Harmonic Drive HP8 and CP8 Miniature Planetary Gearheads
Harmonic Drive HP8 and CP8 Miniature Planetary Gearheads
HP8 and CP8 are miniature planetary gearheads in a 25 mm square package for small servo-driven mechanisms. HP uses a standalone input pinion with a precision through bore, while CP includes a removable input hub-pinion assembly. They are low-backlash planetary transmissions, with a documented backlash limit of 30 arcmin; they should not be described as zero-backlash strain-wave gear units.
Review Summary
Consider HP/CP when a compact motor connection and modest planetary reduction fit a small positioning or instrument axis. Compare input attachment, backlash tolerance, torque duty and load support against the complete mechanism. The 25 mm package and small-motor positioning do not establish a complete actuator, a sterilizable medical assembly or a universal positioning accuracy.
Package 25 mm square miniature planetary gearhead Ratios 5:1 / 16:1 / 25:1 HP input Standalone input pinion with precision through bore CP input Removable input hub-pinion assembly HP-8F ratio 5 0.40 Nm rated; 2.26 Nm repeated; 5.88 Nm momentary; 0.12 kg HP-8F ratio 16 1.07 Nm rated; 2.55 Nm repeated; 5.88 Nm momentary; 0.15 kg HP-8F ratio 25 1.57 Nm rated; 2.26 Nm repeated in July 2026 catalog; 5.88 Nm momentary; 0.15 kg Maximum-speed entry 5000 rpm input in rating table; operating duty qualifications apply Output radial/axial entries Ratio 5: 52/47 N; ratio 16: 76/47 N; ratio 25: 89/47 N Backlash ≤30 arcmin measured at ±5% rated torque Life entry L10 20000 hours at rated torque; not unconditional machine life Price Request a quote for HP or CP, ratio and exact motor interface Applications and Industries
Small servo axes, precision instruments and compact semiconductor or medical-machine mechanisms
Industrial automation
Request a quote for the exact configuration,quantity and delivery schedule.
| Package | 25 mm square miniature planetary gearhead |
| Ratios | 5:1 / 16:1 / 25:1 |
| HP input | Standalone input pinion with precision through bore |
| CP input | Removable input hub-pinion assembly |
| HP-8F ratio 5 | 0.40 Nm rated; 2.26 Nm repeated; 5.88 Nm momentary; 0.12 kg |
| HP-8F ratio 16 | 1.07 Nm rated; 2.55 Nm repeated; 5.88 Nm momentary; 0.15 kg |
| HP-8F ratio 25 | 1.57 Nm rated; 2.26 Nm repeated in July 2026 catalog; 5.88 Nm momentary; 0.15 kg |
| Maximum-speed entry | 5000 rpm input in rating table; operating duty qualifications apply |
| Output radial/axial entries | Ratio 5: 52/47 N; ratio 16: 76/47 N; ratio 25: 89/47 N |
| Backlash | ≤30 arcmin measured at ±5% rated torque |
| Life entry | L10 20000 hours at rated torque; not unconditional machine life |
| Price | Request a quote for HP or CP, ratio and exact motor interface |
