Mechanical steering transmission unit

A mechanical transmission unit, having an input drive shaft (1) and two output driven shafts (6 and 7) that comprises:

• a first pair of bevel gears having a first bevel gear (2a) and a second bevel gear (2b), the first bevel gear being splined to the drive shaft (1), the second bevel gear (2b) being splined to a driven shaft (3), that is at right angle to the drive shaft (1);
• at the ends of the driven shaft (3), two identical differential units (5) are installed, from which the two output driven shafts (6 and 7) originate,
• a cogwheel (8) that is splined to the drive shaft (1) and gears with a couple of cogwheels (9 and 10) that are identical to the cogwheel (8), each of which is splined to the another pair of driven shafts (11 and 12), which are parallel and whose opposite sides lie near the drive shaft (1),
• a second pair of bevel gears (13a and 13b) and a third pair of bevel gears (14a and 14b), which lie near the opposite sides of the first pair of bevel gears (2a and 2b) and are used to link differential gears (5) to their the another pair of driven shafts (11 and 12);
• two identical hydraulic units (15) respectively mounted on the another pair of driven shafts (11 and 12), each of them used to start two antithetical clutches (16a and 16b), the former (16a) controls transmission of motion from the two cogwheels (9 and 10) to their respective driven shafts (11 and 12);
• whereas the second clutch (16b) prevents the free rotation of a frame (17) and the another pair of driven shafts (11 and 12), making them revolve in the same direction;
• it is also being provided that the three pairs of bevel gears (2a and 2b;
• 13a and 13b;
• 14a and l4b) are perfectly identical;
• the first bevel gear of the first pair (2b) is splined to the driven shaft (3) and lies upside down with reference to the two bevel gears (13b and 14b) of the second and third pair.