Blowers generally include two main parts: a rotating part, namely an impeller and shaft; and a stationary part that defines a fluid flow path, typically a chamber such as a volute.
Bearings are usually employed in pairs and in coaxial arrangements to support the rotating part, e.g., shaft. Ideally, the two bearings are located by a stationary member that constrains the two bearings in perfect axial alignment. Real world designs are less than perfect and, therefore, compromise bearing performance.
A widely employed bearing suspension mode involves holding each bearing within a separate housing structure and fitting those housing structures together to approximate a coaxial bearing arrangement.
There are two main classes of constraints on the packaging of bearings. One constraint relates to the practical limits of manufacturing precision, and another constraint relates to the need to attach and efficiently package items that must rotate.
With respect to the first constraint, although the precision of part forming technologies improves continuously, the state of the art is far from perfect. Furthermore, increased precision usually translates to greater expense, often dissuading a manufacturer from embracing the state of the art processes.
The second constraint is driven by the need to place items (such as a rotor/stator) between bearing pairs. This typically leads to the use of a two part housing construction. A consequence of multipart housings is that they accumulate unwanted tolerance build-up at each faying or joint surface, and, as such, each component part must be precisely shaped so that the accumulated dimensional errors remain within acceptable range.
Thus, a need has developed in the art for an improved arrangement that does not suffer from the above-mentioned drawbacks.
USPTO Backgrounds
USPTO Backgrounds