JP2007178267A - Magnetic line type rotation detecting apparatus and bearing with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic line type rotation detecting apparatus, which is easily constituted by combining a magnetic sensor with a magnetic encoder of any pitch of magnetic poles, achieves detection signals according to a purpose of use, and detects rotation with high resolution, and and to provide a bearing with the same. <P>SOLUTION: The magnetic line type rotation detecting apparatus 1 is provided with: a magnetic encoder ring 2 in which a multipole magnet 5 is formed in its surface and which rotates on a ring center; and a magnetic line sensor 3 in which a large number of magnetic sensor elements are arranged in a line and which is opposed to the magnetic encoder ring 2 in a radial direction. The magnetic line sensor 3 detects changes in magnetic field associated with the rotation of the magnetic encoder ring 2. A switch selects output of the magnetic sensor elements of the magnetic line sensor 3. An output circuit amplifies and outputs sensor signals outputted from the magnetic sensor elements. A selection setting of the magnetic sensor elements 3a selected by the switch can be freely set by external input to a control circuit. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic line sensor type rotation detection device used for rotation detection in various devices, and a bearing with a rotation detection device including the rotation detection device.

  Conventionally, optical and magnetic methods have been used as non-contact type rotation detection devices, but optical devices that are easily affected by dust are difficult to use under adverse environmental conditions, and magnetic devices are used. There are many cases. Even if the magnetic type is a magnetic type in which a Hall element or MR element is combined with a magnet, it is necessary to form a magnetic pole finely, and the gap between the sensor and the magnet must be strictly controlled during assembly. In order to increase the resolution, it is necessary to form a pattern with a finer pitch.

  FIG. 11 shows a rolling bearing in which a magnetic rotation detection device of a type in which a Hall element or MR element serving as a detection unit and a magnet serving as a detection unit are combined is incorporated. In the figure, a ring-shaped magnetic encoder 54 serving as a detected portion is fixed to a rotating wheel 52 of a rolling bearing 51, and a magnetic sensor 55 such as a Hall element is used as a detecting portion on a stationary wheel 53 to face the magnetic encoder 54. It is arranged to do. The magnetic encoder 54 is formed by alternately magnetizing N magnetic poles and S magnetic poles at a predetermined pitch in the circumferential direction, and the magnetic sensor 55 detects that the magnetism of the magnetic encoder 54 changes as the rotating wheel 52 rotates. Thus, the rotation pulse signal and the rotation direction can be obtained.

As another example of the magnetic rotation detection device, a magnetic sensor array is configured by arranging a large number of magnetic sensor elements in a matrix, and this magnetism sensor array is arranged opposite to a magnet provided on the rotation side member. There has also been proposed a technique in which a magnetic field distribution generated by the magnetic sensor is detected by the magnetic sensor array, and the rotation angle of the magnet is detected from the detected magnetic field distribution (for example, Patent Document 1).
JP 2003-148999 A

By the way, in the case of the rotation detection device in which the ring-shaped magnetic encoder 54 and the magnetic sensor 55 described above are combined, the magnetic pole pitch in the magnetic encoder 54 is determined by the required angular resolution and the limitation on manufacturing accuracy. There is a possibility of various magnetic pole pitches. Therefore, for example, when a two-phase detection signal is required as in the case of knowing the rotation direction, when two magnetic sensors 55 for obtaining the detection signal of each phase are arranged apart from each other in the circumferential direction of the magnetic encoder 54, It is necessary to adjust the sensor interval in accordance with the magnetic pole pitch of the magnetic encoder 54, and the assembling work becomes complicated.
When the two magnetic sensors 55 are in the same package, a magnetic sensor 55 having a package matching the magnetic pole pitch is prepared, or the number of magnetic poles of the magnetic encoder 54 is set so as to match the interval between the two magnetic sensors 55 of the package. It is necessary to match.

  Even if an encoder ring with magnetic poles formed at a desired magnetic pole pitch is used, if the arrangement pitch of the corresponding sensor is variable and settings can be easily changed, rotation sensors with various resolutions can be configured with the same sensor. it can.

  An object of the present invention is to provide a magnetic line sensor capable of easily constructing a magnetic sensor in combination with a magnetic encoder having an arbitrary magnetic pole pitch, obtaining a detection signal according to the purpose of use, and capable of detecting rotation with high resolution. And a bearing with a rotation detection device provided with the rotation detection device.

