● This catalog provides detailed information on hydraulic pumps, motors, integrated HSTs, cylinders, and valves for vehicles
such as excavators, mini-excavators, loaders, forklift trucks, and agricultural machines. As for information on some products
not included in this catalog, please contact KYB Hydraulic Sales Department.
● Some products require prototype tests based on the specifications of customer machines so as to secure their on-site finetuning. In some cases, new functions need to be added to our products to meet customer requirements.
● The catalog makes general suggestions for product selection, handling precautions, and basic dimensions. Confirmation on
detailed specifications may be necessary for actual use. Please contact KYB Sales Department for clarification of details.
(Refer to Page 66 and to the back cover of the catalog for the contact details of Sales Department.)

Basics of Oil Hydraulics【What is oil hydraulics?】【Unit conversion table】

Products for Each Machine (examples)
Hydraulic Equipment for Excavators and Mini-excavators

Cylinder (CYL) –double-acting type
Piston Pump (PP):variable displacement typeOil hydraulics refer to a group of devices or asystem that drives a hydraulic pump with powersources, such as engines and electric motors, totransform mechanical energy to fluid energy in orderto produce mechanical movement using an actuatorlike a cylinder while controlling energy output.

Traveling Motor(with reduction gear)
Sectional Valve(for excavator)

Monoblock (solid casting)
Valve (for excavator)

Swing Motor(with reduction gear)

Hydraulic Equipment for Forklift Truck※In the hydraulic system, the (mechanical) power source rotates the hydraulic pump, by which the oil isdrawn from the reservoir. The oil flows into the hydraulic actuator via the hydraulic valve. The actuatortransmits generated power to the machine and activates it.

Lift Cylinder –single acting typeGear Pump (GP): fixed
displacement type

Control ValveSemi-monoblock
Valve (for Forklift)

Hydraulic Equipment for Combines【Basic Configuration of Hydraulic Circuit】【Hydraulic Circuit Example】
Gear Pump (GP): fixed
displacement typeMini-motion Package※When the tip of the actuator is loaded, the oilpressure between the pump and actuator rises.
1

HST for Traveling2Caution regarding this Product Brochure

Precautions on the Use of Hydraulic Equipment

Definition of Alert MarksAll Hydraulic Circuits

In this brochure, the“Danger”“Warning”,, and“Caution”signs are defined as follows.
※These warning signs are very important for the operator’s safety. Understand them before using the products.
Danger Improper handling will result in an imminently dangerous situation such as death or serious injury.
Warning Improper handling may potentially risk death or serious injury.
Caution Improper handling may result in slight to moderate injury or damage.

Instruction Manual
The cautions and notices described in this manual are intended to help select products. Please read the manuals of theselected products and fully understand the properties of the selected products before using them.

※When selecting hydraulic components, contact each manufacturer for the characteristics of hydraulic equipment such as
piping, joints, filters, and oil reserviors manufactured by other manufacturers.
 Pressure drop: Pressure drop is proportional to the square of the flow rate. Because the loss may increase depending on
the specific equipment and the size and/or length of joints, the normal flow rate and the maximum flow rate being used also
should be taken into account.
 Circuit temperature control: The temperature of the hydraulic fluid in the entire circuit may rise because of the operation
frequency and/or pressure drop. Consult the component manufacturer to make sure the reservoir and cooler capacity is
sufficient.

Hydraulic Fluids● Applicable hydraulic fluids● Applicable hydraulic fluids

Regulations and Standards
Please observe the warnings and cautions described in this manual and the following regulations and standards for the safe use of products.
[Safety related regulations and standards]
 High Pressure Gas Safety Law,  Industrial Safety and Health Law,  Fire Service Law,  Explosion Protection Classes,
 Construction of Pressure Vessels (JIS B 8243), and  General Rules for Hydraulic Systems (JIS B 8361)

Safety Precautions(1) On Product Handling

Caution Wear necessary protective equipment when handling the product so as to prevent any injury.

Caution Do not step on, strike, drop, or apply stress to the product. Such an act may cause malfunction, damage, or oilCaution Oil on a product or the floor makes it slippery and dangerous. When you find the hydraulic fluid on the product or the

Caution Always be alert to avoid getting your hand pinched or suffering a backache from an unnatural operating posture oroverload when handling the product.
leakage.

floor, wipe it off immediately.

● Strainers and Filters

Apply a 150 mesh strainer to the suction line from a reservoir and a 10μm filter to the return line to the reservoir. Determine
the capacity based on the pump flow rate on the maximum input rotation and maintain the pressure drop below 0.03 MPa.
<Hydraulic fluid contamination level control>
It is recommended to maintain hydraulic fluid contamination within the NAS 9 class range.

● Circuit Oil Temperature

Permissible oil temperature range: -20℃ (starting temperature) up to 100℃ (total 100 hours), and between 20℃ and 80℃
for a continuous operation.
Please contact us when you plan to use the equipment outside the permissible oil temperature range.

Precautions on Handling Pump/Motor■ Mounting



Caution Mounting, dismounting, piping, and wiring should be performed only by a qualified engineer (preferably one who hasWarning Before starting such work, make sure that the machine is turned off, the motor or engine is not in motion, and
Warning Turn off the power supply before doing wiring work. A failure to do so may cause an electric shock.

Caution Keep the mounting holes and surfaces of the product clean. A loose bolt or broken seal may cause damages or oil In general, the pump/motor can be mounted in any direction. But the drain piping should be connected to the reservoir at apoint lower than the oil level after it is taken out from the upper surface of the pump/motor housing. This is to lubricate thereduction gears. Please note that the travel motor and the swing motor are to be mounted in the specified direction.
 Make sure that the rotating direction is correct for both pump and motor.
 Make sure there is some allowance between the pump shaft and driving shaft (with a motor or engine), and between the
motor shaft and driven shaft (on the load side), in either case in the radial direction. Avoid applying thrust load to the pumpor motor shaft.
 Maintain the center dislocation between the pump and driving shafts, and between the motor and driving shafts within 0.1
mm on FIR (full indicator reading).

Caution When mounting the product, use specified bolts only and tighten them with the specified torque. A failure to do so■ Selecting Shaft End Configuration(2) On Mounting and Dismounting products
been trained by KYB) with the required knowledge.
pressure inside the hydraulic piping is zero.
leakage.

may cause malfunction, damage, or oil leakage.

(3) On OperationDanger Use only explosion- or combustion-proofed products in a explosive or combustible state.

Caution If you find something wrong, such as strange sound, oil leakage and smoke, stop the operation immediately and take

Caution Make sure that the hydraulic circuits and wiring are properly connected with no loose connections before the initialWarning Apply a protection cover on the rotation shaft of the pump and motor to avoid your hand or clothing being caught inthe machine.

necessary action. A failure to do so may cause damage, fire, or injuries.

operation.
Caution Use the product only according to the specifications described in the catalog and drawings, and the specifications
provided by KYB.
Caution The product becomes very hot during operation because of a rise in the temperature at the circuit oil and thesolenoid valve. Make sure that the operator’s hand or another part of his body does not touch such heated parts. A
failure to do so may cause burns.
Caution Use the specified or proper hydraulic fluid and keep the contamination level within the recommended range. A
failure to do so may cause malfunction or damage.

(4) On Maintenance and Storage

Caution Any alteration or modification of the product by a customer is strictly prohibited.



Caution Transport or store the product in a proper environment at a proper temperature and humidity with proper dust- andCaution Replacing seals may be necessary after storing the product for a long period.

3

Caution Do not disassemble and reassemble the product without permission of KYB or its authorized agency. A violation

may cause poor performance, damage, or an accident.
rust-preventative measures in place.

Select a shaft end configuration appropriate for the driving system based on the following pump and motor requirements.
 Direct driving: When it is difficult to give some allowance in the radial direction, use a spline shaft. Make sure to apply
lubricant and dust-protection to the spline. Selecting a counterpart spline with the surface hardness over HRC 50 and thesurface roughness below 32a is recommended.
 Coupling driving: When using a flexible coupling, select one with a straight shaft and assemble it in such a way that nothrust load is applied to the pump motor shaft. (See Fig. 2 below.) Applicable shaft configurations vary depending on the product. Please contact us for details.

【Pump/Motor Shaft Driving System】

Fig. 1 Example of
Direct Driving※Spline shaft

Fig. 2 Example of
Coupling Driving※Straight shaft■ Pump Suction Pressure and Piping
During a normal pump operation, maintain pressure on the pump suction port (less than 30 mm from the port surface) above-0.02 MPa. Pressure may come down as low as -0.05 MPa for a short while on a cold start, but air suction from the piping
should be strictly avoided. For the suction side piping, use pipes with a diameter equal to or larger than the diameter of thepump suction port and try to keep the length as straight and short as possible.
4

■ Piston Pump Motor Drain Piping and Case Internal Pressure◇ Drain piping is to be connected to the reservoir at the point lower than the reservoir oil level after being taken out from thepoint higher than the pump/motor housing. This is necessary for lubrication in reduction gears.
Always keep the motor housing filled with oil. Otherwise, it will result in poor lubrication in the housing and cause the seizureof parts.
◇ Maintain the case internal pressure below 0.1 MPa.
Higher drain pressure will shorten the life of internal parts. Smaller or longer piping will raise the internal pressure.
◇ Contact us about the proper drain flow, which varies depending on the condition.
◇ Operating the product without drain piping will raise the pressure in housing and may cause internal damage or oil leakage.
If you have done so, inspect and repair damage or replace the housing. (This will not apply to some pumps that do not needdrain piping.)◇ Fill the housing with oil before starting an operation. Otherwise, it may cause an initial seizure.

Table of Contents
Category

Equipment■ Caution on the Use of the Unit
■ Pumps■ Gear Pumps■ Piston Pumps■ Motors■ Hydraulic Motor (General)………………………………………………………………23■ Motor units■ MSF Series (motor unit) ……………………………………25■ Motors with reduction gear

■ MAG Series (with reduction gear)(for excavator and mini-excavator travel) ………………… 25■ MSG Series (with reduction gear)(for excavator and mini-excavator swing)

Precautionary Cylinder Handling● On Assembly◇ Do not remove the plug placed on each port until it is connected to the piping.
◇ When mounting a valve, use bolts of the right size and work on the provided flat mounting plate so as to protect
the valve from the tightening torque.
◇ Use an operation link that does not apply a horizontal load to the spool. (Manual lever, etc.)● On Operation◇ Set the valve lever at the neutral position when starting an operation. Otherwise, it may cause the actuator tostart running unexpectedly.
◇ Allowable maximum backpressure: The figure in the specifications includes a peak value at the tank port of thevalve. A careful attention is also required when viscosity is high at a low temperature.
※Please read the precautions described in each chapter after page 7.

■ PSV Series (Closed circuit) …………………………………19■ PSVL Series (Open circuit, load sensing type) … … … … 19

With a motor used in an open circuit, cavitation may occur at a low-pressure area when the motor stops running. Install acavitation preventive function in the circuit to avoid such damage.

Precautions on Valve Handling■ KP, KFP, and KFS Series (Single) …………………………8■ PSVD Series (Open circuit) …………………………………19■ Piston Motor Cavitation Prevention● Initial Unpacking
Do not remove the plug placed on the cylinder port until you start assembling the unit. Mount the cylinder on
the prepared equipment right after unplugging it, and fill the cylinder with oil.
● Rust Protection
When leaving the rod extended after the cylinder is mounted on the equipment, apply grease to the exposed rod
surface once a month.

■ Caution on the Use of the Unit ………………………………3■ Hydraulic Pump (General) ………………………………………………………………7

A closed circuit pump requires boost pressure of 0.3 to 0.5 MPa at the suction port.
Lower boost pressure may cause cavitation, noise, poor braking, or damage to the pump.
If the output port of a motor in a series- or meter-out circuit is pressurized highly and constantly, the product life shortens andexcessive back pressure may damage the motor at an early stage of its life. Contact us for permissible maximum back pressure
for each product.

Page■ KFP Series (Tandem) …………………………………………8■ Closed Circuit Pump and Motor Boost Pressure■ Piston Motor Back Pressure

Series…………………25■ Pumps with Motors■ HST (General) ……………………………………………………………………………31■ Cylinders■ Hydraulic Cylinder (General) …………………………………………………………37■ Integrated HST■ HVFD Series ……………………………………………………32■ KCH, KCM, and KCFL Series ………………………………38■ MMP Series (Electro-hydraulic cylinders) …………………43■ Valves■ Hydraulic Valve (General) ………………………………………………………………47■ Multiple Control
Valves■ KVS and KVM Series(for excavators and mini-excavators)……………………………51■ KVS, KVMF, KVML, and KVMT Series

Definition of terms frequently used with hydraulic circuit trouble■ Single-function
valves(for forklift trucks, wheel loaders, etc.) …… … ………………51■ Flow control valve (FC) ………………………………………63■ Down safety valve (DS) ………………………………………63■ Hose rupture valve (HRV) ……………………………………63■ Additional Information■ Principle Formulas ……………………………………………65■ Tightening Torques, Hydraulic Oils, and Flow Restriction
Properties ………………………………………………………66<Main contents of this product guidance>
Products are explained in the following order.
● Category (Pumps, Motors, HSTs, Cylinders, and Valves): General categorization of KYB products● Equipment (Gear Pumps, Piston Pumps, etc.): Each product line
Features (characteristics), basic structure, mechanisms, circuits, functions, specifications, applications, model
names, etc.
● Series: Each model
Dimensions, performance curves, specific functions and characteristics, precautions, etc.
5

6

Pump

Pump

■ KP, KFP, and KFS Series (Single)

Pump: Gear pump

KP05

【General Description】

High reliability is the primary policy for developing KYB pumps and is based on long experience in various applications,advanced technology and excellent production technology. The KFP series pumps having cast-iron bodies are those of highperformance, light in weight, compact in design, and durable.

