JP2006090507A - Rolling bearing unit with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing unit with a sensor capable of obtaining force acting on a raceway member with high precision without causing demerits such as reduction of bearing service life and reduction of rated load. <P>SOLUTION: This sensor device 2 has an amorphous wire 11 provided on an outer ring 5 of the rolling bearing 1 as a detected part receiving distortion, an alternating current magnetic field generation means 13 for applying alternating current magnetic flux on the amorphous wire 11, and a processing means for obtaining stress of the rolling bearing from change of impedance of the amorphous wire 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rolling bearing unit with a sensor in which a rolling bearing and a sensor device for detecting various information of the rolling bearing are integrated.

As such a sensor-equipped rolling bearing unit, Patent Document 1 includes a rolling bearing having a race member and rolling elements, and a strain gauge provided outside an outer ring as a stationary race member of the rolling bearing. Are disclosed.
JP-A-1-206113

  In the conventional rolling bearing unit with a sensor, there is a problem in that the force exerted on the race member by the rolling element has a large measurement error, and the force acting on the race member cannot be obtained accurately from the measured value of the strain gauge. . Therefore, when installing the strain gauge, it is necessary to perform a process such as providing a notch in the race member, and this process has a problem that the bearing life is reduced and the rated load is reduced.

  An object of the present invention is to provide a sensor-equipped rolling bearing unit that can accurately obtain a force acting on a raceway member without demerits such as a reduction in bearing life and a reduction in rated load.

  A rolling bearing unit with a sensor according to the present invention is a rolling bearing unit with a sensor provided with a rolling bearing having a fixed side race member, a rotating side race member and a rolling member, and a sensor device. It has an amorphous wire provided in the detected part, an alternating magnetic field generating means for applying an alternating magnetic flux to the amorphous wire, and a processing means for obtaining the stress of the rolling bearing from the impedance change of the amorphous wire. Is.

As the amorphous wire, a Co-based wire having a thickness of about 20 to 130 microns is usually used. For example, negative magnetostrictive Co _72.5 Si _12.5 B ₁₅ is suitable.

  The amorphous wire is installed, for example, on a fixed ring shoulder as a fixed-side track member. At the time of installation, it may be arranged over the entire circumference in the circumferential direction, or may be arranged only in the vicinity of a portion that receives the maximum load.

When the amorphous wire is installed, groove processing is performed as necessary, and a nonmagnetic film is provided. The nonmagnetic film is made of, for example, aluminum oxide (Al ₂ O ₃ ), and is more preferably formed of a nonmagnetic and electrically insulating material. Since the diameter of the amorphous wire can be reduced to about several tens of microns, the groove performance does not affect the bearing performance (reduction of bearing life, reduction of rated load, etc.).

  As the rolling bearing, any of the rolling bearings such as a deep groove ball bearing, an angular ball bearing, a roller bearing (including a cylindrical roller bearing and a tapered roller bearing), a needle bearing, and a thrust bearing can be used. It can be applied not only to things but also to double rows. The amorphous wire may be provided on the inner diameter of the raceway member, may be provided on the outer diameter, or may be provided on an end face in the axial direction. For example, in the case of cylindrical roller bearings and tapered roller bearings, the sensor installation space is limited compared to ball bearings, and it is difficult to affix strain gauges. Since it can be installed using a part, an end, or a thin part, it is possible to detect a bearing stress that could not be measured with a strain gauge. If the raceway member is provided with a groove (such as a groove for fitting an O-ring for sealing), the amorphous wire can be installed without using the groove by using the groove. You can also.

  The fixed-side track member is attached to a housing or the like, and the rotation-side track member is attached to a rotating shaft or the like. The amorphous wire is generally attached to a fixed-side member such as a fixed-side track member or a housing to which the amorphous wire is fixed. The fixed side member is a member that rotates relative to the rotation side member, and is not necessarily fixed, and the fixed side member includes one that rotates itself.

