Miki Pulley COUPLINGS User manual

COUPLINGS
Flexible Couplings and Hub-shaft Connections
'09.06-0-SO-COUP2(e)-001A
COUPLINGS Flexible Couplings and Hub-shaft Connections
461 Imai-Minami-cho, Nakahara-Ku, Kawasaki-City, Kanagawa, Japan

4
High-reliability
Metal Plate Spring
Format Realizing
Its Best Shape
Through Finite
Element Analysis
SERVO FLEX is an ultrahigh-rigidity flexible coupling derived from Miki Pulley's unique development capability.
It has gained high reliability by its layered plate spring format as its best shape, which is rigid in the
torsional direction and flexible in the bending asymmetrical and axial directions.
SERVO FLEX is also available in a variety of models to cover a wide range of fields and purposes, and this full
selection contributes to the higher precision and efficiency of instruments.
S E R V O F L E X

5

6
F L E X I B L E C O U P L I N G SS E R V O F L E X
High-reliability Metal Plate Spring Format
When jointing a shaft to another shaft, it is extremely difficult to precisely center these two shafts.
It is even more difficult to maintain the centering due to problems such as shaft deflection and shaft thermal expansion as a result
of operating machine equipment, support block distortion after long hours of use, abrasion of the bearing, and for other reasons.
The role of flexible couplings is not only simply to joint the driving shaft and driven shaft but also to resolve the above problems by
selecting appropriate flexible couplings suitable for each purpose.
An optimal design using the advanced finite element method (FEM) is applied for the plate spring shape and
strength design of each model, which are important for the performance of the couplings, and thorough
model analysis is performed by 3D-CAD.
Optimal Design by 3D-CAD and FEM
BENDING RADIALTORQUE THRUST
SFS-SS SFC-SA2 SFC-DA2
0
20,000
15,000
10,000
5,000
Pin bush
Types of coupling
Oldham Cross-slit Heli-cal
Torsional rigidity [N·m/rad]
Ultrahigh-rigidity Metal Plate Spring Flexible Couplings
A layered metal plate spring is adopted for the power transmission part of SERVO FLEX, enabling ideal performance
of the flexible coupling, which is rigid in the torsional direction and flexible in the bending asymmetrical and axial
directions.

7
F L E X I B L E C O U P L I N G S
The stainless-steel plate spring reduces thermal conduction from a servo motor to the driven shaft, which also reduces variations in
accuracy caused by thermal expansion.
80
70
60
50
40
30
20
10
00 15 30 45 60 75 90 105 120 135 150 165 180
A
B
C
Time [min]
Temperature [°C]
ABC
Heat Rejection
Backlash
Pseudo backlash
No Backlash
Elastic (metal) coupling
Metal plate spring: SERVOFLEX
Elastic (rubber and resin) coupling
Rubber, resin compression and resin
plate spring, etc
Corrected coupling
Oldham, pin bush, etc.
The power transmission of SERVO FLEX is performed entirely by a friction lock, enabling no backlash, accurate shaft rotation, and
ultraprecision control operation.
No Backlash

8
Full Selection
òSuperbly strong high-strength aluminum alloy adopted
òLow inertia achieved by the shaft diameter interlock-type hub outer diameter
òNo hazardous substances used, RoHS Directive compliant
òHigh-rigidity single element
òHigh-flexibility double element
òTaper shaft-compatible adapter
òClamp mounting only with one bolt
SFC MODEL
òWide selection
òHigh-rigidity single element
òHigh-flexibility double element
òFloating shaft suitable for long shaft intervals
òTaper shaft-compatible hub
òSelectable from finished-assembly products and parts-delivered products
òShaft bore design freely made from a pilot bore and a simple, strong friction lock
F U L L L I N E U PS E R V O F L E X
SFS MODEL

9
òSFM for the machine tool main shaft, SFF for the feed shaft
òThe main shaft-compatible type allows a maximum rotation speed of 20000 min–1.
òHigh-precision mounting by using an excellent centering mechanism
òIrregularity removed to the extent possible and wind roar lowered during high-speed rotation
òHigh-rigidity single element
òHigh-flexibility double element
òUltrahigh torque transmission of 8000 N·m
òUnique plate spring shape in order to equally combine high torque transmission and flexibility
òHigh-rigidity single element
òHigh-flexibility floating shaft
òShaft bore design freely made from a pilot bore
F U L L L I N E U P
SFF·SFM MODEL
SFH MODEL

