Back to results
US 4,566,849 AGranted
Pressure medium driven machine tool
AssigneeAktiebolaget IRO
InventorClaes H. Flink
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeAktiebolaget IRO
InventorClaes H. Flink
Estimating the term…
Machine tool having a jet turbine driving a rotatable spindle with a tool holder, said spindle is comprised in a spindle housing, said jet turbine consisting of a disc-shaped turbine rotor being closely enclosed by a turbine housing, said turbine rotor having peripherally arranged discrete recesses, each recess having a concave front actuation wall for the jet and one sidewardly arranged outlet opening which opens in the axial direction of the rotor, said housing having at least one inlet nozzle for the jet directed into the recesses and having at least one outlet opening for the spent jet medium. Known machine tools suffer under strong speed losses when the load increases or varies. This disadvantage results from a constant interference between spent air within the recesses and the working jet. Thus, the energy of the jet cannot be used with good efficiency. According to the present invention the energy of the jet can be used with better efficiency, since the inlet nozzle is directed towards the deepest section of the front concave actuation wall by impacting on this wall and since there is provided a guiding path and an additional expansion space below the jet which in combination produce a pumping effect for quickly disposing the spent jet medium. The expansion space is provided by the concave rear wall and the flat bottom of the recess. The guiding path is defined by the concave side wall together with the flat bottom and the concave rear wall.
In a machine tool having a jet turbine driving a rotatable spindle with a tool holder, said spindle being rotatably supported in a spindle housing, said jet turbine having a disc-shaped turbine rotor closely rotatably enclosed by a turbine housing, said turbine rotor having peripherally arranged discrete recesses, each recess having a concave front actuation wall for the jet and one sidewardly arranged outlet opening which opens in the axial direction of the rotor, said housing having at least one inlet nozzle for the jet directed into the recesses and having at least one outlet opening for the spent jet medium, comprising the improvement wherein:
In a tool assembly having a spindle adapted to support thereon a tool holder and rotatably supported within a spindle housing, and a jet turbine for rotatably driving the spindle, the jet turbine including a rotatable disc-shaped rotor which is drivingly coupled to the spindle and is closely rotatably enclosed within a turbine housing, said turbine rotor having a surrounding peripheral wall provided with a plurality of discreet recesses formed therein in angularly spaced relationship therearound, and the turbine housing having an inlet opening for directing a jet of fluid against the rotor and a discharge opening for removing the fluid from the rotor, comprising the improvement wherein the recess projects substantially radially inwardly of the rotor from the surrounding peripheral wall thereof and is defined by a bottom wall and a peripheral side wall, the recess having a depth which is small relative to the cross-section thereof as defined within said peripheral side wall, said recess opening axially through one axial end surface of the rotor for defining an outlet opening from the recess for the discharge of fluid therefrom, said peripheral side wall extending through less than 360.degree. and terminating at said outlet opening, said peripheral side wall including concave front and rear wall portions which are disposed opposite and substantially face one another, said peripheral side wall including a concave side wall portion which is disposed axially opposite the outlet opening and is connected between the front and rear wall portions, said inlet opening extends circumferentially of and substantially tangentially with respect to the peripheral wall of the rotor and positioned so as to direct the jet toward the deepest section of the concave front wall portion so that the jet impinges against the front wall portion in substantially perpendicular relationship thereto, and said discharge opening comprising an enlarged unrestricted flow passage which extends axially of said turbine housing away from said one axial end surface of said turbine rotor, said passage being disposed in open communication with the outlet openings defined by said recesses.
Dependencies are inferred from the claim text.