Product Overview

The ABB 421-1-10479-390​ is a genuine ABB Robotics complete output shaft configuration (also referred to as an output shaft sub-assembly or wrist axis mechanical kit) designed for use in the wrist section—typically Axis 4, Axis 5, or Axis 6—of ABB large-frame industrial manipulators such as the IRB 6600, IRB 6650, and in some cases the IRB 7600 depending on the specific gearbox revision. The ABB 421-1-10479-390​ is not a bare shaft alone; it is a factory-engineered service kit comprising the precision-machined output shaft, pre-loaded angular-contact ball bearings, radial shaft seals, spacer shims for axial preload adjustment, and in many cases the mating sun gear or planet carrier interface components required to rebuild a robot wrist reduction unit to original factory specifications.In the ABB modular robot architecture, the output shaft transmits the reduced torque from the cycloidal or harmonic reduction gear to the next wrist axis or ultimately to the tool flange. The ABB 421-1-10479-390​ is manufactured from case-hardened and ground alloy steel, dimensionally matched to ABB’s original gearbox housings to maintain micron-level backlash control and repeatability better than ±0.05 mm after reassembly. Supplied as a spare part for major overhauls or mid-life refurbishment of high-duty-cycle robots in automotive body shops, foundries, and heavy-payload material-handling cells, the ABB 421-1-10479-390​ allows maintenance teams to restore wrist-axis performance without replacing the entire gearbox housing, significantly reducing downtime and spare-parts cost. Each ABB 421-1-10479-390​ assembly is produced to ABB’s ISO 9001-certified quality standards and is traceable by serial/lot number for validation in regulated manufacturing environments.

Technical Specifications

Product Model | 421-1-10479-390Manufacturer | ABB Robotics (ABB AB, Robotics & Discrete Automation)Product Type | Complete Output Shaft Configuration / Wrist Axis Mechanical Sub-Assembly KitPrimary Application | Output shaft & bearing kit for IRB 6600 / IRB 6650 / select IRB 7600 wrist axes (typically Axis 4/5/6 gearbox)Compatible Robot Families | IRB 6600 (all revisions: -/60, -/125, -/225, -/400), IRB 6650S, IRB 7600 (verify gearbox type)Kit Contents | Hardened output shaft, preloaded angular-contact bearings, radial lip seal(s), adjusting shims / spacers, circlips; may include sun gear or coupling as per revisionShaft Material | Case-hardened chromium alloy steel, ground finish Ra ≤ 0.8 µmBearing Type | Precision angular-contact ball bearings (matched pair / duplex), ABEC-3 / P6 grade or betterSealing | FKM (Viton) or NBR radial shaft seal(s), grease-compatible with ABB robot lubricants (e.g., Mobilux EP 0 / ABB spec)Lubrication Requirement | Must be assembled with ABB-specified robot gearbox grease; pre-grease bearings per ABB service manualMass (Approx.) | 2.8 – 4.2 kg (varies by revision / included components)Operating Environment | Matches robot wrist joint: -10 °C to +60 °C ambient; internal gearbox temp up to +90 °C intermittentInstallation Requirement | Requires robot wrist disassembly; torque wrenches and ABB-alignment fixtures/tools per service manualSpare Part Category | Level-3 Service / Overhaul Part (not a consumable)Cross-Reference Notes | Verify compatibility with specific robot serial number and gearbox type code before ordering; alternate shaft kits exist for IRB 6400 / IRB 4400

Main Features and Advantages

Factory-Matched Tolerances and Preload:The ABB 421-1-10479-390​ is supplied as a matched kit where bearing preload, shaft runout, and shim thickness have been engineered to work together. This eliminates the trial-and-error involved in sourcing loose bearings and shafts independently, and guarantees that the rebuilt wrist joint will meet ABB’s original backlash and stiffness specifications—critical for path accuracy in welding, sealing, and laser-cutting applications.Restores Original Repeatability and Payload Performance:Worn wrist output shafts or degraded bearings manifest as increased axis backlash, “jitter” during low-speed moves, or elevated motor current on the associated servo axis. Replacing these worn internals with a fresh ABB 421-1-10479-390​ returns the robot to its as-new positional repeatability (typically ±0.03 to ±0.06 mm for IRB 6600 class) and eliminates abnormal axis torque signatures that can trigger drive faults.