QML RotationAnimation Element или даже NumberAnimation, например так:
Rectangle {
width: 500
height: 500
Rectangle {
id: rect
anchors.centerIn: parent
smooth: true
transform: Rotation {
origin.x: rect.width / 2
origin.y: rect.height / 2
axis { x: 0; y: 0; z: 1 }
NumberAnimation on angle {
from: 1
to: 360
duration: 2000
loops: Animation.Infinite // или число циклов
}
}
}
}