Abstract: A fluid flow system for a rotatable shaft assembly includes a first fluid flow device installed in a rotatable shaft, and a second fluid flow device installed in the rotatable shaft, spaced axially apart from the first fluid flow device. The first fluid flow device includes a wall portion having a radial dimension that retains oil in the rotatable shaft. The second fluid flow device includes a wall portion having a radial dimension that facilitates discharge of oil from the radial shaft. The first and second fluid flow devices each include a plurality of baffles on the respective wall portions thereof. The plurality of baffles drive the flow of fluid in an axial direction, from the first fluid flow device toward the second fluid flow device, as the first and second fluid flow devices rotate together with the rotatable shaft.

Abstract: An electric motor comprises: a stator, a rotor comprising: a rotor shaft having a hollow interior and configured for rotation inside the stator about a rotor axis, the rotor shaft having at least one inlet into the hollow interior and at least one radial outlet from the hollow interior, and a rotor body and an endring at an end of the rotor body along the rotor axis; and a spacer forming an internal cavity to receive fluid from the hollow interior, the spacer having an outlet from the internal cavity.

Abstract: One or more variable stiffness devices may be positioned between the splined coupling of a pair of rotating mechanical components to reduce or substantially eliminate backlash during operation. The variable stiffness device may include a spring pin that exerts a variable biasing force on mating surfaces of the pair of rotating mechanical components to maintain a relative position of the components in response to rotational and/or torsional forces exerted during operation.

Abstract: One or more variable stiffness devices may be positioned between the splined coupling of a pair of rotating mechanical components to reduce or substantially eliminate backlash during operation. The variable stiffness device may include a spring pin that exerts a variable biasing force on mating surfaces of the pair of rotating mechanical components to maintain a relative position of the components in response to rotational and/or torsional forces exerted during operation.

Abstract: A fluid flow system for a rotatable shaft assembly includes a first fluid flow device installed in a rotatable shaft, and a second fluid flow device installed in the rotatable shaft, spaced axially apart from the first fluid flow device. The first fluid flow device includes a wall portion having a radial dimension that retains oil in the rotatable shaft. The second fluid flow device includes a wall portion having a radial dimension that facilitates discharge of oil from the radial shaft. The first and second fluid flow devices each include a plurality of baffles on the respective wall portions thereof. The plurality of baffles drive the flow of fluid in an axial direction, from the first fluid flow device toward the second fluid flow device, as the first and second fluid flow devices rotate together with the rotatable shaft.