2-6

Swing device consists swing motor, swing reduction gear. Swing motor include mechanical parking valve, relief valve, make up valve and time delay valve.

45070SM01

Port

Port name

A, B

Main port

PF 3/4

Dr

Drain port

PF 3/8

Mu

Make up port

GA,GB Gauge port Au

2-46

PF 1 PF 1/4

Air vent port

PF 1/4

SGo

Reduction gear oil fill port

PT 1/2

SGr

Reduction gear grease fill port

PT 1/8

AGr

Reduction gear air vent port

PT1/8

Dr(RG) Reduction gear drain port

45070SM02

Port size

PT 3/8

PG

Brake release port

PF 1/4

SH

Brake pilot port

PF 1/4

45070SM06

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Inner ring Oil seal Tap aper er ro rollller er be bea ari ring ng Level gauge assy Backing spring Cam plate Return plate Piston assy Lining plate Plate O-ring Piston O-ring Spring Parallel pi pin

16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Piston O-ring Cap Scrowave Teflon ring Bushing Balance pl plate Needle beari rin ng Snap ring Cylinder as assy Housing Collar Plug Snap ring Bypa By passs va valv lve e as assy

2-47

31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

Back up ring O-ring O-ring Cover Time del ela ay val alvve Hexa He xago gon n so soccket bo bolt lt O-ring O-ring Relief va valve O-ring Hexa He xago gon n so soccket bo bolt lt Check Spring Cap Back up ring

45070SR01

1 2 3 4 5 6 7 8 9

Pinion shaft Collar Plate Snap ring Roller bearing Gear casing Collar Snap ring Oil seal

10 11 12 13 14 15 16 17 18

Roller bearing Parallel pin Ring gear Spur gear4 Thrust plate Sun gear Holder assy 1 Bolt Lock washer

2-48

19 20 21 22 23 24 25 26

Holder assy 2 Shaft 2 Spur gear 5 Thrust plate 2 Spring pin Holder 2 Plug Plug

1

When high pressurized oil enters a cylinder through port(a), which is the inlet of balance plate(1), hydraulic pressure acting on the piston causes axial force F. The pressure force F works via the piston(2) upon the return plate(3) which acts upon the swash plate(4) via an hydrostatic bearing. Force F1 perpendicular to swash plate(4) and force F2 perpendicular to cylinder center. Being transferred to the cylinder block(5) through piston, force F2 causes rotational moment at surroundings of cylinder. Since cylinder block has 9 equidistantly arrayed pistons, rotational torque is transmitted to cylinder shaft in order by several pistons connected to the inlet port of high pressurized oil. When the direction of oil flow is reversed, rotational direction of cylinder is also reversed. Output torque is given by the equation. T=

p×q 2Л

, q=Z·A·PCD·tanθ, F1 =

F

, F2=F tanθ, S=PCD×tanθ COSθ

Where p : Effective difference of pressure(kgf/cm2) q : Displacement(cc/rev) T : Output torque(kgf cm) Z : Piston number(9EA) A : Piston area(cm2) θ: Tilting angle of swash plate(degree) S : Piston stroke(cm) ·

      D        C P

θ

S

F2

F1 F

a High pressure oil 4

3

2

5

a High pressure oil

Low pressure oil

1

2-52 (210-7)

2-49

In the system using this type of motor, there is no counter balance functioning valve and there happens the case of revolution exceeding hydraulic supply of motor. To prevent the cavitation caused by insufficient oil flow there is a make up valve to fill up the oil insufficiency. A make up valve is provided immediately before the port leading to the hydraulic oil tank to secure feed pressure required when the hydraulic motor makes a pumping action. The boost pressure acts on the hydraulic motor's feed port via the make up valve. Pressurized oil into the port B, the motor rotate counterclockwise. If the plunger of MCV moves neutral position, the oil in the motor is drain via left relief valve, the drain oil run into motor via right make up valve, which prevent the cavitation of motor.

