Turbo molecular pump

A turbo molecular pump comprising:

• a rotor having rotor blades arranged in multiple stages, each of the rotor blades having a proximal end fixed to the rotor and a distal end;
• and stator blades arranged in multiple stages and each having a proximal end and a distal end, the rotor blades and the stator blades being alternately arranged in spaced-apart relation in an axial direction so that a spatial clearance between the proximal end of each of the rotor blades and the distal end of an adjacent stator blade is smaller than a spatial clearance between the distal end of each of the rotor blades and the proximal end of the adjacent stator blade;
• wherein each of the stator blades comprises a cantilever member having upper and lower surfaces;
• and wherein at least one of the upper and lower surfaces of the cantilever member is contoured to define a flexure curve line represented by the formula Δ=(WL4/8EI) (1−(4X/3L)+(X4/3L4)), where E (kgf/mm2) represents the Young's modulus of the material of the cantilever member, I (mm4) represents the geometrical moment of inertia of the cantilever member, L (mm) represents the length of the cantilever member, W (kgf/mm) represents a load distributed on the cantilever member, and Δ represents a flexure amount of the cantilever member at a distance x (mm) from a distal end of the cantilever member.

A turbo molecular pump comprising:

• a rotor having rotor blades arranged in multiple stages, each of the rotor blades having a proximal end fixed to the rotor and a distal end;
• and stator blades arranged in multiple stages and each having a proximal end and a distal end, the rotor blades and the stator blades being alternately arranged in spaced-apart relation in an axial direction so that a spatial clearance between the proximal end of each of the rotor blades and the distal end of an adjacent stator blade is smaller than a spatial clearance between the distal end of each of the rotor blades and the proximal end of the adjacent stator blade;
• wherein each of the rotor blades comprises a cantilever member having upper and lower surfaces;
• and wherein at least one of the upper and lower surfaces of the cantilever member has at least one step having a contour defining a flexure curve line represented by the formula Δ=(WL4/8EI)(1−(4×/3L)+(X4/3L4)), where E (kgf/mm2) represents the Young's modulus of the material of the cantilever member, I (mm4) represents the geometrical moment of inertia of the cantilever member, L (mm) represents the length of the cantilever member, W (kgf/mm) represents a load distributed on the cantilever member, and Δ represents a flexure amount of the cantilever member at a distance x (mm) from a distal end of the cantilever member.

A turbo molecular pump comprising:

• a rotor having rotor blades arranged in multiple stages, each of the rotor blades having a proximal end fixed to the rotor and a distal end;
• and stator blades arranged in multiple stages and each having a proximal end and a distal end, the rotor blades and the stator blades being alternately arranged in spaced-apart relation in an axial direction so that a spatial clearance between the proximal end of each of the rotor blades and the distal end of an adjacent stator blade is smaller than a spatial clearance between the distal end of each of the rotor blades and the proximal end of the adjacent stator blade;
• wherein each of the stator blades comprises a cantilever member having upper and lower surfaces;
• and wherein at least one of the upper and lower surfaces of the cantilever member has at least one step having a contour defining a flexure curve line represented by the formula Δ=(WL4/8EI)(1−(4×/3L)+(X4/3L4)), where E (kgf/mm2) represents the Young's modulus of the material of the cantilever member, I (mm4) represents the geometrical moment of inertia of the cantilever member, L (mm) represents the length of the cantilever member, W (kgf/mm) represents a load distributed on the cantilever member, and Δ represents a flexure amount of the cantilever member at a distance x (mm) from the distal end of the cantilever beam.

A turbo molecular pump comprising:

• a housing;
• a rotational shaft disposed in the housing for undergoing rotation relative to the housing about a rotational axis;
• a rotor mounted on the rotational shaft for rotation therewith;
• a plurality of rotor blades each having a first end fixed to the rotor and a second end;
• and a plurality of stator blades each having a first end fixed to the housing and a second end, the rotor blades and the stator blades being alternately arranged in spaced-apart relation in the direction of the rotational axis so that a distance between the first end of each of the rotor blades and the second end of an adjacent stator blade is smaller than a distance between the second end of each of the rotor blades and the first end of the adjacent stator blade;
• wherein the rotor blades and the stator blades are contoured to define a flexure curve line represented by the formula Δ=(WL4/8EI)(1−(4X/3L)+(X4/3L4)), where E (kgf/mm2) represents the Young's modulus of the material of the cantilever member, I (mm4) represents the geometrical moment of inertia of the cantilever member, L (mm) represents the length of the cantilever member, W (kgf/mm) represents a load distributed on the cantilever member, and Δ represents a flexure amount of the cantilever member at a distance x (mm) from the second end of the cantilever member.

