JP2007009976A - Rolling bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing device incorporated in the inside of equipment and capable of measuring rolling resistance of the bearing itself in an operation condition. <P>SOLUTION: This rolling bearing device is provided with an inner ring 11, an outer ring 12, and a first rolling body 13 provided between them. The outer ring 12 has an inner ring-like member 2 and an outer ring-like member 3 capable of rotating relatively and a second rolling body 4 provided between them so as to roll. This rolling bearing device is constituted to give predetermined turn energizing force between the inner ring-like member 2 and the outer ring-like member 3 when these members 2, 3 rotate relatively by different shape raceway surfaces formed in the inner ring-like member 2 and the outer ring-like member 3. The outer ring 7 has a sensor 7, which detects torque generated between the inner ring-like member 2 and the outer ring-like member 3 by measuring difference in phase caused by relative rotation of the inner ring-like member 2 and the outer ring-like member 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rolling bearing device having an inner ring, an outer ring, and rolling elements interposed between the inner ring and the outer ring, and relates to an apparatus capable of detecting torque acting on the bearing itself.

  Currently, rolling bearings are used in various devices. However, it is difficult to accurately measure the rolling resistance (torque) of the bearing itself during operation when the rolling bearing is incorporated in the device. As a method for measuring the torque in the rolling bearing, for example, an apparatus as shown in Patent Document 1 can be used. In this device, an axial load is applied to each inner ring constituting a pair of ball bearings, and dynamic torque between an inner cylinder and an outer cylinder provided inside and outside the ball bearing is measured by a load cell. Then, each inner ring is fixed to the inner cylinder in a state where the dynamic torque becomes a desired value to constitute a bearing unit.

JP 2002-257134 A (FIG. 1)

By using the device described in Patent Document 1, it is possible to adjust the preload and measure the rolling resistance before mounting the rolling bearing in the device, but the structure is complicated, and the rolling bearing is inside the device. The rolling resistance cannot be measured in the integrated and operating state.
Accordingly, the present invention has been made in view of the above-described problems, and provides a rolling bearing device that can be incorporated in an apparatus and can measure the rolling resistance (torque) of the bearing itself in an operating state. Objective.

  In order to achieve the above object, a rolling bearing device of the present invention comprises an inner ring and an outer ring, and a first rolling element interposed between the inner and outer rings, and either the inner ring or the outer ring has a diameter. An inner member and an outer member disposed on the inner side and the outer side of the direction, and an outer peripheral surface of the inner member and an inner peripheral surface of the outer member so that the inner member and the outer member can be rotated relative to each other. A second rolling element interposed between the inner member and the outer member, and a sensor for measuring a phase difference caused by relative rotation between the inner member and the outer member, and an outer peripheral surface of the inner member; At least one of the inner peripheral surfaces of the outer member rolls the second rolling element along with the relative rotation of the inner member and the outer member, gradually reducing the holding interval of the second rolling element, The phase difference is solved according to the phase difference caused by the relative rotation. The predetermined size turn biasing force of the direction is characterized in that it comprises at least in part deformed raceway surface which imparts between the inner member and the outer member.

According to such a configuration, when the outer ring of the rolling bearing device includes the inner member, the outer member, and the second rolling element, a rolling resistance (torque) is generated between the outer ring and the inner ring in the rolling bearing device. Then, it is transmitted to the inner member and a rotational force is generated between the inner member and the outer member. This rotational force causes a relative rotation between the inner member and the outer member. That is, the rolling resistance between the outer ring and the inner ring in the rolling bearing device appears as a phase difference between the inner member and the outer member. If the inner member and the outer member have a certain phase difference, a rotational biasing force having a predetermined magnitude is generated between them in the direction in which the phase difference is eliminated. By obtaining the phase difference, it is possible to detect the rotational biasing force generated between the inner member and the outer member. Since this rotational biasing force balances with the rotational force generated between the inner member and the outer member to cause a predetermined phase difference between them, the value of the rotational force can be detected. Therefore, this rolling bearing device can detect the rolling resistance that is provided in the apparatus and that acts on the bearing itself in the operating state.
The same applies when the inner ring of the rolling bearing device has an inner member, an outer member, and a second rolling element, and the rotational force generated between the inner member and the outer member of the inner ring can be detected.
Further, the radial load can be supported by the second rolling element without providing another rolling element between the inner member and the outer member.

