JP2005265175A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel capable of facilitating preload control and applying a preload amount with no variations even when a bearing seal is attached. <P>SOLUTION: The bearing device for a wheel, rotatably supporting the wheel to a vehicle body, comprises an outer member 1, an inner member 2 and a rolling body 3 interposed between the outer member 1 and the inner member 2. The outer member 1 has a vehicle installation flange 1a on an outer periphery, and double row rolling surfaces 6, 7 are formed on its inner-periphery surface. Rolling surfaces 8, 9 facing the rolling surfaces 6, 7 of the outer member 1 are formed on the inner member 2. The plurality of rolling body 3 is interposed between the rolling surfaces between the members 1, 2. A sensor 4 for detecting the pre-load quantity of the bearing is arranged either at the outer member 1 or the inner member 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a wheel bearing device that is used in an automobile and is provided with a preload.

The wheel bearing device is a double-row rolling bearing in the form of an angular ball bearing or a tapered roller bearing, and is preloaded. As a preload application management method in a general double row rolling bearing used for a spindle motor, a disk drive device of information equipment, etc., there is a method related to rotational torque (for example, Patent Document 1).
Japanese Patent Laid-Open No. 2003-74548

  However, since the preload application method is a method in which a constant rotational torque is continuously applied to the bearing and the preload application is stopped when the rotation speed of the bearing reaches the target rotation speed, it is relatively large like a wheel bearing device. When applied to bearings, preload management facilities become a major factor. Further, in order to eliminate the influence of the bearing seal on the torque management, the bearing seal must be assembled after the preload is applied, and the assembling work becomes complicated. Furthermore, during the preloading operation, there is no possibility that dust will be mixed into the bearing portion because there is no bearing seal.

  The object of the present invention is to provide a wheel that is easy to preload control, can provide a preload amount that does not vary even when the bearing seal is mounted, can maintain constant bearing rigidity and rotational torque of each bearing, and can stabilize quality. It is providing a bearing device for a vehicle.

The wheel bearing device of the present invention, an outer member in which double-row rolling surfaces are formed on the inner peripheral surface, an inner member that forms a rolling surface facing the rolling surface of the outer member, A wheel bearing device comprising a double row rolling element interposed between opposing rolling surfaces and rotatably supporting the wheel with respect to the vehicle body, wherein any one of the outer member and the inner member On the other hand, a sensor for detecting a preload amount of the bearing is provided.
According to this configuration, since the sensor for detecting the amount of preload of the bearing is provided on the outer member or the inner member, it is possible to apply the preload to the bearing while monitoring the signal of this sensor. For this reason, even if preload is applied in a state where the seal member is mounted, variations in the amount of preload are reduced, the bearing rigidity and rotational torque of each bearing are constant, and the quality is stabilized. Further, since the preload can be applied while the seal member is incorporated, the assembly of the bearing is easy, and dust does not enter the bearing during the preload application.

  Any of a piezoelectric element, a strain gauge, and a magnetostrictive element may be used as the sensor for detecting the preload amount of the bearing. These piezoelectric elements, strain gauges, or magnetostrictive elements can be mounted on the bearing at a low price. Therefore, it can be used only for preload management at the time of preload application and can be made disposable.

In this invention, the sensor for detecting the preload amount of the bearing may be constituted by a thin film printed directly on one of the outer member and the inner member.
If the sensor is made of a thin film formed directly on the outer member or the inner member by a printing method, it is not necessary to mount the sensor, the assembly of the bearing becomes easier, and the sensor is provided at a low price. be able to.

In the present invention, the inner member has a hub ring and an inner ring fitted to the outer periphery of the hub ring, and the inner ring is formed into a hub ring by a caulking portion that crimps an inboard side end of the hub ring. It may be fixed, and the preload of the bearing may be applied by caulking of the caulking portion.
In the case of this configuration, the operation for crimping the crimping portion also serves as the preload application operation. By managing the detection signal output from the sensor in response to the load applied to the sensor at this time, the preload amount of the bearing can be set with high accuracy.

