JP2006170626A - Bearing with rotation sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing with a rotation sensor hardly generating a damage of a magnetic encoder caused by biting of massive dust or sand particles or the like, capable of detecting not only a rotational frequency but also a rotation detection, and detecting with high reliability. <P>SOLUTION: A rolling bearing 10 is provided with a sensor part 6 for detecting rotation. The sensor part 6 comprises the magnetic encoder 17 mounted on a member 54 on the rotation side between an inward member 54 and an outward member 55 of the rolling bearing 10, and a magnetic sensor 18 mounted on a member 55 on the fixed side oppositely to the magnetic encoder. The sensor part 6 outputs two rotational frequency signals having a phase difference of about 90°. 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 capable of detecting the number of rotations and the direction of rotation in a rolling bearing in a machine facility, a wheel bearing for an automobile, and the like.

  A wireless ABS (anti-lock brake system) sensor has been proposed in which a signal from a rotation sensor mounted on a wheel bearing is transmitted wirelessly to eliminate a harness between a wheel and a vehicle body (for example, Patent Document 1). As the rotation sensor, a multipolar rotary generator is used, and the sensor power and the transmitter power are obtained by self-power generation. This eliminates the need for power supply wiring from the vehicle body to the rotation sensor. By making it wireless in this way, advantages such as weight reduction and avoidance of failure due to disconnection of the harness due to stepping stones can be obtained. In addition, in a wheel bearing, it has been proposed to supply power to a rotation sensor wirelessly (for example, Patent Document 2). According to wireless power feeding, unlike the case of using the power generation function, rotation detection and sensor signal transmission can be performed even when rotation is stopped or at low speed. Also, unlike those equipped with batteries, there is no need to replace and manage batteries.

In addition, as a magnetic encoder for use in a wheel bearing for detecting the rotational speed of a wheel, 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 3). 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.
JP 2002-264786 A JP 2003-146196 A JP 2003-85536 A

  In each of the proposed examples described above, the rotational speed is detected, but the rotational direction cannot be recognized, and there is still one point that is not sufficient for improving the control. For example, there is a control called a hill hold function in an automobile. This is a control function that activates the braking function when the vehicle moves in a direction opposite to the driver's intention. For example, when the vehicle is reverse when the automatic idling is stopped in a state where the gear is engaged in a forward state while waiting for a signal on an uphill, the reverse is detected and a braking operation or the like is performed. Thereby, the safety of the automatic idling stop can be achieved. In the bearings with rotation sensors of the above proposal examples, rotation is detected, but the direction of rotation cannot be identified on the control side, and cannot be used as a sensor for the hill hold function as described above. Even in the case of a rolling bearing in an industrial machine, if the rotational direction can be recognized, more advanced control is possible. However, such a control cannot be performed in a conventional bearing with a rotation sensor.

  In addition, conventional rubber magnets, etc., used for the magnetic encoder of the rotation sensor have a low surface hardness, so that an environment in which sand particles get stuck under a dusty environment, for example, when applied to a wheel bearing, etc. When used below, it is easily damaged and lacks reliability.

  An object of the present invention is to provide a bearing with a rotation sensor that can detect not only the number of rotations but also the rotation direction, and that the magnetic encoder is not easily damaged due to blockage of massive dust or sand particles, and can perform highly reliable detection. It is to be.

  The bearing with a rotation sensor according to the present invention is provided with a sensor portion for detecting the rotation of the rolling bearing in a rolling bearing having an outer member, an inner member, and a plurality of rolling elements interposed between the outer and inner members. . The sensor unit includes a magnetic encoder attached to a rotating member of the inner member and the outer member, and a magnetic sensor attached to a fixed member facing the magnetic encoder. The sensor unit outputs two rotation speed signals having a phase difference of approximately 90 °. The magnetic encoder includes a multipolar magnet in which magnetic poles are alternately formed in the circumferential direction, and a core metal 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, the sensor unit outputs two rotation speed signals having a phase difference of approximately 90 °. Therefore, on the control side, in addition to the rotational speed, the rotational direction can be recognized. In addition, as a multi-pole magnet of a magnetic encoder, a sintered body obtained by sintering a mixed powder of magnetic powder and non-magnetic metal powder is used, so the surface hardness is high and damage due to entrapment of massive dust or sand particles is caused. It is hard to occur and has excellent reliability.