10
Two types of couplings, either a rigid type with one element or a flexible type
with two elements using a spacer, can be selected.
The clamp method, an easy and exact installation method with no backlash,
is adopted for the shaft installation method.
Moreover, it is compatible with the taper shaft by using an adapter.
It also complies with the EU Restriction of Hazardous Substances Directive,
“RoHS Directive” that prohibits six hazardous substances
such as mercury, lead, and others.
SERVO FLEX: A Wide Selection of Metal Plate Spring
Couplings Made of High-power Aluminum Alloy
SFC MODEL
High Rigidity, High Flexibility
An ideal-shaped plate spring, designed based on thorough analysis using the advanced finite element
method (FEM) is applied for the element.
Two types of couplings, either a high-rigidity type with one element or a high-flexibility type with two
elements using a spacer, can be selected.
BENDING RADIALTORQUE THRUST
PLATE SPRING OF IDEAL FORM
SERVO FLEX
SFC

11
SFC MODEL
A Wide Range of Installation Methods
òBy adoption of the clamp method, installation is
easy and exact.
òThe servo motor taper shaft can be optionally
supported.
SERVO FLEX
SFC

SFC MODEL
High-strength aluminum alloy hub SFC
Clamp lock
+ Taper shaft compatible
SFC-£SA2-£B-£B
SFC-£DA2-£B-£B
High-rigidity single element SFC-£SA2-£B-£BC
High-flexibility double element SFC-£DA2-£B-£BC
High-rigidity single element
High-flexibility double element
12
¢Structure and Material
Clamp bolt material: SCM435
Surface treatment: Solid lubricant film treatment
Element material: Plate spring SUS304
Collar SUS304*1
Bolt material: SCM435
Surface treatment: Trivalent chromate treatment*2
Clamp hub material: High-strength aluminum alloy
Surface treatment: Anodic coating film treatment
Clamp bolt material: SCM435
Surface treatment: Solid lubricant film treatment
Element material: Plate spring SUS304
Collar SUS304*1
SFC-SA2 SFC-DA2
Clamp bolt material: SCM435
Surface treatment: Solid lubricant film treatment
Element material: Plate spring SUS304
Collar SUS304
Clamp hub material: High-strength
aluminum alloy
Surface treatment: Anodic coating film treatment
SFC-SA2/DA-BC
Clamp hub material:
High-strength aluminum alloy
Surface treatment:
Anodic coating film treatment
Bolt material: SCM435
Surface treatment: Trivalent chromate treatment
Taper adapter material: Equivalent of S45C
Surface treatment: Black oxide finish
Bolt material: SCM435
Surface treatment: Trivalent chromate treatment *2
Spacer material: High-strength aluminum alloy
Surface treatment: Anodic coating film treatment
* The collar material of the items marked with *1 is S45C from size #080 to size #100,
using trivalent chromium for the surface treatment.
* The bolt surface treatment of the items marked with *2 is antirust coating from size #080
to size #100.
SERVO FLEX
SFC

¢Wide Range of Installation Methods
The clamp method is adopted for the method of mounting on the shaft, so it is
easy to finish only by tightening the right and left sides.
Power transmission is performed entirely by a friction lock. There is no backlash.
A specialized jig is used for assembling couplings, so high-precision concentricity
is ensured.
It is also compatible with the servo motor taper shaft by installing a taper adapter.
13
Taper adapter option
SFC MODEL
The outer diameter of the clamp hub is designed so the outer diameter dimension interlocks with the bore
diameter that customers adopt. By using a small bore diameter to shrink the outer diameter, it is possible to
keep the inertia to the minimum required. One of three pattern shapes is determined automatically according
to the combination of bore diameters to be adopted.
¢Ultralow Inertia
TYPE A TYPE B TYPE C
SERVO FLEX
SFC

