1. Worm Gear Reducer Structure and Parameters
| Parameter | Value |
|---|---|
| Drive Mode | Motor |
| Input Power | 24 kW |
| Input Speed | 1420 r/min |
| Input Torque | 161 N·m |
| Transmission Ratio | 34.6 (Gear Ratio , Worm Gear Ratio ) |
2. Faults in Worm Gear Reducer
| Fault | Cause |
|---|---|
| Severe Heat and Oil Leakage | Sliding friction in worm gear transmission generates heat, causing expansion and potential sealing issues. |
| Severe Wear of Worm Gear | Poor meshing and lubrication lead to increased wear. |
3. Research on Worm Gear Reducer
3.1 Worm Gear Materials
| Name | Material Grade | Usage Characteristics and Application Range |
|---|---|---|
| Worm | 20, 15Cr, 20Cr, 20CrMnTi, 20CrMnMo 40Cr, 40CrNi, 35SiMn, 35CrMo, 38SiMnMo, 40CrNiMo ZCuSn10Pb1, ZCuSn5Pb5Zn5 | Carburizing and quenching (56 – 62HRC) grinding, for high-speed heavy-duty transmission Quenching (45 – 55HRC) grinding, for high-speed heavy-duty transmission Strong anti-scuffing ability, low mechanical strength, expensive, for large sliding speed ( m/s) and long-term continuous work |
| Worm Gear | ZCuAl10Fe3, ZCuAl10Fe3Mn2, ZCuZn38Mn2Pb2, ZCuSn12Ni2 | Weak anti-scuffing ability, high mechanical strength, requires surface hardening of mating worm, cheap, for medium sliding speed ( m/s) |
Selected Materials: Worm – 38CrMoAl (quenched and tempered nitride), Worm Gear – ZCuSn12Ni2.
3.2 Surface Quality of Worm Gear
- Entrust processing to advanced enterprises.
- Establish strict quality management system.
- Ensure surface roughness and tooth thickness tolerance of worm within design range.
3.3 Assembly of Worm Gear
| Factor | Requirement |
|---|---|
| Center Distance | Ensure within design range using coordinate measuring instrument. |
| Lubrication | Worm gear immersion depth is 1/3 of outer diameter, use special lubricating oil, and ensure oil quality. |
| Assembly Clearance | Control side clearance between 0.38 – 0.45 mm. |
| Assembly Error | Contact spot area along tooth length ≥60%, along tooth height ≥65%, and biased towards tooth surface exit. |
3.4 Lubrication of Worm Gear
- Good lubrication can form oil film, reduce wear, and improve transmission efficiency.
- The worm gear reducer requires lubricant with good properties.
4. Tests
4.1 Bench Test
- Test Bed: Can collect various data and display transmission efficiency.
- Test Time: 40 s loading (full load), 5 min idle, for 4 days (8 h/day).
- Test Conclusion:
- Oil temperature is about 30 °C higher than shell temperature. Consider using high-temperature resistant seals.
- Transmission efficiency is 75% – 80%. Can use a gear reducer with 80% of the original transmission ratio.
- After 4 days of testing, there is copper powder in the gear oil, and the worm gear has slight wear, indicating the running-in stage.
4.2 Underground Industrial Test
- After 1 week, the reducer is normal, with a small amount of copper powder in the oil, indicating the running-in stage.
- After 1 month, the reducer is normal, with very little copper powder in the oil, indicating the stable wear stage.
- After 6 months, the reducer is still normal, verifying the success of the improvement.
5. Conclusion
The worm gear reducer for mining shuttle cars has problems such as high temperature, severe wear, and low service life. By studying factors such as material, surface quality, assembly, and lubrication, and conducting tests, a reducer that can be used normally for more than 6 months has been developed, indicating the success of the development.