  The sensor unit may be disposed at an end of the rolling bearing. When the sensor part is arranged at the end part, it is easy to attach to the rolling bearing, but unlike the case where it is arranged in the bearing, the rotation sensor is exposed to the outside unless another sealing means is provided. . Even in such a case, since the multipolar magnet of the magnetic encoder is a sintered body of the above mixed powder, it is difficult to cause damage due to block dust or sand particles and reliability can be ensured.

  In this invention, you may provide the sensor signal transmission part which transmits the sensor signal which the said sensor part outputs wirelessly. When the sensor signal is transmitted wirelessly, signal wiring is not required, and the wiring system around the bearing is simplified or unnecessary.

  Moreover, you may provide the electric power receiving part which receives the operating electric power of the said sensor part and a sensor signal transmission part wirelessly. In that case, both signal wiring and power supply wiring are unnecessary, and wiring around the bearing can be eliminated. Further, it is not necessary to provide a primary battery or a generator, and it can be configured compactly. Unlike the power generation type, operating power can be obtained even when rotation is stopped.

The sensor unit may output an origin signal for each rotation in addition to the two rotation speed signals having the phase difference of approximately 90 °.
By using the sensor unit capable of detecting the origin signal, the absolute position can be detected, and more advanced control can be easily performed.

The bearing with a rotation sensor of the present invention may be a wheel bearing device. That is, the rolling bearing includes an outer member having a double row rolling surface, an inner member having a rolling surface facing the rolling surface, and a double row rolling interposed between the opposing rolling surfaces. A wheel bearing may be provided that includes a moving body and rotatably supports the wheel with respect to the vehicle body.
In the wheel bearing, the rotation speed signal of the sensor unit is used for an antilock brake system (ABS) and a traction control system (TCS). In this case, in the present invention, since the wheel rotation direction can be detected, the sensor unit can be used as a hill hold function sensor. In addition, when a sensor signal transmitter for wirelessly transmitting sensor signals is provided, or when a power receiver for receiving operating power wirelessly is provided, the wheel bearing eliminates the harness between the wheel and the vehicle body. It can be made wireless, which is preferable in terms of weight reduction and prevention of disconnection failure due to rock jumping.

  The bearing with a rotation sensor according to the present invention is provided with a sensor unit for detecting the rotation of the rolling bearing in a rolling bearing having an outer member, an inner member, and a plurality of rolling elements interposed between the outer and inner members. The sensor unit is composed of a magnetic encoder attached to the rotating member of the inner member and the outer member, and a magnetic sensor attached to the fixed member facing the magnetic encoder, The sensor unit outputs two rotation speed signals having a phase difference of approximately 90 °, and the magnetic encoder supports a multipolar magnet in which magnetic poles are alternately formed in the circumferential direction, and the multipolar magnet. Since the multi-pole magnet is a sintered body obtained by sintering a mixed powder of magnetic powder and non-magnetic metal powder, it can detect not only the rotation speed but also the rotation direction and magnetically. Encoder bites massive dust and sand particles Hardly damaged by such an effect is obtained that enables reliable detection.