14
SERVO FLEX
SFC
K
A1
L
SLF C
L
SLF C
L
SLF C
A2
M
M
M
N
N
D
D
d1
D
d2
d1
d2
d2
d1
TYPE A TYPE B TYPE C
¢Specification
SFC-SA2
¢Dimensions
Model
Permissible
tourque
[N·m]
Max. permissible misalignment
Max. rotation
speed
[min
–1
]
Torsional
stiffness
[N·m/rad]
Radial
displacement
[N/mm]
Shape
TYPE
Moment of inertia
[kg·m2]
Mass
[kg]
Price
Parallel offset
[mm]
Angular
misalignment
[ ˚ ]
Axial
displacement
[mm]
SFC-005SA2 0.6 0.02 0.5 ±0.05 10000 500 140 C 0.25×10–6 0.007 –
SFC-010SA2 1.0 0.02 1 ±0.1 10000 1400 140 C 0.58×10–6 0.011 –
SFC-020SA2 2.0 0.02 1 ±0.15 10000 3700 64 C 2.36×10–6 0.025 –
SFC-030SA2 5.0 0.02 1 ±0.2 10000 8000 64
A 4.00×10–6 0.033 –
B 6.06×10–6 0.041 –
C 8.12×10–6 0.049 –
SFC-035SA2 8.0 0.02 1 ±0.25 10000 18000 112 C 18.43×10–6 0.084 –
SFC-040SA2 10 0.02 1 ±0.3 10000 20000 80
A 16.42×10–6 0.076 –
B 22.98×10–6 0.090 –
C 29.53×10–6 0.105 –
SFC-050SA2 25 0.02 1 ±0.4 10000 32000 48
A 54.88×10–6 0.156 –
B 77.10×10–6 0.185 –
C 99.33×10–6 0.214 –
SFC-060SA2 60 0.02 1 ±0.45 10000 70000 76.4
A 143.7×10–6 0.279 –
B 206.1×10–6 0.337 –
C 268.5×10–6 0.396 –
SFC-080SA2 100 0.02 1 ±0.55 10000 140000 128 C 709.3×10–6 0.727 –
SFC-090SA2 180 0.02 1 ±0.65 10000 100000 108 C 1227×10–6 0.959 –
SFC-100SA2 250 0.02 1 ±0.74 10000 120000 111 C 1858×10–6 1.181 –
* The indicated values in the moment of inertia and mass are measured with the maximum bore diameter.
* The torsional stiffness indicates the actual measurement value of element.
Model
d1*1d2*1
D N L LF S A1 A2 C K M
Tightening
torque
[N·m]
Shape
TYPE
CAD
file No.
Min. Max. Min. Max.
SFC-005SA2 4 6 4 6 16 – 16.7 7.85 1.0 – 4.8 2.5 6.5 2-M2 0.4 to 0.5 C C005S2B1
SFC-010SA2 4 8 4 8 19 – 19.35 9.15 1.05 – 5.8*23.15 8.5 2-M2.5*31.0 to 1.1*3C C010S2B1
SFC-020SA2 5 10 5 10 26 – 23.15 10.75 1.65 – 9.5 3.3 10.6 2-M2.5 1.0 to 1.1 C C020S2B1
SFC-030SA2
5 10 5 10
34 21.6 27.3 12.4 2.5
8 –
3.75 14.5 2-M3 1.5 to 1.9
A C030S2B1
5 10 Over10 14 8 12.5 B C030S2B2
Over 10 14 Over10 14 – – 12.5 C C030S2B3
SFC-035SA2 8 16 8 16 39 – 34.0 15.5 3.0 – 14.0 4.5 17 2-M4 3.4 to 4.1 C C035S2B1
SFC-040SA2
8 15 8 15
44 29.6 34.0 15.5 3.0
11 –
4.5 19.5 2-M4 3.4 to 4.1
A C040S2B1
8 15 Over 15 19 11 17.0 B C040S2B2
Over 15 19 Over 15 19 – – 17.0 C C040S2B3
SFC-050SA2
10 19 10 19
56 38 43.4 20.5 2.4
14.5 –
6 26 2-M5 7.0 to 8.5
A C050S2B1
10 19 Over 19 25 14.5 22.0 B C050S2B2
Over 19 25 Over 19 25 – – 22.0 C C050S2B3
SFC-060SA2
12 24 12 24
68 46 53.6 25.2 3.2
17.5 –
7.75 31 2-M6 14 to 15
A C060S2B1
12 24 Over 24 30 17.5 26.5 B C060S2B2
Over 24 30 Over 24 30 — – 26.5 C C060S2B3
SFC-080SA2 20 35 20 35 82 – 68 30 8 – 28 9 38 2-M8 27 to 30 C C080S2B1
SFC-090SA2 25 40 25 40 94 – 68.3 30 8.3 – 34 9 42 2-M8 27 to 30 C C090S2B1
SFC-100SA2 35 45 35 45 104 – 69.8 30 9.8 – 39 9 48 2-M8 27 to 30 C C100S2B1
Unit [mm]
SFC MODEL
CAD CAD
* *1 The torque permitted could be limited depending on the bore diameter. Refer to the “Standard bore diameter” on page15.
* *2 indicates the value when d1 or d2 is ø4 to ø7. It will be 0.6 if d1 or d2 is ø8.
* *3 indicates the value when d1 or d2 is ø4 to ø7. It will be M2 if d1 or d2 is ø8. The tightening torque of M2 is 0.4 to 0.5N·m.
* The dimensional tolerance of the target shaft is h7. However, for a shaft diameter of ø35, the tolerance is . Contact us for tolerances other than h7.
+0.010
- 0.025

