What is a Planetary Gear System?
A planetary gear system comprises a central sun gear, multiple planet gears rotating around it, and an outer ring gear (internal gear) meshing with the planets. This architecture enables high reduction ratios within a compact envelope while distributing torque across multiple contact points. Yantong Tech manufactures planetary gear sets with controlled tooth accuracy, matched heat treatment, and verified assembly clearances to ensure smooth power transmission, balanced load sharing, and extended service life in high-duty industrial applications.
- Precision hobbing and grinding achieve ISO 1328 Grade 6–8 tooth accuracy for all planetary components, ensuring uniform load distribution and low vibration
- Carburizing or nitriding heat treatment delivers HRC 58–62 surface hardness with controlled case depth for predictable wear resistance and fatigue strength
- Full gear measurement data (involute profile, lead, pitch) and material traceability archived by batch to support quality audits and long-term reliability tracking
- Custom planet carrier designs, shaft tolerances (IT6–IT8), and bearing seat dimensions matched to customer assembly requirements for seamless integration
Core Characteristics and Performance Advantages
Engineering features enabling compact design, high torque capacity, and reliable multi-stage reduction in heavy-duty applications
Compact High-Ratio Design
Multiple planet gears share torque load, enabling high reduction ratios (up to 1:100+ in multi-stage configurations) within a compact radial envelope, reducing equipment footprint and installation complexity.
Balanced Load Distribution
Symmetrical planet gear arrangement ensures even torque distribution and radial force cancellation, minimizing bearing loads and extending carrier service life under continuous heavy-duty operation.
Verified Tooth Accuracy & Surface Integrity
Gear measurement center validation confirms involute profile, pitch, and lead tolerances to ISO 1328 Grade 6–8; carburizing depth and hardness (HRC 58–62) verified per specification with magnetic particle testing available for critical applications.
Technical Specifications and Manufacturing Range
Comprehensive parameter overview for planetary gear system design and integration
| Item | Specification Range | Remarks |
|---|---|---|
| Module | m0.5 – m12 | Sun, planet, and ring gears matched per system design |
| Number of Planets | 3 – 6 planets (typically 3 or 4) | Load capacity and balance optimization |
| Reduction Ratio | Single-stage: 3:1 to 10:1 Multi-stage: up to 1:100+ |
Customizable per application requirements |
| Outer Diameter (Ring Gear) | 80 mm – 1200 mm | Larger sizes available upon request |
| Tooth Accuracy | ISO 1328 Grade 6 – 8 (DIN 6–8) | Grinding available for Grade 6 precision |
| Materials | 20CrMnTi / 42CrMo / 18CrNiMo7-6 / SCM415 / 40Cr | Material selection per load and heat treatment requirements |
| Heat Treatment | Carburizing / Nitriding / Induction Hardening | Controlled case depth and core hardness per specification |
| Surface Hardness | HRC 58–62 (Carburized) HRC 50–55 (Nitrided) |
Validated with hardness testing and metallographic examination |
| Surface Roughness | Ra 0.4 – 1.6 μm | Post-grinding or honing finish |
| Inspection | Gear Measurement Center / CMM / Profile Projector | Full inspection reports archived by batch |
Custom Manufacturing Capability for Planetary Gear Systems
Four core competencies supporting high-ratio gearbox design, heavy-duty industrial drives, and precision motion control assemblies
System Design & Ratio Optimization
Planetary gear train calculation, reduction ratio optimization, load-sharing analysis, and planet carrier layout design; reverse engineering from existing gearboxes for OEM replacement or performance improvement.
Precision Hobbing & Grinding
CNC gear hobbing for sun and planet gears, internal gear shaping for ring gears, and finish grinding for high-accuracy profiles (ISO 1328 Grade 6–7); dimensional consistency verified through statistical process control.
Matched Heat Treatment & Hardness Control
Carburizing or nitriding applied to all planetary components with matched case depth and hardness; heat treatment distortion controlled through fixturing and tempering; batch-level traceability maintained for quality audits.
Assembly Verification & Technical Support
Tooth contact pattern checking, backlash measurement, and runout verification before shipment; assembly guidance documents provided; remote technical consultation for installation troubleshooting and performance optimization.
Manufacturing Process: From Component Machining to Verified Planetary Gear Set
Six controlled stages ensuring dimensional consistency, matched heat treatment, and full assembly traceability
Raw Material Verification & Preparation
Incoming steel (20CrMnTi, 42CrMo, or customer-specified alloy) validated with mill certificates; chemical composition and hardness verified before release to machining. All planetary components (sun, planet, ring gears) assigned common batch numbers for traceability.
Turning & Blank Machining
CNC turning establishes outer diameters, bores, and mounting faces for sun, planet, and ring gear blanks. First-piece inspection confirms toolpath accuracy; dimensional consistency maintained through in-process sampling and statistical control.
Gear Hobbing / Internal Gear Shaping
CNC gear hobbing cuts sun and planet gear teeth; internal gear shaping machines ring gear teeth. Module, pressure angle, and helix angle controlled to drawing specification; tooth thickness and profile form verified through in-process checks.
