=6768.7－3687.87×0.3 =6768.7－1106.4 =5662.3(kgf)
4. 低速等速终了时:
F01 = F01－PkL01sinθ
=5662.3－2.129×21.25 sin20
=5662.3－15.5 =5646.8(kgf)
(二).矿车在井筒中运行段:
。
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1. 主加速开始时:
F1 = F01＋∑Ma1
=5646.8＋3687.87×0.5 =5646.8＋1844 =7490.7(kgf) 2. 主加速终了时: F1 = F1－PkL1sinθ
=7490.7－2.129×12.57×sin20 =7490.7－9.15 =7481.6(kgf) 3. 等速开始时:
F2 = F1－∑Ma1
=7481.6－3687.87×0.5 =7481.6－1844
13
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。
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/
=5637.6(kgf) 4. 等速终了时: F2 = F2－PkL2sinθ
=5637.6－2.129×574.86 sin20 =5637.6－418.6 =5219(kgf) 5. 减速开始时:
F3 = F2－∑Ma1
=5219－3687.87×0.5 =5219－1844 =3375(kgf) 6. 减速终了时:
F3 = F3－PkL3sinθ
=3375－2.129×12.57 sin20
=3375－9.15
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/
/
。
/
=3365.9(kgf)
(三)、重矿车在栈桥上运行段: 1. 末等速开始时:
F4 = F3＋∑Ma1
=3365.9＋3687.8×0.5 =3365.9＋1844 =5210(kgf) 2. 末等速终了时:
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F4 =F4－PkL4 sinθ
=5210－2.129×31.25 sin20 =5210－22.8 =5187.2(kgf) 3. 末减速开始时:
F5 = F4－∑Ma0
=5187.2－3687.87×0.3 =5187.2－1106.4 =4080.8(kgf) 4. 末减速终了时:
F5 =F5－PkL5 sinθ
=4080.8－2.129×3.75 sin20 =4080.8－2.73 =4078.1(kgf)
(四)、等效力计算
∑Ft =1/2×(F0＋F0)t0＋1/2×(F01＋F01)t01
＋1/2×(F1＋F1)t1＋1/3×(F2＋F2F2＋F2)t2 ＋1/2×(F3＋F3)t3＋1/2×(F4＋F4)t4 ＋1/2×(F5＋F5)t5
=0.5×(6771.4＋6768.7)×5＋0.5×(5662.3＋ 5646.8)×14.17＋0.5×(7490.7＋7481.6)×4.7 ＋0.33×(5637.6＋5637.2×5219＋5219)×149.4 ＋0.5×(3375＋3365.9)×4.7＋0.5×(5210
15
2
2
2
2
2
2
2
2
2
2
2
2
/2
2
/2
2
/2
2
/2
2
/
/2
2
2
/2
2
/2。
/
/
。
/
＋5187.2)×20.83＋0.5×(4080.8＋4078.1)×5 =2.5×91667157＋7.085×63947991＋2.35×112084925 ＋49.302×88443129＋2.35×22719908 ＋10.415×54051144＋2.5×33283828 =229167893＋453071516＋263399574
＋4360423146＋53391784＋562942665＋83209570 =6005606148
Td =0.5×(t0+t01+t1 +t3+t4+t5)+t2+1/3×Θ
= 0.5×(5+14.17+4.7+4.7+20.83+5)+149.4+0.33×25 =0.5×54.4+149.4+8.25 =27.2+157.65 =184.85(s) Fdx =√∑Ft/ Td
=√6005606148/184.85 =√32489078.43 =5700(kgf)
(五)、等效功率:
Ndx = FdxVmax/(102η)
=5700×3.848/(102×0.90) =238.9(kw)
从以上计算可知,所选电动机容量是合适的。
2222
电动机的过载系数校验:
16