KR101460400B1 - Linear motor - Google Patents

Abstract

Thereby improving the robustness and reducing the size of the body. The linear motor 1 includes a first shaft SH1, a second shaft SH2 arranged in parallel so that the first shaft SH1 is parallel to the first shaft SH1, and a second shaft SH2 disposed between the first shaft SH1 and the second shaft SH2 (2) through which the second shaft (SH2) passes, and a second frame (2) having a first frame (2A) having two connecting members (3) connecting end portions thereof and a first through hole (4) through which the first shaft The second frame 2B having the through hole 8 and the scale 101 and the sensor 103 and the gap direction A between the scale 101 and the sensor 103 is the same as the direction of the first shaft SH1, And a linear encoder 10 arranged so as to substantially coincide with the plane direction B including the axis AX1 of the first shaft SH1 and the axis AX2 of the second shaft SH2, SH2 and the connecting member 3 relatively move back and forth in the axial direction with the mover 30, the first frame 2A and the second frame 2B as the stator 40. [

Description

Linear motor {LINEAR MOTOR}

The specified embodiment relates to a linear motor.

2. Description of the Related Art [0002] Conventionally, there are known a stator in which a plurality of coils wound in a cylindrical shape on an inner diameter side of a metal pipe made of a cylindrical magnetic body are arranged in the axial direction and a stator having a cylindrical shaft (can) There has been proposed a cylindrical linear motor having a movable element in which a plurality of permanent magnets are fitted in the axial direction (for example, see Patent Document 1). This linear motor has a linear encoder composed of a scale (linear scale) provided on the shaft and a sensor (detector) provided on the metal pipe.

International Publication WO 2007/046161 pamphlet (Figs. 8 and 9)

In the linear motor of the related art, since the scale of the linear encoder is provided on the shaft and the sensor is provided on the metal pipe, there is a possibility that the gap between the scale and the sensor fluctuates due to external force or vibration acting on the shaft . That is, there is room for improvement in robustness. In addition, the encoder section provided with the linear encoder having the scale and the sensor, and the electronic section generating the driving force of the mover by the coil and the permanent magnet are each required to have a space twice as large as the stroke. However, And the linear encoder are arranged in series, the dimension of the motor in the axial direction increases, and the size of the motor becomes larger.

SUMMARY OF THE INVENTION An object of the present invention is to provide a linear motor capable of downsizing a body while improving robustness.

According to one aspect of the present invention, there is provided a magnetic bearing device comprising: a first shaft having a plurality of magnetic poles arranged in an axial direction; a second shaft disposed in parallel so that the first shaft is parallel; At least two connecting members connecting ends of the second shaft, a first through hole through which the first shaft penetrates, and a second through hole through which the second shaft penetrates, and an inner peripheral surface of the first through hole And a linear encoder disposed between the second shaft and the second through-hole, the linear encoder including a scale and a sensor, wherein the first shaft and the second shaft are rotatably supported by the main shaft, And a shaft frame which is connected by a connecting member to form a shaft frame of a frame structure, wherein either one of the shaft frame and the main frame is used as a movable member and the other is used as a stator And the linear motor relatively moves back and forth in the axial direction.

According to the linear motor of the present invention, it is possible to reduce the size of the body while improving the robustness

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side sectional view showing the entire configuration of a linear motor according to one embodiment;
Fig. 2 is a cross-sectional view of the linear motor taken along line II-II in Fig. 1,
3 is a side sectional view showing the entire configuration of a linear motor in a modified example in which the linear encoder is disposed on the other side in the first direction of the second shaft,
Fig. 4 is a cross-sectional view of the linear motor taken along line IV-IV in Fig. 3,
5 is a side cross-sectional view showing the entire configuration of a linear motor in a modified example in which the second shaft has a hollow structure,
6 is a cross-sectional view of the linear motor corresponding to the section VI-VI in Fig. 5;

Hereinafter, one embodiment will be described with reference to the drawings.

1 and 2, the linear motor 1 of the present embodiment is a piston type linear motor having a mover of a biaxial structure. The linear motor 1 is so constructed as to be parallel to the first frame 2A, the second frame 2B, the two connecting members 3, the first shaft SH1 and the first shaft SH1 A second shaft (SH2) arranged in parallel, and a linear encoder (10).

