A whirling machine, within mechanical engineering, serves the purpose of crafting rotating parts with precise measurements and tolerances. Its application lies in the production of items like gears, sprockets, and pulleys, ensuring accuracy in dimensions.

Whirling Machine Makes Economic Sense!

⦁ Expensive grinding steps are eliminated.

⦁ Cycle times decrease by up to threefold.

⦁ Improved pitch accuracy and thread profiles.

⦁ Swift setup and changeover times.

⦁ Dry machining negates the necessity for costly cutting fluid.

The Cutting Process and Chip Formation with Whirling Machine

The cutting process involves a high-speed rotating ring that encircles the workpiece, known as the “C axis,” creating the cutting action. The thread pitch is determined by moving the tool head along the “Z axis” while the workpiece rotates.

To match the thread pitch angle, the tool head’s cutting angle is adjusted using the “A axis.” The “X axis” controls the minor diameter of the thread, and switching between right and left-handed threads is achieved by altering the direction of travel along the “Z axis.” The spinning ring mimics the workpiece’s direction, crucial in producing the desired thread direction.

Tool placement within the tool ring allows them to move concerning the workpiece, resulting in the creation of precisely comma-shaped pieces (refer to image 2). Despite the interrupted cutting nature during spinning, the smooth chip generation enables machining of hardened materials up to 65 HRc and brittle materials using tools made of carbide, CBN (Cubic Boron Nitride), or ceramic.

Symbols:

• nW: Rotation speed of whirling tool
• T: Depth adjustment
• nR: Workpiece rotation speed
• X: Eccentricity
• SK: Cutting circle
• K: Comma-shaped chip

Comparing Whirling with Milling

The cutting process is initiated by a high-speed rotating ring encircling a slowly turning workpiece on its “C axis,” causing the cutting action. To determine the thread pitch, the workpiece rotates while the tool head along the “Z axis” moves accordingly.

Adjusting the cutting angle on the tool head around the “A axis” aligns it with the thread pitch angle, while the “X axis” eccentricity controls the thread’s minor diameter. Changing the direction of “Z axis” travel easily switches between right and left-handed threads. Notably, the spinning ring consistently rotates in sync with the workpiece; it’s the travel direction that crafts the desired thread direction.

Tools secured within the tool ring move relative to the workpiece, crafting precisely comma-shaped pieces. Despite being an interrupted cutting process, its smooth chip generation permits cutting hardened materials up to 65 HRc and brittle materials using carbide, CBN (Cubic Boron Nitride), or ceramic tools.

Consider the similarity between whirling and milling when cutting external threads. While both employ multiple cutting teeth, the whirling ring’s progressive entry and exit of the cutting edges offer a more efficient cutting action, resulting in higher metal removal rates. Unlike milling, whirling minimizes radial pressure, reducing stress on both the workpiece and insert, thereby significantly extending tool life and enhancing cost-effectiveness.

Whirling Machine process Video

Comparison of single point and thread whirling process

The spinning head is angled precisely for the helix, the cutter rotates swiftly, the bar stock rotates slowly along its axis, and the thread is formed by advancing along the pitch. As the inserts tear through the material, the thread is shaped in a single pass.

Multi-lead thread Single pass forming examples

Feel free to reach out to delve into the essential criteria for machining multi-lead tread shapes. We can explore mechanical parameters, spindle specifications, insert details, and tooling specifics together.

Thread Geometry

The displayed geometries above are approximate and subject to variation based on specific application details

What is the difference between thread rolling and whirling?

Thread rolling has become a standard practice due to its cost-effectiveness, enhanced surface finish, and extended durability. Meanwhile, thread spinning excels in crafting precise threads with narrow tolerances, making it more suitable for smaller batches.

How does a thread whirler work?

Thread whirling operates much like thread milling, wherein the inserts reside within a cutting ring positioned internally instead of on the outer surface of a milling tool. As the thread whirling ring rotates around a cylindrical component, it executes the thread cutting process in a single pass.

What is thread milling?

Thread milling involves maneuvering a thread mill across or inside a workpiece to attain the desired thread form. Employing multiple radial passes during milling ensures superior chip control.