CN103460575B

CN103460575B - Linear motor

Info

Publication number: CN103460575B
Application number: CN201180069957.6A
Authority: CN
Inventors: 高石阳介; 仲兴起; 小林学
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2011-04-04
Filing date: 2011-04-04
Publication date: 2015-03-25
Anticipated expiration: 2031-04-04
Also published as: KR101374464B1; JPWO2012137241A1; TW201242222A; KR20130115400A; JP5306558B2; TWI426684B; CN103460575A; WO2012137241A1

Abstract

Conventional linear motors had issues in that play and fluctuation were brought about between a bearing and a shaft member for the amount of a minute gap between the bearing and the shaft member, and in that, as a result thereof, precision deteriorated in the positioning of the front-tip section of the shaft that transmits thrust force to a machine. In order to attain a linear motor that can solve these issues, that can get rid of the play and fluctuation between the bearing and the shaft member, and that can enhance positioning precision of a movable section, the linear motor was made to have an anchored section (1) and a movable section (2). The movable section (2) is provided with: permanent magnets (21); and a sliding member (32) that comprises magnetic material, that is arranged at one front-tip section of the permanent magnets (21), and that slides within the anchored section (1) in the axis direction. The anchored section (1) is provided with: a plain bearing (31) that is made to come in contact with the inner face of the anchored section (1), and that supports the sliding member (32) in slidable state; and a coil (11) that is formed within the anchored section (1), and within the inner space of which the movable section (2) moves relative thereto. The sliding member (32) has the center axis thereof arranged to be eccentric to the plain bearing (31) side with respect to the center axis of the cross section of the inner space formed by the coil (11), and is made to come in contact with the plain bearing (31).

Description

Linear motor

Technical field

The present invention relates to a kind of linear motor, it has the sliding bearing be configured between movable part and fixed part and the slide unit configured relative to the eccentricity of central axis of fixed part.

Background technology

In existing linear motor, spindle unit (the 1st sleeve) adopts following structure: the permanent magnet alternately forming N pole and S pole therein in the axial direction, and between permanent magnet, be provided with the magnetic (yoke) for improving thrust.Be arranged on movable part by the coil that the periphery of spindle unit surrounds, the inner side of the movable part being positioned at spindle unit outer circumferential side is provided with bearing, this bearing is used for leading axle parts and relatively carries out rectilinear motion relative to movable part along the axis direction of spindle unit.The linear motor of formation described above is formed as following structure: cylinder or square bearing and movable part are configured centered by spindle unit, between bearing and spindle unit, small gap (for example, referring to patent documentation 1) is provided with in order to make relative motion successfully carry out.

Patent documentation 1: Japanese Unexamined Patent Publication 9-182408 publication (the 4th page, Fig. 1)

Summary of the invention

Existing linear motor is formed as mentioned above, therefore, corresponding with the small gap value arranged between bearing and spindle unit and produce between bearing and spindle unit and rock or change, its result, such as, be provided with mechanically in the shaft type linear motor of the axle of movable part transmitting thrust, the problem that the positioning precision that there is axle leading section declines.

The present invention proposes to solve the problem, and its object is to, and does not make to produce between bearing and spindle unit rock or change, and such as, improves the positioning precision of the axle leading section of shaft type linear motor.

In linear motor involved in the present invention, have: have: fixed part; And movable part, it is positioned at the inside of fixed part, and movable part is set to, and can carry out relative displacement in the axial direction relative to fixed part, movable part has: magnet portion, and it is made up of multiple permanent magnets stacked in the axial direction; And the 1st sliding part, it is configured in a leading section of magnet portion, at the inside of fixed part sliding guidance in the axial direction, be made up of magnetic material, fixed part has: the 1st bearing, and it supports the 1st sliding part slidably, abut with the inner surface of fixed part, be made up of nonmagnetic substance; And multiple coil, they are arranged on the inside of fixed part, produce magnetic flux in the inner space of self and act on magnet portion and make movable part carry out relative displacement, about the 1st sliding part, configure to the 1st bearing lateral deviation heart relative to the section central shaft of the inner space formed by coil by making the central shaft of the 1st sliding part, and the 1st sliding part abuts with the 1st bearing, thus make magnetic attraction from permanent magnet to eccentric direction effect.

