CN103460575A

CN103460575A - Linear motor

Info

Publication number: CN103460575A
Application number: CN2011800699576A
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: 2013-12-18
Anticipated expiration: 2031-04-04
Also published as: JP5306558B2; TWI426684B; TW201242222A; CN103460575B; KR20130115400A; KR101374464B1; WO2012137241A1; JPWO2012137241A1

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 that is configured between movable part and fixed part and with respect to the slide unit of the eccentricity of central axis configuration of fixed part.

Background technology

In existing linear motor, spindle unit (the 1st sleeve) adopts following structure: section alternately forms the permanent magnet of the N utmost point and the S utmost point along axis direction within it, and is provided with the magnetic (yoke) for improving thrust between permanent magnet.The coil that the periphery of spindle unit is surrounded is arranged on movable part, in the inboard of the movable part that is positioned at the spindle unit outer circumferential side, is provided with bearing, and this bearing relatively carries out rectilinear motion with respect to movable part along the axis direction of spindle unit for the leading axle parts.The linear motor formed as mentioned above forms following structure: cylinder or square bearing and movable part are configured centered by spindle unit, for successfully being carried out, relative motion is provided with small gap (for example,, with reference to patent documentation 1) between bearing and spindle unit.

Patent documentation 1: Japanese kokai publication hei 9-182408 communique (the 4th page, Fig. 1)

Summary of the invention

Existing linear motor forms 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, for example, be provided with mechanically in the shaft type linear motor of the axle of movable part transmitting thrust the problem that exists the positioning precision of axle leading section to descend.

The present invention proposes in order to address the above problem, and its purpose is, does not make to produce and rock or change between bearing and spindle unit, for example, 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 along axis direction with respect to fixed part, and movable part has: magnet portion, it consists of a plurality of permanent magnets stacked on axis direction; And the 1st sliding part, it is configured in a leading section of magnet portion, in the inside of fixed part along the axis direction sliding guidance, magnetic material, consist of, fixed part has: the 1st bearing, and it supports the 1st sliding part slidably, inner surface butt with fixed part, consist of nonmagnetic substance; And a plurality of coils, 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, central shaft by making the 1st sliding part configures to the 1st bearing lateral deviation heart with respect to the section central shaft of the inner space formed by coil, and the 1st sliding part and the 1st bearing butt, thereby make magnetic attraction from permanent magnet to the eccentric direction effect.

The effect of invention

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

The accompanying drawing explanation

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

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

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

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

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

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

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

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

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

Embodiment

Embodiment 1

Fig. 1 means embodiments of the invention 1, is the profile of shaft type linear motor, and Fig. 2 means embodiments of the invention 1, is the exploded perspective view of shaft type linear motor.In Fig. 1 and Fig. 2, the 1st, the fixed part of shaft type linear motor, the 2nd, the movable part of shaft type linear motor, can carry out relative displacement along axis direction with respect to fixed part 1.31 work as the 1st bearing, that section forms the sliding bearing of L word shape vertically, the 51st, lead-in wire for power supply, the 11st, for produce a plurality of coils of magnetic flux with lead-in wire 51 inflow currents from power supply, the 12nd, by the resinous bobbin of a plurality of coil 11 insulation, the 13rd, become the upper frame of the magnetic loop of produced magnetic flux, the 14th, become the magnetic loop of produced magnetic flux, section forms the underframe of U word shape vertically, the 15th, for improving the pedestal of mechanical rigid, the 16th, the bearing that axle is supported, the 17th, the carriage of maintenance bearing 16, the 18th, prevent the cover body that foreign matter enters, the 41st, position detector, fixed part 1 is by sliding bearing 31, coil 11, bobbin 12, upper frame 13, underframe 14, pedestal 15, bearing 16, carriage 17, cover body 18 and position detector 41 form.

On the other hand, the 32nd, the slide unit worked as the 1st sliding part, carry out sliding guidance on the surface of sliding bearing 31, the 21st, magnet portion, be a plurality of permanent magnets of laminated configuration, for by and the magnetic flux that produces of a plurality of coil 11 between interact, thereby produce thrust.22 is dividing plate, it consists of magnetic material or nonmagnetic substance, with the N utmost point that alternately forms stacked a plurality of permanent magnets 21 on axis direction and the mode of S utmost point magnetic pole, be configured between a plurality of permanent magnets 21, the 23rd, the axle bonded block, the 24th, mechanically transmit the axle of produced thrust, movable part 2 consists 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.Stretch out to the outside of fixed part 1 another end of axle 24, for position probing.The central shaft of the central shaft of the central shaft of a plurality of permanent magnets 21, 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, forms the structure that can move along the Z direction in Fig. 1.In addition, be configured in the outside of a plurality of permanent magnets 21, the central shaft of the central shaft of a plurality of coils 11 and a plurality of bobbin 12 aligns with the central shaft of axle 24 respectively a plurality of coils 11 and a plurality of bobbin 12 concentric shapes.

