JP2008267422A - Wheel bearing with bidirectional communication function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing using various sensors, when provided on the rotation side, for detecting a rotation position on the rotation side to permit determination with sensor information and rotation position infiormation combined, while making bidirectional communication between the rotation side and the fixation side during rotation or rotation stop, whichever, reducing the number of components, improving a degree of freedom in design, and facilitating wiring. <P>SOLUTION: Double row rolling elements 5 are laid between an outward member 1 as a fixed ring and an inward member 2 as a rotary ring. A bidirectional communication means 21 is provided for making bidirectional communication in no contact between the outward member 1 and the inward member 2. A rotation sensor 82 is provided on the inward member 2 as the rotary ring. The bidirectional communication means 21 has a primary coil 22 installed on the fixed ring and a secondary coil 24 installed on the rotary ring, e.g., so that an alternating current is applied thereto for transmitting electric power or data with electromagnetic induction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a wheel bearing with a bidirectional communication function having a bidirectional communication function for exchanging signals and electric power between a rotating wheel and a fixed wheel, and a function for detecting a rotational position of the rotating wheel. .

  In recent years, various sensors have been provided on the rotation side in order to improve the stability of automobiles. For example, tire abnormality detection devices that detect abnormalities in tires and issue warnings to drivers when necessary are being actively developed. As a specific example, a structure (Patent Document 1) provided with a load sensor on the rotation side as means for detecting the tire contact force, and a number of temperature sensors in the tire as means for detecting the state of wear of each part of the tire. A structure (Patent Document 2) is proposed. In addition to this, a structure in which a strain gauge is provided on a hub flange or the like has been proposed for measuring the torque applied to the drive wheel during braking (Patent Document 3). As described above, when the sensor is installed on the rotation side, it is necessary to supply power for driving the sensor and the transmitter to the rotation side.

In order to meet such a demand, there has been proposed one having a power generation plate that generates power by generating a shape deformation due to a change in air pressure inside the tire (Patent Document 4). Further, a tire power supply device has been proposed in which an electromagnetic coil is provided on the tire rotation side and a magnetic field generating means is provided on the non-rotation side (Patent Document 5). Further, a wheel bearing device in which a power generation device is incorporated in a wheel bearing has been proposed (Patent Document 6). A bearing with a non-contact signal transmission mechanism in which a non-contact signal transmission mechanism is provided on the bearing has also been proposed (Patent Document 7). In addition, there is a means for supplying power to the rotating side by a method such as slip ring or wireless power feeding.
JP-A-2005-082010 JP 2005-212696 A JP 2003-246201 A JP 2006-329772 A JP 2006-232195 A JP 2002-055113 A JP 2002-130262 A

  In each of the structures of Patent Documents 1 to 3, a sensor is provided in the rotating unit, and the sensor output value varies depending on the rotational position. Therefore, in order to perform detection and determination with high accuracy, it is necessary to have rotational position information. Although it is conceivable that the sensor has a function of detecting the rotational position alone, in that case, the structure of the sensor becomes complicated and difficult to realize.

  In addition, the power generation apparatus according to Patent Document 4 that generates power by changing the air pressure of the tire, the tire power supply device provided with the electromagnetic coil on the rotating side and the magnetic field generating means on the non-rotating side of Patent Document 5, and the wheel bearing of Patent Document 6 Any device incorporating a power generator can only supply power to the rotating side. For this reason, it is necessary to provide a means for transmitting the sensor output separately by light, wireless, or the like, which increases the number of parts and reduces the degree of freedom in design. In Patent Document 6, power is generated by a wheel bearing, but it is not used as power supply or communication means to the rotating side. Moreover, as for the structure of patent documents 4-6, all can supply electric power only during rotation. In the configuration of Patent Document 7, since no connector is mounted, wiring on the rotation side is difficult. In addition, when the slip ring is used, friction and wiring are problematic.

  The object of the present invention is to detect the rotation position on the rotation side when various sensors are provided on the rotation side, and to make a judgment combining the sensor information and the rotation position information. For bidirectional communication between the rotating side and the fixed side, the number of parts can be reduced and the degree of freedom in design can be improved. Communication can be performed regardless of whether rotating or stopped, and wiring is easy. It is an object of the present invention to provide a wheel bearing with a bidirectional communication function that does not have a problem of an increase in friction.

