JP6056571B2 - Linear motor - Google Patents

Description

  The present invention relates to a linear motor.

  Conventionally, various types of linear motors having high positioning accuracy and excellent wear resistance have been known as motors used in various applications such as transportation of semiconductor-related articles in a clean environment.

  As a linear motor that can extract larger thrust with the same size as compared with a typical magnetic circuit, a flat plate-shaped mover is provided as a secondary member so that it can move in the linear direction. In addition, there is known one in which a stator as a primary side magnetic field generating member facing the front and back surfaces of the mover is provided, and teeth (magnetic pole teeth) made of magnets or iron cores are formed on the facing surfaces, respectively (Patent Literature) 1). By configuring the mover as a secondary member in this way, the mover can be reduced in weight without requiring a magnet, a coil, or an electrical connection, and can be moved at a higher speed. It has become.

  In addition, the present applicant provides a linear motor having a mover with less loss due to leakage magnetic flux while thinning the magnetic pole teeth of the mover, and a stator as a primary-side magnetic field generating member and a secondary-side member as A linear motor provided with a mover, wherein a mover comprising a plurality of magnetic pole teeth arranged at a predetermined pitch in the moving direction of the mover and a resin-made connecting portion for connecting them to two stators A configuration in which a portion of the mover that is sandwiched between the stators is formed in a plate shape has been devised and applied for a patent (see Patent Document 2).

JP 2010-130892 A JP 2012-210011 A

  In recent years, there has been an increasing demand for using linear motors to move, for example, light objects at a higher speed and higher acceleration, and even the above-described linear motors sufficiently meet such demands. It is expected that a scene that cannot be done will occur.

  Therefore, the present inventor has achieved a further reduction in weight of the mover as a result of earnest research, and fixed the position due to the displacement of the magnetic pole teeth in the mover accompanying the movement of the mover at high speed and high acceleration. It came to invent the linear motor which can avoid the malfunction that the intended function of the needle | mover as a secondary side member which can move relatively to a linear direction with respect to a child is impaired.

  That is, the present invention provides a stator as a primary-side magnetic field generating member having a coil, and a stator that is disposed at a position facing the stator via a predetermined gap in the thickness direction and is relatively movable in a linear direction with respect to the stator. The present invention relates to a linear motor including a mover as a secondary member.

  The linear motor according to the present invention includes, as a stator, a first magnetic pole tooth capable of forming a magnetic field at a predetermined pitch along the moving direction of the mover (hereinafter simply referred to as “moving direction”). Applying, as the mover, a second magnetic pole tooth capable of forming a magnetic field and a non-magnetic holder that holds the second magnetic pole tooth, and having a smooth surface facing the stator, Further, the holder is formed with a holding hole penetrating in the thickness direction for holding the second magnetic pole teeth without gaps and a hollow hole in the cavity arranged along the moving direction, and the holder has a holding hole and a holding hole. It is characterized in that a boundary portion between a hollow hole adjacent to the moving direction or another holding hole functions as a positioning portion in the moving direction of the second magnetic pole tooth held in the holding hole.

  In the present invention, “holding holes” and “thickening holes” are “formed side by side along the moving direction” as a pattern in which holding holes and thinning holes are alternately arranged one by one along the moving direction. A pattern in which a plurality of holding holes and lightening holes are continuously arranged in a row along the moving direction (for example, two each), or the holding holes and the lightening holes are randomly formed along the moving direction. A pattern formed side by side, meaning that any of these patterns is included. Further, the mover of the linear motor according to the present invention may be provided with only one second magnetic pole tooth, or may be provided with a plurality of second magnetic pole teeth. The number of holding holes formed in the holder may be the same as the number of second magnetic pole teeth or more than the number of second magnetic pole teeth, and the linear motor according to the present invention holds the second magnetic pole teeth. A holding hole and a hollow hole or another holding hole adjacent to the holding hole in the moving direction (whether the holding hole and the hollow hole are adjacent in the moving direction or whether the holding holes are adjacent in the moving direction are holders) The boundary portion between the holding hole and the hollow hole in FIG. 2) functions as a positioning portion in the moving direction of the second magnetic pole tooth held in the holding hole. When there is one second magnetic pole tooth and one holding hole, the holding holes cannot be adjacent to each other in the moving direction, and the second magnetic pole tooth held in the holding hole in the moving direction. The portion functioning as the positioning portion is at a boundary portion between the holding hole and the lightening hole adjacent to the holding hole.

  With such a linear motor, the holder constituting the mover as the secondary side member is formed with a hollow portion in addition to the holding hole for holding the second magnetic pole teeth, thereby reducing the weight of the holder. As a result, the weight of the entire movable element can be reduced, and the movable element can be moved at a higher speed and higher acceleration. In addition, since the surface of the mover that faces the stator is formed smoothly, a gap with a uniform predetermined dimension can be secured between the stator and the mover, and the mover is attached to the stator. A normal operation for relative movement in the linear direction can be ensured.

