Patent Application
20180111418
The present invention relates to an axle assembly for small motors including a method for constructing the same.
There are many products, such as snowmobiles, golf carts, chainsaws, small motorized vehicles, and the like, which utilize small internal combustion engines to power them. In these products, the overall cost of construction is an important, if not the most important, criteria for the engine.
Many of these devices that are powered by an internal combustion engine include an axle assembly and transmission having a shaft with a wheel flange formed at one end of the shaft. Previously, many of these axle assemblies have been of a one piece construction in which the axle assembly is first formed by casting a metal part in the general form of the axle assembly and thereafter machining the molded part to its final form. Such machining, furthermore, often requires a plurality of different machining operations.
The necessity to perform multiple machining operations, as well as the initial forging operation, in order to completely machine the axle assembly is not only time consuming, but expensive. Indeed, the expense of the axle assembly significantly increases the overall cost of the engine.
The present invention provides an axle assembly which overcomes the above-mentioned disadvantages of the previously known axle assemblies.
In brief, the axle assembly of the present invention comprises a wheel flange having a central opening. Preferably, the wheel flange is formed from powdered metal which requires little or no further machining after the wheel flange is molded from the powdered metal. The wheel flange may be formed from any conventional powdered metal material and includes a central opening.
An elongated shaft then has an end connection to fit within the wheel flange central opening. The shaft itself is machined from metal, such as steel, in the conventional fashion. Furthermore, one end of the shaft includes a plurality of external splines.
The splined end of the shaft is dimensioned to fit within the central opening of the wheel flange. When the wheel flange and shaft are aligned as desired relative to each other, a binder, such as liquid zinc, is then injected in between the wheel flange and the shaft so that, upon cooling, the binder locks the wheel flange and shaft together. Additional through openings through the wheel flange are preferably formed which also receive the binder. Consequently, once the binder has cooled and solidified, the wheel flange and shaft are rigidly held together.
A better understanding of the present invention will be had upon reference to the following detailed description when read in conjunction with the accompanying drawing, wherein like reference characters refer to like parts throughout the several views, and in which:
With reference first to
The wheel flange 14 is preferably constructed from powdered metal which is molded into its desired shape by a mold (not shown) and then sintered. Consequently, the overall shape of the wheel flange 14 is generally flat and planar. Furthermore, little, if any, machining is required after the wheel flange 14 is molded into its desired shape and sintered which results in a low-cost construction.
Referring now particularly to
As best shown in
As best shown in
After the wheel flange 14 has been fully molded and the shaft 12 machined as previously described, the knurled end 16 of the shaft is positioned centrally within the wheel flange 20 as shown in
Molten zinc is cast into the chamber 31 around the end 16 of the shaft so that the liquid zinc 30 fills not only the space between the end 16 of the shaft 12 and the wheel flange 14, but also extends through and completely fills the holes 26 formed through the wheel flange 14. This liquid zinc also fills within the uneven nor noncircular outer surface of the shaft 12 as well as within the noncircular recesses in the flange 14.
As the zinc 30 cools, the zinc 30 sets and becomes rigid. Upon doing so, the zinc 30 fills not only the noncircular opening 20 and cutouts 24 in the wheel flange 14, but also the noncircular outer surface of the shaft 12 formed by the knurling 22. Consequently, once the molten zinc 30 is set, the zinc 30 rigidly secures the shaft 12 and wheel flange 14 together and with the wheel flange 14 perpendicularly aligned relative to the shaft 12.
From the foregoing, it can be seen that the present invention provides a simple and inexpensive axle assembly which can be accurately and repeatedly manufactured to high precision at relatively low cost. Having described my invention, however, many modifications thereto will become apparent to those skilled in the art to which it pertains without deviation from the spirit of the invention as defined by the scope of the appended claims.