★

KFP23.KFS23

Basic Construction

★

KFS24

[Construction and Mechanism]
1. The shaft connected to the gear is driven byan engine or an electric motor.
2. While the gears are rotating, the oil filling
the gear tooth grooves is moved from thesuction port to the delivery port.
※The shaft is designed to be rotated in one
direction to realize high performance.
When placing an order, please specify
the direction of shaft rotation: C rotation(clockwise viewing from the shaft end) or
A rotation (anti-clockwise viewing from theshaft end) .
Note: Rotating the pump in the direction
opposite to the design will damage theinside of the pump and render it unusable.

3.6ー5.1

DGP4
KFS4
KFS２３

★

Symbol※ Low pulsation gear pump (KFS series)★

Depending on the displacement,pressure and rotation speed are limited.
Please refer to page 10 - 11.

KFS23 series and KFS32 series are low pressure pulsation version of KFP23 series and KFP32 series. Noise in hydraulicsystems is generally caused by the pressure pulsation created by the pump and dual flank engagement gear technology isutilized for these gear pump series to reduce the pressure pulsation.

■ KFP Series (Tandem)

Basic characteristics● Volumetric efficiency (actual flow / theoretical flow)
Operation at a low speed and high pressure increases internal
leakage causing low performance.
● Input power (theoretical shaft power / mechanical efficiency)
Operation at a high speed and high pressure increases shaft
power.
● The actual flow and actual input power are related to the speed
and pressure. Please contact KYB if the properties of each modelneed to be clarified.

KFP32 (Dual model)

Displacement of each Model
020

Displacement (cm3/rev)
40
60
80

100

120

KP05
KFP23
KFS23
KFS24
KFP32
KFS32
KFP51
※ Please consult KYB when selecting an appropriate gear pump model under the same displacement.
7

Symbol
8

Pump

Pump

【Caution to specify a tandem pump(Dual or Triple)】

Dimensions (unit: mm)【Basic construction of tandem pump (dual model)】■ KPO5102 ±0.3
A

3.5

0
-0.2

±0
.2

5

4-Ø9.2

Delivery

5

12.7

.2
±0

<Q x P expression (T value)> ※T values (TT, TR, and TC): Simple expression to obtain allowable shaft torsional torque※ For clockwise rotation (C).
※ The mirror image applies to theanticlockwise rotation (A)4-M6X1.0
14 depth8

Ø50.774.2

Ø16

63.5 ±0.25

0
-0.05

93

25

.2

Suction※With a triple-pump model, the pump nearest theshaft is the front pump, followed by the center
pump, and finally the rear pump.

For dual model:（QF×PF）＋（QR×PR）≦ TT（QR×PR）≦ TR		
For triple model:（QF×PF）＋（QC×PC）＋（OR×PR）≦ TT（QC×PC）＋（QR×PR）≦ TC（QR×PR）≦ TR

63.5 ±0.25

R6.5

25

● Two or three pumps are driven with a single shaft.
● Specifications of each pump are the same as the single pump.
● Supply hydraulic fluid from the single reservoir, even if the front, center(in the triple model), and rear pumps have separate suction ports.
● Set the displacement volume as follows: Front pump ≧ Center pump ≧Rear pump● When only the front pump is operated, the maximum operating pressure
may be applied. When multiple pumps are loaded simultaneously,
however, the torque value (T value) in the following Q x P formula
should not be exceeded.

4-R10

QF : Front pump displacement (cm3/rev)
PF : Front pump pressure (MPa)
QC: Center pump displacement (cm3/rev)
PC: Center pump pressure (MPa)QR: Rear pump displacement (cm3/rev)
PR : Rear pump pressure (MPa)TT, TC, and TR values■ KFP23/KFS23

Coupling hole unit: mm● Spline: L

T o o lNo. ofpressure
P.C.D
Teeth
angle

Model

Ｄ．Ｐ

KP05

Module 1.0

20°

10

KFP23
KFS23
16/32
KFP32
KFS32
KFP51

● Straight: M

Model
KP05
KFP23
KFS23
KFP32
KFS32
KFP51

9

12

11
30°

13
14

12/24

14

ｄ

12.000 〜
12.02014.465 〜
15.87514.59216.020 〜
17.46316.14719.134 〜
20.63819.26120.700 〜
22.22520.82727.589 〜
29.63427.716
12

Direct drive without flexible
Drive with flexible couplingｄＨ couplingＨ
ＤＨ
Ｄ
10.067 〜
13.970 〜
2.000
ーー
10.13714.50011.834 〜
17.463 〜
11.463 〜
17.048 〜
11.91217.742
11.56117.07813.287 〜
19.050 〜
12.958 〜
18.636 〜
13.35819.32913.04118.6662.743
16.521 〜
22.225 〜
16.229 〜
21.811 〜
16.58822.50416.30021.84218.267 〜
23.812 〜
17.961 〜
23.400 〜
18.32924.09218.03723.43024.342 〜
31.750 〜
24.188 〜
31.505 〜
3.657
24.40732.08024.25531.539Ｄ

Ｌ

Ｈ

Ｒ＋ 0.018
12.5 0＋ 0.2
14 ＋ 0.1＋ 0.015
4 0

0.3

21.02 ＋ 0.005＋ 0.030

23.27

＋ 0.1
0

5

＋ 0.030

22 ＋ 0.007＋ 0.02824.8＋ 0.150

6＋ 0.0300＋ 0.028

30.3

＋ 0.2
0

8

＋ 0.036030 ＋ 0.007

0.25 〜 0.4

10

Pump

Pump

Dimensions (unit: mm)■ KFP51■ KFS24
25

130.2

6.5

29

Ø43

106 ±0.3

Ø46

20°

11 +0.3
0

R12
Ø96

2

7/8-14UNF-2B
ＳＡＥ O-ring seal0
Ø82.52 -0.05

17.25

108

(R5.5)

1-5/16-12UN-2B
ＳＡＥ O-ring seal

10
12
24 speciﬁcation table
Diplacement Max operating pressure
Model(cm3/rev)(MPa)
KFS2412
12.5
KFS2415
15.0
KFS2417
17.6
KFS2420
20.2
KFS2422
22.0
KFS2424
24.0
20.6
KFS2425
25.7
KFS2427
27.8
KFS2429
29.4
KFS243131.2
KFS2433
32.8

Speed
[rpm]

600〜3000

W
[mm]
96.5
99.7
103
106.1
108.5
111
113.1
115.7
117.7
120
122

Weight
[kg]
3.3
3.5
3.7
3.9
4
4.2
4.3
4.4
4.6
4.7
4.8

◇ Tandem models and tandem combination with KFP23 and KPO5 series are possible.
◇ Tandem (dual) model and tandem combination with the KFP23 series is possible.

■ KFP23 Tandem■ KFP32/KFS32

Delivery（front・center・rear）

6.4 ±0.460

Suction（front）
Suction（rear）

Ø101.6

2-Ø15

8

Ø120

56

0
-0.05

25

Ø24
20

120

R14

60

79

W

Delivery52.4 ±0.25

84

61

74

63
Suction62

16.5

4-M10X1.5

１４ depth5526.2 ±0.25
Delivery14

See Fig.1
for input shaft

146 ±0.3
174※ Formula to calculate A, B and C (See Table 1.)
YF = Front pump Y length, YR = Rear pump Y length.
(1) If KFP2319 or a smaller pump is used as a front pump
A ＝ 141.1 ＋ YF ＋ YR
B ＝ 63.8 ＋ YF
C ＝ 52.0 ＋ YR
(2) If KFP2323 or a larger pump is used as a front pump
A ＝ 149.1 ＋ YF ＋ YR
B ＝ 67.8 ＋ YF
C ＝ 56.0 ＋ YR

◇ Tandem (dual) model and tandem combination with the KFP23 series is possible.
11◇ KFP23 tandem (dual and triple) are available.
◇ When the max flow rate is less than 100 l/min, thecommon suction port on the front unit can be used.
12

Pump

Pump

Dimensions (unit: mm)■ KFP32 Tandem
20CB

４−Ｍ１２×１．
７５
14 depthØ101.6

25

0
-0.05

R14

79

±0.25

Ø38

64

※ For anticlockwise rotation (A)The mirror image applies to theclockwise rotation (C).

6.4

±0.25

69.9

95

84

35.7

20

16

121

63

134

61

2-Ø15
Ø120

14
146 ±0.3
174※ Formula to calculate A,B and C (See Table 1.)
YF = Front pump Y length
YR = Rear pump Y lengthA ＝ 191.5 ＋ YF ＋ YR
B ＝ 91.4 ＋ YF
C ＝ 72.6 ＋ YR
Rear pump

Front pump

◇ KFP32 tandem (dual) pump is available.
◇ When the max. flow rate is less than 190 l/min.,the common suction port on the front unit can be used.

13

14

Pump

Pump

Performance Curve (Hydraulic fluid: ISO VG32, oil temperature: 50℃ )※ The typical displacements of models of each series are illustrated. Please consult us for models of other displacements.

■ KPO540■ KPO5123■ KFP3228■ KFP3256■ KFP2319■ KFP2333■ KFS3236■ KFS3252■ KFS2320■ KFS2333■ KFP5163■ KFP51100■ KFS2422■ KFS2427

2.0 MPa

2.0 MPa6.9 MPa13.7 MPa

6.9 MPa

20.6 MPa13.7 MPaPa
2.0 M Pa
M
20.6

20.6

MPa

Pa

13.7 M

6.9 MPa
2.0MPa15

20.6 MPa

2.0

20.6

a
MP
a
MP
20.6
a

MP

13.7

MPa

a

6.9 MP

2.0MPa

16

Pump

Pump

Closed Circuit and Open Circuit

Pump: Swashplate type piston pump
【General Description】										● Closed circuit

KYB’s piston pumps are used for construction equipment, agricultural machines, and other industrial equipment in a wide
variety of market sectors. All series are high-performance, high-reliability piston pumps developed on an abundance ofexperience in numerous applications. They are manufactured by advanced production systems. This catalog provides only
piston pumps for general-purpose closed circuit applications and construction equipment open circuit applications.
All rotary parts are manufactured by one of KYB’s affiliated companies, Takako Industries, Inc., which is the world’s leadingcompany in this technology.

Basic Construction※This piston pump has the same basic structure with the piston motor, and is equipped with additional pump functions.
The direction of rotation of the input shaft is fixed.

● Open circuit[Construction and Mechanism]

1. The input shaft connected to the driving powersource rotates. So does the connection between
the cylinder block and the input shaft is made by
the spline.
2. Then, the pistons reciprocate along the cylinder
bores in a movement determined by the swash
plate’
s tilting angle.
3. When the pistons are pulled out from the cylinder
block, oil is drawn from the reservoir. When thepistons are pushed in, oil is delivered to the valve
and actuator side.
4. The suction port and delivery port are divided by
the valve plate.

【Variable Displacement】

Basic characteristics■ Volumetric efficiency, input horsepower, andmechanical efficiency■ Pressure and flow characteristics(horsepower control characteristics)

1. In the open circuit, oil is drawn by the pump from the reservoir, andthe returning oil from the actuator is flown to the reservoir.
2. With a fixed-displacement pump, the speed and direction of an
actuator are controlled with the switching and spool opening of
the control valve. With the variable displacement pump, the pumpcontrols the flow rate and the swash-plate tilting angle can bechanged only in the +α direction.
3. In the open circuit, a single pump can connect to and control
multiple actuators.

Main Functions<Variable displacement pump>
1. The greater the tilting angle of the swash
plate, the greater the reciprocation stroke(displacement) of the piston. When the angle is0, the reciprocation of the piston stops, reducing
the discharge volume to zero.
2. In the closed circuit, the delivery side and suction
side are reversed as the swashplate tilting angle
shifts from +α to − α even though the rotating
direction of the input shaft remains unchanged.

When selecting the pump, examine the following characteristics.

1. The closed hydraulic circuit is constructed with an actuator (motor)
and a pump.
2. The speed and direction of the actuator can be decided bychanging the pump tilt angle to +α, or to –α as the delivery port
and the pump flow change accordingly.
3. The closed circuit features a smooth starting and stopping of theactuator.
4. The pump and the motor can be put into one case and made into a
compact size as integrated HST.

● Volumetric efficiency (actual flow rate /theoretical flow rate)
An operation at a low speed and highpressure increases internal leakage
decreasing volumetric efficiency.
● Actual horsepower (theoretical horsepower/ mechanical efficiency)
An operation at a higher speed and higher
pressure increases mechanical efficiency.
● The actual delivery flow rate (volumetricefficiency) and actual shaft power are
related to the speed and pressure.
Please contact us regarding the specificcharacteristics of individual displacement
volumes of each model.

