The basic components of an electric actuator are a motor, a gearing, and a spindle. However, sometimes a clutch mechanism is added to the actuator design. In this video, our expert Hunter Stephenson explains the purpose of a clutch in an industrial linear actuator, and how the clutch works in the LINAK® actuator LA36.
What is the function of a clutch in an electric linear actuator?
The clutch has two purposes:
The clutch makes industrial electric linear actuators from LINAK® versatile and easy to implement in different machinery. In the actuator, the clutch can handle a push/pull of approximately 1.5 to 2.0 times its rated load at nominal speed before the clutch disengages.
The clutch disengages the rotational movement from the motor to the spindle and the gear. It is important to emphasise, that this is not a safety feature for when a heavy load is applied, while the actuator is powered off. The clutch disengagement mechanism is only applied, when the motor is rotating (powered on).
How does a clutch work?
The clutch disengages when the torque exceeds a pre-set limit. This happens, if the torque from the motor gets too high when running the actuator; the spring plate cannot hold the load and the ball bearings will be pushed out of their notches.
The clutch disengages, as the plates turn without creating movement, which means that the clutch disengages.
When the torque is lowered, the ball bearings will fall into place, and the torque will transfer into a linear movement again.
And in that way it protects the actuator and application in case of overload.
Do actuators with integrated controller have a built-in clutch?
No. For actuators with integrated controller the clutch is an unnecessary component. Instead, actuators with IC Integrated Controller™ use a current limit to ensure that the actuator automatically stops, if it meets an obstacle or other resistance in the application. Current limits are designed to help protect both the application and the actuator.
The clutch serves two purposes in an actuator. One is to protect the industrial machinery and the actuator. The other is to ensure that the actuator can be used without control electronics.
A linear actuator with a clutch mechanism offers great versatility, making it easier to implement the actuator in different machinery.
The clutch protects the actuator and the application in case of overload by disengaging the rotational movement from the motor to the gear and spindle when the torque exceeds a pre-set limit. This safety feature is related to the rotational movement of the motor and therefore it only works when the actuator is running. If you would like to know more about the function of the clutch, check out the video above.
