https://repository.utm.md/handle/5014/15 2026-09-21T13:07:35Z https://repository.utm.md/handle/5014/37165 Ball screw variator DULGHERU, Valeriu; CIOBANU, Radu; CIOBANU, Oleg; SLOBODEANIUC, Stanislav The invention relates to the construction of machines, in particular, to transmissions with a variable transmission ratio. The technical result of the invention consists of the following: The execution of the inner bush with a spherical outer surface, on which one (or two) closed sinusoidal grooves with an inclined axis γ1 are executed with the possibility of varying the angle of inclination of the sinusoidal groove(s) ensures the relatively easy variation of the speed of the driven shaft, using gear elements; The implementation of two closed sinusoidal grooves with a phase shift of 180° on the spherical outer surface of the inner bushing, and on the inner spherical surface of the outer bushing two rows of longitudinal grooves inclined at an angle γ2 and γ2+90°, respectively, ensures increased bearing capacity and compensation of axial forces, which occur in the gear; The execution of the mechanism to vary the inclination of the intermediate bushing with gravity elements ensures the automatic variation of the speed of the driven shaft depending on the load. Patent nr. 1765 Y of 2025.02.28 2025-01-01T00:00:00Z https://repository.utm.md/handle/5014/37164 Wind-solar hybrid modular system BOSTAN, Viorel; BOSTAN, Ion; DULGHERU, Valeriu; CIOBANU, Radu; CIOBANU, Oleg; RABEI, Ivan; GUȚU, Marin The invention relates to renewable energy conversion systems, in particular to wind-solar hybrid systems. The modular hybrid wind-solar system includes a cubeshaped housing (1), on the upper face of which the support (2) is installed, on which the photovoltaic installation (3) is fixed. Inside the cube-shaped housing (1) is installed a vertical axis wind rotor (4) with inclined blades (5) installed with a variable angle of attack. The main axis (6) of the vertical axis wind rotor (4) is installed at the intersection of the diagonals of the upper and lower faces of the cube, the lower end of which is connected to an electric generator with permanent magnets (7). The modular hybrid wind-solar system operates in the following way: The photovoltaic installation (3) is fixedly installed on the support (2) in an angular position in the meridional and azimuthal plane optimal in terms of conversion efficiency. In another variant, the photovoltaic installation is installed on a rotating cylindrical support, which intermittently receives rotational movement from the main axis (6) of the vertical-axis wind turbine (4), ensuring orientation to the sun in the meridional and azimuthal planes, including taking into account the seasonal factor. The electrical energy generated by the photovoltaic installation (3) is transmitted to the battery or through an inverter in the network. The air currents, which act on the inclined blades (5), will drive the wind turbine (4) into rotational movement, which is transmitted through the main axis (6) to the permanent magnet electric generator (7). The electrical energy produced is transmitted through a controller in the network or through an inverter to the battery. In another variant, curved plates can be installed on the edges of the cube-shaped housing (1), which form a baffle, which directs part of the air currents from outside the housing (1) towards the inclined blades 5, increasing the conversion efficiency. Installing the curved plate on the top edge of the cube-shaped housing (1) directs air currents under the photovoltaic installation (3), ensuring cooling of the panels, thus contributing to increasing the conversion efficiency of the photovoltaic installation (3). Patent nr. 1771 Y of 2024.08.31 2025-01-01T00:00:00Z https://repository.utm.md/handle/5014/37163 Hybrid propulsion system for a boat DULGHERU, Valeriu; DUMITRESCU, Cătălin; DUMITRESCU, Liliana; RĂDOI, Radu; CRISTESCU, Corneliu; CIOBANU, Ion; CIOBANU, Radu; CIOBANU, Oleg The invention relates to electrically powered boats, namely, to boats powered by renewable energy. Hybrid propulsion system for a boat, consisting of the boat body (1) installed on two floating bodies (2, 3), two wind turbines (4, 5) with vertical axis Darrieus or Savonius type, a solar photovoltaic system (6), a propeller propulsion mechanism (8) and an electrical energy storage system (7). The photovoltaic solar system (6) is fixedly installed on the roof of the boat in a horizontal position, the first wind turbine (4) with a vertical axis is installed on one side of the boat and has a right-hand blade inclination angle, the second wind turbine (5) with a vertical axis is installed on the opposite side of the boat and has a left-hand propeller inclination angle, the vertical shaft of the first turbine is connected through a bevel gear to the stator of an electric generator, and the vertical shaft of the second wind turbine is connected through a second bevel gear to the rotor of a first electric generator. Patent nr. 133039 RO of 2024.03.29 2025-01-01T00:00:00Z https://repository.utm.md/handle/5014/37162 Micro-hydropower plant with individual blade orientation DULGHERU, Valeriu; RABEI, Iva; GUȚU, Marin; CIOBANU, Radu; CIOBANU, Oleg The invention can be used in hydropower and relates to a micro-flow hydropower plant containing a low-power hydraulic turbine, intended for the production of electrical or mechanical energy in individual households, villages, for irrigation in areas near rivers, using the kinetic energy of flowing river water. The micro-flow hydropower plant includes a platform (1) connected to the shore, on which the electric generator (2) and the multiplier (3) are installed, the driving shaft of which is rigidly connected to the main shaft (4) of the hydrodynamic rotor (5). The hydrodynamic rotor (5) includes blades with a hydrodynamic profile (6) installed on the axles (7) each fixed to the free end of the arms (8). The upper end of the shaft (7) of each hydrodynamic profile blade (6) of the hydrodynamic rotor (5) is kinematically connected to the shaft of the reducer (9) and the electric motor (10), connected to a monitoring system (11) of the angular orientation of the hydrodynamic profile blades (6) relative to the water currents. The orientation of the blades relative to the water currents can also be achieved by a lever system or a cam system. Decision granting patent nr. 2540 of 2025.02.27 2025-01-01T00:00:00Z