JP2009165238A - Mechanism for preventing reverse rotation of synchronous motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanism for preventing reverse rotation of a synchronous motor having a new structure that ensures a space for arranging a reverse rotation prevention ring as a reverse rotation prevention advantageously. <P>SOLUTION: When a rotor 14 rotates forward, a reverse rotation prevention ring 10 is displaced to approach the rotor 14 and forward rotation of the rotor 14 is permitted by locating the reverse rotation prevention ring 10 above an engagement protrusion 80 on the stator side. When the rotor 14 rotates reversely, the reverse rotation prevention ring 10 is displaced to separate from the rotor 14 so that the reverse rotation prevention ring 10 engages with the engagement protrusion 80 on the stator side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a reverse rotation preventing mechanism for a synchronous motor that prevents the rotor of the synchronous motor from starting to rotate in the reverse direction at the time of startup.

  As is well known, the synchronous motor can change the number of rotations by changing the power supply frequency, (2) there is little rotation unevenness or torque unevenness, (3) it is small and lightweight, etc. Has advantages. Therefore, conventionally, the use of a synchronous motor has been studied as a drive source of an actuator using a motor such as a geared motor.

  By the way, the synchronous motor includes a stator on which a coil is mounted and a rotor on which a permanent magnet is assembled. Based on the mutual magnetic action between the magnetic pole of the stator and the magnetic pole of the rotor, which is expressed by energizing the coil. The rotor is rotated with respect to the stator. Further, in a synchronous motor that does not have means for electrically rotating in one direction, it is uncertain whether the rotor starts to rotate in the normal rotation direction or the reverse rotation direction at startup. Have. Therefore, in such a synchronous motor, in order to rotate the rotor in a target direction at the time of starting, generally, when the rotor starts to rotate in the reverse rotation direction, this is forcibly stopped and rotated in the forward rotation direction. A reverse rotation prevention mechanism for correcting the above is provided.

  Specifically, as described in Patent Documents 1 to 5, when a lever-like member as a reverse rotation preventing member is disposed so as to be rotatable around one axis, the rotor rotates in the forward rotation direction. In this case, the lever-shaped member is retracted to a position that allows the rotor to rotate in the forward rotation direction, while the lever-shaped member is prevented from rotating in the reverse rotation direction of the rotor when the rotor rotates in the reverse rotation direction. There has been proposed a reverse rotation prevention mechanism that moves the actuator to a position where it moves.

  However, in the reverse rotation prevention mechanism described in Patent Documents 1 to 5, since the lever-like member needs to be moved in a plane perpendicular to the rotation center axis of the rotor, the drive space of the lever-like member is taken into consideration. There is a problem that a space for arranging the lever-like member has to be secured.

Japanese Utility Model Publication No. 60-22788 Japanese Utility Model Publication No. 6-13369 JP-A-6-62546 JP 2002-10572 A Japanese Patent No. 30668804

  Here, the present invention has been made in the background as described above, and the problem to be solved is to advantageously secure a space for arranging a reverse rotation prevention ring as a reverse rotation prevention member. An object of the present invention is to provide a reverse rotation prevention mechanism for a synchronous motor having a novel structure.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible.