The first frame 2A is provided with a first through hole 4 through which the first shaft SH1 passes and both ends of the first through hole 4 so that the first shaft SH1 is moved in the axial direction And two first linear bearings 5 that support the first linear bearing 5 linearly movably in the left-right direction and the vertical direction in FIG. 2). On the inner circumferential surface of the first through hole 4, a plurality of armature windings 7 wound in a cylindrical shape by copper wire or the like are arranged in the axial direction.

The second frame 2B is formed separately from the first frame 2A and is connected to the first frame 2A via a suitable fixing agent. The first frame 2A and the second frame 2B correspond to a frame described in the claims. Further, the first frame 2A and the second frame 2B may be integrally formed, that is, one frame. The second frame 2B is disposed at both ends of the second through hole 8 and the second through hole 8 through which the second shaft SH2 passes and the second shaft SH2 is linearly moved in the axial direction And two second linear bearings (9) that support the second linear bearings (9).

The connecting member 3 is provided on the load side (right side in Fig. 1) and the half load side (left side in Fig. 1) of the first frame 2A and the second frame 2B. These connecting members 3 are each provided with a first shaft SH1 and a second shaft (not shown) provided in a not-shown recess provided in each of the inner sides (the side opposite to the first frame 2A and the second frame 2B) The end portions of the first shaft SH1 and the second shaft SH2 are connected to each other at the load side and the half load side of the first frame 2A and the second frame 2B, It is connected.

The first shaft SH1 passes through the first through hole 4 of the first frame 2A and is linearly extended in the axial direction by the first linear bearing 5 provided at both ends of the first through hole 4. [ And is axially movable. In the first shaft SH1, permanent magnets 6 constituting a plurality of magnetic poles are arranged at a predetermined pitch in the axial direction. The plurality of permanent magnets 6 are arranged such that their pole faces oppose a plurality of armature windings 7 arranged on the inner circumferential surface of the first through hole 4 via a magnetic gap and are arranged such that N poles or S So that the poles are opposed to each other. Further, in the portion where the permanent magnets 6 are arranged, the magnetic poles of the N poles and the magnetic poles of the S poles are alternately arranged in the axial direction. That is, the member constituting the magnetic pole is not limited to the permanent magnet, and other member (for example, electromagnetism) may be used.

The second shaft SH2 passes through the second through hole 8 of the second frame 2B and is linearly moved in the axial direction by the second linear bearing 9 provided at both ends of the second through hole 8. [ And is axially movable. 1 and 2) in the first direction (vertical direction in Figs. 1 and 2) perpendicular to the axial direction of the second shaft SH2 is formed in a flat surface Respectively. A linear encoder 10 is disposed on one side of the second shaft SH2 in the first direction.

The linear encoder 10 is a magnetic encoder in this example and has a scale 101 provided with a magnetic pattern, a substrate 102 and a sensor 103 for detecting a magnetic field by a magnetic pattern provided on the scale 101 have. The scale 101 is provided on the flat surface of one side of the outer surface of the second shaft SH2 in the first direction. 1 and 2) of the outer peripheral surface of the first frame 2A constituting a part of the inner peripheral surface of the second through hole 8 of the second frame 2B, . The sensor 103 is provided on the substrate 102 so as to face the scale 101 and the gap G in the first direction. The reason why the sensor 103 is provided on the substrate 102 is that the sensor 103 is disposed on the outer peripheral surface of the first frame 2A constituting a part of the inner peripheral surface of the second through hole 8 of the second frame 2B Which is provided on the other side in the first direction. The linear encoder 10 detects the direction of the sensor 101 in the second direction orthogonal to the axial direction of the sensor 103 among the directions related to the scale 101 and the sensor 103 and the gap G in the first direction The gap direction A passing through the substantially center of the first shaft SH1 and the second shaft SH2 is perpendicular to the axis AX1 of the first shaft SH1 and the axis AX2 of the second shaft SH2, And substantially coincides with the plane direction B including the plane direction.

 In the linear motor 1 configured as described above, the first shaft SH1, the second shaft SH2 and the connecting member 3 constitute the mover 30, and the first frame SH1, the second shaft SH2, 2 frame 2B and the like constitute the stator 40. [ In this linear motor 1, the mover 30 and the stator 40 relatively move back and forth in the axial direction. That is, in the electronic part 60 provided on the first frame 2A side (on the first shaft SH1 side), when the armature winding 7 is traditionally wired, the current flowing through the armature winding 7 and the current flowing through the permanent magnets 6 A suction force and a repulsive force are generated between the armature windings 7 and the magnetic poles of the permanent magnet 6 by the interaction of the magnetic fluxes formed by the armature windings 7 and the permanent magnets 6, 40 relative to each other. When the mover 30 moves, the encoder 103 of the encoder unit 70 provided on the side of the second frame 2B (on the second shaft SH2 side) The position (movement amount) of the mover 30 can be detected by detecting the magnetic field by the magnetic pattern.

