JP5734751B2 - Rotation maintenance device - Google Patents

Description

  The present invention relates to a rotation maintaining device that can maintain a rotating state for a long period of time by using a magnetic force.

  It is desirable that the moving body constituting the rotating portion in the rotation maintaining device using magnetic force is maintained in a rotating state for a long period without the rotation speed being attenuated. The inventor has conducted research and development on a rotation maintaining device over a long period of time, and discloses a part of the technology (for example, see Patent Document 1).

JP 2010-43578 A

  Since the “movement state maintaining device” described in Patent Document 1 has a complicated shape and arrangement state of the magnets on the side that applies driving force to the moving body, it is necessary to accurately set the arrangement state of each magnet. Production is difficult.

  The problem to be solved by the present invention is to provide a rotation maintaining device that can be easily manufactured using a magnet having a simple shape and exhibits an excellent continuous rotation function.

The rotation maintaining device of the present invention includes a fixed magnet portion arranged along a first virtual circle and a magnetic force-affected region of the fixed magnet portion along a second virtual circle coaxially opposed to the first virtual circle. A movable magnet portion disposed so as to be able to pass through, and rotation support means for rotatably supporting the movable magnet portion along the second virtual circle,
The fixed magnet portion is formed of a flat lower layer magnet and an upper layer magnet laminated from the first virtual circle toward the second virtual circle,
In the region facing the first virtual circle, a part of the surface of the lower layer magnet is arranged so as to protrude outward from the peripheral edge of the upper layer magnet,
The surfaces of the lower layer magnet and the upper layer magnet are arranged so as to form a downward gradient or an upward gradient with respect to the rotation direction of the movable magnet part,
The movable magnet portion is provided with a hemispherical portion protruding toward the first virtual circle,
The polarity of the surface of the lower layer magnet and the upper layer magnet is the same as the polarity of the hemispherical part of the movable magnet part.

  Here, “the polarity of the surface of the lower layer magnet and the upper layer magnet and the polarity of the hemispherical portion of the movable magnet part are the same” means that the surface of the lower layer magnet and the upper layer magnet and the movable magnet The hemispherical part of the part is N poles or S poles.

  In such a configuration, when an initial rotational force along the first imaginary circle is applied to the movable magnet portion, due to the interaction between the magnetic force of the flat lower layer magnet and the upper layer magnet forming the fixed magnet portion, The repulsive force received when the movable magnet part approaches the magnetic force affected area of the fixed magnet part and the thrust direction received when the movable magnet part passes the magnetic force affected area of the fixed magnet part (axial direction of the first virtual circle) The repulsive force is relaxed and the repulsive force when the movable magnet part moves away from the magnetic force affected area of the fixed magnet part is strengthened. A magnetic biasing track is formed. Therefore, the urging force received by the movable magnet part that has entered the magnetic force energizing track from the fixed magnet part effectively acts on the movable magnet part, and imparts a rotational driving force to the movable magnet part, thereby exhibiting an excellent continuous rotation function. To do.

  In addition, since the fixed magnet portion can be formed of a plate-shaped magnet and the movable magnet portion can be formed of a magnet having a hemispherical portion, the rotation maintaining device can be easily used with a simple-shaped magnet. Can be produced.

  Here, it is desirable to arrange a plurality of adjacent plate magnets along the first virtual circle as the lower layer magnet and to arrange an annular plate magnet as the upper layer magnet. With such a configuration, the repulsive magnetic force and the attractive magnetic force acting in the direction of obstructing the passage of the movable magnet part when passing through the magnetic force affected area of the fixed magnet part are alleviated. It is possible to form a magnetic force biasing trajectory acting on the.

  In addition, a part of the flat magnet located on the side where the movable magnet part is separated from the fixed magnet part along the rotation direction is arranged to protrude along the rotation direction of the movable magnet, and the protruding flat plate A sub-lower layer magnet can be arranged on the lower surface of the magnet. With such a configuration, a magnetic force biasing track having a long biasing region and a strong and smooth biasing action is formed in the magnetic force affected region of the fixed magnet unit along the rotational direction of the movable magnet unit. Therefore, the continuous rotation function is improved. Furthermore, the shape of the magnetic force biasing track can be freely set, and the arrangement interval of the fixed magnet portions can be reduced.