The sensor is preferably a displacement sensor that measures a change in a distance between the inner member and the outer member due to relative rotation between the inner member and the outer member.
According to this configuration, if the phase difference between the inner member and the outer member and the relationship between the interval between the inner member and the outer member in this phase difference are obtained in advance, the displacement sensor measures the change in the interval. The phase difference between the inner member and the outer member can be obtained. For this reason, the phase difference between the inner member and the outer member can be obtained with a simple configuration.
Furthermore, if this displacement sensor is attached to the outer peripheral portion of the inner member or the inner peripheral portion of the outer member, the sensor portion can be configured between the inner member and the outer member in the radial direction, and the rolling bearing device can be made compact. .

  According to the rolling bearing device of the present invention, it is possible to measure the rolling resistance of the bearing itself in a state where it is incorporated in an apparatus and during operation.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a sectional view showing a rolling bearing device according to an embodiment of the present invention. This rolling bearing device includes an outer ring 12, an inner ring 11 that is divided radially inward and outer, and a cylindrical roller 13 as a first rolling element that is interposed between the inner and outer rings 11 and 12 so as to allow rolling. I have. A plurality of cylindrical rollers 13 as first rolling elements are arranged in the circumferential direction between an inner raceway surface 14 formed on the outer periphery of the inner ring 11 and an outer raceway surface 15 formed on the inner periphery of the outer ring 12. It is possible to roll between the raceway surfaces 14 and 15.

In the rolling bearing device shown in FIG. 1, the outer ring 12 is a single annular member, but the inner ring 11 is divided into a radially inner side and an outer side, and an inner annular member (inner member) 2. And an outer annular member (outer member) 3 and a cylindrical roller 4 as a second rolling element interposed between the inner annular member 2 and the outer annular member 3. The inner annular member 2 and the outer annular member 3 are coaxially arranged so that an annular space is formed between them, and the cylindrical roller 4 is interposed in the space, and the inner annular member 2 and the outer annular member 3 are relatively rotatable. The common rotation center of the inner annular member 2 and the outer annular member 3 coincides with the axial center X of the rolling bearing device.
Accordingly, the rolling bearing device is attached to a device having a relatively rotating shaft (not shown) and a housing (not shown). The inner ring member 2 of the inner ring 11 is fitted on the shaft, and the outer ring 12 is attached. This is done by fitting into the inner peripheral surface of the housing. As a result, the rolling bearing device is attached between the shaft and the housing.

In the inner ring 11, the support portion 5 including the cylindrical rollers 4 that relatively support the inner annular member 2 and the outer annular member 3 will be described in detail later, but the inner annular member 2 and the outer annular member 3 are relative to each other. When a predetermined phase difference is generated by the rotation, a rotational biasing force having a predetermined magnitude can be applied between them in a direction to eliminate the phase difference. Note that the rotational biasing force increases as the phase difference increases. That is, a torsion spring property (elasticity in the circumferential direction) can be provided between the inner annular member 2 and the outer annular member 3. The relationship between the phase difference and the rotational biasing force (torsion spring force) is designed in advance according to the shape of the outer peripheral surface of the inner annular member 2 and the inner peripheral surface of the outer annular member 3, the mechanical properties of the cylindrical rollers 4, and the like. Or can be determined in advance.
Furthermore, this rolling bearing device can detect the rolling resistance generated between the outer ring 12 and the inner ring 11. For this reason, the inner ring 11 is caused by relative rotation between the inner annular member 2 and the outer annular member 3. A sensor 7 is provided for determining a phase difference (twist angle) generated. The sensor 7 will be described in detail later.

An outline of detection of the rolling resistance generated between the outer ring 12 and the inner ring 11 in this rolling bearing device will be described.
When rolling resistance is generated between the outer ring 12 and the inner ring 11, the resulting force is transmitted to the outer annular member 3 of the inner ring 11, and a rotational force (torque) is generated between the outer annular member 3 and the inner annular member 2. Arise. Due to this rotational force, the outer annular member 3 rotates relative to the inner annular member 2 to cause a phase difference. Along with this, a rotational biasing force (torsion spring force) in a direction to eliminate the phase difference is applied to the support portion 5. (The generation of the rotational biasing force will be described in detail later). The rotational force due to the rolling resistance and the rotational urging force generated as a reaction force eventually balance, and the outer annular member 3 and the inner annular member 2 are in a balanced state (relatively stationary state) with a predetermined phase difference. Become. That is, the rolling resistance between the outer ring 12 and the inner ring 11 in the rolling bearing device appears as a phase difference between the outer annular member 3 and the inner annular member 2 of the inner ring 11. Therefore, when the sensor 7 detects the phase difference between the outer annular member 3 and the inner annular member 2 in the balanced state, the outer annular member 3 and the inner annular member are derived from the relationship between the phase difference and the rotational biasing force. 2 can be detected. Since this rotational biasing force balances with the rolling resistance (rotational force) to generate a predetermined phase difference, the value of the rolling resistance can be obtained.