The effect of invention

According to the present invention, the positioning precision of the axle leading section of shaft type linear motor can be improved, shaft type linear motor can be applicable in the sophisticated electronics such as surface mounting apparatus, board inspecting machine.

Accompanying drawing explanation

Fig. 1 represents embodiments of the invention 1, is the profile of shaft type linear motor.

Fig. 2 represents embodiments of the invention 1, is the exploded perspective view of shaft type linear motor.

Fig. 3 represents embodiments of the invention 1, is the structure chart of the control part of shaft type linear motor.

Fig. 4 represents embodiments of the invention 1, is the structure chart of the sliding bearing of shaft type linear motor.

Fig. 5 represents embodiments of the invention 2, is the profile of shaft type linear motor.

Fig. 6 represents embodiments of the invention 3, is the profile of shaft type linear motor.

Fig. 7 represents embodiments of the invention 4, is the structure chart of the sliding bearing of shaft type linear motor.

Fig. 8 represents embodiments of the invention 5, is the profile of shaft type linear motor.

Fig. 9 represents embodiments of the invention 6, is the profile of shaft type linear motor.

Embodiment

Embodiment 1

Fig. 1 represents embodiments of the invention 1, and be the profile of shaft type linear motor, Fig. 2 represents embodiments of the invention 1, is the exploded perspective view of shaft type linear motor.In fig. 1 and 2,1 is the fixed part of shaft type linear motor, and 2 is movable parts of shaft type linear motor, can carry out relative displacement in the axial direction relative to fixed part 1.31 work as the 1st bearing, that section is formed as the sliding bearing of L-shaped shape vertically, 51 is power supply lead-in wires, 11 is the multiple coils for producing magnetic flux from power supply lead-in wire 51 inflow current, 12 is the resinous bobbins insulated by multiple coil 11, 13 is upper frames of the magnetic loop becoming produced magnetic flux, 14 is magnetic loops of becoming produced magnetic flux, section is formed as the underframe of U-shaped vertically, 15 is the pedestals for improving mechanical rigid, 16 is the bearings supported axle, 17 is the brackets keeping bearing 16, 18 is the cover bodies preventing foreign matter from entering, 41 is position detectors, fixed part 1 is by sliding bearing 31, coil 11, bobbin 12, upper frame 13, underframe 14, pedestal 15, bearing 16, bracket 17, cover body 18 and position detector 41 are formed.

On the other hand, 32 slide units working, carry out on the surface of sliding bearing 31 sliding guidance as the 1st sliding part, 21 is magnet portion, is multiple permanent magnets of laminated configuration, for the interphase interaction of the magnetic flux by producing with multiple coil 11, thus produce thrust.22 is dividing plate, it is made up of magnetic material or nonmagnetic substance, so that alternately the stacked N pole of multiple permanent magnets 21 of formation and the mode of S pole magnetic pole are configured between multiple permanent magnet 21 in the axial direction, 23 is axle bonded blocks, 24 is the axles mechanically transmitting produced thrust, movable part 2 is made up of slide unit 32, permanent magnet 21, dividing plate 22, axle bonded block 23, and movable part 2 is connected with the end of axle 24.Another end of axle 24 is stretched out, for position probing to the outside of fixed part 1.The central shaft of the central shaft of multiple permanent magnet 21, the central shaft of dividing plate 22 and axle bonded block 23 aligns with the central shaft of axle 24 respectively.Movable part 2 is configured in the inside of fixed part 1, and being formed as can along the structure of the Z-direction movement in Fig. 1.In addition, multiple coil 11 and multiple bobbin 12 are concentrically configured in the outside of multiple permanent magnet 21, and the central shaft of multiple coil 11 and the central shaft of multiple bobbin 12 align with the central shaft of axle 24 respectively.

42 is scales, and 25 is axle leading sections of axle 24, and 26 is scale bonded blocks, and 52 is position detector lead-in wires.Scale 42 adopts following structure, that is, be combined with axle leading section 25 by scale bonded block 26, can with the movement of axle 24 cooperatively action.In addition, scale 42 adopts following structure, namely, record the positional information of optical profile type or magnetic-type therein, utilize the position detector 41 be combined with fixed part 1, the position of the Z-direction in Fig. 1 of detection axis 24, transmit position signalling from position detector lead-in wire 52 to control part.

