Abstract: An electric machine stator is provided and includes laminations consolidated along an axial direction to form a core element such that the core element includes an end lamination at an axial end of the core element. The end lamination includes a body extending in a plane and a plurality of spacer protrusions protruding along the axial direction from the plane. Each of the spacer protrusions of the plurality of spacer protrusions is configured for consolidation with another core element to define a radial vent between the core element and the another core element.

Abstract: A method of removing electrical runout from a measurement surface of a rotatable machine shaft is disclosed. The method includes providing a sensor adjacent to the measurement surface of the rotatable machine shaft, rotating the rotatable machine shaft, measuring a combined runout of the measurement surface, determining an angular location of one or more local valleys on the measurement surface, and re-working the measurement surface at the angular location of the one or more local valleys. Re-work may be by polishing at the one or more local valleys. Various alternative methods are disclosed, as are other aspects.

Abstract: Induction motors may have a rotor that includes a shaft and a plurality of rotor laminations. The plurality of rotor laminations may have a central bore sized to receive the shaft, and the shaft may have a laminated portion that extends throughout the central bore. In other embodiments, the plurality of rotor laminations may have a very small or no central bore, and the shaft may include first and second end pieces respectively attached on opposite sides of the plurality of rotor laminations. In some embodiments, the first and second end shaft pieces may be attached to the rotor laminations with a through bolt that passes through the rotor laminations via a central bore sized no larger than needed to receive the through bolt, allowing each of the rotor laminations to have a larger laminated surface area. Methods of assembling a rotor are also provided, as are other aspects.

Abstract: Vent spacers and induction motor rotor core assemblies for induction motors are disclosed. The induction motor rotor assembly includes at least two rotor packages, each having axial sidewalls, a radial periphery, and axial vents, and a vent spacer positioned between opposing axial sidewalls of the at least two rotor packages. The vent spacer has a hub and a plurality of radially-extending fins coupled to the hub, the fins extending approximately to a radial periphery and extending axially between the opposed axial sidewalls to form a plurality of radial cooling channels extending between the sidewalls. Induction motors and methods of operating the induction motors are disclosed, as are other aspects.

Abstract: An electric machine stator is provided and includes laminations consolidated along an axial direction to form a core element such that the core element includes an end lamination at an axial end of the core element. The end lamination includes a body extending in a plane and a plurality of spacer protrusions protruding along the axial direction from the plane. Each of the spacer protrusions of the plurality of spacer protrusions is configured for consolidation with another core element to define a radial vent between the core element and the another core element.

Abstract: Induction motors may have a rotor that includes a shaft and a plurality of rotor laminations. The plurality of rotor laminations may have a central bore sized to receive the shaft, and the shaft may have a laminated portion that extends throughout the central bore. In other embodiments, the plurality of rotor laminations may have a very small or no central bore, and the shaft may include first and second end pieces respectively attached on opposite sides of the plurality of rotor laminations. In some embodiments, the first and second end shaft pieces may be attached to the rotor laminations with a through bolt that passes through the rotor laminations via a central bore sized no larger than needed to receive the through bolt, allowing each of the rotor laminations to have a larger laminated surface area. Methods of assembling a rotor are also provided, as are other aspects.

Abstract: Vent spacers and induction motor rotor core assemblies for induction motors are disclosed. The induction motor rotor assembly includes at least two rotor packages, each having axial sidewalls, a radial periphery, and axial vents, and a vent spacer positioned between opposing axial sidewalls of the at least two rotor packages. The vent spacer has a hub and a plurality of radially-extending fins coupled to the hub, the fins extending approximately to a radial periphery and extending axially between the opposed axial sidewalls to form a plurality of radial cooling channels extending between the sidewalls. Induction motors and methods of operating the induction motors are disclosed, as are other aspects.

Abstract: A method of removing electrical runout from a measurement surface of a rotatable machine shaft is disclosed. The method includes providing a sensor adjacent to the measurement surface of the rotatable machine shaft, rotating the rotatable machine shaft, measuring a combined runout of the measurement surface, determining an angular location of one or more local valleys on the measurement surface, and re-working the measurement surface at the angular location of the one or more local valleys. Re-work may be by polishing at the one or more local valleys. Various alternative methods are disclosed, as are other aspects.