JP2007256034A - Rotation angle detecting device and bearing provided with detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation angle detecting device which can accurately detect the rotation angle, without errors caused by time delays, and to provide a detection-device equipped bearing in which the rotation angle detecting device is incorporated. <P>SOLUTION: A magnet, arranged with a pair of magnetic poles are formed at an end of a rotating shaft which is rotatable with respect to a fixed member. A magnetic sensor, comprising a large-scale integrated circuit, is provided on the fixed member facing the magnet in the axial direction, and an angle calculation means 7 is provided for detecting the rotation angle of the rotating shaft from the output of the magnetic sensor. The rotation angle detecting device further comprises a rotation speed calculation means 11 for calculating the rotational speed from the temporal change in the rotation angle detected by the angle calculation means 7, and an angle time delay correction means 13 for correcting the time delay of the rotation angle, from the detection of magnetic field by the magnetic sensor to the output of the rotation angle by the angle calculation means 7, by using the rotation speed calculated by the rotation speed calculation means 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotation angle detection device used for rotation angle detection in various devices, for example, rotation angle detection for rotation control of a small motor, and a bearing with a detection device incorporating the rotation angle detection device.

As a rotation angle detection device that can be incorporated into a small device and can detect a rotation angle with high accuracy, a device using a magnetic sensor array has been proposed (for example, Patent Document 1). As shown in FIG. 13, a magnetic sensor array 45 configured by arranging a large number of magnetic sensor elements (MAGFETs) is integrated in a sensor chip 42 together with a circuit 46 such as a signal amplification circuit, an AD conversion circuit, and a digital signal processing circuit. This sensor chip 42 is disposed so as to face the magnet 44 disposed on the rotation side member 41. In this case, the magnet 44 has circumferential anisotropy around the rotation center O, and on the sensor chip 42, the magnetic sensor array 45 is arranged along each side of the four sides of the virtual rectangle. .
In the rotation angle detection device 43 configured in this way, the output of the magnetic sensor array 45 on each side is read by a signal amplification circuit and an AD conversion circuit to detect the magnetic field distribution of the magnet 44, and the magnet 44 is based on the detection result. Is calculated by a digital signal processing circuit.
JP 2003-37133 A

  In the operation of the rotation angle detection device having the above configuration, a cycle of magnetic field measurement → angle calculation → angle output is repeated, and therefore angle data is output at a constant time interval corresponding to the cycle. For this reason, the output angle data has a time delay corresponding to the time required for angle calculation, and there is a problem that accurate angle information at the observation time cannot be obtained. In addition, when controlling the rotation of the motor by detecting the rotation angle and rotation speed using this rotation angle detection device, there is a problem that it is difficult to accurately detect the rotation angle and rotation speed at an arbitrary time. It was.

An object of the present invention is to provide a rotation angle detection device capable of detecting an accurate rotation angle without error due to time delay, and a bearing with a detection device incorporating the rotation angle detection device.
Another object of the present invention is to use a rotation angle detection device capable of accurately detecting a rotation angle at an arbitrary time by detecting the angle of a rotation shaft such as a motor, and a detection device incorporating the rotation angle detection device. Provided bearings.

In the rotation angle detection device according to the present invention, a magnet having a pair of magnetic poles is disposed at the shaft end of a rotating shaft that is rotatable with respect to a fixed member, and the magnet is opposed to the magnet in the axial direction and is large on the fixed member. In a rotation angle detection device provided with a magnetic sensor comprising a scale integrated circuit and provided with an angle calculation means for detecting the rotation angle of the rotary shaft from the output of the magnetic sensor, from the time change of the rotation angle detected by the angle calculation means A rotational speed calculating means for calculating the rotational speed and a rotational speed calculated by the rotational speed calculating means correct a time delay of the rotational angle from the detection of the magnetic field by the magnetic sensor to the output of the rotational angle by the angle calculating means. And an angle time delay correcting means for performing the operation.
The output of the angle calculation means for detecting the rotation angle of the rotating shaft from the output of the magnetic sensor has a time delay from the time when the magnetic sensor samples the magnetic field of the magnet until the rotation angle is calculated and output. Therefore, the actual rotation angle of the rotation axis when the rotation angle data is read may be different from the read data. Therefore, based on the rotation speed calculated by the rotation speed calculation means from the time change of the rotation angle detected by the angle calculation means, the rotation speed calculation means corrects the time delay of the rotation angle detected by the angle calculation means. Thereby, the exact rotation angle of a rotating shaft is detectable.

