WO2023248777A1 - Brushless motor - Google Patents
Brushless motor Download PDFInfo
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- WO2023248777A1 WO2023248777A1 PCT/JP2023/020911 JP2023020911W WO2023248777A1 WO 2023248777 A1 WO2023248777 A1 WO 2023248777A1 JP 2023020911 W JP2023020911 W JP 2023020911W WO 2023248777 A1 WO2023248777 A1 WO 2023248777A1
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- WIPO (PCT)
- Prior art keywords
- brushless motor
- rotor
- axial
- permanent magnet
- hole
- Prior art date
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/22—Rotating parts of the magnetic circuit
- H02K1/27—Rotor cores with permanent magnets
- H02K1/2706—Inner rotors
- H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
- H02K1/274—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets
- H02K1/2753—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets the rotor consisting of magnets or groups of magnets arranged with alternating polarity
- H02K1/276—Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM]
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
- H02K11/21—Devices for sensing speed or position, or actuated thereby
- H02K11/215—Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K29/00—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices
- H02K29/06—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with position sensing devices
- H02K29/08—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with position sensing devices using magnetic effect devices, e.g. Hall-plates, magneto-resistors
Definitions
- the present invention relates to a brushless motor.
- This brushless motor is a so-called IPM motor, and has a rotor rotatably disposed inside a stator formed in a frame shape.
- a magnetic sensor is provided at one end of the stator to detect the magnetic pole position of the rotor.
- the rotor has a rotatable shaft and a cylindrical rotor core that is integrally attached to the shaft.
- This rotor core has a plurality of through holes along the axial direction of the rotating shaft.
- the rotor has a plurality of permanent magnets inserted and fixed into each axial hole of the rotor core.
- Each of the permanent magnets is formed into a plate shape having a predetermined thickness, and has a protruding portion that partially protrudes from an opening at one end of each of the axial holes.
- a magnetic sensor is provided at a position facing the outer peripheral portion of the rotor. This magnetic sensor detects the magnetic pole position of the rotor by detecting magnetic flux generated from each protrusion of a plurality of permanent magnets inserted and fixed into each through hole of the rotor core.
- the magnetic sensor detects the magnetic flux generated from each protrusion of the plurality of permanent magnets, but the distance between the adjacent protrusions is large. Therefore, there is a risk that the recognition of the switching of the magnetic pole by the magnetic sensor may be delayed.
- the timing at which the magnetic poles change becomes slower. Furthermore, since there is no permanent magnet that generates magnetic flux in the space between the protrusions of adjacent permanent magnets, the magnetic flux at the magnetic sensor position becomes weak, and the timing of the magnetic pole switching determination at the magnetic sensor is delayed. If there is a delay in recognizing the switching of the magnetic poles, the ideal energization timing will be delayed, and the current required to generate the same torque will increase. As a result, there is a possibility that the electricity cost and the amount of heat generated by the coil will increase.
- the present invention was devised in view of the above-mentioned conventional technical problems, and reduces the distance between the extension parts (protrusions) of adjacent permanent magnets to reduce the weakening of the magnetic flux at the magnetic sensor position.
- One of the objects of the present invention is to provide a brushless motor that can reduce electricity costs and the amount of heat generated by the coil.
- a plurality of plate-shaped permanent magnets are arranged inside each of the axial holes of the rotor core, and a main body located inside the plurality of axial holes; a permanent magnet having a protrusion protruding in the axial direction from an opening at one end of the axial hole; a rotation detection sensor that is arranged to face the protrusion in the axial direction and detects a magnetic flux component in the rotation axis direction of the permanent magnet; an extending portion provided on at least one side surface of each of the protrusions in the circumferential direction of the rotor and extending in the circumferential direction of the rotor so that adjacent protrusions approach each other through a gap; It is characterized by
- FIG. 1 is a longitudinal sectional view showing an embodiment of a brushless motor according to the present invention.
- 2 is an enlarged view of part A in FIG. 1.
- FIG. FIG. 2 is a schematic diagram showing the mounting positions of three magnetic sensors provided on a circuit board used in this embodiment. It is a distribution diagram of the magnetic flux density of the permanent magnet provided for this embodiment.
- FIG. 2 is an overhead view of a rotor used in this embodiment. (a) is an overhead view showing one of the permanent magnets taken out from the rotor, and (b) is a front view of the same permanent magnet.
- FIG. 2 is a perspective view of a rotor used in this embodiment, viewed from below.
- FIG. 2 is a side view of a rotor used in this embodiment.
- FIG. 9 is a sectional view taken along line BB in FIG. 8.
- FIG. 6 is an enlarged view of section C in FIG. 5.
- FIG. FIG. 6 is a characteristic diagram showing the relationship between magnetic flux density and rotor angle depending on the difference in the distance between the poles between the extension portions of adjacent permanent magnets used in this embodiment.
- FIG. 7 is an overhead view of a rotor used in a second embodiment of the present invention.
- FIG. 12 is an enlarged view of part D in FIG. 11.
- (a) is a perspective view showing another example of the permanent magnet used in the embodiment of the present invention, and (b) is a front view of the same permanent magnet.
- (a) is a perspective view showing still another example of the permanent magnet used in the embodiment of the present invention, and (b) is a front view of the same permanent magnet.
- (a) is a perspective view showing still another example of the permanent magnet used in the embodiment of the present invention, and (b) is a front view of the same permanent magnet.
- FIG. 1 is a longitudinal sectional view of the brushless motor of this embodiment
- FIG. 2 is an enlarged view of part A in FIG. 1
- FIG. 3 shows the mounting positions of three magnetic sensors provided on the circuit board used in this embodiment. It is a schematic diagram. Note that in FIG. 1, radial arrows indicate the radial direction of the rotor 5, and axial arrows indicate the rotational axis direction of the rotor 5.
- the brushless motor 1 is an IPM motor, and as shown in FIGS. 1 and 2, the brushless motor 1 includes a bottomed cylindrical motor housing 2 fixed to a chain case, and a stator fixed to the inner peripheral surface of the motor housing 2. (Stator) 3, a motor output shaft 4 disposed on the inner circumference of the stator 3, a rotor 5 fixed to the outer circumference of the motor output shaft 4, and one end of the motor housing 2 in the axial direction (Fig. It has a control mechanism 6 provided on the middle left side).
- the motor housing 2 is formed by bending, for example, an iron-based metal plate into a cup shape, and has a stator housing space S for housing the stator 3 and the like therein.
- the motor housing 2 has a through hole 2b formed approximately in the center of the bottom wall 2a, into which the motor output shaft 4 is inserted. This through hole 2b is formed inside a cylindrical portion 2c that is bent into a cylindrical shape at the center of the bottom wall 2a. Further, a cylindrical bearing holding portion 2g that holds a first ball bearing 15a, which will be described later, is provided near the cylindrical portion 2c of the bottom wall 2a.
- the motor housing 2 is integrally provided with a flange portion 2d projecting outward in the radial direction on the outer periphery of the open end of the rear end portion.
- This flange portion 2d has three bracket pieces 2e integrally provided at approximately 120° positions in the circumferential direction.
- bolt insertion holes 2f into which three bolts 7 are inserted are formed through each of the three bracket pieces 2e. Note that there may be three or more bracket pieces 2e.
- Each bolt 7 is adapted to fasten and fix the motor housing 2 and a casing 17 of the control mechanism 6, which will be described later, together, and also to fix them to a chain case (not shown). That is, in each bolt 7, a male threaded portion 7b on the outer periphery of the tip of the shaft portion 7a is fastened to a female threaded portion on the chain case, thereby fixing the motor housing 2 and the casing 17 to the chain case. Note that it is also possible to increase the number of bolt insertion holes 2f, bolts 7, etc. to three or more.
- the stator 3 includes a stator core (iron core) 3a and a multi-phase (3-phase U, V, W) coil 3b wound around the outer periphery of the stator core 3a.
- the stator core 3a is formed by laminating a large number of steel plates, and has a ring-shaped yoke (not shown) and a plurality of teeth protruding inward from the yoke.
- the coil 3b is wound around a plurality of teeth via an insulator.
- the motor output shaft 4 is made of, for example, an iron-based metal material, and one end 4a in the direction of the rotating shaft protrudes from the through hole 2b via an oil seal 8, which will be described later.
- the one end 4a of the motor output shaft 4 has a width across flats (not shown) formed along a tangential direction on the outer surface, and a pair of widths cut out from a direction perpendicular to the width across flats. A fitting groove is formed. As shown in FIG. 1, a stopper member 16 that restricts movement of the intermediate member 14 in the right direction in the figure is fitted and fixed in both fitting grooves from the radial direction. Further, one end portion 4a is supported by the motor housing 2 by a first ball bearing 15a held within the bearing holding portion 2g.
- the first ball bearing 15a has a general structure, and includes an outer ring fixed to the inner peripheral surface of the bearing holding part 2g, an inner ring fixed to the outer peripheral surface of one end 4a of the motor output shaft 4, and both wheels. It has a plurality of balls provided with a cage in between.
- the other end 4b of the motor output shaft 4 is rotatably supported by a second ball bearing 15b provided in the casing 17 of the control mechanism 6.
- the second ball bearing 15b like the first ball bearing 15a, includes an outer ring press-fitted into the inner circumferential surface of a bearing holding groove 18a of a cylindrical portion 18, which will be described later, and an outer circumferential surface of the other end 4b of the motor output shaft 4. It has an inner ring into which is press-fitted, and a plurality of balls provided between the two rings via a cage.
- the oil seal 8 has a general structure, and the outer circumferential surface is press-fitted into the inner circumferential surface of the through hole 2b, while the inner seal piece is attached to the outer circumferential surface of one end 4a of the motor output shaft 4 by a backup spring. They are slidably abutted. Thereby, the oil seal 8 restricts oil from flowing into the motor housing 2 from the outside.
- the motor output shaft 4 has one end 4a disposed close to the head of a cam bolt (not shown) with a small gap from the rotation axis direction.
- the entire one end portion 4a including the stopper member 16 can be inserted from the axial direction into a hexagonal groove formed on the front end surface of the head of the cam bolt.
- the stopper member 16 is formed in a C-ring shape and can be elastically deformed in the diameter expanding direction and the diameter contracting direction by its own elastic force.
- An intermediate member 14 is provided at one end 4a of the motor output shaft 4. This intermediate member 14 constitutes a part of an Oldham joint which is a joint connected to a reduction gear (not shown).
- FIG. 4 is a schematic diagram showing the mounting positions of three magnetic sensors provided on the circuit board used in this embodiment
- FIG. 5 is an overhead view of the rotor used in this embodiment
- FIG. 6(a) is a diagram showing the rotor (b) is a front view of the permanent magnet
- FIG. 7 is a perspective view of the rotor used in this embodiment, viewed from below
- FIG. 8 is a perspective view of the rotor used in this embodiment.
- 9 is a sectional view taken along line BB in FIG. 8, and FIG. 10 is an enlarged view of section C in FIG. 5.
- the rotor 5 is arranged on the inner circumferential side of the stator 3, and includes an annular rotor core 9 fixed to the outer circumference of the motor output shaft 4, and an annular rotor core 9 fixed to the outer circumference of the motor output shaft 4.
- the rotor core 9 and the permanent magnets 11 are provided coaxially with respect to the motor output shaft 4.
- the rotor core 9 is integrally formed of a metal material and has a substantially cylindrical outer circumferential portion 9a and a cylindrical inner circumferential portion 9b fixed to the motor output shaft 4. An intermediate portion between the outer circumferential portion 9a and the inner circumferential portion 9b is formed into a honeycomb shape in order to reduce the weight.
- the outer peripheral portion 9a has a shape in which eight arcuate blocks are connected in an annular manner along the circumferential direction, and the inner peripheral surface 9c is formed in an octagonal shape.
- gaps each having a substantially triangular cross section are formed on the outside between each block, and are filled with a covering portion 24 made of a synthetic resin material, which will be described later.
- An insertion hole 9d into which the motor output shaft 4 is inserted and fixed is formed through the inner peripheral portion 9b in the central axial direction.
- each holding hole 10 is formed to penetrate along the inner axial direction of each block portion of the outer peripheral portion 9a.
- Each holding hole 10 is formed in the shape of a linear elongated hole substantially along the circumferential direction when viewed from above, and is formed into a substantially rectangular shape when viewed from the outside in the radial direction. Further, each holding hole 10 is formed so as to have a uniform cross-sectional area from one end opening 10a on the control mechanism 6 side in the axial direction to the other end opening 10b on the opposite side. Further, each holding hole 10 has both end portions 10d and 10e formed in an arc shape when viewed from a plane (see FIG. 6(a)).
- each permanent magnet 11 is made of a common composite alloy material such as neodymium (rare earth sintered magnet) into a plate shape with a predetermined thickness, and its overall shape is It is approximately T-shaped when viewed from above.
