Design and Fabrication of Gearless Power Transmission Mechanism

Abstract

Traditional power transmission across non-parallel or angled shafts relies heavily on bevel, crossed-helical, or worm gear configurations. However, these gear sets introduce manufacturing complexities, high production costs, backlash, and mechanical friction losses. This paper presents the design, kinematic principle, and fabrication of an elbow-link gearless power transmission mechanism. Utilizing a multi-slider kinematic chain formed by 90-degree bent rods sliding within matching drilled hubs, this system transfers continuous rotary power between intersecting and skew shafts at a 1:1 speed ratio without gear teeth. Experimental validation demonstrates smooth, low-noise operation, reduced maintenance requirements, and significant cost savings compared to traditional gear systems.

Introduction

The text presents a gearless transmission mechanism designed to transmit mechanical power between two shafts positioned at 90° to each other. It is proposed as an alternative to conventional bevel, worm, and crossed-helical gears.

The mechanism uses bent elbow links and cylindrical hubs instead of gear teeth. As the input shaft rotates, the links slide and swing inside guide holes, transferring force to the output hub and producing synchronous 1:1 rotation. A three-link arrangement spaced at 120° is identified as a balanced and practical configuration.

The prototype is a bench-scale system using mild-steel shafts and hubs, hardened steel bent rods, pillow-block bearings, and a welded structural frame. Manufacturing involves conventional turning, drilling, bending, heat treatment, and welding, avoiding specialized gear-cutting equipment.

Compared with geared transmissions, the gearless system aims to provide:

• Lower manufacturing cost and complexity
• Reduced gear-mesh friction, wear, and noise
• Lower maintenance requirements
• Greater tolerance for non-standard shaft arrangements
• Simple and inexpensive replacement of links

Potential applications include multi-spindle drilling machines, machine-tool auxiliary drives, periscope and clock mechanisms, confined-space tooling, and light-duty vehicles.

Conclusion

The design and fabrication of the gearless power transmission mechanism demonstrates a cost-effective, quiet, and mechanically viable alternative to conventional right-angle gear drives. By eliminating tooth engagement in favor of multi-link sliding kinematic pairs, the system achieves 1:1 angular power transmission with reduced vibration, minimal manufacturing cost, and simpler maintenance. Future work will focus on dynamic stress analysis under continuous heavy load regimes, wear-resistant material coatings for the sliding pins, and adapting the architecture to dynamically variable shaft angles.

References

[1] Norton, R. L. Design of Machinery: An Introduction to the Synthesis and Analysis of Mechanisms and Machines. McGraw-Hill Education. [2] Shigley, J. E., & Mischke, C. R. Mechanical Engineering Design. McGraw-Hill. [3] Kumar, A., Kumar, A., Kumar, M., Kumar, C., & Kumar, P. (Project Report). \"Design and Fabrication of Gearless Power Transmission Mechanism,\" Department of Mechanical Engineering, Government Polytechnic Muzaffarpur, SBTE Patna. [4] Mabie, H. H., & Reinholtz, C. F. Mechanisms and Dynamics of Machinery. John Wiley & Sons.

Copyright

Copyright © 2026 Mr. Vinay Ranjan Kumar, Mr. Aniket Kumar, Ranjeet Kumar, Amit Kumar, Aditya Kumar, Mausam Kumar, Chitrakant Kumar, Mr. Alok Nath Jha. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.