  The present invention includes a rotor having a stator on which a coil is mounted and a permanent magnet for forming a magnetic pole, and the interaction between the magnetic pole developed in the magnetic pole portion formed on the stator based on energization of the coil and the magnetic pole of the rotor The reverse rotation prevention mechanism of the synchronous motor prevents the reverse rotation of the rotor at the time of starting the synchronous motor that rotates the rotor based on the following: (a) provided on the lower surface of the rotor and protruding downward in the axial direction of the rotor (B) a stator side engagement protrusion that is provided in a portion of the stator that is opposed to the lower surface of the rotor in the axial direction of the rotor and protrudes toward the lower surface of the rotor; (C) a reverse rotation prevention ring disposed between the rotor and the stator in the axial direction in a state of being rotatable around the rotor support shaft inserted through the center hole of the rotor; and (d) reverse rotation. A forward engagement surface formed on the stop ring and engaged with the rotor-side engagement protrusion in the forward rotation direction of the rotor so that the reverse rotation prevention ring is rotationally driven integrally with the rotor in the forward rotation direction of the rotor; (E) formed on the lower surface of the reverse rotation prevention ring and inclined upward in the axial direction of the rotor in the forward rotation direction of the rotor, and the rotor side engagement protrusion and the forward direction engagement surface are engaged with each other. The reverse rotation prevention ring is brought into contact with the stator side engagement protrusion while the reverse rotation prevention ring rotates in the forward rotation direction of the rotor, and the reverse rotation prevention ring is guided above the stator side engagement protrusion to thereby prevent the reverse rotation prevention ring. Is formed on the upper surface of the reverse rotation prevention ring, and is inclined upward in the axial direction of the rotor in the reverse rotation direction of the rotor. Rotate in the opposite direction (G) an upper guide surface that displaces the reverse rotation prevention ring from the rotor in the axial direction by sliding contact with the rotor side engagement protrusion; and (g) formed on the reverse rotation prevention ring so that the rotor side engagement in the reverse rotation direction of the rotor. (H) an anti-rotation ring formed on the anti-rotation ring, and the anti-rotation ring is formed on the anti-rotation ring. By engaging the engagement protrusion and the upper reverse engagement surface and engaging the stator-side engagement protrusion in a state where the reverse rotation prevention ring is rotationally driven integrally with the rotor in the reverse rotation direction of the rotor, A lower reverse engagement surface that prevents reverse rotation of the reverse rotation prevention ring is provided.

  In such a reverse rotation prevention mechanism of the synchronous motor structured according to the present invention, when the rotor starts to rotate in the forward rotation direction, the rotor side engagement protrusion provided on the rotor and the reverse rotation prevention ring are formed. Engagement of the positive direction engagement surfaces allows the reverse rotation prevention ring to be driven to rotate integrally with the rotor in the normal rotation direction of the rotor.

  When the rotor-side engagement protrusion and the forward-direction engagement surface engage with each other and the reverse rotation prevention ring is driven to rotate integrally with the rotor in the forward rotation direction of the rotor, it is formed on the lower surface of the reverse rotation prevention ring. When the lower guide surface is brought into contact with the stator-side engagement protrusion provided on the stator, the reverse rotation prevention ring is guided to the upper side of the stator-side engagement protrusion and is displaced toward the rotor in the axial direction. As a result, the rotor is allowed to rotate in the positive rotation direction.

  On the other hand, when the rotor starts to rotate in the reverse rotation direction, the rotor-side engagement protrusion comes into sliding contact with the upper guide surface formed on the upper surface of the reverse rotation prevention ring, so that the reverse rotation prevention ring is displaced away from the rotor in the axial direction. To be harassed. In addition, with the reverse rotation prevention ring axially spaced apart from the rotor, the upper reverse engagement surface formed on the reverse rotation prevention ring engages with the rotor side engagement protrusion to prevent reverse rotation. The ring is driven to rotate integrally with the rotor in the reverse rotation direction of the rotor.

  When the rotor-side engagement protrusion and the upper reverse engagement surface are engaged and the reverse rotation prevention ring is driven to rotate integrally with the rotor in the reverse rotation direction of the rotor, the reverse rotation prevention ring is formed. Further, the reverse rotation of the reverse rotation prevention ring is prevented by engaging the lower reverse engagement surface and the stator side engagement protrusion. As a result, reverse rotation of the rotor is also prevented.

  Therefore, in the reverse rotation prevention mechanism of the synchronous motor according to the present invention, the forward rotation of the rotor and the prevention of the reverse rotation of the rotor can be rotated around the rotor spindle inserted through the center hole of the rotor. In this state, the reverse rotation prevention ring is arranged in the direction perpendicular to the axis of the rotor support shaft because the reverse rotation prevention ring disposed between the rotor and the stator is axially displaced. No need to drive.

  Therefore, in the reverse rotation prevention mechanism for the synchronous motor according to the present invention, it is possible to advantageously secure a space for arranging the reverse rotation prevention ring.

  In the reverse rotation prevention mechanism of the synchronous motor according to the present invention, the rotational speed of the rotor, the friction coefficient of the surface engaging with the positive engagement surface in the rotor side engagement protrusion, the friction coefficient of the positive engagement surface, etc. When the rotor is rotated in the forward rotation direction, the lower guide surface of the reverse rotation prevention ring and the stator side engagement protrusion once contact each other, and the reverse rotation prevention ring approaches the rotor in the axial direction. When displaced, the state can be maintained. In other words, it is possible to prevent the lower guide surface of the reverse rotation prevention ring and the stator side engagement protrusion from coming into contact with each other repeatedly while the rotor is rotating in the forward rotation direction. As a result, when the rotor rotates in the forward rotation direction, it is possible to suppress the generation of abnormal noise due to the lower guide surface of the reverse rotation prevention ring and the stator side engaging protrusion coming into contact with each other many times.

