JP2004263721A - Rolling bearing unit with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing unit with a sensor having simple construction for detecting a rotating speed while eliminating the need for a detected member which is conventionally required. <P>SOLUTION: A sensor device 2 has a magnetrostrictive sensor 9 provided on a fixed side raceway member 3 for detecting a gap formed between it and the peripheral face of a rotary side raceway member 4 by the decentering of the rotary side raceway member 4 and a signal processing means for finding the rotating speed of the rotary side raceway member 4 from the repeated number of changes of the gap. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rolling bearing unit with a sensor in which a rolling bearing and a sensor device for detecting various kinds of information on the rolling bearing are integrated.
[0002]
[Prior art]
BACKGROUND ART In a railway vehicle or an automobile, a rolling bearing, a sensor device provided on the rolling bearing, and a detected device for supporting rotation of a shaft or a rotating shaft for transmitting rotation to the axle and detecting rotation such as rotation speed and rotation angle of the shaft. A rolling bearing unit with a sensor having members is used.
[0003]
As this type of rolling bearing unit with a sensor, Patent Document 1 discloses a sensor device in which a sensor device is an electromagnetic induction type rotational speed detector and a member to be detected is an annular body (pulsaring) having irregularities of a predetermined shape. Patent Literature 2 discloses a sensor device in which a sensor device is a magnetic sensor and a member to be detected is an annular magnet (a magnetized pulser) having N and S poles at equal intervals.
[0004]
[Patent Document 1]
Published Japanese Utility Model Application No. Hei 6-47867
[Patent Document 2]
Japanese Patent Application Laid-Open No. 11-174069
[Problems to be solved by the invention]
According to the rolling bearing units with a sensor of Patent Document 1 and Patent Document 2 described above, even if there is a difference in the presence or absence of a magnetic pole between the two, it is necessary to attach the detected member to the rotating-side raceway member. There is a problem that the number of parts increases and the cost increases.
[0007]
An object of the present invention is to provide a sensor-equipped rolling bearing unit capable of detecting a rotational speed with a simple configuration by eliminating a conventionally required member to be detected.
[0008]
Means for Solving the Problems and Effects of the Invention
A rolling bearing unit with a sensor according to the present invention has a sensor including a rolling bearing having a fixed-side race member, a rotating-side race member, and a rolling element disposed between the two members, and a sensor device provided on the rolling bearing. In the rolling bearing unit, the sensor device includes a magnetostrictive sensor provided on the fixed-side raceway member and detecting a gap formed between the rotation-side raceway member and the peripheral surface of the rotation-side raceway member. Signal processing means for obtaining a rotation speed.
[0009]
The rolling bearing unit with sensor according to the present invention is suitably used for a hub unit of an automobile, but can also be used for a bearing portion for supporting a rotating body of a motor or the like.
[0010]
The gap formed between the rotation-side raceway member peripheral surface and the peripheral surface of the rotation-side raceway member changes periodically every rotation. By using the number of repetitions of the change in the gap, the rotation speed of the rotation-side raceway member of the rolling bearing is reduced. You can ask.
[0011]
The gap is generated, for example, by the eccentricity of the rotation-side raceway member, and the eccentricity of the rotation-side raceway member can be obtained by machining a part or all of the peripheral surface of the rotation-side raceway member as an eccentric cylindrical surface. When processing and assembling are performed, misalignment occurs due to processing and assembling errors. By using this misalignment instead of the conventional detected member, the detected member can be omitted. The distance from the projecting surface of a bolt or the like provided at equal intervals in the circumferential direction of the rotation-side track member or at one location on the circumference may be detected as the gap.
[0012]
A magnetostrictive sensor is a sensor that measures an inverse magnetostrictive effect (a phenomenon in which a magnetic force appears when a substance is distorted or deformed). As the magnetostrictive sensor, for example, both ends of a magnetic wire when a high-frequency current is applied to a magnetic wire having a high magnetic permeability Examples include a magnetic impedance sensor (MI sensor) that measures an external magnetic field using an electromagnetic phenomenon in which impedance between the external magnetic fields changes due to an external magnetic field, and a stress impedance sensor (SI sensor) that uses that an impedance changes due to stress. According to the MI sensor, for example, a displacement of 1 μm can be detected as a voltage of 1 mV to 3 mV.
