JP2012135177A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor that suitably controls rotating operation of a rotor whose magnetic pole action differs peripherally in pitch because of unequal arrangement of magnetic poles.SOLUTION: A rotor 3 is formed having a magnet magnetic pole angle θ1 larger than a pseudo magnetic pole angle θ2, magnet magnetic poles 18 and pseudo magnetic poles 19 are unequally arranged. A sensor magnet 17 has both magnetization parts 17c, 17d set corresponding to a waveform pitch of an induced voltage generated at winding of a stator arranged opposite the rotor 3. In the motor, the stator generates a rotating magnetic field matching the waveform pitch of the induced voltage.

Description

  The present invention relates to a motor that performs energization control on a stator using a rotation detection sensor.

  In a brushless motor or the like, as described in, for example, Patent Document 1, a sensor magnet that is multipolarly magnetized in the circumferential direction and rotates integrally with a rotor, and a magnetic sensor (for example, a Hall element) disposed opposite to the sensor magnet ) Is detected, and the rotational position of the rotor is detected, and energization control is performed on the stator windings.

  Further, as a rotor used in such a brushless motor or the like, a plurality of magnet magnetic poles having a magnet of one magnetic pole are arranged in the circumferential direction of the rotor core, and pseudo magnetic poles integrally formed with the rotor core are arranged between the magnet magnetic poles, A rotor having a continuous pole type (half magnet type) structure in which the pseudo magnetic pole functions as the other magnetic pole is known.

Japanese Patent No. 3945696

  By the way, for example, in a rotor in which magnetic poles are unequally arranged and a rotor having the above-described continuous pole type structure (half magnet type), the magnetic flux generation mode in the pseudo magnetic pole is different from the magnetic pole generation mode. Therefore, there is a demand for a motor structure that can appropriately perform rotor control by appropriately optimizing the rotor structure including the magnetic pole and pseudo magnetic pole magnetic flux generation modes, and detecting the position of the rotor of the rotor structure. Yes.

  The present invention has been made to solve the above-described problems, and the object thereof is to appropriately control the rotational operation of the rotor in which the magnetic pole action due to the uneven arrangement of the magnetic poles has a different pitch in the circumferential direction. It is to provide a motor.

  In order to solve the above-mentioned problem, the invention according to claim 1 is based on a stator that generates a rotating magnetic field by energizing a wound winding, and is arranged to face the stator and based on the rotating magnetic field. A rotor that rotates in rotation, and the energization control for generating the rotating magnetic field is performed on the stator, wherein the rotor is an induced voltage of the winding based on the rotation operation of the rotor. The gist of the present invention is to generate the rotating magnetic field that matches the waveform pitch of the induced voltage that has different portions in the circumferential direction with respect to the stator.

  In the present invention, the rotor is configured to have a portion in which the waveform pitch of the induced voltage of the winding based on the rotational operation of the rotor differs in the circumferential direction. The motor generates a rotating magnetic field in the stator that matches the waveform pitch of the induced voltage. As a result, the rotational operation of the rotor with different induced voltage waveform pitches in the circumferential direction can be appropriately controlled, and the motor can be driven efficiently.

  According to a second aspect of the present invention, in the motor according to the first aspect, the rotor is configured such that a plurality of magnetic poles having different waveform pitches of the induced voltage in the circumferential direction are unequally arranged so that the rotor can rotate integrally with the rotor. A rotation detection unit that includes a detected member provided and outputs a rotation detection signal detected by a rotation operation of the detected member; and the detected member is arranged in a circumferential direction of a waveform pitch of the induced voltage. In addition, a plurality of detected parts are set to correspond to the waveform pitch of the induced voltage based on the unequal arrangement of the magnetic poles of the rotor based on the rotation detection signal detected by the rotation operation of the detected member. The gist of the present invention is to generate the matched rotating magnetic fields.

  According to the present invention, the rotation detection means provided for the rotor in which a plurality of magnetic poles are unequally arranged so that the waveform pitch of the induced voltage of the winding based on the rotation operation is different in the circumferential direction can be integrally rotated with the rotor. A plurality of detected parts are set as the detection member so as to correspond to the circumferential direction of the waveform pitch of the induced voltage. That is, the change in the rotation detection signal detected by the rotation operation of the detected member corresponds to the waveform pitch of the induced voltage based on the unequal arrangement of the magnetic poles of the rotor. Is used as the energization timing to the stator, so that the change between the energization waveform and the induced voltage can be matched without performing the energization timing correction process or making the correction process extremely easy. That is, the rotational operation of the rotor can be appropriately controlled, and the rotational performance of the motor can be improved.

