JP2008228490A - Motor and valve lift variable mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor and a valve lift variable mechanism equipped with a structure for preventing misregistration and scattering of a permanent magnet, using a simple constitution. <P>SOLUTION: The motor includes a rotating rotor 62 including an outer circumferential surface 62a; a plurality of permanent magnets arranged on the circumferential surface 62a at intervals with each other; a magnet holder 72 arranged on the outer circumferential surface 62a, inserted between the adjacent permanent magnets for regulating the misregistration of the permanent magnets in the circumferential direction; and a magnet cover 81 fitted to the outer circumferential surface 62a so as to cover the permanent magnet for regulating the popping of the permanent magnet in the radial direction. A groove 67 is formed in the rotor 62. The magnet holder 72 and the magnet cover 81 are locked in the same groove 67, each including locking parts 75, 84 for regulating the misregistration in the circumferential direction of a magnet holder 72 and the magnet cover 81. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention generally relates to a motor and a variable valve lift mechanism, and more particularly to a surface permanent magnet (SPM) type motor in which a magnet is attached to a rotor surface and a variable valve lift mechanism including the motor. .

  Regarding a conventional motor, for example, Japanese Patent Application Laid-Open No. 2004-328989 discloses a flywheel magnet generator intended to attach a magnet without protruding from the outer peripheral surface of the peripheral wall portion of the flywheel (patent) Reference 1). In patent document 1, the magnet is arrange | positioned at the through-hole formed in the flywheel. The magnet is positioned at a predetermined position in the through hole by a magnet cover fitted in the through hole.

  Japanese Patent Application Laid-Open No. 2004-23864 discloses a permanent magnet that is mounted without processing, reduces leakage magnetic flux, and prevents permanent portions from being scattered when a portion of the permanent magnet is missing. A rotor of a magnet rotating electric machine is disclosed (Patent Document 2). In patent document 2, the permanent magnet is arrange | positioned on the surface of the rotor core of a motor. The permanent magnet is fixed to the rotor core by covering the surface of the permanent magnet with a flexible magnet cover and fixing both ends of the permanent magnet to the rotor core.

Japanese Patent Application Laid-Open No. 2003-32929 discloses a permanent magnet type rotating electrical machine intended to prevent scattering of permanent magnets due to magnet cracking (Patent Document 3). In Patent Document 3, a permanent magnet is fixed to the outer peripheral surface of the rotor core by covering the permanent magnet with a magnet cover having a shape that follows the outer shape of the permanent magnet and that has an open shape on the outer peripheral surface side of the rotor core. To do.
JP 2004-328989 A Japanese Patent Laid-Open No. 2004-23864 Japanese Patent Laid-Open No. 2003-32929

  As disclosed in the above-mentioned patent documents, in a SPM motor in which a permanent magnet is attached to the rotor surface, a structure for preventing the displacement and scattering of the permanent magnet is provided in the rotor when the motor is driven. In order to improve the workability at the time of assembling the motor and keep the processing cost of the parts low, it is necessary to make the structure for preventing the positional deviation and scattering of the permanent magnet simple.

  Accordingly, an object of the present invention is to solve the above-described problems, and to provide a motor and a valve lift variable mechanism provided with a structure for preventing the displacement and scattering of a permanent magnet with a simple configuration. .

  A motor according to the present invention includes a rotating rotor including a peripheral surface, a plurality of permanent magnets arranged at intervals on the peripheral surface, and inserted between adjacent permanent magnets arranged on the peripheral surface. And a rotation preventing member that restricts the displacement of the permanent magnet in the circumferential direction and a scattering prevention member that is fitted on the circumferential surface so as to cover the permanent magnet and restricts the permanent magnet from protruding in the radial direction. A groove is formed in the rotor. The anti-rotation member and the anti-scattering member include an engaging portion that is engaged with the same groove and restricts the positional displacement of the anti-rotation member and the anti-scattering member in the circumferential direction.

  According to the motor configured as described above, the locking portion is locked in the groove formed in the rotor, thereby preventing the circumferential displacement of the anti-rotation member and the scattering prevention member. At this time, since the locking portion of the anti-rotation member and the locking portion of the anti-scattering member are locked in the same groove, the structure for preventing the positional displacement and scattering of the permanent magnet has a simple configuration. it can.