  Further, in the reverse rotation prevention mechanism for the synchronous motor according to the present invention, it is desirable that a recess opening on the lower surface of the rotor is formed, and a rotor-side engagement protrusion is provided on the upper bottom surface of the recess. . Thereby, it becomes possible to arrange | position a reverse rotation prevention ring in the recess formed in the rotor. As a result, it is possible to more advantageously secure the space for arranging the reverse rotation prevention ring. In other words, even with the reverse rotation prevention ring that can be accommodated and disposed in such a recess, the reverse rotation of the rotor at the time of startup can be advantageously prevented.

  Furthermore, in the reverse rotation prevention mechanism for the synchronous motor according to the present invention, it is desirable that the stator side engaging protrusion is formed separately from the stator. Accordingly, it is possible to advantageously ensure the strength of the stator side engaging protrusion as compared with the case where the stator side engaging protrusion is formed by cutting and raising from the stator. As a result, it is possible to advantageously ensure the durability of the stator side engagement protrusion.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a synchronous motor 12 provided with a reverse rotation prevention ring 10 constituting a reverse rotation prevention mechanism as an embodiment of the present invention. The synchronous motor 12 is a conventionally known AC synchronous motor, and includes a rotor 14 and a stator 18 around which an annular coil 16 is wound. The synchronous motor 12 is housed in an appropriate housing, and transmits the rotational driving force of the rotor 14 to an output member composed of a pulley, a rod, and the like via a speed reduction means composed of a reduction gear train or the like. As a result, the output member is driven and displaced.

  More specifically, as shown in FIGS. 2 to 4, the rotor 14 has a structure in which the output shaft 22 is integrally assembled with the permanent magnet 20. The permanent magnet 20 has a thick cylindrical shape as a whole. In the present embodiment, the outer peripheral surface is magnetized with four N poles and four S poles alternately for a total of eight poles. On the other hand, the output shaft 22 is made of a synthetic resin material and has a thick cylindrical shape having a center hole 26 through which the rotor support shaft 24 is inserted. Further, a rotor pinion 28 is provided at an intermediate portion in the axial direction of the output shaft 22.

  The output shaft 22 having such a structure is such that one end in the axial direction (the lower end in the axial direction in FIG. 2) is inserted into the central hole 30 of the permanent magnet 20 from the other end in the axial direction (the upper end in the axial direction). Thus, it is assembled to the permanent magnet 20. In particular, in the present embodiment, the output shaft 22 is assembled to the permanent magnet 20 so as to be inserted into the central hole 30 of the permanent magnet 20 from the axial middle portion of the permanent magnet 20 to the upper end in the axial direction. . Thus, a recess 32 that opens downward in the axial direction is formed at the center of the lower surface of the rotor 14.

  An assembly member 34 is accommodated in the recess 32. The assembly member 34 is formed of a synthetic resin material, and includes a main body 36 that has a thick annular plate shape. Further, the assembly member 34 is formed with a rotor-side engagement protrusion 38 that protrudes downward in the axial direction on the lower surface in the axial direction (one side in the thickness direction).

  Accordingly, a pair of rotor side engaging protrusions 38 of the present embodiment are formed so as to be opposed to each other in the radial direction across the central hole 40 formed in the main body portion 36. In particular, in the present embodiment, both end surfaces in the circumferential direction of each rotor-side engagement protrusion 38 are spread along the radial direction of the main body 36. In other words, both end surfaces in the circumferential direction of each rotor-side engagement protrusion 38 are spread in a direction orthogonal to a tangent at a position intersecting with the circumferential end surface in a concentric circle of the main body 36.

  In the assembly member 34 having the structure as described above, the support protrusion 42 provided on the lower end surface in the axial direction of the output shaft 22 is inserted into the central hole 40 formed in the main body portion 36, and the shaft of the output shaft 22 is inserted. In the state where the lower end surface in the direction and the upper surface of the main body portion 36 are overlapped, they are accommodated in the recess 32. As a result, the pair of rotor-side engagement protrusions 38, 38 provided on the assembly member 34 are respectively axially below the rotor 14 from the lower surface of the main body portion 36 of the assembly member 34 serving as the upper bottom of the recess 32. It protrudes toward.

