Abstract: The present invention improves the heat resistance and strength of insulation material inserted between a core and a coil of an electrical machine. A slot liner is placed between a core of an electric motor of an electric machine and a conductor of a coil. The slot liner has a multi-layer construction with an aggregate mica insulation sheet, which has excellent mechanical strength, and a peeled mica insulation sheet, which has excellent voltage resistance at high temperatures. The slot liner can include a main insulation sheet and a reinforcement sheet. The reinforcement sheet is placed between the main insulation sheet and the core at the ends of the slot.

Abstract: A motor is provided in which zero-point positioning of the stator and rotor in the axial direction is simple. The operation of replacing the rotor or stator can be done easily. A motor is provided in which zero-point positioning of the stator and rotor in the axial direction is simple and the detection precision can be improved. In a canned motor, a bearing wear monitoring device monitors the wear of the bearings that supports the rotor. The wear of the bearings is determined by measuring the displacement of the rotor based on the output signal of detection coils that are provided in embedding core units on both axial ends of the stator. The center of the embedding core unit at one axial end of the stator and the end face of one axial end of the stator are positioned to coincide with one another. The other axial end of the rotor is made to protrude outside the embedding core unit of the other axial end of the stator by a prescribed dimension.

Abstract: A wear monitoring device for a motor employs pairs of coils on each end of a motor stator. The coils face the rotor and are sensitive to the gap between the rotor and the stator. Each pair of coils is interconnected in series to generate a differential output. Each pair of coils is positioned opposite the other of the pair so that when, as a result of bearing wear, the gap increases between one coil of a pair and the rotor and decreases between the other coil of the pair, a signal is generated on the output. Since the coils are positioned at a separation of 180 degrees and interconnected to produce a differential output, the fundamental-harmonic voltage is canceled out in the differential signal. The differential signal corresponding to pairs of coils located on opposite axial ends of the stator are applied in parallel through respective diodes to a voltage indicator. Thus the voltage indicator is responsive to bearing wear causing the rotor axis to tilt with respect to the stator axis.

Abstract: A slender motor for a cannned motor pump in which a motor rotor is provided between a pair of bearings on a rotor shaft, and a motor stator is provided throuth a path for a cooling and lubrication liquid around the motor rotor, whereby a ratio of axial length to diameter of the motor rotor is so set as to permit the cooling and lubrication liquid passing through the path to provide a bearing effect on the rotor shaft.

Abstract: A multistage canned motor pump comprising a pump section including a plurality of pump chambers and a motor section behind the pump section, both the sections having in common a single rotation shaft, and further a balance disk between the pump and motor sections, wherein an external circulation system is provided so that a part of a treating liquid discharged from a last stage pump chamber is circulated from a front rotor chamber through a pressure chamber accommodating the balance disk to a rear rotor chamber while the remaining part of the treating liquid is supplied to a rear bearing section for lubrication of the bearing section and further circulated through an external pipe to a pump section port for cooling of the motor section, and wherein an annular balance sheet is provided a verge at a high pressure side of the balance disk in the pressure chamber to control a flow rate of the treating liquid to thereby reduce a pressure of a circulation flow of the treating liquid toward the motor section.