A

B

R130SM03

2-50

5

11

6

10

9

7 8

3

12

1 4

1

Body

2

Seat

3

Plunger

4

Spring

5

Adjusting screw

6

Piston

7

Bushing

8

Spring seat

9

Shim

10

O-ring

11

Back up ring

12

O-ring

2

R130SM05

The valve casing contains two cartridge type relief valves that stop the regular and reverse rotations of the hydraulic motor. The relief valves relieve high pressure at start or at stop of swing motion and can control the relief pressure in two steps, high and low, in order to insure smooth operation. Figure illustrates how the pressure acting P

on the relief valve is related to its rising

P=pressure, T=time

Ps

process. Here is given the function, referring to the figure following page.

4 P2 3

P1 2 1

T 2-54(2) 210-7

2-51

① Ports (P,R) at tank pressure.

A2

m

h

n

g

A1 P

R

R130SM04

② When hydraulic oil pressure(P×A1) reaches the preset force(FSP) of spring(4), the plunger(3)

moves to the right as shown. P1×A1=Fsp+Pg×A2 P1=

Fsp+Pg×A2 A1

4

g

P=P1

R130SM04

2-52

③ The oil flow chamber g via orifice m and n. When the pressure of chamber g reaches the preset force(FSP) of spring(4), the piston(6) moves left and stop the piston(6) hits the bottom of bushing(7). 4

m

n

g

P=P2

6 R130SM04

④ When piston(6) hits the bottom of bushing(7), it stops moving to the left any further.

As the

result, the pressure in chamber(g) equals(Ps). Ps×A1=Fsp+Ps×A2 Ps=

Fsp A1-A2

P=Ps

7

6

g R130SM04

2-53

This is the brake system to stop the swing motion of the excavator during operation. In this system, the hydraulic circuit is throttled by the swing control valve, and the resistance created by this throttling works as a brake force to slow down the swing motion. Work

A

Deceleration

B

A

B

MCV

MCV A, B opened

Stop

A

B

MCV

MCV A, B throttled

MCV

MCV A, B closed R130SM05

The mechanical swing parking brake system is installed to prevent the upper structure from swinging downhill because of its own weight when the excavator is parked on a slope since it completely eliminates the hydraulic drift of swing motion while the excavator is on a slop, work can be done more easily and safely.

①

Circumferential rotation of separate plate(9) is constrained by the groove located at housing(26). When housing is pressed down by brake spring(14) through lining plate(10), separate plate(9) and brake piston(12), friction force occurs there. Cylinder(25) is constrained by this friction force and brake acts, while brake releases when hydraulic force exceeds spring force. 45070SM05

9 10 12

2-54

Separate plate Lining plate Brake piston

14 25 26

Spring Cylinder Housing

②

a. When the swing control lever is operated, the swing lock solenoid valve is excited, so the pilot pump discharged oil(P3) goes to the chamber G. This pressure is applied to move the piston(6) to the upward against the force of the spring(9). Thus, it releases the brake force.

45070SM03

1 2 3 4 5 6

Pilot pump Swing lock solenoid valve Spring Brake piston Separate plate Lining plate

2-55

b. When the swing control lever gets back to neutral position, the swing lock solenoid valve is deactivated, so the pilot pump discharged oil(P 3) is not applied to the chamber G. Thus, the brake is actuated by spring force.

45070SM04

1 2 3 4 5

Swing lock solenoid valve Spring Brake piston Separate plate Lining plate

2-56

Swing device consists swing motor, swing reduction gear. Swing motor include mechanical parking valve, relief valve, make up valve and time delay valve.

