JP7263917B2 - Double row bearing arrangement with sensor - Google Patents

Description

The present invention relates to a sensor-equipped double-row bearing device.

In recent years, there has been an increasing need to monitor the state of machinery and equipment in order to improve productivity. . Since the bearing is a mechanical part that directly receives the axial load, it is considered that the bearing can detect the axial load with higher sensitivity than the load sensor attached to other parts such as the housing of the mechanical equipment.

For example, if it is possible to detect the bearing preload and cutting load in a bearing for a spindle of a machine tool, the obtained load information is fed back to the control unit of the machine tool to control the spindle, thereby optimizing the machining conditions. As a result, it is possible to reduce the wear of the tool and shorten the machining time. In addition, by detecting abnormalities in bearings and processing at an early stage or in advance, equipment can be maintained systematically, and maintenance costs can be reduced.

The main shaft bearings for machine tools described above employ a multi-row bearing (in many cases, a bearing with four rows of rolling element raceways). A method is known in which a groove is provided on the outer peripheral surface of the outer ring, a strain gauge is fixed to the bottom surface of the groove with an adhesive or the like, and strain in the radial direction (radial direction) of the outer diameter of the outer ring due to the rolling element load is detected ( For example, see Patent Document 1).

JP 2017-96444 A

In the method of arranging the strain gauges in the circumferential groove formed on the outer peripheral surface of the outer ring, the strain gauges are installed at a plurality of locations (for example, 6 locations) along the circumferential direction in order to accurately measure the load distribution. can be considered.
However, with this method, if, for example, 10 or 12 strain gauges are arranged along the circumferential direction in order to further improve accuracy, there is a risk that the rigidity of the outer ring will decrease. In the conventional method, in order to arrange the lead wires from the strain gauge, it is necessary to form the same number of lateral grooves connected to the circumferential groove along the circumferential direction corresponding to the strain gauge. The existence of the lateral grooves may reduce the rigidity of the outer ring.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sensor-equipped double-row bearing device capable of suppressing a decrease in rigidity of an outer ring.

The sensor-equipped double-row bearing device of the present invention includes:
(1) A bearing having an outer ring, an inner ring disposed radially inward of the outer ring, and a plurality of double-row rolling elements rollably disposed in an annular space between the outer ring and the inner ring. and a sensor provided on the outer peripheral surface of the outer ring for detecting distortion of the outer ring, comprising:
The sensor has a first sensor arranged in a first recess provided on one side in the axial direction of the outer ring, and a second sensor arranged in a second recess provided on the other side in the axial direction of the outer ring. ,
The phases in the circumferential direction of the first sensor and the second sensor are different from each other.

In the sensor-equipped bearing device of the present invention, when a plurality of sensors are provided on the outer peripheral surface of the outer ring, the plurality of sensors are arranged in the first concave portion provided on one side in the axial direction of the outer ring; It is provided separately from the second sensor arranged in the second recess provided on the other side in the axial direction. Moreover, the first sensor and the second sensor are arranged such that the phases in the circumferential direction are different from each other. Therefore, compared with the case where all the sensors are provided on the same outer circumference of the outer ring, it is possible to suppress a decrease in rigidity of the outer ring.

(2) In the sensor-equipped double-row bearing device of (1), the first concave portion and the second concave portion may be circumferential grooves provided along the circumferential direction on the outer peripheral surface of the outer ring. By providing the first sensor in one of the circumferential grooves on the outer peripheral surface of the outer ring and the second sensor in the other circumferential groove on the outer peripheral surface of the outer ring, all A decrease in rigidity of the outer ring can be suppressed as compared with the case where the sensor is provided on the same outer circumference of the outer ring.

(3) In the sensor-equipped bearing device of (1) or (2), the first sensor and the second sensor are strain gauges,
The outer peripheral surface of the outer ring may be provided with axial lateral grooves for arranging lead wires from the strain gauges, which are connected to the circumferential grooves. By providing the lateral groove, the gauge wire from the strain gauge can be easily pulled out to the outside.

