2004-45095, A JP, 2008-199333, A

By the way, in the case of the structure disclosed in Patent Document 2, the first and second sensors include an inner peripheral surface of the outer ring, an outer peripheral surface of the inner ring, and upper and lower surfaces of the rolling element in the axial direction. Since it is arranged in one of the two annular gaps formed between them, the first and second sensors are arranged very close to each other, and in some cases the first and second sensors are arranged. The two sensors could cause magnetic interference with each other.

The present invention has been made in view of such circumstances, and an object thereof is to provide a bearing device with a sensor that can measure a load applied to a shaft with higher accuracy.

The present invention is to measure the rotational speed of an inner ring and an outer ring, one of which is a rotating wheel and the other is a stationary wheel, and a rolling element interposed between the inner ring and the outer ring, and the rotational speed of a detected object, and at the same time, the rotating wheel. As a sensor for measuring the axial load applied between the stationary wheel and the stationary wheel, a first sensor that detects the revolution speed of the rolling element or its retainer and a second sensor that detects the rotation speed of the rotating wheel. A bearing device with a sensor including a sensor, wherein the detection surface of the first sensor and the detection surface of the second sensor are in a perpendicular positional relationship, and the detection surface of the first sensor and the second surface. This is achieved by not intersecting the detection surface of the sensor of.

Further, it is more effectively achieved by estimating the axial load using the ratio of the detected rotation speed of the rotating wheel and the detected revolution speed of the rolling element or the cage.

According to the present invention, by measuring two rotational speeds (an orbital speed and a rotational speed), when analogizing an axial load without using a load sensor, the first and second sensors may cause magnetic interference with each other. It is possible to measure the axial load applied to the shaft with high accuracy without causing it.

It is sectional drawing which shows the structural example in 1st Embodiment of the bearing device with a sensor which concerns on this invention. It is sectional drawing which shows the modification 1 of 1st Embodiment. It is sectional drawing which shows the modification 2 of 1st Embodiment. It is a perspective view which shows the modification 3 of 1st Embodiment. It is sectional drawing which shows the structural example in 2nd Embodiment of the bearing device with a sensor which concerns on this invention.

Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing a configuration example in a first embodiment of a bearing device with a sensor according to the present invention. INDUSTRIAL APPLICABILITY The sensor-equipped bearing device of the present invention is applicable to bearings used in general vehicles such as railroad cars, automobiles, ships, and various bearings such as spindles of machine devices and machine tools. The case where it is applied will be described as an example. The configuration is the same even when the vehicle is not a vehicle.

In FIG. 1, the bearing portion of the sensor-equipped bearing device includes an outer ring (stationary wheel) 11 that is fitted into a housing on the vehicle body side, an inner ring 12 that is fitted onto an axle and rotates together with the axle, an outer ring 11 and an inner ring 12. A plurality of rolling elements (balls or rollers) 13 rotatably arranged between the rollers, and a cage 14 that holds each rolling element 13 between the inner ring raceway and the outer ring raceway in a freely rotatable manner. When the bearing device with the sensor is used, the cage 14 revolves around the inner ring 12 at the same speed as the revolving speed of each rolling element 13 revolving around the center of the shaft.

The sensor-equipped bearing device according to the present invention includes, as a sensor, a revolution speed detection sensor 21 for detecting the revolution speed of the rolling element 13 or the cage 14, and the rotation speed of the rotating wheel (inner ring 12 in this example). And a rotation speed detection sensor 22 for rotating the shaft, and simultaneously detects a revolution speed detection signal from the revolution speed detection sensor 21 and a rotation speed detection signal from the rotation speed detection sensor 22 in association with the rotation of the shaft, and detects the inner ring 12 and the outer ring. When an axial load is applied between the sensor 11 and 11, the axial load can be measured based on those detection signals. That is, the pair of the revolution speed detection sensor 21 and the rotation speed detection sensor 22 functions as a sensor for measuring the rotation speed of the detected object and at the same time measuring the axial load applied between the inner ring 12 and the outer ring 11.