Batch Heat Treatment (Carburizing or Nitriding)
All planetary components undergo matched heat treatment (carburizing to HRC 58–62 or nitriding to HRC 50–55) in the same batch to ensure uniform case depth and core hardness. Heat treatment cycles documented; hardness and case depth validated on test coupons and production samples.
Finish Grinding & Profile Correction
CNC gear grinding (for precision grades) corrects heat treatment distortion and achieves final tooth profile accuracy (ISO 1328 Grade 6–7). Bore and shaft surfaces ground or honed to final tolerance; edges deburred to prevent assembly damage.
Gear Measurement & Assembly Verification
Gear measurement center records involute profile, lead, pitch, and runout data for all components; CMM verifies dimensional tolerances; tooth contact pattern and backlash checked in trial assembly. Inspection certificate, material traceability, and heat treatment report prepared for shipment.
Quality Control and Inspection System for Planetary Gear Sets
Five-stage verification protocol ensuring matched component accuracy, batch consistency, and full assembly traceability
Raw Material & Batch Control
Mill certificates validated for all planetary components (sun, planet, ring gears); chemical composition spot-checked via spectrometer; hardness measured to confirm annealing condition. All components assigned common batch numbers for matched traceability throughout manufacturing and heat treatment.
Machining & Tooth Form Verification
First-piece inspection after hobbing and shaping confirms dimensional compliance for all planetary components; in-process sampling monitors module, pressure angle, tooth thickness, and profile form. Statistical process control (SPC) applied to critical dimensions ensuring uniform accuracy across sun, planet, and ring gears.
Matched Heat Treatment Validation
All planetary gear components heat-treated in same batch to ensure uniform case depth and core hardness; surface hardness (HRC 58–62 carburized or HRC 50–55 nitrided) measured at multiple locations per component. Metallographic examination validates microstructure consistency and effective case depth per specification.
Gear Measurement Center Inspection
Gear measurement center captures involute profile deviation, helix deviation, pitch variation, and total composite error for each component type. Data compared to ISO 1328 tolerance class or customer-specified limits; out-of-tolerance parts segregated and corrected or scrapped. Measurement reports archived by batch number.
Assembly Trial & Contact Pattern Verification
Trial assembly of planetary gear set performed to verify tooth contact pattern, backlash, and runout; Prussian blue or marking compound applied to confirm load distribution across all planet gears. CMM verifies final dimensional tolerances for shafts and bearing seats. Complete inspection data package prepared for shipment.
Applications and Industry Integration
Planetary gear systems delivering compact high-ratio transmission, balanced torque distribution, and reliable operation across six core sectors
Certifications and Quality Standards
Recognized quality systems and compliance documentation supporting international procurement requirements
ISO 9001:2015
IATF 16949 Methods
Material Traceability (EN 10204 3.1)
RoHS / REACH Compliance
Material Selection and Heat Treatment Process
Material composition and matched heat treatment across all planetary components (sun, planet, and ring gears) directly determine system durability, load capacity, and service life. Yantong Tech applies batch-controlled carburizing, nitriding, or induction hardening to achieve specified surface hardness and case depth uniformity, with full process documentation for quality assurance and long-term traceability.
Design and Engineering Collaboration
Manufacturing engineers supporting planetary gear system optimization, reduction ratio calculation, and reverse engineering for OEM replacement
- Planetary gear train calculation and reduction ratio optimization based on load requirements, speed range, and envelope constraints; planet carrier layout design and bearing selection support
- CAD/CAM-based profile design and tolerance control for sun, planet, and ring gears; profile modification analysis for load sharing improvement and noise reduction across multi-planet configurations
- Reverse engineering from existing gearboxes or worn planetary sets for OEM replacement; dimensional measurement, material identification, and heat treatment replication with manufacturability and life extension recommendations
- Technical drawing verification and export documentation support; dimensional clarification, tolerance stack-up analysis, and assembly guidance to ensure fit, function, and load distribution across all planetary components
What Our Clients Say
Trusted by heavy equipment OEMs and planetary gearbox manufacturers across three continents
We sourced a complete planetary gear set for our wind turbine pitch drive from Yantong Tech. All components (sun, planet, and ring gears) were heat-treated in the same batch with matched hardness and full measurement reports. The trial assembly showed excellent load distribution across all planets. This is the manufacturing consistency we need for series production.
Our tower crane project required multi-stage planetary gearboxes with high reduction ratios and compact mounting. Yantong's engineering team calculated the gear train, optimized planet carrier layout, and delivered all components with verified tooth contact patterns. Lead time was competitive and their technical responsiveness during design review was professional.
We needed replacement planetary gears for mining conveyor reducers. Yantong Tech reverse-engineered our worn set, identified materials, and replicated heat treatment specifications. The replacement components assembled smoothly and have been running reliably for 18 months. Good quality and honest communication throughout the project.
Why Engineers and Procurement Teams Choose Yantong Tech for Planetary Gear Systems
Four core competencies supporting high-ratio gearbox reliability, predictable delivery, and long-term partnership
Complete Planetary Set Manufacturing
96-person team with integrated hobbing, internal shaping, grinding, and heat treatment capabilities; module range m0.5–m12, reduction ratios 3:1 to 100+, ISO 1328 Grade 6–8 accuracy achievable through controlled process and matched batch treatment.
