Page 11 - 810 Trianing Book Extract

Machine basics: ield guide for rotating machines
Quick reference guide

For vibration testing, we can simplify a machine to one or two shafts

with two bearings each and something connecting the shafts. Look at Mark this page and the next two pages as a Quick
your machine and identify the shaft(s), bearings, coupling, and driven Guide to Rotating Machines
component. The next three pages show eight different machine types.

Pay attention to the ones that look like your machines.

Component diagram
Example machine
Machine icon in 810

1. Motor detached (no driven)

Measurement location
Measurement location
Measurement
location

Motor
Motor shaft
shaft
only

Bearings

When the motor turns does anything else turn? Is there anything on motor shaft? If yes, then do not select #1.

This option is only for stand-alone motors, such as a motor that has been removed, repaired, and sitting on the
shop loor or test bench. If anything else is connected to the motor, the diagnosis will be wrong.

2. Motor close-coupled with overhung driven

Driven
component
Pump

Does the machine have just two bearings? If no, then do not select #2. See #3 and #4.
This option is for situations where the pump, compressor, or fan is mounted directly on the motor shaft.

3. Motor coupled with overhung driven

Flexible
Flexible coupling
coupling Pump

This option is for machines with four bearings and two shafts going the same speed. Most machines have some
type of lexible element between the shafts to allow some give.

Chapter 4: Step-by-step: setup and measure your machines 59