Patent ID: 6358174
Filing Date: 2002-03-19
Classification: F16H

Abstract:
A continuously variable transmission comprising:two hydraulic units including a pump and a motor, each having a rotational element and a grounded reaction element, at least one of said hydraulic units being variable displacement; a control system for controlling said displacement of said one hydraulic unit; a variable ratio motor gearset having first, second and third meshing gear elements, and a variable ratio pump gearset having first, second and third meshing gear elements; an input shaft connected to said first gear element of said motor gearset; an output shaft connected to said second gear element of said motor gearset and to said rotational element of said second hydraulic unit; said third gear element of said motor gearset being connected to said third gear element of said pump gearset; a brake releasably connecting said first element of said pump gearset to ground; said second gear element of said pump gearset being connected to said rotational element of said first hydraulic unit; said two hydraulic units being hydraulically connected such that the displaced fluid from the first hydraulic unit flows to the second hydraulic unit and vice versa; whereby, input torque applied to said input shaft is transmitted therethrough to said pump, when said brake is engaged, by way of said first and third elements of said variable ratio motor gearset and thence by way of said third, first and second elements of said variable ratio pump gearset, reacting through said engaged brake to ground, to rotate said pump and pressurize a working fluid in said pump cylinders; said transferring of said input torque from said input shaft to said pump creating a reaction torque which is transferred through said second element of said variable ratio pump gearset to said output shaft, said pressurized fluid being conveyed through said opening in said manifold block to said motor and energizing said motor to produce motor torque that is transferred to said output shaft in addition to said reaction torque as output torque in said output shaft.