Archive for the ‘Clutch’ Category

Wichita Clutch on Hurricane Simulator to make homes safer

Monday, August 19th, 2013

Industrial Clutch LK Inspection Checklist

Wednesday, February 6th, 2013

To assist customers inspect and assess the condition of Industrial Clutch “LK” clutches, Torque Inc has developed the “LK-Inspection-Checklist“.  Click on the link to access this helpful aid to ensure all critical parts are inspected during clutch maintenance or repair.

If you have additional questions, contact your local Sales Engineer of our Parts Hot line 800-771-5921.  WE are happy to be of service.

Press Clutch/Brake Hub Mounting Options

Tuesday, November 13th, 2012
There are many methods to mount a Clutch/Brake hub to the shaft of a Stamping Press or other heavy machinery. Torque Inc will help you pick the best type of connection for your application.  The following is a summary of the benefits and limitations of the various methods:

Key with clearance

Using a clearance fit between the hub and the shaft while and hand fitting the key (or two keys) is the most common method. Clearance of a couple of thousandths of an inch with line/line for the keyway is typical. This connection will likely gradually get loose at some point in time, is likely the most common type used on a press.

Key with interference

Adding a slight interference with a hand fit key is a more permanent solution, albeit requiring a modest heating of the hub (to about 250- 300 degrees F through via oil bath, oven or induction heater). Typical fit of line/line to .001”/.002” for shaft size of 6”.

Key with heavier interference

Increasing shrink to .0005” per inch of diameter (ie. .003” interference for 6” bore ) is achievable with a 300-400 degree heat and dry ice of the shaft. This fit is recommended for high shock load/high reversing loads like shears and high stripping force dies, cold forging etc. Care must be taken not to end up with too tight a fit over a key, in that this can cause the hub to split through the keyway. Heavy interference fits are difficult to remove without damaging the shaft/bore interface.

Heavy Interference without key

Using  a .001” per inch of shaft diameter interference (ie. .006”-.009” shrink for a 6” shaft) , or more, can often times gain enough torque to drive without a key or supplemental locking device. However, we do not recommend retrofitting using this method due to the following problems, indluding but not limited to:
1. Precise material specifications are required,
2. Precise machining is required,
3. Installation is tricky
4. Removal does damage to the shaft and hub bore.

The best system is a Engineered Locking Element without a key

Using an engineered locking device such as a Ringfeder, Climax or Bloc creates the advantages of heavy inference shrink fit connection (ie. No backlash ever, removability, ease of assembly and strongest possible shaft and hub design due to no stress risers from keys) without the disadvantages. Some applications are hard to retrofit due to space and material issues. These devices require proper dimensions and installation procedures and torque instruction be followed in order to function properly. However the devices have a 100% success rate when properly engineered and installed (in fact they frequently can carry more torque than the shaft itself can!) .
There are two primary types of keyless locking devices.
Shrink Disc Wichita CCB hub mounting

Wichita Clutch CCB with Shrink Disc mounted hub

The “shrink disc” goes outside of a hub extension and squeezes the hub to the shaft. Advantages are a infinite choice of shaft sizes (ie. Can match any existing shaft assuming it is round and finished properly) and has a relatively high torque rating. Material can be cast iron or steel
Industrial Clutch Hub mounted with Internal Locking Device

Industrial Clutch Hub mounted to shaft with internal locking element.

The internal “locking assembly “ is sometimes easier to fit in (goes inside existing hub) but can only fit a finite number of standard shaft sizes and requires an adequate OD to provide enough strength the keep hub from cracking. Material required to be steel or steel sleeved cast iron.
  • Proper selection of either version of an engineered locking element requires the qualified engineering assistance that Torque Inc. can provide to insure a successful installation.
  • Often the cost of the device is offset by the reduction in labor/machining cost associated with putting a connection together!

Wichita ATD 218 LIHTC on conveyor drive, used as Torque Limiter

Tuesday, October 16th, 2012
Wichita Clutch

Wichita Clutch 224 LIHTC

Wichita Clutch

Alternate view of Wichita Clutch 224 LIHTC installation

Torque Inc Application Engineer Steve Park selected a Wichita Clutch ATD 224 LIHTC (Low Inertia High Torque Clutch) for a custom designed conveyor drive system to provide protection for the drive train elements by functioning as a Torque Limiter. By regulating the air pressure applied to the Wichita Clutch, the end user can accurately adjust the clutch slip torque to a level to allow reliable machine operation under normal conditions and protect the drive train from overload by slipping the clutch,

Assembling a Wichita Clutch, Low Inertia Clutch

Friday, June 29th, 2012

A short video showing the process to assemble a Wichita Clutch, LI (low inertia) Clutch.

Disassembling a Wichita Clutch, Low Inertia Clutch

Friday, June 29th, 2012

A short video showing the process to disassemble a Wichita Clutch, LI (low inertia) Clutch

Wichita Clutch STVC (standard vent clutch) rebuild guide.

Thursday, June 28th, 2012

Here is a helpful sheet to show the items to inspect/replace when rebuilding a Wichita STVC Clutch:

stvc-replacement-guide, Torque-Inc

Any questions, contact your local Sales Engineer.  We are happy to be of service.

Rebuiilding a LI (Low Inertia) Wichita Clutch

Thursday, June 28th, 2012

Here is a helpful sheet to show the items to inspect/replace when rebuilding a Wichita LI Clutch:

LIC-replacement-guide, Torque-Inc

Any questions, contact your local Sales Engineer.  We are happy to be of service.

Quick Release Valves (QRV’s)

Tuesday, June 14th, 2011

Most industrial Air Clutch/Brake applications have Quick Release Valves (QRV or Quick Exhaust) engineered into the air system to provide rapid exhaust of the air pressure by providing a large exhaust port right at the clutch or brake.  Air systems with properly engineered, installed and maintained QRV’s,  offer significantly improved operation of clutches and brakes in high cycle applications (single stroke operation of a press).

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:

Quick Exhaust

Wichita QRV - Quick Release Valve (Quick Exhaust)

Industrial QRV

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

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.

Bad Bearings = Can damage a Clutch.

Saturday, February 5th, 2011

httpv://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.