Force Control Offers PosiStop Brakes for Hazardous Duty Applications

Air operated Posistop oil shear motor and coupler brakes are ideal for severe duty applications, and when equipped with a hazardous duty valve can be used in hazardous environments often mounted on air motors. They are designed for a long service life with minimal maintenance, even in severe and critical applications. Typically furnished as spring-set, pressure release brakes, pressure set brakes are also available for applications where torque needs to be adjusted. Their multiple disc design reduces the inertia of the brake, which puts less load on the motor, and improves efficiency each cycle. Positop motor brakes mount to the back of brakeless motors, while coupler brakes mount to the drive end of the motor, often between the motor and the reducer. Dust, dirt, moisture, and fume proof, they are available in washdown, marine duty, and severe or hazardous duty models. Posistop brakes are ideal for palletizers, conveyors, hoists, winches, elevators, stackers, loaders, and unloaders. Applications are found in coal mining, marine, oil and gas production, chemical, grain, and sugar manufacturing. 

Five models offer torque from 6 lb. ft. to 2,030 lb. Ft, and fit 56 frame up to 440 frame motors. They can be used horizontally or vertically and require minimal air volume up to a maximum of 80 PSI. Special flange mountings can be furnished to accommodate IEC, servo and other flange sizes. Various shaft connections are available including bore and key, split clamped quill, and tapered collet. Designed as dynamic brakes, Posistop brakes can stop a load as well as hold it. Their high thermal capacity allows higher cycle rates and heavier loads.  

Each Posistop model offers several torque options by changing the number of springs and discs. They can be furnished mounted on a motor as an assembled brake motor, or installed on a customer’s motor, gear reducer, or machine frame.

Posistop coupler brakes can be mounted on the drive end between the motor and gear reducer because they are not frequently removed or opened up for maintenance and adjustment.  With oil shear technology, the brake life is often as long as, or longer than the motor service life.

All Posistop brakes feature Teflon liners on all piston sealing areas for a smooth response and long service life. This also eliminates o-ring breakage creating air leaks that can cause unexpected downtime. Bearings are oil lubricated. Solid cast iron or aluminum, totally enclosed housings, protect the brake from adverse environments including dust, dirt, and moisture. The unique collet design hub connection, or split clamped quill eliminates key and keyway failures and ensures easy disassembly.

Oil Shear Technology is the reason the Posistop brakes by Force Control do not need maintenance, adjustment and last up to 10 times longer than standard dry friction motor brakes. Oil Shear Technology is the function of a boundary layer of transmission fluid in shear between the friction disc and drive plate. As the parts come together the fluid under shear will transmit torque between the two parts as well as absorb heat. This heat is then taken away from the friction surface to the housing to be dissipated.

Because the Posistop brakes are air actuated (hydraulic actuation optional) – they function without the problems associated with failed, coils, slow response due to back emf, additional electrical heat, and failure of small linkage parts, found is in electrically actuated brakes. The use of air actually tends to cool the brake rather than warm it. Air actuated brakes are often used with air motors in hazardous environments.