Abstract: A flywheel device includes an enclosure, a top plate that fastens to the enclosure, where the top plate includes a first opening, and a cap, where the cap has a top side and a bottom side, which when fastened to the first opening forms a seal between the bottom side and the first opening, the bottom side including an o-ring groove configured to hold an o-ring, a grease channel concentric with the o-ring groove, and an inlet port configured to enable grease to flow into the grease channel.

Abstract: A flywheel apparatus that magnetically unloads a top rotor bearing is described. The apparatus includes a flywheel housing, a rotor with a vertical axis of rotation that includes a magnetic material, a magnet configured to apply a desired upward off-loading force along the vertical axis of rotation, an upper bearing connected to an upper shaft of the rotor, and a bearing housing disposed between the upper bearing and the flywheel housing that substantially prevents downward axial motion of the upper bearing. The magnet includes an electromagnet. A force sensor is used to measure a force on the upper bearing which is provided as input to a controller that updates the current to the electromagnet. The rotor is maintained in a fixed axial position and a spring disposed below a lower bearing absorbs axial dimension growth of the rotor.

Abstract: A number of flywheel units are arranged in a geometric pattern. Each of the flywheel units is enclosed in a containment unit. The containment unit includes a cylindrical tube, a cover, a bottom support, resting on the ground, on which the containment unit is mounted, and a fill medium surrounding each containment unit. The containment unit may also include a horizontal plate, mounted to the base of tube, which extends outward or radially from the base of tube a pre-determined length. In this case, the fill medium rests directly on top of the portion of the plate that extends outward from tube.

Abstract: A flywheel device includes structures allowing the flywheel system to be assembled offsite, transported safely, and installed with relatively few steps. The flywheel includes a rotor and a housing enclosing the rotor, where the housing includes a bottom plate, a top plate and side walls. The bottom plate and the top plate each includes a hole aligned with the center axis of the rotor. The flywheel also includes multiple bearing housings substantially covering the holes of the bottom plate and the top plate that are aligned to the center axis of the rotor. The flywheel also includes posts that physically contact the primary rotational mass of the rotor to prevent motion of the rotor during transport of the flywheel system. Some or all of these posts may be repositioned or removed during installation so that the rotor can spin freely.

Abstract: A flywheel device includes an enclosure, a top plate that fastens to the enclosure, where the top plate includes a first opening, and a cap, where the cap has a top side and a bottom side, which when fastened to the first opening forms a seal between the bottom side and the first opening, the bottom side including an o-ring groove configured to hold an o-ring, a grease channel concentric with the o-ring groove, and an inlet port configured to enable grease to flow into the grease channel.

Abstract: A flywheel apparatus that magnetically unloads a top rotor bearing is described. The apparatus includes a flywheel housing, a rotor with a vertical axis of rotation that includes a magnetic material, a magnet configured to apply a desired upward off-loading force along the vertical axis of rotation, an upper bearing connected to an upper shaft of the rotor, and a bearing housing disposed between the upper bearing and the flywheel housing that substantially prevents downward axial motion of the upper bearing. The magnet includes an electromagnet. A force sensor is used to measure a force on the upper bearing which is provided as input to a controller that updates the current to the electromagnet. The rotor is maintained in a fixed axial position and a spring disposed below a lower bearing absorbs axial dimension growth of the rotor.

Abstract: A number of flywheel units are arranged in a geometric pattern. Each of the flywheel units is enclosed in a containment unit. The containment unit includes a cylindrical tube, a cover, a bottom support, resting on the ground, on which the containment unit is mounted, and a fill medium surrounding each containment unit. The containment unit may also include a horizontal plate, mounted to the base of tube, which extends outward or radially from the base of tube a pre-determined length. In this case, the fill medium rests directly on top of the portion of the plate that extends outward from tube.

Abstract: A flywheel device includes structures allowing the flywheel system to be assembled offsite, transported safely, and installed with relatively few steps. The flywheel includes a rotor and a housing enclosing the rotor, where the housing includes a bottom plate, a top plate and side walls. The bottom plate and the top plate each includes a hole aligned with the center axis of the rotor. The flywheel also includes multiple bearing housings substantially covering the holes of the bottom plate and the top plate that are aligned to the center axis of the rotor. The flywheel also includes posts that physically contact the primary rotational mass of the rotor to prevent motion of the rotor during transport of the flywheel system. Some or all of these posts may be repositioned or removed during installation so that the rotor can spin freely.