  According to the rolling bearing unit with a sensor of the present invention, when a rotating body such as a main shaft fixed to the rotating side raceway member rotates or a load is applied to the rotating body, the rolling member and the raceway surface and shoulder portion of the raceway member As a result, the amount of strain on the raceway surface and shoulder of the raceway member varies, and this appears as a change in impedance of the amorphous wire. This impedance change is about 100 times that of a normal strain gauge. Therefore, the amount of variation in the acting force on the raceway member can be obtained with high accuracy from the impedance change of the amorphous wire, and the load and rotation speed of the bearing can be detected with high accuracy.

  The sensor-equipped rolling bearing unit may be used as a sensor-equipped hub unit with the fixed-side raceway member attached to the vehicle body side and the rotation-side raceway member attached to the wheel side.

  If it does in this way, it will become possible to detect the contact load of a tire from the output of an amorphous wire, and it can contribute to the stability control of vehicles using a contact load.

  The amorphous wire may be provided so as to be continuous in the circumferential direction with a rectangular waveform (over the entire circumference or only on a part of the circumference). In this way, the amorphous wire has both a circumferential element and an axial element, and not only the measurement of the circumferential deformation by the circumferential element but also the axial deformation by the axial element can be measured. it can.

  According to the rolling bearing unit with a sensor of the present invention, variations in the amount of strain on the raceway surface and shoulder of the raceway member appear as impedance changes in the amorphous wire, and this impedance change is about 100 times that of a normal strain gauge. Even if the detected portion has a very small amount of distortion, it can be detected with high sensitivity. Moreover, when installing the amorphous wire, it is not necessary to process the raceway member, or it is only necessary to perform groove processing of a size of about several tens of microns, resulting in disadvantages such as a reduction in bearing life and a reduction in the rated load. There is no.

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

  1 and 2 show a first embodiment of a rolling bearing unit with a sensor according to the present invention. In the following description, the left and right refer to the left and right in FIG.

  As shown in FIG. 1, the sensor-equipped rolling bearing unit includes a rolling bearing (1) and a sensor device (2) provided thereon.

  The rolling bearing (1) includes an outer ring (fixed side raceway member) (5) fixed to the housing (3), an inner ring (rotation side raceway member) (6) fixed to the rotating shaft (4), A ball (7) which is a plurality of rolling elements arranged between them, and a cage (8) which holds the ball (7).

  The sensor device (2) processes the impedance change of the amorphous wire (11) provided on the outer ring (5), AC magnetic field generating means (13) for applying AC magnetic flux to both ends of the amorphous wire, and the amorphous wire (11). Processing means (12) (not shown in FIG. 1, see FIG. 2).

The amorphous wire 11 is made of Co _72.5 Si _12.5 B ₁₅ having a thickness of about 30 microns.

  The AC magnetic field generating means (13) has an AC magnetic flux generating coil (excitation coil) and an AC power source for exciting the coil, and the amorphous wire (11) is deformed with AC magnetic flux applied to both ends thereof. In this case, the impedance changes, and the impedance change of the amorphous wire (11) is processed in the processing means (12), so that the deformation amount of the amorphous wire (11) and hence the force acting on the outer ring (5) is detected. Is done.

  Outer ring (5) and inner ring (6) are made of high carbon chrome bearing steel (SUJ2), ball (7) is made of ceramic, cage (8) is made of synthetic resin, amorphous wire (11) A non-magnetic film (14) is formed on the surface on which is installed.

  In this embodiment, the amorphous wire (11) is provided on the shoulder of the outer ring (5) over the entire circumference. The distortion of the shoulder portion of the outer ring (5) changes depending on the force received from the ball (7), and the impedance of the amorphous wire (11) changes due to the change in distortion.

  The distortion generated in the shoulder of the outer ring (5) has a waveform as shown in FIG. In addition, since the contact angle is small between the revolution number Nb of the ball (7) and the rotation number Ni of the inner ring (6), there is a relationship of Nb≈Ni / 2. The time required for one rotation of the inner ring (6) is obtained by multiplying T1 or T2) by the number of balls (7) and further doubling it, and finely adjusting the amount of slip of the balls (7). In this way, the rotational speed of the inner ring (6) can be obtained from the number of repetitions of distortion change. The relationship between the revolution number Nb of the ball (7) when the contact angle is α and the rotational speed Ni of the inner ring is as follows: D is the pitch diameter of the ball and d is the ball diameter. D) Ni / 2. On the other hand, the processing means (12) stores an arithmetic expression for obtaining a fluctuation amount of the force acting on the inner ring (6) from the distortion amplitude outputted as the voltage fluctuation amount, and uses the distortion amplitude A. Thus, the maximum value of the force that the inner ring (6) receives from the ball (7) can be obtained, and the force acting on the inner ring (6) can be obtained using this.

