Innovative Double V-Groove Transmission Mechanism for More Efficient Power Tools

In cordless impact tools, transmission efficiency affects not only torque performance, but also battery runtime, motor loading, and manufacturing cost. Porite Taiwan has developed an innovative Double V-Groove Transmission Mechanism that rethinks the conventional impact transmission structure. By integrating key mechanical features and optimizing the V-groove geometry, the design aims to maintain torque performance while reducing operating current and simplifying the manufacturing of critical components.

Rethinking the Conventional Impact Mechanism
In a conventional impact mechanism, V-shaped groove features are incorporated into the drive shaft and hammer. Porite's new concept integrates these functional features into a dedicated double-ball V-groove sleeve, allowing the structures of the drive shaft and hammer to be simplified. 
The mechanism also evolves from a conventional single-ball groove concept to a double-ball V-groove configuration. With a smaller V-groove angle, the design requires less driving force to move the steel balls, helping reduce the load required during operation. 
Comparable Torque with Lower Current Consumption
Testing was conducted on an 18V Impact Gearbox with the output shaft fixed. The existing design achieved an average torque of approximately 95.9–98.8 N·m with a current consumption of approximately 12.9–13.0 A. The Double V-Groove design delivered approximately 97.3–97.9 N·m, while reducing current consumption to approximately 10.7–11.14 A. 
These results indicate that, under the tested conditions, the new mechanism can deliver comparable torque output while requiring less electrical current.
Using a 4Ah battery as an illustrative example, reducing operating current from approximately 13A to 11A increases the calculated continuous operating time from around 18 minutes to 22 minutes, representing approximately 22% longer operating time. Actual battery runtime will depend on application load, duty cycle, battery characteristics, and overall system efficiency. 
Designed for Efficiency and Manufacturability
The benefits extend beyond energy efficiency. Simplification of the drive shaft manufacturing process was estimated to increase daily production capacity from approximately 200 to 600 pieces per day. Eliminating the original V-groove from the hammer also reduced the related manufacturing process from six operations to two, potentially improving tooling life, production capacity, and manufacturing efficiency. 
The Double V-Groove mechanism therefore represents more than a component redesign. It is an integrated approach to energy efficiency, component simplification, and manufacturability, providing a potential new transmission architecture for next-generation power tools.

The Transmission Mechanism was filed by Taiwan Porite, with Taiwan patent application numbers 111147611 and 111213706, with related patent filings also listed for the United States, Germany, Japan, Korea, and China.