HOUSING FOR A VACUUM PUMP

Abstract

Housing for a vacuum pump, in particular a NEG or IGP-NEG combination, comprising a body defining an interior space to accommodate the vacuum pump, wherein a first flange is connected to the housing comprising an opening to connect the vacuum pump to a vessel and a second flange connected to the housing to connect the housing to an additional vacuum pump at least during regeneration. Further, a movable shield element is used movable from a first position to a second position, wherein in the first position the opening of the first flange is unobstructed and in the second position the opening is blocked.

Claims

1. A housing for a vacuum pump, in particular a NEG or IGP-NEG combination, comprising: a body defining an interior space to accommodate the vacuum pump, a first flange connected to the body and comprising an opening to connect the vacuum pump to a vessel, and a second flange connected to the body to connect the housing to an additional vacuum pump at least during regeneration, characterized by a movable shielding element disposed inside the interior space of the body and movable from a first position to a second position wherein in the first position the opening of the first flange is unobstructed and in the second position the opening is blocked without completely sealing the interior space from the vessel.

2. The housing according to claim 1, characterized in that no vacuum valve is arranged at the first flange.

3. The housing according to claim 1, characterized in that the shielding element comprises a magnetic element connected with a magnetic handle outside the body to transfer the movement of the magnetic handle to the shielding element.

4. The housing according to claim 1, characterized in that the shielding element is a sheet metal element.

5. The housing according to claim 1, characterized in the shielding element comprises no sealing.

6. A vacuum pump comprising a NEG element and/or an IGP element and a housing in accordance with claim 1.

7. A vacuum system comprising a vacuum pump according to claim 6 and a vacuum vessel directly connected to the vacuum pump.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is perspective view of a housing in accordance with one embodiment.

DETAILED DESCRIPTION

[0017] FIG. 1 shows the housing according to the present invention comprising a body 10 defining an interior space 12, wherein in the interior space 12 the vacuum pump is disposed (not shown). Further, first flange 14 is connected to the body 10, wherein to the first flange 14 a vacuum chamber or vessel can be connected. Further, the body comprises a second flange 16 connected to the housing, wherein to the second flange 16 another vacuum pump can be connected as backing pump or as vacuum pump to pump the gas particles and molecules which are set free during the regeneration process of the vacuum pump inside the housing. Preferably, the vacuum pump inside the housing is an IGP or NEG.

[0018] Further, the housing comprises a shielding element 18 which is movable from a first position as shown in the figure to a second position in front of an opening 20 of the first flange 14. Therein, the shielding element 18 is guided by guiding tracks 22. If the shielding element 18 is in the second position in front of the opening 20 of the first flange 14, the direct way between the vessel connected to the first flange 14 and the interior space 12 of the housing is obstructed. During the regeneration of the vacuum pump inside the housing, gas particles or molecules set free from the vacuum pump are more likely leaving the interior space 12 through an opening 24 of the second flange 16 than through the opening 20 of the first flange 14. If the opening 20 of the first flange 14 is obstructed by the shielding element 18, the shielding element 18 reduces the conductance between the interior space 12 and the vessel connected to the first flange 14. Flow of the gas particles and molecules inside the housing of the vacuum pump, the flanges 14, 16 and the vessel is in the molecular flow regime. Thus, the shielding element 18 is not necessarily completely sealing the interior space 12 from the housing to the vacuum vessel. Instead, the shielding element just reduces the conductance between the interior space 12 and the vessel reasonably that it is more likely that the gas particles and molecules leave the interior space 12 through the opening 24 of the second flange 16 than returning to the vessel connected to the first flange 14 contaminating the vacuum inside. Therefore, the shielding element, built as shield metal element, neither comprises a sealing nor requires a gap-free design to provide a leak tight configuration.

[0019] The shielding 18 is connected to a magnetic element 26 disposed within the interior space 12 of the housing. The magnetic element 26 is connected to a magnetic handle 28 outside the housing and connected to the magnetic element 26 by a magnetic force such that movement of the magnetic handle 28 is transferred to the magnetic element 26 and thereby to the shielding element 18. Thus, by moving the magnetic handle 28 outside the housing, the shielding element 18 can be moved from the first position to the second position. No mechanical feedthrough is necessary in order to move the shielding element 18. In particular, the body of the housing is made from a non-magnetic material to allow magnetic coupling of the magnetic handle 28 to the magnetic element 26.

[0020] By the present design of the housing, the vacuum pump inside the interior space 12 of the housing can be placed in close proximity to the vacuum vessel connected to the first flange 14. No additional valve needs to be placed between the first flange 14 and the vacuum vessel in order to separate the interior space 12 from the vacuum vessel to avoid contamination of the vacuum inside the vacuum vessel during regeneration of the vacuum pump. Thereby, the conductance is enhanced, enhancing the pump performance of the vacuum pump inside the housing.

[0021] Although elements have been shown or described as separate embodiments above, portions of each embodiment may be combined with all or part of other embodiments described above.

[0022] Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are described as example forms of implementing the claims.