Bellows leakage tester and methods for testing bellows
View Patent ↗Various aspects of the present invention provide a testing apparatus and methods for testing a bellows of a sputter machine for air leakage. One such testing apparatus is configured to simulate conditions of the sputter machine and thereby test a bellows for air leakage in both a compressed and an uncompressed configuration. Accordingly, a bellows can be ensured to be in satisfactory working condition before it is installed in the gate valve assembly and also tested for air leakage after removal from the gate valve assembly.
1. An apparatus for testing air leakage of a bellows, comprising:
a bellows comprising:
a first opening and a second opening, wherein the first opening and second opening are positioned at opposite ends of the bellows;
a first O-ring seal proximate the first opening; and
a second O-ring seal proximate the second opening;
a shaft configured to receive the bellows in an axial direction of the shaft, the shaft configured to pass through the first and second openings of the bellows, and the shaft having a portion configured to engage the first O-ring seal;
a base having an opening on a first side for receiving an end portion of the shaft in the axial direction, the first side configured to engage the second O-ring seal, such that an airtight space is formed inside the bellows between the first O-ring seal and the second O-ring seal;
an air leakage detector; and
an air conduit extending through the base and configured to form an airtight connection between the airtight space and the air leakage detector,
wherein the apparatus is configured to retain the bellows in either of an uncompressed position and a compressed position, and
wherein the air leakage detector is configured to apply a vacuum pressure to the airtight space via the air conduit and thereby test the bellows for air leakage.
2. The apparatus of claim 1 , wherein the shaft and the base are configured to change a volume of the airtight space by moving the shaft in the axial direction.
3. The apparatus of claim 1 , further comprising:
a compression plate configured to engage the bellows such that the compression plate and the first side of the base are respectively in contact with the opposite ends of the bellows,
wherein the compression plate and the first side of the base are configured to retain the bellows in the compressed position by applying compressive forces to the bellows in the axial direction.
4. The apparatus of claim 3 , further comprising side plates extending from the base to the compression plate, wherein the compression plate is removably coupled with the side plates.
5. The apparatus of claim 4 , further comprising a fastener for removably securing the compression plate with one of the side plates.
6. The apparatus of claim 1 , further comprising a retaining shaft configured to retain the shaft in a selected axial position and be inserted through a hole of the base,
wherein the shaft has at least two openings for receiving a portion of the retaining shaft such that the shaft is selectably fixed at a first position or a second position in the axial direction.
7. The apparatus of claim 1 , further comprising a bellows cover configured to enclose in conjunction with the first side of the base a pitch area of the bellows, the bellows cover configured to act as an airtight barrier for the pitch area.
8. The apparatus of claim 7 , wherein the bellows cover, the bellows, and the shaft are concentrically arranged with the shaft at substantially the center of the bellows.