A specific configuration of the support portion 5 between the inner annular member 2 and the outer annular member 3 in the inner ring 11 and generation of a rotation urging force generated by the configuration will be described. FIG. 3 is a sectional view showing only the inner ring 11 in the rolling bearing device of FIG.
The support portion 5 of the inner ring 11 has a cylindrical roller 4 as a second rolling element interposed between the outer peripheral surface of the inner annular member 2 and the inner peripheral surface of the outer annular member 3 so as to allow rolling. ing. Accordingly, the outer circumferential surface of the inner annular member 2 is an inner raceway surface 21 on which the cylindrical roller 4 can roll, and the inner circumferential surface of the outer annular member 3 is an outer raceway surface 31 on which the cylindrical roller 4 can roll. ing.

The shapes of the inner raceway surface 21 and the outer raceway surface 31 are not circumferential surfaces around the axis center (rotation axis) X of the rolling bearing device. That is, the inner raceway surface 21 is constituted by a continuous irregular raceway surface that is different from the circumferential surface around the rotation axis X, that is, the inner variant raceway surface 2k. The outer raceway surface 31 is composed of a continuous outer variant raceway surface 3k as a variant raceway surface. The four inner modified raceway surfaces 2k constituting the inner raceway surface 21 have the same shape, and the four outer variant raceway surfaces 3k constituting the outer raceway surface 31 are also identical in shape. The inner raceway surface 21 is equally divided into four in the circumferential direction (every 90 degrees), and each divided portion is an inner deformed raceway surface 2k. Similarly, the outer raceway surface 31 is also equally divided into four in the circumferential direction (every 90 degrees), and each divided portion is an outer deformed raceway surface 3k.
One cylindrical roller 4 is disposed between each of the irregular raceway surfaces 2k and 3k. Due to the inner deformed raceway surface 2k and the outer deformed raceway surface 3k, the space between the inner annular member 2 and the outer annular member 3 is gradually reduced in the circumferential direction side of the cylindrical roller 4 so that the raceway surface interval gradually decreases in the circumferential direction. A portion (wedge-shaped space portion) is formed, and the cylindrical roller 4 is compressed and elastically deformed by a so-called wedge effect with the relative rotation of the inner annular member 2 and the outer annular member 3. As described above, the inner raceway surface 21 and the outer raceway surface 31 are formed by continuation of the deformed raceway surfaces 2k and 3k, respectively, so that the inner raceway surface 21 and the outer raceway surface 31 are occupied only by the deformed raceway surfaces 2k and 3k, respectively. ing. In addition, the deformed raceway surfaces 2k and 3k are equally arranged in the circumferential direction. Accordingly, the circumferential ranges of the deformed raceway surfaces 2k and 3k are each expanded to the maximum, which contributes to the expansion of the circumferential range in which torsion spring force (circumferential elastic force) is obtained.

The deformed raceway surfaces 2k and 3k will be described. Each of the deformed track surfaces 2k and 3k is a curved surface having a center of curvature at a position different from the rotation axis X.
First, each of the four outer deformed track surfaces 3k constituting the outer track surface 31 is a concave curved surface. Specifically, the outer deformed track surface 3k is an arc surface (circumferential surface) centered on the outer track curvature center Co located closer to the track surface (the outer deformed track surface 3k) than the axis center X. Has been. The curvature radius gro of the outer deformed raceway surface 3k is based on the outer track reference radius Ro which is the radius of the circle circumscribing the cross-sectional outline of the outer raceway surface 31 (the maximum value of the distance between the outer raceway surface 31 and the axis center X). Is also small. Further, in a cross-sectional view, with respect to each of the four outer deformed track surfaces 3k, the outer track curvature center Co has an outer maximum radial position 3m at which the distance from the axial center X becomes a maximum value on the outer deformed track surface 3k, It is on a straight line p3 including the axis center X.

