Abstract: The invention is a flywheel rotor that includes a number of adjacent laminations, stacked one on top of another, where each of the laminations has the same shape and is rotationally symmetric around a center axis, and where the shape is substantially circular and includes a plurality of protrusions exterior to the circumference, and each of the laminations includes at least one hole for a fastening bolt to pass through. The invention typically includes an endplate at each end of stack of laminations. One of the two endplates may attach to a stubshaft.

Abstract: A stacked lamination endplate for a rotor that includes a number of adjacent laminations, stacked one on top of another, wherein each lamination has an identical shape, the shape having a central region, symmetric about a center axis, and a number of spokes, each spoke emanating radially outward from the central region, where each spoke includes a through-hole at its distal end, and wherein the laminations are stacked one on top of another and aligned, enabling, for each spoke, a bolt to be inserted through a corresponding through-hole of each lamination.

Abstract: The invention is a motor/generator that includes a motor/generator housing that encloses a rotor assembly, which rotates a shaft, and a stator assembly that remains stationary, and where the motor/generator is inside a vacuum chamber, which, during normal operation, is evacuated of gas and operates at a lower air pressure than atomospheric air pressure, and a cylindrical vacuum barrier between the rotor assembly and the stator assembly that together with the motor generator housing partitions the motor/generator into an interior rotor volume and an exterior stator volume, enabling the rotor volume and stator volume to operate at different atmospheric pressures.

Abstract: The invention is a motor/generator that includes a motor/generator housing that encloses a rotor assembly, which rotates a shaft, and a stator assembly that remains stationary, and where the motor/generator is inside a vacuum chamber, which, during normal operation, is evacuated of gas and operates at a lower air pressure than atomospheric air pressure, and a cylindrical vacuum barrier between the rotor assembly and the stator assembly that together with the motor generator housing partitions the motor/generator into an interior rotor volume and an exterior stator volume, enabling the rotor volume and stator volume to operate at different atmospheric pressures.

Abstract: The invention is a flywheel rotor that includes a number of adjacent laminations, stacked one on top of another, where each of the laminations has the same shape and is rotationally symmetric around a center axis, and where the shape is substantially circular and includes a plurality of protrusions exterior to the circumference, and each of the laminations includes at least one hole for a fastening bolt to pass through. The invention typically includes an endplate at each end of stack of laminations. One of the two endplates may attach to a stubshaft.

Abstract: The invention is a flywheel rotor that includes a number of adjacent laminations, stacked one on top of another, where each of the laminations has the same shape and is rotationally symmetric around a center axis, and where the shape is substantially circular and includes a plurality of protrusions on the circumference, and each of the laminations includes at least one hole for at fastening bolts to pass through. The invention typically includes an endplate at each end of stack of laminations and one of the two endplates attaches to a stubshaft.

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: The invention is a flywheel rotor that includes a number of adjacent laminations, stacked one on top of another, where each of the laminations has the same shape and is rotationally symmetric around a center axis, and where the shape is substantially circular and includes a plurality of protrusions on the circumference, and each of the laminations includes at least one hole for at fastening bolts to pass through. The invention typically includes an endplate at each end of stack of laminations and one of the two endplates attaches to a stubshaft.

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 energy storage system includes a flywheel housing that encloses a flywheel rotor, a motor/alternator, and a power electronics unit. The power electronics unit includes a power electronics housing directly mounted on the flywheel housing, and one or more power electronic circuits enclosed by the power electronics housing. The direct mounting of the power electronics housing on the flywheel housing enables thermal distribution for passive cooling purposes. The design of the flywheel energy storage system also reduces the vibrational forces imparted by the power electronics housing on the flywheel housing.

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 that surrounds an interior chamber that includes a rotor, which during normal operation is maintained in a vacuum state and spinning, the enclosure includes a first opening, and a valve that attaches to the enclosure, configured to enable, when actuated, ambient air to flow from the exterior of the enclosure into the chamber through the first opening, thus allowing the internal air pressure to rapidly approach ambient air pressure and thereby increase the air drag which acts as a brake on the spinning rotor.

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 flywheel energy storage system includes a flywheel housing that encloses a flywheel rotor, a motor/alternator, and a power electronics unit. The power electronics unit includes a power electronics housing directly mounted on the flywheel housing, and one or more power electronic circuits enclosed by the power electronics housing. The direct mounting of the power electronics housing on the flywheel housing enables thermal distribution for passive cooling purposes. The design of the flywheel energy storage system also reduces the vibrational forces imparted by the power electronics housing on the flywheel housing.

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 leaf spring assembly for a golf car includes a homogenous spring body having a rolled first end, a curving portion extending away from the rolled first end, a flat portion defining a second end, and a bend portion connecting the curving portion to the flat portion. A pin inserted through the rolled first end rotatably connects the rolled first end to a frame member of the golf car. A U-shaped bracket also connected to the frame member slidably supports the flat portion within the bracket permitting vertical deflections of the leaf spring body to be converted to fore-aft deflections of the flat portion.