Improved efficiency, flexibility, convenience, and sustainability – the global trend towards electrification is also playing an increasingly important role when it comes to the hydraulics of mobile machinery. It reduces the strain on operators and contributes to safe and efficient handling. The rapid pace of development has unlocked an endless array of technological possibilities. One of the tangible products of this advancement is the electromechanical actuator (EMA) for the pilot control of small and medium-sized agricultural and construction machines. A look back in time shows which user groups can benefit most from upgrading to a machine with an EMA:
The evolution of hydraulic pilot control: from mechanics to electronics
Since the emergence of the first hydraulically driven mobile machines in the first half of the 20th century, hydraulic systems have undergone steady development. Hydraulic pilot control in particular has passed through various stages of refinement. Over the years, a number of different methods have been used to perform its central function of actuating the main spool in the hydraulic valve.
The earliest principle consisted of adjusting the spool by means of a direct mechanical connection between a hand lever and the main spool. From today’s perspective, however, these purely mechanical systems leave room for improvement. In view of their inadequate precision and lack of operating convenience as well as the aspect of decentralization, these purely mechanical systems were and still often are replaced by hydraulically pilot-controlled systems, in either a fully hydraulic or an electro-hydraulic design. However, these modern systems require an additional pilot control oil circuit, which is used solely for the purpose of activating the system. This not only translates into higher material costs – due to additional components such as hydraulic lines, pilot control pumps, and pressure-reducing valves – but also increases the susceptibility to faults. Oil contamination and fluctuating levels of viscosity, in particular, can quickly lead to malfunctions.
The solution: the Thomas-engineered EMA for electromechanical pilot control
In an effort to address the issue of growing complexity within the pilot control hydraulic system, which is directly associated with the quest for improved performance, Thomas has come up with an innovative solution: a combination of the original mechanical pilot control and state-of-the-art control and drive technology. The EMA provides the best of both worlds. It brings together direct mechanical pilot control with a high-precision electric drive that provides the basis for outstanding decentralization thanks to all-electric connecting cables and operating elements. This significantly improves ease of use and at the same time scales back material costs and reduces the system’s susceptibility to faults. In addition, there is no need for hydraulic pilot control oil circuits – a further boost to efficiency.
Features
- Positioning speed 80 mm/s
- Actuating force 240–340 N
- Working stroke up to 24 mm, repeatability ±16 µm and resolution 6 µm
- Thermal overload protection
- Actuation via CAN bus
- Developed and certified in accordance with DIN EN ISO 13849
For which customer system is the Thomas EMA the right choice?
„
The Thomas-engineered EMA is a prime example of how state-of-the-art drive technology can be combined with proven mechanical principles to optimize machine performance. It opens up new possibilities when it comes to boosting efficiency and conserving resources.“
English 
German