- neodymium rare earth sintered magnet
- the permanent magnet 11 includes a main body 11a inserted into the holding hole 10, and a permanent magnet 11 protruding in the direction of the rotation axis of the rotor 5 from an opening 10a at one end of the holding hole 10 of the main body 11a. It has a protruding part 11b and a pair of extending parts 12, 12 that are integrally provided on both sides of the protruding part 11b in the circumferential direction of the rotor 5, that is, in the width direction perpendicular to the longitudinal direction of the main body 11a. There is.
- the main body 11a and the protrusion 11b are each formed into a plate shape with a substantially uniform width W perpendicular to the longitudinal direction.
- This width length W is formed shorter than the length in the width direction of the holding hole 10, and when the main body 11a is inserted and held in the holding hole 10, as shown in FIG.
- Clearances C1 and C2 are respectively formed between the opposing inner surfaces in the width direction of the opposing holding holes 10.
- Each of the clearances C1 and C2 has a substantially arc-shaped cross section at each end face in the circumferential direction by retaining the shape of the arc-shaped end portions 10d and 10e of each holding hole 10.
- each other end of each permanent magnet 11 on the opposite side in the axial direction from each protrusion 11b is a retreated portion 11c that is retreated further into the holding hole 10 than the other end opening 10b of each holding hole 10. .
- the protruding portion 11b has a protruding amount, that is, a length L from one end opening 10a of the holding hole 10 to the tip surface, of approximately 2 mm in this embodiment.
- the amount of retraction of the retracted portion 11c that is, the length L1 from the hole edge of the other end opening 10b of the holding hole 10 to the rear end surface of the retracted portion 11c is approximately 1 mm in this embodiment.
- each of the extending portions 12, 12 has the same protruding amount H, H in the circumferential direction of the rotor 5, and has the same protruding amount H, H in the axial direction of the rotor 5.
- the width lengths W1 and W1 are also the same and are formed to be the same as the protrusion amount L of the protrusion portion 11b.
- the extending portion 12 has one end surface 12a in the circumferential direction and the opposite end surface of another extending portion 12 adjacent in the circumferential direction of the rotor 5.
- a gap C is formed between each of them and 12b. This gap C is set to such a size that the distance X between the poles does not affect the magnetic flux mutually generated in each of the extending portions 12, 12 facing each other in the circumferential direction.
- each extending portion 12 is provided within a range inside the outer circumferential surface of the outer circumferential portion 9a of the rotor core 9 when the main body 11a is inserted into the holding hole 10.
- the extending portions 12, 12 have both inner and outer lower end edges 12c, 12d on the main body 11a side. is adapted to abut against the edge of one end opening 10a of the holding hole 10, that is, the radial edge of the rotor 5 across the respective clearances C1 and C2. This restricts the maximum insertion position of the permanent magnet 11 into the holding hole 10 of the main body 11a.
- the outer circumferential portion 9a of the rotor core 9, on the side of each protruding portion 11b and the side of each retreated portion 11c, is entirely covered with a covering portion 24 made of a synthetic resin material, which is a non-magnetic material.
- This covering portion 24 is formed into an annular shape so as to cover the entire outer circumferential surface of each protruding portion 11b. Further, the covering portion 24 is filled into the holding hole 10 from the other end opening 10b of the holding hole 10 so as to close each of the retreating portions 11c, and is formed into an annular shape as a whole.
- a part of the covering portion 24 is also filled in the triangular gaps between the blocks B of the outer peripheral portion 9a, and also between both circumferential side surfaces of the permanent magnet 11 and the facing surface of the holding hole 10 in the width direction. It also fills the gaps between.
- the covering portion 24 is filled in the rear end opening of the holding hole 10 so as to close the retracted portion 11c, and this filling portion is filled with the rear end surface of the retracted portion 11c and the outside.
- Holes 13 are provided to communicate with each other.
- Each hole 13 is a support that is placed in advance in a mold and supports the rear end surface of each retreating portion 11c from below when molding a synthetic resin material onto the outer peripheral portion 9a of the rotor core 9 by injection molding, for example. This was formed at the mark left after the pin was removed after being molded.
- the control mechanism 6 has a box-shaped casing 17 made of, for example, a synthetic resin material (non-magnetic material). As shown in FIG. 1, the casing 17 includes a square partition wall 17a disposed on the motor housing 2 side, and a square frame-shaped peripheral wall 17b rising from the outer periphery of the partition wall 17a. There is. Further, a substrate storage space S1 is formed inside surrounded by the partition wall 17a and the peripheral wall 17b.
- the partition wall 17a is integrally provided with a cylindrical portion 18 in the center, and four small-diameter cylindrical boss portions 17e are integrally provided at the four corners of the inner surface.
- Each of the cylindrical boss portions 17e has a female screw hole (not shown), into which four screws (not shown) for fixing the rectangular circuit board 19 are screwed, at the tip thereof.
- the partition wall 17a is provided with a first recess 20a at a portion facing a magnetic sensor 22, which will be described later, in the axial direction, and a portion facing a protrusion 11b of the permanent magnet 11.
- a second recess 20b is provided in the second recess 20b.
- the first recess 20a and the second recess 20b partially overlap in the radial direction, that is, they partially overlap in the radial direction.
- the first recess 20a is formed in the shape of an annular groove, and its radial width is larger than the radial length of the magnetic sensor 22, so that the magnetic sensor 22 can enter therein.
- the second recess 20b is similarly formed in the shape of an annular groove, and its width in the radial direction is formed to be sufficiently larger than the thickness and width of the protrusion 11b, so that the protrusion 11b can enter therein. It has become.
- the circuit board 19 is housed in the board housing space S1, and a conductive circuit (not shown) such as a bus bar that supplies power to the brushless motor 1 is disposed inside. Further, on one side of the circuit board 19, a hole terminal is provided which is coupled by soldering to a plurality of terminal pieces of a connector 21, which will be described later.
- the circuit board 19 has an insertion hole 19a formed in the center through which the cylindrical portion 18 can be inserted, and four small-diameter screw insertion holes into which screws (not shown) are inserted at the four corners. It is formed.
- the board housing space S1 also includes three magnetic sensors 22a, 22b, and 22c, which are rotation detection sensors that are electrically connected to the circuit board 19 and control the drive of the brushless motor 1, and aluminum electrolytic sensors 22a, 22b, and 22c.
- Multiple electronic components such as capacitors, normal coils, common coils, and multiple ceramic capacitors are housed.
- Three magnetic sensors 22a to 22c are provided on the circuit board 19, as shown in FIG. There are three magnetic sensors: a V-phase magnetic sensor 22b provided between the U-phase and the U-phase, and a U-phase magnetic sensor 22c provided between the U-phase and the W-phase. Furthermore, each of the magnetic sensors 22a to 22c detects an axial magnetic flux component (magnetic flux density) rather than a radial magnetic flux component of the permanent magnet 11, and determines whether the magnetic flux density is positive or negative. It has become.
- each of the magnetic sensors 22a to 22c is located on the circuit board 19 at a position away from the arrangement position of the permanent magnet 11 in the direction of the rotation axis of the rotor 5, and in the radial direction. It is located outside of the That is, as shown in FIGS. 3 and 4, each of the magnetic sensors 22a to 22c is arranged at a position deviated outward in the radial direction from the center position of each permanent magnet 11 in the circumferential direction. This is because, as will be described later, the unique arrangement of the permanent magnets 11 increases detection accuracy due to the characteristics of the magnetic sensors 22a to 22c in detecting magnetic flux components (magnetic flux density) in the axial direction.
- each of the magnetic sensors 22a to 22c is arranged so as to straddle an annular gap C3 between the inner circumferential surface of the stator 3 and the outer circumferential surface of the rotor 5.
- P1 is located in the annular gap C3.
- each of the magnetic sensors 22a to 22c is partially disposed between each coil 3b at the mounting position in the circumferential direction of the stator 3, and is connected to the protruding portion 11b (extending portion 12) of the permanent magnet 11 in the axial direction. They are located at almost opposite positions.
- the cylindrical portion 18 is formed into a substantially cylindrical shape with a bottom, and one end and the other end in the axial direction face the stator housing space S and the board housing space S1, respectively, with the partition wall 17a as the center. That is, one end is arranged in the stator accommodation space S, and the other end is arranged in the board accommodation space S1. Further, the cylindrical portion 18 has a bearing holding groove 18a that accommodates and holds the second ball bearing 15b therein.
- the peripheral wall 17b is integrally provided with a connector 21 for both signal and power supply on the outer periphery.
- This connector 21 is formed into a box shape, and one end portion of a pair of terminal pieces (not shown) is arranged inside. The other end of this terminal piece (not shown) located in the board accommodation space S1 is coupled to a hole terminal of a conductive circuit of the circuit board 19 by soldering.
- One end of the pair of terminal pieces located inside the connector 21 is partially connected to an engine control unit (ECU) (not shown) via a female terminal to a battery as a power source. Further, the other part outputs information signals such as magnetic pole position signals detected by each of the magnetic sensors 22a to 22c to the ECU.
- ECU engine control unit
- a cover member 23 is attached to the outer periphery of the peripheral wall 17b on the opposite side from the motor housing 2.
- the cover member 23 is made of, for example, a synthetic resin material and is formed into a plate-like rectangular shape, and an outer peripheral portion 23a bent in a crank shape toward the casing 17 is fixed to the peripheral wall 17b of the casing 17 by a predetermined fixing means. It has become so.
- the ECU controls the rotation of the motor output shaft 4 by energizing the coil 3b of the brushless motor 1 based on signals from the magnetic sensor 22 and the like.
- each of the magnetic sensors 22a to 22c detects an axial magnetic flux component, which is cheaper than one that detects a radial magnetic flux component. Therefore, the cost of the magnetic sensors 22a to 22c itself can be reduced.
- the magnetic sensors 22a to 22c are Hall ICs, and the sensor cores of the Hall ICs are plate-shaped. The magnetic flux passing through the plate-shaped sensor core in the thickness direction is detected.
- each of the magnetic sensors 22a to 22c is arranged at a position away from the permanent magnet 11 in the rotational axis direction of the rotor 5 and at a position outside the rotor 5 in the radial direction. That is, each of the magnetic sensors 22a to 22c is provided at a position shifted outward in the radial direction of the rotor 5 with the permanent magnet 11 as the center. This makes it easier for the magnetic flux density of the permanent magnet 11 to reach its peak value, thereby improving detection performance and making it less susceptible to variations in the axial positions of the magnetic sensors 22a to 22c.
- each of the magnetic sensors 22a to 22c is attached to a measurement position on the outside in the radial direction, and is also attached so as to straddle between the permanent magnet 11 and the coil 3b.
- the peak value of the magnetic flux component in the axial direction of the permanent magnet 11 is high, and it becomes less susceptible to the magnetic flux component generated from the coil 3b.
- the detection accuracy of each of the magnetic sensors 22a to 22c is increased, and stable detection performance can be obtained.
- the magnetic flux density T of the permanent magnet 11 is lower than the central axis P of the permanent magnet 11, as shown in the magnetic flux density distribution diagram of FIG. It can be seen that the Q area on the outside in the radial direction or the R area on the inside in the radial direction from the central axis P is sufficiently higher than the area.
- the magnetic sensor 22 is positioned on the outside of the permanent magnet 11 in the radial direction rather than on the inside, the angular error due to variations in the mounting of the magnetic sensor 22 is reduced, and detection accuracy can be increased. can. That is, if the three magnetic sensors 22a to 22c are mounted on the inside in the radial direction, an error in the mounting angle of the three magnetic sensors 22a to 22c is likely to occur, but if they are mounted on the outside in the radial direction, the error in the mounting angle is less likely to occur.
- each of the magnetic sensors 22a to 22c is attached to a predetermined position on the outside in the radial direction, and the sensor center P1 is placed in the annular gap C3 between the rotor 5 and the stator 3, as shown in FIG.
- the magnet 11 was positioned so as to straddle between the permanent magnet 11 and the coil 3b.
- the peak value of the magnetic flux component in the axial direction of the permanent magnet 11 is high, and it becomes less susceptible to the magnetic flux component generated from the coil 3b.
- the detection accuracy of each of the magnetic sensors 22a to 22c is increased, and stable detection performance can be obtained.
- each of the magnetic sensors 22a to 22c is installed at a position where it straddles the annular gap C3 between the rotor 5 and the stator 3 in the radial direction. Since this is the position where the peak value is high, the detection performance of each magnetic sensor 22a to 22c is high.
- each of the magnetic sensors 22a to 22c is partially disposed between each coil 3b at the mounting position in the circumferential direction of the stator 3, so that the influence of the magnetic flux of the coil 3b can be sufficiently avoided. Control accuracy increases.
- two extension parts 12, 12 are provided on both sides of the protrusion part 11b of each permanent magnet 11, and one end face 12a of one of the extension parts 12 adjacent in the circumferential direction and the rotor 5 Since the distance X between the poles and the other end surface 12b of the other extending portion 12 facing each other in the circumferential direction is made smaller than that of the prior art, the following effects can be obtained.
