Kubota U25-3 Repair Manual

U20-3, U25-3 WSM Hydraulic system (Service section)
IV-S-19
[2] Piston pump P-Q performance curve (Theoretical)
U-20-3
U25-3
0 10.2 21.3 24.4 35.5 44.7 MPa
0
6.8
11.4
15.4
22.0
23.0
l/min
Q=P 1 =P 2 (l/min)
10.45cc/rev P3=210kgf/cm
2
P3=5kgf/cm
2
10cc/rev
P
1+P2=240kgf/cm
2
7cc/rev
P
1+P2=350kgf/cm
2
5.2cc/rev
P
1+P2=440kgf/cm
2
3.1cc/rev
P
1+P2=440kgf/cm
2
7cc/rev
P
1+P2=210kgf/cm
2
10.3cc/rev
P
1 +P 2 =100kgf/cm
2
Measuring conditions
Oil used
Oil temperature
Turning speed
Turning direction
8 3
8 4
P 4
ISO VG46 or equivalent
50 5 C
2,200 rpm
Clockwise
5.8 cc/rev
2.7 cc/rev
4.1 MPa
Measuring conditions
Oil used
Oil temperature
Turning speed
Turning direction
83
84
P4
ISO VG46 or equivalent
50 5 C
2,400 rpm
Clockwise
8 cc/rev
2.7 cc/rev
4.1 MPa
Q=P 1 =P 2 (l/min)
0
0 100 200 300 400 480
2
4
6
8
10
12
14
16
18
20
22
0
2
4
6
8
10
12
14
16
18
20
22
Discharge Capacity: q
1
=q
2
(cc/rev)
Pressure P1+P2 (kgf/cm
2
)
12 cc/rev
P
3=175kgf/cm
2
P3=5kgf/cm
2
11.9 cc/rev
P
1+P2=60kgf/cm
2
11.6cc/rev
P
1+P2=195kgf/cm
2
7.8 cc/rev
P
1+P2=305kgf/cm
2
5 cc/rev
P1+P2=440kgf/cm
2
3.1 cc/rev
P
1+P2=440kgf/cm
2
7.8 cc/rev
P
1+P2=155kgf/cm
2

Kubota U25-3 Specifications

General

Brand	Kubota
Model	U25-3
Category	Excavators
Language	English