SI22564A

SI22564A - Engine cooling by an external rotor and forced flue of air through the engine

Info

Publication number: SI22564A
Application number: SI200700108A
Authority: SI
Inventors: Bojan Lapanja; Mirko PetrovÄŤiÄŤ; Stane Pivk; Igor Jurman; irok Brane Ĺ
Original assignee: Hidria Rotomatika D.O.O.
Priority date: 2007-05-08
Filing date: 2007-05-08
Publication date: 2008-12-31

Abstract

The invention provides with electric power engines featuring external rotors enhanced cooling and thus increased efficiency rates as well cost-effectiveness of its operation. The cooling air enters centrally through the opening (11) as well as through the transverse opening in the hollow shaft (3) inside the engine where the radially designed grooves (13, 15) generate a cooling low. The cooling air is released from the engine through the openings (16) on the rotor cover (7) and slot (17). To protect the engine from harmful effects of dust and water there is prior the intake (11) of air into the shaft (3) a cover featuring a labyrinth (18) or an air-permeable diaphragm.

Description

Predmet izuma je izvedba hlajenja elektromotorja z zunanjim rotorjem. Elektromotor z zunanjim rotorjem ima za razliko od klasičnih indukcijskih motorjev, stator z električnim navitjem nameščen znotraj rotorja. Zunanji rotor je uležajen na osi motorja. Lopatice ventilatorja so nameščene neposredno na rotor. Zato je tak motor racionalnejša izbira za aksialne, pa tudi določene vrste centrifugalnih ventilatorjev. Zaradi potrebe po vse boljših izkoristkih motorja, se pojavljajo tudi vse večje temperature na statorju, ki jih je potrebno zmanjšati. Glavnina toplote se iz motorja odvaja prek zunanjega rotorja, ki se vrti in preko njega teče tok zraka, ki ga poganja ventilator. Obstoječa konstrukcija motorja je zelo neugodna za ovajanje toplote iz statorja. Stator z navitjem, ki je generator toplote v motorju, je povezan z rotorjem samo preko ležajev. Prek ležajev pa se odvede premalo toplote in tako so izkoristki motorja manjši, kot bi lahko bili ob izdatnejšem hlajenju. Ker je stator zaprt v rotorju z okrovom, tudi ni cirkulacije zraka, ki bi ga hladil.The subject of the invention is the cooling of an electric motor with an external rotor. An electric motor with an external rotor, unlike conventional induction motors, has an electric winding stator mounted inside the rotor. The outer rotor is mounted on the motor axis. The fan blades are mounted directly on the rotor. Therefore, such an engine is a more rational choice for axial as well as certain types of centrifugal fans. Due to the need for better engine efficiency, increasing stator temperatures are also emerging that need to be reduced. Most of the heat is discharged from the engine through an external rotating rotor and a fan-driven air stream flows through it. The existing motor construction is very unfavorable for the stator heat dissipation. The winding stator, which is a heat generator in the engine, is connected to the rotor via the bearings only. However, too little heat is released through the bearings and the engine efficiency is less than it could have been if it had been cooled. As the stator is enclosed in a rotor with a casing, there is also no air circulation to cool it.

Predmet izuma je motor z zunanjim rotorjem z prisilnim tokom zraka skozi motor. Zračni tok je dosežen s konstrukcijskimi rešitvami na motorju. Značilnost izuma je v :The subject of the invention is an external rotor motor with forced air flow through the engine. The air flow is achieved through engineered construction solutions. A feature of the invention is in:

- Os motorja je votla in omogoča vstop zraka s sprednje strani motorja.- The motor axis is hollow and allows air to enter from the front of the engine.

- Na osi motorja so izvedene prečne luknje za vstop zraka v prostor, ki je omejen z geometrijo statorja in rotorja.- There are transverse holes in the motor axis for the entry of air into the space, which is limited by the stator and rotor geometry.

- Na notranji strani pokrova rotorja so izvedeni radialni kanali, ki ustvarjajo radialni tok hladnega zraka.- Radial grooves are created on the inside of the rotor cover to create cold air radial flow.

- V pokrovu rotorja so izvedene luknje skozi katere hladilni zrak izstopa iz statorskega prostora v medprostor pri pritrdilni prirobnici in izstopa skozi labirint med rotorskim pokrovom in pritrdilno prirobnico.- There are holes in the rotor cover through which the cooling air exits the stator space into the space between the mounting flange and exits through the maze between the rotor cover and the mounting flange.

Vse opisane spremembe na motorju ustvarjajo prisilni vlek hladilnega zraka skozi motor in s tem hlajenje statorskega navitja, kar izkoristimo za povečanje obremenitve motorja in posledično povečan izkoristek motorja.All the changes described on the engine create a forced draw in of cooling air through the engine and thus the cooling of the stator winding, which is used to increase the load on the engine and consequently increase the engine efficiency.

