JP2006170625A - Bearing with rotation sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing with a rotation sensor hardly influenced by an external noise, hardly generating a damage of a magnetic encoder even when used in a dusty environment, and having excellent reliability. <P>SOLUTION: This bearing is equipped with a rolling bearing 51, the rotation sensor 6A, and a digitizing means for digitizing an output from the rotation sensor 6A. The digitizing means is provided in a wireless sensor unit 4A. The rotation sensor 6A comprises a magnetic encoder 17 mounted on a member 54 on the rotation side between an inward member 54 and an outward member 55, and a magnetic sensor 18 mounted on a member 55 on the fixed side oppositely to the magnetic encoder 17. The magnetic encoder 17 comprises a multipolar magnet 17a on which magnetic poles are formed alternately in the circumferential direction, and a core bar 17b for supporting the multipolar magnet 17a. The multipolar magnet 17a is a sintered body formed by sintering mixed powder of magnetic powder and nonmagnetic metal powder. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bearing with a rotation sensor that is used for bearings in various mechanical equipments, wheel bearings in automobiles, and the like and has a rotation detection function.

  In automobiles and various industrial machines, etc., it has been proposed to perform device control, state management, and the like by providing a rotation sensor on a bearing. Such a sensor output generally transmits a detection signal by wire, but it may be difficult to obtain an appropriate wiring location. In such a case, a wireless sensor system that transmits a detection signal by electromagnetic waves is used. The transmitter is assumed to have a small battery.

  On the other hand, the ABS (Anti-lock Brake System), which controls the braking of a vehicle by detecting the number of wheel rotations with a rotation sensor, prevents accidents due to sensor wire breakage in the tire housing and reduces assembly costs. For this purpose, there has been proposed a wireless type (for example, Patent Document 1) that eliminates a harness between a wheel and a vehicle body and transmits a detection signal as an electromagnetic wave as a rotation sensor. In a typical example of this type of rotation sensor, the power from the vehicle body to the rotation sensor is detected by simultaneously supplying the sensor power and the transmitter power by self-power generation and the rotation speed detection using a multipolar rotary generator. It is comprised compactly, without performing supply (for example, patent document 2).

Patent Document 3 is an invention in which a self-diagnosis circuit is provided in a wheel bearing with a rotation sensor that wirelessly transmits, and it is assumed that the power supply of the sensor and the wireless transmitter is performed by a generator that also functions as a rotation sensor. However, it also touches on wireless power supply.
Patent Document 4 proposes to digitize and transmit a sensor signal. A battery or a generator is used as the power source.

In addition, as a magnetic encoder used for a wheel bearing and detecting a wheel rotation speed, the magnetic encoder includes a multipolar magnet in which magnetic poles are alternately formed in a circumferential direction, and a core metal that supports the multipolar magnet. There has been proposed a polar magnet made of a sintered body obtained by sintering a mixed powder of magnetic powder and non-metallic magnetic powder (for example, Patent Document 5). A multi-pole magnet formed of a sintered body obtained by sintering a mixed powder of magnetic powder and non-metallic magnetic powder can secure a magnetic force that enables stable sensing, and can be made of a conventional rubber magnet. Compared to the above, there are advantages that the surface hardness is hard and damage due to dust biting is less likely to occur. In addition, the multi-pole magnet made of a sintered body of this mixed powder is superior in strength compared to a multi-pole magnet obtained by sintering only magnetic powder, and unlike other multi-pole magnets, There is an advantage that the mounting can be easily performed by caulking or the like.
JP2002-151090 JP 2002-55113 A JP 2003-146196 A JP 2003-58976 A JP 2003-85536 A

In a conventional bearing with a rotation sensor, the output of the rotation sensor is transmitted as an analog signal. However, analog signals are easily affected by disturbance noise, which is insufficient in terms of system reliability. In particular, the problem of the influence of the disturbance noise is large when transmitting wirelessly.
In addition, conventional rubber magnets, etc., used for the magnetic encoder of the rotation sensor have low surface hardness, so that they are subject to dust, such as under the road surface when applied to wheel bearings. When used in, it is easily damaged and lacks reliability.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable bearing with a rotation sensor that is not easily affected by disturbance noise and that is not easily damaged by a magnetic encoder even when used in a dusty environment.

