Provides Force Control Clutches and Brake
Some Advantages of Oil shear Technology
- Lower Cost per Index
- Higher Cycle Rates to 300 CPM
- Reduced Wear and Replacement Parts
- Softer, Smoother, Quieter Engagement
- Longer Life without Maintenance
- Lower Cycling Inertia
- No Adjustment – Ever!
- Severe Duty Applications
- Hazardous Duty Applications
- Washdown/Marine Duty Applications
- Continuous Slip – Tension/Dynos
- High Thermal Capacity – Compact Size
What is Oil Shear Technology?
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.
Why Do Force Control Clutches and Brakes Require so Little Maintenance?
Competitive dry friction clutches and brakes require constant disc replacement, and other maintenance depending on the design. Spring set brakes tend to need constant adjustment due to friction disc wear. Wear and heat cause the friction material to wear away as well as glaze and degrade.
Because heat is a major contributor to early failure, cooling is a major concern. Attempting to allow air through the brake for cooling means dust, dirt, moisture and chemicals can get into the unit causing corrosion, sticking linkages, friction material and other components to faster wear.
There are wet brakes on the market that are just that. The units contain fluid. The fluid helps to remove some of the heat in a totally enclosed unit. However, due to the high unit pressures between the friction disc and drive plates involved, there is no real oil shear process occurring. Therefore, wet brakes still have high wear rates, and limited heat transfer from the working part of the friction disc to the housing.
Oil Shear Technology, as incorporated in Force Control clutches and brakes, solves three of the major problems regarding clutches and brakes.