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SANY Crawler Hydraulic Excavator SY215CLC (CUMMINS QSB6.7 engine). Shop Manual - page 11

Structure and Function

SY215C

4-76

XBs

XAtL

201
336

332
335

321

320

332

261

305

161

163
163

254

251

165

264

204

Dr2

163

XAs

XBtl

204

ZX225-1102039

264

BtL

561

551

521

511

AtL

314

261

332

320

321

335

332

336

201

SWING

TRAVEL LEFT

View D-D

Section D-D (Swing, travel left)

Structure and Function

SY215C

4-77

XAb2

XBb1

202

336
332

339
327

326

332

261

161

511

521

551

561
165
307

163

551
561

311

Xb2

CCb

Dr1

161

261

332

320

329
339

332
336
202

Psp

163

XAb1

BbR

158

204

602

264

303

561

551

LCb

521

511

513

561

552

523

PbL

CRb

158

201
336
332

335
321
320
602
332
261

BOOM2

BOOM1

View E-E

SWING
PRIORITY

View L-L

ZX225-1102040

Section E-E, L-L (Boom 1, boom 2)

Structure and Function

SY215C

4-78

(XBo)

259

164

201

336

332
335
321

320

332

261

604

163

209

971×4

165
309
163
163

511

521

551

561

163
165

209

163

264

604
204

164

154

(Bo)

LCo

(Ao)

BoR

(XAo)

PCk

XBk

BkR

258

ZX225-1102041

561

211

206

264

602

561

551

521

511

AkR

304

261

332

602

320

321

335

332

336

201

OPTION

BUCKET

View F-F

Section F-F (Option, bucket)

Structure and Function

SY215C

4-79

XBa1

XBa2

Dr3

201
336

332
335
321

320
257

332

261

163
165
162
152

152

165
162

302

511

521

551

561

163

165

163

264

602

205

BaR

XAa1

XAa2

204

ZX225-1102042

264

511

521

561

551

256

LCAT2

251

552

561

523

513

158

CRa

306

261

332

320

321

335

332

336

201

View G-G

Section G-G (Arm 1, arm 2)

Structure and Function

SY215C

4-80

612 169 162 152 158 154 164 152

152

162 162

164 154 158152 162 164 154 169 612

162 152

PCV2

XBp2

203 333 331 372 373 337 331 262

310

165

310

163 262 331 337 373 372 331333 203

ZX225-1102043

(XBp1)

PCV1

View H-H

Section H-H (Bypass cut 1, bypass cut 2)

Structure and Function

SY215C

4-81

Mounting

torque (N·m)

NO.

Part name

Q’ty

Mounting

torque (N·m)

NO.

Part name

Q’ty

101

BLOCK, valve A

308

SPOOL ASS’Y, travel

straight

102

BLOCK, valve B

309

SPOOL, option

13~17

151

PLUG

310

SPOOL, bypass cut

34~39

152

PLUG

311

SPOOL, swing priority

220~250

153

PLUG

320

SPRING

69~78

154

PLUG

321

SPRING

7.4~9.8

156

PLUG, ori

322

SPRING

7.5~10

158

PLUG

323

SPRING

10~14

159

PLUG

326

SPRING

161

O-RING

327

SPRING

162

O-RING

329

SPRING

163

O-RING

331

SPRING SEAT

164

O-RING

332

SPRING SEAT

165

O-RING

16~18

333

FLANGE SOCKET

166

O-RING

335

STOPPER

168

O-RING

16~18

336

FLANGE SOCKET

169

O-RING

337

STOPPER

201

COVER, spring

339

STOPPER

202

COVER, spring

372

SPRING

203

COVER, spring

373

SPRING

204

COVER, spool

511

VALVE, cone

205

COVER, spool

512

VALVE, cone

206

COVER, spool

513

VALVE, cone

209

FLANGE

514

VALVE, cone

210

PLATE

521

SPRING

211

PISTON

522

SPRING

49~65

251

VALVE, logic control

523

SPRING

9.8~14

252

OPTION ASS’Y, lock

valve

541

BALL

254 VALVE GP, swing logic

542

SPRING SEAT

256 VALVE GP, arm 2 logic

543

SPRING

69~78

257

CHECK VALVE ASS’Y,

arm regeneration

25~29

550

PLUG

258

PLUG

230~260

551

PLUG

259

PLUG

230~260

552

PLUG

261

O-RING

130~150

553

PLUG

Structure and Function

SY215C

4-82

Mounting

torque (N·m)

NO.

Part name

Q’ty

Mounting

torque (N·m)

NO.

Part name

Q’ty

262

O-RING

561

O-RING

264

O-RING

562

O-RING

25~34

273

SCREW, hex, S,H,C

69~78

601

VALVE, main relief

98~120

274

SCREW, hex, S,H,C

69~78

602

VALVE, port relief

301

SPOOL, travel

120~140

604

VALVE, port relief

302

SPOOL ASS’Y, arm 1

69~78

612

PLUG

303 SPOOL ASS’Y, boom 1

49~65

971

SCREW, hex, S,H,C

304

SPOOL, bucket

140~180

975

SCREW, hex, S,H,C

305

SPOOL, swing

977

PLATE name

306

SPOOL, arm 2

978

307

SPOOL, boom 2

Structure and Function

SY215C

4-83

4.6

Hydraulic System, Part 3

4.6.1

Swing motor

ZX215-1002081

A: Main oil port
B: Main oil port
M: Oil complement port
PA: Pressure detection port
PB: Pressure detection port
DB: Lubricating port
PG: Brake release port
SH: Brake direction port
L: Oil level stick
IP: Gear oil feed port

