Belt / Chain: Description and Operation

BELT AND PULLEY SYSTEM

ECVT Belt And Pulley Mechanism:

PURPOSE
The belt and pulley system is part of the ECVT transaxle stepless speed change mechanism.

OPERATION
The belt and pulley mechanism consists of a pair of pulleys whose groove width can be changed freely in the axial direction and a steel belt consisting of steel blocks and a steel band. The speed is changed continuously from low (pulley ratio 2.503) to overdrive (pulley ratio 0.497) according to the steel belt and pulley contact radius. The pulley groove width is controlled by the hydraulic pressure of the input shaft and output shaft pulleys.

CONSTRUCTION
Both the primary pulley and the secondary pulley consist of a moving sheave with 11° sloping sides and a shaft. A hydraulic pressure chamber is provided for both parts at the back of the moving sheave. Pulley groove width is changed by sliding the moving sheave on the shaft by a ball spline.


STEEL BELT

ECVT Steel Belt:

PURPOSE
The steel belt is part of the ECVT transaxle stepless speed change mechanism.

OPERATION
The steel belt consists of approximately 280 steel blocks and two steel bands made up of 10 laminated steel strips. The feature of this steel band is that where the conventional rubber belt, etc. transmit power by tension, the steel belt transmits power by the compression of steel blocks.

The marging steel band consists of 10 laminated steel strips and is divided into thin parts so that it can withstand small bending, thus preventing fatigue breakage caused by bending. For the steel blocks to transmit power, there must be a friction force between the blocks and the sloped sides of the pulleys. This friction force is generated by the mechanism described below. When hydraulic pressure is applied to the secondary pulley, the steel blocks are squeezed between the sides of the pulley and forced outward. As a result, tension is generated at the band and friction force is generated between the steel blocks and the primary pulley. The steel blocks transmit power by compression, and the steel band maintains the friction force to do this.

CONSTRUCTION
The steel belt consists of approximately 280 steel blocks and two steel bands made up of 10 laminated steel strips.