An inner-rotor motor including: an armature assembly including a rotating shaft, an armature unit coupled to the rotating shaft and a pressing unit; a frame assembly including a frame housing the armature unit, a first bearing unit located on one side with respect to the armature unit in an axial direction, and a second bearing unit located on another side with respect to the armature unit in the axial direction; and an urging structure that urges the rotating shaft in a direction away from the second bearing unit and that presses the pressing unit toward the first bearing unit.

Brushless electric motor for an electric handheld power tool, wherein the electric motor has an end plate and a Hall board which is arranged on the end plate, wherein the Hall board is axially fixed to the end plate by an elastic O-ring.

An electric motor comprises a stator presenting a first surface. A rotor is rotatable relative to the stator. The rotor presents a rotor raceway disposed in spaced relationship with the first surface of the stator. The first surface of the stator defines a plurality of slots in spaced relationship with one another to define a plurality of spaced teeth between the slots. At least one electrical conductor is disposed in each of the slots and configured to selectively create a moving magnetic field for acting upon the rotor for providing rotational movement of the rotor. A portion of the at least one electrical conductor extends substantially into radial alignment with, or past the first surface of the stator to at least partially define a stator raceway of the stator for engaging the rotor raceway of the rotor during relative radial movement between the rotor and the stator.

A rotary electric machine includes an enclosure delimiting an internal space for stator and rotor units. An access hole gives access to the internal space. An internal gasket encircles the access hole adjacent a wall of the enclosure. A closing element is disposed in the internal space, movable towards and away from the wall between a closed configuration compressing the gasket to seal the access hole and an open configuration connecting the internal space with the surrounding atmosphere. An elastic device operates to move the closing element from the open to closed configurations to compress the gasket and seal the access hole. The closing element has a pressure surface facing the access hole and accessible through the access hole via a pin. Pressing the pressure surface causes the closing element to move from the closed configuration to the open configuration.

An electric field mill (EFM) incorporates a novel rotor and shaft grounding mechanism providing a low-impedance path to ground via a bearing packed with electrically conductive grease. A removable bearing washer allows for servicing. The EFM includes a data processing scheme built around a peak detection algorithm and moving much of the signal processing to digital processing. A GPS disciplined sampling clock and cellular connectivity allow for use and maintenance of arrays of widely scattered EFMs.

An apparatus for generating acoustic waves within a medium to stimulate oil recovery within an oil reservoir. The apparatus is operable with a single moving part—a central rotor, and the rotor further includes a “conduit” through which the supply fluid passes.

Systems and methods for increasing hydrocarbon production using an electrical submersible pump are described. The methods typically include, for example, configuring an electrical submersible pump comprising a gas separator to induce a gas lift effect in a well comprising a tubing within a casing. Hydrocarbon production from the well is therefore increased using the electrical submersible pump.

An electrical machine includes a stator with a stator body supporting an electrical stator and a rotor. The rotor is supported by a bearing having a radial bearing section forming a radial gas bearing and an axial bearing section forming an axial gas bearing, the stator side parts of these bearing sections being a stator side radial bearing part and a stator side axial bearing part that are rigidly connected to one another and together form a stator bearing structure. The stator bearing structure is mounted to the other parts of the stator by either the stator side radial or axial bearing part being rigidly mounted to these other parts, and the other bearing part are connected to these other parts by an elastic support or not at all.

An airfoil journal bearing journal bearing includes a bearing housing for rotatably supporting a rotation shaft and including a hollow through which the rotation shaft is inserted, and an airfoil between an inner circumferential surface of the bearing housing and an outer circumferential surface of the rotation shaft. The airfoil includes a first foil region extending in a circumferential direction and enclosing the circumference of the rotation shaft between 180 to 360 degrees, and a pair of second foil regions connected to opposite edges of the first foil region in an axial direction of the rotation shaft, extending in the circumferential direction and enclosing the circumference of the rotation shaft between 180 to 360 degrees, and including a plurality of elastic bumps formed in the circumferential direction on the surface of the second foil regions.

An airfoil journal bearing journal bearing includes a bearing housing for rotatably supporting a rotation shaft and including a hollow through which the rotation shaft is inserted, and an airfoil between an inner circumferential surface of the bearing housing and an outer circumferential surface of the rotation shaft. The airfoil includes a first foil region extending in a circumferential direction and enclosing the circumference of the rotation shaft between 180 to 360 degrees, and a pair of second foil regions connected to opposite edges of the first foil region in an axial direction of the rotation shaft, extending in the circumferential direction and enclosing the circumference of the rotation shaft between 180 to 360 degrees, and including a plurality of elastic bumps formed in the circumferential direction on the surface of the second foil regions.