Heavy industry logistics has long fostered a debate between mechanical and electric drive systems. Recently, the numbers seemed to indicate greater efficiency in electric drive systems in some industries, especially taken on a pound-for-pound basis. However, recent modeling and industry reports has led to some debate as to which type has the true advantage in industry, and it seems to come down to the purpose of the machine powered by the drivetrain. Some companies like NORD Gear have always understood this and manufactured both electrical and mechanical solutions, and this is a view that is gaining more credence on the market.
The first point of argument is usually top speed. Pound-for-pound, electrical drive systems will win. A diesel engine powering a generator powering an electric motor will be able to accelerate to and maintain a much more even, speedier clip. By contrast, mechanical drive systems tend to rely on first and second gear solely when loaded. However, this advantage is dubious. Many industrial applications of drive systems require top speed thresholds for the sake of safety.
Torque is another point of difference, and this is where mechanical drive systems shine. Mechanical drive systems handily beat electric systems for the purposes of torque. This gives mechanical drive systems an advantage on gradients in most cases, and allows them to navigate steeper grades without sacrificing speed or efficiency. However, this benefit can also be rendered redundant if the situation doesn’t call for the regular traversal of gradients.
Maintenance and repair is a more complicated matter, and the argument gets trickier trying to compare which system has the advantage in this regard. On the one hand, electrical systems are easier to repair and maintain, and training personnel to account for them is generally easier. On the other, mechanical systems have a longer history, and more people are already qualified to work on them. This makes it a little less clear cut as to which is the better system from a bottom-line focused analysis.
Comparing mechanical and electrical systems for function and efficiency is simple. However, trying to elect that one is superior to the other requires an in-depth analysis of the situation at hand. If torque matters more than overall efficiency, mechanical systems are generally a better bet, as they are more ubiquitous, and often less expensive. For general purposes with no specialized conditions intervening, however, electrical systems are less expensive to run and more generally efficient. Both are progressing and improving, but your needs will vary.