Hiroki Yamazaki

Title: Hiroki Yamazaki: Inventor in Planetary Gear Technology

Introduction

Hiroki Yamazaki is an inventor based in Ohbu, Japan, associated with Sumitomo Heavy Industries, Ltd. His listed inventions focus on the design and manufacture of inner and outer rollers for internal-meshing planetary gears. Yamazaki is credited with 3 patents.

Latest Patents

Yamazaki’s listed patent work includes “Inner Roller and Outer Roller in Internal-Meshing Planetary Gear” and “Method of Fabricating Inner Roller and Outer Roller in Internal-Meshing.”

The inventions describe an inner roller whose inner-peripheral wall is shaped approximately like a regular polygon. In the illustrated example, the wall approaches a triangle, leaving clearances near its vertices to hold lubricating oil while the inner pin lightly contacts the midpoint of each side. This arrangement is intended to reduce backlash while preserving lubrication, supporting smoother operation and improved durability.

The fabrication method forms the polygon-like inner wall through burnishing while forces are applied at evenly spaced points around a cylindrical blank. A subsequent heat treatment enlarges the residual strains produced during burnishing, helping establish the desired shape.

Career Highlights

Yamazaki’s listed work connects precision forming and heat treatment with the performance of internal-meshing planetary gear systems. The designs address the practical challenge of balancing oil retention with a close, low-backlash fit between the inner roller and pin.

Collaborations

Yamazaki is associated with Sumitomo Heavy Industries, Ltd. His listed coworkers include Kiyoji Minegishi and Masanori Egawa.

Conclusion

Hiroki Yamazaki’s patent work centers on shaping and fabricating planetary gear rollers to combine lubrication, reduced backlash, and durability.