Patent ID: 6860104

Claim:
Automatic transmission, comprising at least one primary hydraulic pump ( 1 ) arranged to be powered by a motor, said primary pump ( 1 ) being arranged to power a number of at least two secondary hydraulic pumps ( 2 1 - 2 n ) which are mechanically connected to an outgoing propeller shaft ( 6 ), the secondary hydraulic pumps being arranged for active powering of said outgoing propeller shaft when the hydraulic pressure caused by the primary pump in a closed room (A) between the primary pump and the secondary pumps, reaches predetermined levels which are different for the various secondary pumps ( 2 1 , 2 2 and . . . 2 n respectively), wherein each of the secondary hydraulic pumps are closed by means of a mechanical spring resistance from a coil spring ( 2 13 - 2 n3 ) against a valve ( 2 12 - 2 n2 ) which abuts a valve seat, until the pressure from the primary pump ( 1 ) gets sufficiently high to overcome the resistance from said coil spring, the secondary hydraulic pumps ( 2 1 , 2 2 and . . . 2 n respectively) having individually adapted springs ( 2 13 , 2 23 and . . . 2 n3 respectively) which open at mutually different pressures, wherein the secondary hydraulic pumps ( 2 1 , 2 2 , . . . 2 n ) all have a respective blind passage ( 2 14 , 2 24 , . . . 2 n4 ) for oil enabling them to passively follow the outgoing propeller shaft ( 6 ) when they do not actively power the shaft, and wherein the secondary hydraulic pumps ( 2 1 , 2 2 , . . . 2 n ) are equipped with ratchet gears which enables them to stop when they do not actively power the outgoing propeller shaft ( 6 ).