LOW PROFILE CRYOPUMP

• US 20130276466A1
• Filed: 04/20/2012
• Published: 10/24/2013
• Est. Priority Date: 04/20/2012
• Status: Active Grant

• Current Assignee: Sumitomo (SHI) Cryogenics of America, Inc. (Sumitomo Heavy Industries Limited)
• Original Assignee: Sumitomo (SHI) Cryogenics of America, Inc. (Sumitomo Heavy Industries Limited)
• Inventors: Longsworth, Ralph
• Granted Patent: US 9,174,144 B2
• Time in Patent Office: Days
• US Class Current: 62/55.5
• CPC Class Codes: B01D 8/00 Cold traps; Cold baffles pumps for evacuating by condensing or freezing F04B37/08

Abstract

Faster cool down time is achieved in a low profile cryopump by having heat transferred directly from the inlet louver to the first stage heat station through one or more tapered thermal busses, and by obviating the need of a thermal shield over the second stage cylinder of the expander by having second stage cryopanels that form a nested tent like structure, at least one of which, extends over the cylinder.

Claims

1. A cryopump cooled by a GM type refrigerator, the cryopump comprising:

a two-stage expander cylinder and an inlet that is in a plane parallel to an axis of the expander cylinder;

a first stage cryopanel assembly attached to a first stage heat station of said expander cylinder, that encloses a second stage cryopanel assembly attached to the second stage of said expander cylinder, said second stage cryopanel assembly comprises plates with flat surfaces one or more of which are folded and extend over at least 90% of the cold end of the second stage cylinder of said expander cylinder.

2. A cryopump in accordance with claim 1, further comprising an inlet louver having flat plates oriented transverse to said expander cylinder.

3. A cryopump in accordance with claim 2, wherein heat is conducted from the inlet louver to said first stage heat station through one or more thermal buses that are tapered over a length where they are attached to the louver.

4. A cryopump in accordance with claim 3, wherein a temperature gradient in a tapered section of said thermal busses is nearly constant.

5. A cryopump in accordance with claim 1, wherein said first stage heat station is proximate the junction in the vacuum housing assembly between the cryopanel housing and the cylinder housing.

6. A cryopump cooled by a GM type refrigerator, the cryopump comprising:

a two-stage expander and an inlet that is in a plane parallel to the axis of the expander cylinder;

a first stage cryopanel assembly attached to the first stage heat station of said expander that encloses

a second stage cryopanel assembly attached to the second stage of said expander,

an inlet louver at the inlet of said first stage cryopanel assembly consisting of flat plates oriented transverse to said expander cylinder in which heat is conducted from said louvers to said first stage heat station through one or more thermal busses that are tapered over the length where they are attached to the inlet louver.

7. A cryopump in accordance with claim 6, wherein said second stage cryopanel assembly comprises plates with flat surfaces one or more of which are folded and extend over at least 90% of the cold end of the second stage cylinder of said expander.

8. A cryopump in accordance with claim 6, wherein the temperature gradient in the tapered section of said thermal busses is nearly constant.

9. A cryopump in accordance with claim 6, wherein said first stage heat station is proximate the junction in the vacuum housing assembly between the cryopanel housing and the cylinder housing.