  A first embodiment of the present invention will be described with reference to FIGS. The bearing with the rotation sensor includes a sensor unit 6 that detects the rotation of the rolling bearing 10, a sensor signal transmission unit 9 that wirelessly transmits a sensor signal output from the sensor unit 6, and the sensor unit. 6 and the sensor signal transmitter 9 are provided with a power receiver 8 that wirelessly receives the operating power. The sensor unit 6 outputs two rotation speed signals (A phase signal and B phase signal) having a phase difference of approximately 90 °. The output of the sensor unit 6 is sent to the sensor signal transmission unit 9 via the signal processing means 14 or directly. Note that the signal processing means 14 and the sensor signal transmission unit 9 receive, in addition to the two rotation number signals output from the sensor unit 6, for example, a detection signal from another sensor unit (not shown) such as a temperature sensor. It may be performed from the sensor signal transmission unit 9 together with the signal.

  In the rolling bearing 10, a plurality of rolling elements 56 are interposed between the rolling surfaces of the inner member 54 and the outer member 55 facing each other. In this example, it is a deep groove ball bearing. 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. The end of the bearing space between the inner and outer members 54 and 55 is sealed with a seal 58. In the rolling bearing 10, either the inner member 54 or the outer member 55 may be on the rotating side, but in this example, the outer member 55 is installed on a housing (not shown) to become a stationary side, A side member 54 is fitted to the shaft 59 to support the shaft 59 rotatably. The rolling bearing 10 is shown as a single row in the example of FIG. 1, but may be a double row. The rolling bearing 10 may be a bearing for any application. For example, it may be a conveyor constituting a machine equipment in a factory, a bearing for supporting a driving roller of a conveyor, a machine tool, a bearing constituting an industrial machine, or a bearing for a vehicle wheel. Examples applied to automobile wheel bearings will be described in detail later.

  The sensor unit 6, the sensor signal transmission unit 9, and the power reception unit 8 are configured as an integrated wireless sensor unit 4. However, a magnetic encoder 17 described later in the sensor unit 6 is separate from the wireless sensor unit 4. When the signal processing means 14 is provided, the signal processing means 14 is also included in the wireless sensor unit 4. A sensor signal receiver 5 that wirelessly supplies power and receives each sensor signal to the wireless sensor unit 4 is provided.

The sensor unit 6 includes a magnetic encoder 17 and a magnetic sensor 18 installed to face the magnetic encoder 17.
As shown in FIG. 2, the magnetic encoder 17 includes a ring-shaped multipole magnet 17a magnetized in multipoles in which magnetic poles N and S are arranged in the circumferential direction, and a ring-shaped core bar that supports the multipole magnet 17a. 17b. According to the combination of the magnetic encoder 17 and the magnetic sensor 18 composed of multipolar magnets, a small and accurate rotation sensor can be configured.
The magnetic sensor 18 has two detectors 18A and 18B that are opposite to each other at two phases whose phases are approximately 90 ° apart from the period of the magnetic change in the circumferential direction of the magnetic encoder 17, and the phases differ by approximately 90 °. A numerical signal is output from each detector 18A, 18B. Each rotation speed signal is a pulse train as shown in FIG. 3, and becomes two rotation speed signals of A phase and B phase having a phase difference of about 90 °.

  The magnetic sensor 18 is a magnetic field sensor, and each of the detection units 18A and 18B is a magnetic field sensor. As this magnetic field sensor, an active magnetic field sensor such as a Hall element type sensor, a fluxgate type magnetic field sensor, or an MI sensor can be used in addition to a magnetoresistive sensor (referred to as “MR sensor”). Of the above, each of the detection units 18A and 18B is preferably a magnetoresistive type. The magnetoresistive magnetic sensor is advantageous for application to wireless power feeding because power consumption can be reduced by increasing the resistance value.

As shown in FIG. 1, in the magnetic encoder 17, the cored bar 17b is formed in a stepped cylindrical shape, and the large diameter side cylindrical portion is fitted into the inner member 54 of the rolling bearing 10 in a press-fitted state. And it is fixed.
The magnetic sensor 18 is housed in a common case 4a together with the power receiver 8 and the sensor signal receiver 9 to constitute the wireless sensor unit 4, and is attached to the outer member 55 via a ring-shaped attachment member 4b.

