A client from the aerospace industry recently contacted our company to build a series of variable and fixed wobblers. These parts allow for the variable displacement of hydraulic fluid from an aircraft hydraulic pump system. Due to the wobblers’ unique shape, combined with the need to provide each part with a hard surface finish on close tolerance dimensions, a complex sequence of machining operations was necessary for successful production.
In order to successfully machine these wobblers, we began by constructing each part using 52100 steel per AMS6440 as a base material. This material was chosen for its stability when high pressured hydraulic fluids are applied. After performing a variety of five axis milling operations, we then heat treated each wobbler, hardening each unit to an Rc level of 55-60RC.
Adept at multiple grinding disciplines, our manufacturers placed each part through various grinding processes, including OD, bump, surface, and plunge grind steps, meeting (±) .0002 inch precision tolerance on journal diameters. Our skillful engineers were able to provide an ultra precision flatness tolerance of one Micron on the seat area of each wobbler.
After grinding, a thin titanium-nitrided coating is applied. We also ensured the quality of our products, using custom designed profilometer instruments to inspect the final microfinish in this seat area.
Using a series of advanced machining processes, Tolerance Masters was able to construct a series of complex wobblers for the aerospace industry. Equipped with a maximum material finish of 1.5-2 RMS and a Rockwell hardness of 55-60, these wobblers met with high client expectation.