Hitachi G10ST User manual

LIST No.
G 10ST: F209
Feb. 2011
PRODUCT NAME
Hitachi 100 mm Disc Grinder
Model G 10ST
G
International Sales Division
PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY ----------------------------------------------1
1. Disassembly -------------------------------------------------------------------------------------------1
2. Reassembly -------------------------------------------------------------------------------------------2
3. Lubrication Points and Types of Lubricant -----------------------------------------------------5
4. Tightening Torque ------------------------------------------------------------------------------------5
5. Wiring Diagrams --------------------------------------------------------------------------------------5
6. Insulation Tests ---------------------------------------------------------------------------------------6
7. No-Load Current Value -----------------------------------------------------------------------------6
STANDARD REPAIR TIME (UNIT) SCHEDULES -------------------------------------------------------------------- 7
CONTENTS Page

-1-
1. PRECAUTIONS ON DISASSEMBLY AND REASSEMBLY
[Bold] numbers in the descriptions below correspond to item numbers in the Parts List and
exploded assembly diagram for the Model G 10ST.
1-1. Disassembly
(1) Disassembly of the Armature
1) Remove the Brush Cap [37] and take out the Carbon Brush [38].
2) Loosen the four Tapping Screws D5 X 25 (Black) [1] that secure the Gear Cover Ass’y
[2] to remove the Armature [24] from the Housing Ass’y [32] together with the Bearing
Holder [23].
3) Loosen the Special Nut M7 [21] that secures the pinion to remove the pinion.
4) Insert the hooks of the J-204 bearing puller between Ball Bearing 628VVC2PS2-L [22]
and the Bearing Holder [23] from both sides, and then secure the hooks with wing bolts.
5) Place the J-204 bearing puller on a supporting jig, and then use a hand press to push
down on the tip of the armature shaft for removing Ball Bearing 628VVC2PS2-L [22].
Then remove the Bearing Holder [23].
(2) Disassembly of the Dust Seal
1) Insert the hooks of the J-204 bearing puller between the commutator and Dust Seal [29]
from both sides, and then secure the hooks with wing bolts.
2) Place the J-204 bearing puller on a supporting jig, and then use a hand press to push
down on the armature shaft for removing the Dust Seal [29] together with Ball Bearing
626VVC2PS2L [30]. Replace the Dust Seal [29] damaged by removing Ball Bearing
626VVC2PS2L [30] with a new one.
(3) Disassembly of Stator
1) Remove the Armature [24] and loosen the Tapping Screw (W/Flange) D4 X 25 (Black)
[48] to remove Tail Cover (B) [47].
2) Loosen the two Machine Screws (W/Washer) M3.5 X 6 [49] that secure the internal wires
of the Cord [51] and Stator [27] to the Switch (1P Solder Type) [50], and then loosen the
two screws of the Pillar Terminal [42]. Remove the two internal wires from the Cord [51]
and Pillar Terminal [42].
3) Remove the Tapping Screw (W/Flange) D4 X 45 (Black) [35] and Tapping Screw
(W/Flange) D4 X 20 (Black) [36]. Remove Tail Cover (A) [34], and then remove the
Earth Terminal [40] from the Housing Ass’y [32].
4) Disconnect the two internal wires of the Stator [27] coming from the Brush Holder [39]
from the Stator [27].
5) Remove the Fan Guide [25] from the Housing Ass’y [32].
6) Loosen the Tapping Screw D4 x 70 [26] that secures the Stator [27]. Remove the Stator
[27] from the Housing Ass’y [32].

-2-
(4) Disassembly of the gear
1) Loosen the four Seal Lock Screws (W/Sp. Washer) M4 x 12 [10] that secure the Packing
Gland [9] to the Gear Cover Ass’y [2], and then remove the Packing Gland [9] from the
Gear Cover Ass’y [2].
2) Remove the Retaining Ring For D11 Shaft [3] that secures the gear to the Spindle [12].
3) Remove the Wave Washer [4] and the gear from the Spindle [12].
1-2. Reassembly
Conduct reassembly by reversing the disassembly procedure, and note the precautions given
below.
(1) Ensure that the terminals of the stator are not bent or otherwise damaged.
(2) Generously lubricate the teeth of the gear and pinion with grease. Rub grease onto the
teeth with your fingers so that the grease reaches the bottom of each tooth. Note that
insufficient lubrication may cause the gear and pinion to wear faster than normal.
(3) Be sure to soak the inner diameter of the Felt Packing [8] with machine oil. Otherwise, its
dust-sealing function will fail to work properly, resulting in premature damage to Ball
Bearing 6201VVCMPS2L [7].
(4) When replacing the Armature [24] and Ball Bearing 626VVC2PS2L [30] on the commutator
side, press inward on the Dust Seal [29] while carefully noting its direction until the end face
of the Dust Seal [29] contacts the end surface of the Armature [24]. Also make sure that
Dust Seal [29] cannot be freely turned by hand. Keep the end face of the armature shaft
about 0.2 mm (reference) inside the end face of Ball Bearing 626VVC2PS2L [30] (see Fig. 1).
The Dust Seal [29] is an important element for improved dust protection of Ball Bearing
626VVC2PS2L [30]. Be sure to replace it with a new one each time.
Fig. 1
(5) When connecting the Earth Terminal [40] to the internal wire (the middle wire among
three) of the Noise Suppressor [45], strip off about 6 mm of the insulation sheath on the
internal wire, and then use a commercially available clamping tool to press-connect the
wire with the Earth Terminal [40].
Fig. 2
Solderless connection
About 0.2 mm (reference)
Armature shaft
Ball Bearing 626VVC2PS2L [30]
Dust Seal [29]