In the present invention, the rotation angle corrected by the angle time delay correction means is obtained at fixed time intervals, and from the rotation angle information at fixed time intervals and the rotation speed information calculated by the rotation speed calculation means, an arbitrary value is obtained. You may provide the rotation angle estimation means which estimates the rotation angle of the said rotating shaft in time.
Since the rotation angle data corrected by the angle time delay correction means is discrete data output at a constant time interval, angle information cannot be obtained more finely than the interval at which the data is updated. Accordingly, the rotation angle estimation means estimates the angle value at the time when the rotation angle data is requested from the rotation angle data and the rotation speed, and estimates the rotation angle at an arbitrary time. As a result, the rotation angle at an arbitrary time can be accurately detected.

  In the present invention, the angle calculation means, the rotation speed calculation means, and the angle time delay correction means may be integrated in a large-scale integrated circuit constituting the magnetic sensor. In the case of this configuration, the rotation angle data output from the semiconductor chip on which the large-scale integrated circuit is integrated indicates the rotation angle at that time. Therefore, for control in various devices that operate by receiving this data. Therefore, the rotation angle detection device can be more easily handled.

  In the present invention, the angle calculation means, the rotation speed calculation means, the angle time delay correction means, and the rotation angle estimation means may be integrated in a large-scale integrated circuit constituting the magnetic sensor. In the case of this configuration, it is possible to realize a small and highly accurate rotation angle detection device that can obtain an accurate rotation angle at an arbitrary time.

The bearing with a detecting device of the present invention is obtained by incorporating the rotational angle detecting device having any one of the above-described configurations of the present invention into a bearing.
According to this configuration, it is possible to reduce the number of parts, the number of assembling steps, and the size of the bearing using device.

A rotation control device for a motor according to the present invention includes a rotation angle detection device having any one of the above configurations according to the present invention, and a control circuit for controlling the excitation current and excitation timing of the motor by the output of the rotation angle of the rotation angle detection device. It is equipped with.
According to this configuration, rotation control of the motor can be performed with high accuracy. In particular, when the rotation angle estimation means is provided, the magnetic pole position of the motor at an arbitrary time can be accurately known, so that the excitation efficiency is increased in order to increase the efficiency of the motor and keep the rotation noise low. For example, when controlling the timing, fine control according to the rotation speed and the rotation angle of the rotor is effective. In this case, it becomes possible to detect the angle with high accuracy by a small rotation angle detection device, and the device can be downsized and improved in performance.

