Product Overview
The rail transit gearbox is a high-precision transmission device for critical locations in high-speed rail, metro, and light rail vehicles, including door control systems, HVAC systems, and braking systems. Requirements for rail transit gearboxes are extremely stringent — ultra-high reliability (failure rate at one-per-million level), extended lifespan (30 years or 3 million cycles), wide temperature range adaptation (-40℃ to +80℃), and high safety protection rating (IP67) — far exceeding general industrial application standards. Any gearbox failure could affect normal train operation or even endanger passenger safety, making product quality and consistency the highest priority.
Yubao Transmission Technology provides high-precision, high-reliability door system drive gearboxes for the rail transit sector, compliant with EN 50155 railway application standards and IEC 61373 vibration/shock standards. Gears use high-strength alloy steel (16MnCr5/20CrMnTi) with carburizing and hardening, ground to DIN Grade 4 accuracy with tooth profile error ≤3μm and tooth alignment error ≤4μm. Wide-temperature synthetic grease (-60℃–+150℃) provides lifetime maintenance-free design with maintenance-free period ≥10 years (or 600,000 km). Every unit undergoes 100% gear inspection + 100% fluorescent penetrant inspection, zero-crack standard, with full lifecycle traceability.
Technical Parameters
Dimensions
| Parameter |
Symbol |
Unit |
Value/Range |
Tolerance |
Notes |
| Overall Length |
L |
mm |
200–500 |
±1 |
Compact design |
| Overall Width |
W |
mm |
150–350 |
±1 |
Adapted to door mechanism |
| Overall Height |
H |
mm |
150–300 |
±1 |
Including mounting interfaces |
| Weight |
— |
kg |
5–25 |
±5% |
Including grease |
| Center Height |
— |
mm |
80–150 |
±0.05 |
Output shaft center to mounting face |
Transmission Parameters
| Parameter |
Symbol |
Unit |
Value/Range |
Tolerance |
Notes |
| Input Speed |
n1 |
rpm |
≤3000 |
max. |
Motor rated speed |
| Output Speed |
n2 |
rpm |
Customized |
— |
Per door speed requirements |
| Reduction Ratio |
i |
— |
10:1–100:1 |
±1% |
Precision grade |
| Rated Output Torque |
T2 |
N·m |
10–100 |
— |
Continuous duty |
| Max Instantaneous Torque |
— |
N·m |
80–300 |
— |
Startup/stall conditions |
| Transmission Efficiency |
η |
% |
≥92 |
≥ |
Single-stage >92% |
| Backlash |
jt |
arcmin |
≤10 |
≤ |
Precision positioning |
Application & Standards
| Parameter |
Symbol |
Unit |
Value/Range |
Tolerance |
Notes |
| Application Location |
— |
— |
Door System/HVAC/Brake |
— |
Primarily door control systems |
| Compliance Standards |
— |
— |
EN 50155/IEC 61373 |
— |
Railway applications/vibration & shock |
| Safety Integrity Level |
SIL |
— |
SIL 2 |
— |
Safety integrity level |
| Failure Rate |
— |
ppm |
≤1 |
— |
One per million |
Structure & Materials
| Parameter |
Symbol |
Unit |
Value/Range |
Tolerance |
Notes |
| Housing Material |
— |
— |
Aluminum Alloy/Ductile Iron |
— |
High-strength lightweight |
| Gear Material |
— |
— |
16MnCr5/20CrMnTi |
— |
High-strength alloy steel |
| Bearing Brand |
— |
— |
NSK/SKF/FAG |
— |
Railway-grade |
| Lubrication Method |
— |
— |
Synthetic Grease |
— |
Wide-temperature lifetime lubrication |
| Sealing Type |
— |
— |
Dual Seal + Labyrinth |
— |
IP67 protection |
| Parameter |
Symbol |
Unit |
Value/Range |
Tolerance |
Notes |
| Protection Rating |
IP |
— |
IP67 |
— |
Dust-tight and immersion-proof |
| Operating Temperature |
— |
℃ |
-40–+80 |
— |
Normal operation |
| Storage Temperature |
— |
℃ |
-40–+80 |
— |
Long-term storage |
| Cold-Start Temperature |
— |
℃ |
-50 |
— |
Cold-start capability |
