Multi-turn gearboxes output torque and withstand bi-directional thrust by the thrust component, so they can be used for gate, stop valves, as well as similar ones. As another kind of typical applications, the torque-only multi-turn gearboxes can be used as the intermediate reduction gearboxes of the combinations. The combination of multi-turn gearbox and multi-turn electric actuator generates large output torque or flexible output speed. A handwheel can be supplied for manual operation.