The principle of Operation and Application of a Linear Shaft

MotorNippon Pulse America, INC

January 13, 2005

To

１． Principal of the Linear Shaft Motor

２． Distinctive Features of the Linear Shaft Motor

３． Actuator Module

４． Application

Development Concept

Simple is the best!

Shaft

Magnet

Coil

Slider

Linear Shaft Motor Structure

Linear Shaft Motor Principle

u w v u w v u w v

u w v u w v u w v

Ｓ Ｎ Ｓ Ｎ Ｓ ＮＳ Ｎ

Coil Flux

Shaft

Flux Thrust

CurrentFleming’s law

Linear Shaft Motor vs. Linear Motor

NS

SN

NS

SN

NS

SN

Core(Iron）

Back York(Iron)

Coil

Coil Magnet

Magnet Adsorption Force

No influence by change of gap

LINEAR SHAFT MOTOR

Linear motor

Cogging by concentration of flux

Linear Shaft Motor Structure

Table

Shaft-motor Shaft

Slider(coil)

Linear encoder

LinearGuideCable bare

Metal fittings

Plate Shaft HolderLinear Guide Table Linear Encoder

Cables

Shaft Motor

Linear Shaft Motor Structure

Linear Shaft Motor

Distinctive FeaturesⅠ   Big thrust (6000N) possibility Quiet, no friction during movement Light weight and compact due to no core Simple structure allows building of unit

from a short stroke up to 4.6M stroke High resolution (0.14nm), and when

combined with high accuracy linear

encoder you can achieve high precision

positioning

Distinctive FeaturesⅡ It is possible to control speed and

positioning with high accuracy by using a linear encoder, even if the mechanical accuracy a little rough.

High-speed drive (6.5m/Sec) Low-speed drive (8 μ m/Sec) Almost uniform in speed (±0.006% at

100mm/Sec) Can be used in strong environments such as

underwater and in a vacuum When compared to other linear motors, it is

compact and lightweight

F-V Curve

F-V curve shows characteristic of a DC motor

(However, the classification for a shaft motor of “The Institute of Electrical Engineers of Japan” is a synchronous motor)

7000N output (Size of Slider:120 x 120 x 540)

0

1000

2000

3000

4000

5000

6000

7000

8000

0 0.5 1 1.5 2 2.5 3 3.5 4VELOCITY (m/ sec)

FORC

E (N

)

0%

10%

20%

30%

40%

50%

60%

70%

80%

F-V定格推力出力効率

FVSpecified ThrustOutputEfficiency

Current in Movement

Only at the time of an acceleration and slowdown, current flows.

In case of a linear motor with a core, about 30% of rated current flows even at the time of constant speeding -10

-505

10152025303540

移動時間

(mm

/s)

速度

-1.5

-1

-0.5

0

0.5

1

1.5

(A)

電流

値

(V)速度 電流値（Ａ）Velocity（ V)　　　 Current（ A)

Velo

city（

mm

/s)

Curr

ent（

A)

Time

Data for Temperature IncreaseQ A A４２７ 温度試験 ＜定格６．４ ２５％ ＝ １．６ ＞

0

5

10

15

20

25

30

0 720 1440 2160 2880 3600 4320 5040 5760

Div= Total ℃経過時間 （１ １時間） ８時間２６分３５秒 最高温度２４．５

℃

温度

（）

CH01:室温 CH02:U－コイル CH03:V－コイル CH04:W－コイル CH05:フィン－Ｌ CH06:フィン－Ｒ

427Q Temperature Test (6.4A 25%=1.6A)

CH01:Rm. Tep. CH02:U Coil CH03:V Coil CH04:W Coil CH05:Fin L CH06:Fin R

Tem

pera

ture

（C

)

Process time(1Div=1 h), Total=8h 26m 35s, Highest Tep.=24.5C

0

5

10

15

20

25

30

35

40

0 60 120 180 240 300

経過時間（分）

℃温

度（

）

1kg Vmax=1m/ s α max=1G荷重 、、 、 、200mm 1ストローク ／両端 秒停止往復運転

テーブル温度

室温

温度上昇＝ﾃｰﾌ ﾙ゙温度ー室温

Temperature Increase on a TableTem

pera

ture

（C

)

Load： !kg, V max=1m/s, α　max=1 G

Stroke： 200mm( Round movement after 1sec stop at at the both ends)

Process time

Temperature on the table

Temperature in the room

Temperature increase = Temperature on the table – Temperature in

the room

Duty Curve

DUTY=Acceleration and slowdown/cycle

In case of a linear motor, constant movement (Duty=1) is not practical.

