JP2007327800A - Rotation angle detector, and electric power steering device equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multirotational rotation angle detector capable of reducing a cost and capable of saving a space. <P>SOLUTION: A resolver 30 is attached to a steering shaft 102 of an electric power steering device. The resolver 30 is provided with the first stator 321 and the second stator 322 fixed onto a stator housing 310, the first rotor 331 fixed onto the first rotary shaft member 341, the second rotor 332 fixed onto the second rotary shaft member 342. The stator housing 310 is screw-connected to the first rotary shaft member 341 by a screw part 360. The first rotary shaft member 341 is thereby moved vertically in accompaniment to rotation. Resultingly, a relative positional relation between the first stator 321 and the first rotor 331 is changed to change a transformation ratio K. A voltage level of an angle signal D output from the resolver 30 is changed thereby. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotation angle detection device for detecting an absolute angle of multiple rotations and an electric power steering device including the rotation angle detection device.

  2. Description of the Related Art Conventionally, a resolver type rotation angle detection device is known as a device for detecting a steering angle of a steering wheel in an electric power steering device. FIG. 7 is a cross-sectional view showing a configuration of a conventional rotation angle detection device in the electric power steering device. This rotation angle detection device is composed of a resolver 40 and a rotation speed detector 50. The resolver 40 includes a stator housing 410, a first stator 421, a second stator 422, a first rotor 431, a second rotor 432, a first rotating shaft member 441, and a second rotating shaft member 442. ing. The first stator 421 and the second stator 422 are fixed to the stator housing 410, the first rotor 431 is fixed to the first rotating shaft member 441, and the second rotor 432 is the second rotating shaft member 442. It is fixed to. The first stator 421 and the first rotor 431 are opposed to each other, and the second stator 422 and the second rotor 432 are opposed to each other. The first rotor 431 and the second rotor 432 are electrically connected to each other. The rotation speed detector 50 includes a rotation speed detection sensor 51 for counting the rotation speed and gears 52 and 53 for fixing the rotation speed detection sensor 51 so that the rotation speed of the resolver 40 can be counted. I have.

  The first stator 421 receives a first voltage signal SR as an excitation signal given from the outside, and transmits it to the first rotor 431 (hereinafter referred to as “first stator winding”). have. The first rotor 431 has a winding (hereinafter referred to as “first rotor winding”) for inducing a voltage (second voltage signal) based on the first voltage signal SR. . The second rotor 432 receives a second voltage signal as an excitation signal from the first rotor 431 and transmits it to the second stator 422 (hereinafter referred to as “second rotor winding”). )have. The second stator 422 has a winding (hereinafter referred to as “sin winding”) in which a sinusoidal voltage is induced on the basis of zero of the absolute angle (when attention is paid to the relationship between the rotation angle and the voltage). And a winding (hereinafter referred to as a “cos winding”) configured to induce a cosine-curve-like voltage with reference to zero of the absolute angle.

  In the rotation angle detection device shown in FIG. 7, when the first voltage signal SR as an excitation signal is given to the first stator winding from the outside, the first rotor winding is applied to the first rotor winding based on the first voltage signal SR. A voltage (second voltage signal) is induced. At this time, the voltage level of the second voltage signal has a magnitude based on a ratio (transformation ratio) between the number of turns of the first stator winding and the number of turns of the first rotor winding. A second voltage signal induced in the first rotor winding is sent to the second rotor winding. In the second stator 422, the voltage as described above is induced in the sin winding and the cos winding using the second voltage signal applied to the second rotor winding as an excitation signal. Then, the relative angle is obtained based on the voltage induced in the sin winding (sin signal) and the voltage induced in the cos winding (cos signal). On the other hand, the rotation speed detection sensor 51 counts the rotation speed of the resolver 40. The absolute angle is detected based on the relative angle and the rotational speed detected as described above.

