CG958G Wheel Loader. Manual - part 17

- 72 - 

(1). Good pressure compensation for changes in steering loads; 

(2). Steering loop is independent from other working loops, and is guaranteed with major flow rate. Flow 

rate going through steering gear is quite small when steering gear is in neutral position, saving energy for the 

system; 

(3). Priority is given to pressure and flow rate in steering loop to ensure a reliable steering; 

(4). Pressure characteristics in neutral position are not affected by displacement. 

System cleanliness is controlled within Grade NAS1683 9. 

 

II. Pump: Denison T6DCM-B24-B05-3R23-C1, position is shown in the figure below: 

 

Denison vane pump meets SAE and IOS standards. Hydrocushion design ensures long service lives of shaft 

and bearing with extremely small noise and high volumetric efficiency. 

                               

 

- 73 - 

 

          1. Hydrocushion: as shown in Figure 1, the inlet and outlet pressure chambers of the pump are opposite 

in radial direction. As a result, the rotor is hydrolastic to free the bearing from hydraulic load, 

guaranteeing a long service life. 

              Figure 2 illustrates an inserter in vane groove. Outlet pressure is continuously applied to the space 

between vanes and the inserter only. Vane top and bottom areas bear inlet or outlet pressure, 

depending on vane positions during the rotation of rotor. See Figure 1, full hydrocushion is realized 

in inlet pressure zone. The outward thrust given the vanes in the inlet area equals to the product of 

outlet pressure and projected area at the tip of inserter. 

 

2. Type of connection: 

Input shaft extension: SAE C DP12/24 T=14, pressure angle: 30º, side fitting, shaft 

extension length: 55.2; 

Flanged connection: rabbet installed: Φ127-0.05, rabbet depth 12.7; Flange installed: 

2-Φ17.5; center distance: 181; pump displacement at shaft end: 79.5cm

3

/r; pump 

displacement at cover end: 17.2cm

3

/r; 

Oil inlet: bore diameter Φ76; threaded hole 4-5/8-11 UNC, depth 28.5, center distance: 

106.4x62 

Pump outlet at shaft end: pressure oil outlet Φ31.8; threaded hole 4-7/16-14UNC, depth 

22.3, center distance: 58.7x30; pump outlet at shaft end is clockwise rotated 90

º

 from oil 

inlet when viewed from cover end of the pump. 

Pump outlet at cover end: pressure oil outlet Φ25;    threaded hole 4-3/8-16UNC (with 

25mm screw), depth 19, center distance 52.4x26.2;  pump outlet at cover end is 

clockwise rotated 135

º

 from oil inlet when viewed from cover end of the pump. 

 

3. Cautions on use of vane pump 

(1). Starting vane pump: all controls should be in neutral position for an unloaded 

starting. Start engine and idle it. 

Winter is the season in which most of vane pump problems occur due to the drop in 

temperature. 

Hydraulic oil should be thoroughly filtered at least once every 2-3 months and replaced 

- 74 - 

if necessary to ensure cleanliness (hydraulic oil is deteriorated in long-time circulation, 

and this is detectable by observing oil color) for a longer service life of hydraulic 

components and a higher performance of engine. 

It is recommended to idle run the engine for at lease 10 minutes to warm up oil before a 

loaded operation, provided oil intake is in good condition after starting. This helps 

prevents poor oil intake caused by high viscosity from damaging pump plunger. 

                           

IMPORTANT 

 
Dismounting and servicing of vane pump by untrained maintenance staff is strictly prohibited. 
 

CAUTION 

 
When replacing rubber tube assembly in vane pump, loader engine should be shut off first to 
release pressure and cool down hydraulic oil (to a safe degree) before the replacement is made. 

 

III. Steering gear: Eaton BZZ1-1000 dynamic (with long rabbet cross piece) 

1. Operating principle: the functionality is realized by a load-sensing system. The flow rate going through 

steering gear is quite low when steering gear is in neutral position to keep constant pressure and save energy 

for the system. During power steering, pressure oil enters stator through valve plug and valve bush, and 

pushes the rotor to rotate with steering wheel to transfer the oil pressure to the left or right chamber of 

steering cylinder, thus realizing steering by pushing guide wheel with cylinder piston rod. Oil in the other 

cylinder chamber returns to oil tank through steering gear. 

2. Technical parameters: 

Maximum inlet pressure: 16Mpa; maximum working backpressure: 2.1 Mpa; type of 

connection: long rabbet connection; pressure loss P-T: <=0.5 Mpa; P-R or P-L: <2.1Mpa; 

factory number: 550-7286 (dynamic). 

Valve block: FK-0/20; valves included: inlet check valve, two-way oil filling valve; set 

pressure of two-way cushion valve: 20Mpa. 

3

3

.

.

 

 

I

I

n

n

s

s

t

t

a

a

l

l

l

l

a

a

t

t

i

i

o

o

n

n

 

 

(

(

1

1

)

)

.

.