Type

M5×180CHB-12A-51A/260

Theoretical displacement 169.4 cm³/rev

Safety valve set pressure 25.5 MPa {255 Kg/cm³}

Rated engine speed

2000 rpm

Brake release pressure

2.7 MPa {27 Kg/cm³}

Specifi cations

1. Safety valve
2. Reverse prevention valve

Structure and Function

SY215C

4-84

ZX215-1002082

A-A

1- Spacer
2- Casing
3- Disc
4- Brake spring
5- Shell

6- Check valve spring
7- Check valve
8- Oil distribution plate
9- Cylinder
10- Brake piston

11- Plate
12- Piston
13- Drive shaft

Structure and Function

SY215C

4-85

4.6.2

Swing holding brake

●

Port PG is connected with the pilot gear pump directly, and a pressure of 3.9MPa is main-
tained.

ZX215-1002083

Pump

Main valve

●

Port SH is connected with port PX of the main valve. Once any movement other than travel
is applied on the main valve, pressure will be generated at port PX, and port PG is intercon-
nected with chamber a beneath piston 7. The pressurized oil compresses brake spring (1)
and pushes the brake piston up. Disc (5) is separated from plate (6), releasing the brake.

ZX215-1002084

Pump

Main valve

●

Otherwise, no pressure is generated at port PX, and port PG is shut off from chamber a be-
neath piston (7). Brake piston (7) is pushed down by brake spring (1). Disc (5) and plate (6)
are pushed together, and the brake is applied.

Structure and Function

SY215C

4-86

4.6.3 Relief valve portion

Structure

●

The relief valve portion consists of relief
valves (1) and (2), check valves (3) and (4).

Function

●

When the machine is in the swing holding
mode, control valve (5) closes the motor
outlet circuit, but the motor rotation contin-
ues due to inertial force. The motor output,
therefore, is abnormally increased, result-
ing in motor damage.

●

In order to avoid the motor damage, the
relief valve relieves the abnormally high
pressure to port (M) from the motor outlet
side (high-pressure side) of the motor.

Structure and Function

SY215C

4-87

Operation

1. When swing begins (suppose pressur-

ized oil enters Port A)

●

When the swing control lever is operated
for right swing, pressurized oil from the
pump is supplied to port (A) via control
valve (5).

●

The pressure on port (A) rises, the starting
torque is generated in the motor, and the
motor is activated.

●

The pressurized oil from the outlet port of
the motor passes from port (B) through the
control valve (5) and returns to the tank.

2. When swing stops

●

When the swing control lever is neutral-
ized, the supply of pressurized oil from the
pump to port (A) is cut off.

●

The pressurized oil from the motor outlet
can't return to the tank since the return cir-
cuit to the tank is closed from control valve
(5). Thus, pressure at port (B) rises.

●

Swing resistance is generated on the mo-
tor and hence the brake starts working.

●

Pressurized oil will be relieved when the
pressure on port (B) rises to the set pres-
sure of relief valve (2).

●

A high braking torque is applied on the mo-
tor, thereby stopping the motor.

●

When relief valve (2) is being actuated, the
relieved pressurized oil and the pressur-
ized oil from port (M) are fed to port (B) via
check valve (4).

●

Above prevents cavitation on port (B).

ZX215-1002085

From port M

ZX215-1002086

From port M

Structure and Function

SY215C

4-88

1- Valve body
2- Spool (A side)
3- Spring (A side)
4- Plug

5- Spool (B side)
6- Spring (B side)
7- Plug

4.6.4

Reverse prevention valve

4.6.4.1 Operation drawing

ZX215-1002087

Swing controller

Swing
motor

Structure and Function

SY215C

4-89

4.6.4.2 Explanatory drawing of effects

Outline

●

Inertia of the swing body, the backlash and
rigidity of the machinery system, and the
compression of the hydraulic oil all may
cause the machine to shake during swing
operation. The reverse prevention valve is
designed to reduce this effect. The valve
contributes in preventing collapsing of load
when the swing is stopped and also con-
tributes in reducing cycle time (enhances
the positioning performance, enabling you
to proceed to the next work quicker than
ever).

ZX215-1002088

With reversal prevention valve

:Without reversal prevention valve

Reversal pressure

Containment pressure

Time

Start

Brake

Motor speed

Pressure MB

Pressure MA

Reversal pressure

Reversal

1st reversal

2nd reversal

ZX215-1002089

d Notch

b f

D4 a D3

Structure and Function

SY215C

4-90

Operation

3. When port (B) brake pressure is gener-

ated

●

Pressure (MB) is conducted to chamber (d)
via the notch. The pressure compresses
spring (6) by use of the difference in areas
of circles (D1 > D2) of spool (5) and moves
spring (6) to the left side. Port (B) and
chamber (e) will be interconnected. Since
pressure (A) is lower than the set pressure
of spring (3), spool (2) does not move and
the pressurized oil is stopped by spool (2).
Thus the braking force is ensured.

4. When motor is stopped

●

The motor rotation is reversed by the clos-
ing pressure generated at port (B). (1st
time: reverse rotation) Reversing pressure
is generated on port (A). Pressure (A) is
conducted to chamber (a), and spool (2)
moves spring (3) to the right side, and A
and B is interconnected. At this time, b
is interconnected with f via the orifice on
spool (5), and reversing pressure on port A
is bypassed to port T, preventing the sec-
ond reverse rotation.

ZX215-1002090

b f

D4 a D3

Notch

ZX215-1002091

Structure and Function

SY215C

4-91

4.6.5 Center swivel joint

ZX215-1002092

H-H

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