In addition, A-A ' section and B-B ' section represent the section along X-Y plane of the shaft type linear motor shown in Fig. 1.

Fig. 3 represents embodiments of the invention 1, is the structure chart of the control part of shaft type linear motor.In figure 3,90 is control parts, and 100 is shaft type linear motors.91 is position control circuits, and 92 is speed control circuits, and 93 is current control circuits, and 99 is current detectors, and control part 90 is made up of position control circuit 91, speed control circuit 92, current control circuit 93, current detector 99.

The positional information detected by scale 42 and position detector 41 is fed back to the control part 90 of shaft type linear motor 100.Position control circuit 91 is by comparing from the location feedback value of position detector 41 and command value and carry out Position Control, speed control circuit 92 by comparing from the output valve of position control circuit 91 and the speed feedback value that carries out differential to location feedback value and obtain and carry out speeds control, current control circuit 93 by from speed control circuit 92 output valve and compare from the current feedback values of current detector 99 and carry out thrust control.

Fig. 4 represents embodiments of the invention 1, is the structure chart of the sliding bearing of shaft type linear motor.61 is magnetic fluxs, 62a and 62b is the magnetic attraction produced due to the impact of the magnetic flux 61 of permanent magnet 21 generation.

Sliding bearing 31 is resin-made (nonmagnetic substance), and as shown in the A-A ' section of Fig. 4, section is formed as L-shaped shape vertically.On the other hand, slide unit 32 is such as S50C material, and upper frame 13 and underframe 14 are such as SPCC material, are magnetic material.Here, slide unit 32 is set to, the central shaft of the inner space of the coil 11 configured with heart shaped with the central shaft relative to axle 24 decentraction, but to the sliding bearing 31 lateral deviation heart.Its result, gap between slide unit 32 and upper frame 13, gap between slide unit 32 and underframe 14, not being present in section is that sliding bearing 31 this side existing of L-shaped shape is (in the A-A ' section of Fig. 4, left surface and lower surface for slide unit 32), but each other across regulation distance be present in and there is not this side of sliding bearing 31 (in the A-A ' section at Fig. 4, right flank and upper surface for slide unit 32).

In the A-A ' section of Fig. 4, magnetic flux 61 is respectively formed at as between the upper frame 13 of magnetic material and permanent magnet 21, as between the two sides of the underframe 14 of the U-shaped of magnetic material and permanent magnet 21, as magnetic material and section is between the lower surface of the underframe 14 of U-shaped and permanent magnet 21.Due to the impact of formed magnetic flux 61, at the slide unit 32 as magnetic material, magnetic attraction 62a and 62b is produced as between the upper frame 13 of magnetic material and the underframe 14 of U-shaped, but sliding bearing 31 this side existing that the section due to the inclined framework 14 on the lower of slide unit 32 is L-shaped shape is arranged, therefore, due to partially leaning on of this slide unit 32, magnetic attraction 62a is that sliding bearing 31 this side existing of L-shaped shape is (in the A-A ' section at Fig. 4 at section, left surface and lower surface for slide unit 32) act on strongly, this side is there is not (in the A-A ' section at Fig. 4 in magnetic attraction 62b at the sliding bearing 31 of L-shaped shape, right flank and upper surface for slide unit 32) generation effect hardly.

In the shaft type linear motor formed as mentioned above, slide unit 32 and section are that the sliding bearing 31 of L-shaped shape is in the state contacted with fixing magnetic attraction 62a all the time, therefore, gap is there is not between slide unit 32 and sliding bearing 31, its result, there is not rocking or changing of causing due to gap of producing in the structure of existing shaft type linear motor, the positioning precision of axle leading section 25 can be improved.In addition, in the structure of existing shaft type linear motor directly by gap shrinks, the size of slide unit 32 and sliding bearing 31 must be processed accurately, but need not this processing be carried out in the structure of shaft type linear motor in the present embodiment 1.

Above, according to the structure of the shaft type linear motor illustrated in the present embodiment 1, the positioning precision of the axle leading section of shaft type linear motor can be improved, therefore, shaft type linear motor can be applicable in surface mounting apparatus and substrate detection machine, the parts densification such as can will installed on electric substrate.