  The bearing with a rotation sensor according to the present invention includes a rolling bearing in which rolling elements are interposed between rolling surfaces provided on the outer periphery of the inner member and the inner periphery of the outer member, and the inner member and the outer member. A rotation sensor comprising a magnetic encoder attached to a rotation-side member, a magnetic sensor attached to a fixed-side member facing the magnetic encoder, and the magnetic sensor provided on the fixed-side member Digitizing means for digitizing the sensor signal output from the magnetic encoder, wherein the magnetic encoder comprises a multipolar magnet having magnetic poles alternately formed in the circumferential direction, and a cored bar that supports the multipolar magnet, The multipolar magnet is a sintered body obtained by sintering a mixed powder of magnetic powder and nonmagnetic metal powder.

  According to this configuration, since the digitizing means is provided and the sensor signal output from the magnetic sensor is digitized, it is difficult to be influenced by disturbance noise, and the reliability is improved. In addition, since a sintered body obtained by sintering a mixed powder of magnetic powder and nonmagnetic metal powder is used as the multipolar magnet of the magnetic encoder, the surface hardness is high and damage due to dust biting is less likely to occur. From the point of view, reliability is improved. Thus, the combination of the digitizing means and the use of the multi-pole magnet of the magnetic encoder as a sintered body of the mixed powder makes it possible to ensure a high degree of reliability.

  The rotation sensor may be arranged at an end of the rolling bearing. When the rotation sensor is arranged at the end, it can be easily attached to the rolling bearing. Unlike the case where it is arranged in the bearing, if it is arranged at the end, the rotation sensor will be exposed to the outside unless another sealing means is provided, but even in such a case, the multipolar magnet of the magnetic encoder Since it is a sintered body of the above mixed powder, it is difficult to cause damage due to dust biting and the like, and reliability can be ensured.

In the present invention, a sensor signal transmission unit that wirelessly transmits a sensor signal digitized by the digitizing means may be provided on a fixed member of the inner member and the outer member.
When the sensor signal is transmitted wirelessly, there is an advantage that no wiring is required, but it is easily affected by disturbance noise. However, since the digitizing means is provided, the wireless transmission is hardly affected by disturbances and is highly reliable.

When the sensor signal transmission unit is provided, a power reception unit that wirelessly receives the operation power for driving the rotation sensor and the sensor signal transmission unit may be provided on the fixed member.
When the power receiving unit that wirelessly receives the operating power is provided, it is not necessary to provide a primary battery or a generator, and the configuration can be made compact. Also, unlike the power generation type, operating power can be obtained even when rotation is stopped. When performing wireless power feeding, it is necessary to avoid interference with the sensor signal. However, since the sensor signal is digitized and transmitted by the digitizing means, there is no fear of interference.

The bearing with a rotation sensor of the present invention can be applied to a wheel bearing. That is, this bearing with a rotation sensor, in any one of the configurations of the present invention, the rolling bearing,
An outer member having a double-row rolling surface, an inner member having a rolling surface facing the rolling surface, and a plurality of rolling elements interposed between the opposing rolling surfaces, A wheel bearing that rotatably supports the wheel with respect to the vehicle body may be used.
The wheel bearing is located in the tire house and exposed to the road surface, and is in a harsh environment that is easily affected by disturbance noise and stone jumping. Therefore, in combination with the digital means in the present invention to avoid the influence of disturbance noise and to make the multi-pole magnet of the magnetic encoder less susceptible to damage as a sintered body of mixed powder, high reliability is secured. be able to. In particular, when the sensor signal transmitter for wireless transmission and the power receiver for wireless reception are provided when applied to a bearing device for a wheel, the reliability of the sensor signal is eliminated while eliminating the harness between the vehicle body and the wheel. Performance, light weight and compactness of the bearing device can be achieved.

