Roller bearings
Wire roller bearings for small installation spaces – lightweight, compact, and resilient
Automation and robotics require roller bearings that combine low weight and small installation space with high rigidity in order to safely absorb torques. Also on the wish list: defined rotational resistance for movements that are as uniform as possible and for designing the appropriate drive power. Franke roller bearings are predestined for these requirements.
The key difference between a standard ball bearing and a Franke wire roller bearing lies in the raceways. In wire roller bearings, the rolling elements do not roll on solid housing rings, but on hardened wires. The flexibility of this principle allows for freer and simpler designs, resulting in better products. Thanks to their patented technology, Franke wire rolling bearings offer maximum design freedom without compromising on load capacity.
The surrounding structure can be made from a wide range of lightweight materials and its geometry can be optimally adapted to the respective application.
Video: The Franke principle in roller bearings
Franke LER bearing elements are suitable for medium rotational speeds and accuracies. They impress with their smooth running, high dynamics, and compact installation space. The straight contact surfaces allow for easy integration into the surrounding design and high rigidity. The favorable price makes the LER bearing element an economical solution. LER bearings are usually installed without play. The preload can be individually adjusted depending on requirements.
The new LER1.5 series has been specifically developed for use in ultra-compact applications such as MRK robots or medical devices. With an installation space of just 5 x 6 mm, the new LER 1.5 also meets the trend toward miniaturization in the handling and automation sector. Small rotary tables, grippers, or manipulators can be moved precisely and with high load capacity.
LER ball bearings (roller bearings with profiled raceways)
Application example: LER 1.5 in sensitive robots
A new generation of robots is on the way: lightweight, quiet, extremely agile, and above all highly sensitive to their surroundings, they are well on their way to blurring the boundaries between humans and machines and establishing themselves as close partners in everyday life and industry. These small, smart robots are not only revolutionizing households and production halls, but are also increasingly conquering areas such as healthcare, logistics, and entertainment.
The global market for compact, intelligent robots is showing impressive growth. Driven by advances in sensor technology, artificial intelligence, and drive technology, the market for collaborative robots (cobots) is expected to grow at double-digit rates annually until 2030. In Asia, Europe, and North America in particular, industries such as automotive production, electronics manufacturing, and the healthcare sector are driving demand.
A key factor in the success of these new generations of robots is the integration of innovative technologies such as wire roller bearings, which enable precise, reliable, and energy-efficient movement. Their compactness and high performance are crucial to meeting the requirements of modern robotics. From precision surgery to automated warehousing, these robots are permanently changing the way we live and work.
In addition to electronics and control expertise, it is mainly mechanical qualities that give modern small robots their edge. A slim design, low weight, and exceptionally high mobility are prerequisites for lightweight robots to be used in all kinds of locations without major installation effort and to perform the tasks required there. For the joints of the robots, designers therefore want bearings that are lightweight and compact, yet highly rigid in order to safely absorb the forces that occur.
Also on the robot builders' wish list: a defined rotational resistance for precise drive power design. Franke wire roller bearings with rectangular profiles meet these requirements. They consist of hardened raceways with profiled running surfaces and are inserted directly into the downstream design. This saves installation space and gives designers maximum freedom in designing the surrounding parts. Since lightweight construction is a major issue in robot design, the use of wire roller bearings allows alternative materials such as aluminum, plastic, or even carbon (CFRP) to be used.
The arrangement of the raceways allows the bearing to be adapted to the prevailing load conditions. Further adjustments can be made via the degree of contact, i.e. the size of the contact area between the rolling elements and the raceway. The large number of joints, especially in the latest robot designs, also bring economic aspects into play when selecting the right bearing. Parameters such as ease of installation, installation time, and, of course, price play a role here. Franke wire roller bearings also impress in these areas. Installation is simple, and the prices for bearing elements or thin-section bearings in series production are extremely attractive.
Video: Franke components in automation
Direct drive with torque motors
In their highest configuration, Franke wire rolling bearings are available complete with drive. Torque motors integrated into the housing act directly on site—without additional drive or transmission components and with maximum efficiency. Wire rolling bearings with integrated drives have been used in computer tomographs for decades. There, they reliably and uniformly accelerate X-ray units weighing up to one ton to speeds of up to 400 rpm, enabling high-resolution images of the human body to be taken.
Direct drives can be combined with all types of wire roller bearings. A LER1.5 with an adapted direct drive could be used to create extremely compact robot joints that only need to be controlled and integrated directly into Franke rotary unions. The customer receives a ready-to-install system. This allows it to be positioned precisely and perform defined cycle steps.
Video: Franke rotary joint with torque (direct drive)
High performance and defined movements
The torque motor has high torque within a defined speed range. The distance between the stator and rotor (air gap) is decisive for the magnitude of the torque. The preloaded Franke rotary connection guarantees a constant air gap. A measuring system can be used to determine the motor position.
The large center clearance of the wire-wound bearings with direct drive can be used to save material or to accommodate additional technology such as measuring systems or control units.
All measuring systems available on the market can be integrated into the rotary joint. Very robust inductive measuring systems are used as standard. They are available as incremental or absolute systems in various accuracy classes.
Franke roller bearings & linear guides in intralogistics
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73431 Aalen
GERMANY
franke-gmbh.de