  A flat middle layer magnet may be interposed between the lower layer magnet and the upper layer magnet. With such a configuration, the repulsive force in the thrust direction received when the movable magnet portion passes through the magnetic force affected region of the fixed magnet portion can be further alleviated, so that the continuous rotation function is improved.

On the other hand, a tubular magnetic member is disposed in a region facing the second virtual circle on the inner periphery of the annular plate magnet so that its axis is parallel to the axis of the annular plate magnet. You can also. With such a configuration, the urging force received when the movable magnet portion passes through the magnetic force affected region of the fixed magnet portion can be increased, so that the continuous rotation function is improved.

  Moreover, a recessed part can also be provided in the top of the hemispherical part of the said movable magnet part. With such a configuration, the repulsive force received when the movable magnet part approaches the magnetic force affected area of the fixed magnet part can be reduced, so that the movable magnet part smoothly enters the magnetic force affected area of the fixed magnet part. And the continuous rotation function is improved.

  Furthermore, a band-plate-like magnetic member can be attached to a region of the hemispherical portion of the movable magnet portion facing the first virtual circle so that the long side direction is along the first virtual circle. With such a configuration, the repulsive force received when the movable magnet part approaches the magnetic force affected area of the fixed magnet part can be reduced, so that the movable magnet part smoothly enters the magnetic force affected area of the fixed magnet part. This is effective in improving the continuous rotation function.

  Further, the movable magnet portion can be formed by laminating a plurality of disc-shaped magnets and hemispherical magnets. With such a configuration, the manufacturing process can be simplified as compared with the movable magnet unit having an integral structure.

  According to the present invention, it is possible to provide a rotation maintaining device that can be easily manufactured using a magnet having a simple shape and exhibits an excellent continuous rotation function.

It is a front view showing the rotation maintenance device which is the first embodiment of the present invention. FIG. 2 is a partially enlarged view of the rotation maintaining device shown in FIG. 1. FIG. 3 is a partially cutaway view seen from the direction of arrow A in FIG. 2. It is the BB sectional view taken on the line in FIG. It is sectional drawing of the movable magnet part which comprises the rotation maintenance apparatus shown in FIG. It is a figure which shows a part of rotation maintenance apparatus which is 2nd embodiment of this invention. It is a figure which shows a part of rotation maintenance apparatus which is 3rd embodiment of this invention. It is the figure seen from the arrow C direction in FIG. It is a figure which shows a part of rotation maintenance apparatus which is 4th embodiment of this invention. It is the figure seen from the arrow D direction in FIG. It is a figure which shows a part of rotation maintenance apparatus which is 5th embodiment of this invention. It is the figure seen from the arrow E direction of FIG. It is a figure which shows a part of rotation maintenance apparatus which is 6th embodiment of this invention. It is the figure seen from the arrow F direction in FIG.

  Based on FIGS. 1-5, the rotation maintenance apparatus 100 which is 1st embodiment of this invention is demonstrated. As illustrated in FIGS. 1 to 3, the rotation maintaining device 100 is coaxially opposed to the plurality of fixed magnet portions 10 arranged along the first virtual circle M1 and the axis M1c of the first virtual circle M1. A plurality of movable magnet units 20 arranged so as to be able to pass through the magnetic force-affected region of the fixed magnet unit 10 along the second virtual circle M2, and the movable magnet units 20 are rotatably supported along the second virtual circle M2, respectively. An arm 21, a hub 22 and a rotating shaft 23, which are rotating support means.

  The plurality of fixed magnet portions 10 are fixed at equal intervals to a flat plate-like fixing member 30 along a first virtual circle M1 centered on the axis M1c, and the rotary shaft 23 has a bearing 24 that is concentric with the axis M1c. And is rotatably supported by the fixing member 30 via the intermediate member. The plurality of movable magnet portions 20 are arranged at equal intervals along a second virtual circle M2 concentric with the axis M1c, and are fixed to the rotary shaft 23 via the arm 21 and the hub 22, respectively. The axis of the second virtual circle M2 and the axis of the rotary shaft 23 coincide with the axis M1c of the first virtual circle M1.

