Pneumatic articulated arm: maintenance and inspection
The articulated arm has no load-bearing medium that could reach discard, and still a clear wear chain: joints, cylinders and the lines running through both. The operator notices wear first as unsteadiness at the load – long before anything can be seen at the joint itself.
- Rule
- DGUV rule 54 (winches, hoisting and traction equipment)
- Interval
- at least annually
- Makes
- any make
A tenth of a millimetre in the joint is two centimetres at the load.
Which rule applies – and at what interval
As hoisting and traction equipment the articulated arm manipulator falls under DGUV rule 54: inspection by a competent person at least once a year, the interval from your risk assessment. Because the unit has neither rope nor chain the focus moves to the load-bearing structure – joints, pins, welds – and to the pneumatic circuit with its load holding. Where the arm hangs from a runway, DGUV rule 52 applies to that runway.
- Rule
- DGUV rule 54 (winches, hoisting and traction equipment)
- Minimum interval
- at least annually
- Inspector
- competent person
What we look at on this unit
| Component | Finding | Discard limit |
|---|---|---|
| Joint pins & bushes | Worn bore, play, running dry | noticeable play at the load attachment |
| Arm segments | Deformation, welds, cracks at load introduction points | any crack, any permanent deformation |
| Lift cylinder | Internal leakage, creep, scoring on the rod | any creep under load |
| Hose routing | Chafing on edges, pins and clamps | chafing down to the reinforcement |
| Valves & handle | Response, return, tightness | handle sticks or responds late |
| Suspension / column | Anchor bolts, rail connection, slew ring | any loose bolted connection |
The limits come from the applicable rules. Where manufacturer data exists for the specific unit, it prevails.
What actually gets done
Measure play at the lever
We measure total play at the load attachment, not at each individual joint. That is the figure the operator feels, and it is the sum of every joint. Only when it is too large do we work through joint by joint.
Pins and bushes
A pin that has run dry wears the bore – and then a new pin alone is not enough, the bush has to be replaced too. Change only the pin and the play is back within six months. So we always check both.
Lines in the moving arm
The pneumatic lines travel through the joints. Every movement rubs them at the same point. A chafing mark is damage with a date, not a blemish – we re-route the line and protect the edge instead of just replacing the hose.
The handle as test rig
We move the arm through the entire working area with a load attached. Delayed response, uneven lifting or creep in certain positions show up here – and nowhere else.
When the task has changed
Different load attachment
The most common and usually sufficient change: new gripper, new beam, quick-change system for two workpiece families.
An additional rotary axis
Where the workpiece has to be turned at its destination, an extra axis on the attachment is cheaper than a bigger unit – and easier on the operator.
Change the reach
A longer segment enlarges the radius but increases the moment. The limit sits in the column, the suspension or the foundation. We recalculate the modified condition before anything is built.
What we offer for it
Lifting Equipment Maintenance
Planned maintenance of chain hoists, wire rope hoists, balancers and manipulators – any make.
Lifting Equipment Inspection
Recurring inspection under German BetrSichV and DGUV rules – chain hoists, rope hoists, balancers, manipulators and jib cranes.
Repair & Overhaul
Repair of lifting equipment and manipulators of any make – from a brake change to a full overhaul.
Upgrades & Modification
Adapting existing lifting equipment to a new task – gripper, control, reach, capacity.
Questions on maintenance and inspection
The arm wobbles at the load. Is that dangerous?
Usually not dangerous, but it is a finding and it gets worse. Play arises in the joints and adds up along the lever to the load. It is put right by replacing pin and bush – the earlier the less work, because a worn bore is more laborious to repair.
How often must an articulated arm manipulator be inspected?
At least annually by a competent person. The binding interval is set by you in the risk assessment – with multi-shift operation or an aggressive environment it is shorter.
Do you service manipulators that are not yours?
Yes, that is the normal case. Where documentation is missing we derive the scope from the design and the applicable rules and record what it is based on.
Let’s talk about your equipment.
Tell us which units you have – including ones from different manufacturers. We will come back with a proposal for scope and interval.