  The wheel bearing with bidirectional communication function according to the present invention includes a fixed wheel having a double-row rolling surface, a rotating wheel having a rolling surface facing the rolling surface of the fixed wheel, and an opposing rolling wheel. In a wheel bearing having a double row rolling element interposed between running surfaces and rotatably supporting a wheel with respect to a vehicle body, non-contact communication is performed in a non-contact manner between the fixed wheel and the rotating wheel. A bidirectional communication means is provided, and a connector connected to the bidirectional communication means is provided on one or both of the fixed wheel and the rotating wheel, and a rotational position of relative rotation of the rotating wheel with respect to the fixed wheel is detected. A rotation sensor is provided on the rotating wheel or the fixed wheel.

  According to this configuration, the following actions are obtained. That is, when a load or other state detection sensor is mounted on the rotation side, there are cases where it is desired to know the position during rotation, but the rotation position is determined from the rotation sensor provided on the fixed ring or the rotation ring. Can be given. As a result, it is not necessary for the state detection sensor to have a function of detecting the rotational position alone, and the waste of the system can be saved. When combining the information of the sensor for detecting the state and the rotational position information, for example, it is possible to detect the unbalance of the wheel, the position of the abnormal sound generated at a specific location, etc., and the characteristics depending on the rotational position and the rotational speed. Correction processing can be performed in the case of different sensors.

In addition, since the bidirectional communication means for performing bidirectional communication between the fixed wheel and the rotating wheel is provided, the signal of the sensor attached to the rotating side of, for example, a tire is transmitted to the fixed side via the bidirectional communication means. Thus, it is not necessary to provide means for wirelessly transmitting the sensor signal. Even if there are a large number of sensors, it is possible to send data to the bus collectively by a relay device, so that only the necessary number of sensors can be connected with a small number of wires. In this case, for example, communication data may be exchanged by using an interface based on a serial communication protocol such as a CAN (Controller Area Network) bus. Further, by using the bidirectional communication means, it is possible to easily supply power from the fixed side to the rotating side. Unlike the generator, the bidirectional communication means can supply electric power without rotating. Therefore, a wireless power feeding function, a battery, a single power generation function, and the like necessary for a sensor attached to a tire or the like can be eliminated. Further, since the connector is provided on at least one of the fixed wheel and the rotating wheel, wiring on the wheel bearing and the vehicle body side or wiring on the wheel bearing and the tire or wheel side is facilitated. Wiring can be performed even after the wheel bearing is incorporated into the vehicle body or wheel, so that assembly is facilitated. Since the bidirectional communication means performs non-contact communication, there is no problem of increased friction.
In this way, communication can be performed in both directions between the rotating side and the fixed side, reducing the number of parts and improving the degree of freedom of design. In addition, communication can be performed during rotation and when rotation is stopped, and wiring is easy. Also, the problem of increased friction for communication does not occur.
When the rotation sensor is provided on the rotating wheel side, when the detection signal is processed in combination with a state detection sensor provided on the rotation side, the signal processing is easy and an error is not easily generated.

In the present invention, the rotation sensor may have a function of outputting a rotation pulse generated at every fixed rotation angle and one zero-phase signal for one rotation of the rotating wheel. The rotation sensor may output an absolute angle signal.
When the absolute angle signal is obtained, the absolute angle is accurately detected without performing the initialization process. Therefore, when the sensors are provided on the tire or the wheel, various detections specifying the circumferential direction portion can be performed.

In the present invention, the rotating wheel may have a connector, and the connector may be connected to the bidirectional communication means and the rotation sensor. In addition, this connector does not need to be fixed to the rotating wheel, and may be pulled out via wiring.
When the bidirectional communication means and the rotation sensor are connected to the connector provided on the rotating wheel, wiring and assembly can be performed more easily.

  In this invention, the bidirectional communication means includes a primary coil wound around a core provided on the fixed wheel and a secondary coil wound around a core provided on the rotating wheel, and the primary coil A magnetic circuit may be constituted by the coil and the secondary coil. A so-called rotary transformer is used. Thereby, it becomes a structure suitable for the wheel bearing which has the rotating wheel which is a rotary body.

