DRIVEN FREE PISTON MECHANISM
The Linear-motor-driven Free Piston System is not only ideal for upgrading
existing systems but can also be used for future design improvement. Compact, quiet, and vibration free,
the extremely reliable Free Piston Pump will enhance your system performance and extend its operating life.
The Electro-magnet and return spring alternatively drive
the piston inside the cylinder, the mechanical resonance
of which is synchronized with the input current cycle. In a
single mechanism, the piston combines the functions of
two normally independent devices; a pump and a motor.
Compact integrated design
This unique system enables the mechanical
resonance of a single part. An incredibly
compact, lightweight design is achieved by
combining what are entirely independent
functions in conventional pumps - the motor
and the compressor - into a superior single,
unified structure.
A silicon diode in between the coils converts
the full-wave input current into half-rectified
current. In turn this activates and deactivates
the electro-magnet, producing a smooth
mechanically resonating action.
Operating Principle
A. The energised
electro-magnet attracts the
piston, compresses the
return spring, and draws air
into the cylinder through the
opened inlet valve.
Hyper pressure control
mechanism
Should the output pressure exceed the
rated value, the piston will automatically
adjust to a shorter stroke. Additionally,
power consumption will automatically
reduce, guarding against possible
temperature overloads.
Self-cooling design
Cool intake air passes through an
opening over the coils to reduce
and control the rise in internal
temperature. As a result of this
feature, it is possible to almost
completely seal the unit, thus
improving the suppression of
internal operating noise.
Outlet
Current
No Current
B. When the electro-magnet
is de-energized, the return
spring pushes the piston
back, forcing
the compressed air out of the
cylinder through the now
opened outlet valve.
Inlet
Fewer components
This uniquely simple and reliable design has no
complicated transmission components such as
crankshafts, connecting rods, ball bearings, etc.
typically found in conventional pump designs.
Fewer parts means fewer problems.
Air Compressors & Vacuum Pumps
Aquarium
Aeration
Air Brush
Soldering Fume Remover
Muscular Electro-Therapy Unit
Our Valued Customers & Applications
Pap smear
Tester
Coffee Maker
3
Nebulizers
Sewage
Treatment
Aeration
Experience gained in well over two decades of designing, engineering, manufacturing and
continually perfecting our products in thousands of applications has resulted in a “functionally intelligent”
package. Please review these key design features and see how every design element contributes overall to
the creation of a superior compressor or vacuum pump.
Compact and Lightweight
Low Noise Level
with the motor and compressor combined
into the single structure
No transmission assemblies,
means less noise
With the piston as the only moving part, efficient space
utilisation enables our pump to be considerably smaller
and lighter than other pumps. This allows the OEM
design engineer increased packaging options for other
internal components.
With no need for complicated transmission mechanisms
riding on ball bearings, or actuating linkages creating
friction and noise, Nitto Kohki's pumps are inherently
quieter. Additionally, the almost completely sealed
configuration further suppresses secondary internal
operating noises.
Low Vibration
Clean Operation - Clean Air
The extremely low mass, short stroke, die cast piston
minimises reactive force vibrations. Secondary vibrations
are isolated or absorbed through the soft elastomeric
mounting pads.
All wearing surfaces use no oil, grease or other
contaminating lubricants. The combination of a precision
Teflon® sleeved piston assisted by an "air-bearing effect"
made possible through a unique air path design, assures
that the outlet air is completely free of oil.
Instant Response
Minimal Pulsating Effect
A very low starting current enables our pumps to
produce immediate performance in quick short cycle
applications, even in the presence of residual back
pressure.
The piston's mechanical resonance speed is synchronised
with the input power frequency regardless of the load,
i.e., 3000 strokes at 50Hz, and 3600 strokes at 60Hz per
minute. This high speed produces shorter pulses which
translate into a smoother, more uniform and “linear”
motion.
Automatic Pressure Adjustment
Low Power Consumption
using an ultra-lightweight piston
enabling easy start-ups in frequent
on-off short cycle applications
with intelligent pressure monitoring
Should an operating condition create excessive pressure,
the piston stroke length proportionally reduces to
accommodate the condition. Along with this adjustment,
power consumption is correspondingly reduced,
decreasing or eliminating the potential for system
malfunctions or permanent damage.
