JP2005348521A - Rotation supporting means and information processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit the signal to show the rotational state of a motor detected from the sensor of a bearing to a control system via a signal transmission path while supporting the rotating shaft of the motor, and also to enhance the noise resistance to the mixing of magnetic noise generated from the main body of the motor into the signal transmission path. <P>SOLUTION: A rotation supporting means is equipped with the above bearing 10 with a rotation sensor, a sensor element mounting board 30, and a controller 60. The board 30 is provided in the bearing 10. The signal detected with a sensor element 32(Hall element) on the board 30 is transmitted to the controller 60. A line driver IC46 on the board 30 generates a signal detected with the sensor 32 and its inverted signal and sends it out via a signal line harness 58. The controller 60 calculates a mutual difference between the sent detection signal and the inverted signal so as to reproduce a sensor signal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotation support device formed to support a rotating body by a motor by a bearing with a rotation sensor.

  Conventionally, a bearing with a rotation sensor to which a sensor for detecting the number of rotations and the rotation direction of a rotating body is attached has been proposed (see Patent Document 1). This bearing with a rotation sensor has a structure in which a rolling bearing including an outer ring, an inner ring, and a rolling element is formed as a bearing body, and a sensor is attached thereto. Among these, the bearing body is configured such that the rotational drive shaft of an electric motor is fixed to the inner ring. The outer ring is provided with a ring-shaped sensor housing on one end face in the axial direction so as to protrude in the axial direction, and a plurality of sensor elements are attached to the inner peripheral side of the sensor housing.

  On the other hand, a flange is attached to the inner ring on one axial end face so as to protrude in the axial direction, and a magnetic encoder is disposed on the flange so as to face the sensor element.

  Since the magnetic encoder rotates with the rotation of the inner ring, the N and S poles of the magnetic encoder are alternately opposed to each sensor element. Each sensor element generates a pulse signal as a detection signal due to a change in the magnetic field generated at this time. Detection signals output from the respective sensor elements are fed back to the control device, and the rotation speed and direction of the electric motor are controlled by the control device.

  FIG. 8 shows a conventional example of a circuit including wiring from the sensor element output circuit to the control device. As shown in the figure, in the conventional case, the detection signal from each sensor element 110 is sent to the receiving unit 100 of the control device via the signal line harness 102 by the signal sending means in the open collector output format. ing. This signal transmission structure is the same for each sensor element 110. That is, the signal transmission means is configured with the transistor 104 as a main part, and the detection signal is input to the base B of the transistor 104.

  Further, the emitter E of the torgin star 102 is grounded, and the collector C thereof is connected to the receiving unit 100 via the signal line harness 102 (here, one signal line). A power line 108 is connected to the signal line 102 via a resistor 106.

  Therefore, when the detection signal is at a low level (L), the transistor 104 is off, so that a high level (H) signal (voltage from the power supply line 108) is input to the receiving unit 100. Also. In the case of the detection signal high level (H), the transistor 104 is turned on, and a current flows from the power supply line 108 to the transistor 104 through the resistor 106 and the signal line harness 102. Therefore, a low level (L) signal is input to the receiving unit 100.

Thus, the signal based on the detection operation of each sensor element 110 can be received by the receiving unit 100.
JP 2002-296288 A

  However, in the case of the above-described conventional example, there is a problem regarding electrical noise mixed in the signal line harness.

  This will be described in detail. The signal detected by the bearing with the rotation sensor is normally fed back to the drive control system as information on the rotation angle (rotation speed) and rotation direction for controlling the rotation speed of the electric motor. On the other hand, since the bearing with the rotation sensor is disposed close to the electric motor body, it is easily affected by the magnetic force associated with the driving of the electric motor, and the signal line harness that electrically connects the sensor element 110 and the drive control system. Electrical noise easily enters 102. When noise enters in this way, the detection signal sent to the drive control system is disturbed, making it difficult to perform highly accurate and reliable control.

  In addition, the length of the signal line harness 102 is limited (the longer the signal line harness 102 is, the more easily affected by electrical noise), which hinders remote control.

