Piston unit of a working cylinder

A piston unit of a working cylinder, comprising:

• a piston rod and a piston, said piston rod having an outer thread at a coupling section on a piston side thereof, said piston having an axial bore having an inner thread, said axial bore receiving said piston rod therein, said outer thread and the inner thread defining a common thread section;
• said outer thread and said inner thread each having a respective taper, said taper of said outer thread and said taper of said inner thread matching with one another, said tapers having a taper angle of 0.3 to 5 degrees relative to a main longitudinal axis of said piston rod, said outer thread and said inner thread having a matching thread geometry;
• said outer thread and said inner thread being constructed for abutting against each other in a clearance-free manner in said common thread section when in a coupling end position and defining a sealing plane by the clearance-free manner;
• said outer thread and said inner thread having an elastic deformation within the elastic limits of said piston rod and said piston with said common thread section in the coupling end position, the elastic deformation occurring by a surface pressure through a tightening torque, and in the coupling end position, said piston rod and said piston being fixed to one another radially and axially without clearance by the elastic deformation and the elastic deformation being within the elastic limits with and without pressurization by a pressure medium in the working cylinder;
• a sealing body with a radial inner ring surface, said sealing body arranged in the thread section in the inner thread of the piston, and said radial inner ring surface of the sealing body having a sealing body thread section defining an axial subsection of said common thread section;
• and
• a recess arranged centrally in said common thread section with respect to an axial direction of the piston unit, said sealing body being disposed in said recess.