中国石油大(北京)机械原理考研习题Chapter 4

1、4-4.(2) if the link AB is a driver and rotates at a constant speed.(a) Find the pressure angle and the transmission angle of the mechanism at the position shown.1 .246135cosad2dal22BD39.131bc2BDcbarccosBCD22261.48BCD180ABCD VCF13537.12dc2)ab(cdarccosADC2221188.65dc2)ab(cdarccosADC222282.52ADCADC12ma

2、x(b) Find the angular stroke max of the link DC37.25)ab(d2cd)ab(arccosADC222161.16ADCADC12(c) Find the crank acute angle between the two limiting positions.98.41)ab(d2cd)ab(arccosADC222234.622)(arccos222bcadcbDCB31.3169.148180bc2) ad(cbarccos1802220ABCminDACBminD(f) Find the maxmum pressure angle an

3、d the minimum transmission angle .Then, oo69.589031.31) , min(minmaxmin(3) if the link CD is a driver , the pressure angle and the transmission angle of the mechanism at the position shown.(a) solution:BFVABCD135088.35al2dlaarccosABDBD22BD2265.25bl2clbarccosCBDBD22BD2oABC65.299035.60ADCDBBCA(b) Solu

4、tion: the maximum pressure angle max is 90and the minimum transmission angle min is 0. Dead-point will happen at this position4-10. Shown are the two positions, B1C1 and B2C2, of coupler BC of a revolute four-bar linkage ABCD. Link AB is the driver. The pressure angle at the first position is 0o. The second position of the mechanism is a toggle position. Design the linka