  In the present embodiment, positioning protrusions 44 are provided on the upper surface of the main body portion 36 of the assembly member 34, and the lower end surface in the axial direction of the output shaft 22 and the upper surface of the main body portion 36 are overlapped. The positioning protrusions 44 are positioned in positioning recesses 46 formed in the lower end surface of the output shaft 22 in the axial direction, whereby the circumferential position of the assembly member 34 with respect to the rotor 14 is defined. .

  Therefore, in the present embodiment, the pair of rotor-side engagement protrusions 38, 38 provided on the assembly member 34 is permanently attached in a state where the assembly member 34 is accommodated in the recess 32 as described above. It is positioned on the boundary line of the magnetic poles magnetized on the magnet 20. Further, the projecting end surfaces of the rotor side engaging projections 38 are positioned axially above the opening end surface of the recess 32 that opens downward in the axial direction. In other words, each of the rotor-side engagement protrusions 38 does not protrude downward in the axial direction from the opening end surface of the recess 32. Furthermore, the protruding end surface of the support protrusion 42 is positioned slightly below the lower surface of the main body 36 in the axial direction. In other words, the support protrusion 42 slightly protrudes downward from the lower surface of the main body 36 in the axial direction.

  On the other hand, the stator 18 includes an upper stator constituent member 48 and a lower stator constituent member 50. The upper stator constituent member 48 is formed of a magnetic material such as iron, and includes an annular plate-like portion 52 having an annular plate shape. Further, a plurality of upper magnetic pole plate portions 54 projecting inward in the radial direction are provided at equal intervals in the circumferential direction on the inner peripheral edge portion of the annular plate-shaped portion 52 of the upper stator component 48 (four in the present embodiment). Is provided. In the present embodiment, the circumferential lengths of the four upper magnetic pole plate portions 54 are the same. The base end portion of each upper magnetic pole plate portion 54 is bent. Accordingly, each upper magnetic pole plate portion 54 protrudes to one side in the thickness direction of the annular plate-like portion 52 (the lower side in the axial direction in FIG. 1).

  The lower stator constituent member 50 is formed of a magnetic material such as iron, and has a shallow bottomed large-diameter bottomed cylindrical shape as shown in FIGS. 5 and 6. In the present embodiment, the peripheral wall portion 56 of the lower stator constituent member 50 is notched into an appropriate shape.

  Further, the lower stator constituting member 50 is provided with a plurality (four in this embodiment) of lower magnetic pole plate portions 58 cut and raised from the bottom wall 57 thereof. Therefore, in the present embodiment, two of the four lower magnetic pole plate portions 58 are wide lower magnetic pole plates having the same circumferential length as the upper magnetic pole plate portion 54 provided on the upper stator constituting member 48. Part 60. On the other hand, the remaining two lower magnetic pole plate portions 58, 58 are narrower in lower circumferential length than the upper magnetic pole plate portion 54 and the wide lower magnetic pole plate portion 60 provided on the upper stator component 48. A side magnetic pole plate 62 is provided. The four lower magnetic pole plate portions 58 are provided so that the wide lower magnetic pole plate portion 60 and the narrow lower magnetic pole plate portion 62 are alternately arranged in the circumferential direction.

  Here, the opposing direction of the pair of wide lower magnetic pole plate portions 60, 60 and the opposing direction of the pair of narrow lower magnetic pole plate portions 62, 62 are not orthogonal. In other words, the pair of narrow lower magnetic pole plate portions 62, 62 are respectively moved from the position orthogonal to the opposing direction of the pair of wide lower magnetic pole plate portions 60, 60 to one side in the circumferential direction around the central axis. They are opposed to each other at a position shifted by the same angle.