  Next, each of the four inner deformed track surfaces 2k constituting the inner track surface 21 is a convex curved surface. Specifically, the inner deformed raceway surface 2k is an arcuate surface (circumferential surface) centered on the inner orbital curvature center Ci located on the side farther from the track surface (the inner deformed track surface 2k) than the axis center X. Has been. The curvature radius gri of the inner deformed raceway surface 2k is based on the inner raceway reference radius Ri, which is the radius of the circle inscribed in the cross-sectional outline of the inner raceway surface 21 (the minimum value of the distance between the inner raceway surface 21 and the axis center X). Is also big. Further, in a cross-sectional view, for each of the four inner deformed raceway surfaces 2k, the inner track curvature center Ci has an inner minimum radial position 2m at which the distance from the axial center X becomes the minimum value on the inner deformed track surface 2k, It lies on a straight line p2 including the axis center X.

The support portion 5 having the inner raceway surface 21 and the outer raceway surface 31 having the shape as described above generates a rotational biasing force as a circumferential torsion spring force between the inner annular member 2 and the outer annular member 3. It has a torsion spring function (rotation urging function) that can be applied. This point will be described.
In this support portion 5, since neither the inner raceway surface 21 nor the outer raceway surface 31 is a circumferential surface centered on the axis center X, a space (rolling space) between the inner raceway surface 21 and the outer raceway surface 31. ) Changes depending on the relative phase relationship between the inner annular member 2 and the outer annular member 3, but the state of FIG. 3 is the outer maximum diameter position 3 m of the outer raceway surface 31 and the inner minimum diameter position 2 m of the inner raceway surface 21. Are in the same phase. Hereinafter, this state is referred to as a reference state. In the reference state, each cylindrical roller 4 is disposed at a circumferential position in contact with the inner minimum diameter position 2m and the outer maximum diameter position 3m (see FIG. 3). This reference state is a state in which the holding interval of the cylindrical rollers 4 (the track surface interval at the contact position of the cylindrical rollers 4) is the widest. Therefore, in this reference state, the compressive force acting on the cylindrical roller 4 from both the raceway surfaces 2k and 3k becomes a minimum value (for example, 0).
Note that the radial distance between the inner minimum diameter position 2m and the outer maximum diameter position 3m in the reference state is substantially the same as the diameter of the cylindrical roller 4, but even if a slight radial gap (plus gap or minus gap) is given. good.

  Next, when the outer annular member 3 rotates with respect to the inner annular member 2 from this reference state, the cylindrical roller 4 rolls on both raceway surfaces 21 and 31, and the holding interval of the cylindrical roller 4 gradually decreases. Therefore, with this rotation, the cylindrical roller 4 is compressed by the inner raceway surface 21 and the outer raceway surface 31 and elastically deformed. Thereby, a rotational biasing force in a direction to eliminate the phase difference generated by the rotation is generated between the inner annular member 2 and the outer annular member 3. This rotational biasing force acts as a torsion spring force (circumferential elastic force) between the inner annular member 2 and the outer annular member 3. In other words, the support portion 5 elastically connects the inner annular member 2 and the outer annular member 3 in the rotational direction. Furthermore, the radial load between the inner annular member 2 and the outer annular member 3 can be supported by the cylindrical rollers 4.

  The point at which the rotation urging force (torsion spring force) is generated in the support portion 5 will be described in more detail. FIG. 4 is a cross-sectional view for explaining the generated rotational biasing force. For easy understanding, a part of the inner deformed raceway surface 2k, a part of the outer deformed raceway surface 3k, and the cylindrical roller 4 are shown. Only the outline is shown. FIG. 4 shows a balanced state in which the outer annular member 3 is rotated counterclockwise by an angle θ relative to the inner annular member 2 in a fixed state. In the reference state, the outer maximum diameter position 3m is located at a position 3mi on the x axis in FIG. 4, and the inner minimum diameter position 2m is also on the x axis. In this reference state, the center Pr of the cylindrical roller 4 is also on the x axis. When the outer annular member 3 is rotated counterclockwise by an angle θ from this reference state, the cylindrical roller 4 rolls counterclockwise to the position shown in FIG. The revolution angle of the cylindrical roller 4 due to this rolling is an angle φi with respect to the inner track curvature center Ci. At this time, if the center of the contact position between the inner deformed raceway surface 2k and the cylindrical roller 4 is Pi and the center of the contact position between the outer deformed track surface 3k and the cylindrical roller 4 is Po, the distance between Pi and Po is The distance between the inner minimum diameter position 2m and the outer maximum diameter position 3m in the reference state is narrower than the diameter of the cylindrical roller 4 (twice the radius Rr of the cylindrical roller 4). Yes. Therefore, the cylindrical roller 4 receives the vertical force Qi from the inner raceway surface 21 and also receives the vertical force Qo from the outer raceway surface 31 and undergoes compression elastic deformation. In a balanced and stationary state, almost no tangential force acts on the cylindrical roller 4, and the points Ci, Co, Pi, Pr, Po are aligned on the straight line L1 as shown in FIG. The directions of the vectors of the vertical force Qi and the vertical force Qo are also the same as the straight line L1. The vertical force Qi ′ received by the inner annular member 2 from the cylindrical roller 4 and the vertical force received by the outer annular member 3 from the cylindrical roller 4 The force Qo ′ is also in the same direction as the straight line L1. The vertical force Qo ′ that the outer annular member 3 receives from the cylindrical roller 4 is different from the radial direction of the rolling bearing device (the direction of the straight line connecting the center Po of the contact position with the cylindrical roller 4 and the shaft center X). Therefore, it has a clockwise component together with the radial component. In this way, the outer annular member 3 receives a clockwise moment (hereinafter also referred to as a rotation biasing moment) generated as a rotation biasing force (torsion spring force). The magnitude of the rotation urging moment is [(size of vector Qo ′) × (distance U1 from axis center X to straight line L1)]. In the balanced state of FIG. 4, the rotational urging moment is balanced with the moment of external force (torque due to rolling resistance in the rolling bearing device) that tries to rotate the outer annular member 3 counterclockwise.

