Patent RU-2529294-C1 (RU)
Inventor: DIDOV VLADIMIR VIKTOROVICH
IPC: F01D15/08
Filed: 2013-08-07
Granted: 2014-09-27
Abstract: FIELD: engines and pumps. 
     SUBSTANCE: first cup-like journal of the first magnetic bearing assembly directed by its bottom to turbine wheel is fitted on engine cylindrical bush adjoining the turbine wheel. Note here that second cup-like journal of the second radial thrust magnetic bearing directed with its bottom to compressor wheel is fitted on the shaft free end. First and second thrust gas bearings, centrifugal compressor wheel and equaliser washer are fitted thereon and locked by nut. Every radial magnetic bearing comprises thin-wall sleeve made of nonmagnetic material. Sleeve outer surface has poles arranged regularly in circle and shaped to trapezoid-like strips made of material with high magnetic permeability. Trapezoid-like strips made of magnetic material arranged between the latter to contact with said poles by side faces. The latter magnetised over axial length in tangentially opposite direction. Wide cross-section base of magnetic strips face the thin-wall surface. Wedges made of strips of nonmagnetic materials are arranged on narrow base side rigidly secured flush with side faces of the poles. Said wedges contact with magnetic strip to make the cylindrical surface extending in working clearance of radial magnetic bearing. Circular ledges of the first and second cup-like journals are fitted in circular recesses. Said ledges are furnished with ring of high-strength fibre on binder made of solidifying synthetic resin. Said ledges are fitted in appropriate ring grooves made in spacer arranged between turbine and compressor casings. Note here that one of ring grooves is opened to compressor while another to turbine. Corrugated sleeve with lengthwise crimps is arranged between the surface of ring grooves and made of resilient material. Inner surfaces of cup-like journal is coated with copper layer and finished to high purity. Thrust magnetic bearing comprises toe bearing made of nonmagnetic material and arranged in cylindrical bore of cup-like journal. Sectors of poles of material with high magnetic permeability are secured between journal bottom and toe bearing surface. Sectors of permanent magnets and sectors of poles are composed by trapezoidal-section strips in contact by side edges. Note here that magnetic sectors face the cylindrical recess bottom by their section wide base. Their narrow bases are covered by flat wedges of nonmagnetic material. Their end surfaces are rigidly secured with end surfaces of appropriate poles to make flat surface which makes with cup-journal the working clearance of thrust magnetic bearing. Radial and thrust magnetic bearings are made of magnetic material with Courier point not lower than 900°C. Elastic washer made of resilient material deformed to make circular crimps is arranged between toe bearing and bottom of bore of both magnetic bearings. Magnetic radial and thrust bearings are locked in place. Axial gas-dynamic bearing comprises spacer and seal with spacer ring arranged there between. Note that first and second thrust gas bearings separated by common toe bearing are fitted there between. Radial gas-dynamic bearing is arranged in clearance between the spacer cylindrical cavity and sleeve surface facing the latter. 
     EFFECT: reliable starting at low temperatures, higher reliability at high dynamic loads and operating efficiency. 
     2 cl, 6 dwg