Dual inlet vacuum pumps

A high-vacuum pump comprising:

• two or more axial flow stages coupled in series, said axial flow stages divided into a first pump section and a second pump section separated from said first pump section by an interstage region, each of said axial flow stages comprising a rotor and a stator;
• a motor;
• a shaft coupled between said motor and the rotor of each of said axial flow stages;
• and
• a housing containing said axial flow stages;
• and
• a high conductance peripheral duct protruded outwardly from said housing and coupled to said interstage region, said peripheral duct surrounding all or part of said interstage region;
• said housing defining a first inlet port coupled to an inlet of said first pump section, a second inlet port coupled to said peripheral duct and an exhaust port coupled to an outlet of said second pump section.

The diffusion pump comprising:

• two or more vapor jet stages coupled in series, said vapor jet stages divided into a first pump section and a second pump section having an interstage region between them;
• a vapor source for supplying a vapor to said vapor jet stages;
• and
• a housing containing said vapor jet stages, said housing including a high conductance peripheral duct surrounding all or part of said interstage region and coupled to said interstage region, said housing defining a first inlet port coupled to an inlet of said first pump section, a second inlet port coupled to said peripheral duct and an exhaust port coupled to an outlet of said second pump section.

A high-vacuum pump comprising:

• one or more axial flow stages and one or more molecular drag stages coupled in series, said axial flow stages and said molecular drag stages divided into a first pump section and a second pump section separated from said first pump section by an interstage region, each of said axial flow stages and said molecular drag stages comprising a rotor and a stator;
• a motor;
• a shaft coupled between said motor and the rotor of each of said axial flow stages and said molecular drag stages;
• a housing containing said axial flow stages and said molecular drag stages;
• and
• a high conductance peripheral duct protruded outwardly from said housing and coupled to said interstage region said peripheral duct surrounding all or prior art of said interstage region;
• said housing defining a first inlet port coupled to an inlet of said first pump section, a second inlet port coupled to said peripheral duct, and an exhaust port coupled to an outlet of said second pump section.