Oil Shear Technology involves the use and control of transmission fluid in a friction device consisting of multiple friction discs and drive plates. This friction stack can be used as a brake or a clutch.
A proprietary re-circulation system built into the hub enables fluid flow through the stack, over the contact surfaces, and out to the housing or an external cooling system. In this way, heat built up within the friction stack is carried out of the stack to be cooled, reducing the wear and degradation of the friction material.
As the stack is compressed, either by pressure (air or hydraulics) or springs, a boundary film of transmission fluid is put into a shear condition between the friction surface and drive plates. Through this shearing phenomenon of the specifically designed fluid, torque is transmitted between the two surfaces accelerating or decelerating the other part. Two things are happening. 1. Much of the work is done through the shearing of the fluid itself; therefore the heat is generated within the fluid, not the friction stack. 2. The fluid film separates the friction disc from the drive plates reducing mechanical wear of the friction material.
The transmission fluid in shear transmits torque between the two components increasing as the clamping pressure increases until mechanical lock up occurs. By cooling the friction surfaces and reducing the mechanical wear, a significant increase of thermal capacity and total cycle life is possible.
Many competitive clutches and brakes depend on friction between dry surfaces surrounded by air to transmit torque. During engagement of dry surfaces, high heat caused by slipping is difficult to dissipate quickly causing wear, glazing, and friction material degradation. This in turn causes positioning inaccuracy, limited service life, and possible safety issues.
Several other benefits are provided by Oil Shear Technology. The transmission fluid used also lubricates the bearings, splines and driver pins reducing wear on those parts for extremely long life.
And the housing itself offers even more benefit. It is a highly efficient heat exchanger pulling heat from the fluid, and dissipating to the outside. Because the transmission fluid must be contained within the brake, the housing is totally enclosed and sealed eliminating outside contaminants such as dirt, dust, chips, food, moisture or chemicals. It also seals contaminates inside, eliminating friction material dust common with many dry friction products.