Spare Parts

Pinion bearings are special bearings used to support the pinion shaft in the ball mill. They play the role of supporting and guiding the pinion shaft to run smoothly during rotation. Pinion bearings usually consist of an inner ring and an outer ring. The inner ring matches the pinion shaft, while the outer ring is fixed in the mechanical structure. There is a certain gap between the inner and outer rings to allow rolling elements (such as balls, rollers, etc.) to rotate freely. It is usually installed between the pinion and the rotating structure to ensure that the gear shaft maintains a stable rotation direction and speed during operation, reduce any unnecessary deviation or vibration caused by rotation, and can effectively reduce the friction between the gear and the bearing and reduce the wear rate. This not only extends the service life of the bearing and gear, but also improves the efficiency of the entire transmission system. Pinion bearings need to withstand large axial and radial forces, especially in ball mills running under high loads. Their design and material ensure that they can continue to work under high loads without being easily deformed or damaged.

1. Deep groove ball bearing: Each ring has a continuous groove raceway, which is mainly used to bear radial loads and can also bear certain axial loads. It has a small friction coefficient, high limit speed and high precision. It is suitable for the pinion gear part of the ball mill that has high speed requirements, relatively small loads and certain precision requirements, such as some small or light-load ball mills.

2. Self-aligning ball bearing: It has double rows of steel balls, and the outer ring raceway is an inner spherical type. It can automatically adjust the axis misalignment caused by the deflection or non-concentricity of the shaft or housing, and mainly bear radial loads. It is suitable for the situation where the pinion shaft of the ball mill may have a certain degree of axis misalignment or deflection, and can effectively reduce the impact caused by installation errors or deformation during operation.

3. Tapered roller bearing: It can bear radial loads and unidirectional axial loads, can bear large combined radial and axial loads, has strong load-bearing capacity, and can limit the axial displacement of the shaft or housing in one direction. It is suitable for the situation where the pinion gear of the ball mill bears both large radial forces and certain axial forces during the power transmission process, such as the pinion gear part of some large ball mills.

4. Double-row self-aligning spherical roller bearings: have good self-aligning performance, can adapt to large flexural deformation and different axial degrees of the shaft, and can withstand large radial loads and certain axial loads. For low-speed, heavy-loaded ball mills with large barrel diameters and large bearing support distances, such as Φ3200×4500 ball mills, it can well ensure the stable operation of the pinion shaft.

5. Ordinary sliding bearings: rely on smooth surfaces to support the rotating shaft, and work smoothly, reliably and without noise. Under liquid lubrication conditions, it can greatly reduce friction loss and surface wear, and the oil film also has a certain vibration absorption capacity, but the starting friction resistance is large. It is suitable for low-speed and heavy-load working conditions, or for the pinion parts of ball mills that are difficult to maintain and add lubricating oil.

6. Hydrostatic bearings: have the characteristics of high reliability, long service life, low energy consumption, and large load-bearing capacity. Whether the ball mill is stationary or rotating, it relies on the external high-pressure oil to form a thick oil film between the bearing and the hollow shaft to achieve full liquid lubrication. The relationship between the lubrication state and the oil film pressure and the hollow shaft speed is very small. Widely used in large energy-saving ball mills.

7. Dynamic pressure bearing: The friction coefficient is smaller than the rolling friction coefficient, which can further reduce the power consumed by friction. The oil supply pressure is low, the oil supply system of the lubricating oil station is simpler, and the operation is convenient. It is used in old ball mills with specifications below φ3.2×4.5m.

1. Transmitting power and torque: The power of the ball mill is provided by the motor, which is transmitted to the pinion through the coupling. The pinion then transmits power and torque to the barrel of the ball mill through meshing with the large gear ring, so that the barrel can rotate at the specified speed, thereby driving the grinding medium and material movement, and realizing the grinding and mixing of materials.

2. Realizing variable speed transmission: Through different tooth ratios with the large gear, the pinion can achieve deceleration or acceleration transmission to meet the ball mill's demand for barrel speed in different working scenarios to achieve the best grinding effect. For example, when processing materials with higher hardness and larger particle size, a lower barrel speed may be required, which can be achieved by matching the pinion with the large gear with a suitable tooth ratio.

3. Controlling the direction of movement: The meshing mode and position relationship between the pinion and the large gear can ensure that the barrel of the ball mill rotates in a specific direction, ensure the stability and consistency of the grinding process, and make the movement trajectory and grinding effect of the material in the barrel meet the production requirements.

4. Influencing the operating efficiency of the equipment: The transmission efficiency of the pinion is directly related to the overall operating efficiency of the ball mill. If the pinion has problems such as wear and tooth shape error, it will lead to unsmooth power transmission, slippage, vibration and other phenomena, making the rotation speed of the cylinder unstable, thereby reducing the grinding efficiency of the material and affecting the production progress and output.