In the rotation angle detection device according to the present invention, a magnet having a pair of magnetic poles is disposed at the shaft end of a rotating shaft that is rotatable with respect to a fixed member, and the magnet is opposed to the magnet in the axial direction and is large on the fixed member. In a rotation angle detection device provided with a magnetic sensor comprising a scale integrated circuit and provided with an angle calculation means for detecting the rotation angle of the rotary shaft from the output of the magnetic sensor, from the time change of the rotation angle detected by the angle calculation means A rotational speed calculating means for calculating the rotational speed and a rotational speed calculated by the rotational speed calculating means correct a time delay of the rotational angle from the detection of the magnetic field by the magnetic sensor to the output of the rotational angle by the angle calculating means. Therefore, it is possible to accurately detect the rotation angle without error due to the time delay.
Since the bearing with the detection device of the present invention incorporates the rotation angle detection device of the present invention in the bearing, the number of parts of the bearing-using device, the number of assembly steps can be reduced, and the size can be reduced. The motor rotation control device according to the present invention includes the rotation angle detection device according to the present invention and a control circuit that controls the excitation current and the excitation timing of the motor by the output of the rotation angle of the rotation angle detection device. Therefore, the rotation control of the motor can be performed with high accuracy. In particular, when the rotation angle detection device has rotation angle estimation means, it is possible to accurately know the magnetic pole position of the motor at an arbitrary time, so that the efficiency of the motor is increased and the rotation noise is kept low. When controlling the excitation timing, fine control according to the rotation speed and the rotation angle of the rotor is effective.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a cross-sectional view of a bearing incorporating the rotation angle detection device of this embodiment. This bearing 20 with a detecting device is a rolling bearing in which a rolling element 24 held by a cage 23 is interposed between rolling surfaces of an inner ring 21 and an outer ring 22. The rolling element 24 is formed of a ball, and the rolling bearing 20 is a single row deep groove ball bearing. A rotating shaft 10 that is a rotating member is fitted into the inner ring 21 in a press-fitted state, and the outer ring 22 is installed in a housing (not shown) of a bearing-using device.

The rotation angle detection device 1 incorporated in the rolling bearing 20 includes a magnet 2 disposed on the inner ring 21 side of the rolling bearing 20 and a rotation sensor 3 disposed on the outer ring 22 side. Specifically, the permanent magnet 2 having a pair of magnetic poles N and S is disposed on the rotating shaft 10 that rotates together with the inner ring 21, and the rotation sensor 3 is disposed on the sensor mounting member 27 that is in a fixed relationship with the outer ring 22. The
As shown in FIG. 2, the magnet 2 has a direction in which the magnetism generated from the pair of magnetic poles N and S is around the axis O of the rolling bearing 20. The magnet 2 is fixed to the center of one end of the rotating shaft 10 so that the axis O of the rolling bearing 20 coincides with the center of the magnet 2. When the magnet 2 rotates integrally with the rotary shaft 10, the N magnetic pole and the S magnetic pole pivot around the bearing axis O.

  The rotation sensor 3 is a sensor that senses the magnetism of the magnet 2 and outputs information on the rotation angle. The rotation sensor 3 is attached to the outer ring 22 side via a sensor attachment member 27 so as to face the magnet 2 in the axial direction of the axis O of the rolling bearing 20. Specifically, the sensor attachment member 27 is attached to the outer ring 22, and the rotation sensor 3 is fixed to the sensor attachment member 27. The sensor mounting member 27 has an outer peripheral cylindrical portion 27 a fitted on the inner diameter surface of the outer ring 22, and a flange portion 27 b formed near the distal cylindrical portion 27 a is engaged with the width surface of the outer ring 22 in the axial direction. Positioning has been made. An output cable 29 for taking out the output of the rotation sensor 3 is also attached to the sensor attachment member 27.

  The rotation sensor 3 is configured by integrating a large scale integrated circuit (LSI) on one semiconductor chip 4 as shown in a plan view in FIG. The large-scale integrated circuit includes a plurality of magnetic sensor elements 5a constituting the magnetic sensor 5, and an arithmetic circuit unit 6 that calculates and outputs a rotation angle from the output of the magnetic sensor element 5a. On the semiconductor chip 4, the magnetic sensor elements 5 a are arranged along each side of the four sides on the virtual rectangle to form the four-side magnetic sensor arrays 5 </ b> A to 5 </ b> D. In this case, the center O ′ of the rectangle coincides with the axis O of the rolling bearing 20. In the four-side magnetic sensor arrays 5A to 5D, the sensor elements 5a are arranged in a line in the example of the figure, but the sensor elements 5a may be arranged in parallel in a plurality of lines. The arithmetic circuit unit 6 is arranged inside the rectangular arrangement of the magnetic sensor arrays 5A to 5D. The semiconductor chip 4 is fixed to the sensor mounting member 27 so that the element formation surface faces the magnet 2.