  A through hole 64 is formed in the center of the bottom wall 57 of the lower stator component 50 so as to penetrate the bottom wall 57 in the thickness direction. A fitting member 66 is assembled to the through hole 64. The fitting member 66 is made of a synthetic resin material and has a thick stepped cylindrical shape having a center hole 68. Specifically, in the fitting member 66 of the present embodiment, two step surfaces 70 and 72 are formed at positions separated in the axial direction in the axially intermediate portion, whereby the fitting member 66 is In addition, one side in the axial direction of the main body portion 74 located at the intermediate portion in the axial direction is a protruding shaft portion 76 having a smaller diameter than the main body portion 74, while the other side in the axial direction of the main body portion 74 is more than the main body portion 74 A large diameter contact portion 78 is provided.

  In addition, on the fitting member 66, the stator side engagement protrusion 80 that protrudes upward in the axial direction on the upper surface of the main body portion 74 is positioned opposite to the protrusion shaft portion 76 in the radial direction, A pair is provided. Therefore, in the present embodiment, both end surfaces in the circumferential direction of the respective stator side engagement protrusions 80 extend in the radial direction of the fitting member 66. In other words, both end surfaces in the circumferential direction of each stator side engaging protrusion 80 are spread in a direction orthogonal to a tangent at a position intersecting with the circumferential end surface in a concentric circle of the fitting member 66.

  The fitting member 66 having such a shape is assembled to the lower stator component member 50 by fitting the main body portion 74 into the through hole 64 from the lower surface side of the bottom wall 57 of the lower stator component member 50. ing. In the present embodiment, the positioning protrusions 82 and 82 projecting from the upper surface of the contact portion 78 are fitted into the positioning recesses 84 and 84 formed in the lower surface of the bottom wall 57 of the lower stator component 50. Thus, the circumferential position of the pair of stator side engaging projections 80, 80 is defined. Incidentally, in the present embodiment, a pair of stator side engagement protrusions 80, 80 are arranged so that one end surface in the circumferential direction of each stator side engagement protrusion 80 extends in a direction opposite to the pair of wide lower magnetic pole plate portions 60, 60. The circumferential position is defined.

  The bobbin 86 around which the coil 16 is wound is assembled so as to be sandwiched between the lower stator constituent member 50 and the upper stator constituent member 48 to which the fitting member 66 is assembled as described above. Thereby, the stator 18 with which the coil 16 was mounted | worn is comprised. As described above, in the state where the lower stator constituent member 50 and the upper stator constituent member 48 are assembled to the bobbin 86 around which the coil 16 is wound, the four upper magnetic pole plate portions 54 and the pair of wide lower portions are arranged. The side magnetic pole plate portions 60 and 60 are respectively positioned at the center in the circumferential direction on a pitch of eight of concentric circles in the stator 18, while the pair of narrow lower magnetic pole plate portions 62 and 62 are respectively The center in the circumferential direction is positioned at a position deviated from the pitch of the eight concentric circles in the stator 18. In other words, in the present embodiment, the positive electrode is constituted by each of the four upper magnetic pole plate portions 54 and the pair of wide lower magnetic pole plate portions 60, 60, while the pair of narrow lower magnetic pole plate portions 62, 62. Each of these constitutes a complementary pole.

  Moreover, the rotor 14 is assembled | attached with respect to the stator 18 with which the coil 16 was mounted | worn as mentioned above. Specifically, the support protrusion 42 provided on the rotor 14 is formed on the outer peripheral surface of the rotor 14 in a state where the support protrusion 42 is placed on the protruding end surface of the protruding shaft portion 76 of the fitting member 66 attached to the stator 18. The magnetic poles are opposed to the upper magnetic pole plate portion 54 and the lower magnetic pole plate portion 58 of the stator 18 in a direction orthogonal to the central axis of the rotor 14 with a predetermined gap.

  Furthermore, as described above, the support protrusion 42 of the rotor 14 is placed on the protruding end surface of the protruding shaft portion 76 provided on the stator 18, so that the fitting member provided on the center hole 26 of the rotor 14 and the stator 18. 66 center holes 68 are connected. The rotor support shaft 24 is inserted into the center holes 26 and 68, so that the rotor 14 is assembled to the stator 18 so as to be rotatable around the rotor support shaft 24. Note that the rotor support shaft 24 of the present embodiment can be handled integrally with the fitting member 66 and the stator 18 by being press-fitted and fixed in the center hole 68 of the fitting member 66.

