Axial flow is one of International Harvester Co.’s most significant developments. Developed in 1977, IHC first used axial flow on its 1440 and 1460 model combines to allow for easier threshing and graining. The use of axial flow meant few parts and less maintenance.
The concept of axial flow introduced by IHC for its combines was considered a risk at the time. The move was revolutionary because most manufacturers were using rotary combines but IHC opted for a full rotary combine by using axial flow. The move, while risky, took place because IHC combines were not in demand as compared to other manufacturers. Three-hundred 1440 and 1460 models were rolled out during the fall of 1977. When the trial period was deemed a success, IHC produced a larger model in 1978, called the 1480. By this time, IHC had respositioned itself at the forefront of this new and emerging technology.
In 1980, IHC improved its axial flow combine models by introducing a self-propelling model – the 1420. Little improvements have been made in the past two decades with regards to IHC axial-flow combines. Minor refinements are made to the newer series.
 Features/How it Works
Axial flow utilizes energy that is obtained from flowing gas. It passes through a chute surrounded by rotating power in an output shaft and is directed to the axis of the shaft. When this occurs, energy is obtained by the flow of the gas as it passes through. Pressure is decreased due to the loss of energy thereby requiring a larger volume for the passage area in order to produce a velocity consistent to the flow.
Axial flows are also referred to as propeller pumps because they characteristically push liquid in the direction of parallel to the shaft of the pump. The process of axial flow is similar to that of a boat’s propeller.
IHC credits axial flow with having several benefits that make it useful for combines. The first is that axial flow has a single rotor, which simplifies the threshing process. During this process, a vacuum of air assists in cleaner environment and few parts are needed, resulting in less maintenance.
The grain quality that is achieved as a result of axial flow has improved since its implementation. Axial flow makes the combines gentler with the crop, producing fewer damaged samples.
Axial flow allows for multiple threshing using a fully revolving force separation.
Axial flow makes combines more adaptable to the crop conditions because the settings are easier to select. With axial flow, combine operators can adjust the preferred settings for threshing and graining. IHC also credits axial flow for its matched capacity. With axial flow, all the operational systems of the combine: feeding, threshing, separating, cleaning, and grain tank capacity are equally matched.