JP6056570B2 - 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

  Recently, there has been an increasing demand for using a linear motor to move, for example, a lightweight object at a higher speed and higher acceleration.

  When the weight of the mover is further reduced in order to meet such demands, a uniform gap of a predetermined dimension can be formed between the stator and the stator if the rigidity of the mover is reduced and the deformation is reduced as the weight is reduced. There may be a scene where the mover cannot be secured and cannot move at high speed and high acceleration. Further, in a linear motor having a mover and a stator that are arranged to face each other via a gap, the magnetic force acting on the mover by the stator is balanced in the height direction that is the opposite direction of the mover and the stator. The design is designed so that forces other than the moving direction do not substantially act on the mover, but in reality, due to tolerances during assembly and manufacturing of the linear motor, Therefore, it is assumed that a suction force to a portion close to the mover works, and due to such an unbalanced suction force, the weight of the mover is reduced and the degree of bending deformation is increased. In addition, when a configuration is adopted in which the mover is linearly moved while guiding the guided portion attached to the mover to the guide rail, there is an uneven load on the guided portion and the guide rail due to the unbalance of the magnetic attractive force. The situation which acts is also assumed, and if it becomes such a situation, the lifetime improvement of the to-be-guided part and a guide rail may be inhibited. In view of this, it is conceivable to increase the size of the guided portion and the guide rail so that it can withstand the uneven load, but it is difficult to say that the configuration is perfect because it cannot be made compact.

  The present inventor, after earnest research, prevents / suppresses the deformation of the mover due to the further weight reduction of the mover and the unbalanced suction force, thereby suppressing the deformation of the mover. A structure in which a gap of a predetermined dimension is secured between the movable element and the movable element can be moved at high speed and high acceleration, and the movable element is linearly moved while the guided portion attached to the movable element is guided to the guide rail. The linear motor is constructed so that the guided portion and the guide rail can be extended in life and reduced in size, and the guided portion can be appropriately attached to a member that contributes to improving the rigidity of the mover. It came to invent.

  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 and a guide rail provided in the vicinity of the stator and capable of guiding the mover in the moving direction.

  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 reinforcing member that increases the rigidity of the non-magnetic holding member that holds the second magnetic pole tooth is applied. The guided portion for attaching the guided portion guided by the guide rail and the stator facing surface disposed at a position closer to the stator in the thickness direction than the surface facing the stator of at least the second magnetic pole teeth of the reinforcing portion It has a part mounting surface, is characterized in that at least the stator facing surface is formed smoothly and parallel to the surface of the first magnetic pole teeth facing the mover.

  In such a linear motor, the mover is configured by using the second magnetic pole teeth and the nonmagnetic reinforcing portion, so the weight of the entire mover can be reduced by reducing the number of components of the mover. The non-magnetic holding member that holds the second magnetic pole teeth is prevented from bending by the reinforcing portion, and the stator has a stator that is thicker than the second magnetic pole teeth in the thickness direction. The stator facing surface arranged at a position close to is formed smoothly, and this stator facing surface is parallel to the surface facing the mover of the first magnetic pole teeth of the stator. A uniform gap of a predetermined dimension can be ensured between the elements, contributing to an improvement in torque and ensuring a normal operation of moving the mover linearly. In addition, due to tolerances at the time of assembly and manufacturing of the linear motor, a suction force acts on a portion of the stator that is relatively close to the mover, and the weight is reduced due to such an unbalanced suction force. If the mover is used, it is assumed that the degree of bending deformation will increase. However, the linear motor of the present invention employs a structure that prevents the non-magnetic holding member holding the second magnetic pole teeth from being bent by the reinforcing portion. Therefore, the deformation of the mover due to the unbalanced suction force can be prevented and suppressed.

