One of the most important things you should prepare for when making safety plans for your Rexroth servomotors and servo drives is how long it takes for a machine to stop after a safety stop switch has been activated. IndraDrive servo technology, which is the latest generation of Rexroth servos, uses a new technology to reduce the safety stop time down to almost nothing. When you have an emergency, split second stop times are very important. Emergency stops aren’t just reserved for when humans do something that may result in an injury—they’re also for when jams occur that could ruin the machinery.
Emergency stop systems can work in five different ways:
- By removing power to the drive
- By disconnecting the drive from the servo
- By using a mechanical brake
- By using dynamic braking through magnets in the servo
- By a full-torque controlled stop
Each of these stop systems has drawbacks and advantages. For instance, if you use high inertia servos, removing the power, disconnecting the drive, or using a mechanical brake might not be enough to stop the servomotor in a reasonable amount of time. Some other approaches can also cause damage to your servomotor that ruin the machinery completely so it has to be replaced.
How is IndraDrive so quick to stop in the event of an emergency? Instead of having a second system that brings the servomotor to a stop, IndraDrive systems have stop commands directly in the drive. Because the drive that runs the servo is also the same thing that stops it, it takes much less time to stop the motion of the servo. IndraDrive systems are made to use emergency stops without damage to the system, too.
IndraDrive is faster, and there’s also less chance of failure. Emergency stops from sources outside of the servo drive might have failures, such as a mechanical brake or a line cutter that disconnects the electricity. In the event that these fail, unless you have other failsafes in place you might be at great risk of emergency stop failure.
If you’re worried about your IndraDrive or have issues with emergency stops not working properly, give us a call and we can help get your machines running safely.