Force Control Industries, Fairfield, Ohio, USA, reports that its Posidyne® clutch brakes, with oil shear technology that allows rapid and precise stopping, starting, reversing, speed change, and positioning, all without adjustment or maintenance, are now available in space-savings piggyback designs.  Special pads cast into the main housings mount an adjustable motor base, allowing the motor to sit atop the clutch brake.  

Other components include a gear belt drive from the motor to the input shaft and an enclosed belt drive guard. This space saving design is ideal for applications where an inline arrangement is not feasible due to space considerations.  Posidyne piggyback clutch brakes are well suited for applications with frequent start/stop cycles, and high cycle rates (up to 300 cycles/min.), which place a high priority on maximizing production and minimizing downtime.

Faster production rates coupled with significantly longer service life than traditional (dry) clutch/brakes (five to ten times longer in many cases) yields increased uptime, productivity, and ROI.  No adjustment, virtually no maintenance, multi-year service life, minimal parts inventory, reduced parts, and replacement ordering cost, adds up to higher production at less cost.

Designed with low inertia cycling components makes the Posidyne clutch brake more efficient, requiring less motor horsepower to accelerate the load, and less torque to stop the load. Their totally enclosed design is impervious to dust, chips, chemicals, coolants, caustic wash down, weather, and more, making them ideal for hostile environments.  They are field proven in diverse applications such as packaging, lumber mills, shingle plants, fiberglass insulation production, food processing, metalworking, and more. 

Posidyne clutch/brakes feature a multiple disc design that produces high torque from a small package.  Re-circulating the fluid dissipates the heat of engagement, which is a common cause of downtime with other clutch/brake assemblies.

A simple actuation system allows torque in the clutch and brake to be precisely controlled. Adjustment for rapid or soft starts and stops is easily accomplished. Manifold mounted control valves reduce response times by eliminating hoses and fittings, and are recommended for high cycle applications. By reducing the high starting inrush currents and the associated power factor imbalance in the motor, these unique clutch/brakes can also reduce energy costs.  

The Posidyne clutch brake can be actuated by air or hydraulic pressure for use in a plant or outside remote applications. The hydraulic actuation package includes a hydraulic pump, solenoid valve, regulators, and a filter. A heat exchanger can be added for additional cooling. 

The Posidyne is inherently explosion proof with the addition of an explosion proof actuation valve, or locating the valve in an explosion proof cabinet. Multiple sizes are available to suit particular applications from 0.5 hp to 350 hp (99 lb. in. to 79,000 lb. in.) with cooling options, control logic, and mounting arrangements to simplify and speed installation.

Force Control notes that oil shear technology is the reason that its brakes last up to 10 times longer than standard dry friction brakes and do not need maintenance, adjustment, or disc replacement. Oil shear technology is the function of a boundary layer of transmission fluid in shear between the friction discs and drive plates. As the parts come together, the fluid in shear will transmit torque between the two parts, as well as absorb heat. This eliminates direct contact of the friction discs and drive plates during high-speed slip.  Heat from the friction surface is dissipated as the fluid circulates to the housing.  

Heat dissipation is a major component when selecting a clutch brake. The Posidyne clutch brake basic unit dissipates heat through a unique internal design pumping system which causes the transmission fluid to be drawn into the center of the hub, flows through the friction stack, and by centrifugal force is pulled out of the stack to the housing. Cooling occurs as the fluid flows down the housing walls. Additional heat can be dissipated by adding water-cooling, or pulling the fluid out of the unit for additional heat exchanger cooling and filtration. These cooling options allow the same compact size Posidyne clutch brake to be used on high inertia loads, or in extremely high or low temperatures.

Additional information is available online.