Longer Durability
due to oil-less construction
due to the high resonating speed
truly energy efficient through integrated
design
Since the low mass piston is the only moving part,
frictional losses are minimised, allowing lower starting
and running current, and thus greater efficiency. Related
benefits are realised through a lower rise in temperature,
facilitating a longer operating life for the pump and the
other components within your system.
Easy maintenance
increased OEM value
only air filter and piston to change
All key design features listed here combine to provide
superior performance in all the important aspects of
superior pump design. This enables the OEM engineer to
have complete confidence in incorporating the unit into
the most demanding systems, in the most advanced
equipment.
Replacement of the piston can be easily performed by
simply removing the four screws holding the head cover
in place. A completely oil-less construction is achieved
through the combination of two elements: the superior
abrasion resistance of the Teflon® seals that cover the
piston contact surfaces and the "air bearing effect"
created by the unique air path design.
4
How to Use This Catalog
This catalogue is designed to aid you in selecting the most appropriate
product for your specific application. The INDEXES on page 1 and 2 show
the corresponding pages of particular models. The page on which each
Explanation of Technical Terms
model is shown consists of a specification table, a performance chart, a
power consumption chart, and an external/mounting dimensions diagram.
Application examples and applicable fluids for
compressors and vacuum pumps
Application: for incorporation into equipment
For compressors
For compressors & vacuum pumps
Rated pressure:
This is the optimum pressure point, where you will get
the best capabilities such as performance and service
life, and where the pump is designed to have almost
the same airflow regardless of input cycle, whether it is
50Hz or 60Hz.
Rated airflow:
The discharge airflow volume at the rated pressure.
Maximum pressure:
The highest obtainable pressure at which the pump
was designed to produce zero discharge airflow (not
assured; referential value only).
Power consumption:
The input wattage value during operation at the rated
pressure.
Current:
The electric current value when operated at rated
pressure (for reference only).
Duty cycle:
The period of operation time in which the coil
temperature will not exceed the coil insulation class
limit for which it was designed.
Airflow
characteristics:
Discharge pressure-airflow curve (for reference only).
Power consumption
characteristics:
Discharge pressure-power consumption curve (for
reference only).
For vacuum pumps
Maximum vacuum:
The highest vacuum the pump can attain with the
pump inlet closed (except some of the exclusive
models).
Free air displacement: The airflow volume at zero vacuum (within three (3)
minutes after the start).
Power consumption:
T h e m a x imum inpu t w a t t a ge o n t h e p o w e r
consumption curve (up to the maximum vacuum point).
Electric current:
The ma ximum electric current on the current
characteristics (for reference only).
Rated operating time: The longest continuous running time within the range of
coil insulation classification (without additional cooling).
Airflow
Vacuum degree-airflow curve (for reference only).
characteristics:
Power consumption
characteristics:
Exhaust
characteristics:
Applicable fluid: Air
Vacuum degree-power consumption curve (for
reference).
The time required to attain the respective vacuum
within a 10 liter container (for reference).
Life expectancy:
Expected accumulated operating hours until the
discharge airflow reduces by 20% under rated
conditions. The actual life might vary in accordance
with the actual operating conditions or environment
such as output pressure setting, maintenance
schedule, ventilation, ambient temperature, duty cycle,
etc.
Please note that operation with quite different supply
voltage than the rated will not only affect the pressure,
the vacuum rate and the airflow but may also influence
the life expectancy of the pump.
Rated frequency:
In the case of AC drive, the rated frequency will be
different by the versions, some are only for 50Hz or for
60Hz, some are for both 50Hz and 60Hz.
Coil insulations:
The suggested classe, most bare units attaining “E”
class, is based on Japanese electric regulations. They
are merely suggestions since bare units are
considered as “components” and are not classified as
complete products or systems.
Insulation Class
(for reference)
(Temperature limit, degrees C)
A
100
E
115
B
125
F
150
H
170
Outside & mounting
dimensions:
Useful for assessing the required space for installation.
Allow extra 5-10 mm each in order to prevent the
pump from hitting its surroundings as it vibrates on
rubber insulating feet.
Rated power supply:
The two major types are 115V AC/60Hz and 230V
AC/50Hz. However, most of the models, not all of
them, can be used at both 50Hz and 60Hz with
different performance characteristics.