- FIG. 11 is a characteristic diagram showing the relationship between the magnetic flux density T and the rotor angle deg due to the difference in the interpolar distance . This represents the results of experiments conducted by the inventor of the present application with various changes in the inter-electrode distance X. This is a comparison between the two electrodes having different interpolar distances X1, X2, and X3.
- the distance between poles X' of the conventional technology was set to 4.66 mm, and as the present embodiment, the distance between poles X1 was set to 3.74 mm in the first example, and the distance between poles X2 was set to 3.74 mm in the second example.
- the interpolar distance X3 was set to 1.15 mm.
- the magnetic sensors 22a to 22c recognize that the magnetic poles have changed when the magnetic flux density T exceeds the sensor threshold. It is clear that as the interpolar distance X becomes smaller, the slope of the magnetic flux density T near the sensor threshold changes.
- the magnetic flux density T with respect to the rotation angle of the rotor 5 is The slope becomes smaller, and the rotor rotation angle is approximately 13 degrees at the sensor threshold.
- the slope is even larger than that of the conventional technique, and the rotor rotation angle is approximately 7.5 degrees at the sensor threshold, which is 5.5 degrees greater than that of the conventional technique. It is clear that the speed is increased by 5 degrees. Therefore, in the second and third examples as well, it becomes possible to recognize the timing at which the magnetic poles of the north and south poles change more quickly than in the prior art.
- the timing at which the magnetic poles of N and S poles change can be recognized quickly, the magnetic flux at the positions of each magnetic sensor 22a to 22c is increased, and the detection delay of each magnetic sensor 22a to 22c is reduced. can be reduced.
- the detection delay of the magnetic sensors 22a to 22c can be reduced, the power consumption rate (electricity cost) and the amount of heat generated by the coil wound around the stator core can be reduced. Furthermore, costs associated with changing element parts compatible with high current can be reduced.
- the main body 11a of the permanent magnet 11 has a retracted portion 11c located inside the other end opening 10b of the axial hole.
- the other end of the main body 11a of the permanent magnet 11 can be cut short by the magnetic force of the extensions 12, 12, so the overall weight and volume of the permanent magnet 11 can be reduced.
- each of the extending portions 12, 12 is provided within a range inside the outer circumferential surface of the outer circumferential portion 9a of the rotor core 9, the extending portions 12, 12 are provided within a range inside the outer circumferential surface of the outer circumferential portion 9a of the rotor core 9.
- Contact with the coil 3b is avoided, and damage to the extension portion, stator core 3a, etc. due to interference due to vibration or the like can be suppressed.
- the protruding portion 11b and the recessed portion 11c are covered with a covering portion 24 made of a synthetic resin material at the front and rear in the axial direction, and the holding hole 10 is also filled with the covering portion 24 to cover the holding hole 10.
- a covering portion 24 made of a synthetic resin material at the front and rear in the axial direction
- the holding hole 10 is also filled with the covering portion 24 to cover the holding hole 10.
- the lengths H, H of the extending portions 12, 12 provided on both side surfaces of the protruding portion 11b of the permanent magnet 11 are set by the extending portions 12 of the other adjacent permanent magnets 11, 12 and is made longer within a range that does not interfere with 12.
- each of the extending portions 12, 12 has both lower end edges 12c, 12d with a clearance of one end opening 10a of the holding hole 10 when the main body 11a is inserted into the holding hole 10. It contacts the hole edge in a manner that covers the entirety of C1 and C2.
- the one end opening 10a of the holding hole 10 is entirely covered by each of the extending portions 12, 12, dust and contaminants are prevented from entering into the holding hole 10 from the one end opening 10a. Can be suppressed.
- [Other examples of permanent magnets] 14 to 16 show a plurality of examples in which the shapes of the protruding portion 11b and the extending portions 12, 12 of the permanent magnet 11 are changed.
- a notch groove 25 is formed in the center of the upper end of the protrusion 11b.
- This cutout groove 25 is formed by cutting out a part of the upper end of the protrusion 11b in a rectangular shape along the direction of the extensions 12 .
- an arcuate groove 26 is formed by continuously cutting out the upper end portions of both the extension portions 12, 12 and the protruding portion 11b in an arcuate concave shape.
- the permanent magnet 11 as a whole can be made lighter and more compact.
- an arcuate protrusion 27 is formed by continuously cutting out the upper ends of both the extensions 12, 12 and the protrusion 11b in an arcuate shape. This example also provides the same effects as the above two examples.
- the present invention is not limited to the configuration of the embodiment described above, and only one extension portion 12, 12 of the permanent magnet 11 is provided on one side of the protrusion portion 11b, and the protrusion portions of the adjacent permanent magnets 11 are It is also possible to form a gap C between it and 11b.
- the protrusion amount L (W1) of the protrusion portion 11b of each permanent magnet 11 and each extension portion 12, 12, and the retraction amount L1 of the retraction portion 11c are determined depending on the specifications of the brushless motor 1, the magnitude of the magnetic force, etc. It is possible to determine the length relatively.
- Applicable devices for the brushless motor 1 include not only valve timing control devices for internal combustion engines, but also various in-vehicle motors such as power steering motors, power window motors, sunroof motors, and power seat motors, as well as home appliances such as air conditioners. It can also be applied to motors used in other applications.
- SYMBOLS 1... Brushless motor, 2... Motor housing, 3... Stator, 3a... Stator core, 3b... Coil (winding), 4... Motor output shaft, 5... Rotor, 6... Control mechanism, 9... Rotor core, 9a...
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Abstract
This brushless motor has: a rotor 5 having a rotor core 9 to which a motor output shaft 4 is fixed; a permanent magnet 11 having a body 11a disposed inside each holding hole 10 formed in the outer circumference of the rotor core and a projection portion 11b projecting in the axial direction from one end opening portion 10a of each holding hole; magnetic sensors 22a to 22c each disposed so as to face the projection portion from the axial direction and detecting a magnetic flux component of the permanent magnet in the rotational axis direction; and two extending portions 12, 12 provided on both side surfaces of the projection portion in the circumferential direction of the rotor core. The extending portions are each formed so that facing one end surface 12a and the other end surface 12b of the facing extending portions of the adjacent permanent magnets are close to each other with a gap C interposed therebetween. This increases a magnetic flux density detected by a rotation detection sensor, thereby enabling the electricity consumption and the heat generation amount of a coil to be reduced.
Description
本発明は、ブラシレスモータに関する。
The present invention relates to a brushless motor.
従来のブラシレスモータとしては、以下の特許文献1に記載されたものが知られている。このブラシレスモータは、いわゆるIPMモータであって、枠状に形成されたステータの内部に回転可能に配置されたロータを有している。ステータの一端側には、ロータの磁極位置を検出する磁気センサが設けられている。
As a conventional brushless motor, one described in Patent Document 1 below is known. This brushless motor is a so-called IPM motor, and has a rotor rotatably disposed inside a stator formed in a frame shape. A magnetic sensor is provided at one end of the stator to detect the magnetic pole position of the rotor.
ロータは、回転可能な回転軸を有すると共に、前記回転軸に一体に取り付けられた円筒状のロータコアを有している。このロータコアは、回転軸の軸方向に沿った複数の貫通孔を有している。
The rotor has a rotatable shaft and a cylindrical rotor core that is integrally attached to the shaft. This rotor core has a plurality of through holes along the axial direction of the rotating shaft.
また、ロータは、ロータコアの各軸方向孔に挿入固定され複数の永久磁石を有している。この各永久磁石は、所定の肉厚を有する板状に形成されて、一部が前記各軸方向孔の一端開口部からそれぞれ突出した突出部を有している。
Further, the rotor has a plurality of permanent magnets inserted and fixed into each axial hole of the rotor core. Each of the permanent magnets is formed into a plate shape having a predetermined thickness, and has a protruding portion that partially protrudes from an opening at one end of each of the axial holes.
また、前記ロータの外周部に対向した位置に磁気センサが設けられている。この磁気センサは、ロータコアの各貫通孔に挿入固定された複数の永久磁石の各突出部から発生する磁束を検出して、ロータの磁極位置を検出するようになっている。
Furthermore, a magnetic sensor is provided at a position facing the outer peripheral portion of the rotor. This magnetic sensor detects the magnetic pole position of the rotor by detecting magnetic flux generated from each protrusion of a plurality of permanent magnets inserted and fixed into each through hole of the rotor core.
前記従来のブラシレスモータにあっては、磁気センサが、前記複数の永久磁石の各突出部から発生する磁束を検出するようになっているが、前記隣接する各突出部の間の距離が離れていることから、磁気センサでの磁極の切り替わりの認識が遅れるおそれがある。
In the conventional brushless motor, the magnetic sensor detects the magnetic flux generated from each protrusion of the plurality of permanent magnets, but the distance between the adjacent protrusions is large. Therefore, there is a risk that the recognition of the switching of the magnetic pole by the magnetic sensor may be delayed.
すなわち、隣接する突出部の間の距離が大きくなると、磁極が変わるタイミングが遅くなる。また、隣接する永久磁石の突出部の間の空間では、磁束を発生する永久磁石がないため、磁気センサ位置での磁束が弱くなることから、磁気センサでの磁極切り替え判定のタイミングが遅くなる。磁極の切り替わりの認識が遅れると、理想とされる通電タイミングが遅れることとなり、同じトルクを発生させる電流が大きくなる。この結果、電費やコイルの発熱量が多くなるおそれがある。
That is, as the distance between adjacent protrusions increases, the timing at which the magnetic poles change becomes slower. Furthermore, since there is no permanent magnet that generates magnetic flux in the space between the protrusions of adjacent permanent magnets, the magnetic flux at the magnetic sensor position becomes weak, and the timing of the magnetic pole switching determination at the magnetic sensor is delayed. If there is a delay in recognizing the switching of the magnetic poles, the ideal energization timing will be delayed, and the current required to generate the same torque will increase. As a result, there is a possibility that the electricity cost and the amount of heat generated by the coil will increase.
本発明は、前記従来の技術的課題に鑑みて案出されたもので、隣接する永久磁石の延出部(突出部)間の距離を短くし、磁気センサ位置での磁束が弱まることを低減させ、電費やコイルの発熱量を低減することができるブラシレスモータを提供することを一つの目的としている。
The present invention was devised in view of the above-mentioned conventional technical problems, and reduces the distance between the extension parts (protrusions) of adjacent permanent magnets to reduce the weakening of the magnetic flux at the magnetic sensor position. One of the objects of the present invention is to provide a brushless motor that can reduce electricity costs and the amount of heat generated by the coil.
好ましい態様の一つとしては、とりわけ、ロータコアの各軸方向孔の内部にそれぞれ配置された板状の複数の永久磁石であって、前記複数の軸方向孔の内部に位置する本体と、前記複数の軸方向孔の一端開口部から軸方向に突出した突出部と、を有する永久磁石と、
前記突出部と軸方向から対向するように配置され、前記永久磁石の回転軸方向の磁束成分を検出する回転検出センサと、
前記各突出部の前記ロータの周方向の少なくとも一方の側面に設けられ、隣り合う前記突出部が隙間を介して互いに近づくように前記ロータの周方向に延びた延出部と、を備えたことを特徴としている。 In one preferred embodiment, a plurality of plate-shaped permanent magnets are arranged inside each of the axial holes of the rotor core, and a main body located inside the plurality of axial holes; a permanent magnet having a protrusion protruding in the axial direction from an opening at one end of the axial hole;
a rotation detection sensor that is arranged to face the protrusion in the axial direction and detects a magnetic flux component in the rotation axis direction of the permanent magnet;
an extending portion provided on at least one side surface of each of the protrusions in the circumferential direction of the rotor and extending in the circumferential direction of the rotor so that adjacent protrusions approach each other through a gap; It is characterized by
前記突出部と軸方向から対向するように配置され、前記永久磁石の回転軸方向の磁束成分を検出する回転検出センサと、
前記各突出部の前記ロータの周方向の少なくとも一方の側面に設けられ、隣り合う前記突出部が隙間を介して互いに近づくように前記ロータの周方向に延びた延出部と、を備えたことを特徴としている。 In one preferred embodiment, a plurality of plate-shaped permanent magnets are arranged inside each of the axial holes of the rotor core, and a main body located inside the plurality of axial holes; a permanent magnet having a protrusion protruding in the axial direction from an opening at one end of the axial hole;
a rotation detection sensor that is arranged to face the protrusion in the axial direction and detects a magnetic flux component in the rotation axis direction of the permanent magnet;
an extending portion provided on at least one side surface of each of the protrusions in the circumferential direction of the rotor and extending in the circumferential direction of the rotor so that adjacent protrusions approach each other through a gap; It is characterized by
本発明の好ましい態様によれば、回転検出センサの検出磁束密度を高めて電費やコイルの発熱量を低減することができる。
According to a preferred embodiment of the present invention, it is possible to increase the detection magnetic flux density of the rotation detection sensor and reduce the electricity cost and the amount of heat generated by the coil.
以下、本発明に係るブラシレスモータの実施形態を図面に基づいて詳述する。
Hereinafter, embodiments of the brushless motor according to the present invention will be described in detail based on the drawings.