According to a first aspect of the present invention, there is provided a magnetic line sensor type rotation detection device comprising: a magnetic encoder ring having a multipolar magnet formed on a surface thereof and rotatable around a ring center; and a plurality of magnetic sensor elements arranged in a line. A magnetic line sensor disposed radially opposite the magnetic encoder ring, a switch for selecting an output of the magnetic sensor element of the magnetic line sensor, and an output circuit for amplifying and outputting a sensor signal output from the magnetic sensor element And a control circuit in which the magnetic sensor element selected by the switch can be freely set by external input, and detects a magnetic field change accompanying rotation of the magnetic encoder ring.
The control circuit can select two magnetic sensor elements from a large number of magnetic sensor elements of the magnetic line sensor so that each phase difference is 90 degrees in accordance with the magnetic pole pitch of the magnetic encoder ring to be detected. And having a function of storing identification information such as an identification number in the magnetic line sensor of the two selected magnetic sensor elements, and the output circuit detects a magnetic field change accompanying the rotation of the magnetic encoder ring. As the rotation signal, a two-phase rotation signal having a phase difference of 90 degrees may be output.

According to this configuration, the rotation direction of the magnetic encoder ring can be detected from two-phase rotation signals having a phase difference of 90 degrees obtained by the two selected magnetic sensor elements, and one of these two-phase rotation signals is detected. The rotation angle can be detected by using one.
In particular, the selection of the output of two magnetic sensor elements having a phase difference of 90 degrees can be freely switched by external input to the control circuit that performs this selection. The rotation detector can be easily configured in combination with a magnetic encoder ring having a magnetic pole pitch of.
Moreover, since the sensor signal to output can be switched with a switch, the rotation signal according to the intended purpose can be obtained.
In addition, since the magnetic line sensor, which is a magnetic sensor, is composed of a large number of magnetic sensor elements arranged in a line, it is possible to detect a movement amount finer than the magnetic pole pitch of the magnetic encoder ring, and the resolution of rotation detection. Can be increased.
In addition, the magnetic line sensor and the signal processing circuit such as the switch, the output circuit, and the control circuit can be integrated on the same sensor chip, or can be compactly integrated, so that space can be saved.
As a result, the magnetic sensor can be easily configured in combination with a magnetic encoder having an arbitrary magnetic pole pitch, and a detection signal corresponding to the purpose of use can be obtained, thereby enabling high-resolution rotation detection.

A magnetic line sensor type rotation detection device according to a second aspect of the present invention is the magnetic line sensor type rotation detection device according to the first aspect of the invention, wherein the magnetic line sensor is arranged to face the magnetic encoder ring in the radial direction. Instead, the magnetic line sensor is arranged to face the magnetic encoder ring in the axial direction.
In the case of this configuration, similarly to the magnetic line sensor type rotation detection device according to the first invention, the magnetic sensor can be easily configured in combination with a magnetic encoder having an arbitrary magnetic pole pitch, and a detection signal corresponding to the purpose of use can be generated. It is possible to obtain rotation detection with high resolution.

In the first and second aspects of the invention, the control circuit has a phase difference of 90 degrees according to the magnetic pole pitch of the magnetic encoder ring to be detected from among a large number of magnetic sensor elements of the magnetic line sensor. A plurality of magnetic sensor elements close to each other in position can be selected, and has a function of storing identification information such as an identification number in the magnetic line sensor of each selected magnetic sensor element. A total output or an average output of a plurality of adjacent magnetic sensor elements is taken, and a two-phase rotation signal having a phase difference of 90 degrees is output as a rotation signal for detecting a magnetic field change accompanying the rotation of the magnetic encoder ring. Also good.
In the case of this configuration, the noise components included in the sensor signals of the individual magnetic sensor elements are averaged, the accuracy of the signal can be increased, and a higher-quality rotation signal can be obtained.

In these inventions, the output circuit differentially amplifies an output of a sensor element at a position 180 degrees out of phase with one selected sensor element, and a sensor at a phase position different from those sensor elements by 90 degrees. Also for the element, the output of the sensor element at a position 180 degrees out of phase with one selected sensor element is differentially amplified, thereby outputting a signal with a phase difference of 90 degrees. Along with the selection of one sensor element, a sensor element at a position 180 degrees out of phase for differential amplification may be selected.
In the case of this configuration, a rotation signal having twice the amplitude can be obtained, and the quality of the rotation signal can be improved. In addition, since a two-phase signal having a phase difference of 90 degrees is generated as a rotation signal obtained with such a differential configuration, highly accurate rotation detection and rotation direction detection are possible.