  The present invention has been made in view of the problems associated with the above-described conventional example. The signal representing the rotation state of the motor detected from the sensor of the bearing is transmitted while the rotation shaft of the motor is supported by the bearing with the sensor. Provided is a rotation support device for an electric motor and an information processing device that are transmitted to a control system via a path and have improved noise resistance against magnetic noise generated from an electric motor main body mixed into a signal transmission path. That is the purpose.

  In order to solve the above-described problems, a rotation support device according to the present invention is a rotation support device in which a rotation shaft of the motor is supported by a bearing disposed in the vicinity of the motor, A hall element sensor for detecting the rotation of the rotating body and an output circuit for outputting the output of the hall element sensor to the receiver side in a differential output form are provided.

  For this reason, the rotating shaft of the motor is rotatably supported by the bearing, and the rotation state of the rotating body of the bearing is detected by the Hall element sensor. The output signal detected by this sensor is transmitted to the receiver side (usually the control system side) by the output circuit in the differential output form. Since the transmitted signal takes a differential output form, it is possible to reproduce the sensor signal by performing the mutual difference calculation on the receiver side, and to remove or suppress the external noise mixed in the sensor circuit or transmission system on the receiver side. A sensor signal can be obtained. Because of the need for the bearing to support the rotating shaft of the motor, the bearing is usually placed near the motor body. For this reason, a lot of magnetic noise that accompanies the drive of the motor body is included in the external noise to be mixed. However, the magnetic noise is suitably removed or suppressed, and the motor is driven with high accuracy and high reliability. Can be controlled. That is, it is possible to provide a rotation support device for a motor with high noise resistance.

  In the basic configuration described above, a magnetic encoder that is magnetized alternately with N and S is provided on at least one of the inner ring and the outer ring, and the Hall element sensors having a plurality of phases are disposed at positions facing the magnetic encoder. The Hall element sensor detects a change in the magnetic pole caused by the rotation of the inner ring or the outer ring, and detects the rotation state of the bearing from the detection result, and the output circuit outputs the output of each phase element. And its inverted output are sent to the receiver side, and the processing circuit on the receiver side performs the difference calculation from these two outputs to eliminate the influence of noise caused by the motor and output the output of each phase element. Configure to play.

  In this case, for example, one of the inner ring and the outer ring is a fixed side raceway, and the other is a rotation side raceway, the element is attached to the fixed side raceway, and the magnetic encoder is attached to the rotation side raceway. May be.

  More preferably, in each configuration described above, the Hall element sensor and the receiver side are connected by a signal line harness via the output circuit, and the sensor line connector of the signal line harness is connected to the sensor side connector. The output circuit may be integrated. On the other hand, the output circuit may be integrally formed on a substrate on which the Hall sensor element is mounted.

  More preferably, the differential output means of the output circuit may comprise a line driver IC.

  On the other hand, an information processing device formed on the receiving side of the rotation support device having each of the above-described configurations, a reproduction circuit means for reproducing the signal of the Hall element sensor from the differential output, and the bearing from the reproduction information It is possible to provide an information processing apparatus including an arithmetic circuit means for calculating a rotation state including the rotation speed and the rotation direction.

  As described above, according to the present invention, the rotation shaft of the motor is supported by the bearing with the sensor, and the signal representing the rotation state of the motor detected from the sensor of the bearing is transmitted to the control system via the signal transmission path. At the same time, it is possible to reliably improve the noise resistance against the magnetic noise generated from the motor main body being mixed into the signal transmission path, and to improve the accuracy and reliability of the drive control of the motor.

(First embodiment)
With reference to FIGS. 1-5, 1st Embodiment of the rotation support apparatus which concerns on this invention is described.

  This rotation support device includes a bearing 10 with a rotation sensor shown in FIG. 1, a control device 60 described later, and a signal line harness 58 described later.

  The rotation sensor bearing 10 includes a bearing outer ring 12, a bearing inner ring 14, a plurality of rolling elements 16 sandwiched between both wheels 12 and 14, and a sensor element mounting substrate 30.