  In addition, in the linear motor of the present invention, the position of each second magnetic pole tooth held in the holding hole in the moving direction is set to the boundary portion between the holding hole and the lightening hole adjacent in the moving direction, or in the moving direction. Since it can be maintained by the boundary part between adjacent holding holes, even if the mover itself moves at high speed and high acceleration, the position of the second magnetic pole teeth on the mover shifts in the mover moving direction as the mover moves. Thus, it is possible to avoid the problem that the intended function of the mover as the secondary member is deteriorated due to the collapse of the appropriate relative positional relationship between the second magnetic pole teeth and the first magnetic pole teeth of the stator. it can.

  And if it is the linear motor of this invention, the positioning part in the moving direction of the 2nd magnetic pole tooth hold | maintained at the holding hole is used as the boundary part of the holding hole adjacent to a moving direction and a lightening hole among holders, or a holder Because it is realized by the boundary part between the holding holes adjacent to each other in the moving direction, parts compared to the aspect realized by a special member provided in the holder or a specially shaped part formed in a specific part of the holder It is possible to reduce the number of points and simplify the shape of the holder itself, which is preferable. Here, if the holder is formed by alternately arranging a plurality of holding holes and a plurality of lightening holes one by one along the movement direction, all the holding holes are arranged adjacent to the lightening holes in the movement direction, A boundary portion between the holding hole and the lightening hole adjacent along the moving direction functions as a positioning portion in the moving direction of the second magnetic pole tooth held in the holding hole.

  Further, if the holder is formed by alternately arranging a plurality of holding holes and lightening holes along the moving direction, the holding hole is adjacent to the lightening hole in the moving direction, and is adjacent to other holding holes in the moving direction. There will be matching retaining holes. In this case, the boundary portion between the holding hole and the lightening hole adjacent along the moving direction, and the boundary portion between the holding holes adjacent along the moving direction, both of these boundary portions are held in the holding hole. It functions as a positioning part in the moving direction of the two magnetic pole teeth.

  Further, if the holder is a holder in which the holding hole and the lightening hole are randomly formed in the moving direction, the portion functioning as the positioning portion in the moving direction of the second magnetic pole tooth held in the holding hole is along the moving direction. If there is a boundary portion between adjacent holding holes along the moving direction, the boundary portion (the boundary portion between the holding holes) is also the second magnetic pole tooth. It functions as a positioning part.

  Further, in the linear motor of the present invention, in order to prevent / suppress the situation where the strength of the mover decreases with the weight reduction of the holder and can be bent, a movable portion provided with a non-magnetic reinforcing portion that increases the rigidity of the holder. It is possible to apply children.

  As a preferable example of the reinforcing portion, at least a holder having a smooth plate-like portion covering a surface facing the stator can be cited. With such a reinforcing portion, the rigidity of the holder is improved, the unevenness between the mover and the stator can be eliminated, and a uniform gap can be secured, contributing to an improvement in torque.

  In addition, the present invention includes a linear motor in which the yoke is provided (formed) on the mover, but from the viewpoint of reducing the weight of the mover, the yoke is not provided (no part that functions as a yoke) is movable. The child is more advantageous. Therefore, in the linear motor of the present invention, it is possible to employ a configuration in which the mover is disposed at a position sandwiched between two stators via a predetermined gap in the thickness direction. With such a configuration, it is possible to reduce the weight of the mover by not providing the yoke, and to provide thrust to the mover, the mover and two stators sandwiching the mover When the magnetic circuit is formed between the movable elements, the second magnetic pole teeth of the movable element are not continuous with the yoke but are configured independently of each other, so that the second magnetic pole teeth of the movable element are continuous with the yoke. It is also possible to relatively reduce the leakage magnetic flux as compared with the configuration, and the magnetic flux density between the first magnetic pole teeth and the second magnetic pole teeth of the mover in each stator is increased to increase the thrust on the mover. It is possible to increase the acceleration of the mover even with the same power, and to speed up the reaction.

  The hollow hole formed in the holder may be formed by a recess that does not penetrate in the thickness direction of the holder, but in terms of weight reduction and ease of processing, it penetrates in the thickness direction of the holder. It is preferable to employ the cut-out holes.

  According to the present invention, the movable member as the secondary member that is driven to move in the linear direction by the stator is configured to hold the second magnetic pole teeth arranged along the moving direction by the non-magnetic holder. The holder is formed with a holding hole penetrating in the thickness direction for holding the second magnetic pole teeth without any gap and a hollow hole in the cavity along the moving direction. Since the boundary part between the holding holes adjacent to each other in the moving direction of the boundary part with the punch hole or the holder functions as a positioning part in the moving direction of the second magnetic pole tooth held in the holding hole, the weight of the mover is reduced. As a secondary side member that can move relative to the stator in the linear direction due to the positional deviation of the magnetic pole teeth in the mover as the mover moves at high speed and high acceleration. The desired function of the mover is damaged. It is possible to provide a linear motor capable avoid a problem that is.

