Vacuum pump

Abstract

The present invention relates to a multi-stage vacuum pump comprising: first and second half-shell stator components and first and second end stator components which when assembled define a plurality of pumping chambers. The half-shell components are assembled together along respective pairs of mutual engaging longitudinal faces and the end stator components are assembled at the ends of the half-shell components at respective pairs of mutual engaging end faces. A longitudinal channel is counter-sunk in at least one longitudinal face of each pair of mutual engaging longitudinal faces for receiving respective longitudinal sealing members for sealing between the half-shell components. Counter-sunk in at least one longitudinal face of each pair of mutual engaging longitudinal faces is a pocket extending transversely from the longitudinal channel for receiving sealant and allowing sealant to flow around a longitudinal sealing member received in the longitudinal channel for preventing the formation of a leakage path.

1 . A multi-stage vacuum pump having a stator comprising:
 (a) first and second half-shell stator components and first and second end stator components which when assembled define a plurality of pumping chambers; and   (b) a longitudinal channel counter-sunk in at least one longitudinal face of each pair of mutual engaging longitudinal faces for receiving respective longitudinal sealing members for sealing between the half-shell components;   wherein the half-shell components being assembled together along respective pairs of mutual engaging longitudinal faces and the end stator components being assembled at the ends of the half-shell components at respective pairs of mutual engaging end faces; and,   wherein counter-sunk in said at least one longitudinal face of each pair of mutual engaging longitudinal faces is a pocket extending transversely from the longitudinal channel for receiving sealant and allowing sealant to flow around a longitudinal sealing member received in the longitudinal channel for preventing the formation of a leakage path.   
     
     
         2 . The multistage vacuum pump of  claim 1 , further comprising shallow recesses counter-sunk at the end portions of the longitudinal faces for receiving a sealant for sealing between the stator components, the depth of the shallow recesses being less than the depth of the longitudinal channels and each pocket extending into a respective said shallow recess from the longitudinal channel. 
     
     
         3 . The multistage vacuum pump of  claim 1 , the pockets have a depth approximately equal to the depth of the longitudinal channels. 
     
     
         4 . The multistage vacuum pump of  claim 1 , wherein pockets extend laterally from both sides of respective longitudinal channels. 
     
     
         5 . The multi-stage vacuum pump of  claim 1 , further comprising an annular channel counter-sunk in at least one end face of each pair of mutual engaging end faces for receiving respective sealing members for sealing between the half-shell components and the end stator components. 
     
     
         6 . The multistage vacuum pump of  claim 5 , wherein the deep pockets are spaced from the annular channels so that the spacing between the half shell stator components at the annular channels is defined by the depth of the shallow recesses for resisting protrusion of annular sealing members received in the annular channels protruding between the half shell stator components. 
     
     
         7 . The multistage vacuum pump of  claim 5 , further comprising supports for supporting the annular sealing members at the recesses when the annular sealing members are received in the annular channels to resist protrusion of the annular sealing members into the recesses when compressed between mutually engaging end faces. 
     
     
         8 . The multistage vacuum pump of  claim 7 , wherein the supports extend across respective recesses transverse to a plane of the longitudinal faces. 
     
     
         9 . The multistage vacuum pump of  claim 7 , wherein the supports are formed by wails extending from the counter sunk surfaces of respective the recesses in alignment with the annular channels. 
     
     
         10 . The multistage vacuum pump of  claim 7 , wherein the annular channels have a channel width for receiving the annular sealing members and the supports have a support width which is less than the channel width to allow sealant in the recesses to contact the annular sealing members. 
     
     
         11 . The multistage vacuum pump of  claim 10 , wherein on both sides of each support a space is provided between the support and the end face so that sealant can flow and directly contact and seal against an annular sealing member in the annular channel on both sides of the support.