  As shown in FIG. 1, the outer peripheral surface of the bearing outer ring 12 which is a stationary side race is fitted into a circular hole or a circular groove provided in a fixing member (not shown) (fixing bracket, casing wall surface, etc.). The For this reason, rotation of the bearing outer ring is prevented, and the bearing with rotation sensor 10 itself is fixed.

  Inside the bearing outer ring 12, a bearing inner ring 14, which is a rotation side race ring, is arranged coaxially with the bearing outer ring 12.

  A plurality of rolling elements 16 are sandwiched between the bearing inner ring 14 and the bearing outer ring 12. By this rolling member 16, the bearing outer ring 12 and the bearing inner ring 14 can be relatively rotated with almost no frictional resistance. In the first embodiment, since the bearing outer ring 12 is fixed, the bearing inner ring 14 is rotatable.

  In FIG. 1, the rolling element 16 has a spherical structure, but may be a rolling element in which elongated cylindrical members are arranged in parallel to the axial direction of the bearing outer ring 12 and the bearing inner ring 14.

The bearing inner ring 14 is used as a support member that supports a rotating shaft 20 of a motor (electric motor) 18 as a drive source as shown in FIG. That is, the rotation sensor bearing 10 is disposed in the vicinity of the motor 18. In the present invention, the term “near” refers to a position in a range (magnetic environment) that is affected by magnetism generated when the motor 18 is driven.
As shown in FIG. 2, a general bearing 22 is fitted into one end portion (left side in FIG. 2) of the rotary shaft 20, and the rotation sensor bearing 10 is fitted into the other end portion (right side in FIG. 2). The motor 18 includes a rotating mechanism including a permanent magnet 24, and a coil 26, and has a structure that rotates the rotating shaft 20 by changing magnetic poles.

  As a result, even when a vibration that causes shaft shake occurs when the rotating shaft 20 rotates, this vibration is suppressed and stable rotation is possible.

  As shown in FIG. 1, a ring-shaped outer ring flange 28 is attached to one end surface (right side of FIG. 1) of the bearing outer ring 12.

  A sensor element mounting board 30 is attached to a part of the periphery of the outer ring flange 28. The sensor element mounting substrate 30 is formed in a so-called fan shape (see FIG. 5), and is attached so as not to interfere with the rotating shaft 20 (see FIG. 2) inserted into the bearing inner ring.

  A pair of sensor elements 32 (only one is shown in FIG. 1) is attached to a part of the sensor element mounting substrate 30. A Hall element is applied to the sensor element 32. A change in magnetic field is formed by the rotation of the bearing inner ring 14 (described later), and the Hall element changes its output signal in accordance with the change in the magnetic field.

  When one sensor element 32 is provided, the rotation angle (rotation speed) can be determined, but the rotation direction cannot be determined. For this reason, the two or more sensor elements 32 are arranged so as to output detection signals whose phases are shifted from each other. Due to this phase shift, the rising and falling timings of both signals differ depending on the rotation direction, so that the rotation direction can be determined. On the other hand, a ring-shaped inner ring flange 34 is mounted on one end surface of the bearing inner ring 14 (the end surface on the side where the outer ring flange 28 is mounted).

  The inner ring flange 34 is provided with a magnetic encoder 36, which is a permanent magnet in which N poles and S poles are alternately arranged in the entire circumferential direction, that is, in a donut shape.

  The outer ring flange 28 and the inner ring flange 34 are arranged so that the sensor element 32 is opposed to the inner peripheral surface side of the magnetic encoder 36.

  As a result, when the bearing inner ring 13 rotates, the magnetic encoder 36 also rotates simultaneously, and each sensor element 32 senses a change in the magnetic field generated by the rotation of the magnetic encoder 36 and is repeated between a predetermined upper limit value and lower limit value. A signal (for example, a sine wave) is output.

  Note that the pair of sensor elements 32 are arranged so that the phases are shifted by 90 ° from each other.

As shown in FIG. 3, each sensor element 32 has a sensing surface (not shown) and includes a V _CC input terminal 38, a GND terminal 40, and an output (OUT) terminal 42.

