Main Reduction Gear – High Precision Gear for EV | DD Gear

Features & Benefits

• High torque capacity for EV final drive
  Tooth size, face width, and root fillets are designed to carry high continuous torque and peak loads from electric motors, including regenerative braking, while keeping safety factors within OEM targets.

• Optimized reduction ratio and efficiency
  The main reduction gear is tailored to the required total ratio of the EV drivetrain. By matching the gear ratio to motor speed and wheel size, it helps balance launch performance, hill-climbing capability, cruising efficiency, and maximum speed.

• Quiet, smooth meshing
  Helical or carefully modified spur teeth with controlled profile, lead, and surface finish support stable contact patterns and low transmission error. This helps EV drive units meet demanding NVH targets while remaining compact.

• Durable materials and heat treatment
  Typical options include carburizing steels (such as 16MnCr5 / 20CrMnTi equivalents) or alloy steels for quench-and-temper. Surface hardness, effective case depth, and core hardness are defined according to torque spectrum, duty cycle, and life requirements, providing resistance to pitting, scuffing, and tooth root fatigue.

• Compact packaging for integrated e-axles
  The main reduction gear can be realized as a cylindrical gear pair, a double helical design, or as part of a planetary gearset, allowing packaging inside integrated e-axles and drive modules with strict envelope and weight constraints.

• From prototypes to series production
  DD Gear can supply rapid prototypes for transmission and e-axle validation, then transition to controlled series production with full documentation, traceability, and stable quality across batches.

Technical Specifications

Final data will be defined according to the customer’s drawing and EV duty cycle.

Applications

• Single-speed EV reduction gearboxes
  Main reduction gears used in single-stage or two-stage transmissions that connect a high-speed traction motor to the differential and drive wheels in battery electric vehicles.

• Integrated e-axles and drive units
  Main reduction gears inside compact e-axles where the motor, inverter, and reduction gearset are combined in a single housing to drive one axle.

• Electric light trucks, buses, and commercial vehicles
  Heavier vehicles that require higher output torque and robust gearsets to handle frequent starts, steep grades, and high gross vehicle weight.

• Hybrid and multi-speed transmissions
  Main reduction or final drive gears in hybrid gearboxes and two-speed EV transmissions, working with additional gearsets to extend the usable speed range and improve efficiency.

Gear Manufacturing Process

Every main reduction gear is produced under a controlled gear manufacturing route designed for precision and durability. A typical process flow is:

1. Forging or bar cutting of gear blanks

2. Lathe machining of bores, hubs, and reference surfaces

3. Hobbing or shaping of gear teeth

4. Drilling, milling, and other CNC machining operations

5. Heat treatment (such as carburizing, quenching, tempering, nitriding)

6. Shot blasting and stress relief as required

7. Finish machining and grinding of critical mounting surfaces

8. Gear grinding (profile or worm grinding) where accuracy demands it

9. Cleaning and rust prevention treatment

10. Final inspection and packaging for shipment

Precision Gear Customization Process

To support custom main reduction gear projects, DD Gear follows a clear, eight-step customization process:

Step 1 – Requirement Collection
Customers provide design requirements, 2D drawings, 3D models, or physical samples, together with basic duty cycle information (torque, speed, life, installation).

Step 2 – Drawing Design & Optimization
Based on the provided drawings or samples, DD Gear prepares or optimizes detailed manufacturing drawings and shares them with the customer for confirmation.

Step 3 – Quotation
After the drawings and technical points are confirmed, we issue a precise quotation covering tooling, piece price, lead time, and quality requirements.

Step 4 – Tooling & Fixture Preparation
Once the price is confirmed, we arrange tooling and fixture production. Any tooling cost is agreed with the customer in advance and can be offset or refunded after mass orders, according to the commercial agreement.

Step 5 – First Sample Approval
After tooling and fixtures are ready, we manufacture the first sample batch—typically within about 30 days—and ship it to the customer for testing.The customer inspects and validates the samples in their gearbox or test bench and provides feedback on dimensions, performance, and any required adjustments.