  As shown in FIGS. 2 to 3, the fixed magnet unit 10 includes a flat lower layer magnet 11 (flat magnets 11 a and 11 b) and an annular ring stacked from the first virtual circle M <b> 1 toward the second virtual circle M <b> 2. A part of the surface 11as, 11bs of the lower layer magnet 11 (flat plate magnets 11a, 11b) is formed outside the peripheral portion 12a of the upper layer magnet 12 in the region along the first virtual circle M1 formed by the plate-shaped upper layer magnet 12. It is arranged to protrude. Further, the surfaces 11as, 11bs of the lower layer magnet 11 (flat magnets 11a, 11b) and the surface 12s of the upper layer magnet 12 are directed to the rotation direction of the movable magnet unit 20 (the arrow R direction along the second virtual circle M2). It is arranged to make a downward slope.

  The movable magnet portion 20 includes a columnar main body portion 20b fixed to the tip of the arm 21, and a hemispherical portion 20a that protrudes from the main body portion 20b toward the first virtual circle M1. The polarities of the surfaces 11as and 11bs of the magnets 11a and 11b and the surface 12s of the upper magnet 12 and the polarity of the hemispherical part 20a of the movable magnet part 20 are the same N poles. As shown in FIG. 2, the flat magnet 11a is circular, and the flat magnet 11b is rectangular. In this embodiment, the polarities of the surfaces 11as and 11bs of the lower layer magnet 11 (flat magnets 11a and 11b) and the surface 12a of the upper layer magnet 12 and the polarity of the hemispherical portion 20a of the movable magnet unit 20 are the same N poles. However, it is only necessary that the polarities are the same, and the present invention is not limited to this, and the same S pole can be used.

  As shown in FIG. 4, the plurality of fixed magnet portions 10 are each attached to the flat portion 30 a of the fixing member 30 via a short cylindrical fixing tool 31. A flange 31f formed at one end of the fixture 31 is fixed to the flat portion 30a of the solid member 30, and a plurality of notches 31a and 31b formed at the other end of the fixture 31 are respectively plate magnets. 11a and 11b are fitted, and the upper layer magnet 12 is stuck on the surfaces 11as and 11bs of the plate-like magnets 11a and 11b that are substantially in the same plane.

  As shown in FIG. 5, the movable magnet portion 20 includes a hemispherical portion 20 a and a main body portion 20 b integrated with the hemispherical portion 20 a, and the base end portion of the main body portion 20 b is accommodated in a disc-shaped connecting member 25. It is fixed to the tip of the arm 21 with a bolt 26 and a nut 27. The bolt 26 is inserted through the shaft center 20c of the movable magnet portion 20 from the hemispherical portion 20a toward the main body portion 20b, and the nut 27 is inserted into the male screw portion 26b protruding from the bottom portion 25a of the connecting member 25 via the washer 28. It is screwed. The hemispherical head portion 26 a at the tip of the bolt 26 protrudes from the tip of the hemispherical portion 20 a of the movable magnet portion 20.

  The movable magnet portion 20 is formed of a main body portion 20b formed by stacking a plurality of annular plate magnets 20bu and a hemispherical magnet 20au stacked on the tip side thereof. Moreover, the movable magnet part 20 is provided with a bent part and a twisted part (not shown) in a part of the arm 21, so that the axis 20c side on the hemispherical part 20a side extends outside the second virtual circle M2. The arm 21 is attached to the tip of the arm 21 in such a posture as to be inclined in the direction of rotation of the movable magnet portion 20 (in the direction of arrow R in FIG. 1).

