Claas VARIANT 260, VARIANT 280 Service Manual

VARIANT 260/280

Technical Systems

Hydraulic System

Hydraulic System VARIANT 260/280 TIC

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TIC VARIANT 260/280 Hydraulic System

Hydraulic system
Contents

Chapter 1 Overall hydraulic system circuit diagram.............................5

Chapter 2 Function .................................................................................15

Chapter 3 Valve components.................................................................29

Index.........................................................................................................57

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Chapter 1 Overall hydraulic system circuit diagram

1.1

Circuit diagram – without active hydraulic system.............................6

1.2

Circuit diagram – with active hydraulic system,

1.3

Circuit diagram – with active hydraulic system,

with integrated pressure holding valve (754) up to serial no. … .....10

without integrated pressure holding valve (754) from serial no. .....12

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1.1 Circuit diagram – without active hydraulic system

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Key to diagram:

6 Valve block

102-1 Filter (option)

When factory-mounted, filter (102-2) is not provided

- in this case, a hydraulic loop line is installed here.
In case of retrofits, filter (102-2) remains in place.

102-2 Filter (series equipment)

232 Lubricating oil pump

is actuated when building up pressure for opening the tailgate.

318-1 Left side tailgate hydraulic cylinder

318-2 Right side tailgate hydraulic cylinder

331 Pick-up raise/lower hydraulic cylinders

2 pieces, spring-loaded

336 Knife support On/Off hydraulic cylinder

338 Rotor cut-out clutch

345 Top tensioning arm hydraulic cylinder

346-1 Bottom left tensioning arm hydraulic cylinder

346-2 Bottom right tensioning arm hydraulic cylinder

370 Drive clutch for roller no. 3. When subject to pressure, the clutch opens so that roller no. 3 does

not drive the belts (when opening the tailgate).

513 Hydraulic accumulator

pressurised to 2 bar

626-C Shut-off tap

for left-side tailgate cylinder. Is combined with 626-D and 626-E.

626-D Shut-off tap

626-E Shut-off tap

627 Shut-off tap

for right-side tailgate cylinder. Is combined with 626-C and 626-E.

for belt tensioner cylinder. Is combined with 626-B and 626-C.

- blocked when 626-C and 626-D are open.

- open when 626-C and 626-D are blocked.

In the initial position (see circuit diagram):

- the oil supply to valve block (6), (input P) is ensured.

- the oil supply to the rotor cut-out clutch (338) is shut off.

When actuated:

- the oil supply to the valve block (6), (input P), is shut off

- the oil supply to the rotor cut-out clutch is provided.

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Hydraulic System VARIANT 260/280 TIC

722-1 Anti-cavitation valve

opening pressure 3.6 bar

722-2 Anti-cavitation valve

opening pressure 3.6 bar

722-3 Anti-cavitation valve

opening pressure 3.6 bar

731-1 Non-return valve

731-2 Non-return valve

731-3 Non-return valve

731-4 Non-return valve

shuts off the pre-pressurizing circuit against the filter circuit.

734-1
734-2

753-1
753-2

754 Pressure relief valve

755 Flow controller

756 Flow controller

801-1 Quick release coupling

801-2 Quick release couplings

912 Baling pressure gauge

Y50 Baling pressure build-up solenoid valve

Y54 ROTOCUT knives OUT solenoid valve

Y55 ROTOCUT knives IN solenoid valve

Non-return valves lock-up valve unit
shut off the tailgate cylinders (318), the rotor cut-out clutch (338) and the drive clutch (370).

Pressure relief valve
limits the pressure in the rod spaces to 250 bar.

maintains the pressure in the tensioning arm circuit at 10 bar.

controls the volume flow for opening the tailgate to 50 l/min. The non-return valve does actually not
exist – here it serves merely for better understanding of the circuit diagram.

controls the volume flow for closing the tailgate to 18 l/min. The non-return valve does actually not
exist – here it serves merely for better understanding of the circuit diagram.

single-acting control unit. Oil supply for knife support and pick-up.

double-acting control unit Open / close tailgate oil supply.

- limits the pressure in the tensioning arm circuit and thus controls the baling pressure.

- is controlled by the electronic box (the desired baling pressure is set by a potentiometer).

- when the power supply fails, the highest baling pressure is reached.

