Real Time has made a variety of custom dynamometers for R&D testing of ATV's and tractors (see our Customer List).
This photo shows a four-motor dynamometer designed to test All-Terrain-Vehicles. Each corner has it's own motor, allowing for independent power absorption from each wheel. Additionally, each corner has provision to couple directly between the axle shafts of the vehicle to jackshafts belted to the dynamometer motors. In this mode, the vehicle is raised off the rolls, and power absorption is achieved directly through the axles. It permits more effective testing of the differentials, universal joints, and couplings, etc., within the vehicle, itself. The front and rear roll pairs are mounted on separate frames to allow adjustment for different ATV wheel-bases.
The drawing below shows one of our tractor dyno configurations. In this design, power is absorbed independently from the right and left drive wheels of the vehicle by two AC motors with variable-speed vector drives.
The ATV and tractor dynamometers may use either the ARTIC-1 or ARTIC-2 Dynamometer Controllers, depending on how many I/O channels are required by the customer.