The 42nd, scale, the 25th, the axle leading section of axle 24, the 26th, scale bonded block, the 52nd, lead-in wire for position detector.Scale 42 adopts following structure, that is, by scale bonded

block

26 and 25 combinations of axle leading section, can move with the movement of axle 24 with matching.In addition, scale 42 adopts following structure,, section records the positional information of optical profile type or magnetic-type within it, the position detector 41 of utilization and fixed part 1 combination, the position of the Z direction in Fig. 1 of detection axle 24, use lead-in wire 52 to control part transmission position signalling from position detector.

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

Fig. 3 means embodiments of the invention 1, is the structure chart of the control part of shaft type linear motor.In Fig. 3, the 90th, control part, the 100th, shaft type linear motor.The 91st, position control circuit, the 92nd, speed control circuit, the 93rd, current control circuit, the 99th, current detector, control part 90 consists of position control circuit 91, speed control circuit 92, current control circuit 93, current detector 99.

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

Fig. 4 means embodiments of the invention 1, is the structure chart of the sliding bearing of shaft type linear motor.The 61st, magnetic flux, 62a and 62b are the magnetic attractions that the impact of the magnetic flux 61 that produces due to permanent magnet 21 produces.

Sliding bearing 31 is resin (nonmagnetic substance), and as shown in the A-A ' section of Fig. 4, section forms the L word shape vertically.On the other hand, slide unit 32 is for example the S50C material, and upper frame 13 and underframe 14 are for example the SPCC material, are magnetic material.Here, slide unit 32 is set to, with central shaft the decentraction of the inner space of the coil 11 of the concentric shape of the central shaft with respect to axle 24 configuration, but to the sliding bearing 31 lateral deviation hearts.Its result, the gap that gap between slide unit 32 and upper frame 13, slide unit 32 and underframe are 14, existing this side of sliding bearing 31 that not to be present in section be the L word shape is (in the A-A ' of Fig. 4 section, left surface and lower surface for slide unit 32), but be present in and do not have sliding bearing 31 these sides (in the A-A ' of Fig. 4 section, being right flank and the upper surface of slide unit 32) across the distance ground of regulation each other.

In the A-A ' of Fig. 4 section, magnetic flux 61 is respectively formed between the upper frame 13 and permanent magnet 21 as magnetic material, between the lower surface and permanent magnet 21 of the underframe 14 that is the U word shape between two sides and permanent magnet 21 as the underframe 14 of the U word shape of magnetic material, as magnetic material and section.Impact due to formed magnetic flux 61, at the slide unit 32 as magnetic material, as producing

magnetic attraction

62a and 62b between the underframe 14 of the upper frame 13 of magnetic material and U word shape, but because slide unit 32 existing this side of sliding bearing 31 that the section of framework 14 is the L word shape on the lower partially arranges, therefore, due to partially leaning on of this slide unit 32, existing this side of the sliding bearing 31 that magnetic attraction 62a is the L word shape at section is (in the A-A ' of Fig. 4 section, left surface and lower surface for slide unit 32) effect strongly, magnetic attraction 62b does not exist this side (in the A-A ' of Fig. 4 section at 31, the sliding bearing of L word shape, right flank and upper surface for slide unit 32) generation effect hardly.

In the shaft type linear motor formed as mentioned above, the state that the sliding bearing 31 that slide unit 32 is the L word shape with section contacts in the magnetic attraction 62a to fix all the time, therefore, there do not is gap between slide unit 32 and sliding bearing 31, its result, there do not is due to what gap caused, rocking or change of producing in the structure of existing shaft type linear motor, can improve the positioning precision of axle leading section 25.In addition, in the situation that directly gap is dwindled in the structure of existing shaft type linear motor, must process accurately the size of slide unit 32 and sliding bearing 31, but needn't carry out this processing in the structure of the shaft type linear motor in the present embodiment 1.

Above, structure according to the shaft type linear motor of explanation in the present embodiment 1, can improve the positioning precision of the axle leading section of shaft type linear motor, therefore, the shaft type linear motor can be applicable in surface mounting apparatus and substrate detection machine, for example can be by the parts densification of installing on electric substrate.