A DC power supply line 44 from the outside is connected to the V _CC input terminal 38, and the sensor element 32 can be driven (detectable state) by this DC power supply. The GND terminal 40 is connected to an external GND.

  Further, the output terminal 42 is connected to the line driver IC 46. The line driver IC 46 mainly includes a pair of OP amplifiers 48, and the output terminals 42 of the sensor elements 32 are connected to input terminals of separate OP amplifiers 48 via connection lines 50.

  The connection lines 50 that connect the output terminal 42 and the OP amplifier 48 are connected to the power supply line 44 through resistors 52, respectively. The power line 44 supplies DC power from the outside to the VCC input terminal 38.

  As a result, the voltage between the resistors 52 that changes based on the output value from the sensor element 32 is input to the OP amplifier 48 as a detection signal of the sensor element 32.

  The OP amplifier 48 detects a binarized detection signal (output signal 1 and output signal 2) based on an input signal and an inverted signal (output signal 1 ′) whose phase is shifted by 180 ° with respect to the detection signal. , And an output signal 2 ′), and the detection signal and the inverted signal (see FIG. 4) are output to the outside via independent signal lines 54, 54 ′, 56, 56 ′.

  As shown in FIG. 5, the sensor element mounting substrate 30 having the above configuration has a fan shape and is previously attached to the outer ring flange 28 of the bearing outer ring 12.

  As shown in FIG. 3, output signal lines (a total of four lines) 54, 54 ', 56, 56' from the pair of OP amplifiers 48 of the line driver IC 46 (hereinafter referred to as a signal line harness 58 when collectively shown). ) Is connected to the control device 60.

  The control device 60 is provided with a pair of difference calculation units 62 corresponding to the two sensor elements 32, and the detection signal from each OP amplifier 48 and the inverted signal thereof are paired to the difference calculation unit 62. Have been entered.

  The difference calculation unit 62 calculates a difference between the detection signal and the inverted signal, and sends a difference signal representing the difference result to the binary signal generation unit 64. The binary signal generator 64 generates a binary signal by comparing the difference signal with a predetermined threshold value.

  This binary signal is in-phase with the detection signal and is a signal in which noise generated during transmission is canceled.

  The calculation result in the binary signal generation unit 64 is sent to the rotation state information determination unit 66, and based on the generated binary signal (that is, the detection signal corresponding to the rotation by the sensor element 32), the bearing inner ring 14 A rotation angle (rotation speed) and a rotation direction are obtained.

  The operational effects of the first embodiment will be described below.

  When the bearing inner ring 14 rotates, the magnetic encoder 36 rotates with this rotation, and the N pole and the S pole alternately face the sensing surface of the sensor element 32.

  Thereby, the sensor element 32 outputs, for example, a sinusoidal signal that periodically changes between a certain upper limit value and lower limit value. This signal is sent from the output terminal 42 to the line driver IC 46.

  The line driver IC 46 generates a detection signal and an inverted signal corresponding to signals respectively input from the pair of sensor elements 32 by driving a pair of built-in OP amplifiers 48. In this first embodiment, a pair of sensor elements 32 having a detection timing phase of 90 ° are arranged, and each OP amplifier 48 generates a detection signal and an inverted signal. Is generated as an output signal (see FIG. 4).

  These four types of output signals are transmitted to the control device 60 through independent signal lines 54, 54 ', 56, 56' (signal line harness 58).

  In the control device 60, the difference between the detection signal and the inverted signal from one sensor element 32 and the difference between the detection signal and the inverted signal from the other sensor element 32 are respectively calculated by the two difference calculation units 62. Calculated.

  Further, each binary signal generator 64 compares the difference signal calculated by each difference calculator 62 with a predetermined threshold value to generate a binary signal.

  Thereby, it is possible to obtain a signal equivalent to the detection signal input from each sensor element 32 and from which noise during transmission is removed.

  This binary signal is input to the rotation state information discriminating unit 66, and the rotation angle (rotation speed) and rotation direction of the bearing inner ring 14 can be obtained based on the binary signal.