  The bearing with a rotation sensor according to the present invention includes a rolling bearing in which rolling elements are interposed between rolling surfaces provided on the outer periphery of the inner member and the inner periphery of the outer member, and the inner member and the outer member. A rotation sensor comprising a magnetic encoder attached to a rotation-side member, a magnetic sensor attached to a fixed-side member facing the magnetic encoder, and the magnetic sensor provided on the fixed-side member Digitizing means for digitizing the sensor signal output from the magnetic encoder, wherein the magnetic encoder comprises a multipolar magnet having magnetic poles alternately formed in the circumferential direction, and a cored bar that supports the multipolar magnet, Since the multi-pole magnet is a sintered body in which a mixed powder of magnetic powder and non-magnetic metal powder is sintered, it is not easily affected by disturbance noise, and even when used in a dusty environment, the magnetic encoder Damage Only difficult, it is assumed that excellent reliability.

  A bearing with a rotation sensor according to a first embodiment of the present invention and a wireless sensor system using the same will be described with reference to FIGS. In this bearing with a rotation sensor, the rolling sensor 51 is provided with a rotation sensor 6A, and a wireless sensor unit 4A is provided.

The rolling bearing 51 includes a plurality of rolling elements 56 interposed between rolling surfaces provided on the outer periphery of the inner member 54 and the inner periphery of the outer member 55. In this example, the rolling bearing 51 is a deep groove ball bearing. Yes. The inner member 54 and the outer member 55 are members that become an inner ring and an outer ring, respectively. In this specification, the term “inner member” and “outer member” are used to unify terms with the wheel bearing described later. I'm calling. Each rolling element 56 is held by a holder 57. One end of the annular space between the inner member 54 and the outer member 55 is sealed with a seal member 58, and the wireless sensor unit 4A is attached to the other end.
In this rolling bearing 1, the inner member 54 is a rotating member, the shaft 59 is fitted to the inner member 54, and the outer member 55 is fitted in a housing (not shown). Mounted.

The rotation sensor 6 </ b> A includes a magnetic encoder 17 attached to the inner member 54 and a magnetic sensor 18 attached to the outer member 55 so as to face the magnetic encoder 17.
The magnetic encoder 17 includes a ring-shaped multipolar magnet 17a in which magnetic poles N and S are alternately formed in the circumferential direction, and an annular cored bar 17b such as a stepped cylinder that supports the multipolar magnet 17a. The magnetic encoder 17 is attached to the inner member 54 by fitting one end of the metal core 17b into the outer diameter surface of the inner member 54 in a press-fitted state.
The magnetic sensor 18 is a magnetic field sensor, and an active magnetic sensor such as a Hall element type sensor, a fluxgate type magnetic sensor, or an MI sensor can be used in addition to a magnetoresistive element type sensor (referred to as an “MR sensor”). . The magnetic sensor 18 is attached to an annular fixture 18a such as a stepped cylinder together with the wireless sensor unit 4A, and one end of the fixture 18a is fitted into the inner diameter surface of the outer member 55 in a press-fit state. The outer member 55 is attached.

The multipolar magnet 18 of the magnetic encoder 17 is a sintered body obtained by sintering a mixed powder of magnetic powder and nonmagnetic metal powder.
The magnetic powder mixed in the multipolar magnet 14 may be isotropic or anisotropic ferrite powder such as barium-based and strontium-based. These ferrite powders may be granular powders or pulverized powders composed of a wet anisotropic ferrite core. When the pulverized powder made of this wet anisotropic ferrite core is used as a magnetic powder, it is necessary to use a mixed powder with a nonmagnetic metal powder as an anisotropic green body formed in a magnetic field.

  The magnetic powder may be a rare earth magnetic material. For example, samarium iron (SmFeN) magnetic powder and neodymium iron (NdFeB) magnetic powder, which are rare earth magnetic materials, may be used alone. The magnetic powder may be manganese aluminum (MnAl) gas atomized powder.