5. It is related to the service life of the equipment: the meshing state of the pinion and the large gear has an important impact on the service life of each other. If the pinion is not installed accurately or lubricated poorly, it will aggravate the wear of the large and small gears, shorten the service life of the gears, and increase the maintenance cost and downtime of the equipment. In addition, the wear of the pinion may also cause failures of other components, such as bearing damage and shaft deformation, further affecting the overall service life of the ball mill.

6. Guarantee product quality: The stable operation of the pinion of the ball mill is crucial to ensure product quality. Stable transmission can make the material evenly ground in the cylinder, ensuring that the particle size distribution of the product is uniform and the quality is consistent. If the pinion fails, resulting in fluctuations in the speed of the cylinder or uneven grinding, the product particle size may not meet the requirements, appearing too coarse or too fine, affecting the performance and quality of the product.

7. Determines production safety: The pinion bears a large load and stress during the operation of the ball mill. If the pinion's strength, wear resistance and other properties are insufficient, or fatigue cracks, broken teeth and other problems occur, it may cause serious safety accidents, such as gear breakage and splashing, sudden cessation of rotation of the cylinder, etc., posing a threat to the life safety of operators and equipment safety.

1. 45 Steel: It is a medium-carbon steel with high strength and good machinability. After quenching and tempering, it can obtain excellent comprehensive mechanical properties. It is often used for the pinion gears of small and medium-sized ball mills with relatively low performance requirements, and the cost is relatively low.

2. zg45# Forged Steel: zg45 steel processed by forging process. Compared with ordinary 45 steel, its internal structure is denser, and its strength and toughness are better. It can withstand greater impact loads and wear, and is suitable for the pinion gears of some ball mills with harsh working conditions and heavy loads.

3. 35SiMn: It has high strength, wear resistance and good hardenability. After quenching and tempering, its comprehensive mechanical properties can be improved. It is widely used in the pinion gears of ball mills and can be used in ball mills of various specifications to meet the requirements of different working conditions.

4. 40Cr: It is a commonly used alloy structural steel with good comprehensive mechanical properties, excellent strength, toughness and wear resistance. After quenching and tempering, it can obtain high hardness and strength, and is suitable for the pinion gears of ball mills that bear large loads and wear.

5. 42CrMo: It has extremely high strength and toughness, good fatigue resistance and hardenability, and can withstand higher loads and more complex stress states. It is often used in large ball mills or occasions where extremely high performance requirements for pinion gears are required.

6. 45MnB: Its performance is similar to that of 40Cr, with high strength and hardness, good wear resistance and hardenability. It can be used as a substitute for 40Cr to manufacture pinion gears of ball mills, which can reduce production costs.

7. 20CrMnTi: It is a low-carbon alloy steel with good carburizing properties and core strength. After carburizing and quenching, it has a high surface hardness and good wear resistance, and the core has good toughness and can withstand impact loads. It is suitable for high-speed and heavy-load pinion gears of ball mills that require wear resistance.

8. 18Cr2Ni4WA: It is a high-strength carburizing steel with high strength, toughness and fatigue resistance. After carburizing, the surface hardness and wear resistance are excellent. It is often used for the pinion gears of large ball mills with extremely high performance requirements or ball mills under special working conditions.

9. ZG270 - 500: It has certain strength and toughness and good casting performance. It can be used to manufacture some pinion gears of ball mills with relatively low performance requirements and large sizes, and its performance can be improved through reasonable heat treatment processes.

10. ZG310 - 570: It has high strength, good hardness and wear resistance, and is often used to manufacture the large gear rings of ball mills that bear large loads. In some specific cases, it can also be used to manufacture pinion gears, especially the pinion gears of large ball mills with high strength requirements.

1. Tooth Surface Wear: Examine the tooth surface. If there is uniform or non-uniform wear on the tooth surface, resulting in a reduction in tooth thickness, it indicates that the pinion gear is experiencing wear. When the tooth surface wear is severe, it will significantly alter the shape and dimensions of the gear, affecting the transmission accuracy of the gear.

2. Tooth Surface Damage: Carefully check if there are cracks, spalling, pitting and other damages on the tooth surface. Cracks may be caused by excessive stress or fatigue during the gear's operation, which is a relatively serious problem and may lead to gear fracture. Spalling refers to the local detachment of the tooth surface material, forming pits or craters, which will affect the meshing performance of the gear and increase vibration and noise. Pitting is manifested by the appearance of tiny pits on the tooth surface, usually caused by excessive contact stress on the tooth surface, resulting in fatigue spalling of the surface material.

