What are the common types of oil pumps for aviation piston engines?

The common types of oil pumps for aviation piston engines mainly include the following:

Gear-type oil pump

Features: Composed of two gears (the driving gear and the driven gear), the engine oil is conveyed through the meshing movement of the gears. The gear-type oil pump has a simple structure, is easy to process, reliable in operation and has a long service life.

Classification: Gear oil pumps can be further divided into internal meshing gear type and external meshing gear type. The external meshing gear oil pump is more common. Its two gears mesh inside the housing. Through the rotation of the gears, a pressure difference is generated, which sucks the engine oil in from the oil inlet and then sends it out from the oil outlet after being pressurized.

Rotor oil pump

Features: Composed of an inner rotor and an outer rotor, the inner rotor is fixed on the driving shaft through a key, and there is a certain eccentricity between the outer rotor and the housing. During the rotation process, four closed working chambers are formed between the inner and outer rotors. The volume of these working chambers constantly changes, thus achieving the transportation of engine oil. The rotor oil pump has a compact structure and small volume, and is suitable for various occasions.

Alternative name: Also known as cycloidal gear pump.

Other types

Axial flow oil pump: Composed of a pump body and a pump shaft, the pump shaft drives the blades to rotate, achieving the transportation of engine oil. This type of oil pump is relatively rare in aviation piston engines.

Spiral oil pump: Composed of a pump body and a pump shaft, the pump shaft drives the spiral blades to rotate, and the oil is conveyed through the pushing effect of the spiral blades. This type of oil pump is relatively rare in aviation piston engines.

Diaphragm oil pump: It generates pressure by the deformation of the diaphragm, thereby achieving the transportation of engine oil. The application of this type of oil pump in aviation piston engines is also relatively rare.

Summary

The common types of oil pumps for aviation piston engines mainly include gear-type oil pumps and rotor-type oil pumps. These two types of oil pumps each have their own characteristics. The gear-type oil pump has a simple structure, is easy to process and operates reliably. The rotor oil pump has a compact structure and small volume, and is suitable for various occasions. In practical applications, engine designers will select the appropriate type of oil pump based on the specific requirements and working environment of the engine.