JP2010063201A - Linear motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a low-price linear motor which keeps high generated field by approximating field generated from a field magnetic pole to sine waves. <P>SOLUTION: Main magnetic pole permanent magnets 12 are arrayed so that their magnetization directions A orthogonal to the main face of a back yoke 11 are alternately directed opposite each other. Sub-magnetic pole permanent magnets 13 are arrayed so that their magnetization directions A aligned with a moving direction of a mover 5 are alternately directed opposite each other to constitute a Halbach array field magnetic pole 14. Magnet pressing members 15 made of a soft magnetic material are arranged on a side where a magnetic field of the sub magnetic pole permanent magnets 12 are generated, and spacers 16 made of a nonmagnetic material are inserted between the sub magnetic pole permanent magnets 13 and the back yoke 11. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a linear motor used for table feed of industrial machines such as machine tools and semiconductor manufacturing apparatuses.

  Conventionally, in the field of industrial machines such as machine tools and semiconductor manufacturing apparatuses, linear motors have been used in order to realize high-speed and high-precision feed processing. Linear motors are direct drive, and can achieve high speed and high acceleration characteristics compared to the drive system combining a conventional rotary servo motor and ball screw, and no response error due to backlash or friction. A highly accurate system can be constructed. However, there is a problem that heat and vibration of the linear motor are easily transmitted to the machine, and there is a demand for reduction in loss and reduction in cogging thrust.

  In order to reduce the loss of the linear motor, it is necessary to increase the generated magnetic field. In order to reduce the cogging thrust of the linear motor, it is necessary to make the generated magnetic field close to a sine wave. Therefore, a conventional linear motor has been proposed in which permanent magnets are arranged in a Halbach array to form a stator, the generated magnetic field is increased, and the generated magnetic field is made close to a sine wave (see, for example, Patent Document 1).

  In the conventional linear motor described in Patent Document 1, a Halbach comprising a main magnetic pole permanent magnet magnetized in the direction of the generated magnetic field and a sub magnetic pole permanent magnet magnetized differently from the direction of the magnetic pole of the main magnetic pole permanent magnet. Since the field poles of the arrangement structure are provided, the magnetic flux is concentrated at the tip of the main pole permanent magnet at the magnetic field generation side and magnetic saturation occurs, and the height of the generated magnetic field is limited.

  In view of such a situation, a part of the magnetic field generation side of the main magnetic pole permanent magnet can be replaced with a soft magnetic material, the magnetic saturation at the magnetic field generation side tip of the main magnetic pole permanent magnet can be reduced, and the generated magnetic field can be further increased (See, for example, Patent Document 2).

JP 2003-70226 A JP 2007-6545 A

  In the conventional linear motor described in Patent Document 2, the sub-pole permanent magnet is manufactured to have the same shape as the main pole permanent magnet including the soft magnetic material. However, since the magnetic flux generated by the secondary magnetic pole permanent magnet has little influence on the magnetic field generated by the field magnetic pole, the amount of the expensive secondary magnetic pole permanent magnet is excessively large, and the price cannot be reduced. There was a problem.

  The present invention has been made to solve the above-described problem, and it is possible to obtain a linear motor capable of realizing a reduction in price while maintaining a high generated magnetic field by bringing a magnetic field generated from a field pole closer to a sine wave. Objective.

In the linear motor according to the present invention, the main magnetic pole permanent magnet magnetized in the direction of the generated magnetic field and the sub magnetic pole permanent magnet magnetized differently from the direction of the magnetic pole of the main magnetic pole permanent magnet are alternately arranged on the main surface of the back yoke. And a stator having a coil, and a mover arranged to be movable with a predetermined gap with respect to the stator, and energizing the coil Thus, the mover is moved on the stator in the arrangement direction of the main magnetic pole permanent magnet and the sub magnetic pole permanent magnet. The main magnetic pole permanent magnets are arranged so that the magnetization directions orthogonal to the main surface of the back yoke are alternately reversed, and the sub magnetic pole permanent magnet is the moving direction of the mover. Magnetization saturation relaxation members made of soft magnetic material are arranged on the magnetic field generating side of the main magnetic pole permanent magnet, and spacers or air layers made of nonmagnetic material are arranged on the side of the secondary magnetic pole. It is interposed between the magnetic pole permanent magnet and the back yoke.

  According to the present invention, since the spacer or air layer of the nonmagnetic material is interposed between the sub-pole permanent magnet and the back yoke, the magnet amount of the sub-pole permanent magnet is reduced by the amount of the spacer or air layer. The price is reduced. In addition, since the magnetic flux generated by the secondary magnetic pole permanent magnet has little influence on the magnetic field generated by the field magnetic pole, the reduction in the height of the generated magnetic field due to the reduction in the magnet quantity of the secondary magnetic pole permanent magnet can be suppressed, and the high magnetic field generated Is maintained.

Embodiment 1 FIG.
1 is a transverse sectional view schematically showing a linear motor according to Embodiment 1 of the present invention, and FIG. 2 is a longitudinal sectional view for explaining the configuration of the main part of the linear motor according to Embodiment 1 of the present invention. 3 is a diagram showing the relationship between the spacer height and the generated magnetic field in the linear motor according to Embodiment 1 of the present invention. The transverse sectional view is a sectional view in a plane orthogonal to the magnet arrangement direction, and the longitudinal sectional view is a sectional view in a plane perpendicular to the main surface of the back yoke and parallel to the magnet arrangement direction.

