Introduction to 3D printed hydraulic components

Welcome to this lecture. My name is Marika Hirvimäki This lecture discusses the differences between traditional manufacturing and additive manufacturing in the case of hydraulic components. A hydraulic manifold is a component that regulates fluid flow between pumps and actuators and other components in a hydraulic system. In terms of functionality, it is similar to a switchboard of an electric circuit as it allows the operator to control the movements of fluid between different parts of a hydraulic machinery. Major applications that use manifolds include heavy construction machinery are machine tools, material handling and production equipment, marine machinery and food processing. The traditional production of hydraulic blocks manifolds causes very high machining costs because of many work steps with special tools.

Hydraulic manifolds are manufactured from an aluminium alloy or stainless steel block which is first cut and machined to required size. Internal channels are created with straight, circular drillings in a solid block of material. In addition, several auxiliary drillings are needed to create the desired channels. Drilling of these channels is difficult as they need to meet accurately at certain points. After drilling some of these pathways require plugs to direct flow through the system. The plugs always open the door to potential leakage. Aluminium alloy manifolds are generally less costly due to lower material costs and ease of machining, but they are less abrasion resistant.

For this reason, stainless steel manifolds are sometimes more desirable, but due to the higher density and hardness of stainless steel these manifolds are heaver and more expensive than aluminium manifolds. There are several benefits in AM for design and manufacture of hydraulic manifolds. Main advantages are listed here. AM allows for realization of many technical ideas that have remained unutilized due to limitation of traditional manufacturing techniques. Increased design freedom enables savings in weight, space and material. In AM it is also possible to fully utilise computational fluid dynamics (CFD) to aid the design process. With redesigning of a component dead or sharp corners can be avoided.

This helps keep the structure clean as there are fewer places where dirt can gather and cause problems during operation. Also the extra horizontal holes that would need to traditionally be plugged are no longer needed and fluid flow is not disturbed by corners and edges. With no plugged holes, leakeges are not a problem. In this case study you can see an example of a simple solid block where two pipes merge into one larger pipe which exits the block. Traditionally, to create this part, you have to drill two holes into the top of the block in such a way that they meet this larger hole that was drilled into the side of the block.

After drilling you have to plug the extra holes and auxiliary drills. In the the middle of block is a point where flow of the fluid is interrupted by a sharp angle change between the pipes. This causes energy loss. By redesigning the component a smooth channel can be created without any unwanted interruption of fluid, and also material is added only where it is needed. This saves manufacturing time, and reduces weight and cost.