Linear Motor Technology

Transcription

1 Linear Motor Technology ---Possible! Only with Linear Motor Technology--- September 29, 2005

2 Major Positioning Axis for Machine Tools Where Linear motors are used All axes for Wire-cut EDM Z Axis Tool Work Piece U Axis V Axis X Axis Linear Encoder Y Axis Tapered workpiece Z-axis X Axis Y Axis For : Machining center,edm, etc For : Wire-cut EDM

3 Linear Motor vs Rotary Motor Coil Encoder Coupling Linear scale Magnet plate Motor Ball screw Linear scale Encoder Encoder Table Table Linear motor Motor Magnet Guide Guide Ball screw Positioning direction = Direction which accuracy is needed.

4 Problem to change Rotary Movement to Linear Movement Accuracy changes over the years Energy ½ M V 2 Friction ½ M V 2 +½ I 2 Accuracy deteriorates Table Table Linear motor Motor Magnet Guide Guide Ball screw Positioning direction=direction which accuracy is needed

5 Linear Motor & Rotary Motor Conclusion Linear motor Linear move Direct drive Rotary motor Rotary move

6 Linear Axis for Machine Tools Z Axis Tool Work Piece X Axis Linear Encoder U Axis V Axis Tapered workpiece Y Axis X Axis Y Axis Machining Center, Die-sinker EDM etc Wire-cut EDM

7 Linear Motor for Machine Tools How the magnetic field is formed Move

8 Subject of Linear Motor with Machine Tools No. 1 Thermal problem caused by motor Heat affects accuracy Mechanical accuracy, such as Linearity accuracy, pitch accuracy, etc deteriorates. Thermally affected area Scratch on the guide may shortens the life

9 Subject of Linear Motor with Machine Tools No. 2 Problem of motor attractive force

10 Subject of Linear Motor with Machine Tools No. 3 Weak against outer force Outer force Table Total weight of moving portion Outer force Table Total weight of moving portion Motor Inertia m Friction:F1 Guide Reaction:F2 Guide Friction: F1 Ball screw Inertial b Lead BP

11 Method to Solve the Subject Thermal problem Linear motor cooling construction Attractive force problem Outer force problm Machine construction design Linear motor selection

12 Solution for Thermal Problem by Linear motor cooling construction (1) Coil Coolant circulates inside to maintain the temperature at the same point. Coil used for our SODICK EDM continuous rating: Cooling fluid: Lubrication fluid Aluminum piping type) Water cooling Copper piping type

13 Thermal Solution by Linear motor cooling construction (2) Top side of coil Coolant Coil Silicon steel plate

14 Thermal Solution by Linear motor cooling construction (3) Temperature rise 80 3 Temperature rise without coolant Temperature rise with coolant

15 Die-sinker EDM Machining theory of die-sinker EDM Resistor Dielectric fluid Electrode Transistor Power supply Debris particles Workpiece

16 Die-sinker EDM: AQ35L 3-axis linear motor is in use Main machine spec Table size mm Inner size of worktank mm X-axis travel 350mm Y-axis travel 250mm Z-axis travel 250mm Max. weight of workpiece 550Kg Max. load on table 50Kg Machine body size mm Machine body weight 3900Kg Energy reduction: Compared with former models: 40% less due to 2 times cutting speed faster, and modified power supply AQ25L AM25L AQ55L AM55L)

17 AQ series: Z-axis Z construction. 1 Cooling pipe Coil Linear scale Magnet Ceramic prop Guide Ceramic plate By cooling coil itself, temperature of linear motor is at ambient temperature + 2

18 AQ series: Z-axis Z construction 2 Min. move increment:0.1, Acceleration speed:1.2g, Max. feed rate: 36m/min High accuracy positioning: 0.1 Magnet To increase the acceleration, its weight needs to reduce. In-house ceramic is in use. High rigidity, light weight, low thermal expansion (1/3 of cast iron) High thrust power is needed In-house developed AC linear motor with core By cooling coil, the temperature of linear motor is within ambient temperature+2 without cooling: 45 Coil Linear motor drive & servo control In-house motion controller is in use. High speed response Linear motors are symmetrically allocated to get rid of attractive force. Magnet plates are adhered onto quill. Coils are arranged on both sides. High accuracy is achieved.

