Abstract: A vacuum pump includes a housing, a rotor cylindrical portion, and a stator cylindrical portion. The housing has an inlet port for sucking gas and an outlet port for discharging the sucked gas. The rotor cylindrical portion is housed in the housing. The stator cylindrical portion is housed in the housing, and is arranged to face the rotor cylindrical portion. A screw groove is formed on one of opposing surfaces of the stator cylindrical portion and the rotor cylindrical portion. The groove depth D of the screw groove is smaller at an end on an exhaust side than at an end on a suction side. The decrement of the groove depth D is greater on the suction side than on the exhaust side.

Abstract: A vacuum pump includes a housing, a rotor cylindrical portion, and a stator cylindrical portion. The housing has an inlet port for sucking gas and an outlet port for discharging the sucked gas. The rotor cylindrical portion is housed in the housing. The stator cylindrical portion is housed in the housing, and is arranged to face the rotor cylindrical portion. A screw groove is formed on one of opposing surfaces of the stator cylindrical portion and the rotor cylindrical portion. The groove depth D of the screw groove is smaller at an end on an exhaust side than at an end on a suction side. The decrement of the groove depth D is greater on the suction side than on the exhaust side.

Abstract: A vacuum pump comprises: a pump rotor portion configured such that multiple rotor blade stages including stacking portions formed in a ring shape and turbine blades radially formed on an outer peripheral side of the stacking portions are stacked on each other; a rotor shaft to which inner peripheral surfaces of the stacking portions of the multiple rotor blade stages stacked on each other are fixed; and a communication path allowing communication between a clearance space between the rotor shaft and each stacking portion and a pump exhaust path in which the turbine blades are arranged and discharging gas in the clearance space through the pump exhaust path.

Abstract: A vacuum pump comprises: a pump rotor portion configured such that multiple rotor blade stages including stacking portions formed in a ring shape and turbine blades radially formed on an outer peripheral side of the stacking portions are stacked on each other; a rotor shaft to which inner peripheral surfaces of the stacking portions of the multiple rotor blade stages stacked on each other are fixed; and a communication path allowing communication between a clearance space between the rotor shaft and each stacking portion and a pump exhaust path in which the turbine blades are arranged and discharging gas in the clearance space through the pump exhaust path.

Abstract: A vacuum pump comprises: a rolling bearing configured to support a rotor shaft provided at a pump rotor; a lubrication fluid storage section configured to store lubrication fluid to be supplied to the rolling bearing; a MEMS element including, at a rotor-shaft-side lubrication fluid circulation path in a lubrication fluid circulation path between the rolling bearing and the lubrication fluid storage section, an infinitesimal flow rate pump configured to discharge a liquid droplet of the lubrication fluid; and a first flow path of a capillary structure configured to move the lubrication fluid of the lubrication fluid storage section to the infinitesimal flow rate pump by capillary force.

Abstract: A vacuum pump comprises: a rolling bearing configured to support a rotor shaft provided at a pump rotor; a lubrication fluid storage section configured to store lubrication fluid supplied to the rolling bearing; a MEMS element including an infinitesimal flow rate pump configured to transfer the lubrication fluid of the lubrication fluid storage section to the rolling bearing; and a first flow path of a capillary structure configured to move the lubrication fluid of the lubrication fluid storage section to the infinitesimal flow rate pump by capillary force.

Abstract: A vacuum pump comprises: a bearing device; and an exhaust function including a rotary body supported by the bearing device and configured to exhaust gas. The bearing device includes a bearing having an outer ring, an inner ring, and a rolling body, a lubricant storage configured to store lubricant, a lubricant supply structure configured to supply, to the bearing, the lubricant stored in the lubricant storage, a holding member configured to hold the bearing, and a porous body disposed outside the outer ring of the bearing and filled with the lubricant supplied from the lubricant supply structure to the bearing.

Abstract: One or more through-holes communicating with one or more of the plurality of screw grooves are formed at the cylindrical stator, a total of circumferential dimensions of the one or more through-holes formed at the cylindrical stator is set at equal to or greater than a circumferential dimension of an outer peripheral surface region of the cylindrical stator facing the second suction port, and a gas path through which inflow gas through the second suction port is guided to a screw groove is provided, the one or more through-holes penetrating through the screw groove and the screw groove being apart from the region facing the second suction port.

Abstract: An oil-lubricated bearing device comprises: a rolling bearing including an inner ring, an outer ring, rolling bodies, and a holder; a tapered member; a lubricant storage disposed on a side provided with the tapered member with respect to the inner ring; and a contact portion. The holder includes pockets each formed with outer and inner ring side openings and configured to hold a corresponding one of the rolling bodies, a lubricant scraping portion formed at an inner peripheral surface of each of the pockets and configured to scrape lubricant adhering to a surface of each of the rolling body, and a second inclined surface formed at an outer peripheral surface portion of the holder adjacent to the outer ring side opening and rising with a slope toward the lubricant storage.

Abstract: A vacuum pump comprises: a first pump stage; a second pump stage provided downstream of the first pump stage; a first suction port provided on a suction side of the first pump stage; and a second suction port provided downstream of the first pump stage and communicating with the second pump stage. The first pump stage includes a siegbahn pump portion suitable for a small exhaust volume, and a turbo-molecular pump portion. The second pump stage includes a Holweck pump portion suitable for a great exhaust volume.

Abstract: A vacuum pump comprises: a bearing device; and an exhaust function including a rotary body supported by the bearing device and configured to exhaust gas. The bearing device includes a bearing having an outer ring, an inner ring, and a rolling body, a lubricant storage configured to store lubricant, a lubricant supply structure configured to supply, to the bearing, the lubricant stored in the lubricant storage, a holding member configured to hold the bearing, and a porous body disposed outside the outer ring of the bearing and filled with the lubricant supplied from the lubricant supply structure to the bearing.

Abstract: An oil-lubricated bearing device comprises: a rolling bearing including an inner ring, an outer ring, rolling bodies, and a holder; a tapered member; a lubricant storage disposed on a side provided with the tapered member with respect to the inner ring; and a contact portion. The holder includes pockets each formed with outer and inner ring side openings and configured to hold a corresponding one of the rolling bodies, a lubricant scraping portion formed at an inner peripheral surface of each of the pockets and configured to scrape lubricant adhering to a surface of each of the rolling body, and a second inclined surface formed at an outer peripheral surface portion of the holder adjacent to the outer ring side opening and rising with a slope toward the lubricant storage.

Abstract: One or more through-holes communicating with one or more of the plurality of screw grooves are formed at the cylindrical stator, a total of circumferential dimensions of the one or more through-holes formed at the cylindrical stator is set at equal to or greater than a circumferential dimension of an outer peripheral surface region of the cylindrical stator facing the second suction port, and a gas path through which inflow gas through the second suction port is guided to a screw groove is provided, the one or more through-holes penetrating through the screw groove and the screw groove being apart from the region facing the second suction port.

Abstract: A vacuum pump comprises: a first pump stage; a second pump stage provided downstream of the first pump stage; a first suction port provided on a suction side of the first pump stage; and a second suction port provided downstream of the first pump stage and communicating with the second pump stage. The first pump stage includes a siegbahn pump portion suitable for a small exhaust volume, and a turbo-molecular pump portion. The second pump stage includes a Holweck pump portion suitable for a great exhaust volume.