Cylinder/reciprocating-piston device, compressed air engine, and vehicle

Abstract

A cylinder/reciprocating-piston device for a compressed air engine includes a hollow cylinder having a hollow-cylinder wall defining a pressure space, a piston that is movable the pressure space, and valves that respectively open/close valve flow channels in the hollow-cylinder wall. The hollow-cylinder has a surface that delimits the pressure space in a radial direction, a ceiling wall that axially upwardly delimits the pressure space, a floor wall that axially downwardly delimits the pressure space, and a piston-rod opening in the floor- and/or ceiling wall that slidably guide(s) a piston rod. The piston divides the pressure space into a first pressure chamber between the piston and the ceiling wall, and a second pressure chamber between the piston and the floor wall. A minimum flow-cross section of one or more of the valve flow channels is preferably at least 10% of the effective cross-sectional surface area of the piston.

1 . A cylinder/reciprocating-piston device for a compressed air engine, the cylinder/reciprocating-piston device including:
 a hollow cylinder, which is closed upwardly and downwardly, having a hollow-cylinder wall,   a piston, and   a plurality of valves each having a valve closure part configured to close off a valve flow channel extending through the valve, the valves being selected from the group consisting of electric valves, pneumatically-actuated valves, hydraulically-actuated valves and mechanically-actuated valves,   wherein:   the hollow-cylinder wall defines a pressure space and comprises:
 a surface that delimits the pressure space in a radial direction, 
 a ceiling wall that upwardly delimits the pressure space in an axial direction, 
 a floor wall that downwardly delimits the pressure space in the axial direction, and 
 a piston-rod opening in at least one of the floor wall and the ceiling wall, the piston-rod opening(s) being configured such that a piston rod attached to the piston is guidable therethrough from outside into the pressure space, 
   the piston is disposed in the pressure space such that the piston divides the pressure space into a first pressure chamber between the piston and the ceiling wall, and a second pressure chamber between the piston and the floor wall,   the piston is displaceable in the pressure space in a pressure-tight manner in the axial direction by a piston stroke that is defined between a first end position, at which the piston is located in the vicinity of or in abutment with the ceiling wall, and a second end position, at which the piston is located in the vicinity of or in abutment with the floor wall,   the hollow-cylinder wall further includes:
 at least one first-pressure-chamber opening, via which a first pressure medium is supplyable into and/or dischargeable from the first pressure chamber through the valve flow channel of at least a first one of the plurality of valves, and 
 at least one second-pressure-chamber opening, via which a second pressure medium is supplyable into and/or dischargeable from the second pressure chamber through the valve flow channel of at least a second one of the plurality of valves, 
   the first pressure chamber has a first displacement that is calculated by multiplying the piston stroke with a first effective cross-sectional surface area of a first side of the piston that faces the first pressure chamber,   the second pressure chamber has a second displacement that is calculated by multiplying the piston stroke with a second effective cross-sectional surface area of a second side of the piston that faces the second pressure chamber, and   the piston, the valves and the pressure space are configured such that:
 when the piston is located at the first end position, a first dead space volume is the sum of a first volume within the first pressure chamber defined between the ceiling wall and the piston at the first end position, if any, and a second volume defined by a space within the valve flow channel(s) of the at least first one of the plurality of valves between the first pressure chamber and the valve closure part(s) thereof disposed in a closed state, the first dead space volume being less than 15% of the first displacement, and 
 when the piston is located at the second end position, a second dead space volume is the sum of a third volume within the second pressure chamber defined between the floor wall and the piston at the second end position, if any, and a fourth volume defined by a space within the valve flow channel(s) of the at least second one of the plurality of valves between the second pressure chamber and the valve closure part(s) thereof disposed in a closed state, the second dead space volume being less than 15% of the second displacement. 
   
