How to define a motor with constant power kW output in solidworks motion

How to define a motor with constant power kW output in solidworks motion

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At my last job I did dozens of motion sims on lifting mechanisms, most involving linear actuators, though some with rotation. Constant speed motors and constant power motors just never worked. I even made test simulations to check agains hand calcs. Very poor results from SW Sim.

Ok, try this. Here's a simple fourbar mechanism that uses a constant power motor. Hopefully this will give you some tips about how to implement such motors. The Excel spreadsheet shows that the output power is constant.

Regards,

Shrikant

Dear Shrikant

I have used the same logic in my assembly for compressing a spring using a gear train driven by a motor. But the input power and power calculated from reaction moment and angular velocity of input shaft is different. I have captured these things in excel file for an elaborate discussion.

Regards

Vishal

Hi Vishal,

If you want to define a rotary motor with constant power, first define a result that measures the angular velocity of the driven part. Then, you need to apply torque to the driven part and set its expression to be (P0)/(omega), where P0 is the constant power of the motor and omega is the angular speed of the driven part (you will have to use the function builder to define this - select the "Expression" button). You need to take care in making sure that omega never goes to zero. You have to apply non-zero initial angular speed to the driven part.

Similarly you can also define a linear motor.

Hope this helps,

Regards,

Shrikant