A serious challenge faced by designers of industrial automation systems is creating durable and reliable electrical connections with dynamically working elements – booms, robot arms, machine tool heads, etc. In this article, TME present chain guides from Brevetti Stendalto and cabling from the LAPP brand designed for such applications.
Chain guides are used in many applications and systems. They not only ensure the proper arrangement of cables during their movement but also protect them from mechanical damage. Moreover, although they are often laid in guide channels, it is possible to use them in self-supporting installations – this translates into cost reduction and greater freedom in construction. Of course, the cables working in such guides must be adapted to such applications: withstand frequent movement, be resistant to pressure, and have proper flexibility. Below TME present products that meet all of these requirements. These are branded articles from two companies specialised in industrial solutions: LAPP and Brevetti Stendalto.
In this article, we discuss topics such as:
- Hybrid cables and those designed for servo mechanisms
- Universal control cabling for guides
- Increased resistance and longevity of LAPP cables
- Wired data transmission in industrial machines
- Prefabricated cables for sensors and servo mechanisms
- Light chain guides for self-supporting installations
- Chain guides with increased resistance
ÖLFLEX and UNITRONIC Cable Series
First, let’s focus on the cables provided by the LAPP brand. The company’s full portfolio consists of several main cabling series, each with its general purpose. They are further divided into groups with more specific specialisations – described below. These products belong to two series: ÖLFLEX and UNITRONIC. The first is designed for various control applications. It is worth noting that they are among the most popular products of this type in the world. They include articles tailored to the needs of the machinery industry, energy, medical and chemical sectors, and even food processing. Meanwhile, the UNITRONIC series includes cables designed for data transfer. Depending on the specific group, they are intended for use in computer networks, automation systems, consumer devices – practically every more and less typical application.
When browsing LAPP’s offer, it is worth noting that the subseries are further divided, and each group has extended letter markings. A commonly encountered symbol is ‘P,’ which refers to polyurethane (PUR) as the material for the outer jacket (an alternative to PVC). The letter ‘F’ comes from the English word flexible, meaning increased cable flexibility and its reduced bending diameter. ‘C’, in turn, refers to Cu (and the English copper) and indicates that the product group is equipped with a shield made of copper braid: thus, the transmitted signals are protected from electromagnetic interference, EMI). Such solutions will be required, for example, when placing signal cables near coils, inductive loads (motors), etc. Additionally, it should be noted that the polyurethane coating is slightly more expensive but has an advantage over PVC insulation. PUR cables are characterised by longer lifespan, flexibility, wider thermal tolerance, and increased resistance to various chemical compounds and oils.
ÖLFLEX CHAIN
In the context of the products described below, ÖLFLEX CHAIN series have particular significance because they group products specifically adapted for use in chain guides. The cables exhibit resistance to working at different sliding distances and with different accelerations; nevertheless, all are designed with the best possible flexibility and continuous bending in mind. They can serve both control and power functions (operating voltages up to 1kV, made in compliance with EU standards and certified according to UL for the American market). They have from 1 to 25 cores in cross-sections up to 300mm2. Importantly, their flexible properties are retained even in extremely low temperatures, for several groups even -50°C.
ÖLFLEX FD
As already mentioned, cables from various ÖLFLEX FD series according to LAPP specifications can also work in dynamically operating installations because they are made to ensure maximum flexibility. Furthermore, in the FD family, we find many solutions with distinctive properties, e.g., resistant to UV radiation, oils/greases, and other chemical factors (acids, alkaline solutions), abrasion, varied temperatures (from -50 to 90°C). The products comply with a range of international standards (e.g., VDE, Eca). They have up to 60 numerically marked cores allowing for use in many control applications. Nearly half of the available versions are placed in a shield, which takes the form of a durable and mechanically working braid of tinned copper wires.
ÖLFLEX SERVO FD 796
As the name suggests, the ÖLFLEX SERVO FD 796 group includes cables for controlling servo mechanisms, stepper motors, actuators, etc. They have up to eight copper cores with diameters from 0.34 to 50mm2 (working with voltages of 600/1000V). Like the products described above, they are characterized by excellent chemical and mechanical resistance (thanks to the use of PUR). This group also includes ‘hybrid’ cables, i.e., those used for simultaneously powering the receiver and delivering the control signal (a typical application in the case of servo mechanisms). Selected articles have double shielding, allowing ÖLFLEX SERVO cables to be laid inside machines.
ÖLFLEX PETRO FD 865 CP
A distinguishing feature of the ÖLFLEX PETRO FD 865 CP series is its adaptation for marine applications (approval of the Norwegian society Det Norske Veritas, DNV). These cables exhibit resistance to the action of oil and ester-based drilling fluids (MUD). The cables also have very high resistance to electromagnetic interference, and the insulation maintains low capacitance when laying long runs, making these products ideal for applications with strict electromagnetic compatibility (EMC) regulations. They can work in dry, wet, exceptionally hostile, and oily environments.
