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US 12,326,140 B2Granted
Sealing device for a piston rod of a reciprocating compressor
AssigneeHoerbiger Wien GmbH
InventorsMartin Lagler, Andreas Kaufmann, Guido Pratelli
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AssigneeHoerbiger Wien GmbH
InventorsMartin Lagler, Andreas Kaufmann, Guido Pratelli
Estimating the term…
In order to provide a sealing device (15) for sealing a piston rod (8) of a reciprocating compressor (1), which provides good sealing properties at compressor standstill, which has a simple structure, which allows for a simple handling and which requires no external source of energy, the sealing device (15) comprises a number of first packing retainers (18), each retainer including a retaining opening (18a) in which a first packing ring (19) is arranged, a second packing retainer (20), including a retaining opening (20a) in which a second packing ring (21) is arranged, the second retainer (20) being positioned closer to the second axial device end (15b) than the number of first packing retainers (18) in an axial direction of the sealing device (15), wherein the second packing ring (21) is an uncut ring, comprising a continuous inner circumferential sealing surface (21a), wherein the second packing ring (21) is made from a material comprising a polymer, the material having a thermal expansion coefficient (α), which is at least two times higher than the thermal expansion coefficient (αFE) of iron, wherein at or below a defined activation temperature an inner diameter (d_i) of the second packing ring (21) is smaller than an outer diameter (D_a) of the piston rod (8) to be sealed, such that in the mounted state of the sealing device (15) in the compressor (1) the second packing ring (21) is prestressed in a radial direction in order to form a tight seal between the continuous inner circumferential sealing surface (21a) of the second packing ring (21) and the outer circumferential surface (8a) of the piston rod (8), wherein at a given operating temperature, the inner diameter (d_i) of the second packing ring (21) is larger than the outer diameter (D_a) of the piston rod (8), such that in the mounted state of the sealing device (15) in the compressor (1) the continuous inner circumferential sealing surface (21a) of the second sealing ring (21) is detached from the outer circumferential surface (8a) of the piston rod (8) in order to provide a leakage path past the second packing ring (21) in the axial direction.
Sealing device for sealing a piston rod of a reciprocating compressor, the sealing device comprising a first axial device end, configured to face toward a cylinder of the compressor, and an opposite second axial device end, configured to face toward a crankcase of the compressor, a number of first packing retainers, each retainer including a retaining opening in which a first packing ring is arranged, a second packing retainer, including a retaining opening in which a second packing ring is arranged, the second retainer being positioned closer to the second axial device end than the number of first packing retainers in an axial direction of the sealing device, wherein the second packing ring is an uncut ring, comprising a continuous inner circumferential sealing surface, wherein the second packing ring is made from a material comprising a polymer, the material having a thermal expansion coefficient, which is at least two times higher than a thermal expansion coefficient of iron, wherein at or below a defined activation temperature an inner diameter of the second packing ring is smaller than an outer diameter of the piston rod to be sealed, such that in the mounted state of the sealing device in the compressor the second packing ring is prestressed in a radial direction in order to form a tight seal between the continuous inner circumferential sealing surface of the second packing ring and an outer circumferential surface of the piston rod, wherein at a given operating temperature that is greater than the activation temperature, the inner diameter of the second packing ring is larger than the outer diameter of the piston rod, such that in the mounted state of the sealing device in the compressor the continuous inner circumferential sealing surface of the second sealing ring is detached from the outer circumferential surface of the piston rod in order to provide a leakage path past the second packing ring in the axial direction.
Reciprocating piston compressor comprising a number of cylinders, in each of which cylinders a piston is arranged, that is movable in a reciprocating manner, wherein each piston is connected to a piston rod, wherein for at least one cylinder of the number of cylinders, a sealing device is provided for sealing a respective piston rod, the sealing device comprising a first axial device end, configured to face toward a cylinder of the compressor, and an opposite second axial device end, configured to face toward a crankcase of the compressor, a number of first packing retainers, each retainer including a retaining opening in which a first packing ring is arranged, a second packing retainer, including a retaining opening in which a second packing ring is arranged, the second retainer being positioned closer to the second axial device end than the number of first packing retainers in an axial direction of the sealing device, wherein the second packing ring is an uncut ring, comprising a continuous inner circumferential sealing surface, wherein the second packing ring is made from a material comprising a polymer, the material having a thermal expansion coefficient, which is at least two times higher than a thermal expansion coefficient of iron, wherein at or below a defined activation temperature an inner diameter of the second packing ring is smaller than an outer diameter of the piston rod to be sealed, such that in the mounted state of the sealing device in the compressor the second packing ring is prestressed in a radial direction in order to form a tight seal between the continuous inner circumferential sealing surface of the second packing ring and an outer circumferential surface of the piston rod, wherein at a given operating temperature that is greater than the activation temperature, the inner diameter of the second packing ring is larger than the outer diameter of the piston rod, such that in the mounted state of the sealing device in the compressor the continuous inner circumferential sealing surface of the second sealing ring is detached from the outer circumferential surface of the piston rod in order to provide a leakage path past the second packing ring in the axial direction.
Dependencies are inferred from the claim text.