  1 and 2, the linear motor 1 is supported on the gantry 2 so as to be movable with a predetermined gap between the stator 10 disposed on the gantry 2 and generating a periodic magnetic field. And a movable element 5 that moves by generating an attractive force and a repulsive force with the periodic magnetic field generated from the stator 10. In FIG. 2, an arrow A indicates the magnetization direction of the permanent magnet.

  The stator 10 is magnetized so that the back yoke 11 made into a rectangular flat plate shape using a magnetic material, the main magnetic pole permanent magnet 12 magnetized in the direction of the generated magnetic field, and the magnetic pole direction of the main magnetic pole permanent magnet 12 are different. And a field pole 14 configured by arranging the auxiliary magnetic pole permanent magnet 13 and the main surface 11a of the back yoke 11 on a Halbach array. Here, as the main magnetic pole permanent magnet 12, for example, an Nd—Fe—B based sintered magnet manufactured in a rectangular parallelepiped and magnetized in the thickness direction is used. Further, as the auxiliary magnetic pole permanent magnet 13, for example, an Nd—Fe—B based sintered magnet that is manufactured in a rectangular parallelepiped and magnetized in the width direction is used. The main magnetic pole permanent magnets 12 and the sub magnetic pole permanent magnets 13 are alternately arranged in the width direction without gaps, and are linearly arranged on the main surface 11 a of the back yoke 11. A plurality of the main magnetic pole permanent magnets 12 are arranged so that the magnetization direction A is orthogonal to the main surface 11a of the back yoke 11 and are alternately reversed. Further, the sub magnetic pole permanent magnet 13 is aligned in parallel with the main surface 11a of the back yoke 11 with the magnetization direction A aligned with the arrangement direction of the main magnetic pole permanent magnet 12 and the sub magnetic pole permanent magnet 13 (magnet arrangement direction). A plurality are arranged so as to be alternately reversed.

  The magnet pressing member 15 as the magnetic saturation relaxation member is made in a U shape that covers the surface and both end surfaces of the main magnetic pole permanent magnet 12 using, for example, an Fe—Co—V soft magnetic material. Yes. Then, the magnet pressing member 15 is disposed so as to be adhered to the surface of the main magnetic pole permanent magnet 12 and to cover the surface of the main magnetic pole permanent magnet 12 if necessary, and both ends thereof are connected to the back yoke. 11 is fastened and fixed by screws (not shown). Thereby, each of the main magnetic pole permanent magnets 12 is firmly held by the back yoke 11 by the fastening force of the screws. A spacer 16 made of a nonmagnetic material is interposed between each of the sub magnetic pole permanent magnets 13 and the back yoke 11. The sub magnetic pole permanent magnet 13 is held on the back yoke 11 via a spacer 16 by an adhesive or the like. Here, the magnet pressing member 15 and the sub magnetic pole permanent magnet 13 are flush with each other.

The stage 3 is attached to the gantry 2 with its both ends engaged with a pair of guide rails 4 extending in the magnet arrangement direction on the gantry 2 with the stator 10 interposed therebetween. As a result, the stage 3 is guided by the guide rails 4 and can move in the magnet arrangement direction.
The mover 5 includes an armature core 6 in which a plurality of teeth 6b are erected from one surface of a rectangular flat core back 6a at predetermined intervals, and a coil 7 wound around the teeth 6b. The mover 5 is attached to the surface of the stage 3 on the stator 10 side with the teeth 6b facing outward. Thereby, the needle | mover 5 is movable to the arrangement direction of a magnet, ensuring the clearance gap between the teeth 6b and the stator 10 uniformly.

Next, the operation of the linear motor 1 configured as described above will be described.
A main magnetic pole permanent magnet 12 and a sub magnetic pole permanent magnet 13 are arranged on the main surface 11 a of the back yoke 11 by a Halbach array to form a field magnetic pole 14. The main magnetic pole permanent magnets 12 are arranged so that the magnetization direction A is perpendicular to the main surface 11a of the back yoke 11 and alternately opposite to each other, and the sub magnetic pole permanent magnets 13 are arranged so that the magnetization direction A is the magnet arrangement. They are arranged so as to coincide with the direction, in parallel with the main surface 11a of the back yoke 11, and alternately in opposite directions. Therefore, the magnetic field of the main magnetic pole permanent magnet 12 and the magnetic field of the sub magnetic pole permanent magnet 13 are superposed, and the distribution of magnetic flux density (periodic magnetic field) formed above the field magnetic pole 14 becomes a substantially sine wave.
Therefore, the mover 5 is guided by the guide rail 4 and moves in the magnet arrangement direction by the attractive force and repulsive force between the magnetic field generated by energizing the coil 7 and the periodic magnetic field.

In this linear motor 1, since the periodic magnetic field formed on the magnetic field generation side of the field pole 14 becomes a substantially sine wave, the counter electromotive force induced in the coil 7 also becomes a substantially sine wave, which is higher than the fundamental wave (sine wave). Wave component can be reduced and cogging thrust is reduced. Furthermore, the generated magnetic field is increased and the loss can be reduced.
Further, since the magnet pressing member 15 made of a soft magnetic material is disposed on the magnetic field generation side of the main magnetic pole permanent magnet 12, magnetic saturation on the magnetic field generation side of the main magnetic pole permanent magnet 12 is alleviated, and the generated magnetic field is further reduced. The loss can be increased and the loss can be further reduced.