[0013]
The rotation-side raceway member is formed of a magnetic material such as high-carbon chromium bearing steel. The fixed-side track member and the rolling element may be made of the same material as the rotating-side track member.However, as for the rolling element, the rolling element does not affect the magnetic field even when approaching or moving away from the magnetostrictive sensor. A non-magnetic material such as a ceramic such as silicon nitride or silicon carbide or a non-magnetic steel material may be used.
[0014]
According to the sensor-equipped rolling bearing unit of the present invention, by detecting a change in the gap caused by the eccentricity of the rotation-side raceway member by the magnetostrictive sensor, a detected member called a pulsaring or a magnetized pulsar is not required, The rotation can be detected, the number of assembling steps and the number of parts are reduced, and the cost can be reduced.
[0015]
The fixed-side track member is an outer ring having a mounting portion fixed to the vehicle body, the rotating-side track member is formed of an inner shaft to which the wheel is mounted, and an inner ring externally fitted to the inner shaft, and the magnetostrictive sensor is an outer ring of the inner ring. It may be fixed to the end of the fixed-side track member so as to face the surface.
[0016]
The magnetostrictive sensor may be provided so as to face the outer peripheral surface of the caulked portion for preventing the inner ring from coming off, or may be provided so as to face the outer peripheral surface of the inner shaft. By fixing to the end of the fixed-side track member so as to face, the signal line of the magnetostrictive sensor can be taken out from the end of the fixed-side track member, and the assembly of the sensor-equipped bearing unit can be easily performed. it can. The magnetostrictive sensor can be easily attached to the fixed-side member by embedding it in a resin and integrating the resin with a fixed-side track member or a cover fixed to the same.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0018]
FIG. 1 shows a first embodiment of a rolling bearing unit with a sensor according to the present invention. In the following description, left and right and up and down refer to left and right and up and down in the figure. The left side is inside the vehicle and the right side is outside the vehicle.
[0019]
As shown in FIG. 1, the rolling bearing unit with a sensor includes a hub unit (1) as a rolling bearing, and a sensor device (2) for detecting the rotation and the ground load.
[0020]
The hub unit (1) is arranged in two rows between the fixed-side track member (3) fixed to the vehicle body side, the rotating-side track member (4) to which wheels are attached, and both members (3) and (4). A ball (5), which is a plurality of rolling elements, and a retainer (6) for holding each row of balls (5) are provided.
[0021]
The fixed-side track member (3) is provided near the left end of the cylindrical portion (12) having two rows of outer raceways formed on the inner peripheral surface, and is provided with a bolt on a suspension device (vehicle body). And a flange portion (13) that is attached by a.
[0022]
The rotation-side race member (4) has a large-diameter portion (15) having a first raceway groove (15a) and a small-diameter portion (16) having an outer diameter smaller than the diameter of the first raceway groove (15a). Inner shaft (14), and a small diameter portion (16) of the inner shaft (14), which is fitted to the outer diameter and whose right surface is closely contacted with the large diameter portion (15) left surface of the inner shaft (14). (17). Near the right end of the inner shaft (14), a flange portion (18) to which a plurality of bolts (19) for attaching a wheel are fixed is provided. A track groove (17a) is formed on the right side of the inner ring (17) so as to be parallel to the track groove (15a) of the inner shaft (14), and a shoulder (17b) is formed on the left part of the inner ring (17). ) Is formed. A sealing device (20) is provided between the right end of the fixed-side track member (3) and the inner shaft (14). A cover (21) is placed over the left end of the fixed-side track member (3).
[0023]
The sensor device (2) includes a magnetostrictive sensor (7) attached to the fixed-side track member (3), and processing means (not shown) for processing the output of the magnetostrictive sensor (7).
[0024]
In this embodiment, the magnetostrictive sensor (7) is a magneto-impedance sensor, and is embedded in a metal cover (21) with a resin (22). The sensor surface at the tip of the magnetostrictive sensor (7) faces the caulking portion (16a) provided at the end of the small diameter portion (16) of the inner shaft (14) to prevent the inner ring (17) from coming off. . A connector (27) for attaching a harness connecting the sensor processing means provided on the vehicle body side and the sensor device (2) is integrally formed with the resin (22). The connector portion (27) is provided with a signal connector pin (23), and the magnetostrictive sensor (7) and the connector pin (23) are connected via the connector (24) and the lead wire (or only the lead wire). It is connected. The detection surface of the magnetostrictive sensor (7) and the outer peripheral surface of the caulked portion (16a) face each other via a radial gap (S). Since the center axis of the rotating side track member (4) is slightly eccentric with respect to the center axis of the fixed side track member (3) (for example, due to misalignment due to an error at the time of manufacturing), the gap (S) is reduced. The radial width changes with the rotation of the rotation-side race member (4). As shown in FIG. 4, the magnetostrictive sensor (7) outputs a voltage value corresponding to the radial width of the gap (S). In the figure, Ti is the rotation period of the rotation-side track member (4), and the gap (S) is a periodic change every rotation. This voltage can be detected not only at the time of normal rotation shown in FIG. 5A, but also at the time of reverse rotation shown in FIG. Therefore, the rotation speed can be obtained from the output of the magnetostrictive sensor (7).
