Maintenance And Inspection - Hitachi DH 50MRY Manual De Instrucciones

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MAINTENANCE AND INSPECTION

WARNING:
Be sure to switch power OFF and disconnect the plug from the receptacle during maintenance and inspection.
1. Inspecting the drill bits
Since use of a dull tool will cause motor
malfunctioning and degraded efficiency, replace
the drill bit with a new one or resharpening without
delay when abrasion is noted.
2. Inspecting the screws
Regularly inspect all screws and ensure that they
are properly tightened. Should any of the screws
be loose, retighten them immediately.
WARNING:
Using this Rotary Hammer with loosen screws is
extremely dangerous.
3. Maintenance of the motor
The motor unit winding is the very "heart" of the
power tool. Exercise due care to ensure the
winding does not become damaged and/or wet
with oil or water.
4. Inspecting the carbon brushes: (Fig. 20)
The motor employs carbon brushes which are
consumable parts. When they become worn to or
near "wear limit", it could result in motor trouble.
When an auto-stop carbon brush is equipped, the
motor will stop automatically. At that time, replace
both carbon brushes with new ones which have
the same carbon brush Nos. shown in the figure.
In addition, always keep carbon brushes clean and
ensure that they slide freely within the brush
holders.
CAUTION:
Using this Rotary Hammer with a carbon brush
which is worn in excess of the wear limit will
damage the motor.
74
0.67" (17 mm)
12
Wear limit
No. of carbon brush
0.28" (7 mm)
Fig. 20
NOTE:
Use HITACHI carbon brush No. 74 indicated in Fig.
20
Replacing carbon brushes:
(For parts name, refer to Fig. 1)
Loosen the two set screws and remove the tail
cover. Remove the brush caps and carbon brushes.
After replacing the carbon brushes, tighten the
brush caps securely and to install the tail cover
with securely tightening two set screws.
5. How to replase grease
This machine is full air-tight construction to protect
against dust and to prevent lubricant leakage.
Therefore, the machine can be used without
lubrication for long periods. Replace the grease as
described below.
Grease replacement period
After purchase, replace grease after every 6
months of usage. Ask for grease replacement at
the nearest HITACHI Authorized Service Center.
Proceed for replacement of grease.
Grease replenishment
CAUTION:
Before replenishing the grease, turn the power off
and pull out the power plug.
(1) Remove the crank cover and wipe off the grease
inside.
(2) Apply 2.0 oz (60 g) of HITACHI Electric Hammer
Grease A (standard accessory, contained in tube)
to the crank case.
(3) After replenishing the grease, install the crank
cover securely.
Crank cover
NOTE:
The HITACHI Electric Hammer Grease A is of the
lower viscosity type. When the supplied grease
tube is consumed, purchase from a HITACHI
Autorized Service Center.
Fig. 21