Parker Hannifin, the global leader in motion and control technologies, has been selected by Industrie Cometto SpA, an Italy-based designer/manufacturer of trailers, semi-trailers and self-propelled vehicles, to supply Parker’s latest EMT (Electric Modular Transporter). Parker was selected thanks to its innovative range of electromechanical solutions – Cometto wanted to replace its previous hydraulic system to achieve greater flexibility in terms of speed and control, and make the vehicle suitable for use in ATEX classified atmospheres.
Industrie Cometto SpA is based in Borgo San Dalmazzo, some 75km south of Turin. From here, the company specialises in the research, design, production and sales of trailers and semi-trailers for heavy transport operations. One of the company’s most recent projects is the EMT, which has been designed to serve factory production lines and stocking areas. Basic EMT modules can be equipped with two or three axle lines and coupled in back-to-back or side-by-side configurations. Offering payloads from 10 to 200 tonnes, the EMT is a self-loading and unloading transporter with the lowest deck height on the market.
The traction and steering system of the EMT are now equipped with Parker products, whereas previously Cometto used a hydraulics-based system. Each transporter can have from 4 to 16 wheels, all of which have to follow a perfect trajectory to ensure that the transporter moves in a co-ordinated way. With this in mind, the drive system has to guarantee precision in terms of speed, position and torque control. Only in this way is it possible to control the motion speed accurately and avoid slips or torque losses around bends.
The traction system on the EMT is fitted with an AC, three-phase, 2.3kW electric motor. This is air cooled and splined directly to a two-stage planetary gearbox inserted in the axial. With regard to the steering system, the position of each wheel axle is controlled electronically using an encoder. To explain further, each suspension unit is linked to the load platform by a rotation system that is driven by a 1kw electric motor – the motor is controlled by an absolute encoder and managed by the customer’s central processing unit.
Importantly, to achieve energy savings, the hydraulic pump is controlled by an AC low-voltage servo-motor, which in turn is driven using a low-voltage mobile servo-drive. In this application, the motor helps the customer to save energy by controlling the motor speed, which in Cometto’s case means hydraulic flow.
Supplying the complete motor and drive package for both non-ATEX and ATEX application, Parker was selected due to the high levels of support it could offer. Parker supported Cometto during various phases of the project, including product selection, sizing, and during initial build. To date, five Cometto EMT vehicles have been completed using Parker technology, four with low-voltage motors and drives, and one with high-voltage. For ATEX-rated EMT vehicles, Parker offers its EX (explosion-proof) servo-motors with AC890 variable speed servo-drives.
As a result of using Parker’s electric motors and drives, the EMT is subject to better speed, position and torque control. The vehicle offers noise-free 360° multi-directional operation based on several selectable steering programs.