The Maybach 210 engine used in the Initial Tiger utilised an external gearbox mounted on the rear wall to drive the cooling fans. The gearbox was driven in turn from a horizontal output at the top rear of the engine (See diagram below).
While later versions of the engine did away with the fan drive gearbox, and limited slip clutches were fitted to the fans themselves (D656/21), the variant seen in 250031 required overload protection between the fan drive gearbox and the fans. In addition the Rpm of the gears inside the fan drives was too high for normal (oil bath) lubrication, therefore oil was pumped in at high pressure from the fan drive gearbox, spraying oil directly onto the gear teeth, then returning to the fan drive gearbox via a lower line.
1. Horizontal drive from engine
2. Overload Clutch
3. High pressure oil feed to fan gears
4. Oil return line to gearbox
5. Rotating oil filler pipe for gearbox sump
When we first set to examining the images of these couplings (2), we were not sure of their exact design, as differing Allied reports and 656/21 mentioned both mechanical and electro-magnetic clutches being used. What we did have however were the words Ortlinghaus and Remschied stamped onto the units. We then discovered the German company Ortlinghaus who had a long history (est. 1898) of clutch and coupling manufacture and got in touch with them. They were very keen to help, and quickly identified the units as one of their mechanical overload type clutches of a design almost identical to one still manufactured. They also cleared up the Remscheid stamp - this is the town where their factory was located and all of their clutches carried this mark on the release ring. Photographs on pages 70, 74, and 172 of the book
Authors: Liejon Schoot, Rob Veenendaal, Alasdair Johnson, Brian Balkwill
Thanks to Ortlinghaus-Werke GmbH