Continuous-acting hydrostatic-mechanical power-shift transmission with toothed clutches

Apparatus for employing a bracing process in a hydrostatic-mechanical transmission, which comprises:

• a four-shaft planetary transmission;
• an infinitely variable hydrostatic transmission, coupled in parallel with said planetary transmission, said hydrostatic transmission adapted to effectuate the infinitely variable adjustment of said hydrostatic-mechanical transmission;
• a plurality of toothed gear wheels;
• two toothed clutches, said toothed gear wheels and said toothed clutches coupled and adapted to achieve the various gears;
• means for adjusting said hydrostatic transmission resulting in a bracing such that gear shifting takes places synchronously, load-free, and without interrupting the tractive force;
• said toothed clutches each comprise;
• a plurality of circular gear faces, which engage gears in said planetary transmission;
• a plurality of gear teeth, said gear teeth situated along at least one gear face of said toothed clutch;
• a synchronous ring, said synchronous ring disposed at a circular gear face;
• and
• a shift mechanism adapted and disposed to shift said planetary transmission by positioning said synchronous ring upon engaging said toothed clutch, such that a smooth delivery of torque is made between said toothed clutch gear face and the new gear to be selected.

The method of employing a bracing process in a hydrostatic-mechanical transmission comprising:

• providing a four-shaft planetary transmission;
• providing an infinitely variable hydrostatic transmission coupled in parallel with the planetary transmission, the hydrostatic transmission effectuating the infinitely variable adjustment of the hydrostatic-mechanical transmission, the hydrostatic transmission being provided with a fixed displacement hydraulic pump, an adjustable displacement hydraulic pump, a series of hydraulic fluid lines, and a control means;
• providing a plurality of toothed gear wheels;
• providing two toothed clutches, the toothed clutches having gear teeth with straight frontal profiles and sloped rear profiles;
• selecting a new gear to be shifted into, said new gear different from a previous gear to be shifted out of;
• adjusting the hydrostatic transmission by modifying the displacement of the adjustable displacement hydraulic pump by use of a regulating variable, such adjustment resulting in increasing the rotational speed of the previous power-transmission shaft of the four-shaft planetary transmission;
• increasing the shaft rotational speed until bracing occurs whereby contact between the previous gear and the toothed clutch of the previous gear occurs on the straight profiles of the previous gear teeth simultaneously with contact occurring between the new gear and the toothed clutch of the new gear on the sloped profiles of the new gear teeth;
• holding closed the toothed clutches of the new gear and the previous gear by an externally supplied holding force;
• and
• eliminating the externally supplied holding force to the previous gear once such bracing occurs, such that contact between the new gear and the toothed clutch of the new gear occurs on the straight profiles of the new gear teeth simultaneously with contact occurring between the previous gear and the toothed clutch of the previous gear on the sloped profiles of the previous gear teeth, resulting in the disengagement of the toothed clutch of the previous gear.