When to use them
Pick planetary when
the axis sees shock loads, reversing torque or continuous duty at a lower reduction ratio — lifts, wheels, grippers and cost-sensitive axes.
Accept the trade-off
more backlash. The EYOU RP line is ≤12 arcmin reverse backlash, against ≤60 arcsec transmission accuracy on our harmonic lines.
Selection tables
EYOU — RP humanoid planetary joints
Planetary reduction for leg and mobile-platform axes, 215–1075 g. 48 V · reverse backlash ≤12 arcmin · dual absolute encoder · CANopen · IP54 · rated speed 115–150 rpm. Torque figures are the rated and peak output columns of the catalogue; a few cells were reconstructed from the PDF table, so we confirm them with the factory at quotation. Source: 意优科技选型手册 2026.08, p. 11.
| Model | Size (OD × L) | Through-bore | Weight | Ratio | Rated power (W) | Rated speed (rpm) | Rated torque (N·m) | Peak torque (N·m) |
|---|---|---|---|---|---|---|---|---|
| RP40C | Φ45 × 52 | Φ4 | 215 g | 25:1 | 25 | 120 | 2 | 6 |
| RP50L | Φ59 × 53.5 | Φ5 | 410 g | 19.53:1 | 79 | 150 | 5 | 15 |
| RP50H | Φ59 × 59.5 | Φ5 | 465 g | 19.53:1 | 157 | 150 | 10 | 30 |
| RP70L | Φ77 × 52.5 | Φ6 | 670 g | 20:1 | 163 | 130 | 12 | 36 |
| RP70H | Φ77 × 58.3 | Φ6 | 760 g | 20:1 | 223 | 125 | 17 | 60 |
| RP90L | Φ96.5 × 56 | Φ8 | 1075 g | 21.91:1 | 421 | 115 | 35 | 120 |
EYOU — PP planetary joint modules
Small-frame planetary joints, Φ32–Φ52, 86–521 g. Low-ratio planetary modules for light axes, grippers and mobile platforms. Rated torque at the rated speed shown. Voltage and protocol per datasheet — ask us for the exact build. Source: 意优科技选型手册 2026.08, p. 12.
| Model | OD | Length | Weight | Ratio | Rated power (W) | Rated speed (rpm) | Rated torque (N·m) | Peak torque (N·m) |
|---|---|---|---|---|---|---|---|---|
| PP05 | Φ32 | 34.2 mm | 86 g | 6:1 | 35 | 50 | 0.2 | 0.48 |
| PP08 | Φ40 | 56.4 mm | 189 g | 36:1 | 36 | 50 | 1.0 | 2.2 |
| PP08D | Φ40 | 47.7 mm | 199 g | 36:1 | 36 | 50 | 1.0 | 2.2 |
| PP11 | Φ52 | 67.6 mm | 390 g | 36:1 | 60 | 50 | 6.6 | 10 |
| PP11D | Φ52 | 61.2 mm | 437 g | 36:1 | 60 | 50 | 6.6 | 10 |
| PP11L | Φ52 | 84.3 mm | 521 g | 36:1 | 72 | 50 | 10 | 18 |
Specs quoted from manufacturer datasheets; final figures confirmed at quotation.
All joint modules → · Cross-brand torque reference →
FAQ
When should I choose planetary over harmonic?
When the axis takes impact or reversing loads, when you do not need extreme reduction, or when unit cost at a given size matters more than peak torque density.
How much backlash should I expect?
The EYOU RP humanoid planetary line is specified at ≤12 arcmin reverse backlash. Our harmonic lines are an order of magnitude tighter.
Can I mix harmonic and planetary modules on one robot?
Yes — it is common. Harmonic for the limbs, planetary for lifts and the mobile base. We quote both on one purchase order and ship them together.