     
     
         2 .- 4 . (canceled) 
     
     
         5 . A cylinder/reciprocating-piston device for a compressed air engine, the cylinder/reciprocating-piston device including:
 a hollow cylinder, which is closed upwardly and downwardly, having a hollow-cylinder wall,   a piston, and   a plurality of valves each having a valve closure part configured to close a valve flow channel extending through the valve, the valves being selected from the group consisting of electric valves, pneumatically-actuated valves, hydraulically-actuated valves and mechanically-actuated valves,   wherein:   the hollow-cylinder wall defines a pressure space and comprises:
 a surface that delimits the pressure space in a radial direction, 
 a ceiling wall that upwardly delimits the pressure space in an axial direction, 
 a floor wall that downwardly delimits the pressure space in the axial direction, and 
   a piston-rod opening in at least one of the floor wall and the ceiling wall, the piston-rod opening(s) being configured such that a piston rod attached to the piston is guidable therethrough from outside into the pressure space,   the piston is disposed in the pressure space such that the piston divides the pressure space into a first pressure chamber between the piston and the ceiling wall, and a second pressure chamber between the piston and the floor wall,   the piston is displaceable in the pressure space in a pressure-tight manner in the axial direction by a piston stroke that is defined between a first end position, at which the piston is located in the vicinity of or in abutment with the ceiling wall, and a second end position, at which the piston is located in the vicinity of or in abutment with the floor wall,   the hollow-cylinder wall further includes:   one or more inlet first-pressure-chamber openings, via which a first pressure medium is supplyable through the valve flow channel of at least a first one of the plurality of valves into the first pressure chamber, and one or more outlet first-pressure-chamber openings, via which the first pressure medium is dischargeable through the valve flow channel of at least a second one of the plurality of valves out of the first pressure chamber, and/or   one or more inlet second-pressure-chamber openings, via which a second pressure medium is supplyable through the valve flow channel of at least a third one of the plurality of valves into the second pressure chamber, and one or more outlet second-pressure-chamber openings, via which the second pressure medium is dischargeable through the valve flow channel of at least a fourth one of the plurality of valves out of the second pressure chamber,   each of the valve flow channels of the plurality of valves has a minimum flow-cross-section in an open state of the valve closure part,   the minimum flow-cross-section of the first one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the first one of the plurality of valves, is/are more than 10% of an effective cross-sectional surface area of the piston, and/or   the minimum flow-cross-section of the second one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the second one of the plurality of valves, is/are more than 10% of the effective cross-sectional surface area of the piston, and/or   the minimum flow-cross-section of the third one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the third one of the plurality of valves, is/are more than 10% of the effective cross-sectional surface area of the piston, and/or   the minimum flow-cross-section of the fourth one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the fourth one of the plurality of valves, is/are more than 10% of the effective cross-sectional surface area of the piston.   
     
     
         6 .- 9 . (canceled) 
     
     
         10 . A compressed air engine comprising:
 at least two cylinder/reciprocating-piston devices ( 1 ), each having a hollow cylinder, which is closed upwardly and downwardly, having a hollow-cylinder wall with at least one piston-rod opening, a piston movably disposed in the hollow cylinder, and a plurality of valves each having a valve closure part configured to close a valve flow channel extending through the valve, the valves being selected from the group consisting of electric valves, pneumatically-actuated valves, hydraulically-actuated valves and mechanically-actuated valves,   a common piston rod connected with the pistons of the cylinder/reciprocating-piston devices and movably extending outward through the piston-rod openings of the hollow-cylinder walls, and   a first crankshaft coupled with the common piston rod such that the back-and-forth movement of the common piston rod is converted into rotational movement of the first crankshaft,   wherein:   each of the hollow-cylinder walls defines a pressure space and comprises:
 a surface that delimits the pressure space in a radial direction, 
 a ceiling wall that upwardly delimits the pressure space in an axial direction, 
 a floor wall that downwardly delimits the pressure space in the axial direction, and 
 the at least one piston-rod opening in at least one of the floor wall and the ceiling wall, the piston-rod opening(s) being configured such that the common piston rod is guidable therethrough from outside into the pressure space, 
   the pistons are respectively disposed in the pressure spaces such that the pistons respectively divide each of the pressure spaces into a first pressure chamber between the piston and the ceiling wall, and a second pressure chamber between the piston and the floor wall,   the pistons are respectively displaceable in the pressure spaces in a pressure-tight manner in the axial direction by a piston stroke that is defined between a first end position, at which the piston is located in the vicinity of or in abutment with the ceiling wall, and a second end position, at which the piston is located in the vicinity of or in abutment with the floor wall,   each of the hollow-cylinder walls further includes:
 at least one first-pressure-chamber opening, via which a first pressure medium is supplyable into and/or dischargeable from the first pressure chamber through the valve flow channel of at least a first one of the plurality of valves, and 
 at least one second-pressure-chamber opening, via which a second pressure medium is supplyable into and/or dischargeable from the second pressure chamber through the valve flow channel of at least a second one of the plurality of valves, 
   the at least two cylinder/reciprocating-piston devices are disposed on the same side relative to a connection of the common piston rod with the first crankshaft, and   the first pressure medium is the same as or different from the second pressure medium.   
     
