🏗️Heavy-Duty & High-Impact Transmission
Construction & Mining Machinery
High-torque, impact-resistant gears, girth rings, and planetary drive sets engineered for excavators, cranes, drilling rigs, and heavy mining crushers.
Custom Planetary Gear Set
Custom Planetary Gear Sets
China direct OEM factory for custom planetary gear sets—manufacturing precision ground sun gears, matched planet pinions, CNC-bored planet carriers, and internal ring gears strictly to your 2D/3D drawings or samples.
Source Factory
China Direct (2,800m² Plant)
Precision Grade
DIN 4-7 / AGMA 11-13
DFM Analysis
< 24 Hours Turnaround
Quality System
ISO 9001:2015
Product overview
Custom Planetary Gear Sets manufacturing starts with confirmed technical requirements.
Review the gear pair, assembly conditions, drawing requirements, specification checks, and inspection points before requesting a quotation.
Planetary gear mechanisms (epicyclic gear trains) deliver unmatched torque-to-weight density, coaxial power transmission, and balanced bearing loads by splitting torque across 3 to 6 parallel planet pinions. However, achieving true load sharing (Kγ ≈ 1.0–1.1) and low acoustic noise requires tight tolerance coupling across all four mating elements. ZhongYi manufactures complete custom planetary gear sets to engineering prints, STEP/IGES CAD models, or reverse-engineered samples—backed by proven OEM supply experience for precision reducer leaders such as Newstart Planetary Reducers. Our integrated production covers input sun gears (integral shafts or splined bores), matched planet pinions with honed needle-bearing raceway bores, 5-axis CNC machined planet carriers, and low-distortion nitrided or carburized internal ring gears. We apply parabolic tooth lead crowning (Cβ) and profile tip relief (Cα) via CNC form grinding and sort planet pinions in serialized matched sets.
Tooth AccuracyDIN 5-7 / AGMA 11-13
Tooth FinishingCNC Ground (Ra ≤0.4µm)
Hardness GradeCarburized 58-62 HRC
Custom Planetary Gear SetsFactory Genuine Spec
Selection guidance
How to specify a custom planetary gear sets for quotation.
Use application and mating-component data to confirm geometry, materials, mounting details, and the acceptance plan.
Before releasing drawings for quotation, verify the three planetary kinematic conditions: (1) Concentricity: Z_ring = Z_sun + 2·Z_planet (or profile-shifted center distance match); (2) Symmetric Planet Spacing: (Z_sun + Z_ring) / N_planets = integer for equal angular pin spacing; and (3) Adjacency clearance between neighboring planet tips. Specify input RPM, continuous rated torque, peak shock torque, operating temperature, and target torsional backlash (in arcminutes). When ordering replacement sets for an existing gearbox, supply the sun gear, all planet pinions, carrier pin center distance, and internal ring gear together so we can match center-distance backlash and tooth modifications.
Technical specifications
Core technical parameters for engineering and procurement review.
| Kit components | Central sun gear/shaft, 3 to 6 matched planet pinions, planetary carrier, and internal ring gear (annulus) |
|---|---|
| Manufacturing basis | Customer 2D/3D CAD prints (STEP/IGES/PDF), gear data sheets, or physical gearbox samples |
| Module & Pitch range | Metric Module M0.5 to M12 (Diametral Pitch DP 48 to DP 2); Spur or Helical (helix angle up to 30°) |
| Tooth accuracy grades | DIN 5 to DIN 7 (ISO 1328 Grade 5–7 / AGMA 11–13) via CNC tooth flank profile grinding |
| Sun & planet metallurgy | 18CrNiMo7-6, 20CrMnTi, or AISI 8620 case-carburized & quenched to 58–62 HRC (case depth 0.6–2.5 mm) |
| Internal ring metallurgy | 42CrMo / 38CrMoAlA plasma/gas nitrided (650–750 HV, low distortion) or 20CrMnTi carburized & ground |
| Planet carrier specs | 42CrMo forged steel (28–34 HRC) or QT600-3 ductile iron; pin hole true position ≤ 0.012 mm |
| Planet bore finishing | Hardened & honed needle bearing bore (ISO H6/G6, cylindricity ≤ 0.005 mm, Ra ≤ 0.2–0.4 µm) |
| Backlash classes | Ultra-Precision (< 3 arcmin), Precision (< 5 arcmin), Standard (< 8–10 arcmin) |
Component Engineering & Metallurgy Matrix
Custom Planetary Gear Sets — Component-by-Component Metallurgy & Tolerance Matrix
Review recommended alloy steels, heat-treatment hardness, tooth/bore finishing routes, and CMM inspection checkpoints for each mating element.
