Gears are key components in air compressors, mainly used for power transmission, speed increasing, and rotor synchronization. They directly affect efficiency, noise, vibration, and service life. Gear Applications by Compressor Type
(1) Screw Air Compressor

1. Synchronization Gears

Ensure the male and female rotors rotate without contact at a fixed speed ratio, preventing collision.

1. Transmission Gears

Transmit power from motor to rotors, replacing belt drives for higher efficiency and stability.

1. Common types: helical gears, herringbone gears
2. Features: high load capacity, low noise, stable meshing.

(2) Centrifugal Air Compressor

1. High-speed gearbox (speed-increasing gears)

Increase motor speed (1500–3000 rpm) to impeller working speed (10,000–50,000 rpm).

1. Integral gear structure

One central gear drives multiple pinion shafts, each with an impeller for multi-stage compression.

1. Features: high speed, high precision, high efficiency.

(3) Roots / Claw Type Oil-free Compressor

1. Synchronous gear set

Guarantees accurate phase and clearance between two rotors.

1. Gearbox is isolated from compression chamber to ensure oil-free air.

(4) Piston Air Compressor

1. Gears drive the crank-connecting rod mechanism, converting rotary motion into reciprocating motion.
2. Mostly used in small or medium piston compressors.

3. Key Technical Requirements for Compressor Gears

1. Accuracy: Grade 5–6 (high speed), Grade 7–8 (medium speed)
2. Materials: 20CrMnTi, 18CrNiMo76, 42CrMo
3. Heat treatment: carburizing and quenching, surface hardness HRC 58–62
4. Lubrication: independent lubrication system for oil-free compressors;

integrated lubrication for oil-injected screw compressors

1. Clearance control: strict backlash and rotor phase tolerance

4. Main Advantages

1. High transmission efficiency: 98%–99.5%
2. Stable and reliable, suitable for 24hour continuous operation
3. Precise synchronization, long service life
4. Compact structure, strong adaptability to pressure and flow requirements