As described above, the linear motor 1 of the present embodiment includes the first shaft SH1 and the second shaft SH2 arranged in parallel, two connecting members 3 connecting the ends of the first shaft SH1 and the second shaft SH2, 1 frame 2A and a second frame 2B and move the mover 30 and the stator 40 relatively in the axial direction. The linear motor 1 of the present embodiment has a linear encoder 10. The linear encoder 10 has a scale 101 provided on the outer circumferential surface of the second shaft SH2 and a sensor 103 provided on the inner circumferential surface of the second through hole 8 of the second frame 2B, The gap direction A between the first shaft SH1 and the sensor 103 is substantially aligned with the surface direction B including the axis AX1 of the first shaft SH1 and the axis AX2 of the second shaft SH2 .

By forming the shaft frame by connecting the end portions of the first shaft SH1 and the second shaft SH2 with the connecting member 3 in this manner, they can be made into a frame-like structure, The rigidity of the second shaft SH2 can be improved. This can improve the rigidity of the second shaft SH2 with respect to the gap direction A so that it is possible to suppress the fluctuation of the gap G between the scale 101 and the sensor 103. [ Therefore, the robustness can be improved.

In the linear motor 1, the electronic part 60, the scale 101, and the sensor 103, which generate the driving force of the mover 30 by the armature winding 7 and the permanent magnet 6, The encoder unit 70 provided with the linear encoder 10 is required to have a space twice as large as the stroke of the encoder unit 70. In this embodiment, the electronic unit 60 and the encoder unit 70 are arranged in parallel The dimension in the axial direction of the linear motor 1 can be reduced to a large extent as compared with the case where the linear motors 1 are arranged in series. In the case of arranging them in series, although the encoder section can be made small in the radial direction as compared with the electromagnetic section, it is general to store them in the frame of the same diameter, and the size of the linear motor becomes unnecessarily large. On the other hand, in the present embodiment, since the electronic part 60 and the encoder part 70 are arranged in parallel, the first frame 2A and the second frame 2 are arranged such that the arrangement space of the encoder part 70 is minimized, It is possible to construct the linear motor 2B, and the size of the linear motor 1 can be reduced.

Therefore, according to the present embodiment, it is possible to reduce the size of the linear motor 1 while improving the robustness.

In addition, in this embodiment, the following effects can be obtained in particular. That is, generally, an optical type and a magnetic type are used as an encoder of a linear motor. The magnetic encoder has characteristics that the structure is simple, the number of parts is small, and the cost is low as compared with the optical encoder, but is weak against gap fluctuation and low in robustness. On the other hand, optical encoders are superior in position resolving ability as compared with magnetic encoders and have high robustness but high cost. In the present embodiment, since the fluctuation of the gap G between the scale 101 and the sensor 103 can be suppressed, a magnetic encoder is used as the linear encoder 10. This makes it possible to reduce the cost of the linear encoder 10.

Furthermore, the embodiments are not limited to the above contents, and various modifications are possible without departing from the spirit and technical idea of the present invention. Hereinafter, such modifications will be described in order.

(1) When the linear encoder is disposed on the other side of the second shaft in the first direction

In the above embodiment, the linear encoder 10 is disposed on one side of the second shaft SH2, but the present invention is not limited to this. Even if the linear encoder is disposed on the other side of the second shaft in the first direction good.

3 and 4, the second shaft SH2 'of the linear motor 1' of the present modification has, in the outer peripheral surface thereof, a plurality of second shafts SH2 'which are orthogonal to the axial direction (rightward and leftward in FIG. 3, And the other side (the upper side in Figs. 3 and 4) of the first direction (the vertical direction in Figs. 3 and 4) is a flat surface. The second shaft SH2 'has a linear encoder 10' disposed on the other side in the first direction.

