SCROLL PUMP WITH AXIAL LOAD CONTROL SYSTEM
A scroll pump includes a first scroll member and a second scroll member. An electromagnet is fixedly connected to one of the first scroll member and a second scroll member, and a magnetic target is fixedly connected to the other of the first scroll member and the second scroll member. The electromagnet is operable to generate a magnetic field between the electromagnet and the magnetic target, thereby establishing an axially-directed magnetic biasing force between the first scroll member and the second scroll member.
1 . A scroll pump comprising:
a first scroll member, the first scroll member comprising:
a first end plate; and
a first scroll extending in an axial direction from the first end plate to a first scroll tip;
a second scroll member, the second scroll member comprising:
a second end plate; and
a second scroll extending in the axial direction from the second end plate to a second scroll tip, wherein the second scroll is intermeshed with the first scroll, wherein the first scroll member and the second scroll member define a working volume therebetween, and wherein the second scroll is movable in the axial direction with the respect to the first scroll; and
an electromagnet fixedly connected to the fixed scroll member, wherein the electromagnet is operable to selectively bias the second scroll member axially with respect to the first scroll member.
2 . The scroll pump of claim 1 wherein the electromagnet comprises a coil.
3 . The scroll pump of claim 2 wherein the electromagnet further comprises a ferromagnetic core.
4 . The scroll pump of any preceding claim further comprising a magnetic target fixed to the other of the first scroll member and the second scroll member.
5 . The scroll pump of claim 4 wherein the magnetic target comprises a ferrous target made of ferromagnetic material.
6 . The scroll pump of claim 4 wherein the magnetic target comprises a permanent magnet.
7 . The scroll pump of any preceding claim further comprising a spring associated with the first scroll member and the second scroll member and operable to bias the second scroll member toward the first scroll member.
8 . The scroll pump of any of any preceding claim further comprising a controller operable to selectively energize and de-energize the coil and thereby selectively cause the electromagnet to bias the second scroll member axially with respect to the first scroll member.
9 . The scroll pump of claim 8 wherein the controller is operable to selectively cause the electromagnet to bias the second scroll member away from the first scroll member.
10 . The scroll pump of claim 8 wherein the controller is operable to selectively cause the electromagnet to bias the second scroll member toward the first scroll member.
11 . The scroll pump of claim 8 wherein the controller is operable to selectively cause the electromagnet to bias the second scroll member toward the first scroll member to mitigate leakage of a working fluid between the first scroll and the second scroll.
12 . The scroll pump of claim 8 wherein the controller is operable to selectively cause the electromagnet to bias the second scroll member away from the first scroll member to induce leakage of a working fluid between the first scroll and the second scroll.