  In the rotation maintaining device 100 shown in FIG. 1, when an initial rotational force in the direction of arrow R is applied to the stationary movable magnet unit 20, the movable magnet unit 20 starts to rotate around the rotation shaft 23. Thereafter, due to the interaction between the magnetic force of the lower layer magnet 11 (flat magnets 11 a and 11 b) forming the fixed magnet unit 10 and the magnetic force of the upper layer magnet 12, the movable magnet unit 20 enters the magnetic force affected region of the fixed magnet unit 10. The repulsive force that is received when approaching and the repulsive force that is received when the movable magnet portion 20 passes through the magnetic force-affected region of the fixed magnet portion 10 (the axial center direction of the first virtual circle M1) are alleviated and movable. The repulsive force when the magnet part 20 leaves | separates from the magnetic force influence area | region of the fixed magnet part 10 is strengthened.

  As a result, a magnetic force biasing track along the passing track of the movable magnet unit 20 is formed in the magnetic force affected region of the fixed magnet unit 10, and the movable magnet unit 20 that has entered the magnetic force biasing track is removed from the fixed magnet unit 10. The biasing force received effectively acts on the movable magnet unit 20, and a rotational driving force in the direction of arrow R (see FIG. 1) is applied to the movable magnet unit 20. Such rotational driving force sequentially acts on the movable magnet unit 10 from the plurality of fixed magnet units 10 and rotationally drives the rotary shaft 23 via the arm 21 and the hub 22 connected to each movable magnet unit 20. The shaft 23 can maintain the rotation in the constant direction R over a long period of time.

  The fixed magnet portion 10 can be formed of a flat lower magnet 11 (flat magnets 11a and 11b) and an upper magnet 12. The movable magnet 20 includes a hemispherical magnet 20au having a hemispherical portion 20a and a plurality of circles. Since it can be formed with the ring-plate magnet 20bu, the rotation maintaining device 100 can be easily manufactured using a magnet having a simple shape.

  Furthermore, the lower layer magnet 11 and the upper layer magnet 12 are configured as described above, so that when the movable magnet unit 20 passes through the magnetic force-affected region of the fixed magnet unit 10, the repulsive magnetic force and attraction acting in the direction that impedes the passage. Since the magnetic force is relaxed, a magnetic force biasing track that effectively acts on the movable magnet unit 20 can be formed.

  In the rotation maintaining device 100, the eight fixed magnet units 10 and the three movable magnet units are arranged, but the numbers of the fixed magnet units and the movable magnet units are not limited. However, the number of fixed magnet parts is larger than the number of movable magnet parts in order to prevent the rotational movement of the movable magnet parts from stopping when the plurality of fixed magnet parts and the movable magnet parts are attracted to each other. In addition, it is desirable to set so that the value obtained by dividing the number of fixed magnet parts by the number of movable magnet parts does not become an integer.

  Next, a second embodiment to a sixth embodiment of the present invention will be described based on FIGS. 6 to 14, the parts denoted by the same reference numerals as those in FIGS. 1 to 5 are the parts having the same structure and function as the parts constituting the rotation maintaining device 100, and the description thereof is omitted.

  In the rotation maintaining device 200 of the second embodiment shown in FIG. 6, the movable magnet portion 20x has a main body portion 20bx formed by laminating a plurality of annular plate magnets 20cu having a tapered cross-sectional shape, and a tip thereof. And a hemispherical magnet 20au attached to the side. A plurality of annular plate magnets 20cu and hemispherical magnets 20au are fixed to the tip of the arm 21 via bolts 26x bent in a "<" shape.

  In the movable magnet portion 20x, the main body portion 20bx is bent in a “<” shape, and the hemispherical portion 20a is inclined so as to face the arrow R direction. Therefore, the movable magnet portion 20x rotating in the arrow R direction is It is possible to reduce the attractive force received from the fixed magnet unit 10 when moving away from the magnetic force affected area of the fixed magnet unit 10, which is effective in improving the continuous rotation function.

  Next, as shown in FIGS. 7 and 8, in the rotation maintaining device 300 of the third embodiment, the fixed magnet unit 40 is a flat plate layered from the first virtual circle M1 toward the second virtual circle M2. The lower layer magnet 41 (disk-shaped magnets 41a, 41b) and the arc-shaped plate-shaped upper layer magnet 42, and in the region along the first virtual circle M1, the surface of the lower layer magnet 41 (disk-shaped magnets 41a, 41b) The portions 41 as and 41 bs are arranged so as to be located outside the peripheral edge portion 42 a of the upper layer magnet 42.