  According to a third aspect of the present invention, in the motor according to the second aspect, the rotor includes a plurality of the magnetic poles arranged in the circumferential direction so that angles (electrical angles) formed in the circumferential direction are different, and the detected object The detected part of the member is configured by alternately arranging a first detected part and a second detected part that differ in the angle (electrical angle) in the circumferential direction according to the magnetic pole of the rotor in the circumferential direction. The gist.

  In this invention, the rotor is configured by arranging a plurality of magnetic poles in the circumferential direction so that the angles (electrical angles) formed in the circumferential direction are alternately different, whereas the detected portion of the detected member is in the circumferential direction. The first and second detected parts having different angles (electrical angles) according to the magnetic poles of the rotor are alternately arranged in the circumferential direction. Thereby, it becomes easy to match the change modes of one cycle (electrical angle 360 °) of the magnetic field change of the rotor and the detection target member.

  According to a fourth aspect of the present invention, in the motor according to the second or third aspect, the detected member of the rotation detecting means includes an N-pole magnetized portion as a first detected portion and an S pole as a second detected portion. The gist of the invention is that it is composed of annular sensor magnets having magnetized portions and alternately arranged in the circumferential direction.

  In this invention, the detected part is composed of an annular sensor magnet in which the magnetized parts magnetized with the first detected part as the N pole and the second detected part as the S pole are alternately arranged in the circumferential direction. Is done. Thereby, a to-be-detected part can be easily comprised as an annular sensor magnet.

  According to a fifth aspect of the present invention, in the motor according to any one of the second to fourth aspects, the circumferential arrangement of the detected portions of the rotation detecting means and the circumferential arrangement of the magnetic poles of the rotor. The gist of this is that they have a one-to-one correspondence relationship.

  In the present invention, the arrangement in the circumferential direction of each detected portion of the rotation detecting means and the arrangement in the circumferential direction of each magnetic pole of the rotor are in one-to-one correspondence, that is, the same electrical angle and mechanical angle. Thereby, the rotation position of each magnetic pole of a rotor can be easily detected by using the detection of the rotation position of a to-be-detected part as it is.

  A sixth aspect of the present invention is the motor according to any one of the first to fifth aspects, wherein the rotor includes a plurality of magnet magnetic poles having a magnet of one magnetic pole in the circumferential direction with respect to the rotor core. In addition, the gist is that the pseudo magnetic pole of the rotor core is arranged between the magnet magnetic poles so that the pseudo magnetic pole functions as the other magnetic pole.

  In the present invention, the motor according to any one of claims 1 to 5 is particularly provided in a motor provided with a rotor having a so-called continuous pole type (half magnet type) structure in which the waveform pitch of the induced voltage is different in the circumferential direction. The effect of can be obtained.

  According to a seventh aspect of the present invention, in the motor according to the fourth aspect, the sensor magnet of the rotation detecting means is configured such that the N-pole magnetized portion and the S-pole magnetized portion have the same area as viewed in the axial direction. And the magnetic pole boundary line of each magnetized portion is inclined with respect to a straight line in the radial direction, and the ratio of the detection portion in each magnetized portion is the same as the waveform pitch of the induced voltage corresponding to each magnetic pole of the rotor The gist is that it is configured to be a rate.

  In this invention, the sensor magnet of the rotation detecting means is configured so that each of the N pole and S pole magnetized portions has the same area as viewed in the axial direction, and the magnetic pole boundary of each magnetized portion is relative to the radial straight line. And the ratio of the detection portion in each magnetized portion is configured to be the same as the waveform pitch of the induced voltage corresponding to each magnetic pole of the rotor. As a result, even if the circumferential length of each magnetized portion in the detection portion of the sensor magnet is different, the area of each magnetized portion is the same, so the magnetic amount of each magnetized portion is made uniform. Figured. That is, since the boundary line between the magnetized portions becomes more appropriate, the error included in the rotation detection signal can be further reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the motor which can control appropriately the rotation operation of the rotor from which the magnetic pole effect | action by the magnetic poles arranged unevenly etc. becomes a different pitch in the circumferential direction can be provided.