  As described above, when the magnetic sensor element 5a and the arithmetic circuit unit 6 are integrated and integrated on the semiconductor chip 4, wiring between the magnetic sensor element 5a and the arithmetic circuit unit 6 becomes unnecessary, and the rotation sensor 3 can be made compact. It is possible to improve the reliability against disconnection and the like, and the assembly operation of the rotation angle detection device 1 is facilitated. In particular, if the arithmetic circuit unit 6 is arranged inside the magnetic sensor arrays 5A to 5D arranged in a rectangular shape as described above, the chip size can be further reduced.

  The arithmetic circuit unit 6 includes an angle calculation unit 7, a rotation speed calculation unit 11, an angle time delay correction unit 13 (FIG. 7), and a rotation angle estimation unit 14 (FIG. 8). The angle calculation means 7 is means for detecting the rotation angle of the rotary shaft 10 from the output of the magnetic sensor 5. The rotation speed calculation means 11 is a means for calculating the rotation speed from the time change of the rotation angle detected by the angle calculation means 7. The angle time delay correction means 13 is a means for correcting the time delay of the rotation angle from the detection of the magnetic field by the magnetic sensor 5 to the output of the rotation angle by the angle calculation means 7. The rotation angle estimation means 14 obtains the rotation angle corrected by the angle time delay means 13 every fixed time, and the rotation angle information for each fixed time and the rotation speed information calculated by the rotation speed calculation means 11 From this, the rotation angle of the rotary shaft 10 at an arbitrary time is estimated.

4 and 5 are explanatory diagrams of the rotation angle calculation processing by the angle calculation means 7 (FIG. 7). 5A to 5D show output waveform diagrams of the magnetic sensor arrays 5A to 5D when the rotary shaft 10 is rotating, and the horizontal axes thereof are magnetic sensor elements in the magnetic sensor arrays 5A to 5D. 5a, the vertical axis indicates the intensity of the detected magnetic field.
Now, assume that there are zero-cross positions at the positions X1 and X2 shown in FIG. 4 that are the boundaries between the N magnetic pole and the S magnetic pole of the detected magnetic field of the magnetic sensor arrays 5A to 5D. In this state, the outputs of the magnetic sensor arrays 5A to 5D have signal waveforms shown in FIGS. Therefore, the zero cross positions X1 and X2 can be calculated by linear approximation from the outputs of the magnetic sensor arrays 5A and 5C.
The angle calculation can be performed by the following equation (1).
θ = tan ⁻¹ (2 L / b) (1)
Here, θ is a value indicating the rotation angle of the magnet 2 as an absolute angle (absolute value). 2L is the length of one side of a quadrangle composed of the magnetic sensor arrays 5A to 5D arranged in a rectangle. b is the lateral length between the zero-cross positions X1 and X2.
When the zero-cross positions X1 and X2 are in the magnetic sensor arrays 5B and 5D, the rotation angle θ is calculated in the same manner as described above based on the zero-cross position data obtained from the outputs.

  FIG. 6 is a timing chart showing a processing operation cycle in which the magnetic sensor circuit 8 (FIG. 7) including the magnetic sensor arrays 5A to 5D and the angle calculating means 7 detects and outputs the rotation angle θ. In the first half section Ta of the time T of one cycle, the magnetic sensor arrays 5A to 5D, which are the magnetic sensors 5 of the rotation sensor 3, sample the magnetic field of the magnet 2 on the rotation side, and in the second section Tb of the one cycle, The angle calculation means 7 calculates the rotation angle θ from the sampled value and outputs it. As described above, since there is a time delay until the angle data is calculated, the actual rotation angle of the rotation shaft 10 when the rotation angle data is read may be different from the read data.

  The rotation speed calculation means 11 (FIG. 7) in the arithmetic circuit section 6 obtains the amount of change from the data of the rotation angle θ output from the angle calculation means 7 every time T as described above. Is calculated.

