| 摘要 |
A nozzle assembly for a plasma arc torch includes inner and outer metal nozzle members and an annular insulating element press-fit between the inner and outer nozzle members so that the nozzle members are electrically insulated from one another and bores of the nozzle members are coaxial. Additionally, the annular insulating element is constructed such that the inner and outer nozzle members are secured together to define a water passageway between the interior surface of the outer nozzle member and the exterior surface of the inner nozzle member. The nozzle assembly may further include an outer insulating element secured onto the exterior surface of the outer nozzle member, in which case the annular insulating element between the nozzle members may not be press-fit to the nozzle members. The annular insulating element may define at least one port for introducing water into the water passageway. The port extends in a direction that is generally tangential to an imaginary circle around the longitudinal discharge axis so that the water swirls in the water passageway. Alternatively, the nozzle assembly includes an annular insulating swirl ring press-fit between the inner and outer nozzle members. The swirl ring is displaced along the longitudinal discharge axis from the first annular insulating element and is positioned between the first annular insulating element and the bore of the inner nozzle member. <IMAGE> |