The scale 101 'of the linear encoder 10' is provided on the flat surface of the other side of the outer surface of the second shaft SH2 '. The substrate 102 'is provided on one side of the inner peripheral surface of the second through hole 8 of the second frame 2B in the first direction. The sensor 103 'is provided on the substrate 102' so as to face the scale 101 'and the gap G' in the first direction. The reason why the sensor 103 'is provided on the substrate 102' is that the sensor 103 'is provided on one side of the inner peripheral surface of the second through hole 8 of the second frame 2B in the first direction . Like the linear encoder 10 in the above-described embodiment, the linear encoder 10 'has a configuration in which the scale 101' and the sensor 103 'have a relationship with the gap G' in the first direction The gap direction A 'passing through the center of the sensor 103' in the second direction perpendicular to the axial direction (the direction perpendicular to the plane of Fig. 3, the left and right direction in Fig. 4) (B) including the axis AX1 of the second shaft SH2 'and the axis AX2' of the second shaft SH2 '.

In the linear motor 1 'of the present modification example, the first shaft SH1, the second shaft SH2' and the connecting member 3 described above constitute the mover 30 ' The first frame 2A, the second frame 2B and the like constitute the stator 40. In this linear motor 1 ', the mover 30' and the stator 40 relatively move back and forth in the axial direction.

Other configurations of the linear motor 1 'are the same as those of the linear motor 1 of the above-described embodiment.

According to the modification described above, as in the above-described embodiment, it is possible to reduce the size of the linear motor 1 'while improving the robustness.

(2) When the second shaft has a hollow structure

5 and 6, the second shaft SH2 "of the linear motor 1" of the present modification has a hollow structure and has a hollow portion 12. Like the second shaft SH2 in the above-described embodiment, the second shaft SH2 " is a member which is perpendicular to the axial direction (The lower side in Figs. 5 and 6) in the one direction (the up and down direction in Figs. 5 and 6) is a flat surface. The second shaft SH2 " , The above-mentioned linear encoder 10 is disposed.

The linear encoder 10 is capable of detecting the position of the sensor 103 in the direction related to the aforementioned gap 101 between the scale 101 and the sensor 103 in the first direction in the same manner as in the above- The gap direction A "passing through the substantially center of the second direction perpendicular to the axial direction (the direction perpendicular to the paper surface in FIG. 5, the lateral direction in FIG. 6) is smaller than the gap direction A" between the axis AX1 of the first shaft SH1 Quot; B "including the axis AX2" of the second shaft SH2 ".

The two connecting members 3 "are connected to the load side of the first frame 2A and the second frame 2B (right side in Fig. 5), as in the case of the two connecting members 3 in the above- (The left side in Fig. 5) of the connecting member 3 ". The end portions of the first shaft SH1 are fitted to recesses (not shown) provided inside the connecting members 3 " The second shaft SH2 "is inserted into through holes (not shown) provided on the inner side of the first frame 2A and the second frame 2B through the first shaft 2A SH1 and the second shaft SH2 "

The first shaft SH1, the second shaft SH2 ", the connecting member 3 and the like constitute the mover 30 "in the linear motor 1" of the present modification, And the second frame 2B constitute the stator 40. With respect to the linear motor 1 ", the movable member 30" and the stator 40 relatively move forward and backward in the axial direction .

More specifically, on the axis AX2 "of the second shaft SH2 ", the end of the load side of the second shaft SH2 " (hereinafter appropriately referred to as the load side end of the second shaft SH2) An electric gripper 14 is mounted as a jig for handling devices, parts, and the like. The electric gripper 14 has two claws 141 and is a jig capable of gripping devices, parts and the like by the two claws 141. The electric gripper 14 is moved in accordance with the movement of the mover 30 ". The wiring 13 connected to one end of the electric gripper 14 to supply electric power to the electric gripper 14, Is inserted into the hollow portion 12 in the second shaft SH2 " through two penetration holes in this example. Therefore, electric power can be supplied to the electric gripper 14 via the wiring 13. [

The other configuration of the linear motor 1 "is the same as that of the linear motor 1 of the above-described embodiment.

According to the present modification described above, it is possible to reduce the size of the linear motor 1 "while improving the robustness, in the same manner as in the above-described embodiment. In the present modification, the second shaft SH2 Is a hollow structure, and the first shaft SH1, the second shaft SH2 ", the connecting member 3, and the like are the movable members 30 ". The wiring 13 for supplying electric power to the electric gripper 14 provided at the load side end portion of the second shaft SH2 "is connected to the inside of the second shaft SH2 " The hollow portion 12 is inserted and inserted.

