JP5447308B2 - Linear motor - Google Patents

Description

  The present invention relates to a linear motor, and more particularly, to a structure of a stator and a mover constituting the linear motor.

  There is a high demand for high speed and high precision for table feed of machine tools and actuators of transfer equipment. Therefore, in recent years, linear motors that are directly driven are often used for machine tools and the like. Compared to a drive system that combines a rotary servo motor and a ball screw, a linear motor can achieve high speed and high acceleration characteristics, and it does not cause response errors due to backlash or friction, so a highly accurate system can be constructed. is there. Linear motors are used in table feed and transport equipment for industrial machines such as machine tools and semiconductor manufacturing equipment.

  The linear motor includes a stator and a mover that are slidable with respect to each other. A general stator is configured by arranging a plurality of permanent magnets on a magnet plate. Adjacent permanent magnets are magnetized so as to have different polarities. A coil is wound around each of the teeth of the mover. When a rotary servo motor and a ball screw are combined, it is necessary to operate at a speed lower than the limit speed and the stroke is limited. However, a linear motor theoretically has no limit speed or stroke limit. However, in the configuration of the linear motor, the number of permanent magnets required increases as the stroke becomes longer. As the permanent magnet of a linear motor, a neodymium magnet is often used for increasing the thrust, which is a cause of the high cost of the linear motor.

  Therefore, in order to reduce the cost, Patent Document 1 proposes a linear motor having a configuration in which no permanent magnet is disposed over the entire stroke. The linear motor includes a first structure having a magnetic pole array arranged such that two adjacent magnetic poles have different polarities, and a second structure having an armature array arranged to face the magnetic pole array. And a third structure having a soft magnetic material row arranged to be positioned between the magnetic pole row and the armature row, and a plurality of soft magnetic materials arranged in a predetermined direction at intervals from each other It is composed of

JP 2009-261071 A

  However, in the configuration of Patent Document 1, since the third structure is disposed between the first structure and the second structure, the gap is on both sides of the third structure. For this reason, the subject that a structure and an assembly are complicated remains. An object of the present invention is to provide a linear motor having a simple structure.

The linear motor related to the present application is a connection in which a plurality of magnetic poles made of a soft magnetic material fixedly arranged in parallel at intervals and a plurality of teeth each wound with a coil are connected to each other by a back yoke portion. A tooth, a core fixed in parallel to the opposing surface of the magnetic pole so that a plurality of permanent magnets have different polarities, and a nonmagnetic coupling member that couples the core and the coupling tooth In addition, both the permanent magnets and the tips of the teeth are arranged in parallel in the same direction as the arrangement direction of the magnetic poles.

  According to the present invention, since the magnetic poles made of a plurality of soft magnetic materials are arranged in the traveling direction, the price can be suppressed, and the structure is simple because the gap is only one surface.

It is sectional drawing of the linear motor in Embodiment 1 of this invention. It is a perspective view of the linear motor in Embodiment 1 of this invention. It is a side view which paid its attention to the teeth side of the linear motor in Embodiment 1 of this invention. It is a side view which paid its attention to the core side of the linear motor in Embodiment 1 of this invention. It is a perspective view which shows the flow of the magnetic flux of the linear motor in Embodiment 1 of this invention. It is a figure which shows the flow of the magnetic flux of the linear motor in Embodiment 1 of this invention. It is sectional drawing of the linear motor in Embodiment 2 of this invention. It is a figure which shows the flow of the magnetic flux of the linear motor in Embodiment 2 of this invention. It is a figure which shows the linear motor of another form in Embodiment 2 of this invention. It is sectional drawing of the linear motor in Embodiment 3 of this invention. It is a figure which shows the flow of the magnetic flux of the linear motor in Embodiment 3 of this invention. It is sectional drawing of the linear motor in Embodiment 4 of this invention. It is a figure which shows the flow of the magnetic flux of the linear motor in Embodiment 4 of this invention. It is sectional drawing of the linear motor in Embodiment 5 of this invention.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a sectional view of a linear motor showing Embodiment 1 for carrying out the present invention. In FIG. 1, a linear motor 100 includes a stator 1 and a mover 2. The stator 1 and the mover 2 are supported with a predetermined gap so as to be slidable with respect to each other. The stator 1 includes a magnetic pole 7 and a stator plate 10. The magnetic pole 7 is made of a soft magnetic material such as iron. Although the magnetic pole 7 is fixedly disposed on the stator plate 10, it may be configured to be directly fixed to a device to which the magnetic pole 7 is attached. When the stator plate 10 is used, it is preferable to use a nonmagnetic material such as stainless steel, aluminum, or an epoxy glass laminate.

