Tilting suspension for a vehicle
A tiltable vehicle ( 100 ) is described comprising a vehicle frame ( 102, 108 ), one front wheel ( 124 ), two rear wheels ( 112 A, 112 B) and two swing arms. The swing arms are pivotably coupled to a pivot point ( 121 ) on the vehicle frame at a first end, and to one of the rear wheels at an opposing end. A swing arm ( 41 ) is rotatable around a rotational axis ( 42 ) lying in a plane of symmetry of the vehicle frame ( 102, 108 ). Each of two linkages ( 63, 64 ) is coupled at a first end to one of the swing arms at the pivot point. The vehicle comprises two connection arms ( 53, 56 ) arranged between the linkages ( 63, 64 ) and one outer end of the rocker arm ( 40 ). The connection arms comprise resilient members ( 61, 62 ) comprising a number of Belleville springs arranged in at least two groups of rings so as to create a non-linear spring characteristic.
1. A tiltable vehicle, comprising:
a vehicle frame;
one front wheel;
two rear wheels;
two swing arms, each of the swing arms being pivotably coupled to a pivot point on the vehicle frame at a first end, and coupled to one of the rear wheels at an opposing end;
a rocker arm rotatably arranged around a rotational axis lying in a plane of symmetry of the vehicle frame;
two linkages, each of the linkages being coupled at a first end to one of the swing arms at the pivot point, wherein the linkages are coupled at an angle to the swing arms;
two connection arms, each being arranged between a second end of one of the linkages and one outer end of the rocker arm;
wherein each of the connection arms comprises a resilient member, the resilient member comprising a number of Belleville springs arranged in at least two groups of rings so as to create a non-linear spring characteristic,
wherein the non-linear spring characteristic is continuously increasing with increasing spring stroke, and
wherein a derivative of the non-linear spring characteristic comprises an increasing stair case function.
2. The vehicle according to claim 1 , wherein the resilient members are arranged so that when the resilient members are increased, the Belleville springs are compressed.
3. The vehicle according claim 1 , wherein each group of Belleville springs comprises at least one of the following configurations:
two springs in series;
two springs in series and one additional spring arranged in parallel at both sides of the two springs in series;
two springs in series and two additional springs arranged in parallel at both sides of the two springs in series; and
two springs in series and three additional springs arranged in parallel at both sides of the two springs in series.
4. The vehicle according to claim 1 , wherein a derivative of the non-linear spring characteristic is an increasing stair case function except for a transition between a first step a second step.
5. The vehicle according to claim 4 , wherein the stair case function has four steps.
6. The vehicle according to claim 5 , wherein the vehicle comprises an electric motor and a battery for powering the motor.
7. The vehicle according to claim 1 , wherein the stair case function has four steps.
8. The vehicle according to claim 7 , wherein the vehicle comprises an electric motor and a battery for powering the motor.