  A reverse rotation prevention ring 10 is disposed between the bottom surface of the rotor 14 and the bottom wall 57 of the lower stator constituent member 50. The reverse rotation prevention ring 10 is made of a synthetic resin material and has a thick annular plate shape as a whole as shown in FIGS. Therefore, an upper guide which is inclined upward in the axial direction in one circumferential direction (the forward rotation direction of the rotor 14 and the counterclockwise direction in FIG. 8) is provided on the upper surface of the reverse rotation prevention ring 10. A surface 88 is formed. A low position surface 90 is formed on the downstream side of the upper guide surface 88, while a high position surface 92 is formed on the upstream side of the upper guide surface 88. Further, a high-position side step surface 94 that extends upward in the axial direction is formed at one circumferential end of the high-position surface 92, and the high-position surface is located on one side in the circumferential direction from the high-position side step surface 94. An upper end surface 96 is formed that is positioned axially above 92. Furthermore, a low-position side step surface 98 that extends downward in the axial direction is formed at one end in the circumferential direction of the upper end surface 96, and on the one side in the circumferential direction from the low-position side step surface 98, reverse rotation prevention is provided. The other low-position surface 90 is formed so as to face the one low-position surface 90 across the central axis of the ring 10.

  That is, in the present embodiment, the low position surface 90, the upper guide surface 88, the high position surface 92, the high position side step surface 94, the upper end surface 96, and the low position side step surface 98 are each the center of the reverse rotation prevention ring 10. A pair is formed so as to be opposed to each other across the axis.

  Further, on the lower surface of the reverse rotation prevention ring 10, there is a lower guide surface 100 that is inclined upward in the axial direction in the other circumferential direction (the reverse rotation direction of the rotor 14 and the clockwise direction in FIG. 8). Is formed. A lower end surface 102 is formed on the downstream side of the lower guide surface 100, while an upper bottom surface 104 is formed on the upstream side of the lower guide surface 100. Further, a lower step surface 106 that extends downward in the axial direction is formed at the other circumferential end of the upper bottom surface 104, and the reverse rotation prevention ring 10 is provided on the other circumferential side of the lower step surface 106. The other lower end surface 102 is formed so as to be opposed to the one lower end surface 102 across the central axis of the other end.

  That is, in the present embodiment, the lower end surface 102, the lower guide surface 100, the upper bottom surface 104, and the lower step surface 106 are respectively opposed to each other with the central axis of the reverse rotation prevention ring 10 interposed therebetween. It is formed.

  The reverse rotation prevention ring 10 having such a shape projects the fitting member 66 that is assembled and fixed to the bottom wall 57 of the lower stator component 50 so that the upper end surface 96 is located on the rotor 14 side. An extrapolated arrangement is provided on the shaft portion 76. Thereby, the reverse rotation prevention ring 10 is rotatably arranged around the rotor shaft 24 inserted into the protruding shaft portion 76 of the fitting member 66 and, further, the center hole 68 of the fitting member 66. .

  In the synchronous motor 12 having the above-described structure, when an alternating current flows through the coil 16, the rotor 14 is caused by the interaction between the magnetic poles appearing on the upper magnetic pole plate portion 54 and the lower magnetic pole plate portion 58 and the magnetic poles of the rotor 14. Begins to rotate. As is apparent from this, in the present embodiment, each of the upper magnetic pole plate portion 54 and the lower magnetic pole plate portion 58 constitutes a magnetic pole portion.

  Then, when the rotor 14 starts to rotate in the forward rotation direction (one direction in the circumferential direction), the rotor-side engagement protrusion 38 provided on the rotor 14 is attached to the reverse rotation prevention ring 10 as shown in FIG. The reverse rotation prevention ring 10 is driven to rotate integrally with the rotor 14 in the forward rotation direction of the rotor 14 by engaging with the formed low position side step surface 98.

  In this way, in the reverse rotation prevention ring 10 that is rotationally driven integrally with the rotor 14 in the forward rotation direction of the rotor 14, the lower guide surface 100 has a stator side engagement as shown in FIG. When brought into contact with the mating protrusion 80, it is displaced so as to jump upward in the axial direction by the rotational force of the rotor 14. As a result, as shown in FIG. 12, the reverse rotation prevention ring 10 is guided above the stator side engagement projection 80, and the reverse rotation prevention ring 10 is displaced toward the rotor 14 in the axial direction. As a result, when the rotor 14 rotates in the forward rotation direction, the reverse rotation prevention ring 10 does not interfere with the rotation of the rotor 14 in the forward rotation direction.

