Abstract: The invention relates to a piston ring whose running surface is provided with a coating containing a plastic material. Said piston ring is characterized in that the coating is composed of at least one polyamide-imide and/or at least one polyether ether ketone with embedded particles which can be embodied as hard material particles, solid lubricant particles, or metallic particles. The invention further relates to a piston/piston ring arrangement comprising at least one inventive piston ring and an agent for coating at least the running surface of the piston ring.

Abstract: The invention relates to a lightweight piston comprising heat pipes. The aim of the invention is to simplify the structure of such a piston while at the same time allowing for an improved heat dissipation from the piston areas subject to heat load while avoiding thermal stress. For this purpose, a plurality of liquid-filled heat pipes each having an evaporator and a condenser end is used, whereby the evaporator end is configured by short pipe sections that are oriented in the thickness at bottom towards the focal point and that are interlinked by means of a composite heat pipe extending in parallel to the piston head. At least two pipe sections functioning as the condenser end are coupled with the composite heat pipe in such a manner as to configure, by way of a pipe connection arranged on the condenser ends, a closed coolant cycle between the evaporator end, composite heat pipe and condenser end of the heat pipe.