  As described above, when the primary coil and the secondary coil are used, the bidirectional communication unit may perform data communication and power transmission at different frequencies. For example, power transmission is performed on the low frequency side, and data transmission is performed on the high frequency side. Thereby, communication of data and electric power can be performed using a common primary coil and secondary coil.

  The wheel bearing with bidirectional communication function according to the present invention includes a fixed wheel having a double-row rolling surface, a rotating wheel having a rolling surface facing the rolling surface of the fixed wheel, and an opposing rolling wheel. In a wheel bearing having a double row rolling element interposed between running surfaces and rotatably supporting a wheel with respect to a vehicle body, non-contact communication is performed in a non-contact manner between the fixed wheel and the rotating wheel. A bidirectional communication means is provided, and a connector connected to the bidirectional communication means is provided on one or both of the fixed wheel and the rotating wheel, and a rotational position of relative rotation between the fixed wheel and the rotating wheel is detected. Since the rotation sensor is provided on the fixed wheel or the rotation wheel, when various sensors are provided on the rotation side, the rotation position can be detected on the rotation side, and the sensor information and the rotation position information are obtained. A combination judgment or the like is possible. In addition, bi-directional communication between the rotating side and the fixed side is possible, reducing the number of parts and improving the degree of freedom of design, enabling communication regardless of whether rotating or stopped, and easy wiring. Therefore, there is an effect that the problem of increased friction due to the friction does not occur.

An embodiment of the present invention will be described with reference to FIGS. 1 is a cross-sectional view taken along the line I-O-I 'of FIG. This embodiment is a third generation inner ring rotating type and is applied to a wheel bearing for driving wheel support. In this specification, the side closer to the outer side in the vehicle width direction of the vehicle 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.
As shown in a cross-sectional view in FIG. 1, the bearing for the wheel bearing with bidirectional communication function is opposed to the outer member 1 in which a double row rolling surface 3 is formed on the inner periphery, and the respective rolling surfaces 3. The inner member 2 in which the rolling surface 4 to be formed is formed, and the outer member 1 and the double row rolling elements 5 interposed between the rolling surfaces 3 and 4 of the inner member 2. This wheel bearing is a double-row angular ball bearing type, and the rolling elements 5 are made of balls and are held by a cage 6 for each row. The rolling surfaces 3 and 4 have a circular arc shape in cross section, and the rolling surfaces 3 and 4 are formed so that the contact angles are aligned with the back surface. Both ends of the bearing space between the outer member 1 and the inner member 2 are respectively sealed by seals 7 and 8 serving as sealing devices.

The outer member 1 is a fixed wheel, and has a flange 1a for mounting a vehicle body attached to a knuckle in a suspension device (not shown) of the vehicle body on the outer periphery, and the whole is an integral part. Bolt holes 14 for mounting the vehicle body are provided in the flange 1a at a plurality of locations in the circumferential direction.
The inner member 2 is a rotating wheel, and includes a hub wheel 9 having a hub flange 9a for attaching the wheel, and an inner ring 10 fitted to the outer periphery of the inboard side end of the shaft portion 9b of the hub wheel 9. The hub wheel 9 and the inner ring 10 are formed with the rolling surfaces 4 of the respective rows. An inner ring fitting surface 12 having a small diameter with a step is provided on the outer periphery of the inboard side end of the hub wheel 9, and the inner ring 10 is fitted to the inner ring fitting surface 12. A through hole 11 is provided at the center of the hub wheel 9. The hub flange 9a is provided with press-fit holes 16 for hub bolts at a plurality of locations in the circumferential direction. In the vicinity of the base portion of the hub flange 9a of the hub wheel 9, a cylindrical pilot portion 13 for guiding a wheel and a braking component (not shown) protrudes toward the outboard side.

  The wheel bearing is provided with bidirectional communication means 21 for transmitting electric power in a non-contact manner between the outer member 1 which is a fixed wheel and the inner member 2 which is a rotating wheel, and the outer member which is a fixed wheel. A rotation detector 80 is provided for detecting a rotational position of relative rotation between the inner member 2 which is a rotating wheel 1 and the inner ring 2. The bidirectional communication means 21 is disposed between the double row rolling surfaces 3 and 3 (4, 4) in the bearing space between the outer member 1 and the inner member 2. The rotation detector 80 is provided between the rolling surfaces 3 and 4 in the outboard side row and the seal 7 on the outboard side in the bearing space.