  Preferably, the groove is formed at one place. According to the motor configured as described above, the structure for preventing the positional displacement and scattering of the permanent magnet can be further simplified as compared with the case where the grooves are formed at a plurality of locations.

  Preferably, the anti-rotation member includes a plurality of tooth-like portions respectively positioned between adjacent permanent magnets, and an annular portion extending in the circumferential direction and connecting the plurality of tooth-like portions. According to the motor configured as described above, the anti-rotation member that prevents the displacement of the plurality of permanent magnets in the circumferential direction can be simply configured.

  Preferably, the rotor repeats normal rotation and reverse rotation when the motor is driven. According to the motor configured as described above, in a motor having a large torque fluctuation applied to the permanent magnet, the structure for preventing the displacement and scattering of the permanent magnet can be simplified.

  A variable valve lift mechanism according to the present invention includes any one of the motors described above. The variable valve lift mechanism converts the rotary motion output from the motor into a linear motion, and variably controls the lift amount of the valve of the internal combustion engine by the linear motion. According to the variable valve lift mechanism configured as described above, the motor that exhibits any of the effects described above is applied to the variable valve lift mechanism.

  As described above, according to the present invention, it is possible to provide a motor and a variable valve lift mechanism provided with a structure for preventing positional displacement and scattering of permanent magnets with a simple configuration.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

  FIG. 1 is a front view showing a variable valve lift mechanism including a motor according to an embodiment of the present invention. FIG. 2 is a perspective view partially showing the variable valve lift mechanism in FIG. In FIG. 2, a part is broken and shown so that the internal structure can be clearly understood.

  Referring to FIGS. 1 and 2, variable valve lift mechanism 100 is a mechanism that varies the valve lift amount of a valve of the internal combustion engine (in this embodiment, an intake valve). The internal combustion engine may be a gasoline engine or a diesel engine.

  The variable valve lift mechanism 100 is provided in the cylinder head of the internal combustion engine. In the cylinder head, a cam shaft 102 on which a cam 103 is formed, a rocker arm 106 pivotally supported, and an intake valve 101 that is driven to open and close according to the rocking of the rocker arm 106 are disposed. The variable valve lift mechanism 100 includes a drive shaft 20 extending in one direction, a support pipe 108 covering the outer peripheral surface of the drive shaft 20, and an input arranged side by side in the axial direction of the drive shaft 20 on the outer peripheral surface of the support pipe 108. An arm 104 and a swing cam 105.

  In this internal combustion engine, a pair of intake valves 101 and a rocker arm 106 are provided for each cylinder, and the pair of intake valves 101 are driven to open and close by a single cam 103. The variable valve lift mechanism 100 is provided with one input arm 104 corresponding to one cam 103 provided in each cylinder. Two swing cams 105 are provided on both sides of the input arm 104 corresponding to each of the pair of intake valves 101 provided in each cylinder.

  The support pipe 108 is formed in a hollow cylindrical shape and is disposed in parallel to the camshaft 102. The support pipe 108 is fixed to the cylinder head so as not to move or rotate in the axial direction. The drive shaft 20 is inserted into the support pipe 108 so as to be slidable in the axial direction. An input arm 104 and two swing cams 105 are provided on the outer peripheral surface of the support pipe 108 so as to be swingable about the axis of the drive shaft 20 and not to move in the axial direction. Yes.

  The input arm 104 includes an arm portion 104a that protrudes away from the outer peripheral surface of the support pipe 108, and a roller portion 104b that is rotatably connected to the tip of the arm portion 104a. The input arm 104 is provided at a position where the roller portion 104 b can come into contact with the cam 103.

  The swing cam 105 has a substantially triangular nose portion 105 a that protrudes away from the outer peripheral surface of the support pipe 108. A cam surface 105b that is curved in a concave shape is formed on one side (the lower side in FIG. 1) of the nose portion 105a. The intake valve 101 is provided with a valve spring. Due to the urging force, the roller 106a rotatably attached to the rocker arm 106 is pressed against the cam surface 105b.

  The input arm 104 and the swing cam 105 swing integrally around the axis of the drive shaft 20. For this reason, when the camshaft 102 rotates, the input arm 104 in contact with the cam 103 swings, and the swing cam 105 swings in conjunction with the movement of the input arm 104. The movement of the swing cam 105 is transmitted to the intake valve 101 via the rocker arm 106, and thereby the intake valve 101 is driven to open and close.

