Siemens S120 configurationmanual Selecting the motors, Motor torque-time diagram

Configuring the motor 5.1 Procedure

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If the individual torques are stable in each section, the integral can be simplified to create a totals formula (see also the following diagram).

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Figure 5-3 Motor torque-time diagram

5.1.4Selecting the motors

You can choose a suitable torque motor using the values determined for the peak torque MmMAX and continuous torque Meff.

You must take the following factors into account when selecting motors:

●Regarding the maximum torque MMAX, the motor should have a control reserve of approx. 10% vis-à-vis the required value MmMAX to prevent unwanted limiting effects if the control loops are overshot.

●The rated motor torque MN must be at least as high as the continuous torque value Meff determined for the duty cycle.

●If certain general conditions (e.g. machining torque or frictional torque) are not known, you are advised to plan for even larger reserves.

●In addition to the requirements resulting from the duty cycle, mechanical installation conditions may influence your choice of motor. For instance, the same motor torque can often be generated in a long motor with a smaller diameter as well as in a short motor with a larger diameter.

●If more than one torque motor generates torque on one axes, the values of the peak and continuous torques of the individual motors must be added together.

66	1FW6 Built-in torque motors
	Configuration Manual, 05/2009, 6SN1197-0AE00-0BP3