  In the first and second aspects of the invention, the control circuit selects a plurality of sensor elements, and the output circuit performs rectangular wave processing on the outputs from the plurality of sensor elements between the magnetic pole pitches. It is also possible to generate a signal pulse corresponding to the movement amount equal to or smaller than the magnetic pole pitch and output the rotation direction and the rotation amount signal by the processing circuit. In the case of this configuration, a rotation signal with high resolution can be obtained.

The bearing with a rotation detection device of the present invention includes the magnetic line sensor type rotation detection device having any one of the above-described configurations of the present invention.
Thus, by integrating the magnetic line sensor type rotation detection device of the present invention into the bearing, the number of parts and the number of assembling steps of the bearing using device can be reduced and the size can be reduced. In this case, the rotation detection device can detect rotation with high accuracy and small size as described above. Therefore, even in a small bearing such as a small-diameter bearing, satisfactory rotation detection is possible.

The magnetic line sensor type rotation detection device of the present invention has a magnetic encoder ring formed on the surface and capable of rotating around the center of the ring, and a large number of magnetic sensor elements arranged in a line shape. Alternatively, a magnetic line sensor arranged in the axial direction, a switch that selects an output of the magnetic sensor element of the magnetic line sensor, an output circuit that amplifies and outputs a sensor signal output from the magnetic sensor element, and The magnetic sensor element to be selected by the switch is provided with a control circuit that can be freely set by an external input, and detects the magnetic field change accompanying the rotation of the magnetic encoder ring. It can be configured easily by combining, and it can obtain a detection signal according to the purpose of use, with high resolution. It is possible to the rotation detection.
Since the bearing with a rotation detecting device of the present invention is provided with the magnetic line sensor type rotation detecting device of the present invention, the number of parts and the number of assembling steps of the bearing using device can be reduced and the size can be reduced.

A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a principle configuration of a magnetic line sensor type rotation detection device of this embodiment. This magnetic line sensor type rotation detection device 1 is configured by arranging a magnetic encoder ring 2 having a multipolar magnet 5 formed on the surface thereof and capable of rotating around the center of the ring, and a large number of magnetic sensor elements 3a (FIG. 2) in a line. The magnetic line sensor 3 is provided.
The magnetic encoder ring 2 is obtained by forming a multipolar magnet 5 on the surface of a ring-shaped back metal 4, and the multipolar magnet 5 has N and S magnetic poles 5 a arranged at a predetermined pitch λ in the circumferential direction of the back metal 4. (Fig. 3) are arranged alternately. The multipolar magnet 5 is made of, for example, a rubber magnet vulcanized and bonded to the surface of the back metal 4. The magnetic encoder ring 2 is attached to a rotation side member, for example, an outer periphery of an inner ring of a rolling bearing by press fitting or the like with the ring center aligned with the axis of the rotation side member.

  The magnetic line sensor 3 is a sensor that detects a change in the magnetic field generated by the multipolar magnet 5 as the magnetic encoder ring 2 rotates. On the surface of one sensor chip 9 as shown in FIG. A large number of magnetic sensor elements 3a are arranged in a line. When the magnetic encoder ring 2 is attached to, for example, an inner ring that is a rotating ring of a rolling bearing, the sensor chip 9 is attached to an outer ring that is a fixed ring of the rolling bearing. Thus, the magnetic line sensor 3 is disposed so as to face the magnetic encoder ring 2 in the radial direction as shown in FIG. The arrangement of the magnetic line sensor 3 in this case is such that the arrangement direction X of the magnetic sensor elements 3a is magnetic in a plan view as shown in a plan view of the positional relationship between the magnetic line sensor 3 and the multipolar magnet 5 in FIG. The magnetic poles 5a of the encoder ring 2 are aligned in the arrangement direction.