The disassembled perspective view of the linear motor which concerns on one Embodiment of this invention. The whole perspective view which abbreviate | omitted the housing | casing among the linear motors concerning the embodiment. The figure which looked at the linear motor which concerns on the same embodiment from the moving direction of the needle | mover. FIG. The bb line end view of FIG. The principal part enlarged view of FIG. The dd line | wire end view of FIG. The figure which looked at the needle | mover in the same embodiment from the moving direction. The e direction arrow directional view of FIG. Ff sectional view taken on the line of FIG. The whole perspective view of the needle | mover in the modification of the embodiment. The figure which looked at the needle | mover shown in FIG. 11 from the moving direction. The figure which looked at the needle | mover in the other modification of the embodiment from the moving direction.

  1 to 4 (FIG. 1 is an exploded perspective view of the entire linear motor L, and FIG. 2 is a perspective view of the linear motor L with the housing 1 omitted. 3 is an overall view of the linear motor L viewed from the moving direction A of the mover 4, and FIG. 4 is a view taken in the direction of the arrow a in FIG. The stators 2 and 3 as generating members and the movable element 4 as a secondary member disposed between the pair of stators 2 and 3 are mainly used as a movable element by the pair of stators 2 and 3. 4 is configured to be movable in a linear direction (the direction of arrow A in FIGS. 1 and 2).

  In the linear motor L of the present embodiment, a relatively lower stator 3 (hereinafter referred to as “lower stator 3”) in the height direction, which is a direction in which the pair of stators 2 and 3 face each other, A guide rail 5 capable of guiding the mover 4 in a predetermined moving direction A is provided in the vicinity of the other stator (referred to as “upper stator 2”). As described above, the moving direction A of the mover 4 is the arrow A direction in FIG. 1, and “moving direction A” in the following means the moving direction A of the mover 4. The “width direction” in the following description refers to a direction orthogonal to the moving direction A of the mover 4 and also orthogonal to the direction (height direction) in which the pair of stators 2 and 3 face each other.

  In the present embodiment, the upper stator 2, the lower stator 3, the mover 4, and the guide rail 55 are configured so as to be accommodated in the common housing 1. The housing 1 includes an upper housing 11 and a lower housing 12.

  As shown in FIGS. 1, 3, and 4, the upper housing 11 has a downward U shape that is open downward in the moving direction A, and hangs downward from the ceiling wall 111 and both side edges of the ceiling wall 111. And a pair of hanging walls 112. In the present embodiment, a pair of upper holding plates 113 that can hold the upper stator 2 in the width direction is provided on the downward surface of the ceiling wall 111. The sensor bracket S1 is attached to one holding plate 113 of the pair of holding plates 113, and the sensor head S2 is fixed to the sensor bracket S1.

  As shown in FIGS. 1, 3, and 4, the lower housing 12 has a U-shape that is open upward in the moving direction A, and extends upward from the bottom wall 121 and both side edges of the bottom wall 121. It is formed by a pair of upright walls 122 that stand up and a protruding wall 123 that protrudes from the upper end of each upright wall 122 toward the other upstanding wall 122 facing each other. In the present embodiment, a pair of lower holding plates 124 that can hold the lower stator 3 in the width direction is provided on the upward surface of the bottom wall 121. The distance between the protruding ends of the pair of standing walls 122 is set larger than the width dimension of the lower stator 3, and the guide rail 5 extending along the moving direction A is fixed to the upward surface of each standing wall 122. doing.

  As shown in FIGS. 2, 3 and 5 (FIG. 5 is an end view taken along the line bb of FIG. 3), the upper stator 2 is connected to the upper stator core portion 21 and the upper stator core portion 21. And a provided coil C. The upper stator core portion 21 is formed of, for example, soft magnetic laminated steel plates (steel plates laminated in the width direction), and moves to an end portion (lower end portion) relatively close to the mover 4 in the height direction. Upper teeth 22 (pole teeth) are formed at regular intervals along the direction A, and permanent magnets M are inserted and fixed between the upper teeth 22 adjacent to each other in the moving direction A, respectively. In the present embodiment, as shown in FIG. 6 (this figure is an enlarged view of the main part of FIG. 5), each permanent magnet M is arranged in such a posture that the S pole or the N pole faces the moving direction A of the mover 4. And the permanent magnets M adjacent to each other in the moving direction A have magnetization directions opposite to each other. Accordingly, the plurality of upper teeth 22 functioning as the magnetic pole teeth (the “first magnetic pole teeth” of the present invention) sandwiched between the permanent magnets M adjacent in the moving direction A are the upper teeth of the S pole along the moving direction A. 22 and the N-pole upper teeth 22 are arranged alternately. The pitch of each permanent magnet M is preferably about half of the pitch of the second magnetic pole teeth 41 to be described later, but is not limited to half the pitch of the second magnetic pole teeth 41 to be described later, and is set to an appropriate pitch. May be.