図1は本実施形態のブラシレスモータの縦断面図、図2は図1のA部拡大図、図3は本実施形態に供される回路基板に設けられた3つの磁気センサの取り付け位置を示す概略図である。なお、図1中、径方向矢印はロータ5の径方向を示し、軸方向矢印はロータ5の回転軸方向を示している。
FIG. 1 is a longitudinal sectional view of the brushless motor of this embodiment, FIG. 2 is an enlarged view of part A in FIG. 1, and FIG. 3 shows the mounting positions of three magnetic sensors provided on the circuit board used in this embodiment. It is a schematic diagram. Note that in FIG. 1, radial arrows indicate the radial direction of the rotor 5, and axial arrows indicate the rotational axis direction of the rotor 5.
ブラシレスモータ1は、IPMモータであって、図1及び図2に示すように、チェーンケースに固定される有底円筒状のモータハウジング2と、このモータハウジング2の内周面に固定されたステータ(固定子)3と、ステータ3の内周側に配置されたモータ出力軸4と、該モータ出力軸4の外周に固定されたロータ5と、モータハウジング2の軸方向の一端側(図1中左側)に設けられた制御機構6と、を有している。
The brushless motor 1 is an IPM motor, and as shown in FIGS. 1 and 2, the brushless motor 1 includes a bottomed cylindrical motor housing 2 fixed to a chain case, and a stator fixed to the inner peripheral surface of the motor housing 2. (Stator) 3, a motor output shaft 4 disposed on the inner circumference of the stator 3, a rotor 5 fixed to the outer circumference of the motor output shaft 4, and one end of the motor housing 2 in the axial direction (Fig. It has a control mechanism 6 provided on the middle left side).
モータハウジング2は、例えば鉄系金属板をカップ状に折曲形成されて、内部にステータ3などを収容するステータ収容空間Sが形成されている。モータハウジング2は、底壁2aのほぼ中央にモータ出力軸4が挿通する貫通孔2bが形成されている。この貫通孔2bは、底壁2aの中央を筒状に折曲された筒部2cの内側に形成されている。また、底壁2aの筒部2cの近傍には、後述する第1ボールベアリング15aを保持する円筒状のベアリング保持部2gが設けられている。
The motor housing 2 is formed by bending, for example, an iron-based metal plate into a cup shape, and has a stator housing space S for housing the stator 3 and the like therein. The motor housing 2 has a through hole 2b formed approximately in the center of the bottom wall 2a, into which the motor output shaft 4 is inserted. This through hole 2b is formed inside a cylindrical portion 2c that is bent into a cylindrical shape at the center of the bottom wall 2a. Further, a cylindrical bearing holding portion 2g that holds a first ball bearing 15a, which will be described later, is provided near the cylindrical portion 2c of the bottom wall 2a.
また、モータハウジング2は、後端部の開口端の外周に径方向外側に突出したフランジ部2dが一体に設けられている。このフランジ部2dは、円周方向の約120°位置に3つのブラケット片2eが一体に設けられている。また、この3つのブラケット片2eには、3つのボルト7が挿入されるボルト挿入孔2fがそれぞれ貫通形成されている。なお、このブラケット片2eは、3つ以上であってもよい。
Further, the motor housing 2 is integrally provided with a flange portion 2d projecting outward in the radial direction on the outer periphery of the open end of the rear end portion. This flange portion 2d has three bracket pieces 2e integrally provided at approximately 120° positions in the circumferential direction. Further, bolt insertion holes 2f into which three bolts 7 are inserted are formed through each of the three bracket pieces 2e. Note that there may be three or more bracket pieces 2e.
各ボルト7は、モータハウジング2と制御機構6の後述するケーシング17とを共締め固定すると共に、これらを図外のチェーンケースに固定するようになっている。つまり、各ボルト7は、軸部7aの先端部の外周に有する雄ねじ部7bがチェーンケースに有する雌ねじ部に締結して、モータハウジング2とケーシング17をチェーンケースに固定するようになっている。なお、ボルト挿入孔2fやボルト7などを3つ以上に増やすことも可能である。
Each bolt 7 is adapted to fasten and fix the motor housing 2 and a casing 17 of the control mechanism 6, which will be described later, together, and also to fix them to a chain case (not shown). That is, in each bolt 7, a male threaded portion 7b on the outer periphery of the tip of the shaft portion 7a is fastened to a female threaded portion on the chain case, thereby fixing the motor housing 2 and the casing 17 to the chain case. Note that it is also possible to increase the number of bolt insertion holes 2f, bolts 7, etc. to three or more.
ステータ3は、図1~図3に示すように、ステータコア(鉄心)3aと、該ステータコア3aの外周に巻き付けられた複数相(3相U,V,W)のコイル3bと、を備えている。ステータコア3aは、鋼板を多数積層して形成され、図外のリング状のヨーク部と、該ヨーク部から内側方向へ突設された複数のティースを有している。コイル3bは、複数のティースにインシュレータを介して巻き付けられている。
As shown in FIGS. 1 to 3, the stator 3 includes a stator core (iron core) 3a and a multi-phase (3-phase U, V, W) coil 3b wound around the outer periphery of the stator core 3a. . The stator core 3a is formed by laminating a large number of steel plates, and has a ring-shaped yoke (not shown) and a plurality of teeth protruding inward from the yoke. The coil 3b is wound around a plurality of teeth via an insulator.
モータ出力軸4は、例えば鉄系金属材によって形成され、回転軸方向の一端部4aが後述するオイルシール8を介して貫通孔2bから突出している。
The motor output shaft 4 is made of, for example, an iron-based metal material, and one end 4a in the direction of the rotating shaft protrudes from the through hole 2b via an oil seal 8, which will be described later.
また、モータ出力軸4の一端部4aは、外面に接線方向に沿って形成された図外の二面幅部を有し、この二面幅部に対して直交する方向から切り欠かれた一対の嵌着溝が形成されている。この両嵌着溝には、図1に示すように、中間部材14の図中右方向への移動を規制するストッパ部材16が径方向から嵌着固定されている。また、一端部4aは、ベアリング保持部2g内に保持された第1ボールベアリング15aによってモータハウジング2に軸受されている。第1ボールベアリング15aは、一般的な構造であって、ベアリング保持部2gの内周面に固定された外輪と、モータ出力軸4の一端部4aの外周面に固定された内輪と、該両輪間にケージを介して設けられた複数のボールとを有している。
The one end 4a of the motor output shaft 4 has a width across flats (not shown) formed along a tangential direction on the outer surface, and a pair of widths cut out from a direction perpendicular to the width across flats. A fitting groove is formed. As shown in FIG. 1, a stopper member 16 that restricts movement of the intermediate member 14 in the right direction in the figure is fitted and fixed in both fitting grooves from the radial direction. Further, one end portion 4a is supported by the motor housing 2 by a first ball bearing 15a held within the bearing holding portion 2g. The first ball bearing 15a has a general structure, and includes an outer ring fixed to the inner peripheral surface of the bearing holding part 2g, an inner ring fixed to the outer peripheral surface of one end 4a of the motor output shaft 4, and both wheels. It has a plurality of balls provided with a cage in between.
一方、モータ出力軸4の他端部4bは、制御機構6のケーシング17に設けられた第2ボールベアリング15bによって回転可能に軸受けされている。第2ボールベアリング15bは、第1ボールベアリング15aと同じく、後述する筒状部18のベアリング保持溝18aの内周面に圧入固定された外輪と、モータ出力軸4の他端部4bの外周面が圧入された内輪と、該両輪間にケージを介して設けられた複数のボールとを有している。
On the other hand, the other end 4b of the motor output shaft 4 is rotatably supported by a second ball bearing 15b provided in the casing 17 of the control mechanism 6. The second ball bearing 15b, like the first ball bearing 15a, includes an outer ring press-fitted into the inner circumferential surface of a bearing holding groove 18a of a cylindrical portion 18, which will be described later, and an outer circumferential surface of the other end 4b of the motor output shaft 4. It has an inner ring into which is press-fitted, and a plurality of balls provided between the two rings via a cage.
オイルシール8は、一般的な構造であって、外周面が貫通孔2bの内周面に圧入されている一方、内周のシール片がバックアップスプリングによってモータ出力軸4の一端部4a外周面に摺動可能に当接している。これによって、オイルシール8が、外部からモータハウジング2内へのオイルの流入を規制している。
The oil seal 8 has a general structure, and the outer circumferential surface is press-fitted into the inner circumferential surface of the through hole 2b, while the inner seal piece is attached to the outer circumferential surface of one end 4a of the motor output shaft 4 by a backup spring. They are slidably abutted. Thereby, the oil seal 8 restricts oil from flowing into the motor housing 2 from the outside.
モータ出力軸4は、図1にも示すように、一端部4aが図外のカムボルトの頭部に回転軸方向から僅かな隙間をもって近接配置されている。一端部4aは、ストッパ部材16を含めた全体がカムボルトの頭部の前端面に有する六角溝の内部に軸方向から挿入可能になっている。
As shown in FIG. 1, the motor output shaft 4 has one end 4a disposed close to the head of a cam bolt (not shown) with a small gap from the rotation axis direction. The entire one end portion 4a including the stopper member 16 can be inserted from the axial direction into a hexagonal groove formed on the front end surface of the head of the cam bolt.
ストッパ部材16は、Cリング状に形成されて、自身の弾性力によって拡径方向及び縮径方向へ弾性変形可能になっている。
The stopper member 16 is formed in a C-ring shape and can be elastically deformed in the diameter expanding direction and the diameter contracting direction by its own elastic force.
モータ出力軸4の一端部4aには、中間部材14が設けられている。この中間部材14は、図外の減速機に接続される継手であるオルダム継手の一部を構成するものである。
An intermediate member 14 is provided at one end 4a of the motor output shaft 4. This intermediate member 14 constitutes a part of an Oldham joint which is a joint connected to a reduction gear (not shown).
図4は本実施形態に供される回路基板に設けられた3つの磁気センサの取り付け位置を示す概略図、図5は本実施形態に供されるロータの俯瞰図、図6(a)はロータから永久磁石の一つを取り出した状態を示す俯瞰図、(b)は永久磁石の正面図、図7は本実施形態に供されるロータを下側から視た斜視図、図8は本実施形態に供されるロータの側面図、図9は図8のB-B線断面図、図10は図5のC部拡大図である。
FIG. 4 is a schematic diagram showing the mounting positions of three magnetic sensors provided on the circuit board used in this embodiment, FIG. 5 is an overhead view of the rotor used in this embodiment, and FIG. 6(a) is a diagram showing the rotor (b) is a front view of the permanent magnet, FIG. 7 is a perspective view of the rotor used in this embodiment, viewed from below, and FIG. 8 is a perspective view of the rotor used in this embodiment. 9 is a sectional view taken along line BB in FIG. 8, and FIG. 10 is an enlarged view of section C in FIG. 5.
ロータ5は、図1、図2、図5~図8に示すように、ステータ3の内周側に配置されており、モータ出力軸4の外周に固定された円環状のロータコア9と、該ロータコア9の外周部9aに有する複数の軸方向孔である複数(本実施形態では8つ)の保持孔10と、該各保持孔10にそれぞれ挿入保持された8枚の永久磁石11と、を備えている。ロータコア9と永久磁石11は、モータ出力軸4に対して同軸状に設けられている。
As shown in FIGS. 1, 2, and 5 to 8, the rotor 5 is arranged on the inner circumferential side of the stator 3, and includes an annular rotor core 9 fixed to the outer circumference of the motor output shaft 4, and an annular rotor core 9 fixed to the outer circumference of the motor output shaft 4. A plurality of (eight in this embodiment) holding holes 10, which are a plurality of axial holes provided in the outer peripheral portion 9a of the rotor core 9, and eight permanent magnets 11 inserted and held in each of the holding holes 10, respectively. We are prepared. The rotor core 9 and the permanent magnets 11 are provided coaxially with respect to the motor output shaft 4.
ロータコア9は、金属材によって一体に形成され、ほぼ円筒状の外周部9aと、モータ出力軸4に固定される円筒状の内周部9bと、を有している。この外周部9aと内周部9bとの間の中間部位が、軽量化を図るためにハニカム状に形成されている。
The rotor core 9 is integrally formed of a metal material and has a substantially cylindrical outer circumferential portion 9a and a cylindrical inner circumferential portion 9b fixed to the motor output shaft 4. An intermediate portion between the outer circumferential portion 9a and the inner circumferential portion 9b is formed into a honeycomb shape in order to reduce the weight.
外周部9aは、周方向に沿って円弧状の8つのブロックが環状に連結された形になっていると共に、内周面9cが八角形状に形成されている。外周部9aは、各ブロックの間の外側に、後述する合成樹脂材の被覆部24によって埋められる断面ほぼ三角形状の隙間がそれぞれ形成されている。内周部9bは、中央の軸方向にモータ出力軸4が挿入固定される挿入孔9dが貫通形成されている。
The outer peripheral portion 9a has a shape in which eight arcuate blocks are connected in an annular manner along the circumferential direction, and the inner peripheral surface 9c is formed in an octagonal shape. In the outer peripheral portion 9a, gaps each having a substantially triangular cross section are formed on the outside between each block, and are filled with a covering portion 24 made of a synthetic resin material, which will be described later. An insertion hole 9d into which the motor output shaft 4 is inserted and fixed is formed through the inner peripheral portion 9b in the central axial direction.