15
T h e l a t e s t C A D d a ta c a n b e d ow n l o a d e d fr o m o u r we b s i t e . h t t p : // w w w. m i k i p u l l e y. c o . j p / The CAD mark indicates that CAD data is available by CD-ROM.
The CAD file No. represents the file name in the CD-ROM.
CAD CAD
SERVO FLEX
SFC
¢Standard bore diameter
Model Standard bore diameter d1·d2 [mm]
4 5 6 6.35 7 8 9 9.525 10 11 12 14 15 16 17 18 19 20 22 24 25 28 30 32 35 38 40 42 45
SFC-005SA2 ò ò ò
SFC-010SA2 ò ò ò ò ò ò
SFC-020SA2 1.2 ò ò ò ò ò ò ò
SFC-030SA2 2.8 3.4 ò ò ò ò ò ò ò ò ò
SFC-035SA2 òò ò òòòòòò
SFC-040SA2 9ò ò òòòòòòòòò
SFC-050SA2 22 òòòòòòòòòòòò
SFC-060SA2 51 òòòòòòòòòòòò
SFC-080SA2 òòòòòòòò
SFC-090SA2 òòòòòòò
SFC-100SA2 òòòòò
* The bore diameters with value or marked òare supported as standard bore diameter.
* The permissible torque of small bore diameter indicated in the column with value is limited by the shaft locking mechanism. The value indicates its operating torque [N·m].
* For bore diameters other than those above, processing cost is added to the standard price.
¢Optional: Taper shaft compatible
Model
Moment of inertia [kg·m2] Mass [kg]
Price
Shape TYPE
B
Shape TYPE
C
Shape TYPE
B
Shape TYPE
C
SFC-050SA2-
£
B-11BC
81.52×10–6 103.7×10–6 0.237 0.266 –
SFC-050SA2-
£
B-14BC
87.34×10–6 109.6×10–6 0.268 0.297 –
SFC-050SA2-
£
B-16BC
94.16×10–6 116.4×10–6 0.306 0.335 –
SFC-060SA2-
£
B-16BC
225.3×10–6 287.8×10–6 0.469 0.528 –
¢Specification SFC-£SA2-£B-£BC
Model CAD file No.
Shape TYPE B Shape TYPE C
SFC-050SA2-£B-11BC C050S2C1 C050S2C2
SFC-050SA2-£B-14BC C050S2C3 C050S2C4
SFC-050SA2-£B-16BC C050S2C5 C050S2C6
SFC-060SA2-£B-16BC C060S2C1 C060S2C2
¢Dimensions
A1
TYPE C
TYPE B
Taper 1/10
0
+0.030
W
A2
0
+0.3
T
WA
M
C
LA
LF
L
LC
D
dA
DA
Model W T WA LA dA DA L D LC LF C A1 A2 M
SFC-050SA2-£B-11BC 4 12.2 18 16 17 22 48.4
56 43.4 20.5 6 14.5 22 2-M5
-£B-14BC 4 15.1 24 19 22 28 53.4
-£B-16BC 5 17.3 24 29 26 30 63.4
SFC-060SA2-£B-16BC 5 17.3 24 29 26 30 69.6 68 53.6 25.2 7.75 17.5 26.5 2-M6
SFC-£SA2-£B-£BC
CAD CAD
Unit [mm]
* The shape type is either TYPE B or TYPE C.
Bore diameter: d1-d2
B: Clamp hub
BC: Taper adapter
Type: SA2
Single element, aluminum hub
Size
SFC - 040 - SA2 - 14 B - 15 B
Ordering Information

