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Bearing Assembly Serves a Simpler Dish
Integrated unit improves mobile receiver
Sure, you may have a satellite
TV system that drops 155+ channels of entertainment into your
living room, so why not have the same for extended trips with
the family? Abetted by the reduced size of modern dishes,
King Controls, St. Louis Park, MN, did just that when they
introduced the King-Dome, a vehicle-top unit that can be used
when either parked for the night or rolling down the highway.
It boasts a 1-touch electronic controller that automatically
finds and locks in the nearest hot satellite signal, positioning
the internal dish for the best reception. The unit is designed
for recreational vehicles, marine applications and other mobile
uses.
Crucial to the product's operation is the point of rotation
between the dish and the base of the unit. The original configuration
used a plastic ball bearing pushed inside a separate aluminum
timing belt pulley. Since the system was mostly constructed
by King Controls, many of the pivot's components were machined
in-house from bar stock. When problems developed over tooth
profiling, project engineers turned to Sarnatech BNL, Foxboro,
MA, a design and manufacturing operation for thermoplastic
bearing assemblies.
The Sarnatech solution, an integrated plastic bearing assembly,
combined the rolling element bearing aspect with injection
molding, thus reducing overall part count and assembly time.
Two locating pins on the side of the plastic angular contact
bearing facilitate assembly of the satellite dish. Once these
pins slip into place, the assembler knows that all the parts
are correctly lined up for the bolts to fit to the outer race
of the bearing. The assembly's inner race sleeve extends on
both sides of the bearing as protection of the cables from
the sheetmetal base piece. POM (acetyl) was used to make the
assembly, with stainless steel balls as a deterrent to problems
caused by ambient moisture. "As well as reducing the
opportunity for errors in the manufacturing process of our
new King-Dome Satellite system, the Sarnatech BNL parts have
also cut the actual cost of that particular part of the assembly
by 50%," states Craig Miller, vice president of manufacturing
at King Controls.
--RM
For more information:
Circle 440 - Sarnatech BNL or connect directly
to their website via the Online Reader Service Program
at http://www.OneRS.net/103df-440
Circle 441 - King Controls or connect directly
to http://www.OneRS.net/103df-441
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