JP2006226477A - Rolling bearing device with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing device with a sensor for improving measuring accuracy for detecting a load, by removing influence of an external magnetic field and influence of an installation error. <P>SOLUTION: A sensor device 2 has a magnetic impedance sensor 8 arranged in a fixed side orbit member 3 and detecting the load acting on the member 3 from a rolling body (a ball) 5. The magnetic impedance sensor 8 is inserted into a hole 3a arranged in the fixed side orbit member 3 so that its facing direction coincides with the direction of a contact angle of the ball 5. The magnetic impedance sensor 8 does not determine an absolute value of strain of a rolling body contact part position caused by a load change, and determines a change in the rolling body contact part position caused by the load change, and converts this change into the load. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

In automobiles, various information is necessary to perform the control. Therefore, a fixed-side track member fixed to the vehicle body side, a rotation-side track member to which wheels are attached, and two members disposed between the two members. It has been proposed to provide a sensor device in a hub unit (rolling bearing) having rows of rolling elements. For example, Patent Document 1 discloses a magnetostrictive sensor that is provided at an end portion of a fixed-side raceway member and detects a change in strain on an end surface of a rotary-side raceway member as a magnetostriction fluctuation amount in order to obtain a load acting on the rolling bearing. What you have is disclosed.
Japanese Patent Laid-Open No. 2004-239397

  According to the rolling bearing device with a sensor of the above-mentioned Patent Document 1, there is a possibility that the assembly accuracy of the hub unit may lead to a measurement error on the end surface of the rotating side raceway member to be detected, and the sensitivity of the sensor is good. For this reason, there was a concern that an error would occur due to an external magnetic field from something other than the hub unit.

  An object of the present invention is to provide a sensor-equipped rolling bearing device in which the measurement accuracy of load detection is improved by removing the influence of an external magnetic field and the influence of assembly errors.

  A rolling bearing device with a sensor according to the present invention is a rolling bearing device with a sensor provided with a rolling bearing having a fixed side race member, a rotary side race member and a rolling element disposed between both members, and a sensor device. The apparatus includes a magnetostrictive sensor that is provided on the fixed-side track member and detects a load acting on the member from the rolling element, and the magnetostrictive sensor is arranged such that the facing direction coincides with the direction of the contact angle of the rolling element. Further, it is inserted into a hole provided in the fixed-side track member, and a change in the position of the rolling element contact portion accompanying a change in load is detected by a magnetostrictive sensor.

  A magnetostrictive sensor is a sensor that measures the inverse magnetostriction effect (a phenomenon in which a magnetic force appears when a material is distorted or deformed). When a high-frequency current is applied to a magnetic wire with high permeability, the impedance between both ends of the magnetic wire is an external magnetic field. Examples thereof include a magnetic impedance sensor (MI sensor) that measures a magnetic field by using an electromagnetic phenomenon that varies depending on the magnetic field.

  The contact angle refers to an angle (design median value) formed by the direction of the rolling element load acting on the contact portion between the rolling element and the race and the plane perpendicular to the central axis of the bearing. When a load acts on this bearing, the position of the contact portion of the rolling element changes. This position can be expressed by how much the contact angle has changed from the design center position.

  If the position of the contact portion of the rolling element changes, the magnetic field in the direction in which the magnetostrictive sensor is facing changes, so the output of the magnetostrictive sensor changes. Therefore, the load is obtained from the output of this sensor. Can do. The direction in which the position of the contact portion changes is clockwise or counterclockwise, and the direction of the force acting depending on which direction is moved is known, and the magnitude of the load is known by the magnitude of change.

  The number of magnetostrictive sensors is appropriately changed according to the required load. If only the magnitude of the load is required, the number of sensors may be one. If it is desired to separately determine the three-direction components of the load acting on the bearing, the number of sensors is preferably at least three. There are four (top, bottom, front and rear).

  According to the rolling bearing device with a sensor of the present invention, since the magnetostrictive sensor is inserted into the hole provided in the fixed-side raceway member, it is prevented that an error is caused by an external magnetic field from anything other than the hub unit, In addition, since the facing direction coincides with the contact angle direction of the rolling element when the load is zero, the contact angle change accompanying the load change is detected by the magnetostrictive sensor, thereby changing the load distribution. Can be detected.

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

  1 and 2 show an embodiment of a rolling bearing device with a sensor according to the present invention. In the following description, the left and right refer to the left and right in the figure. Note that the left is inside the vehicle and the right is outside the vehicle.

  This rolling bearing device with a sensor is used as a hub unit with a sensor, and includes a hub unit (1) and a sensor device (2) for detecting a load acting on the hub unit (1).

  The hub unit (1) is arranged in two rows between the fixed side track member (3) fixed to the vehicle body side, the rotary side track member (4) to which the wheel is attached, and both members (3) and (4). A ball (5), which is a plurality of rolling elements, and a cage (6) for holding each row of balls (5) are provided.

