**2. Antiseizure cylinder block**

A typical cylinder block manufacturing method is shown on the left of **Figure 1**. At this time, the production process of each process does not generate residual

stress enough to have a large effect on the final product [2]. However, when a copper bushing is inserted into the cylinder block to prevent the seizure between the cylinder block and the piston (on right of **Figure 1**), and residual stresses corresponding to the yield stress of the material before using the cylinder block are

occurrence of the seizure and the operating area of the cylinder block overlap (**Figure 2**). As a result, if a failure occurs due to the seizure, the total non-operating time of the equipment becomes longer. This leads to a decline in equipment reliability. Therefore, if the durability of the cylinder block is not adversely affected even if the cost is somewhat high, it is considered necessary to insert the copper bushing even if residual stress occurs to improve the reliability of the main pump.

**3. Methods for durability assessment of cylinder block**

with respect to the cylinder block in which the residual stress is present.

evidence for durability safety, should be selected only by experience.

based on the authority of the standard, but the accuracy of the product with complicated shape is degraded in order to guarantee the performance. The reason is that the standard contains some assumptions and simplifications in the formulas for

If the copper bushing is not inserted, there is a high possibility that the zone of

In general, standard, measurement, experiment and simulation can be considered as methods for durability assessment. The above methods will be described

In the case of the standard, the reliability of the evaluation result can be secured

In case of measurement, there is an advantage that it can confirm the accurate state in real time when using, but there is a disadvantage that it is only possible to check the local state instead of the total state. In addition, there are many difficulties in measuring a cylinder block having a relatively small size as well as a rotating body. Also, there is a risk that the location of the high stressed portion, which is an

Experiments provide a relatively complete assessment of the product as a whole, but it takes time and expense to derive the results of the experiment. Especially, the improvement process and the short processing period, which are often derived when the product development stage is the basic design, make the experiment only used in the final product development stage. These characteristics make the experimental method difficult to use for the purpose of this study (predicting the residual stress and evaluating the durability thereof), which is the working area of the basic

Finally, in the case of simulation, the overall evaluation of the product is possible

and it is possible to respond quickly to the improvement. However, as shown **Figure 3**, unlike the measurement and the experiment, simulation is difficult to consider stochastic effect. Stochastic effects of products not confirmed by

expected to exist.

*Durability Assessment Considering Residual Stress DOI: http://dx.doi.org/10.5772/intechopen.90298*

general use.

design.

**Figure 3.**

**127**

*Deterministic and stochastic in evaluation method.*

**Figure 1.**

*Comparison of production processes.*

**Figure 2.** *Wear-mechanism map.*

### *Durability Assessment Considering Residual Stress DOI: http://dx.doi.org/10.5772/intechopen.90298*

**2. Antiseizure cylinder block**

*New Challenges in Residual Stress Measurements and Evaluation*

**Figure 1.**

**Figure 2.**

**126**

*Wear-mechanism map.*

*Comparison of production processes.*

A typical cylinder block manufacturing method is shown on the left of **Figure 1**.

At this time, the production process of each process does not generate residual

stress enough to have a large effect on the final product [2]. However, when a copper bushing is inserted into the cylinder block to prevent the seizure between the cylinder block and the piston (on right of **Figure 1**), and residual stresses corresponding to the yield stress of the material before using the cylinder block are expected to exist.

If the copper bushing is not inserted, there is a high possibility that the zone of occurrence of the seizure and the operating area of the cylinder block overlap (**Figure 2**). As a result, if a failure occurs due to the seizure, the total non-operating time of the equipment becomes longer. This leads to a decline in equipment reliability. Therefore, if the durability of the cylinder block is not adversely affected even if the cost is somewhat high, it is considered necessary to insert the copper bushing even if residual stress occurs to improve the reliability of the main pump.