16
SERVO FLEX
SFC
¢Specification
Model
Permissible
torque
[N·m]
Max. permissible misalignment Max.
rotation
speed
[min–1]
Torsional
stiffness
[N·m/rad]
Radial
displacement
[N/mm]
Shape
TYPE
Moment of
inertia
[kg·m2]
Mass
[kg]
Price
Parallel offset
[mm]
Angular
misalignment
[ ˚ ]
Axial
displacement
[mm]
SFC-005DA2 0.6 0.05
0.5 (one side) ±0.1 10000 250 70 C 0.36×10–6 0.010 –
SFC-010DA2 1.0 0.11
1 (one side) ±0.2 10000 700 70 C 0.79×10–6 0.015 –
SFC-020DA2 2.0 0.15
1 (one side) ±0.33 10000 1850 32 C 3.40×10–6 0.035 –
SFC-030DA2 5.0 0.18 1
(one side) ±0.4 10000 4000 32
A 7.33×10–6 0.053 –
B 9.39×10–6 0.061 –
C 11.45×10–6 0.069 –
SFC-035DA2 8.0 0.24
1 (one side) ±0.5 10000 9000 56 C 26.78×10–6 0.123 –
SFC-040DA2 10 0.24 1
(one side) ±0.6 10000 10000 40
A 29.49×10–6 0.122 –
B 36.05×10–6 0.136 –
C 42.61×10–6 0.151 –
SFC-050DA2 25 0.28 1
(one side) ±0.8 10000 16000 24
A 96.94×10–6 0.246 –
B 119.2×10–6 0.275 –
C 141.4×10–6 0.304 –
SFC-060DA2 60 0.34 1
(one side) ±0.9 10000 35000 38.2
A 252.4×10–6 0.440 –
B 314.8×10–6 0.498 –
C 377.3×10–6 0.556 –
SFC-080DA2 100 0.52
1 (one side) ±1.10 10000 70000 64 C 1034×10–6 1.051 –
SFC-090DA2 180 0.52
1 (one side) ±1.30 10000 50000 54 C 1776×10–6 1.373 –
SFC-100DA2 250 0.52
1 (one side) ±1.48 10000 60000 55.5 C 2704×10–6 1.707 –
* The indicated values in the moment of inertia and mass are measured with the maximum bore diameter.
* The torsional stiffness indicates the actual measurement value of element.
Model
d1*1d2*1
D N L LF LP S A1 A2 C d3 K M
Tightening
torque
[N·m]
Shape
TYPE CAD file No.
Min. Max. Min. Max.
SFC-005DA2 4 6 4 6 16 – 23.2 7.85 5.5 1.0 – 4.8 2.5 6.5 6.5 2-M2 0.4 to 0.5 C C005D2B1
SFC-010DA2 4 8 4 8 19 – 25.9 9.15 5.5 1.05 – 5.8*23.15 8.5 8.5 2-M2.5*31.0 to 1.1*3C C010D2B1
SFC-020DA2 5 10 5 10 26 – 32.3 10.75 7.5 1.65 – 9.5 3.3 10.6 10.6 2-M2.5 1.0 to 1.1 C C020D2B1
SFC-030DA2
5 10 5 10
34 21.6 37.8 12.4 8 2.5
8 –
3.75 15 14.5 2-M3 1.5 to 1.9
A C030D2B1
5 10 Over 10 14 8 12.5 B C030D2B2
Over 10 14 Over 10 14 – – 12.5 C C030D2B3
SFC-035DA2 8 16 8 16 39 – 48 15.5 11 3 – 14.0 4.5 17 17 2-M4 3.4 to 4.1 C C035D2B1
SFC-040DA2
8 15 8 15
44 29.6 48 15.5 11 3
11 –
4.5 20 19.5 2-M4 3.4 to 4.1
A C040D2B1
8 15 Over 15 19 11 17.0 B C040D2B2
Over 15 19 Over 15 19 – – 17.0 C C040D2B3
SFC-050DA2
10 19 10 19
56 38 59.8 20.5 14 2.4
14.5 –
6 26 26 2-M5 7.0 to 8.5
A C050D2B1
10 19 Over 19 25 14.5 22.0 B C050D2B2
Over 19 25 Over 19 25 – – 22.0 C C050D2B3
SFC-060DA2
12 24 12 24
68 46 73.3 25.2 16.5 3.2
17.5 –
7.75 31 31 2-M6 14 to 15
A C060D2B1
12 24 Over 24 30 17.5 26.5 B C060D2B2
Over 24 30 Over 24 30 – – 26.5 C C060D2B3
SFC-080DA2 20 35 20 35 82 – 98 30 22 8 – 28 9 40 38 2-M8 27 to 30 C C080D2B1
SFC-090DA2 25 40 25 40 94 – 98.6 30 22 8.3 – 34 9 47 42 2-M8 27 to 30 C C090D2B1
SFC-100DA2 35 45 35 45 104 – 101.6 30 22 9.8 – 39 9 50 48 2-M8 27 to 30 C C100D2B1
Unit [mm]
¢Dimensions
L
S
LP LF C
L
S
LP LF C
L
S
LP LF C
MMM
d3 d3 d3
K
A1
A2
N
N
D
d1 d1
D
d2
d1
d2
D
d2
TYPE A TYPE B TYPE C
SFC-DA2
SFC MODEL
CAD CAD
* *1 Permissible torque could be limited depending on the bore diameter. Refer to the “Standard bore diameter” on page 17.
* *2 indicates the value when d1 or d2 is ø4 to ø7. It will be 6.0 if d1 or d2 is ø8.
* *3 indicates the value when d1 or d2 is ø4 to ø7. It will be M2 if d1 or d2 is ø8. The tightening torque of M2 is 0.4 to 0.5N·m.
* The dimensional tolerance of the target shaft is h7. However, for a shaft diameter of ø35, the tolerance is . Contact us for tolerances other than h7.
+0.010
- 0.025

