Hydraulic technicians are indispensable in maintaining the efficiency, reliability and safety of hydraulic and pneumatic systems. Fluid power systems are integrated into industrial machinery and equipment used across the industry, such as manufacturing, construction, agriculture, aerospace, etc. Therefore, having competent fluid power technicians is essential to ensure equipment availability and extend the lifetime of the equipment.
Therefore, it is necessary to ensure the availability of skilled personnel in the workforce who are competent and trained in setting up, adjusting and troubleshooting a hydrostatic transmission (HST). Anyone can become a trained fluid power technician by completing the technical courses and apprenticeships in vocational colleges, TAFEs or RTOs.
Technical training centers must have adequate educational equipment to train the students as fluid power technicians. As such, it is generally unacceptable to use old, antique equipment or borrowed machines or even use actual industrial equipment as learning tools for the students.
Firstly, these equipment are not designed as an educational equipment, hence, there is a challenge to teach every aspect of setup, adjustment and troubleshooting hydrostatic transmission system. Secondly, practising on actual equipment is unsafe as it possess inherent risks that can be disastrous if the students are unable to handle and recognise them. Lastly, the transmission system must also be “broken” for students to learn how to troubleshoot a hydrostatic transmission system effectively.
A hydrostatic transmission system transmits energy through hydraulic fluids and consists of a variable displacement pump and a motor connected by hydraulic lines. It is arguably one of the most complex hydraulic systems to troubleshoot. The mechanics that are assigned to work on hydrostatic
For example, when a pump and or motor suffers a fragmented failure, the manufacturer may spend almost as much to put the machine back to work as it costs to purchase the system, if the mechanics do not have the required competency level to work on the machine. This is because the pump and the motor work in closed loop system . If the parts become fragmented, the bits and pieces of metal invade the loop. Untrained mechanics may not understand the mechanisms and procedures to start up the machine post catastrophic failure.
When the root cause of failures is not diagnosed, the mechanics may replace all the pumps, motors and components in the system, yet still did not fix the problem. This problem is pervasive in several industries – mining, agriculture, military, forestry, oil-field service, construction, manufacturing, et al.
Rory McLaren from Fluid Power Training Institute (FPTI) in the US developed a solution that allows the student to work on a hydrostatic transmission system under varying load conditions. The proposed equipment can be fit with every fault that could disable an HST in real-time. After further development, the Model MF500-HST – the world’s most advanced HST training system was born.
He stated “I decided to base the Model MF500 on a skid steer loader because it needed to have two completely individual HST systems. We chose dual (piggyback) Sauer Danfoss M46 pumps with electronic (joystick) controls. Each pump drives a high torque low speed motor with infinitely variable speed and load capability.“
A view from the “drivers seat.”
The MF500 was designed with the objectives to recreate and simulate in realtime every possible fault in HST pumps and motors that are listed in the troubleshooting manuals of companies like Sauer Danfoss, Rexroth, Linde, Kawasaki, Parker Dennison, etc. The same technology that was used in the MF105 hydraulic training system was implemented in MF500 to make the pumps and motors wear out in realtime.
Example of the realtime faults that can be auto-generated in realtime are listed below.
- Front and rear pumps can wear out.
- Left and right motors can wear out.
- Charge pressure can decrease in neutral.
- With a hot oil shuttle valve, charge pressure can also decrease in forward and reverse.
- Case pressure can increase.
- Electronic displacement control valve (EDC) and joysticks can fail in realtime.
- Machine can track to left or right.
Example of students’ activity:
Step 1 – Student is given a troubleshooting assignment – system is sluggish.
Step 2 – Student selects “system is sluggish” from fault menu:
Step 3 – Student starts the HST and heads up a hill and finds the report is correct.
Step 4 – Student selects the system’s schematic and chooses a “suspect” component:
Step 5 – Student chooses the most simple problem first – the EDC valve:
Step 6 – If a student finds the EDC valve is defective when they touch the symbol for the valve, it will replace it, which is shown in green. If the student selects the EDC and selects “finish” if the problem is not the EDC valve, a message will appear on the screen advising the student that the EDC was not the problem.
The student will continue with the task by testing the volumetric efficiencies of the pumps and or motors.
The student also learns how to navigate the HST’s service manual. When troubleshooting an HST in the field, they need to know where the respective manufacturer wants them to check pressure and/or flow. The service manual can be accessed on the menu on the left-hand side.
The MF500 is designed to work as educational equipment which means pressure and flow testing is non-invasive on the parts. Students don’t spill a drop of oil regardless of how much testing they execute, making it one of the safest hydraulic training equipment.
The purchase of the MF500 also includes the student workbook, which includes the complete curriculum and covers every aspect of best operating procedures and safety recommendations when working with a hydrostatic transmission system.
By using the MF500 as demonstration equipment in your training center, students will learn the skillsets they need to set up, troubleshoot, and perform every pre-start and post-start adjustment/setting recommended by the manufacturer. We can also customise the equipment to suit the requirements of each technical training facility. For example, the MF500 built for Bobcat’s world-class training center in Denver, Colorado was equipped with dual Sauer Danfoss H1 HST’s.
Bestech Australia is the authorized distributor and partner of FPTI in Australia and New Zealand. We supply the highest-quality hydraulic training equipment and offer local technical support to assist you with training, setup, and commissioning. For more information, contact one of our teaching equipment specialists.
