Strain wave servo-gearbox FSG-II-25

coaxialkeyed borecompact

Introduction
The FSG‑II strain wave gear series is designed for robot arm end-effectors and sealed rotary table applications. It uses a cross-slider coupling mechanism for the wave generator. Cam shaft bore dimensions are customizable to match specific motor models. The input shaft connects to the wave generator inner bore via a keyed connection. Typical mechanical layout fixes the circular spline at the base with the flexspline as the output element.

Features

• Wave generator with integrated cam structure for improved self-alignment and relaxed machining tolerances.
• Compact design with high torque capacity across sizes.
• High rotational and positioning accuracy; backlash ≤20 arc sec in typical configurations.
• Coaxial input and output; input bore can be adapted to motor shafts.
• Commonly specified for robot arm end-effectors and sealed rotary tables requiring compact, coaxial reduction.

Specification — Sheet 1 (Starting torque of FSG series; unit: cNm)
Reduction ratio | 11 | 14 | 17 | 20 | 25 | 32 | 40
Size 50 | — | 4.5 | 6.7 | 8.6 | 17 | 34 | 61
Size 80 | — | 3.1 | 4.4 | 5.4 | 10 | 21 | 39
Size 100 | — | 2.8 | 3.7 | 4.7 | 8.8 | 20 | 34
Size 120 | — | — | 3.4 | 4.2 | 8 | 17 | 31
Size 160 | — | — | — | — | 3.6 | 6.9 | 15 | 26

Specification — Sheet 2 (Instant permissible values by model)
Format: Model | Design value | Instant permissible value
FSG‑14 | Mb design 20 Nm | Mb max 40 Nm
| Ft design 180 N | Ft max 320 N
| Fa design 180 N | Fa max 320 N
FSG‑17 | Mb design 30 Nm | Mb max 60 Nm
| Ft design 230 N | Ft max 400 N
| Fa design 230 N | Fa max 400 N
FSG‑20 | Mb design 42 Nm | Mb max 80 Nm
| Ft design 270 N | Ft max 480 N
| Fa design 270 N | Fa max 480 N
FSG‑25 | Mb design 80 Nm | Mb max 160 Nm
| Ft design 440 N | Ft max 770 N
| Fa design 440 N | Fa max 770 N
FSG‑32 | Mb design 220 Nm | Mb max 440 Nm
| Ft design 900 N | Ft max 1600 N
| Fa design 900 N | Fa max 1600 N
FSG‑40 | Mb design 320 Nm | Mb max 650 Nm
| Ft design 1000 N | Ft max 1750 N
| Fa design 1000 N | Fa max 1750 N

Specification — Sheet 3 (Performance summary)
Headers: Model | Reduction ratio | Rated torque at 2000 r/min input (Nm) | (kgfm) | Permissible peak torque at start/stop (Nm) | (kgfm) | Permissible max average load torque (Nm) | (kgfm) | Permissible momentary torque (Nm) | Permissible max input speed (Grease) (r/min) | Permissible average input speed (Grease) (r/min) | Backlash (Arc Sec) | Weight (kg) | Design life (Hour)
Examples (selected entries):
Model 14 @ 50: Rated 7 Nm (0.7 kgfm); peak 23 Nm; avg 9 Nm; momentary 46 Nm; max input speed up to 10000 r/min; backlash ≤20 arc sec; design life hours ~10000.
Model 17 @ 50: Rated 21 Nm (2.1 kgfm); peak 44 Nm; avg 34 Nm; momentary 91 Nm; max input speed up to 10000 r/min.
Model 20–40: Rated torque and permissible torques increase by model and reduction ratio (examples: Model 20 rated 33–120 Nm depending on ratio; Model 25 rated 51–217 Nm; Model 32 rated 99–459 Nm; Model 40 rated 178–802 Nm). Some configurations allow input speeds up to 15000 r/min (grease dependent).

Available sizes / model references (excerpt)

• FSG‑14
• FSG‑17
• FSG‑20
• FSG‑25
• FSG‑32
• FSG‑40

Technical characteristics

• Series: FSG (FSG‑II described).
• Wave generator: integrated cam with cross-slider coupling.
• Input connection: keyed input into wave generator inner bore; cam shaft bore customizable for motor fit.
• Typical configuration: circular spline fixed at base; flexspline as output.
• Reduction ratios available: 11, 14, 17, 20, 25, 32, 40 (and higher ratios such as 50, 80, 100, 120, 160 depending on size).
• Backlash typically ≤20 arc sec; permissible input speeds and design life vary by model and lubrication.
• Applications: robot arm end-effectors, sealed rotary tables and other compact, coaxial reduction requirements in automation.