Hybrid Car - an Inventor's Notebook

HYBRID 1 - gas grazing ponies

The concept of a hybrid gas electric is what drove the next six months of development.

To add a gasoline engine would considerably increase the range of what up to this point had been a purely electric car. The electric could have went perhaps 30 to 50 miles per charge, which would be only one round trip to town. The hybrid, however, could have nearly unlimited range

Having seen that a series hybrid, which used a gasoline engine to charge the batteries ( fig 1 ), was inefficient, I decided to construct a parallel drive system. In the parallel hybrid ( fig 2 ) the gasoline engine provides the main source of power to move the vehicle. The electric motor is used in combination, or parallel to the gas engine, to provide extra power for acceleration and hill climbing.

Hey wait a minute, how can two engines run cheaper than one? Well, most of the time your car engine is lazy. It is true that the Vega had nearly 90 horses under the hood, but for the better part of the time many of these ponies were grazing off the gas tank and not working. It takes only 12 to 15 horse power to maintain a light weight car at highway speeds. The extra ponies work only to accelerate or get you up a grade.  Thereby I theorized that capitalizing on the minimum sized gasoline engine needed to maintain speed on level ground, and then using the electric motor as a supplemental power source for acceleration, considerable economy could be achieved. The search was on for the most economical gasoline engine in the 12 to 15 HP (horse power) range. After studying engineering data provided from the engine manufactures I decided on a Tecumseh model OH16.  This overhead valve design engine could put out 16-peak horsepower and a continuous 12 HP.  To do this it required only 1.2 gallons of gasoline per hour.  If I could obtain a top speed of 50 MPH this could equate to over 40 MPG (miles per gallon), nearly double of what the original Vega would do on short trips.

Torque twisting trouble

A plate was added above the electric drive motor to mount the gasoline engine. The 16 HP Tecumseh was connected to the clutch adaptor through a #40 roller chain. This chain proved too troublesome in that it was very noisy and the chain easily stretched due to the single cylinder gas engine’s cyclical power pulsations.

Hybrid # 1 failed when the aluminum adaptor between the electric motor and the clutch adaptor sheared. The free floating electric motors output shaft, which posed no problem when used as an electric only, was unable to keep the clutch adaptor running true under the heavy, cyclical load from the single cylinder engine.

Because of the early failure no road tests were conducted.

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