The magnetic powder may be a mixture of two or more of samarium iron (SmFeN) magnetic powder, neodymium iron (NdFeB) magnetic powder, and manganese aluminum (MnAl) gas atomized powder. For example, the magnetic powder is a mixture of samarium iron (SmFeN) magnetic powder and neodymium iron (NdFeB) magnetic powder, a mixture of manganese aluminum gas atomized powder and samarium iron magnetic powder, and samarium iron. Any of a mixture of a system magnetic powder, a neodymium iron system magnetic powder, and a manganese aluminum gas atomized powder may be used.
Also, for example, when the magnetic force is insufficient with only the ferrite component, the required amount of samarium iron (SmFeN) magnetic powder or neodymium iron (NdFeB) magnetic powder, which is a rare earth magnetic material, is mixed with the ferrite powder to improve the magnetic force It can also be manufactured at a low cost.

  Further, the nonmagnetic metal powder forming the multipolar magnet 14 may be any one of powders of tin, copper, aluminum, nickel, zinc, tungsten, manganese, etc., or nonmagnetic stainless steel metal powder alone (one type). These powders, mixed powders composed of two or more kinds, or alloy powders composed of two or more kinds can be used.

  A wireless sensor system using the wireless sensor unit 4A will be described with reference to FIG. This wireless sensor system includes a plurality of wireless sensor units 4A and 4B and a sensor signal receiver 5 that wirelessly supplies power to the plurality of wireless sensor units 4A and 4B and receives each sensor signal. The number of wireless sensor units is not particularly limited, and may be one or three or more, but FIG. 1 shows the case of two. One wireless sensor unit 4A among the plurality of wireless sensor units 4A and 4B is provided in the bearing with the rotation sensor in FIG.

  Each of the wireless sensor units 4A and 4B includes a rotation sensor 6A and a sensor unit 6B that detect a detection target, a digitizing unit 7 that converts a sensor signal output from the rotation sensor 6A and the sensor unit 6B into a digital signal, Sensor signal transmitting units 9A and 9B that transmit digitized sensor signals wirelessly, power receiving units 8A and 8B that receive driving power transmitted wirelessly, and a power supply circuit 10 are provided.

  Each of the rotation sensor 6A and the sensor unit 6B may be composed of a single sensor or may have a plurality of sensors. The sensor that constitutes the sensor unit 6B may be, for example, the same rotation sensor as the rotation sensor 6A, an acceleration sensor, a temperature sensor, a vibration sensor, a load sensor, a torque sensor, a preload sensor that detects a preload of the bearing, and the like. It may be.

For example, as shown in FIG. 4A, the magnetic sensor 18 in the rotation sensor 6A is disposed at two locations where the phase is approximately 90 ° away from the period of the magnetic change in the circumferential direction of the magnetic encoder 17. The rotation direction may be detected and the rotation direction data may be transmitted in addition to the period data. In this case, rotation signals of two pulse trains (A phase, B phase) whose phases are shifted by approximately 90 ° as shown in FIG.
For example, as shown in FIG. 4C, the rotation direction is detected by comparing the rotation signals of the two pulse trains with a rotation direction detector 7d provided in the digitizing means 7. The process of obtaining the data of the period T from the pulse train is performed by, for example, the data conversion unit 7b. The periodic data is processed by the signal processing unit 7c to combine the rotation direction data.

  In FIG. 1, a power supply circuit 10 is a circuit that feeds power received by the power receiving units 8A and 8B to the rotation sensor 6A, the sensor unit 6B, the digitizing means 7, and the sensor signal transmitting units 9A and 9B. The power supply circuit 10 may include a capacitor that stores received power, a secondary battery, and a charging circuit thereof (none of which is shown).

