CNC Worm Thread Grinding Machine Replacement of HJMT SK7712

CNC worm thread grinding machine is a highly efficient and precise machine used in various manufacturing industries. It is used to grind various cylindrical worms (ZA, ZN, ZI, ZK, ZC1 profiles). This machine is designed to replace the HJMT SK7712 model, and it is important to note that our products are replacement parts and not original spare parts. We only provide replacement parts for original spare parts, and if you need to buy original spare parts, please contact the original supplier.

Main Technical Parameters of CNC Worm Thread Grinding Machine

 

1、Max. mounting diameter	125mm
2、Max. center distance	350mm
3、Max. grinding diameter	100mm
4、Min. grinding diameter	5mm
5、Max. grinding length	250mm
6、Module range	0.5～4
7、helix angle range	±30°
8、Thread start  number	1～99（any）
9、Max. thread lead	150mm
10、Work spindle speed	0.5～60r/min
11、Max. wheel peripheral speed	45m/s
12、Wheel size
O.D×I.D×Width	400×203×10mm
O.D×I.D×Width	400×203×16mm
13、Max. workpiece weight	15kg
14、Overall dimension (L x W x H)	2600×2350×2600mm
15、Machine weight	appro.4000kg

 

Structure of CNC Worm Thread Grinding Machine

A CNC worm thread grinding machine is a precision tool used for shaping and creating the threads on worm gears. It utilizes CNC (Computer Numerical Control) technology for high accuracy and efficiency. Here's an overview of its main structural components:

1. Bed: The bed is the foundation of the CNC worm thread grinding machine. It is a heavy, rigid structure that supports all other components of the machine. Made typically from cast iron or steel, it provides stability and absorbs vibrations during the grinding process, ensuring precision.
2. Worktable: The worktable is mounted on the bed and is where the workpiece is secured. In a CNC worm thread grinding machine, the worktable often includes precision guides and is capable of precise movements. It can move either linearly or rotate, depending on the design, allowing the workpiece to be positioned accurately for grinding.
3. Wheel Head: The wheel head houses the grinding wheel. This component is critical as it holds and drives the grinding wheel at high speeds. The wheel head can move linearly or pivot, enabling the grinding wheel to approach the workpiece from different angles for precise thread grinding.
4. Dresser: The dresser is used to dress (shape or sharpen) the grinding wheel. This is necessary to maintain the wheel's precision and efficiency. In CNC machines, the dresser is often controlled by the CNC system for accuracy, and it can be either stationary or moveable, depending on the machine design.

Each of these components plays a vital role in ensuring the CNC worm thread grinding machine operates with the precision and efficiency required for producing high-quality worm threads.

Working Principle of CNC Worm Thread Grinding Machine

The CNC worm thread grinding machine is a computer-controlled machine that follows a programmed set of movements to produce high-precision threads on cylindrical workpieces. The machine is equipped with a diamond disc, grinding wheel that is dressed into the required thread profile. The wheel spindle is powered directly by a built-in permanent magnet synchronous motor (PMSM), which has high power and low vibration. The machine's adjustment of helix angle is done and locked automatically by the soft program, which is precise and fast.

Moreover, the diamond disc is driven by an AC servo motor, ensuring a constant speed and low vibration. With a semi-auto dynamic balancing system, it is convenient to change a new wheel without a need for static balance. The machine has a manual alignment device provided to match the pre-cut workpiece off-line, making it suitable for batch manufacturing. On-line aligning device and automatic loading mechanism are available as optional accessories. A full-closed housing and an oil-mist extractor are provided with the machine to improve the working environment.

Workpiece Movement

The workpiece is mounted on the table, which moves longitudinally to grind the worm thread. The table is controlled by the SIEMENS 828D system, with a programmable axis of four. The Axis Z has a table longitudinal traverse (with grating scale) full close-looped, while Axis X has a wheelhead cross feed (with grating scale) full close-looped. The rotation of work spindle is controlled by Axis C (with angular encoder) full close-looped, and Axis A controls the helix angle swivel (with angular encoder) full close-looped.