  As shown in FIG. 2A, the sensor chip 9 includes the magnetic line sensor 3, a switch circuit 6 for selecting the output of the magnetic sensor element 3a of the magnetic line sensor 3, and a sensor signal output from the magnetic sensor element 3a. And a control circuit 8 capable of freely setting the magnetic sensor element 3a selected by the switch circuit 6 by an external input. The switch circuit 6, the output circuit 7, and the control circuit 8 may be formed on a separate chip from the magnetic line sensor 3.

  FIG. 4 is a circuit diagram showing an example of a configuration of a signal processing circuit such as the switch circuit 6, the output circuit 7, and the control circuit 8. In this circuit configuration example, two magnetic sensor elements 3a having a phase difference of 90 degrees are selected from a number of magnetic sensor elements 3a of the magnetic line sensor 3, and these sensor signals are rotated in the direction of rotation. The output circuit 7 amplifies and outputs the two-phase rotation signals for knowing the above. The output circuit 7 includes two amplifiers 7a and 7b that amplify the two-phase sensor signals. The switch circuit 6 includes a group of switches 6a interposed between the output terminal of each magnetic sensor element 3a and the input terminal of one amplifier 7a of the output circuit 7, and the output terminal and output circuit of each magnetic sensor element 3a. 7 and another group of switches 6b interposed between input terminals of the other amplifier 7b.

The control circuit 8 turns on one switch 6a from among a group of switches 6a of the switch circuit 6, thereby converting the sensor signal of one magnetic sensor element 3a from among a large number of magnetic sensor elements 3a to a one-phase rotation signal. And by turning on one switch 6b from among the other group of switches 6b in the switch circuit 6, the sensor signal of the other magnetic sensor element 3a from among the many magnetic sensor elements 3a, It is selected as another one-phase rotation signal having a phase difference of 90 degrees with respect to the one-phase rotation signal. In this case, the selection of the two magnetic sensor elements 3 a is performed in accordance with the magnetic pole pitch λ of the magnetic encoder ring 2. The selection of the magnetic sensor element 3a in the control circuit 8 can be freely set by an external input. The control circuit 8 is provided with a non-volatile memory (not shown) as means for storing identification information such as identification numbers in the magnetic line sensor 3 of the two selected magnetic sensor elements 3a. As long as there is no switching command, the same two stored magnetic sensor elements 3a continue to be selected.
The control circuit 8 can select an arbitrary magnetic sensor signal 3a depending on the magnetic pole pitch λ of the magnetic encoder ring 2 and the form of the necessary signal. The output circuit 7 has a circuit configuration that outputs only two systems (two phases A and B), but may have a circuit configuration having more functions.

FIG. 5A is a waveform diagram of the magnetic distribution of the magnetic encoder ring 2 detected by the magnetic line sensor 3 in the magnetic line sensor type rotation detector 1 having the above configuration. In the figure, the horizontal axis indicates the alignment position of the magnetic sensor elements 3a in the magnetic line sensor 3, and the magnetic distribution detected by the magnetic line sensor 3 when the magnetic encoder ring 2 is at an arbitrary rotational position is represented by a waveform v. A magnetic distribution detected by the magnetic line sensor 3 when the magnetic encoder ring 2 is rotated by a predetermined amount from the position is indicated by a waveform v ′. The dots arranged on the waveform v represent the output obtained from each magnetic sensor element 3 a of the magnetic line sensor 3.
FIG. 5B shows a one-phase (A-phase) rotation signal v3a1 obtained by one magnetic sensor element selected by the control circuit 8 (indicated by reference numeral 3a1 in FIG. 5A), and another 1 FIG. 6 is a waveform diagram of another one-phase (B-phase) rotation signal v3a2 obtained by two magnetic sensor elements (indicated by reference numeral 3a2 in FIG. 5A) with a phase difference of 90 degrees. In the figure, the horizontal axis represents the time axis.

