Abstract: A flywheel includes a disc mounted around a central shaft. An energy-storing section and an energy-releasing section are defined in two sides of the second side. A plurality of rods is slideably mounted on the disc. The rods are arranged in a radiant manner and spaced from one another in a circumferential direction about the central shaft. Each rod has an inner end spaced from the central shaft and an outer end having a spacing to the central shaft larger than the inner end. Each rod slides toward the central shaft under action of gravitational force while the rod is moving through an upper portion of the energy-storing section. Each rod slides away from the central shaft under action of the gravitational force while the rod is moving through a lower portion of the energy-releasing section. A plurality of weights is respectively mounted to the outer ends of the rods.

Abstract: An automatic cleaning device includes a cleaning tube having a longitudinal hole extending along a longitudinal axis. A connecting tube extends from a bottom of an intermediate section of the cleaning tube and is rotatably received in a draining tube in a bottom of a liquid container. Left and right guiding openings are defined in bottoms of left and right sections of the cleaning tube and extend slantingly from an outer periphery through an inner periphery of the cleaning tube. Each guiding opening includes a central axis spaced from the longitudinal axis. The left and right guiding openings have opposite extending directions. Siphon effect is created when a liquid in the liquid container is being drained via the draining tube. The liquid imparts force to inner peripheral walls of the guiding openings, causing the cleaning tube and the connecting tube to rotate about a central axis of the connecting tube.