Grinding Wheel Movement

The grinding wheel moves radially and axially to grind the worm thread. The machine has a diamond disc, grinding wheel that is dressed into the required thread profile. The wheel spindle is powered directly by a built-in permanent magnet synchronous motor (PMSM), which has high power and low vibration. The diamond disc is driven by an AC servo motor, ensuring a constant speed and low vibration. With a semi-auto dynamic balancing system, it is convenient to change a new wheel without a need for static balance.

Cooling and Lubrication

The CNC worm thread grinding machine has a cooling and lubrication system that is essential for high-precision grinding. The system ensures that the grinding wheel remains cool and lubricated during the grinding process, preventing overheating and reducing friction. This helps to minimize wear and tear on the grinding wheel, ensuring a longer lifespan for the machine.

Control System

The control system of the CNC worm thread grinding machine is the SIEMENS 828D system, which has four programmable axes. This system controls the movement of the workpiece and the grinding wheel, ensuring high-precision grinding. The system is easy to use and can be programmed to produce various thread profiles.

Below is a video that shows the CNC Worm Thread Grinding Machine in action:

 

Features of CNC Worm Thread Grinding Machine

• The diamond disc, grinding wheel is dressed into the required thread profile.
• The wheel spindle is powered directly by a built-in permanent magnet synchronous motor (PMSM), which has high power and low vibration.
• The adjustment of helix angle is done and locked automatically by the machine's soft program, which is precise and fast.
• The diamond disc is driven by an AC servo motor, ensuring a constant speed and low vibration.
• With a semi-auto dynamic balancing system, it is convenient to change a new wheel without a need for static balance.
• With a manual alignment device provided to match the pre-cut workpiece off-line, it is suitable for batch manufacturing.
• On-line aligning device and automatic loading mechanism are available as optional accessories.
• A full-closed housing and an oil-mist extractor are provided with the machine to improve the working environment.

How to Operate the CNC Worm Screw Grinder

Before operating the CNC worm screw grinder, it is essential to check all the components of the machine to ensure they are in good condition. The workpiece should also be checked to ensure it meets the processing requirements and has no obvious defects. The grinding wheel should also be checked for any cracks or wear, and the cooling and lubrication system should be checked to ensure it is working correctly.

The following are the steps to follow when operating the machine:

Preparation

1. Check all the components of the CNC worm screw grinder to ensure they are in good condition and that all connections are tight.
2. Check the workpiece to ensure it meets the processing requirements and has no obvious defects.
3. Check the grinding wheel for any cracks or wear.
4. Check the cooling and lubrication system to ensure it is working correctly.

Operation Steps

1. Mount the workpiece on the table using an appropriate fixture to ensure it is securely fixed during the grinding process.
2. Adjust the grinding wheel, including radial and axial runout adjustment, to ensure it is properly aligned and has minimal runout, which could affect the precision of the thread being ground.
3. Enter the processing parameters, including spindle speed, feed rate, pitch, and helix angle, among others. The processing parameters should be selected based on the workpiece's material, size, and precision requirements.
4. Monitor the grinding process closely to observe the workpiece's grinding status and take appropriate measures if any anomalies are detected.
5. After the completion of the grinding process, turn off the machine and clean the working environment.

CNC Worm Thread Grinding Machines Replacement Models

 

Tainuo	HJMT	Matrix
WGM-750	SK7720B	THW-2080
WGM-550(Larger grinding size)	SK7712

 

About Our Company

We are a professional CNC machine tool manufacturer, and our company has a team of experienced engineers and operators who have rich manufacturing experience with CNC equipment. We have developed several patents and intellectual property rights in the field of CNC machinery. Our products are designed using computer-optimized design, and we use full CNC machining technology and a perfect quality control system (ISO9001 certification) to ensure that each product meets our customers' needs.

With our excellent quality and cost-effectiveness, we guarantee a monthly increase in our customer base of up to 10. Our annual machine tool production capacity is around 80 machines, including CNC worm thread grinding machines, gear grinding machines, and other professional grinding machines. Our high-efficiency and high-precision performance, as well as our self-developed software, have always been favored by users.

Our CNC worm thread grinding machine is a high-speed, high-efficiency, and high-precision machine that can compete with international high-end models. We adhere to the principles of excellent quality, advantageous prices, effective supply, and quality services. Our machine tool products are sold all over the world.