Hybrid Technology

Since 1993, our field tests have demonstrated that this technology is eminently suitable for garbage trucks and urban buses - vehicles which apply the brakes frequently. One of our demonstration vehicles has aired twice on The Discovery Channel. Another collected fares as an urban transit bus for 2 years (and counting).

Simply put, what we do is capture the energy created by the application of brakes, instead of wasting all that energy in wearing out brake linings and so on. Our system uses hydraulics to store that energy and propel the vehicle as the energy is required.

Given an appropriate order, we can outfit vehicles at a premium of roughly 10%, with a payback period, depending on usage, of 9 - 18 months.

Cumulo hydrostatic transmission with energy storage is primarily intended for use in vehicles which start and stop frequently and/or carry a heavy workload within limited distances.

Energy in the form of pressurized hydraulic fluid is stored in accumulator, and is recycled for use in the acceleration of the vehicle.

Benefits of the system:

Reduced fuel consumption
Reduced emissions of exhaust pollutants
Less wear on the engine and friction brakes

Hydraulic System:

The hydrostatic system is connected to the vehicle engine and the rear axle. The system consists of the following four main components:

hydraulic machines (pump/motor)
gear
pressure accumulator
fluid tank

Legend: 1) Throttle signal 2)Brake signal 3) Signal to the engine control 4) Control of the transmission 5) Speed signal 6) Volume signal a) Hydraulic machine b) gear 3) Pressure accumulator d) Fluid tank e) Electronic control unit

Control Equipment:

By means of electrical sensors, the system picks up the information in the form of the driver's control signals (throttle/brakes) and the operating mode of the transmission after processing in an electronic control unit, signals are sent to the engine and hydraulic system.

DESCRIPTION OF FUNCTION - The Cumulo Hydrostatic Drive

The Cumulo Hydrostatic Drive transmits propulsive power from the source to the user.

It utilizes:

Secondary control of modern hydraulics.
Microprocessor control of modern electronics
Energy storage in a pressure accumulator

The system has two clearly defined sections:

The primary side, comprising a hydraulic machine mounted onto the propulsive engine and the pressure accumulator

The secondary side which includes the same accumulator and a hydraulic machine mounted onto the drive axle

The user’s requirement for power is governed at the secondary side, i.e. a driver’s request for power via the accelerator will control the hydraulic machine connected to the drive axle. The secondary control with its microprocessors and accumulator consequently ensures an efficient utilization of available energy. The energy source will always supply power from the hydraulic machine to the accumulator and fill it to a predetermined level. Similarly, the brake energy from deceleration will, as a rule, be stored in the accumulator.

The control strategy is based on the conditions that:

The capacity for energy storage is filled to its maximum when the vehicle is at a standstill

The quantity of energy stored will vary according to a predetermined program. This program has been designed to ensure that storage capacity is available for converting the vehicle’s kinetic energy to stored potential energy.

Acceleration from standstill is consequently performed by means of the stored energy. This energy will ensure a low noise level and minimized exhaust emissions. The size of the energy storage is dimensioned on basis of vehicle weight and operating cycle.