17
T h e l a t e s t C A D d a ta c a n b e d ow n l o a d e d fr o m o u r we b s i t e . h t t p : // w w w. m i k i p u l l e y. c o . j p / The CAD mark indicates that CAD data is available by CD-ROM.
The CAD file No. represents the file name in the CD-ROM.
CAD CAD
SERVO FLEX
SFC
Model Standard bore diameter d1·d2 [mm]
4 5 6 6.35 7 8 9 9.525 10 11 12 14 15 16 17 18 19 20 22 24 25 28 30 32 35 38 40 42 45
SFC-005DA2 ò ò ò
SFC-010DA2 ò ò ò ò ò ò
SFC-020DA2 1.2 ò ò ò ò ò ò ò
SFC-030DA2 2.8 3.4 ò ò ò ò ò ò ò ò ò
SFC-035DA2 ò ò ò ò ò ò ò ò ò
SFC-040DA2 9ò ò òòòòòòòòò
SFC-050DA2 22 òòòòòòòòòòòò
SFC-060DA2 51 òòòòòòòòòòòò
SFC-080DA2 òòòòòòòò
SFC-090DA2 òòòòòòò
SFC-100DA2 òòòòò
* The bore diameters with value or marked òare supported as standard bore diameter.
* The permissible torque of small bore diameter indicated in the column with value is limited by the shaft locking mechanism. The value indicates its operating torque [N·m].
* For bore diameters other than those above, processing cost is added to the standard price.
¢Standard bore diameter
Type: DA2
Double element, aluminum hub
Size
SFC - 040 - DA2 - 14 B - 15 B
Bore diameter: d1-d2
B: Clamp hub
BC: Taper adapter
Ordering Information
¢Optional: Taper shaft compatible
Model
Moment of inertia [kg·m2] Mass [kg]
Price
Shape TYPE
B
Shape TYPE
C
Shape TYPE
B
Shape TYPE
C
SFC-050DA2-
£
B-11BC
123.6×10–6 145.8×10–6 0.327 0.356 –
SFC-050DA2-
£
B-14BC
129.4×10–6 151.6×10–6 0.358 0.386 –
SFC-050DA2-
£
B-16BC
136.2×10–6 158.4×10–6 0.396 0.424 –
SFC-060DA2-
£
B-16BC
334.1×10–6 396.5×10–6 0.630 0.688 –
¢Specification SFC-£DA2-£B-£BC
Model CAD file No.
Shape TYPE B Shape TYPE C
SFC-050DA2-£B-11BC C050D2C1 C050D2C2
SFC-050DA2-£B-14BC C050D2C3 C050D2C4
SFC-050DA2-£B-16BC C050D2C5 C050D2C6
SFC-060DA2-£B-16BC C060D2C1 C060D2C2
¢Dimensions
A1
LA
LC
L
LF
Taper 1/10
A2
WA
C
TYPE C
TYPE B
0
+0.030
W
0
+0.3
T
M
D
dA
DA
Model W T WA LA dA DA L D LC LF C A1 A2 M
SFC-050DA2-£B-11BC 4 12.2 18 16 17 22 64.8
56 59.8 20.5 6 14.5 22 2-M5
-£B-14BC 4 15.1 24 19 22 28 69.8
-£B-16BC 5 17.3 24 29 26 30 79.8
SFC-060DA2-£B-16BC 5 17.3 24 29 26 30 89.3 68 73.3 25.2 7.75 17.5 26.5 2-M6
* The shape type is either TYPE B or TYPE C.
SFC-£DA2-£B-£BC
CAD CAD
Unit [mm]

18
SERVO FLEX
SFC
¢Spring characteristics
030SA2
020SA2
005SA2
080SA2 090SA2
100SA2
060SA2
035SA2
050SA2050SA2
040SA2040SA2
035DA2
010DA2
020DA2
005DA2
080DA2 090DA2
100DA2
060DA2
050DA2050DA2
010SA2
040DA2040DA2
030DA2
0
00.5 1.0 1.5 2.0
60
50
40
30
20
10
90
80
70
0 0.5 1.0 1.5 2.0
0
60
50
40
30
20
10
90
80
70
Displacement [mm]
Displacement [mm]
Load [N]Load [N]
030SA2
020SA2
005SA2
080SA2 090SA2
100SA2
060SA2
035SA2
050SA2050SA2
040SA2040SA2
035DA2
010DA2
020DA2
005DA2
080DA2 090DA2
100DA2
060DA2
050DA2050DA2
010SA2
040DA2040DA2
030DA2
0
00.5 1.0 1.5 2.0
60
50
40
30
20
10
90
80
70
0 0.5 1.0 1.5 2.0
0
60
50
40
30
20
10
90
80
70
Displacement [mm]
Displacement [mm]
Load [N]Load [N]
035DA2
010DA2
020DA2
005DA2
080DA2
090DA2
100DA2
060DA2
050DA2050DA2
040DA2040DA2
0 0.1 0.2 0.3 0.4 0.5 0.6
0
300
250
200
150
100
50
350
Parallel offset [mm]
Load [N]
Design Check Items
SFC MODEL
òAxial Load and Displacement Amount
SFC-£SA2
òAxial Load and Displacement Amount
SFC-£DA2
òParallel Offset Direction Load and
Displacement Amount
SFC-£DA2