3. Tooth Surface Discoloration: Under normal circumstances, the color of the gear tooth surface is uniform. If local discoloration is found on the tooth surface, such as blue or black, it may be due to local overheating of the gear during operation. This could be caused by poor lubrication, improper meshing or excessive load, indicating a potential damage risk of the gear.
Journal Wear: Check the journal area of the pinion gear for wear marks. Wear on the journal will lead to a poor fit between the gear and the shaft, and looseness may occur, affecting the transmission

4. Abnormal Noise: When the ball mill is running normally, the sound of the pinion gear is relatively stable. If sharp friction sounds, impact sounds or periodic abnormal noises are heard during operation, it may indicate that the pinion gear has problems such as wear, tooth surface damage or poor meshing. For example, when the tooth surface wear is uneven or there is spalling, the gear will produce irregular vibrations and noises during meshing.

5. Abnormal Vibration: Detect the vibration of the pinion gear during operation by touch or using vibration monitoring instruments. If the vibration significantly increases and exceeds the normal range, it may be due to an increase in the tooth profile error of the pinion gear, a problem with the coaxiality of the gear shaft, or damage to the bearing.

6. Temperature Change: Use temperature sensors or infrared thermometers to measure the temperature of the pinion gear during operation. If the temperature of a certain part of the pinion gear is significantly higher than other parts, or the overall temperature is too high, it may indicate that there are problems such as excessive wear, insufficient lubrication or poor meshing in that part, resulting in increased frictional heat.

7. Lubricating Oil Condition: Check the color, viscosity and impurity content of the lubricating oil. If the lubricating oil turns black, has a reduced viscosity or contains a large number of metal debris and other impurities, it may be that the metal particles generated by the wear of the pinion gear have mixed in, indicating that the pinion gear is worn.

8. Decreased Transmission Efficiency: Compare the transmission efficiency of the pinion gear in the ball mill under normal conditions and the current operating conditions. If it is found that the production efficiency of the ball mill is reduced, or the rotation speed of the ball mill is significantly decreased under the same motor power, it may be that the wear of the pinion gear has led to an increase in transmission loss and a decrease in transmission efficiency.

9. Abnormal Torque: Monitor the torque change of the pinion gear during operation. If the torque suddenly increases or fluctuates abnormally, it may be that the pinion gear encounters additional resistance during meshing. This could be caused by factors such as tooth surface wear, tooth profile deformation or foreign objects entering the meshing area.

1. Regular inspection: Develop a detailed inspection plan and conduct a comprehensive inspection of the pinion regularly, including appearance inspection, tooth surface wear measurement, gear meshing inspection, etc. Early wear and tooth surface damage of the pinion should be discovered in time so that corresponding repair or replacement measures can be taken.

2. Cleaning and protection: Regularly clean the dust, oil stains and debris on the surface of the pinion to prevent impurities from entering the gear meshing area and aggravating wear. At the same time, the surface of the pinion can be treated with anti-corrosion, such as spraying anti-corrosion paint, to prevent the tooth surface from rusting and corrosion.

3. Condition monitoring: Install vibration monitoring, temperature monitoring and other equipment to monitor the operating status of the pinion in real time. By analyzing the vibration spectrum, temperature change and other data, early warning of possible faults of the pinion can be given so that maintenance can be arranged in time to avoid the expansion of the fault.

4. Avoid overload operation: Strictly carry out production operations in accordance with the rated load of the mill and the carrying capacity of the pinion to avoid long-term overload operation. Overload will cause the pinion to bear excessive stress, accelerate tooth surface wear and fatigue damage, and reduce the service life of the pinion.

5. Smooth start and shutdown: During the start and shutdown of the mill, a smooth operation method should be adopted to avoid sudden loading or unloading and reduce the impact load on the pinion. Impact loads may cause cracks, peeling and other damage to the pinion tooth surface, affecting its normal operation.

6. Control the working environment: Try to keep the working environment of the mill clean and dry, and avoid the influence of harsh environments such as humidity and dust on the pinion. A humid environment can easily cause the pinion to rust, and too much dust will increase the wear of the tooth surface.

7. Reasonable selection: According to the working load, speed, transmission power and other parameters of the mill, select the pinion with appropriate module, number of teeth, tooth width and material to ensure that its load-bearing capacity and transmission efficiency meet the working requirements, and avoid the pinion from failing and excessive wear due to overload during operation.

8. Accurate installation: During the installation process, the meshing clearance, tooth deviation and tooth surface contact accuracy between the pinion and the large gear must be strictly controlled to meet the technical requirements of the equipment. Accurate installation can ensure uniform force between the gears and reduce wear and failure caused by local stress concentration.
Ensure coaxiality: The coaxiality between the pinion shaft and the relevant transmission shaft should be adjusted to the specified range to avoid uneven force on the pinion due to the deflection of the shaft, which will cause problems such as increased wear and tooth surface fatigue.

9. Select the appropriate lubricant: According to the working conditions of the mill pinion, such as speed, load, working temperature, etc., select a lubricant with good anti-wear, anti-extreme pressure and anti-oxidation properties. For mill pinions with heavy loads, lubricants containing extreme pressure additives can be used to form a strong oil film on the tooth surface to reduce friction and wear.