各保持孔10は、図5、図6(a)、図7~図10に示すように、外周部9aの各ブロック部位の内部軸方向に沿って貫通形成されている。各保持孔10は、平面から視てほぼ円周方向に沿って直線状の長孔状に形成されて、径方向外側からの透過視でほぼ矩形状に形成されている。また、各保持孔10は、軸方向の制御機構6側の一端開口部10aからその反対側の他端開口部10bまで均一な断面積で貫通形成されている。また、各保持孔10は、それぞれ平面から視た両端部10d、10eが円弧状に形成されている(図6(a)参照)。
As shown in FIGS. 5, 6(a), and 7 to 10, each holding hole 10 is formed to penetrate along the inner axial direction of each block portion of the outer peripheral portion 9a. Each holding hole 10 is formed in the shape of a linear elongated hole substantially along the circumferential direction when viewed from above, and is formed into a substantially rectangular shape when viewed from the outside in the radial direction. Further, each holding hole 10 is formed so as to have a uniform cross-sectional area from one end opening 10a on the control mechanism 6 side in the axial direction to the other end opening 10b on the opposite side. Further, each holding hole 10 has both end portions 10d and 10e formed in an arc shape when viewed from a plane (see FIG. 6(a)).
各永久磁石11は、図5~図10に示すように、一般的なネオジウムなどの複合合金材(希土類焼結磁石)で所定肉厚の板状に形成されていると共に、全体の形状が正面から視てほぼT字形状に形成されている。
As shown in FIGS. 5 to 10, each permanent magnet 11 is made of a common composite alloy material such as neodymium (rare earth sintered magnet) into a plate shape with a predetermined thickness, and its overall shape is It is approximately T-shaped when viewed from above.
すなわち、永久磁石11は、図6に示すように、保持孔10の内部に挿入配置された本体11aと、本体11aの前記保持孔10の一端開口部10aからロータ5の回転軸方向へ突出した突出部11bと、この突出部11bのロータ5の周方向、つまり本体11aの長手方向に直交する幅方向の両側面に一体に設けられた一対の延出部12、12と、を有している。
That is, as shown in FIG. 6, the permanent magnet 11 includes a main body 11a inserted into the holding hole 10, and a permanent magnet 11 protruding in the direction of the rotation axis of the rotor 5 from an opening 10a at one end of the holding hole 10 of the main body 11a. It has a protruding part 11b and a pair of extending parts 12, 12 that are integrally provided on both sides of the protruding part 11b in the circumferential direction of the rotor 5, that is, in the width direction perpendicular to the longitudinal direction of the main body 11a. There is.
本体11aと突出部11bは、図6(b)に示すように、長手方向に直交する幅長さWがほぼ均一な長さの板状にそれぞれ形成されている。この幅長さWは、保持孔10の幅方向長さよりも短く形成されて、本体11aが保持孔10に挿入保持された際には、図10に示すように、両側面と該両側面と対向する保持孔10の幅方向の対向内面との間にクリアランスC1、C2がそれぞれ形成されている。この各クリアランスC1、C2は、各保持孔10の円弧状の両端部10d、10eの形状がそのまま存在することによって周方向の各端面が横断面ほぼ円弧状に形成されている。
As shown in FIG. 6(b), the main body 11a and the protrusion 11b are each formed into a plate shape with a substantially uniform width W perpendicular to the longitudinal direction. This width length W is formed shorter than the length in the width direction of the holding hole 10, and when the main body 11a is inserted and held in the holding hole 10, as shown in FIG. Clearances C1 and C2 are respectively formed between the opposing inner surfaces in the width direction of the opposing holding holes 10. Each of the clearances C1 and C2 has a substantially arc-shaped cross section at each end face in the circumferential direction by retaining the shape of the arc-shaped end portions 10d and 10e of each holding hole 10.
また、各永久磁石11は、各突出部11bと軸方向で反対側の各他端が各保持孔10の他端開口部10bよりも保持孔10の内部に後退した後退部11cとなっている。
Further, each other end of each permanent magnet 11 on the opposite side in the axial direction from each protrusion 11b is a retreated portion 11c that is retreated further into the holding hole 10 than the other end opening 10b of each holding hole 10. .
突出部11bは、図2に示すように、その突出量、つまり、保持孔10の一端開口部10aから先端面までの長さLが、本実施形態では約2mmになっている。一方、後退部11cは、その後退量、つまり保持孔10の他端開口部10bの孔縁から後退部11cの後端面までの長さL1が、本実施形態では約1mmになっている。
As shown in FIG. 2, the protruding portion 11b has a protruding amount, that is, a length L from one end opening 10a of the holding hole 10 to the tip surface, of approximately 2 mm in this embodiment. On the other hand, the amount of retraction of the retracted portion 11c, that is, the length L1 from the hole edge of the other end opening 10b of the holding hole 10 to the rear end surface of the retracted portion 11c is approximately 1 mm in this embodiment.
そして、各延出部12、12は、図4(b)に示すように、ロータ5の周方向のそれぞれ突出量H、Hが同一に形成されていると共に、ロータ5の軸方向のそれぞれの幅長さW1、W1も同一でかつ突出部11bの突出量Lと同じに形成されている。また、延出部12は、図3及び図4(a)及び図8に示すように、周方向の一端面12aとロータ5の周方向で隣接する別の延出部12の対向する他端面12bとの間に隙間Cがそれぞれ形成されている。この隙間Cは、その極間距離Xが周方向で対向する各延出部12,12に互いに発生する磁束に影響がない大きさに設定されている。
As shown in FIG. 4(b), each of the extending portions 12, 12 has the same protruding amount H, H in the circumferential direction of the rotor 5, and has the same protruding amount H, H in the axial direction of the rotor 5. The width lengths W1 and W1 are also the same and are formed to be the same as the protrusion amount L of the protrusion portion 11b. Further, as shown in FIGS. 3, 4(a), and 8, the extending portion 12 has one end surface 12a in the circumferential direction and the opposite end surface of another extending portion 12 adjacent in the circumferential direction of the rotor 5. A gap C is formed between each of them and 12b. This gap C is set to such a size that the distance X between the poles does not affect the magnetic flux mutually generated in each of the extending portions 12, 12 facing each other in the circumferential direction.
極間距離Xを変更した場合の磁束密度とロータの回転角度との関係については、後述するブラシレスモータの作用の項で図11の特性図に基づいて説明する。
The relationship between the magnetic flux density and the rotation angle of the rotor when the interpolar distance
また各延出部12は、本体11aが保持孔10に挿入配置されている状態で、ロータコア9の外周部9aの外周面より内側の範囲内に設けられている。さらに、各延出部12、12は、図10に示すように、本体11aを保持孔10の一端開口部10aから内部に挿入配置した際に、本体11a側の内外の両下端縁12c、12dが保持孔10の一端開口部10aの端縁、つまり、各クリアランスC1,C2をそれぞれ挟んだロータ5の径方向端縁に当接するようになっている。これによって、永久磁石11は、本体11aの保持孔10に対する最大挿入位置が規制される。
Further, each extending portion 12 is provided within a range inside the outer circumferential surface of the outer circumferential portion 9a of the rotor core 9 when the main body 11a is inserted into the holding hole 10. Further, as shown in FIG. 10, when the main body 11a is inserted into the holding hole 10 through the opening 10a at one end, the extending portions 12, 12 have both inner and outer lower end edges 12c, 12d on the main body 11a side. is adapted to abut against the edge of one end opening 10a of the holding hole 10, that is, the radial edge of the rotor 5 across the respective clearances C1 and C2. This restricts the maximum insertion position of the permanent magnet 11 into the holding hole 10 of the main body 11a.
また、ロータコア9の外周部9aは、各突出部11b側と各後退部11c側の全体が非磁性材である合成樹脂材からなる被覆部24によって覆われている。この被覆部24は、各突出部11bの外周面全体を被覆するように円環状にされている。また、被覆部24は、各後退部11cを塞ぐように保持孔10の他端開口部10bから保持孔10内に充填されて全体が円環状にされている。また、被覆部24は、その一部が外周部9aの各ブロックB間の三角隙間にも充填されていると共に、永久磁石11の周方向両側面と保持孔10の幅方向の対向面との間の隙間にも充填されている。
Further, the outer circumferential portion 9a of the rotor core 9, on the side of each protruding portion 11b and the side of each retreated portion 11c, is entirely covered with a covering portion 24 made of a synthetic resin material, which is a non-magnetic material. This covering portion 24 is formed into an annular shape so as to cover the entire outer circumferential surface of each protruding portion 11b. Further, the covering portion 24 is filled into the holding hole 10 from the other end opening 10b of the holding hole 10 so as to close each of the retreating portions 11c, and is formed into an annular shape as a whole. In addition, a part of the covering portion 24 is also filled in the triangular gaps between the blocks B of the outer peripheral portion 9a, and also between both circumferential side surfaces of the permanent magnet 11 and the facing surface of the holding hole 10 in the width direction. It also fills the gaps between.
被覆部24は、図1~図3に示すように、保持孔10の後端開口内に後退部11cを塞ぐように充填されているが、この充填箇所には後退部11cの後端面と外部とを連通する孔部13がそれぞれ設けられている。この各孔部13は、例えば射出成形によってロータコア9の外周部9aに合成樹脂材を成形する際に、成形型内に予め配置されていて各後退部11cの後端面を下側から支持する支持ピンを成形後に抜いた後の跡に形成されたものである。
As shown in FIGS. 1 to 3, the covering portion 24 is filled in the rear end opening of the holding hole 10 so as to close the retracted portion 11c, and this filling portion is filled with the rear end surface of the retracted portion 11c and the outside. Holes 13 are provided to communicate with each other. Each hole 13 is a support that is placed in advance in a mold and supports the rear end surface of each retreating portion 11c from below when molding a synthetic resin material onto the outer peripheral portion 9a of the rotor core 9 by injection molding, for example. This was formed at the mark left after the pin was removed after being molded.
制御機構6は、例えば合成樹脂材(非磁性材)によってボックス状に形成されたケーシング17を有している。このケーシング17は、図1に示すように、モータハウジング2側に配置された四角形状の仕切壁17aと、該仕切壁17aの外周縁から立ち上がった四角形枠状の周壁17bと、を有している。また、仕切壁17aと周壁17bで囲まれた内側には、基板収容空間S1が形成されている。
The control mechanism 6 has a box-shaped casing 17 made of, for example, a synthetic resin material (non-magnetic material). As shown in FIG. 1, the casing 17 includes a square partition wall 17a disposed on the motor housing 2 side, and a square frame-shaped peripheral wall 17b rising from the outer periphery of the partition wall 17a. There is. Further, a substrate storage space S1 is formed inside surrounded by the partition wall 17a and the peripheral wall 17b.
仕切壁17aは、中央に円筒状の筒状部18が一体に設けられていると共に、内面の四隅部に4つの小径な円柱ボス部17eが一体に設けられている。この各円柱ボス部17eは、先端部に四角形の回路基板19を固定する図外の4本のビスが螺着する図外の雌ねじ孔がそれぞれ形成されている。
The partition wall 17a is integrally provided with a cylindrical portion 18 in the center, and four small-diameter cylindrical boss portions 17e are integrally provided at the four corners of the inner surface. Each of the cylindrical boss portions 17e has a female screw hole (not shown), into which four screws (not shown) for fixing the rectangular circuit board 19 are screwed, at the tip thereof.
仕切壁17aは、図1及び図2に示すように、後述する磁気センサ22と軸方向で対向する部位に第1凹部20aが設けられていると共に、永久磁石11の突出部11bと対向する部位に第2凹部20bが設けられている。この第1凹部20aと第2凹部20bは、径方向において一部が重なっており、つまり、一部が径方向でオーバーラップしている。
As shown in FIGS. 1 and 2, the partition wall 17a is provided with a first recess 20a at a portion facing a magnetic sensor 22, which will be described later, in the axial direction, and a portion facing a protrusion 11b of the permanent magnet 11. A second recess 20b is provided in the second recess 20b. The first recess 20a and the second recess 20b partially overlap in the radial direction, that is, they partially overlap in the radial direction.
第1凹部20aは、円環溝状に形成されて、その径方向の幅長さが磁気センサ22の径方向長さよりも大きく形成されて、磁気センサ22が入り込み可能になっている。一方、第2凹部20bは、同じく円環溝状に形成されて、その径方向の幅長さが突出部11bの厚さ幅よりも十分に大きく形成されて、該突出部11bが入り込み可能になっている。
The first recess 20a is formed in the shape of an annular groove, and its radial width is larger than the radial length of the magnetic sensor 22, so that the magnetic sensor 22 can enter therein. On the other hand, the second recess 20b is similarly formed in the shape of an annular groove, and its width in the radial direction is formed to be sufficiently larger than the thickness and width of the protrusion 11b, so that the protrusion 11b can enter therein. It has become.