■ LS Control characteristics

The pump displacement can be changed by external control of the swash-plate tilting
angle. (A two-way delivery flow in the closed circuit.)● Manual type: The swash plate angle is controlled with a lever link.
<Regulator>
The regulator for the control of the swash plate angle of an open circuit pump has thefollowing control devices:● Horsepower control: The swash plate angle (and the pump displacement) changes
depending on the pump delivery pressure in order not to exceed the engine
horsepower, thereby making constant the maximum input torque to the pump, andultimately making constant the pump’s horsepower consumption. This control iseffective in preventing the engine from stalling due to the pump power consumption
exceeding the engine power, and in utilizing the engine horsepower efficiently.
(PSVD)● Load sensing control: This control aims to deliver the required flow that matches theongoing operation. The pump delivers the required flow to the actuator at requiredpressure. The pump swash plate angle (and pump displacement) fluctuates so thatdifferential pressure between the upstream and downstream sides of the LS valve
can remain constant. Then, no sufficient flow and less heat generation can be made,which generates energy-saving system.

PSVD

PSVL

In the tandem configuration, the second pump isconnected with coupling in the axial direction.

【Tandem pumps（Dual,Triple）】● Two or three pumps are driven with a single
input shaft. Flow rates in the first and second
pumps can be set independently. The piston
pump is used to drive travel motors. The thirdpump may be used as a charge pump in theclosed circuit as well.
(PSV2)<Tandem dual configuration (single flow)>Single flow typecylinder block

Valve
plate

Split flow type cylinder
block with each port
split into internal andexternal ports forseparate delivery

Valve
plate

【Single flow and split flow】

P1: First pump pressure P2: Second pump pressure Pg: Gear pump pressure
17※It is possible to control the flow rate almost
proportional to the pump rotating speed.

● As described in the basic construction of
the piston pump, a typical piston pump is asingle flow type with one suction port and
one delivery port. On the other hand, a split
flow type pump has two independent delivery
systems with alternately positioned ports ona single cylinder block. (PSVD)<Split flow>※A single cylinder block with a two flow
system

18

Pump

Pump

Dimensions (unit: mm)

Pump: Piston Pump
Typical piston pumps are variable and high-pressure
types mainly used for construction equipment, etc,
engaged in heavy-duty work. They are widely used inareas that require horsepower control, load-sensing,and other control functions.

<Closed circuit>

17■ PSV-10 (single)

H2:Tandem pump for Loader/HST
SP:Hydraulic pilot■ PSV Series (Closed circuit)

Ports
P1,P2
S
T

Hydraulic circuit
Pressure port
G1/2(PF1/2)
Suction port
G1/2(PF1/2)
Case drain port G3/8(PF3/8)■ PSV-16 (single)

H

PSV2-16※ The direction of rotation of the input shaft is to be set in one direction.
Please specify either "CW" or "CCW" as the direction of rotation.

Hydraulic circuit
Ports
P1,P2
B1
B2
S
T

■ PSVD Series (Open circuit)

PSVD2-4242.3×232

2，200

Pressure port
G1/2(PF1/2)
Pilot port
G3/8(PF3/8)
Charge port
G3/8(PF3/8)
Suction port
G1/2(PF1/2)
Case drain port G1/2(PF1/2)■ PSV2-10 (tandem)※ Only CW is available (clockwise when viewing from the input shaft side).
PSVD2-21

Hydraulic circuit

76

19

Suction

P2

9

40
415

(467)

212

130

88

2-Ø20
56

56

within R14(12±2)

P3

27

P1

15

38

IN

30

G1/2(PF1/2)
G3/8(PF3/8)
G1/2(PF1/2)
G3/4(PF3/4)
G1/2(PF1/2)

MAX.79Pressure port
Pilot port
Charge port
Suction port
Case drain port

OUT

Ports
P1,P2,P3,P4
B1
B2
S
T1

P4

Ø6

3.2a

1007AHFSG

KP
10Hydraulic circuit

2-Ø20

5

45

Ｔ２port（plug）
PF1/2-A
ＪＩＳ Ｂ２３５１ O-ring boss

91
91
anticlockwise rotation
82
82
MAX. 140.5
56
56

3.2a

394.5（Ｓ１，Ｂ１ port positions）

4-PF1/2-A
JIS B2351
O-ring boss

7

41

PSVL-42

Unload valve
Ｔ１port ＰＦ１／２−Ａ
ＪＩＳ Ｂ２３５１ O-ring boss

Ø6

Ｓ１portＰＦ３／４ O-ring bossover １７．
５depth（ＪＩＳ Ｂ ２３５１）

7■ PSV2-16 (tandem)

4-Ø13※ Load sensing type variable displacement pump
※Use together with a load-sensing (LS) valve. (See Page 49.)
※Only CW type is available (clockwise when viewing from the input shaftside).

1

MAX.79

2，
200

71

32

Ｂ２ port position

84.6

Pressure port
G3/8(PF3/8)
Pilot port
G3/8(PF3/8)
Charge port
G3/8(PF3/8)
Suction port
G3/4(PF3/4)
Case drain port G3/8(PF3/8)

27

PSVLー84

Ports
P1,P2,P3,P4
B1
B2
S
T1,T2

85.5

(Open circuit and load sensing)

Unload position■ PSVL Series

20

Pump

Pump

■ PSVH2-28
T2

Pp4

Ｂ２ port ＰＦ３／８−Ａ
ＪＩＳＢ２３５１ O-ring boss

Pp3

Ｐｐ３，
Ｐｐ４，
Ｐｐ５，
Ｐｐ６ port ＰＦ１／４−Ａ
ＪＩＳＢ２３５１ O-ring boss

×

PgC
Pg3
×

B3 B1
P3

●

●

●
●

●

●

●

●

●

●

Ｔ２ port ＰＦ１／２−Ａ
ＪＩＳＢ２３５１ O-ring boss

●

●

●

●

P1

●
●

●

●

●

×
Pg4

S

Hydraulic circuit

●

×
T Pg2

■ PSVD2-21■ PSVD2-27

P2■ PSVL-54■ PSVL-84

127

P4

●

■ PSVD2-17

Ｐｐ１ port ＰＦ１／４−Ａ
ＪＩＳＢ２３５１ O-ring boss

130.4

Ｓ port ＰＦ１−Ａ
ＪＩＳＢ２３５１ O-ring boss

Pg1
×

●

203.4

１４６
（standard mounting pitch）

B2

137

Pp1

Pp6

Ø101.6(SAE B-B)

Pp5

Ｂ３ port ＰＦ１／２−Ａ
ＪＩＳＢ２３５１ O-ring boss

15

Ｂ１ port ＰＦ１／２−Ａ
ＪＩＳＢ２３５１ O-ring boss

Ｐ１，
Ｐ２，
Ｐ３，
Ｐ４ port ＰＦ１／２−Ａ
ＪＩＳＢ２３５１ O-ring boss
Ｔ１ port ＰＦ１／２−Ａ
ＪＩＳＢ２５３１ O-ring boss

64.5
104.4
１５６．
４（Ｐ１ and Ｐ２ port positions）
１９８．
４（Ｐ３ and Ｐ４ port positions）
２９０（Ｐｐ５ and Ｐｐ６ port positions）
４４８（Ｓ and Ｂ１ port positions）
５１３（Ｂ３ port positions）
534

117

87

SAE J498b FLAT ROOT SIDE FIT(CLASS 1)
46■ PSVD2-42〈開回路〉■ PSVD2-17、21、27 and 42 [Split flow (Single cylinder block with two flow systems)]

PSVD2-42

238

72 62〜112 １８２．
５ ２７１ ２３２
1

Hydraulic circuit

2

3<Open Circuit:road sensing>
PSVD2-42

PF3/4 PF3/4 PF1/2 PF3/8

228.6■ PSVL-42■ PSVL-42、54 and 84 [Load sensing] ※To be used with an LS valve. (See Page 55.)

Hydraulic circuit

PSVL-84292

PSVL-84PF1

72

182.5 271

230 228.6

Performance Curve Operating oil: ISOVG46 Oil temperature: 50℃<Closed circuit>■ PSV-10■ PSV-16

17<Load sensing system working mechanism>(multiple operations)■ PSVH2-28

60
40● The maximum load pressure Pls is selected by the shuttle valve,
which controls the pump regulator and the pressure compensator
valve.
● The pressure compensator valve adjusts the flow at Ac so that
PC upper stream pressure equals (Pls + β)
● Differential pressure (Pp-Pc) between the uppersteam anddownstream sides of A1 and A2, which control the flow to eachactuator, remains constant, enabling multiple operations under
different loading conditions.

20

21

22

Motors

Motors【Main Components of the Travel Motor (MAG)】◇ Reduction gear
● A case rotation type simple planetary reduction gear is adopted.
◇ Motor (standard component)● Counterbalance valve (standard component for all models): Prevents the motor from overrunning on a down slope. The
valve is effective to prevent cavitation.
● Two speed mechanism (standard component for all models): Two step speed change can be done under the same flow,which allows a wider range of speed control. (See Page 24)● Shockless relief valve (standard component for MAG-50 through 230): Reduces shocks at the stop and prevents
cavitation.
● Anti-cavitation valve (with no relief mechanism) (standard component for MAG-18 through 33): This valve has stopping
performance similar to the shockless version and can prevent cavitation.
● Parking brake (standard component for MAG-50 through 230 and optional for MAG-12 through 33): A multiple-plate wet
disk brake system is adopted.
(Optional Component)● Automatic two-speed system (except for MAG-12): Speed is automatically switched from Low to High or vice versa
according to travel load pressure.

Motor: Piston Motor (Swash plate type)
Basic Construction【Main Components of the Swing Motor (MSG)】◇ Reduction gear
● Shaft rotation type planetary reduction gear is adopted.
● Motor lubricant circulation system: Hydraulic fluid is also used as a reduction gear lubricant. No maintenance is required.
◇ Motor (standard component for all models)● Shockless relief valve: Reduces shocks at the stop and prevents cavitation.
● Parking brake: Multiple-plate disk brake is adopted. (Output torque ratio over 100%)● Make-up valve: Prevents cavitation.
(Optional Components for All Models)● Parking brake delaying valve: Delays the response time of the parking brake● Anti-reaction valve: Reduces the reaction at the time the motor stops.

■ Motor unit
[Construction and Mechanism]

1. When high-pressure oil supplied from the pumpflows into the cylinder block through the valve
plate, the swash plate is pushed by the force ofthe piston assembly.
2. The piston assembly receives reaction force
against it and produces reaction force in therotating direction.
The total force of high-pressure side piston
assembly produces a rotating force in the cylinder
block, and the torque is transmitted to the shaft
through the spline, resulting in the rotation of the
shaft.
3. The oil delivered from the outlet port returns to
the reservoir through the valve plate.
4. The inlet and outlet sides can be switched by an
external valve operation to rotate the motor in thereverse direction.

Basic Characteristics
The motor’s general characteristics (performance)
are as follows.

Output torque calculation formula:

T=

P×D
2×π

× ηm

D: Motor displacement [cm3/rev]
T: Output torque [N-m]
P: Effective pressure [MPa]ηv: Mechanical (torque) efficiency○ Output torque can be obtained from motor displacement,pressure, and mechanical efficiency.
○ The torque efficiency is affected by mechanical friction
and other factors, and drops at a higher speed and lower
pressure.

■ Traveling motor (with reduction gear)

Output speed calculation formula:
N=

Q×103
D

× ηv

N: Speed [rpm]
Q: Flow rate [L/min.]ηv: Volumetric efficiency○ The speed can be decided by motor capacity, flow rate,
and volumetric efficiency.
○ Volumetric efficiency is affected by leakage inside themotor (from the high pressure side to the low pressureside), and decreases at a slower speed and higher
pressure.

■ Swing motor (with reduction gear)

Hydraulic circuit【Characteristics of the Shockless Relief Valve】

Hydraulic circuit
23

24

Motors

Motors【Two-speed Change Mechanism】(MAG series for travel systems)

Motor: Piston Motor Unit

The swashplate has three surface sections, a, b, and c, and can be tilted by externalpilot pressure with two steel balls at the rear of the swashplate working as fulcrums.

【Swash Plate Piston Motor】

2nd Speed : High speed (low torque)

1st Speed : Low speed (high torque)

The MSF series is a compact, light, swashplate type
piston motor, which has been used for construction andagricultural machines.
All rotary parts are manufactured by one of
KYB-affiliated companies, Takako Industries, Inc., whichis the world’s leading company in this technology.

■ MSF Series (motor unit)
MSF-2350

MSF-23

23.4

24.5

3000

70

MSF-3026.1～30.2

25.0

2000

60

MSF-5042.2～50.9

28.0

2000

90

Models for fan and mixer drum driving applications are also available.
Please contact us for details.

Motor: Piston motor (with reduction gear)
The MAG series offers high-torque motors for mediumor high-speed traveling crawler vehicles. It consists ofa case rotation planetary reduction gear and a swash
plate piston motor, and is equipped with a two-speed
change unit and a parking brake unit. .
The two-speed change mechanism supports theautomatic speed change according to the load. The
MSG series motors incorporating a shaft-rotation typesimple planetary reduction gear and the swash plate
motor are ideal solutions for the swing system of
excavators and mini-excavators. The motor is equippedwith a parking brake in our standard version.