| Noise Level |
— |
dB(A) |
≤55 |
≤ |
Measured at 1m distance |
| Design Life |
— |
years |
≥10 |
— |
Or 600,000 km |
| Switch Cycles |
— |
cycles |
≥3,000,000 |
— |
Within design life |
| Maintenance-Free Period |
— |
years |
≥10 |
≥ |
Or 600,000 km |
| Salt Spray Resistance |
— |
h |
≥1000 |
— |
ISO 9227 |
| Vibration Resistance |
— |
— |
IEC 61373 Cat.1 |
— |
Railway vehicle Category 1 |
| Shock Resistance |
— |
— |
IEC 61373 Cat.1 |
— |
50g/30ms half-sine |
Gear Accuracy Indicators
| Accuracy Parameter |
DIN Grade 4 |
DIN Grade 5 |
Inspection Method |
| Tooth Profile Error |
≤3μm |
≤5μm |
Gleason 300GMS |
| Tooth Alignment Error |
≤4μm |
≤6μm |
Gleason 300GMS |
| Cumulative Pitch Error |
≤8μm |
≤12μm |
Gleason 300GMS |
| Single Pitch Deviation |
±2μm |
±3μm |
Gleason 300GMS |
| Radial Runout |
≤10μm |
≤15μm |
Double Flank Tester |
Quality Control System
| Control Stage |
Control Measure |
Standard |
| Raw Materials |
100% spectroscopic analysis + ultrasonic testing |
EN 10084 |
| Heat Treatment |
Case depth metallographic inspection + hardness gradient testing |
Case depth 0.5–0.8mm |
| Precision Machining |
100% gear inspection after grinding |
DIN Grade 4 |
| NDT |
100% fluorescent penetrant inspection (zero crack standard) |
ISO 3452 |
| Assembly |
Cleanroom assembly, full torque monitoring |
Process specification |
| Testing |
Performance bench + thermal cycling + vibration testing |
EN 50155 |
| Traceability |
Unique serial number, full lifecycle data archive |
≥30 years |
Environmental Adaptation Verification
| Test Item |
Test Conditions |
Acceptance Criteria |
| Low-Temperature Start |
-50℃ for 24h then start |
Start torque ≤3× rated |
| High-Temperature Operation |
+80℃ continuous 72h |
Efficiency degradation ≤5%, no leakage |
| Thermal Cycling |
-40℃↔+80℃, 100 cycles |
No cracks, no leakage, stable performance |
| Vibration Testing |
IEC 61373 Cat.1 Class B |
No loosening, no damage |
| Shock Testing |
50g/30ms half-sine wave |
No damage, accuracy maintained |
| Salt Spray Testing |
ISO 9227, 1000h |
No red rust, no coating blistering |
| Protection Testing |
IP67, 1m depth 30min |
No water ingress |
| EMC Testing |
EN 50121-3-2 |
Meets railway EMC requirements |
Product Features
- Ultra-High Reliability: Failure rate ≤1ppm, SIL 2 safety level, ensuring safe train operation
- Extended Lifespan: Design life 30 years or 3 million switch cycles, maintenance-free ≥10 years
- Wide Temperature Range: Cold-start at -50℃ to continuous operation at +80℃, adapting to global climates
- Ultra-High Precision: Ground to DIN Grade 4, tooth profile error ≤3μm, precise door positioning
- Reliable Sealing: IP67 protection + 1000-hour salt spray test, adapting to tunnel humidity
- Vibration & Shock Resistant: Meets IEC 61373 Railway Vehicle Category 1 most stringent standard
- Full Lifecycle Traceability: Unique serial number, raw material to finished product full process data archived ≥30 years
Typical Applications
| Application Location |
Specific Function |
Technical Characteristics |
| Door System |
Passenger compartment door/driver door drive |
Precise door speed control, anti-pinch protection |
| HVAC System |
Damper regulation/compressor drive |
Low noise, long-term continuous operation |
| Braking System |
Brake control mechanism drive |
Ultra-high reliability, SIL safety level |
| High-Speed Rail |
Fuxing/Harmony door systems |
350km/h operation, severe vibration environment |
| Metro |
Urban rail vehicle door systems |
Frequent start-stop, high duty cycle |
| Light Rail/Tram |
Low-floor door drive |
Space-constrained, compact design |