  The coil C is wound around a slot provided for each predetermined number of upper teeth 22 of the upper stator 2 cores. In the present embodiment, settings are made so that U-phase, V-phase, and W-phase currents flow from a three-phase AC power source (not shown). And when the area | region provided with the number (namely, three coils C) of the coil C which can energize the three-phase current in the upper stator 2 is regarded as one set, the upper stator 2 of the present embodiment moves It can be said that a plurality of sets (two sets in the illustrated example) are arranged in the direction A.

  The lower stator 3 has the same shape as the upper stator 2 as shown in FIGS. 2, 3, and 5 to 7 (FIG. 7 is an end view taken along the line dd in FIG. 4). The lower teeth 32 that function as the first magnetic pole teeth of the invention are different from the upper stator 2 in that the lower teeth 32 are set to be opposite to the upper teeth 22 of the upper stator 2 facing in the height direction. That is, the lower stator 3 includes a lower stator core portion 31 and a coil C provided on the lower stator core portion 31, and is, for example, a soft magnetic laminated steel plate (width orthogonal to the moving direction A). A plurality of lower teeth 32 along the moving direction A at the end portion (upper end portion) relatively close to the mover 4 in the height direction of the lower stator core portion 31 formed by the steel plates laminated in the direction). And a lower slot around which the coil C is wound is formed. Then, as shown in FIG. 6, the permanent magnets M are inserted between the lower teeth 32 aligned in the movement direction A, and the magnetism between the permanent magnets M adjacent in the movement direction A is set in the opposite direction. Accordingly, the plurality of lower teeth 32 functioning as the magnetic pole teeth (the “first magnetic pole teeth” of the present invention) sandwiched between the permanent magnets M adjacent in the movement direction A are below the S pole along the movement direction A. The side teeth 32 and the lower teeth 32 of the N pole are arranged alternately.

  Such upper stator 2 and lower stator 3 are respectively held by the upper holding plate 113 and the lower holding plate 124 in the housing 1, and are parallel to each other at a position where the movable element 4 is sandwiched in this holding state. The relationship is maintained. As described above, in the linear motor L of the present embodiment, the upper first magnetic pole teeth 22 (upper teeth 22) arranged at positions facing the height direction of the upper stator 2 and the lower stator 3. And the lower first magnetic pole teeth 32 (lower teeth 32) are set to have different magnetic poles.

  1 to 3 and FIGS. 7 to 10 (FIG. 8 is an overall view of the mover 4 viewed from the moving direction A, and FIG. 9 is a side view of the mover 4 (direction e in FIG. 8). As shown in FIG. 10 is a sectional view taken along line ff in FIG. 9), a plurality of second magnetic pole teeth arranged at a predetermined pitch along the moving direction A and capable of forming a magnetic field. 41, a non-magnetic holder 42 that holds the plurality of second magnetic pole teeth 41, a case 43 that can accommodate the holder 42 that holds the second magnetic pole teeth 41, and a guide 43 provided in the case 43 and guided to the guide rail 5. The surface to be opposed to the upper stator 2 and the lower stator 3 is formed smoothly. In the present embodiment, the dimension of the mover 4 in the movement direction A is set to a length corresponding to one set of the upper stator 2 and the lower stator 3 described above.

  The holder 42 is, for example, an integrally molded product made of a resin in which holding holes 421 for holding the second magnetic pole teeth 41 without gaps and hollow holes 422 in the cavity are alternately formed along the moving direction A. In the present embodiment, holes that penetrate in the thickness direction are applied as the holding holes 421 and the lightening holes 422. The holding hole 421 and the lightening hole 422 are common in that both are elongated in the width direction of the holder 42 and have a substantially rectangular shape in a cross section parallel to the thickness direction. In the mover 4 of the present embodiment, the opening size of the holding hole 421 in the moving direction A is set larger than the opening size of the lightening hole 422 in the moving direction A. A configuration in which the opening size of the lightening hole 422 in the moving direction A is set larger than the opening size of the holding hole 421 in the moving direction A may be adopted.

  In the state where the second magnetic pole teeth 41 are held in the respective holding holes 421 without any gap, the boundary portion 423 between the holding hole 421 adjacent to the moving direction A and the lightening hole 422 in the holder 42 is in the moving direction A. It functions as a positioning portion for each second magnetic pole tooth 41.