It is a schematic block diagram of the motor in this embodiment. It is a disassembled perspective view of the rotor and sensor magnet in the same embodiment. (A) is a top view of the rotor in the embodiment, (b) is a plan view of the sensor magnet. (A) is explanatory drawing which shows the relationship between an electrical angle and the induced voltage which generate | occur | produces in a stator, (b) is explanatory drawing which shows the relationship between an electrical angle and the rotation detection signal of a sensor magnet, (c) is an electrical angle and a stator. It is explanatory drawing which shows the relationship with the electricity supply waveform with respect to. It is a top view of the sensor magnet in another example. (A) is a top view of the rotor in another example, (b) is a top view of the sensor magnet in another example. (A) is a top view of the rotor in another example, (b) is a top view of the sensor magnet in another example. (A) is a top view of the rotor in another example, (b) is a top view of the sensor magnet in another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1, the motor M of the present embodiment is an inner rotor type brushless motor, and is configured by housing a stator 2 and a rotor 3 inside a motor case 1. The motor case 1 includes a bottomed cylindrical case body 5 and a substantially disc-shaped cover plate 6 that closes an opening of the case body 5. An annular stator 2 is fixed to the inner peripheral surface of the case body 5, and a winding 10 for generating a rotating magnetic field for rotating the rotor 3 is wound around the teeth 2 a of the stator 2.

  A rotor 3 having a rotating shaft 11 is disposed inside the stator 2. A base end portion of the rotary shaft 11 formed in a substantially columnar shape is pivotally supported by a bearing 12 provided in the center of the bottom of the case body 5, while a portion on the front end side of the rotary shaft 11 is formed on the cover plate. 6 is supported by a bearing 13 provided at the center in the radial direction. Further, the distal end portion of the rotating shaft 11 passes through the central portion in the radial direction of the cover plate 6 and protrudes outside the motor case 1.

  A substantially cylindrical rotor core 14 made of a magnetic material is fixed to the rotating shaft 11 at a portion closer to the base end than the central portion in the axial direction so as to face the stator 2 in the radial direction. A press-fit hole 14 a that penetrates the rotor core 14 in the axial direction is formed in the central portion in the radial direction of the rotor core 14. The rotor core 14 is fixed so as to rotate integrally with the rotary shaft 11 by press-fitting the rotary shaft 11 into the press-fitting hole 14a. A magnet 15 is embedded in the rotor core 14 along the axial direction.

  A sensor magnet 17 that is formed in an annular shape and has a plurality of magnetic poles in the circumferential direction is fixed at a position between the tip portion of the rotating shaft 11 and the rotor core 14. The sensor magnet 17 has a plate shape with a constant axial thickness, and has an outer diameter equal to the outer diameter of the rotor core 14. The sensor magnet 17 and the rotor core 14 are fixed at positions separated from each other in the axial direction.

  A circuit board 21 on which a circuit element (not shown) for controlling the motor M is mounted is fixed to the inner surface 6 a of the cover plate 6. The circuit board 21 is opposed to the axial end surface 17a of the sensor magnet 17 on the opposite side of the rotor core 14 in the axial direction. On the circuit board 21, the magnetic sensor 22 is disposed at a position that can face the outer peripheral side portion of the sensor magnet 17 in the axial direction. The magnetic sensor 22 is, for example, a Hall IC. The circuit board 21 is electrically connected to a drive control circuit (not shown) provided outside the motor M.

  As shown in FIG. 2, the sensor magnet 17 fixed to the distal end side of the rotating shaft 11 is formed with a fixing hole 17 b penetrating in a circular shape in the axial direction at the central portion in the radial direction. A portion on the distal end side of the rotating shaft 11 is fitted into the fixing hole 17b. Thereby, the sensor magnet 17 is fixed so as to be rotatable with respect to the rotating shaft 11 similarly to the rotor core 14.

  The rotor core 14 is formed with fitting holes 14b penetrating the rotor core 14 in the axial direction at four locations that are equiangularly spaced in the circumferential direction (90 ° intervals in the present embodiment). The fitting hole 14b has a substantially rectangular parallelepiped shape that is long in the axial direction. Moreover, the cross-sectional shape seen from the axial direction of the fitting hole 14b is formed in the substantially rectangular shape where the longitudinal direction followed the orthogonal direction of radial direction. And in each fitting hole 14b, the magnet 15 formed along the shape is each embedded and fixed.