  The multipolar magnet 17a 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.

In addition, 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 of two or more, or alloy powders of two or more can be used.

  In FIG. 1, the sensor signal receiver 5 includes a sensor signal receiving unit 13 that receives the sensor signal transmitted from the sensor signal transmitting unit 9, and a power supply power transmitting unit 12 that wirelessly transmits operating power to the power receiving unit 8. With. The sensor signal receiver 5 may receive sensor signals and transmit operating power to the plurality of wireless sensor units 4. In that case, for example, for each wireless sensor unit 4, the sensor signal to be transmitted has a different frequency.

Transmission / reception between the sensor signal transmission unit 9 and the sensor signal reception unit 13 and between the feeding power transmission unit 12 and the power reception unit 8 may be performed by electromagnetic waves, or by light waves, infrared rays, ultrasonic waves, Alternatively, it may be performed by magnetic coupling.
When communication is performed using electromagnetic waves, the frequency of the sensor signal to be wirelessly transmitted and the frequency of the feeding power are different from each other, and the plurality of sensor signals provided are also different from each other. Here, the frequency of the feed power is f1, and the frequency of the sensor signal is f2. When one sensor signal receiver 5 receives sensor signals and transmits operating power to a plurality of wireless sensor units 4, the sensor signal frequency is set to a different frequency for each wireless sensor unit 4. And The frequency of the supplied power may be the same or different for each wireless sensor unit 4.

  The power reception unit 8 includes a tuning circuit, a detection rectification circuit, and the like when wireless power feeding is performed using electromagnetic waves. The power receiving unit 8 may include a capacitor or a secondary battery that stores received power, and a charging circuit thereof.

The A-phase and B-phase rotation speed signals of the sensor unit 6 are processed by the signal processing unit 14 into a form suitable for wireless transmission by the sensor signal transmission unit 9 and transmitted from the sensor signal transmission unit 9.
The sensor signal transmission unit 9 transmits, for example, two rotation number signals of A phase and B phase on one carrier wave. The format in which two rotation speed signals are carried on one carrier wave may be, for example, transmission by time division or superposition with appropriate signal processing. The signal processing means 14 is a circuit that performs such processing for performing time-division transmission or superimposition. By transmitting two rotation speed signals on one carrier wave, power consumption for wireless transmission is reduced. Wireless power supply is not as efficient as power supply by wiring or power supply by generator, so it is necessary to transmit a large amount of power to the power supply, and the reduction in power consumption of the sensor transmitter is a great advantage in terms of energy saving. Become.

  FIG. 4 shows a specific example of processing in which the signal processing means 14 transmits two rotation number signals of A phase and B phase on one carrier wave. In this case, the signal of frequency fA (Hz) is ASK (Amplitude shift keying) modulated with the A phase signal (a), and the signal of frequency fB is modulated with the B phase signal. FIGS. 7B and 7D show the ASK modulation results of the A-phase and B-phase signals, respectively. The carrier wave is FM-modulated and transmitted with the signal (e) obtained by adding the two ASK-modulated signals (b) and (d). On the receiving side, the sensor signal is demodulated after separating the above summed signal (e) into two ASK modulated signals (b) and (d) by a filter. The signal processing means including the filter and the demodulating means may be provided in the sensor signal receiving unit 13 or may be provided separately from the sensor signal receiving unit 13.

The sensor signal transmission unit 9 converts the two rotation speed signals (A phase signal and B phase signal) having a phase difference of approximately 90 ° into two carrier waves having different frequencies f2 and f3 as shown in FIG. 5, for example. It is good also as what carries by carrying each. In that case, as shown in the figure, two sensor signal transmitters 9 are provided, and the sensor signal transmitters 9 and 9 are provided with a rotation speed signal of the A-phase detector 18A and a rotation speed signal of the B-phase detector 18A. May be transmitted. On the sensor signal receiver 5 side, for example, two sensor signal receivers 13 and 13 corresponding to the respective transmission frequencies f2 and f3 are provided.
In this way, when the two rotation speed signals are transmitted by being carried on carriers having different frequencies f2 and f3, processing for placing two signals on one carrier is unnecessary, and the sensor signal transmitter 9 or The configuration including the signal processing means in the previous stage can be simplified.