Japanese Patent Application Laid-Open No. 2001-194251 discloses a first resolver signal output from the first resolver provided on the upper shaft of the torsion bar and an output from the second resolver provided on the lower shaft of the torsion bar. An invention of a power steering device that detects a steering torque and a steering angle based on a second resolver signal is disclosed.
JP 2001-194251 A

  According to the conventional configuration shown in FIG. 7, in addition to the resolver 40, a rotation speed detector 50 for counting the rotation speed is provided. Further, according to the configuration disclosed in the above Japanese Patent Application Laid-Open No. 2001-194251, two resolvers are provided. Conventionally, the relative angle can be detected only by (one) resolver, but the absolute angle of multiple rotations cannot be detected. For this reason, in order to detect the absolute angle of multiple rotations, as described above, a configuration including a sensor for detecting the number of rotations or a configuration including a plurality of resolvers has been required. As a result, cost reduction and space saving are problems.

  Therefore, an object of the present invention is to provide a multi-rotation angle detector that can realize cost reduction and space saving.

A first invention is a resolver type rotation angle detection device including a first rotation transformer that transmits an excitation signal to a secondary side in a non-contact manner and a second rotation transformer that generates a position signal from the excitation signal,
The first rotary transformer
A first stator having a first stator winding for receiving a first voltage signal as an excitation signal;
According to the relative positional relationship with the first stator winding based on the first voltage signal, which is provided inside the first stator and is configured to be rotatable around a predetermined rotation axis. A first rotor having a first rotor winding for generating a second voltage signal,
The second rotary transformer is
A second rotor having a second rotor winding that rotates with the first rotor and receives the second voltage signal from the first rotor winding;
A second voltage signal that is provided outside the second rotor and generates a third voltage signal as a position signal corresponding to a rotation angle of the second rotor based on the second voltage signal as an excitation signal; A second stator having a stator winding,
Only the first rotor moves in the predetermined rotation axis direction with rotation, and the relative positional relationship between the first stator winding and the first rotor winding changes due to the movement. It is characterized by.

A second invention is an electric power steering apparatus including a steering shaft composed of a first shaft and a second shaft connected by a torsion bar,
A rotation angle detection device according to the first aspect of the present invention is provided that detects a rotation angle of the first shaft or the second shaft.

A third invention is an electric power steering device including a steering shaft composed of a first shaft and a second shaft connected by a torsion bar,
Each of the first shaft and the second shaft includes the rotation angle detection device according to the first invention, and the rotation angles of the first shaft and the second shaft detected by the rotation angle detection device. The steering torque and the steering angle are detected based on the above.

  According to the first aspect, the relative positional relationship between the first stator winding and the first rotor winding changes with the rotation of the first rotor. For this reason, the transformation ratio of the 1st rotation transformer (rotation transformer) comprised by the 1st stator and the 1st rotor changes with rotation of the 1st rotor. Here, the voltage level of the third voltage signal as the position signal (angle signal) generated by the second stator winding is the voltage of the second voltage signal applied as the excitation signal to the second rotor winding. Depends on the level. The second voltage signal is generated by the first rotary transformer based on a first voltage signal supplied as an excitation signal from the outside to the first stator winding. Therefore, the voltage level of the third voltage signal depends on the transformation ratio of the first rotary transformer. Further, the transformation ratio changes as the first rotor rotates as described above. For this reason, even if the relative angles are the same, the voltage level of the third voltage signal has a different magnitude if the rotational speed is different. Therefore, the rotational speed can be detected by the third voltage signal. Thereby, the absolute angle of multiple rotations can be detected from the relative angle and the rotation speed based only on the third voltage signal. Therefore, the absolute angle of multiple rotations can be detected without providing other sensors.

  According to the second aspect, in the electric power steering apparatus, the rotation angle of the multi-rotation of the handle can be detected by only one rotation angle detection device. In addition, a rotation angle detection device can be used to detect torque due to steering operation. For this reason, parts required for the entire electric power steering apparatus are reduced, and the cost is reduced.

