linear motor technology.pdf

8/11/2019 Linear Motor Technology.pdf

1/73

Linear Motor Technology

Motor & Drive Systems Conference 2008

Jrgen Khnle

TD-PE/Jrgen Khnle Linear Motor Technology 25 January 2008 modified: 25 January 2008, JKHL


2/73

A small linear motor history

Who discovered the basics of the linear motor technology?

When was the first linear motor designed?

When was the first patent applied for?

TD-PE/Jrgen Khnle Linear Motor Technology 25 January 2008 modified: 25 January 2008, JKHL 2


3/73

c ae ara ayBuilds the first experimentalelectrical motor

1831 Michael Faraday (UK)Explain the electrical induction



4/73

or tz . von aco ermanyFirst usable electrical motor



5/73

ames er axweTheory of electrodynamicsand their mathematical

formulas.



6/73

arce eprez ranceElectric hammer with linearmotor



7/73


8/73

We discussing about a very old technology

First linear motor application 1882125 ears a o

First patent 1885



9/73

Linear Motor Technology

Linear motor technologies (application view)

SWOT analysis of these linear motor technologies



10/73

Linear Motor Technologies (Application View)

Customers are interested in the solution of their application and not the specific linear motorec no ogy. e ma n cr er a or e se ec on o near mo ors are:

Dynamics for short positioning times

Or Accuracy

Customers are looking mainly on the difficulties in the application. The technology based maindisadvantages are:

e magne s genera e a s rong magne c e w g a rac on orce o ron par s.

Due the used materials (iron, copper, steal) are the linear motors very heavy.



11/73

Linear Motor Flat Bed

Every rotary motor Theoretical the rotary And formed to a flatpr nc p e can e use

to build linear motorsmotor can be cut bed linear motor



12/73

Flat Bed Linear Motor Technologies (Application View)

Linear motors with permanent magnets Linear motors without permanent magnets

Bed with permanent magnets

Main advantage

High power density

Bed with sheeted metal

Main advantage

No magnetic fields

Main disadvantage

Permanent magnets attract iron parts withhigh force.

Main disadvantage

Power density is poor.

bed. A good linear guide system is necessary.



13/73

Tubular Linear Motor

Flat bed linear motor

the side

To get a tubular linear



14/73

Tubular Linear Motor Technologies (Application View)

Short Coil System Long Coil System

Main advantage High power density

system Main advantage

No external ma netic fields

Permanent magnets attract iron parts withhigh force.

Main disadvantage

Reduced power density



15/73

SWOT Analysis Linear Motors with Permanent Magnets

Strength Weakness High power density

High load capacity

High attraction force between slider and bed

Heavy duty linear guide system necessary

Difficult assembly due high attraction force

Magnets get more and more expensive

Opportunity

Highest load carrying capacity

Threats

Permanent magnets can loose Machining centers c arac er s cs, magne empera ure

exceeds 8090C



16/73

SWOT Analysis Linear Motors without Permanent Magnets

Strength Weakness No external magnetic field

High load capacity

Air bearing easy possible

Poor power density

Machining of the bed is very expensive

With air bearing smooth operation possible

Opportunity

Due the smooth operation ideal for

Threats

Very heavymeasur ng mac nes an g accuracy



17/73

SWOT Analysis Linear Motors Short Coil System

Strength Weakness High power density

Simple production

High attraction force between slider andmagnetic rod

Difficult assembly due high attraction force

Magnets get more an more expensive

Opportunity

Compact design

Threats

Permanent magnets can loose Handling c arac er s cs, magne empera ure

exceeds 8090C



18/73

SWOT Analysis Linear Motors without Permanent Magnets

Strength Weakness No external magnetic field

High load capacity

Drive similar to pneumatic cylinders

Poor power density

Opportunity

Change of pneumatic cylinder designs to

Threats

Very heavynear mo ors



19/73

Comparison Between the Different Linear Motor Technologies

Drive Flat bed with Flat bed Short coil Long coiltechnology permanent

magnets

without

magnets

system system

Load 200 kg 200 kg 200 kg .200 kg

Stroke 10 m 10 m 3 m 0.5 m

Velocity 10 m/s 4 m/s 10 m/s 3 m/s

Acceleration 250 m/s 80 m/s >250 m/s >250 m/s

rec s on . .