-3-
(6) Mount the Cord [51] according to the following procedure when replacing the standard cord
(with integrally molded cord armor).
1) Remove the standard cord (with integrally molded cord armor) according to the
procedure described in 8-1 (3).
2) Strip off about 10 mm of coating from
the tip of the internal wire of the Cord
[51], and then crimp the Terminal [44]
to the brown or black internal wire as
shown in Fig. 5.
3) Insert the Cord [51] into Tail Cover (A)
[34] as shown in Fig. 6.
4) Mount each internal wire by reversing
the removal procedure. Then mount
Tail Cover (B) [47] to Tail Cover (A)
[34] and secure both with the Tapping
Screw (W/Flange) D4 X 25 (Black)
[48].
(a) For China and Korea (b) For Taiwan
(c) For other countries
Fig. 6
Cord [51]
Terminal [44]
Fig. 5

-4-
Guide Plate
OFF side
ON side
Internal wire from Cord [51]
Machine Screw (W/Washer) M3.5 x 6 [49]
Switch (1P Solder Type) [50]
Internal wire from Stator [27]
Internal wire from Noise Suppressor [45]
Machine Screw (W/Washer) M3.5 X 6 [49]
: Tail Cover (A) [34]
(7) Correctly connect the internal wires of the Stator [27] as shown in Fig. 5and Fig. 6.
(8) Correctly connect each internal wire as shown in Fig. 4, and be careful not to route the
wires between any parts.
Fig. 5
Fig. 6
(9) When replacing the Gear Cover Ass’y [2], lubricate the needle bearing part with mixed oil.
Mixed oil: A mixture of Hitachi Power Tool Grease No. 2 (Unilube No. 00, Code No. 939302
recommended) and turbine oil
• Mixture ratio------------------------- 1:1 (weight ratio)
• Quantity ------------------------------ 0.5 cc
Colorless
Bottom of the housing
Internal wire coming from the
Noise Suppressor [45]
Brush Holder [39]
Insert the terminal securely then push
and fold the terminal toward the outside
of the housing as much as possible.
Colorless

-5-
1-3. Lubrication Points and Types of Lubricant
• Pinion chamber of Gear Cover Ass’y [2] ------ Cosmo Molybden Grease No. 2 (7 g)
Generously rub grease onto the gear and pinion.
• Needle bearing--------------------------------------- Mixed oil (0.5 cc)
Mixed oil: Mixture of Hitachi Power Tool Grease No. 2
(Unilube No. 00, Code No. 939302) and turbine oil
Mixture ratio-------------- 1:1 (weight ratio)
1-4. Tightening Torque
• Tapping Screws D4 [26] [35] [36] [48] ----- 2.0 ± 0.5 N•m (20 ± 5 kgf•cm, 1.5 ± 0.4 fb-lbs.)
• Seal Lock Screw M4 [6] [10] ------------------- 1.8 ± 0.4 N•m (18 ± 4 kgf•cm, 1.3 ± 0.3 fb-lbs.)
• Tapping Screw D5 X 25 (Black) [1] ----------- 2.9 ± 0.5 N•m (30 ± 5 kgf•cm, 2.2 ± 0.4 fb-lbs.)
•
Machine Screw (W/Sp. Washer) M5 X 16(Black) [14] - 1.6 ± 0.4 N•m (16 ± 4 kgf•cm, 1.2 ± 0.3 fb-lbs.)
• Special Nut M7 [21]------------------------------- 6.4 ± 1.0 N•m (65 ± 10 kgf•cm, 4.7 ± 0.7 fb-lbs.)
• Brush Cap [37]------------------------------------- 0.6 ± 0.2 N•m (6 ± 2 kgf•cm, 0.4 ± 0.1 fb-lbs.)
1-5. Wiring Diagram
(1) For China and Korea
(2) For Taiwan
(3) For other countries
Noise Suppressor [45]
Noise Suppressor [46]
Black
White
Cord [51]
Switch [50]
Stator [27]
Stator [27]
Colorless
Choke coil
Choke coil
Pillar Terminal [42]
Stator [27]
Stator [27]
Switch [50]
Black
White
Cord [51]
Noise Suppressor [45]
Noise Suppressor [46]
Cord [51]
Black
White
Switch [50]
Colorless
Stator [27]
Stator [27]