As can be seen from the waveform diagram of FIG. 5, according to the magnetic line sensor type rotation detection device 1, a magnetic encoder ring is obtained from two-phase rotation signals having a phase difference of 90 degrees obtained from the two selected magnetic sensor elements 3a. 2 rotation directions can be detected, and the rotation angle can be detected by using any one of these two-phase rotation signals. In this case, the signal output from the output circuit 7 may be used as a rotation signal as it is, but a signal obtained by converting the output signal into a rectangular wave signal by a comparison circuit may be used as the rotation signal.
In particular, in the magnetic line sensor type rotation detection device 1, the selection of the outputs of the two magnetic sensor elements 3a having a phase difference of 90 degrees can be freely switched by external input to the control circuit 8 that performs this selection. Therefore, the rotation detection device 1 can be easily configured by combining the magnetic line sensor 3 as a magnetic sensor with the magnetic encoder ring 2 having an arbitrary magnetic pole pitch.
Moreover, since the sensor signal to output can be switched by the switch circuit 6, the rotation signal according to the intended purpose can be obtained.
In addition, since the magnetic line sensor 3 that is a magnetic sensor is formed by arranging a large number of magnetic sensor elements 3a in a line, it is possible to detect a movement amount finer than the magnetic pole pitch λ of the magnetic encoder ring 2, The resolution of rotation detection can be increased.
Further, the magnetic line sensor 3 and the signal processing circuits such as the switch circuit 6, the output circuit 7, and the control circuit 8 can be integrated on the same sensor chip 9, or can be compactly integrated, so that space can be saved.

The main advantages of this embodiment are summarized below.
(1) Combined with a magnetic encoder ring 2 having an arbitrary magnetic pole pitch.
(2) Since a signal to be output can be switched by a switch, a sensor output corresponding to the purpose of use can be obtained.
(3) Since the magnetic line sensor 3 is used as a sensor and is composed of a large number of magnetic sensor elements 3a, a movement amount finer than the magnetic pole pitch can be detected, and the resolution can be increased.
(4) Since the sensors and signal processing circuits 6, 7, and 8 are gathered together at the same pitch or compact, space saving is possible.

  In the example of the circuit configuration of FIG. 4, the case where two magnetic sensor elements 3 a are selected in order to obtain two-phase rotation signals is shown, but a plurality of adjacent magnetic sensors are used for each one-phase rotation signal. The element 3a may be selected, and an average output or total output of sensor signals of the plurality of magnetic sensor elements 3a may be used. The control circuit 8 has a function of storing identification information such as identification numbers of the magnetic line sensors 3 of the plurality of magnetic sensor elements 3a to be selected. In this case, noise components included in the sensor signals of the individual magnetic sensor elements 3a are averaged, so that the accuracy of the signal can be increased and a higher-quality rotation signal can be obtained.

  Further, in the circuit configuration example of FIG. 4, as the two magnetic sensor elements 3a to be selected, those having a phase difference of 180 degrees between these sensor signals, that is, those having opposite phases to each other, are selected, and the difference between these two signals is selected. May be used as a single rotation signal. FIG. 6 shows a waveform diagram in this case. That is, FIG. 6A is a waveform diagram of the magnetic distribution of the magnetic encoder ring 2 detected by the magnetic line sensor 3 as in FIG. FIG. 6B shows a one-phase (A-phase) rotation signal v3a1 obtained by one magnetic sensor element (indicated by reference numeral 3a1 in FIG. 6A) selected by the control circuit 8, and other ones. FIG. 7 is a waveform diagram of another one-phase (B phase) rotation signal v3a2 obtained by two magnetic sensor elements (indicated by reference numeral 3a2 in FIG. 6A). In this case, a rotation signal having twice the amplitude is obtained, and the quality of the rotation signal can be improved. Further, by generating a two-phase signal having a phase difference of 90 degrees as a rotation signal obtained with such a differential configuration, highly accurate rotation detection and rotation direction detection can be performed.

  Further, in the circuit configuration example of FIG. 4, the magnetic sensor element 3 a selected by the control circuit 8 is a plurality of adjacent ones corresponding to one magnetic pole of the magnetic encoder ring 2, for example, and the output circuit 7 The sensor signal of the sensor element 3a may be subjected to rectangular wave processing, and the rectangular wave may be further processed by a logic circuit to generate a pulse signal corresponding to the amount of movement below the magnetic pole pitch λ as a rotation signal. FIG. 7 shows an example of the waveform in this case. In this example, five magnetic sensor elements 3a among the magnetic line sensors 3 are selected, and the sensor signals of these five magnetic sensor elements 3a are subjected to rectangular wave processing as shown in (A) to (E). By processing the rectangular wave with a logic circuit, an output pulse finer than the magnetic pole pitch λ is generated as shown in (F). In the logic circuit, “1” or “0” of the output (F) of (F) is determined according to the respective states (A) to (E), thereby generating an output pulse finer than the magnetic pole pitch λ. . Thereby, a rotation signal with high resolution can be obtained.

