JP5268312B2 - Linear motor and linear motor mounting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact linear motor for preventing a base from being deformed by suction by a stator, thus reducing a thickness of the base. <P>SOLUTION: The linear motor includes: a stator 5 having a plurality of permanent magnets 21; the base 4 to which the stator 5 is attached; a movable element 10 disposed so as to face the plurality of permanent magnets 21; and a guiding apparatus 9 for guiding a linear movement of the movable element 10 relative to the base 4. A plurality of through-holes 24 opened in the stator 5 and a plurality of through-holes 25 opened in the base 4 are respectively disposed in the same position so as to pass the same fastening member 30 through them. The stator 5 and the base 4 are attached to each other by passing the same fastening member 30 through the through-hole 24 in the stator 5 and the through-hole 25 in the base 4. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a linear motor that linearly moves a mover relative to a stator, and a linear motor mounting method for mounting a base of the linear motor to a mating part such as a surface plate.

  The linear motor is a motor that linearly moves the mover relative to the stator. The stator of the linear motor is provided with a plurality of permanent magnets so that N poles and S poles are alternately formed. A mover is slidably disposed on the stator via a gap. The mover is provided with a core facing the permanent magnet. For example, a U-phase, V-phase, and W-phase three-phase coil is wound around the core. When a three-phase alternating current having a phase difference of 120 degrees is passed through a three-phase coil of U, V, and W phases, a moving magnetic field is generated in the three-phase coil. The magnetic field generated by the permanent magnet and the moving magnetic field generated by the three-phase coil act, and the mover moves linearly.

  One type of linear motor is a type in which a stator is attached to a base, and a guide device such as a linear guide that guides the linear motion of the mover is attached to the base (see, for example, Patent Document 1). The guide device keeps the gap between the stator and the mover constant while the mover moves linearly.

In this type of linear motor, as shown in FIG. 7, first, the stator 1 of the linear motor is attached to the base 2 with a fastening member 1a such as a bolt. In general, the operation of attaching the stator 1 to the base 2 is an assembly operation of the linear motor itself, and is performed by the manufacturer of the linear motor. Next, the base 2 to which the stator 1 is attached is attached to a mating part 3 such as a surface plate using a fastening member 2a such as a bolt. The operation of attaching the base 2 to the counterpart component is performed when the assembled linear motor is used at the installation location, and is therefore performed by the user of the linear motor. When the base 2 is attached to the mating component 3, the through hole 2 b of the base 2 opened on the side of the stator 1 is used.
JP 2006-74975 A

  However, the magnetic force acting between the stator and the mover of the linear motor is large, and a large attractive force that pulls up acts on the stator. This suction force has a magnitude several times as large as the maximum thrust of the linear motor, and may be several tens to several hundred kg. If the positions of the stator through hole and the base through hole are shifted as in the conventional linear motor mounting method, the base may be deformed by the suction force acting on the stator. In order to prevent deformation of the base, it was necessary to make the base thick and to have rigidity.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a linear motor that can prevent the base from being deformed by the suction force of the stator, thereby making the base thin and compact, and a method for attaching the linear motor.

In order to solve the above-mentioned problems, the invention according to claim 1 is a magnetic material disposed opposite to the stator having a plurality of permanent magnets, a base to which the stator is attached, and the permanent magnets. A linear motor comprising: a mover having a core made of a coil and a coil wound around the core; and a guide device that guides the mover to linearly move with respect to the base. And a plurality of through holes formed in the base are arranged at the same position so that the same fastening member can be passed therethrough, and are identical to each through hole of the stator and each through hole of the base. through fastening members, Closing the stator and the base to the other components, the stator has a plurality of second through holes for mounting the stator to the base is provided, said base Are provided with a plurality of screw holes aligned with the plurality of second through holes, and a second fastening member is passed through each second through hole of the stator, and the second fastening member is It is a linear motor that attaches the stator to the base by tightening in each screw hole of the base .

  The invention according to claim 2 is the linear motor according to claim 1, wherein the stator has a magnet plate to which the plurality of permanent magnets are mounted, and the plurality of through holes of the stator are It is provided on both sides in the width direction of the magnet plate with a permanent magnet interposed therebetween.

The invention of claim 3 is, in the linear motor according to claim 2, wherein the plurality of second through hole of said magnet plate is provided across the permanent magnets on both sides in the width direction of the magnet plate The plurality of through holes of the stator and the plurality of second through holes of the magnet plate are arranged in a line in the longitudinal direction of the magnet plate.

