An electromagnet unit in which influence of a noise on a displacement sensor is suppressed and which can be installed in a space-saving manner and a vacuum pump including the electromagnet unit are provided. An electromagnet unit includes a radial electromagnet which controls a shaft to a predetermined position, a radial sensor which detects a position of the shaft, and a printed board interposed between the radial electromagnet and the radial sensor and on which a wiring pattern for sensor connecting coils of the corresponding two radial sensors to each other and a wiring pattern connecting coils of the corresponding two radial electromagnets to each other are provided. The wiring pattern for sensor and the wiring pattern for electromagnet are disposed so as not to overlap when seen from the axial direction.

A bearing cage for a rotor bearing of a turbomolecular pump. The bearing cage includes a plurality of bearing pockets each of which, in use, houses a bearing ball such that the bearing ball operably engages an inner race and an outer race of the rotor bearing. Each bearing pocket of the bearing cage has a primary chamber for housing the bearing ball and each bearing pocket further includes a sump.

A vacuum pump system comprising a main vacuum pump that is connected to a chamber that is to be evacuated. An auxiliary pump is connected to an outlet of the main vacuum pump. Furthermore, a sealing gas supply device is connected to the main vacuum pump. The sealing gas supply device is switched on and off with the aid of a control device as a function of a predetermined control variable. Additionally, a method for controlling the vacuum pump system.

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.

A vibration damping connector system to connect between a vacuum chamber and a vacuum pump such that the vacuum pump is supported by the vibration damping connector system includes a first cylindrical member and a second cylindrical member that provide a flow passage through which gas can flow from the vacuum chamber to the vacuum pump. At least one sealing member is disposed intermediate the first and second cylindrical members to provide a gas seal and a securing system securely connect the first and second cylindrical members. At least one resilient member disposed intermediate the securing system and a cylindrical member so that when the at least one sealing member is compressed by a pressure reduction caused in use by operation of the vacuum pump, the at least one resilient member can expand to enable the securing system to maintain a secure connection.

The invention relates to a vacuum system, comprising a vacuum pump, preferably turbomolecular pump, and at least one vacuum chamber, wherein the vacuum pump comprises: at least a first and a second inlet and a common outlet; at least a first and a second pumping stage, each pumping stage comprising at least one rotor element being arranged on a common rotor shaft, wherein the first inlet is connected to an upstream end of the first pumping stage and the second inlet is connected to an upstream end of the second pumping stage; a direction element for preventing a gas flow from a downstream end of the first pumping stage to the second inlet; a conduit having a conduit inlet and a conduit outlet, wherein the conduit inlet is connected to the downstream end of the first pumping stage and the conduit outlet is connected to a location downstream of the second pumping stage; wherein the first inlet and the second inlet of the pump are connected to the same vacuum chamber.

Provided is a vacuum pump including a turbomolecular mechanism having rotor blades and stator blades alternately arranged in multiple stages in an axial direction inside a casing having an inlet port that sucks gas from an outside and an outlet port that exhausts the sucked gas to the outside, the vacuum pump including: a plurality of annular spacers that are stacked on each other and position the stator blades in the axial direction; the casing that has a cylindrical portion arranged to surround outer peripheries of the plurality of stacked spacers and a base portion attached to a lower portion of the cylindrical portion; and an upper radial positioning portion and a lower radial positioning portion provided at two vertical positions inside the cylindrical portion and coaxially hold at least a spacer of an uppermost stage and a spacer of a lowermost stage among the plurality of stacked spacers.

A turbomolecular vacuum pump is provided, including: a stator; a rotor configured to rotate in the stator about an axis of rotation; and a regulation valve configured to modify an inlet conductance of the turbomolecular vacuum pump by axial displacement towards or away from a suction orifice of the turbomolecular vacuum pump, a face of the regulation valve facing the suction orifice having a hollow form.

A vacuum pump comprises: a cylindrical rotor; multiple heat insulating pins; and a stator having a cylindrical portion arranged with a predetermined gap in an outer peripheral side of the rotor and a fixing portion to be fixed to a pump base through the multiple heat insulating pins. The heat insulating pins have a lower thermal conductivity than those of the stator and the pump base, and support the fixing portion.

Provided is a pump backstream prevention structure for semiconductor fabrication equipment, including a sensor, an isolation air supply pipe, and a control unit. A time delay from a point in time at which the dry pump starts to malfunction to a point in time at which the isolation valve is closed is reduced, compared to a method of closing the isolation valve by a controller of the semiconductor fabrication equipment. Accordingly, a backstream in which particles move from the pumping pipe to the process chamber before the closing of the isolation valve is prevented.