Lubrication of expansion machines

A method for lubricating an expansion machine in a thermodynamic circuit process device, wherein said thermodynamic circuit process device comprises an expansion machine, a multi-stage pressure-increasing pump and a working medium with a lubricant additive, and wherein said method comprises the steps of:

• step-by-step pressurizing the working medium with the lubricant additive with the multi-stage pressure-increasing pump;
• branching off a part of said working medium with the lubricant additive between two stages of the multi-stage pressure-increasing pump at a suited pressure level;
• and
• feeding the branched off part of the working medium with the lubricant additive at the suited pressure level to one or more bearing points of the expansion machine for lubricating the one or more bearing points, wherein the one or more bearing points receive the working medium with the lubricant additive at the suited pressure level.