  In addition, the linear motor of the present invention employs a configuration in which the linear movement of the mover is guided by the guide rail to maintain a stable operation of the mover, while being guided by an unbalance of the magnetic attractive force. It is possible to prevent / suppress the situation in which an unbalanced load acts on the part and the guide rail, and to extend the life of the guided part and the guide rail. In addition, with the linear motor of the present invention, there is no need to increase the size of the guide rail and the guided portion so that it can withstand an uneven load, and the guide rail and the guided portion can be made compact. Furthermore, the linear motor of the present invention can eliminate the unbalance of the magnetic attractive force, and can reduce the load acting on the guided portion and the guide rail as compared with the configuration in which the unbalance of the magnetic attractive force occurs. It is possible to reduce the rated load, and it is possible to select a light and small guided part as a guided part. As a result, if a small and light guided part is attached to the movable element, An even greater acceleration can be obtained.

  In addition, in the linear motor of the present invention, a dedicated member for attaching the guided portion is secured to the movable piece by securing a guided portion attaching surface for attaching the guided portion to the reinforcing portion that contributes to improving the rigidity of the movable piece. There is no need to provide it, and the number of parts can be reduced.

  As described above, with the linear motor of the present invention, it is possible to achieve both weight reduction and rigidity improvement of the entire mover, ensuring a uniform gap between the mover and the stator, and guiding the guided portion. The entire mover can be moved at a faster speed and higher acceleration while being guided by the rail.

  As described above, with the linear motor of the present invention, it is possible to achieve both weight reduction and rigidity improvement of the entire mover, ensuring a uniform gap between the mover and the stator, and guiding the guided portion. The entire mover can be moved at a faster speed and higher acceleration while being guided by the rail.

  Furthermore, in the linear motor of the present invention, it is possible to set the stator-facing surface of the reinforcement portion and the guided portion mounting surface in steps, but if the ease of processing and high dimensional accuracy are ensured, the fixed portion is fixed. It is desirable that the child facing surface and the guided portion mounting surface are formed on the same plane.

  In the linear motor of the present invention, if the surface of the guided portion that contacts the guided portion mounting surface and the guided portion mounting surface are formed smoothly, the guided portion with respect to the guided portion surface mounting surface of the reinforcing portion is guided. It is possible to maintain a good mounting state of the part and a stable linear movement of the mover through the guided part.

  In the present invention, a preferred example of the reinforcing portion includes a non-magnetic case that can accommodate the holding member.

  Further, in the linear motor of the present invention, in order to reduce the weight of the mover while ensuring a good housing state of the holding member by the case and a good mounting state of the guided portion with respect to the case, The lightening portion can be formed in a portion that does not contribute to the accommodation and does not contribute to the attachment of the guided portion.

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.

  According to the present invention, the mover as the secondary member that is driven to move in the linear direction by the stator, the second magnetic pole teeth that are arranged at a predetermined pitch along the moving direction and can form a magnetic field, A nonmagnetic body reinforcing member that increases the rigidity of the nonmagnetic body holding member that holds the second magnetic pole teeth, and the stator-facing surface of the reinforcing part is formed smoothly. It is possible to reduce the weight and improve the rigidity, and adopt a structure that guides the linear movement of the mover by the guide rail to maintain the stable operation of the mover, and the guided part guided by the guide rail It is possible to attach to the guided part mounting surface formed on the reinforcing part that contributes to improving the rigidity of the guide, thereby simplifying the mounting process of the guided part to the predetermined part (guided part mounting surface) of the movable element and the reinforcing part Good guided part against It is possible to provide a linear motor capable of maintaining a mounted state. In addition, by adopting the above-described configuration, it is possible to prevent and suppress the deformation of the mover due to the unbalanced suction force while reducing the weight of the mover.

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 disassembled perspective view of the needle | mover in the same embodiment. 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. 12 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 11 (FIG. 8 is an exploded perspective view of the mover 4 and FIG. 9 is an overall view of the mover 4 seen from the moving direction A. FIG. Is a side view of the mover 4 (a view taken in the direction of arrow e in FIG. 9), and FIG. 11 is a cross-sectional view taken along the line ff in FIG. A plurality of second magnetic pole teeth 41 that can form a magnetic field and a reinforcing portion that increases the rigidity of a nonmagnetic holding member that holds the plurality of second magnetic pole teeth 41, and includes an upper stator 2 and a lower side The surface facing the 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.

  In the present embodiment, a non-magnetic holder 42 that holds the plurality of second magnetic pole teeth 41 is used as the holding member. 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.