Unit: ㎜

P1

■ MSF-50 (motor unit)

L3

L5

P1 inlet C rotation

P2 inlet A rotation

L6
I

25

25

P2

P1

162
136

2

F

P2 inlet A rotation

10.7

2-φ16

M12×1.75

80

CMAG-12VP-120E
MAG-18VP-230E
MAG-18VP-350E
MAG-26VP-400E
MAGー33VPー650G
MAGー50VPー1100F

32

54
48

L9

90.5

SAE Flange Y
L10

L7L8

P1 inlet C rotation
32

φ 34
φ 127

φ

112

G

φ D1
φ D4

2-φD3

274
50

H

90.5
220

Type
MSF-12
MSF-18
MSF-23MSF-30
MSF-50

φD3
11
15
15
15
18

φD4
82.5
101.6
101.6
101.6
127

L1
170
188
230
230
276

L2
122
137
170
170
164

L3
48
51
60
60
112

L4
100.5
113
138.5
138.5
136

Type
MSF-12
MSF-18
MSF-23MSF-30
MSF-50

A
16
20
24
24
25

B
54
57
67
67
81

C
60
74
80
80
81

E
48
54
64
64
73

Y
106.4
146
146
146
181

Main port
PF3/8
PF1/2
PF1/2
PF1/2
PF3/4

Type

F

G

Key type
H

I

φD1

L5
62
67.5
92
92
60

L7
14
12
12
12
16

L8
5.5
11
11
11
28

L9
5
5
5
10

L10
131
180
180
180
220

L11
96.5
125
125
125
156

H
M8×1.25
depth 20

L6
16

Drain port
PF1/4
PF3/6
PF1/4
PF1/4
PF3/8
Spline type

L6

29

18

38.5

JISB1603 Involute spline
EXT 20×14z×1.25m×20(a class)

MSF-125

20

M8×1.25
depth 20

MSF-187

26.9

M10×1.5
depth 20

28

24

38.5

SAE Involute spline
Flat root side fit
DP16/32 tooth13class6

M10×1.25
depth 18

27

MSF-237

26.9

M10×1.5
depth 20

38

24

44

SAE Involute spline
Flat root side fit
DP16/32 tooth14class6

M10×1.25
depth 18

30

MSF-307

26.9

M10×1.5
depth 20

38

24

44

SAE Involute spline
Flat root side fit
DP16/32 tooth14class6

M10×1.25
depth 1840

MSF-50

10

37

M12×1.75
depth 20

48

34

54

JISB1603 Involute spline
EXT 30×16z×1.667m×20(a class)M10×1.5
depth 1934

MAG-170VP

25

L4

D

B

P2

L2

A

L1

E

A

Models for winches and skid-steer loaders are also available.
Please contact us for details.

MSG-27P

Switching the variable valve position to 2nd speed with thecontrol valve leads the motor driving pressure to the swash
plate control piston. As the force of the piston overcomes
the driving force of the motor and the force of the spring,
the face“b”of swash plate is pressed to the fixed face,making the swash plate tilt at a minimum angle β to
generate a smaller displacement. (2nd speed).

■ MSF-12、18、23、30 (motor unit)

MAGー170VPー4000H■ MSG Series (with reduction gear)

High speed = Small displacement

When the control valve position is switched to 1st speed, thevariable valve connects the swash plate control piston chamber
behind the swash plate with the reservoir and the section“a”of
the swash plate is pressed against the fixed face by the driving
force of the motor on the piston and the spring on the cylinder
block side. As a result, the swash plate tilts at a maximum
angle α to output a larger displacement (1st speed).

Dimensions■ MAG Series (with reduction gear)

MAG-33V

Low speed = Large displacement

78

40

3000

20 20

3500

24.5

78

20.6

16.4～18.4

80

8～12.5MSF-1873

MSF-1226

Motors

MotorsDimensions (unit: mm)■ MAG-12V (for travel)■ MSG-27P-10E and 16E (for swing)
Model

MSG-27P-10E
MSG-27P-16E

L1
208
240

L2
131.5
163.5

L3
130
162

L4
123
155

L5
76
83

Output shaft pinion
Model

φD1

φD2

φD3

φD4

L1

L2

L3

L4

L5

MAG-12V-120E

179

140

140

177

209

95

45

50

51

Model

A

B

C

E

F

MAG-12V-120E

43

16.5

39

37

54.5

Main port

Drain port

Pilot port

W

G1/4(PF1/4) G1/4(PF1/4) G1/4(PF1/4) 8-M10

Mounting flange (Y): Vehicle mounting P.C.D. (Mounting screw X)

X

φY

φZ

8-M10

155

155

Connecting flange (Z): Sprocket mounting P.C.D. (Mounting screw W)■ MAG-18VP, 26VP, 33VP, and 50VP (for travel)

Model

ModuleNo. of Teeth

MSG-27P-10E
MSG-27P-16E

5
6

11
11

Tool
pressure
angle

20°
20°

※ SH port: Signal pressure port for a model with an optional parking brake delaying valve mechanism.

■ MSG-27P-23E (for swing)
Model

φD1

φD2

φD3

φD4

L1

L2

L3

L4

L5

MAG-18VP-230F(W/A.C.V)
MAG-18VP-350F(W/A.C.V)
MAG-26VP-400F(W/A.C.V)
MAG-33VP-650G(W/A.C.V)
MAG-50VP-1100F(W/R.V)

190

150

160

200

250

104

40

59

61

215

165

190

238

263

115

50

48

41.5

215

165

204

255

288

120

70

48

41.5

264

200

230

286

296

128

68

50

43.5

284

210

265

332

354

145

80

70

61

Model

A

B

C

E

F

Main port

Drain port

Pilot port

φY

φZ

MAG-18VP-230F(W/A.C.V)
MAG-18VP-350F(W/A.C.V)
MAG-26VP-400F(W/A.C.V)
MAG-33VP-650G(W/A.C.V)
MAG-50VP-1100(W/R.V)

46.5

19.5

40

37

58

PF-3/8

PF-1/4PF-1/413-M10 12-M10

170

180

54

22

45

41

71

PF-1/2

PF-1/4PF-1/4

11-M12 11-M12

192

215

54

22

45

41

71

PF-1/2

PF-3/8

PF-1/4

9-M12 11-M12

192

232

54

22

45

41

71

PF-1/2

PF-3/8

PF-1/49-M14 9-M14

240

262

58

23

50

48

71

PF-1/2

PF-3/8

PF-1/412-M16 12-M14

250

300

Mounting flange (Y): Vehicle mounting P.C.D. (Mounting screw X)

WX

Connecting flange (Z): Sprocket mounting P.C.D. (Mounting screw W)■ MAG-85VP (for travel)■ MSG-44P-21 (for swing)

Model

φD1

φD2

φD3

φD4

L1

L2

L3

L4

L5

MAG-85VP-1800E

350

290

324

394

387

180

83

89

107

MAG-85VP-2400E

400

330

365

437

713

200

100

75

93

Model

A

B

C

E

φY

φZ

MAG-85VP-1800E

71

28

84

108

G3/4(PF3/4) G1/2(PF1/2) G1/4(PF1/4) 16-M16 15-M15

Main port

Drain port

Pilot port

320

364

MAG-85VP-2400E

71

28

84

108

G3/4(PF3/4) G1/2(PF1/2) G1/4(PF1/4) 16-M16 22-M16

370

405

Mounting flange (Y): Vehicle mounting P.C.D. (Mounting screw X)

WX

Connecting flange (Z): Sprocket mounting P.C.D. (Mounting screw W)■ MAG-170VP and 180VP (for travel)
Precautions for handling MAG/MSG series

Model

φD1

φD2

φD3

φD4

L1

L2

L3

L4

L5

MAG-170VP-4000H

370

300

402

469

512

239.5

99

128

131

MAG-180VP-6000G

484

380

450

530

619

312.5

102.5

157.5

160.5

Model

A

B

C

E

Main
port

Drain port

Pilot port

φY

φZ

MAG-170VP-4000H

−

54

95

110

PF-1

PF-1/2

PF-1/430-M16 22-M16

340

440

MAG-180VP-6000G

−

54

94.5

110

PF-1

PF-1/2

PF-1/418-M24 26-M20

440

492

Mounting flange (Y): Vehicle mounting P.C.D. (Mounting screw X)
27

W

X

◇These series are designed for excavators and mini-excavators with open circuit. MAG models are also available for closed
circuit travel motors and winch applications. Please contact us for details.
◇ We may recommend motor capacities and speed ratios suitable for the customer’s requirements. Please let us know what
your application requirements are.
◇ MAG motor is to be installed with its output shaft horizontally positioned and the main port facing sideways or upward. Whenthe main port is set facing sideways, use the upper one out of two drain ports. Do not install MSG motor with the output
shaft facing downward. Also use the specific drain port. It should not be substituted with the vent port.
◇ Do not use the parking brake of MSG motor for dynamic braking. Configure the circuit so that the parking brake applies after
the motor stops.
◇ Please read the“Precautionary on the Use of Hydraulic Equipment”on Page 4. Please contact us with any questions.

Connecting flange (Z): Sprocket mounting P.C.D. (Mounting screw W)
28

Motors

MotorsPerformance Curve Operating oil:ISOVG46 Oil temperature: 50℃<Motor unit>■ MSF-12■ MSF-18■ MSF-23■ MSF-30■ MSF-50■ MAG-50VP■ MAG-85VP■ MAG-170VP■ MAG-180VP<Motor with reduction gear for swing system>■ MSG-27P-10E■ MSG-27P-16E■ MSG-27P-23E■ MSG-44P-21<Motor with reduction gear for travel>

29■ MAG-12VP■ MAG-18VP■ MAG-26VP■ MAG-33VP

30

HST

HST

Integrated HST (Pump and Motor)
HST stands for Hydrostatic Transmission and is used in a travel system to connect the hydraulic pump with the motor in a closed
circuit enabling continuous speed change from Forward to Stop/Neutral and Reverse or vice versa. HST is smoother in operationand smaller in size than mechanical transmissions installed on automobiles.

Integrated HST enables an easy combination of a speed reducer and a transmission. This unit is designed to meet the vehicle
travel requirements for tractors, combine harvesters, snowplows, etc.
It can be combined with electronic control or servo functions.

■ HVFD Series

Integrated HST (Pump & Motor)
Basic Construction● HVFD18F-R35 Circuit example

HVFD28V37

Basic Characteristics■ Output Horsepower characteristic ■ Output Speedcharacteristics■ Output torquecharacteristic

HVFD42FーR38

41.5 : 41.5

38

2600

0〜260026※The direction of rotation of the pump input shaft can be set in either the CW or CCW direction for HVFD10 Series only. Please specify the
type: either CW (clockwise) or CCW (counterclockwise) for another series, when ordering.

【Light and Heavy duty Models】● Light duty models: Suitable for the travel system of vehicles that serve light load work such as lawn mowers and combine
harvesters, up to 18kw or smaller.
● Heavy duty models: Suitable for the travel system of vehicles that serve moderate load work such as tractors and combine
harvesters with engine horsepower of 18 to 59kw.

① Theoretical output speed: (Pump displacement)/(motor displacement)×(Input speed)② Actual speed: (Theoretical output speed)×(Volumetric efficiency)③ Theoretical output torque: (Motor displacement)×(HST load pressure)■ Servo Regulator (Manual Operation) [SL]Lever operation torque characteristic
HVFD37F-R35-SL example■ Servo Regulator(Electric Control) [EL]Ampere - Output speed
characteristics

1500mA

1500mA

31

Main Mechanism【Neutral mechanism】● OrificeStandard neutral mechanism allowing a relatively large neutral width.
● Movable thrust plate
This method is less affected by the given conditions such as the input speed and oil temperature, allowing a stable neutral
width. This is superior to the orifice method in neutral zone stability and adjustability of the neutral point.
【Option】											● Charge pump
When the charge pump is used together with an oil hydraulic unit installed on the vehicle, select the charge pumpdisplacement approximately 25% of the HST pump.
● Servo regulator
This component features the following advantages:◇ Low operation torque allowing an easy operation and lower noise caused by link vibrations.
◇ Good responsiveness and a stable neutral characteristic.
◇ The fail-safe mechanism is included as a standard accessory for automatic return to the neutral
position in case of a hydraulic power source failure or link connection failure.
◇ Can be mounted on to a manual type HST.
32

HST

HST

Dimensions (unit: mm)■ HVFD10F■ HVFD23F

Hydraulic circuit
Hydraulic circuit■ HVFD18F■ HVFD28F

Hydraulic circuit

Hydraulic circuit■ HVFD21F■ HVFD37F

Hydraulic circuit

Hydraulic circuit

33

34

HST

HST

■ HVFD42F
Ｔ port ＰＦ１／２
ＪＩＳＢ２３５１ O-ring type
243

20.5

110.5
79.5

36

° β α 20.5°

118
105

temperature：50℃〈HST:Heavy load model〉■ HVFD18F-R35■ HVFD23F-R35

Input
shaft

■ HVFD28F-R35■ HVFD37F-R35

P.T.O.Shaft

149

105

T

Hydraulic circuit

45

78

37

74.5

83
73max.

61min.
62

Operating oil：ISOVG46 oil

87
79

8

101max.
61min.

Performance Curve

93max.