  On the other hand, the mover 2 includes a tooth 3, a coil 4, a permanent magnet 5, a core 6, and a connecting member 8. The teeth 3 are composed of a back yoke portion 3a and a tip portion 3b. The tip portion 3 b faces the magnetic pole 7. A coil 4 is wound around each of the teeth 3. The permanent magnet 5 is affixed to the stator facing surface 6 a of the core 6. The connecting member 8 connects the teeth 3 connected to the core 6. The teeth 3 and the core 6 are respectively arranged on the left and right in the figure.

FIG. 2 shows a perspective view of the linear motor 100. In this figure, the coil 4 is omitted. The magnetic poles 7 are arranged in parallel in a direction perpendicular to the traveling direction of the linear motor at an interval. The teeth 3 are connected to each other by a back yoke portion 3a. The permanent magnets 5 are arranged in parallel so that adjacent permanent magnets have different polarities. The permanent magnet 5 is fixed by being attached to the core 6 with an adhesive.

FIG. 3 shows a left side view of FIG. This figure is a side view focusing on the teeth side of the linear motor. The coil 4 is disposed on each of the teeth 3. Here, three teeth 3 around which a coil 4 is wound are shown. Each tooth 3 is connected to each other by a back yoke portion 3 a to form a connection tooth 11. The magnetic pole 7 is opposed to the tip 3b of the tooth 3 with a gap. The tips 3 b of the teeth 3 are arranged in parallel in the same direction as the arrangement direction of the magnetic poles 7.

FIG. 4 shows a right side view of FIG. This figure is a side view focusing on the core side of the linear motor. Here, four permanent magnets 5 arranged in parallel are shown. The arrows drawn on the permanent magnets 5 indicate the directions of magnetization of the respective permanent magnets. The permanent magnets 5 are arranged in parallel in the same direction as the arrangement direction of the magnetic poles 7. A plurality of permanent magnets 5 are attached to the stator facing surface 6a of the core 6 so that adjacent permanent magnets have different polarities. The magnetic pole 7 is opposed to the stator facing surface 5a of the permanent magnet 5 with an interval. Regarding the number of teeth, permanent magnets and magnetic poles, the best ratio among possible combinations is considered to be the number of teeth: number of permanent magnets: number of magnetic poles = 3: 4: 3.

The flow of magnetic flux is shown in FIG. In FIG. 5, the coil and the connecting member are omitted. The magnetic circuit is configured such that the magnetic flux generated from the permanent magnet 5 passes through the magnetic pole 7 of the stator 1 and reaches the teeth 3, passes through the magnetic pole 7, passes through the interior of the permanent magnet 5 and the core 6, and returns to the original state. Yes. In order to reduce the leakage flux of the magnetic circuit, it is preferable to use a nonmagnetic material such as stainless steel or aluminum as the material of the connecting member 8.

  FIG. 6 shows the magnetic flux flowing through the magnetic pole 7 of the stator. The direction in which the magnetic flux flows is determined in accordance with the magnetization direction of the permanent magnet 5. In order to make the flow of magnetic flux smooth, the width of the stator facing surface 3c of the tooth 3 is substantially the same as the width of the stator facing surface 5a of the permanent magnet 5, and the thickness of the magnetic pole 7 is fixed to that of the stator facing surface 3c. It is preferable that the width of the child facing surface 5a is substantially the same. Further, a gap (interval between the stator facing surface 3c or the stator facing surface 5a and the magnetic pole 7) is 2 between the teeth 3 and the permanent magnet 5 so that magnetic flux does not easily leak between the teeth 3 and the permanent magnet 5. The distance should be more than double.

  By setting it as such a structure, it can be set as the structure which does not use a permanent magnet for the stator 1. FIG. Since the magnetic poles 7 made of a plurality of soft magnetic materials are arranged in the traveling direction of the linear motor, it is inexpensive even when the stroke is increased. Further, since the gap is one surface, the structure is simple. Like a general linear motor, it is composed of a stator and a mover that face each other, and can be assembled by the same procedure as in the prior art.

Embodiment 2. FIG.
FIG. 7 is a cross-sectional view of a linear motor showing Embodiment 2 for carrying out the present invention. This figure is also a sectional view of a plane perpendicular to the traveling direction of the linear motor. In the second embodiment, the tooth 3 around which the coil is wound and the core on which the plurality of permanent magnets 5 are attached are arranged opposite to each of the two surfaces of the adjacent magnetic poles. The permanent magnet 5 is opposed to the upper surface 7 a of the magnetic pole 7. The tip of the tooth 3 faces the side surface 7 b on one side of the magnetic pole 7.

