Custom Planetary
Gear Carriers

A planetary gear carrier (planet arm) holds the planet gear pin holes at equal angular spacing around the sun gear. The carrier rotates as the planet gears orbit — in a standard reduction gearbox, the carrier is the output element. Planet pin hole positional accuracy directly controls load sharing between planets and is the most critical dimension on the carrier.

(1) Pin hole positional accuracy (pitch circle radius): ±0.005 mm for servo / robot joints, ±0.010 mm for automotive, ±0.003 mm for aerospace. (2) Pin hole diameter: H6 for precision, H7 for standard. (3) Pin hole parallelism to carrier axis: angular tilt causes edge loading on planet gears. HXC measures all three on every carrier with a Zeiss CMM.

20CrMnTi carburized for automotive. 42CrMo4 through-hardened for industrial. Al 7075-T6 anodized for robot joints. Ti Grade 5 for aerospace / medical. SUS316L for cleanroom. C45 for general industrial.

Standard: 3 planets (120° spacing) or 4 planets (90°). HXC also machines 5-planet and 6-planet carriers for high-torque or low-noise applications — more planets reduce individual tooth load but require higher positional accuracy for good load sharing.

Yes — most servo gearbox carriers have integrated output flanges, splines, or coupling bores. HXC 5-axis turning-milling centres complete all features — pin holes, output spline, bearing seats — in one setup, ensuring concentricity to 0.005 mm TIR between the planet pin circle and the output axis.

Automotive (DIN 6): H7 bore, ±0.010 mm position. Servo / robot (DIN 5): H6 bore, ±0.005 mm. Aerospace (AGMA 10+): H5 bore, ±0.003 mm. Tighter tolerances require 100% CMM measurement — not just lot sampling. HXC offers 100% CMM as standard on all precision carrier orders.

Minimum OD approximately Ø20 mm (3 planets, Ø6 mm each). Minimum pin hole diameter Ø2 mm with ±0.003 mm positional accuracy — suitable for medical and precision instrument micro-planetary stages.

Prototype (1–3 pcs, 5-axis): 7–10 days. Small batch (10–50 pcs): 10–16 days. Production (100–500 pcs): 14–20 days.