There are many types of CNC lathes, but they generally consist of three parts: the lathe body, the CNC device, and the servo system.
I. Lathe Body
- Spindle and Spindle Box: The rotational accuracy of the CNC lathe spindle has a significant impact on the precision of machined parts, and its power and rotational speed also affect machining efficiency. For CNC lathes with automatic speed regulation, the transmission structure of the spindle box is simplified. However, for modified CNC lathes with both manual and automatic control machining functions, the original spindle box is generally retained.
- Guideways: The guideways of a CNC lathe ensure the feed motion. They significantly influence the lathe’s rigidity, accuracy, and smoothness during low-speed feeds, which is a crucial factor affecting the quality of machined parts. While some CNC lathes still use traditional sliding guideways, many mass-produced CNC lathes now use plastic-coated guideways.
- Mechanical Transmission Mechanism: Apart from gear transmissions and other mechanisms within the spindle box, CNC lathes have simplified the transmission chains compared to conventional lathes. The gearbox, feed box, slide box and most of their transmission mechanisms were eliminated, and only the longitudinal and transverse feed helical transmission mechanisms were retained. A gear pair that can eliminate backlash was added between the drive motor and the lead screw (not added to a few lathes).
II. Numerical Control Unit
In the field of CNC machine tools, the numerical control unit is the core of the machine tool. It mainly receives the CNC machining program from the input device in its internal memory, compiles and processes it through its circuitry or software, and then outputs control information and instructions to control the operation of various parts of the machine tool, enabling it to move in an orderly manner.
III. Servo System
The servo system comprises two components: the servo unit and the drive unit.
The servo unit acts as the connection between the CNC machine and the lathe. It amplifies the weak signals from the CNC machine, transforming them into high-power drive signals. Depending on the received commands, servo units can be either pulse-type or analog-type.
The drive unit programs the CNC signals amplified by the servo unit into mechanical motion. Through simple connecting components, it drives the lathe, allowing the worktable to precisely position itself along its trajectory, ultimately producing the desired product.
