US 6,520,878 B1Granted

Driving pulley for scooters and other vehicles

AssigneeCvtech R & D Inc.

InventorsAlexandre Leclair, Christian Mercier, Josée Lacouline, Rémi Breton

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Abstract

The driving pulley (12) is used in a continuously variable transmission (CVT) and comprises two flanges (22,24) around which a drivebelt (20) is partially wound. The first flange (22) is fixed in translation with reference to the drive shaft (16) while the second flange (24) is movable, with reference to the first flange (22), between a distal position and a proximal position. The driving pulley (12) is provided with an arrangement which allows the return force on the second flange (24) to be maximum when the second flange (24) is at the distal position, and minimum when the second flange (24) is at the proximal position. The driving pulley (12) is also capable of being disengaged from the drivebelt (20) at a low rotation speed. This driving pulley (12) is particularly well adapted for use on a scooter.

Claims23

Dependent claims

A driving pulley for a continuously variable transmission, the driving pulley being coaxially mountable around a drive shaft and rotatable at a variable rotation speed, the driving pulley comprising:

a first flange having one side provided with a conical wall;
a second flange having opposite first and second sides, the second flange being coaxial with the first flange and having a conical wall provided on the first side thereof, the conical wall facing the conical wall of the first flange to form a drivebelt-receiving groove around which a drivebelt is partially wound, the second flange being axially movable with reference to the first flange between a distal position and a proximal position;
a first means for connecting the first flange to the drive shaft in a torque-transmitting engagement;
a second means for connecting the second flange to the drive shaft in a torque-transmitting engagement;
a third means for generating a first force urging the second flange to move towards the first flange, the third means being responsive of the rotation speed of the driving pulley;
and
a fourth means for generating a second force urging the second flange to move away from the first flange;
the driving pulley being characterized in that:
the fourth means generate the second force with a maximum magnitude when the second flange is substantially at the distal position and with a minimum magnitude when the second flange is substantially at the proximal position;
and
the drivebelt-receiving groove is wider than the drivebelt when the second flange is at the distal position, whereby there is no contact between the conical wall of the second flange and a corresponding side of the drivebelt when the second flange is at the distal position.

8 more elements

A driving pulley for a continuously variable transmission, the driving pulley being coaxially mountable around a drive shaft and rotatable at a variable rotation speed, the driving pulley comprising:

a first flange having one side provided with a conical wall;
a second flange having opposite first and second sides, the second flange being coaxial with the first flange and having a conical wall provided on the first side thereof, the conical wall facing the conical wall of the first flange to form a drivebelt-receiving groove around which a drivebelt is partially wound, the second flange being axially movable with reference to the first flange between a distal position and a proximal position;
first means for connecting the first flange to the drive shaft in a torque-transmitting engagement;
second means for connecting the second flange to the drive shaft in a torque-transmitting engagement;
a set of flyweights to generate a first force urging the second flange to move towards the first flange, each flyweight being symmetrically-disposed around the drive shaft between a corresponding pair of opposite and outwardly-converging ramps, one of the ramps of each pair being provided on the second side of the second flange and the other being provided on an interior side of an end plate facing the second side of the second flange and fixed with reference to the first flange;
and
means for generating a second force urging the second flange to move away from the first flange;
the driving pulley being characterized in that the means for generating a second force comprise at least one torsion spring having at least one coiled portion and a lever arm, the lever arm being in a sliding engagement with a corresponding convexly curved ramp, the coiled portion being connected to one among the second flange and the end plate, and the convexly curved ramp being provided on the other among the second flange and the end plate.

5 more elements

Dependencies are inferred from the claim text.