**3. Analysis**

In this chapter, the meta-action method is described in detail, including the FMA decomposition method and meta-action structure. Some applications of this method

• Action layer: in order to ensure the normal completion of the movement, the level of actions combination is the action layer. The actions in the layer

are all meta-actions, and there is no inclusion relationship.

*Reliability Technology Based on Meta-Action for CNC Machine Tool*

order action.

*3.2.1 Meta-action*

guide rail, etc.

*3.2.2 Meta-action unit*

• power input parts,

• transmission parts,

• supporting parts,

• motion output parts.

ment function of the main shaft.

**51**

must be present:

in mechanical products.

**3.2 Meta-action and meta-action unit**

*DOI: http://dx.doi.org/10.5772/intechopen.85163*

and worm wheel rotating meta-action.

According to the path of action transmission, the actions can be divided into first-order action, second-order action, …, and N-level action. For example, the movement of the worm and gear drive is divided into two meta-movements. The worm rotation is a first-order action, and the worm gear rotation is a second-

The function of a CNC machine tool is accomplished by motion, which in turn is usually done by a transmission system. The latter can be decomposed into the most basic motion unit. Therefore, meta-action may be defined the smallest motion

The meta-action of CNC machine tool can be usually divided into moving metaaction and rotating meta-action. The former realizes the most basic moving functions, such as the linear movement of piston in the cylinder, the linear movement of a nut along the axis of a screw, the movement of a moving guide rail on the static

The latter accomplishes the most basic rotating functions, such as a pair of gear transmission that may be divided into two gear rotating meta-actions. A pair of worm and gear transmission can be decomposed into worm rotating meta-action

In design and manufacture, the performance of a CNC machine tool can be

In order to realize the movement of components, the following four elements

For example, in order to carry out the rotational motion function of the spindle, it is necessary to have a motor coupling, a pulley, or a gear as the power input, an intermediate drive shaft and a gear as the transmission parts, a supporting part (such as a spindle box) for mounting the transmission parts, and a spindle body as the motion output. These parts form an assembly that facilitates the rotation move-

In view of the above, one might define the MU as the unified whole of all parts, which can ensure the normal operation of the meta-action according to the structural relations. The MU must have the following basic elements: power input, power

controlled only by managing the performance of meta-action.

#### **Figure 1.**

*FMA-structured decomposition.*

are represented as well. Also, the use of meta-action reliability technology is described in this section, to provide references for increasing CNC machine tools' degree of reliability. The applications are introduced in three aspects: reliability modeling, design, and manufacturing.