  The second magnetic pole teeth 41 are formed by laminating steel plates as so-called electromagnetic steel plates, which are ferromagnetic plate materials, in the width direction. In addition, the 2nd magnetic pole tooth 41 comprised by laminating | stacking the steel plate as an electromagnetic steel plate in the moving direction A may be sufficient. Of the second magnetic pole teeth 41 respectively held in the holding holes 421 of the holder 42, the upper part faces the upper first magnetic pole tooth 22, and the lower part faces the lower first magnetic pole tooth 32. Further, each second magnetic pole tooth 41 is independent in the movement direction A by a boundary portion 423 between the holding hole 421 and the lightening hole 422 in the holder 42. In the linear motor L including the mover 4 having the second magnetic pole teeth 41 set in such a configuration and arrangement, the mover 4 is generated by a magnetic field applied from each stator (the upper stator 2 and the lower stator 3). It is possible to suppress eddy currents generated inside and prevent a decrease in magnetic efficiency.

The case 43 is a non-magnetic material that has a holder accommodating portion 431 that can accommodate the holder 42 therein, and has the entire surface that faces the upper stator 2 and the lower stator 3 smooth. In addition to non-magnetism, the case 43 is required to have insulation, small specific gravity, and high rigidity. In this embodiment, CFRP (carbon fiber reinforced plastic: carbon) is used as a material that satisfies all of these requirements.
fiber reinforced plastics). That is, the linear motor L of this embodiment employs the mover 4 including the case 43 that is an integrally molded product made of CFRP.

  The holder accommodating portion 431 of the case 43 is open to the outside in the movement direction A, and the ends of the case 43 and the holder 42 in the movement direction A coincide with each other when the holder 42 is accommodated in the holder accommodating portion 431. Further, the width dimension of the case 43 is larger than the width dimension of the holder 42 and does not contribute to the accommodation of the holder 42 (that is, the holder housing portion 431 is not formed). Can be attached. In the present embodiment, the guided portion 44 is fixed to the case 43 using the screw insertion holes 432 formed at the four corners of the case 43.

  Each guided portion 44 includes a guide engaging portion that is set to a smooth surface that contacts the downward surface of the case 43 and that can be engaged with the guide rail 5 in a state where the guide rail 5 is sandwiched from the width direction. It is a thing. The linear motor L of the present embodiment is configured such that two guided portions 44 arranged at a position separated by a predetermined dimension along the moving direction A are guided with respect to one guide rail 5. .

  A sensor scale S3 extending in the moving direction A is fixed to the upward surface of the case 43 by an appropriate method. The sensor scale S3 is disposed in an area of the upward surface of the case 43 that does not overlap with the holder accommodating portion 431 in a plan view, and is read by the sensor head S2 provided in the housing 1 described above. It contributes to position grasp.

  In the linear motor L of the present embodiment, a lightening portion 433 is formed in a portion of the case 43 that does not contribute to accommodation of the holder 42 and does not contribute to attachment of the guided portion 44. Specifically, as shown in FIG. 10, a lightening portion 433 that opens only to the side of the case 43 is formed in a portion of the case 43 where the holder accommodating portion 431 can be sandwiched in the width direction.

  As shown in FIG. 6, the case 43 having such a configuration is such that the region of the upward surface that overlaps the holder accommodating portion 431 in plan view faces the upper stator 2, and of the downward surface, the holder in plan view. A region overlapping the accommodating portion 431 faces the lower stator 3. Further, the case 43 itself is smooth in the entire upward surface and the entire downward surface, and is configured in a flat plate shape as a whole. Such a case 43 exhibits a function as a reinforcing portion that increases the rigidity of the holder 42.

  Then, as shown in FIG. 6, the linear motor L according to the present embodiment has a surface that faces the upper stator 2 of the mover 4 (specifically, a holder housing portion in a plan view of the upward surface of the case 43). 431) and the upper stator 2 and the surface facing the lower mover 43 (specifically, the upper surface of the case 43 that overlaps the holder accommodating portion 431 in plan view) and the lower side A gap (magnetic gap) having a predetermined size is formed between the stator 3 and the stator 3.

  In the linear motor L of the present embodiment including the mover 4, the upper stator 2, and the lower stator 3 set in such a relative positional relationship, the mover is moved by the upper stator core portion 21 and the lower stator 3. The magnetic force acting on 4 is balanced in the height direction so that forces other than the moving direction A do not substantially act on the mover 4.

  In the linear motor L configured in this manner, the polarities of the upper first magnetic pole teeth 22 and the lower first magnetic pole teeth 32 facing in the height direction are different. By flowing a phase alternating current, various patterns of magnetic circuits passing through the stators (upper stator 2 and lower stator 3) and the movable element 4 are formed. The magnetic flux alternating between the upper first magnetic pole teeth 22, the second magnetic pole teeth 41, and the lower first magnetic pole teeth 32 passes through the gap between the stator 2 and the lower stator 3). And the second magnetic pole teeth 41, and between the second magnetic pole teeth 41 and the lower first magnetic pole teeth 32, an attraction force can be generated in the mover 4.

