What are the differences in efficiency between cylindrical gear reducers and planetary gear reducers

The difference in efficiency between cylindrical gear reducers and planetary gear reducers is mainly reflected in three aspects: transmission structure, power loss, and application scenarios. The specific comparisons are as follows:

1. Transmission efficiency comparison

1. ‌Cylindrical gear reducer‌

2. Efficiency range : Single-stage transmission efficiency can reach 98%-99% (straight-tooth cylindrical gears are minimal due to line contact friction), and the multi-stage transmission efficiency is gradually reduced (such as the double-stage efficiency is about 94%-96%)

• ‌Source of loss‌ : Mainly due to gear meshing friction and bearing resistance, the helical gear efficiency is slightly lower than that of spur gears (97%-98%)

• Planetary gear reducer

• Efficiency range : usually 85%-95% ‌, due to the multi-gear meshing shunt power, the energy loss is large

• ‌Source of loss‌ : complex meshing between planetary wheels and sun gears/rings, bearing friction and lubrication resistance‌

2. Causes of efficiency differences

1. ‌Structural Complexity‌

• The cylindrical gear reducer has a simple structure, a direct single-stage transmission path, and low friction loss

• Planetary gear reducers need multiple gears to work together, and power shunts lead to energy dispersion loss

• ‌Processing Accuracy Requirements

• Planetary gears require high-precision grinding teeth (meshing accuracy ≤0.005mm) to reduce vibration losses, but the processing cost is high

• Cylindrical gears have relatively low accuracy requirements, and ordinary gear hobbing can meet the needs‌

3. Applicable scenario selection

1. ‌Preferential cylindrical gear reducer

• Scenarios where are required and space allowshigh efficiency (such as conveyors, mixers)

• Single-stage transmission ratio 3-5, multi-stage can reach more than 100 (but the volume is increased)

• ‌Preferential planetary gear reducer‌

• Requires compact structure (30%-50% small size) or high torque density (such as robot joints, wind power equipment)

• Sacrifice part of the efficiency for space and carrying capacity advantages‌

4. Supplementary Notes

• ‌Lugraining impact‌ : Both efficiency is affected by lubrication conditions. It is recommended to use L-CKD 320 lubricating oil to reduce friction loss.

• ‌Noise comparison‌ : Planetary gears are usually loaded with multiple wheels, and the noise is usually lower than 65dB, which is better than cylindrical gears (75-85dB)