Smooth, load free start with centrifugal clutches
Centrifugal clutch with pivoting flyweights
Key features of centrifugal clutches
Looking for a centrifugal clutch for your application? At Amsbeck, we have been manufacturing centrifugal clutches and centrifugal brakes since 1982.
Below is an overview of how our centrifugal clutches work and the advantages they offer:
Centrifugal clutches enable soft start and no-load start-up. This allows the engine to start without load or run under no-load conditions. This feature is especially beneficial for applications that require high starting torque.
As a result, the engine can be sized for normal operating speed instead of peak start-up torque, allowing for a smaller and more cost-efficient solution.
Operating principle
When the rotating elements of the centrifugal clutch begin to spin, centrifugal force pushes them outward. This outward force is initially balanced by spring tension up to the defined engagement speed.
Once the engagement speed is reached, the centrifugal force overcomes the spring force, and the friction linings make contact with the clutch housing. Torque begins to build as the clutch enters slip mode and accelerates the application to operating speed.
As speed increases, centrifugal force rises quadratically, increasing torque
accordingly. Once the target speed is reached, slipping stops and torque is
transmitted through friction.
By adjusting springs, friction materials, size, number of elements, and operating speed, both engagement speed and torque can be precisely tailored to the application.
Centrifugal clutch with free flyweights
Engagement behavior
The engagement speed depends on the operating speed of the drive and the required power transmission. Because clutch performance increases with the square of speed, a minimum operating speed is required.
Engagement speed is defined as the point at which centrifugal force overcomes spring tension. By selecting springs with different stiffness levels, the engagement speed can be adjusted to match the application.
Based on our experience, we configure the clutch so that torque at operating speed exceeds the required level. This helps prevent slipping, even during temporary drops in speed.
Heat generation in centrifugal clutches
Friction generates heat, and during the slip phase, this energy is almost entirely converted into heat. It is therefore critical to minimize slip time.
The organic friction linings used by Amsbeck absorb only a small portion of this heat.
Most of the heat is transferred to the housing and surrounding components or dissipated into the environment.
Design Types
There are many types of centrifugal clutches. At Amsbeck, we primarily use two proven designs:
- Centrifugal clutch with free flyweights
- and centrifugal clutch with pivoting flyweights
In the standard design, centrifugal elements are mounted on the hub using a dovetail profile. This allows torque to be transmitted independently of the direction of rotation.
The dovetail guide also creates a servo effect that increases torque transmission depending on the angle of the guide. In the pivoting flyweight design, the centrifugal elements are guided with minimal play via a pivot pin. The rigid carrier plate improves damping and ensures smooth, low-vibration, and low-noise operation.
Due to a self-reinforcing effect similar to a duplex drum brake, very high torque can be achieved in one direction of rotation. In the opposite direction, this effect is not present, and torque capacity is reduced to approximately 50%.
Regardless of the design or engine type, each clutch is tailored to your application. Whether your engine shaft is keyed or tapered, we customize the clutch for optimal fit and performance.
Applications
Centrifugal clutches are used in a wide range of applications, including: Construction equipment, transport refrigeration systems, sweepers, mowers, chainsaws, emergency generators, pump drives, lawn equipment, fans, kart racing, stump grinders, descent control systems, and hydro and wind turbines.
Get in touch
Not sure if a centrifugal clutch is the right solution for your application? Contact us by phone, email, or through our contact form. Our team will be happy to support you with the technical design.
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150 North Michigan Avenue
35th Floor
Chicago, Illinois 60601