| Epicyclic Component | Recommended Material | Heat Treatment & Surface Hardness | Tooth / Bore Finishing Route | Critical Metrology Checkpoint |
|---|---|---|---|---|
| Central Sun Gear / Sun Shaft | 18CrNiMo7-6, 20CrMnTi, AISI 8620 | Case Carburizing & Quenching (58–62 HRC) | CNC Profile Grinding (DIN 5–6, Ra ≤ 0.4 µm) | Profile/lead crowning (Cα, Cβ), pitch error (Fp), journal TIR ≤ 0.005 mm |
| Matched Planet Pinions (3–6 pcs) | 18CrNiMo7-6, 20CrMnTi, AISI 8620 | Case Carburizing & Quenching (58–62 HRC) | CNC Tooth Grinding + Bore Honing (Ra ≤ 0.2 µm) | Grouped span measurement (ΔMk ≤ 0.004 mm), bore cylindricity ≤ 0.005 mm |
| Internal Ring Gear (Annulus) | 42CrMo (4140), 38CrMoAlA, 20CrMnTi | Plasma/Gas Nitriding (650–750 HV) or Carburizing | CNC Gear Shaping, Broaching, or Internal Grinding | Pitch circle roundness, minimal distortion, flange concentricity |
| Planet Carrier (Single / Double Wall) | 42CrMo Forged Steel, 40Cr, QT600-3 | Quenching & Tempering (28–34 HRC) | 5-Axis CNC Machining & Precision Pin Boring | Pin hole true position ≤ 0.012 mm, pin parallelism, bearing seat runout |
* Note: All four planetary components are manufactured in-house and serialized in matched sets. Custom material grades and micro-geometry modifications are confirmed per customer CAD drawing.
Custom options
Manufacturing details that can be reviewed before quotation.
- Single-stage (3:1 to 10:1) and multi-stage compound (up to 1000:1+) epicyclic gear train kits
- Parabolic tooth lead crowning (Cβ: 3–15 µm) and tip/root profile relief (Cα) to prevent edge loading
- Hardened needle roller bearing raceway bores, pre-fitted caged bearings, or bronze journal bushings
- Integral input sun pinion shafts with DIN 5480 splines, keyways, or servo motor clamping hubs
- Serialized planet gear sorting by weight and span measurement (over-pins diameter) for equal load sharing
Quality control
Inspection points tied to the approved technical file.
- Zeiss 3D CMM verification of planet carrier pin hole true position (≤ 0.012 mm), parallelism, and coaxiality
- Klingelnberg CNC gear measuring center report for sun and planet profile (Fα), lead crowning (Fβ), and pitch (Fp)
- Double-flank gear rolling inspection of composite radial runout (Fi") and assembled center-distance backlash
- Serialized span measurement (over-pins diameter Mk) grouping within ≤ 0.004 mm across each planet set
- Metallurgical micro-Vickers hardness gradient testing of effective case depth and EN 10204 3.1 MTR certification
All products can be custom manufactured from 2D/3D CAD drawings or physical samples.
Quality Control & Inspection Matrix
Engineering Evidence & 100% Inspection for Custom Planetary Gear Sets.
Overseas procurement teams require verifiable technical data, not unsupported claims. Every production batch at ZhongYi is inspected against approved CAD blueprints and international standards (DIN, AGMA, ISO).
Component-Specific Quality Focus:
Custom planetary gear components are manufactured and verified as synchronized kinematic assemblies. Quality documentation provided with shipment includes individual Klingelnberg gear geometry charts, Zeiss CMM carrier pin-hole coordinate reports, case-carburizing or nitriding hardness curves, tooth contact pattern checks, and grouped planet pinion matching certificates.
Coordinate Metrology
Zeiss / Hexagon 3D CMM
Validates 3D spatial GD&T, bore concentricity, center distance, and geometric tolerances down to ±0.002 mm.