The sensor signal receiver 5 includes a sensor signal receiver 13 that receives sensor signals transmitted from the sensor signal transmitters 9A and 9B of the wireless sensor units 4A and 4B, and a power receiver 8A of the wireless sensor units 4A and 4B. And a feed power transmission unit 12 that wirelessly transmits operating power to 8B.
Transmission / reception between the sensor signal transmission units 9A and 9B and the sensor signal reception unit 13 and between the feeding power transmission unit 12 and the operating power reception units 8A and 8B may be performed by electromagnetic waves, or may be performed using light waves, infrared rays, or ultrasonic waves. Or by magnetic coupling.
The feed power transmission unit 12 is, for example, an electromagnetic wave that is a continuous wave of an unmodulated wave. The power receiving units 8A and 8B are configured by a tuning circuit, a detection rectification circuit, and the like when wireless power feeding is performed by electromagnetic waves.
The frequency of the sensor signal to be wirelessly transmitted and the power supply power are different from each other, for example, and the plurality of sensor signals provided are also different from each other. Here, the frequency of the feeding power is f1, and the frequencies of the sensor signals are f2 and f3. The frequency of the sensor signal and the power supply power may be the same. In this case, the sensor signal is transmitted by spread spectrum communication as described later.

The digitizing means 7 has a data switch 7a, a data converter 7b, and a signal processor 7c as shown in FIG. 3, for example. The data switch 7a is provided when the rotation sensor 6A and the sensor unit 6B have a plurality of sensors 6a, 6b, and 6c, and switches the data input from the sensors 6a, 6b, and 6c and transmits the data to the data conversion unit 7b. In the example shown in the figure, each of the plurality of sensors 6a to 6c is a rotation sensor, a temperature sensor, and a vibration sensor. The switching by the data switch 7a is performed periodically by, for example, a timer, or is performed in response to an appropriate switching command.
The data converter 7b converts the input analog signal into a digital signal.

  The signal processing unit 7c adds an identification number for each of the wireless sensor units 4A and 4B when a plurality of wireless sensor units 4A and 4B are provided for the common sensor signal receiving unit 13 (FIG. 2). When there is one wireless sensor unit, no identification number is required. Further, when the signal processing unit 7c includes a plurality of sensors 6a to 6c in the rotation sensor 6A and the sensor unit 6B in the same wireless sensor unit 4A and 4B, the signal processing unit 7c adds an identification number for identifying each sensor 6a to 6c. These wireless sensor unit identification number and sensor identification number are added to the sensor signal to be transmitted. The signal processing unit 7c may further add redundant bits such as an error correction code.

  The signal digitized by the digitizing means 7 is wirelessly transmitted from the sensor signal transmitting units 9A, 9B by electromagnetic waves having predetermined frequencies f1, f2. This transmission may be performed by light waves, infrared rays, ultrasonic waves, or magnetic coupling in addition to electromagnetic waves as described above.

Transmission by the sensor signal transmission units 9A and 9B is performed by, for example, spread spectrum communication. As the method, a frequency hopping method, a direct spreading method, or the like is used.
The sensor signal transmitters 9A and 9B may transmit the wireless sensor units 4A and 4B in order in time division. Also, a communication request transmission unit (not shown) provided in the sensor signal receiver 5 issues a data communication request command to the wireless sensor units 4A and 4B, and the wireless sensor units 4A and 4B receiving the command send sensor signals. It may be sent. As described above, when time division or a request command is used, communication can be performed without interference even if the frequencies transmitted from the wireless sensor units 4A and 4B are the same. Further, if the wireless sensor units 4A and 4B transmit the above identification numbers, the signals of the plurality of wireless sensor units 4A and 4B can be identified.

  Since spread spectrum communication is resistant to disturbances and interference, sufficient reliability can be ensured even when radio waves in the same frequency band as power transmission electromagnetic waves, which are continuous waves of unmodulated waves, are used. By using electromagnetic waves in the same frequency band, the power receiving units 8A and 8B and the sensor signal transmitting units 9A and 9B can use the same high-frequency component for components such as an antenna, so the component cost can be reduced. .

  Further, the frequency of the electromagnetic wave for sensor signal transmission is determined for each wireless sensor unit 4A, 4B, and the sensor signal receiver 13 of the sensor signal receiver 5 is an individual receiver (corresponding to the natural frequency of each wireless sensor unit 4A, 4B) ( (Not shown).

