Liquid fuel supply unit for a liquid fuel burner and a liquid fuel burner system

A liquid fuel supply unit for a liquid fuel burner with a gas atomizing nozzle, the supply unit comprising a liquid fuel feed pump, and a compressor and a motor, said liquid fuel feed pump having an inlet connectable to a liquid fuel conduit from a liquid fuel source, such as an oil tank, and an outlet connectable to an inlet of a liquid fuel metering device, said compressor having an outlet being connectable to the gas atomizing nozzle of the liquid fuel burner, wherein the unit comprises a unitary common drive shaft, the liquid fuel feed pump and the compressor both comprise a rotary impeller and the motor comprises a rotor where the rotary impellers and the rotor are mounted on the unitary common drive shaft for the liquid fuel feed pump and the compressor.