Step 6 – Mass Production
When the sample is approved, we start mass production according to the agreed production plan and quality standards.

Step 7 – Finished Product Inspection
After production, we inspect hardness, dimensions, runout, tooth accuracy, and other critical characteristics to ensure full compliance with the drawing and standards.

Step 8 – Shipping Arrangement
Once inspection is passed and shipment is approved by the customer, we arrange booking, packaging, and delivery to the specified destination.

Quality Assurance & Inspection

DD Gear applies the same quality philosophy to all precision gears:

• Quality management systems based on ISO 9001 and IATF 16949

• Process control from incoming material to final inspection, including:

  • Material certification and chemical composition checks

  • Hardness and case depth verification after heat treatment

  • Gear measurement for profile, lead, pitch, and runout

  • Surface roughness testing on gear flanks and journals

  • Dimensional inspection with calibrated gauges and CMMs

• Traceability for each batch with inspection records and reports

• Optional documentation such as PPAP/FAIR packs on request

Packaging

Usage & Installation Notes

• Ensure correct alignment and bearing support for shafts carrying the main reduction gear to avoid additional load, noise, and wear.
• Verify backlash and tooth contact between the driving and driven reduction gears as defined in the gearbox design; improper settings can affect efficiency, noise, and fatigue life.
• Use the specified lubricant and maintain oil level, cleanliness, and cooling performance inside the gearbox or e-axle housing.
• Do not exceed defined torque, speed, and temperature limits for the main reduction gear; these are set based on material, heat treatment, and tooth geometry.
• During maintenance, inspect tooth flanks and roots for pitting, scuffing, or cracks, especially in high-torque commercial or performance EV applications.
• Store finished parts in dry, clean conditions with anti-rust protection and avoid impact on teeth and mounting surfaces.

Company Strength – DD Gear

• Specialized in small module, high-precision gears and shafts for EVs, humanoid robots, AGVs, and intelligent automation.

• Integrated manufacturing from forging and machining to heat treatment and gear grinding.

• Quality systems aligned with automotive standards, with experience supporting OEM and Tier 1 projects.

• Engineering support covering concept feasibility, DFM reviews, and failure analysis feedback.

• Global export capability with experience serving customers in multiple countries.

Q1: What information do you need for a main reduction gear quotation?
We normally need 2D drawings (PDF), 3D models (STEP/IGES if available), material and heat treatment requirements, expected annual volume, and basic application data such as vehicle type, target gear ratio, input torque and speed, and duty cycle.

Q2: Can you support ratio studies or design optimization?
Yes. Our engineering team can review your duty cycle and layout and provide suggestions on tooth counts, module and helix angle, face width, and material/heat treatment windows to help balance torque capacity, efficiency, and NVH.

Q3: What lead time should we expect for prototypes and production?
Prototype main reduction gears are usually available in around 2–3 weeks after final drawing confirmation and tooling readiness. Mass production lead time depends on quantity and process route and will be confirmed during quotation.

Q4: Do you also supply the complete gearbox or e-axle?
DD Gear specializes in precision gears, shafts, and gear components. We supply the main reduction gear and related parts; complete gearbox or e-axle integration is handled by the customer or their system integrator.

Q5: What accuracy levels can you achieve on main reduction gears?
Gear accuracy levels are defined together with the customer according to efficiency and NVH targets. We work to ISO / DIN / AGMA standards and can achieve automotive-grade accuracy with ground teeth when required.

Q6: What is your typical MOQ for main reduction gears?
MOQ depends on the complexity of the part and tooling. We support flexible MOQ for development and pilot builds, then align batch sizes with your SOP/series production plan.

Q7: Can you provide inspection reports with each batch?
Yes. Dimensional inspection reports, gear measurement charts, hardness and case-depth records, and other documents can be provided according to your requirements.