Operating ambient
temperature:
Operating ambient
humidity:
0 ∼ 40˚C
30 ∼ 85% non-condensing
For liquid pumps
Self-priming power:
The power that the pump will draw 25˚C water up.
1kPa is equal to the power that draws up 25˚C water by 10cm.
Improvement suggestion
For DC pumps
Operating ambient temperature:
0~40˚C ( 5~50˚C for only DP0105 )
Operating ambient humidity:
30~85% without condensation present
Verify in your application if the pump outlet must be unloaded before restarting.
While our compressors and vacuum pumps employ a unique internal coil
cooling feature to reduce or control the rise in internal temperature, please be
advised that operating at higher than rated pressures may result in elevated
temperatures. Should these temperatures become excessive, operating duty
cycles may need to be reduced, or the use of an auxiliary cooling fan should
be considered.
This catalogue will give the guidelines to let you determine the appropriate model for your application(s). However, in certain cases you may need further detailed
information, which will be provided in the form of a specifications sheet for each model/version by our technical staff who will further assist you in your selection.
Specifications and designs are subject to change at any time without notice.
It is recommended for OEM customers to confirm the specifications required in writing before placing orders.
5
Precautions for Use
Before using any of our products, please be sure to read the following precautions and
the product’s operation manual.
Precautions for Compressors
•
•
•
•
•
•
•
•
CAUTION
WARNING
CAUTION
WARNING
CAUTION
WARNING
•
•
There is a risk of an explosion, fire or electric shock.
CAUTION
WARNING
Make sure the unit is operated in a completely dry area.
There is the risk of a short circuit causing a fire or an electric shock.
connected to a double insulation device.
Not earthing the unit may result in a fire or an electric shock.
The unit must be installed at a level higher than the water surface when it is used for bubbling.
If installed at a lower level, fluid may flow into the unit and cause an electric shock.
Do not allow anything to be placed on or to fall onto the electric cable,
which may damage the cable, causing a fire or an electric shock.
Do not pull, cut, twist, heat up or unnecessarily bend the electric cable,
which may damage the cable, causing a fire or an electric shock.
When installing the unit into another device, the cable from the unit should be
connected securely to the wiring of the device by such as soldering, crimping or
screw fastners.
A loose connection may cause a fire or an electric shock.
The unit must not be disassembled or repaired by any other person than who has
received Nitto Kohki technical training. (Except in the case of filter and piston
maintenance and inspection in accordance with the operation manual.)
Otherwise it may result in a fire or an electric shock due to faulty operation.
The unit must be disconnected from its power source before the cleaning or
replacing filters.
Failure to do so may result in an electric shock or injury.
There is a risk of an explosion, fire or electric shock.
•
•
•
•
•
•
•
•
•
•
Insert the power plug securely to the hilt of the contact blades so that it does not wobble.
Failure to do so may result in an electric shock.
Do not put anything on the power cable.
This may causes a fire or an electric shock.
Do not place anything near the unit (within 50cm reach)
This may cause a fire or an electric shock.
Do not use the unit where flammables, such as gasoline, solvents, lacquer,
benzene, etc. are being used.
This may cause a fire or an explosion.
Check the power plug at least once a year for dirt and dust and clean.
Failure to do so may result in an electric shock or a fire.
The power plug must be disconnected before the air filter is cleaned or replaced.
Negligence may cause an electric shock or accident.
Always grasp the power plug not the cable when disconnecting the unit from the power socket.
Pulling it out by grasping the cable may cause an electric shock or short circuit.
Any disassembled air filter must be put back before resuming the operation.
Negligence may cause a fire or an electric shock.
Never try to disassemble or repair the unit.
This may cause an electric shock or an injury. Any repairs must be done by an electrician
authorized by Nitto distributors.
Do not cover Blower with a box or the like without proper or adequate ventilation.
This may cause malfunction and fire.
Please confirm the suitability of the liquid that passes through the unit before use.
Otherwise there will be possible leak, burst, fire or electric shock.
•
Please avoid any liquid that contaminated with solids such as deblis or dust.
If dust sticks to the valve, the unit may not give a good performance. When intrusion of
dust is expected, place a filter to the inlet.