19 Machining depth (mm) Machining sample. 1 (by Die-sinker EDM) No flush cutting Current linear motor drive machine When linear machine was introduced Ball screw machine Electrode Copper(2 pc.) Workpiece Die steel Electrode size 20 x 20 mm Size reduction 0.4 mm side Machining depth 30 Surface roughness 5 mry Finishing time 110 minutes Rough cutting time (min)

20 Machining sample, 2 (by die-sinker EDM) Deep rib machining by graphite electrode (without flushing) 2 h 10 m(70 mm)(no flushing) Machining depth (mm) Linear motor MC Conventional ball screw MC 2 h(40 mm) Machining time (min)

21 Machining sample, 3 (by die-sinker EDM) Cutting condition ON300 OFF140 IP10 Electrode Cu (10 10mm) Workpiece SKD11 Cutting depth:30mm Sodick linear motor drive technology can produce: 1) Max.Z-axis speed: 36 mm/min 2) Debris particles can be flown out thanks to high speed jumping. 3) No debris particles, no 2 nd discharge 4) Wall can be straight without 2 nd discharge Cutting depth (mm) Left side gap(mm) Electrode Flushing nozzle Right side gap(mm) Jump speed 1m/min (no flush) Jump speed 1m/min Flush:0.05MPa Jump speed 36m/min No flush

22 Machining sample 4 (by Die-siner EDM) Z-axis cutting direction By repeating measurement & cutting, ultra accurate & micro machining is achieved. AP1L Premium

23 Wire-cut EDM Basic theory of Wire-cut EDM Wire electrode Condenser Workpiece Power supply Dielectric fluid

24 Accuracy is maintained over the years, because of direct drive Roundness after 4 years installation Roundness after 10 years installation

25 Machining Capability of AP200L 20 mm / Oil fluid / 10th CUT Thickness :20mm Workpiece : SKD11 Model :AP200L Taylor Hobson Talyrond 250 Roundness: 0.68 m Measurement mode: Internal

26 Machining Capability of EXC100L Workpiece : Optical fiber connector Hole diameter pitch accuracy: within 0.5 m

27 Linear Milling Machine: MC430L Main spec: Travel(X,Y,Z : Max. load on table: 10 Machine dimension: W D H (Power supply/service tank are included) This machine is equipped with in-house built high performance cooling capacity linear motor with core Low portion heavy & rigid construction

28 MC430L X-axis construction Linear motor (4 pc)

29 MC430L Cutting Sample Size : 0.2 mmt 15 mmh Top Taper 0.1 mmt) Material Copper Cutting time 134 min Rough 48 min Finish 86 min Cutting condition : Spindle speed 20,000-30,000 min-1 Cutting feed speed 2, mm/min Cutting depth(ad/rd) : To be advised separately Cutting tool 2 tools This thin slit is cut by very small chip each-cut. This method is only possible with high speed spindle & linear motor accurate move

30 No vibration & High speed machining Model : AZ 150 Machining optics, medicals, etc with high speed, high accuracy Development concept for AZ 150 In order to minimize the vibration at time of high speed move, control mechanism is used to cancel X,Y-axis. To minimize the swing & expansion of spindle, pneumatic static bearing is used for spindle. High frequency induction Shrink-fit holder is directly mounted onto spindle to enable full automated operation

31 Construction to Enable Vibration Free Newly developed active vibration-free table, enabling high speed & micron feed. A table has dual tables, which move at opposite directions to balance the movement. table Counter-table Model table to explain counter movement

32 High Speed Linear Press SP100LX

33 Construction of SP100LX Power-up of linear motor, while minimizing vibration with original X-axis construction Linear Linear motor motor coil coil 8 pc pc Roller Roller guide guide Move Move plate plate Magnet Magnet plat plat 4 pc pc

34 Machining Capability of SP100LX Machining by parts mold for tape Mold shape Machining

35 Ultra Precision Machine Super NANO 100 Nano EDM AE 05

36 Element Technology to Produce Ultra Accuracy Machining Sodick s Development starts with the development of basic element. NC CONTROL, Motion control: Developed by Sodick Developed by Sodick Material : Ceramic Drive : Linear motor (core-less)

37 Element Technology for Ultra Accuracy Machining Table size : mm Guide : 80 80mm Travel : 100mm Z-axis, small stroke guide Bearing rigidity : Horizontal : 200N/ m Vertical :200N/ m Air consumption: 7 Nl/min Linearity: 0.04 /100 Linearity: 0.10 /100 Measurement is done by reversing, using glass mirror and electric micrometer.

38 NANO Positioning Technology

39 Orifice Drilling Sample by NANO EDM Tungsten carbide electrode is formed on the EDM itself. With a minute feed, the drilling smaller than 3 m has become possible 1.8 Tungsten carbide electrode 2.9 orifice 5

40 Future Popularity for Linear motor Large machine With a thrust ripple of a Core Linear motor and modified thrust ripple, smaller than 3 m minute cutting has become possible. Small machine With high rigidity of core-less linear motor and reduced thrust ripple, 1 m cutting feed has become possible. Ultra Precision Machine Small than 1A stop accuracy by higher performance motor. Cutting move accuracy with less than 10 NANO meter.

41 ---Possible! Only with Linear Motor Technology---