Tilting system

Corner tilting

The problem with three-wheel vehicles with a symmetrical wheel layout is the tipping moment when cornering, which cannot be controlled at high speeds if the vehicle has a short wheelbase. To solve this problem the vehicle's centre of gravity can be moved towards the centre of the corner, for example by angling the complete vehicle using the same concept as when a motorcycle corners.

This results in a force vector from centrifugal force in the Y direction and the weight force in the Z direction, which ideally runs through the wheel contact point of the single wheel and the centre point between the contact points of the parallel wheels.

This is the solution that is adopted by "tilting three wheelers" (TTW), although there are different technical methods of achieving it:

1. Change the camber of the two parallel wheels (front or rear) with or without tilting the vehicle

2. Angle the vehicle around a pivot relative to the axis of the two parallel wheels

Both concepts can be achieved with and without active chassis controls, and whilst the parallel wheels for concept 1 can be either at the front (for example MB F300) or rear (for example Honda Gyro), for concept 2 they can only be at the rear.

Vehicles that use concept 1 have been around since the forties (for example Ernst Neumann-Neander 1948) and this method has regularly been used for concept cars (Mercedes Benz F300 "Life Jet" 1997).

Almost every well-known manufacturer has developed working prototypes of scooter-type vehicles.

Vehicles that use concept 2 include, for example, the "GM Lean Machine" dating from 1983, the "Carver" from Vandenbrink and various scooter-type vehicles from Honda, including the Honda Gyro / Honda Stream dating from 1984. There has been a BMW concept on this basis in the BMW Museum in Munich since 1991.

In addition there is an incredible number of DIY solutions and one-off builds, very small manufacturers, design studies, university projects and ideas from car manufacturers.




Tilting technology:

The CLEVER vehicle is a cabin tilter (1F1T). The cabin with the front wheel
is connected to the power unit and the two rear wheels by a pivot bolt. The rotary movement of the cabin is produced by two hydraulic cylinders (actuators) that are installed between the cabin and the power unit.
The actuators create the rotary angle of the cabin of +/-45° relative to the vertical power unit.




The hydraulic system consists of a pump that is driven direct by the engine and a pressure accumulator that maintains the oil pump if the pump suffers a defect.





The two single-action hydraulic cylinders are controlled by an electromagnetically actuated valve.

The signals for the hydraulic control valve come from a freely programmable computer that processes the input signals from a sensor system, such as speed, tilt angle of the cabin and lateral acceleration.