机械原理课程设计报告专业班级机械****班级序号**学生姓名***2012 —2013 学年第2 学期长江大学机械工程学院一、原始数据:二、往复泵传动方案设计:(1)齿轮设计采用压力角为20°的直齿圆柱齿轮,根据相关资料查得:齿轮的最小齿数不得小于17,否则会发生根切,且直齿圆柱齿轮的传动比一般在3-6,最大不会超过8(2)齿轮传动的基本简图:(3)传动比的具体分配方案:依题意有:n1=1300r/min,n4=115r/minI14=(-1)mZ2Z3Z4/Z1Z2Z3=Z4/Z1=n1/n4=1300/115=260/23因为传动比大于8,所以应采取如图分级传动,在此,取齿轮1的齿数为23,则齿轮4的齿数为260,具体传动比分配如下:I12=Z2/Z1=5=n1/n2→Z2=115,n2=260r/min2和3在同一根轴上,则有:n3=n2=260r/minI34=Z4/Z3==n3/n=2.261→Z3=115,n4=115r/min综上所述:传动比的分配方案为,I12=5,I34=2.261 三、曲柄滑块机构的设计(使用到VB)如图所示:点B运动到B1、B2位置是曲柄滑块机构运动的两极限位置,当点B运动到B3位置(B3在A点正下方),压力角α取最大值。
由几何关系有:Sin(αmax)=( L AB+e)/ L BC(L AB+ L BC)2-e2={[( L BC - L AB)2-e2]1/2+s}2整理得:L BC=( L AB+e)/ sin(αmax)L BC=[(4S2L AB2-4S2e2- S4)/(16L AB2-4S2)]1/2VB程序编写Private Sub Command1_Click()Const PI = 3.141592e = 20s = 305a = 56Text1 = Val(Text2) * Sin(a * PI / 180) - eText2 = Sqr((4 * s * s * Val(Text1) * Val(Text1) - 4 *s * s * e * e - s * s * s * s) / (16 * Val(Text1) *Val(Text1) - 4 * s * s))End Sub截图所以Lab =108.62mm,Lbc=155.14mm四、往复泵的运动分析:整个曲柄滑块机构在任意θ角处的运动简图如下:(P 为速度瞬心)0由图可知:d=((L-R)2-e2)1/2=42.00mm, ω1=2πN/60=12.04, ω1·L AB=ω2·L BP,则:ω2=Rcosθ·ω1/Lcosβ(1)位置分析:有几何关系有:x=Rcosθ+Lcosβ+d其中,Rsinθ+e=Lsinβ故:sinβ= (Rsinθ+e)/L , cosβ=[1-(Rsinθ+e)2/L2]1/2因此,x=Rcosθ+L[1-(Rsinθ+e)2/L2]1/2+d(2)速度分析:V=dx/dt=-Rsinθ·ω1-Lsinβ·ω2=-Rsinθ·ω1- Lsinβ·Rcosθ·ω1/Lcosβ=-Rsinθ·ω1-((Rsinθ+e)·Rcosθ·ω1/L)/[1-(Rsinθ+e)2/L2]1/2(3)加速度分析;a=dv/dt=-Rω12cosθ-L(cosβω22+sinβ·λ)λ=Rω1·(-sinθcosβω1+ sinβcosθω2)/(L·cos2β) ·{-sinθ[1-(Rsinθ+e)2/L2]1/2ω1+[(Rsinθ+e)/L] =Rω1cosθω}/{ L·[1-(Rsinθ+e)2/L2]}2因此,a=-Rω12cosθ-L(cosβω22+sinβ·Rω1·{-sinθ[1-(Rsinθ+e)2/L2]1/2ω1+[(Rsinθ+e)/L] cosθω2}/{ L·[1-(Rsinθ+e)2/L2]})(4)表格数据如下:(5)运动线图a.位移图(横坐标为θ,纵坐标为S/dm):程序:Private Sub Command1_Click()Dim x!, y!Scale (-8, 4)-(8, -4)Line (-8, 0)-(8, 0)Line (0, 4)-(0, -4)CurrentX = 6.2: CurrentY = -0.2: Print "X/rad" CurrentY = 3.9: CurrentX = 0.2: Print "Y/dm"For x = 0 To 6.283 Step 0.0001y = 1.0862 * Cos(x) + 1.5514 * Sqr(1 - (1.0862 * Sin(x) + 0.2) * (1.0862 * Sin(x) + 0.2) / (1.5514 * 1.5514)) + 0.42PSet (x, y)Next xEnd Sub截图:b.速度图(横坐标为θ,纵坐标为V(单位:dm/s)) 程序:Private Sub Command1_Click()Dim x!, y!, n!, m!Scale (-8, 15)-(8, -15)Line (-8, 0)-(8, 0)Line (0, 15)-(0, -15)CurrentX = 6.2: CurrentY = 0.2: Print "X/rad" CurrentY = 15: CurrentX = 0.2: Print "Y dm/s" For x = 0 To 6.283 Step 0.0001n = (1.0862 * Sin(x) + 0.2) / 1.5514m = 1.0862 * Cos(x) * 12.04 / (1.0862 * Sqr(1 - n * n))y = (-1.0862) * Sin(x) * 12.04 - 1.0862 * n * m PSet (x, y)Next xEnd Sub截图c.