US 12,258,963 B2
Scroll pump with fluid recirculation valve
Alan Ernest Kinnaird Holbrook, Burgess Hill (GB); David Bedwell, Burgess Hill (GB); and Nigel Paul Schofield, Burgess Hill (GB)
Assigned to Edwards Limited
Appl. No. 18/251,484
Filed by Edwards Limited, Burgess Hill (GB)
PCT Filed Oct. 28, 2021, PCT No. PCT/GB2021/052799
§ 371(c)(1), (2) Date May 2, 2023,
PCT Pub. No. WO2022/096859, PCT Pub. Date May 12, 2022.
Claims priority of application No. 2017511 (GB), filed on Nov. 5, 2020.
Prior Publication US 2024/0018960 A1, Jan. 18, 2024
Int. Cl. F04C 18/02 (2006.01); F04C 27/00 (2006.01); F04C 28/24 (2006.01); F04C 29/00 (2006.01); F04C 29/12 (2006.01)
CPC F04C 18/0215 (2013.01) [F04C 18/0292 (2013.01); F04C 27/005 (2013.01); F04C 28/24 (2013.01); F04C 29/0021 (2013.01); F04C 29/12 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A scroll pump, comprising:
an inlet and an outlet;
a fixed scroll and an orbiting scroll intermeshed with each other, wherein the fixed scroll and orbiting scroll define a space therebetween for pumping fluid through the scroll pump from the inlet to the outlet,
a biasing apparatus configured to bias the orbiting scroll against the fixed scroll;
a fluid recirculation channel separate to the biasing apparatus, wherein the fluid recirculation channel extends from the space to the inlet through either the fixed scroll or the orbiting scroll; and
a fluid recirculation valve disposed in the fluid recirculation channel, wherein:
when in an open state, the fluid recirculation valve is configured to permit flow of fluid from the space to the inlet through the fluid recirculation channel,
when in a closed state, the fluid recirculation valve is configured to block flow of fluid through the fluid recirculation channel, and
the fluid recirculation valve is configured to switch from the closed state to the open state whenever a pressure differential across the fluid recirculation valve is equal to or exceeds a certain threshold value;
wherein the scroll pump comprises a drive shaft configured to drive rotation of the orbiting scroll, wherein the biasing apparatus is configured to exert a force directly on a bearing coupling the orbiting scroll to the drive shaft.