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Notes:

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1.2 Circuit diagram – with active hydraulic system, with integrated pressure holding valve (754)
up to serial no. …

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Key to diagram:

6 Valve block
102-1 Filter (option)
102-2 Filter
232 Lubricating oil pump
318-1 Tailgate left hydraulic cylinder
318-2 Tailgate right hydraulic cylinder
331 Pick-up hydraulic cylinder
336 Knife support hydraulic cylinder
338 Rotor cut-out clutch
345 Top right tensioning arm hydraulic cylinder
346-1 Bottom left tensioning arm hydraulic cylinder
346-2 Bottom right tensioning arm hydraulic cylinder
370 Roller 3 drive clutch
410 Orifice plate diam. 1.5 mm (for oil flow limiting)
513 Hydraulic accumulator (pressurised to 2 bar)
626-C Shut-off tap
626-D Shut-off tap
626-E Shut-off tap
627 Shut-off tap
722-1 Anti-cavitation valve (open pressure 3.6 bar)
722-2 Anti-cavitation valve (open pressure 3.6 bar)
722-3 Anti-cavitation valve (open pressure 3.6 bar)
732-1 Non-return valve
732-2 Non-return valve
732-3 Non-return valve
732-4 Non-return valve
732-5 Non-return valve
732-6 Non-return valve
734-1 Lock-up valve unit (non-return valve)
734-2 Lock-up valve unit (non-return valve)
753-1, -2 Pressure relief valve 250 bar
754 Pressure holding valve is blocked = no function
755 Flow controller
756 Flow controller
801-1 Quick release coupling

(single-acting additional control unit on tractor)

801-2 Quick release couplings

(double-acting additional control unit on tractor)
912 Baling pressure gauge
Y50 Baling pressure solenoid valve
Y54 2/3 way valve, knife support out
Y55 2/3 way valve, knife support in

Z17 Pressure switch (90 bar)

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1.3 Circuit diagram – with active hydraulic system, without integrated pressure holding valve (754)

from serial no. ...

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Key to diagram:

6 Valve block
102-1 Filter (option)
102-2 Filter
232 Lubricating oil pump
318-1 Tailgate left hydraulic cylinder
318-2 Tailgate right hydraulic cylinder
331 Pick-up hydraulic cylinder
336 Knife support hydraulic cylinder
338 Rotor cut-out clutch
345 Top right tensioning arm hydraulic cylinder
346-1 Bottom left tensioning arm hydraulic cylinder
346-2 Bottom right tensioning arm hydraulic cylinder
370 Roller 3 drive clutch
410 Orifice plate diam. 1.5 mm (for oil flow limiting)
513 Hydraulic accumulator (pressurised to 2 bar)
626-C Shut-off tap
626-D Shut-off tap
626-E Shut-off tap
627 Shut-off tap
722-1 Anti-cavitation valve (open pressure 3.6 bar)
722-2 Anti-cavitation valve (open pressure 3.6 bar)
722-3 Anti-cavitation valve (open pressure 3.6 bar)
732-1 Non-return valve
732-2 Non-return valve
732-3 Non-return valve
732-4 Non-return valve
732-5 Non-return valve
732-6 Non-return valve
734-1 Lock-up valve unit (non-return valve)
734-2 Lock-up valve unit (non-return valve)
753-1, -2 Pressure relief valve 250 bar
755 Flow controller
756 Flow controller
801-1 Quick release coupling

(single-acting additional control unit on tractor)

801-2 Quick release couplings

(double-acting additional control unit on tractor)
912 Baling pressure gauge
Y50 Baling pressure solenoid valve
Y54 2/3 way valve, knife support out
Y55 2/3 way valve, knife support in

Z17 Pressure switch (90 bar)

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Chapter 2 Function

2.1

Function – without active hydraulic system .....................................16

Function – with active hydraulic system,

2.2

Function – with active hydraulic system,

2.3

with integrated pressure holding valve (754) up to serial no. ... ......20

without integrated pressure holding valve (754) from serial no.......24

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2.1 Function – without active hydraulic system

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Description of function:

Close tailgate Volume flow enters the valve block (6, port T) via port (801-2 B) and flows

to the lock-up valve unit non-return valve (734-1). The lock-up valve unit
is opened.
Pressurized oil flows into the rod spaces of hydraulic cylinders (318-1 and
318-2) via the opened lock-up valve unit non-return valve (734-1) and
port D.
The volume flow displaced from the ram spaces of hydraulic cylinders
(318-1 and 318-2) flows into the tank via the shut-off taps (626 C and D),
the flow controllers (756 and 755), the shut-off tap (627) and filter (102-1).
The flow controller controls the returning volume flow to 18 l/min., making
the tailgate closing velocity lower than the opening velocity.

