JP2006057813A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel capable of simultaneously detecting a rotating speed of the wheel and detecting grounding load with high responsiveness, protecting sensors from mud water and dusts with compact constitution, and improving its durability. <P>SOLUTION: This bearing device comprises an outer member 1 having a double row raceway surface 4 on its inner periphery, an inner member 2 having a double row raceway surface 5 in opposition to the raceway surface 4, and double row rolling elements 3 placed between the raceway surfaces 4, 5 opposite to each other. Both ends of an annular space between the outer member 1 and the inner member 2 are sealed by sealing means 7, 8. An annular detected part 14 having a magnetic encoder 15 is mounted on an outer periphery of the inner member 2 between the double row raceway surfaces 4, 5. A rotation sensor 18 opposite to the magnetic encoder 15 and a displacement sensor 19 opposite to the detected part 14 are integrated as a sensor assembly 17, and the sensor assembly 17 is mounted on the outer member 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wheel bearing device incorporating various sensors such as a rotation sensor.

In recent years, for safe driving in automobiles, various data such as wheel rotation speed are detected by sensors, and based on these sensor signals, ABS (anti-lock brake system) control, driving without spinning the driving wheels Force control, brake force control to control skid during cornering, etc. are implemented. For example, in order to detect a grounding load applied to a vehicle, a displacement sensor is fixed to a vehicle body mounting flange of an outer member of a bearing, and a magnetized portion is provided at a position facing the displacement sensor on the outer periphery of the outer member. There has been proposed a wheel bearing device configured to detect a distance fluctuation amount between a displacement sensor and a magnetized portion with a displacement sensor and convert the detection result into a grounding load (for example, Patent Document 1).
Japanese Patent Laid-Open No. 2003-336652

  However, in the wheel bearing device having the above configuration, the displacement sensor and the magnetized portion are exposed to the outside, and there is a possibility that accurate detection cannot be performed because these detection members are damaged by muddy water or dust. There is also a problem with durability. Moreover, the sensor provided in this wheel bearing apparatus only detects a ground load. Therefore, when detecting the rotation speed of the wheel in addition to the ground load, it is necessary to separately install a rotation sensor, which makes it difficult to install the wiring to the vehicle and increases the cost due to an increase in the number of parts. Also become.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a wheel bearing device that can detect wheel rotational speed and ground contact load simultaneously and with good responsiveness, protect each sensor from muddy water and dust with a compact structure, and have high durability. Is to provide.

  The wheel bearing device of the present invention is interposed between an outer member having a double row raceway surface on the inner periphery, an inner member having a double row raceway surface facing these raceway surfaces, and the opposing raceway surfaces. In a wheel bearing device that includes a double-row rolling element and sealing means that seals both ends of an annular space between the outer member and the inner member, and supports the wheel rotatably with respect to the vehicle body, a magnetic encoder A sensor combination in which a ring-shaped detected portion having an outer periphery is provided on the outer periphery of the inner member between the double-row track surfaces, and a rotation sensor facing the magnetic encoder and a displacement sensor facing the detected portion are integrated. A body is provided on the outer member.

  According to this configuration, when the inner member rotates integrally with the wheel, the rotation sensor of the sensor combination provided on the outer member detects a magnetic change of the magnetic encoder in the detected portion provided on the inner member. , Detect the rotation speed of wheels In addition, when a ground load is applied to the wheel, distortion, displacement, or posture change occurs in the detected portion on the outer periphery of the inner member in accordance with the installation load. However, it can be detected as a change in the gap between the displacement sensor and the detected portion, and the ground load applied to the wheel can be detected from this detection signal. Since the rotation sensor and the displacement sensor are integrated as a sensor combination, that is, a multi-sensor, both sensors can be installed in a compact manner, and the rotation speed and installation load data can be detected simultaneously. And since it detects near a wheel, responsiveness improves. In addition, since the sensor assembly and the magnetic encoder are disposed in the bearing space sealed at both ends by the sealing means, the magnetized portions of these sensors and magnetic encoders can be used for muddy water on the road surface without providing a separate sealing means. It can be protected from dust and has good durability.

