A submersible pump electrical motor has a stator with a stator bore, a shaft with rotor sections in the stator bore, and a shaft bearing between rotor sections. The bearing has a bearing body having a hub and centralizing arms circumferentially spaced around the hub. Each of the arms curves and is biased against the stator bore wall. A tab on at least one of the arms engages a slot in the stator bore wall. The bearing body, the hub, and the arms are formed of a single-piece monolithic metal that undergoes elastic deflection of the arms when the bearing body is installed in the stator bore.

A coaxial pump or turbine module includes an integral, modular motor or generator comprising a magnet structure containing radial or axial permanent magnets and/or induction coils detachably fixed to a rotor, and a stator housing detachably fixed to the module housing. Working fluid is directed axially through a flow path symmetrically distributed within an annulus formed between the module housing and the stator housing. The stator housing can be cooled by the working fluid, or by a cooling fluid flowing between passages of the flow path. The flow path can extend over substantially a full length and rear surface of the stator housing. A plurality of the modules can be combined into a multi-stage apparatus, with rotor speeds independently controlled by corresponding variable frequency drives. Embodiments include guide vanes and/or diffusers. The rotor can be fixed to a rotating shaft, or rotate about a fixed shaft.

A motor may include a rotor comprising a rotating shaft and a bearing component structured to rotatably support. The bearing component may include a sliding surface that the rotor sliding-contacts from a first side in an axial direction. The rotor may include a holding member structured to hold the rotating shaft from an outer circumferential side; a magnet held by the holding member; and a metal component fixed to the rotating shaft and held by the holding member so as to protrude to the outer circumferential side from the rotating shaft.

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 electric submersible pump assembly with integral heat exchanger, high-speed self-aligning bearings, and dual bearing thrust chamber is described. The described pump assembly, modules, and components may be used for operating an electric submersible pump at high speeds as well as over a wide range of speeds and flowrates without replacing downhole equipment. The described pump assembly may be shorter than comparable pump assemblies and may be assembled offsite, thereby leading to faster and easier installation with less down time. By operating over a wide range of speeds, the disclosed pump assembly allows the operator to reduce overall inventory, reduce down time for the well, and avoid other complications associated with replacing a pump assembly or other downhole components.

A rotating portion includes a hollow shaft extending along a central axis. The hollow shaft includes a through hole passing therethrough in an axial direction. The rotating portion includes an upper screw to close an upper opening that is an opening at an upper end portion of the through hole. The rotating portion includes a lower screw to close a lower opening that is an opening at a lower end portion of the through hole. The hollow shaft includes an upper groove portion into which the upper screw is screwed at the upper opening. The hollow shaft includes a lower groove portion into which the lower screw is screwed at the lower opening. A lubricating oil is in contact with the lower screw. The lower groove portion is shorter in axial length than the upper groove portion, and the lower screw is smaller in axial pitch than the upper screw.

A fluid dynamic bearing device includes a shaft disposed along a center axis, a sleeve cylindrically extending around the shaft, a thruster that closes a lower end of the sleeve, dynamic pressure grooves in the shaft or the sleeve, and a lubricating oil present therebetween. The shaft includes a shaft main body and a shaft flange extending radially outward from a lower end of the shaft main body. An inner peripheral surface of the sleeve includes a first inner peripheral surface that faces an outer peripheral surface of the shaft main body in the radial direction and a second inner peripheral surface that faces an outer peripheral surface of the shaft flange in the radial direction. The sleeve includes a sleeve inner lower surface and a circulation hole.

An electric submersible pump assembly with integral heat exchanger, high-speed self-aligning bearings, and dual bearing thrust chamber is described. The described pump assembly, modules, and components may be used for operating an electric submersible pump at high speeds as well as over a wide range of speeds and flowrates without replacing downhole equipment. The described pump assembly may be shorter than comparable pump assemblies and may be assembled offsite, thereby leading to faster and easier installation with less down time. By operating over a wide range of speeds, the disclosed pump assembly allows the operator to reduce overall inventory, reduce down time for the well, and avoid other complications associated with replacing a pump assembly or other downhole components.

A lubricant supported electric motor includes a stator presenting a stator raceway, and a rotor movable relative to the stator about an axis. The rotor presents a rotor raceway disposed in radially spaced and opposing relationship with the stator raceway to define a gap therebetween. A lubricant is disposed in the gap for supporting the rotor relative to the stator. The stator raceway includes a bearing structure comprised of a plurality of hydrodynamic surfaces aligned in parallel relationship along the stator raceway and a plurality of hydrostatic pockets disposed in radially recessed relationship relative to the hydrodynamic surfaces.

A motor includes a shaft along a central axis, an inner ring fixed on an outer circumferential surface of the shaft, a tubular sleeve extending axially around the shaft, an outer ring fixed to an inner circumferential surface of the sleeve via an adhesive agent, a cap annularly expanding around the shaft and covering an axially upper side of the inner and outer rings, and a bearing portion including dynamic pressure grooves in at least one of an outer circumferential surface of the inner ring and the inner circumferential surface of the sleeve. In the bearing portion, a stationary portion and a rotating portion face each other across a gap where lubricating oil is present. At least one interface of the lubricating oil is in a radial gap between the inner and outer rings. The cap includes a recess recessed axially downward over an entire circumference. At least a portion of an outer circumferential surface of the recess portion is fixed by press-fitting to an inner circumferential surface of the sleeve.