10. Regularly check and replace lubricants: Establish a regular lubricant inspection system to monitor lubricant viscosity, moisture, impurity content and other indicators to ensure that the performance of the lubricant meets the requirements. According to the equipment manufacturer's recommendations and actual operating conditions, regularly replace the lubricant to prevent the lubrication effect from being lost due to aging and contamination of the lubricant.

11. Optimize lubrication methods: Use appropriate lubrication methods, such as oil spray lubrication, oil bath lubrication, etc., to ensure that the lubricant can be fully and evenly supplied to the pinion tooth surface and bearing parts, improve the lubrication effect, and reduce wear.

There are two situations for this problem, and we will explain them separately. Pinions between different types of ball mills are usually not interchangeable, but they may be interchangeable when the pinions of different ball mills meet the following conditions:

1. The size parameters are exactly the same: the key size parameters including module, number of teeth, tooth width, pressure angle, pitch circle diameter, etc. must be exactly the same. Only when these dimensions are the same can the pinion mesh with the corresponding large gear correctly and achieve smooth transmission. For example, the pinion modules of the two ball mills are both 25, the number of teeth is both 24, and the tooth width is both 80mm, etc., which meet the basic conditions for interchangeability. Another prerequisite is that they must be produced by the same manufacturer. For example, the pinion produced by FL smidth and the pinion produced by TONGLI may be incompatible. Please refer to the drawings to see if they match.

2. Consistent material and performance: The material and mechanical properties of the pinion must be the same. Pinions of different materials have different properties such as strength, hardness, and wear resistance. If the material and performance of the interchangeable pinion do not match the original equipment, it may cause premature wear and damage of the pinion, and even affect the normal operation of the entire ball mill. For example, if the original pinion is made of 42CrMo, the interchangeable pinion must also be made of 42CrMo and undergo the same heat treatment process to ensure that its hardness, strength and other performance indicators are consistent.

3. The overall compatibility of the equipment: In addition to the parameters and performance of the pinion itself, its compatibility with other parts of the ball mill should also be considered. Including the meshing with the large gear, the matching with the bearing, the connection with the transmission shaft, etc. If these aspects are incompatible, even if the pinion size and material are the same, it may not work properly. For example, the meshing clearance between the pinion and the large gear, the tooth surface contact accuracy, etc. must meet the equipment requirements, otherwise vibration, noise and other problems will occur.

4. The same manufacturing standards and precision: The manufacturing standards and precision grades of the pinion should be consistent. Different manufacturing standards and precisions will affect the dimensional accuracy, form and position tolerances, surface roughness, etc. of the pinion, and thus affect its transmission performance. For example, the pinions of the two ball mills meet the GB/T 10095 standard, and the precision grade is 8. Such pinions can ensure the accuracy and stability of the transmission when interchanged.

However, the pinions between different types of ball mills are usually not interchangeable for the following reasons:

1. Differences in dimensional parameters: Ball mills come in a variety of specifications, such as Φ2.4×11m, Φ4.8×72m, etc. The key dimensional parameters of the pinion modules, number of teeth, and tooth width of ball mills of different specifications are often different. For example, in the table, the pinion module of the Φ2.4×11m ball mill is 25 and the number of teeth is 24; while the pinion module of the Φ3×9m (tube) ball mill is 22 and the number of teeth is 35. These dimensional differences make it impossible for the gears to mesh correctly and to achieve effective power transmission.

2. Different material and performance requirements: The working conditions of different types of ball mills vary greatly. Some process high-hardness materials, while others operate in special environments such as high temperature and high humidity. This leads to different requirements for the material and performance of the pinion. For example, for ball mills that process high-hardness materials, the pinion gear needs to be made of a material with higher wear resistance (such as ZG42CrMo); for those working in a corrosive environment, special corrosion-resistant materials may be required. If interchanged, the pinion gear may quickly wear out and be damaged because it does not meet the actual working conditions.

3. Overall matching of equipment: The pinion gear of the ball mill needs to work with large gears, bearings, transmission shafts and other components. The design and manufacturing standards of these components of different types of ball mills are different. Interchanging the pinion gear will destroy the original matching relationship of the equipment, resulting in increased vibration, increased noise, reduced transmission efficiency and other problems, affecting the normal operation and service life of the ball mill.

Choosing Tongli ball mill pinion means choosing high cost performance. As the source manufacturer, we independently complete the steel casting and forging links, without middlemen adding layers of price, and directly pass on the benefits to customers. For many years, we have focused on the production of ball mill pinion gears. With mature and complete manufacturing processes and large-scale production capacity, we have greatly reduced costs while ensuring product quality, allowing you to obtain high-quality products at a lower price.