  Each magnet 15 is magnetized so that the radially outer side surface 15 a side is N-pole and the radially inner side surface 15 b side is S-pole, and forms an N-pole magnetic pole (hereinafter referred to as magnet magnetic pole) 18 on the rotor core 14. ing. And the magnet 15 is arrange | positioned in each fitting hole 14b. In the rotor core 14, pseudo magnetic poles 19 are respectively formed between magnet magnetic poles 18 adjacent in the circumferential direction, and function as S poles in a pseudo manner. That is, the magnet magnetic poles 18 and the pseudo magnetic poles 19 are alternately arranged at equiangular (45 °) intervals. The rotor 3 is configured as an 8-pole so-called continuous pole type (half magnet type) including an N-pole magnet magnetic pole 18 and an S-pole pseudo magnetic pole 19.

  As shown in FIG. 3 (a), the rotor 3 has magnetic pole angles (electrical angles) θ1 and θ2 that have straight and straight lines (straight lines L1 to L3) passing through the centers of both ends in the circumferential direction of the magnet 15 as the starting point and the ending point. The magnetic pole 18 and the pseudo magnetic pole 19 are set at different angles. More specifically, a straight line passing through the center of the end of the magnet 15 in the circumferential direction (counterclockwise direction) and the axis center O of the rotating shaft 11 is defined as a straight line L1, and the end of the magnet 15 in the circumferential direction (clockwise direction). A straight line passing through the center of the part and the axis center O of the rotating shaft 11 is defined as a straight line L2. In this case, an angle θ1 formed by the straight line L1 and the straight line L2 on both sides in the circumferential direction of the magnet 15 is a magnet magnetic pole angle θ1. In the pseudo magnetic pole 19, a straight line passing through the center of the circumferential direction (counterclockwise direction side) of the magnet 15 adjacent to the clockwise direction side and the axis center O of the rotating shaft 11 is defined as a straight line L 3. Incidentally, the straight line L3 is the straight line L1 with respect to the magnet 15 adjacent to the clockwise direction side. In this case, an angle θ2 formed by the straight line L2 and the straight line L3 is set as a pseudo magnetic pole angle θ2.

  In the rotor 3 of the present embodiment, the magnet magnetic pole angle θ1 is formed at an angle larger than the pseudo magnetic pole angle θ2, and the magnetic poles 18 and 19 are unequally arranged. Thereby, the magnetic field change in both the magnetic poles 18 and 19 in consideration of the magnetic flux generation mode between the magnet magnetic pole 18 having a magnetic force forcing force and the pseudo magnetic pole 19 having no magnetic force forcing force can be made suitable. In the rotor 3 described above, the sum of the magnetic pole angles θ1 and θ2 of one magnet magnetic pole 18 and pseudo magnetic pole 19 results in an electrical angle of 360 ° (θ1 + θ2 = 360 °). And, it can be expected that the range of the magnet magnetic pole angle θ1 is more preferable by setting “190 ° ≦ θ1 ≦ 215 °”, for example.

  As shown in FIG. 3B, the sensor magnet 17 of the present embodiment includes an N-pole magnetized portion 17c having N poles in the circumferential direction (rotational direction) with the magnetic pole boundary lines Ls1 to Ls3 as radial straight lines. It is configured as an annular magnet in which S pole magnetized portions 17d of S poles are alternately arranged. Both magnetized portions 17c and 17d have a fan shape whose width in the circumferential direction increases radially outward.

  Here, in FIG. 4, the horizontal axis of the graph is an electrical angle (360 °), (a) is the induced voltage generated in the winding 10 in the vertical axis, and (b) is the vertical axis output from the magnetic sensor 22. In the graph (c), the relationship between the rotation detection signal and the energization waveform supplied to the stator 2 is shown in the graph.

  As shown in FIG. 4A, the induced voltage waveform H1 generated in the winding 10 at an electrical angle of 360 ° has a maximum value at the center of the magnetic pole pitch angle (waveform pitch) of the magnetic pole 18, and the pseudo magnetic pole 19 The sine wave takes the minimum value at the center of the magnetic pole pitch angle. Further, the induced voltage waveform H1 is different from the section (“pseudo magnetic pole pitch” in the figure) in which the section affected by the magnet magnetic pole 18 (“magnet magnetic pole pitch” in the figure) is affected by the pseudo magnetic pole 19. Here, the length of each section of the magnet magnetic pole pitch and the pseudo magnetic pole pitch is a waveform pitch.