  The sensor signal transmission units 9A and 9B perform sensor signal transmission by digital modulation such as ASK (Amplitude Shift Keying), FSK (Frequency Shift Keying), PSK (Phase Shift Keying), or QPSK (Quadrature PSK) on the carrier wave. It may be performed over time.

  According to the bearing with the rotation sensor of this configuration, the digitizing means 7 is provided as shown in FIG. 2, and the sensor signal output from the rotation sensor 6A is digitized. improves. Further, since the sintered body obtained by sintering a mixed powder of magnetic powder and nonmagnetic metal powder is used as the multipolar magnet 17a of the magnetic encoder 17 in FIG. 1, the surface hardness is high and damage due to dust biting or the like is caused. In this respect, the reliability is improved. As described above, the combination of the digitizing means 7 and the fact that the multi-pole magnet 17a of the magnetic encoder 17 is made of a sintered body of the mixed powder makes it possible to ensure high reliability.

  Since the rotation sensor 6A is disposed at the end of the rolling bearing 51, the rotation sensor 6A can be easily attached to the rolling bearing 51. Unlike the case where it is arranged in the bearing 51, if it is arranged at the end, the rotation sensor 6A will be exposed to the outside unless another sealing means is provided. Since the pole magnet 17a is a sintered body of the above mixed powder, it is difficult to cause damage due to dust biting and the like, and reliability can be ensured.

  Further, according to the wireless sensor system having the above configuration, each of the wireless sensor units 4A and 4B is supplied with operating power wirelessly. There is no need to provide a machine, and the wireless sensor units 4A and 4B can be configured to be compact and lightweight. Maintenance is also easy because no battery replacement is required. Also, unlike power generation, communication is always possible.

Further, since the sensor signal is digitized and transmitted by the digitizing means 7, it is difficult to be influenced by disturbances, and the reliability of the system is improved. By digitizing the sensor signal, the identification number for each wireless sensor unit 4A, 4B can be easily transmitted, and a plurality of wireless sensor units 4A, 4B can be identified by a single frequency electromagnetic wave. The system configuration becomes simple. When the sensor unit 6 of each of the wireless sensor units 4A and 4B has a plurality of sensors 6a to 6c, when the identification numbers of the sensors 6a to 6c are added, the sensors 6a to 6c can be easily identified.
When the digitized sensor signal is transmitted by the spread spectrum method, it is easy to distinguish it from the electromagnetic wave for power transmission that is a continuous wave of the unmodulated wave, and the reliability of the system is improved. Further, by transmitting the sensor signal by the spread spectrum method, radio waves in the same frequency band can be used for transmission and power supply of the sensor signal, and the cost can be reduced by sharing the parts.

  FIG. 5 shows an embodiment in which a rotation sensor bearing using this wireless sensor system is applied to a wheel bearing device. The wheel bearing device 33 includes an outer member 1 having a double-row rolling surface, an inner member 2 having a rolling surface facing the rolling surface, and the opposing rolling surfaces of both rows. A plurality of intervening rolling elements 3 are provided, and the wheels are rotatably supported with respect to the vehicle body. The wheel bearing device 33 in the figure is of the fourth generation type, and the inner member 2 is composed of a hub wheel 2A and an outer ring 15a of a constant velocity joint 15, and these hub wheel 2A and constant velocity joint outer ring 15a. Moreover, the rolling surface of each row | line | column by the side of the inner member 2 is formed.

One wireless sensor unit 4 </ b> A is installed on the outer member 1 of the wheel bearing device 33. The other wireless sensor unit 4B in FIG. 1 may be omitted, and may be installed on the wheel for detecting tire air pressure, for example, separately from the wheel bearing device 33.
The wireless sensor unit 4A has a rotation sensor 6A. The rotation sensor 6A is composed of a magnetic encoder 17 and a magnetic sensor 18 attached to face the magnetic encoder 17. As in the example of FIG. 1, the magnetic encoder 17 is composed of a multipolar magnet having magnetic poles alternately formed in the circumferential direction and a cored bar that supports the multipolar magnet. It consists of a sintered body obtained by sintering mixed powder with magnetic metal powder.