  In addition, the surfaces 41as and 41bs of the lower layer magnet 41 (disk-shaped magnets 41a and 41b) and the surface 42s of the upper layer magnet 42 move along the second virtual circle M2 in the direction of the arrow R with respect to the movable magnet unit 20. It is arranged so as to form an upward slope. The disk-shaped magnets 41a and 41b are attached to the fixing member 30 via short cylindrical fixing members 33a and 33b sharing the flange portion 33f.

  Next, the rotation maintaining device 400 according to the fourth embodiment shown in FIGS. 9 and 10 is configured so that the fixed magnet unit 50 arranged along the first virtual circle M1 is coaxially opposed to the first virtual circle M1. A movable magnet portion 20y disposed so as to be able to pass through the magnetic force-affected region of the fixed magnet portion 50 along the two virtual circles M2, and a rotation support means for rotatably supporting the movable magnet portion 20y along the second virtual circle M2. And the like.

  The fixed magnet portion 50 is formed by a flat plate-like lower layer magnet 51 (disk-shaped magnets 51a and 51b) and an annular plate-shaped upper layer magnet 52 that are stacked from the first virtual circle M1 toward the second virtual circle M2. A disk-shaped middle layer magnet 53 is interposed between the lower layer magnet 51 and the upper layer magnet 52. In a region facing the first virtual circle M1, a part of the surfaces 51as, 51bs of the lower layer magnet 51 (disk-shaped magnets 51a, 51b) is disposed so as to protrude outward from the peripheral portion 53a of the middle layer magnet 53, and the middle layer The peripheral portion 53 a of the magnet 53 is disposed so as to protrude outward from the peripheral portion 52 a of the upper layer magnet 52.

  The surfaces 51as and 51bs of the lower layer magnet 51 (disk-shaped magnets 51a and 51b), the surface 53s of the middle layer magnet 53, and the surface 52s of the upper layer magnet 52 are raised with respect to the rotation direction (arrow R direction) of the movable magnet portion 20y. It is arranged to make a gradient. In addition, in a region facing the second virtual circle M <b> 2 on the inner circumference of the annular plate-shaped upper layer magnet 52, the annular magnetic member 54 has an axis 54 c parallel to the axis 52 c of the annular upper layer magnet 52. It is arranged to make. The magnetic member 54 is formed of a material having a property of attaching to a magnet such as iron or nickel.

  A hemispherical portion 60a protruding toward the first virtual circle M1 is provided on the tip side of the movable magnet portion 20y, and the surfaces 51as and 51bs of the lower layer magnet 51 (disk-shaped magnets 51a and 51b) and the surfaces of the middle layer magnet 53 are provided. The polarity of 53s and the surface 52s of the upper layer magnet 52 and the polarity of the hemispherical part 60a of the movable magnet part 20y are the same N pole. A hole 60b that is recessed toward the center of the hemispherical surface is provided at the top of the hemispherical part 60a, and the head part 26ya of the bolt 26y that fixes the movable magnet part 20y to the arm 21 is buried in the hole 60b. It is tightened with.

  By interposing the disc-shaped middle layer magnet 53 between the lower layer magnet 51 and the upper layer magnet 52, the repulsive force in the thrust direction received when the movable magnet unit 20y passes the magnetic force affected region of the fixed magnet unit 50 is obtained. Since it can be relaxed, the continuous rotation function is improved.

  Further, by arranging the annular magnetic member 54 in the inner peripheral area of the annular upper layer magnet 52, the biasing force received when the movable magnet part 20y passes through the magnetic force affected area of the fixed magnet part 50 is increased. Therefore, the continuous rotation function is improved.

  Further, by providing a concave portion (hole 60b) on the top of the hemispherical portion 60a of the movable magnet portion 20y, the repulsive force received when the movable magnet portion 20y approaches the magnetic force affected area of the fixed magnet portion 50 can be reduced. Therefore, the movable magnet unit 20y can smoothly enter the magnetic force affected region of the fixed magnet unit 50, and the continuous rotation function is improved.

