Inmotive has signed a joint development agreement with Suzuki to develop an Ingear 2-speed EV transmission (earlier post) for a future Suzuki electric vehicle.

The Ingear is an efficient 2-speed transmission designed specifically for EVs. Many EV powertrains in the market are single-speed; typically, there are two helical reduction gears between the motor and the wheels.

Ingear replaces the second reduction gear with a continuous chain drive and an innovative morphing sprocket that resizes during a shift. The entire shift happens during a single revolution of the wheels.

To shift, an actuator directs outer gear segments in or out of the chain path, while the motor speed is carefully adjusted so that shifts are barely perceptible and can be completed in as little as 19 milliseconds.

Combined with a chain and chain-tensioner, Ingear provides for 2:1 or similar gearing ratios. The extremely efficient chain is always kept in line with the morphing sprocket.

Low-gear is used to move the car from a standing start to half of highway speed. High-gear is used for higher-speed driving. By enabling the electric motor to operate more efficiently, more of the battery’s power is used to move the car, and less is wasted as motor and transmission heat. Less waste means more range from each charge.

Ingear’s patented geometry keeps the motor in continuous connection with the wheels. Torque from the motor continues to flow to the wheels, even during shifting while torque fill algorithims maintain a smooth passenger experience. Similarly, regeneration is continuous, even while downshifting.

Inmotive says that through this compact and simple design, the Ingear can improve electric vehicle cost, range and efficiency. An Ingear can extend EV range by up to 15% and improve acceleration by up to 15%. Its patented geometry delivers a smooth and quiet ride.