  As described above, the inner deformed track surface 2k is a convex curved surface, and the outer deformed track surface 3k is a concave curved surface. In addition, each inner deformed track surface 2k and each outer deformed track surface 3k form a smoothly continuous curved surface. Only the boundary position 21b between the adjacent inner deformed raceway surfaces 2k is not a smoothly continuous curved surface in the inner raceway surface 21 (see FIG. 3), and the smoothly continuous curved surface in the outer raceway surface 31. Only the boundary position 31b between the adjacent outer deformed raceway surfaces 3k is not (see FIG. 3). Accordingly, the gradually reducing space portion formed on the side of the cylindrical roller 4 has the inner annular member 2 until the contact position between the cylindrical roller 4 and the raceway surfaces 21 and 31 reaches one of the boundary positions 21b and 31b. The space between the raceway surfaces at the contact position of the cylindrical roller 4 due to the relative rotation between the outer ring member 3 and the outer ring member 3 is gradually changed. Then, by the mechanism described with reference to FIG. 4, a rotational biasing force (torsion spring force) in a direction to eliminate the phase difference caused by the rotation of the outer annular member 3 is generated between the inner annular member 2 and the outer annular member 3. To be granted.

  According to such a support portion 5, it is possible to provide a torsion spring property between the inner annular member 2 and the outer annular member 3 without using a torsion coil spring, and the configuration can be simplified. Further, the support portion 5 has a very high degree of design freedom such as torsional rigidity (spring constant). That is, the torsional rigidity and the like can be freely designed by designing the irregular raceway surfaces 2k and 3k (curvature, position of the center of curvature, etc.) and the rigidity of the cylindrical roller 4. Therefore, characteristics such as torsional rigidity can be set over a wide range by changing the shapes of the deformed raceway surfaces 2k and 3k without changing the size (physique) of the member. Furthermore, in the case of using a torsion coil spring, the relationship between the phase difference (twist angle) and the torsional rigidity is linear (constant), but according to this support portion 5, by changing the shapes of the deformed raceway surfaces 2k and 3k, It is also possible to freely change the torsional rigidity according to the phase difference, such as changing the torsional rigidity non-linearly with respect to the phase difference (torsion angle). FIG. 5 shows an example of the relationship between the rotational angle θ and the torsional rigidity when the rotational angle of the outer annular member 3 with respect to the inner annular member 2 is θ. Thus, the rotation angle θ (phase difference) and the torsional rigidity are in a monotonically increasing relationship, and the phase difference and the rotational biasing force are in a predetermined relationship.

  Further, in the support portion 5 shown in FIG. 3, an inner ring raceway surface 21 constituted by a continuous series of four inner ring deformed raceway surfaces 2k equally distributed in the circumferential direction, and four outer rings equally distributed in the circumferential direction. The outer ring raceway surface 31 formed by the continuous raceway surface 3k and the four cylindrical rollers 4 are provided, and the cylindrical rollers 4 are equally spaced in all the cylindrical rollers 4 as the outer annular member 3 rotates. It is set as the structure which changes to. Thereby, the direction and magnitude | size of the torsion spring force produced between the inner annular member 2 and the outer annular member 3 can be made uniform in all the cylindrical rollers 4, and torsion spring property will arise uniformly in the circumferential direction. .