  In the rotor 3 of the present embodiment, the time during which the magnet magnetic pole 18 is opposed to the tooth 2a in the rotation operation is longer than the time during which the pseudo magnetic pole 19 is opposed. Therefore, the induced voltage waveform H1 is generated such that the waveform pitch of the magnet magnetic pole 18 is longer than the waveform pitch of the pseudo magnetic pole 19, and the arrangement of the waveform pitch according to the circumferential direction (rotation direction) of the rotor 3 is different. Incidentally, the position P1 at which the magnet magnetic pole pitch is switched to the pseudo magnetic pole pitch (position where the induced voltage waveform H1 is zero-crossed) is a position shifted to the 360 ° side from the electrical angle of 180 °.

  Based on this, in the setting of the sensor magnet 17, the angle θs1 formed by the magnetic pole boundary line Ls1 on the counterclockwise direction side of the N pole magnetized portion 17c and the magnetic pole boundary line Ls2 on the clockwise direction side and the S pole magnetized portion The angle θs2 formed by the magnetic pole boundary line Ls3 and the magnetic pole boundary line Ls2 on the clockwise direction side of 17d is configured according to the waveform pitch of the induced voltage waveform H1. In this case, the magnetized portions 17c and 17d have a setting in which the magnetic poles 18 and 19 of the rotor 3 are aligned in the circumferential direction on a one-to-one basis. Has been. As a result, at an electrical angle of 360 ° for one cycle, the cycle in which the magnetic fields of the sensor magnet 17 and the rotor 3 change (each magnetic pole switches) can be matched. As a result, the cycle of the waveform H2 (see FIG. 4B) of the rotation detection signal output from the magnetic sensor 22 coincides with the cycle of the induced voltage waveform H1.

  In the motor M configured as described above, when power is supplied to the winding 10 of the stator 2, the rotor 3 is rotated based on the rotating magnetic field generated in the winding 10. As the rotor 3 rotates, the sensor magnet 17 also rotates. The magnetic sensor 22 facing the sensor magnet 17 in the axial direction detects a magnetic field in which both magnetized portions 17c and 17d change alternately by the rotational operation of the sensor magnet 17, and a pulse signal corresponding to the detected change in the magnetic field. A rotation detection signal is output to the drive control circuit. The drive control circuit supplies power to the winding 10 with the period (rise and fall) of the rotation detection signal as the energization timing.

Hereinafter, the operation of the present embodiment will be described.
In the motor M of the present embodiment, the angles θs1 and θs2 formed by both magnetized portions 17c and 17d of the sensor magnet 17 are set based on the waveform pitch of the induced voltage waveform H1 generated between the rotor 3 and the motor M. Therefore, the period of the waveform H2 (see FIG. 4B) of the rotation detection signal output from the magnetic sensor 22 coincides with the period of the induced voltage waveform H1. Since the motor M uses the period of the waveform H2 of the rotation detection signal as the energization timing for supplying power to the stator 2, the energization waveform H3 in which the drive control circuit energizes the stator 2 (see FIG. 4C). Can be made to coincide with the period of the induced voltage waveform H1, and a rotating magnetic field matched to the induced voltage waveform H1 can be generated. That is, the efficiency of the rotation performance of the motor M can be increased.

  Further, the sensor magnet 17 is configured such that the two magnetized portions 17c and 17d have a one-to-one correspondence with the magnetic poles 18 and 19 of the rotor 3 based on the waveform pitch of the induced voltage waveform H1. As a result, the rotational positions of both magnetized portions 17 c and 17 d of the sensor magnet 17 detected by the magnetic sensor 22 are substantially coincident with the rotational positions of the magnetic poles 18 and 19 of the rotor 3. The rotational position can be used as the rotational position of the magnetic pole of the rotor 3.

  Incidentally, when the sensor magnet used in a motor having a conventional full magnet type rotor in which the angle of both magnetized portions is 180 ° with respect to the rotor 3 as described above is used, for example, rotation detection is performed. The trailing edge of the signal is in the vicinity of an electrical angle of 180 ° in FIG. 4B, and a deviation from the position P1 of the induced voltage waveform H1 occurs. Therefore, in order to supply power to the stator 2 based on the period of the rotation detection signal, for example, it is necessary to perform a correction process with an energization timing according to the structure of the rotor 3 of the present embodiment in the drive control circuit. The load may increase.

