Abstract: An electric motor includes a case, a stator having stator windings, a rotor having a rotor shaft, and at least one main rotor bearing coupling the rotor shaft to the case. Common mode charge builds up on the rotor due to imbalances of the stator. The at least one main rotor bearing has a first electrical resistance between the rotor shaft and the case. The electric motor further includes a rotor discharge bearing coupling the rotor shaft to the case. The rotor discharge bearing has a second electrical resistance between the rotor shaft and the case that is less than the first electrical resistance, causing the common mode charge to discharge through the rotor discharge bearing. In a differing embodiment, a rotor discharge brush coupled between the case and the rotor shaft along the longitudinal axis of the rotor shaft discharges the common mode charge.

Abstract: Systems and methods for cooling power transmission systems are include providing oil through an aperture defined in a housing to a stator cooling ring, through the stator cooling ring and into stator cooling channels, through the stator cooling channels and into spaces defined between the housing and jet rings, and through holes in the jet rings and onto the end-windings. The stator cooling ring, stator cooling channels and jet rings can encircle the stator and end-windings and, via the holes in the jet rings, spray pressurized jets of oil from various angles onto the end-windings, and in particular middle regions thereof. Seals may be used between the jet rings and housing, and between the jet rings and stator ends. The seals may be compressed so as to form an interference fit between the jet rings and housing or stator ends as the case may be.

Abstract: An electric motor includes a case, a stator that includes end-windings, a rotor coupled to the case via at least one rotor bearing, at least one drive motor fluid pump, and drive motor electronics. The rotor includes a hollow cylindrical body, a first shaft portion, and a second shaft portion, a fluid feed tube having a fluid receive end and a fluid feed end, the fluid feed end extending into the hollow cylindrical body, and a plurality of fluid exit ports. The drive motor electronics power the stator with or without causing rotation of the rotor. The drive motor fluid pump pumps fluid into the hollow cylindrical body via the fluid feed tube, pumps the fluid out of the plurality of fluid ports, and onto the stator end-windings to collect heat from the rotor and the stator. The heated fluid may be used for heating a battery.

Abstract: An electric motor includes a case, a stator having stator windings, a rotor having a rotor shaft, and at least one main rotor bearing coupling the rotor shaft to the case. Common mode charge builds up on the rotor due to imbalances of the stator. The at least one main rotor bearing has a first electrical resistance between the rotor shaft and the case. The electric motor further includes a rotor discharge bearing coupling the rotor shaft to the case. The rotor discharge bearing has a second electrical resistance between the rotor shaft and the case that is less than the first electrical resistance, causing the common mode charge to discharge through the rotor discharge bearing. In a differing embodiment, a rotor discharge brush coupled between the case and the rotor shaft along the longitudinal axis of the rotor shaft discharges the common mode charge.

Abstract: Systems and methods for cooling power transmission systems are include providing oil through an aperture defined in a housing to a stator cooling ring, through the stator cooling ring and into stator cooling channels, through the stator cooling channels and into spaces defined between the housing and jet rings, and through holes in the jet rings and onto the end-windings. The stator cooling ring, stator cooling channels and jet rings can encircle the stator and end-windings and, via the holes in the jet rings, spray pressurized jets of oil from various angles onto the end-windings, and in particular middle regions thereof. Seals may be used between the jet rings and housing, and between the jet rings and stator ends. The seals may be compressed so as to form an interference fit between the jet rings and housing or stator ends as the case may be.

Abstract: An electric motor includes a case, a stator having stator windings, a rotor having a rotor shaft, and at least one main rotor bearing coupling the rotor shaft to the case. Common mode charge builds up on the rotor due to imbalances of the stator. The at least one main rotor bearing has a first electrical resistance between the rotor shaft and the case. The electric motor further includes a rotor discharge bearing coupling the rotor shaft to the case. The rotor discharge bearing has a second electrical resistance between the rotor shaft and the case that is less than the first electrical resistance, causing the common mode charge to discharge through the rotor discharge bearing. In a differing embodiment, a rotor discharge brush coupled between the case and the rotor shaft along the longitudinal axis of the rotor shaft discharges the common mode charge.

Abstract: An electric motor includes a case, a stator that includes end-windings, a rotor coupled to the case via at least one rotor bearing, at least one drive motor fluid pump, and drive motor electronics. The rotor includes a hollow cylindrical body, a first shaft portion, and a second shaft portion, a fluid feed tube having a fluid receive end and a fluid feed end, the fluid feed end extending into the hollow cylindrical body, and a plurality of fluid exit ports. The drive motor electronics power the stator with or without causing rotation of the rotor. The drive motor fluid pump pumps fluid into the hollow cylindrical body via the fluid feed tube, pumps the fluid out of the plurality of fluid ports, and onto the stator end-windings to collect heat from the rotor and the stator. The heated fluid may be used for heating a battery.

Abstract: An electric motor includes a case, a stator that includes end-windings, a rotor coupled to the case via at least one rotor bearing, at least one drive motor fluid pump, and drive motor electronics. The rotor includes a hollow cylindrical body, a first shaft portion, and a second shaft portion, a fluid feed tube having a fluid receive end and a fluid feed end, the fluid feed end extending into the hollow cylindrical body, and a plurality of fluid exit ports. The drive motor electronics power the stator with or without causing rotation of the rotor. The drive motor fluid pump pumps fluid into the hollow cylindrical body via the fluid feed tube, pumps the fluid out of the plurality of fluid ports, and onto the stator end-windings to collect heat from the rotor and the stator. The heated fluid may be used for heating a battery.

