• Journal of Advanced Marine Engineering and Technology
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• 제30권8호
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• pp.863-869
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• 2006

A new CVT, the inner spherical traction CVT (ISCVT) is introduced. Transmission of the most scooters is the self-controlled variable pulley-belt type of CVT having some disadvantages in the fuel consumption and the limitation of the transmittable power due to the slippage between the belt and pulley. Unlike this, ISCVT controlled directly by driver is more efficient and the contact mechanism having the same line of contact normal of the spherical rotors of different radii on common center causes that the power density and torque capacity are remarkably improved. The prototype with the specifications of 50cc scooter is designed and tested.

• International Journal of Precision Engineering and Manufacturing
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• 제9권1호
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• pp.7-11
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• 2008

A new continuously variable transmission (CVT) for electric bicycles was developed using a traction drive mechanism with inner and outer spherical rotors. This electric bicycle CVT permits three propulsion modes: human-power only, motor-power only, or a combination of motor power and human power. In addition, the electric bicycle CVT has high power efficiency, large torque capacity, improved drivability, and good packageability. A prototype was manufactured based on a conceptual design, a performance analysis, and a detailed design. This prototype has a rated power of 250 W and input motor speed of 20 rad/s for an overall speed ratio in the range 0.3-1.2. A bench test was conducted to measure the power transmission performance of the prototype.

• International Journal of Automotive Technology
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• 제8권5호
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• pp.593-598
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• 2007

A new continuously variable transmission for bicycles(B-CVT) is developed by using a traction drive mechanism having inner and outer spherical rotors. The B-CVT has high power efficiency, large torque capacity, improved drivability and good packageability. The ratio change mechanism for the B-CVT is very simple, in contrast with other traction drive CVTs. After completing a conceptual design, a performance analysis and a detail design, a prototype of the B-CVT has been manufactured. The prototype has rated power of 100 watts, pedal speed of 6 rad/s and an overall speed ratio of 1.0-4.0. A bench test and an actual bicycle test have been performed to verify the practicability of the B-CVT.