Wichita Team in 2011 Hotter'N Hell 100

Team Wichita Clutch for 2011 Hotter’N Hell 100.  Details Hotter’N Hell 100, Temps reached 109 degrees during this years ride.  Way to go guys.

To properly engineer, install or maintain a system with QRV’s,  it’s important to understand what they are and how they work.  The most popular QRV’s supplied by Torque Incorporated are:

Wichita QRV - Quick Release Valve (Quick Exhaust)

Industrial Clutch QRV - Rotary Seal

The Wichita QRV’s are engineered to mount to the Airtube Spuds to provide rapid exhaust from the Wichita Clutch/Brake.  The Industrial Clutch QRV – Rotary Seal is engineered to mount to the Cylinder of an Industrial LK Clutch (and Verson clutches) to provide rapid exhaust and controlled clutch engagement by modifying the orifices in the poppet assembly.

Quick Release Valve (QRV or Quick Exhaust) operation is fairly easy to understand, the basic schematic using a Quick Release Valve (QRV or Quick Exhaust) is below:

QRV Basic Schematic in Clutch/Brake Air System

When the 3/2 valve is engaged to pressurize the clutch/brake, the air pressure at P1 is greater than the air pressure at P2 causing the poppet in the QRV to close the exhaust port, allowing air to flow from the supply to the clutch/brake.  When the 3/2 valve is released, removing pressure from the Clutch/Brake, the air pressure P1 is less than the air pressure P2 causing the poppet in the QRV to seal off the input.  This allows the the air to exhaust the clutch/brake directly through the QRV.

While the operation of QRV’s is very simple,  we see many issues with their application and installation.

• When QRV’s are installed it is critical that the volume of air between the 3/2 valve and QRV is small enough so P1 remains significantly lower than P2 until the clutch/brake is fully exhausted.
• QRV’s should never be installed in series.
• QRV’s are typically only used on Clutches in Stamping Press applications when a separate clutch and brake are used.

QRV’s have wearing parts, their operation should be checked regularly as part of your Preventative Maintenance Program or if you experience erratic stopping or an increase in stop time.  Checking operation can be accomplished by simply cycling the air system and monitoring the QRV to ensure there is a strong puff of air when the system should exhaust.  If the QRV does not respond with a strong blast of exhaust, it should be replaced or rebuilt depending on style.

It is best to run QRV’s without mufflers, if possible, the mufflers tend to slow the exhaust and trap air system contaminates in the QRV.  If you need to abate the noise created by the QRV, use a muffler with a large surface area to not restrict the exhaust flow.

Your Torque Inc. local Sales Engineer is an expert with QRV’s and is available to help you with any issues with your clutch/brake air system design, installation, operation and maintenance.  If you have any questions give us a call, we are happy to be of service.

Mach III Clutch, Inc. announces new spring engaged industrial friction clutches for torque transmission in the absence of air pressure or during power-off conditions. Mach III spring engaged clutches are available in both regular duty and heavy duty models offering fixed torque transmission from 506 to 24,375 pound inches. These clutches release when air pressure is applied to overcome spring the pressure. Catalog models currently available mount at the end of the shaft and include a finished pilot for easy mounting of a sprocket or pulley. Spring engaged friction clutches are made to order with bore and keyway sizes specified by the buyer for shaft sizes from 0.625 to 3.5 Inches. Metric sizes are also available. more

www.youtube.com/watch?v=Xx9PHzP5Q8c

Bad Flywheel Bearings can quickly destroy a clutch.  Bearing failures cause excess misalignment that can seriously affect clutch life on shears and presses.

http://www.manufacturingtalk.com/news/jaz/jaz113.html

• Copper Wear Plates
• ID/OD O-rings
• Nut’s and Bolts
• Springs if used in current rev. of Parts List.
• Friction Material, Rivets and Washers (partial)- or – Complete Drive Plate assemblies (complete)

KKB Renwal Kit Parts Breakdown

Contact your local Torque Inc., Application Engineer if you have any questions.  They are happy to be of assistance.

Brake Drive Plate with teeth worn by excessive angular alignment.

Above is a photo of a customer who was rapidly wearing teeth of a Wichita 118 KKB.  This is a typical symptom of excessive angular alignment.

Uncoiler Brake with rapid tooth wear, ready to check alignment.

Angular Alignment was over .300", Wichita specification is .009" TIR.

Angular Alignment is checked by placing the magnetic base of a dial indicator of the shaft and indicating the face of the back water jacket at an 18″ diameter (for Wichita 118″ KKB).  This application indicated over .300″ TIR, well beyond the maximum limit of .009″ TIR published by Wichita Clutch.  This explains the rapid tooth wear of the Drive Plates and Hub.  It was noted the high/low point wear at 3 o clock and 9 o clock with the 12 and 6 o clock positions being the same reading.

Steel Uncoiler using Pillow Block Bearings that need to be restrained.

Uncoiler is built using Pillow Brock Bearings to support the mandrel.  This design, like others we see using Pillow Block Bearings, has the tension force in the same plane as the Pillow Block Bearing mounting surface.  Under high tension operation there is a real potential for the bearings to slip.  Most users correct this design issue by welding hard stops to the uncoiler base with jacking screws to restrain the bearings from sliding and allowing easy adjustment for brake alignment.

Air system starving Clutch and Brake

The clutch is the Blue Pressure Line and the Brake is the Red Pressure Line.  You will notice it takes over 200 msec to get the brake to 60 PSI and the same time for the clutch to reach 50 PSI.  A larger surge tank will greatly reduce this time and allow much more consistent operation and better tonnage higher in the stroke in press or shear applications.  You will also notice there is no overlap during engagement because of a timer in the controls delaying the clutch valve firing.  There is considerable overlap during disengagement, which was corrected by adding another timer below:

Air sytem starving Wichit Clutch and Brake on Shear, no overlap.

Notice how the Blue pressure curve of the clutch now drops off quickly before the brake sets.  In addition to being done with a timer in the control system, Torque Inc. application engineers can accomplish this same function with a properly designed Herion Press Safety Valve system using two XSz valves and adjusting the timing in the pilot circuit.

www.youtube.com/watch?v=F7B3NNB7hgw