Embodiment 2

In embodiments of the invention 1, be illustrated for the situation only an end of movable part 2 being formed as sliding bearing 31, but as shown in Figure 5, also the both ends of movable part 2 can be formed as, as the sliding bearing 31a of the 1st bearing and the sliding bearing 31b as the 2nd bearing, by above-mentioned structure, also identical effect can be obtained.With that the both ends of movable part 2 are formed as sliding bearing 31a, 31b is corresponding, at the position that sliding bearing 31a, 31b carry out sliding, namely in the both sides of fixed part 1, be provided as the slide unit 32a of the 1st sliding part and the slide unit 32b as the 2nd sliding part.

Embodiment 3

In embodiments of the invention 1 and embodiment 2, two faces for the sliding bearing 31 using L-shaped shape guarantee that the situation of the positional precision of X and Y-direction is illustrated, but when requiring the direction of positional precision to be only a direction such as X-direction, as shown in Figure 6, sliding bearing 35 also can be formed as the tabular parallel with the lower surface of underframe 14 vertically.In the case, the effect identical with embodiment 1 and embodiment 2 can also be obtained.

Embodiment 4

Fig. 7 represents embodiments of the invention 4, is the structure chart of the sliding bearing of shaft type linear motor.71 is the 1st intermediate members, in the figure 7 as intermediate member.

Sliding bearing 31 is resin-made (nonmagnetic substance), and as shown in the A-A ' section of Fig. 7, section is formed as L-shaped shape vertically, abuts with the right flank of intermediate member 71 and upper surface.In addition, intermediate member 71 is the magnetic materials such as such as SPCC material, and as shown in the A-A ' section of Fig. 7, section is formed as L-shaped shape vertically, abuts with the left surface of underframe 14 and lower surface.On the other hand, slide unit 32 is such as S50C material, and upper frame 13 and underframe 14 are such as SPCC material, are magnetic material.Here, slide unit 32 is arranged alignedly with the central shaft of the inner space of the coil 11 configured with heart shaped relative to the central shaft of axle 24.Its result, gap between slide unit 32 and upper frame 13, gap between slide unit 32 and underframe 14, be not present in sliding bearing 31 that section is L-shaped shape and intermediate member 71 this side existing (in the A-A ' section of Fig. 7, left surface and lower surface for slide unit 32), but each other across regulation distance be present in sliding bearing 31 and intermediate member 71 does not exist this side (in the A-A ' section at Fig. 7, right flank and upper surface for slide unit 32).

In the A-A ' section of Fig. 7, magnetic flux 61 is respectively formed at as being between the right flank of the intermediate member 71 of L-shaped shape and permanent magnet 21 between the lower surface of the intermediate member 71 of L-shaped shape and permanent magnet 21 between the upper frame 13 of magnetic material and permanent magnet 21, as between the right flank of the underframe 14 of the U-shaped of magnetic material and permanent magnet 21, as the section of magnetic material being, as the section of magnetic material.Pass through the impact of formed magnetic flux 61, at the slide unit 32 as magnetic material, as the upper frame 13 of magnetic material, magnetic attraction 62a and 62b is produced between the underframe 14 of U-shaped and the intermediate member 71 of L-shaped shape, but magnetic attraction 62a is that the sliding bearing 31 of L-shaped shape and intermediate member 71 this side existing are (in the A-A ' section at Fig. 7 at section, left surface and lower surface for slide unit 32) act on strongly, this side is there is not (in the A-A ' section at Fig. 7 in magnetic attraction 62b at the sliding bearing 31 of L-shaped shape and intermediate member 71, right flank and upper surface for slide unit 32) act on hardly.

In the shaft type linear motor formed as mentioned above, slide unit 32 and section are that the sliding bearing 31 of L-shaped shape is in the state contacted with fixing magnetic attraction 62a all the time, therefore, gap is there is not between slide unit 32 and sliding bearing 31, its result, there is not rocking or changing of causing due to gap of occurring in the structure of existing shaft type linear motor, the positioning precision of axle leading section 25 can be improved.In addition, in the structure of existing shaft type linear motor directly by gap shrinks, the size of slide unit 32 and sliding bearing 31 must be processed accurately, but do not need to carry out this processing in the structure of shaft type linear motor in the present embodiment 1.