  The magnetic sensor 18 detects a periodic magnetic change in the circumferential direction of the magnetic encoder 17, detects a relative rotation between the inner member 2 and the outer member 1, and outputs a rotation signal. This rotation signal is a pulse train, but the pulse period data is digitized and transmitted. The magnetic sensor 18 is a magnetic field sensor, and an active magnetic sensor such as a Hall element type sensor, a fluxgate type magnetic sensor, or an MI sensor can be used in addition to the magnetoresistive element type sensor. The magnetic sensor 18 is arranged at two positions where the phase is approximately 90 ° away from the period of the magnetic change in the circumferential direction of the pulsar ring 17 to detect the rotation direction, and transmits the rotation direction data in addition to the period data. Also good.

  The wireless sensor unit 4 </ b> A is a unit in which the circuit box unit 24 and the sensor installation unit 23 are integrated, and the circuit box unit 24 is installed on the outer surface of the outer member 1. The sensor installation portion 23 faces the bearing inner space through a radial hole provided in the outer member 1. In the circuit box unit 24, a communication function unit including the power reception unit 8A and the sensor signal transmission unit 9A in FIG. 1, the digitizing means 7, and the power supply circuit 10 are provided. Is installed. In the sensor installation unit 23, a sensor 22 that detects other information other than rotation is installed as another sensor constituting the sensor unit 6B (FIG. 2). The sensor 22 is, for example, a temperature sensor, a vibration sensor, a load sensor, a preload sensor, or the like.

The sensor signal receiver 5 is attached to the vehicle body side. For example, it is attached in the tire house of the vehicle body. The sensor signal received by the sensor signal receiver 5 is sent to an electric control unit (ECU) that controls the entire vehicle provided on the vehicle body, and is used for various controls and abnormality monitoring.
The rotation sensor 6A detects rotation by the pulsar ring 17 and the magnetic sensor 18 and feeds power wirelessly. Therefore, the rotation sensor 6A can detect rotation up to the O speed and can be used for an anti-lock brake system, traction control, and the like. And the sophistication of vehicle control can be improved. By detecting the direction of rotation, it can be used for hill hold control, for example, control corresponding to reverse detection during uphill movement and vice versa.
By detecting other than rotation, such as a load sensor and a temperature sensor, by other sensors 22, the bearing can be made intelligent and used for bearing failure diagnosis and various vehicle controls.

  As described above, when applied to the wheel bearing device 33, the wheel bearing device 33 is made intelligent, and the sensor is wirelessly transmitted and combined with wireless power feeding to eliminate the harness between the wheel and the vehicle body. Highly reliable vehicle control can be achieved by digitizing signals.

FIG. 6 shows an example in which a bearing with a rotation sensor using this wireless sensor system is applied to another type of wheel bearing device 33. This wheel bearing device 33 is of a third generation type, and the inner member 2 is composed of a hub wheel 2A and an inner ring 2B fitted to the outer periphery of one end thereof, and the hub wheel 2A and the inner ring 2B. A rolling surface of each row on the inner member 2 side is formed on the outer periphery. The constant velocity joint 15 has a shaft portion provided on the outer ring 15a inserted into the hub wheel 2A and coupled to the hub wheel 2A with a nut.
The wireless sensor unit 4A is attached to the end of the outer member 1. The sensor unit 6A of the wireless sensor unit 4A includes a rotation sensor 6A, and includes a magnetic encoder 17 attached to the inner member 2 and a magnetic sensor 18 provided to face the magnetic encoder 17. The magnetic encoder 17 has a multi-pole magnet made of a mixed powder sintered body attached to a cored bar as in the above embodiments. The magnetic encoder 17 is provided as a seal component that seals the bearing space between the outer member 1 and the inner member 2. As the magnetic sensor 18, a magnetoresistive sensor, a Hall element sensor, or the like is used. Other configurations are the same as the example shown in FIG.