Thereby, it is not necessary to connect the wiring 13 to the front end portion of the second shaft SH2 "in the transverse direction, so that the driving resistance acting on the mover 30" by the tension of the wiring 13 can be reduced have. In addition, since the member for changing the flow direction is also unnecessary, the weight of the mover 30 "can be reduced, and thus the tact time can be improved. , The guide member for preventing the shaft 30 of the mover 30 "from being shaken is also unnecessary, so that the weight of the entire linear motor 1 can be further reduced and the size can be reduced. Further, since the wiring 13 can be disposed in the second shaft SH2 ", the space can be saved as compared with the case where the wiring is wound around the outside of the linear motor.

The jig to be mounted on the load side end portion of the second shaft SH2 "is not limited to the electric gripper 14 but may be mounted on another jig. For example, the second shaft SH2 " , And when a pick capable of vacuum suction is attached to a device or a component as a jig, a fluid tube for connecting the pick to one end and sucking a fluid such as air to the pick is inserted into the hollow of the second shaft (SH2 " In this case, it is not necessary to connect the fluid tube to the distal end portion of the second shaft SH2 " in the transverse direction, so that the tension of the fluid tube causes the mover 30 can be reduced. In addition, since the fluid tube can be disposed in the second shaft SH2 ", it is possible to reduce the space saving compared to a case in which the fluid tube is wound around the outside of the linear motor .

(3) Other

The scale 101 or the like of the linear encoder 10 or the like is provided on the outer circumferential surface of the second shaft SH2 or the like and the sensor 103 is mounted on the second through hole 8 of the second frame 2B The scale may be provided on the inner peripheral surface of the second through hole 8 of the second frame 2B and the sensor may be provided on the outer peripheral surface of the second shaft SH2 or the like.

In the above, two connecting members 3 for connecting the first shaft SH1 and the second shaft SH2 or the like are provided. However, the present invention is not limited to this, and three or more connecting members may be provided .

In the above description, the case where the linear encoder 10 or the like is a magnetic encoder has been described as an example, but the present invention is not limited to this, and the present invention is also applicable to a case where the linear encoder is an optical encoder.

The case where the first shaft SH1, the second shaft SH2 and the like and the connecting member 3 and the like are the mover, the first frame 2A and the second frame 2B are the stator, The present invention is also applicable to the case where the first shaft, the second shaft, and the connecting member are the stator and the frame is the movable member.

In addition to the above, the methods according to the above-described embodiments and modified examples may be appropriately combined.

In addition, although not specifically illustrated, the above-described embodiments and modifications are variously modified within the scope not departing from the spirit of the invention.

1, 1 ', 1 ": linear motor 2A: first frame
2B: second frame 3, 3 ": connecting member
4: first through hole 6: permanent magnet
7: armature winding 8: second through hole
10, 10 ': linear encoder 30, 30', 30 ": mover
40: stator 101, 101 ': scale
103, 103 ': sensor A, A', A ": gap direction
AX1: Axis (Axis of 1st shaft)
AX2, AX2 ', AX2 ": Axis (axis of second shaft)
B, B ', B ": plane direction SH1: first shaft
SH2, SH2 ', SH2': Second shaft

Claims (4)

A first shaft having a predetermined first axis,
And a second shaft having a predetermined second axis,
Wherein the first shaft and the second shaft are arranged in parallel so that the first axis and the second axis are different from each other and parallel to each other,
A plurality of magnetic poles arranged on the first shaft along the first axis,
At least two connecting members connecting the ends of the first shaft and the second shaft,
A frame having a first through hole through which the first shaft penetrates and a second through hole through which the second shaft penetrates, a frame in which a plurality of armature windings are arranged on an inner circumferential surface of the first through hole,
And a sensor provided on either one of the outer circumferential surface of the second shaft and the inner circumferential surface of the second through hole, and a sensor provided on the other side, wherein a gap direction between the scale and the sensor is defined by the first axis of the first shaft, And a magnetic linear encoder arranged so as to coincide with a plane direction including the second axis of the second shaft and to be positioned between the first axis and the second axis,
Wherein the first shaft, the second shaft, the connecting member, and the frame are moved in the axial direction relative to each other with the mover as the movable member and the other member as the stator.
Linear motor. The method according to claim 1,
Characterized in that the second shaft has a hollow structure
Linear motor. delete delete

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