19
T h e l a t e s t C A D d a ta c a n b e d ow n l o a d e d fr o m o u r we b s i t e . h t t p : // w w w. m i k i p u l l e y. c o . j p / The CAD mark indicates that CAD data is available by CD-ROM.
The CAD file No. represents the file name in the CD-ROM.
CAD CAD
SERVO FLEX
SFC
¢Selection procedure
Servo motor specification Compatible coupling specification
Rated output
[kW]
Rated revolution
[min–1]
Rated torque
[N·m]
Max. torque
[N·m]
Shaft dia.
[mm]
Single element Double element Max. bore
dia. [mm]
Model (SFC-£SA2) Model (SFC-£DA2)
0.05 3000 0.16 0.48 8 010SA2 010DA2 8
0.1 3000 0.32 0.95 8 020SA2 020DA2 10
0.2 3000 0.64 1.90 14 030SA2 030DA2 14
0.4 3000 1.30 3.80 14 035SA2 035DA2 16
0.5 2000 2.39 7.16 24 050SA2 050DA2 25
0.5 3000 1.59 4.77 24 050SA2 050DA2 25
0.75 2000 3.58 10.7 22 050SA2 050DA2 25
0.75 3000 2.40 7.20 19 040SA2 040DA2 19
0.85 1000 8.12 24.4 24 060SA2 060DA2 30
1 2000 4.78 14.4 24 050SA2 050DA2 25
1 3000 3.18 9.55 24 050SA2 050DA2 25
1.2 1000 11.5 34.4 35 080SA2 080DA2 35
1.5 2000 7.16 21.6 28 060SA2 060DA2 30
1.5 3000 4.78 14.3 24 050SA2 050DA2 25
2 2000 9.55 28.5 35 080SA2 080DA2 35
2 3000 6.37 15.9 24 050SA2 050DA2 25
3 1000 28.60 85.9 35 090SA2 090DA2 35
3.5 2000 16.70 50.1 35 080SA2 080DA2 35
3.5 3000 11.10 27.9 28 060SA2 060DA2 30
5 2000 23.90 71.6 35 080SA2 080DA2 35
5 3000 15.90 39.7 28 060SA2 060DA2 30
7 2000 33.40 100 35 090SA2 090DA2 35
¢Simplified selection
Td = Ta × K (see below)
(1) Calculate torque Ta applied to the coupling based on the
motor output P and coupling operating rotation speed n.
Ta [N·m] = 9550 × P [kW]
n [min−1]
Load character
Constant Fluctuations: Slight Fluctuations: Medium Fluctuations: Large
1.0 1.25 1.75 2.25
In servo motor drive, multiply the service factor K=1.2 to 1.5
by the maximum torque of servo motor Ts.
Td = Ts × (1.2 to 1.5)
Tn ≥Td
(2) Calculate corrected torque Td applied to the coupling after
deciding the service factor K based on load conditions.
(5) Confirm if the required shaft diameter does not exceed the
maximum bore diameter of the selected size.
(3) Select a coupling size with permissible torque Tn that
becomes equal or greater than the corrected torque Td.
(4) Depending on the bore diameters, the coupling permissible
torque may be limited. Refer to the “Specification” and
“Standard bore diameter”.
The table indicates suitable sizes based on the rated output, rated torque and maximum torque of general-purpose servo motors. Since
torque characteristics of servo motors differ depending on the manufacturer, select the coupling size after confirming the specification of the
manufacturer.
For machines whose load torques periodically fluctuate
drastically, contact us.

20
SERVO FLEX
SFC
Size LF dimension [mm]
005 7.85
010 9.15
020 10.75
030 12.4
035 15.5
040 15.5
050 20.5
060 25.2
080 30
090 30
100 30
¢Feed-screw systems
¢How to evaluate the eigenfrequency of
feed-screw system
¢Mounting
Motor
Feed
screw
Bearing
Table
Coupling
J1 J2
Rotative direction
Axial direction
LF
LF
(1) Oscillation phenomena of servo motors
If the eigenfrequency of the entire feed-screw system is under
400 to 500Hz, oscillation may occur depending on the gain
adjustment of the servo motor.
The problems can be avoided by raising the eigenfrequency
of the mechanical system or adjusting the tuning function (filter
function) of the servo motor.
(1) Select the coupling according to the normal operating torque
and maximum torque of the servo motor/stepping motor.
Nf: Eigenfrequency of the entire feed-screw system [Hz]
k: Torsional stiffness of the coupling and feed screw [N·m/rad]
J1: Moment of inertia of the driving side
J2: Moment of inertia of the driven side
The concentricity of the right and left bore diameters is ensured
by adjusting with an specialized jig. However, the assembly
accuracy may be disturbed if a strong impact is given to the
product. Please handle it with care.
(1) Confirm the clamping bolts are loosened. Remove the rust,
dust and oil content on the inside diameter surface of the
shaft and coupling. (Wipe off the oil content completely with a
waste cloth, etc.)
(4) Make sure that the insertion length of the coupling into the
shaft is kept in the position so that the target shaft is in
contact with the entire length of the flange (LF dimension) as
illustrated below.
(2) Resonance caused by stepping motors
Resonance can occur within a certain speed range due
to the pulsation frequency of the stepping motor and the
eigenfrequency of the entire system. Resonance can be
avoided by not applying the resonant rotation speed, or by
reviewing the eigenfrequency in the design phase.
Cont act us for unclear p oints concerning oscill ation
phenomena of servo motors.
Contact us for unclear points concerning resonance of
stepping motors.
(2) In the following feed-screw system, evaluate the entire
eigenfrequency: Nf from the torsional stiffness: kof the
coupling and feed screw, the moment of inertia: J1 of the
driving side and the moment of inertia: J2 of the driven side.
(3) Confirm the two clamping bolts are loosened and the coupling
is movable to the axial and rotative directions.
If it does not move smoothly, adjust centering of both shafts
again.
If the concentricity can not be confirmed with the method
described above, confirm the mounting accuracy by other
measures.
(2) Insert the coupling into the shaft. At this time, do not apply
more than necessary force such as compression or pulling to
the element part of the coupling.
After the coupling is mounted into the motor, do not apply
excessive compression when inserting the coupling into the
mating shaft.
Design Check Items
SFC MODEL