  FIG. 7 shows an example in which the rotation sensor bearing using this wireless sensor system is applied to another type of wheel bearing device 33. The wheel bearing device 33 is for a third generation driven wheel. In this example, the wireless sensor unit 4A is attached to the cover 25 that covers the bearing end. The wireless sensor unit 4A includes a rotation sensor 6A including a magnetic encoder 17 and a magnetic sensor 18. The magnetic encoder 17 is composed of a cored bar 17a and a multipolar magnet 17b as shown in the example of FIG. 1, and the multipolar magnet 17 is composed of a sintered body of the mixed powder. The tip of the sensor unit 6 </ b> A having the magnetic sensor 18 is inserted into a hole provided in the cover 25, and the circuit box 24 is installed on the outer surface of the cover 25. The other configuration in this embodiment is the same as the example shown in FIG. The inner ring 2B is coupled to the hub wheel 2A by a caulking portion 100 formed by caulking the end of the hub wheel 2A.

It is sectional drawing of the bearing with a rotation sensor concerning 1st Embodiment of this invention. It is a block diagram which shows the conceptual structure of the wireless sensor system applied to the bearing with the rotation sensor. It is a block diagram of the internal structural example of the digitization means. (A) is explanatory drawing of the example of the rotation sensor of the sensor part in the wireless sensor system, (B) is a waveform diagram of the output pulse, (C) is a block diagram of an internal configuration example as a modification of the digitizing means is there. It is sectional drawing which shows an example of the bearing for wheels which is a bearing with a rotation sensor concerning other embodiment of this invention. It is sectional drawing which shows the wheel bearing apparatus concerning other embodiment. It is sectional drawing which shows the wheel bearing apparatus concerning other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer member 2 ... Inner member 4A, 4B ... Wireless sensor unit 5 ... Sensor signal receiver 6A ... Rotation sensor 6B ... Sensor part 6a-6c ... Sensor 7 ... Digitization means 7a ... Data switch 7b ... Data conversion Unit 7c ... Signal processing unit 8A, 8B ... Power receiving unit 9A, 9B ... Sensor signal receiving unit 12 ... Feed power transmitting unit 13 ... Sensor signal receiving unit 17 ... Magnetic encoder 17a ... Multipolar magnet 17b ... Core 18 ... Magnetic sensor 51 ... Rolling bearing 54 ... Inner member 55 ... Outer member 56 ... Rolling element

Claims (5)

  A rolling bearing in which rolling elements are interposed between rolling surfaces provided on the outer periphery of the inner member and the inner periphery of the outer member, respectively, and attached to the rotating side member of the inner member and the outer member And a rotation sensor comprising a magnetic sensor mounted on a fixed member facing the magnetic encoder, and a sensor signal provided on the fixed member and output from the magnetic sensor is digitized. Digitizing means, wherein the magnetic encoder comprises a multipolar magnet having magnetic poles alternately formed in the circumferential direction and a cored bar that supports the multipolar magnet. A bearing with a rotation sensor, which is a sintered body obtained by sintering mixed powder with magnetic metal powder.   The bearing with a rotation sensor according to claim 1, wherein the rotation sensor is disposed at an end portion of the rolling bearing.   3. The rotation according to claim 1, wherein a sensor signal transmitter for wirelessly transmitting a sensor signal digitized by the digitizing means is provided on a fixed member of the inner member and the outer member. Bearing with sensor.   The bearing with a rotation sensor according to claim 3, wherein the fixed member is provided with a power receiving unit that wirelessly receives operating power for driving the rotation sensor and the sensor signal transmitting unit.   The rolling bearing according to any one of claims 1 to 4, wherein the rolling bearing is opposed to an outer member having a double row rolling surface, an inner member having a rolling surface facing the rolling surface, and And a plurality of rolling elements interposed between the rolling surfaces of the two rows.

Images