In this volume, we will learn about the energy (kinetic energy) that the movable part of a machine possesses.

(1) Kinetic energy

The energy that a moving object possesses is called "kinetic energy" (Ek).

- The joule (J) is used for the unit of kinetic energy.

- 1 J (joule) is equal to the work done to an object when a force of 1 N (Newton) acts on that object to move a distance of 1 m.

- The kinetic energy Ek (J) that an object with a mass m (kg) in motion at a velocity v (m/s) can be expressed in the following formula:

(2) Machine safety mechanism for kinetic energy

- In a linear drive mechanism, a movable body continues its movement while possessing kinetic energy Ek.

- In case of accidents due to a lightning strike or power outage that could suspend the operation control, it is necessary to incorporate a safety mechanism into a machine in order to avoid damages and injuries caused by the kinetic energy that the movable body possesses.

- Installing a damper on both ends of the linear guide is a common method of incorporating a safety mechanism into a linear driving unit (see [Fig.1]).

- When you install an actuator with little frictional resistance into a linear motor mechanism, designing a safety mechanism is especially important. In such a case, large-sized dampers are adopted (see [Fig.2]).