Precision bearings sort out satellite comms

Edited by the Engineeringtalk editorial team Jul 3, 2003

Sarnatech BNL has begun production of a custom designed plastic bearing for US-based KVH Industries, the world's leading provider of mobile satellite communications and television based antennas.

Sarnatech BNL has begun production of a custom designed plastic bearing for US-based KVH Industries, the world's leading provider of mobile satellite communications and television based antennas.

The bearing - at 242mm in diameter, Sarnatech BNL's largest regularly manufactured part - is being used in two of KVH's sophisticated satellite antenna systems - the TracVision L2 land mobile satellite TV antenna and TracVision G6 marine satellite TV antenna.

Such sensitive state-of-the-art equipment demands a precision bearing that is able to move precisely and accurately in order to maintain a consistent and uninterrupted satellite signal as the vehicle moves.

However, when KVH began to experience problems with its former bearing which was failing to meet the high standards their product demands, it commissioned bearing expert Sarnatech BNL to come up with a solution.

KVH's original bearing was distorting and disassembling in operation, pushing apart at very low loads.

It was also complex to create and the high cost due to the machining process was also unsatisfactory.

The brief to Sarnatech BNL was to resolve these problems quickly - a challenge taken up by the company's engineering team, led in the USA by Andrew Richards.

An azimuth bearing made from acetal with stainless-steel balls, the Sarnatech BNL solution offers significant improvements in the original bearing's performance.

The redesign of the raceways increased push apart force by 300 times avoiding disassembly in operation and the company's tooling strategy meant the minimising of machining operations, cutting the piece part cost by over 25%.

The team was also able to integrate additional features such as pads to provide more stability for the end product.

"One of the challenging aspects of this bearing was to manufacture thin section parts with tight tolerances over large dimensions whilst allowing free running and stability", explains Sarnatech BNL's R and D Manager, Jason Gregory.

"The development undertaken at Sarnatech BNL enabled us to add a planar deflection of the races of 3mm (peak to peak) with little increase in rotational inertia enabling us to be confident that the parts could be attached to a non flat surface without unduly effecting the bearing's capabilities".

"Sarnatech BNL's knowledge of plastics processing, together with their previous experience with applications similar to ours made them the obvious choice of partner for us on this project", said Chris Watson, spokesperson for KVH Industries.

"Not only did Sarnatech BNL solve the disassembly problem, but during our testing of the products we found that load bearing capabilities had increased by 20 times.

Distortion was also eliminated and the feel and rotational performance of the bearing greatly improved - the cost savings were an added bonus, covering the tooling costs in only four months".

"KVH are very confident with us and our new design", said Terry Holmes, VP Sales and Marketing at Sarnatech BNL (USA).

"So much so, that two further products for KVH have recently been secured and will enter production later this year.

We are looking forward to a long and rewarding partnership with KVH Industries".