Inner Race Hard Turning and Hard Milling Automated Machining Solution
High-Efficiency Precision Manufacturing Empowering Automotive Industry Upgrades
In the global automotive components manufacturing industry, the constant velocity joint (CV joint) is the core element of the drive system. Its performance directly affects the vehicle's power transmission efficiency and driving smoothness.
As a professional Chinese supplier of machine tools and automation solutions, we have partnered with one of the largest automobile manufacturers to develop a fully automated and high-efficiency CV joint production line.
The line integrates lathes, milling machines, grinding machines, thread rolling machines, and drilling-milling machines, realizing a complete workflow from rough machining to precision finishing and from stand-alone machines to a fully automated system.
Among the core components of the CV joint, the Inner Race inner race works together with the bell housing, cage, and tripod housing to form the transmission assembly.
Today, we will focus on the automated hard turning and hard milling process for the Inner Race.
I. Process Overview: From Finish Turning to Hard Turning and Hard Milling
Before entering the hard turning and hard milling stage, the Inner Race has completed rough turning, finish turning, and internal spline broaching.
After heat treatment, the hardness of the workpiece reaches HRC45–60, where conventional cutting methods can no longer meet the machining requirements.
Therefore, Hard Turning and Hard Milling technologies are employed. inner race
Our integrated hard turning and hard milling machine can complete inner race groove milling and spherical hard turning in a single setup, achieving high precision, high efficiency, and low labor intensity.
II. Hard Turning: Precision Surface and Geometric Accuracy
Hard turning is mainly used for finishing the spherical surface, outer diameter, end face, and inner bore of the Inner Race.
The inner race process utilizes a high-rigidity spindle and CBN cutting tools, achieving micro-cutting at high speeds. The surface roughness can reach Ra 0.4–0.8 μm.
Through precise control of cutting parameters and tool path, hard turning significantly improves dimensional accuracy and concentricity, ensuring perfect assembly between the Inner Race and the bell housing.
Advantages over traditional grinding:
One-time clamping eliminates repeated positioning errors.
High material removal rate reduces machining time.
Improved residual compressive stress enhances fatigue strength.
Green and clean manufacturing - no coolant contamination.
inner race
III. Hard Milling: Accurate Grooves and Mirror-Finish Surfaces
The grooves of the Inner Race feature complex geometry that requires precise angles and continuous spherical transitions.
Hard milling technology, using a high-speed spindle and precision milling cutters, ensures stable cutting on hardened materials.
Features of the hard milling process(inner race):
All inner race grooves can be machined in one single setup.
Guarantees inner race groove form accuracy, angular integrity, and sharp edges.
Achieves inner race mirror-finish surfaces (Ra 0.2 μm) without secondary polishing.
Multi-axis control enables complex contour machining with excellent consistency(inner race).
This inner race process achieves the perfect balance between precision and efficiency, providing the CV joint with superior reliability and durability.
IV. Machine Structure and Automation System
1. Fully Automatic Loading and Unloading
The machine is equipped with a dual-gantry, three machine linkage system, where a manipulator performs continuous material loading and unloading across three machines.
Modular grippers and positioning devices allow for quick changeovers for different parts.
The machining area is completely isolated from the loading zone for safety and easy maintenance.
The automation system supports unattended operation, greatly reducing labor costs.
inner race
2. Storage Magazine
A four-channel storage magazine design accommodates approximately 120 workpieces(inner race), enabling long-term continuous operation.
3. Transfer and Buffer System
The transfer unit conveys workpieces from the magazine to the buffer station while assisting the manipulator in part handling.
The buffer table ensures that the manipulator can unload parts without waiting, effectively avoiding cycle delays.
4. Pushing Device
The pushing mechanism accurately positions each workpiece(inner race) for the next process, ensuring smooth and precise workflow transitions.
V. Machine Core Configuration
Spindle-Type Swing Rotary Table: Maximum clamping diameter 35 mm, maximum workpiece length 60 mm.
Equipped with angular grating encoders for smooth motion and stable precision.
Dry Cutting Technology: Air cooling system, energy saving and environmentally friendly; eliminates coolant use and reduces maintenance costs.
High Precision Servo Drive System: Ensures synchronized multi-axis motion and repeatable positioning accuracy.
VI. Precision Positioning Function
After the manipulator picks up the workpiece(inner race) from the buffer table, it places it onto a precision positioning station, where the correct orientation and position are verified via vision or mechanical detection.
This ensures that each Inner Race maintains the same alignment during clamping, eliminating orientation deviation and guaranteeing accuracy in the subsequent hard turning and hard milling operations.
VII. Intelligent Manufacturing and Quality Assurance
The entire production line can be connected to an MES system or factory data center, enabling real time monitoring of machining parameters, workpiece status, and tool life.
With process traceability and intelligent alerts, both productivity and yield rates are significantly improved.
The machine has undergone multiple rounds of testing and customer on-site verification, maintaining stable long term operation even under demanding production environments.
VIII. Conclusion
The Inner Race hard turning and hard milling integrated machine - featuring high precision, high efficiency, and intelligent control - has been successfully applied to automated CV joint production lines.
Compared to traditional multi-machine sequential processing, this solution simplifies the manufacturing process, reduces clamping times, and improves both consistency and surface quality.
This automation solution not only provides automobile manufacturers with reliable and stable component processing capability but also demonstrates our strong expertise in precision machining and automation system integration.
Moving forward, we will continue to advance in the field of transmission component manufacturing, delivering more efficient, eco-friendly, and intelligent machine tool solutions to customers worldwide.