A rotor for an LSIPM comprises a plurality of permanent magnets defining a number of poles (P) of the LSIPM, and a plurality of rotor bars spaced about the rotor defining a rotor bar area (BA). The rotor bars are formed of a conductive material having an associated conductivity (?.sub.RB). End members are disposed on axial opposite ends of the rotor core. The end members are in electrical contact with the rotor bars. The end members are formed from a material having an associated conductivity (?.sub.EM). Each end ring member has a minimum geometric cross sectional area (ERA) and outer diameter that generally corresponds to the rotor core outer diameter. The ERA is greater than 0.5 times the rotor bar area per the number of poles (BA/P) times a ratio of the rotor bar material conductivity to the end member material conductivity (?.sub.RB/?.sub.EM).

Disclosed in the present invention is a shaft construction for motor-generators and alternators that provides effective airflow and improved overall cooling without the need for an external fan. The shaft comprises a plurality of circumferentially disposed centrifugal fan blades and longitudinal cooling channels. As the shaft rotates, the centrifugal fan blades pull the air inwardly across the winding end-turns on one end of the stator into the housing and propels the air at high pressure through the cooling channels along the shaft to cool the rotor inner circumferential surfaces, winding end-turns on the other end of the stator and bearings mounting surfaces, and exhausts through the exhaust vents on the ends of the housing. The airflow path provides effective cooling of the stator windings, rotor, shaft and bearings that prevents high temperature gradients, thus resulting in improved motor-generator performance.

A rotor for an electric machine having a rotor shaft, a winding support coupled to the rotor shaft in rotationally fixed manner, and at least one winding arranged on the winding support or a squirrel cage arranged on the winding support, wherein the rotor includes at least one heat pipe running at an angle to the rotor shaft.

A downhole tubing rotator that has a housing configured into a production tubing string in a well in a reservoir, the housing being generally cylindrical with a hollow center and containing a two pole, three phase induction squirrel cage motor operatively connected to a tubing rotator configured to clamp onto a production tubing joint and rotate one or more production tubing joints (but not an entire production tubing string) when the motor is activated. An armor-protected insulated power and control cable connects the motor to a control box positioned at a surface of a reservoir and various sensors provide feedback for the unit. Methods of using this tool are also provided.

A squirrel-cage rotor has at least one laminated rotor core that has grooves and the squirrel-cage rotor has at least one rotor cage with electrically conductive rotor bars that are embedded in the grooves of the laminated rotor core in such a manner that the rotor bars have at their two end regions an overlap beyond the laminated rotor core, and the rotor cage has short-circuit rings that are attached at the end face to the laminated rotor core and have slots that are arranged in the region of their outer periphery and the end regions of the rotor bars protrude into said slots.

An AC electric machine that includes a dual magnetic phase material ring is disclosed. The AC electric machine includes a stator assembly and a rotor assembly positioned within the stator assembly and configured to rotate relative thereto, the rotor assembly comprising a rotor core including a stack of rotor laminations that collectively form the rotor core, the rotor core including a plurality of rotor poles separated by gaps therebetween. The AC electric machine also includes a dual magnetic phase material ring positioned about the stack of rotor laminations, the dual magnetic phase material ring comprising a first ring portion comprising a magnetic portion and a second ring portion comprising a non-magnetic portion.

A rotor for an electric machine. A laminated core with a plurality of short-circuit bars that pass through it and are joined at both ends by way of a respective short-circuit ring. A support disc, which is made of a material that has a higher strength than the material of the short-circuit ring, is axially arranged at each short-circuit ring.

A magnetic mass for an electric machine rotor movable about an axis extends along the axis and comprises: first longitudinal through-holes able to receive a respective first tie rod and at a first distance with respect to the axis of rotation, in a radial direction substantially perpendicular to the axis of rotation; first tie rods, received in a respective first longitudinal hole. The magnetic mass also comprises: at least one second longitudinal through-hole able to receive a respective second tie rod and at a second distance with respect to the axis of rotation in a radial direction substantially perpendicular to the axis of rotation, the second distance being different from the first distance, and at least one second tie rod received in a respective second longitudinal hole.

A motor is disclosed. The motor includes a stator with a stator coil to generate a periodic magnetic field and a rotor. An air gap is disposed between the stator and the rotor. The rotor has at least one rotor ring, a portion of the rotor ring is disposed in the air gap. Due to the magnetic field, a periodic current is induced in the rotor ring. The current flowing through the portion of the rotor ring disposed in the air gap flows in a first direction to rotate the rotor relative to the stator.

The rotor for an electrical machine with a non-through shaft intended to drive a transmission line comprises two half-shafts enclosing a cylindrical magnetic mass. The magnetic mass comprises at least two adjacent identical cells, the cells being configured to prevent the propagation of metadamping in the rotor over a range of excitation frequencies of the transmission line, the rotation frequency range of the transmission line being hypercritical.