Contributing Monkie G Monkie
Published on February 19, 2008
Venture Vehicles plans to initially offer two propulsion packages for the VentureOne: the hybrid E50 and Q100, and all-electric Venture EV model. Manufacturer’s Suggested Retail Prices (MSRP) will range from $18,000 for the E50, to $23,000 for the all-electric EV model with a wide range of accessories available for each. A Must See is the Carver in Action in a series of videos on the Venture Vehicles site, here is a direct link.
All three classes will incorporate the patented Dynamic Vehicle Control system, or DVC, developed by Carver Engineering, which allows the vehicle to tilt up to 45 side-to-side at a rate of 85 per second. For nearly thirteen years Carver Engineering B.V., a Netherlands-based engineering firm, has been developing Dynamic Vehicle Control, or DVC, technology in order to enable a new class of tilting three-wheeled vehicles. Originally conceived in 1994, DVC technology has gone through 18 different generations, and is now essentially perfected.
Carver Engineering was faced with the challenge of designing a slender vehicle that would not fall over, as most slim vehicles were prone. Their solution was to make the vehicle do what two-wheeled vehicles did, tilt when cornering.
However, due to the size and weight required to make the vehicle enclosed, the tilting operation could not be left to the driver’s control. Therefore, an automatic system that takes over the balance control was required in order to maintain the ideal tilting angles under all imaginable driving conditions, such as at all speeds and accelerations and during rapid emergency maneuvers, and also on slippery or slanting road surfaces. The result was DVC technology, a hydro-mechanical system that splits the steering input from the driver into a front-wheel steering angle and a tilting angle of the chassis.
This predictable, intuitive, and easy to use system automatically adjusts the distribution between the front-wheel angle and tilting angle at varying speeds and road conditions to ensure balance under all circumstances. At lower speeds the steering input is fully directed to the front wheel and the vehicle remains upright. As the vehicle increases speed, the input is more translated into a tilting angle and not into a front-wheel angle. The DVC system operates on a combination of hydraulic and mechanical technologies for a high reliability, quick response and natural feel.
The VentureOne’s EV electro-mechanical powertrain presents additional technical advantages. In comparison with a traditional internal combustion engine, an electric motor is relatively simple and far more efficient. The moving parts consist primarily of the armature (dc motors) or rotor (ac motors) and bearings, and efficiency is 35% – 50% higher than that of an internal combustion engine. The torque of an EV is better suited to a vehicle’s demands as well. At low speeds a vehicle needs high torque for acceleration, as cruising speeds are approached the demand for torque lessens. An EV develops maximum torque at low rpm, and torque continues to decline with speed, similar to what a vehicle demands. An EV also does not require a transmission in the traditional sense. In fact the Venture One has no transmission due to the favorable output curve of the electric motor. To reverse the electrical input polarity is simply reversed, which in turn reverses the direction of the motor.
The battery inside the VentureOne will be provided by A123Systems, a multinational manufacturing company based in Watertown, Massachusetts. The batteries address all three major factors that affect battery performance; high power, intrinsic safety, and long life. A 123 Systems battery technology is based upon highly active nanoscale materials that are inexpensive, nontoxic, and extremely stable in electrochemical systems. This high power chemistry is based on proprietary compositions with much higher charge and discharge rates.
Venture Vehicles has made preliminary estimated power calculations using conservative assumptions. The assumptions made include a sub-optimal drag coefficient, 0.32, a heavier vehicle, 1,400 lbs., and a heavier driver, 200 lbs. The calculations also include a total motor power of 50 kW and a 90% motor efficiency rate. Even with the aforementioned assumptions, the results show a 0-60 mph acceleration of six seconds, and a maximum speed in excess of 100 mph. The results also show more than adequate performance over grades as great as 12%. As a result of the testing, the company is confident that a 3.0 kWh power reserve is sufficient and would allow for a 20 mile EV.
The VentureOne’s Hybrid propulsion system is of a series design. The system consists of a small internal combustion engine connected to a 15 to 20 kW generator, two in-wheel 25 kW electric motors, a four gallon fuel tank, and a 3 kWh Li-Ion battery pack. The system is able to take energy normally lost as heat due to braking and return it to the battery, increasing overall system efficiency.