Reduction gear

Swing motor

A

SGr

B

Mu SGo

Dr AGr

Dr(RG)

Relief valve

SH PG

50072SM01

SH PG DB

Port

Port name

A, B

Main port

PF 3/4

Dr

Drain port

PF 1/2

Mu

Make up port

GA,GB Gauge port Au

C PB

PA

B

2-56-1

PF 1 PF 1/4

Air vent port

PF 1/4

SGo

Reduction gear oil fill port

PT 3/4

SGr

Reduction gear grease fill port

PT 1/4

AGr

Reduction gear air vent port

PT 1/4

Dr(RG) Reduction gear drain port A

Port size

PT 1/2

PG

Brake release port

PF 1/4

SH

Brake pilot port

PF 1/4

117 121 118 114 706 707 702 712 472 106

A

303

471 443

502

438 444

432 106

469 488 355 351 052 501 503

994

468 487

A

304 746 101 491 745 437 433 451

124 301 122 123 113 116 111 744

742 031 743 131 464 485

401

051

993

SECTION A - A 50072SM02

031 051 052 101 106 111 113 114 116 117 118 121 122 123 124 131 301

Brake valve Relief valve Reactionless valve assy Drive shaft Spacer Cylinder block Spherical busing Cylinder spring Push rod Spacer(F) Spacer(R) Piston Shoe plate Retainer Shoe Valve plate Casing(F)

303 304 351 355 401 432 433 437 438 443 444 451 464 468 469 471 472

Valve casing(K) Front cover Plunger(K) Spring Socket bolt Snap ring Snap ring Snap ring Snap ring Roller bearing Roller bearing Spring pin VP Plug VP Plug RO Plug O-ring O-ring

2-56-2

485 487 488 491 501 502 503 702 706 707 712 742 744 745 746 993 994

O-ring O-ring O-ring Oil seal Adapter Socket bolt O-ring Brake piston O-ring O-ring Brake spring Friction plate Dust plug Dust plug Dust plug PT Plug PT Plug

25 37 36 13

3

35 34

5

2

30

29

6

7 10

9

11 18 19

26 31 28

27 38

33

32

1

8 14 12 23 15 16 21 17 20 24 22 39

50072SM03

1 2 3 5 6 7 8 9 10 11 12 13 14

Casing Drive shaft Spacer Roller bearing Oil seal Roller bearing Thrust plate Carrier 2 Stop ring Ring gear Knock pin Pinion gear Thrust washer

15 16 17 18 19 20 21 22 23 24 25 26 27

Planet gear 2 Pin 2 Spring pin Sun gear 2 Carrier 1 Side plate 1 Pin 1 Needle cage Bushing 2 Planet gear 1 Lock washer Side plate 3 Sun gear 1

2-56-3

28 29 30 31 32 33 34 35 36 37 38 39

Stop ring Plug Plug Socket bolt Gage pipe Gage bar Cover plate Hex bolt Lock plate Hex bolt Stop ring Side plate 2

1

When high pressurized oil enters a cylinder through port(a), which is the inlet of balance plate(1), hydraulic pressure acting on the piston causes axial force F. The pressure force F works via the piston(2) upon the return plate(3) which acts upon the swash plate(4) via an hydrostatic bearing. Force F1 perpendicular to swash plate(4) and force F2 perpendicular to cylinder center. Being transferred to the cylinder block(5) through piston, force F2 causes rotational moment at surroundings of cylinder. Since cylinder block has 9 equidistantly arrayed pistons, rotational torque is transmitted to cylinder shaft in order by several pistons connected to the inlet port of high pressurized oil. When the direction of oil flow is reversed, rotational direction of cylinder is also reversed. Output torque is given by the equation. T=

p×q 2Л

, q=Z·A·PCD·tanθ, F1 =

F

, F2=F tanθ, S=PCD×tanθ COSθ

Where p : Effective difference of pressure(kgf/cm2) q : Displacement(cc/rev) T : Output torque(kgf cm) Z : Piston number(9EA) A : Piston area(cm2) θ: Tilting angle of swash plate(degree) S : Piston stroke(cm) ·

      D        C P

θ

S

F2

F1 F

a High pressure oil 4

3

2

5

a High pressure oil

Low pressure oil

1

2-52 (210-7)

2-56-4

In the system using this type of motor, there is no counter balance functioning valve and there happens the case of revolution exceeding hydraulic supply of motor. To prevent the cavitation caused by insufficient oil flow there is a make up valve to fill up the oil insufficiency. A make up valve is provided immediately before the port leading to the hydraulic oil tank to secure feed pressure required when the hydraulic motor makes a pumping action. The boost pressure acts on the hydraulic motor's feed port via the make up valve. Pressurized oil into the port B, the motor rotate counterclockwise. If the plunger of MCV moves neutral position, the oil in the motor is drain via left relief valve, the drain oil run into motor via right make up valve, which prevent the cavitation of motor.