1.Well-equipped and leading technology
We are equipped with advanced and complete production and testing equipment, with several hobbing machines with a diameter of 3m-10m, which can accurately process gears of different specifications; several submerged arc welding machines of various models to ensure welding quality; heat treatment furnaces can optimize materials and improve performance; CNC vertical lathes, CNC lathes and other processing equipment to ensure dimensional accuracy. At the same time, the complete testing system effectively ensures that every pinion meets high quality standards.

2. High-quality material selection and excellent performance
Tongli ball mill pinion gears are made of high-strength alloy steel, and the material quality strictly follows the world's mainstream standards. This makes the pinion not only high in strength, high in precision, and high in torque, but also sturdy and durable. It shows an extremely low failure rate in actual work, which can escort your production operation to a continuous and stable level.

3. Intimate service, worry-free after-sales
From product delivery to installation and use, our intimate service is always with you. Provide detailed online installation guidance to ensure the correct installation of accessories and the smooth operation of equipment; also provide follow-up maintenance guidance to help you maximize the service life of the product and reduce the probability of failure, so that you have no worries.

4. Scientific management, efficient and stable
In terms of production management, we have introduced advanced production management systems and quality control systems. From raw material procurement, production and processing to product inspection, packaging and shipment, every link is strictly operated in accordance with standardized procedures. Through scientific production scheduling and lean production concepts, we can not only ensure that products are delivered on time, but also effectively control production costs, improve production efficiency, and ensure the stability and consistency of product quality.

5.Rich cases and good reputation
Over the years, Tongli ball mill pinions have been widely used in mining, cement, electricity, chemical industry and other industries, and have established long-term and stable cooperative relations with many well-known companies. The rich success stories have witnessed the reliability of our products and high-quality services. The high recognition and good reputation of our customers are the driving force for our continuous progress, and also prove that choosing Tongli ball mill pinion gear is your wise decision.

1. Before installing the pinion of the ball mill, you must be fully prepared. Carefully check the pinion and its related parts, such as shafts, keys, bearings, etc., to ensure that there are no damage, cracks, deformation, etc., and the dimensional accuracy meets the design requirements.

2. Use a clean cloth or solvent to thoroughly clean the surface of the pinion, shaft and the parts that match it, remove impurities such as oil, rust, burrs, etc., and make the installation surface smooth. At the same time, prepare installation tools such as wrenches, vernier calipers, dial indicators, jacks, copper rods, lubricating oil, sealants, etc. to ensure that the installation site is clean and tidy, there is enough space for operation, and the large gears and other related parts of the ball mill have been installed in place and stable.

3. There are also strict steps for the installation of pinions and shafts. First, correctly install the key into the keyway of the shaft to ensure that the key and keyway fit tightly without looseness. If the pinion and the shaft are interference fit, the pinion is usually heated. Oil bath heating or electric heating can be used. The heating temperature is generally controlled between 80-120℃, depending on the material and size of the pinion. Apply a proper amount of lubricating oil on the surface of the shaft. After the pinion is heated to the specified temperature, quickly put it on the shaft, align the keyway with the key, and then gently tap or use a press to install the pinion in place to ensure that the axial and radial positions of the pinion on the shaft meet the requirements. After installation, let it cool naturally or use appropriate methods to cool.

4. Then install the pinion assembly and bearing. First install the bearing seat to the corresponding position of the ball mill, fix it with bolts, and use a level and a dial indicator to measure and adjust its horizontality and verticality. Install the bearing on the shaft. Large bearings may need to be heated for installation. Pay attention to the installation direction and clearance adjustment. Then carefully put the pinion shaft assembly with the bearing installed into the bearing seat, and then install the bearing cover and other components, tighten the bolts, but do not tighten them too much to facilitate subsequent adjustments.

5. The meshing adjustment of the pinion and the large gear is crucial. First, by moving the pinion shaft or adjusting the position of the bearing seat, let the pinion and the large gear engage initially to ensure that the center distance of the two gears meets the design requirements. Then use a feeler gauge or lead wire method to check the meshing clearance, select several points evenly on the circumference of the gear to measure, and ensure that the meshing clearance is within the specified range. Generally, the meshing clearance between the pinion and the large gear of the ball mill is between 0.25-0.4mm. Then apply a thin layer of red lead powder or a special meshing inspection coating on the tooth surface of the pinion, turn the pinion, observe the meshing marks on the tooth surface of the large gear, and adjust the position of the pinion according to the position and shape of the marks, so that the meshing marks are distributed in the middle of the tooth surface, and the contact area is not less than 70% of the tooth surface. After the meshing adjustment is completed, check the tightness of all bolts again to ensure that the pinion is firmly installed.

