Liquid system and motor vehicle comprising such a liquid system

A liquid system for a motor vehicle, comprising:

• at least one supply line which is capable of being supplied with a liquid;
• at least one functional unit which is arrangeable on a movable component of the motor vehicle and which has a communicating connection to the supply line, wherein
• the supply line has at least one immovable line portion, which is arrangeable on an immovable component of the motor vehicle, and at least one movable line portion, which is arrangeable on the movable component and which is connected to the functional unit,
• the supply line has at least one rotary coupling by which the immovable line portion has a communicating connection to the movable line portion,
• the rotary coupling has an immovable coupling part, which is connected to the immovable line portion, and a movable coupling part, which is connected to the movable line portion,
• the two coupling parts are connected to one another rotatably about an axis of rotation to form the rotary coupling,
• the axis of rotation is identical to a pivot axis of a hinge by which the movable component is arranged pivotably on the immovable component, and
• the two coupling parts are designed such that, in an unconnected state, each is closed in liquid-tight fashion and, when transferred into a state in which they are connected to one another, the two coupling parts are opened so as to conduct liquid, whereby the immovable and movable line portions and their respectively connected coupling parts are fillable with the liquid before the two coupling parts are connected to one another to form the rotary coupling.