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ASAMBLARI ARBORE-BUTUC<br />

Asamblari demontabile = Temporare<br />

Transmit moment de torsiune<br />

A Prin forma - Forte normale B Prin frecare - Forte tangentiale<br />

Inele de siguranta<br />

Pene<br />

Canel<strong>uri</strong><br />

As. Poligonale<br />

Stift<strong>uri</strong>i<br />

Arbore conic<br />

Rotatie<br />

Inele tronconice<br />

Interferenta<br />

(as. presate)<br />

strangere<br />

maxima<br />

Translatie<br />

BUTUC<br />

Bucsa<br />

Fa<br />

Ff /2<br />

dm<br />

2α<br />

Mt<br />

BUTUC<br />

d max<br />

ARBORE<br />

ARBORE<br />

D min<br />

BUTUC<br />

Feb. 2011 - T. Cicone<br />

1/18<br />

OM-I Cap 4. Asamblari A/B<br />

PENE – Generalitati<br />

Componente prismatice, montate partial in arbore si partial intr-un canal practicat in butuc<br />

Pene paralele<br />

Pene disc<br />

l<br />

b<br />

h<br />

Transmit<br />

momentul<br />

de torsiune<br />

prin forma<br />

BUTUC<br />

Pene concave<br />

ARBORE<br />

SHAFT<br />

Mt<br />

Pene inclinate<br />

l<br />

b<br />

h<br />

l<br />

b<br />

h<br />

Feb. 2011 - T. Cicone<br />

2/18<br />

Pene inclinate simple<br />

Pene inclinate cu nas<br />

OM-I Cap 4. Asamblari A/B<br />

1


PENE PARALELE<br />

Pana Tip A Pana Tip B Umar (salt de<br />

diametru)<br />

Gaura de centrare<br />

filetata pentru fixarea<br />

saibei de capat<br />

Feb. 2011 - T. Cicone<br />

Capat de<br />

abore<br />

3/18<br />

Gaura de<br />

centrare filetata<br />

OM-I Cap 4. Asamblari A/B<br />

PENE PARALELE<br />

h<br />

l<br />

b<br />

Tip A<br />

b<br />

h<br />

Tip B<br />

b<br />

b<br />

Tip C<br />

b<br />

Cele mai utilizate<br />

l<br />

Cele mai ieftine<br />

Standardizate in functie de diametru<br />

Feb. 2011 - T. Cicone<br />

4/18<br />

OM-I Cap 4. Asamblari A/B<br />

2


PENE PARALELE – Metoda de calcul<br />

h<br />

F t<br />

Ipoteze<br />

Fara joc<br />

Aliniere perfecta<br />

F t<br />

F t2<br />

M t l<br />

σ<br />

d<br />

k<br />

b<br />

t = t2<br />

= h 2<br />

M 1 t<br />

ARBORE<br />

l ef<br />

BUTUC<br />

σ k<br />

F t1<br />

Ft 1 = Ft<br />

2 = Ft<br />

= 2M<br />

t<br />

d<br />

t 1 t 2<br />

Forfecare<br />

Ft<br />

τ<br />

f<br />

=<br />

A<br />

Feb. 2011 - T. Cicone<br />

f<br />

2M<br />

≅<br />

d b l<br />

τ a =70-120MPa<br />

t<br />

ef<br />

b<br />

b<br />

b<br />

l<br />

Tip A<br />

Tip B<br />

Tip C<br />

A = bl<br />

f<br />

ef<br />

2<br />

πbπ<br />

b<br />

+<br />

4<br />

A = bl bl<br />

f ef<br />

=<br />

A = bl<br />

f<br />

ef<br />

h<br />

2<br />

πb<br />

+<br />

8<br />

5/18<br />

b<br />

Presiune de contact<br />

Ft<br />

σk<br />

= =<br />

A d<br />

σ ak =100-150MPa<br />

k<br />

static<br />

2M<br />

t<br />

4Mt<br />

≅<br />

( t1<br />

−c) lef<br />

dhlef<br />

mobile<br />