ÖLFLEX ROBUST FD
ÖLFLEX ROBUST belongs to LAPP’s most resistant products, developed with mobile applications in mind (with resistance to high accelerations) and in very harsh environmental conditions. Unlike the offer described above, the outer jacket here is made of thermoplastic elastomer TPE with very high chemical resistance. They can be used not only outside buildings but also in chemical plants, car washes, sewage treatment plants, composting plants, dairies, processing, and bottling plants. ÖLFLEX ROBUST cables retain their high flexibility even in low temperatures (down to -40°C). They come in typical control configurations, i.e., equipped with 2 to 25 cores (diameters up to 16mm2) adapted to work with voltages of 300/500V.
UNITRONIC
As already mentioned, the UNITRONIC series has a slightly different area of application: these cables are primarily prepared for data transmission (mainly transmission within Profibus). However, they are still products designed with industrial automation and robotics in mind (adapted to work in continuous motion). Such cabling is essential for centralising the control of automation systems using digital signals (low frequencies). Depending on the chosen subgroup, UNITRONIC cables can be characterised by thermal tolerance ranging from -40 to 90°C. They are available in shielded (braid made of tinned copper fibres) and unshielded versions. They have from two to 28 cores, allowing the use of a single cable to collect signals from multiple sensors and the simultaneous implementation of several transmission protocols. The outer jacket made of polyurethane remains resistant to hydrolysis, microorganisms, and oils.
ETHERLINE
With the development of the so-called ‘Internet of Things’ (IoT) in industrial automation, network-based communication (e.g., Profinet, Ethernet) is increasingly used. And in this area, LAPP offers specialised solutions: cables from the ETHERLINE series. Inside, there are cores made and arranged according to high standards (copper links twisted in pairs, shielding, etc.) allowing real-time control of industrial processes (category 6a, up to 10Gb/s). At the same time, attention was paid to the high durability of the outer jacket, made of PUR or PVC, and the mechanical workability of the cable, for which ordinary products are not adapted at all. Noteworthy here is the choice of products with a wide thermal tolerance (up to 80°C), resistant to chemicals, UV radiation, and other harmful environmental factors.
Sensor and servo drive cabling
In many, if not most cases, cables laid in chain guides will be used to connect sensors and servo drives with standard connections. In such cases, instead of spending time on individual connections, it is better to use cables that have factory-installed connectors. LAPP provides such solutions. Their key advantages are mechanical durability. This is manifested not only in the ability to work in motion, in machines, but also in the protection class: IP65 or IP67, i.e., complete resistance to dust penetration and high or complete water resistance. LAPP’s UNITRONIC SENSOR series cables have pre-installed M8 or M12 connectors on one end (from 3 to 8 pins), and exposed cores on the other. In addition to cables for various types of microsensors, the portfolio also includes valve cables. Selected models have an LED indicating the sensor status. The cabling is compatible with products from many brands, including Omron.
The second extensive group of LAPP cables is products for controlling servo mechanisms. Here too, the connectors are factory-installed, which primarily reduces installation and maintenance time. They are adapted to the most popular, advanced drives for automation – made in Siemens, Lenze, Rockwell, SEW standards. They are available in lengths from 2 to 20m. They are, of course, adapted for use in mobile applications: robotics, manipulators, cranes, etc.
Brevetti Stendalto chain guides
The basic functionality of chain guides is very simple – they ensure the proper arrangement of cables in dynamic applications, i.e., when they are to be in periodic (or constant) motion. Meanwhile, due to the number and diversity of applications requiring such elements, as well as the harsh conditions in which they work, these products must be designed and manufactured very precisely. Therefore, products from specialised manufacturers, such as Brevetti Stendalto Stendalto, are usually used. The offer also includes accessories for guides, such as mounting brackets, pins (which may require periodic replacement due to constant friction), as well as special vertical and horizontal separators ensuring proper cable arrangement.
LIGHT Series
LIGHT chain guides are characterised by relatively low weight. The links of this model do not form a closed structure, but they allow for safe cable routing, guaranteeing a bending radius from 50 to 150mm. The external height of these models is 38mm with a width from 57 to 120mm. The chains are available in versions with an opening frame (inside and outside the radius) and non-opening. A single, central pin ensures durable chain connection and resistance to twisting and stretching. When using guide channels, it can be used on long sliding routes.
MEDIUM Series
In MEDIUM guides, the cabling is completely covered by chain links and thus protected from mechanical damage. The series includes models with the smallest sizes available from Brevetti Stendalto Stendalto (external width 30mm and height 18mm), which translates into a very small bending radius (40mm). These are products perfectly adapted to work in mechanisms where acceleration occurs in all 3 directions (up to 50m/s2), such as CNC automation, robotic laser processing, etc. As with other series, the manufacturer ensured the availability of various mounting brackets. The frames of the links can be opened from the inner or outer side of the bend (depending on the model).
Protection Series
The main advantage of the Protection series guides is the reinforced body, which protects the cables inside from mechanical injuries, as well as splinters of processed materials, sawdust, and similar contaminants. Here, for structural reasons, opening is done exclusively using a cover in the opening frames.
Guides with a bending radius ranging from 75 to 125mm are available. Despite the heavier construction, Protection guides can still work in self-supporting applications at speeds up to 10m/s and accelerations of 50m/s2.