Externalmagnetic

Yes No Yes No


Guide system Circulating balllinear guide

Air bearing;Linear guides

Slider bearing;Linear guides

Slider bearing;Linear guides


20/73

Hybrid Linear Motor Technology

Combination of linear motor and pneumatic in one axis

SWOT analysis of the hybrid linear motor technology



21/73

Comparison Servo-Pneumatic Drive with Linear Direct Drive

Servo-Pneumatic Drive Linear Direct Drive

High speed (3 m/s)

Medium acceleration (30 m/s)

Slow force generation (30 ms)

High speed (>3 m/s)

High acceleration (150 m/s)

Quick force generation (1 ms) Medium accuracy (0,1 mm)

Complex control loop

High power density

High accuracy (1 m)

Simple control loop

Low power density


Cost efficient

No heat generation

High purchasing costs

Strong heat generation

21


22/73

Comparison Dynamic Force Generation: Linear Direct Drives

Linear Direct Drive

peak force

Quick force generation

force reduction 1

controller amplifier: overheat

- .

Force must be reduced. Reasons:

Force reduction 2

linear motor: overheat

-

after 1 s: overheating of thecontroller amplifier

Depends on the cooling

after 110 min: overheating ofthe linear motor


me1 ms 1 - 10 min1 s


23/73

Comparison Dynamic Force Generation: Pneumatic Cylinder

pneumatic cylinder

peak force = continuous force

Slow force generation

No temperature depending force

(depending on the

iston osition


me10 ms 100 ms


24/73

Comparison Dynamic Force Generation: Hybrid Axis

peak force linear motor + pneumatic Ideal force generation

No force reduction necessary

1,5 times peak force

2 5 times continuous force

1 ms 1 min1 s time



25/73

Force distribution in the frequency domain

High frequency components of the reference force are the inputs of the current controller

Low frequency components of the reference force are the inputs of the pressure controller


n s way: au oma c compensa on o s a c orce e grav y


26/73

Measurement data of a positioning experiment

Total Force

ec r ca orce

Pneumatic Force

Forc

[N]

Mass load 5 kg

Positioning time 0.35 sec


Time[sec]


27/73

System ConceptFCT Software

Hybrid Axis + Internal Interface

motor +

temperature ext. Controller

ition

ramming

internal

wiring

switch

measuring

system

48Vfirmware

for interface

pressuresensors

Posi

pro

pneumatic

controlsignal

firmware

for controller

connections

Platform:

HME + HMP cylinder

+ pressure sensors

compressed airmax. 500 mm

servo valve

6 bar

220V


power supply

supply

(volume / filter)


28/73

Technical Data HME-P

Project Hybrid Axis: Linear direct drive with pneumatic support

Mechanical dimension HME

More dynamic than the single linear motor

Linear direct drive

By redundant system higher security

Both drive systems work active controlled and parallel

Plug & Work

Guide

Low self-heating

Higher duty cycle

Size 16 2 Internal

Stroke [mm] 100, 200, 320 100, 200, 320,400

Thrustforce

Continuous [N] 140 260

Pneumatic cylinder

n er ace


Pea N 240 375

Repeatability [mm] 0.03 0.03


29/73

Comparison: Servo-Pneumatic, Linear Direct Drive and Hybrid Drive

ervo- neuma c near rec r ve y r r ve

Peak force 120 N 200 N 250 N

Absolute accuracy 0.2 mm 0.03 mm(temparture extenstion)