21
T h e l a t e s t C A D d a ta c a n b e d ow n l o a d e d fr o m o u r we b s i t e . h t t p : // w w w. m i k i p u l l e y. c o . j p / The CAD mark indicates that CAD data is available by CD-ROM.
The CAD file No. represents the file name in the CD-ROM.
CAD CAD
SERVO FLEX
SFC
Size Clamp bolt Tightening torque [N·m]
005 M2 (0.4 to 0.5)
010 M2 (0.4 to 0.5)
010 M2.5 (1.0 to 1.1)
020 M2.5 (1.0 to 1.1)
030 M3 (1.5 to 1.9)
035 M4 (3.4 to 4.1)
040 M4 (3.4 to 4.1)
050 M5 (7.0 to 8.5)
060 M6 (14 to 15)
080 M8 (27 to 30)
090 M8 (27 to 30)
100 M8 (27 to 30)
* If the bore diameter is ø8, size 010 will be M2.
* For the above tightening torque, solid lubricant film treatment is applied to the bolt
and the torque coefficient is 0.18.
* The value of the tightening torque is between the minimum and the maximum values.
The bolts should be tightened by the tightening torque within this range.
(5) As a principle, the target shaft is a circular shaft. However, if
shafts other than a circular shaft have to be used for a certain
reason, be careful with the shaft installation position as
illustrated below. (Note that key slot, D-cut, etc. must not be
processed on the filling side of the ¢part.)
Certain shaft installation positioning may result in damage
to the coupling itself and lowering of shaft-retaining force. It
is recommended to use a circular shaft for fully satisfactory
coupling performance.
(6) After checking that no force such as compression, tension,
etc. is applied to the axial direction, the shaft is retained so
that the whole length of the clamp hub is in contact with both
shafts, and two clamp bolts are tightened at an appropriate
torque value.
To tighten the clamp bolts, a calibrated torque wrench is used
within the range of the clamp bolt-tightening torque as shown
in the table below.
òSolid lubricant film treatment is applied to the clamp bolt,
so make sure that Miki Pulley’s specified clamp bolt is used
and no coatings such as oil, etc. are applied. If any coating is
applied to the surface, the clamp bolt, the coupling itself, and
other parts might be damaged due to excessive shaft force.
òExample of Good Mounting
òExample of Bad Mounting
¢
Coupling bore diameter surface
treatment
For the SERVO FLEX SFC model, depending on the process,
although there are two types of parts, one with bore diameter
surface treatment such as additional processing and key slot
processing and the other without surface treatment, there is no
problem in terms of performance of the couplings. Contact us
for advice regarding whether bore diameter surface treatment
should be used according to the customers’ conditions of use.

22
Three types of couplings, either a high-rigidity type with one element, a high-flexibility type with two elements using a
spacer, or a floating shaft with configurable spacer length can be selected.
A variety of methods are available for mounting on a shaft such as a friction lock compatible with a large diameter, a high-
precision friction lock, a taper shaft-compatible method, and others.
The pilot bore item has also been standardized, enabling methods such as the key/set screw method, shrink fit-compatible
method, and others.
SERVO FLEX: A Wide Selection of Metal Plate Spring
Couplings Made of Steel
SFS MODEL
High Rigidity, High Flexibility
An ideal-shaped plate spring, designed based
on thorough analysis using the advanced
finite element method (FEM), is applied for the
element.
Three types of couplings, either a high-rigidity
type with one element, a high-flexibility type
with two elements using a spacer, or a floating
shaft with configurable spacer length can be
selected.
BENDING RADIAL
TORQUE THRUST
PLATE SPRING OF IDEAL FORM
SERVO FLEX
SFS