Metro Automatic Door Brushless DC Geared Motor Introduction

BLDC Motor for Railway Vehicle Safety Barrier Opening/Closing – The automatic door motor products can be summarized into two major motor platforms, the AD series and ADS series, combined with WORM / planetary gearbox solutions.

Product Platform & Positioning

• Application:​ Drive for automatic doors and safety barrier opening/closing on railway vehicles.
• Motor Type:​ Compact, low-power BLDC (Brushless DC) motor, requiring an external/matched drive circuit.
• General Specifications:
• Market:​ Introduced to the Chinese vehicle market in May 2015.

Motor Series

AD Series (Standard BLDC)

1. AD50

• Overall length: 125 mm, Outer diameter: φ65, Shaft diameter: φ8, Weight: 1.4 kg
• Commonly used gearboxes: Right-angle planetary (PV87A type), also compatible with WORM / inline planetary
  
• Application: Automatic doors with belt + screw or traction mechanism
  

2. AD75

• Overall length: 150 mm, Outer diameter: φ65, Shaft diameter: φ8, Weight: 1.9 kg
• Commonly used gearbox: Offset-shaft WORM (worm gear)
• Application: Belt-driven automatic doors requiring low noise, low slippage, and high opening force
  

ADS Series (Compact High-Output BLDC)

1. ADS25 (Mass Production)

• Overall length: 100 mm, Outer diameter: φ65, Weight: 1.2 kg
• Rated speed: 2700 rpm
• Commonly used gearbox: Inline planetary
• Application: Narrow spaces, belt-sliding doors; compact with high output
  

2. ADS50 (Under Development)

• Overall length: 125 mm, Weight: 1.4 kg
• ADS50-60: DC60V / 183W / 2700 rpm / 0.65 N·m / 4.7 A
• ADS50-110: DC110V / 183W / 2700 rpm / 0.65 N·m / 2.6 A
  

3. ADS75 (Under Development)

• Overall length: 150 mm, Weight: 1.9 kg
• ADS75-110: DC110V / 260W / 2700 rpm / 0.92 N·m / 3.7 A
• Positioning: Higher output model
  

Gearbox Options (Selected According to Door Mechanism Structure)

1. WORM Gearbox (for AD series)

• Models: W71A-15 / W71A-10
• Gear ratio: 15 (efficiency 80%) / 10 (efficiency 70%)
• Rated torque: 4 N·m
• Axial / Radial load: 3.0 N / 3.5 N
• Weight: 0.9 kg
• Features: Self-locking tendency; suitable for manual door opening when not powered; left/right or double-sided shaft output available
  

2. Inline Planetary Gearbox (PH Series)

• PH50A-5: Gear ratio 4.5, efficiency 90%, rated 1.2 N·m, 0.7 kg
• PH50A-20: Gear ratio 20.25, efficiency 81%, rated 5.6 N·m, 0.9 kg
• Multi-stage planetary available for outer diameters φ52 / φ62:
• Features: Low idle torque; door leaf can be easily pushed manually when power is off
  

3. Right-Angle Planetary Gearbox (PV Series)

• PV87A-22: Gear ratio 21.87, efficiency 73%, rated 4.5 N·m
• Axial / Radial load: 200 N / 500 N, Weight: 3 kg
• Features: Right-angle shaft output, low idle torque; suitable for manual opening/closing without power

Typical Combinations & Door Types

Competitive Comparison (per technical document)

• NIDEC / NSSC:​ Operates even with 30% voltage drop; light manual opening during power failure
  
• Overseas competitors:​ Cannot operate under low voltage; abnormal noise, shaft breakage
  
• Chinese competitors:​ No low-voltage support; heavy manual opening