Piston-cylinder assembly

1. A piston-cylinder assembly ( 1 , 50 ), comprising:

a cylindrical housing ( 3 ),

a main piston ( 2 , 51 ), and

at least one trailing piston ( 11 , 12 , 52 ),

wherein the main piston and the at least one trailing piston are disposed in the cylindrical housing in an axially displaceable manner, the main piston ( 2 , 51 ) dividing a piston chamber ( 7 ) of the cylindrical housing ( 3 ) into two pressure chambers ( 8 , 9 ) having a variable volume, configured to supply a pressurized fluid to the main piston ( 2 , 51 ) on two opposite sides and to the at least one trailing piston ( 11 , 12 , 52 ) on one side, the at least one trailing piston ( 11 , 12 , 52 ) being guided in an axially displaceable manner on a cylindrical outer lateral face ( 38 ) of the main piston ( 2 , 51 ) which extends to the side of a circular piston web ( 10 , 61 ) acting as an axial counter bearing, the piston web ( 10 , 61 ) extending radially outward from an outer lateral face ( 38 ) of the main piston ( 2 , 51 ), the at least one trailing piston ( 11 , 12 , 52 ) having a thrust portion ( 13 , 14 , 54 ) at an end proximate to the piston web, the thrust portion extending axially inward toward the piston web ( 10 , 61 ),

wherein the cylindrical housing includes a travel limiter ( 28 , 53 ) for limiting an axial travel range of the at least one trailing piston ( 11 , 12 , 52 )

wherein, under pressure, the at least one trailing piston ( 11 , 12 , 52 ) follows the main piston ( 2 , 51 ) via the thrust portion ( 13 , 14 , 54 ) until the trailing piston ( 11 , 12 , 52 ) hits the travel limiter ( 28 , 53 ),

wherein the piston web ( 10 , 61 ) of the main piston ( 2 , 51 ) has an axial recess ( 30 , 31 , 55 ), and the thrust portion ( 13 , 14 , 54 ) of the at least one trailing piston ( 11 , 12 , 52 ) is geometrically adapted to the axial recess ( 30 , 31 , 55 ) to be insertable into the recess ( 30 , 31 , 55 ) with a positive lock when the respective trailing piston ( 11 , 12 , 52 ) approaches the piston web ( 10 , 61 ) of the main piston ( 2 , 52 ).

2. The piston-cylinder assembly according to claim 1 ,

wherein the at least one trailing piston is two trailing pistons ( 11 , 12 ) arranged in the cylindrical housing ( 3 ) and separated from one another by the piston web ( 10 ), which is axially centrally arranged on the main piston ( 2 ),

wherein a first trailing piston ( 11 ) of the two trailing pistons, which has a first thrust portion ( 13 ), is guided in an axially movable manner in a first pressure chamber ( 8 ) on the cylindrical outer lateral face of the main piston ( 2 ),

wherein a second trailing piston ( 12 ) of the two trailing pistons, which has a second thrust portion ( 14 ), is guided in an axially movable manner in a second pressure chamber ( 9 ) on the cylindrical outer lateral face of the main piston ( 2 ), and

wherein the piston web ( 10 ) has two axial recesses ( 30 , 31 ), a first recess ( 30 ) facing the first trailing piston ( 11 ), and a second recess ( 31 ) facing the second trailing piston ( 12 ) so that each trailing piston ( 11 , 12 ) is insertable into an associated recess ( 30 , 31 ) of the piston web ( 10 ) when approaching the piston web ( 10 ).

3. The piston-cylinder assembly according to claim 2 , wherein the first and second thrust portions ( 13 , 14 ) of the two trailing pistons ( 11 , 12 ) are each formed from a plurality of arcuate first and second thrust segments ( 32 , 33 ) circumferentially spaced from one another and radially opposite from each other so as to circumferentially alternate with one another, wherein the first and second recesses ( 30 , 31 ) of the piston web ( 10 ) are each formed from a plurality of pocket-shaped first and second recess segments ( 34 , 35 ) which are circumferentially spaced from one another, axially opposing first and second recess segments ( 34 , 35 ) of the piston web ( 10 ) so that each of the first recess segments ( 34 ) is assigned to a respective one of the first thrust segments ( 32 ), and each of the second recess segments ( 35 ) is assigned to a respective one of the second thrust segments ( 33 ) for engaging one another in pairs.

4. The piston-cylinder assembly according to claim 2 , wherein the first thrust portion ( 13 ) of the first trailing piston ( 11 ) has a first shoulder ( 36 ), wherein the second thrust portion ( 14 ) of the second trailing piston ( 12 ) has a second shoulder ( 37 ), wherein the first and second shoulders ( 36 , 37 ) are circumferentially closed or non-continuous, the first shoulder ( 36 ) acting as a first axial stop surface for limiting the travel range of the first trailing piston ( 11 ) on the travel limiter ( 28 ) in a first axial direction and simultaneously limiting an insertion depth into the first recess ( 30 ), and the second shoulder ( 37 ) acting as a second axial stop surface for limiting the travel range of the second trailing piston ( 12 ) on the travel limiter ( 28 ) in a second axial direction and simultaneously limiting an insertion depth into the second recess ( 31 ).

5. The piston-cylinder assembly according to claim 1 , wherein a respective travel limiter ( 28 ) for each of the at least one trailing piston ( 11 , 12 ) is a double-sided retaining web of the cylindrical housing ( 3 ) which extends radially inward toward the piston web ( 10 ).

6. The piston-cylinder assembly according to claim 1 , wherein a respective travel limiter ( 53 ) for each of the at least one trailing piston ( 52 ) is a single-sided step on the cylindrical housing ( 3 ) which extends radially inward toward the main piston ( 51 ).

7. The piston-cylinder assembly according to either claim 1 , wherein the at least one trailing piston is only one trailing piston ( 52 ).

8. The piston-cylinder assembly according to claim 7 , wherein the piston web ( 61 ) extends into the axial center of the main piston ( 51 ), and wherein an outer lateral face of the piston web ( 61 ) forms a bearing surface ( 56 ) for attaching a functional element ( 57 ) of a position detection device.

9. The piston-cylinder assembly according to claim 7 , wherein the piston web ( 61 ) extends into the axial center of the main piston ( 51 ), and wherein an outer lateral face of the piston web ( 61 ) forms a bearing surface ( 56 ) for attaching a functional element ( 57 ) of a position locking device.

10. An automatic transmission of a vehicle, comprising a piston-cylinder assembly ( 1 , 50 ) according to claim 1 , forming a three-position actuator and configured as a transmission actuator of the automatic transmission.