  Next, a fifth embodiment of the present invention will be described based on FIGS. 11 and 12, the parts denoted by the same reference numerals as those in FIGS. 9 and 10 are parts having the same structure and function as the parts constituting the rotation maintaining device 400, and the description thereof is omitted.

  In the rotation maintaining device 500 shown in FIGS. 11 and 12, the strip-shaped magnetic member 71 is disposed in the long side direction in the region facing the first virtual circle M1 in the hemispherical portion 70a on the distal end side of the movable magnet portion 20z. 71L is attached along the first virtual circle M1. The magnetic member 71 has a strip-like long side direction 71L curved along the spherical surface of the hemispherical portion 70a, and one short side portion 71a of the head portion of the bolt 26z exposed on the top of the hemispherical portion 70a. It is attached to the movable magnet portion 20z by being fixed to 26za. The magnetic member 71 can be formed of a material having a property of attaching to a magnet, such as iron or nickel.

  Since the magnetic member 71 is attached to the hemispherical portion 70a of the movable magnet portion 20z, the repulsive force received when the movable magnet portion 20z approaches the magnetic force affected area of the fixed magnet portion 50 can be reduced. The movable magnet portion 20z can smoothly enter the 50 magnetic force affected region, which is effective in improving the continuous rotation function.

  Although the material of each member constituting the rotation maintaining device 100, 200, 300, 400, 500 is not limited, the fixing member 30 and the arm 21 are formed of a nonmagnetic material (material that does not reach the magnet), the connecting member 25, the bolt The 26, 26x, 26y, 26z and the nut 27 are preferably formed of a magnetic material (material that attaches to the magnet). In addition, since the present invention is not limited to the rotation maintaining devices 100, 200, 300, 400, 500, for example, the fixed magnet portions 10, 40, 50 are movable magnets with the movable magnet portions 20, 20x, 60, 70 fixed. It can also be set as the structure rotated relatively with respect to the part 20,20x, 60,70.

  Next, based on FIG. 13, FIG. 14, 6th embodiment of this invention is described. 13 and 14, the parts denoted by the same reference numerals as those in FIGS. 9 and 10 are the parts having the same structure and function as the parts constituting the rotation maintaining device 400, and the description thereof is omitted. . Further, in the rotation maintaining device 600 shown in FIGS. 13 and 14, the above-described movable magnet unit 20 (or the movable magnet units 20x, 20y, and 20z) can be used, but this is not shown.

  In the rotation maintaining device 600 shown in FIGS. 13 and 14, the fixed magnet portion 60 is a flat lower layer magnet 61 (flat magnets 61a and 61b) laminated from the first virtual circle M1 toward the second virtual circle M2. ) And an annular plate-shaped upper layer magnet 62, and in a region along the first virtual circle M <b> 1, a part of the surfaces 61 as and 61 bs of the lower layer magnet 61 (flat plate magnets 61 a and 61 b) is the periphery of the upper layer magnet 62. It arrange | positions so that it may protrude outside the part 62a. Further, the surfaces 61as and 61bs of the lower layer magnet 61 (flat magnets 61a and 61b) and the surface 62s of the upper layer magnet 62 are in the direction of rotation of the movable magnet portion (not shown) (arrow R along the second virtual circle M2). (Direction) is arranged so as to form an upward slope. As shown in FIG. 13, the flat magnet 61a has a substantially disc shape, and the flat magnet 61b has an arc plate shape.

  As shown in FIGS. 13 and 14, a part of the plate-like magnet 61 b located on the side where the movable magnet portion (not shown) is separated from the fixed magnet portion along the rotation direction (arrow R direction) is movable magnet. The sub-lower layer magnet 65 having a substantially disc shape is disposed on the lower surface of the projected flat magnet 61b. In addition, a part of the surface 65s of the sub-lower magnet 65 protrudes from the peripheral edge 61c of the flat magnet 61b.

