INDUSTRY COMPONENT

Sun Gear

A central gear in planetary gear systems that meshes with planet gears to transmit torque and reduce speed.

View Specifications

Component Specifications

Definition
The sun gear is the central component in a planetary gear system, typically located at the rotational axis. It engages with multiple planet gears arranged around it, which in turn mesh with an outer ring gear. This configuration allows for high torque transmission, compact design, and significant speed reduction ratios. Sun gears are critical in applications requiring precise speed control, load distribution, and efficient power transfer in confined spaces.
Working Principle
The sun gear rotates around its central axis, driving the planet gears that orbit around it. The planet gears are mounted on a carrier and also mesh with a stationary or rotating ring gear. This arrangement creates multiple gear meshes simultaneously, distributing the load and enabling high torque capacity with minimal space. The speed reduction ratio is determined by the number of teeth on the sun gear, planet gears, and ring gear, following the formula: Reduction Ratio = (Ring Gear Teeth / Sun Gear Teeth) + 1.
Materials
Typically made from alloy steels (e.g., AISI 4140, 4340) for strength and durability, often heat-treated (carburized or induction hardened) to achieve surface hardness of 58-62 HRC. Alternative materials include stainless steel for corrosion resistance or bronze for low-noise applications. Surface finishes may include grinding or honing to achieve precise tooth profiles and reduce friction.
Technical Parameters
ParameterTypical rangeNotes & selection driver
Module1.5-5 mm
Backlash0.05-0.15 mm
Hardness58-62 HRC
Face Width10-50 mm
Accuracy GradeISO 1328 Class 6-8
Pressure Angle20°
Number Of Teeth15-40

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards
ISO 1328, DIN 3960, AGMA 2000

Parent Products

This component is used in the following industrial products

Reduction Gears

Mechanical components that reduce rotational speed while increasing torque in robotic systems.

View Product Details

Planetary Gear Set

A compact, high-torque gear arrangement consisting of central sun gear, multiple planet gears, and outer ring gear.

View Product Details

Planetary Gear Reducer

A compact, high-torque gear reduction mechanism that transmits and reduces rotational speed within a slewing unit.

View Product Details

Engineering Analysis

Risks & Mitigation
  • Tooth wear due to improper lubrication
  • Misalignment causing uneven load distribution
  • Fatigue failure from cyclic loading
  • Overheating due to excessive friction
FMEA Triads
Trigger: Inadequate lubrication or contamination
Failure: Accelerated tooth wear and pitting
Mitigation: Implement regular lubrication schedules and use filtered oil systems; monitor oil quality and temperature.
Trigger: Misalignment during assembly
Failure: Uneven load distribution leading to premature failure
Mitigation: Use precision alignment tools during installation; perform periodic alignment checks and adjust as needed.
Trigger: Excessive torque or shock loads
Failure: Tooth breakage or deformation
Mitigation: Design with appropriate safety factors; install torque limiters or overload protection devices.

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance
Tooth profile tolerance per ISO 1328 Class 6-8; backlash controlled within 0.05-0.15 mm
Test Method
Gear mesh analysis using coordinate measuring machines (CMM); hardness testing via Rockwell scale; fatigue testing under cyclic loading conditions

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation
Request current drawings, revision history, and a signed specification sheet.
Manufacturing capability
Verify equipment lists, process limits, capacity, and representative production evidence.
Inspection readiness
Confirm test methods, calibrated equipment, sampling plans, and traceable reports.
Supplier transparency
Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Sun Gear

Manufacturer profiles associated with Sun Gear.

Sourcing Sun Gear from China?
Tell us your specification and target quantity — we will match it against manufacturer records and come back with the factories that fit.
Request manufacturers We manufacture this

Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

Related Components

Chrome Plating
Hard chrome plating is an electroplating process that deposits a layer of chromium onto metal surfaces to enhance wear resistance, corrosion protection, and reduce friction for hydraulic cylinder piston rods.
Upper Tool (Punch)
Upper Tool (Punch) is the active forming component in metal plate bending machines that applies precise downward force to create bends in sheet metal.
Main Frame
The main frame is the primary structural component of a hydraulic press, providing rigidity and stability to withstand high compressive forces during metal forming operations.
Shaft Bearing
Precision component supporting rotating shafts in vibration motors to reduce friction and maintain alignment.

Frequently Asked Questions

What is the primary function of a sun gear?

The sun gear transmits rotational motion to the planet gears in a planetary system, enabling torque multiplication and speed reduction in a compact design.

How does a sun gear differ from a standard spur gear?

A sun gear is designed specifically for planetary configurations, meshing with multiple planet gears simultaneously, whereas a standard spur gear typically engages with a single gear. This allows for higher load capacity and efficiency in confined spaces.

What materials are commonly used for sun gears?

Alloy steels like AISI 4140 or 4340 are most common, often heat-treated for hardness. Stainless steel or bronze may be used for specialized applications requiring corrosion resistance or reduced noise.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification
This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Request Manufacturing Insight for Sun Gear

Thank you. Your request has been sent. We'll respond within 1–3 business days.
Sorry, we couldn't send your message. Please try again, or email us at contact@cnfx.com.
Yoke Bracket
Get QuotesChat