An Evolution in bearing case design
By embracing 3D printing technology Bowman International have been able to develop a modern, bespoke solution for the production of their bearing cages. As there are few design constraints restricting how a part can be manufactured, 3D printing has allowed Bowman to design specific products around the technology. As a result Bowman’s patented ‘Rollertrain’ cage technology is truly a stand-out innovation.
The Rollertrain Cage boasts a unique interlocking structure which uses the rolling elements to pin together each section of the cage. This revolutionary, design creates enough additional space around the circumference of the cage to incorporate two to four more rollers than comparative products. It is these additional rollers which allow the load to be spread over a higher number of rolling elements that increase the performance of the overall cage, making it a suitable specification choice for any application which would benefit from higher load capacity or extended life expectancy, without having to amend any other part of the bearing assembly.
Bowman have reported an up to 70% increase in the load bearing capacity of its split bearings and an increased working life increase of up to 500%. This is revolutionary for additive manufacturing as performance has been improved through the use of 3D printing.
Jacob Turner, Head of Bowman Additive Production explains; “The Rollertrain cage combines the very latest in 3D printing with world-renowned materials science. Together, this offers OEMs and plant maintenance engineers a split bearing which delivers superior performance and longer product life, alongside simplified mounting and maintenance procedures – not forgetting less vibration and noise during operation.”
The Evolution of a partnership – Europac3D & HP with Bowman International
Working alongside Europac3D, Bowman International tested the parts and were impressed both with the capabilities of the HP Multi Jet Fusion’s printed polymers as well as the speed and accuracy of the part production.
When testing the parts from the HP machine the Isotropic properties of the bearing cages were significant; the parts had equal strength in X Y and Z directions. This was a huge advantage in comparison to relative technology that has suffered from deficiencies in parts, accountable to weakness in the Z, or vertical, axis of the printer. As the HP machines has such rapid fusing speed in layers the Z axis strength passed production tests with flying colours and therefore delivered the preferred choice for Bowman.
Bowman’s HP Multi Jet Fusion machine is the first of its kind in the UK to use PA11 nylon polymer, a fine bioplastic polyamide powder which provides end products with the elasticity, durability and functionality required for use with in rolling element bearings. The PA11 nylon has a superior thermal resistance and is characterised by good elasticity, high elongation at break and high impact resistance as well as resistance to chemicals, especially hydrocarbons, aldehydes, UV, alcohols, detergents, oils, fats, mineral bases and salts.
John Beckett, Managing Director of Europac3D, comments; “Bowman International’s use of the HP’s Multi Jet Fusion printer is illustrative of how the part production market is being truly revolutionised by 3D printing. The new HP printers are able to accurately mass produce bespoke parts which in turn can cut costs and speed up production times.”
Since the new HP Multi Jet Fusion printer was introduced to the market in Spring 2017, the demand for the product has been unprecedented from both bureau printing businesses who rely on the quality of build and speed of printing, through to businesses looking to 3D print bespoke parts that are robust, accurate and available for immediate use.