TURBOCAM Automated Production Systems Has a New Balancing Cell

04-Jan-2012 – Barrington, N.H. (U.S.A.) – TURBOCAM Automated Production Systems (TAPS), a division of TURBOCAM Inc., recently launched a semi-automated balance cell. We met with Jim Quinney, TAPS Engineering Manager, to discuss this new and exciting accomplishment.

TAPS Engineering Manager tests the Schenck measurement station.

Q. Can you give us a brief summary of the project?

A. Sure. TAPS has been interested in balancing impellers for years. We decided to take the plunge into developing an automated balancing cell early in 2011. The intent of the manufacturing cell is to utilize automation, a CNC 4-axis mill, and a Schenck measurement station to correct the imbalance of turbocharger impellers with one attempt.

Q. What is a manufacturing cell?

A. A manufacturing cell is an efficient grouping of all the resources required to manufacture a product. These resources, which usually include people, supplies, machines, tools, and other production equipment, are arranged in close proximity to enhance communication and allow everyone to see what is going on at all times.

Q. Why do parts need to be balanced?

A. The impellers that TAPS manufactures can rotate at up to 150,000 RPM in service. Unbalanced components produce noise and in severe cases can cause premature failure of other components, including bearings. Rotating components have an imbalance tolerance. If the measured imbalance of the part exceeds that tolerance, balance correction is required. This is done by removing mass at specified locations.

Schenck balance measurement machine.

Q. What makes a part unbalanced?

A. The manufacturing process is generally responsible for the imbalance of the part.

Material can play a significant part. Castings can cause balance issues due to the presence of voids in the material. Forgings and bar are better due to the homogenous nature of the material.

The machining process can also play a large role in the imbalance of a component. To be a perfect part the mass has to be equally distributed around the center of rotation. Balance issues can either be systematic or random. If the mill is not calibrated correctly or the mill fixturing is sloppy or worn, the blades can be milled slightly off center creating imbalance. If the part is put into the lathe chuck with a chip on one of the jaws, the part will have a turned geometry cut non-concentric or misaligned to the milled features (blades).

A Fanuc robot tends the cell.

Q. Is having a balancing cell new?

A. Yes and no. TAPS has never sold balanced components before; therefore, a balance cell is new. TURBOCAM Inc. has sold balanced components for years; therefore, a balance cell is not new. TAPS has taken the knowledge gained by TURBOCAM Inc. and applied automation to it. The goal is to be able to measure a part, correct the imbalance, and re-measure the part in about two minutes. A secondary goal is to have parts within tolerance with one correction as this adds greatly to the efficiency of the cell.

Q. What is included in the cell?

A. The cell consists of a Schenck measurement station, a 4-axis mill (correction station), a robot, and a conveyor. The key to the cell is data flow. The measurement station measures the imbalance of the part. Once the part is measured the part is either in tolerance, out of tolerance and correctable, or out of tolerance and not correctable. This information is transmitted to the robot and the appropriate action is taken. The measurement station also has to transmit the measurement data to the correction station. This measurement data is essentially variables that get used to determine the location and the amount of mass that is removed from the part. Without correct data flow, the cell will not function.

4-axis mill to correct part imbalance.

Q. What remains to be done?

A. We have just a few finishing touches and one small hurdle and this project will be completed. The robot program needs a few more tweaks, and manual testing needs to be completed on the correction station. The measurement station needs to be converted to run in automated mode. The hurdle that remains is to resolve a data management issue between the correction station and the measurement station.

The balancing cell is something new and exciting for TAPS—it adds value. There will be kinks to work out, but through skill and determination, the process will be completed.