  The variable valve lift mechanism 100 includes a mechanism that changes the relative phase difference between the input arm 104 and the swing cam 105 around the axis of the support pipe 108, and this mechanism appropriately changes the valve lift amount of the intake valve 101. To do. That is, if the relative phase difference between the two is increased, the swing angle of the rocker arm 106 with respect to the swing angle of the input arm 104 and the swing cam 105 is increased, and the valve lift amount of the intake valve 101 is increased. If the relative phase difference between the two is reduced, the swing angle of the rocker arm 106 with respect to the swing angle of the input arm 104 and the swing cam 105 is reduced, and the valve lift amount of the intake valve 101 is reduced.

  Next, the mechanism for changing the relative phase difference will be described in more detail. As shown in FIG. 2, the space defined between the input arm 104 and the two swing cams 105 and the outer peripheral surface of the support pipe 108 is rotatable with respect to the support pipe 108 and has a shaft. A slider gear 107 is slidably supported in the direction.

  The slider gear 107 is provided with a helical gear 107b in which a right-hand spiral helical spline is formed at the central portion in the axial direction. Further, the slider gear 107 is provided with helical gears 107c that are located on both sides of the helical gear 107b and in which a helical spline having a left-handed spiral shape is formed opposite to the helical gear 107b.

  On the other hand, helical splines corresponding to the helical gears 107b and 107c are formed on the surfaces of the input arm 104 and the two swing cams 105 that define a space for accommodating the slider gear 107, respectively. That is, the input arm 104 is formed with a right-hand spiral helical spline, and the helical spline meshes with the helical gear 107b. Further, the swing cam 105 is formed with a helical spline having a left-hand thread, and the helical spline meshes with the helical gear 107c.

  The slider gear 107 is formed with a long hole 107a extending between the one helical gear 107c and the helical gear 107b and extending in the circumferential direction. The support pipe 108 is formed with a long hole 108a extending in the axial direction so as to overlap a part of the long hole 107a. The drive shaft 20 inserted into the support pipe 108 is integrally provided with a locking pin 20a that protrudes through the overlapping portion of the two long holes 107a and 108a.

  When the drive shaft 20 moves in the axial direction, the slider gear 107 is pushed by the locking pin 20a, so that the helical gears 107b and 107c move in the axial direction of the drive shaft 20 at the same time. In response to the movement of the helical gears 107b and 107c, the input arm 104 and the swing cam 105 that are spline-engaged with the helical gears 107b and 107c do not move in the axial direction. To turn. At this time, since the input arm 104 and the swing cam 105 have the opposite directions of the formed helical splines, the rotation directions are opposite to each other. As a result, the relative phase difference between the input arm 104 and the swing cam 105 changes, and the valve lift amount of the intake valve 101 is changed as described above.

  Next, a rotation-linear motion conversion mechanism that converts the input rotational motion into linear motion and moves the drive shaft 20 in FIGS. 1 and 2 in the axial direction will be described. FIG. 3 is a cross-sectional view showing a rotation / linear motion conversion mechanism connected to the drive shaft in FIGS. 1 and 2.

  Referring to FIG. 3, the rotation-linear motion conversion mechanism 10 is disposed on a sun shaft 31 extending on a central axis 201 that is a virtual axis, and on the outer periphery of the sun shaft 31, and its circumferential direction is centered on the central axis 201. And a plurality of planetary shafts 41 and nuts 51 provided so as to surround the plurality of planetary shafts 41.

  The sun shaft 31 is arranged on the central axis 201 so as to be aligned with the drive shaft 20 in FIG. The sun shaft 31 is connected to the drive shaft 20 by a coupling mechanism such as a coupling mechanism (not shown). The sun shaft 31 pushes and pulls the drive shaft 20 in the axial direction of the central shaft 201.

  Sunshaft 31 includes a threaded portion 33 and gear portions 34 and 35. A gear portion 34 and a gear portion 35 are arranged on both sides of the screw portion 33 in the axial direction of the central shaft 201. Sunshaft 31 includes a spline portion 32. When the spline portion 32 is spline-engaged with the non-rotating collar 58, the linear motion of the sun shaft 31 in the axial direction of the central shaft 201 is allowed and the rotational motion of the sun shaft 31 around the central shaft 201 is restricted. Has been.

