Patent ID: 7666114

Claim:
An electric variable inertia apparatus comprising: a housing assembly having a housing having a closed rear and an open front; a positioning assembly mounted securely in the housing and having a base mounted securely in the housing and having a front, a rear, a cavity formed coaxially in and communicating with the rear of the base; and a central hole formed coaxially through the front of the base, communicating with the cavity and having a narrow end communicating with the front of the base; and a broad end communicating with the cavity; and a rear shaft bearing mounted in the broad end of the central hole; and a cover assembly mounted securely on the open front of the housing and having a cover mounted securely on the open front of the housing and having a central hole formed through the cover; and a frame shaft bearing mounted in the central hole in the cover; a servo drive device to provide a variable rotatory driving force, being an external motor mounted in the housing between the base and the cover and having an internal stator including a coil assembly, and an external rotor being mounted rotatably around the internal stator and having a tubular body mounted rotatably around the internal stator and having an inner surface, a front end, and a rear end, a flange formed on and protruding radially out from the front end of the tubular body, and a magnet assembly mounted on the inner surface of the tubular body near the front end of the tubular body rotatably around the coil assembly of the internal stator; a planetary gear mechanism mounted in the housing between the external motor and the cover and having a ring gear being mounted securely on and simultaneously rotating with the external rotor of the servo drive device and having a toothed inner surface, a planet gear assembly being mounted in and engaging the ring gear and having a planetary frame connected to an external input device, mounted in the housing and having an external drive shaft protruding out of the frame shaft bearing in the cover; and multiple planet gears being mounted on the planetary frame and meshing with the toothed inner surface of the ring gear, and a sun gear assembly having a rotated shaft mounted through the rear shaft bearing in the broad end of the central hole in the base and having a front end and a rear end, and a sun gear being mounted securely on the front end of the rotated shaft and meshing with the planet gears; and a load assembly being a flywheel connected securely to the rear end of the rotated shaft of the sun gear assembly and rotating simultaneously with the rotated shaft to generate rotational inertia; whereby, by controlling the servo drive device connected with the ring gear at a specific rotational velocity according to the rotational velocity of the planetary frame connected to the external input device, the load assembly is rotated to generate a widely ranging rotational inertia to react to the external input device.