  The fixed-side raceway member (3) has a bearing outer ring (fixed ring) function, and includes a cylindrical portion (12) in which two rows of outer ring raceways are formed on the inner peripheral surface, and a cylindrical portion (12 ) And a flange portion (13) attached to the suspension device (vehicle body side portion) with a bolt.

  The rotation side raceway 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). The inner ring (14), and the inner ring (14), the inner ring (14), which has a small diameter part (16) and is fitted to the outer diameter, and the right side is in close contact with the left side of the large diameter part (15) of the inner axis (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 is fixed is provided. A raceway groove (17a) is formed in the right part of the inner ring (17) so as to be parallel to the raceway groove (15a) of the inner shaft (14), and a shoulder part (17b ) Is formed. A sealing device (20) is provided between the right end portion of the fixed-side track member (3) and the inner shaft (14). A male screw is provided at the left end of the small diameter portion (16) of the inner shaft (14), and the inner ring (17) is connected to the inner shaft (14) by a nut (21) screwed to the male screw. It is fixed to. A cover (22) is covered with the left end portion of the fixed race member (3).

  The sensor device (2) includes a magnetostrictive sensor (8) that is provided on the fixed-side track member (3) and detects a load acting on the member (3) from the ball (5). The magnetostrictive sensor (8) has a bottomed hole (3a) provided in the fixed-side track member (3) so that its facing direction coincides with the contact angle design median direction (A) of the ball (5). Inserted and fixed.

  When a load acts on the hub unit (1), the position of the contact portion of the ball (5) changes. When the position of the contact portion of the ball (5) changes, the magnetic field in the direction in which the magnetostrictive sensor (8) is exposed changes, so the output of the magnetostrictive sensor (8) changes. That is, in FIG. 2, A indicates the contact angle design median direction, and the position of the rolling element contact portion at this time is indicated by a region B. When a relatively leftward load is applied to the fixed-side raceway member (3) in this state, the direction of the contact angle changes to the direction A1, and the position of the rolling element contact portion changes to the region B1. Conversely, when a relatively rightward load is applied to the fixed-side track member (3), the direction of the contact angle changes to the direction A2, and the position of the rolling element contact portion changes to the region B2. The position of the rolling element contact portion can be expressed by how much the contact angle has changed from the design center position of the contact angle. In addition, the direction in which the position of the rolling element contact portion changes is clockwise or counterclockwise, and the direction of the force acting depending on the direction of movement is known, and the magnitude of the load is known by the magnitude of change. . Therefore, by obtaining a relational expression between the load acting on the hub unit (1) and the output of the sensor (8) in advance, the load can be obtained from the output of the sensor (8).

  According to the magnetostrictive sensor (8), it is possible to determine the absolute value of the strain in this region from the inverse magnetostrictive effect at the rolling element contact portion. The value may be smaller. On the other hand, in the rolling bearing device with a sensor of the present invention, a change from the contact angle central design value of the rolling element contact portion is detected, and there is an advantage that it is difficult to receive a change in wear.

  Note that the number of magnetostrictive sensors is appropriately changed according to the required load. For example, as shown in FIG. 1, when the number of sensors is one, the magnitude of the load at the sensor installation position can be obtained. In this case, by counting the number of repetitions of the change in the contact portion position, it is also possible to obtain the rolling element revolution speed and hence the rotation speed of the rotation side raceway member. In addition, when it is desired to separately determine the three-direction components (vertical direction, left-right direction, and front-rear direction) of the load acting on the hub unit, the number of sensors is at least three (either top or bottom, front part And the rear part), preferably four (top part, bottom part, front part and rear part). In this case, not only the magnitude of each load component but also the torsion (moment) can be seen by considering whether the direction in which the position of the rolling element contact portion changes is clockwise or counterclockwise.

  In the above description, the sensor-equipped hub unit has been described. However, the sensor device can be integrated with a double-row rolling bearing other than the hub unit.

FIG. 1 is a longitudinal sectional view showing an embodiment of a rolling bearing device with a sensor according to the present invention. FIG. 2 is an enlarged vertical section of the main part.

Explanation of symbols

(1) Rolling bearing
(2) Sensor device
(3) Fixed side raceway member
(4) Rotating track member
(5) Ball (rolling element)
(8) Magneto-impedance sensor (magnetostrictive sensor)
(31) AC power supply

Claims (1)

In a rolling bearing device with a sensor comprising a fixed-side raceway member, a rotary-side raceway member, a rolling bearing having rolling elements arranged between both members, and a sensor device,
The sensor device has a magnetostrictive sensor that is provided on the fixed-side track member and detects a load acting on the member from the rolling element, and the facing direction of the magnetostrictive sensor coincides with the direction of the contact angle of the rolling element. As described above, the sensor-equipped rolling bearing device is inserted into a hole provided in the fixed-side raceway member, and a change in the position of the rolling element contact portion accompanying a load change is detected by a magnetostrictive sensor.

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