B2

Ｔ port ＰＦ１／２
ＪＩＳＢ２３５１ O-ring typeＪ
ＩＳＢ１６０３ Involute spline
ＥＸＴ：２５×１３ｚ×１．
６６７ｍ×２０（ｂ Class）

76.5max.

40

OutputShaft

Ｊ
ＩＳＢ１６０３ Involute spline
ＥＸＴ：２５×１３ｚ×１．
６６７ｍ×２０（ｂ Class）
185max.

38

26
41.5

4-Ø11

Ｊ
ＩＳ Ｂ１６０３ Involute spline
ＥＸＴ：２５×１３ｚ×１．
６６７ｍ×２０（ｂ Class）

82

82
２−φ８Ｈ７ 8 depth■ HVFD28V37 (two-speed)■ HVFD42F-R38

Hydraulic circuit

Performance Curve Operating oil: ISOVG46 Oil temperature: 50℃<HST: Light load model>■ HVFD10F-N15,N18

35<HST: Two-speed motor type>■ HVFD21F-R18,R23■ HVFD28V37-R35

36

Cylinders

Cylinders

Cylinder: For construction equipment and industrial vehicles■ KCH, KCM, and KCFL Series
For excavator, mini-excavator, and forklift
truck applications[Basic Construction and Calculation Formula of Hydraulic Cylinder]<Double-acting cylinder><Single-acting cylinder>[Construction and Mechanism]→

D: Cylinder bore (mm) P: Pressure (MPa)d: Rod diameter (mm) Q: Flow rate (L/min.)Load direction

1. The pressurized hydraulic fluid through the bottom
port extends the cylinder rod, and the fluid on therod side returns to the reservoir.
2. The pressurized hydraulic fluid from the rod port
retracts the cylinder, and the fluid on the bottom side
returns to the reservoir.
<Calculating Thrust >● Theoretical thrust
Extension thrust F1 N=π/4・D2×P
Retraction thrust F2 N=π/4・(D2-d2)×P● Actual thrust: To be obtained by multiplying theabove theoretical thrust value with the coefficientη(0.95 for vehicle)<Calculating velocity>									
Q● Extending velocity V1［m/min］=
×103
π/4・D2Q● Retracting velocity V2［m/min］=
×103
π/4・
（D2 ーd 2）※Flow rate Q is calculated using the pump’s delivery flow (meter-in), but the value may be significantly affected by
the flow control with the valve return-side restriction (meter-out) depending on the load direction and pressure.
In such case, calculate the tank return-side flow rate using the following formula:
Flow rate Q[L/min] = 60CA √2ΔP
ρThen go back to the above formula and calculate the velocity based on the

return-side cylinder area. (Single -acting cylinder, etc.)
C: Flow coefficient (0.6-0.7) A: Valve restriction (opening) area (mm2) ΔP: Pressure difference before and after
restriction (MPa) : Hydraulic fluid density (kg/m3)<Buckling strength and stroke>● The stroke of the cylinder to which retraction load is applied is restricted by the buckling strength.
An approximate value of the buckling load is obtained from the following formula:Wa (allowable retraction load (at full extension: N)) = Pk (buckling strength N) / S (safety ratio: typically 1.5-2.5 or
more)
Since the value will vary depending on the support mechanism (whether the load is supported by the rod only or the
tube as well.) please contact us.
● Consider installing a cylinder support and linkage mechanism to avoid thrust load on the cylinder.

[Precautions for operation]● Speed① A speed exceeding 60 m/min affects the durability of the cylinder with standard specifications.
② Install a cushion device for equipment protection and safety if a stroke end speed consistently exceeds 18 m/min.
③ For protection and safety of the cylinder, care must be taken not to cause a great impact on it when stopping it.
④ When designing a hydraulic circuit, pay attention to return flow rate increase at cylinder retraction.
⑤ Operation slower than 0.5 m/min will affect performance (particularly vibration performance). Please contact us when a low
speed operation is expected.
● Starting operation① Remove air inside the cylinder completely when starting an operation. If air remains, operate at a low speed until the air isremoved completely.
② A rapid pressure rise while air remains in the cylinder may damage/burn the seal due to a so-called diesel effect (abnormal
air temperature rise caused by isentropic compression).
③ Avoid negative pressure inside the cylinder during the operation because cavitation may cause malfunction.
37

KCH

KCM

KCFL

■ Main Features of the KCH andKCM Series● Compact, lightweight, and strong
KYB has developed its compact, lightweight, anddurable cylinders based on their long marketing
experience, in-house test systems, capability todesign products according to its strength andfatigue analysis, and manufacturing and inspection
technologies enabling high quality productproduction.
● SealKYB enhanced its seal’s durability by developing
and evaluating seals and sealing systems in-house,protecting them from dirt and dust, and optimizing
the oil film.
● Piston rod
Piston rod sliding surfaces are treated withinduction hardening and protected with hard
chromium plating for engineering purposes or
nickel-chrome plating to improve wear- andcorrosion-resistance and surface strength against
scratches.
● Safety precautions, other
Please install a cushioning device to reduce thestroke end shocks, and various valves such as
hose rupture and slow return valves if required.
(See Page 61 for additional valves.)
Also, Stroke Sensing Cylinders and Pipe-Less
Cyliders with Hollow Rod passage are available.
(for Specific types only)■ Cushion Mechanism for Cylinders● As the piston approaches the stroke end, compressed oil reduce
shocks at the stroke end.
● The cushioning device can be installed on either the rod orbottom side of the cylinder or on both ends.
38

Cylinders

CylindersDimensions of the Rod Head and Cap

Dimensions (unit: mm)● Standard clevis dimensions for KCH/ KCM series are shown as follows.
● When different sizes on clevis widths of the rod heads and caps and pin diameters are required, please contact us.

■ KCH Series (for excavator)■ Rod head dimensions※ KCH and KCM【Note】● The cylinder head portion length A, piston portion length B, and the port position depend on
customers'request. Please contact us for details.
● See the opposite page (p.38) for standard sizes of a rod head and a cap.
● Cylinder bore D greater than the figures in the table below are also available. However, theconstruction of those models may be slightly changed.

<Port sizes>
Cylinder bore
φD

Rod diameterφdMaxstroke

95
100
105
110
115
120
125
130
135
140
145
150

65,70
70
70,75
70,75,80
80,85
80,85
85,90
85,90,95
90,95,100
90,90,95
90,95,100,105
95,100,105,110

1100
1100
1200
1200
1400
1400
1500
1600
1700
1700
1900
1900

Retracted
length L(min.)
1250
1250
1250
1250
1250
1250
1300
1350
1350
1350
1530
1530

Port size J
1/2
1/2 or 3/4
1/2 or 3/4
1/2 or 3/4
1/2 or 3/4
1/2 or 3/4
3/4 or 1
3/4 or 1
3/4 or 1
3/4 or 1
3/4 or 1
1 or 1-1/4■ Cap dimensions
Port size
1/2
3/4
1
1-1/4

a
40.5
50.8
57.2
66.7

b
18.2
23.8
27.8
31.8

c
φ13.5
φ17.5
φ22
φ26.5

Screw size
M8×1.25
M10×1.5
M12×1.75
M14×2

The port shape is equivalent to an SAE high pressure flange.

■ KCM Series (for mini-excavator)● With port on cap※ KCH and KCM
The drawing shows the
KCH series dimensions.
KCM has the standard
PF (O ring boss) port.
Please contact us whenan SAE flange port isrequired.

φd
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110

φP
35
40
45
50
50
60
65
60
75
85
85
85
85
90
110

E
39
42
50
50
55
60
62
68
70
75
75
83
105
85
100

M
50
60
70
70
70
85
98
90
105
95
95
105
120
120
140

G
60
60
75
75
80
85
88
95
95
95
90
105
110
125
135

φD
95
100
105
110
115
120
125
130
135
140
145
150

φP
50
60
70
65
70
60
65
75
65
75
90
85

E
55
55
62
65
70
70
70
70
70
75
85
85

M
70
85
85
95
95
95
95
110
105
120
120
130

G
110
136
155
170
170
175
165
170
150
185
150
190

φD
70
75
80
85
90
95
100
105
110
115
120

φP
40
50
50
60
50
60
60
60
65
60
75

E
36
45
50
55
50
55
55
55
58
58
65

M
55
60
60
70
70
70
75
75
75
70
90

G
60
65
80
75
80
75
80
80
85
125
165

● With port on cap【Note】● The cylinder head portion length A, piston portion length B, and the port position
depend on customers request. Please contact us for details.
● See the opposite page (p. 38) for standard sizes of a rod head and a cap.

Cylinder bore
φD

Rod diameterφdMaxstroke

70
75
80
85
90
95
100
105
110
115
120
125

40
40,45
45,50
45,50,55
50,55
55,60,65
55,60,65
55,60,65,70
60,65,70
65,70,75
65,70,75
70,75

500
600
700
800
800
900
900
900
900
1000
1000
1000

39

Retracted
length L(min.)
400
400
400
530
530
530
530
700
750
750
800
800

Port size J
G3/8(PF3/8)
G3/8(PF3/8)
G3/8(PF3/8)
G1/2(PF1/2)
G1/2(PF1/2)
G1/2(PF1/2)
G1/2(PF1/2)
G1/2(PF1/2)
G1/2(PF1/2)
G1/2(PF1/2)
G1/2(PF1/2)
G1/2(PF1/2)※ KCM only
Please contact us
regarding the positionand size when installingports on the cylinder
tube.

40

Cylinders

Cylinders■ KCFL Series (for forklift truck)

Dimensions (unit: mm)

KCFL series cylinders are designed to fit forklift truck masts and be adequate for lifting work. Three types (L1, L2, and L3) areavailable for three mast types.
● KCFL series lifting cylinder types
L1 for the second cylinder of standard and 3-stage mast, L2 for the second cylinder of 2-stage mast, and L3 for the firstcylinder of 2/3 stage full free mast

■ KCFL1 (for the second cylinder of standard and 3-stage mast)■ Forklift truck mast mechanism and lifting cylinder(1) 2-stage standard mast(2) 2-stage full free mast(3) 3-stage full free mast
φD

φd

J

45
50
55
60
65

35
40

G3/8(PF3/8)

45

G1/2(PF1/2)

50

G1/2(PF1/2)

G3/8(PF3/8)

Standard
stroke1000 〜 2500

● The cylinder head length A and piston length B depend on customer's request.
Please contact us for details.
● Contact us for mounting part dimensions: φf1, e1, φf2, and e2■ KCFL2 (for the second cylinder of the 2-stage mast)

φD
45
50
55

41

C

30
32
35
38
40
42

65
67
68
68.5

J1

J2

G1/2(PF1/2)
G1/2(PF1/2)
G3/4(PF3/4)

Standard
strokeG3/8(PF3/8)
G1/2(PF1/2)
G1/2(PF1/2)

1000 〜 2500

● The cylinder head length A and piston length B depend on customer's request. Pleasecontact us for details.
● Contact us for mounting part dimensions: φf1, e1, φf2, and e2● J1 port is connected to J port on KCFL3. (KCFL2 extends after KCFL3 extends.)■ Main Features of KCFL Series● Small diameter, light weight, and high strength…Cylinders
for forklift mast applications are designed to fit the mastmechanism with small diameters and high strength. The
single-acting cylinder with a small diameter and lightweight has been achieved by a thinner tube and special
welding technologies. The second cylinder for 2-stage
masts employs a hollow ram for lighter weight and easy
lubrication.
● Seal…Seals made by KYB are utilized for smooth motion
and prevention of internal leakage.
● Tube…The inside wall is finished with roller burnishing forsmooth motion and high durability.
● Rod…The surface is hard-chromium plated for engineering
purposes (nickel-chromium plated for special specifications)for rust proof and wear resistance.
● Safety/shock absorption … A down safety valve may be
added to ensure safety in the event of piping rupture orother accidents, which may bring the cylinder to a complete
stop. A cushion mechanism may be built in each cylinder
to reduce shocks at the time of retraction.
● KYB's standard models are of the internal drain type.
Visibility can be improved due to no drain hose.

φd● Special valves for forklift truck use…Low energy
consumption type valves (KVMF series) to enable a
precise and safe forklift operation, flow control valves
to control a lowering speed, and down safety valves areavailable. (See pages 49, 58, 61, and 62 for additional
valves.)■ KCFL3 (for the first cylinder of 2- and 3-stage mast)<Down safety valve installation circuit example>

φD

φd

65
70
75
80
85
90

50
55
60

J

Standard
strokeG1/2(PF1/2)

500 〜 1300

65

● The cylinder head length A and piston length B depend on customer's request.
Please contact us for details.
● Contact us for mounting part dimensions: φf1, e1, φf2, and e2
42Cylinders

CylindersElectro-Hydraulic Cylinder: Mini-Motion Package (MMP)【General description】
Mini-Motion Package (MMP) is a hydraulic linear actuator integrated with a DC motor, a hydraulic pump, valves, and a cylinder.
By making the best use of unique features of hydraulic system that are not gained by mechanical types such as electricscrews, this is the best choice of labour-saving and automated work environment including machines, facilities of office andresidential environment.
A new design concept different from the conventional hydraulic systems enables the broadening of new applications.

