Robit HDSA2 Manual

2’’-6’’ SHOCK ABSORBERS – MAINTENANCE AND SERVICE MANUAL
Certicate No. 2446700
ISO9001
2’’-6’’
HD SHOCK
ABSORBERS
11/06/2018 2’’-6’’ SHOCK ABOSRBERS – MAINTENANCE AND SERVICE MANUAL
www.robitgroup.com

2’’-6’’ SHOCK ABSORBERS – MAINTENANCE AND SERVICE MANUAL
1
8
23
9
5
4
6
710
This manual is published by and copyright © of Robit. All Rights Reserved. Always operate your Robit drilling equipment
according to the instructions contained within this operating manual. Further copies of this manual can be downloaded from the Robit
website; www.robitgroup.com. For urgent support or sales enquiries, sales(at)robitgroup.com.
ALWAYS THINK
SAFETY FIRST!
2
1. Parts List
Ref Description
Part number
HDSA2 HDSA3 HDSA4 HDSA5 HDSA6
1 Top connector SA02HD0810F SA03HD0801M
(2 3/8’’ reg. pin)
SA04HD0801M
(2 3/8’’ reg. pin)
SA05HD0803M
(3 1/2’’ reg. pin)
SA06HD0803M
(3 1/2’’ reg. pin)
2Seal ‘O’ ring* N / A SA03HD03 SA04HD03 SA05HD03 SA06HD03 (2 of)*
3 Splined Nut HSB2837ST SA03HD01 SA04HD01 SA05HD01 SA06HD01
4 Breakout washer N / A SA03HD25 SA04HD25 SA05HD25 SA06HD25
5 Splined Nut Seal SA02HD10 SA03HD10 SA04HD10 SA05HD10 SA06HD10
6 Retainer ring HSB2S37ST SA03HD011 SA04HD011 SA05HD011 SA06HD011
7 Thrust guide SA02HD12 SA03HD12 SA04HD12 SA05HD12 SA06HD12
8 Thrust guide ‘O’ ring SA02HD12A SA03HD12A SA04HD12A SA05HD12A SA06HD12A
9 Buer x 2** SA02HD05 (1 of)** SA03HD05 SA04HD05 SA05HD05 SA06HD05
10 Bottom connector SA02HD0911M SA03HD0901F
(2 3/8’’ reg. box)
SA04HD0901F
(2 3/8’’ reg. box)
SA05HD0903F
(3 1/2’’ reg. box)
SA06HD0903F
(3 1/2’’ reg. box)
Complete
Shock Absorber
SA02HD11MF-B SA03HD01MF-B S04HD01MF-B S05HD03MF-B S06HD03MF-B
NB. * HDSA6 features 2 seal‘O’ rings
** HDSA2 uses 1 buer
Important:
Refer to the above component parts table when following the servicing and maintenance guidelines, as internal conguration
may vary slightly depending on the shock absorber model you are using.
Size HDSA2 HDSA3 HDSA4 HDSA5 HDSA6
Eective length 346 mm / 13.62’’ 457 mm / 17.93’’ 483 mm / 19.02’’ 514 mm / 20.27’’ 578 mm / 22.76’’
Outside diameter 62 mm / 2.44’’ 79.4 mm / 3.13’’ 95.4 mm / 3.76’’ 115 mm / 4.53’’ 140 mm / 5.51’’
Net weight 7,5 kg / 16.5 lbs 14,3 kg / 31.5 lbs 22,1 kg / 48.7 lbs 33,2 kg / 73.2 lbs 53,0 kg / 116.8 lbs

2’’-6’’ SHOCK ABSORBERS – MAINTENANCE AND SERVICE MANUAL
3
2. Servicing & Maintenance
The Robit HD range of Shock Absorbers, suitable for 2” through to 6” DTH hammers should be serviced
after every 500 hours of operation or every 6 months of intermittent use.
To disassemble the unit the Top Connector (item 1) needs to be unscrewed from the Bottom Connector
(item 10). This can best be achieved by locking the Bottom Connector either in a vice or hammer
splitting bench, depending on the size of the Shock Absorber and splitting the Top Connector at the
spanner ats on the Splined Nut (item 3).
If the Shock Absorber is proving particularly dicult to break open, then by cutting through the
Breakout Washer (item 4) with a pencil grinder or similar, this should facilitate easier opening. Take care
not to cut into the Locking Nut. Note the 2” HDSA2 does not feature a breakout washer.
Remove and carefully inspect the Buers (item 9). If either of them is showing any signs of wear,
distortion or fatigue they must both be replaced.
Remove the Retainer Ring (item 6) and Slide the Splined Nut o the Top Connector. Examine the Seal
“O” Ring (item 2) and also the Seal and if they are showing any signs of wear or distortion, they must be
replaced.
It is inevitable that there will be progressive wear between splines of the Top Connector shaft
and those of the Splined Nut. When this wear pattern exceeds 2mm in either component, it is
recommended that this component be replaced. Excessive wear will eventually lead to failure of the
Top Connector shaft or thread with the consequent loss of both hammer and bit.
Before re-assembling the Shock Absorber, make sure all the components are cleaned and then apply a
good quality, heat resistant grease to the splines of the Top Connector shaft and the splines of the Nut.
This will both reduce wear and help in splitting when the unit is next ready for service.
With the Top Connector held in the vertical position, slide over the Splined Nut and attach the Retainer
Rings to the Top Connector. Ensure that the Thrust Guide and Buers are all in line then place the
Bottom Connector over the Splined Nut and tighten down fully to a maximum torque value as shown
below for the appropriate Shock Absorber size.
Maximum Torque Values
2 ‘‘ HDSA2 170 kgm
3 ‘‘ HDSA3 200 kgm
4 ‘‘ HDSA4 250 kgm
5 ‘‘ HDSA5 400 kgm
6 ‘‘ HDSA6 700 kgm

2’’-6’’ SHOCK ABSORBERS – MAINTENANCE AND SERVICE MANUAL
11/06/2018 2’’-6’’ SHOCK ABSORBERS – MAINTENANCE AND SERVICE MANUAL
www.robitgroup.com