  FIG. 8 shows the flow of magnetic flux in the stator in the second embodiment. For smooth magnetic flux flow, it is preferable that the width of the stator facing surface 3a of the teeth and the width of the stator facing surface 5a of the permanent magnet are substantially the same, and a substantially square magnetic pole shape is used. For this reason, compared with Embodiment 1, a magnetic pole volume becomes 1/2 or less, and cost reduction is possible. In the first and third embodiments, the coil end always exists between the core to which the tooth and the permanent magnet are attached, and the required length of the magnetic pole increases accordingly. However, since the coil end does not directly face the magnetic pole by adopting the arrangement of the second embodiment, the volume of the magnetic pole can be reduced and the cost can be reduced as compared with the third embodiment.

FIG. 9 is a diagram showing another form of the second embodiment. This figure is also a sectional view of a plane perpendicular to the traveling direction of the linear motor. In this embodiment, the arrangement locations of the teeth and the permanent magnets are changed in the form shown in FIG. The tip of the tooth 3 faces the upper surface 7 a of the magnetic pole 7. The permanent magnet 5 faces the side surface 7 b on one side of the magnetic pole 7.

Embodiment 3 FIG.
In the third embodiment, similarly to the first embodiment, a tooth around which a coil is wound and a core to which a permanent magnet is attached are arranged on the same upper surface of the magnetic pole as in the case of the linear magnetic pole. FIG. 10 is a cross-sectional view of a linear motor showing Embodiment 3 for carrying out the present invention. It is sectional drawing of a surface perpendicular | vertical to the advancing direction of a linear motor like FIG. In the third embodiment, the mover has a core (first core) 61 and a core (second core) 62 arranged on both sides of the plurality of teeth 3 connected to each other, and these components are connected by the connecting member 8. Concatenated. A plurality of permanent magnets (first permanent magnets) 51 are affixed to the stator facing surface 61a so that adjacent permanent magnets have different polarities. Similarly, a plurality of permanent magnets (second permanent magnets) 52 are affixed to the stator facing surface 62a so that adjacent permanent magnets have different polarities.

  In the configuration of FIG. 1, the magnetic attraction force is large between the magnetic pole and the permanent magnet, and the magnetic attraction force between the teeth around which the magnetic pole and the coil are wound is small. A moment is generated. Such a moment of force causes a reduction in the life of a guide mechanism such as a linear guide used for sliding the mover 2. However, by adopting the configuration of the third embodiment, the moment of force applied to the mover 2 becomes almost zero, so that the life of the guide mechanism can be extended.

  FIG. 11 shows the flow of magnetic flux in the stator in the third embodiment. In the figure, the magnetization directions of the permanent magnet 51 and the permanent magnet 52 are shown. The permanent magnets arranged in the same row with respect to the magnetic pole 7 are magnetized in the same direction. To smooth the flow of magnetic flux as in FIG. 6, the widths of the stator facing surfaces 51a, 52a of the permanent magnets 51, 52 on both sides of the width of the stator facing surface 3c of the teeth are halved, and The thickness of the magnetic pole 7 of the stator is preferably substantially the same as the width of the stator facing surface of the permanent magnet. In other words, the thickness of the magnetic pole in the third embodiment is 1/2 times that in the first embodiment, and the effect of reducing the magnetic pole cost when the stroke is increased is great.

Embodiment 4 FIG.
FIG. 12 is a cross-sectional view of a linear motor showing Embodiment 4 for carrying out the present invention. This figure is also a sectional view of a plane perpendicular to the traveling direction of the linear motor. In the fourth embodiment, a core in which a plurality of permanent magnets are attached to both sides of a tooth around which a coil is wound in the configuration shown in FIG. In the fourth embodiment, the mover has a core (first core) 61 and a core (second core) 62 arranged on both sides of the plurality of teeth 3 connected to each other, and these components are connected by the connecting member 8. Concatenated.

A plurality of permanent magnets (first permanent magnets) 51 are attached to the core 61 so that adjacent permanent magnets have different polarities. Similarly, a plurality of permanent magnets (second permanent magnets) 52 are attached to the core 62 so that adjacent permanent magnets have different polarities. The permanent magnet 51 faces the side surface 7c. The teeth 3 are opposed to the upper surface 7a. The permanent magnet 52 faces the side surface 7b.