  Thus, in the linear motor L according to the present embodiment, the first magnetic pole that can form a magnetic field in the stator (the upper stator 2 and the lower stator 3) that has the coil C and functions as a primary magnetic field generating member. Teeth (upper first magnetic pole teeth 22 and lower first magnetic pole teeth 32) are provided at a predetermined pitch along the moving direction A of the mover 4 (hereinafter simply referred to as “moving direction A”), and the secondary side member The movable element 4 that functions as a second magnetic pole tooth 41 that is arranged at a predetermined pitch along the moving direction A and can form a magnetic field, and a non-magnetic holder 42 that holds the plurality of second magnetic pole teeth 41. The surface facing the stator (upper stator 2 and lower stator 3) is formed smoothly. Therefore, the mover 4 does not need to be provided with the coil C. In this respect, the mover 4 can be reduced in size and weight as compared with the configuration in which the mover functions as a primary magnetic field generation unit. . Further, in the linear motor L according to the present embodiment, as the holder 42, a holding hole 421 penetrating in the thickness direction for holding the second magnetic pole teeth 41 without a gap and a hollow hole 422 in the cavity are moved along the moving direction A. Since the alternately formed ones are applied, the weight of the mover 4 can be further reduced, the mover 4 can be moved at a higher speed and higher acceleration, and the holder 42 can be moved. Since the boundary portion 423 between the holding hole 421 adjacent to the moving direction A and the lightening hole 422 is functioning as a positioning portion in the moving direction A of the second magnetic pole tooth 41 held in the holding hole 421, the movable portion 421 is movable. Even if the movement of the child 4 itself is high speed and high acceleration, the position of the second magnetic pole tooth 41 in the mover 4 is shifted in the moving direction A of the mover 4 along with the movement, and is fixed to the second magnetic pole tooth 41. Child (upper side As a secondary member resulting from the collapse of the appropriate relative positional relationship between the first magnetic pole teeth (the upper first magnetic pole teeth 22 and the lower first magnetic pole teeth 32) of the child 2 and the lower stator 3). It is possible to avoid the problem that the expected function of the mover 4 is lowered. Moreover, since the surface which opposes a stator (the upper stator 2, the lower stator 3) among the movers 4 is formed smoothly, it is movable with the stator (the upper stator 2, the lower stator 3). A gap having a uniform predetermined dimension can be ensured between the child elements 4, contributing to an improvement in torque, and ensuring a normal operation of moving the movable element 4 linearly relative to the stators 2 and 3. it can.

  Moreover, in the case of the linear motor L according to the present embodiment, the positioning part in the moving direction A of the second magnetic pole tooth 41 held in the holding hole 421 is a separate dedicated member provided in the holder 42 or a specific part of the holder 42 Compared with the aspect realized by the specially shaped portion formed in the above, the number of parts can be reduced and the shape of the holder 42 itself can be simplified.

  In particular, in the linear motor L of the present embodiment, since the movable element 4 including the case 43 that can accommodate the holder 42 in the internal space is applied, the case 43 functions as a reinforcing portion that increases the rigidity of the holder 42. Moreover, the weakening accompanying thickness reduction and weight reduction of the needle | mover 4 can be prevented effectively.

  In the linear motor L according to the present embodiment, the reinforcing portion is realized by the case 43 having a smooth plate-like portion covering the surface of the holder 42 that faces the stator (the upper stator 2 and the lower stator 3). Therefore, the rigidity of the mover 4 can be effectively increased while preventing large variations in the magnetic flux density passing through the second magnetic pole teeth 41 when the coil C is energized.

  In particular, in the linear motor L of the present embodiment, the movable element 4 is disposed at a position sandwiched between two stators (upper stator 2 and lower stator 3) in the thickness direction (height direction) via a predetermined gap. Therefore, the second magnetic pole teeth 41 adjacent to each other in the moving direction A of the mover 4 can be formed independently without being continuously formed via the yoke, and the coil C can be energized. Leakage magnetic flux that may sometimes occur in the mover 4 may be relatively reduced as compared with a configuration in which the second magnetic pole teeth 41 adjacent to each other in the moving direction A of the mover 4 are continuously formed via the yoke. The first magnetic pole teeth (upper first magnetic pole teeth 22 and the lower first magnetic pole teeth 32) and the second magnetic pole teeth 41 of the mover 4 in each stator (upper stator 2, lower stator 3). The magnetic flux density between the two is further increased to increase the thrust on the mover 4 It can, be the same power by further increasing the acceleration of the mover 4 also, it is possible to speed up the reaction.

  In addition, the linear motor L according to the present embodiment employs a hole penetrating in the thickness direction of the holder 42 as the hollow hole 422 formed in the holder 42, so that the holder can be easily processed. 42 contributes to the weight reduction of the movable element 4 and the weight of the entire movable element 4.

