Compliantly mountable turbine cartridge assembly for gas-driven dental handpiece

A turbine cartridge assembly removably positionable within a housing of a gas-driven motor of a dental handpiece wherein the housing is defined by a substantially cylindrical side wall and by a pair of oppositely disposed end walls transverse to said side wall, and includes turbine cartridge assembly support means located on portions of the end walls of the housing;

• said turbine cartridge assembly comprising:
• a rotor shaft having a plurality of vanes thereon, said rotor shaft defining an axis of rotation;
• a first bearing assembly comprising an inner race fixed to said rotor shaft, an outer race, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race;
• a second bearing assembly comprising an inner race fixed to said rotor shaft, an outer race, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race of said second bearing assembly;
• radial support means associated with each of said first and second bearing assemblies, said radial support means providing radial support for said turbine cartridge assembly when in contact with the substantially cylindrical side wall of the housing, when said turbine cartridge assembly is operatively positioned within the housing of the handpiece;
• means for yieldingly coacting with the turbine cartridge assembly support means of the housing of the handpiece for axially pre-loading said first and said second bearing assemblies when said turbine cartridge assembly is operably positioned within the housing, said means for yieldingly coacting with said turbine cartridge support means comprising a ring-like spring washer retained about the outer race of at least one of said first and second bearing assemblies, said spring washer having a spring constant sufficient to provide a static pre-load to said bearing assemblies in the range of about 0.5 to about 1.5 pounds, when said turbine cartridge assembly is operably positioned within a handpiece housing with the spring washer interposed between said bearing assembly outer race and the turbine cartridge support means of the housing, said turbine cartridge assembly being adapted for placement in, and removal from, the housing as a unitary assembly.

A turbine cartridge assembly removably positionable within a housing of a gas-driven motor of a dental handpiece wherein the housing is defined by a substantially cylindrical side wall and by a pair of oppositely disposed end walls transverse to said wall, and includes turbine cartridge assembly support means located on portions of said end walls of said housing;

• said turbine cartridge assembly comprising:
• a rotor shaft having a plurality of vanes thereon, said rotor shaft defining an axis of rotation;
• a first bearing assembly comprising an inner race fixed to said rotor shaft, an outer race, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race;
• a second bearing assembly comprising an inner race fixed to said rotor shaft, an outer race, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race of said second bearing assembly;
• radial support means associated with each of said first and second bearing assemblies, said radial support means providing radial support for said turbine cartridge assembly when in contact with the substantially cylindrical side wall of a handpiece housing;
• bearing pre-load means associated with at least one of said bearing assembly outer races for yieldingly coacting with the turbine cartridge assembly support means in the housing of the handpiece for axially pre-loading said first and said second bearing assemblies when said turbine cartridge assembly is operably positioned within the housing, said turbine cartridge assembly being adapted for placement in, and removal from, the housing as a unitary assembly;
• retaining means mounted on each of said bearing assembly outer races for preventing movement of said radial support means or said means for yieldingly coacting with the housing turbine cartridge assembly support means or both in an axial direction away from said rotor shaft vanes.

A dental handpiece comprising a gas-driven motor, said motor including a housing and a turbine cartridge assembly within said housing, said housing defined by a substantially cylindrical side wall and by a pair of oppositely disposed end walls transverse to said side wall, said housing having turbine cartridge assembly support means located on portions of said end walls for supporting said turbine cartridge assembly, said turbine cartridge assembly removably positionable as a unitary assembly within said housing, said turbine cartridge assembly comprising:

• a rotor shaft having a plurality of vanes thereon, said rotor shaft having an axis of rotation substantially coincident with the axis of said substantially cylindrical side wall of said housing;
• a first bearing assembly comprising an inner race fixed to said rotor shaft, an outer race, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race;
• a second bearing assembly comprising an inner race fixed to said rotor shaft, an outer race, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race of said second bearing assembly;
• radial support means associated with each of said first and second bearing assemblies, said radial support means comprising a resilient member interposed between each of said bearing assemblies and an adjacent portion of said housing side wall for providing radial support for said turbine cartridge assembly when in contact with said substantially cylindrical side wall of said housing;
• rigid axial support means connected to each of said outer races of said first and second bearing assemblies for axially supporting said outer races upon said turbine cartridge support means of said housing;
• and
• retaining means associated with each of said bearing assembly outer races for retaining said radial support means upon said turbine cartridge assembly and preventing movement of said radial support means in an axial direction away from said rotor shaft vanes during removal, or insertion, of said turbine cartridge assembly from, or in, said motor housing.