Tooth Geometry Analysis
Klingelnberg CNC Gear Analyzer
Inspects involute tooth profile error (fα), lead crowning (fβ), pitch cumulative error (Fp), and radial runout (Fr).
Hardness & Case Depth
Digital Micro-Vickers & Rockwell Testers
Verifies surface hardness (58–62 HRC), core toughness, and effective carburized / nitrided case depth gradient.
Chemical Metallurgy
Direct-Reading Optical Spectrometer
100% chemical composition verification of alloy steel forgings (20CrMnTi, 42CrMo, 18CrNiMo7-6, Stainless, POM).
Inspection Deliverables with Every Shipment
Complete Batch Traceability & Certified Test Reports
- EN 10204 Type 3.1 Mill Test Certificate (Chemical & Mechanical Properties)
- Zeiss 3D CMM Full Dimensional Inspection Sheet
- Klingelnberg Tooth Profile & Lead Crowning Graph Report
- Effective Carburized Case Depth & Hardness Curve Data
- 100% Pre-Shipment Visual, Thread & Anti-Rust Quality Verification
Our Factory Quality Commitment:
We maintain strict incoming material spectroscopy, in-process CNC tooth coordinate monitoring, and 100% final pre-shipment dimensional inspection. All custom gear batches are backed by our full manufacturing warranty.
ISO 9001:2015 Certified
DIN 4-7 / AGMA 11-13 Standards
Applications
Custom Planetary Gear Sets operating environments.
Confirm load, speed, duty cycle, environment, lubrication, and assembly constraints before selecting the final material and manufacturing route.
- High-precision servo planetary gearboxes for industrial robotics, AGV wheel drives, and CNC automation
- Hydrostatic final wheel drives, track travel drives, and winch reducers for excavators and mining equipment
- Slewing drives and swing reducers for mobile cranes, forestry machinery, and aerial work platforms
- Wind turbine pitch and yaw drive gearboxes, solar trackers, and agricultural tractor transmissions
Application Markets
View All 5 Industry Hubs →Where Custom Planetary Gear Sets Are Engineered & Deployed
Discover how this gear category meets extreme torque, low backlash, quiet operation, and weather-resistance demands in primary industry sectors:
🌬️20-Year Outdoor Longevity & High Wind Torque
Renewable Energy
Heavy-torque yaw/pitch gears, slewing ring drives, and precision worm drives engineered for 20-year service life in wind turbines and solar tracking fields.
Technical FAQ
Common questions before ordering custom planetary gear sets products.
Critical specifications are confirmed against final drawings before production.
Why is planet gear tooth crowning critical in planetary gearboxes?▼
Tooth lead crowning is essential because it prevents severe edge loading caused by elastic torsional deflection of the planet carrier under heavy torque. By grinding a micro-curved barrel profile (3–15 µm) along the tooth flank, stress remains centered across the tooth face, doubling or tripling gearbox fatigue life.
What is the kinematic assembly condition for symmetric planetary gears?▼
For N planet gears to be equally spaced around the sun gear at 360°/N intervals, the sum of the sun gear teeth (Z_sun) and internal ring gear teeth (Z_ring) must be evenly divisible by the number of planets: (Z_sun + Z_ring) / N = integer. Additionally, standard concentricity requires Z_ring = Z_sun + 2·Z_planet.
Should internal ring gears be carburized or nitrided?▼
Nitriding (using 42CrMo or 38CrMoAlA alloy steel) is preferred for most thin-walled internal ring gears because low-temperature plasma or gas nitriding produces minimal thermal distortion while achieving 650–750 HV surface wear resistance without costly internal grinding. For extreme shock-load mining or wind drives requiring deep case depth (> 1.5 mm), 20CrMnTi or 18CrNiMo7-6 carburizing followed by CNC internal tooth grinding is recommended.
How do you finish the inside bore of planet gears for needle roller bearings?▼
In compact planetary reducers, the planet gear bore serves directly as the outer raceway for needle rollers. We case-harden the bore to 58–62 HRC and perform precision internal cylindrical grinding or honing after heat treatment, holding bore tolerance to ISO H6/G6, cylindricity within 0.005 mm, and surface roughness to Ra ≤ 0.2–0.4 µm.