Matched Component Traceability
All planetary components (sun, planet, ring gears) assigned common batch numbers; material certificates (EN 10204 3.1), heat treatment reports, gear measurement data for each component type, and trial assembly records archived for quality audits and long-term reference.
System-Level Engineering Support
Manufacturing engineers with planetary gear train design experience engage directly with customer technical teams; reduction ratio calculation, planet carrier layout optimization, and load-sharing analysis provided before quotation to ensure system-level performance.
Realistic Pricing & Delivery
Quotations based on actual component complexity, matched heat treatment batch requirements, and grinding capacity; lead time commitments honored through rolling safety stock for standard modules and milestone tracking for custom planetary sets.
NEW_UI_NOTIFICATION_START I've updated the file. NEW_UI_NOTIFICATION_ENDPackaging and Export Logistics
Protection protocol ensuring gear set integrity from factory to your receiving dock
Corrosion Prevention & Sealed Protection
Surfaces are treated with rust-inhibiting oil or VCI protection depending on transit duration and climate, and each gear is sealed in PE bags with desiccant to control humidity from factory loading to overseas delivery.
Tooth Edge Protection & Anti-Impact Support
Large gears are positioned on rigid pallets or supports that bear the weight, while tooth edges are wrapped or cushioned to avoid contact damage during loading and transport. Wrapping also helps reduce dust and moisture exposure before crating.
Reinforced Crating & Export-Ready Loading
Gears are secured in reinforced plywood crates with proper corner strength and lifting points, and crate dimensions are planned for safe forklift engagement and container loading according to destination requirements.
Frequently Asked Questions About Planetary Gear Systems
Quick answers to common technical and commercial inquiries
Technical Questions
Commercial Questions
How to Start Cooperation with Yantong Tech
A transparent seven-step process from inquiry to ongoing technical support
Send Your Drawing / Specification
Submit technical drawings for sun, planet, and ring gears (PDF, DWG, STEP) or complete gearbox assembly via email. Include specifications for material, heat treatment, accuracy grade, reduction ratio, and any special requirements. Our engineering team reviews for manufacturability and system-level compatibility within 24 hours.
Initial Contact
Drawing review and system feasibility confirmation
Technical Clarification
Engineering dialogue and tolerance verification
Technical Review & Proposal
Our manufacturing engineers discuss planetary gear train configuration, reduction ratio optimization, load-sharing requirements, and clarify tolerances for all components. Any manufacturability concerns (planet spacing, ring gear internal shaping access, heat treatment distortion control) or improvement suggestions communicated before quotation.
Quotation & Lead Time Confirmation
Detailed quotation provided with breakdown of material, machining for all components, matched batch heat treatment, grinding (if required), and inspection costs. Lead time estimated based on current production schedule and heat treatment batch availability. Payment terms and shipping arrangements confirmed.
Commercial Agreement
Transparent pricing and delivery commitment
Manufacturing Phase
Batch-controlled process and milestone tracking
Production & Batch Manufacturing
Manufacturing executed per documented process plan with all planetary components (sun, planet, ring gears) assigned common batch numbers. First-piece inspection, in-process checks, and matched batch heat treatment validation performed at each stage. Production milestones updated for customer visibility on lead time status.
Inspection & Trial Assembly
Final 100% inspection including gear measurement, dimensional verification, hardness testing for all components. Trial assembly performed to verify tooth contact pattern, backlash, and load distribution across all planet gears. Inspection certificates, material traceability, heat treatment reports, and assembly records compiled for customer approval before shipment.
Quality Assurance
Full documentation and assembly verification
Logistics & Delivery
Protected packaging and export documentation
Packaging & Shipping
Planetary gear sets packed as matched components with anti-rust coating, foam protection, and component identification labels. Plywood crates with steel reinforcement for heavy sets. Export documentation prepared for customs clearance. Tracking information provided upon shipment dispatch.
Technical Consultation & After-sales Follow-up
Remote technical support available for assembly guidance, backlash adjustment, and performance feedback. Quality issues addressed through root cause analysis and corrective action. Long-term partnership built on continuous improvement, system-level performance feedback, and mutual trust.
Ongoing Support
Technical consultation and continuous improvement
Ready to Source Reliable Planetary Gear Systems?
Send your planetary gear train specifications and receive an engineering reply within 24 hours — no obligation, just transparent technical dialogue.
- Complete planetary sets: Module m0.5–m12, reduction ratios 3:1 to 100+, ISO 1328 Grade 6–8 accuracy
- Matched batch heat treatment: Carburizing, nitriding, or induction hardening for all components with full process documentation
- Trial assembly verification: Tooth contact pattern checking, backlash measurement, and load distribution validation before shipment
- System-level engineering support: Reduction ratio calculation, planet carrier layout optimization, and reverse engineering for OEM replacement
- ISO 9001 certified with IATF 16949 methods for automotive-level quality assurance and full component traceability