  According to the third aspect, in the electric power steering apparatus, improvement in steering feeling and reduction in cost are realized.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

<1. Resolver configuration>
FIG. 1 is a cross-sectional view showing a configuration of a resolver-type rotation angle detection device (hereinafter referred to as “resolver”) 30 according to an embodiment of the present invention. The resolver 30 includes a stator housing 310, a first stator 321, a second stator 322, a first rotor 331, a second rotor 332, a first rotating shaft member 341, and a second rotating shaft member 342. I have. The first stator 321 and the second stator 322 are fixed to the stator housing 310, the first rotor 331 is fixed to the first rotating shaft member 341, and the second rotor 332 is the second rotating shaft member 342. It is fixed to. The first stator 321 and the first rotor 331 are opposed to each other, and the second stator 322 and the second rotor 332 are opposed to each other. Further, the first rotor 331 and the second rotor 332 are electrically connected to each other.

  In the present embodiment, the resolver 30 is attached to the steering shaft 102 of the electric power steering apparatus. One end of the steering shaft 102 is fixed to the handle. As shown in FIG. 1, a key 103 is provided on the steering shaft 102 of the electric power steering apparatus, and a key groove 350 is provided on the first rotating shaft member 341 of the resolver 30. The key groove 350 of the first rotating shaft member 341 is loosely fitted to the key 103 of the steering shaft 102 so as to be slidable. Further, the first rotating shaft member 341 and the second rotating shaft member 342 rotate with the rotation of the steering shaft 102 around the rotating shaft 200. Here, the stator housing 310 and the first rotating shaft member 341 are screwed together by a screw portion 360. Thereby, the 1st rotating shaft member 341 moves up and down with rotation. As a result, the relative positional relationship between the first stator 321 and the first rotor 331 changes as the handle rotates.

  As described above, the first stator 321 and the first rotor 331 are opposed to each other. The first stator 321 has a first stator winding for receiving a first voltage signal SR as an excitation signal given from the outside and transmitting it to the first rotor 331. The first rotor 331 has a first rotor winding for inducing a voltage (second voltage signal) based on the first voltage signal SR. As described above, the first stator 321 and the first rotor 331 form a transformer (first rotary transformer) having the first stator 321 as the primary side and the first rotor 331 as the secondary side. ing.

  As described above, the second stator 322 and the second rotor 332 face each other, and the first rotor 331 and the second rotor 332 are electrically connected to each other. The second rotor 332 has a second rotor winding for receiving a second voltage signal as an excitation signal from the first rotor 331 and transmitting it to the second stator 322. Further, the second stator 322 includes a sin winding that is configured so that a sinusoidal voltage is induced with reference to the absolute angle zero degree (when attention is paid to the relationship between the rotation angle and the voltage) A cosine winding configured to induce a cosine-curve voltage with reference to zero angle. As described above, the second stator 322 and the second rotor 332 form a transformer (second rotary transformer) having the second stator 322 as the primary side and the second rotor 332 as the secondary side. ing.

<2. Absolute angle detection>
Next, detection of the absolute angle of multiple rotations in this embodiment will be described. The first stator winding is supplied with a first voltage signal SR as an excitation signal from the outside. At this time, with respect to the transformer constituted by the first stator 321 and the first rotor 331, the voltage across the first stator winding is V1, and the voltage across the first rotor winding is V2. When the transformation ratio is K, the following equation (1) is established.
K = V1 / V2 (1)

  Here, if the number of turns N of the winding in the portion facing the first stator winding in the first rotor winding increases, the transformation ratio K decreases. On the other hand, if the number of turns N is reduced, the transformation ratio K is increased.