In addition, since the member made of the soft magnetic material for magnetic saturation of the main magnetic pole permanent magnet 12 is used as the magnet pressing member 15, the number of parts for attaching the main magnetic pole permanent magnet 12 is reduced. Since the magnet pressing member 15 is fastened and fixed to the back yoke 11 using screws, the main magnetic pole permanent magnet 12 can be firmly fixed to the back yoke 11.
Further, since the spacer 16 made of a non-magnetic material is interposed between the sub magnetic pole permanent magnet 13 and the back yoke 11, the amount of the sub magnetic pole permanent magnet 13 can be reduced as much as the spacer 16 is interposed. . That is, the amount of expensive magnet material used can be reduced, and the price can be reduced.

  Next, in the linear motor 1, the result of magnetic field analysis by changing the height of the spacer 16 is shown in FIG. In FIG. 3, the horizontal axis represents the ratio of the height of the spacer 16 to the height of the main pole permanent magnet 12, and the vertical axis represents the generated magnetic field at each spacer height with respect to the generated magnetic field when the spacer height is 0%. It is a ratio. The spacer height of 0% is a case where the spacer 16 is not interposed and the auxiliary magnetic pole permanent magnet 13 exists in the entire region between the main magnetic pole permanent magnets 12 including the magnet pressing member 15. 100% is the case where the spacer 16 having the same height as the main magnetic pole permanent magnet 12 is interposed between the sub magnetic pole permanent magnet 13 and the back yoke 11.

  From FIG. 3, it can be seen that as the spacer height increases, the rate of decrease in the generated magnetic field increases. As a result, the magnetic field generated when the spacer height was 100% was reduced by 12% with respect to the magnetic field generated when the spacer height was 0%. In other words, it can be seen that the contribution of the magnetic flux generated from the sub-pole permanent magnet 13 to increasing the generated magnetic field is small. Further, the magnetic field generated when the spacer height was 30% was reduced by only 1% with respect to the magnetic field generated when the spacer height was 0%. For this reason, priority is given to the effect of reducing the amount of magnets used, and the height of the spacer 16 may be made equal to the height of the main magnetic pole permanent magnet 12, but the spacer height is made larger than 0% and 30% or less. It is preferable to reduce the amount of magnets used to reduce the price while ensuring a large magnetic field height.

  In the first embodiment, the magnet pressing member is fastened and fixed to the back yoke. However, the means for fixing the magnet pressing member to the back yoke is not limited to this. The pressing member may be fixed to the back yoke by riveting or welding.

Embodiment 2. FIG.
FIG. 4 is a perspective view for explaining the configuration of a stator applied to a linear motor according to Embodiment 2 of the present invention, and FIG. 5 shows the configuration of the stator applied to the linear motor according to Embodiment 2 of the present invention. It is a longitudinal cross-sectional view explaining these.

  4 and 5, the magnet pressing member 17 as the magnetic saturation relaxation member is formed in a rectangular flat plate shape using, for example, a Fe—Co—V soft magnetic material. And the flange part 17a extended to the outward of the length direction of a short side from the upper edge of both long sides of the magnet pressing member 17 is formed over the whole region of the length direction of a long side. Further, screw insertion holes 18 are formed in the thickness direction at both ends of the magnet pressing member 17. The end spacer 19 is made of a non-magnetic material in a rectangular flat plate shape having a thickness equivalent to that of the main magnetic pole permanent magnet 12, and a screw insertion hole (not shown) is formed in the thickness direction. .

The magnet holding member 17 is overlapped so as to cover the surface of the main magnetic pole permanent magnet 12 on the magnetic field generation side, and the end spacer 19 extends to the outside in the long side length direction of the main magnetic pole permanent magnet 12. The screw 20 is interposed between the back yoke 11 and attached to the back yoke 11 by inserting the screw 20 through the screw insertion hole 18 of the magnet pressing member 17 and the screw insertion hole of the end spacer 19. Thereby, the main magnetic pole permanent magnet 12 is firmly fixed to the back yoke 11. Each flange portion 17 a of the magnet pressing member 17 abuts on the long side edge of the upper surface of the sub magnetic pole permanent magnet 13, and the sub magnetic pole permanent magnet 13 and the spacer 16 are firmly fixed to the back yoke 11 by the fastening force of the screw 20. The
Other configurations are the same as those in the first embodiment.

  Also in the stator 10A configured as described above, the main magnetic pole permanent magnet 12 and the auxiliary magnetic pole permanent magnet 13 are arranged on the main surface 11a of the back yoke 11 by the Halbach array, so that the field magnetic pole 14 is configured. Similar to the stator 10 in the first embodiment, the distribution (periodic magnetic field) of the magnetic flux density formed above the field pole 14 becomes a substantially sine wave. A spacer 16 is interposed between the sub magnetic pole permanent magnet 13 and the back yoke 11. Therefore, also in the second embodiment, the same effect as in the first embodiment can be obtained.

  According to the second embodiment, the main magnetic pole permanent magnet 12, the sub magnetic pole permanent magnet 13, and the spacer 16 can be fixed together to the back yoke 11 by the magnet pressing member 17, so that the assembly of the stator 10A is improved. The

  In the second embodiment, the magnet pressing member is fastened and fixed to the back yoke using a screw. However, the means for fixing the magnet pressing member to the back yoke is not limited to this. For example, the magnet pressing member may be fixed to the back yoke by riveting or welding.

Embodiment 3 FIG.
6 is a longitudinal sectional view for explaining the structure of a stator applied to a linear motor according to Embodiment 3 of the present invention.

