Hitachi WR 25SE User manual

PRODUCT NAME
Hitachi Impact Wrench
Model WR 25SE
LIST No.
xxx. 2014
REPAIR GUIDE ----------------------------------------------------------------------------------------------------------------- 1
1. Precautions on disassembly and reassembly------------------------------------------------------------- 1
STANDARD REPAIR TIME (UNIT) SCHEDULE ----------------------------------------------------------------------10
CONTENTS
Overseas Sales Division
LIST No.
WR 25SE: E730
Jan. 2015
W

-1-
Fig. 1 • Disassembly of handle (A).(B) set and its vicinity
WARNING: Be sure to turn off the power switch and disconnect the power cord plug from the
power supply before conducting repair.
1. Precautions on disassembly and reassembly
[Bold] numbers in the description below correspond to the item numbers in the Parts List and exploded
assembly diagram for the Model WR 25SE.
1. Disassembly of handle (A).(B) set and its vicinity
(1) Removal of handle (A).(B) set
Remove the four Screws D4 x 20 [45], two Bolts M5 x 20 [44] on handle (B) and two Screws D4 x 16
[41] to remove handle (B). Remove the remaining two Bolts M5 x 20 [44] to remove handle (A).
(2) Removal of hammer case (C) ass’y
Remove the four Bolts M6 x 50 [1]. Supporting Hammer Case (C) Ass’y [6], tap the tip of Anvil (C) [12]
with a wooden hammer to remove Hammer Case (C) Ass’y [6].
(3) Removal of the other parts
Remove Packing (C) [26] from between Hammer Case (C) Ass’y [6] and Inner Cover (C) [27].
Remove Anvil (C) [12] from the bearing portion of Hammer Case (C) Ass’y [6].
SELLING POINTS
Disassembly
REPAIR GUIDE
[5]
[6]
[1]
[12]
[26]
[27]
[34]
[36]
[41]
[40]
[44]
[45]
[48]
[37]
[46]

-2-
Fig. 3
Fig. 2
2. Removal of hammer spring (C)
Using a hand press, push down the raised portions of Hammer (D) [11] to compress Hammer Spring (C)
[17] fully. In this position, use a small flat-blade screwdriver to extract the two Steel Balls D10.3 [13] from
the cam grooves of Spindle (C) [20] and Hammer (C) [14]. Then slowly release the hand press and
remove Hammer (C) [14] from Spindle (C) [20] to remove Hammer Spring (C) [17].
NOTE: Be careful not to lose the thirty-five Steel Balls D4.76 [15] and Hammer Washer (C) [16]
mounted between Hammer (C) [14] and Hammer Spring (C) [17].
[16]
[17]
[12]
[13]
[14]
[15]
[19]
[20]
[21]
[20]
[14]
[13]
Raised portion of the hammer
Top of the spindle cam
Steel ball guide groove
[18]
[22]
[23]
[25]
[27]
[24]

-3-
Fig. 4 • Disassembly of the motor unit
3. Disassembly of the motor unit
(1) Removal of rotor ass’y (C)
Remove Rotor Ass’y (C) [30] together with Inner Cover (C) [27] from Housing (C) [34].
NOTE: Keep the removed Rotor Ass’y (C) [30] away from iron or other metal because Rotor
Ass’y (C) [30] has a magnetic force.
(2) Removal of the power supply unit
Remove the two Screws D5 x 70 [32]. Supporting Housing (C) [34], tap the end surface of Housing (C)
[34] with a wooden hammer to remove the power supply unit.
[33]
[27]
[28]
[29]
[30]
[31]
[32]
[38]
[34]
[36]

-4-
Fig. 5 • Removal of the switch
4. Removal of the switch
Remove the four Screws M3.5 x 5 [39] and remove the Switch [38].
[42]
[38]
[39]
[47]
[46]
[33]
[42]
[43]
[43]
[48]

