Using a timing belt for a Dynamometer

[robs314]

Hello, I was wondering if someone could help me understand this situation.

I am designing a motor/generator dynamometer, which is to be arranged as shown in the attached picture.

There is a fixed high power DC motor transmitting power via a Syncronous / Timing belt to a motor which is under test. The Motor Under Test is on a pivoted plate above it, so the reactionary torque produced by the rotating plate should be measurable with a load cell.

I have come across plenty of material on driving-driven pairs of pulleys, but none on driven-driven arrangements.

Firstly, I want to make sure that my free body diagrams show the forces ( and reaction forces on the frame) going in the right directions.

Secondly, I want to be clear about what is the 'worst case' and normal operation for the belt design and maximum allowable stress in the shafts.
For this, I want to be sure of the conditions which would provide the biggest load to the belt and shafts.

If anyone can offer me any help, I would be grateful. Once I'm able to specify the belt and shaft dimensions, I can work backwards from that and evaluate torsions etc in the frame, which I am prepared for.

However, it's just a stumbling block until I get my head round it.

Many thanks

 

[Achy47]

Thank you for reaching out for help with your motor/generator dynamometer design. It sounds like you have a complex and interesting project on your hands. I am happy to offer my assistance and help you understand the situation better.

Firstly, let's discuss the free body diagrams. It is important to accurately depict the forces and reaction forces in order to understand the mechanics of the system. I recommend using a vector diagram to show the direction and magnitude of the forces acting on the system. This will help you visualize the forces and ensure they are going in the correct direction. Additionally, make sure to include all forces, such as the weight of the motor under test and the tension in the belt, in your diagram.

Secondly, the 'worst case' for the belt and shaft design will depend on the maximum load and torque that the motor under test can generate. It is important to consider the maximum load and torque that the system will experience in order to determine the appropriate belt and shaft dimensions. I suggest consulting with a mechanical engineer or using a computer simulation program to analyze the stress and strain on the belt and shaft under different load conditions.

As for the conditions that would provide the biggest load to the belt and shafts, it will depend on the specific application and use of the motor/generator dynamometer. For example, if the motor under test is designed to operate at high speeds and produce high torque, then that would be the biggest load on the system. Again, consulting with a mechanical engineer or using simulation software can help you determine the maximum load conditions for your specific design.

I hope this helps you understand the situation better and provides some guidance for your design. Best of luck with your project!