Please avoid any liquid that may crystallize.
If crystals stick to the valve, the unit may not give a good performance. Preparatory test
on the unit with the liquid is recommended.
When in use of compressors and vacuum pumps
As compressors and vacuum pumps employ self-cooling system, if used at more
than rated pressure, duty cycle of some of the models will be shortened.
•
•
•
•
•
•
•
There is the risk of a short circuit causing a fire or an electric shock.
Do not let the unit take in any gas other than air.
Do not place the unit on the spot where may be soaked with water or
covered with snow.
This may cause an electric shock or a fire.
Do not use the unit in a damp or wet place.
This may cause an electric shock or fire.
Always place the unit above water level.
Failure to do so may result in an electric shock or fire.
Use a waterproof wall outlet socket to supply power to the unit.
Failure to do so may cause an electric shock or fire.
Use a power supply equipped with a set of earth leakage and overcurrent
breakers.
Failure to do so may result in an electric shock or fire.
Electric work must be done by a qualified electrician.
Failure to do so may result in an electric shock or fire.
Do not modify the unit.
Modification may cause a fire or an electric shock.
Do not use with the outlet port closed or at free displacement.
This may cause an electric shock, malfunction, or fire.
Do not use the unit with a power supply other than the voltage shown on the unit.
Negligence may cause a fire or an electric shock.
Never touch the power plug with wet hands.
This may causes an electric shock.
Precautions for Liquid Pumps
•
•
•
•
•
•
Make sure the unit is operated in a completely dry area.
The unit must be installed at a level higher than the water surface when it is used for
bubbling.
If installed at a lower level, fluid may flow into the unit and cause an electric shock.
Do not allow anything to be placed on or to fall onto the electric cable,
which may damage the cable, causing a fire or an electric shock.
Do not pull, cut, twist, heat up or unnecessarily bend the electric cable,
which may damage the cable, causing a fire or an electric shock.
When installing the unit into another device, the cable from the unit should be
connected securely to the wiring of the device by such as soldering, crimping or screw
fastners.
A loose connection may cause a fire or an electric shock.
The unit must not be disassembled or repaired by any other person than who has
received Nitto Kohki technical training. (Except in the case of filter and piston
maintenance and inspection in accordance with the operation manual.)
Otherwise it may result in a fire or an electric shock due to faulty operation.
The unit must be disconnected from its power source before the cleaning or replacing
filters.
Failure to do so may result in an electric shock or injury.
Do not let the unit take in any gas other than air.
Do not install the unit in a completely enclosed case (box).
This may cause a fire or an electric shock.
The unit must be used as assembled in a device that has the appropriate casing
and wiring.
Using it without appropriate casing may cause fire, electric shock or burns.
Do not give the unit heavy external shock during storage and transportation,
which may cause malfunction of the unit.
Do not use the unit with a power supply other than the voltage shown on the unit.
Negligence may cause a fire or an electric shock.
Use the unit within the proposed ambient temperature range.
Using it out of the range may cause a fire or an electric shock.
Units must not be modified.
Modification may cause a fire or an electric shock.
Do not place flammable substances near the unit.
This may cause a fire.
In case there is a chance of moisture, particles, dirt or dust in the air the unit suck in,
an additional filtration device must also be installed on the inlet port of the unit.
Contaminated air may cause an electric shock.
Units with grounding screws should be earthed (grounded), except when
Precautions for Blowers
•
•
•
•
•
•
•
•
•
•
There is a risk of an explosion, fire or electric shock.
The unit must be used as assembled in a device that has the appropriate casing and wiring.
Using it without appropriate casing may cause fire, electric shock or burns.
Do not give the unit heavy external shock during storage and transportation,
which may cause malfunction of the unit.
Do not use the unit with a power supply other than the voltage shown on the unit.
Negligence may cause a fire or an electric shock.
Do not install the unit in a completely enclosed case (box) without proper or adequate
ventilation.
This may cause a fire or an electric shock.
Use the unit within the proposed ambient temperature range.
Using it out of the range may cause a fire or an electric shock.
Units must not be modified.
Modification may cause a fire or an electric shock.
Do not place flammable substances near the unit.
This may cause a fire.
Units with grounding screws should be earthed (grounded), except when connected
to a double insulation device.