6. After the installation is completed, inspection and testing are also carried out. Perform a comprehensive inspection of the installation of the pinion to check whether the connection of each component is firm, whether the lubrication system is normal, and whether the seal is good. Before power-on trial operation, manually turn the pinion and the large gear of the ball mill to check for abnormalities such as jamming and collision to ensure flexible rotation. Then turn on the power supply for no-load test run for no less than 2 hours, and closely observe the operation of the pinion, including temperature, vibration, noise, etc., to check whether the bearing temperature is too high, whether the gear meshing is smooth, and whether there are abnormal noises and vibrations. After the no-load test run is qualified, gradually load the gear for load test run, and continue to monitor the various operating parameters of the pinion to ensure that it can work normally under different load conditions.

1.Wood pattern making
First, according to the design drawings of the ball mill pinion, select suitable wood. Generally, choose wood with uniform texture and not easy to deform, such as pine or birch. Skilled carpenters process the wood into a wood pattern that is exactly the same shape and size as the pinion through precise measurement and cutting. During the production process, the dimensional accuracy of the wood pattern must be strictly controlled to ensure that the tolerance is within the allowable range, because the quality of the wood pattern directly affects the accuracy of subsequent castings. After completing the preliminary shape production, the surface of the wood pattern is finely polished to make it smooth and reduce the impact on the surface quality of the casting during the casting process. At the same time, mark the key dimensions and positioning marks on the wood pattern to facilitate the operation of subsequent processes.

2.Molding
Moulding is the process of burying the wood pattern in the molding sand to make a casting. First prepare the appropriate molding sand, which is usually composed of quartz sand, binder and additives, and its performance directly affects the quality of the casting. Place the wood pattern in the molding sand box, then fill in the molding sand and compact it. There are many ways to compact the molding sand, such as vibration, compaction, sand shooting, etc. Choose the appropriate method according to the actual production situation to ensure that the molding sand tightly wraps the wooden mold to form a clear cavity. During the compaction process, care should be taken to avoid cracks or looseness in the molding sand to avoid affecting the molding of the casting. After the molding sand is compacted, carefully remove the wooden mold, leaving a cavity with the same shape as the pinion. At this time, it is also necessary to open channels such as gates and risers in the cavity so that the molten metal can flow smoothly into the cavity during pouring and discharge the gas and excess molten metal in the cavity.

3.Pouring
According to the performance requirements of the ball mill pinion, select appropriate casting materials, such as various alloy steels or cast steels. Heat the selected material in a furnace to a molten state and reach a suitable pouring temperature. Generally speaking, the pouring temperature should be precisely controlled according to the type and composition of the material to ensure that the molten metal has good fluidity and filling properties. Before pouring, check the integrity of the mold and the smoothness of the gates and risers again. After preparation, pour the molten metal slowly and steadily into the cavity, avoiding splashing or turbulence of the metal, so as to avoid entraining gas or inclusions and affecting the quality of the casting. The pouring process should continue until the cavity is completely filled, and pay attention to the riser to ensure that the riser can play the role of shrinkage compensation and exhaust.

4.Pit – sand cleaning
After pouring, the casting is cooled to a certain temperature in the sand, and then it is taken out of the sand box and placed in a special sand cleaning pit. The purpose of sand cleaning is to remove the residual sand on the surface and inside of the casting. First, most of the sand is removed from the casting by vibration, knocking, etc. For some difficult-to-remove sand, water blasting, shot blasting or chemical sand cleaning can be used. Water blasting sand cleaning is to use the steam explosion force generated by the cooling of the casting and the water to separate the molding sand from the casting; shot blasting sand cleaning is to use high-speed projectiles to hit the surface of the casting to remove the molding sand and oxide scale; chemical sand cleaning is to use chemical solutions to react with the molding sand to dissolve or fall off the molding sand. During the sand cleaning process, care should be taken to avoid damage to the surface of the casting, and at the same time ensure that the sand is thoroughly cleaned to create good conditions for subsequent processing procedures.

5.Heat treatment
Heat treatment is a key process to improve the material properties of the ball mill pinion. According to the material and use requirements of the pinion, select the appropriate heat treatment process, such as quenching, tempering, normalizing, quenching and tempering. Quenching is to heat the pinion gear to above the critical temperature, keep it warm for a certain period of time and then cool it quickly to improve its hardness and strength; tempering is to heat the pinion gear to a certain temperature range below the critical temperature after quenching, keep it warm and then cool it to eliminate quenching stress and improve toughness; normalizing is to heat the pinion gear to above the critical temperature, keep it warm and then cool it in the air, which can refine the grains and improve the structure and performance; quenching and tempering is a combination of quenching and high-temperature tempering, which can enable the pinion gear to obtain good comprehensive mechanical properties. During the heat treatment process, parameters such as heating temperature, holding time and cooling rate must be strictly controlled to ensure that the heat treatment effect meets the requirements. At the same time, professional heat treatment equipment and instruments are used to accurately measure and control parameters such as temperature and time to ensure the
stability of heat treatment quality.