  A voltage V2 calculated from equation (1) is induced in the first rotor winding. The induced voltage V <b> 2 is sent from the first rotor 331 to the second rotor 332 as a second voltage signal. In the second rotor 332, the second voltage signal is applied to the second rotor winding as an excitation signal. Here, the second rotor 332 faces the second stator 322 having the above-described sin winding and cos winding. As a result, a voltage corresponding to the rotation angle is induced in the sin winding and the cos winding of the second stator 322 based on the voltage level V2 of the second voltage signal. Specifically, as described above, a sinusoidal voltage (hereinafter referred to as “sin signal”) is induced in the sin winding with reference to the absolute angle zero degree, and the absolute angle zero in the cos winding. As a result, a cosine curve voltage (hereinafter referred to as “cos signal”) is induced. In the present embodiment, the third voltage signal is configured by the sin signal and the cos signal.

  In the present embodiment, as the first rotating shaft member 341 rotates, the relative positional relationship between the first stator 321 and the first rotor 331 changes. For this reason, the number N of turns of the first rotor winding in the portion facing the first stator winding changes due to the rotation. That is, the transformation ratio K of the transformer constituted by the first stator 321 and the first rotor 331 changes due to the rotation. As a result, if the number of turns N increases, the transformation ratio K decreases, so that the voltage level V2 of the second voltage signal increases as can be understood from the equation (1). On the other hand, if the number of turns N decreases, the transformation ratio K increases, so that the voltage level V2 of the second voltage signal decreases. Thus, the voltage level V2 of the second voltage signal changes according to the rotation. As a result, even if the relative angles are the same, for example, the voltage levels of the sine and cos signals generated at the first rotation are different from the voltage levels of the sine and cos signals generated at the second rotation. Thereby, the number of rotations can be detected based on the difference in the voltage level, and the absolute angle at the time of multiple rotations is obtained from the relative angle and the number of rotations.

<3. Resolver operation>
Next, the operation of the resolver 30 according to the present embodiment will be described in detail with reference to FIGS. 2 and 3. As described above, the first rotating shaft member 341 moves up and down with rotation. For this reason, for example, when the steering angle (absolute angle) of the handle is zero degree, the handle rotates as shown in FIG. 1 (with the first stator 321 and the first rotor 331). As a result, the positional relationship shown in FIG. 2 is obtained. Here, as described above, the transformation ratio K of the transformer constituted by the first stator 321 and the first rotor 331 changes due to the vertical movement of the first rotating shaft member 341 accompanying the rotation of the handle. This will be described with reference to FIG. 3A to 3E show the relative positional relationship between the first stator 321 and the first rotor 331. FIG.

  FIG. 3A shows the positional relationship between the first stator 321 and the first rotor 331 when the steering angle (absolute angle) of the steering wheel is zero degrees. At this time, all portions of the first rotor winding are in positions facing the first stator winding. For this reason, the transformation ratio K of the transformer comprised by the 1st stator 321 and the 1st rotor 331 becomes small. This increases the voltage level V2 of the second voltage signal induced in the first rotor winding.

  When the handle is rotated rightward from the state shown in FIG. 3A, the state shown in FIG. 3B is obtained. At this time, almost half of the first rotor windings are in a position facing the first stator winding. For this reason, the transformation ratio K is medium. As a result, the voltage level V2 of the second voltage signal induced in the first rotor winding becomes moderate.

  When the handle is further rotated rightward from the state shown in FIG. 3B, the state shown in FIG. 3C is obtained. At this time, a small portion of the first rotor winding is in a position facing the first stator winding. For this reason, the transformation ratio K becomes large. As a result, the voltage level V2 of the second voltage signal induced in the first rotor winding is reduced.

  On the other hand, when the handle is rotated leftward from the state shown in FIG. 3A, the state shown in FIG. At this time, almost half of the first rotor windings are in a position facing the first stator winding. For this reason, as in the state shown in FIG. 3B, the transformation ratio K is medium, and the voltage level V2 of the second voltage signal induced in the first rotor winding is medium. It becomes size.