FIG. 7 is a block diagram showing a part of the circuit configuration of the rotation sensor 3. Magnetic data obtained by sampling each time by the magnetic sensor arrays 5 </ b> A to 5 </ b> D is amplified and AD converted and input to the angle calculation means 7. The angle calculation means 7 calculates the rotation angle θ each time by performing the arithmetic processing shown in FIGS. 4 and 5 based on the sampling values of the magnetic sensor arrays 5A to 5D each time.
On the other hand, the rotation speed calculation means 11 calculates the rotation speed ω and the rotation direction from the amount of change in the rotation angle data θ output from the angle calculation means 7 every time T and the elapsed time T obtained by the timer 12. Is calculated. The calculation of the rotational speed ω is performed as follows, for example.
Assuming that the rotation angle θ (n) sampled every time changes, the rotation speed ω can be obtained from the angle change amount between successive samplings as shown in the following equation (2).
ω = {θ (n + 1) −θ (n)} / T (2)
However, θ (n) and θ (n + 1) represent rotation angles obtained by the n-th and (n + 1) -th sampling.

The angular time delay correction means 13 corrects the rotation angle θ calculated by the angle calculation means 7 based on the rotation speed ω data obtained in this way and the elapsed time obtained by the timer 12. That is, the angle time delay correction means 13 is necessary for the angle calculation means 7 to calculate the rotation angle θ (n) when the rotation shaft 10 is rotating at the rotation speed ω calculated by the rotation speed calculation means 11. It can be estimated by the following equation (3) how much the rotation angle θ changes during the time Tb.
θ (n + Tb) = θ (n) + ω × Tb (3)
However, (theta) (n + Tb) is a rotation angle at the time of the calculation by the angle calculation means 7 having been completed from the n-th sampling.
Since the rotation angle detection device 1 is configured to detect the rotation of the magnet 2 provided at the shaft end of the rotation shaft 10 by the rotation sensor 3, the rotation speed ω varies rapidly due to the inertia of the rotation shaft 10 that is a rotating body. Therefore, it is possible to estimate a rotation angle with a considerably high accuracy by correcting the rotation angle.
Here, the rotation speed calculation means 11 and the angle time delay correction means 13 are provided together with the angle calculation means 7 as a part of a large-scale integrated circuit integrated on the semiconductor chip 4. The rotation angle θ data output from the chip 4 indicates the rotation angle at that time, and the rotation angle detection device 1 is easier to handle for control in various devices that operate by receiving this data.
The rotation speed calculation unit 11 and the angle time delay correction unit 13 may be provided separately from the semiconductor chip 4.

FIG. 8 is a block diagram showing the configuration of the rotation angle estimating means 14 in the arithmetic circuit section 6. In the figure, the rotation angle detection circuit 9 shows a circuit unit including the angle calculation stage 7, the rotation speed calculation stage 11, the timer 12, and the angle time delay correction means 13 in FIG. 7. Since the rotation angle data θ corrected by the time delay obtained by the rotation angle detection circuit 9 is discrete data output at intervals of the fixed time T as described above, it is finer than the interval at which the data is updated. Angle information cannot be obtained.
Therefore, the rotation angle estimation means 14 predicts and interpolates the angle value at the time when the rotation angle data is requested from the rotation angle data θ and the rotation speed ω. Specifically, as shown in FIG. 9, the rotation angle estimation means 14 receives the request trigger a from time t2 when the latest rotation angle data (for example, θ2) output from the rotation angle detection circuit 9 is output. The elapsed time [Delta] t is measured by the timer 15, and the angle change amount predicted from the rotational speed [omega] is added to the data. That is, the rotation angle estimation means 14 temporarily stores the rotation angle data θ, the rotation speed ω, and the elapsed time in the memory 16 and predicts the rotation angle θ when the request trigger signal a is received from these values. . As a result, the rotation angle data θ 2 + Δθ at time t 2 + Δt when the request trigger a is input can be output. That is, the rotation angle at an arbitrary time can be accurately detected and output even when the rotating shaft 10 is rotating or stationary. The rotation angle θ calculated by the arithmetic circuit unit 6 is output by the output cable 29 (FIG. 1).
Here, as a part of a large-scale integrated circuit integrated on the semiconductor chip 4, the rotation angle estimation means 14 is provided together with the angle calculation means 7, the rotation speed calculation means 11 and the angle time delay correction means 13. Therefore, a small and highly accurate rotation sensor 3 capable of obtaining accurate rotation angle information at an arbitrary time is configured, and a compact rotation angle detection device 1 can be realized.
Note that the rotation angle estimation means 14 may be provided separately from the semiconductor chip 4.
In the above example, a semiconductor sensor using a magnetic sensor array is used as the magnetic sensor. However, the same effect can be obtained by using a semiconductor sensor such as a vector type magnetic sensor for detecting the direction of the magnetic field. Can be obtained.