  On the other hand, when the rotor 14 starts to rotate in the reverse rotation direction (the other direction in the circumferential direction), the rotor-side engagement protrusion 38 provided on the rotor 14 is formed on the reverse rotation prevention ring 10 as shown in FIG. By making sliding contact with the upper guide surface 88, the reverse rotation prevention ring 10 is displaced away from the rotor 14 in the axial direction (see FIG. 1).

  In addition, when the rotor 14 rotates in the reverse rotation direction in the state where the reverse rotation prevention ring 10 is displaced from the rotor 14 in the axial direction in this way, as shown in FIG. The provided rotor-side engagement protrusion 38 is engaged with a high-position side step surface 94 formed on the reverse rotation prevention ring 10 so that the reverse rotation prevention ring 10 is integrated with the rotor 14 in the reverse rotation direction of the rotor 14. It can be driven to rotate.

  Then, the reverse rotation prevention ring 10 rotated integrally with the rotor 14 in the reverse rotation direction of the rotor 14 in this way is formed in the reverse rotation prevention ring 10 as shown in FIG. The lower step surface 106 is engaged with the stator side engaging protrusion 80 so as to prevent the reverse rotation prevention ring 10 from rotating backward. As a result, the reverse rotation of the rotor 14 driven to rotate integrally with the reverse rotation prevention ring 10 is also prevented.

  As is apparent from the above description, in the present embodiment, the forward engaging surface is configured by the low position side step surface 98, and the upper reverse engaging surface is configured by the high position side step surface 94. The lower step engagement surface 106 forms a lower reverse engagement surface. In the present embodiment, the reverse rotation prevention ring 10 formed with the upper guide surface 88, the low position side step surface 98, the high position side step surface 94, the lower guide surface 100, and the lower step surface 106, the rotor side The engagement protrusion 38 and the stator side engagement protrusion 80 constitute a reverse rotation prevention mechanism for the synchronous motor 12.

  In the synchronous motor 12 having the above-described structure, the reverse rotation prevention ring 10 is displaced upward in the axial direction (rotor 14 side) during the forward rotation of the rotor 14 so as not to interfere with the forward rotation of the rotor 14. On the other hand, the reverse rotation prevention ring 10 is displaced downward in the axial direction (on the bottom wall 57 side of the lower stator constituent member 50) during the reverse rotation of the rotor 14 to prevent the reverse rotation of the rotor 14. Therefore, there is no need to drive and displace the reverse rotation prevention ring 10 in a direction perpendicular to the rotor support shaft 24. Therefore, it is not necessary to consider the drive space in the direction perpendicular to the axis of the reverse rotation prevention ring 10 when securing the installation space for the reverse rotation prevention ring 10. It can be secured.

  In particular, in the present embodiment, since the reverse rotation prevention ring 10 is accommodated in the recess 32 formed on the lower surface of the rotor 14, it is possible to advantageously secure a space for arranging the reverse rotation prevention ring 10. It becomes.

  Further, in the present embodiment, since the stator side engaging protrusion 80 is provided on the fitting member 66 assembled to the lower stator constituent member 50, the stator side engaging protrusion 80 of the lower stator constituent member 50 is provided. The strength of the stator side engaging projection 80 can be advantageously ensured as compared with the case where the stator side engaging projection 80 is cut and raised from the bottom wall 57.

  As mentioned above, although one Embodiment of this invention was explained in full detail, this is an illustration to the last, Comprising: This invention is not limited at all by the specific description in this Embodiment.

  For example, in the first embodiment, the stator side engagement protrusion 80 may be formed by cutting and raising from the bottom wall 57 of the lower stator component 50.

  In addition, although not listed one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

