Skewed halbach array rotor

A rotor assembly, comprising:

• a plurality of magnets each having a long dimension and a longitudinal axis associated with the long dimension, the plurality of magnets each having a corresponding magnetic pole orthogonal to the longitudinal axis and the magnets being arranged and oriented relative to adjacent ones of the magnets to form a substantially cylindrical Halbach array the combined magnetic field of which is concentrated on an outer cylindrical surface side of the substantially cylindrical Halbach array, wherein the substantially cylindrical Halbach array has a rotational axis and each of at least a subset of the magnets is oriented in a fixed position such that the longitudinal axis of the magnet is at a prescribed skew angle to the rotational axis;
• and
• a retaining structure adjacent to at least a subset of the magnets comprising the plurality of magnets and configured to hold one or more of said subset of magnets in place;
• wherein each of the magnets has a first end at a first extreme of the longitudinal axis and a second end at a second extreme of the longitudinal axis;
• and the retaining structure comprises an end plate that includes a plurality of evenly spaced angled block structures, each angled block structure including a ramp or wedge portion to receive the first end of a magnet included in the plurality of magnets and hold the magnet at the prescribed skew angle.