Vacuum pump
AssigneeSeiko Instruments Inc.
InventorYoshihiro Yamashita
Life of this patent
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Abstract
A vacuum pump comprises a pump case having an interior space, a rotor disposed in the interior space of the pump case, and a thread stator disposed in the interior space of the pump case and opposite to an outer peripheral surface of the rotor. At least one heater is arranged in the thread stator for heating the interior space of the pump case. An output device outputs a parameter constituting a factor for determining a temperature of the rotor. A memory stores a database containing information corresponding to a relationship between the parameter output by the output device and a preselected temperature of the heater. A controller inputs the parameter output by the output device and selects from the database stored in the memory the preselected temperature of the heater in accordance with the input parameter.
Claims28
A vacuum pump comprising:
- a pump case having an interior space;
- a rotor disposed in the interior space of the pump case;
- a thread stator disposed in the interior space of the pump case and opposite to an outer peripheral surface of the rotor;
- a thread groove formed in one of the thread stator and the rotor;
- at least one heater disposed in the thread stator for heating the interior space of the pump case;
- send-out means for sending out a parameter constituting a factor for determining a temperature of the rotor;
- a memory for storing a database containing information corresponding to a relationship between the parameter sent out from the send-out means and a preselected temperature of the heater;
- and
- control means for inputting the parameter sent out by the send-out means and for selecting from the database stored in the memory the preselected temperature of the heater in accordance with the input parameter.
A vacuum pump comprising:
- a pump case having an interior space;
- a rotor disposed in the interior space of the pump case;
- a thread stator disposed in the interior space of the pump case and opposite to an outer peripheral surface of the rotor;
- at least one heater disposed in the thread stator for heating the interior space of the pump case;
- output means for outputting at least one parameter constituting a factor for determining a temperature of the rotor;
- and
- control means for determining a temperature of the heater in accordance with the parameter output from the output means.
A vacuum pump comprising:
- a case having an interior space;
- a gas inlet through which a gas is pumped into the interior space of the case;
- a gas outlet for discharging the gas from the interior space of the case;
- a rotor disposed between the gas inlet and the gas outlet;
- a stator disposed in the interior space of the case and having a plurality of stator blades disposed opposite to an outer peripheral surface of the rotor;
- a thread stator disposed in the interior space of the case in contact with the gas outlet and one of the stator blades;
- and
- at least one heater disposed in the thread stator for directly heating the thread stator to thereby heat the gas outlet and the stator blade by thermal conduction.
Dependencies are inferred from the claim text.