Patent ID: 9673667
Date: 2017-06-06
CPC Classifications: H02K

Claim:
1. A method for fabricating a permanent magnet electrical machine, the method comprising: providing a stator that includes conductive windings wound thereon and one or more permanent magnets embedded in the stator; positioning a magnetic keeper element on the stator so as to form a magnetic flux path with the one or more permanent magnets, with the magnetic keeper element closing the magnetic flux path of the one or more permanent magnets by providing a low reluctance flux path to magnetic flux generated by the one or more permanent magnets; and performing a vacuum pressure impregnation (VPI) process on the stator to increase a thermal conductivity of the conductive windings, the VPI process including a curing step that is performed at a selected temperature; wherein the magnetic keeper element sets an operating point of the one or more permanent magnets to an internal flux density level above a demagnetization threshold associated with the selected temperature at which the curing step is performed.