The rotation detector 80 is attached to the detected body 81 attached to the inner peripheral surface of the outer member 1 which is a fixed ring, and detects the detected body 81 attached to the outer peripheral surface of the inner member 2 which is a rotating ring. And a rotation sensor 82. The rotation detector 80 only needs to be able to detect the rotational position of the relative rotation of the inner member 2 with respect to the outer member 1, and may be of any type such as a magnetic type or an optical type. Considering the influence of muddy water, dust and the like that has entered from the magnetic field, the magnetic type is preferable.
The rotation detector 80 may simply output a pulse train by rotation. In addition, the rotation detector 80 has a function of outputting a zero-phase signal once per rotation of the rotating wheel, or an absolute angle signal. Is used.
Specific examples of the rotation detector 80 will be described later with reference to FIGS.

  The bidirectional communication means 21 includes a primary coil 22, a stator core 23, a secondary coil 24, a rotor core 25, and wirings 26 and 27. The primary coil 22 and the secondary coil 24 are provided so as to constitute one magnetic circuit. The stator core 23 is made of a ring-shaped member having a groove on the inner diameter surface, and a primary coil 22 is wound in the groove. The rotor core 25 is made of a ring-shaped member having a groove on the outer diameter surface, and a secondary coil 24 is wound in the groove. A part of the stator core 23 and the rotor core 25 is provided with a wiring hole (not shown) for passing wiring. The stator core 23 and the primary coil 22 are in the radial direction on the inner diameter surface of the outer member 1 that is a fixed ring, and the rotor core 25 and the secondary coil 24 are on the outer diameter surface of the inner member 2 that is a rotating wheel. It is installed so as to face. The stator core 23 and the rotor core 25 are fixed to the outer member 1 and the inner member 2 by a method such as press fitting or adhesion. In order to position the stator core 23 and the rotor core 25 in the axial direction, a step, a protrusion (not shown), or the like may be provided on the inner diameter surface of the outer member 1 or the outer diameter surface of the inner member 2.

  The outer member 1 that is a fixed ring is provided with a wiring hole 28 through which the wiring 26 connected to the primary coil 22 passes from the inner diameter surface to the outer diameter surface. The hub wheel 9 of the inner member 2 that is a rotating wheel is provided with a wiring hole 29 through which the wiring 27 connected to the secondary coil 24 passes from the outer diameter surface to the inner diameter surface. A wiring groove 30 is provided in a part of the wiring groove 27 so as to extend the wiring 27 in the axial direction. When assembling the primary coil 22 and the stator core 23, the wire 26 may be fitted to the inner diameter surface of the outer member 1 from the axial direction in a state where the wire 26 is passed through the wire hole 28 in advance.

Connectors 31 and 32 for connecting the wirings 26 and 27 to the vehicle body side and the tire or wheel side are provided at the ends of the wirings 26 and 27, respectively. The connector 32 connected to the tire or wheel side is fixed to the end face on the outboard side of the hub wheel 9 in the inner member 2 at an inner diameter portion than the pilot portion 13. The connector 31 for connecting to the vehicle body side is provided in a state where it is not fixed to the outer diameter surface of the outer member 1.
In addition to the above-described wiring 27, a wiring 27A of a rotation sensor 82 of a rotation detector 80 is connected to the tire / wheel side connector 32. The wiring 27A is a wiring that supplies power to the rotation sensor 82 and outputs a signal. The wiring 27A is inserted into a wiring hole 29A provided in the inner member 2 so as to penetrate in the axial direction at the attachment position of the rotation sensor 82. The wiring hole 29A has an inner diameter side end opened to the wiring groove 30.

  The connectors 31 and 32 are the above-described wirings 26 and 27, which are a power line when supplying power from the fixed side to the rotating side, and a signal line when transmitting output signals from the state detecting sensor 90 and the like from the rotating side to the fixed side. Connected. Both the power line and the signal line may be connected.