Another wheel bearing device of the present invention includes an outer member having a vehicle body mounting flange on the outer periphery in which double-row rolling surfaces are formed on the inner peripheral surface, and a rolling that faces the rolling surface of the outer member. A wheel bearing device comprising an inner member having a surface and a double row rolling element interposed between opposing rolling surfaces, the wheel bearing device rotatably supporting a wheel with respect to a vehicle body, wherein the outer member One of the inner member and the inner member is provided with a sensor for detecting a preload amount of the bearing, and the sensor is assembled so as to obtain a predetermined preload using a signal of the sensor.
As described above, the preload can be applied with high accuracy by adjusting the preload application using the signal of the preload sensor provided on the outer member or the inner member. Further, since the preload can be applied while the seal member is incorporated, the assembly of the bearing is easy, and dust does not enter the bearing during the preload application.

Still another wheel bearing device of the present invention includes an outer member having a vehicle body mounting flange on the outer periphery in which double-row rolling surfaces are formed on the inner peripheral surface, and a rolling member facing the rolling surface of the outer member. A wheel bearing device comprising an inner member having a running surface and a double-row rolling element interposed between opposing rolling surfaces, the wheel bearing device rotatably supporting a wheel with respect to a vehicle body, The member has a hub ring and an inner ring fitted to the outer periphery of the hub ring, and the inner ring is fixed to the hub ring by a caulking portion that crimps the inboard side end of the hub ring. A bearing preload is applied by caulking of the caulking portion, and a sensor for detecting the bearing preload amount is attached to the outer member and the radial displacement of the outer diameter surface of the inner ring, or A wound coil that detects either or both of the changes in magnetoresistance due to stress applied to the inner ring. And it may be.
When swing caulking or the like of the caulking portion is performed, the inner ring expands in the radial direction in proportion to the caulking amount, and hoop stress is generated. Therefore, when a sensor for detecting a displacement amount or a change in magnetic resistance is provided opposite to the outer diameter surface of the inner ring, the radial spread or hoop stress of the inner ring is detected by the sensor. Therefore, the preload can be managed by this sensor output.

In this configuration, the sensor is detachably attached to the outer member, the sensor is attached to the outer member when the bearing is assembled, and is detached from the outer member when the bearing is used. Also good.
If the sensor is removed after caulking, the sensor can be used for caulking other wheel bearing devices, and can be produced at low cost. In this case, if the sensor is set using the seal mounting portion of the outer member, a new sensor installation space is not required for the bearing. Further, since the inner ring is directly detected by the sensor, it is not necessary to provide a special member in the wheel bearing device for sensing.

The wheel bearing device assembly method according to the present invention includes a wheel bearing device having a structure in which the inner ring is fitted to the hub wheel and the inner ring is fixed to the hub wheel at the inboard side end of the hub wheel as described above. This is applied to the case where the hub ring is swaged by swing swaged. This assembling method is characterized in that the signal of the sensor is processed continuously or intermittently during the rocking caulking, and the rocking caulking is terminated when a preset signal target value is reached. .
When bearing preload is applied by swinging caulking or the like while monitoring the sensor output in this way, variations in the preload amount of the bearing are eliminated, the bearing rigidity and rotational torque of each bearing are constant, and the quality is stabilized.

In this assembling method, after the press-fitting of the inner ring into the hub ring and before the caulking, the starting torque, the natural frequency, or the rigidity of the wheel bearing device is measured, and based on the measured value, the swinging is performed. The signal target value in caulking may be determined.
The amount of preload when the inner ring is press-fitted into the hub ring varies greatly due to the accumulation of these errors because the measurement of the dimensions of individual parts involves errors. Moreover, the change in the amount of preload due to swing caulking also varies. Therefore, if any of bearing stiffness, starting torque, and natural frequency is measured after press-fitting, and the deviation from the target value is fed back to the swing tightening amount, the pre-load variation due to press-fitting can be offset, It is possible to prevent the preload variation at the time from being taken over by a subsequent process.

  The wheel bearing device of the present invention, an outer member in which double-row rolling surfaces are formed on the inner peripheral surface, an inner member that forms a rolling surface facing the rolling surface of the outer member, A wheel bearing device comprising a double row rolling element interposed between opposing rolling surfaces and rotatably supporting the wheel with respect to the vehicle body, wherein any one of the outer member and the inner member On the other hand, a sensor that detects the amount of preload of the bearing is provided, so preload management is easy, and it is possible to apply a preload amount that is uniform even when the bearing seal is installed, so that the bearing rigidity and rotational torque of each bearing are constant. Can stabilize the quality.