(4) In the sensor-equipped bearing device of (3), the circumferential position of the lateral groove on one axial side of the outer ring is such that the circumferential region of the lateral groove formed on the one axial side of the outer ring is It is desirable that it is set so as not to overlap in the circumferential direction with the region in the circumferential direction of the lateral groove formed on the other side in the axial direction. By setting the circumferential region of the lateral groove on one axial side so as not to overlap the circumferential region of the lateral groove on the other axial side of the outer ring, the decrease in rigidity of the outer ring is more effectively suppressed. can do.

(5) In the sensor-equipped bearing device of (4), the number of lateral grooves on one axial side of the outer ring is the same as the number of lateral grooves on the other axial side of the outer ring,
The lateral grooves on one axial side of the outer ring and the lateral grooves on the other axial side of the outer ring are provided at equal intervals along the circumferential direction,
It is preferable that each lateral groove on one side in the axial direction is provided so as to be positioned in the circumferential direction between two adjacent lateral grooves on the other side in the axial direction. By providing each lateral groove on one side in the axial direction so as to be positioned in the circumferential direction between two adjacent lateral grooves on the other side in the axial direction, it is possible to more effectively suppress a decrease in rigidity of the outer ring. can.

According to the sensor-equipped double-row bearing device of the present invention, it is possible to suppress a decrease in rigidity of the outer ring.

1 is a partial cross-sectional view of an embodiment of a sensor-equipped double-row bearing device of the present invention; FIG. FIG. 2 is an explanatory development view of the outer peripheral surface of the outer ring of the sensor-equipped double-row bearing device shown in FIG. 1 ; FIG. 5 is an explanatory development view of the outer peripheral surface of the outer ring in another embodiment of the sensor-equipped double-row bearing device of the invention; 1 is a partial cross-sectional view of an example of a double-row angular contact ball bearing with an integrated outer ring; FIG. FIG. 2 is a partial cross-sectional view of an example of a double-row angular contact ball bearing with an integrated inner ring;

DETAILED DESCRIPTION OF THE INVENTION A sensor-equipped double-row bearing device of the present invention will be described in detail below with reference to the accompanying drawings. The present disclosure is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

FIG. 1 is a partial cross-sectional view of a sensor-equipped double-row bearing device 1 according to an embodiment of the present invention, and FIG. 2 is an explanation of development of the outer peripheral surface of the outer ring of the sensor-equipped double-row bearing device 1 shown in FIG. It is a diagram. A sensor-equipped double-row bearing device 1 includes a bearing 10 and a strain gauge 20 that is a sensor for detecting strain of an outer ring.

The bearing 10 in this embodiment is a double-row angular contact ball bearing in which single-row angular contact ball bearings are combined face-to-face. It includes a second inner ring 12b, a plurality of double rows of balls (rolling elements) 13, and annular retainers 14a and 14b. The first outer ring 11a and the second outer ring 11b, and the first inner ring 12a and the second inner ring 12b are members formed annularly using bearing steel such as bearing steel or carburized steel. The inner ring 12a is disposed radially inward of the outer ring 11a so as to be concentric with the outer ring 11a. The inner ring 12b is arranged radially inward of the outer ring 11b so as to be concentric with the outer ring 11b.

A first outer ring raceway surface 11a1 and a second outer ring raceway surface 11b on which the balls 13 roll are formed on the inner peripheral surfaces of the first outer ring 11a and the second outer ring 11b, respectively. A first inner ring raceway surface 12a1 and a second inner ring raceway surface 12b1 on which the balls 13 roll are formed on the outer peripheral surfaces of the first inner ring 12a and the second inner ring 12b, respectively. The plurality of balls 13 are held in the circumferential direction at predetermined intervals by retainers 14a and 14b, and are arranged in an annular space between the first outer ring 11a and the first inner ring 12a, and in the second outer ring 11b and the second inner ring. 12b can freely roll in the annular space.

