Current leadthrough for a vacuum pump

Abstract

The vacuum pump comprises a casing ( 10 ) closed by a vacuum cover ( 20 ). Between an end wall ( 14 ) of the casing ( 10 ) and the vacuum cover ( 20 ), a circuit board ( 16 ) is arranged for current feedthrough. The circuit board ( 16 ) is sealed by two sealing elements ( 15, 21 ) of different diameters so that an annular partial region ( 22 ) is on its outer side subjected to the atmospheric pressure and is on its inner side subjected to the vacuum. It is avoided that the circuit board ( 16 ) laterally projects beyond the contour of the casing ( 10 ).

1 . A vacuum pump comprising a vacuum-tight casing, said casing accommodating a motor and a pump rotor and being provided with a pump inlet and a pump outlet, said pump further comprising a current feedthrough, said current feedthrough including a circuit board, an inner side of said circuit board being arranged in abutment on an end face of the wall of the casing with interposition of a first sealing means, and an outer side of said circuit board being arranged in abutment on a vacuum cover of the casing with interposition of a second sealing means, wherein said first and second sealing means are arranged with a lateral displacement relative to each other so that a partial region of the circuit board is on its outer side subjected to atmospheric pressure and is on its inner side subjected to a generated vacuum. 
     
     
         2 . The vacuum pump according to  claim 1 , further including external electric conductors extending from said partial region and connected to traces of the circuit board. 
     
     
         3 . The vacuum pump according to  claim 2 , wherein said external conductors are connected to a plug device fastened to the casing. 
     
     
         4 . The vacuum pump according to  claim 1 , wherein the vacuum cover is arranged in a protective cover and is movable relative thereto. 
     
     
         5 . The vacuum pump according to  claim 4 , wherein the protective cover is provided with a positioning means for positioning the vacuum cover. 
     
     
         6 . The vacuum pump according to  claim 1 , wherein the circuit board is formed with an opening for pressure compensation. 
     
     
         7 . The vacuum pump according to according to  claim 1 , wherein the circuit board carries electrical components on its inner side and/or its outer side. 
     
     
         8 . The vacuum pump according to  claim 1 , wherein the circuit board is provided with pump detection electronics. 
     
     
         9 . The vacuum pump according to  claim 1 , wherein the first and second sealing means are annular sealing elements with different opening diameters. 
     
     
         10 . The vacuum pump according to  claim 3 , wherein the plug device is mounted to a protective cover of the casing. 
     
     
         11 . The vacuum pump according to  claim 3 , wherein the first and second sealing means are first and second O-rings, the first O-ring being larger in diameter than the second O-ring. 
     
     
         12 . The vacuum pump according to  claim 5 , wherein the positioning means includes a shoulder of the protective cover. 
     
     
         13 . A vacuum pump comprising:
 a vacuum-tight casing, the casing holding a motor and a pump rotor and defining a pump inlet and a pump outlet;   a circuit board, an inner side of said circuit board being arranged in abutment on an end face of the casing, and an outer side of said circuit board facing away from the end face of the casing:   a vacuum cover covering a portion of the outer side of the circuit board and defining a hollow space therebetween;   a first annular sealing element disposed between the casing end face and the circuit based inner side;   a second annular sealing element being disposed between the circuit board outer face and the vacuum cover, the second annular sealing element being smaller than the first annular sealing element.   
     
     
         14 . The vacuum pump according to  claim 13 , wherein an opening is defined in the circuit board such that a pressure in the casing and a pressure in the hollow space between the vacuum cover and the circuit board outer side is balanced, such that a region of the circuit board outer side inside the second annular sealing element is subject to the pressure in the casing and a region of the circuit board outside of the second annular sealing element is subject to atmospheric pressure. 
     
     
         15 . The vacuum pump according to  claim 14 , wherein the pressure in the casing is a vacuum.