Transmission mechanism of knitting circular knitting machine: structural composition and key points of operation control

The transmission mechanism is controlled by a leveler to operate an infinitely variable speed electric motor. The electric motor uses a V-belt or synchronous belt (toothed belt) to drive the driving shaft gear, which is then transmitted to the large plate gear, thereby driving the needle cylinder to carry the knitting needles and perform weaving. The active shaft extends onto the large circular machine and drives the yarn feeding disc to deliver yarn in a measured amount. Require the transmission mechanism to operate smoothly and without noise.
Transmission mechanism of knitting circular knitting machine: structural composition and key points of operation control
The transmission mechanism of the knitting large circular knitting machine is the core power system that drives the operation of the needle cylinder, the triangular fit, and the synchronization of yarn feeding and pulling. Its stability directly determines the weaving accuracy, fabric quality, and equipment operating efficiency. It is mainly divided into two modules: mechanical transmission and electrical control, which are adapted to the weaving needs of different machine models.
1、 The core structural composition of the transmission mechanism
1. Power source components
The core is a variable frequency speed regulating motor, and some high-end models are equipped with servo motors, which can achieve stepless and smooth speed regulation, meeting different speed requirements from low-speed debugging to high-speed weaving. The motor power needs to be matched with the large circular machine model: single-sided machines are suitable for smaller power motors (such as 1.5-3kW), while complex models such as double-sided jacquard machines and looped machines require high-power motors (such as 5-11kW) to ensure sufficient power under heavy load conditions. The motor is connected to the transmission components through a coupling to reduce operational vibration.
2. Mechanical transmission unit
It is a key carrier of power transmission, and the mainstream transmission methods are divided into two types:
-Belt drive: suitable for medium and low-speed conventional circular machines, consisting of an active pulley, a driven pulley, and a V-belt, with the advantages of simple structure, easy maintenance, and shock absorption and buffering. It is necessary to accurately adjust the tightness of the belt. If it is too loose, it may slip and cause unstable speed, while if it is too tight, it will exacerbate bearing wear.
-Gear transmission: commonly used in high-speed and high-precision models (such as electronic jacquard circular machines), it transmits power through precise gear meshing inside the gearbox, with accurate transmission ratio, stable speed, and no risk of slipping. The gearbox needs to be filled with specialized gear oil to ensure gear lubrication and heat dissipation, and prevent tooth surface wear.
Both transmission methods ultimately drive the main shaft of the syringe to rotate, driving the syringe and needle to complete reciprocating circular motion.
3. Synchronous linkage mechanism
Ensure the coordinated operation of various weaving processes to avoid fabric defects caused by speed differences:
-Yarn feeding synchronization mechanism: Connected to the main machine and the yarn feeder through a transmission shaft or chain, the yarn feeding speed is accurately matched with the needle cylinder speed, and the transmission ratio can be adjusted according to the fabric organization requirements to achieve stable transportation of ground yarn, colored yarn, and spandex yarn.
-Pulling and winding synchronization mechanism: using chain or gear transmission, the needle cylinder speed signal is transmitted to the pulling roller and the fabric winding roller to ensure that the pulling speed is synchronized with the weaving speed, preventing fabric stretching deformation or loose winding. Some models are equipped with differential speed regulation devices, which can adjust the pulling and coiling speed to meet the needs of different weight fabrics.
4. Electrical control module
It is the “brain” of the transmission system, consisting of a frequency converter, PLC controller, touch screen, and speed sensor:
-The frequency converter is responsible for adjusting the motor speed, achieving precise setting and smooth switching of weaving speed, and also has overload protection function;
-The PLC controller receives signals from the speed sensor and coordinates the operating rhythm of the motor, yarn feeder, and tension winding mechanism;
-The touch screen enables parameter visualization operations, allowing for direct setting of weaving speed and storage of process parameters. Some models support remote speed control and fault diagnosis.
2、 Differentiated design of transmission mechanisms for different models
1. Conventional single-sided/double-sided circular knitting machines: often use a combination of belt drive and variable frequency motors, with a simple structure and low cost, to meet the weaving needs of basic tissues such as plain weave, ribbed weave, and cotton wool. The speed is generally controlled at 15-30r/min.
2. High speed jacquard circular knitting machine: equipped with gear transmission and servo motor, with high transmission accuracy and low operating noise, it can stably achieve high-speed weaving at 30-50r/min, and accurately drive the electronic needle selector to avoid pattern distortion.
3. Woolen loop machine/three line lining machine: equipped with a multi axis linkage transmission structure, in addition to driving the needle cylinder, it also needs to independently drive the looped sinker or lining yarn guide, and achieve synchronous speed regulation of multiple components through a differential gearbox to ensure the forming quality of special fabrics.
3、 Key points for operation and maintenance of transmission mechanism
1. Speed matching debugging: Set a reasonable speed according to the fabric variety and yarn material, and reduce the speed for fine and weak yarns and complex patterns to avoid breakage; Coarse count yarn and simple structure can be appropriately accelerated to improve production efficiency.
2. Lubrication and maintenance: The belt drive needs to be regularly inspected for belt wear and timely replaced with aging belts; Gear transmission requires periodic replacement of gear oil to maintain the oil level within the scale range and prevent gear dry wear.
3. Vibration and abnormal noise investigation: Before starting up, perform an idle check. If abnormal vibration or abnormal noise occurs, check whether the coupling is loose, whether the gear mesh is poor, and whether the bearings are worn. Tighten or replace the components in a timely manner.
4. Electrical system maintenance: Keep the frequency converter and control cabinet dry and ventilated, and regularly clean dust; Check if the wiring of the speed sensor is secure to avoid signal interruption and loss of control of the speed