A first embodiment of the present invention will be described with reference to FIGS. This embodiment is a third generation inner ring rotating type and is an example applied to a bearing for supporting a driven wheel.
The wheel bearing device includes an outer member 1 having double-row rolling surfaces 6 and 7 on the inner periphery, and an inner member 2 having rolling surfaces 8 and 9 facing the rolling surfaces 6 and 7, respectively. And the double row rolling elements 3 interposed between the rolling surfaces 6 and 8 and between the rolling surfaces 7 and 9. The outer member 1 is attached to a knuckle (not shown) or the like of the vehicle body at one end via a vehicle body attachment flange 1a.

  The inner member 2 has a wheel mounting flange 2 a, and a wheel (not shown) is mounted on the wheel mounting flange 2 a with a bolt 14. This wheel bearing device is a double-row angular contact ball bearing. Each of the rolling surfaces 6 to 9 has an arcuate cross section, and the contact angle of each of the rolling surfaces 6 to 9 is adjusted to be back to back. Is formed. The rolling elements 3 are formed of balls and are held by the cage 10 for each row. An annular space between the outer member 1 and the inner member 2 is sealed by a seal member 11 outside the rolling element 3 on the outboard side. The outboard side refers to the side that is the outer side in the vehicle width direction when the wheel bearing device is attached to the vehicle, and the inboard side refers to the side that is the center side in the vehicle width direction.

  The outer member 1 is a member on the fixed side, and is an outer member main body 1A having the above-mentioned vehicle body mounting flange 1a, and an outer ring fitted to the inner periphery of the inboard side end of the outer member main body 1A. 1B, and the outer member main body 1A and the outer ring 1B are formed with the rolling surfaces 6 and 7 in each row of the rolling surfaces 6 and 7 in the double row. Between the outer member main body 1A and the outer ring 1B, there is provided a ring-shaped sensor 4 for detecting a preload amount of the bearing applied in the axial direction. The sensor 4 is composed of a piezoelectric element, and lead wires 5a and 5b are connected to electrode terminals thereof. The lead wires 5a and 5b penetrate the outer member main body 1A and are drawn to the outside. The sensor 4 composed of a piezoelectric element generates a voltage when a load is applied from the outside, and a voltage corresponding to the load is obtained between the lead wires 5a and 5b as a preload detection signal. As the sensor 4, a strain gauge may be used in addition to the piezoelectric element.

  The inner member 2 is composed of a hub wheel 2A integrally having a wheel mounting flange 2a and another inner ring 2B, and the two are integrated by tightening the crimping portion 2b at the end of the inboard side of the hub wheel 2A. It is supposed to be combined. Each of the hub wheel 2A and the inner ring 2B is formed with the rolling surfaces 8, 9 in each row of the double-row rolling surfaces 8, 9. Since the hub wheel 2A is for a driven wheel, it has a shape that does not have an inner diameter hole.

  The operation of the above configuration will be described. A sensor 4 made of a piezoelectric element is sandwiched between the outer member main body 1A and the outer ring 1B, and a load is also applied to the sensor 4 as an axial load is applied to the outer ring 1B. FIG. 2 shows voltage waveforms generated in the sensor 4 made of a piezoelectric element at this time. In the figure, with the waveform peak at the center, the left side shows a plus portion of the change in the preload, and the right side shows the discharge of the charge stored in the sensor 4 made of a piezoelectric element. Therefore, a value obtained by integrating the hatched portion on the left side of the peak of the voltage waveform corresponds to the preload amount of the bearing. Therefore, by managing the integration amount, the initial preload amount can be given with high accuracy without variation. Further, even if the preload amount is detected in a state where the seal member 11 is assembled in advance, the seal member 11 does not affect the detection accuracy, so that the assembling operation is simplified and the preload application operation is performed in the bearing. Garbage is not mixed.

  FIG. 3 shows voltage waveforms when a strain gauge is used as the sensor 4 and a load is applied to the strain gauge. From this figure, it can be seen that the voltage generated in the sensor 4 changes stepwise as the load applied to the sensor 4 made of a strain gauge increases. Therefore, in this case, the preload amount of the bearing can be accurately set by managing the potential difference of the stepped voltage generated from the sensor 4.

