■“ARL1” Series Piston Pumps
Features
● Low noise and high reliability based on the long established experience
The noise at full cut-off with a pressure of 7 MPa, pump rotational speed of 1500 r/min, and measured distance of 1 m is as low
as 55 dB(A) (representative value of ARL1-16). This series also has a high reliability based on Yuken’s long-time experience of
manufacturing piston pumps.
Lightweight and compact
Compared to the AR Series Variable Displacement Piston Pumps, this series is reduced by 40 % both in mass and volume,
realizing a greatly lightweight and compact design.
Specifications
Model Number Designation
Hydraulic Fluids
Use petroleum base oils such as anti-wear type hydraulic
oils equivalent to ISO VG-32 or 46. The recommended
viscosity range is from 20 to 400 mm2/s and temperature
range is from 0 to 60 °C, both of which have to be satisfied
for the use of the above hydraulic oils.
Control of Contamination
Due caution must be paid to maintaining control over
contamination of the operating oil which can otherwise
lead to breakdowns and shorten the life of the unit.
Please maintain the degree of contamination within NAS
Grade 10.
The suction port must be equipped with at least a 100 μm
(150 mesh) reservoir type filter and the return line must
have a line type filter of under 10 μm.
Mounting
When installing the pump the filling port should be positioned
upwards.
Alignment of Shaft
Employ a flexible coupling whenever possible, and avoid
any stress from bending or thrust.
Maximum permissible misalignment is less than 0.1 mm
TIR and maximum permissible misangular is less than
0.2°.
Suction Pressure
Permissible suction pressure at inlet port of the pump is
between -16.7 and +50 kPa.
For piping to the suction port, use the pipes of the same
diametre as that of the specified pipe flange to be used.
Make sure that the height of the pump suction port is
within one metre from the oil level in the reservoir.
Hints on Piping
When using steel pipes for the suction or discharge ports,
excessive load from the piping to the pump generates
excessive noise.
Whenever there is fear of excessive load, please use rubber
hoses.
Suction Piping
In case the pump is installed above the oil level, the
suction piping and suction line filter should be located
lower than the pump position to prevent air in the suction
line.
Drain Piping
Install drain piping according to the chart and ensure that
pressure within the pump housing should be maintained at
a normal pressure of less than 0.1 MPa and surge pressure
of less than 0.5 MPa.
Length of piping should be less than 1 m, and the pipe end
should be submerged in oil.
In case ARL1 pump, a screw-in torque of fitting is 55 to
75 Nm. Do not apply bending and thrust torque to the
fitting.
Recommended Drain Piping Size：
Model ：ARL1 ，Fitting Size：3/8 ， Inside Dia. of Pipe：10 mm
Bleeding Air
It may be necessary to bleed air from pump case and
outlet line to remove causes of vibration. An air bleed
valve (Model Number ST1004-*-10*, Page 265) is
recommended for this purpose.
Starting
Before first starting, fill pump case with clean operating
oil via the filling port.
In order to avoid air blockage when first starting, adjust
the control valves so that the discharged oil from the
pump is returned direct to the reservoir or the actuator
moves in a free load.
Volume of Pre-fill Oil Required：Model ：ARL1 ，Volume cm3 ：285
Setting Discharge Pressure and Delivery
At the time of shipment, the unit has been preset to
maximum delivery and minimum discharge pressure.
Adjust the preset delivery and pressure to meet your
system requirements.
Adjustment of Discharge Pressure
Turning the adjustment screw clockwise, increases pressure.
Volume adjusted by each full turn of the pressure adjustment screw：
Model Numbers ：ARL1，Adjustment Volume MPa (PSI)：1.5
Displacement Adjustment Function
This pump does not have a displacement adjustment
function.
Install a flow control valve, if necessary
