DC gear-motor QJS20

planetarycoaxial0.2 - 0.5 Nm

Product overview
QJS 20mm All‑Metal Planetary Gear Motor (Model: QJS20) is a compact planetary gearbox solution engineered for applications requiring high torque density in a 20 mm outer diameter package. Available in 1–4 stage configurations, it delivers stage-dependent continuous and momentary torque ranges with machined metal gears and stainless steel output shaft for reliable mechanical transmission in industrial and mobile robotic systems.

Key features

• Compact 20 mm outer diameter planetary gearbox
• Stage options: 1–4 for tailored reduction ratios
• Momentary torque up to 6.5 kgf·cm (stage-dependent)
• All‑metal gears, metal case and stainless steel output shaft with ball bearings
• Wide operating temperature range: -25°C to +100°C and 20%–85% RH
• Customization available (design & manufacturing)

Parameters
Model: QJS20
Gear stages: 1 | 2 | 3 | 4
Reduction ratio: 4.6 | 16, 24, 36 | 64, 96, 144, 216 | 256, 384, 576, 864, 1296
Gear length (mm): 20 | 22.8 | 25.6 | 28.1
Max allowable continuous torque (kgf·cm): 1 | 1.8 | 2.5 | 3.6
Max allowable momentary torque (kgf·cm): 2 | 2.8 | 4 | 6.5
Efficiency (%): 90 | 81 | 73 | 65
Motor length: depends on specified motor
Outer diameter: 20 mm
Gearbox type: planetary structure
Output shaft material: stainless steel
Output shaft bearing type: ball bearings
Gear material: machined metal gear
Case material: metal
Operating humidity: 20%–85% RH
Operating temperature: -25°C–+100°C
Customization: design & manufacturing available

Applications
Designed for smart robots, robot dogs, robotic lawnmowers and outdoor service robots, intelligent hardware and smart devices, pool and cleaning robots, humanoid robots and dexterous hands, and medical & precision equipment where compact, high-torque reduction is required.

Technical specifications

• Model: QJS20
• Outer diameter: 20 mm
• Gearbox type: all‑metal planetary structure
• Available gear stages: 1 to 4
• Reduction ratios: 4.6 up to 1296 depending on stages
• Gear lengths (mm): 20 / 22.8 / 25.6 / 28.1
• Max continuous torque: 1–3.6 kgf·cm (stage-dependent)
• Max momentary torque: 2–6.5 kgf·cm (stage-dependent)
• Efficiency range: 65%–90% (stage-dependent)
• Output shaft: stainless steel with ball bearings
• Gear material: machined metal gears
• Case material: metal
• Operating humidity: 20%–85% RH
• Operating temperature: -25°C to +100°C
• Customization: design & manufacturing available