On the design of ejectors for deep hole machining

A comprehensive study of ejectors used in deep-hole drills was conducted in order to understand the role of the ejectors with annular nozzles in the tool design. An analytical method was used to derive the equation for the operating energy characteristic of ejectors. The experimental investigations were carried out to explain the ejector's optimal design parameters necessary to achieve maximum hydraulic efficiency. The experiments also defined the principal criteria and compared different types of ejector nozzles suitable for deep-hole drills. Further investigation revealed the precise location of the ejector nozzle(s) in the deephole drill assembly and helped clarify the capabilities of the ejectors.