Spring-force self-aligned multiball pitch artifact

• Spring force self-aligned multiball pitch artifact is proposed.
• Design method of the parts of the artifact is clarified.
• The artifact is assembled successfully.
• Advanced manufacturing techniques or special tools are not required for manufacturing.
• Measurement experiments clarified the fundamental validity of the artifact.

Gear noise is influenced by pitch deviation of micrometer order, and, therefore, the pitch of gears is inspected in manufacturing processes using measurement instruments. Master gears or artifacts are used to evaluate the accuracy of the pitch measurement instrument, but their accuracy is not sufficiently high and they are not easy to manufacture. In a previous study, the concept of a novel high-precision pitch artifact composed of simple components was proposed for the evaluation of the accuracy of pitch measurement instruments. Simple components, such as balls, cylinders, and planes, can accomplish an accuracy on the order of several tens of nanometers. Therefore, this artifact can be realized with high accuracy. In the present study, we propose a spring-force self-aligned multiball pitch artifact, in which simple components are assembled using spring force. The design of the artifact is discussed, and the artifact is manufactured. Measurement experiments using a coordinate measurement machine and a pitch measurement instrument are carried out, and the proposed pitch artifact is demonstrated to be fundamentally valid for accuracy evaluation.