  Thus, according to this rolling bearing unit with a sensor, the rotation (rotation speed, rotation speed, rotation angle, etc.) of the rolling bearing (2) is obtained by the amorphous wire (11), and the force applied to the rolling bearing (2) is reduced. These are detected with high accuracy, and these are output to the control means, and appropriate control is performed on the rotating shaft (4).

  In the above, the amorphous wire (11) is provided over the entire circumference of the shoulder of the outer ring (5), but is not limited to this, and may be disposed only in the vicinity of the portion that receives the maximum load. .

  As shown in FIG. 3 (the vertical direction is the circumferential direction and the horizontal direction is the axial direction), the amorphous wire (11) is provided so as to be continuous in the circumferential direction with a rectangular waveform. You may make it. In this way, the amorphous wire (11) will have both a circumferential element (11a) and an axial element (11b), not only measuring the circumferential deformation by the circumferential element (11a), Axial deformation due to the axial element (11b) can also be measured.

When the amorphous wire (11) is installed, since the outer ring (5) is a magnetic body (high carbon chromium bearing steel), a nonmagnetic film (14) made of Al ₂ O ₃ is provided. If necessary, grooving may be performed. When grooving, the part may be made thick. Since the amorphous wire (11) can have a diameter of about several tens of microns, the groove performance does not affect the bearing performance (reduction of bearing life, reduction of rated load, etc.).

  Also, as shown in FIG. 4, some bearings are provided with an annular groove (14) as an off-the-shelf product. In this case, the amorphous wire (11) is formed without forming a separate groove. Can be installed.

  Furthermore, in the case of a tapered roller bearing, since there is no space for installing a strain gauge, conventionally, it has been difficult to measure the stress acting on the strain gauge. For example, as shown in FIG. 4, the outer ring (22), the inner ring (23), a plurality of tapered rollers (24) disposed between both wheels (22) and (23), and a cage (25) for holding these tapered rollers (24), and a cage (25) In the tapered roller bearing (21), the end portion on the small diameter side is bent radially inward, and the bent portion (25a) faces the small flange portion (23a) of the inner ring (23) with a gap therebetween. The stress of the tapered roller bearing (21) can be easily detected by installing the amorphous wire (11) on the small flange portion (23a) or by installing the amorphous wire (11) on the shank indicated by reference numeral (26).

  Although not shown, the amorphous wire can be easily installed in a cylindrical roller bearing or a double row rolling bearing, and can be applied to various configurations in automobiles, machine tools, and the like.

FIG. 1 is a longitudinal sectional view showing an embodiment of a rolling bearing unit with a sensor according to the present invention. It is a block diagram of the sensor apparatus of the rolling bearing unit with a sensor by this invention. FIG. 3 is a diagram showing an example of installation of the amorphous wire according to the present invention. FIG. 4 is a longitudinal sectional view showing another embodiment of the rolling bearing unit with sensor according to the present invention. FIG. 5 is a longitudinal sectional view showing still another embodiment of the rolling bearing unit with sensor according to the present invention.

Explanation of symbols

(1) Rolling bearing unit
(2) Sensor device
(5) Outer ring
(6) Inner ring
(7) Ball (rolling element)
(8) Cage
(11) Amorphous wire
(13) AC magnetic field generation means

Claims (2)

In a rolling bearing unit with a sensor provided with a rolling bearing having a stationary race member, a rotary race member and a rolling member, and a sensor device,
The sensor device includes an amorphous wire provided in a detected part to be strained, an AC magnetic field generating unit that applies an AC magnetic flux to the amorphous wire, and a processing unit that determines a stress of the rolling bearing from the impedance change of the amorphous wire. Rolling bearing unit with sensor, characterized in that   The rolling bearing unit with a sensor according to claim 1, wherein the amorphous wire has a rectangular waveform and is continuous in the circumferential direction.

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