6.Pre-finishing inspection (finishing (inspection))
Before finishing, the pinion gear is fully inspected. First, an appearance inspection is carried out to check whether there are cracks, sand holes, pores, shrinkage holes and other defects on the surface of the pinion gear. If there are defects, repair or scrap them according to the severity of the defects. Then use measuring tools such as calipers, micrometers, dial indicators, etc. to measure the key dimensions of the pinion, including the top circle diameter, root circle diameter, tooth width, module, number of teeth, etc., to ensure that the dimensions meet the design requirements. For some important dimensions, the measurement accuracy must reach the micron level. In addition, non-destructive testing methods such as ultrasonic testing and magnetic particle testing can also be used to detect whether there are defects inside the pinion. Only after a comprehensive inspection to confirm that the pinion is of qualified quality can the next step of the finishing process be entered.

7.Rough processing
The purpose of rough processing is to remove most of the excess on the pinion blank to make it close to the final shape and size. Rough processing is usually carried out on machine tools such as lathes, milling machines, and planing machines. On the lathe, the outer circle, inner hole and other rotating surfaces of the pinion are rough-turned to remove most of the excess while ensuring a certain dimensional accuracy and surface roughness. On the milling machine, use a suitable milling cutter to rough mill the pinion tooth profile to initially form the tooth profile. On the planing machine, the plane of the pinion can be rough-planed. During the rough machining process, the cutting parameters such as cutting speed, feed rate and cutting depth should be reasonably selected according to the material, size and processing requirements of the pinion to improve the processing efficiency and ensure the processing quality. At the same time, it is necessary to pay attention to controlling the cutting force and cutting heat during the machining process to avoid deformation or cracking of the pinion due to excessive cutting force or excessive cutting heat.

8.Inspection after rough machining
After the rough machining is completed, the pinion is inspected again. The main inspection contents include dimensional accuracy, shape accuracy and surface roughness. Use measuring tools to measure the dimensions after rough machining, compare them with the design dimensions, and check whether the dimensional deviation is within the allowable range. For the shape accuracy of the tooth shape, a tooth shape template or a gear measuring instrument can be used for detection to ensure that the tooth shape meets the design requirements. At the same time, check the surface roughness of the pinion and use a roughness meter to measure it to determine whether the surface roughness meets the requirements of subsequent fine machining. If it is found that the dimensional deviation is too large, the shape accuracy does not meet the requirements, or the surface roughness exceeds the standard, the cause should be analyzed in time and corresponding measures should be taken to adjust or repair, such as re-adjusting the processing parameters and reworking. Only after the inspection after rough machining confirms that the pinion is of qualified quality, can the finishing process be entered.

9.Finishing (inspection)
Finishing is a key process to ensure the final quality and accuracy of the pinion of the ball mill. In the finishing stage, the pinion's tooth shape, tooth surface and other key surfaces are mainly precision-machined. For the finishing of the tooth shape, methods such as grinding and shaving are usually used. Grinding is the use of a grinding wheel to grind the tooth shape, which can obtain very high tooth shape accuracy and surface roughness; shaving is the use of a shaving cutter to cut the tooth shape, which can further improve the tooth shape accuracy and reduce the surface roughness. For other key surfaces of the pinion, such as the outer circle and inner hole, methods such as fine turning and fine grinding can be used to achieve the dimensional accuracy and surface roughness required by the design. In the finishing process, the processing parameters must be strictly controlled, and high-precision processing equipment and tools must be used to ensure processing accuracy and surface quality. At the same time, real-time detection must be carried out, and processing parameters must be adjusted in time to ensure the stability of processing quality.

10.Assembly
After finishing and passing the final inspection, the ball mill pinion is assembled with other related parts. Before assembly, all parts involved in the assembly are cleaned and inspected to ensure that the surface is clean and free of impurities, and the dimensional accuracy and shape accuracy meet the requirements. According to the design requirements and assembly process, the pinion is installed on the corresponding shaft, and fixed with keys, pins and other connectors to ensure that the connection between the pinion and the shaft is firm and reliable, and the concentricity meets the requirements. Then, the shaft assembly with the pinion installed is installed on the bearing seat of the ball mill, the position and clearance are adjusted, and the bearing cover and other parts are installed. During the assembly process, attention should be paid to the installation sequence and installation method of each component to avoid assembly errors or damage to the components. At the same time, use appropriate tools and gauges to measure and adjust the key dimensions and positions in the assembly process to ensure that the assembly quality meets the requirements.

11.Packaging
After assembly, the ball mill pinion is packaged. The purpose of packaging is to protect the pinion from damage during transportation and storage. First, apply a layer of anti-rust oil on the surface of the pinion to prevent it from rusting. Then, use plastic film or oil paper to wrap the pinion to isolate and protect it. For some pinions with high precision requirements, desiccant can also be placed in the package to prevent moisture from affecting its precision and performance. Finally, put the packaged pinion into a suitable packaging box and fill the packaging box with foam plastics, sponges and other cushioning materials to prevent damage due to collision during transportation. Mark the product name, model, specification, quantity, production date, manufacturer and other information on the outside of the packaging box for easy identification and management.