1 and 3, the support portion 5 is a four-element type in which four cylindrical rollers 4 are arranged at equal intervals. However, the present invention is not limited to this, and the support portion 5 includes three cylindrical rollers 3. It may be a uniform distribution or a five or more distribution.
Further, the deformed raceway surface is formed on both the inner raceway surface 21 of the inner annular member 2 and the outer raceway surface 31 of the outer annular member 3. The deformed raceway surface is at least one of the inner raceway surface 21 and the outer raceway surface 31. What is necessary is just to be formed. That is, although not shown, the outer ring raceway surface 31 is constituted by four continuous outer ring raceway surfaces 3k as in FIG. 3, but the inner ring raceway surface 21 is a circumferential surface (round circle) centered on the axis center X. ). Alternatively, the inner ring raceway surface 21 is composed of four continuous inner ring raceway surfaces 2k as in FIG. 3, but the outer ring raceway surface 31 is a circumferential surface (perfect circle) centered on the axis center X. Also good. By forming the deformed raceway surface on only one side, processing becomes easy.

Next, the sensor 7 for measuring the phase difference caused by the relative rotation between the inner annular member 2 and the outer annular member 3 will be described. For example, the sensor 7 can be an angle sensor such as a rotary encoder that directly detects the phase difference between the inner annular member 2 and the outer annular member 3 as an angle. The contactless displacement sensor 7 is used to measure a change in the distance between the inner raceway surface 21 of the annular member 2 and the outer raceway surface 31 of the outer annular member 3.
The phase difference can be detected by such a non-contact type displacement sensor 7 because the inner deformed shape is formed in the gradually reducing space portion formed in the circumferential direction side of the cylindrical roller 4 as the second rolling element. The shape of the raceway surface 2k and the outer deformed raceway surface 3k is formed in a predetermined shape as described above, and when the inner ring member 2 and the outer ring member 3 are rotated relative to each other, the deformed raceway surfaces 2k and 3k are deformed. The distance between the inner raceway surface 21 of the inner annular member 2 and the outer raceway surface 31 of the outer annular member 3 at a predetermined circumferential position on the raceway surfaces 2k and 3k (for example, a measurement position of the non-contact sensor 7) is a predetermined relationship. This is because it changes continuously. That is, it is possible to obtain the relationship between the phase difference between the inner annular member 2 and the outer annular member 3 and the distance between the inner raceway surface 21 and the outer raceway surface 31 in advance.

That is, the displacement sensor 7 of FIGS. 1 and 3 is provided on the outer peripheral portion of the inner annular member 2, and the detection direction is set to the radially outward direction to the outer raceway surface 31 of the opposing outer annular member 3. The distance is measured. The displacement sensor 7 is provided at the boundary position between the adjacent inner deformed track surfaces 2k, 2k, and the displacement sensor 7 measures the minimum distance dimension to the outer track surface 31 in the reference state. When the inner annular member 2 and the outer annular member 3 are rotated relative to each other and balanced with a predetermined phase difference, the displacement sensor 7 measures the distance to the outer raceway surface 31 at the measurement position. Since the relationship between the interval between the inner raceway surface 21 and the outer raceway surface 31 and the phase difference between the inner annular member 2 and the outer annular member 3 is obtained in advance, the measured value (interval) from the reference state is thereby obtained. Change (difference) can be detected, and the phase difference from the reference state can be obtained by the change.
Although not shown, the displacement sensor 7 may be provided on the inner peripheral portion of the outer annular member 3 so that the detection direction is radially inward. The phase difference between the inner annular member 2 and the outer annular member 3 is detected by the displacement sensor 7. Can be requested.

According to the rolling bearing device as described above, it is possible to measure the rolling resistance of the bearing itself in a state of being incorporated in an apparatus and during operation. Thereby, for example, the lubrication state between the inner ring and the outer ring can be monitored. That is, it is possible to detect the magnitude of the rolling resistance caused by the stirring resistance, and it becomes easy to perform the lubrication feedback control. Further, the occurrence of separation on the raceway surface can be detected in advance by detecting the rolling resistance, so that the occurrence of an abnormality on the raceway surface can be known at an early stage.
Further, by setting the torsion spring force in the support portion 5 to be small (weak), a small change in the rolling resistance in the rolling bearing device can be detected. For example, this rolling bearing device can be used for a turning tool mounting portion of a machine tool. In particular, if applied to a machine tool for performing delicate machining, a change in torque at the machined part (attachment part) can have a large effect on machining accuracy, and small torque fluctuations at the machined part can be detected. Is reflected in the output of the machine tool to enable precise machining.

