Dr Clutch

Cycling a new clutch-brake in the installation will lap in the friction surfaces and raise the clutch-brake torque to its nominal torque rating. Before burnishing, the clutch-brake torque will be up to 40% less than the nominal rating.

When the clutch-brake engages, the friction linings generate heat. This is normal and not a problem as long as the measured heat of the inside metal parts does not exceed 110° C.

With correct oil flow and oil temperature the wet hydraulic clutch-brake rarely needs maintenance; however, you should check the piston travel every 2000 hours of operation.

If the clutch-brake was stopping properly before the press was single stroked at the higher rate, chances are the friction linings were glazed due to excessive heat. Replace the linings.

You should set the air line lubricator for 1-2 drops for every cubic millilitre of air. Too much oil can collect in the air chamber and cause a sluggish response.

The cooling oil temperature should not be too cool or too hot but regulated at a stable temperature range that is within the clutch-brake system specifications. If the temperature is too cool then the oil will become more viscous and the torque could be affected. If the temperature is too hot then the clutch-brake can be damaged quickly.

Grease and oil contamination on the linings will reduce the torque. You can try a commercial brake cleaner solvent and lightly clean the lining surface. Follow the guidelines on the cleaner. The linings will absorb grease and oil and if the contamination is too great, then you should replace the linings.

This is really dependent upon your application and you should always follow the machine manufacturer’s guideline. As a general rule you can rebuild every 3 million clutch-brake cycles or every two years of operation.

Tooth clutches are designed to be engaged and released at zero rpm. Depending upon the load you may be able to engage and release at a very low speed. This should be reviewed so the clutch is not damaged.