The longitudinal cross-sectional view which shows the synchronous motor by which the reverse rotation prevention ring which comprises the reverse rotation prevention mechanism of the synchronous motor as one Embodiment of this invention was distribute | arranged. The longitudinal cross-sectional view of the rotor which comprises the synchronous motor of FIG. The top view of the rotor. The bottom view of the rotor. The longitudinal cross-sectional view of the lower side stator structural member which comprises the stator of the synchronous motor of FIG. The top view of the same lower side stator structural member. The longitudinal cross-sectional view of the reverse rotation prevention ring distribute | arranged to the synchronous motor of FIG. The top view of the reverse rotation prevention ring. The bottom view of the reverse rotation prevention ring. The top view for demonstrating the state which the low position side level | step difference surface of a rotor side engaging protrusion and a reverse rotation prevention ring is engaging. The side view for demonstrating the contact state of a stator side engaging protrusion and the lower guide surface of a reverse rotation prevention ring. The longitudinal cross-sectional view for demonstrating the state by which the reverse rotation prevention ring was made to approach and displace to a rotor. The side view for demonstrating the state which the rotor side engaging protrusion has slidably contacted with the upper side guide surface of the reverse rotation prevention ring. The top view for demonstrating the state which the high position side level | step difference surface of a rotor side engaging protrusion and a reverse rotation prevention ring is engaging. The top view for demonstrating the state which the stator side engagement protrusion and the lower side level | step difference surface of a reverse rotation prevention ring are engaging.

Explanation of symbols

10: Reverse rotation prevention ring, 12: Synchronous motor, 14: Rotor, 16: Coil, 18: Stator, 20: Permanent magnet, 24: Rotor support shaft, 26: Center hole, 38: Rotor side engaging protrusion, 54: Upper magnetic pole plate portion, 58: lower magnetic pole plate portion, 80: stator side engaging projection, 88: upper guide surface, 94: high position step surface, 98 low position step surface, 100: lower guide surface, 106 : Lower step surface

Claims (3)

A rotor having a stator having a coil and a permanent magnet for forming a magnetic pole is provided, and interaction between the magnetic pole developed in the magnetic pole portion formed on the stator and the magnetic pole of the rotor based on energization of the coil A synchronous motor reverse rotation preventing mechanism for preventing reverse rotation of the synchronous motor at the time of starting the synchronous motor for rotationally driving the rotor based on:
A rotor-side engagement protrusion provided on the lower surface of the rotor and protruding downward in the axial direction of the rotor;
A stator-side engagement protrusion provided on a portion of the stator that is opposed to and spaced from the lower surface of the rotor in the axial direction of the rotor, and protrudes toward the lower surface of the rotor;
An anti-reverse ring disposed between the rotor and the stator in an axial direction in a rotatable state around a rotor support shaft inserted through the center hole of the rotor;
Formed on the reverse rotation prevention ring and engaged with the rotor-side engagement protrusion in the forward rotation direction of the rotor, thereby causing the reverse rotation prevention ring to rotate integrally with the rotor in the forward rotation direction of the rotor. A positive engagement surface;
It is formed on the lower surface of the reverse rotation prevention ring and is inclined upward in the axial direction of the rotor in the positive rotation direction of the rotor, and the rotor side engagement protrusion and the positive direction engagement surface are engaged with each other. The reverse rotation prevention ring is brought into contact with the stator side engagement protrusion while rotating in the forward rotation direction of the rotor, and the reverse rotation prevention ring is guided above the stator side engagement protrusion, thereby A lower guide surface for axially moving the anti-reverse ring toward the rotor;
It is formed on the upper surface of the reverse rotation prevention ring and is inclined upward in the axial direction of the rotor in the reverse rotation direction of the rotor. The rotor rotates in the reverse direction and the rotor side engagement protrusion comes into sliding contact. A lower guide surface that axially displaces the reverse rotation prevention ring from the rotor;
The reverse rotation prevention ring is formed on the reverse rotation prevention ring and engages with the rotor-side engagement protrusion in the reverse rotation direction of the rotor, thereby rotating the reverse rotation prevention ring integrally with the rotor in the reverse rotation direction of the rotor. An upper reverse engagement surface;
Formed on the reverse rotation prevention ring, the rotor side engagement protrusion and the upper reverse engagement surface are engaged, and the reverse rotation prevention ring is driven to rotate integrally with the rotor in the reverse rotation direction of the rotor. The synchronous motor is provided with a lower reverse engagement surface that prevents reverse rotation of the reverse rotation prevention ring by engaging with the stator side engagement protrusion in a state in which the synchronous motor is engaged. mechanism.   The reverse rotation prevention mechanism of the synchronous motor according to claim 1, wherein a recess is formed in the lower surface of the rotor, and the rotor-side engagement protrusion is provided on an upper bottom surface of the recess.   The reverse rotation preventing mechanism for a synchronous motor according to claim 1, wherein the stator side engagement protrusion is formed separately from the stator.

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