Above, according to the structure of the shaft type linear motor illustrated in the present embodiment 4, the positioning precision of the axle leading section of shaft type linear motor can be improved, therefore, shaft type linear motor can be applicable in surface mounting apparatus and board inspecting machine, the parts densification such as can will installed to electric substrate.

Embodiment 5

In embodiments of the invention 4, the situation employing intermediate member 71 for the end only at movable part 2 is illustrated, but as shown in Figure 8, also the intermediate member 71a of the 1st intermediate member and the intermediate member 71b as the 2nd intermediate member can be used as at the both ends of movable part 2, according to said structure, also identical effect can be obtained.

Embodiment 6

In embodiments of the invention 4 and embodiment 5, two faces for the intermediate member 71 using L-shaped shape guarantee that the situation of the positional precision of X and Y-direction is illustrated, but when requiring the direction of positional precision to be only a direction such as X-direction, as shown in Figure 9, also axially intermediate member 75 can be formed as the tabular parallel with the lower surface of underframe 14.In the case, the effect identical with embodiment 5 with embodiment 4 can also be obtained.

In the structure of the shaft type linear motor illustrated in the present embodiment 4 to embodiment 6, situation about being formed respectively as individual components for intermediate member 71,71a, 71b and underframe 14 is illustrated, but have at underframe 14 in the structure of the so new underframe 14 of intermediate member 71,71a, 71b, also can obtain identical effect.

In addition, in embodiments of the invention 1 to embodiment 6, be illustrated for situation about applying the present invention in shaft type linear motor, but be not limited to this, also can obtain identical effect even if be applied in other linear motor.

The explanation of label

1 fixed part, 2 movable parts, 11 coils, 12 bobbins, 13 upper frames, 14 underframes, 15 pedestals, 16 bearings, 17 brackets, 18 cover bodies, 21 permanent magnets, 22 dividing plates, 23 axle bonded blocks, 24 axles, 25 axle leading sections, 26 scale bonded blocks, 31 sliding bearings, 31a sliding bearing, 31b sliding bearing, 32 slide units, 32a slide unit, 32b slide unit, 35 sliding bearings, 41 position detectors, 42 scales, 51 power supply lead-in wires, 52 position detector lead-in wires, 61 magnetic fluxs, 62a magnetic attraction, 62b magnetic attraction, 71 intermediate members, 71a intermediate member, 71b intermediate member, 75 intermediate members, 90 control parts, 91 position control circuits, 92 speed control circuits, 93 current control circuits, 99 current detectors, 100 shaft type linear motors.

Claims

1. a linear motor, it has: fixed part; And movable part, it is positioned at the inside of this fixed part, and this movable part is set to, and can carry out relative displacement in the axial direction relative to this fixed part,

The feature of this linear motor is,

Described movable part has: magnet portion, and it is made up of multiple permanent magnets stacked in the axial direction; And the 1st sliding part, it is configured in a leading section of this magnet portion, at the inside of described fixed part sliding guidance in the axial direction, is made up of magnetic material,

Described fixed part has: the 1st bearing, and it supports described 1st sliding part slidably, abuts, be made up of nonmagnetic substance with the inner surface of described fixed part; And multiple coil, they are arranged on the inside of described fixed part, produce magnetic flux in the inner space of self and act on described magnet portion and make described movable part carry out relative displacement,

About described 1st sliding part, by making the central shaft of described 1st sliding part relative to the section central shaft of the inner space formed by described coil to described 1st bearing lateral deviation heart configuration, and described 1st sliding part abuts with described 1st bearing, thus make magnetic attraction from described permanent magnet to eccentric direction effect.

2. linear motor according to claim 1, is characterized in that,

The interior profile of described fixed part is rectangular shape, and described 1st sliding part is rectangular shape, and the section of described 1st bearing is L-shaped shape.

3. linear motor according to claim 1, is characterized in that,

The interior profile of described fixed part is rectangular shape, and described 1st sliding part is rectangular shape, and the section of described 1st bearing is tabular.