In this embodiment, a circumferential groove, which is a concave portion for providing a sensor, is formed on the outer peripheral surface of the outer ring. More specifically, a first circumferential groove 15a, which is a first concave portion, is formed along the circumferential direction in the outer peripheral surface of the first outer ring 11a on one axial side (left side in FIG. 1), and the other axial side (left side in FIG. A second circumferential groove 15b, which is a second concave portion, is formed along the circumferential direction on the outer peripheral surface of the second outer ring 11b (on the right side in FIG. 1). A plurality of (for example, six) strain gauges 20 are arranged at regular intervals along the circumferential direction in the first circumferential groove 15a. A plurality of (for example, six) strain gauges 20 are arranged at regular intervals along the circumferential direction in the second circumferential groove 15b. The number of strain gauges 20 arranged in the first circumferential groove 15a is the same as the number of strain gauges 20 arranged in the second circumferential groove 15b. In this specification, the recesses (the first recess and the second recess) include not only circumferential grooves formed along the entire circumference along the circumferential direction on the outer peripheral surface of the outer ring, but also grooves formed at predetermined intervals on the outer peripheral surface of the outer ring. Also included are recesses, which are provided and described below.

A first lateral groove 16a connected to a first circumferential groove 15a formed in the outer peripheral surface is formed in the outer peripheral surface of the first outer ring 11a. The first lateral groove 16a is formed along the axial direction and perpendicular to the first circumferential groove 15a. The first lateral groove 16a is formed corresponding to the position of the strain gauge 20 provided in the first circumferential groove 15a. Therefore, the number of first lateral grooves 16a is the same as the number of strain gauges 20 provided in the first circumferential groove 15a. A lead wire 21 from a strain gauge 20 is arranged in the first lateral groove 16a.

A second lateral groove 16b connected to a second circumferential groove 15b formed in the outer peripheral surface is formed in the outer peripheral surface of the second outer ring 11b. The second lateral groove 16b is formed along the axial direction and perpendicular to the second circumferential groove 15b. This second lateral groove 16b is formed corresponding to the position of the strain gauge 20 provided in the second circumferential groove 15b. Therefore, the number of second lateral grooves 16b is the same as the number of strain gauges 20 provided in the second circumferential groove 15b. A lead wire 21 from a strain gauge 20 is arranged in the second lateral groove 16a.

In this embodiment, the first lateral groove 16a and the second lateral groove 16b are formed on the large end sides of the first outer ring 11a and the second outer ring 11b, respectively. The first lateral groove 16a can be formed at the end opposite to the big end of the first outer ring 11a, and similarly the second lateral groove 16b can be formed at the end opposite to the big end of the second outer ring 11b. You can also

In this embodiment, the strain gauge 20, which is the first sensor arranged in the first circumferential groove 15a, and the strain gauge 20, which is the second sensor arranged in the second circumferential groove 15b, are out of phase with each other in the circumferential direction. configured differently. Specifically, the positions of the strain gauges 20 are set such that the strain gauge 20 of the second circumferential groove 15b is located between two adjacent strain gauges 20 arranged in the first circumferential groove 15a in the circumferential direction. It is When six strain gauges 20 are arranged in each circumferential groove, the strain gauges 20 are arranged at positions of 0°, 60°, 120°, 180°, 240°, and 300° with respect to a certain point of the first circumferential groove 15a. In the second circumferential groove 15b, the strain gauges 20 are arranged at positions of 30°, 90°, 150°, 210°, 270°, and 330° with respect to the certain point.

The first lateral groove 16a and the second lateral groove 16b are provided for arranging the lead wire 21 from the strain gauge 20. As shown in FIG. Therefore, when six strain gauges 20 are arranged in each circumferential groove, the number of first lateral grooves 16a and second lateral grooves 16b is also six. When the strain gauges 20 are arranged at intervals of 60° along the circumferential direction as described above, the first lateral grooves 16a and the second lateral grooves 16b are also formed at intervals of 60° along the circumferential direction. Each first lateral groove 16a is circumferentially positioned intermediate two adjacent second lateral grooves 16b. Also, each second lateral groove 16b is located in the middle of two adjacent first lateral grooves 16a in the circumferential direction.