12.Delivery
After packaging, TONGLI arranges a suitable transportation method to deliver the ball mill pinion to the customer according to the customer's requirements and order information. Before delivery, communicate with the customer to confirm details such as delivery time, delivery location and delivery method. Choose a reputable transportation company to ensure that the pinion can be delivered to the customer safely and promptly. At the same time, provide relevant product quality certification documents, inspection reports and other information so that customers can accept the product quality. During the delivery process, track the transportation situation, deal with possible problems in a timely manner, and ensure the smooth completion of the delivery process.

In the world of open gears, reliability and efficiency are key, and our pinions are designed to meet these needs.

Our pinions are designed for mill and kiln drive applications with high precision and work perfectly with the ring gear for smooth and reliable operation. We have been focusing on the design and manufacture of pinions for decades, and have continuously improved and optimized them to meet your specific needs. We can tailor-make your own pinions with the perfect combination of materials, hardness and surface treatment to extend the service life of open gears.

Our pinions are rich in designs, including self-aligning, spur, helical or double helical, drilled and solid types. The materials are made of forged alloy steel. The treatment processes include full hardening, quenching and tempering, carburizing and grinding, induction hardening and nitriding. They are suitable for a wide range of application scenarios.

Our team of strong engineers will fully consider the need for tooth modification when installing new pinion gears, and perform tooth profile and lead correction to ensure high pinion fit, maximum output and minimum noise. We can also redesign installed pinions to meet your needs to replace high-performance or different speed pinions, and optimize new gearing to meet new requirements.
When it comes to heat treatment, we are the industry leader with a variety of heat treatment processes that we have developed, improved and patented. Modern heat treatment facilities guarantee the best quality and characteristics of materials, producing first-class and reliable pinions. Throughout the manufacturing process, we implement strict quality control procedures, using strict testing methods such as non-destructive testing, ultrasonic testing, magnetic particle testing and penetrant testing as well as NDT - QA inspections to ensure that the products are flawless and the gear components comply with applicable international standards such as UNI EN ISO, AWS, ASTM, ASME and DIN.

Our production capabilities are also excellent. Our experienced engineers use the latest finite element modeling software to design and manufacture open gear pinions according to your precise needs. Modern production sites and continuous technological progress ensure that our pinions meet the needs of today and the challenges of the future. And the use of high-quality materials, modern heat treatment technology and strict standards makes the pinions we produce durable and help mills and kilns to maintain easily and run smoothly. In addition, with a wide range of designs, materials, surface treatments and functional ranges, we provide you with a precisely adapted gear to maintain the best functionality of open gears. We also use advanced manufacturing processes to produce pinions to order to meet your exact needs, reverse engineer replacement pinions to fit existing configurations, and even improve your process by increasing torque capacity or changing speed.

Classic open gear arrangement and customized power train
The classic open gear arrangement mainly consists of the main motor, the intermediate gear device for speed reduction, and the pinion gear meshing with the ring gear. We not only have a standardized product range, but also combine it with a individually designed ring gear and pinion gear to customize a dedicated power train for your specific application. This flexible combination ensures that your equipment can get the most suitable power support.
Design and application advantages of pinion gear

There are two common forms of pinion gear design. One is a solid shaft design with the gear integrated as part of the shaft; the other is a drilled assembly pinion gear with a shaft. This design allows the use of higher-grade materials only in the gear area, so that the pinion gear can be optimized according to your unique needs.

In the case of high torque transmission, we strongly recommend the use of self-aligning pinions. The spherical bearings used between the shaft and the drilled pinion gear enable the teeth to oscillate slightly, allowing the self-aligning pinion gear to effectively compensate for the slight runout deviation of the mill or kiln. To ensure the correct hardness match between the pinion and the ring gear, we take the meshing assembly into account during the design process and modify the carburizing and case hardening processes accordingly. Through these process optimizations, we produce pinion and ring gear wear parts with the longest service life.
Backed by experience and expertise

Our advanced modern manufacturing processes are impressive, but it is the skilled team of engineers and operators behind them that really makes our pinions the best in the industry. Our engineers and machine operators are professionally trained in complex engineering software, which enables them to manufacture high-quality open gears made of different materials to precisely meet your specifications. We can manufacture all gear components of the entire power train according to your needs, or just provide individual components.

In addition, based on in-depth engineering analysis and years of rich experience, we can also provide you with design improvements to further improve the reliability of the parts and ensure the long-term smooth operation of your mill or kiln. Choosing our drive system solutions means choosing professionalism, efficiency and reliability.