Vacuum pump
A vacuum pump capable of suppressing the solidification of gas in a normal operation of a pump is provided. Provided is a vacuum pump including a casing that has an inlet port for sucking gas from outside and an outlet port for exhausting the gas to the outside; a turbo-molecular-pump mechanism that is disposed in the casing and includes rotor blades and stator blades alternately arranged in multiple stages in an axial direction; a thread-groove-pump mechanism that is disposed in the casing and is connectedly disposed on an exhaust side of the turbo-molecular-pump mechanism; first temperature regulating means that is configured to regulate cooling of the turbo-molecular-pump mechanism; and second temperature regulating means that is configured to regulate heating of the thread-groove-pump mechanism.
1. A vacuum pump comprising:
a casing, the casing having an inlet port for sucking gas from outside and an outlet port for exhausting the gas to the outside;
a turbo-molecular-pump mechanism, the turbo-molecular-pump mechanism being disposed in the casing and including rotor blades and stator blades alternately arranged in multiple stages in an axial direction;
a thread-groove-pump mechanism, the thread-groove-pump mechanism being disposed in the casing and being connectedly disposed on an exhaust side of the turbo-molecular-pump mechanism;
a bearing, the bearing rotatably holding a rotating portion of the turbo-molecular-pump mechanism and a rotating portion of the thread-groove-pump mechanism; and
a motor portion configured to rotate the rotating portions,
the vacuum pump further comprising:
first temperature regulating means configured to regulate cooling of the turbo-molecular-pump mechanism; and
second temperature regulating means configured to regulate heating of the thread-groove-pump mechanism, wherein
the turbo-molecular-pump mechanism is divided into an upper-stage-group gas transfer unit that is disposed downstream from the inlet port and is cooled by the first temperature regulating means, and a lower-stage-group gas transfer unit that is disposed upstream of the thread-groove-pump mechanism and is heated by the second temperature regulating means, and
heat insulating means is provided between the first temperature regulating means and the lower-stage-group gas transfer unit, wherein a portion of the heat insulation means extends axially adjacent the lower-stage-group gas transfer unit.
2. The vacuum pump according to claim 1 , further comprising:
a second heat insulating means, the second heat insulating means being provided between a stator of the thread-groove-pump mechanism and a stator of the motor portion.
3. The vacuum pump according to claim 1 , wherein
the bearing and a stator of the motor portion are always cooled.
4. The vacuum pump according to claim 1 , wherein
a stator of the turbo-molecular-pump mechanism includes a first temperature sensor and a cooling structure;
a stator of the thread-groove-pump mechanism includes a second temperature sensor and a heating structure;
the first temperature regulating means regulates a temperature of the cooling structure of the turbo-molecular-pump mechanism based on a temperature detected by the first temperature sensor of the turbo-molecular-pump mechanism, and
the second temperature regulating means regulates a temperature of the heating structure of the thread-groove-pump mechanism based on a temperature detected by the second temperature sensor of the thread-groove-pump mechanism.
5. The vacuum pump according to claim 1 , wherein
a temperature of the lower-stage-group gas transfer unit is regulated by the second temperature regulating means via the thread-groove-pump mechanism.
6. The vacuum pump according to claim 1 , wherein
the heat insulating means is in contact with the lower-stage-group gas transfer unit and is disposed with a clearance created between the heat insulating means and the upper-stage-group gas transfer unit.
7. The vacuum pump according to claim 5 , wherein
the turbo-molecular-pump mechanism includes a clearance that axially separates the upper-stage-group gas transfer unit from the lower-stage-group gas transfer unit.
8. The vacuum pump according to claim 1 , wherein
the heat insulating means is a stainless material.
9. The vacuum pump according to claim 5 , wherein
the first temperature regulating means regulates a temperature of the upper-stage-group gas transfer unit based on a temperature detected by a first temperature sensor for detecting the temperature of the upper-stage-group gas transfer unit, and
the second temperature regulating means regulates a temperature of the thread-groove-pump mechanism based on a temperature detected by a second temperature sensor for detecting the temperature of the thread-groove-pump mechanism.
10. The vacuum pump according to claim 1 , wherein
the bearing and a bearing portion of the motor portion are magnetic bearings.
11. The vacuum pump according to claim 1 , wherein
the second temperature regulating means controls the temperature with reference to a sublimation curve based on a relationship between a temperature and a pressure of the gas.