Helical Gear

Features & Benefits

• Smooth, quiet meshing
  Angled teeth engage gradually along the helix, reducing impact and vibration compared with spur gears and enabling quieter operation at higher speeds.

• Higher load capacity & speed capability
  Multiple teeth share the load at any instant, giving stronger tooth capacity and allowing helical gears to carry bigger loads and higher speeds than spur gears of similar size.

• High efficiency in compact gearboxes
  Properly designed helical gears typically deliver efficiencies in the mid-90% range or higher per stage, enabling compact multi-stage gearboxes with low power loss.

• Flexible shaft arrangements
  Standard helical pairs transmit power between parallel shafts; crossed helical (screw) gears can transmit between non-parallel shafts for special layouts.

• Small-module precision for emerging industries
  DD Gear specializes in small-module helical gears for EV, robotics, AGVs, medical devices and automation, controlling tooth profile, lead and pitch to stringent accuracy classes under ISO/DIN systems.

• Custom materials & heat treatment
  According to torque, duty cycle and noise targets, we choose carburizing steels, nitriding steels or Q&T steels, combined with appropriate heat treatment and gear grinding to improve strength, pitting resistance and NVH performance.

Technical Specifications

Final values will be defined according to your drawings and performance requirements.

Applications

• Automotive & EV transmissions
  Helical gears are widely used in manual, automatic and dual-clutch transmissions and EV reduction gearboxes to provide smooth, quiet gear shifts and efficient torque transfer.

• Industrial gearboxes & gearmotors
  Helical gear units transmit torque and speed from motors to driven machines in conveyors, mixers, pumps, compressors, blowers and general industrial machinery.

• Robotics & automation
  High-precision helical gears are used in robotics joints, actuators and motion stages where quiet operation and high positional repeatability are required.

• Power plants, steel and rolling mills
  Large helical gear sets in mills, power-plant drives and heavy material-handling systems provide robust, efficient transmission under continuous duty.

• Packaging, printing and textile machinery
  Compact helical gear trains deliver smooth motion for synchronized axes in packaging, printing, textile and other precision machinery.

Gear Manufacturing Process

Every custom helical 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 shaft blanks

2. Lathe machining of shaft diameters 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 journals and critical 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

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 center distance and alignment of shafts to maintain the designed contact pattern and avoid edge loading.

• Consider axial thrust from helical gears and select appropriate thrust bearings or opposing helix angles (double-helical) to balance forces.

• Use the recommended gear oil or grease, viscosity and additive package suitable for helical gear contacts to maintain high efficiency and long life.

• Avoid exceeding design limits for torque, speed and temperature; long-term overload may increase pitting and tooth-root fatigue.

• During maintenance, inspect flanks for pitting, scuffing and wear, and monitor noise or vibration changes as early indicators of misalignment or damage.

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 helical gear quotation?
We normally need 2D drawings (PDF) and, if possible, 3D models; material and heat-treat requirements and expected annual volume.

Q2: Can you help us choose between spur and helical gears?
Yes. In general, helical gears are preferred when you need higher loads, higher speeds, and lower noise, while spur gears are simpler and more economical for moderate speeds and when noise is less critical. We can discuss trade-offs for your specific gearbox.

Q3: Do you supply complete gearboxes?
DD Gear focuses on gear and shaft components. We usually supply helical gears and related shafts/rings; housings, bearings and complete gearboxes are assembled by our customers or their system partners.

Q4: What accuracy levels can you achieve on helical gears?
We manufacture cylindrical helical gears according to ISO 1328 / DIN 3961/3962 / AGMA accuracy classes and agree the specific class with you based on noise, efficiency and cost targets.

Q5: How efficient is a helical gear stage?
Well-designed helical gear stages typically achieve around 94–99% efficiency, depending on ratio, lubrication and speed.

Q6: Do helical gears always generate axial thrust?
Yes. Because of the helix angle, helical gears create axial forces that must be supported by bearings. We can help define helix direction and bearing arrangements to manage these loads.