-5-
Fig. 6 • Disassembly of the power supply unit
5. Disassembly of the power supply unit
Remove the four Screws M3.5 x 5 [39] from the Switch [39].
Internal wire (black)
Internal wire (white) Internal wire (black)
[38]
Sensor PCB ass’y
[48]
[46]
Filter PCB ass’y
[47]
Noise suppressor PCB ass’y
Main PCB ass’y
Internal wire (white)
Internal wire (white)
[43]
[42]
[43]
[43]
[39]
Internal wire (red)

-6-
Fig. 7 • Reassembly of the power supply unit and its vicinity
Perform reassembly by reversing the disassembly procedure. However, special attention should be given
to the following items.
1. Reassembly of the power supply unit and its vicinity
(1) Perform wiring according to the connecting diagram on page 9 when replacing the Switch [38] or Stator
Controller (C) Set [33] with new one.
(2) Connect the internal wires of Stator Controller (C) Set [33] to the Switch [38] paying attention to the
colors of the internal wires. Then secure them with the four Screws M3.5 x 5 [39].
(3) Be careful not to get the internal wires caught in the power supply unit.
2. Reassembly of the impact mechanism
(1) Mount Hammer Washer (C) [16], Hammer Spring (C) [17], Spring Sheet (C) [18], and Spindle (C) [20]
in this order into Hammer (C) [14], which contains the thirty-five Steel Balls D4.76 [15].
(2) Match the peak of the cam groove of Spindle (C) [20] with the steel ball insertion groove of Hammer
(C) [14]. Use a hand press or similar tool to press the raised portion of Hammer (C) [14] so as to
compress Hammer Spring (C) [17] until it contacts Spindle (C) [20], and then hold it there.
(3) Put the two Steel Balls D10.3 [13] in the steel ball insertion groove. Check that the Steel Balls D10.3
[13] are in the cam groove, and then release the hand press.
(4) Mount the Idle Gear Set (2 pcs.) [21] and the two Needle Rollers [19] on Spindle (C) [20].
3. Reassembly of the main body
(1) Secure the stator to Housing (C) [34] with the two Screws D5 x 70 [32] and insert controller ass’y (A)
into the lower portion of the stator.
(2) Mount Rotor Ass’y (C) [30], Fan Guide (C) [28], and Inner Cover (C) [27] to Housing (C) [34].
NOTE: Be careful of the direction of Fan Guide (C) [28].
(3) Mount Metal (A) [25] and Packing (C) [26] to Inner Cover (C) [27].
NOTE: Be careful of the direction of Packing (C) [26].
(4) Mount Washer (A) [24] and Ring Gear (C) [23] to the impact mechanism assembled in the above step
2 and mount it to Inner Cover (C) [27].
NOTE: Mount Ring Gear (C) [23] with its protrusion toward the hammer case.
Reassembly
B
Internal wire
(
black
)
Internal wire (yellow)
Internal wire (green)
Internal wire (blue)
[38]
[39]
View from B

-7-
Fig. 8 • Reassembly of the main body
Mount Washer (B) [11] with its
chamfered side toward the anvil.
Fig. 8 • Reassembly of the main body
Be careful not to
g
et the internal wires cau
g
ht.
Put the white and black internal
wires (filter PCB) between the screw
boss and rib as shown in the figure.
Place the noise suppressor PCB in
handle
(
B
)
as shown in the fi
g
ure.
(5) Mount Washer (B) [11] to Anvil (C) [12]. Apply a small amount of grease to the two Needle Rollers [22]
and mount it to Ring Gear (C) [23].
NOTE: Be careful of the direction of Washer (B) [11].
(6) Mount Washer (C) [9] and Damper (C) [10] to Hammer Case (C) Ass’y [6].
(7) Secure Hammer Case (C) Ass’y [6] to Housing (C) [34] with the four Bolts M6 x 50 [1]. Then secure
Handle (B) [37] with the two Bolts M5 x 20 [44].
(8) Mount power supply unit (C) to Handle (B) [37] as shown in Fig. 9. Mount the Cord Clip [40] with its
protrusion upward and secure it with two Screws D4 x 16 [41].
(9) Secure handle (A) to Hammer Case (C) Ass’y [6] with the two Bolts M5 x 20 [44]. Then secure it to
handle (B) with four Screws D4 x 20 [45].

