A clutch and a brake may seem interchangeable at first glance, but they perform two distinct functions. A clutch is a transmission and control device that transfers energy from the driver to the driven shaft. On the other hand, a brake is a mechanism that stops, regulates, or holds a moving load at rest by converting kinetic energy into heat.
Clutches and brakes employ diverse technologies, including pneumatic, electromagnetic, mechanical, and hydraulic. However, there are several factors to consider when choosing the best clutch and brake systems for optimal performance.
This article will list the factors and characteristics that must be present in industrial clutch and brake systems.
How Do Clutches and Brakes Work?
A clutch is a mechanism that interlinks and separates two rotating bodies. These two distinct bodies may be shafts, gears, bearings, a prime mover or motor, or any combination of the mentioned components. Regardless of applications, the purpose of a clutch is to transfer torque from a rotating drive system to a non-rotating or stationary system.
A brake is a frictional mechanism that halts a moving inertial load or holds a component in place. The inertia load typically results from multiple rotating parts that must stop. Hydraulic or pneumatic brakes feature a thrust plate and a piston that presses against the clutch or brake static. These may be either pressure-set or spring-set-pressure-release.
When the electromagnet is energized, the thrust plate is retracted, thereby releasing the brake stack. On the other hand, when the brake’s power is removed, the spring force is pushed back to produce static torque. The vast majority of electric brakes are spring-set and electric release.
Factors To Consider When Choosing the Best Industrial Clutching and Braking Systems
The following are the factors and characteristics that you must consider when selecting the best clutching and braking solutions for your industrial application:
Thermal Capacity
Heat is a common byproduct of engagement in clutches and brakes, and can pose a significant challenge for such systems. The temperature generated can often exceed 400°C, depending on the velocity and inertia of the system. To prevent damage from this heat, it is important to select a clutch or braking system made from high-quality materials.
One solution to address this issue is Oil Shear Technology. By using this technology, the heat generated by engagement is more effectively dissipated. The friction surfaces are also less likely to become overheated, warped, or melted. This makes such systems more durable and reliable, and can help extend their lifespan.
Size
The appropriate size of a clutch or brake depends heavily on its operational requirements. Typically, these parameters consist of rotational speed, time, driving device, inertia load, and cycle rates. For instance, a large brake is required to emergency stop a 36 in. grinding wheel spinning at 3600 RPM within 5 seconds.
Static and Dynamic Torque Values
Static and dynamic torque values reflect the efficiency potential of a clutch or brake. Dynamic clutching is when a clutch brings a fixed output to the input rpm by assuming the kinetic-energy delta of the slower axis. On the other hand, dynamic braking is required for industrial applications in which the brake regulates rotational axis motion by absorbing changes in kinetic energy.
Static-torque values (values describing clutch and brake behavior when the units do not absorb kinetic energy) largely depend on the torsional load. For example, to achieve static torque operation with a clutch, it must engage before input rotation, serving as a coupling between input and output. Contrarily, to perform static torque operation with a brake, the system should only hold the output element still.
Type of Actuation
Actuation refers to the method in which a piston or thrust plate is moved in order to compress/decompress a friction stack. There are three primary types of actuation: electric, hydraulic, and pneumatic. Hydraulic and pneumatic actuators have pistons that can be set by pressure or spring.
Service Life
The service life of a clutch or brake is a critical factor in both automotive and industrial settings. In the industrial world, service life is typically measured in terms of the number of cycles a system can endure. For example, our X-class clutch-brakes were designed for 10 to 20 million cycles, which is far longer than a Nexen dry friction system. They also typically last less than 1 million cycles.
In addition, dry friction clutches and brakes require constant adjustment and maintenance, such as setting air gaps and replacing friction discs. This constant wear and heat can reduce the service life of such systems, and lead to more frequent maintenance requirements.
Aside from the five factors mentioned, other considerations include the following:
- Environmental conditions
- Response time
- Space or weight restrictions
- Routine maintenance
- Auxiliary equipment maintenance
- Certifications such as ISO Compliance, Hazardous Waste Regulations, and others
High-Quality Clutches and Brakes From Force Control Industries
Since 1969, Force Control Industries has provided oil shear clutches and brakes to diverse industries, including the automotive, food and beverage, marine, and material handling sectors. Moreover, thousands of Force Control products are in production worldwide, 24 hours a day, with minimal maintenance costs and downtime.
Our products include numerous clutches, brakes, clutch/brake combinations, dynamometer system, and custom drives & controls. For more information, contact us today!