0.01 mm

Max. speed 3 m/s 3 m/s 3 m/s

Cycles/sec cont.

operation

1 1.2 2.0

Max. payload vertical 5 kg 2 kg 7 kg

Duty cycle at Fmax 100 % 5 % 50 %

Costs complete system 70 % 100 % 120 %



30/73

SWOT Analysis Hybrid Linear Motor Axis

Strength

Weakness g acce era on

High accuracy Double continuous force Three times eak force

g ynam cs on y w re a ve y smaloads

Expensive technology Stiff mountin surface necessar

Very compact design Low heat generation of the drive Higher security (redundant system)

Play in the assembly must be small Compressed air necessary Failure rate higher (more components)

unc on o a o ng ra e n egra e With same performance cheaper than a

comparable linear motor

ore cu ns a a on

Opportunity Offers highest possible dynamics Combination of dynamics and accuracy

Threats Belt driven systems can reach similar

dynamics, but the not the accuracy


Costs saving of 2535% of a linear motor

with similar performance


31/73

Why are linear motors necessary?

Where is the place of linear motors in the drive technologies?

SWOT analysis of the drive technologies and selection support



32/73


33/73

Elements Pneumatic Axis

Fixin holesfor load

Piston



34/73

General Technical Data Standard Pneumatic Load 100 kg

Symbol

Acceleration 30 m/s

Precision 100 m

Stiffness medium Stroke 10 m

*

Flexibility not programmable

Power Density high

a n enance ma n enance- ree



35/73

Applications Standard Pneumatic 1 axis application (example)

Assembly by force fitting

Load Medium 30 kg 100 kg 200 kg

Dynamics Medium 0,5 m/s 3 m/s >5 m/s

2 axis application (example)Assembly of bulb socket

Stroke Medium 2 m 5 m 10 m

Accuracy Low 100 m 50 m


36/73

SWOT Analysis Standard Pneumatic

Strength Weakness Low costs

High power density

Simple technology

Expensive energy

No low speeds possible

Constants speed difficult

overload possible

Long time holding force without additionalenergy

Noisy

leakage

Opportunity

Simple applications with 2 positions

Threats

Large number of competitors

(Servopneumatic)



37/73


38/73

SWOT Analysis Servo Pneumatic

Strength Weakness Low costs

High power density

Simple technology

Expensive energy

No low speeds possible

Constants speed difficult

overload possible

Long time holding force without additionalenergy

Noisy

Leakage

Strokes 202000 mm

Opportunity

Unique selling position of Festo (no

Threats

Technology unknowncompe or

Future: hybrid technology (combination ofpneumatics and electrical drives)

Energy costs

Price reduction of electrical drives



39/73

Belt Driven Axis

1. Elements

2. General Data

3. Applications

4. SWOT Analysis

Picture shows DGEL-_-ZR



40/73

Elements Belt Driven Axis

Fixing holese er or oa

Axis)

Pulley (inside

Axis)


Motor adaptor


41/73

General Technical Data Belt Driven Axis Load up to 200 kg

Symbol

Acceleration 100 m/s

Precision 100 m

230VAC

Stiffness medium Stroke up to 10 m

*

Flexibility high

Power Density medium

a n enance ma n enance- reeBelt axis

with

motor


The symbol of the mechanics is not included in a standard. We will use it in future for ProPne


42/73

Applications Belt Driven Axis 1 axis application (example)

Transport of parts in a machine

2 axis application (example)

Unloading parts from a machineLoad High 30 kg 100 kg 200 kg


Stroke Short 2 m 5 m 10 m

Accuracy Low 100 m 50 m


43/73

SWOT Analysis Belt Driven Axis

Strength Weakness Cost optimized electrical axis

Long strokes

Light weight

Medium stiffness

Belt sensitive against lubricants and solvents

Wear

X-lengths possible

Belt is exchangeable (cheap spare part)