As described above, the circumferential position of the strain gauge 20 in the circumferential groove, that is, the circumferential position of the lateral groove is set, and the strain gauge 20 in the first circumferential groove 15a and the strain gauge 20 in the second circumferential groove 15b are set. By making the phases in the directions different from each other, it is possible to suppress a decrease in rigidity of the first outer ring 11a and the second outer ring 11b, which are the outer rings.

FIG. 3 is an explanatory development view of the outer peripheral surface of the outer ring of a sensor-equipped double-row bearing device according to another embodiment of the present invention. The outer ring is composed of a first outer ring 31a on one side in the axial direction and a second outer ring 31b on the other side in the axial direction. The configurations of the inner ring, the balls that are rolling elements, and the retainer that holds the balls in a rollable manner are the same as in the embodiment shown in FIGS. .

In this embodiment, a plurality of first recesses 35a, which are first recesses, are provided at regular intervals along the circumferential direction on the outer peripheral surface of the first outer ring 31a. A plurality of second recesses 35b, which are second recesses, are provided at regular intervals along the circumferential direction on the outer peripheral surface of the second outer ring 31b. A strain gauge 20 is disposed in each first recess 35a and each second recess 35b.

A first lateral hole 36a connected to the first recess 35a is formed in one side surface of the first outer ring 31a in the axial direction. The first horizontal hole 36a is formed along the axial direction. This first horizontal hole 36a is formed corresponding to the position of the strain gauge 20 provided in the first recess 35a. Therefore, the number of first horizontal holes 36a is the same as the number of strain gauges 20 provided in the first recesses 35a. A lead wire 21 from a strain gauge 20 is arranged in the first horizontal hole 16a.

A second lateral hole 36b connected to the second recess 35b is formed in the side surface of the second outer ring 31b on the other side in the axial direction. The second horizontal hole 36b is formed along the axial direction. This second horizontal hole 36b is formed corresponding to the position of the strain gauge 20 provided in the second recess 35b. Therefore, the number of second horizontal holes 16b is the same as the number of strain gauges 20 provided in the second recesses 35b. A lead wire 21 from a strain gauge 20 is arranged in the second horizontal hole 16a.

Also in this embodiment, the strain gauge 20, which is the first sensor arranged in the first recess 35a, and the strain gauge 20, which is the second sensor arranged in the second recess 35b, are out of phase in the circumferential direction. set differently from each other. Specifically, in the circumferential direction, the phases are set to be shifted by 30°, similar to the embodiment shown in FIGS. In this manner, the phases in the circumferential direction of the first recess 35a in which the strain gauge 20 is installed and the second recess 35b in which the strain gauge 20 is installed are different from each other. A decrease in rigidity of the second outer ring 11b can be suppressed.

[Other Modifications]
The embodiments disclosed above are illustrative in all respects and are not restrictive.
For example, in the above-described embodiment, the strain gauges are arranged such that the strain gauge provided on one side in the axial direction is positioned between two adjacent strain gauges provided on the other side in the axial direction in the circumferential direction. However, the invention is not limited to such arrangements. It is sufficient that the first sensor on one side in the axial direction and the second sensor on the other side in the axial direction are arranged so as to be out of phase with each other. If the region w1 in the circumferential direction of the lateral groove formed on the other side in the axial direction does not overlap in the circumferential direction with the region w2 in the circumferential direction of the lateral groove formed on the other side in the axial direction, the strain gauge on the one side in the axial direction will be connected to the two adjacent regions on the other side in the axial direction. Even if it is not located in the middle of the strain gauge, it is possible to obtain a certain effect of suppressing the decrease in rigidity of the outer ring. However, in order to more effectively suppress the decrease in rigidity of the outer ring, the position of the strain gauge 20 on one side in the axial direction should be changed to the position of the two adjacent strain gauges 20 on the other side in the axial direction, as in the above-described embodiment. It is desirable to set it in the middle or near the middle.