Glede na stopnjo zaščite pred škodljivimi učinki vode in prahu, ter varnost delovanja po IEC 60529 (IP Code), ki je obvezna za ta tip ventilatorjev, se izvede zaščita na vstopu zraka v votlo os motorja.Depending on the degree of protection against the adverse effects of water and dust, and the safety requirements of IEC 60529 (IP Code), which is mandatory for this type of fan, air intake protection is provided to the hollow axis of the engine.

Značilnost izuma zaščite pred škodljivimi vplivi je, da ob zadostnem - potrebnem dovodu zraka v votlo os, poskrbi, da v motor ne more prodreti voda in prah v škodljivih količinah. Zaščita se lahko izvede na dva načina:A feature of the invention for protection against adverse influences is that, with sufficient air supply to the hollow axis, it ensures that water and dust cannot enter the engine in harmful quantities. Protection can be done in two ways:

- Pokrovček z luknjami ob strani, nameščen na rotorju, pri vstopu zraka v votlo gred, dovoli vstop zraka, vendar preprečuje neposreden dostop vodi in prahu.- The cap with holes on the side, mounted on the impeller, allows air to enter when air enters the hollow shaft, but prevents direct access to water and dust.

- Namesto pokrovčka namestimo na rotor zračno-prepustno toda vodo-nepropustno membrano (expanded polytetrafluoroethylene (ePTFE), ki zagotovi še višjo stopnjo zaščite. Velikost membrane se določi glede na prepustnost membrane in potrebno količino zraka za hlajenje.- Instead of a cover, an expanded polytetrafluoroethylene (ePTFE) air-permeable but water-permeable membrane (ePTFE) is mounted on the rotor to provide an even greater degree of protection.The size of the membrane is determined by the permeability of the membrane and the amount of cooling air required.

Na obstoječih tehničnih rešitvah ni poznana konstrukcija, ki bi omogočala dodatno hlajenje s samodejno centrifugalno cirkulacijo zraka skozi motor in zaščito po IEC 60529 (IP Code). Vse znane rešitve se ukvarjajo z hlajenjem motorja z hladilno kapljevino na različne načine, kar pa zaradi zahtevnosti izvedbe, ni primemo za velikoserijsko proizvodnjo.Existing technical solutions do not know the design that would allow additional cooling with automatic centrifugal air circulation through the engine and protection according to IEC 60529 (IP Code). All known solutions deal with the cooling of a liquid-cooled engine in various ways, which, due to the complexity of the design, is not suitable for large-scale production.

Izum bo opisan z izvedbenim primerom in sliko, ki prikazuje:The invention will be described by way of example and figure showing:

Slika 1: Prerez motorja z zunanjim rotorjem z glavnimi sestavnimi deli in dodelavami za izvedbo ter shematski prikaz poti hladilnega zraka skozi motorFigure 1: Cross section of an external rotor motor with main components and finishes for execution and schematic representation of the cooling air path through the engine

Na sliki 1 je prikazan tipičen asinhronski motor z zunanjim rotorjem. Motor se največkrat uporablja za pogon aksialnih, pa tudi centrifugalnih ventilatorjev. Motor je sestavljen iz statorja in rotorja. Stator je sestavljen iz statorskega paketa 1, statorskega navitja 2 in osi motorja 3. Statorski paket 1 je sestavljen iz lamel elektro pločevine, navitje 2 je iz bakrene žice. Statorski paket 1 je natisnjen na os motorja. Stator je uležajen z ležajema 4 v rotor. Rotor je sestavljen iz rotorskega paketa 5 (izdelanega iz lamel elektro pločevine), zalitega v aluminijasto ohišje 6 in aluminijastega pokrova rotorja 7. Stator je preko osi 3, pritrjen na pritrdilno prirobnico 8, ki služi za pritrditev motorja (ventilatorja) na stroj.Figure 1 shows a typical induction motor with an external rotor. The motor is most commonly used to drive axial as well as centrifugal fans. The motor consists of a stator and a rotor. The stator consists of a stator package 1, a stator winding 2 and an axis of the motor 3. The stator package 1 consists of electric sheet blades, the winding 2 is made of copper wire. Stator package 1 is printed on the motor axis. The stator is mounted with bearings 4 in the rotor. The rotor consists of a rotor package 5 (made of sheets of electrical sheet) embedded in an aluminum housing 6 and an aluminum rotor cover 7. The stator is via an axis 3, attached to the mounting flange 8, which serves to attach the motor (fan) to the machine.

