Surgical robot system

An instrument assembly for a surgical robot system that includes at least one robotic manipulator, the instrument assembly comprising:

• at least one instrument with at least one instrument shaft configured for partial insertion into a patient;
• a drive train assembly with at least one drive train for actuating a degree of freedom of an end effector of the instrument shaft;
• at least one modular drive unit for actuating the drive train assembly, whereby the degree of freedom of the end effector is actuated;
• and
• an instrument housing, comprising:
• at least one drive train housing part on which at least a part of the drive train assembly is located, and
• at least one drive unit housing part with a hollow space which is configured for accommodating the drive unit, the drive unit housing part having a seal for sealing an insertion opening of the hollow space under sterile conditions and a dynamic sterile barrier, which isolates the hollow space under sterile conditions and through which the drive train assembly can be actuated;
• wherein the drive unit is laterally offset with respect to a longitudinal axis of the instrument shaft in a direction toward a connection of the instrument housing with a robot of the surgical robot system.