  The nut 51 has a cylindrical shape centered on the central axis 201. The nut 51 is supported by a bearing 59 so as to be rotatable about the central shaft 201. The nut 51 is disposed with a gap between it and the sun shaft 31. The nut 51 includes a threaded portion 52. A ring gear 50 is fixed to the nut 51. The ring gear 50 is provided on the outer periphery of each of the gear part 34 and the gear part 35. The rotation-linear motion conversion mechanism 10 includes a motor 61 that inputs a rotational motion to the nut 51.

  The planetary shaft 41 is disposed in the gap between the sun shaft 31 and the nut 51. Planetary shaft 41 includes a screw portion 42 and gear portions 43 and 45. The screw portion 42 is screwed into the screw portion 33 of the sun shaft 31 and the screw portion 52 of the nut 51. The gear portion 43 meshes with the gear portion 34 of the sun shaft 31 and the ring gear 50. The gear portion 45 meshes with the gear portion 35 of the sun shaft 31 and the ring gear 50.

  The male screw constituting the screw portion 33 of the sun shaft 31, the male screw constituting the screw portion 42 of the planetary shaft 41, and the female screw constituting the screw portion 52 of the nut 51 are all multi-threaded screws having the same pitch. The pitch circle diameters of these screws are Ds, Dp and Dn, respectively, and the number of threads of each screw is Ns, Np and Nn, respectively. In this embodiment, since the sun shaft 31 is stroked in the axial direction of the central axis 201, for example, the number of threads of each screw is determined so as to satisfy the relationship of Ns: Np: Nn = (Ds + 1): Dp: Dn. ing. It should be noted that the pitch circle diameter and the number of threads of each screw may take other relationships.

  When the nut 51 rotates, the rotational motion is transmitted to the planetary shaft 41 by the meshing of the threaded portion between the nut 51 and the planetary shaft 41. At this time, the gear portion 43 of the planetary shaft 41 meshes with the gear portion 34 of the ring gear 50 and the sun shaft 31, and the gear portion 45 of the planetary shaft 41 meshes with the gear portion 35 of the ring gear 50 and the sun shaft 31, respectively. . The planetary shaft 41 revolves around the central axis 201 while rotating while remaining stationary in the axial direction of the central axis 201.

  The rotational movement of the planetary shaft 41 is transmitted to the sun shaft 31 by the engagement of the threaded portion between the planetary shaft 41 and the sun shaft 31. As a result, the sun shaft 31 linearly moves in the axial direction of the central axis 201.

  Next, the structure of the motor 61 in the present embodiment provided in the rotation / linear motion conversion mechanism 10 in FIG. 3 will be described in detail. FIG. 4 is a cross-sectional view of the motor taken along line IV-IV in FIG.

  Referring to FIGS. 3 and 4, motor 61 is an SPM motor. The motor 61 includes a rotor 62, a plurality of permanent magnets 71, a magnet holder 72, and a magnet cover 81. The rotor 62 is fixed to the nut 51. The plurality of permanent magnets 71 are provided on the rotor 62. A stator 63 is disposed on the outer periphery of the rotor 62. A coil 65 is wound around the stator 63. When the coil 65 is energized, the rotor 62 rotates about the central axis 201 together with the nut 51.

  FIG. 5 is a perspective view showing a rotor constituting the motor in FIG. In the figure, a range surrounded by a two-dot chain line V in FIG. 4 is shown. 4 and 5, rotor 62 includes an outer peripheral surface 62a. The outer peripheral surface 62a faces the stator 63 in FIG. The outer peripheral surface 62a extends annularly around the central axis 201. The rotor 62 includes a protrusion 66. The protruding portion 66 protrudes from the outer peripheral surface 62 a and extends in the circumferential direction about the central axis 201.

  A groove 67 is formed in the rotor 62. The groove 67 is recessed from the outer peripheral surface 62a. The groove 67 is formed so as to divide the protrusion 66 in the circumferential direction. In the present embodiment, the groove 67 is formed at one place of the rotor 62.

