The structure of a double-spindle CNC lathe

Ⅰ. Overall mechanical main structure

The main structure of the double-spindle CNC lathe inherits the rigid design concept of CNC lathes and has been specifically optimized for the double-spindle layout:

1. bed part ‌ : Generally, the ‌ integral casting one-piece structure ‌ is adopted. Some models use secondary high-temperature quenching process to enhance rigidity. The mainstream layout is divided into two types:

The 45° forward-inclined bed is convenient for chip removal and maintenance adjustment, and it is currently the mainstream design.

Horizontal flat bed: More suitable for the processing requirements of large-diameter long shaft parts.

The outside of the bed is equipped with fully enclosed sliding doors, which not only ensure operational safety but also facilitate opening the cover for debugging and maintenance.

2. slide table and feed system ‌ : Independent slide table seats and large drag plates are respectively configured at the left and right ends, equipped with longitudinal and transverse high-precision ball screw pairs + servo motor drive; The saddle generally adopts high-precision rolling guides, featuring high repeat positioning accuracy and a rapid traverse speed of up to 24m/min, ensuring the response speed and precision stability of processing at both ends.

Ⅱ. Dual-spindle core drive system

The dual-spindle system is the core of the entire equipment. According to processing requirements, it is divided into two mainstream layouts, each with its own focus in structural design:

1. parallel opposed double-spindle layout ‌ : The left and right spindles are respectively located on both sides of the workpiece, allowing simultaneous clamping of both ends of the workpiece for synchronous processing. Structural features include:

The headstock adopts a three-support structure. The main shaft mostly uses a combination of tapered roller bearings and double-row self-aligning roller bearings, featuring high reverse accuracy and convenient adjustment.

The main drive system can be configured with variable frequency drive or servo drive, supporting stepless speed regulation. The power is directly transmitted to the main shaft through the helical toothed belt, ensuring smooth and low-noise operation.

It adopts a dual-spindle synchronous drive structure and a closed-loop position feedback system. The self-developed synchronous control algorithm can ensure that the positioning accuracy difference of the Z-axis at both ends is less than 0.003 millimeters, guaranteeing dimensional consistency.

2. main and auxiliary series layout (turning center type) ‌ : The main spindle at the front is responsible for rough machining, and the auxiliary spindle at the back is responsible for butt finishing. The structure is more focused on flexible processing:

The main and auxiliary spindles mostly adopt precision electric spindles, equipped with high-precision NSK-grade bearings, and their rotational speeds are higher than those of traditional opposed types.

It is equipped with high-precision roller linear guides and C3-grade ball screws for transmission, ensuring high rigidity and low thermal deformation. It supports Y-axis/C-axis linkage and, in combination with a power tool turret, can complete compound processing such as turning, milling and drilling.

3. clamping structure ‌ : The ‌ hydraulic clamping system ‌ is commonly used to ensure the stability and safety of the processing. Common clamping methods include spring chucks (suitable for medium and small diameter bar stock) and hydraulic chucks (suitable for large diameter disc and sleeve parts).

Ⅲ. Control System and Auxiliary Structures

1. numerical control system ‌ : The mainstream adopts ‌ dual-channel bus type, dual-program/dual-system single-channel numerical control system ‌, which supports two processing modes: one is synchronous processing of different procedures at both ends, and the other is independent control at both ends, adapting to the speed and feed requirements of different procedures. It can also be expanded with additional functions such as milling, drilling, and tapping according to the requirements of the workpiece.

2. auxiliary functional structure ‌ :

Tool magazine/tool turret: It mostly adopts a row tool structure to enhance processing efficiency. It can also be equipped with multi-station tool turrets and power tool turrets according to requirements to meet the processing needs of complex parts.

Chip removal system: Some models can be optionally equipped with an automatic chip conveyor. The inclined bed structure itself is also more conducive to chip removal. Some models offer multiple layout options such as side chip removal and rear chip removal.

Lubrication system: It adopts a design combining splash lubrication and forced lubrication. Some high-end models are equipped with an automatic centralized lubrication system, which can automatically set the oil injection interval to ensure the accuracy and service life of moving parts.

Feed limit: The feed box is equipped with a metric and imperial thread conversion mechanism, and the slide box is fitted with a safety device. The longitudinal direction can be set to automatically stop the feed, and it supports fixed-length processing.