The connectors 31 and 32 are one of plug-in connector pairs in which a pair of connectors are inserted and connected to each other, and may be either a plug type or a socket type. The connectors 31 and 32 may be multipolar or coaxial.
FIG. 3 is a schematic view showing an example of the connector 32 fixed to the hub wheel 9 and the connector 33 of the tire-side wiring 34 connected to the connector 32.

  The fixed-side connector 31 and the rotary-side connector 32 are connected to the connectors 31 and 32 through the connectors 35 and 33 and their wirings 37 and 34. 38, 39. Via these two-way communication auxiliary means 38 and 39, they are connected to the power source, the state detection sensor 90 and the like.

The bidirectional communication auxiliary means 38, 39 is an electric circuit or the like for performing bidirectional communication by causing the bidirectional communication means 21 to function, for example, means for generating an alternating voltage for transmitting electric power, or transmitting data. Processing such as generation of a carrier wave to be performed and superimposition of a signal on the carrier wave are performed.
For example, an example in which electric power is transmitted from the fixed side to the rotating side and data of the state detection sensor 90 is transmitted from the rotating side will be described. In this case, the fixed-side bidirectional communication assisting means 38 includes an alternating current generating function unit that converts a direct current of a power source (not shown) into an alternating current having a frequency for transmission via the bidirectional communication means 21. , And a demodulating means for extracting a signal component from the received current. The bidirectional communication means 39 on the rotation side includes a rectifying means for converting the received alternating current into a direct current for use as a power source for the state detection sensor 90, and a modulation means for superimposing the output signal of the state detection sensor 90 on the carrier wave. It is supposed to have.
In this example, the two-way communication auxiliary means 38 and 39 perform data communication and power transmission at different frequencies. In this case, power is performed on the low frequency side and data is performed on the high frequency side.

When a large number of state detection sensors 90 are provided on the rotation side, a relay device is provided in the bidirectional communication auxiliary means 39 on the rotation side, and the relay device receives communication data such as a plurality of sensor outputs by serial communication. Provide an interface. As this interface, for example, a serial communication protocol such as CAN is used. The fixed-side bidirectional communication auxiliary means 38 is provided with means for extracting a signal transmitted by serial communication as an output of each state detection sensor 90.
The fixed-side bidirectional communication auxiliary means 38 may be provided independently, or may be incorporated in an electric control unit (ECU) of an automobile. Further, the bidirectional communication assisting means 39 on the rotation side may be provided independently or may be assembled as an integral part of the state detection sensor 90.

  Further, a confirmation means 49 for confirming whether or not the communication by the bidirectional communication means 21 is normally established may be provided. The confirmation means 49 may be provided, for example, in the fixed-side bidirectional communication auxiliary means 38, or may be provided in the fixed-side connector 31 or between the connector 31 and the primary coil 22.

  The state detection sensor 90 connected to the rotation-side connector 32 is, for example, a tire air pressure sensor, a tire abnormality detection sensor, a load sensor, or the like. The state detection sensor 90 has, for example, a detection result corresponding to the wheel rotation position and a function of correcting the output using the rotation position detected by the rotation sensor 82.

In FIG. 1, as a specific example of providing a plurality of the state detection sensors 90, for example, as a tread sensor serving as a tire contact force detecting means, a pressure sensitive sensor such as a pressure sensitive conductive rubber body is provided on the tread portion of the tire. In addition, a plurality of them are embedded in the tire width direction and the circumferential direction. In addition, there is an example in which a plurality of temperature sensors are provided in the tire in order to detect tire abnormality. In addition to this, there are an example in which strain gauges are provided at a plurality of locations on a tire and a wheel, and an example in which vibration sensors and the like are provided at each part of the tire.
In addition to sensors, the connector 32 may be connected to an IC tag embedded in a tire or a wheel.