  In particular, in a conventional linear motor, due to tolerances during assembly and manufacturing, a suction force acts on a portion of the stator that is relatively close to the mover, and due to such an unbalanced suction force, If the mover is lightened, the degree of bending deformation is assumed to be large. However, in the linear motor L of the present embodiment, the bending of the non-magnetic holding member 42 that holds the second magnetic pole teeth 41 is reinforced. Since the structure which prevents by the case 43 which is a part is employ | adopted, the deformation | transformation of the needle | mover 4 resulting from an unbalanced attraction | suction force can also be prevented and suppressed.

  In addition, the linear motor L of the present embodiment employs a configuration in which the movable element 4 is linearly moved while guiding the guided portion 44 to the guide rail 5, thereby maintaining the stable operation of the movable element 4 while performing magnetic attraction. It is possible to prevent / suppress a situation in which an unbalanced load acts on the guided portion 44 and the guide rail 5 due to the force imbalance, and it is possible to extend the life of the guided portion 44 and the guide rail 5. Further, according to the linear motor L of the present embodiment, there is no need to increase the size of the guided portion 44 and the guide rail 5 so as to be able to withstand an uneven load, and the linear guide including the guided portion 44 and the guide rail 5 is used. The entire mechanism can be made compact. Furthermore, since the linear motor L of the present embodiment can eliminate the unbalance of the magnetic attractive force, it acts on the guided portion 44 and the guide rail 5 as compared with the configuration in which the magnetic attractive force is unbalanced. By reducing the load, the rated load can be reduced, and it is possible to select a light and small guided portion 44 to be guided by the guide rail 5, and as a result, a small and lightweight guided portion can be selected. By attaching the portion 44 to a part of the mover 4, it is possible to obtain a larger acceleration of the mover 4. In particular, the linear motor L according to the present embodiment employs the movable element 4 including a plurality of guided portions 44 provided to be separated from each other, thereby preventing / suppressing the unbalance of the magnetic attractive force. It is possible to avoid a situation in which the load acting on each part of the guide rail 5 with which each guided portion 44 contacts is greatly different, and to ensure smooth linear movement of the entire movable element 4 via each guided portion 44. However, the above-described guided portion 44 and the guide rail 5 can have a long life and a small size.

  The specific configuration of each unit is not limited to the above-described embodiment. For example, in the above-described embodiment, the hole penetrating in the thickness direction (the direction facing the stator via the gap) is exemplified as the lightening hole, but a concave portion that does not penetrate in the thickness direction is applied as the lightening hole. May be. Moreover, you may be the structure which mixed the hollow hole penetrated in the thickness direction and the hollow hole which has not penetrated in the thickness direction.

  The holder only needs to be a non-magnetic material, and can be formed from an appropriate non-magnetic material other than resin.

  In the above-described embodiment, the case provided with the holder accommodating portion is exemplified as the reinforcing portion of the nonmagnetic material that increases the rigidity of the holder. However, the case is made of a nonmagnetic material that covers the surface of the holder that faces the stator. You may implement | achieve a reinforcement part with a flat member. In this case, if the linear motor has a pair of stators arranged opposite to each other in the thickness direction of the mover, for example, as shown in FIG. 11 and FIG. It is also possible to adopt a configuration in which the holder 42 is sandwiched in the thickness direction by two plate-like members (flat plates) 49 made of nonmagnetic materials that are individually coated. 11 and 12 exemplify a configuration in which the sensor scale S3 is provided on each plate-like member 49, but a configuration in which the sensor scale S3 is provided only on any one of the plate-like members 49 may be employed. .

  Further, in the case of a linear motor in which a stator is arranged at a position facing one of the surfaces in the thickness direction of the mover, for example, as shown in FIG. 13, the holder 42 faces the stator (not shown). The reinforcing portion can be realized by a single plate-like member (flat plate) 49 made of a nonmagnetic material covering the surface. In FIG. 11 to FIG. 13, the same reference numerals are given to portions and portions corresponding to the above-described embodiment.

  Moreover, you may implement | achieve a reinforcement part by the site | part integrally formed in the holder in order to raise the rigidity of a holder. When these configurations are employed, the case is not an essential member and may be a mover without a case.

  In addition, when a mover provided with a case is applied, the case and the holder can be integrally formed by an appropriate bonding process or the like, or the case and the holder can be integrally formed.

  If a cut portion (through hole, recess, notch or slit opened in a predetermined direction) is formed in a part of a member or part that functions as a reinforcing portion that increases the rigidity of the holder, it is useful for reducing the weight of the mover.

  You may comprise a reinforcement part with the plate-shaped member which consists of a nonmagnetic material which coat | covers the surface (a side surface or the end surface of a moving direction) which does not oppose a stator among holders. Or a reinforcement part can also be implement | achieved by the nonmagnetic reinforcement provided in the opening edge of the holding hole or the lightening hole among the holders, and the nonmagnetic rib provided in each lightening hole.