Not earthing the unit may result in a fire or an electric shock.
Precautions for Vacuum Pumps
•
•
•
•
•
•
•
•
•
Do not let the unit take in any gas other than air.
When you want to prolong the duty cycle, it is recommended for you to cool
the compressor with fans. For instance, AC0902, whose duty cycle is 30
minutes, is effective.
•
•
•
The performance is measured with the unit at its proper position, which is described
in the user’ s manual. Different unit positions or the nozzle directions may result in
different performances.
•
Do not use the compressor near
flammable gas.
Do not use the compressor in the
rain or in wet and damped place.
Do not suck corrosive gas.
Please check with our distributor in advance if you like to use the compressor/vacuum pump at free displacement (0MPa), or
the vacuum pump with inlet port closed, or the compressor at maximum pressure.
Handling Problems
In any of the right cases, stop operation immediately,
switch off the power and disconnect the unit from the
power supply. Ask our distributor for repair.
••
•
When oil such as lubricant has been applied to the unit in error.
When the unit has suffered a severe shock such as being dropped.
When liquid such as water has entered into the unit by mistake.
•
Be sure to install and use the compressor
at a position higher than water level.
×
When an abnormal operation is observed, such as
the emission of smoke, or an unusual smell or noise.
6
Conversion Tables
Flow Rate
Pressure
2
kgf/cm (bar)
psig
CFM
LPM
CFM
LPM
0.30
3.0
42.7
0.035
1.00
2.12
60.0
0.28
2.8
39.8
0.070
2.00
2.25
63.7
0.25
2.5
35.6
0.20
2.0
28.5
0.100
2.83
2.47
70.0
0.18
1.8
25.6
0.105
3.00
2.50
70.8
0.15
1.5
21.3
0.177
5.00
2.65
75.0
0.12
1.2
17.1
0.250
7.08
2.75
77.9
0.10
1.0
14.2
0.353
10.0
2.83
80.0
14.2
3.00
85.0
MPa
0.08
0.8
11.4
0.500
0.07
0.7
9.96
0.530
15.0
3.18
90.0
0.05
0.5
7.11
0.708
20.0
3.25
92.0
0.045
0.45
6.40
0.04
0.4
5.69
0.750
21.2
3.50
0.035
0.35
4.98
0.883
25.0
3.53
100
0.034
0.34
4.84
1.00
28.32
3.75
106
0.03
0.3
4.27
1.06
30.0
3.89
110
35.0
4.00
113
99.1
0.02
0.2
2.84
1.24
0.018
0.18
2.56
1.25
35.4
4.24
120
0.015
0.15
2.13
1.41
40.0
4.50
127
0.011
0.11
1.56
1.50
42.5
5.00
142
0.01
0.1
1.42
0.007
0.07
1.00
1.59
45.0
5.30
150
0.005
0.05
0.71
1.75
49.6
6.00
170
0
0
0
1.77
50.0
7.00
198
2.00
56.6
7.06
200
Pressure
Vacuum
kPa
0
mmHg
mbar
in.Hg
0
from
to
0
0
-13.3
-100
-133
-3.94
kgf/cm
-26.7
-200
-267
-7.87
bar
-33.3
-250
-333
-9.84
psig
-44.0
-330
-440
-13.0
-45.3
-340
-453
-13.4
-46.7
-350
-467
-13.8
-53.3
-400
-533
-15.7
-60.0
-450
-600
-17.7
-66.7
-500
-667
-19.7
-73.3
-550
-733
-21.7
-80.0
-600
-800
-23.6
-93.3
-700
-933
-27.6
-100
-750
-1000
-29.5
-101.3
-760
-1013
-29.9
Gauge pressure
Absolute vacuum
7
Pressure / Flow Rate / Vacuum
MPa
MPa
1
2
kgf/cm2
bar
psig
10
10
142
0.1
1
1
14.2
0.1
1
1
14.2
0.007
0.07
0.07
1
mmHg
in.Hg
mbar
Vacuum
from
to
kPa
kPa
-1
-7.50
-0.295
mmHg
-0.133
-1
-0.0394
in. Hg
-3.39
-25.4
mbar
-0.1
-0.75
-1
-0.0295
-10
-1.335
-33.92
-1