-6-
1-6. Insulation Tests
Upon completing disassembly and repair, carefully measure the insulation resistance and
conduct a dielectric strength test.
Insulation resistance: 7 MΩor more with 500 VDC megohm tester
Dielectric strength test: 4,000 VAC/1 minute with no abnormalities ----- 220 to 240 V products
2,500 VAC/1 minute with no abnormalities----- 110 to 127 V products
1-7. No-load Current Value
After no-load running for 30 minutes, the no-load current value should be as follows:
Voltage (V) 110 220 230 240
Current (A) max. 2.7 1.4 1.4 1.3

-7-
2. STANDARD REPAIR TIME (UNIT) SCHEDULES
MODEL Variable
Fixed 10 20 30 40 50 60 min.
G 10ST
General Assembly
Armature
Ball Bearing
628VVC2PS2-L
Bearing
Holder
Dust Seal
Ball Bearing
626VVC2PS2L
Rubber
Bushing
Gear Cover
Ass'y
Pushing
Button
Lock Pin
Housing
Ass'y
Stator
Packing
Gland
Ball Bearing
6201VVCMPS2L
Spindle
Gear and
Pinion Set
Work Flow
Switch
Ta i l C o v e r ( A )
Ta i l C o v e r ( B )
Cord
Wheel Guard
Ass'y

Model G 10ST
DISC GRINDER
LIST NO. F209
2011·2·16
(E1)
3
51
27
501
1
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
28
22
23
24
25
26 27
29
30
31
32
33
34
35
36
37
38
39
42
43
44
40
41
45
47
48
49
50
46
2
502

PART
S
G 10ST
DESCRIPTION REMARKS
1 320-523 TAPPING SCREW D5 X 25 (BLACK) 4
2 316-484 GEAR COVER ASS'Y 1 INCLUD. 5, 20
3 316-487 RETAINING RING FOR D11 SHAFT 1
4 316-486 WAVE WASHER 1
5 301-943 LOCK PIN 1
6 323-556 SLOTTED HD. SCREW (SEAL LOCK) M4 X 8 2
7 620-1VV BALL BEARING 6201VVCMPS2L 1
8 301-946 FELT PACKING 1
9 316-489 PACKING GLAND 1
10 307-127 SEAL LOCK SCREW (W/SP. WASHER) M4 X 12 4
11 302-047 WOODRUFF KEY 1
12 316-485 SPINDLE 1
13 301-945 FRINGER 1
14 308-386 MACHINE SCREW (W/SP. WASHER) M5 X 16(BLACK 2
15 301-949 SET PLATE 1
16 331-076 WHEEL GUARD ASS'Y 1 INCLUD. 14, 15
17 320-497 WHEEL WASHER 1
18 316-820 D. C. WHEELS 100MM X 4T A36Q (25 PCS.) 1
19 321-795 WHEEL NUT (C) 1
20 301-944 PUSHING BUTTON 1
21 301-941 SPECIAL NUT M7 1
22 628-VVC BALL BEARING 628VVC2PS2-L 1
23 316-480 BEARING HOLDER 1
*24 360-909C ARMATURE 110V 1
*24 360-909E ARMATURE 220V 1
*24 360-909F ARMATURE 230V-240V 1
25 319-898 FAN GUIDE 1
26 320-677 TAPPING SCREW D4 X 70 2
*27 340-796C STATOR 110V 1
*27 340-796E STATOR 220V 1
*27 340-796D STATOR 220V 1 FOR CHN, KOR
*27 340-796F STATOR 230V-240V 1
28 331-840 GEAR AND PINION SET 1
29 313-775 DUST SEAL 1
30 626-VVM BALL BEARING 626VVC2PS2L 1
31 309-929 RUBBER BUSHING 1
32 333-573 HOUSING ASS'Y 1 INCLUD. 31
33 NAME PLATE 1
34 333-574 TAIL COVER (A) 1
35 301-815 TAPPING SCREW (W/FLANGE) D4 X 45 (BLACK) 1
36 302-086 TAPPING SCREW (W/FLANGE) D4 X 20 (BLACK) 1
37 936-551 BRUSH CAP 2
38 999-021 CARBON BRUSH (1 PAIR) 2
39 313-777 BRUSH HOLDER 2
*40 314-854 EARTH TERMINAL 1 FOR NOISE SUPPRESSOR
*41 980-063 TERMINAL 1 FOR NOISE SUPPRESSOR
*42 938-307 PILLAR TERMINAL 1 FOR MAL, CHN, KOR
*43 959-140 CONNECTOR 50091 (10 PCS.) 1 EXCEPT FOR MAL, CHN, KOR, TPE
*43 959-141 CONNECTOR 50092 (10 PCS.) 1 FOR TPE
44 980-063 TERMINAL 1 FOR CORD
- 2 - 2 - 11
*ALTERNATIVE PARTS
ITEM
NO. NO. USED
CODE NO.
ITEM
NO. NO. USED
CODE NO.