Custom Gear Mold Manufacturing: Process And Key Considerations

1. Step-by-Step Custom Gear Mold Manufacturing Process

A. Requirements Analysis & Technical Specifications

• Define Application Needs

• Load type (constant/shock loads)

• Speed range (high/low RPM)

• Operating environment (corrosion, temperature)

• Key Gear Parameters

• Module (m)

• Number of teeth (z)

• Pressure angle (typically 20°)

• Material (steel, brass, engineering plastics)

B. 3D Modeling & Simulation

• Software Tools

• CAD design (SolidWorks, AutoCAD)

• Finite Element Analysis (FEA, e.g., ANSYS) for stress testing

• Gear meshing simulation (e.g., KISSsoft)

• Output Deliverables

• Gear parameter sheet (including tolerances)

• Engineering drawings (heat treatment, surface finish specs)

C. Gear Mold Manufacturing Process Selection

D. Prototyping & Testing

• Inspection Criteria

• Tooth profile accuracy (involute deviation)

• Pitch error accumulation

• Surface hardness (Rockwell C test)

• Dynamic balancing (for high-speed gears)

• Iterative Refinement

• Adjust machining parameters based on test data

• Repeat prototyping until compliance (typically 2-3 cycles)

  
  

2. Critical Considerations for Custom Gear Molds

A. Material Selection & Heat Treatment

• Common Materials Comparison

  Material	Applications	Heat Treatment	Tensile Strength
  20CrMnTi (Case-hardened steel)	High-load gears (transmissions)	Carburizing (HRC 58-62)	1200 MPa
  1045 Carbon Steel	General industrial gears	Quenching & Tempering (HRC 28-32)	600 MPa
  Brass (H62)	Low-noise applications	None	300 MPa
  POM Plastic	Corrosion-resistant, lightweight	None	60 M

• Heat Treatment Challenges

• Warping control: Use vacuum/press quenching

• Surface decarburization: Protective atmosphere (e.g., nitrogen)

B. Tolerances & Surface Finishing

• Key Tolerance Requirements

• Tooth profile error: ≤0.02 mm (precision gears)

• Helix deviation: ≤0.03 mm/100 mm

• Bore fit: H7/h6

• Surface Treatment Options

• Nickel/Chrome plating: Anti-corrosion + wear resistance

• Shot peening: Enhances fatigue life

• DLC coating: Extreme wear resistance

C. Cost Optimization Strategies

• Design Phase

• Avoid excessive tolerances (each IT grade increase raises cost by 30%+)

• Modular designs (shared mold bases)

• Production Phase

• For ≥500 units, prioritize powder metallurgy

• Multi-cavity molds (4-8 cavities) for plastic gears

D. Common Failure Modes & Prevention

3. Real-World Applications

Case 1: EV Reduction Gear

• Requirements: High-speed (15,000 RPM) + low noise

• Custom Solution:

• Material: 20CrMoH (vacuum carburized)

• Process: Precision grinding (Ra 0.4 µm)

• Testing: Noise level <65 dB

Case 2: Food-Grade Plastic Gear

• Requirements: Corrosion resistance + maintenance-free

• Custom Solution:

• Material: PEEK + 30% carbon fiber

• Process: Injection molding (120°C mold temp)

• Post-processing: Ultrasonic deburring

  
  

4. Conclusion

Keys to Successful Custom Gear Molds:

1. Clear requirements definition (load, speed, lifespan)

2. Simulation-driven design (minimize trial-and-error costs)

3. Process-material alignment (e.g., ground teeth for hardened steel)

4. Strict quality control (ISO 1328 or AGMA 2000 standards)