According to the bearing with the rotation sensor having this configuration, the relative rotation between the inner member 54 and the outer member 55 is detected as a rotation number signal by the sensor unit 6, wirelessly transmitted from the sensor signal transmission unit 9, and sensor signal It is received by the sensor signal receiver 13 of the receiver 5. The sensor unit 6 outputs two rotation speed signals of an A-phase signal and a B-phase signal having a phase difference of approximately 90 °, and these two rotation speed signals are received by the sensor signal receiving unit 13. Besides, the direction of rotation is also detected. For this reason, it is possible to increase the functionality of the control of the equipment equipped with the rolling bearing 10.
Further, since a 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, the surface hardness is high, and it is caused by entrapment of massive dust or sand particles. It is hard to cause damage and has excellent reliability.

  Drive power is transmitted wirelessly from the feed power transmission unit 12 of the sensor signal receiver 5 to the bearing with the rotation sensor, and is received by the power reception unit 8 to receive the sensor unit 6, the sensor signal transmission unit 9, and signal processing means. 14 (FIG. 1 only) or the like. For this reason, it is unnecessary to provide a battery or a generator in a bearing with a rotation sensor of a wireless sensor type, there is no troublesome management of battery life as in the case of using a battery, and low speed as in the case of driving with a generator. There is no problem of undetectability during rotation, and rotation can be detected from O-speed. As described above, both transmission of the sensor signal and power supply to the sensor unit 6 and the like can be performed wirelessly, and not only the rotation speed but also the rotation direction can be detected.

6 and 7 show another embodiment of the present invention. In this embodiment, there is provided a multiplication means 19 that multiplies the rotation speed signal output from the sensor unit 6 and transmits it to the sensor signal transmission unit. The multiplying means 19 may be one that detects the rising and falling edges of the rotation speed signal composed of pulses from the sensor unit, and doubles the rotation speed signal. Further, the multiplication means 19 uses four rotation speed signals having different phases. Multiplication may be used.
7A and 7C show the A-phase rotation speed signal and the B-phase rotation speed signal respectively output from the detection sections 18A and 18B of the sensor section 6, and FIG. 7B shows the A-phase rotation speed signal. An output pulse obtained by multiplying the rotation number signal by 2 by the multiplication means 19 as described above is shown. FIG. 4D shows an output pulse obtained by multiplying the B-phase rotation number signal by 2 by the multiplying means 19 as described above. Note that the rotation speed signal may be multiplied by only one of the A phase and the B phase. If either one is multiplied, the rotation speed can be detected with high accuracy, and the rotation direction can be directly compared between the A-phase and B-phase rotation speed signals.
FIG. 8 shows a waveform diagram in the case of quadruple multiplication. From the A-phase rotation speed signal and the B-phase rotation speed signal having different phases shown in FIGS. 9A and 9B, a quadruple signal shown in FIG.

The rotation speed signal multiplied by the multiplication means 19 in FIG. 6 is processed by the transmission processing means 14a into a format suitable for transmission by the sensor signal transmission section 9. The multiplication means 19 and the signal processing means 14a constitute a signal processing means 14.
Note that the rotation speed signals of the A-phase and B-phase detection units 18A and 18B may be respectively multiplied by the multiplication means 19 and transmitted from different sensor signal transmission units 9 as in the example of FIG. .