  FIG. 4 shows another embodiment of the present invention. In this embodiment, in the first embodiment shown in FIG. 1, the outer member 1 is a single member, and the sensor 4 is provided on the inner member 2. The inner member 2 includes a hub ring 2A and an inner ring 2B, as in the case of the first embodiment. The ring-shaped sensor 4 made of a piezoelectric element or the like is installed between a crimping portion 2b formed at the inboard side end of the hub wheel 2A and a width surface of the inner ring 2B facing the crimping portion 2b. . By crimping the crimping portion 2b, the inner ring 2B and the sensor 4 are positioned in the axial direction and fixed to the hub wheel 2A in a state where the sensor 4 is sandwiched between the inner ring 2B and the crimping portion 2b. Other configurations are the same as those in the first embodiment.

  In the case of this configuration, the output voltage of the sensor 4 made of a piezoelectric element changes due to the above-described caulking operation for applying a preload to the bearing. Therefore, the amount of preload of the bearing can be accurately set by managing this output voltage. it can. In addition, since the work of crimping the crimping portion 2b also serves as a preload application work, it is not necessary to perform a special work for preload application other than the assembly work of the bearing, and the work can be simplified. Even when a strain gauge is used for the sensor 4, the preload amount can be set with high accuracy as described above.

FIG. 5 shows still another embodiment of the present invention. In this embodiment, a spacer 12 is interposed between the sensor 4 and the caulking portion 2b of the hub wheel 2A in the embodiment shown in FIG. That is, the inner ring 2B, the sensor 4, the spacer 12, and the caulking portion 2b are arranged in this order from the inner ring 2B toward the caulking portion 2b. Other configurations are the same as those in the embodiment of FIG.
Thus, by interposing the spacer 12, a uniform load can be applied to the sensor 4 made of a piezoelectric element when preload is applied, and more accurate preload management is possible.

6 and 7 show still other embodiments of the present invention. In the embodiment of FIG. 6, the sensor 4 is directly printed on the outer ring 1B or the outer member main body 1A by a printing method instead of the configuration in which the sensor 4 is provided separately from the outer member 1 in the embodiment of FIG. This is an example in which the thin film is formed. In the embodiment of FIG. 7, instead of the configuration in which the separate sensor 4 is provided in the embodiment of FIG. 5, the sensor 4 is made of a thin film printed directly on the inner ring 2B or the spacer 12 by a printing method. It is an example.
When the sensor 4 is made of a thin film formed directly on the outer member 1 or the inner member 2 by a printing method as in these embodiments, the mounting operation of the sensor 4 is not required and the assembly of the bearing is not required. It becomes easier and a sensor can be provided at a low price.

  In each of the above-described embodiments, an example using a piezoelectric element or a strain gauge has been described as the sensor 4 for detecting the preload amount. However, other elements may be used as long as the load can be detected. good. For example, a magnetostrictive element may be used as the sensor 4. An example is shown in FIG. In this example, the sensor 4 includes a ring-shaped magnetostrictive material 4a and a ring-shaped detection portion 4b including a yoke 4ba and a coil 4bb, and the magnetostrictive material 4a is interposed between the inner ring 2B and the crimping portion 2b. I am letting. The detector 4b is attached to the end of the inner ring 2B. The preload can be managed by detecting the magnetostrictive material 4a whose permeability is changed by the preload at the time of caulking and detecting it with the detection unit 4b having the coil 4bb.

Moreover, in each said embodiment, the shape of the sensor 4 is not restricted to a plate shape or a thin film shape, For example, a pipe shape etc. may be sufficient. The sensor 4 is not limited to the ring shape, and may be provided locally at a plurality of locations in the circumferential direction, for example.
Moreover, although each said embodiment demonstrated the case where it applied to the 3rd generation type wheel bearing apparatus, this invention is applicable regardless of a generation form. For example, in the embodiment of FIG. 1, a second-generation type wheel bearing device in which double row inner rings (not shown) are provided on the hub wheel 2 </ b> A may be used.

