FIELD: electric engineering, in particular, specific structural features of electric machines, namely - inductive generators.
SUBSTANCE: in synchronous generator, which contains frontal and back lids with apertures, stator in form of a packet with working winding, rotor with excitation source, hollow shaft of rotor with radial apertures and with central aperture, which is connected to input aperture of cooling system, air conductor and rectifier, according to given invention, rectifier is made in form of horizontal assembly with linear placement of diodes, where horizontal assembly is positioned in aperture of hollow shaft and held by cantilevers which pass through walls of air ducts and are held on lids. Usage of aforementioned structure allows substantial improvements to generator cooling, especially that of its rectifier, which is positioned first along air route, and also provides for increased compactness of structure, because shaft hollow is used for placement of rectifier, which simultaneously allows to reduce axial dimensions of generator.
EFFECT: improved operational characteristics due to reduction of consumed power and improvement of thermo-physical characteristics.
The invention relates to electric machines, and in particular to synchronous generators.
Known synchronous generators containing the shaft, cover with bearings, a shaft mounted rotor in the form of stars with magnetic contact with the stator, in addition to one of the covers (unilateral action) set coil winding with the magnetic circuit being in magnetic communication with the second axial magnet mounted on the rotor and having a magnetic contact with an asterisk. The same coil can be mounted on the second cover (bilateral stimulation). Structural variants of a given generator is described, for example, in .
The disadvantage of this machine are large masses and dimensions, and that the end windings of the stator behind the stator during the cooling air cools the already heated from the frontal parts of the air, lying in front of the stator.
Closest to the claimed invention to the technical essence and the achieved results is contactless synchronous generator , which contains the front and back cover with holes, a stator in the form of a package with an operating winding, a rotor with excitation source, a hollow rotor shaft with a radial hole; the hole of the hollow shaft is connected with the inlet of the cooling system, the air duct, the rectifier.The disadvantage of this device is the low efficiency of the ventilation effect of the slits in the area of the curve claw poles, as these slots have a relatively small area, and low efficiency of the ventilating action of the claw poles because of their console location.
The technical result consists in the improved performance by reducing power consumption and improve thermal characteristics, is ensured by the fact that in a synchronous generator, containing front and back cover with holes, a stator in the form of a package with an operating winding, a rotor with excitation source, a hollow rotor shaft with radial holes, the hole of the hollow shaft is connected with the inlet of the cooling system, the air duct, the rectifier, while, according to the invention, the rectifier is made in the form of a horizontal Assembly with a linear arrangement of the diodes, while the horizontal Assembly is placed in the hole of the hollow shaft and is fastened using brackets passing through the wall of the passage and secured to the covers.
The drawing shows a General view of the synchronous generator.
The generator contains inlet pipe 1, the drive pulley 2, the front cover 3, a stator 4 with the coil, the clamping screws 5, the back cover 6, which is the case is prameela 7. The hollow shaft 9 provided with a cover 8. In the shaft a radial holes 10 and 11, the lid 3 and 6 are radial holes 12. On the shaft is installed asterisk with the body 13 and teeth 14. The asterisk adjacent axial magnetic core 15, which is in magnetic contact through the gap 16 with the magnetic coil 17 and 18. The coil is equipped with ferromagnetic cheek 19 having radial slots 20 located opposite the holes 10 and 11. The shaft rotates in bearings 21, the drive pulley 2 mounted on the shaft 9 by pins and nuts 22, the shaft has a Central inlet opening 23 of the cooling system. The rectifier is made in the form of a horizontal Assembly having a rod 24, which is fixed to the diode 25 with radiators 26. The rod 24 is fixed to the bracket 27, passing through the wall of the entrance lad 1 air duct and is secured to the front cover 3.
The device operates as follows. The input flow of air through the pipe 1 enters the Central hole 23, in which is placed a horizontal Assembly with diodes 25 and radiator 26. The air passes through a radial hole 10 and 11, then the centrifugal effect caused by the presence of teeth 14 stars who play the role of the blades, is ejected through the holes 12 in the cover 3 and 6 in the environment. However, due to the symmetric double-sided excitation,and the symmetrical arrangement of apertures 10, 11 and 12, both side end parts of the stator are cooled by the fresh air, not heated, as in the generators of the traditional type.
The use of this design can significantly improve the cooling of the generator, especially the rectifier, which is located on the first move air, it also significantly improves the compactness of the design, since the hollow shaft is used for the rectifier, which simultaneously makes it possible to reduce the axial dimension.
Sources of information
1. Zhezherin R.P. Induction generators / M.-L., Gosenergoizdat, 1961, 319 S., Il.
2. RF patent №2231199 - Contactless synchronous generator / A.m.litvinenko, application No. 2003109938, publ. 07.04.2003, bull. No. 17, IPC 7 NC 19/06.
