Free Flow Bearing Technology
As a leading designer and manufacturer of innovative plastic bearing solutions, BNL has led the development of anti-clog ‘free flow’ bearing technology for use in the water and leisure industry, where low friction properties and clog resistance are particularly important.
Low Friction
Applications such as spa jets and suction and pressure side pool cleaners operate solely on water flow and will only function if the water flow from the pump is used efficiently. The operational parts of these applications are therefore required to be capable of working with very little applied torque.
Using BNL’s more traditional thermoplastic bearing technology, starting inertias as low as 0.12Nmm would be considered the norm. However, using the company’s innovative “free flow” bearing designs, torques as low as 0.041Nmm are achieved (compared with similar sized metal options with
torque values of around 0.235Nmm*).
Clog Resistance
To address the problem of clogging from debris commonly found in the operating environment of these applications, BNL has developed an innovative patent-pending cage and race design. This revolutionary anti-clog bearing technology allows water and debris to flow freely through the system, yielding a greater flow path compared to conventional bearing technology.
With all of the sharp edges removed and the ball clearances increased to reduce potential obstruction points, a smooth and precise rotating jet is guaranteed - even under low pressure and flow conditions.
With our many years’ experience of spa and pool applications, we understand that the use of a caged bearing is not always practical, for example with smaller diameter bearings.
To address this, BNL has also pioneered the development of a cage-less ‘open design’ bearing.
Traditional spa and pool cleaner bearing designs typically utilise shields and seals to prevent debris from entering the workings of the bearing, however this can lead to serious problems. The tight seal necessary to keep out debris raises the torque required to turn the bearing and since zero clearances cannot be permanently maintained, the likelihood of bearing seizure caused by debris becoming trapped between the seals and the races increases over time. Additionally, as the bearing wears, the shield can begin to rub on the inner or outer race causing the bearing to essentially become a high friction bushing or cease rotating altogether. Shield and seal free, BNL’s ‘open design’ bearings ensure that bearing seizure and high torque are removed from the equation.
Increased Flow Path
With both innovative concepts, the anti-clog features result in an average 114% increase in the flow path compared with traditional designs, as debris that would ordinarily be trapped by a traditional cage design or seal, is instead allowed to pass straight through the bearing. These free flow designs enable a continuous passage of water through the bearing, allowing any debris to be washed out. The end result is a bearing that continues to function with minimal increases in inertia. Furthermore, the overall resistance to clogging is higher than sealed products due to the increased clearance afforded by the designs.
* based on standard sealed metal bearing data
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