Queerbox
The 'Queerbox' was the nickname for an early sequential manual transaxle used by Lotus racing cars of the late-1950s and early-1960s, and was very similar in design and operation to a motorcycle gearbox. It was infamously unreliable.
Lotus Twelve origins
The
Design
The shifting mechanism was chosen with the additional input of Richard Ansdale. Space requirements, and the length of the gear cluster, meant that the selection mechanism would have to be mounted inside the gear cluster, rather than the usual motorcycle arrangement of dog clutches between the gears, an external drum to control their engagement and forks to connect the two. The mechanism needed to lock the selected gear onto the shaft, never engage more than one at a time, and all had to work at racing speeds.[4]
Such gearboxes had been built before, but neither widely used nor successfully.
The tubular "selector sleeve" slid back and forth over the input shaft and was splined to rotate with it. The gears of the input shaft were not attached to it and could rotate freely. They rode on the outside of the selector sleeve, not on the shaft itself. The output shaft of the gearbox had all five gears splined to it and in constant mesh with the other gears. [ii] On the outside of the selector sleeve was a ring of dogs, which could engage one gear at a time as the sleeve was slid back and forth through the gear cluster. The faces of these dogs were not flush but were slightly offset so that they engaged one by one.[4]
Unreliability
Initial servicing of the Queerbox was undertaken by
The task of fixing the Queerbox's unreliability problems, fell to Keith Duckworth, a young Lotus engineer. He then fell out with Chapman, who would not support the cost of the fix that Duckworth felt was needed, leading to Duckworth leaving to set-up Cosworth with Mike Costin. [7]
Notes
- ^ A sequential manual transmission is one where gears can only be selected in order, without skipping gears. Most road cars use an "H-pattern" shift, where any gear can be chosen in any order. A "paddle-shift system", with two buttons for 'change up' and 'change down,' is a form of "sequential" transmission, but not all sequential transmissions have a button-controlled shift, rather than a lever.
- ^ First gear was slightly different.
- ^ Hill would make his Formula One debut at Monaco in May 1958, driving a Lotus Twelve.
References
- ^ Ludvigsen, Colin Chapman, pp. 119–121
- ^ Ludvigsen, Colin Chapman, pp. 80–105
- ^ Ludvigsen, Colin Chapman, p. 82.
- ^ a b c d e Ludvigsen, Colin Chapman, pp. 82–83.
- ^ Ludvigsen, Colin Chapman, pp. 82–83, 85.
- ^ Ludvigsen, Classic Grand Prix Cars, pp. 187–188.
- ^ Robson (2017), pp. 23–26.
Bibliography
- ISBN 1-84425-318-X.
- ISBN 978-1-84425-413-2.
- Robson, Graham (2017). Cosworth - The Search For Power (6th ed.). Veloce Publishing. pp. 23–26. ISBN 978-1845848958.