[0025]
The position at which the magnetostrictive sensor is mounted can be changed as appropriate. As shown in FIG. 2, the magnetostrictive sensor (8) is fixed inside the cover (21), and its sensor surface is a shoulder of the inner ring (17). (17b) You may make it face the outer peripheral surface. The other points in FIG. 2 are the same as in FIG.
[0026]
As shown in FIG. 3, the magnetostrictive sensor (9) is fixed to a substantially central portion in the axial direction of the fixed-side track member (3), and the sensor surface at the tip thereof has a large diameter portion of the inner shaft (14). (15) The outer peripheral surface may be exposed. In the figure, the magnetostrictive sensor (9) is buried in a resin case (25) together with an oscillation circuit. The case (25) includes a connector (27) for attaching a harness connecting the processing means (11) provided on the vehicle body side and the sensor device (2), and the case (25) is a fixed-side track member. A flange portion (25a) for fixing to the outer peripheral surface of (3) is integrally formed. A signal connector pin (23) is provided inside the connector section (27), and the magnetostrictive sensor (9) and the connector pin (23) are connected via a lead wire (24). The case (25) is inserted into a mounting hole (3a) formed in the fixed-side track member (3), and the flange portion (25a) is fixed to the fixed-side track member (3) by bolts (26).
[0027]
As shown in FIGS. 2 and 3, even when the magnetostrictive sensors (8) and (9) are attached, the outputs of the magnetostrictive sensors (8) and (9) are as shown in FIG. The rotation speed can be obtained from the outputs of the sensors (8) and (9).
[0028]
Note that the magnetostrictive sensor is not directly supported on the cover (21) or the case (25) by resin as shown in FIG. 1, FIG. 2 or FIG. 3, but is directly attached to the fixed-side track member (3). Is also good.
[0029]
In the above description, an example is shown in which the rotational speed of the rotation-side race member (4) of the hub unit (1) is determined. The rotational speed of the member can be determined. In this case, as the rolling bearing, besides a ball bearing, a roller bearing, a needle bearing, or the like can be used, and a single row or a double row may be used.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of a rolling bearing unit with a sensor according to the present invention.
FIG. 2 is a longitudinal sectional view showing a second embodiment of a rolling bearing unit with a sensor according to the present invention.
FIG. 3 is a longitudinal sectional view showing a third embodiment of a rolling bearing unit with a sensor according to the present invention.
FIG. 4 is a diagram illustrating an example of an output of a magnetostrictive sensor.
[Explanation of symbols]
(1) Hub unit (2) Sensor device (3) Fixed track member (4) Rotation track member (7) (8) (9) Magnetostrictive sensor (magnetic impedance sensor)

Claims (3)

A fixed-side race member, a rolling-side bearing member and a rolling bearing having a rolling element disposed between the two members, and a sensor-equipped rolling bearing unit including a sensor device provided on the rolling bearing,
The sensor device includes a magnetostrictive sensor that is provided on the fixed-side track member and detects a gap formed between the fixed-side track member and the circumferential surface of the rotary-side track member, and a signal that determines the rotation speed of the rotary-side track member from the number of repetitions of the gap change. A rolling bearing unit with a sensor, comprising: a processing unit. 2. The rolling bearing unit with a sensor according to claim 1, wherein the change in the gap is caused by an eccentricity of the rotating-side track member with respect to the fixed-side track member. The fixed-side track member is an outer ring having a mounting portion fixed to the vehicle body, the rotating-side track member is formed of an inner shaft to which the wheel is mounted, and an inner ring externally fitted to the inner shaft. The rolling bearing unit with a sensor according to claim 1, wherein the rolling bearing unit with the sensor is fixed to an end of the fixed-side track member so as to face the surface.

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