# US 2015/0176584 A1 · Scroll pump > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0176584 A1 - Document ID: US20150176584A1 - Status: Published application - Kind: A1 - Application number: 14/411,701 - Filed: 2013-06-10 - Published: 2015-06-25 - Earliest claimed: 2012-07-06 - Assignees: Edwards Limited - Applicants: Edwards Limited - Inventors: Nigel Paul Schofield - Web page: https://patentgrep.com/patent/US20150176584A1 ## CPC - F04C 27/005: {Axial sealings for working fluid} - F01C 19/08: Axially-movable sealings for working fluids - F04C 18/0215: {where only one member is moving} - F04C 27/008: {for other than working fluid, i.e. the sealing arrangements are not between working chambers of the machine} - F04C 2240/807: Balance weight, counterweight - F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS - F01C: ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES (internal-combustion aspects F02B53/00, F02B55/00) ## Abstract The present invention provides a scroll pump comprising: a scroll mechanism having an orbiting scroll and a fixed scroll; a drive shaft having a concentric shaft portion and an eccentric shaft portion connected to the orbiting scroll. The shaft is arranged to be driven by a motor so that rotation of the shaft imparts an orbiting motion to the orbiting scroll relative to the fixed scroll for pumping fluid along a flow path from an inlet to an outlet of the scroll mechanism. An axial lip seal is located between the orbiting scroll and the fixed scroll for resisting leakage of fluid from outside the scroll mechanism into the flow path. ## Claims ### Claim 1 A scroll pump comprising: a scroll mechanism comprising an orbiting scroll and a fixed scroll; and a drive shaft comprising a concentric shaft portion and an eccentric shaft portion connected to the orbiting scroll, the drive shaft being arranged to be driven by a motor so that rotation of the drive shaft imparts an orbiting motion to the orbiting scroll relative to the fixed scroll for pumping fluid along a flow path from an inlet to an outlet of the scroll mechanism, wherein an axial lip seal is located between the orbiting scroll and the fixed scroll for resisting leakage of fluid from outside the scroll mechanism into the flow path. ### Claim 2 (depends on 1) The scroll pump of claim 1, wherein the axial lip seal is fixed relative to one of the orbiting scroll or the fixed scroll and seals against the other of the orbiting scroll or the fixed scroll so that an orbiting motion is imparted to the lip seal relative to the other scroll. ### Claim 3 (depends on 1) The scroll pump of claim 1, wherein the axial lip seal extends across an axial gap between the orbiting scroll and the fixed scroll. ### Claim 4 (depends on 1) The scroll pump of claim 1, wherein the inlet of the scroll mechanism is located at a radially outer portion of the scroll mechanism and the outlet of the scroll mechanism is located at a radially inner portion of the scroll mechanism, and wherein the axial lip seal is located radially inward from the outlet. ### Claim 5 (depends on 1) The scroll pump of claim 1, wherein the axial lip seal is annular and extends around the axis of the drive shaft. ### Claim 6 (depends on 1) The scroll pump of claim 1, wherein the drive shaft extends through respective openings in the fixed scroll and the orbiting scroll and is fixed to the orbiting scroll on an opposite side of the fixed scroll to the motor, and wherein, during use, the openings are at or close to atmosphere and the axial lip seal resists leakage of gas from the openings into the flow path. ### Claim 7 (depends on 6) The scroll pump of claim 6, wherein a lubricated bearing arrangement is located between at least one of: (1) the fixed scroll and the concentric shaft portion, (2) the fixed scroll and the orbiting scroll, or (3) the eccentric shaft portion and the orbiting scroll, and wherein the axial lip seal resists the leakage of lubricant from the bearing arrangement into the flow path. ### Claim 8 (depends on 6) The scroll pump of claim 6, wherein gas pressure in the openings acting on the axial lip seal causes an increased sealing force to be generated by the lip seal. ### Claim 9 (depends on 2) The scroll pump of claim 2, wherein the axial lip seal extends across an axial gap between the orbiting scroll and the fixed scroll. ### Claim 10 (depends on 2) The scroll pump of claim 2, wherein the inlet of the scroll mechanism is located at a radially outer portion of the scroll mechanism and the outlet of the scroll mechanism is located at a radially inner portion of the scroll mechanism, and wherein the axial lip seal is located radially inward from the outlet. ### Claim 11 (depends on 3) The scroll pump of claim 3, wherein the inlet of the scroll mechanism is located at a radially outer portion of the scroll mechanism and the outlet of the scroll mechanism is located at a radially inner portion of the scroll mechanism, and wherein the axial lip seal is located radially inward from the outlet. ### Claim 12 (depends on 9) The scroll pump of claim 9, wherein the inlet of the scroll mechanism is located at a radially outer portion of the scroll mechanism and the outlet of the scroll mechanism is located at a radially inner portion of the scroll mechanism, and wherein the axial lip seal is located radially inward from the outlet. ### Claim 13 (depends on 2) The scroll pump of claim 2, wherein the axial lip seal is annular and extends around the axis of the shaft. ### Claim 14 (depends on 3) The scroll pump of claim 3, wherein the axial lip seal is annular and extends around the axis of the shaft. ### Claim 15 (depends on 4) The scroll pump of claim 4, wherein the axial lip seal is annular and extends around the axis of the shaft. ### Claim 16 (depends on 9) The scroll pump of claim 9, wherein the axial lip seal is annular and extends around the axis of the shaft. ### Claim 17 (depends on 2) The scroll pump of claim 2, wherein the drive shaft extends through respective openings in the fixed scroll and the orbiting scroll and is fixed to the orbiting scroll on an opposite side of the fixed scroll to the motor, and wherein, during use, the openings are at or close to atmosphere and the axial lip seal resists leakage of gas from the openings into the flow path. ### Claim 18 (depends on 3) The scroll pump of claim 3, wherein the drive shaft extends through respective openings in the fixed scroll and the orbiting scroll and is fixed to the orbiting scroll on an opposite side of the fixed scroll to the motor, and wherein, during use, the openings are at or close to atmosphere and the axial lip seal resists leakage of gas from the openings into the flow path. ### Claim 19 (depends on 4) The scroll pump of claim 4, wherein the drive shaft extends through respective openings in the fixed scroll and the orbiting scroll and is fixed to the orbiting scroll on an opposite side of the fixed scroll to the motor, and wherein, during use, the openings are at or close to atmosphere and the axial lip seal resists leakage of gas from the openings into the flow path. ### Claim 20 (depends on 5) The scroll pump of claim 5, wherein the drive shaft extends through respective openings in the fixed scroll and the orbiting scroll and is fixed to the orbiting scroll on an opposite side of the fixed scroll to the motor, and wherein, during use, the openings are at or close to atmosphere and the axial lip seal resists leakage of gas from the openings into the flow path. ### Claim 21 (depends on 9) The scroll pump of claim 9, wherein the drive shaft extends through respective openings in the fixed scroll and the orbiting scroll and is fixed to the orbiting scroll on an opposite side of the fixed scroll to the motor, and wherein, during use, the openings are at or close to atmosphere and the axial lip seal resists leakage of gas from the openings into the flow path.