Baling Baled material pulls the hydraulic cylinders (346-1, 346-2 and 345) to the

outside by means of the tensioning arms. This builds up baling pressure
in the rod spaces of these cylinders.
The pressure can be read on pressure gauge (912 baling pressure).
The baling pressure enters valve block (6) via input (X).
The baling pressure is applied at the baling pressure build-up solenoid
valve (Y50).
When the set baling pressure has been reached, the baling pressure
build-up solenoid valve (Y50) opens, making volume flow flow via port (E)
into the ram sides of hydraulic cylinders (346-1, 346-2 and 345).
The hydraulic accumulator (513) compensates the volumetric difference.

Open tailgate Volume flow flows into valve block 6 (port P) via port (801-2 A), filter

(102-1) and the rotor clutch / 2

nd

belt drive shut-off tap (627).
The volume flow flows via the open shut-off taps (626C and 626D) into
the ram spaces of hydraulic cylinders (318-1 and 318-2), via ports (A and
B). During this process, the flow rate is regulated to 50 l/min. by the flow
controllers (756 and 755).
At the same time, the lubricating oil pump (232) is supplied.
Pressurized oil is tapped directly downstream of inlet (P) of valve block (6)
which opens the lock-up valve unit non-return valve (734-1).
The volume flow displaced from the rod spaces of hydraulic cylinders
(318-1 and 318-2) flows through the open lock-up valve unit non-return
valve (734-1) and port (T) to the quick release coupling (801-2 B).
Downstream of the rotor clutch / 2nd belt drive shut-off tap (627),
pressurized oil flows to the rotor cut-out clutch (338) and to the drive
clutch (370) for roller 3.
The clutches open so that the rotor and the drive of roller 3 are switched
off while the tailgate is opened.

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r

Relieving the belts during
maintenance work in the
baling chamber

Tensioning the belts The baling chamber service shut-off valve still is in the "Tailgate blocked"

Swinging in the knife

When actuating the "Swing in knife support" button, the 2/3 way

support

- Switch on control box (baler CCT) so the baling pressure build-up

solenoid valve (Y50) is energized.

- Disengage the p.t.o. shaft.

- Open the tailgate as far as necessary and secure it.

- Actuate the baling chamber service shut-off valve (626):

The shut-off taps (626 C) and (626 D) of the tailgate are now shut off and
the shut-off tap (626 E) is open.
Oil flows into valve block 6 (port P) via port (801-2 A), filter (102-1) and
the rotor clutch / 2

nd

belt drive shut-off tap (627).
Volume flow continues to flow via filter (102-2), non-return valve (731-4)
and port (E) into the ram spaces of hydraulic cylinders (346-1, 346-2 and

345) through the open shut-off tap (626 E).
The cylinders extend and the belts are relieved.
The volume flow displaced from the rod spaces of hydraulic cylinders
(346-1, 346-2 and 345) flows to the baling pressure build-up solenoid
valve (Y50) via port (X). This valve is electronically regulated to 0 bar
when the tailgate is open and oil may therefore flow freely through it.
The rod spaces and the ram spaces of the belt tensioner cylinders (346-1,
346-2 and 345) are now connected with each other.
There is the same pressure in both cylinder spaces, but since the greater
force is generated on the ram surface (greater by the force of the rod
surface), the cylinders extend and relieve the belts.

position; now the double-acting control unit provided on the tractor is set
to the "Lower" position
The hydraulic cylinders (346-1, 346-2 and 345) are retracted by springs
on the left baler side.
The volume flow displaced from the ram spaces flows via port (E) and
uses two different paths, depending on the pressure:

- when the pressure is above 10 bar, it flows into the tank via the

pressure relief valve (754), the flow controllers (756 and 755), port
(P) and port (801-2 A).

- when the pressure is below 10 bar, the non-return valves (722-1,

722-2 and 722-3) open and provide volumetric compensation so that
the tensioning arms can return to their initial position faster.

When maintenance work is finished, the tailgate is closed; during this, the
belts must be driven so that they will not be squeezed.

directional control valve (Y55) "ROTOCUT knives IN" is energized.
Volume flow flows into the ROTOCUT knives hydraulic cylinders (336) via
port (801-1) and the energized 2/3 way valve.
The ROTOCUT knives hydraulic cylinders (336) extend and swing in the
knife support.
The extended ROTOCUT knives hydraulic cylinders (336) are kept in thei
position by the non-return valve inside the 2/3 directional control valve
(Y54).

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