-8-
(1) Apply Nippeco SEP-3Agrease (Code No. 930035 (100 g)/930038 (2.5 kg)) to the following:
•Pinion tooth flanks of Rotor Ass’y (C) [30]
•Tooth flanks of the Ring Gear [23]
•Two Needle Rollers [19]
•Tooth flanks and inner circumference of the Idle Gear Set (2 pcs.) [21]
(2) Apply Doubrex 251 grease to the following:
•Between Hammer (C) [14] and Spring Sheet (C) [18]
•Inside of Hammer Case (C)Ass’y [6]
•Spindle (C) [20]: Cam groove, sliding portion, and engaging portions with Anvil (C) [12] and Metal (A)
[25]
•Cam groove and raised portions of Hammer (C) [14]
•Anvil (C) [12]: 13 mm dia. hole, sliding portion with Washer (B) [11], claw, and sliding portion with the
O-ring
•Two Steel Balls D10.3 [13]
•Thirty-five Steel Balls D4.76 [15]
•Both end surfaces of Washer (C) [9] and Damper (C) [10]
•Seal Lock Screw (W/Sp. Washer) M5 x 12 [4] -------------------------3.4 ± 0.7 N•m (35 ± 7 kgf•cm)
•Hex. Socket Hd. Bolt (W/Washers) M5 x 20 [44] ----------------------5.9 ± 1.5 N•m (60 ± 15 kgf•cm)
•Seal Lock Hex. Socket Hd. Bolt M6 x 50 [1] ----------------------------10.8 ± 1.0 N•m (110 ± 10 kgf•cm)
•Tapping Screw (W/Flange) D4 x 20 (Black) [45]-----------------------1.8 ± 0.3 N•m (18 ± 3 kgf•cm)
•Hex. Hd. Tapping Screw D5 x 70 [32] ------------------------------------2.9 ± 0.5 N•m (30 ± 5 kgf•cm)
•Tapping Screw (W/Flange) D4 x 16 [41]---------------------------------1.8 ± 0.3 N•m (18 ± 3 kgf•cm)
Check the following after reassembly:
(1) Operate the Switch [38] and check that the switch moves smoothly and the switch operations (ON,
OFF, forward and reverse) are normal.
(2) Press the Switch [39] in “R” direction and slowly release the switch. Check that the switch returns to
the original position. Then press the Switch [38] in “L” direction and slowly release the switch. Check
that the switch returns to the original position.
(3) Check that the rotational direction of Anvil (C) [12] matches the direction of rotation made when you
press the Switch [38]. When the Switch [38] is set to the “R” position, Anvil (C) [12] must rotate
clockwise as viewed from the rear (opposite to Anvil (C) [12].)
On completion of reassembly after repair, measure the insulation resistance and conduct the dielectric
strength test between the plug pins and the outside metallic parts such as Anvil (C) [12].
Insulation resistance: 7 Mȍor more
Dielectric strength: 2,500 V for 1 minute --------------------------------------- 110 V to 120 V
4,000 V for 1 minute --------------------------------------- 220 V to 240 V
Screw tightening torque
Checking after reassembly
Application of lubricant
Insulation test

-9-
Fig. 11 • Connecting diagram
M
Sensor PCB (A) ass’y
Switch [38]
Main PCB ass’y
Filter PCB ass’y
After no-load operation for 30 minutes, the no-load current value should be as follows.
Voltage 110 V 120 V 220 V 230 V 240 V
Current max. 3.5 A 3.5 A 1.5 A 1.5 A 1.5 A
No-load current
Connecting diagram