Običajno je v os statorja 3 izvrtana izvrtina 9, ki je namenjena razvodu kablov v priključno škatlo 10. V primeru izuma je luknja 9 podaljšana po celi dolžini osi. Tako dobimo vstop 11 za hladilni zrak. Z dodatnimi prečnimi luknjami 12 v osi 3, omogočimo vstop hladilnega zraka v spodnji del motorja. Tu radialni kanali 13, ustvarijo radialni tok hladilnega zraka, ki skozi režo 14 med statorskim paketom 1 in rotorskim paketom 5, izstopa v zgornji del motoija. Podobna pot zraka je tudi skozi zgornji del motorja. Skozi luknjo 9 v osi 3, hladilni zrak doseže prečne luknje 14 in vstopa v zgornji del motoija. Tako kot v spodnjem delu motorja, tudi v zgornjem radialni kanali 15, na pokrovu rotorja 7, ustvarjajo radialni tok hladilnega zraka. Skozi luknje 16 na pokrovu rotorja 7, hladilni zrak izstopa v prostor med pokrovom rotorja 7 in prirobnico motorja 8. Iz medprostora zrak skozi špranjo 17, izstopa iz motoija.Typically, a bore 9 is drilled into the stator axis 3 to distribute the cables to the terminal box 10. In the case of the invention, the hole 9 is extended along the entire length of the axis. This gives inlet 11 for cooling air. With additional transverse holes 12 in axis 3, the cooling air can be entered into the lower part of the engine. Here, the radial channels 13 create a radial flow of cooling air that exits through the gap 14 between the stator pack 1 and the rotor pack 5 into the upper part of the moto. A similar air path is also found through the top of the engine. Through hole 9 in axis 3, cooling air reaches the transverse holes 14 and enters the top of the moto. As in the lower part of the engine, in the upper radial duct 15, on the rotor cover 7, they generate a radial flow of cooling air. Through the holes 16 on the rotor cover 7, the cooling air exits into the space between the rotor cover 7 and the flange of the motor 8. From the interspace, air through the slot 17 exits the moto.

Skupna površina lukenj 12 in 14 mora biti enaka ali večja (kolikor dopuščajo mehanske razmere) od površine vstopne luknje 11 v osi motoija 3 (ΣΑ12 + ΣΑ14 > Ali). Skupna površina izstopnih lukenj 16 na pokrovu rotorja, pa je lahko bistveno večja od površine vstopne luknje 11 v osi motorja 3 (ΣΑ16 »Ali).The total surface area of holes 12 and 14 must be equal to or greater (as far as mechanical conditions allow) than the surface of the inlet hole 11 in the axis of the moto 3 (ΣΑ12 + ΣΑ14> Ali). The total surface area of the outlet holes 16 on the rotor cover may, however, be substantially larger than the surface of the inlet hole 11 in the axis 3 of the motor 3 (ΣΑ16 »Ali).

Na sliki 1 je s puščicami shematsko prikazana pot zraka skozi motor.In Figure 1, the arrows show schematically the air path through the engine.

Zaščita pred vdorom prahu in vode, katera bi lahko imela škodljive posledice po IEC 60529 (IP Code) je potrebna pri vstopu 11 hladilnega zraka v luknjo 9, osi 3. Izvedba je odvisna od zahtevane stopnje zaščite.Protection against dust and water intrusion, which could have adverse effects in accordance with IEC 60529 (IP Code), is required when the cooling air enters 11 into hole 9, axis 3. The design depends on the required protection level.

Zaščita 18 preprečuje neposreden vstop vode skozi vstop 11, v luknjo 9, osi 3. Hkrati pa skozi stransko režo 19 prepušča dovolj zraka za hlajenje motorja.Protection 18 prevents direct entry of water through the inlet 11, into the hole 9, the axis 3. At the same time, it passes sufficient air through the side slot 19 to cool the engine.

Namesto zaščite 18, lahko uporabimo tudi zračno-prepustno, toda vodo-nepropustno membrano (expanded polytetrafluoroethylene (ePTFE)), (ni na sliki), ki jo vgradimo v venec 20 in s tem preprečimo vstop vode in prahu v motor.Instead of protection 18, we can also use an expanded, polytetrafluoroethylene (ePTFE) air-permeable but not water-permeable membrane (not pictured), which is mounted in the crown 20 to prevent water and dust from entering the engine.

Pri izstopu hladilnega zraka ni potrebna dodatna zaščita, saj zadostuje že obstoječa špranja, med pokrovom rotorja 7 in pritrdilno prirobnico 8.No additional protection is required when the cooling air outlet is available, since existing slits are sufficient, between the rotor cover 7 and the mounting flange 8.

Claims

A motor with an external rotor consisting of a stator package (1) with copper winding (2) into which an axle (3) is printed, to which a rotor (6) with a rotor package (5) is suspended via bearings (4). ) and the rotor cover (6), characterized in that it passes through the hole (11) and further through the transverse holes (12, 14) in the axis (3) of the moto whose surface must be equal to or greater than the surface of the hole (11) cooling air into the space (20), where the radial ducts (13) generate a radial air stream that cools the winding of the statue (2) and then exits the motor through holes (16) between the stator and the rotor through holes (16) on the rotor cover (7). ), the surface of which must be substantially larger than the surface of the hole (11), and further through the slot (17), below the flange of the motor (8).