A

B

R130SM03

2-56-5

5

11

6

10

9

7 8

3

12

1 4

1

Body

2

Seat

3

Plunger

4

Spring

5

Adjusting screw

6

Piston

7

Bushing

8

Spring seat

9

Shim

10

O-ring

11

Back up ring

12

O-ring

2

R130SM05

The valve casing contains two cartridge type relief valves that stop the regular and reverse rotations of the hydraulic motor. The relief valves relieve high pressure at start or at stop of swing motion and can control the relief pressure in two steps, high and low, in order to insure smooth operation. Figure illustrates how the pressure acting P

on the relief valve is related to its rising

P=pressure, T=time

Ps

process. Here is given the function, referring to the figure following page.

4 P2 3

P1 2 1

T 2-54(2) 210-7

2-56-6

① Ports (P,R) at tank pressure.

A2

m

h

n

g

A1 P

R

R130SM04

② When hydraulic oil pressure(P×A1) reaches the preset force(FSP) of spring(4), the plunger(3)

moves to the right as shown. P1×A1=Fsp+Pg×A2 P1=

Fsp+Pg×A2 A1

4

g

P=P1

R130SM04

2-56-7

③ The oil flow chamber g via orifice m and n. When the pressure of chamber g reaches the preset force(FSP) of spring(4), the piston(6) moves left and stop the piston(6) hits the bottom of bushing(7). 4

m

n

g

P=P2

6 R130SM04

④ When piston(6) hits the bottom of bushing(7), it stops moving to the left any further.

As the

result, the pressure in chamber(g) equals(Ps). Ps×A1=Fsp+Ps×A2 Ps=

Fsp A1-A2

P=Ps

7

6

g R130SM04

2-56-8

This is the brake system to stop the swing motion of the excavator during operation. In this system, the hydraulic circuit is throttled by the swing control valve, and the resistance created by this throttling works as a brake force to slow down the swing motion. Work

A

Deceleration

B

A MCV

MCV A, B opened

Stop

B

A

B

MCV

MCV A, B throttled

MCV

MCV A, B closed R130SM05

The mechanical swing parking brake system is installed to prevent the upper structure from swinging downhill because of its own weight when the excavator is parked on a slope since it completely eliminates the hydraulic drift of swing motion while the excavator is on a slop, work can be done more easily and safely.

①

Circumferential rotation of separate plate(9) is constrained by the groove located at housing(26). When housing is pressed down by brake spring(14) through lining plate(10), separate plate(9) and brake piston(12), friction force occurs there. Cylinder(25) is constrained by this friction force and brake acts, while brake releases when hydraulic force exceeds spring force. 45070SM05

9 10 12

2-56-9

Separate plate Lining plate Brake piston

14 25 26

Spring Cylinder Housing

②

a. When the swing control lever is operated, the swing lock solenoid valve is excited, so the pilot pump discharged oil(P3) goes to the chamber G. This pressure is applied to move the piston(6) to the upward against the force of the spring(9). Thus, it releases the brake force.

45070SM03

1 2 3 4 5 6

Pilot pump Swing lock solenoid valve Spring Brake piston Separate plate Lining plate

2-56-10

b. When the swing control lever gets back to neutral position, the swing lock solenoid valve is deactivated, so the pilot pump discharged oil(P 3) is not applied to the chamber G. Thus, the brake is actuated by spring force.

45070SM04

1 2 3 4 5

Swing lock solenoid valve Spring Brake piston Separate plate Lining plate

2-56-11