In the linear motor L of the present embodiment, the reinforcing portion is configured by the case 43 that can accommodate the holder 42 that holds the second magnetic pole teeth 41. The case 43 has a holder accommodating portion 431 that can accommodate the holder 42 therein, and is a flat non-magnetic material in which an upward surface and a downward surface are formed smoothly. 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 case 43 faces the stators 2 and 3 in the thickness direction (the direction in which the movable element 4 and the stators 2 and 3 face each other with a gap) from the surface of the second magnetic pole teeth 41 facing the stators 2 and 3. It has stator facing surfaces 43a and 43b arranged at close positions and a guided portion mounting surface 43c for mounting the guided portion 44 guided by the guide rail 5. Here, the stator facing surfaces 43a and 43b are thicker than the surface of the second magnetic pole teeth 41 facing the stators 2 and 3 (the direction in which the movable element 4 and the stators 2 and 3 face each other through a gap). ) Can be regarded as a surface facing the stators 2 and 3 with priority. Since the linear motor L of the present embodiment employs an arrangement in which the mover 4 is sandwiched between the upper stator 2 and the lower stator 3 in the thickness direction, the stator facing surfaces are respectively provided on the upward surface and the downward surface of the case 43. 43a and 43b are set. More specifically, in the linear motor L of the present embodiment, the upper stator has a surface that overlaps the holder 42 in the thickness direction among the upward surfaces of the case 42 and a surface that overlaps the holder 42 in the thickness direction among the downward surfaces of the case 42. It functions as the facing surface 43a and the lower stator facing surface 43b. Here, the surface of the case 43 facing the upper stator 2 in the second magnetic pole teeth 41 (in this embodiment, the surface of the second magnetic pole teeth 41 facing the upper stator 2 is the upward surface of the holder 42. When the upper covering surface 43d is a surface that covers the surface of the second magnetic pole tooth 41, that is, a surface that directly contacts the surface of the second magnetic pole tooth 41 facing the upper stator 2, The upper stator facing surface 43a is a surface having a front-back relationship with the upper covering surface 43d. Similarly, the surface of the case 43 that faces the lower stator 3 in the second magnetic pole teeth 41 (in this embodiment, the surface of the second magnetic pole teeth 41 that faces the lower stator 3 is the surface of the holder 42. A surface that covers the surface facing the lower stator 3 in the second magnetic pole teeth 41, in other words, a surface that is on the same plane as or substantially the same plane as the downward surface. In this case, the lower stator facing surface 43b is a surface having a front-back relationship with the lower covering surface 43e. And in the linear actuator L of this embodiment, the stator opposing surfaces 43a and 43b which form a flat plane are made of the first magnetic pole teeth 22 and 32 in the stator (upper stator 2 and lower stator 3). It is set to be parallel to the surface facing the mover 4.

  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. Here, the upper covering surface 43d and the lower covering surface 43e in the case 43 described above are surfaces that define the space of the holder housing portion 431 and are synonymous with surfaces that face the thickness direction (height direction). Further, the width dimension of the case 43 is larger than the width dimension of the holder 42, and the holder accommodating portion 431 is formed at the center in the width direction of the case 43, and the portion where the holder accommodating portion 431 is not formed (in this embodiment, the case 43 In each corner portion 43), a guided portion 44 can be attached. In the case 43 of the present embodiment, the guided portions 44 are fixed to the four corners of the downward surface of the case 43 using the screw insertion holes 432 formed at the four corners of the case 43. That is, the four corners of the downward surface of the case 43 function as guided portion mounting surfaces 43 c for mounting the guided portion 44. Here, in this embodiment, since the entire downward surface of the case 43 is formed smoothly, the guided portion mounting surface 43c is also a smooth surface. Further, in the case 43, the guided portion mounting surface 43c and the stator facing surface (the lower stator facing surface 43b) facing the lower stator 3 are flat smooth surfaces formed on the same plane.

  Each guided portion 44 has a smooth surface 44a that contacts the downward surface of the case 43, and a guide engaging portion 44b that can be engaged with the guide rail 5 with the guide rail 5 sandwiched from the width direction. It is equipped with. 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. 11, 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.

