New igus cable guide for SCARA robots avoids cable entanglement

SCARA robots are ideal for picking and assembling tasks in the industry. The problem, however, is that its service life is affected by the rapid wear and tear of its bellows, which can also become very short. To address this issue, igus has developed an alternative that can be retrofitted with SCARA cable solutions to significantly extend service life.

For the highly dynamic applications of SCARA robots, igus has developed a new SCARA cable solution. It consists of a swivel joint fitted with ball bearings and an e-rib for stabilising corrugated hoses. (Source: igus GmbH).

Watching a SCARA robot at work can quickly make you vertigo. This is because this horizontally articulated arm robot needs to run fast on four axes. Its inner and outer arms perform horizontal rotational movements. And the ball screws for gripping objects make rotational and linear movements. This allows the robot arm to reach almost any position within its working radius. It is fast and precise, but the high loads it carries mean that the cables and hoses wired to the outside of the arm need to be replaced or repaired frequently. This is also a problem being faced by some manufacturers in the automotive industry, who want to optimise their energy supply systems, including bellows and swivel bearings. ‘In order to meet user needs, we addressed the weaknesses of hoses and connectors and eventually developed the SCARA cable solution after two years of research and testing.’ Says Matthias Meyer, head of the igus ECS triflex and robotics business unit. It is a customised cable guide that safely guides the power from the first axis to the ballscrew and ensures that the cable does not get tangled even when the system is in continuous operation.

Ball bearings and additional reinforcement

The SCARA cable solution has three constituent parts, namely swivelling bearings for the mobile and stationary ends and a corrugated hose with e-rib. Its special feature is its unique swivel joint, which absorbs torsional forces. The integrated ball bearings ensure that the energy supply system runs smoothly even under high acceleration. In addition, the corrugated hose is reinforced with e-rib so that it can only move in one spatial direction. Side guiding elements allow the bellows to have a certain overhead length.

SCARA cable solution extends the service life of the energy supply system

In the 3.800 square metre igus Cologne test laboratory, we tested the new energy supply system and the results were satisfactory. In addition, in co-operation with the robot manufacturer EPSON, we tested the performance of the new energy supply system on a SCARA robot under extreme conditions. For example, we applied accelerations of up to 6G to it during some movements. As a result, it continued to operate after more than 3 million cycles at a rotational frequency of more than 5.000 degrees per minute.’ Tests have proven that using this SCARA cable solution extends the life of the energy supply system already applied to SCARA robots. Not only does the robot get longer uptime, but it also requires no maintenance and operates trouble-free.’ Meyer adds. The new energy supply system is available either as a pre-assembled system that can be quickly retrofitted or as three separate components for retrofitting.