■①〜⑩ All the following components are integrated in this hydraulic linear actuator.
<Application>

Hydraulic Circuit

Main applications■ No new hydraulic facilities are required.
■ The cylinder can be easily mounted with additional pins on both ends andcompleted electrical wiring.
■ Low energy consumption and cost saving as the hydraulic pump is operated onrequest.
■ The DC motor and hydraulic circuit are completely sealed and thus there is no
oil leakage, allowing the preservation of the environment.
■ Smooth and strong operation are unique to the hydraulic system. Max. thrust:
8000N (816 kgf)
■ The pilot-operated check valve secures load retention. No backlash is
generated, which is different from mechanical types.
■ The relief valve prevents overload. The motor is protected from overload
operation by the circuit breaker.

■ For the automation and energy saving of general
purpose / industrial equipment■ For compact transport equipment, hoists, foodprocessing equipment, and clamps■ For small vehicles, agricultural vehicles, andattachments■ For office, medical, beauty, nursing, and fitness
equipment■ For Sports, recreation, and amusement equipment■ For the automation and energy saving systems
such as residences, buildings, and green houses,
including automatic sunroofs■ Others

Model

▲

▲

① DC motor② Gear pump
③ Relief valve④ Pilot-operated checkvalve⑤ Control valve⑥ Manual release valve(for emergency)⑦ Overload relief valve⑧ Oil reservoir⑨ Slow return valve⑩ Cylinder

Features

Retraction Stop Extension※Refer also to the following mechanism
descriptions for the components, 〜Explanation of the operating mechanism■ "Stop" and load retention■ Cylinder "retraction"■ Cylinder "extension"

When the DC motor ① rotates in the reverse
direction, the gear pump ② begins to rotate
and the control valve moves to theposition.
High pressure oil pumped out from the gear
pumps passes through the pilot-operated checkvalve ④ and flows into the cylinder from the B
port side. The hydraulic fluid returning from the
A port side of the cylinder ⑩ flows back into thegear pumps and the surplus oil drains back to
the oil reservoir. The relief valve ③ activates if
the system overloads or the cylinder stretchesout to the limit of its stroke.
※Connecting the black lead to the terminal( ＋ ) and the white lead to the terminal ( − )retracts the cylinder.

When the DC motor ① rotates in the normal
direction, the gear pump ② begins to rotate, thecontrol valve ⑤ moves to theposition, andhydraulic oil is drawn from the oil reservoir ⑧．
High pressure oil from the gear pump passes
through the pilot-operated check valve ④ andflows into the cylinder from the A port side.
Hydraulic oil returning from the B port side of
the cylinder ⑩ flows back into the gear pumps.
The relief valve ③ activates if the systemoverloads or the cylinder stretches out to thelimit of its stroke.
※ Connecting the black lead to the terminal (−)
and the white lead to the terminal ( ＋ ) extends
the cylinder.

When power to the DC motor ① isinterrupted, the cylinder ⑩ stops
and the load is retained by the pilotoperated check valve. (Assuminginternal oil leakage of 0.3 cm3/min or
less.)Max pressure corresponding to theretained load is 13.7 MPa. Whenpressure increases to 13.7MPa due
to an increase in the temperature, forexample, the overload relief valve ⑦
activates for protection.(The cylinder
starts working when the overload relief
valve activates.)Specifications
Hydraulic system spec.
Series

MMP4-A

Reliefvalve setpressure
(MPa)

4.1

Cylinder max.
retentionpressure(Overload relief
valve setting)
(MPa)

7.1

Rated
extension
thrust (N)φ34-φ20

3100

13.7

Characteristics: Typical values at the ambient temperature 25℃ and rated voltage
MMP4-B

Cylinder size(mm)

φ40-φ204300

φ34-φ205800

13.7
φ40-φ208000Power supply spec.
Stroke
(mm)
150
200
150
200
250
300
350
150
200
150
200
250
300
350

Operatingtemperature
range℃

Rated voltage(V)

Entire unit

Relief valve operation
current (A)

Rated
time
(sec.)− 20 〜 50

DC12
DC24
DC100

23（DC12V）
11（DC24V）
2.4（DC100V)30− 20 〜 50

DC12
DC24
DC100

40.8（DC12V）
18.5（DC24V）
4.4（DC100V)

30

Dimensions

Weight(kg))

φ34-φ20×150
φ34-φ20×200
φ40-φ20×150
φ40-φ20×200
φ40-φ20×250
φ40-φ20×300
φ40-φ20×350
φ34-φ20×150
φ34-φ20×200
φ40-φ20×150
φ40-φ20×200
φ40-φ20×250
φ40-φ20×300
φ40-φ20×350

4.2
4.5
4.3
4.7
5.1
5.4
5.8
4.2
4.5
4.3
4.7
5.1
5.4
5.8

■ Waterproof : JISD0203 D2 compliant■ Vibration durability: JISD1601 Class 3 B compliant

Dimensions (unit: mm)
Cylinder size
Cylinder bore i.d.rod diameter×stroke

The above charts show the characteristics of MMP without the slow return valve orifice  . Cylinder's extension and retraction
speeds differ due to the receiving area difference.
● Example
Model: MMP4-A2B250AA
With a cylinder of φ40-φ20-250 and a motor of DC 24 V
When the extension thrust is 2000N
Extension speed: Approx. 16 mm/s (15.6 sec/250 mm)
Electric current: Approx. 6 A
Retraction speed: Approx. 20 mm/s (12.5 sec/250 mm)
Electric current: Approx. 7 A
43

φ34-φ20×150
φ34-φ20×200
φ40-φ20×150
φ40-φ20×200
φ40-φ20×250
φ40-φ20×300
φ40-φ20×350

Max.
retraction
H1 H2
lengthL280
31 28.5
330
280
330
380
33 31
430
480

Recommended
pin diameter-0.025

φ 14 -0.068
44Cylinders

Cylinders■ Selecting an orifice (slow return valve)

Caution on Selecting/Using Models
Select proper models according to the following selection procedure and check sheet:● MMP specifications and characteristic values are typical ones and may vary depending on operational conditions like thetemperature. Try to select the model with thrust and speed large enough to meet requested specifications.
● Maximum internal leakage may amount to 0.3 cm3/min. Apply a mechanical lock for secure load retention.

■ Selection Procedure● If a hunting phenomenon occurs with the weight of the cylinder, an orifice will be required on the return side. (Hunting
phenomenon: Uncontrollable intermittent motion of a cylinder)※Select orifices for Port A and B according to the load applied to the cylinder.
※When the cylinder is diagonally positioned, select kind of load by its own weight from A 〜 D.
※An orifice is installed to prevent a hunting phenomenon. It is not useful for speed control.
※Please contact us if you do not know the criteria for selection.

(1) Determine maximum thrust, maximum speed, power supply, and stroke required of an MMP cylinder from the applicationand specifications of the equipment.
(2) Select the relief valve set pressure, power supply, cylinder size, and cylinder stroke from the specifications andcharacteristics of the selected MMP model.
(3) Select orifices for port A and B from the load to be applied to the cylinder at page 44.
A: Port A orifice (retraction load), B: Port B orifice (extension load), D: Port A and B orifices (retraction and extension load)(4) Electric wiring and Switching※The customer should prepare the power supply and switching system. Please contact us for any details.

【Wiring example】<12 and 24 VDC>

<100 VDC>
Orifice diameter (calculated value)● Use a bipolar, double throw, instantaneous-contact
type switch with the switching off position at theneutral point at the center for 12/24 VDC switching.

● Use a 100-VDC MMP with the 100-VAC power supply via
an full-wave rectifier.

(5) Selecting wire
● Select a wire diameter suitable for a DC motor operation voltage applied in the range ±10% of the rated voltage.

■ Caution on cylinders in operation【Note】
1. In the case of D (compression and tension load), select both A (compressionload) and B (tension load).
2. Please contact us for the parts marked with an asterisk (※).
3. Make sure to test the selected MMP on the intended equipment.

【Selection example】
For a compression load of 6 kN on the cylinder of
φ40, select an orifice of φ0.6.

■ Check sheet<Relief valve>

Do not activate the relief valve over 2 seconds. Otherwise, a rise in the oil temperature or a malfunction may result. The
relief valve set pressure is fixed (at 4.1 or 7.1 MPa) and cannot be changed.

<Duty cycle / Circuit breaker>● All models are designed for an intermittent operation and will automatically shut down when operated continuously.
Use the MMP under the rated pressure (thrust) in intervals of 30 seconds within ED25% (pause over 90 seconds).
● When the allowable duty cycle is exceeded, the circuit breaker built in the DC motor will automatically turn off the MMP.
● When the DC motor cools down, the circuit breaker will automatically reset enabling the restart of the MMP.
Continuing to use the MMP in conditions, in which the circuit breaker is often triggered, is not recommended.

<Manual operation in case of an emergency>● In case of power failure, electric wire break, and other emergencies, the cylinder may be extended or retracted using themanual release valve ⑥ .
After loosening the manual release valve by turning it two or three times with a hex wrench, the cylinder can be extended or
retracted by the hand or by its own weight. (Be careful of a free fall.)Mounting● Mount the MMP with two parallel pins (recommended diameter: φ14 -0.025) and secure in place with split pins.
-0.068● The MMP can be easily mounted by securing the rod side to the load side and the bottom side to the frame of the equipment.

■ Storage

When the MMP is not going to be used for a long period, keep the cylinder in the fully retracted position.
If the cylinder is kept in the extended position for a long time, dust deposits or rust may damage the oil seal, causing eventual malfunction.

■ Disposal

When disposing the MMP, unplug the oil tank, remove operating oil from the oil reservoir and cylinder.
When removing the plug, do it slowly after extending the cylinder. Otherwise, the oil may gush out because the tank is pressurized.
45

46

Valves

ValvesBasic Circuit (parallel, tandem, and series circuits)● Parallel circuit
Oil from the pump is supplied to thefirst, second, and third section inparallel (simultaneous).

The multiple control valve mainly provides the directional control function for supplying oil to each actuator, but also has pressure and flow
control functions.
● Pressure control valves: relief, pressure reducing, and unloading valves, etc. ● Flow control valves: throttle, flow dividing, and pressurecompensation valves, etc. ● Directional control valves: directional change and check valves, etc.
<Classification by body construction>◇ Mono-block type: The circuit and functions are designed for a specific model with simple construction (single-function valves)◇ Sectional type: The basic circuit, variations, and the number of spools can be flexibly designed (general purpose and single-function
valves)◇ Semi-mono-block type: With mono-block as basic circuit design, additional valves are arranged to be sectional. (Special-purpose valve)

Valve: Multiple Control Valve
Basic construction, operation, and accessory valves■ Directional Control Operation【KVS65 model-sectional type】※Load check valve: This valve prevents a drop in the load on theactuator caused by reverse flow of oil from the actuator during
a spool change.
※Position: A three-position type (spool neutral, push, and pull)is commonplace, but the two- and four-position types (for the
loader's boom section, etc.) are also available.

● Tandem circuit
Oil from the pump is supplied to the first,
second, and third section in this order withthe priority placed on the upstream side.

● Series circuit
Priority is placed on the upstream section
and the return oil of the upstream section is
supplied to the downstream section (s).

<Characteristics>◇ Each machine can be operated independently◇ On a simultaneous operation, the lowest-pressure circuit is activatedfirst, followed by the mid-pressure circuit and then by the highestpressure circuit.
◇ Simultaneous operation is possible with an adjustment of spools.

◇ When the upstream section operates, thedownstream section stops.
◇ Adjustment of the upstream spool enables thedownstream section operation.

◇ A simultaneous operation is possible irrespective ofthe load.
◇ Pump pressure is the sum of all sections.

※The above examples are representative of each model, and multiple circuit models may be combined or a special circuit (e.g.
two-pump conflux) may be integrated. Please contact us for circuit configurations.
※Carry over: Oil from the pump inlet may flow to the next circuit through the outlet of the last section.

Basic Characteristics

For the selection of a multiple control valve, the following characteristics should be
examined.
【Pressure drop characteristics】
The relationship between pressure drop and flow rate is expressed by the formula:P = β･Q2/A2
Q: Flow rate, β: Coefficient, A: Valve opening area, and P: Pressure
As pressure increases by the square of the flow rate, make sure not to let the flow rate
exceed a rated value even momentarily. As the number of spools increases, the equivalentarea becomes smaller and the pressure drop increases.
※Our products are designed in a compact form to reduce pressure loss.

【Relief override performance】■ Combination Relief Valve Operation  Relief valve
The work port pressure exceeds the pilot spring force, opening the pilot poppet
to flow oil to the tank port. The pressure difference between the front- andbacksides of the main poppet caused by the flow opens the main poppet to flow
oil from the work port to the tank port.
The mechanism enables a compact design and better performance (smaller
override) than a direct-type relief valve.
 Anti-cavitation (port relief)
When pressure on the port side is decreased lower than one on the tank side bycavitation, etc., the difference of the pressure receptive areas between the tank
and work port sides of the main poppet opens the main poppet to let oil flowfrom the tank side to the port side.
※The port relief valve of a combination type provides relief and anti-cavitation
functions.
■ Spool Operation and Return to Neutral Position● Manual operation: Most small valves are manually operated with levers.
● Pilot operation: Most large-scale valves and multiple-valve-units for excavator and mini-excavator applications use a pilot valve allowing
light force or parallel operation.
● Solenoid-operation: On-off or proportional changeover of the spool can be performed using the solenoid-operated valve.
【Return to neutral position】● Often a return spring is adopted for the return to the neutral position, but a mechanical or electric detent system is also used.