In addition, as a material for holders and cases, glass fiber reinforced plastic (GFRP: glass
fiber reinforced plastics), stainless steel, titanium, ceramic, etc. may be applied. These are all non-magnetic materials, are insulators, have low specific gravity and high rigidity, and are suitable materials for exhibiting the functions required for holders and cases.

  Further, a linear motor having one stator and one mover may be used. In this case, by providing the mover with a portion (yoke) that continuously forms a magnetic path between the second magnetic pole teeth adjacent in the movement direction, the stator and the mover arranged in a one-to-one relationship. A smooth flow of the magnetic flux between them can be ensured.

  The guide mechanism for guiding the movement of the mover in the linear direction may be realized by a configuration or mechanism other than the combination of the guide rail and the guided portion described above.

  In addition, when viewed from the direction in which the mover and the stator face each other, either or both of the first magnetic pole teeth and the second magnetic pole teeth are inclined by a predetermined angle with respect to the moving direction of the mover (skew). It is also possible to adopt a configuration in which the postures are arranged at equal pitches.

  Further, in the above-described embodiment, the holder is alternately formed with the holding holes and the lightening holes along the moving direction, and the boundary portion between the holding hole and the lightening hole adjacent to each other in the moving direction of the holder is the second. Although the configuration functioned as the positioning portion in the moving direction of the magnetic pole teeth is illustrated, as the holder, the holding hole and the lightening hole are formed randomly (no regularity) along the moving direction, or the holding hole and the lightening are removed. With a regularity along the moving direction (for example, a pattern in which one hole is formed for each holding hole n (n is an integer of 2 or more), or a hole with a hole (n is an integer of 2 or more) ) A pattern in which one holding hole is provided for each piece, or m holes (m is an integer of 2 or more) and n is the same number as n for each holding hole n (n is an integer of 2 or more). Or a different number) pattern, or n holes (n is an integer of 2 or more) The holding hole m (m is an integer of 2 or more, may be the same number as n A may be an aneuploid) such as a pattern that number) can also be applied those formed. Thus, when applying a holder in which the holding holes and the lightening holes are not alternately formed along the movement direction, the boundary part where the holding holes and the lightening holes are adjacent in the movement direction of the holders, A boundary portion where the holding holes are adjacent to each other, and a boundary portion where the lightening holes are adjacent to each other are formed. Of these, a boundary portion where the holding holes and the lightening holes are adjacent to each other, and a boundary portion where the holding holes are adjacent to each other. The second magnetic pole teeth held in the holding holes may function as positioning portions in the moving direction.

  Further, when the mover has only one second magnetic pole tooth, it is sufficient that the holder has at least one holding hole. The holding hole holding the second magnetic pole tooth and the holding hole Positioning portion in the moving direction of the second magnetic pole tooth that is held in the holding hole at the boundary portion with the hole adjacent to the moving direction (the hollow hole or other holding hole not holding the second magnetic pole tooth) As long as it functions as

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

2, 3 ... Stator (Upper stator, Lower stator)
22, 32 ... 1st magnetic pole tooth (upper 1st magnetic pole tooth, lower 1st magnetic pole tooth)
4 ... Movable element 41 ... 2nd magnetic pole tooth 42 ... Holder 421 ... Holding hole 422 ... Mouth hole 423 ... Boundary part 43, 49 ... Reinforcement part (case, flat plate)
C ... Coil L ... Linear motor

Claims (5)

A stator as a primary side magnetic field generating member having a coil, and a secondary side member disposed at a position facing the stator via a predetermined gap in the thickness direction and relatively movable in a linear direction with respect to the stator A linear motor having a movable element as a
The stator is provided with first magnetic pole teeth capable of forming a magnetic field at a predetermined pitch along the moving direction of the mover,
The mover includes a second magnetic pole tooth capable of forming a magnetic field, and a non-magnetic holder that holds the second magnetic pole tooth, and a surface facing the stator is formed smoothly.
In the holder, a holding hole penetrating in the thickness direction for holding the second magnetic pole teeth without gap and a hollow hole in the cavity are formed side by side along the moving direction, and the holding hole and the holding of the holder are formed. A boundary portion between the hollow hole adjacent to the hole in the moving direction or the other holding hole functions as a positioning portion in the moving direction of the second magnetic pole tooth held in the holding hole. A linear motor characterized by that. The linear motor according to claim 1, wherein the mover includes a nonmagnetic reinforcing portion that increases the rigidity of the holder. The linear motor according to claim 2, wherein the reinforcing portion has a smooth plate-like portion that covers at least a surface of the holder that faces the stator. 4. The linear motor according to claim 1, wherein the movable element is arranged at a position sandwiched between two stators via a predetermined gap in the thickness direction. 5. The linear motor according to claim 1, wherein the lightening hole is a hole penetrating in a thickness direction of the holder.

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