回路基板19は、図1に示すように、基板収容空間S1内に収容配置されて、内部にはブラシレスモータ1へ給電するバスバーなどの図外の導電回路が配設されている。また、回路基板19の一側部には、後述するコネクタ21の複数の端子片と半田付けによって結合されるホール端子が設けられている。また、回路基板19は、中央に筒状部18が挿通可能な挿通孔19aが貫通形成されていると共に、四隅には図外の各ビスが挿入される小径な4つのビス挿入孔がそれぞれ貫通形成されている。
As shown in FIG. 1, the circuit board 19 is housed in the board housing space S1, and a conductive circuit (not shown) such as a bus bar that supplies power to the brushless motor 1 is disposed inside. Further, on one side of the circuit board 19, a hole terminal is provided which is coupled by soldering to a plurality of terminal pieces of a connector 21, which will be described later. In addition, the circuit board 19 has an insertion hole 19a formed in the center through which the cylindrical portion 18 can be inserted, and four small-diameter screw insertion holes into which screws (not shown) are inserted at the four corners. It is formed.
また、基板収容空間S1は、内部に回路基板19の他に、この回路基板19と導通してブラシレスモータ1の駆動を制御する回転検出センサである3つの磁気センサ22a、22b、22cやアルミ電解コンデンサ及びノーマルコイル、コモンコイル、複数のセラミックコンデンサなどの複数の電子部品(図外)が収容配置されている。
In addition to the circuit board 19, the board housing space S1 also includes three magnetic sensors 22a, 22b, and 22c, which are rotation detection sensors that are electrically connected to the circuit board 19 and control the drive of the brushless motor 1, and aluminum electrolytic sensors 22a, 22b, and 22c. Multiple electronic components (not shown) such as capacitors, normal coils, common coils, and multiple ceramic capacitors are housed.
各磁気センサ22a~22cは、図3に示すように、回路基板19上に3つ設けられており、つまり、W相とV相の間に設けられたW相用の磁気センサ22aと、V相とU相の間に設けられたV相用の磁気センサ22bと、U相とW相の間に設けられたU相用の磁気センサ22cの3つ有している。また、各磁気センサ22a~22cは、永久磁石11の径方向の磁束成分ではなく、軸方向の磁束成分(磁束密度)を検出するものであって、磁束密度のプラス、マイナスを判定するようになっている。
Three magnetic sensors 22a to 22c are provided on the circuit board 19, as shown in FIG. There are three magnetic sensors: a V-phase magnetic sensor 22b provided between the U-phase and the U-phase, and a U-phase magnetic sensor 22c provided between the U-phase and the W-phase. Furthermore, each of the magnetic sensors 22a to 22c detects an axial magnetic flux component (magnetic flux density) rather than a radial magnetic flux component of the permanent magnet 11, and determines whether the magnetic flux density is positive or negative. It has become.
各磁気センサ22a~22cは、図1及び図2に示すように、回路基板19上で、永久磁石11の配設位置に対して、ロータ5の回転軸方向へ離れた位置で、かつ径方向の外側にずれた位置に設けられている。つまり、各磁気センサ22a~22cは、図3及び図4に示すように、各永久磁石11の周方向の中央位置よりも径方向の外側にずれた位置に配置されている。これは、後述するように、磁気センサ22a~22cの軸方向の磁束成分(磁束密度)を検出する特性から、永久磁石11に対する前記特異な配置構成によって検出精度を高めるためである。
As shown in FIGS. 1 and 2, each of the magnetic sensors 22a to 22c is located on the circuit board 19 at a position away from the arrangement position of the permanent magnet 11 in the direction of the rotation axis of the rotor 5, and in the radial direction. It is located outside of the That is, as shown in FIGS. 3 and 4, each of the magnetic sensors 22a to 22c is arranged at a position deviated outward in the radial direction from the center position of each permanent magnet 11 in the circumferential direction. This is because, as will be described later, the unique arrangement of the permanent magnets 11 increases detection accuracy due to the characteristics of the magnetic sensors 22a to 22c in detecting magnetic flux components (magnetic flux density) in the axial direction.
また、この各磁気センサ22a~22cは、図3に示すように、ステータ3の内周面とロータ5の外周面との間に有する環状隙間C3を跨ぐように配置され、径方向のセンサ中心P1が環状隙間C3に位置している。
Further, as shown in FIG. 3, each of the magnetic sensors 22a to 22c is arranged so as to straddle an annular gap C3 between the inner circumferential surface of the stator 3 and the outer circumferential surface of the rotor 5. P1 is located in the annular gap C3.
また、各磁気センサ22a~22cは、ステータ3の周方向の取り付け位置において各コイル3bの間に一部が配置されていると共に、永久磁石11の突出部11b(延出部12)と軸方向でほぼ対向する位置に設けられている。
Further, each of the magnetic sensors 22a to 22c is partially disposed between each coil 3b at the mounting position in the circumferential direction of the stator 3, and is connected to the protruding portion 11b (extending portion 12) of the permanent magnet 11 in the axial direction. They are located at almost opposite positions.
筒状部18は、ほぼ有底円筒状に形成されて、軸方向の一端部と他端部が仕切壁17aを中心としてステータ収容空間Sと基板収容空間S1にそれぞれ臨んでいる。つまり、一端部が、ステータ収容空間Sに配置され、他端部が、基板収容空間S1に配置されている。また、筒状部18は、内部に第2ボールベアリング15bを収容保持するベアリング保持溝18aを有している。
The cylindrical portion 18 is formed into a substantially cylindrical shape with a bottom, and one end and the other end in the axial direction face the stator housing space S and the board housing space S1, respectively, with the partition wall 17a as the center. That is, one end is arranged in the stator accommodation space S, and the other end is arranged in the board accommodation space S1. Further, the cylindrical portion 18 has a bearing holding groove 18a that accommodates and holds the second ball bearing 15b therein.
周壁17bは、外周部に信号と給電を兼ねたコネクタ21が一体に設けられている。このコネクタ21は、ボックス状に形成され、内部に図外の端子片の一対の一端部が配置されている。この端子片は、基板収容空間S1内に位置する図外の他端部が回路基板19の導通回路のホール端子と半田付けによって結合されている。端子片のコネクタ21内に位置する一対の一端部は、一部が図外のエンジンコントロールユニット(ECU)に雌端子を介して電源であるバッテリーに接続されている。また、他の一部が、各磁気センサ22a~22cで検出された磁極位置信号などの情報信号をECUに出力するようになっている。
The peripheral wall 17b is integrally provided with a connector 21 for both signal and power supply on the outer periphery. This connector 21 is formed into a box shape, and one end portion of a pair of terminal pieces (not shown) is arranged inside. The other end of this terminal piece (not shown) located in the board accommodation space S1 is coupled to a hole terminal of a conductive circuit of the circuit board 19 by soldering. One end of the pair of terminal pieces located inside the connector 21 is partially connected to an engine control unit (ECU) (not shown) via a female terminal to a battery as a power source. Further, the other part outputs information signals such as magnetic pole position signals detected by each of the magnetic sensors 22a to 22c to the ECU.
また、周壁17bは、モータハウジング2と反対側の外周にカバー部材23が取り付けられている。カバー部材23は、例えば合成樹脂材で板状の四角形状に形成されており、ケーシング17方向へクランク状に折曲された外周部23aが、所定の固定手段によってケーシング17の周壁17bに固定されるようになっている。
Further, a cover member 23 is attached to the outer periphery of the peripheral wall 17b on the opposite side from the motor housing 2. The cover member 23 is made of, for example, a synthetic resin material and is formed into a plate-like rectangular shape, and an outer peripheral portion 23a bent in a crank shape toward the casing 17 is fixed to the peripheral wall 17b of the casing 17 by a predetermined fixing means. It has become so.
ECUは、磁気センサ22などからの信号に基づいて、ブラシレスモータ1のコイル3bに通電してモータ出力軸4の回転制御を行う。
〔ブラシレスモータの作用効果〕
本実施形態のブラシレスモータの作用及び効果について以下に説明する。 The ECU controls the rotation of themotor output shaft 4 by energizing the coil 3b of the brushless motor 1 based on signals from the magnetic sensor 22 and the like.
[Function and effect of brushless motor]
The functions and effects of the brushless motor of this embodiment will be explained below.
〔ブラシレスモータの作用効果〕
本実施形態のブラシレスモータの作用及び効果について以下に説明する。 The ECU controls the rotation of the
[Function and effect of brushless motor]
The functions and effects of the brushless motor of this embodiment will be explained below.
すなわち、本実施形態によれば、各磁気センサ22a~22cは、それぞれが径方向の磁束成分を検出するものよりも安価な軸方向の磁束成分を検出するものを使用している。このため、磁気センサ22a~22c自体のコストを削減することができる。磁気センサ22a~22cは、ホールICであって、前記ホールICのセンサコアは板状である。その板状のセンサコアを厚みの方向に通過する磁束を検出するようになっている。
That is, according to the present embodiment, each of the magnetic sensors 22a to 22c detects an axial magnetic flux component, which is cheaper than one that detects a radial magnetic flux component. Therefore, the cost of the magnetic sensors 22a to 22c itself can be reduced. The magnetic sensors 22a to 22c are Hall ICs, and the sensor cores of the Hall ICs are plate-shaped. The magnetic flux passing through the plate-shaped sensor core in the thickness direction is detected.
しかも、前記各磁気センサ22a~22cは、永久磁石11に対してロータ5の回転軸方向に離れた位置で、かつロータ5の径方向の外側の位置に配置されている。つまり、各磁気センサ22a~22cは、永久磁石11を中心としてロータ5の径方向の外側へずらした位置に設けられている。これによって、永久磁石11の磁束密度のピーク値に入り易くなるので、検出性能が高くなると共に、各磁気センサ22a~22cの軸方向位置のバラツキの影響を受けにくくなる。
Moreover, each of the magnetic sensors 22a to 22c is arranged at a position away from the permanent magnet 11 in the rotational axis direction of the rotor 5 and at a position outside the rotor 5 in the radial direction. That is, each of the magnetic sensors 22a to 22c is provided at a position shifted outward in the radial direction of the rotor 5 with the permanent magnet 11 as the center. This makes it easier for the magnetic flux density of the permanent magnet 11 to reach its peak value, thereby improving detection performance and making it less susceptible to variations in the axial positions of the magnetic sensors 22a to 22c.
また、本実施形態では、各磁気センサ22a~22cを、径方向の外側の測定位置に取り付けると共に、永久磁石11とコイル3bの間に跨って取り付けた。これによって、永久磁石11の軸方向の磁束成分のピーク値が高く、かつコイル3bから発生する磁束成分に影響されにくくなる。この結果、各磁気センサ22a~22cのそれぞれの検出精度が高くなるとと共に、安定した検出性能を得ることができる。
Furthermore, in this embodiment, each of the magnetic sensors 22a to 22c is attached to a measurement position on the outside in the radial direction, and is also attached so as to straddle between the permanent magnet 11 and the coil 3b. As a result, the peak value of the magnetic flux component in the axial direction of the permanent magnet 11 is high, and it becomes less susceptible to the magnetic flux component generated from the coil 3b. As a result, the detection accuracy of each of the magnetic sensors 22a to 22c is increased, and stable detection performance can be obtained.
また、本願発明者により永久磁石11の磁束密度分布を調べた結果、永久磁石11は、図4の磁束密度分布図に示すように、その特性上、磁束密度Tが永久磁石11の中央軸線Pの領域よりも、この中央軸線Pから径方向の外側のQ領域か径方向の内側のR領域が十分に高くなっていることが分かる。
Further, as a result of investigating the magnetic flux density distribution of the permanent magnet 11 by the present inventor, it was found that, due to its characteristics, the magnetic flux density T of the permanent magnet 11 is lower than the central axis P of the permanent magnet 11, as shown in the magnetic flux density distribution diagram of FIG. It can be seen that the Q area on the outside in the radial direction or the R area on the inside in the radial direction from the central axis P is sufficiently higher than the area.
また、磁気センサ22を、永久磁石11を中心とした径方向の内側よりも外側に位置させた方が、磁気センサ22の取り付けのバラツキによる角度誤差が小さくなって、検出精度を高くすることができる。つまり、径方向の内側に取り付け場合は、3つの磁気センサ22a~22cの取り付け角度誤差が生じ易くなるが、径方向の外側に取り付ければ取り付け角度誤差が発生し難くなる。
Furthermore, by locating the magnetic sensor 22 on the outside of the permanent magnet 11 in the radial direction rather than on the inside, the angular error due to variations in the mounting of the magnetic sensor 22 is reduced, and detection accuracy can be increased. can. That is, if the three magnetic sensors 22a to 22c are mounted on the inside in the radial direction, an error in the mounting angle of the three magnetic sensors 22a to 22c is likely to occur, but if they are mounted on the outside in the radial direction, the error in the mounting angle is less likely to occur.