  By arranging the sub-lower layer magnet 65, the urging area is long and the urging action is strong in the magnetic force affected area of the fixed magnet part 60 along the rotation direction (arrow R direction) of the movable magnet part. A smooth magnetic force energizing track is formed, and it exhibits an excellent continuous rotation function. Furthermore, the shape of the magnetic force energizing track can be freely set, and when a plurality of fixed magnet portions 60 are arranged, the arrangement interval can be reduced.

  The rotation maintaining device of the present invention can be widely used in industrial fields such as mechanical devices that need to maintain a rotating state for a long period of time.

100, 200, 300, 400, 500, 600 Rotation maintaining device 10, 40, 50, 60 Fixed magnet part 11, 41, 51, 61 Lower magnet 11a, 11b Plate magnet 11as, 11bs, 41as, 41bs, 51as, 51bs , 61as, 61bs, 65s Surface 12, 42, 52, 62 Upper layer magnet 12a, 42a, 52a, 61c, 62a Peripheral part 12s, 42s, 52s, 62s Surface 20, 20x, 20y, 20z Movable magnet part 20a Hemisphere part 20b Main body Part 20c, 52c, 54c Axis center 20au Hemispherical magnet 20bu Disk-like magnet 21 Arm 22 Hub 23 Rotating shaft 24 Bearing 25 Connecting member 26, 26x, 26y, 26z Bolt 27 Nut 28 Washer 30 Fixing member 30a Flat part 31, 33a 33b Fixing tool 31a, 31 Notch 31f, 33f flange portion 41a, 41b discoid magnet 54, 71 magnetic members 71a short side portion 71L long side direction M1 first imaginary circle M2 second virtual circle M1c axial R rotational direction

Claims (8)

A fixed magnet portion arranged along the first virtual circle and a movable magnet arranged so as to be able to pass through the magnetic force-affected region of the fixed magnet portion along the second virtual circle coaxially opposed to the first virtual circle. A magnet part; and a rotation support means for rotatably supporting the movable magnet part along the second virtual circle,
The fixed magnet portion is formed of a flat lower layer magnet and an upper layer magnet laminated from the first virtual circle toward the second virtual circle,
In the region facing the first virtual circle, a part of the surface of the lower layer magnet is arranged so as to protrude outward from the peripheral edge of the upper layer magnet,
The surfaces of the lower layer magnet and the upper layer magnet are arranged so as to form a downward gradient or an upward gradient with respect to the rotation direction of the movable magnet part,
The movable magnet portion is provided with a hemispherical portion protruding toward the first virtual circle,
The rotation maintaining device, wherein the polarity of the surface of the lower layer magnet and the upper layer magnet is the same as the polarity of the hemispherical part of the movable magnet part.   The rotation maintaining device according to claim 1, wherein a plurality of adjacent plate magnets are arranged along the first virtual circle as the lower layer magnet, and an annular plate magnet is arranged as the upper layer magnet.   A portion of the flat magnet positioned on the side where the movable magnet portion is separated from the fixed magnet portion along the rotation direction thereof is arranged to protrude along the rotation direction of the movable magnet, and the protruding flat magnet The rotation maintaining device according to claim 2, wherein a sub-lower layer magnet is arranged on the lower surface of the rotation.   The rotation maintaining device according to claim 2 or 3, wherein a flat middle layer magnet is interposed between the lower layer magnet and the upper layer magnet. The tubular magnetic member is arranged in a region facing the second virtual circle on the inner circumference of the annular plate magnet so that its axis is parallel to the axis of the annular plate magnet. The rotation maintenance apparatus in any one of -4.   The rotation maintaining device according to claim 1, wherein a concave portion is provided on the top of the hemispherical portion of the movable magnet portion.   The band plate-like magnetic member is attached to a region facing the first virtual circle in the hemispherical portion of the movable magnet portion so that the long side direction is along the first virtual circle. A rotation maintaining device according to claim 1.   The rotation maintaining device according to any one of claims 1 to 7, wherein the movable magnet portion is formed by laminating a plurality of disk-shaped magnets and hemispherical magnets.

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