High dynamics

Tension at long strokes

Damages due mechanical block possible

Opportunity

Dynamic applications

Threats

Large number of competitors



44/73

Lead Screw Axis

1. Elements

2. General Data

3. Applications

4. SWOT Analysis

Picture shows DGEL-_-SP-KF



45/73

Elements Lead Screw Axis

Motor

Bearing

Adaptor


Bearing Spindle Nut


46/73


47/73

Applications Lead Screw Axis 1 axis application (example)

Adjustment of positions (rare movements)

Load Medium 30 kg 100 kg 200 kg

Dynamics Low 0,5 m/s 3 m/s >5 m/s

Stroke Short 2 m 5 m 10 m

Accuracy Medium 100 m 50 m


48/73

SWOT Analysis Lead Screw Axis

Strength Weakness High forces

Medium accuracy

Interesting costs

Low speed

Medium acceleration

Lubrication very important

Self locking Friction (low efficiency)

Opportunity

Cost sensitive applications

Threats

Lifetime of the screw



49/73

Ball Screw Axis

1. Elements

2. General Data

3. Applications

4. SWOT Analysis

Picture shows DGEL-_-SP-KF



50/73

Elements Ball Screw Axis

Motor

Bearing

Adaptor


Bearing Spindle Nut


51/73

General Technical Data Ball Screw AxisLoad up to 200 kg

Symbol

Acceleration 50 m/s

Precision 20 m

230VAC

Stiffness highStroke up to 2 m

*

Flexibility high

Power Density medium

a n enance u r ca onScrew Axis

with

motor


The symbol of the mechanics is not included in a standard. We will use it in future for ProPne


52/73

Applications Ball Screw Axis 1 axis application (example)

Loading of machines (adjustable)

Load High 30 kg 100 kg 200 kg


2 axis application (example)Testing of printed circuit boards (PCB)

Stroke Short 2 m 5 m 10 mAccuracy High 100 m 50 m


53/73

SWOT Analysis Ball Screw Axis

Strength Weakness High forces

High accuracy

Medium speed

Medium acceleration

Limited strokes

Not repairable

Only standard strokes For longer strokes only limited speed

Opportunity

High loads with higher dynamics and

Threats

Costs for linear motors will fall

accuracy Belt systems can move similar loads, but notwith the accuracy



54/73

Linear Motor Axis

1. Elements

2. General Data

3. Applications

4. SWOT Analysis



55/73

Elements Linear Motor Axis

Slider with coils

Linear guide


Measuring system


56/73

General Technical Data Linear Motor Axis

Load up to 30 kg

Symbol

Velocity 510 m/s

Acceleration 150 m/s

Precision 3 m230VAC

Noise level low

Stiffness high (depends on motorcontroller) Motorcontroller

Stroke up to 10 m

Costs 4 * pneumatics

Flexibility high (free programmable)

Power Density low

Maintenance lubrication of guides

M

3 ~Linear Motor



57/73

Applications Linear Motor Axis 1 axis application (example)

Loading of machines (precise) 2 axis application (example)

Positioning for optical quality test

3 axis application (example)

Load Low 30 kg 100 kg 200 kg

Dynamics High 0,5 m/s 3 m/s >5 m/s

Filling of micro arraysStroke Long 2 m 5 m 10 m

Accuracy High 100 m 50 m


58/73

SWOT Analysis Linear Motor Axis

Strength Weakness

High acceleration

High speeds

High accuracy

High dynamics only with relatively smallloads

Expensive technology

Long strokes Often specialist nowle ge necessary

Stiff mounting surface necessary Play in the assembly must be small

Opportunity

Offers highest possible dynamics

Threats

Belt driven systems can reach similar

Combination of dynamics and accuracy ynam cs, u e no e accuracy



59/73

Comparisons Electrical Axis

Content

Comparison Between the Different Axis Technologies (Technical Data)

Comparison Between the Different Axis Technologies (Recommendation)

