Electric propulsion device for vehicle, in particular human-powered vehicle

Abstract

The invention relates to an electric propulsion device (10) for a vehicle (11), in particular a human-powered vehicle (11), preferably in the form of a bicycle or the like, comprising: a support body (12); an electric propulsion device (14), preferably in the form of an electric motor, in particular of the brushless type, for the forward actuation of the vehicle, having a corresponding rotatable shaft (140) for outputting the power generated by the same electric actuation device or motor (14); and means (16) for outputting the power generated by the electric propulsion device (10), in particular means (16) comprising said operational connection means (193), i.e. Elongated and closed loop members or hinge chains (193), for engaging or engaging the transmission (19) of the vehicle. The means for transmitting the power generated by the electric actuating means or motor (14) to the means (16) for outputting the power generated by the electric propulsion device (10) comprise a first speed reducer stage (18a) and a second speed reducer stage (18b).

Description

technical field [0001] The invention relates to an electric propulsion device for a vehicle, in particular a human-powered vehicle. [0002] The vehicle is preferably in the form of a bicycle or similar. Background technique [0003] Electric motors for pedal assist bicycles are gradually gaining popularity in the market, leading to continuous innovation in this field. [0004] Until a few years ago, the motors of e-bikes were usually mounted in the hub of the wheel, so that the volume required for these motors takes advantage of otherwise unused space. [0005] Over the years, these motors have begun to show their limits. In fact, usually a brushless motor with an outer rotor, the magnets of which are fixed directly to the hub of the wheel, without reduction stages, the motor draws a lot of current to generate the necessary torque. Also, the lack of torque prevents e-bikes from tackling steep climbs (eg, more than 10% inclines), which might be acceptable for urban use on...

AI Technical Summary

Problems solved by technology

[0007] However, this hub-mounted configuration of the motor with one or two planetary reduction stages presents some disadvantages

The first disadvantage is that the overall volume of the planetary stage takes up valuable space in the active parts of the motor, i.e. the parts used to generate power (stator, rotor, windings)

The second disadvantage is that the transmission, although reduced, may rely on a single fixed reduction ratio, so the motor is forced to operate over a wide rpm range (eg: from 0 to 2000rpm) that deviates far, in most cases , from a regime that guarantees maximum efficiency

[0013] However, the crank-driven configuration has some disadvantages: the added complexity, and therefore the cost of production, compared to a motor located on the hub; and the size required for the primary drivetrain (which transfers motion from the electric motor to the bike's bottom bracket) and weight

[0018] However, this system has a single internal reduction stage, however this still involves large size, weight and cost

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