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Opcija 7

The document provides calculations for selecting bearings for two supports (A and B) over 10,000 hours of operation at 400 revolutions per minute. For support A, the required radial force is 111.5 N, axial force is 150 N, and permissible power is over 93.273 million N. For support B, the required radial force is 350.35 N and permissible power is over 350.35 million N. Based on the calculations and specifications, bearing 7204 is selected for both supports A and B.

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elma spahic
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48 views3 pages

Opcija 7

The document provides calculations for selecting bearings for two supports (A and B) over 10,000 hours of operation at 400 revolutions per minute. For support A, the required radial force is 111.5 N, axial force is 150 N, and permissible power is over 93.273 million N. For support B, the required radial force is 350.35 N and permissible power is over 350.35 million N. Based on the calculations and specifications, bearing 7204 is selected for both supports A and B.

Uploaded by

elma spahic
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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Download as DOCX, PDF, TXT or read online on Scribd
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2.

Proračun ležajeva:
𝐹𝐴𝑥 = 64,55 𝑁

𝐹𝐵𝑥 = 250 𝑁

𝐹𝐴𝑦 = 90,90 𝑁

𝐹𝐵𝑦 = 245,50 𝑁

𝐵𝑟𝑜𝑗 𝑜𝑏𝑟𝑡𝑎𝑗𝑎 ∶ 400 𝑚𝑖𝑛−1

𝑡 = 10 000 ℎ

2 2
𝐹𝑟𝐴 = √𝐹𝐴𝑋 + 𝐹𝐴𝑌 = √64,552 + 90,902 = √4166,05 + 8264,44 = √12430,50 =
= 111,50 𝑁

2 2
𝐹𝑟𝐵 = √𝐹𝐵𝑋 + 𝐹𝐵𝑌 = √2502 + 245,502 = √62500 + 60245,66 = √122747,66 =

= 350,35 𝑁

𝐹𝑎𝐴 = 150 𝑁; 𝐹𝑎𝐵 = 0 𝑁

OSLONAC A: d=20mm 7204 7304 3204 3304


LEŽAJ
OSLONAC B: d=20mm 7204 7304 3204 3304

OSLONAC A 𝑭𝒓𝑨 111,50 111,50 111,50 111,50


RADIJALNA SILA
OSLONAC B 𝑭𝒓𝑩 350,35 350,35 350,35 350,35

AKSIJALNA SILA 𝑭𝒂 150 150 150 150

𝒀𝑨 0,57 0,57 1,17 1,17


FAKTOR PROP.
𝒀𝑩 0,57 0,57 1,17 1,17

𝑭𝑨𝑲 = 𝑭𝒓𝑨 /𝟐 ∙ 𝒀𝑨 97,80 97,80 47,72 47,72


SAMOINDUKOVANA
𝑭𝑩𝑲 = 𝑭𝒓𝑩 /𝟐 ∙ 𝒀𝑩 307,32 307,32 149,72 149,72
SILA
𝑭𝑩𝑲 − 𝑭𝑨𝑲 209,52 209,52 102,08 102,08

UKUPNA AKSIJALNA 𝑭𝒂𝑨 = 𝑭𝒂 + 𝑭𝑩𝑲 457,32 457,32 197,64 197,64


SILA ZA SLUCAJ
𝑭𝑨𝑲 ≤ 𝑭𝑩𝑲 I 𝑭𝒂 > 𝟎 𝑭𝒂𝑩 = 𝑭𝑩𝑲 307,32 307,32 149,72 149,72

1
𝑫𝒊𝒏𝒂𝒎𝒊č𝒌𝒂 𝒎𝒐ć 𝒏𝒐š𝒆𝒏𝒋𝒂:
𝑁𝑑 = 106

𝑛𝑡 = 400 𝑚𝑖𝑛−1

𝑡 = 10000 ℎ

𝑛𝜀 = 𝑛 ∙ 𝑡 ∙ 60 = 400 ∙ 10000 ∙ 60 = 240 ∙ 106 𝑜𝑏𝑟𝑡𝑎𝑗𝑎

3 𝑁0 3 106 3
𝐶𝑁 = √ ∙𝐶 = √ ∙ 106 = 𝐶 ∙ √0,00416 = 0,16 ∙ 𝐶
𝑛𝜀 240 ∙ 106

𝑰𝒛𝒃𝒐𝒓 𝒍𝒆ž𝒂𝒋𝒂:

𝑳𝒆ž𝒂𝒋 𝑨 (𝒌𝒖𝒈𝒍𝒊č𝒏𝒊 𝒍𝒆ž𝒂𝒋 ); 𝒅 = 𝟐𝟎 𝒎𝒎

LEŽAJ A 7204 7304 3204 3304

C,N 10400 13700 15300 18600

𝑪𝑶 7350 9300 11000 14000

e 1,14 1,14 0,86 0,86

𝑭𝒓𝑨 111,50 111,50 111,50 111,50

𝑭𝒂𝑨 150 150 150 150

𝑭𝒂 /𝑭𝒓 1,34 1,34 1,34 1,34

x 1 1 1 1

y 0 0 0 0

𝑭𝒆𝒌𝒗 = 𝑿 ∙ 𝑭𝒓𝑨 + 𝒀 ∙ 𝑭𝒂𝑨 111,50 111,50 111,50 111,50

𝑪𝑵 = 𝟎, 𝟏𝟔 ∙ 𝑪 1664 2192 2448 2976

2
𝐶 𝛼 10400 3
𝑁=( ) ∙ 𝑁0 = ( ) ∙ 106 = 93,273 ∙ 106
𝐹𝐸𝐾𝑉 111,50

𝑁 93,273 ∙ 106
𝑡= = = 14,005 ∙ 106
𝑛𝛼 6,66
𝑡
𝑇𝐴 = = 3890,28 ℎ
3600

𝑳𝒆ž𝒂𝒋 𝑩 (𝒌𝒖𝒈𝒍𝒊č𝒏𝒊 𝒍𝒆ž𝒂𝒋 ); 𝒅 = 𝟐𝟎 𝒎𝒎

LEŽAJ A 7204 7304 3204 3304

C,N 10400 13700 15300 18600

𝑪𝑶 7350 9300 11000 14000

e 1,14 1,14 0,86 0,86

𝑭𝒓𝑨 350,35 350,35 350,35 350,35

𝑭𝒂𝑩 0 0 0 0

𝑭𝒂 /𝑭𝒓 0 0 0 0

x 1 1 1 1

y 0 0 0 0

𝑭𝒆𝒌𝒗 = 𝑿 ∙ 𝑭𝒓𝑨 + 𝒀 ∙ 𝑭𝒂𝑨 350,35 350,35 350,35 350,35

𝑪𝑵 = 𝟎, 𝟏𝟔 ∙ 𝑪 1664 2192 2448 2976

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