Embodiment 2

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

Embodiment 3

In embodiments of the invention 1 and embodiment 2, two faces for the sliding bearing 31 that uses the L word shape guarantee that the situation of the positional precision of X and Y-direction is illustrated, but be only for example directions X of a direction in the situation that require the direction of positional precision, as shown in Figure 6, sliding bearing 35 also can form the tabular parallel with the lower surface of underframe 14 vertically.In the case, also can access the effect identical with embodiment 1 and embodiment 2.

Embodiment 4

Fig. 7 means 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 Fig. 7 as intermediate member.

Sliding bearing 31 is resin (nonmagnetic substance), and as shown in the A-A ' section of Fig. 7, section forms the L word shape vertically, with right flank and the upper surface butt of intermediate member 71.In addition, intermediate member 71 is that as shown in the A-A ' section of Fig. 7, section forms the L word shape vertically, with left surface and the lower surface butt of underframe 14 such as magnetic materials such as SPCC materials.On the other hand, slide unit 32 for for example SPCC material, is magnetic material for for example S50C material, upper frame 13 and underframe 14.Here, slide unit 32 arranges alignedly with the central shaft of the inner space of the coil 11 of the concentric shape configuration of the central shaft with respect to axle 24.Its result, gap between gap between slide unit 32 and upper frame 13, slide unit 32 and underframe 14, the sliding bearing 31 that not to be present in section be the L word shape and existing this side of intermediate member 71 are (in the A-A ' of Fig. 7 section, left surface and lower surface for slide unit 32), but be present in sliding bearing 31 and there is not this side (in the A-A ' of Fig. 7 section, being right flank and the upper surface of slide unit 32) in 71 of intermediate members across the distance ground of regulation each other.

In the A-A ' of Fig. 7 section, magnetic flux 61 is respectively formed between the upper frame 13 and permanent magnet 21 as magnetic material, between the right flank and permanent magnet 21 of the intermediate member 71 that is the L word shape between the lower surface and permanent magnet 21 of the intermediate member 71 that is the L word shape between right flank and permanent magnet 21 as the underframe 14 of the U word shape of magnetic material, as the section of magnetic material, as the section of magnetic material.Impact by formed magnetic flux 61, at the slide unit 32 as magnetic material, upper frame 13 as magnetic material, produce

magnetic attraction

62a and 62b between the underframe 14 of U word shape and the intermediate member 71 of L word shape, but existing this side of the sliding bearing 31 that magnetic attraction 62a is the L word shape at section and intermediate member 71 is (in the A-A ' of Fig. 7 section, left surface and lower surface for slide unit 32) effect strongly, magnetic attraction 62b does not exist this side (in the A-A ' of Fig. 7 section at sliding bearing 31 and 71 of the intermediate members of L word shape, right flank and upper surface for slide unit 32) effect hardly.

In the shaft type linear motor formed as mentioned above, the state that the sliding bearing 31 that slide unit 32 is the L word shape with section contacts in the magnetic attraction 62a to fix all the time, therefore, there do not is gap between slide unit 32 and sliding bearing 31, its result, there do not is due to what gap caused, rocking or change of occurring in the structure of existing shaft type linear motor, can improve the positioning precision of axle leading section 25.In addition, in the situation that directly gap is dwindled in the structure of existing shaft type linear motor, must process accurately the size of slide unit 32 and sliding bearing 31, but not need to carry out this processing in the structure of the shaft type linear motor in the present embodiment 1.

Above, structure according to the shaft type linear motor of explanation in the present embodiment 4, can improve the positioning precision of the axle leading section of shaft type linear motor, therefore, the shaft type linear motor can be applicable in surface mounting apparatus and board inspecting machine to the parts densification that for example can install to electric substrate.

Embodiment 5

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

Embodiment 6

In embodiments of the invention 4 and embodiment 5, two faces for the intermediate member 71 that uses the L word shape guarantee that the situation of the positional precision of X and Y-direction is illustrated, but be only for example directions X of a direction in the situation that require the direction of positional precision, as shown in Figure 9, also can be along axially intermediate member 75 being formed to the tabular parallel with the lower surface of underframe 14.In the case, also can access the effect identical with embodiment 5 with embodiment 4.

In the structure of the shaft type linear motor illustrated in the present embodiment 4 to embodiment 6, situation about forming as individual components respectively for

intermediate member

71,71a, 71b and underframe 14 is illustrated, but have in the structure of the so new underframe 14 of

intermediate member

71,71a, 71b at underframe 14, 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 the shaft type linear motor, but be not limited to this, even be applied to, in other linear motor, also can obtain identical effect.