  9 to 12 show still another embodiment of the present invention. This wheel bearing is an inner ring rotating type, and has an outer member 1 having double-row rolling surfaces 6 and 7 on the inner periphery, and rolling surfaces 8 and 9 that face the rolling surfaces 6 and 7, respectively. The inner member 2 and the double row rolling elements 3 interposed between the double row rolling surfaces 6 to 9 are provided. This wheel bearing is a double-row angular contact ball bearing, each of the rolling surfaces 6-9 is arc-shaped in cross section, and each of the rolling surfaces 6-9 is formed such that the contact angle is back to back. Has been. The rolling elements 3 are formed of balls and are held by the cage 10 for each row. An annular space between the outer member 1 and the inner member 2 is sealed by a seal member 11 outside the rolling element 3 on the outboard side. The outer member 1 is attached to a knuckle (not shown) or the like of the vehicle body at one end via a vehicle body attachment flange 1a.

  The inner member 2 includes a hub wheel 2A integrally having a wheel mounting flange 2a, and an inner ring 2B fitted by press-fitting to the outer periphery of the inboard side end of the hub wheel 2A, and the inboard side end of the hub wheel 2A. By caulking the caulking part 2b of the part, the two are combined together. Each of the hub wheel 2A and the inner ring 2B is formed with the rolling surfaces 8, 9 in each row of the double-row rolling surfaces 8, 9.

  As shown in an enlarged view in FIG. 10, a wound sensor 15 including a yoke 15 a and a coil 15 b is disposed on the inner diameter surface of the outer member 1. The sensor 15 has an inner surface close to the outer surface of the inner ring 2B. The sensor 15 may be an annular one or only a part of the outer member 1 in the circumferential direction. This sensor 15 is for managing the amount of caulking when the inner ring 2B is fixed by the caulking portion 2b of the hub wheel 2A.

  In the swing caulking, as shown in FIGS. 11A and 11B, before and after the caulking, the cylindrical portion 2b 'projected from the inboard side end of the hub wheel 2A is used as the caulking tool 20. This is a method of caulking so as to expand the diameter by swinging the sway. The caulking tool 20 includes a small-diameter portion 20a having a distal end fitted into the cylindrical portion 2b 'and a shoulder portion 20b that comes into contact with the distal end surface of the cylindrical portion 2b'. The swing is performed by rotating the tool center O1 in an inclined posture so that the tool center O1 becomes a locus of the conical surface.

  Next, an assembly method according to an embodiment of the present invention will be described. When the caulking portion 2b is swung and caulked with the sensor 15 disposed on the inner diameter surface of the outer member 1 as described above, the inner ring 2B expands in the radial direction in proportion to the caulking amount and the hoop. Stress will be generated. Therefore, when the winding type sensor 15 is installed, the amount of change appears as a change (decrease) in magnetic resistance, so that the preload can be managed by the output of the sensor 15. The signal output at this time appears as shown in FIG.

  This assembling method is a method in which the signal of the sensor 15 is processed continuously or intermittently during the rocking caulking, and the rocking caulking is terminated when a preset signal target value is reached. When bearing preload is applied by swinging and tightening while monitoring the output of the sensor 15 in this way, variations in the preload amount of the bearing are eliminated, the bearing rigidity and rotational torque of each bearing are constant, and the quality is stabilized.

  The amount of preload when the inner ring 2B is press-fitted into the hub ring 2A varies greatly due to the accumulation of these errors because the measurement of the dimensions of the individual parts involves errors. Moreover, the change in the amount of preload due to swing caulking also varies. Therefore, in order to prevent the former preload variation at the time of press-fitting from being carried over to the subsequent process, the bearing stiffness, starting torque, or natural frequency is measured after press-fitting and the deviation from the target value is used as the swing tightening amount. provide feedback. Thereby, the preload amount dispersion | variation by press injection can be offset.

In the final product, the sensor 15 is inserted into a place where it becomes a seal built-in portion, so that it is not necessary to secure a new space for sensing, which is convenient.
As shown in FIG. 12, in the final product, a seal 21 is incorporated at the inboard side end between the outer member 1 and the inner member 2.