Synchronous generator containing the front and back cover with holes, a stator in the form of a package with an operating winding, a rotor with excitation source, a hollow rotor shaft with radial holes, the hole of the hollow shaft is connected with the inlet of the cooling system, the air duct, the rectifier, wherein the rectifier is a horizontal Assembly with a linear arrangement of the diodes, while the horizontal Assembly is placed in the hole of the hollow shaft and is fastened using brackets, passing through the walls of the passage and secured to the covers.
FIELD: electric engineering and electric mechanical engineering, namely - systems for cooling electric machines, primarily turbo-generators, with closed ventilation cycle.
SUBSTANCE: in accordance to the invention, electric machine includes body (1), comprising coolers (5), (6) of stator (2) and rotor (4), stator (2), having radial channels (11) in end zones of core, rotor (4), installed in stator (2) with air gap and having ventilation channels (13) with inputs and outputs on different rotation radiuses, ventilators (7), positioned on both sides of rotor barrel, and chambers (8), (9), one of which, chamber (8) for collecting cold air, is positioned between coolers (5) of stator and external surface of stator core (2), and another one, chamber (9) for collecting heated air, is positioned in placement zones of frontal parts of winding (10) of stator (2), outputs of stator coolers (5) and inputs into radial channels (11) of end zones of stator core are connected to chamber (8) for collecting cold air, and outputs of radial channels (11) of end zones, inputs of rotor coolers (6), inputs into ventilators (7) and outputs of rotor channels are connected to chamber (9) for collecting heated air, while outputs of coolers (6) of rotor (4) are connected to inputs of rotor channels, and high pressure zone (14) of ventilators (7) is connected to stator coolers inputs. In accordance to the invention, press plates have channels (12), inputs of which are connected to chamber (8) for collecting cold air, and outputs are connected to chamber (9) for collecting hot air, and main zone of stator core has water cooling system in form of coolers, positioned between packets (3) of stator core. Method for cooling the electric machine characterized above is realized as follows. Cooling air from stator coolers through the chamber for collecting cold air of stator, set up between stator coolers and external surface of stator core, and from rotor coolers, is directed by means of forcing elements, namely ventilators, positioned on both sides of rotor barrels, and rotor channels, along various routes into channels of rotor and stator core, and the air heated up in these channels is directed into chamber for collecting heated air, set up in zones of placement of frontal parts of stator winding, to inputs of rotor coolers and to inputs of ventilators and further - to stator coolers, where one route is set up from stator coolers, from outputs of which cooling air is directed from external surface of stator core into radial channels of end zone of stator core, another route is set up from rotor coolers, from outputs of which cooling air is directed into rotor channels. One more route, in accordance to the invention, is set up starting at rotor coolers, from outputs of which cooling air is directed into channels of press plates of stator core, while cooling of stator winding and main stator core is performed by water, circulating in pipes of coolers, which are positioned between main stator core packets.
EFFECT: increased cooling efficiency of stator winding and core, reduced material consumption of high power electric machines.
2 cl, 1 dwg
FIELD: electrical engineering.
SUBSTANCE: proposed motor-fan unit that can be used, for instance, in mining mechanical engineering is built around squirrel-cage induction motor and has frame with stator and rotor mounted therein. Novelty is that rotor carries fan blades, stator and rotor have conical surfaces, angles at vortices of stator and rotor cones are greatly different with respect to their contact between mentioned conical surfaces in absence of their wedging to afford antifriction bearing function, and stator mounts cleat preventing rotor-to-stator shift , for instance in axial direction.
EFFECT: simplified design at enhanced operating reliability of motor-fan unit.
1 cl, 2 dwg
FIELD: electromechanical engineering; automatic control systems for maintaining temperature and moisture content of electrical machine windings within desired optimal values.
SUBSTANCE: novelty is that newly introduced in electrical machine computer unit are machine temperature and moisture content mathematical model unit, correction unit, measuring unit, comparison unit, and control action signal shaping unit. Applied to inputs of mathematical model unit are signals arriving from outputs of machine and drier current and voltage sensors, machine and fan shaft speed, cooling medium temperature, and cooling duct outlet air moisture content sensors, as well as control action correcting computation process of armature, main-pole, and interpole winding insulation local maximal temperature and moisture content. Correcting unit functions to compare calculated and measured values of mean temperature and moisture content of main-pole, compensating, and interpole winding insulation, mean calculated values of these parameters passed from mathematical-model unit, and their measured values picked off measurement unit being applied to correction unit input; control action correcting computation of mentioned parameters picked off correction unit is sent to mathematical-model unit. Comparison unit is used to compare calculated values of mentioned parameters with their desired values and to generate error signals applied to comparison unit input which present difference between calculated and desired values of mentioned parameters; applied to comparison unit inputs are calculated values of mentioned parameters arriving from mathematical-model unit output as well as desired values of these parameters. Output signal of control-action signal shaping unit is passed to input of machine cooling system fan controlled drive; comparison-unit output error signals, signal indicating device change-over to emergency running taken off correction unit, as well as signals picked off electrical-machine output power computing unit and from electrical-machine current sensor are passed from correction unit to shaping-unit inputs.
EFFECT: enlarged functional capabilities.