     
         11 . The compressed air engine according to  claim 10 , further including one of:
 a pressure regulator configured to adjust the pressure of the first and second pressure medium supplied to the first and second pressure chambers via the valves, or   a first pressure regulator configured to adjust the pressure of the first pressure medium supplied to the first pressure chamber via the at least first one of the plurality of valves and a second pressure regulator configured to adjust the pressure of the second pressure medium supplied to the second pressure chamber via the at least second one of the plurality of valves.   
     
     
         12 . The compressed air engine according to  claim 10 , further including:
 a rotational angle sensor configured to detect the rotational position of the first crankshaft to facilitate controlling of the plurality of valves in a manner depending on the detected rotational position of the first crankshaft, and   a control system configured to control the plurality of valves such that the cylinder/reciprocating-piston devices are selectively switchable between:
 a 1-stroke mode, wherein in every movement between the first and second end positions the piston is impinged with pressure medium, and 
 a multi-stroke mode, wherein in some but not all movements between the first and second end positions the piston is not impinged with pressure medium, 
   wherein the valves are selected from the group consisting of electric valves, pneumatically-actuated valves, and hydraulically-actuated valves.   
     
     
         13 . The compressed air engine according to  claim 10 , wherein:
 the control system is further configured to change the rotational direction of the first crankshaft and/or   the at least two of the cylinder/reciprocating-piston devices are differently designed.   
     
     
         14 .- 15 . (canceled) 
     
     
         16 . The compressed air engine according to  claim 10 , further comprising:
 first piston rod and a second piston rod, each of which is connected to the first crankshaft and to one of the at least two cylinder/reciprocating-piston devices.   
     
     
         17 . The compressed air engine according to  claim 10 , wherein:
 the at least two cylinder/reciprocating-piston devices, and/or crank arms of the first crankshaft, which connect the crankshaft to the common piston rod, are configured differently such that the at least two cylinder/reciprocating-piston devices have different displacements and/or different stroke heights.   
     
     
         18 . The compressed air engine according to  claim 10 , wherein:
 the pressure of the first and/or second pressure medium of each of the first and second pressure chambers of the at least two of the cylinder/reciprocating-piston devices is adjustable independently of one another, and/or   the first pressure media of the at least two of the cylinder/reciprocating-piston devices are, at least in part, different from each other, and/or   the second pressure media of the at least two of the cylinder/reciprocating-piston devices are, at least in part, different from each other.   
     
     
         19 . (canceled) 
     
     
         20 . The compressed air engine according to  claim 10 , wherein:
 the valves are selected from the group consisting of electric valves, pneumatically-actuated valves, and hydraulically-actuated valves, and   a control system is configured to control the plurality of valves of at least two cylinder/reciprocating-piston devices such that at least two of the cylinder/reciprocating-piston devices operate with different stroke times and/or with different pressure differences between the first and second pressure chamber in the first and second end positions, and/or are switchable-off independently of one another, and/or   the control system is configured to determine control times of the plurality of valves in a manner that is dependent on a load situation.   
     
     
         21 . (canceled) 
     
     
         22 . The compressed air engine according to  claim 10 , wherein the first crankshaft is connected with the common piston rod via a connecting rod such that the common piston rod is linearly guided. 
     
     
         23 . The compressed air engine according to  claim 10 , further including:
 a second crankshaft configured to operate as a dual crank drive together with the first crankshaft,   wherein:   the first crankshaft and the second crankshaft are configured to rotate in opposite directions at the same rotational speed, and   the common piston rod is connected with the first and second crankshafts ( 75 ) via a connecting rod such that the common piston rod is linearly guided, and during rotation of the dual crank drive about a 360-degree crank angle, the pistons are configured to be respectively moved from the first end position to the second end position, and back again to the first end position.   
     
     
         24 . A vehicle comprising:
 at least one compressed air engine according to  claim 10 ,   at least one pressure tank configured to store at least the first pressure medium and fluidly connected with the at least one first-pressure-chamber openings of the at least two cylinder/reciprocating-piston devices.   
     