  Moreover, in the bearing 20 with a detection apparatus of FIG. 1, since the said rotation angle detection apparatus 1 is integrated in the rolling bearing 20, the number of parts of a bearing using apparatus, the reduction of an assembly man-hour, and compactization can be achieved.

  FIG. 10 is a block diagram showing a schematic configuration of an example of a motor rotation control device such as a servo motor or a brushless motor equipped with the rotation angle detection device 1 having the above-described configuration. The motor rotation control device 30 includes the rotation angle detection device 1, a driver circuit 32 that switches the excitation current of the stator coil for rotating the rotor 31 according to the rotation angle detection value of the detection device, And a control circuit 33 for adjusting the excitation current switching timing and controlling the rotation state of the motor. Here, the stator coil has three phases, and switching of the excitation current to the stator coil of each phase is performed by the driver circuit 32. The control circuit 33 performs switching control of the excitation current based on the rotation angle θ of the rotor 25 detected by the rotation angle detection device 1, and also performs feedback angle control of the excitation current by feeding back the excitation current flowing through the stator coil. . In particular, according to the rotation angle detection device 1, since the magnetic pole position of the motor at an arbitrary time can be accurately known, the excitation timing is controlled in order to increase the efficiency of the motor and to keep the rotation noise low. In some cases, fine control according to the rotation speed and the rotation angle of the rotor is effective. In this case, the small rotation angle detection device 1 can detect the angle with high accuracy, and the device can be reduced in size and performance.

FIG. 11 shows an example in which the bearing 20 with the detection device of FIG. 1 is incorporated into the shaft end of the rotating shaft 10 of the brushless motor 34. The brushless motor 34 includes a cylindrical motor housing 35 whose both ends are closed, a rotating shaft 10 concentrically disposed on the motor housing 35, a rotor 36 provided on the rotating shaft 10, and a radial direction of the rotor 36. And a stator 37 provided on the inner peripheral surface of the motor housing peripheral wall 35a. The rotary shaft 10 is rotatably supported at both ends of the motor housing 35 by the bearing 20 with the detection device and the other bearing 19.
In this case, since the rotation angle detection device 1 is integrated with the bearing 20, it is compact and does not require assembly adjustment, reduces the number of assembly steps, and is highly convenient.

  FIG. 12 shows another example in which the rotation angle detection device 1 is incorporated in the shaft end of the rotation shaft 10 of the brushless motor 34. Here, instead of attaching the sensor attachment member 27 to the outer ring 22 of the bearing 20, a sensor attachment member 47 is attached to a bearing fitting portion 39 formed on the motor housing end wall 35b. The rotation sensor 3 is attached via the circuit board 38. That is, in this example, the rotation angle detection device 1 is completely separated from the bearing 20. A stepped portion 39a concentric with the axis O of the rotary shaft 10 is formed in the bearing fitting portion 39, and an annular convex portion 47b provided on the back surface of the main body 47a of the sensor mounting member 47 is formed on the stepped portion 39a. The rotation sensor 3 (FIG. 1) is arrange | positioned concentrically with the rotating shaft 10 by making it fit. The sensor mounting member 47 is fixed to the motor housing end wall 35b by fitting the annular protrusion 47b to the stepped portion 39a of the bearing fitting portion 39 and fastening the sensor mounting member main body 47a with the mounting screw 40. The In this case, the axial position of the rotation sensor 3 with respect to the bearing 20 is determined, and the axial position of the magnet 2 with respect to the bearing 20 is determined when the rotating shaft 10 is fitted to the inner ring 21 of the bearing 20. The axial gap (gap) between the magnet 2 and the rotation sensor 3 can be kept within a specified range in a state where the magnet 2 and the rotation sensor 3 are fitted.