  As described above, in the first embodiment, when the signal detected by the sensor element 32 (Hall element) is transmitted to the external control device 60, the line driver IC 46 is applied to generate the detection signal and its inverted signal. The two signals are sent as a pair. As a result, even if noise is superimposed on the detection signal and its inverted signal during transmission, it is possible to eliminate the noise by calculating the difference between the detection signal and its inverted signal. The length of the signal line harness 58 that is electrically connected to the terminal 60 is not limited, and the remote operation area can be expanded.

  This will be described in relation to magnetic noise generated by the motor 32. In the rotation support device according to the first embodiment, since the rotation shaft 20 of the motor 18 is supported by the bearing 10 with the rotation sensor, the sensor element mounting substrate 30 (sensor element 32) of the bearing 10 with the rotation sensor is inevitably required. In particular, it is arranged in a state of being very close to the motor body (arrangement in the vicinity of the motor). For this reason, the sensor element 32 is under the influence of the magnetism generated by the motor body as it is driven, and the magnetic noise (external noise) is very likely to be mixed in the signal detected by the sensor element 32. . In particular, as the signal line harness 58 that connects the sensor element mounting substrate 30 and the control device 60 becomes longer, such a problem becomes more apparent.

  On the other hand, according to the rotation support device according to the first embodiment, as described above, even when magnetic noise from the motor body is mixed in the wiring of the sensor element mounting substrate 30 and the signal line harness 58, the sensor With the configuration in which the detection signal is output to the control device (receiver) in a differential output form, it is possible to reliably eliminate or suppress such noise and greatly improve noise resistance.

  Therefore, while it is possible to make the drive control of the motor 18 accurate and reliable, it is also possible to lengthen the signal line harness 58, so that the degree of freedom of design regarding the installation position of the control device 60 can be increased. Various advantageous effects are also obtained, such as being able to be raised. Also, when the rotation sensor bearing 10 is newly configured as in the present embodiment, the sensor element 32 and necessary circuit components are mounted on the sensor element mounting substrate 30. Thereby, the compact bearing 10 with a rotation sensor which can send out a detection signal and its inversion signal is realizable.

(Second Embodiment)
Next, a second embodiment of the rotation support device according to the present invention will be described with reference to FIGS. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description of the configuration is omitted.

  A feature of the second embodiment resides in that a signal transmission system in which noise countermeasures of the present invention are applied is applied to an existing bearing with a rotation sensor.

  Specifically, the rotation sensor bearing 10 and the signal line harness 58 are configured to be detachable electrically and mechanically by a connector 68.

6 and 7 show this detachable structure. As shown in the figure, the connector 68 includes a bearing body side member (hereinafter referred to as a male member) 70 and a harness side member (hereinafter referred to as a female member) 72. Among them, the male member 70 is an output terminal of the sensor element mounting substrate 30, that is, a V _CC input terminal 38 (common), a GND terminal 40 (common), and an output (OUT) of a pair of sensor elements (hall elements) 32. A total of four output terminals 70A, 70B, 70C, 70D wired from the terminal 42 (independent) are provided. The female member 72 is attached to one end of the signal line harness 58 and is provided with input terminals 72A, 72B, 72C, 72D that are electrically connected to the output terminals 70A, 70B, 70C, 70D.

  In this connection structure, since the wiring from the sensor element mounting substrate 30 of the rotation sensor bearing 10 is connected to the output terminals 70A, 70B, 70C, and 70D of the male member 70, the female member 72 is attached to the existing structure. It only needs to be attached and there is no need to change the internal structure.

  On the other hand, the female member 72 incorporates an additional board on which the line driver IC 48 and the resistor 52, which are features of the present invention, are wired. For this reason, the circuit equivalent to 1st Embodiment can be easily comprised by connecting the male member 70 and the female member 72 of the connector 68. FIG.

  By integrating the output circuit with the connector 68, the line driver IC 48 can generate a detection signal and its inverted signal without changing the internal configuration of the existing bearing with a rotation sensor. In each of the above-described embodiments, the bearing inner ring 14 rotates. However, the bearing outer ring 12 may rotate.