  FIG. 8 shows an example of a bearing 10 with a rotation detection device incorporating the magnetic line sensor type rotation detection device 1. This bearing 10 with rotation detector is press-fitted to the outer periphery of one end portion of an inner ring 12 that is a rotating ring of the rolling bearing 11 and the magnetic encoder ring 2 in the magnetic line sensor type rotation detector 1 and the rolling bearing 11. A sensor chip 9 including the magnetic line sensor 3 in the magnetic line sensor type rotation detection device 1 is attached to an inner periphery of one end of an outer ring 13 which is a fixed ring of the outer ring 13 via an annular member 14 made of a metal ring or the like. . The magnetic line sensor 3 is disposed so as to face the multipolar magnet 5 of the magnetic encoder ring 2 in the radial direction. As described above, by integrating the magnetic line sensor type rotation detection device 1 with the rolling bearing 11, the number of parts and the number of assembling steps of the bearing using device can be reduced and the size can be reduced. In this case, the rotation detection device 1 can detect rotation with high accuracy with a small size as described above. Therefore, even in a small bearing such as a small-diameter bearing, satisfactory rotation detection is possible.

FIG. 9 shows another embodiment of the present invention. In the first embodiment shown in FIGS. 1 to 7, the rotation detecting device 1A with a magnetic line sensor according to this embodiment includes a ring-shaped magnetic encoder ring 2 as shown in a plan view in FIG. The multi-pole magnet 5 is arranged on the side surface facing the axial direction of the back metal 4, and the magnetic line sensor 3 is arranged with respect to the multi-pole magnet 5 as shown in a front view in FIG. The multi-pole magnet 5 of the magnetic encoder ring 2 is arranged so as to face in the axial direction. Other configurations are the same as those in the first embodiment.
In this case, the magnetic line sensor 3 detects the magnetic field change accompanying the rotation of the magnetic encoder ring 2 from the axial direction. Other functions and effects are the same as those of the first embodiment.

  FIG. 10 shows an example of a rotation detection device-equipped bearing 10A incorporating the magnetic line sensor type rotation detection device 1A of the embodiment of FIG. The bearing 10 </ b> A with the rotation detection device is also press-fitted with the magnetic encoder ring 2 in the magnetic line sensor type rotation detection device 1 </ b> A on the outer periphery of one end of the inner ring 12 that is the rotation ring of the rolling bearing 11. A sensor chip 9 including the magnetic line sensor 3 in the magnetic line sensor type rotation detection device 1A is attached to the outer periphery of one end of an outer ring 13 which is a fixed ring of the outer ring 13 via an annular member 14A made of a metal ring or the like. . The magnetic line sensor 3 is disposed so as to face the multipolar magnet 5 of the magnetic encoder ring 2 in the axial direction.

It is a partial front view which shows the principle structure of the magnetic line sensor type | mold rotation detection apparatus concerning 1st Embodiment of this invention. (A) is a top view of the sensor chip in the magnetic line sensor type rotation detection device, and (B) is a perspective view of the sensor chip. It is a top view which shows the positional relationship of the magnetic line sensor and multipolar magnet in the same magnetic line sensor type | mold rotation detection apparatus. It is a circuit diagram which shows one structural example of the signal processing circuit in the same magnetic line sensor type | mold rotation detection apparatus. (A) is a waveform diagram of a magnetic field distribution detected by a magnetic line sensor, and (B) is a waveform diagram of sensor signals of two magnetic sensor elements having a selected phase difference of 90 degrees. (A) is a waveform diagram of a magnetic field distribution detected by a magnetic line sensor, and (B) is a waveform diagram of sensor signals of two magnetic sensor elements having a selected phase difference of 180 degrees. FIG. 5 is a waveform diagram when a sensor signal of a plurality of magnetic sensor elements of a magnetic line sensor is subjected to rectangular wave processing and logic circuit processing to generate a pulse signal as a rotation signal. It is sectional drawing of the bearing with a rotation detection apparatus which incorporated the magnetic line sensor type | mold rotation detection apparatus of the said embodiment. (A) is a partial front view which shows the principle structure of the magnetic line sensor type | mold rotation detection apparatus concerning other embodiment of this invention, (B) is a partial top view of the magnetic line sensor type | mold rotation detection apparatus. It is sectional drawing of the bearing with a rotation detection apparatus which incorporated the magnetic line sensor type | mold rotation detection apparatus of the said embodiment. It is sectional drawing of the bearing with a rotation detection apparatus using the conventional Hall sensor or MR sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A ... Magnetic line sensor type rotation detection apparatus 2 ... Magnetic encoder ring 3 ... Magnetic line sensor 3a ... Magnetic sensor element 5 ... Multipolar magnet 5a ... Magnetic pole 6 ... Switch circuit 7 ... Output circuit 8 ... Control circuit 10, 10A ... Bearing with rotation detector