In addition, in the above-described embodiment, the double-row bearing device in which the ball rolling raceway has two rows is exemplified, but the present invention is also applicable to a double-row bearing device having three or more rows of raceways. be able to.
In the above-described embodiment, the outer ring is composed of the first outer ring and the second outer ring that are separate from each other, and the inner ring is composed of the first inner ring and the second inner ring that are separate from each other. For example, the present invention can also be applied to a double-row bearing assembly having an integral outer ring 41 as shown in FIG. Similarly, the present invention can also be applied to a double row bearing assembly having an integral inner ring 42 as shown in FIG. 5, for example. In the outer ring 41 shown in FIG. 4, for example, two rows of circumferential grooves are formed on the outer peripheral surface, the first sensor is arranged in the circumferential groove on one side in the axial direction, and the first sensor is arranged in the circumferential groove on the other side in the axial direction. The second sensor is arranged so that the phase in the circumferential direction is different from that of the sensor.

Further, in the above-described embodiment, a double-row bearing device in which single-row angular contact ball bearings are combined face-to-face is exemplified, but the present invention is not limited to this. For example, a double-row bearing device in which single-row angular contact ball bearings are combined back-to-back or a double-row bearing device in which single-row angular contact ball bearings are combined in parallel may be used. A double-row bearing device in which two single-row deep groove ball bearings are arranged adjacent to each other may also be used.

Further, in the above-described embodiments, the double-row bearing device in which the rolling elements are balls is exemplified, but the present invention is not limited to this, and the rolling elements may be rollers, for example.

1: Double row bearing device with sensor 10: Bearing 11a: First outer ring 11b: Second outer ring 12a: First inner ring 12b: Second inner ring 13: Balls (rolling elements) 14a, 14b: Cage 15a: First circumferential groove 15b: Second peripheral groove 16a: First lateral groove 16b: Second lateral groove 20: Strain gauge 21: Lead wire 31a: First outer ring 31b: Second outer ring 35a: First recess 35b: Second recess 36a: First Lateral hole 36b: Second horizontal hole

Claims (2)

a bearing having an outer ring, an inner ring disposed radially inward of the outer ring, and a plurality of double-row rolling elements rollably disposed in an annular space between the outer ring and the inner ring; and the outer ring. A sensor-equipped double-row bearing device comprising a sensor provided on the outer peripheral surface of the outer ring to detect the strain of
The sensor has a first sensor arranged in a first recess provided on one side in the axial direction of the outer ring, and a second sensor arranged in a second recess provided on the other side in the axial direction of the outer ring. ,
Phases in the circumferential direction of the first sensor and the second sensor are different from each other,
The first recess and the second recess are circumferential grooves provided along the circumferential direction on the outer peripheral surface of the outer ring,
The first sensor and the second sensor are strain gauges,
the outer peripheral surface of the outer ring is provided with an axial lateral groove for arranging a lead wire from the strain gauge, which is connected to the circumferential groove;
The circumferential position of the lateral groove on one axial side of the outer ring is such that the circumferential region of the lateral groove formed on the one axial side is the circumferential region of the lateral groove formed on the other axial side of the outer ring. A double-row bearing device with a sensor, which is set so as not to overlap in the circumferential direction. The number of lateral grooves on one axial side of the outer ring is the same as the number of lateral grooves on the other axial side of the outer ring,
The lateral grooves on one axial side of the outer ring and the lateral grooves on the other axial side of the outer ring are provided at equal intervals along the circumferential direction,
2. The sensor-equipped double-row bearing device according to claim 1 , wherein each lateral groove on the one axial side is provided so as to be positioned in the circumferential direction between two adjacent lateral grooves on the other axial side. .

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