Harmonic gear reducer FHD-20

coaxialhollow-shaft10 - 20 Nm

Introduction
The FHD series harmonic reducer features an ultra-short top-hat flexspline (hat-shape) designed for applications requiring extreme compactness and reduced axial length. The combined-type FHD targets a flat-profile layout, offering approximately 50% shorter axial length compared with the FHG series. High-rigidity cross-roller bearings on the output side support designs with limited installation space and high stiffness requirements.

Features

• Ultra-thin hollow profile with top-hat flexspline
• Compact, low-profile design for space-constrained installations
• High torque capacity across multiple frame sizes
• High rigidity with near-zero backlash (≤20 arc sec typical)
• Coaxial input and output

Starting torque of FHD series (unit: cNm)
Type / Reduction ratio : 14 | 17 | 20 | 25 | 32
50 : 6.2 | 19 | 25 | 39 | 60
80 : 5.0 | 16 | 23 | 36 | 55
100 : 4.8 | 17 | 22 | 34 | 50

Mechanical limit values (static/dynamic) — summary by model
FHD-14 : Mb di 41 Nm / Mb max 80 Nm ; Ft di 270 N / Ft max 490 N ; Fa di 270 N / Fa max 490 N
FHD-17 : Mb di 59 Nm / Mb max 140 Nm ; Ft di 330 N / Ft max 570 N ; Fa di 330 N / Fa max 570 N
FHD-20 : Mb di 117 Nm / Mb max 230 Nm ; Ft di 550 N / Ft max 975 N ; Fa di 550 N / Fa max 975 N
FHD-25 : Mb di 213 Nm / Mb max 420 Nm ; Ft di 790 N / Ft max 1400 N ; Fa di 790 N / Fa max 1400 N
FHD-32 : Mb di 400 Nm / Mb max 800 Nm ; Ft di 1240 N / Ft max 2100 N ; Fa di 1240 N / Fa max 2100 N

Performance & operating data — selected values (per model and reduction ratio)
Note: values given per reduction ratio (examples shown) — Rated torque at 2000 r/min input (Nm) | Permissible peak torque at start/stop (Nm) | Permissible maximum average load torque (Nm) | Permissible maximum 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)
Model FHD-14, Reduction 50 : Rated torque 3.7 Nm | Peak 12 Nm | Avg 4.8 Nm | Momentary 23 Nm | Max input 8500 r/min | Avg input 3500 r/min | ≤20 Arc Sec | Weight FHD-I:0.34 / FHD-II:0.64 Kg | Design life 9000 h
Model FHD-14, Reduction 80 : Rated torque 5.1 Nm | Peak 15 Nm | Avg 6.2 Nm | Momentary 29 Nm | Design life 10000 h
Model FHD-14, Reduction 100 : Rated torque 5.4 Nm | Peak 19 Nm | Avg 7.7 Nm | Momentary 35 Nm | Design life 10000 h
Model FHD-17, Reduction 50 : Rated torque 11 Nm | Peak 23 Nm | Avg 18 Nm | Momentary 48 Nm | Max input 7300 r/min | Avg input 3500 r/min | ≤20 Arc Sec | Weight FHD-I:0.42 / FHD-II:0.87 Kg | Design life 9000 h
Model FHD-17, Reduction 80 : Rated torque 14 Nm | Peak 29 Nm | Avg 21 Nm | Momentary 54 Nm | Design life 10000 h
Model FHD-17, Reduction 100 : Rated torque 16 Nm | Peak 37 Nm | Avg 27 Nm | Momentary 71 Nm | Design life 10000 h
Model FHD-20, Reduction 50 : Rated torque 17 Nm | Peak 39 Nm | Avg 24 Nm | Momentary 69 Nm | Max input 6500 r/min | Avg input 3500 r/min | ≤20 Arc Sec | Weight FHD-I:0.54 / FHD-II:1.14 Kg | Design life 9000 h
Model FHD-20, Reduction 80 : Rated torque 23 Nm | Peak 49 Nm | Avg 28 Nm | Momentary 78 Nm | Design life 10000 h
Model FHD-20, Reduction 100 : Rated torque 28 Nm | Peak 57 Nm | Avg 34 Nm | Momentary 95 Nm | Design life 10000 h
Model FHD-25, Reduction 50 : Rated torque 27 Nm | Peak 69 Nm | Avg 38 Nm | Momentary 127 Nm | Max input 5600 r/min | Avg input 3500 r/min | ≤20 Arc Sec | Weight FHD-I:0.95 / FHD-II:1.75 Kg | Design life 9000 h
Model FHD-25, Reduction 80 : Rated torque 42 Nm | Peak 91 Nm | Avg 62 Nm | Momentary 157 Nm | Design life 10000 h
Model FHD-25, Reduction 100 : Rated torque 47 Nm | Peak 110 Nm | Avg 75 Nm | Momentary 184 Nm | Design life 10000 h
Model FHD-32, Reduction 50 : Rated torque 53 Nm | Peak 151 Nm | Avg 75 Nm | Momentary 268 Nm | Max input 4800 r/min | Avg input 3500 r/min | ≤20 Arc Sec | Weight FHD-I:1.90 / FHD-II:3.56 Kg | Design life 9000 h
Model FHD-32, Reduction 80 : Rated torque 79 Nm | Peak 202 Nm | Avg 126 Nm | Momentary 350 Nm | Design life 10000 h
Model FHD-32, Reduction 100 : Rated torque 96 Nm | Peak 233 Nm | Avg 151 Nm | Momentary 420 Nm | Design life 10000 h

Technical specifications

• Series: FHD series (ultra-thin top-hat flexspline)
• Design: ultra-short axial length (~50% shorter vs FHG series), hat-shape flexspline, hollow ultra-thin profile
• Output bearing: high-rigidity cross-roller bearings on output side
• Backlash: ≤20 arc sec typical (near-zero)
• Coaxial input/output
• Available sizes: FHD-14, FHD-17, FHD-20, FHD-25, FHD-32; multiple reduction ratios (examples: 50, 80, 100)
• Data provided: starting torque (cNm), rated torques, permissible loads (Ft, Fa), peak and momentary torque values, permissible speeds and weights per model
• Weights (examples): FHD-14 FHD-I 0.34 kg / FHD-II 0.64 kg; FHD-32 FHD-I 1.90 kg / FHD-II 3.56 kg
• Permissible max input speeds (grease) vary by model (examples: FHD-14 up to 8500 r/min, FHD-32 up to 4800 r/min)