  In FIG. 6, the divided main magnetic pole permanent magnet 12 </ b> A is manufactured in a shape obtained by dividing the main magnetic pole permanent magnet 12 into two in the length direction of the short side. The divided magnet pressing member 17A is formed in a shape obtained by dividing the magnet pressing member 17 into two in the length direction of the short side. The two divided main magnetic pole permanent magnets 12A are arranged two by two with the magnetization direction A aligned between the adjacent sub magnetic pole permanent magnets 13, and one is arranged at each end in the magnet arrangement direction. Thereby, the divided main magnetic pole permanent magnets 12A disposed between the sub magnetic pole permanent magnets 13 are arranged so that the magnetization directions A are alternately reversed.

  The magnet pressing member 17 is overlaid so as to cover the surface of the two adjacent divided main magnetic pole permanent magnets 12A on the magnetic field generation side, and an end spacer (not shown) is attached to the end of the magnet pressing member 17 and the back yoke 11. And a screw (not shown) is fastened to the back yoke 11 and attached. Further, the divided magnet pressing members 17A are overlapped so as to cover the magnetic field generation side surfaces of the divided main magnetic pole permanent magnets 12A at both ends in the magnet arrangement direction, and end spacers (not shown) of the divided magnet pressing members 17A. It is interposed between the end portion and the back yoke 11, and is attached by fastening a screw (not shown) to the back yoke 11. The magnet pressing member 17 and the divided magnet pressing member 17A are formed with movement restricting projections 17b that restrict the movement of the divided main magnetic pole permanent magnet 12A in the arrangement direction of the magnets.

Thereby, the divided main magnetic pole permanent magnet 12A is firmly fixed to the back yoke 11 by the fastening force of the screw. The flange portions 17a of the magnet pressing member 17 and the split magnet pressing member 17A are in contact with the long side edge portion of the upper surface of the sub magnetic pole permanent magnet 13, and the sub magnetic pole permanent magnet 13 and the spacer 16 are tightened by the screw tightening force. It is firmly fixed to.
Other configurations are the same as those in the second embodiment.

  Also in the stator 10B configured in this manner, the split main magnetic pole permanent magnet 12A and the sub magnetic pole permanent magnet 13 are arranged on the main surface 11a of the back yoke 11 by the Halbach array, so that the field magnetic pole 14 is configured. Similar to the stator 10A in the second embodiment, the distribution of magnetic flux density (periodic magnetic field) formed above the field pole 14 is a substantially sine wave. A spacer 16 is interposed between the sub magnetic pole permanent magnet 13 and the back yoke 11. Further, the divided main magnetic pole permanent magnet 12A, the sub magnetic pole permanent magnet 13, and the spacer 16 can be collectively fixed to the back yoke 11 by the magnet pressing member 17 and the divided magnet pressing member 17A. Therefore, also in the third embodiment, the same effect as in the second embodiment can be obtained.

  According to the third embodiment, the divided main magnetic pole permanent magnets 12A produced in a shape obtained by dividing the main magnetic pole permanent magnet 12 into two in the length direction of the short side are arranged at both ends in the magnet arrangement direction to form four poles. Since it is comprised, the stator of desired stroke length is easily realizable by adjusting the number of the stators 10B arranged in the arrangement direction of a magnet. Therefore, stators with different stroke lengths can be produced simply by preparing a plurality of types of stators with different numbers of poles. Further, it is not necessary to produce a stator every time the stroke length is different, and the cost can be reduced. Furthermore, the length of the back yoke 11 can be shortened, and the price can be reduced.

  In the third embodiment, the stator is configured to have four poles. However, the number of poles of the stator is not limited to four, and the divided main magnetic pole permanent magnets are arranged in the magnet arrangement direction. What is necessary is just to be arrange | positioned at both ends.

Embodiment 4 FIG.
FIG. 7 is a longitudinal sectional view for explaining the structure of a stator applied to a linear motor according to Embodiment 4 of the present invention.

  In FIG. 7, the divided sub magnetic pole permanent magnet 13 </ b> A is manufactured in a shape obtained by dividing the sub magnetic pole permanent magnet 13 into two in the length direction of the short side. The spacer 21 is made of a nonmagnetic material in a reverse T-shaped cross section composed of a bottom 21a and a partition wall 21b erected from the center of the bottom 21a, and the length direction of the short side from both sides of the upper end of the partition wall 21b. A flange portion 21c extending outward is formed across the entire length direction. Further, the divided spacer 21A is formed in a shape in which the spacer 21 is divided into two in the length direction of the short side. The divided sub magnetic pole permanent magnets 13A are arranged in two pieces with the bottom surface and the side surfaces in close contact with the bottom 21a and the partition wall 21b of the spacer 21, with the magnetization direction A aligned between the adjacent main magnetic pole permanent magnets 12, respectively. One bottom surface and one side surface are in close contact with the bottom 21a and the partition wall 21b of the divided spacer 21A, and one is disposed at each end in the magnet arrangement direction. Thereby, the divided sub magnetic pole permanent magnets 13 </ b> A arranged between the main magnetic pole permanent magnets 12 are arranged so that the magnetization directions A are alternately reversed.

  The magnet pressing member 17 is overlaid so as to cover the surface of the main magnetic pole permanent magnet 12 on the magnetic field generation side, and an end spacer (not shown) is interposed between the end of the magnet pressing member 17 and the back yoke 11. The screw (not shown) is fastened to the back yoke 11 and attached.