  6 is a perspective view showing a state in which a permanent magnet is assembled to the rotor in FIG. 4 and 6, permanent magnet 71 is arranged on outer peripheral surface 62a. The permanent magnet 71 is provided in a form protruding from the outer peripheral surface 62a. The permanent magnet 71 is bonded to the outer peripheral surface 62a with an adhesive (not shown). The plurality of permanent magnets 71 are arranged at intervals in the circumferential direction of the central shaft 201. The plurality of permanent magnets 71 are arranged at equal intervals.

  FIG. 7 is a perspective view showing a magnet holder assembled to the rotor in FIG. FIG. 8 is a perspective view showing a state where a permanent magnet and a magnet holder are assembled to the rotor in FIG.

  With reference to FIGS. 7 and 8, magnet holder 72 is arranged on outer peripheral surface 62 a of rotor 62. The magnet holder 72 includes an annular portion 74 and a plurality of tooth-like portions 73. In a state where the magnet holder 72 is assembled to the rotor 62, the annular portion 74 extends annularly around the central axis 201. The plurality of tooth-like parts 73 are arranged at intervals in the circumferential direction of the annular part 74. The plurality of tooth-like portions 73 are arranged at equal intervals. Each of the plurality of tooth-like portions 73 extends from the annular portion 74 in the axial direction of the central axis 201. The plurality of tooth-like portions 73 are connected to each other by an annular portion 74. The magnet holder 72 is made of resin. The annular portion 74 and the plurality of tooth-like portions 73 are integrally formed.

  The plurality of tooth-like portions 73 are respectively inserted into gaps between the permanent magnets 71 adjacent in the circumferential direction. The annular portion 74 is inserted into a gap formed between the permanent magnet 71 and the protrusion 66. The magnet holder 72 restricts the displacement of the permanent magnet 71 in the circumferential direction.

  The magnet holder 72 includes a locking portion 75. The locking part 75 projects from the annular part 74 inward in the radial direction of the central shaft 201. The locking portion 75 protrudes toward the outer peripheral surface 62a. The locking portion 75 is disposed on the opposite side of the plurality of tooth-like portions 73 with respect to the annular portion 74 in the axial direction of the central shaft 201. The locking part 75 is inserted in the groove 67. Since the locking portion 75 is locked in the groove 67, the circumferential displacement of the magnet holder 72 is restricted.

  FIG. 9 is a perspective view showing a state where a permanent magnet, a magnet holder, and a magnet cover are assembled to the rotor in FIG. FIG. 10 is a cross-sectional view of the rotor taken along line XX in FIG. Referring to FIGS. 9 and 10, magnet cover 81 is fitted on outer peripheral surface 62a. The magnet cover 81 is provided so as to cover the plurality of permanent magnets 71 arranged on the outer peripheral surface 62a. In other words, the plurality of permanent magnets 71 are sandwiched between the outer peripheral surface 62 a and the magnet cover 81. The magnet cover 81 has a shape extending in an annular shape around the central axis 201. The magnet cover 81 is made of stainless steel. The magnet cover 81 restricts the permanent magnet 71 from protruding in the radial direction.

  The magnet cover 81 includes a folded portion 82 and a claw portion 83. The folded portion 82 is formed by folding one end of the central shaft 201 in the axial direction toward the inside in the radial direction. The claw portion 83 is formed by folding the other end of the central shaft 201 in the axial direction toward the inside in the radial direction. The claw parts 83 are formed at predetermined intervals in the circumferential direction of the central axis 201. The rotor 62 is sandwiched in the axial direction of the central shaft 201 by the folded portion 82 and the claw portion 83. The magnet cover 81 is fixed in the axial direction of the central shaft 201 by the folded portion 82 and the claw portion 83.

  The magnet cover 81 includes a locking portion 84. The locking portion 84 protrudes inward in the radial direction of the central shaft 201. The locking portion 84 protrudes toward the outer peripheral surface 62a. The locking portion 84 is inserted into the groove 67 together with the locking portion 75. Since the locking portion 84 is locked in the groove 67, the circumferential displacement of the magnet cover 81 is restricted.

