Drive mechanism for infinitely variable transmission
View Patent ↗A variator transmission comprises an input shaft ( 18 ), an input disc ( 10 ) mounted on the input shaft for rotation therewith and an output disc ( 12 ) facing the input disc and arranged to rotate coaxially therewith, the input and output discs defining between them a toroidal cavity. Two rollers ( 14, 16 ) are located in the toroidal cavity and first and second roller carriage means are provided upon which the first and second rollers respectively are rotatably mounted and end load means ( 34, 36 ) urge the rollers into contact with the input and output discs to transmit drive. The two roller carriage means are mounted on opposite sides of the pivotal axis of a lever ( 50 ) and the pivotal axis of the lever ( 50 ) is movable in both the radial and non-radial directions with respect to the rotational axis of the input and output discs.
1. A variator transmission comprising:
a housing;
an input shaft;
an input disc mounted on the input shaft for rotation therewith;
an output disc facing the input disc and arranged to rotate coaxially therewith, the input and output discs defining between them a toroidal cavity;
two rollers located in the toroidal cavity;
first and second roller carriage means upon which the first and second rollers respectively are rotatably mounted;
end load means to urge the rollers into contact with the input and output discs to transmit drive;
lever means having a pivotal axis, the two roller carriage means being mounted on the lever means on opposite sides of the pivotal axis; and
pivoting means for pivoting the lever means about the pivotal axis;
whereby the pivotal axis of the lever means is movable in the radial direction with respect to the rotational axis of the input and output discs and also has a component of movement in a non-radial direction.
2. A variator transmission as claimed in claim 1 , wherein the pivoting means comprises an elongate recess in the lever means, engageable with a projection which is fixed with respect to the housing.
3. A variator transmission as claimed in claim 2 , wherein the projection comprises a pivot pin fixed with respect to the housing, on which a slider block is pivotally mounted, the slider block being engaged with the recess in the lever means.
4. A variator transmission as claimed in claim 3 , wherein the width of the slider block is substantially the same as the width of the recess.
5. A variator transmission as claimed in claim 2 , wherein the recess in the lever means comprises a slot.
6. A variator transmission as claimed in claim 1 , wherein the pivotal axis of the lever means is movable through a predetermined distance.
7. A variator transmission as claimed in claim 1 , wherein the pivoting means for pivoting the lever means about the pivotal axis comprises an arm portion.
8. A variator transmission as claimed in claim 1 , further comprising pivot means between each roller carriage means and the lever means.
9. A variator transmission as claimed in claim 8 , wherein the pivot means comprises a spherical joint.
10. A variator transmission as claimed in claim 1 , wherein the input shaft and the output disc form the inputs of a mixing epicyclic gear train.
11. A variator transmission as claimed in claim 10 , wherein the mixing epicyclic gear train is arranged coaxially with respect to the input shaft.
12. A variator transmission as claimed in claim 10 , further comprising reduction gear means connected to the output of the mixing epicyclic gear train.
13. A variator transmission as claimed in claim 1 , wherein the end load means comprises resiliently deformable means.
14. A variator transmission as claimed in claim 13 , wherein the end load means comprises only resiliently deformable means.
15. A variator transmission as claimed in claim 13 , wherein the resiliently deformable means extends between a transmission housing and one of the input and output discs.
16. A variator transmission as claimed in claim 15 , wherein the resiliently deformable means comprises a spring.