Atlas Copco DHR56A Rotation Unit for DTH Drilling

The new DHR series is available in 18 complete standard versions, with both fixed and floating adapters, for all common types and dimension threads.

Air-Powered

All the air-powered variants in the DHR series have powerful vane motors, noted for their superior operational reliability and high wear resistance under tough conditions. The pre-greased planet gear only needs lubrication every third month.

• Suitable for use with 3-6" DTH hammers
• High torque
• Suitable for operating pressures up to 8 bar (116 psi)
• Minimal service and maintenance requirements
• Suitable for mounting on all kinds of rigs

Reduction Gears That Can Tackle More or Less Anything

DHR rotation units can be equipped with any of three different size reduction gears, that feature different gear ratio combinations to suit all motor alternatives.

• Power and stability
• Designed for simple, effective assembly
• Robustly dimensioned spindles and bearings
• Simple lubrication, four times a year

DHR Rotation Units for Air-Powered Units
Type	Ordering No.	Recommended for DTH-Hammer
DHR 56A-6	4350 2558 56	5 - 6 in

Mounted Adapters, Types, and Designations
No.	Adapter	Type/Thread
6	Fixed	API 3-1/2" REG. Female

Technical Data






Air-Powered Units

Type	DHR 56A
Length mm (in)	1120* (44)
Height from base to center of spindle mm (in)	138 (5.5)
Weight, kb (lb)	242 (535)
No. of drive motors	2
Torque, max., Nm (lb, ft)...
at 6 bar (87 psi)	2850 (2100)
at 8 bar (116 psi)	3700 (2730)
Spindle speed max., rpm	63
Air Consumption At...
at 30 rpm, l/s (cfm)
at 6 bar (87 psi)	150 (320)
at 8 bar (116 psi)	190 (403)

*with floating adapter