pyöritin

Pyöritin is a Finnish noun that can refer to a person who spins or whirls, but it is also used as a technical term for a rotating component in machinery. In engineering contexts, pyöritin most often denotes the rotating element of a machine, commonly known in English as a rotor. This is the part that turns, typically connected to a shaft and housed inside a stator, and it may carry windings, magnets, or a cage structure depending on the machine type.

In electrical machines such as motors and generators, the pyöritin interacts with the stationary part of the machine to convert electrical energy to mechanical energy or vice versa. Common rotor constructions include squirrel-cage rotors and wound rotors, and designs may vary to optimize torque, speed, efficiency, and cooling. The term is sometimes used interchangeably with roottori, which is the standard Finnish word for rotor in many technical texts, although roottori is more precise in formal contexts.

A broader or more informal sense of pyöritin can refer to any device that spins or agitates content within a system, such as an agitator or mixer component. In everyday language, the word may also appear when describing someone who spins things for a living or as a playful caption, though such usage is less common and highly context-dependent.

Etymology and related terms: pyöritin derives from the verb pyöriä, meaning to spin, with the agentive suffix -tin. Related concepts include pyörimisnopeus (rotational speed), pyöritys (rotation), and roottori (rotor).