In this invention, the said to-be-detected part may consist of a core metal which supported the said magnetic encoder and this encoder. The cored bar may have a cross-sectional hat shape having a groove-shaped portion in which the magnetic encoder is provided, and an overhanging portion protruding from both sides of the opening edge of the groove-shaped portion. In this case, the rotation sensor may be arranged to face the magnetic encoder, and the two displacement sensors may be arranged to face the protruding portions on both sides of the cored bar.
When a magnetic encoder is a rubber magnet, a plastic magnet, a sintered magnet, etc., a cored bar is often required, but by using this cored bar as a detected portion of a displacement sensor, a dedicated cored bar can be used. This eliminates the need for parts and assembly man-hours. Since the core bar has a hat-shaped cross section and two displacement sensors are provided so as to face the protruding portions on both sides thereof, the detection signals of both displacement sensors are compared, averaged, and appropriately processed. Thus, it is possible to detect the load direction and improve detection accuracy.

  Further, the displacement sensor may be arranged to face the magnetic encoder. In this case, the magnetic encoder for detecting rotation also serves as the detected part of the displacement sensor, and the structure can be further simplified.

In the present invention, the sensor combination may be a resin-molded combination of the rotation sensor and the displacement sensor.
By resin-molding both sensors together, they can be easily integrated, and handling of the integrated sensor combination becomes easy.

  The wheel bearing device of the present invention is interposed between an outer member having a double row raceway surface on the inner periphery, an inner member having a double row raceway surface facing these raceway surfaces, and the opposing raceway surfaces. In a wheel bearing device comprising a double row rolling element and a sealing means for sealing both ends of an annular space between the outer member and the inner member, an annular detected portion having a magnetic encoder Since the outer member is provided with a sensor combination that is provided on the outer periphery of the inner member between the raceway surfaces of the row and is integrated with a rotation sensor that faces the magnetic encoder and a displacement sensor that faces the detected portion. Rotational speed and ground contact load can be detected simultaneously and with good responsiveness, and each sensor can be protected from muddy water and dust with a compact structure, and can have high durability.

A first embodiment of the present invention will be described with reference to FIGS. The wheel bearing device of this embodiment is an example applied to a wheel bearing for driving wheel support, which is a third generation inner ring rotating type. In this specification, the side closer to the outer wheel in the vehicle width direction when attached to the vehicle is referred to as the outboard side, and the side closer to the center of the vehicle is referred to as the inboard side. In FIG. 1, the left side is the outboard side and the right side is the inboard side.
In FIG. 1, a bearing portion A of this wheel bearing device includes an outer member 1 having double-row raceway surfaces 4 on the inner periphery, and an inner member having raceway surfaces 5 facing the raceway surfaces 4 on the outer periphery. 2 and double row rolling elements 3 interposed between the double row raceway surfaces 4 and 5. The bearing portion A is a double-row angular ball bearing. Each of the raceway surfaces 4 and 5 has an arcuate cross section, and each of the raceway surfaces 4 and 5 is formed so that the contact angle is back to back. Yes. The rolling elements 3 are formed of balls and are held by the cage 6 for each row.

  The outer member 1 is a member on the fixed side, and has a vehicle body mounting flange 1a for fixing to a knuckle (not shown) on the outer periphery, and the whole is an integral member. The vehicle body mounting flange 1a is fastened to a knuckle installed in a vehicle body (not shown) with a plurality of bolts (not shown) in the circumferential direction.

  The inner member 2 is a member on the rotation side, and a hub wheel 2A having a wheel mounting flange 2a on the outer periphery, and a separate member fitted to the outer diameter surface of the end portion on the inboard side of the hub wheel 2A. It consists of an inner ring 2B. The outer ring 12a of the constant velocity joint 12 is connected to the hub wheel 2A. Each row of raceway surfaces 5 is formed on the hub wheel 2A and the inner ring 2B. The inner ring 2B is clamped and fixed in the axial direction with respect to the hub wheel 2A by a crimping portion 2Aa provided at the inboard side end of the hub wheel 2A. The hub wheel 2A has a center hole 9, and a stem portion 13 formed integrally with the constant velocity joint outer ring 12a is inserted into the center hole 9. The stem portion 13 has a male screw portion 13b at the tip, and the nut 11 screwed into the male screw portion 13b is pressed against the end face 2c on the outboard side of the central hole 9, so that the constant velocity joint outer ring 12a is a hub. It is connected to the wheel 2A by being pushed to the outboard side. The wheel mounting flange 2a is located at the end of the hub wheel 2A on the outboard side, and a wheel (not shown) is attached to the wheel mounting flange 2a with a bolt 10 via a brake rotor.