  In this case, considering the simplicity of wiring, it is preferable to provide the sensor element 32 on the fixed side starting wheel and the magnetic encoder 36 on the rotating side starting wheel, but a sliding contact or the like may be used. For example, the magnetic encoder 36 may be provided on the fixed side starting wheel, and the sensor element 32 may be provided on the rotating side starting wheel.

  Although a Hall element is applied as the sensor element 32, other sensor elements such as a photo interrupter may be used, depending on the rotational speed.

It is sectional drawing of the bearing with a rotation sensor which concerns on 1st Embodiment concerning this invention. It is a front view at the time of applying the bearing with a rotation sensor which concerns on 1st Embodiment as a bearing of the rotating shaft of an electric motor. It is a circuit diagram for obtaining the rotation state information by the detection signal of the rotation sensor according to the first embodiment. It is a timing chart which shows the output signal from a line driver IC. (A) is a top view of the sensor element mounting board | substrate which concerns on 1st Embodiment, (B) is a bottom view of FIG. 5 (A). It is sectional drawing of the bearing with a rotation sensor which concerns on 2nd Embodiment concerning this invention. It is a circuit diagram for obtaining the rotation state information by the detection signal of the rotation sensor according to the second embodiment. It is a circuit diagram for obtaining the rotation state information by the detection signal of the rotation sensor according to the conventional example.

Explanation of symbols

10 Bearing with rotation sensor 12 Bearing outer ring (fixed raceway ring)
14 Bearing inner ring (rotating raceway)
16 Rolling member 18 Motor (electric motor)
20 Rotating shaft 28 Flange for outer ring 30 Sensor element mounting board (sensor side connector)
32 Sensor element (Hall element sensor)
34 Flange for inner ring 36 Magnetic encoder 42 Output (OUT) terminal 46 Line driver IC (output circuit)
48 OP amplifier (differential output means)
52 Resistance 54, 54 ', 56, 56' Signal line 58 Signal line harness 60 Control device (information processing device)
62 Difference calculation unit (reproduction circuit means)
64 Binary signal generator (reproduction circuit means)
66 Rotation state information discriminating section (arithmetic circuit means)
68 Connector 70 Bearing body side member (male member)
72 Harness side member (female member)

Claims (7)

  A rotation support device in which a rotation shaft of a motor is supported by a bearing disposed in the vicinity of the motor, the Hall element sensor for detecting the rotation of the rotating body of the bearing, and the Hall element sensor An output circuit that outputs the output of the output to the receiver side in a differential output form.   A magnetic encoder magnetized alternately with N and S is provided on at least one of the inner ring and the outer ring, and the Hall element sensor having a plurality of phases is provided at a position facing the magnetic encoder, and a magnetic pole generated by rotation of the inner ring or the outer ring. Is detected by the Hall element sensor, and the rotation state of the bearing is detected from the detection result, and the output circuit sends the output of each phase element and its inverted output to the receiver side. The apparatus according to claim 1, wherein the processing circuit on the receiver side performs a difference operation from these two outputs to eliminate the influence of noise caused by the motor and reproduce the output of each phase element. .   One of the inner ring and the outer ring is a fixed-side track ring, and the other is a rotation-side track ring, the element is mounted on the fixed-side track ring, and the magnetic encoder is mounted on the rotation-side track ring. The apparatus of claim 2 characterized in that:   The Hall element sensor and the receiver side are connected by a signal line harness through the output circuit, and the output circuit is integrated with a sensor side connector of the signal line harness. The bearing with a rotation sensor according to any one of claims 1 to 3.   The apparatus according to any one of claims 1 to 3, wherein the output circuit is integrally formed on a substrate on which the Hall sensor element is mounted.   6. The apparatus according to claim 1, wherein the differential output means of the output circuit comprises a line driver IC. 6. An information processing apparatus formed on the receiving side according to claim 1, wherein reproduction circuit means for reproducing a signal of the Hall element sensor from the differential output, and rotation speed and rotation direction of the bearing from reproduction information. And an arithmetic circuit means for calculating a rotation state including the information processing apparatus.

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