σ ak =20-40MPa<br />

OM-I Cap 4. Asamblari A/B<br />

PENE PARALELE – Metoda de proiectare<br />

Solicitare de contact<br />

Solicitare de forfecare<br />

Cunoscut diametrul, d<br />

4M<br />

σ<br />

k<br />

≅<br />

d hl<br />

ef<br />

2M<br />

t<br />

τ<br />

f<br />

≅<br />

d bl<br />

Din<br />

standard<br />

t<br />

ef<br />

b × h<br />

h ≅ 0. 8b<br />

σ 2<br />

σ ≈ 1. 4τ<br />

k<br />

> τ<br />

f ak af<br />

Solicitarea de contact este<br />

mai importanta<br />

4M<br />

b ≈ 0. 25d<br />

t<br />

l<br />

ef<br />

><br />

l ef standard<br />

d hσ<br />

ak<br />

sau nu<br />

l > lungime butuc<br />

Distributie ne-uniforma<br />

l tot =1.7×l<br />

Feb. 2011 - T. Cicone<br />

6/18<br />

OM-I Cap 4. Asamblari A/B<br />

3


PENE PARALELE – Standard<br />

d<br />

b<br />

h<br />

pana<br />

Lungimea<br />

penei<br />

b<br />

Canalul<br />

nominal Ajustaj liber Ajustaj normal Ajustaj<br />

presat<br />

In arbore In butuc In<br />

N9 D10 N9<br />

de la pâna la de la pana<br />

Abateri limită<br />

la<br />

arbore In butuc<br />

D10<br />

In arbore şi<br />

in butuc P9<br />

t 1 (in arbore)<br />

22 30 8 7 18 90 8 +0,036 +0,098 0<br />

±0,0180 -0,015 4,0<br />

3,3<br />

30 38 10 8 22 110 10<br />

0 +0,040 -0,036<br />

-0,051<br />

5,0<br />

+0,2<br />

0<br />

3,3<br />

38 44 12 8 28 140 12<br />

5,0 3,3<br />

44 50 14 9 36 160 14<br />

+0,043 +0,120 0<br />

±0,0215 -0,018<br />

0 +0,060 -0,043<br />

-0,061<br />

5,5 3,8<br />

50 58 16 10 45 180 16 6,0 4,3<br />

58 65 18 11 50 200 18 7 4,4<br />

65 75 20 12 56 220 20<br />

7,5 4,9<br />

75 85 22 14 63 250 22<br />

+0,052 +0,149 0<br />

± 0,0260 -0,022<br />

0 +0,065 -0,052<br />

-0,074<br />

9 5,4<br />

85 95 25 14 70 280 25 9 5,4<br />

95 110 28 16 80 320 28 10 6,4<br />

110 130 32 19 90 360 32<br />

-0,026 11 7,4<br />

130 150 36 20 100 400 36<br />

+0,062 +0,180 0<br />

±0,0310 -0,088<br />

12<br />

8,4<br />

0 +0,080 -0,062<br />

150 170 40 22 100 400 40 13<br />

+0,2<br />

9,4<br />

0<br />

170 200 45 25 110 450 45 15 10,4<br />

200 230 50 28 120 500 50 17 11,4<br />

Nomi<br />

nal<br />

t 2 (in butuc)<br />

Nomi<br />

nal<br />

Abateri<br />

Abateri<br />

+0,2<br />

0<br />

+0,2<br />

0<br />

Feb. 2011 - T. Cicone<br />

7/18<br />

OM-I Cap 4. Asamblari A/B<br />

PENE PARALELE – Concluzii<br />

Avantaje<br />

Dezavantaje<br />

Capacitate portanta buna<br />

Tehnologie simpla<br />

Standardizate<br />

Montaj usor si rapid<br />

Calcul simplu si exact<br />

Concentrator de efort<strong>uri</strong> important (K σ ≈2÷3)<br />

Nu asigura centrarea<br />

Nu se recomanda pentru miscari axiale frecevente ale butucului<br />

SPECIFICATII tip b × h × l Exemplu A12×10 ×50<br />

Feb. 2011 - T. Cicone<br />

8/18<br />

OM-I Cap 4. Asamblari A/B<br />

4

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