qNachi Fujikoshi hydraulic pumps arefinished by high-grade, precisionmachining technology unique to thecomprehensive manufacturer NachiFujikoshi using carefully selectedmaterials and traditional heat treat-ment technology. High performanceand quality are assured with all mod-els of Nachi Fujikoshi hydraulicpumps.

wNoise has been thoroughly reducedon hydraulic pumps, a general sourceof noise on machinery and equip-ment. All models such as the low-noise type IP series can be operatedquietly with little noise.

eAttention has been paid to surfacetreatment and selection of materialsin NACHI hydraulic pumps so thatthey can be applied extensively withfire-resistant hydraulic operating fluid.

qLimit the eccentricity between thedrive shaft and hydraulic pump shaftto 0.05 mm, keep the angle errorwithin 1° and use flexible couplingsfor connections.

wWhen operating hydraulic pumps withbelts, gears and chains, prevent aradial or thrust load exceeding theallowable value from being applied onthe pump shaft. Also, if necessary,install a device that prevents a load(bending force) from being applied atright angles on the shaft. Mounthydraulic pumps so that the pumpshaft is horizontal.

eUse a rigid pump mounting base.rThe direction of rotation is determined

on each hydraulic pump. Operate the hydraulic pump in thecorrect direction of rotation afterchecking the indicated model No. onthe nameplate or the arrow indicatingthe direction of rotation on the body.The direction of rotation is clockwisewhen viewed from the shaft end.

tLimit the suction pressure to withinthe range -0.03 to +0.03 MPa {-0.3 to+0.3 kgf/cm2}.

yWith external drain type hydraulicpumps, directly connect the drain tothe tank, insert the drain pipe underthe oil level, and limit the drain backpressure to 0.03 MPa {0.3 kgf/cm2}.

uWhen connecting steel pipes to thesuction and discharge sides, preventforce pressure from being applied onthe hydraulic pump by the piping.

iSet the clamping length of couplingsand hydraulic pump shafts so that it iswithin at least 2/3 or more of the cou-pling width. Also, use a size of cou-pling that matches the shaft diameter.

oWhen inserting couplings into shafts,insert them gently. When removingcouplings from shafts, be sure to usea pulley extractor. Avoid hitting theshaft when attaching or removingcouplings.

!0Connect to the suction port above thehorizontal to keep oil inside hydraulicpumps.

!1Provide an air bleed valve in circuitswhere it is difficult to release air atstartup.

!2Be sure to use only specified bolts onhydraulic pumps. Use 12T or equiva-lent.

Uni-pumps are compact pump/motorunits which have a motor directly cou-pled to the hydraulic pump. Variable dis-charge volume type vane pumps andpiston pumps are available. As each ofthese pumps are ideally integrated withthe motor, they can be easily installed,and more compact equipment configu-rations can be achieved economically. ¡Standard motor:

totally-enclosed splashproofhousing surface flange cooledself-actuating type (totallyenclosed fan-cooled type)3.7 kW to 4P or less: Class Einsulation5.5 kW to 4P or more: Class BinsulationVoltage 200V…50/60 Hz

220V…60 Hz

qUse mineral oil-based hydraulic oper-ating fluid.

wProvide a suction filter of about 100 to150 mesh on the suction port.

eWhen operating hydraulic pumps at ahigh pressure or when using fire-resistant hydraulic operating fluid, oilcontamination greatly affect pumpservice life. So, use a filter of 25µm orless.

rConsult your agent when using fire-resistant hydraulic operating fluid. When using water- or glycol-basedhydraulic operating fluid, refer to pageN-3 for details on applicable models ofhydraulic pumps.

tFor details on the viscosity ofhydraulic operating fluid, refer to theseparate item "Hydraulic OperatingFluid."

The following describes the meanings ofthe following terms used in this catalog:¡Rated pressure:

The maximum pressure atwhich a hydraulic pump can beused continuously.

¡Maximum operating pressure:The maximum pressure (includ-ing surge pressure) at which ahydraulic pump can be usedwithin six seconds at most with-in 1/10 of the cycle time.

¡Allowable peak pressure:The maximum pressure (setpressure + surge pressure) thatcan be momentarily allowed

¡The following shows the standards inLists of Sealing Parts:JIS standard B2401 (O-ring)JIS standard B2407 (backup ring)SAE standard AS568 (O-ring)

¡Pipe apertures mentioned in this cata-log that are indicated as "G*/*" com-ply with JIS B2351 O-ring seal sys-tems. Note, however, that G3/4adopts dimensions before JIS revi-sions were made in 1990. NachiFujikoshi adopts P24 as the O-ringsize whereas P22.4 is stated in cur-rent JIS standards.

1.Pump discharge flow rate

Qp= (r/min)

q=discharge volume per rotation(cm3/rev)

N=revolution speed(min-1)ηv=volume efficiency

2.Power required for pump drive

WP1= (kW)

= (PS)

P=discharge pressure(MPa)η=overall efficiency

3.Motor revolution spee

N= ·(1–S)(min-1)

f=frequency(50Hz, 60Hz)P=number of motor polesS=slip rate

120·fP

P·Qp44η

P·Qp60η

q·N·ηv1000

Features

Uni-pumps

Management of HydraulicOperating Fluid

Calculation FormulaRequired when Selecting

Hydraulic Pumps andMotor

Installation andMaintenance

A

A-1

Terms Used in This Catalog

NA

CH

I Hyd

raulic P

um

ps

A_Piston(P01-15)_E.q 03.11.20 0:45 PM Page 1

A

A-2

Hyd

raulic P

um

ps

Hydraulic Pump Selection Table

Pump Type Name

Type Classifi-cation

RatedPressure

MPa{kgf/cm2}

Displacement cm3/rev

Page

Var

iabl

e pi

ston

pum

psV

aria

ble

disc

harg

e vo

lum

e va

ne p

umps

Inte

rnal

gea

r pu

mp

PVS series variable piston pump PVS

21{214}

Uni-pump UPV21

{214}

PZS series variable piston pump

PZS21

{214}

PZ load-sensitive variable piston pump PZ

21{214}

PZH series high-pressure variable piston pump

PZH35

{357}

VDS series compact variable vane pump VDS

7{71.4}

Uni-pump USV7

{71.4}

VDR13 design series variable vane pump VDR

6{61.2}

Uni-pump UVD6

{61.2}

VDR22 design series variable vane pump VDR

14{143}

Uni-pump UVD7

{71.4}

VDC series high-pressure variable vane pump VDC

14{143}

Uni-pump

UVN series variable vane uni-pump UVN

8{81.6}

UVC7

{71.4}

A-3

A-19

A-22

A-35

A-42

B-1

B-4

B-6

B-12

B-15

B-22

B-25

B-37

B-39

C-1

C-14

IPH series IP pump IPH25

{255}

IPH series double IP pump IPH21

{214}

1 2 5 10 20 50 100 200 500 1000 2000 5000

3

3

45

45

42 220

2208

28 40

3 8.3

3 8.3

4

4

27.8

27.8

5 44.4

33.35

5

5

88.9

16.1

33.3

3.6 125.9

7.2 251.8

8.1

A_Piston(P01-15)_E.q 03.11.20 0:45 PM Page 2