4. a linear motor, it has: fixed part; And movable part, it is positioned at the inside of this fixed part, and this movable part is set to, and can carry out relative displacement in the axial direction relative to this fixed part,

The feature of this linear motor is,

Described movable part has: magnet portion, and it is made up of multiple permanent magnets stacked in the axial direction; And the 1st and the 2nd sliding part, they are configured in two leading sections of this magnet portion, at the inside of described fixed part sliding guidance in the axial direction, are made up of magnetic material,

Described fixed part has: the 1st and the 2nd bearing, and they support the described 1st and the 2nd sliding part slidably, abut, be made up of nonmagnetic substance with the inner surface of described fixed part; And multiple coil, they are arranged on the inside of described fixed part, produce magnetic flux and act on described magnet portion, and make described movable part carry out relative displacement in the inner space of self,

About the described 1st and the 2nd sliding part, configure to the described 1st and the 2nd bearing lateral deviation heart relative to the section central shaft of the inner space formed by described coil by making the central shaft of the described 1st and the 2nd sliding part, and the described 1st and the 2nd sliding part abuts with the described 1st and the 2nd bearing, thus make magnetic attraction from described permanent magnet to eccentric direction effect.

5. linear motor according to claim 4, is characterized in that,

The interior profile of described fixed part is rectangular shape, and the described 1st and the 2nd sliding part is rectangular shape, and the section of the described 1st and the 2nd bearing is L-shaped shape.

6. linear motor according to claim 4, is characterized in that,

The interior profile of described fixed part is rectangular shape, and the described 1st and the 2nd sliding part is rectangular shape, and the section of the described 1st and the 2nd bearing is tabular.

7. a linear motor, it has: fixed part; And movable part, it is positioned at the inside of this fixed part, and this movable part is set to, and can carry out relative displacement in the axial direction relative to this fixed part,

The feature of this linear motor is,

Described fixed part has: the 1st intermediate member, and it is made up of magnetic material, relative to the central shaft of described fixed part, is fixed on the inner surface of described fixed part in the mode of rotation asymmetry; 1st bearing, it supports described 1st sliding part slidably, abuts, be made up of nonmagnetic substance with described 1st intermediate member; And multiple coil, they are arranged on the inside of described fixed part, produce magnetic flux and act on described magnet portion, and make described movable part carry out relative displacement in the inner space of self,

Described 1st sliding part by abutting with described 1st bearing, thus makes the magnetic attraction from described permanent magnet act on to described 1st intermediate member side.

8. linear motor according to claim 7, is characterized in that,

The interior profile of described fixed part is rectangular shape, and described 1st sliding part is rectangular shape, and the section of described 1st bearing and described 1st intermediate member is L-shaped shape.

9. linear motor according to claim 7, is characterized in that,

The interior profile of described fixed part is rectangular shape, and described 1st sliding part is rectangular shape, and the section of described 1st bearing and described 1st intermediate member is tabular.

10. a linear motor, it has: fixed part; And movable part, it is positioned at the inside of this fixed part, and this movable part is set to, and can carry out relative displacement in the axial direction relative to this fixed part,

The feature of this linear motor is,

Described fixed part has: the 1st and the 2nd intermediate member, and they are made up of magnetic material, relative to the central shaft of described fixed part, are fixed on the inner surface of described fixed part in the mode of rotation asymmetry; 1st and the 2nd bearing, they support the described 1st and the 2nd sliding part slidably, abut, be made up of nonmagnetic substance with the described 1st and the 2nd intermediate member; And multiple coil, they are arranged on the inside of described fixed part, produce magnetic flux and act on described magnet portion, and make described movable part carry out relative displacement in the inner space of self,

Described 1st and the 2nd sliding part by abutting with the described 1st and the 2nd bearing, thus makes the magnetic attraction from described permanent magnet act on to the described 1st and the 2nd intermediate member side.

11. linear motors according to claim 10, is characterized in that,

The interior profile of described fixed part is rectangular shape, and the described 1st and the 2nd sliding part is rectangular shape, and the section of the described 1st and the 2nd bearing and the described 1st and the 2nd intermediate member is L-shaped shape.

12. linear motors according to claim 10, is characterized in that,

The interior profile of described fixed part is rectangular shape, and the described 1st and the 2nd sliding part is rectangular shape, and the section of the described 1st and the 2nd bearing and the described 1st and the 2nd intermediate member is tabular.