COMBINED ELECTRIC PROPULSION PLANT OF OPEN TYPE Russian patent published in 2007 - IPC H02K5/12 H02K7/14 B63H23/24 

FIELD: naval electric engineering, in particular, immersed electric machines which may be used in composition of electric propulsion plant of underwater manned and unmanned small-dimension objects with unlimited immersion depth, and also as maneuvering propulsion devices, active rudders of any underwater or above-water objects.

SUBSTANCE: in combined electric propulsion plant, containing a screw built into hollow cylindrical rotor, stator with windings and bearing shields, combined in single structure, an asynchronous electric motor with hollow three-layered rotor is used, which is made in form of assembly of three concentric cylinders of varying thickness of various materials with predetermined electromagnetic properties, in accordance to the invention, external cylinder with thickness h_ext combines functions of working element and screen and has screw-groove profile on the surface, middle working cylinder with thickness h_wrk, in which working vortex currents are induced, is made of separate segments in amount of n_segm, each segment has clean longitudinal grooves in axial direction in amount of n_grv, all segments are mutually closed on ends with current-conductive short-circuit rings, internal cylinder with thickness n_in, acting as magnetic duct, composed of separate plates 0,5-2 mm thick and covered by protective sealing screen on the outside, while geometric dimensions of rotor elements are selected from ratios h_ext=(2-2,5)Δ_ν≈2-3mm, h_wrk=0,9Δ₂, h_in=(1,2-1,5)Δ₃, h_k=Δ_ν, a_k=0,7-1mm, v_k=3-3,5mm, n_segm=2p, h_p=(0,6-0,7)Δ₂, a_n=1,5-2mm, V_n=τ/4, where Δ_ν, Δ₂, Δ₃ - depth of penetration of magnetic field into corresponding cylinder, h_K, a_K and v_k - respectively, depth, width and step of screw groove, 2p - number of poles, h_p, a_p and v_k - respectively, depth, width and distance between longitudinal grooves, τ - polar division of rotor, ν - harmonic of high order field.

EFFECT: suggested combined electric propulsion plant with asynchronous motor makes it possible to fully realize all advantages of asynchronous motors with multi-layer hollow rotor during their operation in composition of propulsion electric plats; motors of aforementioned design are simpler to manufacture as opposed to synchronous ones with constant magnets, are powered by standard three-phased network, controlled by standard launch-control equipment, have no negative influence on powering network, have reduced vibration, ensure best energy characteristics (efficiency and cos φ) with nominal load, and high launch momentum at low launch current, soft mechanical characteristic and high switching speeds improve main operational characteristics of the plant in transfer modes (launch, reverse, rotation frequency adjustment) and increase its efficiency as a whole.

3 cl, 3 dwg