Abstract: A speed-adjustable returning device of a valve actuator including a transmission assembly, an energy storage device arranged at one side of the transmission assembly and is operatively coupled thereto, an arrestment device arranged beside the energy storage device and is operatively coupled to the transmission assembly, and a valve device arranged at one side of the transmission assembly and is operatively coupled thereto. Under a condition of normal power supply, the energy storage device is controlled to store energy, and when power supply is interrupted, the energy storage device releases the stored energy to drive the transmission assembly to operate in a reversed direction so that the transmission assembly drives the arrestment device in such a way that the arrestment device makes the transmission assembly and the energy storage device operated at fixed speeds to thereby make the valve device operated at a fixed speed.

Abstract: A linear travel structure of an electrical operating device includes a body, a substrate, a cover, a first transmission assembly, a second transmission assembly, and a third transmission assembly. The body receives the substrate to mount thereto so as to enclose and define a first receiving space. The cover is mounted to the body and, together with the substrate, encloses and defines a second receiving space. The substrate includes an electrical machine mounted thereto and received in the second receiving space. The first transmission assembly, the second transmission assembly, and the third transmission assembly are all received in the first receiving space. The electrical machine is connected in cascade with the first, second, and third transmission assemblies for operation therewith. With such a multiple-staged transmission arrangement, advantages including high transmission efficiency, high bearing capacity, high speed ratio, and small volume, can be achieved over the conventional devices.

Abstract: A linear travel structure of an electrical operating device includes a body, a substrate, a cover, a first transmission assembly, a second transmission assembly, and a third transmission assembly. The body receives the substrate to mount thereto so as to enclose and define a first receiving space. The cover is mounted to the body and, together with the substrate, encloses and defines a second receiving space. The substrate includes an electrical machine mounted thereto and received in the second receiving space. The first transmission assembly, the second transmission assembly, and the third transmission assembly are all received in the first receiving space. The electrical machine is connected in cascade with the first, second, and third transmission assemblies for operation therewith. With such a multiple-staged transmission arrangement, advantages including high transmission efficiency, high bearing capacity, high speed ratio, and small volume, can be achieved over the conventional devices.