     
         25 .- 30 . (canceled) 
     
     
         31 . The compressed air engine according to  claim 10 , wherein, in at least one of the at least two cylinder/reciprocating-piston devices:
 the first pressure chamber has a first displacement that is calculated by multiplying the piston stroke with a first effective cross-sectional surface area of a first side of the piston that faces the first pressure chamber,   the second pressure chamber has a second displacement that is calculated by multiplying the piston stroke with a second effective cross-sectional surface area of a second side of the piston that faces the second pressure chamber, and   the piston, the valves and the pressure space are configured such that:
 when the piston is located at the first end position, a first dead space volume is the sum of a first volume within the first pressure chamber defined between the ceiling wall and the piston at the first end position, if any, and a second volume defined by a space within the valve flow channel(s) of the at least first one of the plurality of valves between the ceiling wall and the valve closure part(s) thereof disposed in a closed state, the first dead space volume being less than 15% of the first displacement, and 
 when the piston is located at the second end position, a second dead space volume is the sum of a third volume within the second pressure chamber defined between the floor wall and the piston at the second end position, if any, and a fourth volume defined by a space within the valve flow channel(s) of the at least second one of the plurality of valves between the floor wall and the valve closure part(s) thereof disposed in a closed state, the second dead space volume being less than 15% of the second displacement. 
   
     
     
         32 . The compressed air engine according to  claim 10 , wherein, in at least one of the at least two cylinder/reciprocating-piston devices:
 the at least one first-pressure-chamber opening extends through the ceiling wall, and   the at least one second-pressure-chamber opening extends through the floor wall.   
     
     
         33 . The compressed air engine according to  claim 10 , wherein, in at least one of the at least two cylinder/reciprocating-piston devices:
 the at least one first-pressure-chamber opening includes one or more inlet first-pressure-chamber openings, via which the first pressure medium is supplyable through the valve flow channel of at least the first one of the plurality of valves into the first pressure chamber, and one or more outlet first-pressure-chamber openings, via which the first pressure medium is dischargeable through the valve flow channel of at least a third one of the plurality of valves out of the first pressure chamber, and/or   the at least second first-pressure-chamber opening includes one or more inlet second-pressure-chamber openings, via which the second pressure medium is supplyable through the valve flow channel of at least the second one of the plurality of valves into the second pressure chamber, and one or more outlet second-pressure-chamber openings, via which the second pressure medium is dischargeable through the valve flow channel of at least a fourth one of the plurality of valves out of the second pressure chamber.   
     
     
         34 . The compressed air engine according to  claim 10 , wherein, in at least one of the at least two cylinder/reciprocating-piston devices:
 each of the valve flow channels of the plurality of valves has a minimum flow-cross-section in an open state of the valve closure part,   the minimum flow-cross-section of the first one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the first one of the plurality of valves, is/are more than 10% of an effective cross-sectional surface area of the piston, and/or   the minimum flow-cross-section of the second one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the second one of the plurality of valves, is/are more than 10% of the effective cross-sectional surface area of the piston, and/or   the minimum flow-cross-section of the third one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the third one of the plurality of valves, is/are more than 10% of the effective cross-sectional surface area of the piston, and/or   the minimum flow-cross-section of the fourth one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the fourth one of the plurality of valves, is/are more than 10% of the effective cross-sectional surface area of the piston.   
     
     
         35 . The compressed air engine according to  claim 34 , wherein:
 the minimum flow-cross-section of the first one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the first one of the plurality of valves, is/are more than 20% of an effective cross-sectional surface area of the piston, and/or   the minimum flow-cross-section of the second one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the second one of the plurality of valves, is/are more than 20% of the effective cross-sectional surface area of the piston, and/or   the minimum flow-cross-section of the third one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the third one of the plurality of valves, is/are more than 20% of the effective cross-sectional surface area of the piston, and/or   the minimum flow-cross-section of the fourth one of the plurality of valves, or the sum of the minimum flow-cross-sections of a plurality of the fourth one of the plurality of valves, is/are more than 20% of the effective cross-sectional surface area of the piston   
     
     
         36 . The compressed air engine according to  claim 10 , wherein at least one of the at least two cylinder/reciprocating-piston devices has a first piston-rod opening in the floor wall and a second piston-rod opening in the ceiling wall. 
     
     
         37 . The compressed air engine according to  claim 31 , wherein:
 the first dead space volume is less than 5% of the first displacement, and   the second dead space volume is less than 5% of the second displacement.