A specific example of the rotation detector 80 will be described. FIG. 5 shows an example of a rotation detector 80 with a zero-phase signal output. In this example, a ring-shaped first detected body 81a shown in FIG. 5A and a ring-shaped second detected body 81b shown in FIG. It is provided side by side in the direction. The first detected body 81a is composed of a multipolar magnet provided with magnetic poles N and S alternately in the circumferential direction. The second detected body 81b is provided with a magnetic pole at one place in the circumferential direction. The rotation sensor 82 includes first and second magnetic sensors 82a and 82b facing the inner peripheral side of the first detected body 81a, and a zero-phase detecting magnetic sensor facing the second detected body 81b. 82c. The first and second magnetic sensors 82a and 82b are arranged with a phase difference of 90 ° with respect to the magnetic pole pitch of the first detected body 81a. Each of the magnetic sensors 82a to 82c is attached to a ring-shaped sensor attachment member 82d, and attached to the outer peripheral surface of the inner member 2 via the sensor attachment member 82d.
The rotation detector 80 configured as shown in the figure detects the magnetic pole of the first detected object 81a and generates a rotation pulse when the first and second magnetic sensors 82a and 82b rotate together with the rotating wheel. Since the first and second magnetic sensors 82a and 82b generate rotation pulses having phases different from each other by 90 °, the rotation direction is also detected by using the outputs of both magnetic sensors 82a and 82b. Further, the zero-phase detection magnetic sensor 82c rotates together with the rotating wheel, so that one zero-phase signal is output as a pulse by one rotation of the rotating wheel. By using this zero-phase signal and the rotation pulse, the rotational position of the rotating wheel can be detected as an absolute position.

FIG. 6 shows an example of a rotation detector 80A that outputs an absolute angle signal. The rotation detector 80A is provided in the same manner as described above instead of the rotation detector 80 of FIG. In this example, ring-shaped first and second detected bodies 81Aa and 81Ab shown in FIGS. 1A and 1B are provided side by side in the axial direction as the detected body 81A. The first and second detected bodies 81Aa and 81Ab have magnetic pole pitches different from each other, and magnetic poles N and S are alternately arranged in the circumferential direction. Two magnetic sensors 82A1 and 82A2 constituting the rotation sensor 82A are provided for each of the detected bodies 81Aa and 81Ab.
In the case of the rotation detector 80A having this configuration, when the two magnetic sensors 82A1 and 82A2 rotate together with the rotating wheel, the first and second detected bodies 81Aa and 81Ab are detected to output rotation pulses having different pitches. To do. By processing these two rotation pulses, the absolute angle is detected.

According to the wheel bearing with bidirectional communication function configured as described above, the following actions are obtained. When the state detection sensor 90 for detecting tire air pressure, tire abnormality, working load, etc. is mounted on the rotation side as described above, it may be desired to know the position during rotation. In this case, the rotational position can be given from the rotation sensor 82 provided on the hub wheel 9 constituting the rotating wheel. As a result, it is not necessary for the state detection sensor 90 to have a function of detecting the rotational position alone, and the waste of the system can be saved. In this case, a signal processing circuit for processing using the detection information of the state detection sensor 90 and the rotation sensor 82 is provided on the state detection sensor 90 or a wiring board used in combination therewith. This signal processing circuit may be provided in the bidirectional communication means 39.
When the sensor information of the state detection sensor 90 and the rotational position information are combined, for example, it is possible to detect an unbalance of the wheel, and it is possible to detect the position of an abnormal sound generated at a specific location. In addition, when a load sensor or a tread sensor is provided as the state detection sensor 90 as described above, processing can be performed using the reference angle of the rotational position obtained from the rotation sensor 82. In the state detection sensor 90, when the characteristic varies depending on the rotation speed, the characteristic difference due to the rotation speed can be corrected by the correction process.
When an IC tag is embedded in a tire or a wheel, information on the product such as the tire or wheel is recorded on the IC tag and is detected via the connector 32 and the bidirectional communication means 21, thereby improving traceability. be able to.

  Further, according to the wheel bearing with bidirectional communication function having the above-described configuration, the bidirectional communication means 21 is provided, so that, for example, power is supplied from the outer member 1 side that is a fixed wheel to the inner member 2 side that is a rotating wheel. In this case, when an AC voltage is applied to the primary coil 22, it is transmitted to the secondary coil 24 as inductive power by the magnetic flux generated in the cores 23 and 25. Therefore, power can be supplied without contact. In this case, unlike the generator, the bidirectional communication means 21 can supply electric power without rotating. Therefore, a wireless power feeding function, a battery, a single power generation function, and the like necessary for a sensor attached to a tire or the like can be eliminated.

