Rotary indexer CRD

zero-backlash

Overview
Nexen Group’s patented Rotary Indexer Systems use Roller Pinion technology combined with precision-grade bearings and drive mechanisms. Packaged in rigid or guarded housings, the PRD and CRD families are engineered for precise incremental positioning, variable motion profiles via servo programming, fast acceleration and substantial load capacity. Prepackaged systems can start/stop at any incremental position and absorb peak torque inputs, enabling up to 2x faster indexing vs cam-driven designs.

The Nexen Group Rotary Indexer Advantage

• Indexing precision up to ±11 ArcSec and repeatability as low as ±1.2 ArcSec (model-dependent).
• Zero-backlash options (Harmonic / RPS configurations) delivering motor-to-load transmission with negligible lost motion.
• High load capacity (examples up to 1575 kN on PRD with cross-roller bearing).
• High output torque: maximum acceleration torque up to 4,811 Nm and nominal torque up to ~2,625–2,750 Nm (model-dependent).
• High speed capability: selected models up to 304 RPM (model-dependent).
• Large open-center design options for application flexibility.
• Smooth operation through RPS technology, preloaded cross-roller bearings and integrated motor/precision gearheads.

Differences between PRD and CRD Systems
PRD (Precision Rotary Indexer): precision-machined steel plate construction with guarded gear/pinion, optional low-backlash Planetary or zero-backlash Harmonic gearheads; common output bolt circle diameters: 400, 750, 1100, 1500 mm. CRD (Compact Rotary Indexer): sealed rigid cast-iron housing with enclosed gear/pinion; options include motor/gearbox-ready input or pre-installed low-backlash Planetary or zero-backlash Harmonic gearheads; common output bolt circle diameters: 150, 250, 350, 550 mm.

Representative Comparison Table (selected rows & columns)

• CRD-PL — Low-backlash Planetary | IP65 cast iron | Output Ø examples 150–550 mm | Nominal torque 323–697 Nm | Max velocity 120–225 RPM.
• CRD-MRS-PL — Planetary | IP65 cast iron | Wide ratio range; nominal torque 119–299 Nm | Velocity 23.5–304 RPM.
• CRD-HG — Zero-backlash Harmonic | IP65 cast iron | Nominal torque 380–820 Nm | One-way positional accuracy 20–43 ArcSec | Velocity 11–25 RPM.
• PRD-PL (guarded) — Low-backlash Planetary | Guarded steel plate | Output Ø examples 400–1500 mm | Nominal torque 544–1870 Nm | Velocity 27–94 RPM.
• PRD-HG (guarded) — Harmonic | Guarded | Nominal torque 326–1122 Nm | One-way repeatability 1.6–2.4 ArcSec | Low-speed high-torque configurations available.

Resources cited on this page (brochures and technical literature)
Downloadable technical data sheets and product brochures are available for CRDX / PRDX / CRD family variants, including dimensional data, performance curves and configuration guides.

Technical specifications

• Indexing precision: up to ±11 ArcSec (model-dependent).
• Repeatability: down to ±1.2 ArcSec (model-dependent).
• Zero-backlash options: Harmonic and RPS configurations available.
• Maximum acceleration torque: up to 4,811 Nm (model-dependent).
• Nominal torque: up to ~2,625–2,750 Nm (model-dependent).
• Maximum speed: up to 304 RPM (model-dependent).
• Maximum load capacity (PRD example): up to 1575 kN with precision cross-roller bearing.
• Housing options: IP65 sealed rigid cast iron; guarded; open-center variants.
• Available output bolt circle diameters: PRD examples 400, 750, 1100, 1500 mm; CRD examples 150, 250, 350, 550 mm.
• Typical applications: cutting systems, gantry systems, medical devices, robotics, aerospace, machine tools, semiconductor, material handling, assembly/custom machines, defense, theme park/theatrical systems.