Thereby, the main magnetic pole permanent magnet 12 is firmly fixed to the back yoke 11 by the fastening force of the screw. Further, the flanges 17a and 21c of the magnet pressing member 17, the spacer 21, and the divided spacer 21A are in contact with the long side edge portion of the upper surface of the divided sub magnetic pole permanent magnet 13A, and the divided sub magnetic pole permanent magnet 13A, the spacer 21, The split spacer 21A is firmly fixed to the back yoke 11 by the fastening force of the screws.
Other configurations are the same as those in the second embodiment.

Also in the stator 10C configured in this manner, the main magnetic pole permanent magnet 12 and the divided sub magnetic pole permanent magnet 13A are arranged on the main surface 11a of the back yoke 11 by the Halbach array, so that the field magnetic pole 14 is configured. Similar to the stator 10A in the second embodiment, the distribution of magnetic flux density (periodic magnetic field) formed above the field pole 14 is a substantially sine wave. Further, the spacer 21 made of a nonmagnetic material and the bottom 21 a of the divided spacer 21 A are interposed between the divided sub-pole permanent magnet 13 A and the back yoke 11.
Further, in the stator 10C, the fastening force of the magnet pressing member 17 to the back yoke 11 acts on the divided sub magnetic pole permanent magnet 13A via the flange portion 17a, so that the divided sub magnetic pole permanent magnet 13A and the bottom portion 21a are connected to the flange portion. A pressure is sandwiched between 17a and the back yoke 11. Accordingly, the main magnetic pole permanent magnet 12, the divided sub magnetic pole permanent magnet 13 </ b> A, the spacer 21, and the divided spacer 21 </ b> A can be collectively fixed to the back yoke 11 by the magnet pressing member 17.
Therefore, also in the fourth embodiment, the same effect as in the second embodiment can be obtained.

  According to the fourth embodiment, the divided sub magnetic pole permanent magnets 13A produced in a shape obtained by dividing the sub magnetic pole permanent magnet 13 into two in the length direction of the short side are arranged at both ends in the magnet arrangement direction to form four poles. Since it is comprised, the stator of desired stroke length is easily realizable by adjusting the number of the stators 10C arranged in the arrangement direction of a magnet. Therefore, stators with different stroke lengths can be produced simply by preparing a plurality of types of stators with different numbers of poles. Further, it is not necessary to produce a stator every time the stroke length is different, and the cost can be reduced. Furthermore, the length of the back yoke 11 can be shortened, and the price can be reduced.

In the fourth embodiment, the stator is assumed to have four poles. However, the number of poles of the stator is not limited to four, and the divided sub-pole permanent magnet is arranged in the magnet arrangement direction. What is necessary is just to be arrange | positioned at both ends.
In the fourth embodiment, the spacer and the divided spacer are fixed to the back yoke by the fastening force for fixing the magnet pressing member to the back yoke. However, the spacer and the divided spacer and the divided sub-pole permanent magnet are Further, the spacer, the divided spacer, and the back yoke may be fixed using an adhesive, or the spacer and the divided spacer are extended in the length direction from the divided sub-pole permanent magnet, and the extended portion is fastened to the back yoke. You may make it wear.

Embodiment 5 FIG.
FIG. 8 is a perspective view for explaining the configuration of a stator applied to a linear motor according to Embodiment 5 of the present invention, and FIG. 9 shows the configuration of the stator applied to the linear motor according to Embodiment 5 of the present invention. It is a longitudinal cross-sectional view explaining these.

  8 and 9, the magnetic plate 31 is produced by punching out a silicon steel plate, which is a soft magnetic material, into a rectangular flat plate shape. Each of the base portion 32 and the base portion 32 is formed from one long side of the base portion 32. A protrusion 33 is provided in the length direction of the short side and is arranged at a predetermined interval in the length direction of the long side of the base portion 32, and is defined between the protrusion portion 33 adjacent to the base portion 32. And a slot portion 34 for accommodating the auxiliary magnetic pole permanent magnet 13. Note that the flange portion 33 a extends in the length direction of the base portion 32 from both ends of the tip portion of the projection portion 33. In addition, a storage hole 35 for storing the main magnetic pole permanent magnet 12 is formed on the base portion 32 side of the protrusion 33. Further, the slot depth of the slot portion 34 is shallower than the height of the protrusion 33 extending from the base portion 32, and a storage hole 36 for storing the spacer 16 is formed between the bottom portion of the slot portion 34 and the base portion 32. It is drilled in between. Furthermore, a through hole 37 is formed in the center of the protrusion 33. Here, the storage hole 35 corresponds to a main magnetic pole permanent magnet storage hole, the slot 34 corresponds to a sub magnetic pole permanent magnet storage hole, and the storage hole 36 corresponds to a hole.

  The stator core 30 is formed by laminating a predetermined number of magnetic plates 31 and laminating through bolts 38 so that the base portion 32, the protruding portion 33, the slot portion 34, the accommodation holes 35 and 36, and the through hole 37 overlap each other. The nut 39 is inserted into the through hole 37 that is continuous in the direction, and is fastened with a nut 39 that is screwed to the extending end of the through bolt 38. Here, the base part 32 is connected to the stacking direction to form a back yoke, and the protrusion 33 is connected to the stacking direction to form a magnet pressing member.

  The main magnetic pole permanent magnet 12 is inserted and held in a storage hole 35 which is coated with an adhesive as necessary and is continuous in the stacking direction. Further, the auxiliary magnetic pole permanent magnet 13 is inserted and held in a slot portion 34 which is coated with an adhesive as necessary and is continuous in the stacking direction. Further, the spacer 16 is inserted and held in a storage hole 36 which is coated with an adhesive as necessary and is continuous in the stacking direction.

