Abstract: Magnetic sample holders for abrasive operations include an array of magnets embedded in a matrix material. Each magnet of the array is positioned between about 0 mm and about 4 mm from at least one adjacent magnet of the array. Exposed surfaces of the magnets of the array are coplanar with a planar working surface of the matrix material. Methods of forming a polycrystalline diamond compact element include magnetically securing an alloy sample to an array of magnets embedded in a matrix. Each of the magnets of the array is within about 4 mm of at least one adjacent magnet of the array. A portion of the alloy sample is abraded away, and the alloy sample is positioned proximate to diamond grains and a substrate. The alloy sample, diamond grains, and substrate are subjected to a high pressure/high temperature process to sinter the diamond grains.

Abstract: A rotor, motor, pump and a cleaning apparatus are provided. The rotor includes a shaft and two magnets fixed to the rotary shaft. Each magnet comprises a radial outer surface, a radial inner surface, and two connecting surfaces that connect the radial outer surface and the radial inner surface at opposite ends of the magnet. The radial outer surface has an arc section. The radial inner surfaces of the two magnets cooperatively define an inner bore for the shaft to pass therethrough. A ratio of a pole arc angle of each magnet to a 180-degree angle is in the range of 0.75 to 0.95.

Abstract: An electric motor (100) features a external stator (28), an internal rotor (150) rotatably mounted within the external stator, the rotor having a lamination stack (200, 200?, 200?) composed of a plurality of rotor plates (201, 201?, 201?) in which are formed at least one first recess (614) and at least one second recess (630), a rotor magnet (224) being located in each first recess (614), the second recess (630) being associated with a jamming element (40) mounted therein. A clamping member (692,694) is arranged between the first recess (614) and the second recess (630). The clamping member and the second recess (630) are shaped so as to enable support of the jamming element (40) on the lamination stack, and to permit application of a force (F) on the clamping member in the direction of the rotor magnet. The second recess (630) serves as a through-opening for receiving a shaft (40), and the shaft (40) serves as the jamming element (40).