Structure of rotor connection of multi-axial multi-stage roots pump

1. A structure comprising a rotor body including a rotor shaft arranged on and extending from a first end face of the rotor body; a sub-shaft cavity opened in the rotor shaft wherein the sub-shaft cavity and the rotor shaft are arranged concentrically and coaxially; a first locating keyway opened on a first side inside the sub-shaft cavity and a second locating keyway opened on a second side inside the sub-shaft cavity in a symmetrical position with said first locating keyway, wherein said first and second locating keyway each begin at an edge of the sub-shaft cavity; a sub-shaft arranged on and extending from a second end face of the rotor body, wherein the sub-shaft and the rotor shaft are arranged concentrically and coaxially; and a first sub-shaft locating keyway opened on a first side of the sub-shaft and a second sub-shaft locating keyway opened on a second side of the sub-shaft in a symmetrical position with said first sub-shaft locating keyway, and wherein said first and second sub-shaft locating keyway being at an edge of the sub-shaft.

2. The structure of claim 1 , wherein a depth of each said first and second locating keyway is less than a depth of the sub-shaft cavity, and wherein the depth of sub-shaft cavity is less than a length of the rotor shaft.

3. The structure of claim 1 , wherein a length of each said first and second sub-shaft locating keyway is less than a length of the sub-shaft.

4. The structure of claim 1 , wherein both the rotor shaft and the sub-shaft are made of cast iron, and wherein the sub-shaft and the sub-shaft cavity are interference fitted.

5. A plurality of rotor bodies in rotor connection with one another, wherein each rotor body of the plurality of rotor bodies are characterized in that each rotor body includes a rotor shaft arranged on a first end face of each said rotor body; a sub-shaft cavity opened in the rotor shaft of each said rotor body wherein the sub-shaft cavity and the rotor shaft are arranged concentrically and coaxially within each said rotor body; a first locating keyway opened on a first side inside the sub-shaft cavity of each said rotor body and a second locating keyway opened on a second side inside the sub-shaft cavity of each said rotor body in a symmetrical position with said first locating keyway, wherein said first and second locating keyway each begin at an edge of the sub-shaft cavity of each said rotor body; a sub-shaft arranged on a second end face, opposite said first end face, of each said rotor body wherein the sub-shaft and the rotor shaft of each said rotor body are arranged concentrically and coaxially; and a first sub-shaft locating keyway opened on a first side of the sub-shaft of each said rotor body and a second sub-shaft locating keyway opened on a second side of the sub-shaft of each said rotor body in a symmetrical position with said first sub-shaft locating keyway, and wherein said first and second sub-shaft locating keyway being at an edge of the sub-shaft of each said rotor body; wherein the sub-shaft of one rotor body is securable within a sub-shaft cavity of an other rotor body adjacent said one rotor body through the use of two sub-rotor shaft keys placed within the first and second locating keyways, respectively, within the sub-shaft cavity of the other rotor body and the first and second sub-shaft locating keyways within the sub-shaft of the one rotor body.

6. The plurality of rotor bodies in rotor connection with one another of claim 5 , wherein a depth of each said first and second locating keyway of each rotor body of the plurality of rotor bodies is less than a depth of the sub-shaft cavity of each rotor body of the plurality of rotor bodies, and wherein the depth of sub-shaft cavity of each rotor body of the plurality of rotor bodies is less than a length of the rotor shaft of each rotor body of the plurality of rotor bodies.

7. The plurality of rotor bodies in rotor connection with one another of claim 5 , wherein a length of each said first and second sub-shaft locating keyway of each rotor body of the plurality of rotor bodies is less than a length of the sub-shaft of each rotor body of the plurality of rotor bodies.

8. The plurality of rotor bodies in rotor connection with one another of claim 5 , wherein both the rotor shaft of each rotor body of the plurality of rotor bodies and the sub-shaft of each rotor body of the plurality of rotor bodies are made of cast iron, and the sub-shaft of each rotor body of the plurality of rotor bodies and the sub-shaft cavity of each rotor body of the plurality of rotor bodies are interference fitted.

9. The plurality of rotor bodies in rotor connection with one another of claim 5 , wherein a first end of each sub-rotor shaft key is a plane end face utilized for positioning within the rotor shaft of the one rotor body, and a second end of each sub-rotor key is an arc-shaped end face utilized for positioning within the sub-shaft of the other rotor body.