Abstract: A deposited material sensor is arranged, in a flow path of a gas from an inlet port to an outlet port, on an upstream side or a downstream side of a predetermined flow path position where a cause of disruption to operation of the vacuum pump is to occur. In addition, the deposited material sensor detects a presence or absence of deposited material at the arrangement position of the deposited material sensor, and the arrangement position of the deposited material sensor is a position where a thickness of the deposited material at the predetermined flow path position assumes a predetermined thickness that corresponds to a maintenance time of maintenance for suppressing the cause when a detection state of the deposited material sensor changes from deposited material absent to deposited material present.

Abstract: A vacuum pump includes a plurality of exhaust stages provided between an inlet port and an exhaust port so as to function as means for exhausting gas molecules, and a number of blades provided between the inlet port and an uppermost exhaust stage of the plurality of exhaust stages so as to rotate together with a rotary blade that constitutes the uppermost exhaust stage as a particle transport stage for transporting particles in an exhaust direction of the gas molecules, the number being smaller than the number of rotary blades that constitutes the uppermost exhaust stage.

Abstract: A deposited material sensor is arranged, in a flow path of a gas from an inlet port to an outlet port, on an upstream side or a downstream side of a predetermined flow path position where a cause of disruption to operation of the vacuum pump is to occur. In addition, the deposited material sensor detects a presence or absence of deposited material at the arrangement position of the deposited material sensor, and the arrangement position of the deposited material sensor is a position where a thickness of the deposited material at the predetermined flow path position assumes a predetermined thickness that corresponds to a maintenance time of maintenance for suppressing the cause when a detection state of the deposited material sensor changes from deposited material absent to deposited material present.

Abstract: A vacuum pump includes: a particle transferring portion that functions as a means for transferring a particle in an exhaust direction of the gas particle by increasing or reducing a height of an upstream end of at least a part of rotor blades among a plurality of rotor blades that constitute an uppermost exhaust stage to realize a stepped structure in which heights of the upstream ends differ as the uppermost exhaust stage as a whole, and in a rotating body constituted by the plurality of rotor blades, the particle transferring portion, and a cylindrical portion that supports the plurality of rotor blades, an imbalance created with respect to the rotating body as a whole by a presence of a rotor blade of which a height of the upstream end has become higher than other rotor blades due to the stepped structure has been corrected.

Abstract: A vacuum pump includes a plurality of exhaust stages provided between an inlet port and an exhaust port so as to function as means for exhausting gas molecules, and a number of blades provided between the inlet port and an uppermost exhaust stage of the plurality of exhaust stages so as to rotate together with a rotary blade that constitutes the uppermost exhaust stage as a particle transport stage for transporting particles in an exhaust direction of the gas molecules, the number being smaller than the number of rotary blades that constitutes the uppermost exhaust stage.

Abstract: A turbo molecular pump has a rotor having rotor blades arranged in multiple stages. Each of the rotor blades has a proximal end fixed to the rotor and a distal end. Stator blades are arranged in multiple stages. Each stator blade has a proximal end and a distal end. The rotor blades and the stator blades are 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. Each of the rotor blades comprises a cantilever member having upper and lower surfaces.

Abstract: In an internal grinding machine of the type in which a workpiece is supported by three contact points by a fixed shoe and two rolls, the present invention facilitates correct feed and discharge of workpieces one by one without regard to the diameter of a workpiece. This is made possible by furnishing an internal grinding machine with a workpiece guide plate having a V-shape projection at its underside by the side of an upper roll in such a manner that the workpiece guide plate can swing up and down. When a workpiece is fed, the workpiece temporarily pushes up the V-shape projection, then reaches the end of the shoe. And it is pushed downward at the end of the shoe by the end portion of the workpiece guide plate, and is fed into the support space. When a finished workpiece is pushed by the workpiece newly fed in the manner as described above and discharged from the support space, the finished workpiece temporarily pushes up the said V-shape projection and is discharged.