  The shape of the cylindrical roller 4 (second rolling element) in the support portion 5 is not particularly limited as long as it rolls with the relative rotation between the outer annular member 3 and the inner annular member 2. Therefore, it is not limited to the cylindrical roller 4 as in the above-described embodiment, and may be, for example, a ball or a tapered roller, and a rolling element used in a conventional rolling bearing having an inner ring and an outer ring can be appropriately applied. In order to increase the degree of freedom in setting torsional rigidity, a hollow rolling element (for example, a hollow cylindrical roller or a hollow sphere) that is easily elastically compressed and deformed can be used.

In the rolling bearing device of the present invention, any one of an inner ring 11 and an outer ring 12 has an inner annular member 2, an outer annular member 3, a cylindrical roller 4 as a second rolling element supporting them, and an inner annular member. What is necessary is just to have the sensor 7 for calculating | requiring the phase difference (torsion angle) produced by the relative rotation of the member 2 and the outer annular member 3.
FIG. 2 shows another embodiment of the rolling bearing device of the present invention, in which the outer ring 12 has these. That is, the inner ring 11 is an annular member, and the outer ring 12 has an inner annular member (inner member) 2, an outer annular member (outer member) 3, and a cylindrical roller 4 as a second rolling element. is doing. The inner annular member 2 and the outer annular member 3 are coaxially arranged so that an annular space is formed between them, and the cylindrical roller 4 is interposed in the space, and the inner annular member 2 and the outer annular member 3 are relatively rotatable. The common rotation center of the inner annular member 2 and the outer annular member 3 coincides with the axial center X of the rolling bearing device.
Therefore, when the rolling bearing device is attached to a device having a relatively rotating shaft (not shown) and a housing (not shown), the inner ring 11 is fitted on the shaft, and the outer annular member 3 of the outer ring 12 is attached. The rolling bearing device is mounted between the shaft and the housing, by being fitted on the inner peripheral surface of the housing.

In the outer ring 12, the support portion 5 including the cylindrical rollers 4 that relatively support the inner annular member 2 and the outer annular member 3 is similar to the inner annular member 2 and the outer annular member as in the case of the inner ring 11 of FIG. 1. When a predetermined phase difference is generated due to relative rotation with the member 3, it is possible to apply a rotational biasing force having a predetermined magnitude in a direction in which the phase difference is eliminated. Note that the rotational biasing force increases as the phase difference increases. That is, a torsion spring property (elasticity in the circumferential direction) can be provided between the inner annular member 2 and the outer annular member 3. The relationship between the phase difference and the rotational biasing force (torsion spring force) is designed in advance according to the shape of the outer peripheral surface of the inner annular member 2 and the inner peripheral surface of the outer annular member 3, the mechanical properties of the cylindrical rollers 4, and the like. Or can be determined in advance.
Further, this rolling bearing device can detect the rolling resistance generated between the outer ring 12 and the inner ring 11. For this reason, the inner ring 11 has a position generated by relative rotation between the inner annular member 2 and the outer annular member 3. A sensor 7 for obtaining a phase difference (twist angle) is provided.

The detection of the rolling resistance generated between the outer ring 12 and the inner ring 11 in this rolling bearing device will be described.
When rolling resistance occurs between the outer ring 12 and the inner ring 11, the resulting force is transmitted to the inner annular member 2 of the outer ring 12, and a rotational force (torque) is generated between the inner annular member 2 and the outer annular member 3. Arise. Due to this rotational force, the inner annular member 2 rotates with respect to the outer annular member 3 to produce a phase difference. Along with this, a rotational biasing force (torsion spring force) in a direction to eliminate the phase difference is applied to the support portion 5. appear. The rotational force due to the rolling resistance and the rotational urging force generated as a reaction force are eventually balanced, and the inner annular member 2 and the outer annular member 3 are in a balanced state (relatively stationary state) with a predetermined phase difference. Become. That is, the rolling resistance between the outer ring 12 and the inner ring 11 in the rolling bearing device appears as a phase difference between the inner annular member 2 and the outer annular member 3 of the outer ring 12. Therefore, when the sensor 7 detects the phase difference between the inner annular member 2 and the outer annular member 3 in the balanced state, the inner annular member 2 and the outer annular member are determined from the relationship between the phase difference and the rotational biasing force. 3 can be detected. Since this rotational biasing force balances with the rolling resistance (rotational force) to generate a predetermined phase difference, the value of the rolling resistance can be obtained.

