Dual transmission with triangularly arranged gear center positions

A twin transmission for a duo electric machine powertrain with single-wheel drive, to be driven by two electric machines, each for driving a respective road wheel of a motor vehicle, the twin transmission comprising:

• a first sub-transmission and a second sub-transmission;
• one single middle stationary axle;
• an input shaft configured for connection to each of the two electric machines, through which input shaft one of the first and second sub-transmission of the twin transmission is driven as a result of a drive power of said one of the two electric machines;
• a spur gear intermediate bearing, on which at least one gear is located and supported;
• the single middle stationary axle being configured for support of the spur gear intermediate bearing, the single middle stationary axle being fixed to a transmission case and being configured to stiffen the transmission case;
• and
• an output shaft configured for being connected with a wheel half-axle,
• wherein:
• the input shaft and the output shaft are arranged for torque transfer by rotation through a tooth meshing of gears having a first gear center for the input shaft, a second gear center for the single middle stationary axle and a third gear center for the output shaft,
• a transmission train from the input shaft, via the spur gear intermediate bearing, to the output shaft is configured with the first gear center, the second gear center, and the third gear center following a shape of an upside down letter V,
• the input shaft and the output shaft are located on an uniform, geometrically defined plane, which is spanned by the third gear center and by an axis of the input shaft through the first gear center, wherein the plane is configured for being arranged parallel to a plane spanned by four road wheel carriers of the motor vehicle,
• the spur gear intermediate bearing is a deflection stage for a torque, and
• the spur gear intermediate bearing has at least one freewheel body and at least one gear that is mounted as an idler wheel, so that introduced transverse forces are at least partially compensated by diverting transverse forces on the idler wheel with respect to the single middle stationary axle.

A dual transmission for a powertrain of a motor vehicle, comprising

• two input shafts being configured to be driven by two electric machines of the motor vehicle, and
• two separate single transmissions, each single transmission configured for being connected with a separate wheel of the motor vehicle and to provide a respective speed reduction,
• wherein each single transmission is a two-stage spur gear transmission with three positions for gear centers in a common transmission case, a first position of the three positions being occupied by an input shaft of the two input shafts and a second position of the three positions being occupied by an output gear,
• wherein an input shaft center and an output gear center are arranged in a middle region of the dual transmission and the input shaft of each single transmission extends transversely to a case longitudinal direction of the transmission case,
• wherein an arrangement of the input shaft center and the output gear center defines a horizontal reference plane within the transmission case at a first distance from a transmission case bottom, when the dual transmission is in a mounting orientation corresponding to a mounted position of the dual transmission in the motor vehicle,
• wherein a third position of the three positions is for a center of a middle stationary axle, the middle stationary axle being fixed to the transmission case and configured to stiffen the transmission case, the middle stationary axle being arranged parallel to the horizontal reference plane at a second distance from the transmission case bottom greater than the first distance,
• wherein the first position, the second position and the third position define connecting lines between the third position and the first position and between the third position and the second position, said lines forming respective angles with the horizontal reference plane, each said respective angle being selected from a range between 10° and 50°.