■ Various accessory valves: An additional accessory valve may be installed on the inlet port of the pump or on each port.

● The main relief valve is used to control the maximum pressure of the pump. ● The overload relief valve (port relief valve) is used toprevent overload of the actuator.
● The anti-cavitation valve is used to prevent cavitation in the actuator. ● The shut-off valve is used for plugging when no relief valve or
anti-cavitation valve is used.
47◇ Cracking pressure: Pressure levelto open the relief valve◇ Full flow pressure: Pressure andflow rate set for operation◇ Override: Pressure difference
between the cracking and full flow

Note 1: Please specify the set pressure as「full flowpressure:
MPa atL/min.」
Please contact us when cracking pressure is required to
be set.
Note 2: When setting the pressure of main relief valve
and port relief valve, remember that pressure difference
between the two, exceeding the override pressure isrequired (over 2 MPa) to prevent pressure interference
during a simultaneous operation. ※A combination relief
valve is supplied as a standard accessory in order torealize a compact design and high performance (static anddynamic characteristics).

【Metering characteristic】

Peak pressure on relief
operation should be taken
into account.

<Spool stroke opening area (flow rate) characteristic >P to T opening: For opening or closing the flow from the pump to the reservoir in the neutral
passage and regulating the partial flow to actuators.
P to C opening: For opening or closing the flow from the valve to the actuator and regulating
the flow rates to actuators.
C to T opening: For opening or closing the flow from the actuator to the reservoir andregulating the return flow from the actuator.
※The flow characteristic (----- ) varies depending on load conditions on the P and C
sides. Therefore, some systems require prototype tests.
※Spool opening adjustment (metering) during changeover enables fine-tuning of theequipment or the absorption of lever operation impact.
※Spool setting adequate for the system is possible by combination of opening area.
<Spool stroke (spool effort)>○ Against the spring force returning to the neutral position (), the friction of themoving part works in the positive direction while moving from neutral to full stroke and in
the negative direction while returning from full stroke to neutral.
(----- )○ The operation force is shown with (----- ) when the oil does not flow. The hydraulicoperation generates"flow force"according to the flow rate and pressure. When flow force
is too large, it may prevent the spool from returning or affect fine tuning capacity duringpilot operation. This way a decrease in flow force from the spool can ensure smooth
performance.
※KYB products feature light lever operation and high durability by ① strict moving partclearance management, ② use of low-friction sealing and wiper sealing, and ③ adoptionof fluid-force-reduction spools.
48

Valves

ValvesAdditional functions of the special-purpose valve
Additional functions of the single valve※Based on our long experience, we have made available necessary additional functions for each machine.
These functions are provided as standard specifications for some models and as options for others. Please contact us
regarding your application.
■ For Excavator and Mini-excavator[Refer to both the explanations for  to  and the circuit diagram on the right]※In most cases, more than two pump ports are installed to regulate flows separately for the travel motors (left and right), swing
motor, and bucket cylinder. Each boom and arm cylinder requires two sections, such as Boom 1 and 2, and Arm 1 and 2, so
as to improve work efficiency. On top of that, a auxiliary section is installed for attachment purposes. In total there are nine
sections.
※Various functions are incorporated to operate all actuators in simultaneous operation.

 Straight travel circuit

When attachment sections are operated with two travel motors in action, thestraight travel valve works to supply oil from P2 pump to other sections andoil from P1 pump to left and right travel motors.
※Straight travel is possible while operating travel motors and anotherattachment sections at the same time.

<Circuit Diagram example (for abrief explanation)> Conflux circuit

During a boom or arm operation with other actuators not in use, the oil flow to
Boom 2 and Arm 2 is added to the oil flow to Boom 1 and Arm 1, causing an
increase in the total oil flow.
※Increasing cylinder speed improves work efficiency.

 Priority in a multiple operation

In a simultaneous operation of actuators with different working pressure, it
prevents much oil from flowing into lower pressure line.
※A simultaneous operation of the swing and arm sections or the boom and arm
sections becomes easy.
⑤ Regeneration circuit (e.g. boom regeneration)

 Regeneration circuit

The circuit combines return oil from the actuator with oil from the pump. The
circuit is used for arm and boom.
※Increasing the cylinder speed is useful in preventing cavitation and recycling
oil discharged from the pump. (Energy saving effect)

 Anti-drift valve

The poppet valve and the pilot unit for the opening and closing of the poppet
valve are incorporated between the flow from the spool and the cylinder port.
Better sealing performance with the poppet valve reduces oil leakage. It isalso very useful in preventing the boom or arm from falling down.

⑥ Anti-drift valve

 Two-stage main relief valve

Adding signal pressure to the standard main relief valve can raise set
pressure.
※ It is usable when more driving force is required.
Please contact us for other additional functions such as a spool switch
detection function and a pump control signaling function (load sensing,positive/negative control, etc.).

49※Two valves for the boom and bucket compose a basic mono-block onwhich sections for attachments can be added. (KVML)
 Boom lowering floating position
In addition to the three positions for Neutral, Lifting, and Lowering of
the boom, the fourth position for drifting (lowering by its own weight) is
given by connecting the line between the cylinder rod and bottom and thereservior.
※This position is required for leveling the ground.
※Traveling is possible while keeping the valve at the detent position.
 Boom lowering detent
The boom is kept at the drifting position with magnetic detent.
 Boom lifting detent
The boom is kept at the lifting position with magnetic detent.
 Bucket crowding detent
A mechanism to maintain a bucket crowding position■ For wheel loader application (steering) [KVMT]【Load sensing valve】(KVSX)※To be used in combination with the LS valve and LS pump. (Load pressure
sensing variable displacement pump at page 17.)
※See page 20 for the working mechanism of the load sensing system.
 By using the valve in conjunction with the pump to provide the discharge for
only the required pressure and required flow according to lever operation, alow energy consumption system can be realized easily.
 Since the valve is not influenced by load, it is easy to improve simultaneous
operation performance by electronic control.
 A compact design can be made with less piping and no conflux circuit.
 Easy flow setting for each valve section.
 The tuning period can be reduced as the flow characteristic can be easily
estimated.

※Two valves for lifting and tilting compose the basic mono-block on which
sections for attachments can be added. (KVMF)
 Flow priority valve (VPF)
The pump flow is delivered to the hydraulic power steering system withpriority through the PF port.
A type corresponding to the load sensing steering unit is also available.
※The performance is not affected by the engine speed.
[Various safety mechanisms] ※For securing safe operation
 Lift lock valve
This is a safety valve, prohibiting the lift from falling down. The return line
to the cylinder is stopped by solenoid valves.
※A lever operation in error while the engine is off will not lower the lift.
 Unloading valve
This is to insure safety by prohibiting the lift raising operation byconnecting the pump line to the reservoir line with electric signals to thesolenoid valve※A lever operation in error will not raise the lift.
 Tilt lock valve
The supply side pressure opens the return line.
※Load drop from the fork due to mast tilting is prevented even when thelever is operated accidentally while the engine is off.
 Flow regulator valve (FRV)
A safety valve (flow control valve) to limit the maximum lift lowering speed.
※The lift lowering speed can be adjusted.

■ For wheel loader application (boom and arm)
[Refer to both explanations for  to  and the circuit diagram on the right] Neutral flow cut-off valve

The valve closes the neutral flow of the control valve to raise pump pressure.
※The valve enables the division of oil from the control valve to additional valves
for attachment.

■ For forklift truck applications[Refer to both explanations for ① to ⑤ and the circuit diagram on the right]⑦ Two-stage relief valve※ A special valve for articulated wheel loader steering※A pressure compensation valve is incorporated in the mono-block
construction.
※Light steering force generates great power.
<Operation mechanism>(1) Manual: Mechanical linkage compatible(2) Floor amplifier
Main spool switching by means of a stroking adjustment corresponding to
supply flow
※Suitable for orbit pump systems.
<Pump method>
Both single- and tandem-pump systems are available.
※Please select the one appropriate for your system.
<Pressure compensator model>
As the supply flow is controlled by the main spool opening, a flow rateadequate for steering can be maintained at both high and low speed.

50

Valves

ValvesValve: Multiple Control Valve
A control valve works a single actuator or multiple
actuators simultaneously, and may incorporate
multiple functions.
KYB provides a wide variety of valves which
includes hydraulic control valves, and electro-hydrovalves with electric and hydraulic control systems
combined.
Multiple mono-block cast products are manufactured
by KYB-YS Casting Center, one of KYB's affiliatedcompanies.

Dimensions (typical example) (unit: mm)■ KVS Series: General purpose【General purpose KVS-31】Mainly used for mini-excavators, forklift trucks and industrial equipment【Optional functions】
Main relief valve
Overload relief valve
Anti-cavitation valve
DetentFour positions
Carryover■ KVS and KVM Series● For excavators and mini- excavators

KVSE-72

KVSX-14【General purpose KVS-65】Mainly used for mini-excavators, forklift trucks, and industrial equipment

KVMG-270【Optional functions】
Main relief valve
Overload relief valve
Anti-cavitation valve
DetentFour positions
Carryover【Optional functions for forklift trucks】
Flow priority valve
Tilt lock valve■ KVS, KVMF, and KVMT Series● Multiple control valve for forklift trucks, wheel loaders, and other applications

KVMF-70

KVMT-200
51

52

Valves

Valves【General purpose KVS-200】Mainly used for medium- and large-sized construction equipment

Dimensions (typical example) (unit: mm)【General purpose KVS-65PSL】

Mainly used for compact construction equipment, forklift trucks, and industrial equipment【KVS-65PSL optional functions】
Main relief valve
Overload relief valve
Anti-cavitation valve
DetentFour positions
Carryover【Optional functions】
Main relief valve
Overload relief valve
Anti-cavitation valve
DetentFour positions
Carryover

−
−
−

−
−

【Optional functions for forklift trucks】
Flow priority valve
Tilt lock valve<KVS-65PSL main features>● Based on KVS-65, operating the spool with the internal pilot type proportional solenoid pressure
reducing valve.
● The pressure compensation mechanism (optional) enables stable flow unaffected by load pressure
fluctuation.

[General purpose KVS-600]Mainly used for various large-sized construction equipment【General purpose KVS-120】Mainly used for a variety of compact construction equipment, 【Optional functions】
forklift trucks, and industrial equipment

Main relief valve
Overload relief valve
Anti-cavitation valve
DetentFour positions
Carryover【Optional functions】
Main relief valve
Overload relief valve
Anti-cavitation valve
DetentFour positions
Carryover−−−【Optional functions for forklift trucks】
Flow priority valve
Tilt lock valve

53

54

Valves

Valves■ KVSE/KVSX Series: Special models for mini- excavators【General purpose KVS-1000】Mainly used for various large-sized construction equipment

Various functions for mini- excavators are incorporated.

【Optional functions】
Main relief valve
Overload relief valve
Anti-cavitation valve
DetentFour positions
Carryover

D

3/4

19.1

1

25.4

1 1/4

31.8

1 1/2

38.1

2

50.8

2 1/2

63.5

−
−
−

※ Available on request【Built-in functions】
Straight travel
Attachment
Internal boom conflux
Spool neutral position detecting signal
Pump control signal output
Overload relief valve【Optional functions】
Anti-drift valve
Add-on for spool section
Add-on of third pump spec.
Regeneration circuit
Arm closing variable regeneration
Two-staged main relief
Flow priority at multiple operation
Neutral cut-off valve※ Available on request【Built-in functions】
Straight travel
Attachment
Internal boom conflux
Spool neutral position detecting signal
Pump control signal output
Overload relief valve【Optional functions】
Anti-drift valve
Add-on for spool section
Add-on of third pump spec.
Regeneration circuit
Arm closing variable regeneration
Two-staged main relief
Flow priority at multiple operation
Neutral cut-off valve

※
−
−

−

−

【KVSE-72 for mini- excavators】● Split Flange Dimensions
Nominalsizes【KVSE-36 for mini- excavators】

Ｅ

F

47.6
50.8
52.4
57.2
58.7
66.7
69.8
79.4
77.8
96.8
88.9
ー

22.2
23.8
26.2
27.8
30.2
31.8
35.7
36.5
42.9
44.4
50.8
ー

H
(Ref. sizes)

17.5
19.1
17.5
22.3
23.8
20.7
22.3
30.2
22.3
33.4
25.4
ー

G

M10×1.5
M10×1.5
M12×1.75
M12×1.75
M14×2
M14×2
M16×2
M14×2
M20×2.5
M14×2
ーUpper rows: Standard pressure (3000 psi)
Lower rows: High pressure (6000 psi)

55

※
−
−

−

−

56

Valves

Valves■ KVMM/KVMG Series: Special models for excavators

Dimensions (typical example) (unit: mm)【KVSX-12 for mini-excavator load sensing】【KVMX-18】For excavators in the 6-9 ton class range

Max※ To be used in combination with the LS pump. (See“Load sensing pump”
at page 19.)

