Bushing blocks optimization for an external gear pump    

Maria Pia D'Ambrosio - SixSigmaIn Team & Marco Manara - Casappa spa

This project aims at the optimization of the design of the bushing blocks assembled into a specific type of external gear pump produced by Casappa, one of the world leader manufacturer of this kind of machinery. The bushing block is one of the key parts of a gear pump. Its optimization depends on a large amount of parameters and has to fulfil multiple economical, functional and mechanical requirements. The proper optimization of the blocks is a crucial element of the pump design. In the specific case here analyzed, due to important economical needs and to constraints coming from the production process, a re-design of many key geometrical characteristics of the blocks is required. The purpose of this study is to optimize several responses simultaneously. These responses come from different mathematical models (up to four) and are related to performance, noise level and cost of the pump. The optimization is carried out using statistical definition of the process tolerances and DFSS (Design For Six Sigma) tools, such as Monte Carlo simulation, which is performed through @RISK. The presentation discusses how automation can be applied to the process measurements (using CMM - Coordinate Measuring Machine - data acquisition) of the block dimensions, in order to define the process natural variation and the type of distribution better approximating the real data. These evaluations are then used as input of a Monte Carlo simulation with multiple models and responses. The above mentioned techniques will lead to a combined optimization of the design parameters. This optimization will enable to achieve all the targets and to satisfy both economical requirements and process constraints.

Case Study : Step I 

8.49 minutes video

Case Study : Step II 

9.02 minutes video