It is sectional drawing of the bearing with a detection apparatus incorporating the rotation angle detection apparatus with a rotational speed signal output which concerns on one Embodiment of this invention. It is an enlarged side view which shows the rotation angle detection apparatus installation part in the same bearing. It is a top view of the semiconductor chip which constitutes an example of the rotation sensor in the bearing. It is explanatory drawing of the angle calculation process by the angle calculation means of the rotation sensor. It is a wave form diagram which shows the output of the magnetic sensor array in the rotation sensor. It is a timing chart which shows the cycle of the processing operation which the rotation sensor detects and outputs a rotation angle. It is a block diagram which shows a part of circuit structure of the rotation sensor. It is a block diagram which shows the rotation angle estimation means in the rotation sensor. It is explanatory drawing which shows the processing operation of a rotation angle estimation means. It is a block diagram which shows schematic structure of an example of the drive device of the motor incorporating a rotation angle detection apparatus. It is sectional drawing of an example of the brushless motor incorporating the rotation angle detection apparatus. It is a partial expanded sectional view of the other example of the brushless motor incorporating the rotation angle detection apparatus. It is a perspective view of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rotation angle detection apparatus 2 ... Magnet 3 ... Rotation sensor 4 ... Semiconductor chip 5 ... Magnetic sensor 7 ... Angle calculation means 10 ... Rotating shaft 11 ... Rotation speed calculation means 13 ... Angle time delay correction means 14 ... Rotation angle estimation means 20 ... Bearing 27 with detection device ... Sensor mounting member (fixing member)
30 ... Motor rotation control device

Claims (6)

A magnet having a pair of magnetic poles is arranged at the shaft end of a rotating shaft that is rotatable with respect to the fixed member, and a magnetic sensor comprising a large-scale integrated circuit is provided on the fixed member so as to face the magnet in the axial direction. In the rotation angle detection device provided with an angle calculation means for detecting the rotation angle of the rotation shaft from the output of the magnetic sensor,
Rotation speed calculation means for calculating the rotation speed from the time change of the rotation angle detected by the angle calculation means, and rotation by the angle calculation means from detection of the magnetic field by the magnetic sensor by the rotation speed calculated by the rotation speed calculation means. A rotation angle detection device comprising angle time delay correction means for correcting a time delay of the rotation angle until the angle is output.   2. The rotation angle corrected by the angle time delay correction unit according to claim 1 is obtained at fixed time intervals, and from any rotation angle information for each fixed time interval and rotation speed information calculated by the rotation speed calculation unit, an arbitrary value is obtained. A rotation angle detection device provided with rotation angle estimation means for estimating the rotation angle of the rotation shaft at the time of.   3. The rotation angle detection device according to claim 1, wherein the angle calculation unit, the rotation speed calculation unit, and the angle time delay correction unit are integrated in a large-scale integrated circuit constituting the magnetic sensor.   3. The rotation angle detection device according to claim 2, wherein the angle calculation unit, the rotation speed calculation unit, the angle time delay correction unit, and the rotation angle estimation unit are integrated in a large-scale integrated circuit constituting the magnetic sensor.   The bearing with a detection apparatus which incorporated the rotation angle detection apparatus of any one of Claim 1 thru | or 4 in the bearing.   A motor comprising: the rotation angle detection device according to any one of claims 1 to 4; and a control circuit that controls the excitation current and excitation timing of the motor according to an output of the rotation angle of the rotation angle detection device. Rotation control device.

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