  Further, the bidirectional communication means 21 transmits the signal of a sensor (not shown) attached to the rotation side of, for example, a tire to the fixed side via the bidirectional communication means 21, so that the sensor signal is transmitted wirelessly. It is not necessary to provide a means for transmitting. Even if there are a large number of sensors, it is possible to send data to the bus by using a repeater as described above, so that the required number of sensors can be connected with a small number of wires. In that case, the communication data may be exchanged by using an interface based on a serial communication protocol such as a CAN bus as described above.

  Further, by connecting to the tire or wheel via the connector 32, the wiring does not get in the way when the wheel bearing is installed on the wheel, and the wiring in the tire can be performed even before the wheel bearing is installed. It becomes possible. As the connectors 31 and 32, it is preferable to use a connector that is waterproof in a plugged connection state that is in a fitted state. By doing so, it can be used even under poor conditions such as undercarriage of automobiles. The wiring 27 on the hub wheel 9 side is preferably fixed in the wiring groove 30. Then, when the constant velocity joint is assembled, the wiring 27 does not get in the way and can be assembled without being disconnected. If parts of the wiring holes 28 and 29 and the wiring groove 30 are molded with a molding resin (not shown) or the like, water or the like can be prevented from entering the bearing. The primary coil 22 and the secondary coil 24 may be covered with a cover (not shown) made of resin or the like that serves as a protective partition, thereby protecting the coils 22 and 24.

  In this embodiment, a rotary transformer structure composed of a primary coil 22 and a secondary coil 24 is shown as the bidirectional communication means 21, but the bidirectional communication means 21 is non-contact data communication and power supply. In addition, the power may be transmitted using infrared rays, light, radio waves, ultrasonic waves, capacitive coupling, magnetic coupling, or the like. However, in the case of a rotating body such as a wheel bearing, a rotary transformer structure like this embodiment is considered suitable.

FIG. 4 shows still another embodiment of the present invention. In this wheel bearing with bidirectional communication function, the bidirectional communication means 21 includes a primary coil for transmission 22 a and a primary coil for reception 22 b provided on the stator core 23, and a secondary coil for transmission provided on the rotor core 25. 24a and the receiving secondary coil 24b.
The stator core 23 is a ring-shaped member having two grooves on the inner periphery, and a primary coil for transmission 22a and a primary coil for reception 22b are accommodated in each groove, and the primary for transmission and reception are contained therein. The coils 22a and 22b are common. The rotor core 25 is a ring-shaped member having two grooves on the outer periphery, and a secondary coil for transmission 24a and a secondary coil for reception 24b are accommodated in each groove, and these primary coils for transmission and reception. 24a and 24b are common.

  The stator core 23 is attached to the inner peripheral surface of the outer member 1 that is a fixed wheel, and the rotor core 25 is attached to the outer peripheral surface of the hub wheel 9 constituting the rotating wheel. The primary coil for transmission 22a of the stator core 23 and the secondary coil for transmission 24a of the rotor core 25 are opposed to each other to form a magnetic circuit, and the primary coil for reception 22b of the stator core 23 and the secondary coil for reception of the rotor core 25 are received. 24b face each other to constitute a magnetic circuit.

  The fixed-side wiring 26 has a power wiring and a data wiring. The power wiring is connected to the transmission primary coil 22a, and the data wiring is connected to the reception primary coil 22b. The rotation-side wiring 27 has a power line and a signal line, the power line is connected to the secondary coil for transmission 24a, and the signal line is connected to the secondary coil for reception 24b.

Moreover, in this embodiment, the rotation detector 80 is installed between the outer member 1 and the inner member 2 next to the bidirectional communication means 21. The rotation detector 80 includes a detection object 81 provided on the outer periphery of the inner member 2 that is a rotating wheel, and a rotation sensor 82 attached to the inner periphery of the outer member 1 that is a fixed wheel. The wiring 26A of the rotation sensor 82 is connected to the primary coil 22a (or 22b) of the bidirectional communication means 21. The wiring 26 </ b> A is inserted into a wiring hole 26 </ b> A provided in the outer member 1. As the rotation detector 80, for example, the rotation detectors 80 and 80A shown in FIG. 5 and FIG.
In this embodiment as well, as in the first embodiment, the rotation sensor 82 may be provided on the inner member 2 side that is a rotating wheel.