そこで、本実施形態では、各磁気センサ22a~22cを、径方向の外側の所定位置に取り付けると共に、図3に示すように、センサ中心P1をロータ5とステータ3との間の環状隙間C3に位置させて永久磁石11とコイル3bの間に跨って取り付けた。これによって、永久磁石11の軸方向の磁束成分のピーク値が高く、かつコイル3bから発生する磁束成分に影響されにくくなる。この結果、各磁気センサ22a~22cのそれぞれの検出精度が高くなるとと共に、安定した検出性能を得ることができる。
Therefore, in this embodiment, each of the magnetic sensors 22a to 22c is attached to a predetermined position on the outside in the radial direction, and the sensor center P1 is placed in the annular gap C3 between the rotor 5 and the stator 3, as shown in FIG. The magnet 11 was positioned so as to straddle between the permanent magnet 11 and the coil 3b. As a result, the peak value of the magnetic flux component in the axial direction of the permanent magnet 11 is high, and it becomes less susceptible to the magnetic flux component generated from the coil 3b. As a result, the detection accuracy of each of the magnetic sensors 22a to 22c is increased, and stable detection performance can be obtained.
さらに、各磁気センサ22a~22cを、ロータ5とステータ3の間の環状隙間C3を径方向から跨ぐような取り付け位置としたが、この位置は前述のように、永久磁石11の最も磁束密度のピーク値が高くなる位置であることから、各磁気センサ22a~22cの検出性能が高くなる。
Furthermore, each of the magnetic sensors 22a to 22c is installed at a position where it straddles the annular gap C3 between the rotor 5 and the stator 3 in the radial direction. Since this is the position where the peak value is high, the detection performance of each magnetic sensor 22a to 22c is high.
また、各磁気センサ22a~22cは、ステータ3の周方向の取り付け位置において各コイル3bの間に一部が配置されていることから、コイル3bの磁束の影響を十分に回避できるため、モータの制御精度が高くなる。
Furthermore, each of the magnetic sensors 22a to 22c is partially disposed between each coil 3b at the mounting position in the circumferential direction of the stator 3, so that the influence of the magnetic flux of the coil 3b can be sufficiently avoided. Control accuracy increases.
そして、本実施形態では、各永久磁石11の突出部11bの両側面に2つの延出部12,12を設け、周方向で隣接する一方の延出部12の一端面12aとこれにロータ5の周方向から対向する他方の延出部12の他端面12bとの間の極間距離Xを従来技術のものよりも小さくしたことから、以下の作用効果が得られる。
In the present embodiment, two extension parts 12, 12 are provided on both sides of the protrusion part 11b of each permanent magnet 11, and one end face 12a of one of the extension parts 12 adjacent in the circumferential direction and the rotor 5 Since the distance X between the poles and the other end surface 12b of the other extending portion 12 facing each other in the circumferential direction is made smaller than that of the prior art, the following effects can be obtained.
図11は本実施形態に供される隣接する永久磁石11、11の延出部12、12の間の極間距離X間の相違による磁束密度Tとロータ角度degの関係を示す特性図である。これは、本願発明者が、極間距離Xを種々変更して実験を行った結果を表したもので、前記公報記載の従来技術における極間距離X’と、本実施形態における例示として大小3つの極間距離X1、X2、X3が相違するものとを比較したものである。
FIG. 11 is a characteristic diagram showing the relationship between the magnetic flux density T and the rotor angle deg due to the difference in the interpolar distance . This represents the results of experiments conducted by the inventor of the present application with various changes in the inter-electrode distance X. This is a comparison between the two electrodes having different interpolar distances X1, X2, and X3.
この実験では、従来技術の極間距離X’を4.66mmに設定し、本実施形態として、第1例では極間距離X1を3.74mmに設定し、第2例では極間距離X2を2.82mmに設定し、第3例では極間距離X3を1.15mmに設定した。
In this experiment, the distance between poles X' of the conventional technology was set to 4.66 mm, and as the present embodiment, the distance between poles X1 was set to 3.74 mm in the first example, and the distance between poles X2 was set to 3.74 mm in the second example. In the third example, the interpolar distance X3 was set to 1.15 mm.
この図11の特性図からして、磁気センサ22a~22cは、磁束密度Tがセンサ閾値を超えることによって磁極が変わったことを認識する。極間距離Xが小さくなるに伴って、センサ閾値付近の磁束密度Tの傾きが変化することが明らかである。
From the characteristic diagram in FIG. 11, the magnetic sensors 22a to 22c recognize that the magnetic poles have changed when the magnetic flux density T exceeds the sensor threshold. It is clear that as the interpolar distance X becomes smaller, the slope of the magnetic flux density T near the sensor threshold changes.
すなわち、永久磁石11の突出部11bに延出部12、12を有さない従来技術の極間距離X’では、図中、破線で示すように、ロータ5の回転角度に対して磁束密度Tの傾きが小さくなって、センサ閾値ではロータ回転角度が約13degとなっている。
That is, in the case of the distance X' between the poles of the conventional technology in which the protruding part 11b of the permanent magnet 11 does not have the extending parts 12, 12, the magnetic flux density T with respect to the rotation angle of the rotor 5 is The slope becomes smaller, and the rotor rotation angle is approximately 13 degrees at the sensor threshold.
これに対して、本実施形態における第1例~第3例では磁束密度Tの傾きが漸次大きくなって、第1例(極間距離X1)では、図中、細い実線で示すように、従来技術(破線)より傾きがやや立ち上がって、センサ閾値ではロータ回転角度が約11.5degとなっている。したがって、従来技術の13deg-11.5deg=1.5degとなり、従来技術よりも1.5deg分だけ速くなっていることが明らかである。これによって、従来技術よりもN極とS極の磁極が変わったタイミングを早く認識することが可能になる。
On the other hand, in the first to third examples of this embodiment, the slope of the magnetic flux density T gradually increases, and in the first example (distance between poles X1), as shown by the thin solid line in the figure, The slope is slightly higher than the technology (broken line), and the rotor rotation angle is about 11.5 degrees at the sensor threshold. Therefore, it is clear that the conventional technique is 13deg−11.5deg=1.5deg, which is 1.5deg faster than the conventional technique. This makes it possible to recognize the timing at which the north and south magnetic poles change earlier than in the prior art.
第2例(極間距離X2)では、図中、中程度の太さの実線で示すように、従来技術より傾きがさらに大きくなって、センサ閾値ではロータ回転角度が約10degとなり、従来技術よりもさらに3deg分だけ速くなっていることが明らかである。
In the second example (distance between poles It is clear that the speed is further increased by 3 degrees.
第3例(極間距離X3)では、図中、太い実線で示すように、従来技術より傾きが一層大きくなって、センサ閾値ではロータ回転角度が約7.5degとなり、従来技術よりも5.5deg分だけ速くなっていることが明らかである。したがって、第2例、第3例でも、従来技術よりもN極とS極の磁極が変わったタイミングをさらに早く認識することが可能になる。
In the third example (distance between poles X3), as shown by the thick solid line in the figure, the slope is even larger than that of the conventional technique, and the rotor rotation angle is approximately 7.5 degrees at the sensor threshold, which is 5.5 degrees greater than that of the conventional technique. It is clear that the speed is increased by 5 degrees. Therefore, in the second and third examples as well, it becomes possible to recognize the timing at which the magnetic poles of the north and south poles change more quickly than in the prior art.
以上のように、本実施形態では、N極とS極の磁極が変わるタイミングが早く認識できることから、各磁気センサ22a~22c位置での磁束を高め、該各磁気センサ22a~22cの検出遅れを低減することができる。
As described above, in this embodiment, since the timing at which the magnetic poles of N and S poles change can be recognized quickly, the magnetic flux at the positions of each magnetic sensor 22a to 22c is increased, and the detection delay of each magnetic sensor 22a to 22c is reduced. can be reduced.
すなわち、従来技術のように、磁気センサの検出速度が遅れると、通電タイミングが遅れることになり、これによって、同じトルクを発生させる電流が大きくなる。
That is, as in the prior art, if the detection speed of the magnetic sensor is delayed, the timing of energization is delayed, and as a result, the current that generates the same torque increases.
これに対して、本実施形態では、磁気センサ22a~22cの検出遅れを低減できることから、電力量消費率(電費)やステータコアに巻回されたコイルの発熱量の低減化が図れる。また、高電流対応の素子部品の変更に伴うコストの低減化が図れる。
In contrast, in the present embodiment, since the detection delay of the magnetic sensors 22a to 22c can be reduced, the power consumption rate (electricity cost) and the amount of heat generated by the coil wound around the stator core can be reduced. Furthermore, costs associated with changing element parts compatible with high current can be reduced.
また、本実施形態では、隣り合う両延出部12,12の間に前述した所定の極間距離X1~X3の隙間Cが設けられていることから、隙間Cがない場合、すなわち、各延出部12,12が接触している場合に起こりえる、振動などによる罅や破損などの発生を抑制できる。
In addition, in this embodiment, since the gap C of the predetermined inter-pole distances X1 to X3 described above is provided between both adjacent extensions 12, 12, if there is no gap It is possible to suppress the occurrence of cracks, damage, etc. due to vibration, etc., which may occur when the protruding parts 12, 12 are in contact with each other.
本実施形態では、永久磁石11の本体11aが、軸方向孔の他端開口部10bよりも内側に配置された後退部11cを有している。つまり、延出部12,12の磁力の分だけ永久磁石11の本体11aの他端部を短くするカットできるので、永久磁石11の全体の重量と体積を低減させることが可能になる。
In this embodiment, the main body 11a of the permanent magnet 11 has a retracted portion 11c located inside the other end opening 10b of the axial hole. In other words, the other end of the main body 11a of the permanent magnet 11 can be cut short by the magnetic force of the extensions 12, 12, so the overall weight and volume of the permanent magnet 11 can be reduced.
また、前述したように、各永久磁石11の本体11aを保持孔10の内部に挿入した際に、延出部12,12の両下端縁12c、12dが保持孔10の一端開口部10aの孔縁に当接してそれ以上の挿入が規制される。これによって、永久磁石11の保持孔10に対する最大挿入の位置決めがなされる。この結果、各永久磁石11の保持孔10への挿入作業が容易になる。
Further, as described above, when the main body 11a of each permanent magnet 11 is inserted into the holding hole 10, both lower end edges 12c and 12d of the extension parts 12, 12 are inserted into the opening 10a at one end of the holding hole 10. It comes into contact with the edge and further insertion is restricted. Thereby, the maximum insertion position of the permanent magnet 11 into the holding hole 10 is determined. As a result, the work of inserting each permanent magnet 11 into the holding hole 10 becomes easier.
各延出部12,12は、ロータコア9の外周部9aの外周面より内側の範囲内に設けられていることから、ロータコア9の径方向外側にあるステータコア3aや該ステータコア3aに巻回されたコイル3bとの接触が回避されて、振動などによる干渉によって延出部やステータコア3aなどの破損などの発生を抑制できる。
Since each of the extending portions 12, 12 is provided within a range inside the outer circumferential surface of the outer circumferential portion 9a of the rotor core 9, the extending portions 12, 12 are provided within a range inside the outer circumferential surface of the outer circumferential portion 9a of the rotor core 9. Contact with the coil 3b is avoided, and damage to the extension portion, stator core 3a, etc. due to interference due to vibration or the like can be suppressed.
さらに、永久磁石11は、合成樹脂材の被覆部24によって突出部11bや後退部11cの軸方向の前後が被覆され、保持孔10内にも被覆部24が充填されて被覆されている。このため、永久磁石11の位置ずれなどが抑制されるので、磁界の安定化が図れると共に、衝撃による永久磁石11の割れや飛散を抑制できる。
〔第2実施形態〕
図12及び図13は本発明の第2実施形態を示し、基本構成は第1実施形態のものと同じであるが、各延出部12、12のロータ5の周方向の長さH、Hを長く形成した。 Further, in thepermanent magnet 11, the protruding portion 11b and the recessed portion 11c are covered with a covering portion 24 made of a synthetic resin material at the front and rear in the axial direction, and the holding hole 10 is also filled with the covering portion 24 to cover the holding hole 10. As a result, displacement of the permanent magnet 11 is suppressed, so that the magnetic field can be stabilized, and cracking and scattering of the permanent magnet 11 due to impact can be suppressed.
[Second embodiment]
12 and 13 show a second embodiment of the present invention, and the basic configuration is the same as that of the first embodiment, but the lengths H and H of each extending portion 12 and 12 in the circumferential direction of the rotor 5 are was formed for a long time.
〔第2実施形態〕
図12及び図13は本発明の第2実施形態を示し、基本構成は第1実施形態のものと同じであるが、各延出部12、12のロータ5の周方向の長さH、Hを長く形成した。 Further, in the
[Second embodiment]
12 and 13 show a second embodiment of the present invention, and the basic configuration is the same as that of the first embodiment, but the lengths H and H of each extending
すなわち、図12に示すように、永久磁石11の突出部11bの両側面に設けられたかく延出部12、12の長さH,Hを、隣接する他の永久磁石11の延出部12、12と干渉しない範囲でさらに長く形成したものである。
That is, as shown in FIG. 12, the lengths H, H of the extending portions 12, 12 provided on both side surfaces of the protruding portion 11b of the permanent magnet 11 are set by the extending portions 12 of the other adjacent permanent magnets 11, 12 and is made longer within a range that does not interfere with 12.
