Rolling bearing design examples

The articulated robot is used as a service or mobile robot. With a dead weight of just 10 kg and a nominal load of 3 kg, it is made of lightweight CFRP materials that offer high rigidity with minimal weight.

Wire race bearings are used for the movement axes, which combine high rigidity, low weight and a small installation space. Thanks to their compact design, they can be seamlessly integrated into the design of the robot. As the rolling bearing has no influence on the material of the enclosing structure, this can be freely selected.

The bearing is characterized by a high load capacity from all directions and ensures precise, low-friction movement of the robot joints.

A concept vehicle is equipped with one direct drive per wheel. This requires a compact, high-performance bearing that offers a high load capacity despite taking up minimal space. The maximum speed is 1,000 rpm, and due to the proximity to the direct drive, the balls of the rolling bearing must be non-magnetic. The solution is a custom-made bearing with ceramic balls that has been specially developed to meet these requirements. The rolling bearing is integrated directly into the customer's design and can absorb forces from all directions, including tilting moments. The installation space was optimized in close cooperation and the assembly of the prototype bearing is carried out jointly at Franke.

Specially developed thin-section bearings in a special design are used in medical centrifuges for blood samples. Each unit is equipped with two backlash-free bearings that ensure maximum precision and smooth running. The bearing races are chemically nickel-plated and, in combination with stainless steel balls, are particularly corrosion-resistant - ideal for long-term use in sensitive laboratory environments. With a rotational resistance of less than 0.3 Nm, they enable smooth and efficient rotation, which ensures accurate analysis of blood samples.

A specially developed drive system with integrated gear rims is used for maximum precision and stability during tube end machining. Due to limited space, the gear rims are integrated directly into the outer ring - a solution that guarantees maximum precision and rigidity.

The material combination of the surrounding components can be flexibly adapted to the specific requirements. We also supply the complete assembly as a customized unit - consisting of spiders, pinion and wire race bearing. We also offer customized bearing solutions for smaller quantities, which are optimally adapted to the respective machining requirements.

An absolutely low-noise roller bearing is required for the fan of a domestic ventilator. The bearing must not only ensure minimal running noise, but also compensate for manufacturing tolerances of the injection-molded housing. As the housing has a compact design, only limited installation space is available. To further reduce noise, the ball cage of the roller bearing is only fitted with every second ball. The injection-moulded housing has also been optimized to make series assembly easier for the customer. The bearing seat is precisely adjusted using a threaded ring.

The rolling bearings for laser optics in aircraft must offer maximum precision and high rigidity. Specially developed for use in aircraft protection, they must also effectively compensate for thermal expansion to ensure reliable performance. A custom-made slewing ring is used as a cylindrical roller bearing made of aluminum as well as an additional three-point bearing. The slewing ring achieves a concentricity and axial run-out accuracy of 0.03 mm. Thanks to the lightweight aluminum construction, a considerable weight reduction is achieved. The load ratings, rigidity and accuracy are determined by the precisely manufactured races. The three-point bearing has a bearing angle of 45°, while the movable outer ring optimally compensates for thermal expansion.

The main bearing of a baggage scanner not only has to ensure smooth and even rotation at up to 150 rpm, but also accommodate other components such as slip rings, X-ray detectors and drive elements. In addition, low noise levels, a large center clearance and a maintenance-free, durable design with over 50 million revolutions are required. The solution is a slewing ring manufactured specifically for the application as a 4-point bearing made of aluminum with custom-designed housing rings. Thanks to its compact design and large center clearance, the bearing offers optimum integration into the system. The lightweight aluminum design also ensures a significant weight reduction.

The rolling bearing for a mobile satellite antenna must not exceed a maximum total weight of 1 kg and must ensure smooth running and high tilting rigidity at the same time. The solution is a customer-specific, ready-to-install slewing ring made of aluminum with external gearing. Its compact design allows a large centerline clearance with minimal space requirements. The integrated toothed belt gearing ensures precise and reliable power transmission.

As the hubless rim of a Formula Student electric racing car, the aluminum-carbon rim is intended to accommodate drive and braking devices in its center. The rolling bearing used must offer a large center clearance, require minimal installation space and at the same time safely transmit high forces and torques. Franke rolling bearings are integrated directly into the housing parts of the rim as double-row angular contact ball bearings. The wire race bearing reliably supports the loads that occur and works independently of the material of the surrounding construction. The compact design of the wires and rolling elements reduces the required installation space to a minimum. Thanks to the double-row angular contact ball bearing arrangement, the design enables highly dynamic motion sequences and ensures maximum performance with minimum weight.

The main bearing of the computer tomograph plays a decisive role in precise imaging. Even at high speeds, it must run quietly and with low vibration, while ensuring precise radial and axial run-out. The Franke slewing ring impresses with extremely smooth running at speeds of up to 300 rpm. An elastomer ensures effective noise reduction to 60 dBA. The bearing is also characterized by a low rotational resistance of less than 20 Nm and electrical insulation between the inner and outer ring.