The stator 10D configured as described above is configured in the same manner as the stator 10A in the second embodiment except that the back yoke and the magnet pressing member are configured integrally.
Also in the fifth embodiment, the main magnetic pole permanent magnet 12 and the auxiliary magnetic pole permanent magnet 13 are arranged on the back yoke in which the base portion 32 is connected in the stacking direction, so that the field pole 14 is configured. Similarly to the stator 10 in the first embodiment, the distribution (periodic magnetic field) of the magnetic flux density formed above the field pole 14 is a substantially sine wave. Since the laminated body of the protrusions 33 made of a soft magnetic material is positioned on the magnetic field generation side of the main magnetic pole permanent magnet 12, magnetic saturation on the magnetic field generation side of the main magnetic pole permanent magnet 12 is alleviated. Since the spacer 16 is disposed below the sub magnetic pole permanent magnet 13, the volume of the sub magnetic pole permanent magnet 13 is reduced, and the amount of magnet used is reduced.

  According to the fifth embodiment, since the plurality of magnet pressing members and the back yoke are composed of the stator core 30 formed by laminating and integrating the magnetic plates 31, that is, one component, the assembly of the stator 10D is easy. It becomes.

In the fifth embodiment, the stator core is made by stacking and integrating magnetic plates made by punching a plate member made of soft magnetic material. However, the stator core is made of a lump of soft magnetic material. The body may be made by machining.
In the fifth embodiment, the stator core is manufactured by passing through a laminated body of magnetic plates and fastening and using bolts and nuts. However, the stator core is a laminated body of magnetic plates. May be prepared by pressure bonding.

Embodiment 6 FIG.
10 is a longitudinal sectional view for explaining the structure of a stator applied to a linear motor according to Embodiment 6 of the present invention.

In FIG. 10, the magnetic plate 31 </ b> A is divided into a shape in which three protrusions 33 are arranged in the length direction of the long side of the base portion 32, and the protrusion 33 is divided into two in the length direction of the long side of the base portion 32. The projections 33A are arranged on both sides in the arrangement direction of the three projections 33, and the accommodation holes 35a for accommodating the divided main magnetic pole permanent magnet 12A are formed on the projection 33 and the base 32 side of the division projection 33A. ing. The stator core 30A is manufactured by laminating a predetermined number of magnetic plates 31A, inserting the through bolts 38 into the continuous through holes 37, and fastening the nuts 39 screwed to the extending ends of the through bolts 38. Is done. Then, the divided main magnetic pole permanent magnet 12A is coated with an adhesive as necessary, and is inserted into and held in each storage hole 35a.
Other configurations are the same as those in the fifth embodiment.

The stator 10E configured as described above is configured in the same manner as the stator 10B in the third embodiment except that the back yoke and the magnet pressing member are configured integrally.
Therefore, according to the sixth embodiment, in addition to the effects of the fifth embodiment, the stator 10E is a divided main magnetic pole manufactured in a shape in which the main magnetic pole permanent magnet 12 is divided into two in the length direction of the short side. Since the permanent magnet 12A is arranged at both ends in the magnet arrangement direction and is configured with four poles, the stator having a desired stroke length can be simplified by adjusting the number of stators 10E arranged in the magnet arrangement direction. Can be realized. Therefore, stators with different stroke lengths can be produced simply by preparing a plurality of types of stators with different numbers of poles. Further, it is not necessary to produce a stator every time the stroke length is different, and the cost can be reduced. Furthermore, the length of the stator core 30A can be shortened, and the price can be reduced.

Embodiment 7 FIG.
FIG. 11 is a longitudinal sectional view for explaining the structure of a stator applied to a linear motor according to Embodiment 7 of the present invention.

In FIG. 11, in the magnetic plate 31 </ b> B, four protrusions 33 are arranged in the length direction of the long side of the base part 32, and the partition 40 extends from the center position between the adjacent protrusions 33. A partition wall 40A having a shape obtained by dividing the base portion 32 in the length direction of the long side of the base portion 32 is disposed on both sides of the four protrusions 33 in the arrangement direction. Here, a divided slot portion 34a for accommodating the divided sub magnetic pole permanent magnet 13A is formed between the protruding portion 33 and the partition wall portion 40 and between the protruding portion 33 and the divided partition wall portion 40A. Further, a housing hole 36a for housing the divided spacer 16A having a shape obtained by dividing the spacer 16 into two in the length direction of the long side of the base portion 32 is formed on the base portion 32 side of the divided slot portion 34a. The stator core 30B is produced by laminating a predetermined number of magnetic plates 31B, inserting the through bolts 38 into the continuous through holes 37, and fastening the nuts 39 screwed to the extending ends of the through bolts 38. Is done. Then, the divided sub magnetic pole permanent magnet 13A is coated with an adhesive if necessary and inserted and held in each divided slot 34a, and the divided spacer 16A is coated with an adhesive if necessary and inserted into each storage hole 36a. Retained.
Other configurations are the same as those in the fifth embodiment.

The stator 10F configured as described above is configured in the same manner as the stator 10C in the fourth embodiment except that the back yoke and the magnet pressing member are configured integrally.
Therefore, according to the seventh embodiment, in addition to the effect of the fifth embodiment, the stator 10F is a divided sub magnetic pole manufactured in a shape in which the sub magnetic pole permanent magnet 13 is divided into two in the length direction of the short side. Since the permanent magnet 13A is arranged at both ends in the magnet arrangement direction and is configured with four poles, a stator having a desired stroke length can be simplified by adjusting the number of stators 10F arranged in the magnet arrangement direction. Can be realized. Therefore, stators with different stroke lengths can be produced simply by preparing a plurality of types of stators with different numbers of poles. Further, it is not necessary to produce a stator every time the stroke length is different, and the cost can be reduced. Further, the length of the stator core 30B can be shortened, and the price can be reduced.