  The case 43 having such a configuration exhibits a function as a reinforcing portion that increases the rigidity of the holder 42. Further, as described above, the case 43 overlaps the holder housing portion 431 in a plan view among the upward surfaces of the case 43. The region functions as the upper stator facing surface 43a, and the region of the downward surface of the case 43 that overlaps the holder accommodating portion 431 in plan view functions as the lower stator facing surface 43b.

  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 movable element 4, the upper stator 2, and the lower stator 3 set in such a relative positional relationship, the upper stator 2 and the lower stator 3 are used to move the movable element 4. The acting magnetic force 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.

  As described above, in the linear motor L according to the present embodiment, the first magnetic pole teeth (upper first magnetic pole teeth 22 and lower first magnetic pole teeth 32) that can form a magnetic field are predetermined along the moving direction A of the mover 4. As a mover 4 that is disposed at a position facing a stator (upper stator 2, lower stator 3) that functions as a primary side magnetic field generation member provided at a pitch and that has a coil C, and functions as a secondary side member, Reinforcement that increases the rigidity of the second magnetic pole teeth 41 that can be arranged at a predetermined pitch along the moving direction A and can form a magnetic field, and the nonmagnetic holding member (holder 42) that holds the plurality of second magnetic pole teeth 41. Even if the first magnetic pole teeth and the holding member (holder 42) are thinly formed in order to reduce the weight of the mover 4, the case 43 is used. To increase the overall rigidity of the mover 4 In addition, the stator facing surfaces 43a and 43b facing the stator (the upper stator 2 and the lower stator 3) of the case 43 are formed smoothly and the first magnetic pole teeth 22 and 32 are movable. Since it is parallel to the surface facing the child 4, a uniform gap having a predetermined dimension can be secured between the stator (upper stator 2 and lower stator 3) and the movable element 4. This contributes to an improvement in torque, and can ensure a normal operation in which the mover 4 is linearly moved relative to the stators 2 and 3. Further, if the thickness of the case 43 is set to be small, it is useful for reducing the thickness of the entire movable element 4, and the movable element 4 that is thinner than the conventional movable element can be realized while having good rigidity by the case 43. As a result, a reduction in thrust can be suppressed as much as possible to reduce the size and weight, and it is possible to provide a linear motor L having a high level of practicality and functionality that includes the mover 4 capable of realizing high acceleration. In addition, in the 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. A situation in which an unbalanced load acts on the guided portion 44 and the guide rail 5 due to force imbalance can be prevented / suppressed, and a linear guide mechanism configured using the guided portion 44 and the guide rail 5 can be prevented. Long life can be achieved. 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 uneven loads, and the guided portion 44 and the guide rail 5 can be made compact. Can also be realized. 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.

  In addition, the linear motor L according to the present embodiment includes a guided portion 44 that is guided by the guide rail 5 fixed at a position that does not interfere with the stator (the upper stator 2 and the lower stator 3). Therefore, it is not necessary to provide a dedicated member for attaching the guided portion 44 to the movable element 4 separately from the case 43, so that the number of parts can be reduced. In addition, the surface of the guided portion 44 that contacts the guided portion mounting surface 43c and the guided portion mounting surface 43c of the case 43 are formed as flat smooth surfaces that are parallel to each other. Simplification of the mounting process of the guided portion 44 and a good mounting state of the guided portion 44 with respect to the case 43 can be maintained. In particular, in the linear motor L according to this embodiment, the guided portion mounting surface 43c is formed on the same plane as the stator facing surface (lower stator facing surface 43b). Compared with the aspect in which the child facing surface is formed on a stepped surface, it is possible to obtain the merit that it is excellent in processability and that it is easy to ensure high processing accuracy and dimensional accuracy.