A turbo molecular pump comprising:

• a housing;
• a rotational shaft disposed in the housing for undergoing rotation relative to the housing about a rotational axis;
• a rotor mounted on the rotational shaft for rotation therewith;
• a plurality of rotor blades each having a first end fixed to the rotor and a second end;
• and a plurality of stator blades each having a first end fixed to the housing and a second end,the rotor blades and the stator blades being alternately arranged in spaced-apart relation in the direction of the rotational axis so that a distance between the first end of each of the rotor blades and the second end of an adjacent stator blade is smaller than a distance between the second end of each of the rotor blades and the first end of the adjacent stator blade;
• wherein each of the stator blades comprises a cantilever member having upper and lower surfaces, at least one of the upper and lower surfaces having at least one step disposed at a position of the cantilever member in the range of 60-85% of a length thereof as measured from the second end of the cantilever member.

A turbo molecular pump comprising:

• a housing;
• a rotational shaft disposed in the housing for undergoing rotation relative to the housing about a rotational axis;
• a rotor mounted on the rotational shaft for rotation therewith;
• a plurality of rotor blades each having a first end fixed to the rotor and a second end;
• and a plurality of stator blades each having a first end fixed to the housing and a second end, the rotor blades and the stator blades being alternately arranged in spaced-apart relation in the direction of the rotational axis so that a distance between the first end of each of the rotor blades and the second end of an adjacent stator blade is smaller than a distance between the second end of each of the rotor blades and the first end of the adjacent stator blade;
• wherein each of the stator blades comprises a cantilever member having upper and lower surfaces, at least one of the upper and lower surfaces having at least one step having a contour defining a flexure curve line represented by the formula Δ=(WL4/8EI)(1−(4X/3L)+(X4/3L4)), where E (kgf/mm2) represents the Young's modulus of the material of the cantilever member, I (mm4) represents the geometrical moment of inertia of the cantilever member, L (mm) represents the length of the cantilever member, W (kgf/mm) represents a load distributed on the cantilever member, and Δ represents a flexure amount of the cantilever member at a distance x (mm) from the second end of the cantilever member.

A turbo molecular pump comprising:

• a housing;
• a rotational shaft disposed in the housing for undergoing rotation relative to the housing about a rotational axis;
• a rotor mounted on the rotational shaft for rotation therewith;
• a plurality of rotor blades each having a first end fixed to the rotor and a second end;
• and a plurality of stator blades each having a first end fixed to the housing and a second end, the rotor blades and the stator blades being alternately arranged in spaced-apart relation in the direction of the rotational axis so that a distance between the first end of each of the rotor blades and the second end of an adjacent stator blade is smaller than a distance between the second end of each of the rotor blades and the first end of the adjacent stator blade;
• wherein each of the stator blades comprises a cantilever member having upper and lower surfaces, at least one of the upper and lower surfaces having a plurality of steps.

A turbo molecular pump comprising:

• a housing;
• a rotational shaft disposed in the housing for undergoing rotation relative to the housing about a rotational axis;
• a rotor mounted on the rotational shaft for rotation therewith;
• a plurality of rotor blades each having a first end fixed to the rotor and a second end;
• and a plurality of stator blades each having a first end fixed to the housing and a second end, the rotor blades and the stator blades being alternately arranged in spaced-apart relation in the direction of the rotational axis so that a distance between the first end of each of the rotor blades and the second end of an adjacent stator blade is smaller than a distance between the second end of each of the rotor blades and the first end of the adjacent stator blade;
• wherein each of the rotor blades comprises a cantilever member having upper and lower surfaces;
• and wherein at least one of the upper and lower surfaces of the cantilever member is contoured to define a flexure curve line represented by the formula Δ=(WL4/8EI)(1−(4X/3L)+(X4/3L4)), where E (kgf/mm2) represents the Young's modulus of the material of the cantilever member, I (mm4) represents the geometrical moment of inertia of the cantilever member, L (mm) represents the length of the cantilever member, W (kgf/mm) represents a load distributed on the cantilever member, and Δ represents a flexure amount of the cantilever member at a distance x (mm) from the second end of the cantilever member.

A turbo molecular pump comprising:

• a housing;
• a rotational shaft disposed in the housing for undergoing rotation relative to the housing about a rotational axis;
• a rotor mounted on the rotational shaft for rotation therewith;
• a plurality of rotor blades each having a first end fixed to the rotor and a second end;
• and a plurality of stator blades each having a first end fixed to the housing and a second end, the rotor blades and the stator blades being alternately arranged in spaced-apart relation in the direction of the rotational axis so that a distance between the first end of each of the rotor blades and the second end of an adjacent stator blade is smaller than a distance between the second end of each of the rotor blades and the first end of the adjacent stator blade;
• wherein each of the stator blades comprises a cantilever member having upper and lower surfaces;
• and wherein at least one of the upper and lower surfaces of the cantilever member is contoured to define a flexure curve line represented by the formula Δ=(WL4/8EI)(1−(4X/3L)+(X4/3L4)), where E (kgf/mm2) represents the Young's modulus of the material of the cantilever member, I (mm4) represents the geometrical moment of inertia of the cantilever member, L (mm) represents the length of the cantilever member, W (kgf/mm) represents a load distributed on the cantilever member, and Δ represents a flexure amount of the cantilever member at a distance x (mm) from the second end of the cantilever member.