Thus, by providing the multiplication means 19 and multiplying, the number of rotation pulses can be increased without reducing the pitch of the magnetic poles or the like in the magnetic encoder 17 serving as the detected portion of the sensor unit 6. Therefore, the rotation detection accuracy can be increased with a simple configuration at low cost.

As shown in FIG. 9, the multiplication means 19 </ b> A may be provided in the sensor signal receiver 5 and the multiplication means 19 (FIG. 6) of the wireless sensor unit 4 may be omitted. The multiplication means 19A of FIG. 9 is a means for multiplying the rotational speed signal received by the sensor signal receiving unit 13 of the sensor signal receiver 5. This multiplication means 19A may also be one that doubles or four times as in the examples of FIGS. The sensor signal receiver 5 and the rolling bearing 10 having the wireless sensor unit 4 of FIG. 1 constitute a bearing system with a rotation sensor.
Thus, when the multiplying means 19A is provided on the receiving side, the portion that operates by wireless power feeding can be simplified, which is advantageous in power feeding.

  FIG. 10 shows an example in which the sensor unit 6 has an origin signal. In the sensor unit 6, a magnetic encoder 17 includes a multipolar magnet 17a formed of a portion in which the magnetic poles N and S are arranged in the circumferential direction, and an origin detected unit 17c provided adjacent to the axial direction of the multipolar magnet 17a. And a cylindrical metal core 17b provided in common to the multipolar magnet 17a and the origin detected part 17c. The origin detected portion 17 b is configured by one or two or three magnetic poles provided at one place on the entire circumference of the magnetic encoder 17. The origin detected portion 17b is a sintered body or the like made of the same material as the multipolar magnet 17a. The magnetic sensor 18 includes A-phase and B-phase detectors 18A and 18B that are installed to face the multipolar magnet 17a, and a detector 18C that faces the origin detected part 17b. The sensor unit 6 constitutes the wireless sensor unit 4 in the example of FIG. 1 or the example of FIG. 5 or FIG.

  The origin signal detected by the detection unit 18C is processed by, for example, the signal processing unit 14 of FIG. 1 and is superimposed on the A-phase and B-phase rotation speed signals, or the A-phase and B-phase rotation speed signals. Separately, it is transmitted from the sensor signal transmitter 9. The transmitted origin signal is received by the sensor signal receiver 13 in the sensor signal receiver 5.

  As described above, when the sensor unit 18 capable of outputting the origin signal is used, the absolute position can be detected, and more advanced control can be easily performed.

  Next, examples in which this rotation sensor bearing is applied to a wheel bearing will be described with reference to FIGS. In FIG. 11, the wheel bearing 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 both opposing rolling surfaces. A plurality of rolling elements 3 interposed therebetween are provided, and the wheels are rotatably supported with respect to the vehicle body. The wheel bearing 33 shown in the figure is of the fourth generation type, and the inner member 2 is composed of a hub wheel 2A and an outer member 15a of the constant velocity joint 15 and these hub wheel 2A and constant velocity joint outer ring. A rolling surface of each row on the inner member 2 side is formed in 15a.

  A wireless sensor unit 4 is installed on the outer member 1 of the wheel bearing 33. In this wireless sensor unit 4, the circuit box unit 24 and the sensor installation unit 23 are integrated to form a unit, 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, the power receiving unit 8, the sensor signal receiving unit 9, and the signal processing unit 14 of FIG. 1 are provided. In the sensor installation unit 23, the detection units 18A and 18B of the magnetic sensor 18 constituting the sensor unit 6 are installed. The magnetic encoder 17 is installed on the inner member 2 on the rotation side at a position facing the sensor installation unit 23. That is, it is provided on the outer peripheral surface of the hub wheel 2A. As in the embodiment shown in FIG. 1, the magnetic encoder 17 is composed of a multipolar magnet and a cored bar that supports the multipolar magnet, and the multipolar magnet is a mixed powder of magnetic powder and nonmagnetic metal powder. The sintered body is sintered.