3 cl, 2 dwg
FIELD: electromechanical engineering; rotors of air-cooled electrical machines.
SUBSTANCE: proposed rotor is provided with guide vanes made of nonmagnetic material and tangentially disposed between poles, baffle plates in the form of semi-bowl, radial troughs disposed on butt-end surface of rotor, and axial ducts communicating with respective radial ones. Rotor incorporates provision for raising current density thereby enhancing electrical machine efficiency.
EFFECT: improved cooling conditions for all stator and rotor parts, reduced temperature and enlarged service life of windings.
5 cl, 4 dwg
FIELD: electrical and electromechanical engineering; closed-cycle cooling systems for turbogenerators and other electrical machines using fans as delivery members.
SUBSTANCE: proposed method for gas cooling of electrical machine using closed-cycle exhaust-ventilation system involves delivery of cooling gas from stator coolers and from rotor coolers through fans disposed either side of rotor barrel and through rotor ducts, whose inlets and outlets are disposed on different radii of rotor motion, over three parallel paths to rotor ducts and stator core ducts; gas heated within these ducts is conveyed to stator and rotor coolers through hot gas accumulating chamber organized in vicinity of stator end windings. In the process gas heated in rotor ducts and some portion of gas heated in stator ducts is conveyed by means of fans to stator coolers, and remaining portion of gas heated in stator ducts is passed directly to rotor coolers. For implementing this method, electrical machine is provided with cooling ducts in main area of stator core uniformly distributed over its circumference. Entrance in and exit from each duct is made on core outer surface so that they do not communicate with stator-to-rotor gap thereby eliminating intercommunication between stator and rotor cooling systems and affording uniform winding and iron temperature distribution through length and circumference of stator core. Hot gas formed in stator-to-rotor gap does not reach stator ducts which raises stator winding and iron cooling effectiveness. Proposed cooling system provides for reducing slot height and stator core outer diameter thereby enabling reduction of material input due to reduced consumption of electric steel, winding copper, and high-voltage insulating materials. Novelty is also that cooling of stator core butt-end part is organized over single-jet circuit in which gas flows over radial cooling ducts between iron stacks from stator core periphery to end windings thereby raising cooling effectiveness for stator core butt-ends and ensuring electrical machine running consuming reactive-power. Total gas flow circulating in electrical machine cools down stator end windings and its butt-end structural components which makes it possible to dispense with any additional delivery sources for cooling these components.
EFFECT: enhanced efficiency due to reduced windage loss, augmented cooling efficiency of stator core and winding, and reduced material input.
1 cl, 1 dwg
FIELD: mechanical engineering; rotary electrical machines such as air-cooled turbogenerators with closed-circuit cooling system.
SUBSTANCE: proposed electrical machine provided with closed-circuit cooling system has frame with stator accommodating wound rotor whose shaft is mounted on magnetic journal bearings; coolers incorporating vents and built in frame; and exciter mounted on rotor shaft; novelty is that machine frame encloses stator and rotor, magnetic bearings and exciter are provided with respective housings integrated in electrical machine cooling system by means of air ducts providing communication between machine frame and bearing housings as well as between the former and exciter housing.
EFFECT: facilitated maintenance and adjustment of cooling system; enhanced cooling efficiency of bearings and exciter.
7 cl, 5 dwg
FIELD: electric engineering, possible use in all controllable drives: propeller screws, electricity-driven transportation means, power plants of aircrafts, engines for conveyors, pumps, including down-pumps, hoisting equipment, mining machines, plants, tools, home appliances and the like.
SUBSTANCE: inductor engine consists of salient-pole rotor and salient-pole stator with phase windings concentrated at its poles, connected to direct current network through inverter with two controllable semiconductor keys in each phase. Phase windings in the engine are made with even number of phases, which are connected in pairs in parallel circuits, in each branch of which diodes are enabled in accordance to relation to current in circuit. Parallel circuits of windings are connected in accordance to star or triangle schematic and are connected to diagonals of inverter bridge. During operation of engine voltage pulses from inverter are sent to phases in alternating order, and current flows in phases, which after closure of keys is routed in parallel circuits to adjacent phases, powers them and decreases magnetization current. As a result number of inverter power keys is decreased two times, and number of output conductors is decreased four times.
EFFECT: increased power coefficient of inductor engine, decreased dimensions and costs of transformer for powering the engine and decreased number of output conductors.
2 cl, 4 dwg
FIELD: electrical engineering; low- and medium-power synchronous machines, primarily generators, for off-line power plants.
SUBSTANCE: proposed ac compound generator has rectifier whose plus and minus outputs are connected in parallel with field winding and input, to three-phase stator winding and field capacitors. In addition, generator is provided with diodes, current-limiting resistor, and contacts; field capacitors are connected through contacts to phase leads of stator winding; cathodes of diodes are connected through current-limiting resistor to plus terminal of rectifier and to field winding and its anodes, to phase leads of stator winding or to its taps.
EFFECT: simplified design at flat external characteristic in steady state and transient conditions.
1 cl, 2 dwg