Countless pioneering inventions were made by design engineer Wilhelm Maybach in the early days of the automobile. Gottlieb Daimler’s congenial partner solved a large number of technical problems, and many of his patents have retained their basic validity to this day.

On December 24, 1897, for instance, the tubular radiator developed by Maybach was registered as a utility model (no. 107 418) in Germany.

This radiator significantly improved engine cooling and was used for the first time in the so-called Phoenix car (1897), the first passenger car of Daimler-Motoren-Gesellschaft with an engine installed at the front.That period ranked among Maybach’s most prolific years.

Other examples of his pioneering work are the belt drive and the manual transmission – the patent applications for these developments (DRP 68 492, 70 577, 75 069) were filed as early as September 13, 1892, together with the patent for flywheel cooling (DRP 70 260).

The patents were granted between May 1893 and May 1894, and the relevant assemblies were used for the first time in the belt-driven Daimler car of 1895.

The belt-driven Daimler car was an attractive proposition with its quiet running characteristics, comparatively high speed and smooth gearshifts. It was therefore a popular car among car aficionados, among them the Prince of Wales, crowned King Edward VII at a later stage, who set out on his first automotive journey in such a car in 1896.The car had four forward gears and one reverse. Maybach’s patents ensured that another gear could be selected with the help of tensioner pulleys only when the previously engaged gear had been released.

The first patent on belt drive was entitled “Belt- or load-change transmission with alternately pressed-on tensioner pulleys”; the second was about a “Mechanism for the engagement and release of a belt or cable by means of tensioner pulleys”. The third dealt with the resilient mounting of the drive unit. The fourth patent on flywheel cooling of 1892 exclusively dealt with the recirculation of the coolant – one of the pressing problems in that day and age.

The engines had reached such a high level of operational reliability that they were capable of running for several hours. In older designs, a major portion of the coolant evaporated once it had done its job, and the water tank had to be replenished time and again. This solution was no longer acceptable given the longer distances to be covered. Flywheel cooling contributed to a greater range in a simple but effective manner: Maybach’s invention channeled the coolant to the inside of the flywheel rim where it was tossed about and thus cooled, collected again and returned to the reservoir.

From today’s point of view, this approach may sound strange but it did indeed represent major progress at the time. With flywheel cooling, water requirements dropped to a third of the previous quantity – from six to nine liters per horsepower and hour to just two to three liters.This closed-circuit cooling was used for stationary and automotive engines and replaced by the tubular radiator in 1897. Engine power had continued to rise to around ten hp (7.4 kW).

The cooling had to keep pace with this development, and Maybach once again came up with an effective solution. Maybach described its mode of operation as follows: “Device for cooling the water which flows around the cylinders of explosion engines, consisting of a flat receptacle which holds a large number of tubes; a suitable air stream generated in the direction of ventilation passes through the tubes and extracts heat from the cooling water.” The tubes were made of brass due to this material’s good heat conductivity. The more powerful Phoenix engines were no longer built as modified two-cylinder units but as four-cylinder units right from the start.

At the same time, Daimler-Motoren-Gesellschaft abandoned the belt transmission and installed a manual four-speed gear-wheel transmission in the Phoenix car.The tubular radiator of the Phoenix car continued to be used for quite a while until ever higher engine output called for further improved cooling. In response, Maybach invented the more effective honeycomb radiator for which a patent application was filed a few years later, on December 20, 1900 (DRP 122 766). This design solved the cooling problem once and for all. It made its debut in the 35 hp Mercedes, the first car of Daimler-Motoren-Gesellschaft with the brand name “Mercedes”.

It is considered to be the first modern car as it was with this car, developed by Wilhelm Maybach, that automotive engineering finally disassociated itself from carriage construction. The innovations of the 35 hp Mercedes included not only the honeycomb radiator but also a pressed-steel frame with a low center of gravity, a powerful engine, a steering column set at an angle, a shift gate, equal-sized wheels on the front and rear axles and a low weight.