In the fifth to seventh embodiments, the spacer is interposed between the sub magnetic pole permanent magnet and the back yoke. However, the spacer is omitted and an air layer is provided between the sub magnetic pole permanent magnet and the back yoke. In this case, the amount of magnet used can be reduced, and the weight of the stator can be reduced.
In the first to seventh embodiments, the material of the spacer is not particularly described. However, the spacer may be a nonmagnetic material, such as nonmagnetic stainless steel, aluminum, glass epoxy resin, or engineering plastic. Is possible.

Embodiment 8 FIG.
FIG. 12 is a longitudinal sectional view for explaining the structure of a stator applied to a linear motor according to Embodiment 8 of the present invention.

  In FIG. 12, the back yoke 11A is manufactured in a rectangular flat plate shape using a magnetic material, and a semicircular groove 41 having a groove direction in the length direction of the short side of the back yoke 11A is formed on the surface of the back yoke 11A. It is recessed so that it may arrange with a predetermined pitch in the length direction of a long side. A permanent magnet 42 formed in a semi-cylindrical body is inserted and held in each groove 41 with an adhesive applied as necessary. Further, a semi-cylindrical magnet pressing member 43 made of a soft magnetic material as a magnetic saturation relaxation member is inserted on the inner peripheral side of the permanent magnet 42, and the extending end from the permanent magnet 42 is fastened to the back yoke 11A. It is attached. Here, for example, an Nd—Fe—B based sintered magnet produced in a semi-cylindrical body is used as the permanent magnet 42 and is magnetized in the radial direction. The semi-cylindrical permanent magnet 42 can be easily manufactured by magnetizing after dividing the ring magnet into two. Then, the permanent magnets 42 having the magnetization direction A radially inward and the permanent magnets 42 having the magnetization direction A radially outward are alternately arranged in the length direction of the long side of the back yoke 11A to thereby form the field pole 14A. Is configured.

  Also in the stator 10G configured as described above, the field pole 14A is configured by causing the permanent magnet 42 to generate a flow of magnetic flux close to the Halbach array, and therefore the period formed on the magnetic field generation side of the field pole 14A. The magnetic field becomes a substantially sine wave. Further, since the magnet pressing member 43 made of a soft magnetic material is disposed on the inner diameter side of the semi-cylindrical permanent magnet 42, the magnetic saturation on the magnetic field generation side of the permanent magnet 42 is alleviated and the generated magnetic field can be increased. .

  According to the eighth embodiment, the permanent magnet 42 has a semi-cylindrical shape, and the permanent magnet 42 having the magnetization direction A radially inward and the permanent magnet 42 having the magnetization direction A radially outward are alternated. Therefore, it is not necessary to divide the permanent magnet located at the end portion into two considering the end portion of the stator, and the stator can be easily manufactured. That is, the stator may be manufactured so that the midpoint between the arranged permanent magnets 42 is the end of the stator, and the stator can be easily manufactured according to the required length of the back yoke 11A. it can.

  In the first to seventh embodiments, a spacer made of a non-magnetic material is interposed between the sub magnetic pole permanent magnet and the back yoke to reduce the magnet amount of the sub magnetic pole permanent magnet, thereby reducing the cost. ing. In the eighth embodiment, it is only necessary to change the magnetization direction A of the permanent magnet 42 formed in the semi-cylindrical body, and it is not necessary to prepare the main magnetic pole permanent magnet and the sub magnetic pole permanent magnet, and the number of parts is reduced. As a result, the number of assembly steps can be reduced and the price can be reduced.

Also in the eighth embodiment, as described in the fifth to seventh embodiments, a stator core is manufactured by stacking and integrating magnetic plates formed with storage holes for storing semi-cylindrical permanent magnets. The stator may be manufactured by embedding a permanent magnet in the accommodation hole of the stator core.
In the eighth embodiment, the permanent magnet manufactured in the semi-cylindrical body is used. However, the shape of the permanent magnet is not limited to the semi-cylindrical body, and any cylindrical arc-shaped cylinder may be used. Good. Here, the circular arc-shaped cylinder is a cylinder having a central angle of 180 ° or less obtained by cutting a part of the cylinder along a plane perpendicular to the radial direction. A circular arc-shaped cylinder having a central angle of 180 ° corresponds to a semi-cylindrical body. And if a permanent magnet is produced with the circular arc-shaped cylinder which makes a center angle less than 180 degrees, the thickness of a back yoke can be made thin.

In each of the above-described embodiments, the main magnetic pole permanent magnet, the sub magnetic pole permanent magnet, and the permanent magnet are Nd—Fe—B based sintered magnets. Magnets, rare earth magnets, cast magnets, bonded magnets and the like can be used.
In each of the above embodiments, an Fe-Co-V material or a silicon steel plate is used for the magnet pressing member. However, the magnet pressing member may be a soft magnetic material, such as pure iron or mild steel. It can be used.