  The sensor receiver 5 is attached to the vehicle body side. For example, it is mounted in a tire house (not shown) of the vehicle body. The sensor signal received by the sensor 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.

  According to the wheel sensor-equipped wheel bearing with this configuration, the rotational speed signal of the sensor unit 6 is used for an antilock brake system (ABS) and a traction control system (TCS). Currently, the intelligentization of automobiles is progressing rapidly, and many functions to assist the driver are being proposed or realized. As one of the intelligent vehicles, the wheel bearing with wireless sensor of this configuration can output the A phase and B phase and detect the wheel rotation direction. Can be used as For example, when an automatic idling is stopped while waiting for a signal on an uphill and the transmission is shifted to a forward state, when the vehicle retreats, the reverse is detected and a braking operation or the like is performed. Further, when the vehicle moves forward while being shifted in the reverse direction, the forward movement is detected and a braking operation or the like is performed. Thereby, the safety of the automatic idling stop can be achieved. To describe the hill hold control a little more, when the automatic vehicle starts off the slope, when the foot is released from the brake, if the slope of the slope is large, the vehicle may move backward without having only the creep of the torque converter. In particular, when idling is stopped, the possibility of this occurring increases. This is a function for detecting the reverse and braking it. If the vehicle retreats when starting on a hill, it may cause a sudden start by stepping on the accelerator too much. For this purpose, this function is used to brake backwards. As described above, if outputs of the A phase and the B phase are obtained as the rotation speed signal and the rotation direction can be detected, it can be used for such control.

  In addition, this wheel bearing with a rotation sensor wirelessly sends and receives sensor signals and feeds power, eliminating the harness between the wheel and the vehicle body, reducing weight, and avoiding disconnection failures due to stone jumps, etc. Is done. Unlike the case of using the power generated by a rotation sensor with a power generation function for wireless power feeding, rotation can be detected up to O speed, more advanced control can be performed, and the battery life is as in the case of using a battery. Saves management and battery replacement.

FIG. 12 shows an example in which this rotation sensor bearing is applied to another type of wheel bearing. This wheel bearing 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 are A rolling surface of each row on the inner member 2 side is formed. 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 4 is attached to the end of the outer member 1. The sensor unit 6 of the wireless sensor unit 4 includes a magnetic encoder 17 and a magnetic sensor 18. Although the magnetic encoder 17 and the magnetic sensor 18 are provided so as to face each other in the axial direction, the magnetic encoder 17 supports a multipole magnet and the multipole magnet in the same manner as shown in FIGS. It is made of a cored bar, and the multipolar magnet is a sintered body obtained by sintering a mixed powder of magnetic powder and nonmagnetic metal powder. The magnetic sensor 18 includes two detectors 18A and 18B (not shown in FIG. 12) separated from each other by approximately 90 °. The magnetic encoder 17 is provided as a component of a seal device 27 that seals the bearing space between the outer member 1 and the inner member 2. As in the embodiment shown in FIG. 1, the magnetic encoder 17 is composed of a multipolar magnet and a cored bar that supports the multipolar magnet, and other configurations of the wheel bearing 33 are the same as the example shown in FIG. is there.

In the case of this embodiment, since the sensor unit 6 is disposed at the end of the bearing, there is a risk that massive dust, sand particles, etc. may be caught between the multipolar magnet of the magnetic encoder 17 and the magnetic sensor 18. Since the multipolar magnet of the magnetic encoder 17 is a sintered body obtained by sintering the mixed powder of magnetic powder and nonmagnetic metal powder as described above, the multipolar magnet made of a conventional rubber magnet or the like is used. Compared to the above, the surface hardness is high, and even if a lump of dust or sand particles is bitten, it is difficult to damage and has high reliability.