It is sectional drawing of the wheel bearing apparatus concerning 1st Embodiment of this invention. It is an output voltage waveform diagram of an electrostrictive element provided as a sensor in the wheel bearing device. It is an output voltage waveform diagram of a strain gauge provided as a sensor in the wheel bearing device. It is sectional drawing of the wheel bearing apparatus concerning other embodiment of this invention. It is sectional drawing of the wheel bearing apparatus concerning other embodiment of this invention. It is sectional drawing of the wheel bearing apparatus concerning other embodiment of this invention. It is sectional drawing of the wheel bearing apparatus concerning other embodiment of this invention. It is sectional drawing of the wheel bearing apparatus concerning other embodiment of this invention. It is sectional drawing of the wheel bearing apparatus concerning other embodiment of this invention. It is the expanded sectional view which expanded a part of FIG. It is explanatory drawing of the rocking caulking in the assembly process of the wheel bearing apparatus. It is sectional drawing which shows the state of the final product of the wheel bearing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer member 1a ... Car body mounting flange 2 ... Inner member 2b ... Clamping part 2A ... Hub wheel 2B ... Inner ring 3 ... Rolling element 4 ... Sensor 6-9 ... Rolling surface 15 ... Sensor

Claims (11)

An outer member in which a double row rolling surface is formed on the inner peripheral surface, an inner member that forms a rolling surface opposite to the rolling surface of the outer member, and an opposing rolling surface are interposed. In a wheel bearing device comprising a double row rolling element, and rotatably supporting the wheel with respect to the vehicle body,
A wheel bearing device, wherein a sensor for detecting a preload amount of the bearing is provided on one of the outer member and the inner member.   2. The wheel bearing device according to claim 1, wherein the sensor for detecting a preload amount of the bearing is a piezoelectric element.   The wheel bearing device according to claim 1, wherein the sensor that detects a preload amount of the bearing is a strain gauge.   The wheel bearing device according to claim 1, wherein the sensor that detects the amount of preload of the bearing is a magnetostrictive element.   5. The sensor according to claim 1, wherein the sensor for detecting a preload amount of the bearing is configured by a thin film printed directly on one of the outer member and the inner member. This is a wheel bearing device.   6. The inner ring according to claim 1, wherein the inner member includes a hub ring and an inner ring fitted to an outer periphery of the hub ring, and the inner ring has an inboard side end of the hub ring. A wheel bearing device, wherein the bearing is fixed to a hub ring by a crimped portion, and the preload of the bearing is applied by the crimping of the crimped portion. An outer member in which a double row rolling surface is formed on the inner peripheral surface, an inner member that forms a rolling surface opposite to the rolling surface of the outer member, and an opposing rolling surface are interposed. In a wheel bearing device comprising a double row rolling element, and rotatably supporting the wheel with respect to the vehicle body,
One of the outer member and the inner member is provided with a sensor for detecting a preload amount of the bearing, and is assembled so as to obtain a predetermined preload using a signal of the sensor. A wheel bearing device that is characterized.   2. The inner ring according to claim 1, wherein the inner member includes a hub ring and an inner ring fitted to an outer periphery of the hub ring, and the inner ring is a caulking portion obtained by caulking the inboard side end of the hub ring. The preload of the bearing is applied by the caulking of the caulking portion, and a sensor for detecting the amount of the preload of the bearing is attached to the outer member and is connected to the outer diameter of the inner ring. A wheel bearing device that is a wound coil that detects one or both of a radial displacement of a surface and a change in magnetic resistance due to a stress applied to an inner ring.   The wheel sensor according to claim 8, wherein the sensor is detachably attached to the outer member, and the sensor is attached to the outer member when the bearing is assembled, and is removed from the outer member when the bearing is used. Bearing device.   The wheel bearing device according to claim 8 or 9, wherein the caulking portion is caulked, and the inboard side end of the hub wheel is caulked by rocking caulking. A method for assembling a wheel bearing device, wherein the sensor signal is processed continuously or intermittently during dynamic caulking, and swing caulking is terminated when a preset signal target value is reached. .   The start torque, the natural frequency, or the rigidity of the wheel bearing device is measured after the inner ring is press-fitted into the hub ring and before the caulking, and the oscillation is performed based on the measured value. A method of assembling a wheel bearing device for determining a signal target value in caulking.

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