Wiith deep natural frequency & adjustable dampening
(pat.) for vibration isolation of measuring & testing
machines, optical and electronic equipment, laser
machines, fine machining plant, vehicle & motor
performance testers etc.
The Air Spring Isolator BiAir® consists of either a
steel or cast aluminum body whose air volume is enclosed
by a thin-walled, flexible and pressure-resistant
rolling diaphragm. The piston is seated on this
diaphragm & is pushed into the air volume.
This design causes highly effective vibration isolation.
In order to obtain as high a dampening effect as
possible, the air space is split into two chambers (load
and dampening volume) that are connected by an air tube.
The amount of dampening can be easily changed by the
adjustable valve located on the outside of the air
spring. As the load on the air spring changes, air is
forced through the bypass valve creating friction. This
friction creates up to an 18% dampening effect.
Additional safety valves protect the rolling diaphragm
from getting damaged by over inflation.
Range of Application
Highly effective vibration isolation of sensitive
measuring (CMM) and testing machines, fine machining
plant, as well as optical and electronic equipment.
Another important range of application is the vibration
isolated foundation of vehicle, motor and other
BiAir® Air Spring isolators are extremely well suited
for the isolation of foundations e.g. equivalent machine
Air springs with higher max. loads as well as air
springs with lower natural frequencies can be supplied
Advantages compared with conventional steel springs
BiAir® Air Spring Isolators with level control are an
active system. The machine foundation level consistency
will always be preserved! Automatic leveling adjustment.
BILZ level controller systems
Level control is an important part of an optimally
functioning air spring system. The automatic level
controller can be utilized to overcome the problem
associated with load changes in air spring isolated
machines, which can result in tilting of the machine.
The height of the specific elements BiAir® or FAEBI® can
be controlled by changing the air pressure in the air
spring isolators. Quick inflation or deflation will hold
the machines level even if their center of gravity keeps
The circuit consists of at least three air springs. If
more air springs are needed for structural or loading
reasons, the system must always include 3 position
points, e.g. three controlled components to avoid being
in a statically indeterminate condition . This is
achieved by connecting sets of air springs in parallel.
BiAir® mechanical-pneumatic positioner / controller
The mechanical-pneumatic control valves are a simple yet
effective solution. The level is constantly scanned by a
plunger. The plunger position is transmitted to a spool
valve. Depending on the spool valve position, pressure
is either applied to the air spring or vented from the
inside of the air spring. The machine level can be
maintained at an accuracy ± 1/100 mm (10 microns).
Principally three control valves are used. The incoming
air supply is conditioned with a pressure regulator to
limit system pressure to a maximum of 6 bar and with a
water trap to remove vapor & an air filter to remove
dust & any foreign bodies from the air supply
Each system consists of 3 position sensors, 3
electro-pneumatic control valves, one control unit
(digital computer logic), the pressure regulator and
filter units. Even the most severe conditions are
mastered by the electro-pneumatic positioner. It is used
mainly where high reset precision and extremely short
reaction times are required. Any deviation (difference
between desired value and actual value) from the desired
height (desired value) of the air spring isolator is
measured at a precision of up to 1/100 mm (10 microns)
accuracy by means of position sensors. In the control
unit, these electronic signals will then be processed
and the air spring elements will be inflated or deflated
accordingly for level equalization via the pneumatic
The control unit consists of a printed circuit
board, containing the entire logic of the 3 control
circuits, 3 air pressure gauges for the air springs,
adjusting screws for the adjustment of the machine,
selection of the controller speed, and a switch to
enable complete deflation of the air springs. The
control unit can be supplied either as a 19 inch rack
mount unit or completely enclosed within a cabinet.
As an optional feature, a special software package
is available. By means of this software, the adjustment
& optimization of controlled conditions, the
registration of adjustment parameters as well as error
determination can be carried out via the serial
interface (serial interface provided on the control
unit). Furthermore, the integrated serial interface
enables a connection between available machine computers
or systems to be isolated. A number of more complex
system modes can be realized this way.
BiAir® electro-pneumatic positioner /controller
Important advantages of the BILZ level control are:
High reset accuracy e.g. level accuracy of ± 1/100
mm (10 microns)
Extremely short reaction time (within the
The general possibility of being able to optimally
adapt (increase and reset) the speed of the system
to the specific conditions (control circuit)
Wear resistant and sturdy relief valves
Simple and effective set-up operation