Patent ID: 8327820

Claim:
A pressure-operated engine having an annular structure, which comprises a driven shaft ( 2 ) extending along the annular axis; an annular housing ( 11 , 13 ) including a housing wall and at least one rotating piston ( 4 ) rotating in said annular housing along a circular path, sealed against said housing, said at least one rotating piston ( 4 ) being connected to said driven shaft through a connecting link in a rotationally fixed manner and delimiting in said annular housing a co-rotating ring-segment-like pressure chamber ( 20 ) at least on the side located in the direction of rotation as seen from said pressure chamber; connections to a pressure-medium supply ( 21 ) and to an exhaust system ( 24 ), which are formed in predetermined positions of said annular housing, characterized in that said rotating piston ( 4 ) comprises a piston housing ( 29 ) and, in said piston housing, an internal piston ( 31 ) which is pressed towards said pressure chamber ( 20 ) by a pre-stressing force ( 36 , 37 ), which also supports oneself on said piston housing, said internal piston ( 31 ) being linearly displaceable against said pre-stressing force in relation to said piston housing in a longitudinal direction of said piston, the line of displacement of said internal piston ( 31 ) tangentially passing the axis of said driven shaft ( 2 ) at a distance; wherein said internal piston ( 31 ) loaded by said pre-stressing force ( 36 , 37 ) is subjected to an attenuation of movement, with respect to said piston housing ( 29 ), for its forward stroke and for its return stroke effected by said pre-stressing force; wherein said pre-stressing force is applied by at least one compression spring ( 36 , 37 ) and said attenuation of movement is effected by a throttled displacement (in 57 ) of a flow medium in said piston housing ( 29 ); and wherein said internal piston ( 31 ) consists of two coaxial piston elements ( 33 , 34 ) which are fitted, at a distance from each other, to a common piston rod ( 35 ) extending along the piston-displacement line, the first, with respect to the rotation of said driven shaft, outer piston element ( 33 ) of said two coaxial piston elements ( 33 , 34 ) being adjacent to said pressure chamber ( 20 ), and said internal piston ( 31 ) penetrates with its piston rod volumes ( 55 , 56 ) filled with flow media, which are connected to each other by at least one connecting channel ( 57 ) having a reduced flow-through cross-sectional area, during the movement of said internal piston against said pre-stressing force ( 36 , 37 ) said first, outer piston element ( 33 ) penetrating into said first volume ( 55 ) and displacing the flow medium out of it and said second, with respect to the rotation of said driven shaft, inner piston element ( 34 ) withdrawing from said second volume ( 56 ) and vacating flow-medium space.