  In addition, the linear motor L of the present embodiment includes a guided portion 44 guided by a guide rail 5 fixed at a position where it does not interfere with the stator (the upper stator 2 and the lower stator 3). Since the stator (upper stator 2, lower stator 3) is configured to be attachable to the guided portion mounting surface 43c set to a portion that does not face (a portion that does not overlap with the stators 2 and 3 in plan view), Magnetic flux passing through the first magnetic pole teeth (upper first magnetic pole teeth 22, lower first magnetic pole teeth 32) of the stator (upper stator 2, lower stator 3) and the second magnetic pole teeth 41 of the mover 4. By arranging the guide rail 5 and the guided portion 44 at a position deviating from the path, the magnetic flux density between the stator (upper stator 2 and lower stator 3) and the movable element 4 can be determined when the coil C is energized. The guided part 44 is guided to the guide rail 5 while maintaining the value of the period. It is possible to maintain a stable operation of the mover 4 by.

  Further, in the linear motor L of the present embodiment, the case 43 is formed with a lightening portion 433 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. It is possible to reduce the weight of the movable element 4 while ensuring a good accommodation state of the holder 42 by 43 and a good attachment state of the guided portion 44 to the case 43.

  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, in order to give thrust to the mover 4, when a magnetic circuit that follows each stator (upper stator 2, lower stator 3) and the mover 4 is formed, The magnetic flux passing through the second magnetic pole teeth 41 of the mover 4 from the first magnetic pole teeth follows the first magnetic pole teeth of the other stator without following the portions of the mover 4 other than the second magnetic pole teeth 41. Compared to the 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 leakage magnetic flux that can be generated inside the mover 4 can be configured. The movable element 4 and each stator (upper stator 2, The magnetic flux density passing through the side stator 3) can be further increased to increase the thrust on the mover 4, and even with the same power, the acceleration of the mover 4 can be further increased to speed up the reaction. Is possible.

  The specific configuration of each unit is not limited to the above-described embodiment. For example, depending on the shape of the guide rail or guided part, the guided part mounting surface should be set to a surface closer to the stator than the stator facing surface or a surface farther from the stator than the stator facing surface If it is good, the guided portion mounting surface and the stator facing surface may be set to different heights (step differences).

  In addition, when the entire or a part of the guided portion that contacts the guided portion mounting surface is uneven (including a curved surface), the shape of the guided portion mounting surface also depends on these shapes. What is necessary is just to change suitably so that the favorable attachment state without the shakiness of the to-be-guided part with respect to the to-be-guided part attachment surface may be implement | achieved.

  Further, the portion other than the stator facing surface (including the guided portion mounting surface) of the reinforcing portion may have an uneven shape (non-smooth shape).

  Further, the stator facing surface and the guided portion mounting surface may be surfaces facing different directions.

  In the above-described embodiment, the case is illustrated as the reinforcing portion. However, the reinforcing portion may be realized by a flat plate member made of a nonmagnetic material that covers the surface of the second magnetic pole tooth facing the stator. In this case, if the linear motor has a pair of stators opposed to each other in the thickness direction of the mover, for example, as shown in FIGS. 12 and 13, the holding member (holder 42) faces the stator (not shown). The reinforcing portion is constituted by two plate-like members (flat plates) 49 made of a non-magnetic material that individually covers the surfaces to be formed. Of each plate-like member 49 functioning as a reinforcing portion, it is in a front-back relationship with respect to the surfaces (the upper covering surface 49d and the lower covering surface 49e) that directly contact the second magnetic pole teeth 41 and cover the second magnetic pole teeth 41. One surface is a stator facing surface (upper stator facing surface 49a, lower stator facing surface 49b), and a surface to which the guided portion 44 is attached is a guided portion mounting surface 49c. 12 and 13 exemplify a configuration in which each plate-like member 49 is provided with a sensor scale S3. However, only one of the plate-like members 49 is provided with a sensor scale S3. Also good.

  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. The reinforcing portion can be realized by a single plate-like member (flat plate) 49 made of a nonmagnetic material that covers the surface facing the surface. Of the plate-like member 49 that functions as a reinforcing portion, a surface that is in direct contact with the second magnetic pole teeth 41 and has a front / back relationship with respect to the surfaces that cover the second magnetic pole teeth 41 (covering surface 49d, lower covering surface 49e). Is a stator facing surface (upper stator facing surface 49a, lower stator facing surface 49b), and a surface to which the guided portion 44 is mounted is a guided portion mounting surface 49c. In FIG. 12 to FIG. 14, 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 formed integrally with the holding member in order to raise the rigidity of a holding member. For example, the holding member and the reinforcing portion can be integrally or integrally formed by injection molding or adhesion treatment.

