fluid couplings - Laumayer

FLUID COUPLING SELECTION
7.4 CALCULATION EXAMPLE
Assuring: Pm = 20 kW n m = 1450 rpm
Supponendo: P L = 12 kW n L = 700 rpm
Supponendo: J = 350 kgm
Supponendo: T = 25 °C
Transmission via belts.
From selection graph on Tab. A, selected size is 12K.
A) Acceleration time
From curve TF 5078-X (supplied on request) slip S = 4%
100 - 4
nu = 1450 • ( )= 1392 rpm
100
2 700
Jr = 350 • ( )= 88,5 Kgm
1392
9550 •
20
Mm = = 131 Nm
1450
9550 • 12
ML = = 82 Nm
1392
Ma = 1,65 •131 • 82 = 134 Nm
1392 • 88,5
ta = = 96 sec
9,55 • 134
B) Max allowable temperature
1392 88,5 • 1392
+
4
10 76,5
C = 4,2 kcal/°C (Tab. C)
Q = • ( ) = 361 kcal
Ta =
361
4,2
= 86 °C
K = 8,9 (Tab. D)
12
TL = 2,4 = 13 °C
• 4
•
8,9
T f = 25 + 86 + 13 = 124 °C
Viton gaskets needed
C) Max working cycles per hour
tL = 10 • 361
= 724 sec
86
2 + 13 3
( ) • 8,9
3600
H = = 4 starts per hour
96 + 724
2
2
82 •
96
8
10
FACTOR K
Size
6
7
8
9
11
12
13
15
17
19
21
24
27
29
34
D34
Tab. C
THERMAL CAPACITY
K
kcal/°C
0,6
1,2
1,5
2,5
3,2
4,2
6
9
12,8
15,4
21,8
29
43
56
92
138
CK
kcal/°C
OUTPUT SPEED rpm
--
3,7
5
6,8
10
14,6
17,3
25,4
32
50
63
99
–
CCK
kcal/°C
--
10,3
15,8
19,4
27,5
33,8
53,9
66,6
101
–
Tab. D
FACTOR K