  In this embodiment, electric power is transmitted between the primary coil 22a and the secondary coil 24a, and data is transmitted between the primary coil 22b and the secondary coil 24b. Other configurations in this embodiment are the same as those in the first embodiment.

In each of the above embodiments, the two-way communication means 21 is disposed between the double row rolling surfaces 3 and 3 or at the outboard side end of the wheel bearing device. Bi-directional communication means 21 may be provided to supply power and transmit output signals to the sensor installed at the constant velocity joint. In that case, the primary coil 22 may be provided on the inboard side end surface of the outer member 1 serving as a fixed ring, and the secondary coil 24 may be provided on the inner ring 10.
In each of the above embodiments, the outer member 1 is a fixed ring, but the present invention can also be applied to a wheel bearing device in which the inner member is a fixed ring and the outer member is a rotating wheel.
Furthermore, this invention can be applied not only to wheel bearings for driving wheels but also to wheel bearings for driven wheels.

It is sectional drawing of the bearing for wheels with a bidirectional | two-way communication function concerning 1st Embodiment of this invention. It is the side view which looked at the same bearing for wheels with a bidirectional communication function from the inboard side. It is the schematic which shows an example of a connector. It is sectional drawing which shows other embodiment of this invention. (A), (B) is a partial side view of each part which shows an example of a rotation detector, respectively. (A), (B) is a partial side view of each part which shows another example of a rotation detector, respectively.

Explanation of symbols

1. Outer member (fixed ring)
2 ... Inward member (rotating wheel)
3, 4 ... rolling surface 5 ... rolling element 21 ... bi-directional communication means 22 ... primary coil 23 ... stator core 24 ... secondary coil 25 ... rotor cores 26, 27 ... wiring 28, 29 ... wiring hole 30 ... wiring groove 31, 32 ... Connectors 38, 39 ... Bidirectional communication auxiliary means 80, 80A ... Rotation detectors 81, 81A ... Detected bodies 82, 82A ... Rotation sensors

Claims (8)

A fixed ring having a double row rolling surface, a rotating wheel having a rolling surface facing the rolling surface of the fixed wheel, and a double row rolling element interposed between the facing rolling surfaces. In the wheel bearing that supports the wheel rotatably with respect to the vehicle body,
Bidirectional communication means for bidirectionally communicating in a non-contact manner is provided between the fixed wheel and the rotating wheel, and one or both of the fixed wheel and the rotating wheel are connected to the bidirectional communication means. A wheel bearing with bidirectional communication function, characterized in that a rotation sensor for providing a connector and detecting a rotational position of relative rotation of the rotating wheel with respect to the fixed wheel is provided on the rotating wheel or the fixed wheel.   2. The wheel bearing according to claim 1, wherein the rotation sensor is provided on the rotating wheel.   3. The bidirectional communication function according to claim 1, wherein the rotation sensor has a function of outputting a rotation pulse generated at every fixed rotation angle and a zero-phase signal for one rotation of the rotating wheel. Wheel bearing.   3. The wheel bearing with bidirectional communication function according to claim 1, wherein the rotation sensor outputs an absolute angle signal.   5. The wheel bearing with a bidirectional communication function according to claim 1, wherein the rotating wheel has a connector, and the connector is connected to the bidirectional communication means and the rotation sensor.   6. The bidirectional communication device according to claim 1, wherein the bidirectional communication means is wound around a primary coil wound around a core provided on the fixed wheel and a core provided on the rotating wheel. A bearing for a wheel with a bidirectional communication function, comprising a secondary coil, wherein the primary coil and the secondary coil constitute a magnetic circuit.   7. The wheel bearing with bidirectional communication function according to claim 6, wherein the bidirectional communication means performs data communication and power transmission at different frequencies.   The fixed-side bidirectional communication auxiliary means according to any one of claims 1 to 7, further comprising means for generating an AC voltage for transmitting electric power from the fixed wheel side to the rotating wheel side in the bidirectional communication means. Rotating-side bidirectional communication auxiliary means having means for generating a carrier wave for transmitting data from the rotating wheel side to the fixed wheel side and superimposing a signal on the carrier wave is provided in the bidirectional communication means. Wheel bearing with bidirectional communication function.

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