  In addition, when the reinforcing portion that increases the rigidity of the holding member is configured by a case, a hole penetrating in a predetermined direction (thickness direction, width direction, etc.) of the case or opening in a predetermined direction is formed as a thinned portion formed in the case Notches, slits, or recesses may be employed. The number of the lightening portions and the formation location can also be changed and selected as appropriate.

  The holding member and the reinforcing portion may be a non-magnetic material, and can be formed from an appropriate non-magnetic material other than resin or CFPR. Glass fiber reinforced plastics (GFRP: glass fiber reinforced plastics), stainless steel, titanium, ceramics, or the like may be applied as the material for the holding member and the reinforcing portion. These are all non-magnetic materials, and are insulating materials with low specific gravity and high rigidity, and are suitable materials for exhibiting the functions required for holding members and reinforcing parts. is there.

  In the above-described embodiment, the hole penetrating in the thickness direction (the direction facing the stator through the gap) is exemplified as the hollow hole formed in the holder, but the concave portion that does not penetrate in the thickness direction as the hollow hole is illustrated. You may apply. 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. Alternatively, it may be a holder that does not have a lightening hole.

  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.

  A configuration in which a single or three or more guided portions are guided with respect to one guide rail, or a configuration in which one or three or more guide rails are arranged at positions that do not interfere with the stator in the entire linear motor. May be.

  Further, in a state in which the mover and the stator are viewed from the directions facing each other, both or either one of the first magnetic pole teeth and the second magnetic pole teeth are inclined at a predetermined angle with respect to the moving direction of the mover. It is also possible to adopt a configuration in which (skew posture) is arranged at an equal pitch.

  Further, the mover may have only one second magnetic pole tooth. In this case, the holding member may be a non-magnetic material that exhibits the function of holding a single second magnetic pole tooth, and the reinforcing portion is a non-magnetic material that increases the rigidity of the holding member. It is enough. The holding member is not limited to the holder having the shape described in the above-described embodiment, but can be changed to various shapes according to the shape and number of the second magnetic pole teeth, or can be configured by parts other than the holder. The holding member may be integrally formed with the reinforcing portion or may be integrally formed with the reinforcing portion by an appropriate process.

  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 ... Holding member (holder)
43 ... Reinforcing part (case)
431... Holder housing portion 433... Thinned portions 43 a and 43 b. Stator facing surface (upper stator facing surface, lower stator facing surface)
43c ... Guided portion mounting surface 44 ... Guided portion 49 ... Reinforcing portion (plate-like member)
49a, 49b ... stator facing surface (upper stator facing surface, lower stator facing surface)
49c: Guided portion mounting surface 49f ... Stator facing surface 5 ... Guide rail C ... Coil L ... Linear motor

Claims (6)

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 provided with a movable piece as a guide rail provided in the vicinity of the stationary piece and capable of guiding the movable piece in a moving direction,
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 is
A second magnetic pole tooth capable of forming a magnetic field, and a non-magnetic reinforcing portion that increases the rigidity of the non-magnetic holding member that holds the second magnetic pole tooth,
The reinforcing part is
At least a stator facing surface arranged at a position closer to the stator in the thickness direction than a surface facing the stator of at least the second magnetic pole teeth, and a guided portion to which a guided portion guided by the guide rail is attached. A linear motor comprising a guide mounting surface, wherein at least the stator facing surface is formed smoothly and parallel to a surface of the first magnetic pole teeth facing the mover. The linear motor according to claim 1, wherein the stator facing surface and the guided portion mounting surface are formed on the same plane. The linear motor according to claim 1, wherein a surface of the guided portion that contacts the guided portion mounting surface and the guided portion mounting surface are formed smoothly. The linear motor according to claim 1, wherein the reinforcing portion is configured by a nonmagnetic case that can accommodate the holding member. The linear motor according to claim 4, wherein a thinned portion is formed in a portion of the case that does not contribute to accommodation of the holding member and does not contribute to attachment of the guided portion. 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.

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