  When the handle is further rotated leftward from the state shown in FIG. 3D, the state shown in FIG. At this time, a small portion of the first rotor winding is in a position facing the first stator winding. For this reason, as in the state shown in FIG. 3C, the transformation ratio K increases, and the voltage level V2 of the second voltage signal induced in the first rotor winding decreases.

  As described above, the transformation ratio K of the transformer increases and the voltage level V2 of the second voltage signal decreases as the handle rotates to the right or left from the zero-degree absolute angle position. The second voltage signal whose voltage level changes in this way is applied to the second rotor winding, and a sin signal and a cos signal are generated using the second voltage signal as an excitation signal. Here, since the voltage level V2 of the second voltage signal increases as the rotational speed decreases, the voltage levels of the sin signal and the cos signal increase, and the voltage level V2 of the second voltage signal decreases as the rotational speed increases. Therefore, the voltage levels of the sin signal and the cos signal become small. Therefore, even if the relative angles are the same, the voltage levels of the sin signal and the cos signal are different if the rotational speed is different. For example, when the steering wheel can make a maximum N rotations to the right, the voltage level when the relative angle of the first rotation is 30 degrees, the voltage level when the relative angle of the second rotation is 30 degrees,... (N-1) The voltage level when the relative angle of the rotation is 30 degrees and the voltage level when the relative angle of the N rotation is 30 degrees are all different. Further, the magnitudes of these voltage levels are the largest at the first rotation and the smallest at the Nth rotation. As described above, since the rotation speed and the relative angle are detected based on the voltage levels of the sin signal and the cos signal output from the resolver 30, the absolute angle can be obtained.

<4. Overall configuration of electric power steering device>
Next, an example in which the resolver 30 described above is used as a torque sensor of an electric power steering device will be described. FIG. 4 is a schematic diagram showing the configuration of the electric power steering apparatus together with the vehicle configuration related thereto. This electric power steering apparatus includes a steering shaft 102 having one end fixed to a handle 100 as an operation means for steering, a rack and pinion mechanism 104 connected to the other end of the steering shaft 102, and an operation of the handle 100. A torque sensor 3 for detecting a steering torque applied to the steering shaft 102, a vehicle speed sensor 4 for detecting a traveling speed of the vehicle, and a motor for generating a steering assist force for reducing a driver's load due to a steering operation. 6, a reduction gear 7 that transmits a steering assist force generated by the motor 6 to the steering shaft 102, and a power supply from the in-vehicle battery 8, and the motor 6 based on sensor signals from the torque sensor 3 and the vehicle speed sensor 4. An electronic control unit (ECU) 5 for controlling the drive of Eteiru.

  When the driver operates the handle 100, the motor 6 is driven by the ECU 5 based on the steering torque and steering angle detected based on the sensor signal from the torque sensor 3 and the vehicle speed detected by the vehicle speed sensor 4. As a result, the motor 6 generates a steering assist force, and this steering assist force is applied to the steering shaft 102 via the reduction gear 7, thereby reducing the driver's load due to the steering operation. That is, the sum of the steering torque applied by the steering operation and the steering assist force Ta generated by the motor 6 is given to the rack and pinion mechanism 104 via the steering shaft 102 as the output torque Tb. Thus, when the pinion shaft rotates, the rotation is converted into a reciprocating motion of the rack shaft by the rack and pinion mechanism 104. Both ends of the rack shaft are connected to a wheel 108 via a connecting member 106 composed of a tie rod and a knuckle arm, and the direction of the wheel 108 changes according to the reciprocating motion of the rack shaft.

