# US 2021/0277899 A1 · Multistage pump assembly with at least one co-used shaft > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0277899 A1 - Document ID: US20210277899A1 - Status: Published application - Kind: A1 - Application number: 16/810,819 - Filed: 2020-03-05 - Published: 2021-09-09 - Earliest claimed: 2020-03-05 - Assignees: Elivac Inc.; Raymond Zhou Shaw - Inventors: Raymond Zhou Shaw - Web page: https://patentgrep.com/patent/US20210277899A1 ## CPC - F04C 18/126: {with radially from the rotor body extending elements, not necessarily co-operating with corresponding recesses in the other rotor, e.g. lobes, Roots type} - F04C 23/001: {of similar working principle} - F04C 25/02: for producing high vacuum (sealing arrangements F04C27/00; silencing F04C29/06) - F04C 29/005: {Means for transmitting movement from the prime mover to driven parts of the pump, e.g. clutches, couplings, transmissions} - F04C 2240/60: Shafts - F04C 2240/70: Use of multiplicity of similar components; Modular construction - F04C 2240/806: Pipes for fluids; Fittings therefor - F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS ## Abstract A multistage pump assembly with at least one co-used shaft comprises a first pump set including at least two vacuum chambers. Each vacuum chamber of the first pump set is installed with at least one rotor and a first driving shaft, the rotor is installed to the first driving shaft in the same vacuum chamber of the first pump set. The first driving shafts in the first pump set are co-shafted, that is, rotors in the at least two vacuum chambers of the first pump set are installed at the same first driving shaft. A second pump set includes at least one vacuum chamber which includes at least one rotor and a second driving shaft. An outlet of the second pump set is connected to an inlet of the first pump set through an air tube. ## Claims ### Claim 1 A multistage pump assembly with at least one co-used shaft comprising: a first pump set including at least two vacuum chambers, each vacuum chamber of the first pump set being installed with at least one rotor and a first driving shaft, the rotor being installed to the first driving shaft in the same vacuum chamber of the first pump set; the first driving shafts in all the vacuum chamber of the first pump set are co-shafted, that is, rotors in the at least two vacuum chambers of the first pump set are installed at the same first driving shaft; a second pump set including at least one vacuum chamber which includes at least one rotor and a second driving shaft; and wherein an outlet of the second pump set is connected to an inlet of the first pump set through an air tube. ### Claim 2 (depends on 1) The multistage pump assembly with at least one co-used shaft as claimed in claim 1, wherein the second pump set includes at least two vacuum chambers, each vacuum chamber of the second pump set being installed with at least one rotor and a second driving shaft, the rotor of the second pump set being installed to the second driving shaft in the same vacuum chamber of the second pump set; the second driving shafts in all the vacuum chambers of the second pump set are co-shafted, that is, rotors in the at least two vacuum chambers of the second pump set are installed at the same second driving shaft. ### Claim 3 (depends on 1) The multistage pump assembly with at least one co-used shaft as claimed in claim 1, wherein the first driving shafts of the first pump set are formed by a first separated driving shaft and a second separated driving shaft which are connected by a connector and are separated with a distance so as to prevent expansion from heating; and the first separated driving shaft is installed to a first vacuum chamber of the at least two vacuum chambers in the first pump set; and the second separated driving shaft is installed to a second vacuum chamber of at least two of the at least one vacuum chambers in the first pump set. ### Claim 4 (depends on 3) The multistage pump assembly with at least one co-used shaft as claimed in claim 3, wherein the first driving shafts of the first pump set further comprising a third separated driving shaft which is connected to one end of the second separated driving shaft, and the end is far away from another end of the second separated driving shaft which is connected to the first separated driving shaft; the second separated driving shaft and the third separated driving shaft are connected through another connector. ### Claim 5 (depends on 4) The multistage pump assembly with at least one co-used shaft as claimed in claim 4, wherein the third separated driving shaft is connected to a spindle of a driving motor. ### Claim 6 (depends on 3) The multistage pump assembly with at least one co-used shaft as claimed in claim 3, wherein the first vacuum chamber further includes a first driven shaft which is connected with a first gear; and the first separated driving shaft is connected to a second gear; the first gear is engaged with the second gear. ### Claim 7 (depends on 3) The multistage pump assembly with at least one co-used shaft as claimed in claim 3, wherein the second vacuum chamber further includes a second driven shaft which is connected with a third gear; and the second separated driving shaft is connected to a fourth gear; the third gear is engaged with the fourth gear. ### Claim 8 (depends on 1) The multistage pump assembly with at least one co-used shaft as claimed in claim 1, wherein the driving shafts in all the vacuum chambers of the same pump set are coaxial. ### Claim 9 (depends on 1) The multistage pump assembly with at least one co-used shaft as claimed in claim 1, wherein each of the first and second pump set is selected from one of a multistage root pump set, screw rod form vacuum pump set and multistage claw form vacuum pump set. ### Claim 10 (depends on 1) The multistage pump assembly with at least one co-used shaft as claimed in claim 1, wherein not the driving shafts in all the vacuum chambers of the same pump set are co-shafted, but the driving shafts in some of the vacuum chambers of the same pump set are coaxial.