  In the configuration of FIG. 10, since the attractive force between the magnetic pole and the permanent magnet and between the magnetic pole and the tooth is unbalanced, a moment of force with the traveling direction as the center of the axis is generated in the entire mover as in FIG. Such a moment of force causes a reduction in the life of a guide mechanism such as a linear guide used for sliding the mover. However, with the configuration shown in FIG. 12, the moment of force applied to the mover becomes almost zero, so that the life of the guide mechanism can be extended while reducing the cost of the magnetic poles.

  The flow of the magnetic flux of the stator is shown in FIG. In the figure, the magnetization directions of the permanent magnet 51 and the permanent magnet 52 are shown. The permanent magnets arranged in the same row with respect to the magnetic pole 7 are magnetized in the same direction. In order to make the flow of magnetic flux smooth as before, the width of the stator facing surface of the permanent magnet should be ½ times the width of the stator facing surface of the teeth. As a result, the magnetic pole volume is further halved compared to the second embodiment, and the magnetic pole can be reduced in cost.

Embodiment 5 FIG.
FIG. 14 is a cross-sectional view of a linear motor showing Embodiment 5 for carrying out the present invention. In FIG. 12, the portions of the cores 61 and 62 adjacent to the coil are replaced with a material having better thermal conductivity than iron to form the heat radiating plate 9, and the coil 4 and the heat radiating plate 9 are brought into contact with each other. Examples of the material of the heat sink 9 include aluminum and copper.

  In the configuration of FIG. 12, since the coil 4 is inside the cores 61 and 62, the heat generated in the coil 4 is difficult to escape outside the mover. However, by adopting the configuration of the fifth embodiment, the heat generated in the coil 4 is transmitted to the heat radiating plate 9, reaches the surface of the mover, and becomes easy to radiate heat.

  100 linear motor, 1 stator, 2 mover, 3 teeth, 4 coil, 5 permanent magnet, 6 core, 7 magnetic pole, 8 connecting member, 9 heat sink

Claims (8)

A plurality of magnetic poles made of a soft magnetic material fixedly arranged in parallel at intervals;
A plurality of teeth each having a coil wound around each other and connected to each other at the back yoke portion;
A core that is fixedly arranged in parallel on the facing surface of the magnetic pole so that a plurality of permanent magnets have different polarities from adjacent permanent magnets;
A non-magnetic coupling member that couples the core and the coupling teeth;
A linear motor in which both the permanent magnet and the tip of the teeth are arranged in parallel in the same direction as the magnetic pole arrangement direction. 2. The linear motor according to claim 1, wherein the tip of the teeth and the permanent magnet are both opposed to the top surface of the magnetic pole. The linear motor according to claim 1, wherein a tip portion of the teeth faces a side surface of the magnetic pole, and a permanent magnet faces the upper surface of the magnetic pole. The linear motor according to claim 1, wherein a tip end portion of the teeth is opposed to an upper surface of the magnetic pole, and a permanent magnet is opposed to a side surface of the magnetic pole. A plurality of magnetic poles made of a soft magnetic material fixedly arranged in parallel at intervals;
A plurality of teeth each having a coil wound around each other and connected to each other at the back yoke portion;
A first core that is fixedly arranged in parallel on the facing surface of the magnetic pole so that the first plurality of permanent magnets have different polarities from adjacent permanent magnets;
A second core that is fixedly arranged in parallel on the facing surface of the magnetic pole so that a second plurality of permanent magnets different from the first plurality of permanent magnets has a different polarity from the adjacent permanent magnet;
A non-magnetic coupling member that couples the first core, the coupling teeth, and the second core;
The connecting teeth are disposed between the first core and the second core, and the permanent magnets and the tips of the teeth are both arranged in parallel in the same direction as the arrangement direction of the magnetic poles. . The linear motor according to claim 5, wherein the first plurality of permanent magnets, the tips of the teeth, and the second plurality of permanent magnets are opposed to the upper surface of the magnetic pole. The first plurality of permanent magnets is opposed to the first side surface of the magnetic pole, the tip portion of the teeth is opposed to the upper surface of the magnetic pole, and the second plurality of permanent magnets is the second magnetic pole second opposed to the first side surface. The linear motor according to claim 5, wherein the linear motor faces the side surface. The linear motor according to claim 5, wherein the first core and the second core are coupled to the connecting member via a heat radiating member that contacts the outer periphery of the coil.

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