Drive arrangement for a human-powered vehicle

Abstract

A drive mechanism for providing assistance in the propulsion of an HPV, the HPV having: a central shaft assembly including a central shaft body and a pair of cranks, and a central shaft output for forward delivery of propulsion drive, the central shaft output being attached to the central shaft body. The drive unit includes: a drive wheel configured to deliver torque to the bottom bracket body via a connector axially positioned outside a bearing supporting the bottom bracket body; a motor including a rotor; a motor output wheel capable of rotating about an axis parallel to and offset from the bottom bracket body when the drive unit is connected to the bottom bracket assembly; a drive element capable of coupling the motor output wheel to the drive wheel to deliver torque from the motor to the drive wheel; a one-way clutch located in the power transmission system between the rotor and the bottom bracket assembly, the one-way clutch being configured to engage when the rotor is rotating at an engagement speed and disengage when the rotor is rotating at a speed below the engagement speed; and a controller configured to receive data from one or more sensors and estimate the force applied to the bottom bracket body by the rider via the crank based on the data, and configured to use this information to determine the level of torque that the motor will apply to the rotor.

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