  On the other hand, in the motor M of the present embodiment, as described above, the cycle of the waveform H2 of the rotation detection signal detected from the sensor magnet 17 can correspond to the cycle of the induced voltage waveform H1 generated in the winding 10. The cycle of this rotation detection signal is used as the energization timing to the stator 2, so that the energization waveform and the induced voltage cycle are matched without performing the energization timing correction process or making the correction process extremely easy. Thus, the rotational performance of the motor M can be improved.

Next, characteristic effects of the present embodiment will be described.
(1) In the motor M of the present embodiment, the rotor 3 is configured such that the magnet magnetic pole angle θ1 is larger than the pseudo magnetic pole angle θ2 so that the waveform pitch of the induced voltage waveform H1 of the winding 10 based on the rotational operation differs in the circumferential direction. Is set to On the other hand, the magnetized portions 17c and 17d of the sensor magnet 17 provided so as to be able to rotate integrally with the rotor 3 are set so as to correspond to the circumferential direction of the waveform pitch of the induced voltage waveform H1. That is, the change in the rotation detection signal detected by the rotation operation of the sensor magnet 17 corresponds to the waveform pitch of the induced voltage waveform H1 based on the unequal arrangement of the magnetic poles 18 and 19 of the rotor 3, so In this case, by using the change in the rotation detection signal as the energization timing to the stator 2, the energization waveform and the induced voltage are made to coincide with each other without performing the energization timing correction process or making the correction process extremely easy. be able to. That is, the rotational operation of the rotor 3 can be appropriately controlled, and the rotational performance of the motor M can be improved.

  (2) The rotor 3 is configured by alternately arranging the magnetic poles 18 and 19 having different magnetic pole angles θ1 and θ2 in the circumferential direction, whereas the sensor magnet 17 is an angle (electrical angle) formed in the circumferential direction. Both magnetized portions 17c and 17d having different θs1 and θs2 depending on the waveform pitch of the induced voltage corresponding to the magnetic poles 18 and 19 of the rotor 3 are alternately arranged in the circumferential direction. Thereby, it becomes easy to match the change modes for one cycle (electrical angle 360 °) of the magnetic field change of the sensor magnet 17 and the rotor 3.

  (3) N-pole N-pole magnetized portions 17c and S-pole S-pole magnetized portions 17d are alternately arranged in the circumferential direction (rotation direction) as members to be used for detecting the rotational position of the rotor 3. An annular sensor magnet 17 is used. Thereby, the member to be detected can be easily configured as an annular sensor magnet 17 in which magnetic poles are magnetized in the circumferential direction.

  (4) The sensor magnet 17 and the rotor 3 are configured so that each magnetic pole has a one-to-one correspondence, that is, the same electrical angle and mechanical angle. Thereby, the rotation position of each magnetic pole 18 and 19 of the rotor 3 is easily detectable by using the detection of the rotation position of both the magnetized parts 17c and 17d of the sensor magnet 17 as it is.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the magnetized portions 17c and 17d of the sensor magnet 17 are configured with radial straight lines as magnetic pole boundary lines Ls1 to Ls3. However, as shown in FIG. 5, the magnetic pole boundary lines Ls1 to Ls3. A straight line that is inclined at a predetermined angle with respect to a straight line in the radial direction is very good. In this case, the detection portions of the magnetized portions 17c and 17d detected by the magnetic sensor 22 (the circumferential lengths of the magnetized portions 17c and 17d) are changed depending on the predetermined angles of the magnetic pole boundary lines Ls1 to Ls3. It becomes possible. Incidentally, both the magnetized portions 17c and 17d have a rotationally symmetric shape, and can cope with both rotational directions. And the sensor magnet 17 is comprised so that the area seen from the axial direction of the rotating shaft 11 of both the magnetized parts 17c and 17d may become the same area. As a result, even if the circumferential lengths of the magnetized portions 17c and 17d at the detection portion of the sensor magnet 17 are different, the areas of the magnetized portions 17c and 17d are the same. The magnetic amounts of 17c and 17d can be made uniform. That is, since the boundary lines Ls1 to Ls3 between the magnetized portions 17c and 17d are more appropriate, the error included in the rotation detection signal can be further reduced.

