UK | BNL Bearings | Integrated Plastic Bearing Design | UK

At BNL, we challenge traditional perceptions of what a ‘bearing’ is.

Through our integrated plastic bearing design we offer added-value engineering solutions to our customers. Using plastic design and moulding techniques, we combine components, features and functions, with the inner or outer of the bearing, creating an integrated bearing design.

Integration reduces costs, weight and assembly steps, whilst improving performance, energy efficiency and maintenance time.

We design bearings that integrate feature gear teeth, strengthening ribs, haptic features, brackets, shafts, pulley forms – we work with our customers to identify where integration can give them the best advantage.

Whatever the aim, whether it is to reduce cost, save space, or improve whole system performance, integrated plastic bearings do not just meet their specifications, but can provide many added-value benefits too.

Reducing component count & cost

We can reduce component count and cost through replacing or integrating features and functions, including: pulleys, rollers, clips & fixings, shafts, gear forms, poke yoke characteristics, optical sensor features, belt drives and haptics.

We use plastic moulding techniques perfected over half a century to combine a variety of components into a single, plastic part. Our integrated clips and fixings also mean that installation and maintenance can be quicker, easier and less expensive by replacing screws, bolts and pins with ‘snap-fit’ functionality.

Our plastic bearing designs are generally much lighter than a steel equivalent, but by removing components and fixings from the product, our bearing designs can be up to 50% lighter than an alternative multi-component solution. By reducing weight, we can reduce torque to rotate on start-up and in operation, so smaller, less expensive motors can be used.

We reduce components by integrating functions too. Our integrated plastic control knob designs have both rotary and axial operation, left-right slide, plus turn and push-button functions, and can also include a fixed area for a display to be positioned in the centre of the bearing, without compromising the axial and rotary movement.

Strengthening ribs and tolerance absorption

We strengthen our bearings and plastic shafts using rib structures designed into the outer or inner race or into shaft integrations. These structures can redistribute stress without adding excessive material to the part, to ensure we can keep the weight low whilst making the product more robust.

Where a bearing needs to fit onto and shaft or into a housing, we also use smaller versions of rib designs as ‘crush’ ribs on the inner or outer of the bearing that will take up tolerance against the ovality of the shaft or housing.

On our steering column bearings these crush ribs have evolved into our own “flexible fingers”, which are adaptive to maintain diametric clearances and ‘axial float’ over different environmental conditions, as well as compensating for assembly tolerances. This helps to simplify assembly for our customers by combating imprecise staking assembly methods and allows for expansion so the assembled column can meet low then high operating temperatures required in testing.

Discover more about how we use these integrated features in our steering column bearings.

Haptics

The growth of connectivity and convenience in car controls and the domestic environment, has led to a demand for more diverse user interfaces for automotive cockpits and domestic appliances. We have worked alongside some of the leading OEMs in the controls and displays industry, contributing to some key innovations in the field.

Our custom bearing designs offer unique benefits to automotive customers especially, who each tend to require a different feel and sound to create proprietary OEM haptics. We can achieve this through integrating springs and designing customisable, moulded detents and wave forms, to give a range of controls products to suit different specifications. We can further ‘tune’ the torque of the bearing and create varying resistance for a different haptic feel. Ranging from a simple rotary knob with minimal haptic feedback, to a louder ‘click’ and ‘heavy’ feel, we can create proprietary haptics for each customer.

Find out more about how we design and integrate moulded haptic features in out control knob bearings.

Shaft Design

We have been integrating shafts and bearings for decades as part of our designs for photocopiers, ATMs and mail handling applications. We anticipate and design for stress on the parts, integrating strengthening ribs and moulding with different materials, to redistribute stress and strengthen the shaft. We use compartmentalized tooling to combat warp, shrinkage and movement of material in the moulding process, improving tolerances across the shaft.

Our shaft and bearing products replace expensive, over-specified metal equivalents in machines and use less material, keeping weight low without losing strength.

Read more about our bearings for photocopiers, cash and mail handling.

Adaptive DC & Tuneable Torque

Adaptive DC

We can adapt DC to meet a range of operational requirements. Our in-house tooling and design teams can adapt DC to balance radial stiffness with thermal stability, maintaining smooth operation. For our steering column customers, we finely tune clearances to allow for staking during assembly but also to prevent lash from too much clearance.

We are experienced in achieving precise clearances via moulding processes; our tooling and moulding teams can achieve very accurate bearing manufacture.

Tuneable torque / Low torque

Some applications require a low torque; for example, pool cleaners, where the bearing must spin freely within the water or a photocopier, which needs bearings that spin freely and smoothly for accurate printing.

Plastic bearings generally have lower torque than steel bearings as they are lighter and require no lubrication to operate smoothly. In addition, through integration, material choices and specialist manufacturing processes we can provide bearings that have as little as a third of the torque of an equivalent steel bearing.

Benefits to the customer are not just in better performance – our bearings often replace bushes that have unacceptably high torque, so that the customer can use a lower specification and size of a motor to drive our lighter, lower torque bearing design, using less energy on start-up and in operation.

We have developed the capability of ‘tuning’ torque to rotate to meet specific requirements, including in our rotary control bearings, where we use this technique to generate different types of haptic feedback.

Our engineering team has been working hard on the designs that allow for tuning torque and adapting DC for different applications; see our plastic bearing innovations and development.

Load, Speed, Stability

Load & Speed

A full complement design, without a cage, lowers the torque to rotate of the bearing allowing it to spin faster and more freely. However, as the balls sit directly on the plastic, high loads can cause them to indent the plastic creating a ‘notchy’ feel and increasing torque to rotate, so they do have fairly low load capability. Double row designs will redistribute the load and preserve bearing performance, spreading the load across two rows of balls that can be caged or full complement, or even spin independently of each other, to increase load capability. We use both design features in different combinations to achieve required speeds and loads for a product.

Stability

By offering a single, moulded plastic part that replaces a selection of components fixed together, our integrated bearings offer better stability for a range of applications.

For automotive and smart controls applications, our integrated plastic bearings provide a more stable solution than a multi-component encoder, reducing the feel of ‘wobble’. In photocopiers and printers, our integrated pulley and bearing designs provide stability for a high-quality print. They also replaced existing bushes, lowering torque to rotate so the photocopiers run faster, providing a marketing benefit for our customer in increased copies per minute.