Machinery's Handbook, 31st Edition
2736 SHAFT ALIGNMENT 5th Arrangement.— Place rim and face indicators as shown in Fig. 5a . In the figure, notice that the origin of the dimensions B and C is the line of the rim indicator.
r
f
A
A f B A f C
2 2 ! ! # ! ! #
F r R r
= − + = − +
F
R
B
C
Fig. 5a. Dial Indicator Arrangement 5
+ -
o
-
-
+
o
-
o
o
o
+
o
-
+
+
+
Fig. 5b. Interpreting Dial Indicator Readings for Indicator Arrangement 5 Solid lines represent the desired location for the dashed lines (movable unit). The plus, minus, and zero readings on the indicators are represented by one of these nine scenarios. Depending on the magnitude of the variables, the generic graph gives a mental picture of what the formulas should yield. Example: Calculate the shims necessary for a pump and motor alignment where dimen sions are A = 4.0 inches, B = 5.50 inches, and C = 17 inches. The two indicator dials read r = plus (+) 0.042 inch and f = minus ( − ) 0.036 inch respectively. Solution: The top right block in Fig. 5b corresponds to the positive rim value and a nega tive face value of the indicators, and indicates that both ends of the motor need to be moved down. This requirement is confirmed by the negative shim numbers that provide the exact distance as follows:
A f B
A f C
. 2 0042 = − + = − + − =− + − =− 2 ! ! # ^
. 2 0042 = − + = − + − =− + − =− 2 inch ! ! # ^
F r
R r
. 40 0036 550 . . #
. 40 0036 170 . . #
. . 0021 00495 00705 . inch
. . 0021 0153 0174 .
h
h
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