Technique utilizing duty well is the art of using a shaft motor.

435Q

0

500

1000

1500

2000

2500

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

DUTY

推

力（

Ｎ）

+10℃

+20℃

+30℃

+40℃

+50℃

+60℃

+70℃

+80℃

+90℃

+100℃Thru

st（

N)

435Q

Duty

Repetition Positioning Accuracy

Available within ±1.2 pulses of encoder resolution （ 3σ ）（ encoder resolution ： less than １０ｎｍ）

No influence with Expansion and contraction of a shaft

Time(s)

静的位置決め性能（エンコーダ分解能８．６ｎｍ）

-0.005

-0.004

-0.003

-0.002

-0.001

0

0.001

0.002

0.003

0.004

0.005

0 10 20 30 40 50 60 70 80

Time (s)

Dis

tance

(mm

)

静的位置決め性能（エンコーダ分解能８．６ｎｍ）

-60-55-50-45-40-35-30-25-20-15-10-505

1015202530354045505560

0 10 20 30 40 50 60 70 80

Time (s)

Dis

tance

(mm

)

Used with 8.6nm resolution encoder

Used with 8.6nm resolution encoder D

ista

nce（

mm

)D

ista

nce（

mm

)Time(s)

:Enlargement

Model 　 S160T 　　　　

Condition

　Ｖ max≒１ｍ／ sec

　 αmax≒１Ｇ

High Precise Positioning up to ±0.1μm, without overshoot

Precise Positioning

Acceleration| Ｇ |

time(sec) 0.1 　　　　 　　　　　 0.2 0.3

2

4

6

8

0

1

2

3

0

Acceleration and

slowdown

Speed

-10

Type Ｗ

Stroke ： 700mm

Constant Speed:

3.3m/s

Performance Characteristics

of High SpeedVelocity（ m/s)

Highest Speed

Conditions

６．３ｍ／ｓｅｃ

Motor ：Ｓ４３５Ｑ

Loading ：２６ｋｇ

Stroke ：８５０ｍｍ

Encoder ： 1μ ｍ

μ 低速送り （８ ｍ／ｓ） 移動距離２ｍｍ

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

0.05

0 50 100 150 200 250

Time (s)

Velo

city

(mm

/s)

8m/sec

Velo

city（

mm

/sec)

Time (sec)

Lowest Speed

Conditions

Velocity ： 8 ｍ / ｓｅｃ

Motor ：Ｓ３２０Ｄ

Loading ：１０ｋｇ

Stroke ：２ｍｍ

2.5 3 .0 3 .5 4 .0T im e (Seconds)

99 .990

99.995

100.000

100.005

100.010

100.015

C hanne l 1 Ve loc ity (M illim eter/sec)

Uniformity in speed ： ±0.006 ％Velocity（mm/sec)

Uniformity in High Speed

Conditions

Velocity ： 100mm/ ｓｅｃ

Motor ： S320D

Loading ： 10kg

Stroke ： 220mm

Encoder ： 0.1ｍ

Time（ｓ ec）

≒ ±一定速度 ５ｍｍ／ｓ（ ０．１％）

4.994.9914.9924.9934.9944.9954.9964.9974.9984.999

55.0015.0025.0035.0045.0055.0065.0075.0085.0095.01

0 100 200 300 400 500 600 700 800 900 1000 1100

Time (s)

Vel

ocity

(mm

/s)）

Velocity（mm/sec)

Time（ｓ ec）

Uniformity in Low SpeedUniformity in speeding ： ±0.01 ％

Conditions

Velocity ： 5mm/ｓｅｃ

Motor ： S320D

Loading ： 10kg

Stroke ： 220mm

Encoder ： 0.1 ｍ

シャフトモーター４３５Ｑの保持力

0

200

400

600

800

1000

1200

0 2 4 6 8 10 12 14 16 μ偏移 （ ｍ）

推

力（

Ｎ）

Holding Thrust of S435D

Deviation (m)

