BACKGROUND

Technological Field

The present disclosure relates generally a wedge to be positioned between coils in an electrical generator, and more specifically to a wedge including a plurality of materials.

Description of Related Art

Electrical generators typically include a shaft that is driven for rotation, and which carries a plurality of field coils. The coils are typically separated by wedges. Wedges on electromagnetic machines are typically electrically conductive and thus have associated losses due to eddy currents. Wedges can be used smooth the area between laminations, thereby reducing friction and windage losses, however historically this has increased eddy current losses. Thus one loss cannot be reduced without increasing the other. Historically wedges have been generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved wedges having improved thermal conductivity while minimizing other losses. The present disclosure provides a solution for this need.

SUMMARY OF THE INVENTION

A rotor for a generator includes a shaft, a rotor core radially outward from the shaft and having a plurality of poles spanning axially along the rotor core, a plurality of windings wrapped axially around each of the plurality of poles, a plurality of wedges, each wedge being positioned between two adjacent poles of the plurality of poles, each wedge having a central portion comprising at least a first material, a first wing integrally attached to the central portion, and a second wing integrally attached to the central portion opposite the first wing, wherein the first wing, and the second wing include a second material.

Each of the windings can contact the second material of each of the wedges and not contact the first material of each of the wedges. The central portion can include the second material. The first material can be electrically non-conductive. The second material can be electrically conductive. The first material can include titanium. The second material can include aluminum. The central portion is primarily composed of the second material.

The central portion can include a quadrilateral section radially outward from a triangular central leg separating the first wing from the second wing. The quadrilateral section can include the first material and the second material. The quadrilateral section can include three outward facing edges, wherein each of the edges includes the second material, and two of the edges do not include the first material. The quadrilateral section can includes a first “L” shaped portion including the second material. The quadrilateral section includes a second “L” shaped portion can include the second material bracketing a portion of the first material with the first “L” shaped portion. It is also considered that the first wing and the second wing include the first material, a portion of an outer edge of the first wing, and a portion of an outer edge of the second wing include the first material. The central portion can include an aperture configured to allow coolant oil flow. The central portion can include a fastener located radially inward of the aperture. The fastener can include steel.

These and other features of the systems and methods of the subject disclosure will become more readily apparent to those skilled in the art from the following detailed description of the preferred embodiments taken in conjunction with the drawings.