According to a fourth aspect of the present invention, in the linear motor according to any one of the first to third aspects, an inner diameter of the through hole of the base is larger than an inner diameter of the through hole of the stator.

The invention according to claim 5 is a linear motor mounting method in which a stator having a plurality of permanent magnets is attached to a base of a linear motor in which a mover moves linearly with respect to the base, and the base is attached to a counterpart component. The mover includes a core made of a magnetic material disposed to face the plurality of permanent magnets, and a coil wound around the core, and a plurality of second through holes in the stator. The stator is attached to the base by tightening the plurality of second fastening members into the plurality of screw holes of the base, and a plurality of through holes that are opened in the stator and the base A plurality of through holes to be opened are arranged at the same position so that the same fastening member can be passed, and the through holes of the stator and the through holes of the base are passed through the same fastening member. Stator and said base is a mounting method of a linear motor attached to the mating component.

  According to the first aspect of the present invention, since the plurality of through holes opened in the stator and the plurality of through holes opened in the base are arranged at the same position, a large suction force for pulling up the stator Even if works, it is possible to prevent the base from deforming due to excessive force acting on the base. Therefore, it is possible to make the base thin or to reduce the height of the base. In addition, since it is not necessary to provide a base through hole on the side of the stator, the width of the base is also compact.

  According to the invention described in claim 2, since the through holes are provided on both sides of the magnet plate with the permanent magnet interposed therebetween, it is possible to effectively prevent the magnet plate from being deformed by the attractive force acting on the permanent magnet. it can.

According to the third aspect of the present invention, since the through hole and the second through hole of the stator are arranged in a line in the longitudinal direction of the magnet plate, the lateral width of the stator and the base can be made compact. .

According to the fourth aspect of the present invention, even if an error occurs in the pitch of the plurality of through holes of the stator and the base, the fastening member can be passed through these through holes. If it is assumed that the inner diameter of the through hole of the stator and the through hole of the base are the same, the hole diameter for passing the fastening member is reduced according to the amount of the pitch deviation, so it is difficult to pass the fastening member. .

According to the invention described in claim 5 , since the plurality of through holes opened in the stator and the plurality of through holes formed in the base are arranged at the same position, a large suction force for pulling up the stator Even if works, it is possible to prevent the base from deforming due to excessive force acting on the base. Therefore, it is possible to make the base thin or to reduce the height of the base. In addition, since it is not necessary to provide a base through hole on the side of the stator, the width of the base is also compact.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a perspective view (including a cross-sectional view of a table) of a linear motor in one embodiment of the present invention, and FIG. 2 shows a front view. A linear motor stator 5 is mounted on the elongated base 4. On the base 4, a linear guide 9 which is a guide device for guiding the linear motion of the table 3 is attached. The table 3 is attached to the upper surface of the moving block 7 of the linear guide 9. On the lower surface of the table 3, a linear motor movable element 10 is suspended between the left and right linear guides 9. As shown in the front view of FIG. 2, a gap g is provided between the stator 5 and the mover 10. The linear guide 9 keeps the gap g constant regardless of the position of the table 3 that moves linearly.

  The base 4 includes a bottom wall portion 4a and a pair of side wall portions 4b provided on both sides in the width direction of the bottom wall portion 4a. A stator 5 is attached to the upper surface of the bottom wall portion 4a. The track rail 8 of the linear guide 9 is attached to the upper surface of the side wall 4b. A moving block 7 is slidably assembled to the track rail 8. A plurality of balls are interposed between the track rail 8 and the moving block 7 so as to be able to roll (not shown). The moving block 7 is provided with a circuit-shaped ball circulation path for circulating a plurality of balls. When the moving block 7 slides with respect to the track rail 8, a plurality of balls roll and move between them, and the plurality of balls circulate in the ball circulation path. For this reason, the smooth slide of the moving block 7 with respect to the track rail 8 becomes possible.

  A table 3 is attached to the upper surface of the moving block 7 of the linear guide 9. The table 3 is made of a nonmagnetic material such as aluminum. A movable body is attached to the table 3. A position detecting means 12 such as a linear scale for detecting the position of the table 3 with respect to the base 4 is attached to the table 3. The position signal detected by the position detection means is sent to a driver that drives the linear motor. The driver controls the current supplied to the mover 10 so that the table 3 moves according to the position command from the host controller, for example.