<5. Configuration of torque sensor>
FIG. 5 is a schematic diagram schematically showing the configuration of the torque sensor 3 of the electric power steering apparatus. The torque sensor 3 includes a first resolver 30a and a second resolver 30b. The detailed configuration of the first resolver 30a and the second resolver 30b is as shown in FIG. In the torque sensor 3, a steering shaft (hereinafter referred to as “input shaft”) 102 a having one end fixed to the handle 100 and a steering shaft (hereinafter referred to as “output shaft”) having one end connected to the rack and pinion mechanism 104. ) 102b is connected to the torsion bar 102c. The first resolver 30a is provided on the input shaft 102a, and the second resolver 30b is provided on the output shaft 102b. That is, the first resolver 30a is provided for detecting the rotation angle of the input shaft 102a, and the second resolver 30b is provided for detecting the rotation angle of the output shaft 102b. Of the rotation angles of the input shaft 102a, the absolute angle is represented by the symbol θa, and among the rotation angles of the output shaft 102b, the absolute angle is represented by the symbol θb.

  The first resolver 30a outputs a first sin signal sin θa and a first cos signal cos θa for detecting an absolute angle (hereinafter referred to as “first absolute angle”) θa of the input shaft 102a. The The second resolver 30b outputs a second sin signal sin θb and a second cos signal cos θb for detecting the absolute angle (hereinafter referred to as “second absolute angle”) θb of the output shaft 102b. The Here, when the handle 100 rotates, the torsion bar 102c twists, and the first absolute angle θa and the second absolute angle θb become different values. A steering torque applied to the steering wheel 100 is obtained based on the difference between the absolute angles (θa−θb).

<6. Configuration of control device>
FIG. 6 is a block diagram showing a configuration of the electric power steering apparatus as viewed from a control viewpoint. The ECU 5, which is a control device for the electric power steering apparatus, includes an angle detection unit 10, a torque detection unit 11, a target current calculation unit 12, a subtractor 14, a PI control unit 15, a motor drive unit 20, and current detection. And a container 19. Of the components of the ECU 5, the angle detection unit 10, the torque detection unit 11, the target current calculation unit 12, the subtractor 14, and the PI control unit 15 are realized in software by a microcomputer executing a predetermined program. Is done.

  The torque sensor 3 outputs an angle signal D for detecting the steering angle and the steering torque in accordance with the operation of the handle 100. The angle signal D includes the first sin signal sin θa, the first cos signal cos θa, the second sin signal sin θb, and the second cos signal cos θb described above. The angle detection unit 10 detects the first absolute angle θa and the second absolute angle θb based on the angle signal D, and outputs them. The torque detector 11 receives the first absolute angle θa and the second absolute angle θb, detects the steering torque based on the difference (θa−θb), and outputs it as a steering torque signal Ts. The vehicle speed sensor 4 detects the traveling speed of the vehicle on which the electric power steering device is mounted, and outputs a signal indicating the detected value as the vehicle speed signal Ss.

  The target current calculation unit 12 sets a target current value It based on the first absolute angle θa as the steering angle of the steering wheel, the steering torque signal Ts, and the vehicle speed signal Ss. The current detector 19 detects a current actually supplied to the motor 6 and outputs a current detection value Is indicating the current. The subtractor 14 calculates a deviation (It−Is) between the target current value It output from the target current calculation unit 12 and the current detection value Is output from the current detector 19. The PI control unit 15 generates a voltage command value V by proportional-integral control calculation based on this deviation (It−Is). The motor drive unit 20 applies a voltage to the motor 6 based on the voltage command value V. By applying this voltage, a current flows through the motor 6 to assist the driver's steering operation.

