Digital Displacement® Hybrid Transmission Operation

IVT

The simplest configuration uses a Digital Displacement® Pump attached to the engine to drive a Digital Displacement® Wheel Motor attached to the driving wheels (which can be at the front, rear, or both).

The IVT (Infinitely Variable Transmision) does not have fixed gear ratios, allowing the engine to run at exactly the right RPM for maximum efficiency and minimum emissions. It also changes ratios much faster than a conventional gearbox, enabling the use of efficient high overdrive ratios while cruising.

Note that the IVT system is not actually a hybrid transmission, since there is no energy storage.

IVT + Regeneration

Regenerative braking can be added to the IVT by fitting a small Accumulator (a cylinder filled with gas and hydraulic fluid and capable of storing energy) and upgrading the DDP to a DDPM.

A car’s kinetic energy is normally wasted when the brakes are applied. With a regeneration-equipped transmission, braking energy (blue arrows) is recovered and saved into the Accumulator. When the car next accelerates the energy is returned to the wheels (red arrows), reducing the energy required from the engine.

IVT + Regeneration + Start/Stop

Engine Start/Stop can be implemented quite easily by adding the ability to start the engine from the Accumulator. Hydraulic starter motors are compact and start the engine much faster than an electric starter motor.

When the car is braking or stationary the engine can be switched off completely. When the driver presses the accelerator, energy from the Accumulator is instantly sent to the wheels to drive the car forward, and simultaneously sent to the engine to start it rapidly. Accessories (alternator, power steering etc.) Can be driven from the Digital Displacement® Pump Motor while the engine is stopped.