An electric submersible pump (ESP) assembly. The ESP assembly comprises a centrifugal pump, an electric motor mechanically coupled by a drive shaft to the centrifugal pump, wherein the electric motor comprises a stator and a rotor, a bearing, wherein the bearing is disposed inside the electric motor, and a magnetic shield disposed in the electric motor between bearing and the rotor and stator.

A gas dynamic bearing includes a shaft extending along a central axis extending vertically, and a sleeve with a hole opening at least at one end of the sleeve in an axial direction, at least a portion of the shaft housed inside the hole. The sleeve includes dynamic pressure grooves in an inner peripheral surface of the hole. The shaft includes a core portion, and a protective portion that is disposed on an outer peripheral surface of the core portion and that includes at least a portion facing the inner peripheral surface of the hole in a radial direction. The protective portion includes a first protective portion and a second protective portion. The first protective portion is at least above or below the second protective portion in the axial direction, and includes at least a portion with a thickness in the radial direction more than a thickness of the second protective portion in the radial direction.

In a moving body guiding device which supplies lubricating oil between a guiding surface of a supporting body and a sliding surface of the moving body and guides a moving body, a lubricating oil pocket having a periphery enclosed by a land portion is provided on the sliding surface of the moving body, a closed loop oil groove is formed along the inside of the land portion, a front portion and a rear portion inside the lubricating oil pocket communicate with one another by means of a lubricating oil pocket return passage at least partially opening in the oil groove, and lubricating oil that has accumulated in the rear portion, in a movement direction, concomitant with movement of the moving body, flows to the front portion in the movement direction.

A bearing assembly may include a first bearing ring, a second bearing ring, and at least one row of rolling elements having a plurality of rolling elements that are disposed so as to be capable of rolling on a first raceway of the first bearing ring and on a second raceway of the second bearing ring. At least one hydrostatically supported first sliding bearing segment may be disposed on the first bearing ring. Further, the hydrostatically supported first sliding bearing segment may interact with a first bearing face that is disposed on the second bearing ring. The hydrostatically supported first sliding bearing segment may be mounted so as to be movable in a movement direction that is perpendicular to the first bearing face.

In a moving body guiding device which supplies lubricating oil between a guiding surface of a supporting body and a sliding surface of the moving body and guides a moving body, a lubricating oil pocket having a periphery enclosed by a land portion is provided on the sliding surface of the moving body, a closed loop oil groove is formed along the inside of the land portion, a front portion and a rear portion inside the lubricating oil pocket communicate with one another by means of a lubricating oil pocket return passage at least partially opening in the oil groove, and lubricating oil that has accumulated in the rear portion, in a movement direction, concomitant with movement of the moving body, flows to the front portion in the movement direction.

A motor includes a shaft, a shell, a sleeve, an abrasion-resistance piece, a bearing, an oil seal, and several compressed springs. The shaft has an axial line. The shell is connected to the shaft. The sleeve has an accommodating space, and the wall of the accommodating space forms a first inclined surface which is inclined at an angle with respect to the axial line. The abrasion-resistance piece is disposed at the bottom of the accommodating space. The bearing is disposed in the accommodating space, and the outer wall of the bearing forms a second inclined surface corresponding to the first inclined surface. The shaft passes through the bearing and abuts the abrasion-resistance piece. The oil seal is affixed to the wall of the accommodating space and covers the bearing. The compressed springs are connected between the oil seal and the bearing.

A motor includes a shaft, a shell, a sleeve, an abrasion-resistance piece, a bearing, an oil seal, and several compressed springs. The shaft has an axial line. The shell is connected to the shaft. The sleeve has an accommodating space, and the wall of the accommodating space forms a first inclined surface which is inclined at an angle with respect to the axial line. The abrasion-resistance piece is disposed at the bottom of the accommodating space. The bearing is disposed in the accommodating space, and the outer wall of the bearing forms a second inclined surface corresponding to the first inclined surface. The shaft passes through the bearing and abuts the abrasion-resistance piece. The oil seal is affixed to the wall of the accommodating space and covers the bearing. The compressed springs are connected between the oil seal and the bearing.

A gas dynamic bearing includes a shaft extending along a central axis extending vertically, and a sleeve with a hole opening at least at one end of the sleeve in an axial direction, at least a portion of the shaft housed inside the hole. The sleeve includes dynamic pressure grooves in an inner peripheral surface of the hole. The shaft includes a core portion, and a protective portion that is disposed on an outer peripheral surface of the core portion and that includes at least a portion facing the inner peripheral surface of the hole in a radial direction. The protective portion includes a first protective portion and a second protective portion. The first protective portion is at least above or below the second protective portion in the axial direction, and includes at least a portion with a thickness in the radial direction more than a thickness of the second protective portion in the radial direction.

A system includes a hydraulic energy transfer system configured to exchange pressures between a first fluid and a second fluid, wherein the first fluid has a pressure higher than the second fluid. The hydraulic transfer system includes a cylindrical rotor configured to rotate circumferentially about a rotational axis and having a first end face and a second end face disposed opposite each other, a first end cover having a first surface that interfaces with the first end face of the cylindrical rotor, and a hybrid hydrodynamic-hydrostatic bearing system configured to resist axial displacement of the cylindrical rotor.

A hydrodynamic bearing contains a body of which an inner surface forms a cavity arranged to accommodate and surround a rotary shaft. The cavity has a plurality of pads installed on the inner surface so as to support and guide the rotary shaft in rotation in a direction of rotation w from upstream to downstream. Each pad has an upper surface of which one portion, referred to as the active surface, acts as a sliding surface for the rotary shaft. The bearing having at least one pad included in an active angular sector of the bearing and at least one pad included in a passive angular sector of the bearing such that the active surface of each pad of the passive angular sector is lower than the active surface of each of the pads of the active angular sector.