<7. Effect>
According to the present embodiment, the first rotor 331 of the resolver 30 is configured to move up and down with rotation. For this reason, the transformation ratio K of the transformer comprised by the 1st stator 321 and the 1st rotor 331 changes with rotation. Thereby, the voltage level of the 2nd voltage signal induced by the 1st rotor winding changes with rotation. Here, the voltage level of the angle signal (sin signal and cos signal) D output from the resolver 30 is based on the voltage level of the excitation signal applied to the second rotor winding. Two voltage signals are given as excitation signals. Accordingly, the voltage level of the excitation signal applied to the second rotor winding changes with rotation, and the voltage level of the angle signal D changes accordingly. For this reason, even if the relative angle is the same, the voltage level of the angle signal D is different if the rotational speed is different. Thereby, the rotation speed can be detected based on the voltage level of the angle signal D. As a result, an absolute angle of multiple rotations is detected from the relative angle and the rotation speed. As described above, the absolute angle of multiple rotations can be detected only by the resolver 30 according to the present embodiment without providing other sensors.

  Further, according to the present embodiment, in the electric power steering apparatus, the resolver 30 functions not only to detect the steering angle of the steering wheel but also to detect the torque applied by the steering wheel operation. For this reason, parts required for the entire electric power steering apparatus are reduced. Thereby, cost reduction and space saving are realized in the electric power steering apparatus.

It is sectional drawing which shows the structure of the resolver type rotation angle detection apparatus which concerns on one Embodiment of this invention. In the said embodiment, it is sectional drawing which shows the structure of the resolver after rotation. In the said embodiment, it is a figure for demonstrating the change of the transformation ratio accompanying rotation of a resolver. In the said embodiment, it is the schematic which shows the structure of an electric power steering apparatus with the vehicle structure relevant to it. In the said embodiment, it is the schematic which showed typically the structure of the torque sensor of the electric power steering apparatus. The block diagram which shows the structure which looked at the electric power steering apparatus from the control viewpoint in the said embodiment. It is sectional drawing which shows the structure of the rotation angle detection apparatus which concerns on a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 ... Torque sensor, 4 ... Vehicle speed sensor, 5 ... Electronic control unit (ECU), 6 ... Motor, 30 ... Resolver type rotation angle detector, 30a ... 1st resolver, 30b ... 2nd resolver, 102 ... Steering Shaft, 102a ... Input shaft, 102b ... Output shaft, 102c ... Torsion bar, 103 ... Key, 200 ... Rotating shaft, 310 ... Stator housing, 321 ... First stator, 322 ... Second stator, 331 ... First Rotor, 332 ... second rotor, 341 ... first rotating shaft member, 342 ... second rotating shaft member, 350 ... key groove, 360 ... threaded portion

Claims (3)

A resolver-type rotation angle detection device including a first rotation transformer that transmits an excitation signal to the secondary side in a non-contact manner and a second rotation transformer that generates a position signal from the excitation signal,
The first rotary transformer
A first stator having a first stator winding for receiving a first voltage signal as an excitation signal;
According to the relative positional relationship with the first stator winding based on the first voltage signal, which is provided inside the first stator and is configured to be rotatable around a predetermined rotation axis. A first rotor having a first rotor winding for generating a second voltage signal,
The second rotary transformer is
A second rotor having a second rotor winding that rotates with the first rotor and receives the second voltage signal from the first rotor winding;
A second voltage signal that is provided outside the second rotor and generates a third voltage signal as a position signal corresponding to a rotation angle of the second rotor based on the second voltage signal as an excitation signal; A second stator having a stator winding,
Only the first rotor moves in the predetermined rotation axis direction with rotation, and the relative positional relationship between the first stator winding and the first rotor winding changes due to the movement. A rotation angle detector. An electric power steering apparatus comprising a steering shaft composed of a first shaft and a second shaft connected by a torsion bar,
The electric power steering apparatus comprising the rotation angle detection device according to claim 1, wherein the rotation angle detection device according to claim 1 detects a rotation angle of the first shaft or the second shaft. An electric power steering apparatus comprising a steering shaft composed of a first shaft and a second shaft connected by a torsion bar,
The rotation angle detection device according to claim 1 is provided in each of the first shaft and the second shaft, and the rotation angles of the first shaft and the second shaft detected by the rotation angle detection device. A steering torque and a steering angle are detected based on the electric power steering apparatus.

Images