Question

(c) To couple the shaft with a bearing, a basic size of 40 mm is considered. The bearing surface has been manufactured to H7 tolerance. If the clearance between this bearing surface and the outer surface of the shaft is expected to be 20-60 um, use the MMC (Maximum Material Condition) method of tolerancing to dimension the hole and the shaft. (5 Marks)

Answer 1

sulution $ Systems because capital letter Qiu ginen, Basic size (d): 409) - Bearing or hale tulerame ē HT 'Note - this is hole basis systems represent hale & hale & Auleront gate i rep tolerance grate to represent zero fundamental deviation). Tolerance grade for H7 = 177 = 16i where, i = 0045 D 3 torool in. in mm in m.) where be t on D=JDID Di, De are step dia in which Basic size (d) lees ef de to room, ther. D;= 30 roroos, Da - 50 mm, :D= 30x50 = 38.7298 novos 11=0.45(38.7298) 3+ 0.001( 38:7298) Ilm iz 1.56124 elon = 0.001561 77 .: Bearing (hele) tolerance = 161 = 16X0.001561=0.0249.8 moss = 24.98 mm max clearance between hale & Shaft = Gollm. min , " " " = 20 lm. 2 840+0.02498 040273 - - 24.98.15 Hole Basic Size: 40 mm 20 UT Golem shaft. : Shaft tulerance (CD) = 60-(20+24.98) - 15.02 loon

. upper limit of shaft = tomm - 200m 240 - 0020 = 39.98 mm lower limit of shaft = toom - zalem - 15.02 less - 40 -0.020 -0.01502 ī 39.965 ms. Note for max material condition, amount of material for Shaf & chole wool should be maximum, so in this case we should select maxs size of shaft & min Size of the hode .Shaft Size = 39.98 mm ? Hole size= 40.60 mm J Aus