Abstract: Systems and methods for cooling power transmission systems are include providing oil through an aperture defined in a housing to a stator cooling ring, through the stator cooling ring and into stator cooling channels, through the stator cooling channels and into spaces defined between the housing and jet rings, and through holes in the jet rings and onto the end-windings. The stator cooling ring, stator cooling channels and jet rings can encircle the stator and end-windings and, via the holes in the jet rings, spray pressurized jets of oil from various angles onto the end-windings, and in particular middle regions thereof. Seals may be used between the jet rings and housing, and between the jet rings and stator ends. The seals may be compressed so as to form an interference fit between the jet rings and housing or stator ends as the case may be.

Abstract: An electric motor includes a case, a stator that includes a stator laminaiton and end-windings, a rotor coupled to the case via at least one rotor bearing. The rotor includes a hollow cylindrical body, a first shaft portion, and a second shaft portion. The hollow cylindrical body includes an inner wall, an outer wall, a first distal end, and a second distal end. The first shaft portions couples to the first distal end and the second shaft portion couples to the second distal end. The second shaft portion includes a fluid feed tube formed therewith having a fluid receive end and a fluid feed end, the fluid feed end extending to a central inner portion of the hollow cylindrical body. A plurality of fluid exit ports adjacent the first distal end and the second distal end of the hollow cylindrical body spray fluid onto components of the stator.

Abstract: An electric motor includes a case, a stator that includes a stator laminaiton and end-windings, a rotor coupled to the case via at least one rotor bearing. The rotor includes a hollow cylindrical body, a first shaft portion, and a second shaft portion. The hollow cylindrical body includes an inner wall, an outer wall, a first distal end, and a second distal end. The first shaft portions couples to the first distal end and the second shaft portion couples to the second distal end. The second shaft portion includes a fluid feed tube formed therewith having a fluid receive end and a fluid feed end, the fluid feed end extending to a central inner portion of the hollow cylindrical body. A plurality of fluid exit ports adjacent the first distal end and the second distal end of the hollow cylindrical body spray fluid onto components of the stator.

Abstract: An electric motor includes a case, a stator that includes end-windings, a rotor coupled to the case via at least one rotor bearing, at least one drive motor fluid pump, and drive motor electronics. The rotor includes a hollow cylindrical body, a first shaft portion, and a second shaft portion, a fluid feed tube having a fluid receive end and a fluid feed end, the fluid feed end extending into the hollow cylindrical body, and a plurality of fluid exit ports. The drive motor electronics power the stator with or without causing rotation of the rotor. The drive motor fluid pump pumps fluid into the hollow cylindrical body via the fluid feed tube, pumps the fluid out of the plurality of fluid ports, and onto the stator end-windings to collect heat from the rotor and the stator. The heated fluid may be used for heating a battery.

Abstract: An electric motor includes a case, a stator having stator windings, a rotor having a rotor shaft, and at least one main rotor bearing coupling the rotor shaft to the case. Common mode charge builds up on the rotor due to imbalances of the stator. The at least one main rotor bearing has a first electrical resistance between the rotor shaft and the case. The electric motor further includes a rotor discharge bearing coupling the rotor shaft to the case. The rotor discharge bearing has a second electrical resistance between the rotor shaft and the case that is less than the first electrical resistance, causing the common mode charge to discharge through the rotor discharge bearing. In a differing embodiment, a rotor discharge brush coupled between the case and the rotor shaft along the longitudinal axis of the rotor shaft discharges the common mode charge.

Abstract: The invention provides a chemical-mechanical polishing composition including first abrasive particles, wherein the first abrasive particles are wet-process ceria particles, have a median particle size of about 40 nm to about 100 nm, are present in the polishing composition at a concentration of about 0.005 wt. % to about 2 wt. %, and have a particle size distribution of at least about 300 nm, a functionalized heterocycle, a pH-adjusting agent, and an aqueous carrier, and wherein the pH of the polishing composition is about 1 to about 6. The invention also provides a method of polishing a substrate, especially a substrate comprising a silicon oxide layer, with the polishing composition.

Abstract: The invention provides a chemical-mechanical polishing composition including first abrasive particles, wherein the first abrasive particles are wet-process ceria particles, have a median particle size of about 40 nm to about 100 nm, are present in the polishing composition at a concentration of about 0.005 wt. % to about 2 wt. %, and have a particle size distribution of at least about 300 nm, a functionalized heterocycle, a pH-adjusting agent, and an aqueous carrier, and wherein the pH of the polishing composition is about 1 to about 6. The invention also provides a method of polishing a substrate, especially a substrate comprising a silicon oxide layer, with the polishing composition.

Abstract: The invention provides a chemical-mechanical polishing composition including first abrasive particles, wherein the first abrasive particles are wet-process ceria particles, have a median particle size of about 40 nm to about 100 nm, are present in the polishing composition at a concentration of about 0.005 wt. % to about 2 wt. %, and have a particle size distribution of at least about 300 nm, a functionalized heterocycle, a pH-adjusting agent, and an aqueous carrier, and wherein the pH of the polishing composition is about 1 to about 6. The invention also provides a method of polishing a substrate, especially a substrate comprising a silicon oxide layer, with the polishing composition.

Abstract: The invention provides a chemical-mechanical polishing composition including first abrasive particles, wherein the first abrasive particles are wet-process ceria particles, have a median particle size of about 40 nm to about 100 nm, are present in the polishing composition at a concentration of about 0.005 wt. % to about 2 wt. %, and have a particle size distribution of at least about 300 nm, a functionalized heterocycle, a pH-adjusting agent, and an aqueous carrier, and wherein the pH of the polishing composition is about 1 to about 6. The invention also provides a method of polishing a substrate, especially a substrate comprising a silicon oxide layer, with the polishing composition.