加速度图(横坐标为θ,纵坐标为a(单位:m/s2)程序:Private Sub Command1_Click()Dim x!, y!, n!, m!, w!Scale (-8, 20)-(8, -20)Line (-8, 0)-(8, 0)Line (0, 20)-(0, -20)CurrentX = 6.2: CurrentY = 0.2: Print "X/rad" CurrentY = 20: CurrentX = 0.2: Print "Y m/s2"For x = 0 To 6.283 Step 0.0001n = (0.10862 * Sin(x) + 0.02) / 0.10862m = 0.10862 * Cos(x) * 12.04 / (0.10862 * Sqr(1 - n * n))w = 0.10862 * 12.04 * ((-Sin(x)) * Sqr(1 - n * n) * 12.04 + n * Cos(x) * m) / (0.10862 * (1 - n * n))y = (-0.10862) * 12.04 * 12.04 * Cos(x) - 0.10862 * (Sqr(1 - n * n) * m * m + n * w)PSet (x, y)Next xEnd Sub截图五、曲柄滑块机构的动力分析:六、附件a.位移计算编程及截图:程序:Private Sub Command1_Click()Const PI = 3.14159Dim m!m = PI * Val(Text1) / 180Text2 = Val(108.6 * Cos(m) + 155.1 * Sqr(1 - (108.6 * Sin(m) + 20) * (108.6 * Sin(m) + 20) / (155.1 * 155.1))) + 42#End SubPrivate Sub Command2_Click()Text1 = ""Text2 = ""End Sub截图b.速度计算及截图:Private Sub Command1_Click()Const PI = 3.14159Dim m!m = PI * Val(Text1) / 180Text2 = (-108.6) * Sin(m) * 12.04 - ((108.6 * Sin(m)+ 20) * 108.6 * Cos(m) * 12.04 / 155.1) / Sqr(1 - (108.6 * Sin(m) + 20) * (108.6 * Sin(m) + 20) / (155.1 * 155.1))End SubPrivate Sub Command2_Click()Text1 = ""Text2 = ""End Sub截屏c.加速度计算及截图:程序:Private Sub Command1_Click()Const PI = 3.14159Dim m!m = Val(Text6) * PI / 180Text1 = Val((108.7 * Sin(m) + 18) / 154.6)End SubPrivate Sub Command2_Click()Const PI = 3.14159Dim m!m = Val(Text6) * PI / 180Text2 = Val(Sqr(1 - Val(Text1) * Val(Text1)))End SubPrivate Sub Command3_Click()Const PI = 3.14159Dim m!m = Val(Text6) * PI / 180Text3 = 108.6 * Cos(m) * 12.04 / (155.1 * Val(Text2))End SubPrivate Sub Command4_Click()Const PI = 3.14159Dim m!m = Val(Text6) * PI / 180Text4 = 108.6 * 12.04 * ((-Sin(m)) * Val(Text2) * 12.04 + Val(Text1) * Cos(m) * Val(Text3)) / (155.1 * Val(Text2) * Val(Text2))End SubPrivate Sub Command5_Click()Const PI = 3.14159Dim m!m = Val(Text6) * PI / 180Text5 = (-108.6) * 12.04 * 12.04 * Cos(m) - 155.1 * (Val(Text2) * Val(Text3) * Val(Text3) + Val(Text1) * Val(Text4))End SubPrivate Sub Command6_Click()Text1 = ""Text2 = ""Text3 = ""Text4 = "'"Text5 = ""Text6 = ""End Sub截屏七、主要参考文献《机械原理》-高等教育出版社《VB程序设计教程》(第三版)-高等教育出版社八、对课程设计的总结:。