  FIG. 3 shows a cross-sectional view along the moving direction of the mover 10. A mover is attached to the lower surface of the table 3 via a heat insulating material 13. The mover 10 includes a core 14 made of a magnetic material such as silicon steel, and a three-phase coil 16 wound around the salient poles 14a, 14b, and 14c of the core 14. The core 14 includes a base plate 14d attached to the lower surface of the table 3, and comb-shaped salient poles 14a, 14b, and 14c projecting downward from the base plate 14d. Each of the three salient poles 14a, 14b, and 14c is wound with any of the U-phase, V-phase, and W-phase coils 16a, 16b, and 16c. A three-phase alternating current having a phase difference of 120 degrees flows through the three-phase coil 16. After winding the three-phase coil 16 around the salient poles 14a, 14b, 14c, the core 14 and the three-phase coil 16 are sealed with resin.

  A pair of auxiliary cores 18 are attached to the lower surface of the table 3 with the mover 10 interposed therebetween. The auxiliary core 18 is made of a magnetic material such as general structural rolled steel or silicon steel. By providing the auxiliary core, cogging generated in the core 14 can be reduced.

  FIG. 4 shows a plan view of the stator 5 attached to the base 4. The stator 5 is unitized, and a plurality of stators 5 unitized according to the length of the base 4 are attached to the base 4. The stator 5 includes a thin plate-shaped magnet plate 20 and a plurality of plate-shaped permanent magnets 21 arranged in a line on the magnet plate 20. The permanent magnet 21 is a rare earth magnet such as a neodymium magnet having a high coercive force. One of the N pole and the S pole is formed on the front side of the permanent magnet 21, and the remaining one is formed on the back side. Permanent magnets 21a and N poles are alternately arranged on the magnet plate 20 so that N poles and S poles are alternately formed in the longitudinal direction. The permanent magnet 21 is fixed to the magnet plate 20 by adhesion or the like.

  The magnet plate 20 is made of a magnetic material such as general structural rolled steel or silicon steel. The magnet plate 20 is formed in an elongated plate shape. The permanent magnet 21 fixed to the magnet plate 20 is covered with a cover plate 22. The cover plate 22 is also fixed to the magnet plate 20 by adhesion or the like.

  A plurality of through holes 24 are formed at a constant pitch in the longitudinal direction of the magnet plate 20 on both sides in the width direction of the magnet plate 20 sandwiching the permanent magnet 21 (direction orthogonal to the moving direction of the mover 10). Further, the magnet plate 20 is provided with a second through hole 26 adjacent to the through hole 24. The second through holes 26 are also formed at a constant pitch in the longitudinal direction of the magnet plate 20 on both sides in the width direction of the magnet plate 20 sandwiching the permanent magnet 21. The interval in the width direction of the through holes 24 is equal to the interval in the width direction of the second through holes 26, so that the through holes 24 and the second through holes 26 are aligned in the longitudinal direction of the magnet plate 20.

  FIG. 5 shows a perspective view of the stator 5 and the base 4. A plurality of through holes 25 are formed in the base 4 at the same positions as the plurality of through holes 24 of the stator 5. The inner diameter of the through hole 25 of the base 4 is larger than the inner diameter of the through hole 24 of the stator 5. In addition, a plurality of screw holes 27 are processed in the base 4 at the same positions as the plurality of second through holes 26 of the stator 5. The stator 5 is attached to the base 4 by a plurality of stator attachment bolts 28 which are second fastening members. The stator 5 can be attached to the base 4 by passing the stator attaching bolts 28 through the respective second through holes 26 of the stator 5 and tightening the respective bolt holes 27 of the base 4. The operation of attaching the stator 5 to the base 4 is performed by the manufacturer of the linear motor.

  The base 4 to which the stator 5 is attached is attached to a counterpart component such as a surface plate by the user of the linear motor. In this mounting operation, first, the main body mounting bolts 30 as fastening members are passed through the through holes 24 of the stator 5 and the through holes 25 of the base 4. Next, the stator 5 and the base 4 are attached to the mating part all at once by fastening the main body mounting bolt 30 to the screw of the mating part.

  Even if a plurality of through-holes 24 opened in the stator 5 and a plurality of through-holes 25 opened in the base 4 are arranged at the same position, even if a suction force for pulling up the stator 5 works, the base 4 It is possible to prevent the base 4 from being deformed by applying an excessive force. For this reason, it becomes possible to make the base 4 thin. When the inner diameter of the through hole 25 of the base 4 is larger than the inner diameter of the through hole 24 of the stator 5, an error occurs in the pitch of the plurality of through holes 24 and 25 of the stator 5 and the base 4. However, the body mounting bolt 30 can be passed through these through holes 24 and 25.