The explanation of label

1 fixed part, 2 movable parts, 11 coils, 12 bobbins, 13 upper frames, 14 underframes, 15 pedestals, 16 bearings, 17 carriages, 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, the 31a sliding bearing, the 31b sliding bearing, 32 slide units, the 32a slide unit, the 32b slide unit, 35 sliding bearings, 41 position detectors, 42 scales, lead-in wire for 51 power supplys, lead-in wire for 52 position detectors, 61 magnetic fluxs, the 62a magnetic attraction, the 62b magnetic attraction, 71 intermediate members, the 71a intermediate member, the 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 along axis direction with respect to this fixed part,

This linear motor is characterised in that,

Described movable part has: magnet portion, and it consists of a plurality of permanent magnets stacked on axis direction; And the 1st sliding part, it is configured in a leading section of this magnet portion, in the inside of described fixed part, along the axis direction sliding guidance, by magnetic material, is formed,

Described fixed part has: the 1st bearing, and it supports described the 1st sliding part slidably, and the inner surface butt with described fixed part, consist of nonmagnetic substance; And a plurality of coils, they are arranged on the inside of described fixed part, and 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 the 1st sliding part, central shaft by making described the 1st sliding part with respect to the section central shaft of the inner space formed by described coil to described the 1st bearing lateral deviation heart configuration, and described the 1st sliding part and described the 1st bearing butt, thereby make magnetic attraction from described permanent magnet to the 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 the 1st sliding part is rectangular shape, and the section of described the 1st bearing is the L word shape.

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

The section of described the 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 along axis direction with respect to this fixed part,

This linear motor is characterised in that,

Described movable part has: magnet portion, and it consists of a plurality of permanent magnets stacked on axis direction; And the 1st and the 2nd sliding part, they are configured in two leading sections of this magnet portion, in the inside of described fixed part, along the axis direction sliding guidance, by magnetic material, are formed,

Described fixed part has: the 1st and the 2nd bearing, and they support the described the 1st and the 2nd sliding part slidably, and the inner surface butt with described fixed part, consist of nonmagnetic substance; And a plurality of coils, they are arranged on the inside of described fixed part, and produce magnetic flux and act on described magnet portion in the inner space of self, and making described movable part carry out relative displacement,

About the described the 1st and the 2nd sliding part, by make the described the 1st and the central shaft of the 2nd sliding part with respect to the section central shaft of the inner space formed by described coil, to the described the 1st and the 2nd bearing lateral deviation heart, configure, and the described the 1st and the 2nd sliding part and the described the 1st and the 2nd bearing butt, thereby make magnetic attraction from described permanent magnet to the 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 the 1st and the 2nd sliding part is rectangular shape, the described the 1st and the section of the 2nd bearing be the L word shape.

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

The described the 1st and the section of the 2nd bearing be 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 along axis direction with respect to this fixed part,

This linear motor is characterised in that,

Described fixed part has: the 1st intermediate member, and it consists of magnetic material, with respect to the central shaft of described fixed part, is fixed on the inner surface of described fixed part in the mode of non-rotating symmetry; The 1st bearing, it supports described the 1st sliding part slidably, with described the 1st intermediate member butt, nonmagnetic substance, consists of; And a plurality of coils, they are arranged on the inside of described fixed part, and produce magnetic flux and act on described magnet portion in the inner space of self, and making described movable part carry out relative displacement,

Described the 1st sliding part by with described the 1st bearing butt, thereby make magnetic attraction from described permanent magnet to described the 1st intermediate member side effect.

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

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

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

The section of described the 1st bearing and described the 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 along axis direction with respect to this fixed part,

This linear motor is characterised in that,

Described fixed part has: the 1st and the 2nd intermediate member, and they consist of magnetic material, with respect to the central shaft of described fixed part, are fixed on the inner surface of described fixed part in the mode of non-rotating symmetry; The the 1st and the 2nd bearing, they support the described the 1st and the 2nd sliding part slidably, with the described the 1st and the 2nd intermediate member butt, nonmagnetic substance, consist of; And a plurality of coils, they are arranged on the inside of described fixed part, and produce magnetic flux and act on described magnet portion in the inner space of self, and making described movable part carry out relative displacement,

The the described the 1st and the 2nd sliding part by with the described the 1st and the 2nd bearing butt, thereby make magnetic attraction from described permanent magnet to the described the 1st and the 2nd intermediate member side effect.

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

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

12. linear motor according to claim 11, is characterized in that,

The the described the 1st and the 2nd bearing and the described the 1st and the section of the 2nd intermediate member be tabular.