There is disclosed a fluid machine which, in one embodiment comprises a motor (10), the motor (10) comprising a shaft (12) rotatable about a main shaft axis (14); a sleeve (16) located around the shaft (12) and having a main sleeve axis (18) offset from the main shaft axis (14), the sleeve (16) being movably mounted on the shaft (12) such that, in use, the main sleeve axis (18) follows a path extending around the main shaft axis (14); and wherein the motor (10) further comprises means (20) for converting movement of a fluid through the motor (10) to a rotational motion of the shaft (12) via said movement of the sleeve (16). There is also disclosed a pump (100) having converting means (120) for converting a rotational motion of a shaft (112) to movement of a fluid through the pump (100) via movement of a fluid through the pump (100) via movement of a sleeve (116), and a clutch (200) having converting means (220) for converting a rotational motion of a sleeve (216) to a rotational motion of a shaft (212).