  FIG. 6 shows a conventional example (shown in FIG. 6A) in which the through hole 24 of the stator 5 and the through hole 25 of the base 4 are shifted, and the through hole 24 of the stator 5 and the through hole 25 of the base 4. Are compared at the same position with the example of the present invention (shown in (b) in the figure) of the overall dimensions of the linear motor. In the example of the present invention, since the thickness t1 of the base 4 can be reduced, the height h1 of the entire linear motor can be made lower than the height h2 of the conventional example. Moreover, since it is not necessary to provide the through hole 25 of the base 4 beside the through hole 24 of the stator 5 as in the conventional example, the lateral width W1 of the base 4 can be made smaller than W2 of the conventional example.

  The present invention is not limited to the above-described embodiment, and can be embodied in various embodiments without departing from the scope of the present invention. For example, the present invention can be applied to a linear stepping motor using a permanent magnet as a stator. In addition to the linear guide, a combination of a track shaft and a spline bearing can be used for the guide device. Furthermore, the number of phases of the coil is not limited to three phases, and may be two phases.

  Further, the fastening member may not be passed through all of the plurality of through holes of the stator and the plurality of through holes of the base, but may be passed through at least a part of the plurality of through holes according to the number of screw holes of the counterpart part.

1 is a perspective view of a linear motor according to an embodiment of the present invention (including a partial cross-sectional view of a table) Front view of linear motor Sectional view along the moving direction of the mover Top view of stator Perspective view of stator and base Front view comparing dimensions of linear motor ((a) in the figure shows a conventional example, and (b) in the figure shows an example of the present invention) Sectional drawing which shows the attachment method of the conventional stator and base

Explanation of symbols

3 ... Table 4 ... Base 5 ... Stator 9 ... Linear guide (guide device)
DESCRIPTION OF SYMBOLS 10 ... Movable element 20 ... Magnet plate 21 ... Permanent magnet 24 ... Magnet plate (stator) through hole 25 ... Base through hole 26 ... Magnet plate (stator) second through hole 27 ... Base screw hole 28 ... Stator mounting bolts (second fastening member)
30 ... Main body mounting bolt (fastening member)

Claims (5)

A stator having a plurality of permanent magnets, a base to which the stator is attached , a core made of a magnetic material disposed to face the plurality of permanent magnets , and a mover having a coil wound around the core ; In a linear motor comprising: a guide device that guides the mover to linearly move with respect to the base;
A plurality of through holes opened in the stator and a plurality of through holes opened in the base are arranged at the same position so that the same fastening member can be passed therethrough,
The through each through hole and the base the same fastening members to each through hole of the stator, Installing the stator and the base to the other parts,
The stator is provided with a plurality of second through holes for attaching the stator to the base,
The base is provided with a plurality of screw holes aligned with the plurality of second through holes,
A linear motor that attaches the stator to the base by passing a second fastening member through each second through hole of the stator and fastening the second fastening member to each screw hole of the base . The stator has a magnet plate on which the plurality of permanent magnets are mounted;
The linear motor according to claim 1, wherein the plurality of through holes of the stator are provided on both sides in the width direction of the magnet plate with the permanent magnet interposed therebetween. The plurality of second through holes of the magnet plate are provided across the permanent magnets on both sides in the width direction of the magnet plate,
The linear motor according to claim 2, wherein the plurality of through holes of the stator and the plurality of second through holes of the magnet plate are arranged in a line in a longitudinal direction of the magnet plate.   4. The linear motor according to claim 1, wherein an inner diameter of the through hole of the base is larger than an inner diameter of the through hole of the stator. In a linear motor mounting method in which a stator having a plurality of permanent magnets is attached to a base of a linear motor in which a mover moves linearly with respect to the base, and the base is attached to a counterpart component
The mover has a core made of a magnetic material disposed to face the plurality of permanent magnets, and a coil wound around the core ,
The plurality of second fastening members are passed through the plurality of second through holes of the stator, and the plurality of second fastening members are fastened to the plurality of screw holes of the base, whereby the stator is attached to the base. attachment,
A plurality of through holes opened in the stator and a plurality of through holes opened in the base are arranged at the same position so that the same fastening member can be passed through,
A linear motor mounting method for mounting the stator and the base to a mating part through the same fastening member through each through hole of the stator and each through hole of the base.

Images