1 is a cross-sectional view schematically showing a linear motor according to Embodiment 1 of the present invention. It is a longitudinal cross-sectional view explaining the structure of the principal part of the linear motor which concerns on Embodiment 1 of this invention. It is a figure which shows the relationship between the spacer height and generated magnetic field in the linear motor which concerns on Embodiment 1 of this invention. It is a perspective view explaining the structure of the stator applied to the linear motor which concerns on Embodiment 2 of this invention. It is a longitudinal cross-sectional view explaining the structure of the stator applied to the linear motor which concerns on Embodiment 2 of this invention. It is a longitudinal cross-sectional view explaining the structure of the stator applied to the linear motor which concerns on Embodiment 3 of this invention. It is a longitudinal cross-sectional view explaining the structure of the stator applied to the linear motor which concerns on Embodiment 4 of this invention. It is a perspective view explaining the structure of the stator applied to the linear motor which concerns on Embodiment 5 of this invention. It is a longitudinal cross-sectional view explaining the structure of the stator applied to the linear motor which concerns on Embodiment 5 of this invention. It is a longitudinal cross-sectional view explaining the structure of the stator applied to the linear motor which concerns on Embodiment 6 of this invention. It is a longitudinal cross-sectional view explaining the structure of the stator applied to the linear motor which concerns on Embodiment 7 of this invention. It is a longitudinal cross-sectional view explaining the structure of the stator applied to the linear motor which concerns on Embodiment 8 of this invention.

Explanation of symbols

  5 Movers, 7 coils, 10, 10A, 10B, 10C, 10D, 10E, 10F, 10G Stator, 11, 11A Back yoke, 11a main surface, 12 main magnetic pole permanent magnet, 12A split main magnetic pole permanent magnet, 13 sub Magnetic pole permanent magnet, 13A divided sub magnetic pole permanent magnet, 14, 14A field magnetic pole, 15 magnet pressing member (magnetic saturation relaxation member), 16 spacer, 16A divided spacer, 17 magnet pressing member (magnetic saturation relaxation member), 17A divided magnet pressing member Member (magnetic saturation relaxation member), 17a collar, 20 screw, 21 spacer, 21A split spacer, 30, 30A, 30B stator core, 31, 31A, 31B magnetic plate, 32 base, 33 protrusion, 33A split protrusion Part, 34 slot part (sub-pole permanent magnet storage hole), 34a split slot part (sub-pole permanent magnet) Stone storage hole), 35, 35a storage hole (main magnetic pole permanent magnet storage hole), 36, 36a storage hole (hole), 42 permanent magnet, 43 magnet pressing member (magnetic saturation relaxation member), A magnetization direction.

Claims (8)

A main magnetic pole permanent magnet magnetized in the direction of the generated magnetic field and a sub magnetic pole permanent magnet magnetized differently from the direction of the magnetic pole of the main magnetic pole permanent magnet are alternately arranged linearly on the main surface of the back yoke. A stator having a coil, and a mover that has a coil and is movably disposed with a predetermined gap with respect to the stator. A linear motor that moves the mover in the arrangement direction of the main magnetic pole permanent magnet and the auxiliary magnetic pole permanent magnet,
The main magnetic pole permanent magnets are arranged so that the magnetization directions which are perpendicular to the main surface of the back yoke are alternately reversed,
The sub-pole permanent magnets are arranged so that the magnetization directions as the moving directions of the movers are alternately reversed,
A magnetic saturation relaxation member made of a soft magnetic material is disposed on the magnetic field generating side of the main magnetic pole permanent magnet,
A linear motor, wherein a spacer or an air layer made of a nonmagnetic material is interposed between the auxiliary magnetic pole permanent magnet and the back yoke.   2. The linear motor according to claim 1, wherein the magnetic saturation relaxation member is fixed to the back yoke, and the main magnetic pole permanent magnet is held between the magnetic saturation relaxation member and the back yoke.   An edge portion of the end of the magnetic saturation relaxation member opposite to the main magnetic pole permanent magnet in the moving direction of the mover contacts the surface of the sub magnetic pole permanent magnet opposite to the back yoke, and the sub magnetic pole permanent magnet The linear motor according to claim 2, wherein a magnet is held between the magnetic saturation relaxation member and the back yoke.   In the stator, the back yoke and the magnetic saturation relaxation member are integrally configured, and a main magnetic pole permanent magnet housing hole into which the main magnetic pole permanent magnet is inserted and held, and the auxiliary magnetic pole permanent magnet are inserted and held. The linear motor according to claim 1, further comprising a stator core having a sub-magnetic pole permanent magnet housing hole and a hole in which the spacer is inserted, held, or formed with an air layer. A stator configured by linearly arranging permanent magnets on a back yoke, and a mover that has a coil and is movably disposed with a predetermined gap with respect to the stator. A linear motor that moves the mover in the arrangement direction of the permanent magnet on the stator by energizing the coil,
The permanent magnet is manufactured in a circular arc-shaped cylinder whose magnetization direction is a radial direction, the inner diameter side of the circular arc-shaped cylinder is directed to the mover side, and the magnetization direction is a radially inward direction. It is arranged in a straight line so as to alternately turn radially outward,
A linear motor, wherein a magnetic saturation relaxation member made of a soft magnetic material is disposed on the inner diameter side of the permanent magnet.   6. The linear motor according to claim 5, wherein the magnetic saturation relaxation member is fixed to the back yoke, and the permanent magnet is held between the magnetic saturation relaxation member and the back yoke.   The stator includes a stator core in which the back yoke and the magnetic saturation relaxation member are integrally formed, and a permanent magnet housing hole into which the permanent magnet is inserted and held is formed. The linear motor according to claim 5.   The linear motor according to claim 4 or 7, wherein the stator core is configured by laminating plate members made of a soft magnetic material.

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