
-11-
Rod
Air chamber
First gear
Piston pin
O-ring
Armature
Tool shaft
Slip mechanism
Second shaft
Motor shaft
Piston
Strike
Second hammer
Second gear
Cylinder
Ring groove
Reciprocating bearing
Second pinion
Cylinder flange
Second shaft spline
Clutch
Washer
Fig. 3
1. Lubrication
Replenish the grease lubricant when disassembling the tool or in case grease leaks due to a defective seal.
Grease must be changed once a year to prolong tool service life. Special grease is used in the striking
section. Should the striking section (inside the gear cover) be disassembled, completely remove the old
grease from all parts and, at reassembly, replenish 30 g of new grease in the gear cover and 10 g in the
groove of the inner cover. Be careful not to exceed the designated amount of grease. Excessive grease will
reduce striking efficiency.
2. Tool Structure
Transmission of rotation
See Fig. 3. Armature rotation is transmitted to the second shaft via the first gear, causing the second
shaft to rotate. The second pinion mounted on the second shaft engages with the second gear mounted
on the outer circumference of the cylinder. The cylinder is coupled to the second gear by means of a slip
mechanism, and both rotate together. The end of the cylinder also functions as the drill bit retainer. The
cylinder is key-connected to the inserted drill bit by means of two key rails and a steel ball, and transmits
rotation to the drill bit.
Piston reciprocating mechanism
The Model DH 22PH adopts a spiral drive system (i.e., mechanism using a reciprocating bearing),
resulting in a more compact design with the armature shaft arranged in parallel with the tool shaft. Figure
3 shows the structure of the piston reciprocating mechanism.
Armature rotation is transmitted to the second shaft via the first gear. Rotation of the second shaft is then
transmitted through a spline on the second shaft to the clutch, which engages with a reciprocating
bearing, causing the bearing to rotate. However, circular grooves on the inner race of the reciprocating
bearing are positioned at an angle of inclination relative to the second shaft. The rotation of the inner
race and shaft causes the angle of inclination to change regularly in the forward and backward directions
with respect to the second shaft, and produces a rocking motion in the outer race of the reciprocating
bearing. Finally, a rod extending from the outer race of the reciprocating bearing is connected to the
piston by a piston pin, causing the piston reciprocating motion.
REFERENCE MATERIALS
Содержание DH 22PH
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