 

 

M

M

a

a

k

k

e

e

 

 

s

s

u

u

r

r

e

e

 

 

t

t

h

h

a

a

t

t

 

 

s

s

t

t

e

e

e

e

r

r

i

i

n

n

g

g

 

 

g

g

e

e

a

a

r

r

 

 

i

i

n

n

s

s

t

t

a

a

l

l

l

l

e

e

d

d

 

 

i

i

s

s

 

 

c

c

o

o

a

a

x

x

i

i

a

a

l

l

 

 

t

t

o

o

 

 

s

s

t

t

e

e

e

e

r

r

i

i

n

n

g

g

 

 

p

p

o

o

s

s

t

t

 

 

w

w

i

i

t

t

h

h

 

 

c

c

l

l

e

e

a

a

r

r

a

a

n

n

c

c

e

e

 

 

k

k

e

e

p

p

t

t

 

 

i

i

n

n

 

 

a

a

x

x

i

i

a

a

l

l

 

 

d

d

i

i

r

r

e

e

c

c

t

t

i

i

o

o

n

n

 

 

t

t

o

o

 

 

a

a

v

v

o

o

i

i

d

d

 

 

d

d

i

i

e

e

b

b

a

a

c

c

k

k

 

 

o

o

f

f

 

 

v

v

a

a

l

l

v

v

e

e

 

 

p

p

l

l

u

u

g

g

.

.

 

 

C

C

h

h

e

e

c

c

k

k

 

 

s

s

t

t

e

e

e

e

r

r

i

i

n

n

g

g

 

 

w

w

h

h

e

e

e

e

l

l

 

 

t

t

o

o

 

 

s

s

e

e

e

e

 

 

i

i

f

f

 

 

o

o

p

p

p

p

o

o

s

s

i

i

t

t

e

e

 

 

r

r

o

o

t

t

a

a

t

t

i

i

o

o

n

n

 

 

i

i

s

s

 

 

s

s

m

m

o

o

o

o

t

t

h

h

 

 

a

a

f

f

t

t

e

e

r

r

 

 

i

i

n

n

s

s

t

t

a

a

l

l

l

l

a

a

t

t

i

i

o

o

n

n

.

.

 

 

- 75 - 

(

(

2

2

)

)

.

.

 

 

P

P

i

i

p

p

e

e

l

l

i

i

n

n

e

e

s

s

 

 

s

s

h

h

o

o

u

u

l

l

d

d

 

 

b

b

e

e

 

 

i

i

n

n

s

s

t

t

a

a

l

l

l

l

e

e

d

d

 

 

a

a

s

s

 

 

p

p

e

e

r

r

 

 

t

t

h

h

e

e

 

 

f

f

o

o

u

u

r

r

 

 

o

o

i

i

l

l

 

 

p

p

o

o

r

r

t

t

s

s

 

 

m

m

a

a

r

r

k

k

e

e

d

d

 

 

o

o

n

n

 

 

s

s

t

t

e

e

e

e

r

r

i

i

n

n

g

g

 

 

g

g

e

e

a

a

r

r

:

:

 

 

“

“

P

P

”

”

 

 

–

–

 

 

t

t

o

o

 

 

b

b

e

e

 

 

c

c

o

o

n

n

n

n

e

e

c

c

t

t

e

e

d

d

 

 

w

w

i

i

t

t

h

h

 

 

o

o

i

i

l

l

 

 

p

p

u

u

m

m

p

p

;

;

 

 

“

“

T

T

”

”

 

 

–

–

 

 

t

t

o

o

 

 

b

b

e

e

 

 

c

c

o

o

n

n

n

n

e

e

c

c

t

t

e

e

d

d

 

 

w

w

i

i

t

t

h

h

 

 

o

o

i

i

l

l

 

 

t

t

a

a

n

n

k

k

;

;

 

 

“

“

A

A

”

”

 

 

a

a

n

n

d

d

 

 

“

“

B

B

”

”

 

 

a

a

r

r

e

e

 

 

t

t

o

o

 

 

b

b

e

e

 

 

c

c

o

o

n

n

n

n

e

e

c

c

t

t

e

e

d

d

 

 

w

w

i

i

t

t

h

h

 

 

l

l

e

e

f

f

t

t

 

 

a

a

n

n

d

d

 

 

r

r

i

i

g

g

h

h

t

t

 

 

c

c

h

h

a

a

m

m

b

b

e

e

r

r

 

 

o

o

f

f

 

 

s

s

t

t

e

e

e

e

r

r

i

i

n

n

g

g

 

 

c

c

y

y

l

l

i

i

n

n

d

d

e

e

r

r

 

 

r

r

e

e

s

s

p

p

e

e

c

c

t

t

i

i

v

v

e

e

l

l

y

y

.

.

 

 

S

S

e

e

c

c

t

t

i

i

o

o

n

n

 

 

v

v

i

i

e

e

w

w

 

 

o

o

f

f

 

 

r

r

o

o

t

t

o

o

r

r

 

 

a

a

n

n

d

d

 

 

s

s

t

t

a

a

t

t

o

o

r

r

 

 

 

 

 

 

 

 

S

S

e

e

c

c

t

t

i

i

o

o

n

n

 

 

v

v

i

i

e

e

w

w

 

 

o

o

f

f

 

 

v

v

a

a

l

l

v

v

e

e

 

 

p

p

l

l

u

u

g

g

 

 

a

a

n

n

d

d

 

 

v

v

a

a

l

l

v

v

e

e

 

 

b

b

u

u

s

s

h

h

 

 

 
 
 
 
 
 
 
 
 
 
 
 
 
4.Structure diagram of steering gear: 
 
 

 

 
 
                                                                Figure 1