Stator vane of turbo molecular pump

1. A stator vane for a turbo molecular pump, the stator vane comprising: two stator vane, halves each having inner and outer rim portions and a plurality of radially arranged stator blades connected integrally between the inner and outer rim portions, the inner rim portion of each stator vane half having a pair of inner rim ends and the outer rim portion of each stator vane half having a pair of outer rim ends, the stator vane halves being disposed in abutment with one another along an abutment line to form an annular body with the inner rim ends of one of the stator vane halves being disposed in confronting relation with the respective inner rim ends of the other of the stator vane halves and with the outer rim ends of the one of the stator vane halves being disposed in confronting relation with the respective outer rim ends of the other of the stator vane halves, at least each of the inner rim ends or each of the outer rim ends of one of the two stator blade halves being formed shorter in a circumferential direction of the annular body with respect to the abutment line to form a gap between the confronting inner rim ends or the confronting outer rim ends.

2. A stator vane for a turbo molecular pump according to claim 1 ; wherein the gap is in the range of 0.3 to 0.7 mm.

3. A stator vane for a turbomolecular pump according to claim 2 ; wherein the gap is 0.5 mm.

4. A stator vane for a turbo molecular pump according to claim 1 ; wherein the at least each of the inner rim ends or each of the outer rim ends has a cutout that forms the gap between the confronting inner rim ends or the confronting outer rim ends.

5. A stator vane for a turbo molecular pump according to claim 4 ; wherein the gap is in the range of 0.3 to 0.7 mm.

6. A stator vane for a turbomolecular pump according to claim 3 ; wherein the gap is 0.5 mm.

7. A vacuum pump having the stator vane of a turbo molecular pump according to claim 1 .

8. A stator vane for a turbomolecular pump according to claim 1 ; wherein only each of the inner rim ends of each of the stator blade halves is formed shorter in a circumferential direction of the annular body with respect to the abutment line to form a gap between the confronting inner rim ends.

9. A stator vane for a turbo molecular pump according to claim 8 ; wherein the gap is in the range of 0.3 to 0.7 mm.

10. A stator vane for a turbomolecular pump according to claim 9 ; wherein the gap is 0.5 mm.

11. A stator vane for a turbo molecular pump according to claim 8 ; wherein each of the inner rim ends has a cutout that forms the gap between the confronting inner rim ends.

12. A vacuum pump having the stator vane of a turbo molecular pump according to claim 8 .

13. A stator vane for a tubular molecular pump, the stator vane comprising:

a first stator blade segment having first inner and outer rim portions and a plurality of radially arranged stator blades connected integrally between the first inner and outer rim portions, the first inner rim portion having first inner rim ends and the first outer rim portion having first outer rim ends;

a second stator blade segment having second inner and outer rim portions and a plurality of radially arranged stator blades connected integrally between the second inner and outer rim portions, the second inner rim portion having second inner rim ends and the second outer rim portion having second outer rim ends, the second stator blade segment being configured for abutment with the first stator blade segment along an abutment line to form an annular body with the first inner rim ends being disposed in confronting relation with the respective second inner rim ends and with the first outer rim ends being disposed in confronting relation with the respective second outer rim ends; and

means defining a gap between the confronting first and second inner rim ends or the confronting first and second outer rim ends when the first and second blade segments are disposed in abutment with one another.

14. A stator vane for a turbo molecular pump according to claim 13 ; wherein the means defining the gap comprises each of the first inner rim ends, each of the first outer rim ends, each of the second inner rim ends, or each of the second outer rim ends being formed shorter in a circumferential direction of the annular body with respect to the abutment line to form the gap between the confronting first and second rim ends or the confronting first and second outer rim ends.

15. A stator vane for a turbo molecular pump according to claim 14 ; wherein each of the first inner rim ends or each of the second inner rim ends are formed shorter in a circumferential direction of the annular body with respect to the abutment line to form the gap.

16. A stator vane for a turbo molecular pump according to claim 14 ; wherein each of the first outer rim ends or each of the second outer rim ends are formed shorter in a circumferential direction of the annular body with respect to the abutment line to form the gap.

17. A stator vane for a turbo molecular pump according to claim 13 ; wherein the means defining the gap comprises a cutout formed on each of the first inner rim ends or each of the second inner rim ends.

18. A stator vane for a turbo molecular pump according to claim 13 ; wherein the gap is in the range of 0.3 to 0.7 mm.

19. A stator vane for a turbomolecular pump according to claim 18 ; wherein the gap is 0.5 mm.

20. A vacuum pump having the stator vane of a turbo molecular pump according to claim 13 .