The specific configuration of the support portion 5 between the inner annular member 2 and the outer annular member 3 in the outer ring 12 and the generation of the rotational biasing force generated by the configuration are the same as described above with reference to FIGS. 1 and 3. Yes, the description is omitted.
Further, the displacement sensor 7 of the outer ring 12 is also a non-contact type sensor as in the case of FIGS. The displacement sensor 7 in FIG. 2 is provided on the inner peripheral portion of the outer annular member 3, and the detection direction is radially inward, and the distance to the inner raceway surface 21 of the opposing inner annular member 2 is determined. Measuring. The displacement sensor 7 is provided at a boundary position between the adjacent outer deformed track surfaces 3k, 3k, and the displacement sensor 7 measures the minimum distance to the inner track surface 21 in the reference state. When the inner annular member 2 and the outer annular member 3 are rotated relative to each other and balanced with a predetermined phase difference, the displacement sensor 7 measures the distance to the inner raceway surface 21 at the measurement position. Since the relationship between the interval between the inner raceway surface 21 and the outer raceway surface 31 and the phase difference between the inner annular member 2 and the outer annular member 3 is obtained in advance, the measured value (interval) from the reference state is thereby obtained. Change (difference) can be detected, and the phase difference from the reference state can be obtained by the change.

  According to the rolling bearing device as described above, it is possible to measure the rolling resistance of the bearing itself in a state of being incorporated in an apparatus and during operation. Thereby, for example, the lubrication state between the inner ring and the outer ring can be monitored.

Further, in the embodiment of FIGS. 1 and 2, the rolling bearing device of the present invention is not limited to the illustrated form, and may be of another form within the scope of the present invention. Alternatively, a rolling element that has been used in a rolling bearing having an inner ring and an outer ring can be appropriately applied. Although the inner member has been described as an annular member in FIG. 2, the present invention is not limited to this, and the inner member may be a solid member integrated with the shaft.
Further, since the rolling bearing device of FIG. 1 has the sensor 7 on the inner ring 11 side, it is preferably used for a device in which the outer ring 12 rotates together with the housing on the outer side.
Further, since the rolling bearing device of FIG. 2 has the sensor 7 on the outer ring 12 side, it is preferably used for a device in which the inner ring 11 rotates together with a shaft (not shown) on the inner side.

It is sectional drawing which shows the rolling bearing apparatus which concerns on one Embodiment of this invention. It is sectional drawing which shows other embodiment of a rolling bearing apparatus. It is sectional drawing which shows the inner ring | wheel among the rolling bearing apparatuses of FIG. It is a figure for demonstrating the principle which a torsion spring force produces. It is a graph which shows the relationship between a rotation angle and torsional rigidity.

Explanation of symbols

2 Inner ring member (inner member)
3 Outer ring member (outer member)
4 Cylindrical roller (second rolling element)
5 Supporting part 7 Sensor 11 Inner ring 12 Outer ring 13 Cylindrical roller (first rolling element)
21 Inner raceway surface (outer peripheral surface)
2k Inner deformed raceway surface 31 Outer raceway surface (inner circumferential surface)
3k Outer profile surface X axis center

Claims (2)

An inner ring and an outer ring, and a first rolling element interposed between the inner and outer rings,
One of the inner ring and the outer ring includes an inner member and an outer member disposed on the inner side and the outer side in the radial direction, and the inner member and the outer member so that the inner member and the outer member can be relatively rotated. A second rolling element interposed between the outer peripheral surface and the inner peripheral surface of the outer member in a rollable manner, and a sensor for measuring a phase difference caused by relative rotation of the inner member and the outer member; Have
At least one of the outer peripheral surface of the inner member and the inner peripheral surface of the outer member rolls the second rolling member with the relative rotation of the inner member and the outer member, and the holding interval of the second rolling member is increased. A deformed raceway surface that gradually narrows and applies a rotational biasing force of a predetermined magnitude between the inner member and the outer member in a direction to eliminate the phase difference according to the phase difference caused by the relative rotation. A rolling bearing device having at least a part thereof.   The rolling bearing device according to claim 1, wherein the sensor is a displacement sensor that measures a change in a distance between the inner member and the outer member due to relative rotation between the inner member and the outer member.

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