  FIG. 13 shows an example applied to another type of wheel bearing 33. The wheel bearing 33 is for a third generation driven wheel. In this example, the wireless sensor unit 4 is attached to a cover 25 that covers the bearing end. As in the embodiment of FIG. 12, the wireless sensor unit 4 has a sensor unit 6 in which a magnetic encoder 17 and a magnetic sensor 18 are opposed to each other in the axial direction, and the magnetic encoder 17 is attached to the inner member 2. It has been. Further, the inner ring 2B is coupled by crimping the shaft end of the hub ring 2A. Other configurations in this embodiment are the same as the example shown in FIG.

It is explanatory drawing which combined sectional drawing of the bearing with a rotation sensor concerning 1st Embodiment of this invention, and the block diagram which shows the conceptual structure of the control system. It is explanatory drawing of the sensor part in the bearing with the rotation sensor. It is a wave form diagram of the rotation speed signal of the sensor part. It is a wave form diagram of the signal processing example of the rotation speed signal. It is a block diagram which shows the conceptual structure of the control system of the bearing with a rotation sensor concerning other embodiment of this invention. It is a block diagram which shows the conceptual structure of the control system of the bearing with a rotation sensor concerning further another embodiment of this invention. FIG. 6 is a waveform diagram of a rotation speed signal and a doubled output of the sensor unit. It is a waveform diagram of the rotation speed signal and quadruple output of the sensor unit. It is a block diagram of the sensor signal receiver in the bearing system with a rotation sensor concerning other embodiment of this invention. It is a perspective view of the modification of a sensor part. It is sectional drawing of the bearing with a rotation sensor applied to the wheel bearing concerning further embodiment of this invention. It is sectional drawing of the bearing with a rotation sensor applied to the wheel bearing concerning further another embodiment of this invention. It is sectional drawing of the bearing with a rotation sensor applied to the wheel bearing concerning further another embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer member 2 ... Inner member 4 ... Wireless sensor unit 5 ... Sensor signal receiver 8 ... Electric power receiving part 9 ... Sensor signal receiving part 10 ... Rolling bearing 12 ... Feed power transmission part 13 ... Sensor signal receiving part 14 ... Signal processing means 17 ... magnetic encoder 17a ... multipolar magnet 17b ... core metal 18 ... magnetic sensors 18A to 18C ... detecting sections 19, 19A ... multiplication means 54 ... inner member 55 ... outer member

Claims (6)

  A sensor unit for detecting the rotation of the rolling bearing is provided in a rolling bearing having an outer member, an inner member, and a plurality of rolling elements interposed between the outer and inner members. And a magnetic encoder attached to the rotating member of the outer member, and a magnetic sensor attached to the fixed member facing the magnetic encoder, and the sensor section has a phase difference of approximately 90. Two rotational speed signals are output, and the magnetic encoder is composed of a multipolar magnet in which magnetic poles are alternately formed in the circumferential direction, and a cored bar that supports the multipolar magnet. A bearing with a rotation sensor, wherein the magnet is a sintered body obtained by sintering a mixed powder of magnetic powder and nonmagnetic metal powder.   2. The bearing with a rotation sensor according to claim 1, wherein the sensor portion is disposed at an end portion of the rolling bearing.   3. The bearing with a rotation sensor according to claim 1, further comprising a sensor signal transmission unit that wirelessly transmits a sensor signal output from the sensor unit.   The bearing with a rotation sensor according to claim 3, wherein a power receiving unit that wirelessly receives operating power of the sensor unit and the sensor signal transmitting unit is provided.   5. The rotation sensor according to claim 1, wherein the sensor unit outputs an origin signal for each rotation in addition to the two rotation speed signals having the phase difference of approximately 90 °. With bearing.   6. The rolling bearing according to claim 1, wherein the rolling bearing has an outer member having a double row rolling surface, an inner member having a rolling surface facing the rolling surface, and an opposing member. A bearing with a rotation sensor, which is a wheel bearing that includes a double row rolling element interposed between the rolling surfaces to support the wheel rotatably with respect to the vehicle body.

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