  In this case, the magnetic sensor 22 may be opposed to the sensor magnet 17 in the radial direction without facing the axial direction, that is, the outer surface of the sensor magnet 17 may be changed. In this way, the detection time (detection distance) of each magnetized portion 17c, 17d by the magnetic sensor 22 can be increased, which can contribute to improvement in detection accuracy.

  In the above embodiment, the magnet magnetic poles 18 and the pseudo magnetic poles 19 are configured as so-called continuous pole types (half magnet types) that are alternately arranged at equal angular (45 °) intervals in the circumferential direction of the rotor 3. However, it is not limited to this.

  For example, as shown in FIG. 6A, the magnets 15 of a pair of magnet magnetic poles 31 sandwiching the axis center O are shifted by a predetermined angle in the circumferential direction, for example, clockwise, and the magnetic poles 18 and 19 are unequally arranged. It is good. In this case, the magnet magnetic pole angle θ1 of the magnet magnetic pole 31 is the magnet magnetic pole angle θ3 of the magnet magnetic pole 32 disposed between the magnet magnetic poles 31 in the circumferential direction (the angle formed by the straight lines L3 and L4 passing through the centers at both ends in the circumferential direction). And the same angle. On the other hand, the pseudo magnetic pole angle θ2 of the pseudo magnetic pole 41 provided on the clockwise side of the magnet magnetic pole 31 is equal to the pseudo magnetic pole angle θ4 of the pseudo magnetic pole 42 provided on the clockwise side of the magnet magnetic pole 32 (straight lines L4 and L5 in the figure). The angle is smaller than the angle formed by For the rotor 3 having such a configuration, for example, as shown in FIG. 6B, the sensor magnet 17 has angles θs1 to θs4 formed by the magnetized portions 17c and 17d based on the waveform pitch of the induced voltage. The angle may be set to be configured.

  Further, as shown in FIG. 7A, for example, the circumferential length of the magnets 15 constituting the pair of magnet magnetic poles 33 sandwiching the axis center O is made shorter than the length of the magnets 15 of the adjacent magnet magnetic poles 18. May be provided. Also in this case, as shown in FIG. 7B, the angles θs1 to θs3 formed by the two magnetized portions 17c and 17d of the sensor magnet 17 are changed based on the waveform pitch of the induced voltage generated in the rotor 3. .

  Further, as shown in FIGS. 8A and 8B, the angles θs1 and θs2 formed by both magnetized portions 17c and 17d of the sensor magnet 17 are, for example, half the magnetic pole angles θ1 and θ2, and the sensor magnet 17 The number of magnetic poles may be changed to twice the number of the rotor 3 (“16” in FIG. 8). Also in this case, the ratio of the angles θs1 and θs2 is configured to be the same as the waveform pitch of the induced voltage corresponding to the magnetic poles 18 and 19 of the rotor 3.

  In the above embodiment, the sensor magnet 17 is used as the member to be detected used for detecting the rotational position of the rotor 3, but the present invention is not limited to this. For example, even if it is configured with a magnetic body having a plurality of salient poles (non-magnetized) in the circumferential direction, a magnetic body whose gap permeance changes continuously in the circumferential direction, etc. Good.

  In the above embodiment, the angle (electrical angle) and the number of magnetic poles of each magnetic pole between the sensor magnet 17 and the rotor 3 are examples, and may be changed as appropriate. Further, the correspondence relationship between the magnetic poles of the sensor magnet 17 and the rotor 3 is 1: 1, but may be one-to-many (many-to-one).

  In the above embodiment, the rotor 3 is configured as a so-called IPM type in which the magnet 15 is embedded in the rotor core 14. However, the present invention is not limited to this. For example, the so-called SPM in which the magnet 15 is disposed on the outer peripheral surface of the rotor core 14. It may be changed to a rotor having a continuous pole type structure.

Next, a technical idea that can be grasped from the above embodiment and another example will be added below.
(A) In the motor according to claim 3,
In the rotor, each magnetic pole angle (electrical angle) having a straight line passing through both ends of the magnet in the circumferential direction as θ1 and θ2 is θ1 + θ2 = 360 °, and the magnetic pole angle θ1 of the magnet magnetic pole is 190. A motor characterized by being arranged unequally so as to be within a range of ° ≦ θ1 ≦ 215 °.

