Bently Nevada RK4 Specifications

RK4 Rotor Kit

Datasheet

Bently Nevada Machinery Condition Monitoring

Description

The RK 4 Rotor Kit closely simulates actual rotating machine
behavior. Its unique geometry and its ability for users to
isolate and control individual machine characteristics make it
useful as both a teaching aid and as a research and
development tool.

Machine malfunctions and experiments that can be
demonstrated include, but are not limited to:

l Rotor unbalance - both single plane and multiplane
l Shaft rub condition
l Oil whirl and oil whip instabilities

In addition to machinery behavior, the rotor kit can be used
to teach the fundamentals of proximity probe placement,
gapping, and troubleshooting. It can also help technicians
learn how to read and interpret proximity probe signals using
an oscilloscope.

141592 Rev. L

Performance and Features

The RK 4 Rotor Kit has a V-frame design that has been
developed to provide better control of the housing dynamic
stiffness properties. The mechanical tolerances have also
been tightened, resulting in more accurate machine behavior
modeling. The RK 4 Rotor Kit motor can closely hold the
desired speed with changes in loading conditions. This has
been accomplished by incorporating a direct current motor
and high performance control circuitry. The motor can run in
either a clockwise or counter-clockwise direction and has
adjustable slow roll speed capability. It can be controlled
remotely by using a ±5 volt control input, such as a signal
generator or dc power supply, to drive the motor speed
control device. Rotor speed is displayed on a digital
tachometer with a large LCD readout.

RK4 Rotor Kit
Datasheet 141592 Rev. L

The RK 4 Rotor Kit consists of:

l A mechanical base (including motor,

coupling, rotor shaft, two balance wheels,
two journal bearings and bearing blocks,
six proximity probes, three probe mounts,
a rub screw, and three safety covers).

l A Proximitor assembly that contains five

Proximitor units.

l A direct current motor speed control

device.

The motor speed control device provides power
for both the rotor kit and the Proximitor
assembly. A measurement and diagnostic
tool, such as an oscilloscope or other
diagnostic instrument, should be ordered
separately in order to observe the RK 4 machine
behavior.s

An optional Oil Whirl/Whip kit can be ordered.
The Oil whirl kit consists of:

l A high pressure oil pump assembly.
l An oil whirl bearing assembly.
l A rotor kit shaft with oil bearing journal.
l A load frame.

Fluid-induced instabilities (both oil whirl and
whip) as well as basic journal bearing behavior
can be demonstrated using the oil whirl/whip
kit. The oil whirl bearing is made from
transparent plastic, allowing the user to view
the oil film development during operation. The
load frame is used to remove the effect of
gravity on the rotor and to position the rotor to
any desired eccentricity ratio.

The kit includes:

l A mechanical base (including motor,

coupling, drive assembly, drive belts, and
two proximity probes for motor speed
control and Keyphasor signal pickup).

l A motor speed control unit.

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