Selection of Axis Technologies Based on the Needs of the Application



60/73

Comparison Between the Different Axis Technologies (Technical Data)

Drive Standard Belt Driven Screw Driven Ball Screw Linear Motortechnology Pneumatics Axis Axis Driven Axis Axis

Load Up to 100 kg Up to 200 kg Up to 100 kg Up to 200 kg Up to 30 kg

Stroke Up to 8.5 m Up to 10 m Up to 2 m Up to 2 m Up to 10 m

3 m s 510 m s 0 5 m s 35 m s 510 m s

Acceleration 30 m/s 100 m/s 30 m/s 50 m/s 150 m/s

Precision 100 m 100 m 50 m 20 m 3 m

Noise Very noisy Noisy Low Medium Low

Stiffness Medium Medium Very high High High

Costs 1 2*pneumatics 2,5*pneumatics 3*pneumatics 4*pneumatics


Flexibility Not

programmable

Programmable Programmable Programmable Programmable


61/73

Comparison Between the Different Axis Technologies (Recommendation)


Load ++ +++ ++ +++ +

Stroke +++ +++ ++ ++ +++

++ +++ + ++ +++

Acceleration + +++ + ++ +++

Precision ++ ++ ++ +++ +++

Noise + ++ ++ +++ +++

Stiffness ++ ++ +++ +++ +++

Costs +++ ++ ++ + +


Flexibility + +++ +++ +++ +++


62/73

Selection of Axis Technologies Based on the Needs of the Application


High Load + +

Long Stroke + + +

High Velocity + +

High Accel. + +

High Precision + +

High Stiffness + + +

Low Costs + +


High Flexibility + + + +


63/73

Future Outlook

What are the main future trends in the field of linear motors and other direct drives.



64/73

Reasons for Automatization

High level of process standardization

Environmental conditions

High quantities

Unburden employees

Process capability

ReproducibilityControl of large

number of variants in

a production

Productivity

Labor cost reduction


0% 10% 20% 30% 40% 50% 60% 70%

User's View Manufacturer's ViewSource: WZL, RWTH Aachen and Institute Production Technology of Fraunhofer Institute


65/73

Control of Large Number of Variants in a Production

ort o o o pneumat c cy n ers atFesto in 1954:

50 catalo ue roducts



66/73


ort o o o pneumat c cy n ers atFesto today

>25000 catalo ue roducts



67/73


ro uct on mac nes nee

several variants / products onone machine

Leads to the use of free

programmable electrical axis

Higher througput to improvethe return on investment

Higher needs on accuracy to

Leads to the use of high dynamic

linear motors


mprove e repro uc y

67


68/73

Reasons for Automatization

High level of process standardization

Environmental conditions

High quantities

Unburden employees

Process capability

Reproducibility

Productivity

Labor cost reduction

Control of the cost

factor production


0% 10% 20% 30% 40% 50% 60% 70%

User's View Manufacturer's ViewSource: WZL, RWTH Aachen and Institute Production Technology of Fraunhofer Institute


69/73

Control of the cost factor production

ro uct on mac nes nee

the labor costs

Leads to the use of high dynamic

Higher needs on accuracy toimprove the reproducibility



70/73

Labor Costs in Selected Countries

Annual crowin rate


Indonesia China India Russia Poland Tsch. R. Korea Japan USA Germany

Source: BCG


71/73

Price Trends Machines and Components for Machines

increases for quantities than for turnoverforecasted.

The average price for most machines will ustomers

decrease in the next years by 35%.

A quantity rise of 24% is forecasted. Our

Festo


Source: European Machinery Production Yearbook 2007, IMS Research


72/73

Technology Trends

Markets requests less products in themedium technology area and go more to lowand high technology areas.

High Tech

For low technology area

costs factor is the leading reason

Medium TechMarket Market

or g ec no ogy eve

increase of productivity is the leadingreason

ow ec



73/73


linear motor technology.pdf

Documents