  A spline groove 2b is formed in the center hole 9 of the hub wheel 2A, and a spline groove 13a formed on the outer peripheral surface of the stem portion 13 is fitted into the spline groove 2b. The open end portions on the outboard side and the inboard side of the annular space formed between the inner and outer members 2 and 1 are sealed with contact-type seals 7 and 8 which are sealing means.

  A ring-shaped detected portion 14 having a magnetic encoder 15 is fitted on the outer periphery between the raceway surfaces 5 of both rows of the inner member 2. As shown in FIG. 2 by enlarging the portion B of FIG. 1, the detected portion 14 includes a magnetic encoder 15 and a cored bar 16 that supports the magnetic encoder 15. The metal core 16 has a cross-sectional hat shape having a groove-shaped portion 16a in which the magnetic encoder 15 is provided, and an overhanging portion 16b projecting to both sides from the opening edge of the groove-shaped portion 16a. The magnetic encoder 15 is composed of a multipolar magnet in which magnetic poles N and S are alternately arranged at a predetermined interval in the circumferential direction, for example, as shown in a cross-sectional view of the upper half part in FIG.

  Between the raceway surfaces 4 of both rows of the outer member 1, there are a rotation sensor 18 that faces the magnetic encoder 15 in the radial direction and a displacement sensor 19 that faces the detected portion 14 in the radial direction. An integrated sensor combination 17 is provided. The sensor combination 17 is a multi-sensor having a rotation sensor 18 and a displacement sensor 19. Specifically, the sensor combination body 17 is obtained by resin-molding the rotation sensor 18 and the displacement sensor 19 together in a sensor fixing portion 20 that is a case fixed through the outer member 1 in the radial direction. Is configured. At least one or more sealing means such as an O-ring is interposed in the penetration portion of the sensor fixing portion 20 in the outer member 1 to prevent water, oil, or the like from entering the inside from the penetration portion. .

  The rotation sensor 18 includes a magnetic sensor such as a Hall element or a magnetoresistive element, and detects a magnetic change of the magnetic encoder 15 that rotates integrally with the inner member 2. The number of the rotation sensors 18 may be one, but the two rotation sensors 18 may be arranged at two locations whose phases are approximately 90 ° apart from the periodic magnetic change in the circumferential direction of the magnetic encoder 18. When the two rotation sensors 18 are arranged in this manner, the rotation signals output from the respective rotation sensors 18 have a phase difference of about 90 °, so that not only the rotation speed but also the rotation direction can be detected.

  Two displacement sensors 19 are arranged so as to face the protruding portions 16b on both sides of the metal core 16, respectively. The displacement sensor 19 is, for example, a reluctance type in which a coil is wound around a yoke, and detects a change in the radial gap between the protruding portion 16b of the detected portion 14 and the displacement sensor 19 as a load applied to the wheel.

  FIG. 4 shows another configuration example of the detected unit 14 in this embodiment. In the detected portion 14, a magnetic encoder 15 is provided over substantially the entire width of the surface of the ring-shaped cored bar 16. In the sensor combination 17, not only the rotation sensor 18 but also two displacement sensors 19 are arranged side by side in the encoder width direction so as to face the magnetic encoder 15. Other configurations are the same as those in the example of FIG.

  According to the wheel bearing device having this configuration, when the inner member 2 rotates integrally with the wheel, the rotation sensor 18 of the sensor combination 17 provided on the outer member 1 is detected by the detected member provided on the inner member 2. 14 detects a magnetic change of the magnetic encoder 15. The rotational speed of the wheel can be detected from this detection signal. Further, when a grounding load is applied to the wheel, the displacement sensor 19 of the sensor combination 17 detects a change in the gap between the displacement sensor 19 and the detected portion, so that the grounding load applied to the wheel from the detection signal is detected. Can be detected.

  In this wheel bearing device, the annular detected portion 14 having the magnetic encoder 15 is provided between the double-row raceway surfaces 5 and 5 on the outer periphery of the inner member 2, and rotates opposite to the magnetic encoder 15. Since the sensor combination body 17 in which the displacement sensor 19 facing the sensor 18 and the detected portion 14 is integrated is provided on the outer member 1, the rotation speed of the wheel and the detection of the ground load can be detected simultaneously and with good responsiveness. The rotation sensor 18 and the displacement sensor 19 can be arranged in a compact manner, and these sensors 18 and 19 and the magnetic encoder 15 can be protected from muddy water and dust and have excellent durability.

