Dry Master Clutch Application Data Sheet
Interpretation of data requested:
Master Clutch: A clutch that connects an engine through its flywheel to the transmission and is normally operated manually by a foot pedal. It may have a full facing or a set of buttons.
Maximum Plate Load: The maximum force that the pressure plate can exert on the driven disk.
Number of Driven Disks: Necessary because there are many dry disk clutches with one or two driven disks.
Driven Disk: The disk running at transmission input velocity with the friction material fixed to it. There are a few dry master clutches with more than two driven disks.
Driven Disk Configuration: A description of how the friction material is arranged on the driven disk. Sample configurations include a full organic facing, or three VSR-10 buttons per side.
Swept Diameters: The largest and smallest diameters swept by the friction material as it traverses the flywheel or pressure plate. They are important because they provide the effective radius of the clutch.
Average Torque During Slip: Used to determine the energy and coefficient of friction requirements. It is an approximation that is relatively easy to obtain. If the customer has a more sophisticated torque requirement then obtain it to help us simulate the clutch conditions.
Flywheel and Pressure Plate Mass: Used to calculate the relative heat sink size.
The flywheel is the large plate fixed to the end of the engine crankshaft and the pressure plate is the opposing disk on the transmission side of the clutch held in the clutch cover assembly.
Intermediate Plate: A reaction disk located between the two driven disks of a two disk clutch. A three disk clutch has two intermediate disks and a four disk clutch has three intermediate plates. (three and four disk clutches are generally found only in race or grand touring cars such as a Ferrari)
Flywheel and Pressure Plate Materials plus the intermediate plate materials may determine what kind of friction material may be used in the application. For instance nodular iron will not run well against buttons but ordinary gray cast iron will.
Maximum and Ending Speeds of the engagement are usually the start and end of the slipping engagement. Most often the ending speed is zero rpm. There are some conditions such as when a forklift or other such vehicle is picking up a pallet where a carefully controlled approach is required. In those instances there may be a constant slipping speed for several seconds followed by a clutch release or a full lockup. Details should be listed in the comments section.
Typical Engagement Speed: The starting differential speed of the most common type of engagement. Hopefully operators do not do maximum abuse engagements all the time. Most of the time one would expect an emphasis on precision and smoothness rather than maximum performance.
Slipping Time: The total length of time the friction material and the opposing disks are touching and transmitting torque. For a standard truck acceleration it is usually .8 to 1.2 seconds. For backing up or other precise vehicle movement it may be several seconds.
Engine Power: Will determine some of the extremes of the service cycle that the clutch will be exposed to.
Vehicle Type: Will describe how the clutch will normally be used. Any further description of the type of use would be additional help.