The revolution speed detection sensor 21 has a detection element 21a as a detection unit that detects the revolution speed of the rolling element 13 or the cage 14, and an encoder 21b as a detected unit. Further, in the present embodiment, the encoder 21b is fixedly installed on the side of the cage 14 via the back yoke 21c, and the rolling element 13 or the cage 14 (or both) is provided by the detection element 21a that is installed to face the axial direction. It is configured to detect the revolution speed of.

On the other hand, the rotation speed detection sensor 22 has a detection element 22a as a detection unit for detecting the rotation speed of the rotating wheel, and an encoder 22b as a detection target portion. Then, the encoder 22b is fixed to the rotary wheel side via the back yoke 22c, and more specifically, the back yoke 22c is fixed to the shoulder portion 12a formed at the outer peripheral end of the inner ring 12, which is the rotary wheel, in the radial direction. The detection element 22a installed so as to face the sensor detects the rotation speed of the rotating wheel (in this example, the inner ring 12).

In this embodiment, magnetic sensitive sensors are used as the detection elements 21a and 22a of the detection sensors 21 and 22, and multipolar magnets are used as the encoders 21b and 22b. Further, the detection elements 21a and 22a are mounted by incorporating the respective lead wires 21d and 22d into the tip portion of the sensor unit 23, and a signal is transmitted to an external control system via a cable 24 drawn from the sensor unit 23. It is configured to output.

As shown in FIG. 1, the sensor unit 23 itself is fixed to the sensor cover 25 so that the surface of the sensor mounting portion is exposed on the rolling element 13 side. Further, the sensor cover 25 is fixedly coupled to a stationary wheel (the outer wheel 11 in this example).

In the present embodiment, the arithmetic unit for calculating the axial load applied between the rotating wheel and the stationary wheel based on the detection signal from the revolution number detection sensor 21 is the signal processing unit of the detection sensors 21 and 22. It is mounted on the sensor unit 23. Then, in the external control system, for example, a signal indicating the axial load and a signal indicating the rotation speed of the detection target (the shaft, a rotating object connected to the shaft, etc.), or generated based on these signals A form is adopted in which a signal indicating a result of abnormality diagnosis of the bearing portion is transmitted. The calculation process of the axial load may be performed by an external control system or may be performed by another computing unit connected to the cable 24.

Here, a method of calculating the axial load will be described. When an axial load is applied between the rotating wheel 12 and the stationary wheel 11, the contact angle of the rolling element 13 changes, and the revolution speed of the rolling element 13 changes accordingly. Therefore, the speed ratio (=the revolution speed of the rolling element 13/the rotation speed of the rotating wheel 12) can be obtained by measuring the revolution speed of the rolling element 13 and the rotation speed of the rotating wheel 12, and from the change of the speed ratio, Axial load can be calculated. Therefore, if information indicating the relationship between the speed ratio and the change in load is recorded in advance on a recording medium that can be read by an arithmetic unit that receives a signal, the axial load can be calculated based on that information.

In this embodiment, the revolution number of the encoder 21b formed of a multi-pole magnet integrated with the cage 14 is detected by the magnetic sensitive sensor 21 such as a Hall IC, but the rolling element 13 made of a magnetic material is used. May be provided so as to directly detect the revolution number of the rolling element 13. Also, the cage 14 itself may be made of magnetic plastic and multi-polarized.

(Modification 1 of the first embodiment)
FIG. 2 is a cross-sectional view showing a modified example 1 of the first embodiment. In the case of the first embodiment shown in FIG. 1 described above, when the detection elements 21a and 22a are incorporated in the distal end portion of the cylindrical sensor unit 23, the respective lead wires 21d and 22d of the detection elements 21a and 22a are arranged in the radial direction. Was installed separately. On the other hand, in the case of the first modification, the lead wires 21d and 22d are incorporated close to the tip of the sensor unit 23.

In accordance with this, as shown in FIG. 2B, the radial dimension of the sensor unit 23 may be reduced. Even with such a structure, there is no hindrance to the revolution speed detection and the rotation speed detection, and the function does not change as compared with the first embodiment.