Claims (8)

  A magnetic encoder ring on the surface of which a multipolar magnet is formed and rotatable around the center of the ring; a magnetic line sensor in which a large number of magnetic sensor elements are arranged in a line and arranged in a radial direction facing the magnetic encoder ring; A switch that selects the output of the magnetic sensor element of the magnetic line sensor, an output circuit that amplifies and outputs the sensor signal output from the magnetic sensor element, and the magnetic sensor element that is selected by the switch can be freely set by an external input. And a magnetic line sensor type rotation detection device for detecting a magnetic field change accompanying rotation of the magnetic encoder ring.   A magnetic encoder ring having a multipolar magnet formed on its surface and rotatable around the center of the ring; a magnetic line sensor in which a large number of magnetic sensor elements are arranged in a line and arranged opposite to the magnetic encoder ring in the axial direction; A switch that selects the output of the magnetic sensor element of the magnetic line sensor, an output circuit that amplifies and outputs the sensor signal output from the magnetic sensor element, and the magnetic sensor element that is selected by the switch can be freely set by an external input. And a magnetic line sensor type rotation detection device for detecting a magnetic field change accompanying rotation of the magnetic encoder ring.   3. The control circuit according to claim 1, wherein the control circuit has a phase difference of 90 degrees according to the magnetic pole pitch of the magnetic encoder ring to be detected from among a large number of magnetic sensor elements of the magnetic line sensor. Two magnetic sensor elements can be selected, and the function of storing identification information in the magnetic line sensor of the two selected magnetic sensor elements is provided, and the output circuit is accompanied by rotation of the magnetic encoder ring. A magnetic line sensor type rotation detection device that outputs a two-phase rotation signal having a phase difference of 90 degrees as a rotation signal for detecting a magnetic field change.   3. The control circuit according to claim 1, wherein the control circuit has a position at which the phase difference is 90 degrees in accordance with the magnetic pole pitch of the magnetic encoder ring to be detected from among a plurality of magnetic sensor elements of the magnetic line sensor. A plurality of magnetic sensor elements adjacent to each other and having a function of storing identification numbers in the magnetic line sensors of the selected magnetic sensor elements, and the output circuit includes the plurality of magnetic sensors adjacent to each other. A magnetic line sensor type rotation detection device that takes a total output or an average output of sensor elements and outputs a two-phase rotation signal having a phase difference of 90 degrees as a rotation signal for detecting a magnetic field change accompanying rotation of the magnetic encoder ring.   5. The output circuit according to claim 3, wherein the output circuit differentially amplifies the output of the sensor element at a position 180 degrees out of phase with one selected sensor element and is 90 degrees different from the sensor elements. Also for the sensor element at the phase position, the output of the sensor element at a position 180 degrees out of phase with one selected sensor element is differentially amplified, thereby outputting a signal with a phase difference of 90 degrees. A magnetic line sensor type rotation detection device that selects a sensor element at a position that is 180 degrees out of phase that is differentially amplified along with the selection of one sensor element.   6. The method according to claim 1, wherein the control circuit selects a plurality of sensor elements, and the output circuit performs rectangular wave processing on outputs from the plurality of sensor elements between the magnetic pole pitches. A magnetic line sensor type rotation detection device which generates a signal pulse corresponding to a movement amount equal to or less than a magnetic pole pitch by a processing circuit including a logic circuit and outputs a rotation direction and a rotation amount signal.   7. The magnetic line sensor type rotation detection device according to claim 1, wherein the output circuit shapes an output signal into a rectangular wave and outputs the rectangular signal.   The bearing with a rotation detection apparatus provided with the magnetic line sensor type rotation detection apparatus in any one of Claims 1 thru | or 7.

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