Can ZhongYi manufacture individual replacement planet gears for an existing drive?▼
While we can manufacture single gears, we strongly recommend replacing all planet pinions (all 3, 4, or 5 pieces) as a matched set alongside the sun gear. Mixing a new planet pinion with worn mates disrupts load sharing (Kγ), causing the new gear to carry disproportionate torque and fail prematurely.
What materials are recommended for heavy-duty planetary gears?▼
We recommend vacuum-degassed case-carburizing alloy steels such as 18CrNiMo7-6 (DIN 1.6587), 20CrMnTi, or AISI 8620 for sun and planet gears to achieve 58–62 HRC surface hardness with a tough 32–40 HRC core. Planet carriers are typically machined from forged 42CrMo (AISI 4140) quenched and tempered to 28–34 HRC for high torsional stiffness.
24-Hour Engineering Quote & DFM Review
Upload Your Drawings for Custom Planetary Gear Sets Manufacturing
Send your 2D blueprints or 3D CAD models. Our senior gear engineering team will review tooth geometry, module/pitch, materials, heat treatment feasibility, and provide transparent factory pricing within 24 hours.
Supported CAD Blueprint & Drawing Formats:
STEP (.step / .stp)AutoCAD (.dwg / .dxf)IGES (.igs)SolidWorks / 3D CADPDF Technical BlueprintsWorn Physical Samples
Mutual NDA Protection
We sign strict Non-Disclosure Agreements to safeguard proprietary designs.
< 24h DFM Feedback
Rapid manufacturability review, tolerance checks, and unit quotation.
Direct Factory Engineering
Direct technical communication with senior master gear artisans.
Technical Engineering Cluster
In-Depth Design, Calculation & Sourcing Guides for Custom Planetary Gear Sets
Review kinematic assembly formulas, AGMA 6123 load-sharing tooth crowning methods, carburizing vs. nitriding metallurgy, and RFQ drawing checklists.
Kinematics & Design9 min read
Planetary Gear Ratio & Assembly Condition Calculation Guide (With Examples)
Before releasing a planetary gear set drawing for CNC machining, engineers must verify three mandatory geometric constraints—concentricity, symmetric planet spacing, and adjacency clearance—alongside the Willis kinematic speed ratio.
Engineering GuideRead Article →
Kinematics & Design10 min read
Planetary Gear Load Sharing (Kγ) and Tooth Lead Crowning Explained
Adding more planet pinions does not automatically multiply torque capacity in a linear 1:1 ratio. Without micro-geometry tooth lead crowning and tight carrier pin position control, a single overloaded planet can carry over 50% of the total load.
Engineering GuideRead Article →
Reducer Comparison8 min read
Planetary Gear vs. Harmonic Drive vs. Cycloidal Drive: Engineering Selection Guide
Choosing the wrong speed reducer architecture for a robotic joint, AGV drivetrain, or CNC axis either starves the system of mechanical efficiency or drives BOM costs up by 300%. Here is a quantitative engineering comparison.
Engineering GuideRead Article →
Reducer Comparison8 min read
Helical vs. Spur Planetary Gears: Noise, Axial Thrust, and Torque Capacity
Upgrading a planetary stage from straight spur teeth to angled helical teeth can drop gearbox noise by 4 to 8 dB(A) and boost torque ratings by 20%–30%—but it introduces overturning moments on the planet needle bearings that must be engineered properly.
Engineering GuideRead Article →
Manufacturing & Metallurgy9 min read
Materials & Heat Treatment for Planetary Gears: Carburizing vs. Nitriding
Applying the same heat-treatment specification to all four components of a planetary gear set is a costly mistake. Here is why sun and planet pinions demand deep case carburizing while internal ring gears thrive on plasma nitriding.
Engineering GuideRead Article →
Troubleshooting & MRO9 min read
Planetary Gear Failure Modes: Diagnosing Pitting, Tooth Breakage, and Backlash
In 70% of catastrophic planetary gearbox breakdowns, the broken gear teeth found in the sump are the final symptom—not the root cause. Use this metallurgical and kinematic diagnostic guide to pinpoint failure origins.
Engineering GuideRead Article →
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