Mounting screw【Built-in functions】
Straight travel
Attachment
Internal two sections conflux
Spool neutral position detecting signal
Pump control signal output
Overload relief valve【Optional functions】
Anti-drift valve
Add-on for spool section
Add-on of third pump spec.
Regeneration circuit
Arm closing variable regeneration
Two-staged main relief
Flow priority at multiple operation
Neutral cut-off valve

JIS O-ring boss
Work port※ Available on request【Built-in functions】
Straight travel
Attachment
Internal boom conflux
Spool neutral position detecting signal
Pump control signal output
Overload relief valve【Optional functions】
Anti-drift valve
Add-on for spool section
Add-on of third pump spec.
Regeneration circuit
Arm closing variable regeneration
Two-staged main relief
Flow priority at multiple operation
Neutral cut-off valve−※−

JIS O-ring boss
Pump port

−
※
−
○
○
○
○
○
−
○
○
○
−
−

JIS O-ring boss
Tunk port

−
−
−
−
−
−

【KVMM-80】For excavators in the 6-9 ton class range【KVSX-14 for mini-excavator load sensing】※ To be used in combination with the LS pump. (See“Load sensing variable displacement pump”
at page 19.)

※ Available on request

57【Built-in functions】
Straight travel
Attachment
Internal boom conflux
Spool neutral position detecting signal
Pump control signal output
Overload relief valve【Optional functions】
Anti-drift valve
Add-on for spool section
Add-on of third pump spec.
Regeneration circuit
Arm closing variable regeneration
Two-staged main relief
Flow priority at multiple operation
Neutral cut-off valve

−
※
−

−
−
−
−
−
−

【Built-in functions】
Straight travel
Attachment
Internal two sections conflux
Spool neutral position detecting signal
Pump control signal output
Overload relief valve【Optional functions】
Anti-drift valve
Add-on for spool section
Add-on of third pump spec.
Regeneration circuit
Arm closing variable regeneration
Two-staged main relief
Flow priority at multiple operation
Neutral cut-off valve

−

−

58

Valves

Valves【KVMG-400】For excavators in the 40-50 ton class range

Dimensions (typical example) (unit: mm)【KVMM-160】For excavators in the 10-16 ton class range【Built-in functions】
Straight travel
Attachment
Internal two units conflux
Spool neutral position detecting signal
Pump control signal output
Overload relief valve【Optional functions】
Anti-drift valve
Add-on for spool section
Add-on of third pump spec.
Regeneration circuit
Arm closing variable regeneration
Two-staged main relief
Priority at multiple operation
Neutral cut-off valve【Built-in functions】
Straight travel
Attachment
Internal boom conflux
Spool neutral position detecting signal
Pump control signal output
Overload relief valve【Optional functions】
Anti-drift valve
Add-on for spool section
Add-on of third pump spec.
Regeneration circuit
Arm closing variable regeneration
Two-staged main relief
Flow priority at multiple operation
Neutral cut-off valve−−■ KVMF Series: Special models for forklift trucks【KVMF-70】For forklift trucks in the 1-3 ton range【KVMG-270】For excavators in the 20-30 ton class range【Configuration】

ParallelTandemManualOperation type
Pilot
Additional sections Add-on
Overload relief valve
Circuit【Built-in functions】
Straight travel
Attachment
Internal two units conflux
Spool neutral position detecting signal
Pump control signal output
Overload relief valve【Optional functions】
Anti-drift valve
Add-on for spool section
Add-on of third pump spec.
Regeneration circuit
Arm closing variable regeneration
Two-staged main relief
Priority at multiple operation
Neutral cut-off valve

59−[Features]○ Flow priority valve (VPF): Standard
accessory(Removable on request)○ Flow regulator valve (FRV): Standard−−

accessory(Removable on request)[Option]○ Lift lock valve○ Tilt lock valve−○ Unload valve
60

Valves

Valves■ KVML Series: For loaders (main) and forklift trucks■ KVMT Series: For loader (steering) applications【KVML-200 for loader and forklift trucks】For wheel loaders (2-3.5 m3) and forklift trucks (over 7 tons)※ A special valve for articulated wheel loader steering【KVMT-200 for loader (steering)】For wheel loaders in the 2.5-5.5 m3 range【Configuration】【Configuration】

ParallelTandemManualOperation type
Pilot
Additional sections Add-on
Overload relief valve
CircuitParallelCircuit
TandemManualOperation type
Pilot
Additional sections Add-on
Overload relief valve−−−[Features][Option]○ Built-in pressure compensation valve○ The detent function is added to the○ Both single- and double-pump types

drift position of the boom section

are available○ Tilt lock valve○ Carryover circuit provided【KVMT-400 for loader (steering)】For wheel loaders in the 6-13 m3 and over range【KVML-270 for loader (main)】For wheel loaders in the 2.5-4 m3 range【Configuration】

ParallelTandemManualOperation type
Pilot
Additional sections Add-on
Overload relief valve
Circuit【Configuration】

ParallelTandemManualOperation type
Pilot
Additional sections Add-on
Overload relief valve
Circuit−−−[Features][Features]○ Built-in pressure compensation valve○ The boom section is of the four-○ Both single- and double-pump types

position switching type with the drift
position added to the lowering position61

are available○ Carryover circuit provided

62

Valves

ValvesDown Safety Valve■ Features

Valve: Single-function Valve
Please consult us for other models not included in this catalog.

The valve detects hydraulic piping damage or an abnormal (excessive) flow rate and blocks or reduces the flow. The down
safety valve is available with“flow blocking”
and“flow reduction”
types. Mounting one at the actuator port improves work andequipment safety. (The valve functions comply with the Japan Industrial Vehicle Association Standard's safety criteria.)■ Flow Control Valve■ Down Safety Valve

Symbol■ Hose Rupture Valve■ Performance curve※The hose rupture valves are designed for each application considering the equipment and cylinder specifications, and thus
the details have been omitted here. (Please contact KYB sales department.)

Hydraulic oil: ISO VG32 / Oiltemperature: 40℃● Pressure drop characteristic■ Dimensions (unit: mm)

Flow Control Valve■ Features
This is the in-line directional flow control valve with pressure compensation function. The flow is maintained at a fixed rate
without being affected by the load fluctuation, and the reverse direction is made to free flow.
This valve is suitable for controlling maximum speed and regulating the lowering of speed.

■ Performance curve
Hydraulic oil: ISO VG32 / Oil temperature: 40｡C

Model L1
DS-03 49
DS-04 67
DS-06 −

L1
87
120
153

L2
100
120
153

A
15
20
20

B
70
84
113

C
12
16
18

φD
37
48
60

E.F.J
G3/8(PF3/8)
G1/2(PF1/2)
G3/4(PF3/4)

G
32
41
55

H
18
20
22

Note:
E: JIS B8363 parallel pipe male threads-female seat joint
F: JIS B8363 parallel pipe male threads-female sheet joint as well as JIS B2351 O-ring seal type
J: JIS B8363 parallel pipe male threads-male seat joint
63

B
8
10
−

C
12
16
−

D
E
F/G/R
H
17 14.5 G3/8(PF3/8) 22
25 18.2 G1/2(PF1/2) 27−− G3/4(PF3/4) 36

L2
69
89
98

J
41
55
58

K
M
L3
Q
16 PT3/8 75 18
18 PT1/2 93 20
20 PT3/4 100 22

φN
25
31
40

Note:
F: JIS B8363 parallel pipe male threads-female seat joint
G: JIS B2351 parallel threads O-ring seal joint
R: JIS B8363 parallel pipe male threads-male seat joint
M: JIS B0203 pipe tapered threads■ Dimensions (unit: mm)

Model
FC-03
FC-04
FC-06

A
12
16
20

Caution upon handling● Select a model with sufficient blocked flow against an excessive flow expected during switchover.
● Do not use in applications in which open-close cycles are constantly repeated.
● The following pressures should be retained after blocking:DS-03: More than 1.8 MPa
DS-04: More than 2.2 MPa
DS-06: More than 1.5 MPa

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2. Tightening Torque for Piping (Reference data)
1.Main Formulas (Source: Extracted from the Practical Hydraulic System Pocket Book) published by the Japan Fluid Power Association)<Formulas for Pump and Motor Characteristics (The International System of Units)><Cylinder related formulas>■ Reciprocation load and cylinder selection
A double acting movement is considered to generate thefollowing loads.
Static friction resistance F1 ＝ μS・m・g〔N〕
Dynamic friction resistance F2 ＝ μD・m・g〔N〕
dV
Inertia load F3 ＝ m・ａ＝ m・ dt 〔N〕
Elasticity load F4 ＝ k・x〔N〕
Where,
μs: Moving angle static friction coefficient
μD: Moving surface dynamic friction coefficient
M: Load mass〔kg〕
g: Gravitational acceleration〔m/s2〕
a: Acceleration〔m/s2〕
V: Cylinder velocity〔m/s〕
t: Acceleration time〔s〕
k: Spring constant〔N/mm〕
x: Spring displacement〔mm〕
Select a cylinder considering the load magnitude. Whenthe compression force is great, consider the rod bucklingstrength.
Determine standard dimensions of the hydraulic cylinder tosatisfy the calculated dimensions.
Piston rod diameter d ＝ √ π・σ 〔mm〕
4×F・S

Reference：1kW ＝ 103 Ｎ・m/s ＝ 102kgf・m/s
1PS ＝ 735.5 Ｎ・m/s ＝ 75kgf・m/s<Motor related formulas>■ Revolution load and hydraulic motor selection
Rotation is considered to generate the following loads.
Static friction torque
Breakaway torque T1=μS・m・g・R〔N・m〕
Dynamic friction torque T2=μD・m・g・R〔N・m〕
dω
GD2
2π・N
N・GD2
Inertia torque T3=I・
＝
・
＝
〔N・m〕
dt
4
60t
38t
Where,
R: Bearing radius of rotating object (m)I: Inertia moment of rotating object〔kg・m2〕
GD２: Flywheel effect
ω: Revolution angular velocity ω= 2π・N 〔rad/s2〕60
ω : Revolution angular acceleration ω = 2π・N 〔rad/s2〕t60tt
N: Revolution velocity (min-1)
t: Acceleration time (s)Sum of GD2 in multi-axis rotation:
N3 2
22
GD2=GD 21＋ GD 22・ N＋ GD23・
N1
N1
Where,
GD2: Whole GD2 on one axis
GD 21 and N1: GD2 on the first axis and revolution velocity
GD 22 and N2: GD2 on the second axis and revolution velocity
GD 23 and N3: GD2 on the third axis and revolution velocity
Select a hydraulic motor considering the magnitude of the load
torque. The output torque of a hydraulic motor varies at operation
start and during operation, and the former is more important.
ηT 〔N*m〕Consequently D = 2π・T 〔cm3〕
T= P・D・
P・
ηT
2π
2π・T
P=
〔MPa〕
D・
ηT
D・N
Q= 1000η 〔L/min〕
V
Where,
D: displacement volume of a hydraulic motor〔cm3〕
T: Output torque of a hydraulic motor〔N・m〕
P: Effective pressure of a hydraulic motor〔MPa〕
N: Revolution velocity of a hydraulic motor〔min-1〕
ηTT: Torque efficiency of a hydraulic motor

（

）

（

）

ηT v: Volumetric efficiency of a hydraulic motor
65

Note: The tightening torque may vary depending on various conditions such as material, specifications, tightening methods, etc.
The following figures represent hypothetical conditions:(1) Metric screw
Coarse pitch strength grade II				

Unit : N・ｍ（kgf・m）

Fine pitch strength grade II				

Unit : N・ｍ（kgf・m）（kgf・m）(2) G O-ring boss joint Unit: N・ｍ（kgf・m）(3) Unified O-ring boss joint Unit: N・ｍ

4（Ａ1＋Ａ２）
Cylinder bore D ＝√〔mm〕
π

Where,
F: Cylinder load〔N〕
S: Safety factor
σ: Tensile strength〔N/mm2〕π
A1: Piston rod area A1 ＝ 4 ・d 2〔mm2〕A2: Cylinder effective area A2 ＝ F 〔mm2〕PR
PR: Pressure on cylinder〔MPa〕
Determine the cylinder size and obtain the required pressureand flow.
F
P1 ＝
〔MPa〕
A1
Q ＝ A1・V×10-3〔L/min〕
Where P1: Pressure required of a cylinder〔MPa〕
Q: Flow rate required of a cylinder〔L/min〕
F: Cylinder thrust〔N〕
A1: Inlet side pressure receiving area〔mm2〕
V: Cylinder velocity〔m/min〕

3. Working oil viscosity - Temperature graphs

4. Throttle pressure - Flow characteristic<Valve related formulas>(1) Pressure and flow rate Q before and after throttle

Ｑ＝ 60ｃＡ√ 2ΔＰ
ρ

Q: Flow rate〔L/min〕
c: Flow coefficient〔0.6 〜 0.7〕
A: Throttle area (opening)〔mm2〕
ΔP: Pressure difference before and after throttle〔MPa〕
ρ: Hydraulic oil density〔kg/3〕(2) Spool leak amount q
π db3
q= 12μl （l ＋ 1.5ε2）ΔＰ

q: Leak amount〔cm3/s〕
d: Spool diameter〔mm〕
l: Lap length (clearance length)〔mm〕
b: Clearance (hole dia. - shaft dia.) /〔μm（10-3mm）〕
ε: Eccentricity (spool eccentric distance) / b
μ: Viscosity (Pa*S)△ P: Front and rear pressure difference〔MPa〕

Use hydraulic oil ISO VG32 in cold areas and ISO VG46 inwarm areas.

Flow rate Q [L/min.]66

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