  According to this configuration, when each magnetic pole angle (electrical angle) having a straight line passing through both ends in the circumferential direction of the magnet as θ1 and θ2 (θ1 + θ2 = 360 °) is set, the magnetic pole angle θ1 of the magnet magnetic pole is It is set to any one of the range of 190 ° ≦ θ1 ≦ 215 °. Thereby, the magnetic field change in both magnetic poles in consideration of the difference in the magnetic flux generation mode can be made suitable. Then, by setting the detected portion in accordance with the induced voltage associated with the rotational operation of the rotor with the optimized structure, the rotational operation of the rotor can be appropriately controlled, and the rotational performance of the motor is reliably improved. It becomes possible.

  DESCRIPTION OF SYMBOLS 2 ... Stator, 3 ... Rotor, 10 ... Winding, 11 ... Rotating shaft, 14 ... Rotor core, 15 ... Magnet, 17 ... Sensor magnet (detected member, rotation detection means), 17c ... N pole magnetized part (1st Detected portion, detected portion, rotation detecting means), 17d... S pole magnetized portion (second detected portion, detected portion, rotation detecting means), 18, 31, 32, 33... Magnetic pole (magnetic pole), 19, 41, 42 ... pseudo magnetic pole (magnetic pole), 22 ... magnetic sensor (rotation detecting means), M ... motor, θ1 to θ4 ... magnetic pole angle (angle), H1, H2 ... waveform, L1 to L5 ... straight line, Ls1 Ls5: Magnetic pole boundary line, θs1 to θs4: Angle.

Claims (7)

A stator that generates a rotating magnetic field by energizing the wound winding;
A rotor arranged to face the stator and rotating based on the rotating magnetic field,
A motor in which energization control for generation of the rotating magnetic field is performed on the stator,
The rotor has a portion in which the waveform pitch of the induced voltage of the winding based on the rotational operation of the rotor is different in the circumferential direction,
The motor generating the rotating magnetic field matched with the waveform pitch of the induced voltage having different portions in the circumferential direction with respect to the stator. The motor according to claim 1,
In the rotor, a plurality of magnetic poles having different waveform pitches of the induced voltage in the circumferential direction are unequally arranged,
A rotation detecting means having a detected member provided so as to rotate integrally with the rotor, and outputting a rotation detection signal detected by a rotation operation of the detected member;
The detected member is set with a plurality of detected parts so as to correspond to the circumferential direction of the waveform pitch of the induced voltage,
The rotating magnetic field matched with the waveform pitch of the induced voltage based on the unequal arrangement of the magnetic poles of the rotor is generated based on the rotation detection signal detected by the rotation operation of the detected member. motor. The motor according to claim 2,
The rotor has a plurality of magnetic poles arranged in the circumferential direction so that angles (electrical angles) formed in the circumferential direction are alternately different,
The detected portion of the detected member is configured by alternately arranging a first detected portion and a second detected portion having different circumferential angles (electrical angles) according to the magnetic poles of the rotor in the circumferential direction. A motor characterized by that. The motor according to claim 2 or 3,
The member to be detected of the rotation detecting means has an N-pole magnetized portion as a first detected portion and an S-pole magnetized portion as a second detected portion, and each magnetized portion is alternately arranged in the circumferential direction. A motor characterized by comprising a sensor magnet. The motor according to any one of claims 2 to 4,
A motor configured to have a one-to-one correspondence between a circumferential arrangement of each detected portion of the rotation detecting means and a circumferential arrangement of each magnetic pole of the rotor. The motor according to any one of claims 1 to 5,
In the rotor, a plurality of magnet magnetic poles having a magnet of one magnetic pole with respect to the rotor core are arranged in the circumferential direction, and the pseudo magnetic pole of the rotor core is arranged between the magnet magnetic poles so that the pseudo magnetic pole functions as the other magnetic pole. A motor characterized by being configured to perform. The motor according to claim 4,
In the sensor magnet of the rotation detecting means, the N-pole magnetized portion and the S-pole magnetized portion are configured with the same area as viewed in the axial direction, and the magnetic pole boundary line of each magnetized portion is relative to a radial straight line. The motor is configured such that the ratio of the detection portion at each magnetized portion is the same as the waveform pitch of the induced voltage corresponding to each magnetic pole of the rotor.

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