これによって、各延出部12、12は、図13に示すように、本体11aが保持孔10に挿入配置された状態で、両下端縁12c、12dが保持孔10の一端開口部10aのクリアランスC1,C2の全体を覆う形で孔縁に当接している。
As a result, as shown in FIG. 13, each of the extending portions 12, 12 has both lower end edges 12c, 12d with a clearance of one end opening 10a of the holding hole 10 when the main body 11a is inserted into the holding hole 10. It contacts the hole edge in a manner that covers the entirety of C1 and C2.
したがって、本実施形態によれば、各延出部12、12によって保持孔10の一端開口部10a全体が覆われることから、該一端開口部10aから保持孔10内に塵やコンタミなどの侵入を抑制することができる。
Therefore, according to the present embodiment, since the one end opening 10a of the holding hole 10 is entirely covered by each of the extending portions 12, 12, dust and contaminants are prevented from entering into the holding hole 10 from the one end opening 10a. Can be suppressed.
他は第1実施形態と同じであるから、前述した第1実施形態と同一の作用効果が得られる。
〔永久磁石の他例〕
図14~図16は永久磁石11の突出部11bや延出部12、12の形状を変更した複数の例を示したものである。 Since the rest is the same as the first embodiment, the same effects as the first embodiment described above can be obtained.
[Other examples of permanent magnets]
14 to 16 show a plurality of examples in which the shapes of the protrudingportion 11b and the extending portions 12, 12 of the permanent magnet 11 are changed.
〔永久磁石の他例〕
図14~図16は永久磁石11の突出部11bや延出部12、12の形状を変更した複数の例を示したものである。 Since the rest is the same as the first embodiment, the same effects as the first embodiment described above can be obtained.
[Other examples of permanent magnets]
14 to 16 show a plurality of examples in which the shapes of the protruding
まず、図14(a)(b)に示す例は、突出部11bの上端部の中央に切欠溝25が形成されている。この切欠溝25は、突出部11bの上端部の一部が延出部12、12方向に沿って矩形状に切り欠かれている。
First, in the example shown in FIGS. 14(a) and 14(b), a notch groove 25 is formed in the center of the upper end of the protrusion 11b. This cutout groove 25 is formed by cutting out a part of the upper end of the protrusion 11b in a rectangular shape along the direction of the extensions 12 .
これによって、永久磁石11の重量及び体積が減少することから、該永久磁石11全体の軽量化とコンパクト化が図れる。
This reduces the weight and volume of the permanent magnet 11, making it possible to make the entire permanent magnet 11 lighter and more compact.
図15(a)(b)に示す例は、両延出部12,12,と突出部11bの上端部を円弧凹状に連続して切り欠いた円弧溝26が形成されている。
In the example shown in FIGS. 15(a) and 15(b), an arcuate groove 26 is formed by continuously cutting out the upper end portions of both the extension portions 12, 12 and the protruding portion 11b in an arcuate concave shape.
この場合も、永久磁石11の重量及び体積が減少することから、該永久磁石11全体の軽量化とコンパクト化が図れる。
Also in this case, since the weight and volume of the permanent magnet 11 are reduced, the permanent magnet 11 as a whole can be made lighter and more compact.
図16(a)(b)に示す例は、両延出部12,12,と突出部11bの上端部を円弧凸状に連続して切り欠いた円弧突部27が形成されている。この例ついても、前記2つの例と同じ作用効果が得られる。
In the example shown in FIGS. 16(a) and 16(b), an arcuate protrusion 27 is formed by continuously cutting out the upper ends of both the extensions 12, 12 and the protrusion 11b in an arcuate shape. This example also provides the same effects as the above two examples.
本発明は、前記実施形態の構成に限定されるものではなく、永久磁石11の延出部12,12を、突出部11bの一側面に1つだけ設けて、隣接する永久磁石11の突出部11bとの間に隙間Cを形成することも可能である。
The present invention is not limited to the configuration of the embodiment described above, and only one extension portion 12, 12 of the permanent magnet 11 is provided on one side of the protrusion portion 11b, and the protrusion portions of the adjacent permanent magnets 11 are It is also possible to form a gap C between it and 11b.
また、各永久磁石11の突出部11bと各延出部12,12の突出量L(W1)や後退部11cの後退量L1を、ブラシレスモータ1の仕様や磁力の大きさなどによって、それぞれの長さを相対的に決定することが可能である。
In addition, the protrusion amount L (W1) of the protrusion portion 11b of each permanent magnet 11 and each extension portion 12, 12, and the retraction amount L1 of the retraction portion 11c are determined depending on the specifications of the brushless motor 1, the magnitude of the magnetic force, etc. It is possible to determine the length relatively.
ブラシレスモータ1の適用対象機器としては、内燃機関のバルブタイミング制御装置ばかりか、パワーステアリングのモータやパワーウインドウ用モータ、サンルーフ用モータ、パワーシート用モータなど各種車載モータ、さらにはエアコン等の家電製品などに使用されるモータにも適用可能である。
Applicable devices for the brushless motor 1 include not only valve timing control devices for internal combustion engines, but also various in-vehicle motors such as power steering motors, power window motors, sunroof motors, and power seat motors, as well as home appliances such as air conditioners. It can also be applied to motors used in other applications.
1…ブラシレスモータ、2…モータハウジング、3…ステータ、3a…ステータコア、3b…コイル(巻線)、4…モータ出力軸、5…ロータ、6…制御機構、9…ロータコア、9a…外周部、9b…内周部、10…保持孔、10a…一端開口部、10b…他端開口部、11…永久磁石、11a…本体、11b…突出部、11b…後退部、12…延出部、17…ケーシング、18…筒状部、19…回路基板、22(22a~22c)…磁気センサ(回転検出センサ)、23…カバー部材、24…合成樹脂材の被覆部、25・26・27…永久磁石の他例、C…隙間、C1・C2…クリアランス、X(X1~X3)…極間距離、X’…従来技術の極間距離。
DESCRIPTION OF SYMBOLS 1... Brushless motor, 2... Motor housing, 3... Stator, 3a... Stator core, 3b... Coil (winding), 4... Motor output shaft, 5... Rotor, 6... Control mechanism, 9... Rotor core, 9a... Outer periphery, 9b...Inner peripheral part, 10...Holding hole, 10a...One end opening, 10b...Other end opening, 11...Permanent magnet, 11a...Main body, 11b...Protrusion part, 11b...Retreating part, 12...Extending part, 17 ...Casing, 18...Cylindrical part, 19...Circuit board, 22 (22a to 22c)...Magnetic sensor (rotation detection sensor), 23...Cover member, 24...Synthetic resin covering part, 25, 26, 27...Permanent Other examples of magnets, C...gap, C1/C2...clearance, X(X1-X3)...distance between poles, X'...distance between poles of conventional technology.
Claims (8)
- ステータコアと、前記ステータコアに巻装された複数の巻線と、を有するステータと、
前記ステータの内側または外側に配置され、周方向に所定間隔で形成された複数の軸方向孔が形成されたロータコアを有するロータと、
前記ロータコアの各軸方向孔の内部にそれぞれ配置された板状の複数の永久磁石であって、前記複数の軸方向孔の内部に位置する本体と、前記複数の軸方向孔の一端開口部から軸方向に突出した突出部と、を有する前記永久磁石と、
前記突出部と軸方向から対向するように配置され、前記永久磁石の磁束成分を検出する回転検出センサと、
前記各突出部の前記ロータの周方向の少なくとも一方の側面に設けられ、隣り合う前記突出部が隙間を介して互いに近づくように前記ロータの周方向に延びた延出部と、
を備えたことを特徴とするブラシレスモータ。 A stator including a stator core and a plurality of windings wound around the stator core;
A rotor having a rotor core arranged inside or outside the stator and having a plurality of axial holes formed at predetermined intervals in the circumferential direction;
A plurality of plate-shaped permanent magnets are arranged inside each of the axial holes of the rotor core, the main body being located inside the plurality of axial holes, and one end opening of the plurality of axial holes. the permanent magnet having a protrusion protruding in the axial direction;
a rotation detection sensor that is arranged to face the protrusion in the axial direction and detects a magnetic flux component of the permanent magnet;
an extending portion provided on at least one side surface of each of the protrusions in the circumferential direction of the rotor and extending in the circumferential direction of the rotor so that adjacent protrusions approach each other through a gap;
A brushless motor characterized by: - 請求項1に記載のブラシレスモータであって、
前記延出部は、前記突出部の前記ロータの周方向の両側面に設けられていることを特徴とするブラシレスモータ。 The brushless motor according to claim 1,
The brushless motor is characterized in that the extending portion is provided on both side surfaces of the protruding portion in the circumferential direction of the rotor. - 請求項2に記載のブラシレスモータであって、
周方向で隣り合う前記延出部の間に、隙間が形成されていることを特徴とするブラシレスモータ。 The brushless motor according to claim 2,
A brushless motor characterized in that a gap is formed between the circumferentially adjacent extending portions. - 請求項1に記載のブラシレスモータであって、
前記永久磁石の本体は、前記突出部に対して軸方向の反対側の端面が前記軸方向孔の他端開口部よりも内側に配置されていることを特徴とするブラシレスモータ。 The brushless motor according to claim 1,
The brushless motor is characterized in that the end surface of the permanent magnet main body on the opposite side in the axial direction with respect to the protrusion is disposed inside the other end opening of the axial hole. - 請求項1に記載のブラシレスモータであって、
前記延出部は、前記本体側の端縁が前記ロータコアの軸方向孔の一端開口部の孔縁の一部に軸方向から当接していることを特徴とするブラシレスモータ。 The brushless motor according to claim 1,
The brushless motor is characterized in that an edge of the extending portion on the main body side abuts a part of a hole edge of an opening at one end of the axial hole of the rotor core from the axial direction. - 請求項1に記載のブラシレスモータであって、
前記軸方向孔は、前記永久磁石の本体よりも前記ロータの周方向に長い長孔状に形成され、
前記延出部は、前記本体側の端縁が前記軸方向孔の一端開口部の孔縁のうち径方向外側の孔縁と径方向内側の孔縁の少なくとも一方に軸方向から当接していることを特徴とするブラシレスモータ。 The brushless motor according to claim 1,
The axial hole is formed in a long hole shape that is longer in the circumferential direction of the rotor than the main body of the permanent magnet,
An end edge of the extending portion on the main body side is in axial contact with at least one of a radially outer hole edge and a radially inner hole edge of the hole edge of the opening at one end of the axial hole. A brushless motor characterized by: - 請求項6に記載のブラシレスモータであって、
前記軸方向孔は、前記永久磁石の本体が挿入配置された状態で、幅方向の両側部と前記本体の両側面との間にクリアランスが形成され、
前記延出部は、前記本体側の端縁が前記一端開口部の孔縁の径方向外側と径方向内側の両方の孔縁に軸方向から当接していると共に、前記一端開口部側の前記クリアランスを覆っていることを特徴とするブラシレスモータ。 The brushless motor according to claim 6,
When the main body of the permanent magnet is inserted into the axial hole, a clearance is formed between both sides in the width direction and both sides of the main body,
The extending portion has an end edge on the main body side that is in axial contact with both a radially outer and a radially inner hole edge of the one end opening, and the end edge of the extending portion on the one end opening side is in contact with both the radially outer and radially inner hole edges of the one end opening. A brushless motor characterized by covering the clearance. - 請求項6に記載のブラシレスモータであって、
前記延出部は、前記ロータコアの前記軸方向孔が形成された外周部の外周面より内側の範囲内に位置することを特徴とするブラシレスモータ。 The brushless motor according to claim 6,
The brushless motor is characterized in that the extending portion is located within a range inside an outer circumferential surface of an outer circumferential portion of the rotor core in which the axial hole is formed.
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Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
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JPH11136888A (en) * | 1997-10-28 | 1999-05-21 | Toshiba Corp | Permanent magnet motor and manufacture thereof |
JP2004222387A (en) * | 2003-01-14 | 2004-08-05 | Toyota Motor Corp | Permanent magnet temperature sensor, permanent magnet motor, and drive system thereof |
JP2005110403A (en) * | 2003-09-30 | 2005-04-21 | Toshiba Corp | Rotor of motor |
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Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
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JPH11136888A (en) * | 1997-10-28 | 1999-05-21 | Toshiba Corp | Permanent magnet motor and manufacture thereof |
JP2004222387A (en) * | 2003-01-14 | 2004-08-05 | Toyota Motor Corp | Permanent magnet temperature sensor, permanent magnet motor, and drive system thereof |
JP2005110403A (en) * | 2003-09-30 | 2005-04-21 | Toshiba Corp | Rotor of motor |
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