Integrated Lightweight Electric Vehicle Transmissions

Application example:
YASA P400 Series Motors with lightweight gearboxes

Xtrac, a leader in the design and manufacture of vehicle transmissions, has a family of highly configurable gearboxes available that address the growing market requirement for single speed, lightweight and power dense electric vehicle (EV) transmissions. Driven by YASA P400 Series motors, the Xtrac P1227 Integrated Lightweight Electric Vehicle (ILEV) transmissions provide up to 3900 Nm and 320kW peak at the wheels from just 95kg for gearbox and  two motors combined in a full torque vectoring configuration.

This family of transmissions can be configured into one of the three arrangements shown below.

Torque Vectoring

A dual reduction gear set which delivers separate torque control to each of the driven wheels for torque vectoring.

Specification:

  • Reduction ratio of 2.5:1 to 5:1
  • Peak torque input = 800Nm (400Nm per e- motor)
  • Maximum input speed = 8,000rpm
  • Standard automotive output flanges.
  • Splash lubrication with integrated electric oil pump
  • High strength Aluminium alloy L169 casings
  • Ground helical gears for optimal NVH
  • Gearbox weight approximately 45kg
  • Motor weight 25kg per motor.

Split Torque Vectoring

Providing the ability to package the integrated motor and transmission closer to the wheels in either a ‘C’ or ‘Z’ configuration.

Specification:

  • Reduction ratio of 2.5:1 to 5:1
  • Peak torque input = 400Nm
  • Maximum input speed = 8,000rpm
  • Standard automotive output flange
  • Splash lubrication with integral electric oil pump
  • High strength Aluminium alloy L169 casings
  • Ground helical gears for optimal NVH
  • Gearbox weight 23kg
  • Motor weight 25kg per motor

Differential

Integrating a reduction gear set and either open or limited slip differential to provide the ultimate electric drive transaxle.

Specification:

  • Reduction ratio of 2.5:1 to 6:1
  • Peak torque input = 800Nm with 2 motors
  • Maximum input speed = 8,000rpm
  • Standard automotive output flanges.
  • Splash lubrication (provision for external oil pump)
  • High strength Aluminium alloy L169 casings
  • Ground helical gears for optimal NVH
  • Gearbox weight 28kg
  • Motor weight 25kg per motor

The design draws on Xtrac’s precision design and manufacturing engineering capabilities with a specific focus on ensuring the ground helical gear sets adopted for this transmission are low noise for the most demanding electric vehicle applications.