Patent ID: 7387587
Filing Date: 2008-06-17
Classification: F16H

Abstract:
1. A epicyclic transmission having-at least one input and one output and involving interaction of three mechanically distinct rotating elements with any suitable form that allows the transfer of torque between input and output, namely a sun element, a ring element and a planet element in each of at least first and second unequal co-axial epicyclic assemblies, a first element of the first assembly and a first element of the second assembly able to rotate independently, the first rotating element of the second assembly able to be within the first rotating element of the first assembly, a second rotating element of the first assembly and a second rotating element of the second assembly being constrained to rotate at a common angular velocity, a third element of the first assembly being connected to a motive source, and control means for progressively changing the gear-ratio applied to a load connected to the first element of the first assembly of the transmission characterised in that the first and second assemblies each represent unequal fixed gear ratios respectively between the input and the output, the first and second assemblies arranged so that if individually each assembly has their first element constrained and their third element rotated in a certain direction the second element will try to rotate in an opposite direction relative to the tendency of the other assembly, the control means being operative to progressively increase or decrease the output gear ratio in accordance with the demand for an output lower or higher gear stage of operation.