Rotary piston machine

Abstract

The rotary piston machine has a bypass channel, which is formed through two openings ( 15, 16 ) provided in a sidewall ( 6 ) of its delivery housing ( 4 ) and a channel ( 17 ) extending into this sidewall ( 6 ) in such a way that the bypass channel ( 17 ) is restricted on one side by a wall area of the sidewall ( 6 ) and on the opposite side by a channel cover ( 19 ) embedded in this sidewall ( 6 ). The housing ( 25 ) of a pressure relief valve ( 14 ) is formed cup-shaped in the channel cover ( 19 ) in whose cylindrical inner surface ( 27 ) a closing member ( 2 ) is operated piston-like. The machine which is designed from few individual parts is suitable especially for the space-saving and direct coupling in the engine space of a motor vehicle, in which its pressure relief valve ( 14 ) provided in the bypass channel overcomes the disadvantages of the rotational speed-dependent pressure difference between suction and pressure sides.

1 . Rotary piston machine with a delivery housing ( 4 ) enclosing at least two rotary pistons ( 2 ,  3 ), restricted by two side walls ( 5 ,  6 ) parallel to each other, to which at least one inflow channel and at least one outflow channel ( 12 ,  13 ) is provided, in which the rotary pistons ( 2 ,  3 ) are fixed on a shaft supported in the sidewalls ( 5 ,  6 ) of the delivery housing ( 4 ) and by a shaft passing to the outside through one of these sidewalls ( 6 ) ( 20 ,  21 ) and in which a pressure side of the delivery housing ( 4 ) is connected to a suction side of the same through a bypass channel ( 17 ), which runs along one of these side walls ( 6 ) and has a pressure-relief valve ( 14 ) characterized in that one sidewall ( 6 ) containing the bypass channel ( 17 ) acts as intermediate wall between the delivery housing ( 4 ) and a gearbox housing ( 11 ) containing the means ( 23 , 24 ) for the control of the rotary piston motion. 
   
   
       2 . Machine according to  claim 1 , characterized in that an area of the channel cover ( 19 ) of the bypass channel ( 17 ) is formed as valve housing ( 25 ) of a pressure relief valve ( 14 ). 
   
   
       3 . Machine according to  claim 2 , characterized in that the cup-shaped valve housing ( 25 ) telescopically encloses a closing member ( 26 ) made as hollow piston so that the housing inner wall forms a cylindrical surface ( 27 ) for this, in which a valve spring ( 28 ) which determines the closing pressure is enclosed between the two. 
   
   
       4 . Machine according to  claim 1 , characterized in that two rotary pistons ( 2 ,  3 ) arranged externally axially to each other are enclosed in the delivery housing ( 4 ) and their drive shafts ( 20 ,  21 ) extending through the intermediate wall ( 6 ) are connected to the gear wheels ( 23 ,  24 ) enclosed in the gearbox housing ( 11 ) meshing with each other so that these gears ( 23 , 24 ) form the means for the control of the rotary piston motion, in which the part of the bypass channel ( 17 ) provided on the intermediate wall ( 6 ) extends at right angles to a line ( 22 ) connecting the drive shafts ( 20 , 21 ) and the valve housing ( 25 ) extends into the gearbox housing ( 11 ) at the side beside the gear pair ( 23 , 24 ). 
   
   
       5 . Machine according to  claim 1 , characterized in that several rotary pistons ( 2 , 3 ) are enclosed in the delivery housing ( 4 ) and are controlled by gears ( 23 ,  24 ) enclosed in the gearbox housing ( 11 ) meshing with each other, which form the means for the control of the rotary piston motion, in which the shafts ( 20 ,  21 ) carrying a rotary piston ( 2 , 3 ) and a gear ( 23 , 24 ) are made hollow respectively. 
   
   
       6 . Machine according to  claim 5 , characterized in that one of the gears ( 23 ,  24 ) meshing with each other is made of steel and the other of a nonferrous metal. 
   
   
       7 . Machine according to  claim 1  characterized in that the bypass channel ( 17 ) is formed through openings ( 15 ,  16 ) provided in one of the sidewalls ( 6 ) of the delivery housing and a channel ( 17 ) passing along the sidewall ( 6 ) in such a way that a part of the bypass channel ( 17 ) is restricted on one side by a wall area of the sidewall ( 6 ) of the delivery housing and on the opposite side by a channel cover ( 19 ).