STATUS OF TECHNIQUES IN THE PAST During the 50ties of twentieth century mass production cars had third speed in the gearbox. In the end of the century they are five-speed. Increasing of number of gears improve two of fundamental indicators of automobiles-dynamics and economy. Increasing of number of gears is attained by mechanical supplementation of one more gear, in the gearbox, which is with the constant gear ratio. The changes of gear ratio are attained by gradually change of gears-manual or automatically.

The contemporary practice and theory of mechanisms and machines consider that is impossible to construct of toothed gear, which m the course of work (permanent rotating motion of toothed wheel) can gentle change the gear ratio.

Otherwise consider that is impossible to one of gearing toothed wheel in the course of work to change the number of teeth (variable) with value of changing of number of teeth Z<1.

TECHNICAL CHARACTER OF INVENTION The variable toothed gear is composed by drive shaft on which is installed by spline toothed gear with constant number of teeth with hemisphere shape (the number of teeth is even number bigger than 17). The toothed wheel with changing number of teeth is compound and is symmetric conical differential toothed gear composed from conical satellite toothed wheel installed immobility on driven shaft of variable toothed gear and gearing with two conical planet teethed wheels. On the internal side of conical planet teethed wheels are made tooth sector, which is canal, which in cross section is hemisphere circumferences. The canals are lines composed by crossing of mentally situated divisor circumference (the center of which coincide with the center of conical planet toothed wheel) of teethed wheels with hemispheres, teeth and step between teeth equal to two hemisphere, with the relevant step first, second and so on, to the end of tooth sector.

The step is project on the all of the mentally situated divisor circumference. The tooth sector is symmetric toward one canal (line), which is on the radius of tooth sector. The line of each canal crosses the center of the semicircle of the canal. The central angle of the tooth sector is equal to 200°. The teeth sectors of the two conical planet teethed wheels are situated one by the other opposed to the diameter and in this reciprocal position is settled owing to gearing of conical satellite tooth wheel with the conical planet teethed wheels. The teeth sectors of two conical planet teethed wheels are gearing consecutive, synchronic and simultaneous (200') with the toothed wheel with constant number of teeth with hemispherical shape.

The consecutive, synchronic and simultaneous gearing is accomplished from symmetric conical differential toothed gear. The supple (variable) changing of gearing ratio and centre distance between toothed wheel with constant number of teeth with hemisphere shape and teeth sectors is realized with move of toothed wheel with constant number of teeth with hemispherical shape at axle of drive shaft of variable toothed gear. The drive shaft of variable toothed gear is situated in the middle between two conical planet teethed wheels of symmetric conical differential toothed gear.

The variable toothed gear enable of made on this basis gearbox to change me gear ratio supple and practically to have limitless number of tooth gear.

The variable toothed gear reduces to simple terms construction of gearbox.

DESCRIPTION OF SUPPLEMENT FIGURES Figure 1-Kinematic scheme of variable toothed gear with one driven shaft.

Figure 2-Kinematic scheme of variable toothed gear with two driven shafts.

Figure 3-Kinematic scheme of gearbox for transports realized on the basis of variable toothed gear.

Figure 4-Schematically figure of teeth sector.

REALIZATION OF INVENTION Variable toothed gear Fig. 1 consist of drive shaft I splined joint with toothed wheel with constant number of teeth with hemisphere shape 2, gearing with teeth sectors 6 with canals, which in cross section are semicircles situated on internal side of conical planet teethed wheels 5, gearing with conical satellite toothed wheel 4, immobility connected with driven shaft 3 of variable toothed gear.

The other implementation for example, showed on the Fig. 2 driven shafts 3 are two, they are immobility connected with the conical planet teethed wheels 5.

On the Fig. 3 is showed gearbox of means of transport realized on the basis of variable toothed gear.

The gearbox include drive shaft 1, which is assembled toothed coupling reverse 9 and bearing splined shaft 7 and toothed wheel with the constant number of teeth with hemispherical shape 8 for reverse speed. On the splined shaft 7 is assembled toothed wheel with constant number of teeth with hemispherical shape of teeth 2.

The teethed wheels with constant number of teeth with hemispherical teeth 2 and 8 are gearing with the teeth sectors 6 with canals, which in the cross section are semicircles, situated inside on the conical planet teethed wheels 5 gearing with conical satellite toothed wheel 4 immobile connected with driven shaft 3 of variable toothed gear. The shaft 3 appears driven for the gearbox too.

MAKE USE OF INVENTION The changing of gear ratio of variable toothed gear is accomplished at/with/axle motion oh toothed wheel with constant number of teeth with hemispherical shape 2 at axle of drive shaft 1-Fig. 1 and Fig. 2 The changing of gear ratio of gearbox Fig 3 realized on the basis of variable toothed gear is accomplish with axle motion of toothed wheel with constant number of teeth with hemispherical shape 2 on the axle of splined shaft 7. The toothed coupling for reverse 9 connected drive shaft 1 with sphned shaft 7 for motion forward. The toothed coupling for reverse 9 connected drive shaft 1 with the toothed wheel with constant number of teeth with hemispherical shape 8 for motion back. The toothed wheel with constant number of teeth with hemispherical shape 8 is fixed in axle direction according drive shaft 1 in result of which variable toothed gear, made on the basis work as gear with constant gear ratio.