  When the valve lift amount is controlled, the rotor 62 pushes and pulls the drive shaft 20 by repeating forward and reverse rotations, so that a large torque fluctuation is applied to the permanent magnet 71. On the other hand, the rotor 62 is provided with the magnet holder 72 and the magnet cover 81 to prevent the permanent magnet 71 from being displaced in the circumferential direction or protruding in the radial direction. At this time, in the present embodiment, the locking portion 75 of the magnet holder 72 and the locking portion 84 of the magnet cover 81 are locked in the same groove 67 formed in the rotor 62. For this reason, compared with the case where the groove | channel for latching each latching | locking part is provided separately, the rotor 62, the magnet holder 72, and the magnet cover 81 can be made into a simple structure. Moreover, the workability | operativity at the time of the assembly | attachment of the magnet holder 72 and the magnet cover 81 can be improved.

  The motor 61 in the embodiment of the present invention includes an outer peripheral surface 62a as a peripheral surface, a rotating rotor 62, a plurality of permanent magnets 71 arranged on the outer peripheral surface 62a at intervals from each other, and an outer peripheral surface 62a. A magnet holder 72 that is disposed and inserted between the permanent magnets 71 adjacent to each other and restricts the displacement of the permanent magnet 71 in the circumferential direction, and is fitted on the outer peripheral surface 62 a so as to cover the permanent magnet 71. And a magnet cover 81 as an anti-scattering member that restricts the pop-out of the permanent magnet 71 in the radial direction. A groove 67 is formed in the rotor 62. The magnet holder 72 and the magnet cover 81 are locked in the same groove 67, and include a locking portion 75 and a locking portion 84 that restrict displacement of the magnet holder 72 and the magnet cover 81 in the circumferential direction, respectively.

  According to the motor 61 in the embodiment of the present invention configured as described above, a structure for preventing the displacement and scattering of the permanent magnet 71 can be easily configured. Further, by using the motor 61 for the variable valve lift mechanism, a highly reliable valve lift variable mechanism can be manufactured at low cost.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a front view which shows the valve lift variable mechanism containing the motor in embodiment of this invention. It is a perspective view which shows partially the valve lift variable mechanism in FIG. It is sectional drawing which shows the rotation-linear motion conversion mechanism connected to the drive shaft in FIG. 1 and FIG. It is sectional drawing of the motor along the IV-IV line | wire in FIG. It is a perspective view which shows the rotor which comprises the motor in FIG. It is a perspective view which shows the state which assembled | attached the permanent magnet to the rotor in FIG. It is a perspective view which shows the magnet holder assembled | attached to the rotor in FIG. It is a perspective view which shows the state which assembled | attached the permanent magnet and the magnet holder to the rotor in FIG. It is a perspective view which shows the state which assembled | attached the permanent magnet, the magnet holder, and the magnet cover to the rotor in FIG. It is sectional drawing of the rotor along the XX line in FIG.

Explanation of symbols

  61 motor, 62 rotor, 62a outer peripheral surface, 67 groove, 71 permanent magnet, 72 magnet holder, 73 toothed portion, 74 annular portion, 75, 84 locking portion, 81 magnet cover, 100 valve lift variable mechanism 201 central axis.

Claims (5)

A rotor including a circumferential surface and rotating;
A plurality of permanent magnets spaced apart from each other on the peripheral surface;
An anti-rotation member that is disposed on the peripheral surface and is inserted between the permanent magnets adjacent to each other, and restricts the displacement of the permanent magnet in the circumferential direction;
A scattering preventing member that is fitted on the peripheral surface so as to cover the permanent magnet and restricts the permanent magnet from protruding in the radial direction;
A groove is formed in the rotor,
The anti-rotation member and the anti-scattering member each include an engaging portion that is engaged with the same groove and restricts displacement of the anti-rotation member and the anti-scattering member in the circumferential direction.   The motor according to claim 1, wherein the groove is formed at one place.   The rotation preventing member includes a plurality of tooth-like portions respectively positioned between the permanent magnets adjacent to each other, and an annular portion extending in a circumferential direction and connecting the plurality of tooth-like portions. The motor according to 1 or 2.   The motor according to any one of claims 1 to 3, wherein the rotor repeats forward rotation and reverse rotation when the motor is driven. A motor according to any one of claims 1 to 4, comprising:
A variable valve lift mechanism that converts a rotary motion output from the motor into a linear motion, and variably controls a lift amount of a valve of the internal combustion engine by the linear motion.

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