gear motor

Anyone one know of any manufacturer that makes a AC inverter duty motor similiar to the attachment but a Brake could be installed could you share?
Thanks

irondesk40 said:

Anyone one know of any manufacturer that makes a AC inverter duty motor similiar to the attachment but a Brake could be installed could you share?
Thanks

Click to expand...

What is your need for the brake? The reason I ask is because if you use a worm drive gear motor package, the mechanical brake as a holding brake may be unnecessary and if you just want to stop it fast, you may be able to do that electronically with the VFD.

Thanks for the reply
Basically, the boss who is the Director is convinced it has to be a AC inverter Duty Motor that is moving a spray head to a certain distance and then stops and he wants it to stop without coasting or Decel.
Wanted to use a Stepper but you know the saying, boss may not be right, but he is the boss. Plus he is a mechanical engineer, and has experience with using AC brake motors.
Actually told him that we could just use the Bodine and a Powerflex 525 drive and i think it is capable of applying a DC brake. Not exactly sure, will look into that because i think he just may change his mind and go that direction if it is possible.

Check out Oriental Motor:
https://www.orientalmotor.com/ac-motors-gear-motors/three-phase-ac-gear-motors.html

Some of their three phase motors have an electromagnetic brake option.

jraef said:

What is your need for the brake? The reason I ask is because if you use a worm drive gear motor package, the mechanical brake as a holding brake may be unnecessary and if you just want to stop it fast, you may be able to do that electronically with the VFD.

Click to expand...

Have had time to look at this again and due to how quick we have to get something working due to production demands, which is why we are building this new machine, have convinced the boss to use the Inverter to apply as you suggested a DC braking to stop the motor fast.
Could you give more detail if possible?
Thanks

A good Regen VFD can decel to stop quicker and smoother the you can with a motor brake. from what I see is you would do better with a VFD

Thanks
Think i have the director on board, going to try and hook up a powerflex 525 since i have about 7 of them laying around and a motor and demonstrate it to him. He has to see it to convince him.

jraef said:

What is your need for the brake? The reason I ask is because if you use a worm drive gear motor package, the mechanical brake as a holding brake may be unnecessary and if you just want to stop it fast, you may be able to do that electronically with the VFD.

Click to expand...

Took your advice and tried to DC injection. Works pretty good but have to now move 20 inches in 2 seconds and if i run the drive at 100 percent, i get overshoot. For example if i tell it to run 18 inches at 100 percent speed, which is a output speed of the gear motor of 128 rpms when the gear motor itself is running full speed.

Called tech support today to speak about the DC injection and he had me set the stop mode if i remember correctly to DC brake, Auto as the stop mode. If i remember it was selection 4, and the amount of time to apply the brake to 3 seconds and max break current of 1 amp.
Know the DC injection is turning on because if i stop the inverter i can not turn the belts by hand until the DC injection turns off.
Starting think its the fact that with the 1000ppr encoder it is just turning too fast. IN the program i compare the current high speed counter count and if it equals the number of pulses required for the distance i turn the motor off.
Looks like i may have to try convince the boss its time to order and install a allen bradley kinetics drive.

Exactly when does the DC injection take place. Is it as soon as you turn off the run input to the drive, or is there a delay setting that tells it exactly when to inject the DC injection?
Thanks

DC Injection starts as soon as you release the run command on most VFD’s.
Or on some VFD’s you can set the frequency below it will turn on you also set it to remain on for a few seconds after the motor is stopped.
You can also set the VFD to turn on DC Injection for a few seconds on the start command to prevent the current inrush the would happen if the motor was spinning when the VFD is started.

But in your application DC Injection Breaking is not a good choice.
DC Injection is designed to stop a fan or pump when you turn off the VFD.
At best the braking torque from DC Injection is about 50% at motor full speed and reduces to 0% as the armature speed is reduced to near zero speed. At near zero speed you produce no torque. Remember that you are only injecting DC current between 2 of the 3 motor windings. And you will only get breaking torque while the motor armature is moving through the DC filed as the armature slows down the torque produced is reduced. It will never hold an armature stationary. The torque produced with DC Injection would never be consistent enough to control stopping to a position.
You best choice would be a good VFD capable of operating in regenerative mode. I would also require a DB or breaking resistor to dump the energy. That would give you consistent programmable deceleration time regardless of the load on the motor. DC Injection or mechanical brakes will never give you consistent stop times brake ware and load will have a large influence on the stopping time.

Thanks for info
Is the powerflex 525 considered good enough and capable of the degenerative brake you mentioned.

I don't know about the Powerflex 525 I only run into them when thy are installed or specked by others I generally use Yaskawa A1000 I know they can. But don't forget you need the DC resistor no natter what drive you use.

this thread should help you:
http://www.plctalk.net/qanda/showthread.php?t=108128

To help clarify some things
DCIB can never completely stop or hold a motor. You have to remember that as the speed goes down the torque produced also goes down so just before the armature completely stops the torque is at zero.
Also in most applications when you stop the VFD it ramps down the output frequency from set point to 0. When the VFD output gets down to zero it will turn off the output to the motor. This happens weather you are using DCIB or just a ramp to stop, on coast to stop the output is turned off when the stop command is received.
When you use DCIB the VFD will ramp down to the DCIB frequency and turns off the AC output and turns on the DC Injection for the set time then turns all outputs off.
To hold the armature at zero speed you must keep the VFD powered and in run and set the speed to zero. Some VFD’s have a function call Zero Servo that is designed to stop and hold the armature when it’s activated.
On the Yaskawa A1000 set the speed reference command to -10 to +10 V
To hold set reference to 0 you still need to keep the VFD in run. If you remove the run command or disconnect the power the VFD doesn’t care what the motor is doing. If you need to hold position with power off then them you need a mechanical motor brake.
And yes the DCIB will heat the motor but it’s on for only a limited time and at a limited power motor heating is not much of a problem. If motor heating on breaking is a problem then you have way undersized the system.
With the Yaskawa VFD and Black Max Motor they are rated for 100% torque 100% time at zero speed or holding I have never had a problem in many years.