  In addition, since the sensor combination 17 is configured by resin-molding the rotation sensor 18 and the displacement sensor 19 together in the sensor fixing portion 20, the rotation sensor 18 and the displacement sensor 19 can be installed with high positional accuracy, and the detection accuracy accordingly. Can be improved.

  FIG. 5 shows another embodiment of the present invention. The wheel bearing device of this embodiment is of a double row angular ball bearing type and is classified as a first generation type. This wheel bearing device includes an outer member 21 having raceway surfaces 24 in a double row on the inner periphery, an inner member 22 having raceway surfaces 25 opposed to the respective raceway surfaces 24, the outer members 21 and the inner members. It is comprised with the double-row rolling element 23 interposed between the track surfaces 24 and 25 of the direction member 22. FIG. The inner member 22 is obtained by fitting a bearing inner ring 22B to the outer periphery of the hub 22A. The bearing inner ring 22B is a divided type in which two inner rings 22B1 and 22B2 are arranged. The rolling elements 23 are formed of balls, and are held by a holder 26 for each row. The raceway surfaces 24 and 25 in each row have an arc shape in cross section, and are formed so that the contact angles are back to back. Both ends of the annular space formed between the outer member 21 and the inner member 22 are sealed with contact-type seals 27 and 28, respectively.

  A brake rotor and a wheel (both not shown) are overlapped and fastened with bolts 40 to a wheel mounting flange 22a at the outer end of the hub 22A on the outboard side. The hub 22 </ b> A has a central hole 29, and a stem portion 43 formed integrally with the outer ring 42 a of the constant velocity joint 42 is inserted into the central hole 29, and a nut screwed into the male screw portion 43 b at the tip of the stem portion 43. 41 is pressed against the opening edge 22 c of the central hole 29. As a result, the constant velocity joint outer ring 42a is pressed to the outboard side with respect to the hub 22A and connected to the hub 22A. When the nut 41 is tightened, the inner ring 22B is clamped and fixed in the axial direction with respect to the hub 22A by pressing the cross-section 42aa of the stem portion 43 of the constant velocity joint outer ring 42a against the width surface of the inner ring 22B2. .

  Also in this example, as in the first embodiment, the ring-shaped detected portion 14 having the magnetic encoder 15 is fitted to the outer periphery between the raceway surfaces 25 of both rows of the inner member 22. Further, a sensor combination body 17 in which the rotation sensor 18 and the displacement sensor 19 are integrated is provided between the raceway surfaces 24 of both rows of the outer member 21 so as to penetrate the outer member 21. The sensor assembly 17 is penetrated through through holes 46 and 47 which are aligned with the knuckle 45 and the outer member 1 in which the outer member 1 is press-fitted and penetrated in the radial direction. Sealing means such as an O-ring is provided between the inner diameter surface of the through hole 46 of the knuckle 45 and the sensor combination 17.

  FIG. 6 shows still another embodiment of the present invention. The wheel bearing device of this embodiment is also of a double row angular ball bearing type, classified as a second generation type, and is for driving wheel support. The wheel bearing device includes an outer member 31 having a double row raceway surface 34 on the inner periphery, an inner member 32 having a raceway surface 35 facing each of the raceway surfaces 34, the outer member 31 and the inner member. It is comprised with the double-row rolling element 33 interposed between the track surfaces 34 and 35 of the direction member 32. FIG. The raceway surfaces 34 and 35 in each row have a circular arc cross section, and are formed so that the contact angles are back to back. The rolling elements 33 in each row are formed of balls, and are held by a holder 36 for each row. Both ends of the annular space formed between the outer member 31 and the inner member 32 are sealed by contact seals 37 and 38, respectively.

  The outer member 31 is an integral part and has a vehicle body mounting flange 31a on the outer periphery for fixing to a knuckle (not shown). The inner member 32 includes a hub 32A having a wheel mounting flange 32a on the outer end of the outer board and a bearing inner ring 32B fitted to the outer diameter surface of the hub 32A. The bearing inner ring 32B includes two inner rings 32B1 and 32B2. It is a split type that is arranged in the axial direction. Of the double-row raceway surfaces 35 facing the raceway surface 34 of the outer member 31, the raceway surfaces 35 of each row are provided on the inner rings 32B1 and 32B2 of each row. A brake rotor and a wheel (both not shown) overlap and are fastened and fixed with bolts 40 to a wheel mounting flange 32a at the outer end of the hub 32A on the outboard side.

