Spindle Repair Glossary

SPINDLE REPAIR GLOSSARY

The glossary section is here to increase your understanding of spindle related terminology. If you need additional information, please contact us, we love to talk about what we do.

Stator

The stator is the stationary part of the electric 3 phase induction motor system found in a spindle. It can also be known as a field. The stator consists of wire windings that when energized create a magnetic field that pushes the rotor making the spindle shaft rotate.

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ROLLER BEARINGS

Roller bearings are used in spindle applications that require a high level of radial load capacity. Some examples of this are large centerless grinding spindles, large low speed milling spindles and spindles that have radial loads from drive belts.

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CERAMIC DISC TYPE ROTARY UNIONS

Ceramic disc type rotary unions are used in machine tool spindle applications of various makes, models and applications. This is a typical set up where one end mounts to the drawbar and one end mounts to the machine.

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THERMISTOR

A thermistor is a type of resistor whose resistance varies with temperature. Spindle usage: Thermistors are placed on or near the spindle stator to monitor the heat of the motor windings. The machine control monitors the outputs of the thermistor and if the outputs reach an overheat level the spindle is shut down.

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Spindle Shaft

The Spindle Shaft consists of the Pulley Taper, Bearing Journal, Shaft Pilot, Threads, Shoulder, and Shaft Tooling Face. Definitions and explanations of each individual component are described here.

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Spindle Housing

The Spindle Housing is home to the Flange Housing Flange, Shoulder, and the Bore Housing Bearing Bore. Definitions and explanations of each individual component are described here.

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Rotary Union

The rotary union of a spindle is mounted to the rear of the shaft and it permits the movement of liquid from a stationary point into the rotating shaft. Typically rotary unions are used for the transfer of coolant in through tool coolant applications.

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What is a Rotor?

The rotor is the non-stationary part of the electric 3 phase induction motor system found in a spindle. It is part of the spindle shaft. It rotates because the wires and magnetic field of the motor are arranged so that a torque is developed about the rotor’s axis.

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Preload of Angular Contact Bearings

Preloading bearings is the process of removing the internal clearance of the bearing by applying a permanent thrust load. This applied force makes the rolling elements run in a single “track” and it removes any axial play in the bearing assembly.

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Oil Seals

Oil seals are a common way to reduce bearing contamination in machine tool spindle applications. They are used primarily in low speed applications because they make contact with the rotating shaft and have a limiting surface feet per minute specification.

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I really didn’t expect this; You guys really pulled it off! My many thanks to your outstanding crew for helping us get back into production.
— Dan Eaton, Taylor Metalworks
Its great not to be sending spindles out on a regular basis since you addressed my problems, but I know they will still be coming sooner or later. Never a problem when we get them back , run better than new. Hope everything is ok there. Please tell everyone there that we here appreciate everything that you do to keep us up and running and the quick turnarounds. Have delt with the rest now deal with the best. Have a great week end and up and coming holiday.
— Northland Customer
Thank you NTE just received spindle today and WOW ! what a nice job. Can’t wait to use it. Thank the Northland team for us for a job well done 
— Northland Customer
Both of the spindles that you repaired are on the machines and running great. We don’t have any spares for those grinders. We probably will not be purchasing a spare, as you have been able to turn around the repairs quickly and the price of a spare is cost prohibitive.
— Northland Customer
I am writing to thank Northland Tool for going the extra mile and saving my company from expensive machine downtime and expensive repairs. We have always sent our Chiron spindles for repair as a shaft with bearings. None of our previous rebuilders pointed out the bearing fretting or the fact that the housing in the machine was out of tolerance and causing premature failure to the spindles. After Northland fixed the housings the spindles have never sounded as good or run as well! Great job guys!
— Northland Customer
The detailed cause of failure reports and the expert technical advice that Northland Tool provides is bar none the best I have ever seen. We struggled to keep two of our large our milling spindles running for longer than 6 to 12 months. Northland Tools evaluation showed that the hydraulic nuts were not holding the assembly together causing premature spindle failure. We discussed this in detail and mutually decided to modify the spindle shaft to prevent this from occurring again. The first spindle we performed this on is still in the machine running like new after 3 years. That’s over three times the life of previous repairs and it’s still going strong. Easily over $40,000.00 of savings so far on that one machine and counting.
— Northland Customer
Your people go above and beyond the call of duty when it comes to spindle repair. When we had difficulty with the spindle installation and we were able to talk directly to a spindle technician that helped us troubleshoot the issue it helped us out of a bind. We have sent several spindles to you and have nothing but great things to say.
— Northland Customer
Thank you for your attention with my quick turn spindle repair. Your status updates allowed me to plan around machine downtime and I now know that you deliver on your promises. In the past other spindle repair vendors talked a big game and consistently failed to deliver. You not only delivered my spindle before the due date but you kept me informed throughout the entire repair process.
— Northland Customer
You performed a miracle with my BIG PLUS spindle. After crashing the spindle severely damaging the taper we found that a replacement spindle was not only cost prohibitive but had a long delivery. Your repair was a fraction of the cost of new and you never would know that the spindle was damaged to the extent it was.
— Northland Customer

TRUSTED BY

Lockheed Martin Triumph Group General Dynamics RBC Bearings
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