A turbine cartridge assembly removably positionable within a housing of a gas-driven motor of a dental handpiece wherein the housing is defined by a substantially cylindrical side wall and by a pair of oppositely disposed end walls transverse to said said wall, and includes turbine cartridge assembly support means located on portions of said end walls of said housing;

• said turbine cartridge assembly comprising:
• a rotor shaft having a plurality of vanes thereon, said rotor shaft defining an axis of rotation;
• a first bearing assembly comprising an inner race fixed to said rotor shaft, an outer race, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race;
• a second bearing assembly comprising an inner race fixed to said rotor shaft, an outer race, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race of said second bearing assembly;
• radial support means associated with each of said first and second bearing assemblies, said radial support means providing radial support for said turbine cartridge assembly when in contact with the substantially cylindrical side wall of a handpiece housing;
• retaining means mounted on each of said bearing assembly outer races for preventing movement of said radial support means in an axial direction away from said rotor shaft vanes during removal, or insertion, of said turbine cartridge assembly from, or in, said motor housing.

A dental handpiece comprising a gas-driven motor, said motor including a housing and a turbine cartridge assembly within said housing, said housing defined by a substantially cylindrical side wall and by a pair of oppositely disposed end walls transverse to said side wall, said housing having turbine cartridge assembly support means located on portions of said end walls for supporting said turbine cartridge assembly, said turbine cartridge assembly removably positionable as a unitary assembly within said housing, said turbine cartridge assembly comprising:

• a rotor shaft having a plurality of vanes thereon, said rotor shaft having an axis of rotation substantially coincident with the axis of said substantially cylindrical side wall of said housing;
• a first bearing assembly comprising an inner race fixed to said rotor shaft, an outer race having an outer wall facing radially outwardly of the axis of said rotor shaft, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race;
• a second bearing assembly comprising an inner race fixed to said rotor shaft, an outer race having an outer wall facing radially outwardly of the axis of said rotor shaft, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race of said second bearing assembly;
• a flange connected to each of said outer race outer walls, said flange extending radially outwardly from said outer race;
• a substantially flat washer interposed between said flange on said first bearing assembly outer race and said turbine cartridge support means of said housing, said flat washer having an inner diameter smaller than the outer diameter of said radially extending flange, and having an outer diameter of sufficient dimension so that said flat washer supports said outer race upon said turbine cartridge assembly support means of said housing;
• a ring of resilient material frictionally engaged about a circumferential portion of said outer race outer wall of each of said bearing assemblies to provide radial support for said turbine cartridge assembly upon said motor housing side wall, said ring having an outer diameter sufficient to provide a compression fit between said outer race outer wall and a portion of said housing side wall;
• a groove running circumferentially about said outer race outer wall of each of said bearing assemblies, said groove lying in a plane substantially perpendicular to the axis of said rotor shaft;
• a spring-like snap ring retained within each of said grooves by the spring bias of said snap ring, said snap ring forming an annular-shaped collar extending radially outwardly of said outer race outer wall, each of said collars having an outer diameter in the radial direction sufficient to retain said flat washer and said ring of resilient material upon each of said turbine cartridge assembly outer race outer walls in cooperation, respectively, with said flange of each of said bearing assembly outer race outer walls;
• and
• a resilient spacer ring interposed between said flange and said flat washer of said second bearing assembly outer race, said spacer ring having a spring-like resilience adapted to transmit a controlled compression force between said outer race and a portion of said housing end wall adjacent said second bearing assembly so as to provide axial pre-loading of said first and second bearing assemblies within said motor housing.

A dental handpiece comprising a gas-driven motor, said motor including a housing and a turbine cartridge assembly within said housing, said housing defined by a substantially cylindrical side wall and by a pair of oppositely disposed end walls transverse to said side wall, said housing having turbine cartridge assembly support means located on portions of said walls for supporting said turbine cartridge assembly, said turbine cartridge assembly removably positionable as a unitary assembly within said housing, said turbine cartridge assembly comprising:

• a rotor shaft having a plurality of vanes thereon, said rotor shaft having an axis of rotation substantially coincident with the axis of said substantially cylindrical side wall of said housing;
• a first bearing assembly comprising an inner race fixed to said rotor shaft, an outer race, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race;
• a second bearing assembly comprising an inner race fixed to said rotor shaft, an outer race, and a plurality of movable bearing elements frictionally engaged with and confined between said inner race and said outer race of said second bearing assembly;
• radial support means associated with each of said first and second bearing assemblies, said radial support means providing radial support for said turbine cartridge assembly upon said substantially cylindrical side wall of said housing;
• bearing pre-load means comprising flexible axial support means associated with each of said outer races of said first and second bearing assemblies for yieldingly supporting said outer races upon said turbine cartridge support means of said housing;
• first retaining means for retaining said radial support means and said flexible axial support means upon said outer race of said first bearing assembly, said first retaining means preventing movement of said radial support means in an axial direction away from said rotor shaft vanes;
• and
• second retaining means for retaining said radial support means and said flexible axial support means upon said outer race of said second bearing assembly, said second retaining means preventing movement of said radial support means and said flexible support means in an axial direction away from said rotor shaft vanes;
• whereby said flexible axial support means coact with turbine cartridge support means of said housing to provide axial pre-loading of said first and second bearing assemblies when said turbine cartridge assembly is operatively positioned within said housing.