Thru

st（

N)

Holding Thrust

Due to servo control, thrust is not held after achieving the position to be programmed

Holding thrust up to the maximum is maintained during operation

Holding thrust depends on the gain

Holding thrust is also depends on the resolution of an encoder

Magnetic force abruptly decreases when leaving from the surface of the shaft

Very little influence in proportion to the distance from N-S pitch

No relation between the pitch of both poles and positioning accuracy

Thrust field is different from magnetic field

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0 15 30 45 60 75 90 105 120

POSITION (mm)

MA

GN

ETIC

FLU

X D

EN

SIT

Y (

T)

10 mm表面からの距離 5 mm 0 mm

Magnetic Field

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 5 10 15 20 25 30表面からの距離（ｍｍ）

磁界

の強

さ（

Ｔ）

Distance from surface (mm)

Position (mm)Mag

neti

c Fl

ux D

ensi

ty(T

)

Distance from surface： 10mmDistance from surface：　 5mmDistance from surface：　 0mm

Mag

neti

c Fo

rce

Advantages for Manufacturing

• Quality Control – Saving time in inspection– Simple QC in total due to the simple structure

• Cost Control – Low cost in making a guide– Basically low cost in structure

• Process Control – High productivity （ due to simple assembling ）– Flexibility of production （ Exchangeable in productio

n process ）– Easy maintenance

（ In comparison to a conventional liner motor）

Development and Production

Odate Factory （ Akita ）

Development and Designing

For Customer Application

Development（ Technical Center in Tokyo）

Production （ Iwaki, Odate, Chaina Factories ）

Motor, Driver, Controller, Communication System

3 pcs of Driver for Shaft Motor

Shaft Motor

Slider of Shaft Motor

Slider of Shaft Motor

Shaft Motor

Limit Sensor with T-NET

Limit Sensor with T-NET

Multiple Movement for 4 axes with stepping motor

2 axes driver for stepping motor

Movement Sensor with T-NET

Controller Unit NPM-104EMBC

NPMC6045-4104 board built-in (4 axes control) NPMCTNET-I/O 104

board G9001 built-in

Application of Linear Shaft Motor for Medical Purpose

Business for Linear Shaft Motor

Development of Motor ： GMC HillstoneDevelopment of Peripherals ： Nippon Pulse

MotorProduction of Motor ： GMC Hillstone

Nippon Pulse MotorProduction of Peripherals ： Nippon Pulse

MotorSales of System Actuator ： Nippon Pulse

Motor

System of Actuator

1. Motor and Driver2. Motor, Driver and Controller 3. Motor, Driver, Controller and Encoder4. Motor, Driver, Controller, Encoder and

Communication System

Propose with Module Actuator Supply to Our Customers with the Best Module Actuator

5. ?6. ?

Shaft

Magnet Coil

Slider

What is a shaft motor?This is a direct drive-linear-servomotor which is controlling

movement by switching on the current to the shaft arrayed inside with magnets and the coil rolled in the shape of a cylinder

Structure of a shaft motor

Cables for moving part

Cables for encoder

Table

Magnet shaft

Linear encoder

Linear guide

Moving part (coil) Shaft holder

ApplicationUsing high resolution High precision position accuracyUsing stability in speeding and less than 0.05% of unevenness of movement Precise measurementUsing 0.1μm of repetition positioning accuracy Pinpoint alignment A system can be compact and it can build simply. System

design with high flexibility

2 heads of a shaft motor are used at the X-axis

1 head of a shaft motor is used at the Y-axis

Features of a shaft motorQuiet, no friction during movement

Big thrust (6000N)Repetition of position accuracy is available in 0.1μm.Compared with the other drive system, it is very stable in speeding and possible to control with stable speed.Possible to operate by a high-speed drive (6.5 m/Sec) to low-speed drive (8μm /Sec).Can be used in strong environments such as underwater and in a vacuum. A system is compact and simple.

Summary