Page 42 - Rotating Machinery Pratical Solutions to Unbalance and Misalignment
P. 42

Rotating Machinery: Practical Solutions

                 D = [G/.014190252] * [1000/F]  2                      (2.25)

                 D = [70.47090965 * G * [1000/F]  2                    (2.26)
                 Now using the above relations to build the relation of accel-
            eration to velocity:

                 V = X ω                                               (2.27)
                       o
            And;

                 A = X ω  2                                            (2.28)
                       o
            And;
                 G = A/386.4                                           (2.29)
            Thus:
                 G = X ω2/386.4                                        (2.30)
                       o
                 G = X ω* ω/386.4                                      (2.31)
                       o

            And substituting from Equation (2.27):
                 G = V ω/386.4                                         (2.32)

                 G = V*(2πf)/386.4                                     (2.30)
            And:
                 G = 2πFV/(60 * 386.4)                                 (2.31)
            Rearranging:
                 G= FVπ/11,592                                         (2.32)
            Or:

                 G = FV/3,689.848201                                   (2.33)
                 V = 3,689.848201 * G/F                                (2.34)


                 The use of these equations will transform the three forms of
            vibration characteristics to one another.

            Example 2.2
                 A shaft has a peak-to-peak displacement reading of 3.4 mils
            @ 36.5 Hz. What is the velocity and what is the acceleration?
   37   38   39   40   41   42   43   44   45   46   47