(Modification 2 of the first embodiment)
FIG. 3 is a cross-sectional view showing a modified example 2 of the first embodiment. In the case of the first embodiment shown in FIG. 1 and the modified example 1 of the first embodiment shown in FIG. 2 described above, when the detection elements 21a and 22a are incorporated into the distal end portion of the cylindrical sensor unit 23, detection is performed. The lead wires 21d and 22d of the elements 21a and 22a are separately incorporated. On the other hand, in the case of the second modification, the lead wires 21d are collectively incorporated in the tip end portion of the sensor unit 23.

Accordingly, as shown in FIG. 2B, the radial dimension of the sensor unit 23 may be reduced. Further, the structure as shown in FIG. Even with such a structure, there is no hindrance to the revolution speed detection and the rotation speed detection, and the function does not change as compared with the first embodiment.

(Modification 3 of the first embodiment)
FIG. 4 is a perspective view showing a modified example 3 of the first embodiment. In the case of the first embodiment shown in FIG. 1 described above, when the detection elements 21a and 22a are incorporated in the distal end portion of the cylindrical sensor unit 23, the respective lead wires 21d and 22d of the detection elements 21a and 22a are arranged in the radial direction. Was installed facing the. On the other hand, in the case of the third modification, the lead wire 21d and the lead wire 22d are incorporated at the tip of the sensor unit 23 so as not to face each other.

In addition, in the case of the third modification, the lead wires 21d and the lead wires 22d are assembled so that the mounting positions thereof are substantially right angles. Further, even with such a structure in which the respective lead wires do not face each other, there is no hindrance to the revolution speed detection and the rotation speed detection, and the function does not change as compared with the first embodiment.

(Second embodiment)
FIG. 5 is a cross-sectional view showing a structural example of a sensor-equipped bearing device according to a second embodiment of the present invention. The same components as those of the first embodiment shown in FIG. Omit it.

In the case of the first embodiment shown in FIG. 1 described above, the detection element 21a of the revolution speed detection sensor 21 and the encoder 21b are arranged to face each other in the axial direction. The detection element 22a of the rotation speed detection sensor 22 and the encoder 22b are arranged to face each other in the radial direction. On the other hand, in the case of the present embodiment, the detection element 21a of the revolution speed detection sensor 21 and the encoder 21b are installed to face each other in the radial direction, and the detection element 22a of the rotation speed detection sensor 22 and the encoder 22b are installed to face each other in the axial direction. It is configured. Comparing the configurations of FIG. 1 and FIG. 5, there is no difference in the function of the bearing device with the sensor, and either one may be applied in consideration of the characteristics of the application.

11 Outer ring 12 Inner ring 12a Shoulder portion 13 Rolling body 14 Retainer 21 Revolution speed detection sensor 21a Detection element 21b Encoder 21c Back yoke 21d Lead wire 22 Rotation speed detection sensor 22a Detection element 22b Encoder 22c Back yoke 22d Lead wire 23 Sensor unit 24 Cable 25 sensor cover

Claims (2)

A bearing portion having an inner ring and an outer ring, one of which is a rotating wheel and the other of which is a stationary wheel, and a rolling member interposed between the inner and outer rings, and the rotating speed of the detected object and the rotating wheel and the stationary wheel. As a sensor for measuring an axial load applied between the rolling element and the cage, a first sensor for detecting the revolution speed of the rolling element or its retainer and a second sensor for detecting the rotation speed of the rotating wheel are provided. A bearing device with a sensor,
The detection surface of the first sensor and the detection surface of the second sensor have an orthogonal positional relationship, and the detection surface of the first sensor and the detection surface of the second sensor do not intersect ,
The detection surface of the first sensor and the detection surface of the second sensor are displaced from each other at all positions of the outer ring in the radial direction, the axial position, and the circumferential position, and
The bearing device with a sensor, wherein the first detection element of the first sensor and the second detection element of the second sensor are fixed to the tip portion of the sensor unit via respective lead wires. .. The bearing device with a sensor according to claim 1, wherein the axial load is estimated using a ratio of the detected rotation speed of the rotating wheel and the detected revolution speed of the rolling element or the cage.

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