# US 6,305,910 B1 · Multi-stage pump device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,305,910 B1 - Document ID: US6305910B1 - Status: Granted - Kind: B1 - Application number: 09/538,504 - Filed: 2000-03-30 - Granted: 2001-10-23 - Earliest claimed: 1999-03-30 - Assignees: Aisin Seiki Kabushiki Kaisha - Inventors: Atsuyuki Miura; Yoshihiro Naito; Noboru Ohtani; Koichi Nakayama - Web page: https://patentgrep.com/patent/US6305910B1 ## CPC - F01C 21/007: {General arrangements of parts; Frames and supporting elements} - F04C 23/001: {of similar working principle} - F05C 2251/042: Expansivity - F01C: ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES (internal-combustion aspects F02B53/00, F02B55/00) - F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS - F05C: INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES ## Abstract A multi-stage pump device includes a plurality of pump devices, each of the pump devices having a pump portion feeding working fluid under pressure, and a connecting portion provided between at least two of the pump devices, through which working fluid pumped by the respective pump devices passes. The connecting portion is expandable in a direction of the length thereof and is provided with a sealing structure to prevent a leakage of the working fluid. The connecting portion may be two telescopically arranged pipes or a bellows. ## Claims ### Claim 1 A multi-stage pump device comprising; a plurality of pump devices, each of the pump devices having a pump portion feeding working fluid under pressure; and a connecting portion provided between at least two of the pump devices, through which working fluid pumped by the respective pump devices passes, wherein the connecting portion is expandable in a direction of the length thereof, and wherein the connecting portion is provided with a sealing structure to prevent a leakage of the working fluid. ### Claim 2 (depends on 1) The multi-stage pump device of claim 1, wherein said connecting portion comprises two telescopically arranged pipes. ### Claim 3 (depends on 1) The multi-stage pump device of claim 1, wherein said sealing structure is an O-ring arranged between said pipes. ### Claim 4 A multi-stage pump device comprising; a plurality of pump devices, each of the pump devices having a pump portion feeding working fluid under pressure; and a bellows provided between at least two of the pump devices, through which working fluid pumped by the respective pump devices passes. ### Claim 5 A multi-stage pump device comprising: at least two pump units; and working fluid guide means for establishing a fluid flow connection between said pump units, wherein said guide means is capable of being deformed relative to each pump unit. ### Claim 6 (depends on 5) A multi-stage pump device as set forth in claim 5, wherein the guide means includes a pair of telescopic pipes which are extended from the pump units, respectively, and a seal member provided between the pipes. ### Claim 7 (depends on 5) A multi-stage pump device as set forth in claim 5, wherein the guide means comprises a bellows. ### Claim 8 (depends on 7) A multi-stage pump device as set forth in claim 7, wherein the bellows is made of rubber. ### Claim 9 A multi-stage pump device comprising; a plurality of pump devices, each of the pump devices having a pump portion feeding working fluid under pressure and a driving portion which is tightly connected with a supporting frame; and a connecting portion provided between at least two of the pump devices, through which working fluid pumped by the respective pump devices passes, wherein the connecting portion is expandable in a direction of the length thereof, and wherein the connecting portion is provided with a sealing structure to prevent a leakage of the working fluid. ### Claim 10 (depends on 9) The multi-stage pump device of claim 9, wherein said connecting portion comprises two telescopically arranged pipes. ### Claim 11 (depends on 9) The multi-stage pump device of claim 9, wherein said sealing structure is an O-ring arranged between said pipes. ### Claim 12 A multi-stage pump device comprising; a plurality of pump devices, each of the pump devices having a pump portion feeding working fluid under pressure and a driving portion which is tightly connected with a supporting frame; and a bellows provided between at least two of the pump devices, through which working fluid pumped by the respective pump devices passes. ### Claim 13 A multi-stage pump device comprising: at least two pump units; working fluid guide means for establishing a fluid flow connection between said pump units, wherein said guide means is capable of being deformed relative to each pump unit; at least two driving units; and each driving unit is tightly connected with a supporting frame. ### Claim 14 (depends on 13) A multi-stage pump device as set forth in claim 13, wherein the guide means includes a pair of telescopic pipes which are extended from the pump units, respectively, and a seal member provided between the pipes. ### Claim 15 (depends on 13) A multi-stage pump device as set forth in claim 13, wherein the guide means comprises a bellows. ### Claim 16 (depends on 15) A multi-stage pump device as set forth in claim 15, wherein the bellows is made of rubber.