| 摘要 |
Disclosed is a low-cost composite-type vacuum pump having a strength capable of withstanding high loads and using a cylindrical rotor formed from a fiber-reinforced plastic material. Having a turbomolecular pump unit (14) and a thread groove pump unit (15), the composite vacuum pump is formed by press-fitting a connection part (20a) of a rotor (17) of the turbomolecular pump unit (14) into the upper end of a cylindrical rotor (21) formed from the fiber-reinforced plastic material of the thread groove pump unit (15). The connection part (20a) of the rotor (17) is formed on the bottom end of the rotor (17) integrally with said rotor (17) and in the shape of a cylinder with an L-shaped cross section, and is provided with: a contact part (28) having an outer diameter allowing press-fitting into the inside surface of the cylindrical rotor (21); and a small diameter section (29) positioned above said contact part (28) and, having an outer diameter smaller than the inner diameter of the aforementioned cylindrical rotor (21), capable of being placed inside the cylindrical rotor (21) away from the inner surface of the cylinder rotor (21). |