The hub 32A has a central hole 39. Similarly to the example of FIG. 5, a stem portion 43 formed integrally with the outer ring 42a of the constant velocity joint 42 is inserted into the central hole 39, and a male screw at the tip of the stem portion 43 is inserted. The nut 41 screwed into the portion 43 b is pressed against the end face 32 c of the central hole 39. Accordingly, the constant velocity joint outer ring 42a is pressed to the outboard side with respect to the hub 32A and is connected to the hub 32A. When the nut 41 is tightened, the inner ring 32B is clamped and fixed in the axial direction with respect to the hub 32A by pressing the base end section 42aa of the stem portion 43 of the constant velocity joint outer ring 42a against the width surface of the inner ring 32B2. .
A ring-shaped detected portion 14 having a magnetic encoder 15 is fitted on the outer periphery between the raceway surfaces 35 of both rows of the inner member 32, and between the raceway surfaces 34 of both rows of the outer member 31. The sensor combination 17 in which the rotation sensor 18 and the displacement sensor 19 are integrated is provided through the outer member 31 as in the case of the first embodiment.

  FIG. 7 shows still another embodiment of the present invention. The wheel bearing device of this embodiment is also of a double row angular ball bearing type and is classified as a fourth generation type and is for driving wheel support. In the wheel bearing device according to the first embodiment shown in FIG. 1, instead of forming the raceway surface 5 of the inboard side row on the inner ring 2B fitted to the outer periphery of the hub wheel 2A, the inner ring 2B is replaced with the inner ring 2B. An inboard side raceway surface 5 is formed on the outer diameter surface of the constant velocity joint outer ring 12a. The inboard-side seal 8 is disposed between the inner diameter surface of the outer member 1 and the constant velocity joint outer ring 12a. The constant velocity joint outer ring 12a is connected to the hub wheel 2A by inserting the stem portion 13 into the center hole 9 of the hub wheel 2A and performing spline fitting. Other configurations are the same as those in the first embodiment.

  In each of the above embodiments, the case where the present invention is applied to a wheel bearing device for supporting a driving wheel has been described. However, the present invention is also applicable to a wheel bearing device for supporting a driven wheel.

It is sectional drawing of the wheel bearing apparatus concerning 1st Embodiment of this invention. It is an expanded sectional view of the B section in FIG. It is a cross-sectional view which shows the upper half part of the to-be-detected part provided in the bearing apparatus for wheels. It is an expanded sectional view showing other examples of composition of the detected part. 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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer member 2 ... Inner member 3 ... Rolling bodies 4, 5 ... Track surface 7, 8 ... Seal 14 ... Detected part 15 ... Magnetic encoder 16 ... Core metal 16a ... Groove-shaped part 16b ... Overhang part 17 ... Sensor combination 18 ... rotation sensor 19 ... displacement sensor 21 ... outer member 22 ... inner member 23 ... rolling elements 24 and 25 ... raceway surfaces 27 and 28 ... seal 31 ... outer member 32 ... inner member 33 ... rolling element 34, 35 ... raceway surfaces 37, 38 ... seals

Claims (4)

An outer member having a double-row raceway surface on the inner periphery, an inner member having a double-row raceway surface facing these raceway surfaces, a double-row rolling element interposed between the opposing raceway surfaces, and the outer A wheel bearing device that includes sealing means for sealing both ends of the annular space between the side member and the inner member, and supports the wheel rotatably with respect to the vehicle body.
An annular detected portion having a magnetic encoder is provided on the outer periphery of the inner member between the double-row track surfaces, and a rotation sensor facing the magnetic encoder and a displacement sensor facing the detected portion are integrated. A wheel bearing device, wherein a sensor combination is provided on the outer member.   2. The detection target according to claim 1, wherein the detected portion includes the magnetic encoder and a metal core that supports the encoder, and the metal core includes a groove-shaped portion in which the magnetic encoder is provided, and an opening of the groove-shaped portion. It has a cross-sectional hat shape that has an overhanging portion that protrudes from the edge to both sides, the rotation sensor is disposed to face the magnetic encoder, and the displacement sensors are respectively opposed to the overhanging portions on both sides of the cored bar. Two wheel bearing devices arranged as described above.   The wheel bearing device according to claim 1, wherein the displacement sensor is arranged to face the magnetic encoder. The wheel bearing device according to any one of claims 1 to 3, wherein the sensor combination is a resin mold of the rotation sensor and the displacement sensor.

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