挤出段螺杆设计计算.

挤出段螺杆设计计算（参考文献米糠榨油机榨螺设计）2011-9-14 一．挤出部分基本尺寸：

进料段：

1]螺杆外径D=145mm=0.145m

2]螺杆根径D1=106mm=0.106m

3]螺距S1=250mm=0.25m

4]螺棱外宽b1=16mm=0.016m

5]l螺棱内宽b2=26mm=0.026m

6]进料长度z1=5500mm=5.5m

7]总长度z=6000mm=6m

压缩末段；

1]螺杆外径D=145mm=0.145m

2]螺杆根径D2=134mm=0.134m

3]螺距S2=50mm=0.050m

4]螺棱外宽b3=14mm=0.014m

5]螺棱内宽b4=24mm=0.024m

6]末段长度z2=500mm=0.5m

二．计算：

1]进料段平均直径D=D-H1

D=0.145-0.0195=0.1255=0.126m=126mm

2]进料段螺棱高H1=(D-D1)/2

H1=0.145-0.106/2=0.0195m=19.5mm

3]压缩末段螺棱高H3=(D-D2)/ 2

H3=0.145-0.134/2=0.0055m=5.5mm

4]压缩比ε=(D-H1) H1/(D-H3) H3

ε=（0.145-0.0195）x0.0195/(0.145-0.0055)x0.0055=3.2

5]进料段螺旋升角tanυ1=S 1/πD

tanυ1=0.25/3.14x0.145=0.5490

υ1=28.787°

6]进料端螺旋根升角tanυ2=S1/πD1

tanυ2=0.25/3.14xo.106=0.7511

υ2=36.9°

7]进料端螺旋平均升角tanφ= S1/πD

tan=0.25/3.14x0.126=0.631

φ=32.25°

8]进料段螺槽外宽B 1= S1- b1=0.25-0.016=0.234m

9] 进料段螺槽根宽B 2= S1- b2=0.25-0.026=0.224m

10]进料段螺槽外法向宽度W1= B1xcosυ1=0.234xcos28.787°=0.205m

11] 进料段螺槽根法法向宽度W2= B2xcosυ2=0.224xcos36.9°=0.179m

12]进料段螺棱外法向宽度e 1= b1xcos υ1 =0.016xcos28.787°=0.014m

13]进料段螺槽平均法向宽度W均=Scos φ-e1=0.25xcos32.25°-0.014=0.198m

14]进料段因数K=( D/D)x(sin φ+fcos φ)/(cos φ-fsin φ);式中f—摩檫系数0.3

K=(0.126/0.145)x(sin32°+0.3xcos32°)/(cos32°-0.3xsin32°)=0.9876

15}M=(2H 1/W 1)xsinυ[K+( D/D)cos φ]+sinυ[K+(D 1/D)cos υ1]

M=(2x19.5/205)sin28.787°[0.988+(126/145)cos32°]+sin28.787°[0.988+106/145cos36.9°=0.815

16]物料升角sinθ=[（1+K 2-M2）1、2-KM]/(1+K2)=0.172

θ=9.9°

17]能量消耗e w=πNDWZFcosθ（P 2-P 1）/Ln(P 2/P 1)

式中N—6r/min/60=0.1r/s;

P 2—压缩段出口压力=2.0MPa=2000000Pa

P 1—加料段入口压力=0.4MPa=400000Pa

Z—螺杆总长度6m

e W=3.14x(6/60)x0.145x0.205x6x0.3xcos9.9°(2000000-400000)/Ln2000000/400000

=16548W=16.5KW

18]物体体积输送率：（每转一转固体输送量）

Q v/n=π2DH1(D-H1)xtanυ1xtanθx[W均/(W均+ε)]/(tanυ+tanθ)

=3.142x0.145x(0.145-0.0195)xtan28.787°xtan9.9°x[0.198/0.198+3.2]/( tan28.787°

+tan9.9°)=0.00137m3/r=1.37x10-3m3/r

19]物料质量输送率：Q g=ρQ v;式中—ρ—米糠容量=0.32公斤/升，公斤/升；1000升=1米3 Q g=0.32x1000x0.00137=0.438公斤(kg)

20]螺杆轴向压力P a=(4.3059—3.094Lg△P)△PxA; 式中A=πD2

P a=(4.3059—3.094xLg2)2x3.14x0.1452/4=0.1115MN

21]螺杆压应力σy=P a/A r ; A r=πD21/4

σy=0.1115/(3.14x0.1062/4)=12.67MN

22]螺杆扭矩M n=9549N max/n max xη=9549x16.5/6x0.95=27642N.m

23]螺杆剪应力τ=M n/W n x106 ;

抗扭截面模量W n=πD31/16=3.14x0.1063/16=0.0002337

τ=27642/0.0002337x106=118.261MN/m2

24]强度校核（σy2+4τ2）1/2≤[σ]=278MN/m2(螺杆材料38CrMoAiA许用应力) （12.6702+4x118.2612）1/2=236.86MN/m2≤[σ]=278MN/m2

25]刚度校核:1167M n(1+μ)/ED4≤[I]=1°/m

1167x27642x(1+0.3)/200x109x0.1454=0.474°≤[I]