Product Description

Rotary Kiln Spur Girth Gear Used in Construction Industry Machinery

Product Description

Girth Gears: Rotary kiln Girth Gear,ball mill Girth Gear
Girth Gears offered find extensive application in different industry sectors including in sponge iron plants, steel & cement industry, mining industry, wind mills as well as in other industry sectors. These are made available in module range of 10 Module to 70 Module and in minimum diameters of 100 mm to 15000 mm. Further, these comprise maximum weight of 70 MT single pieces. Here the range of hardened & ground gear boxes/gears comprise Worm gear boxes, Helical / Double helical gears/gearboxes, Helical-Bevel gearboxes, Planetary Gearboxes and others.

ZTIC Gear Cutting Machines include:
Ø16m CNC Hobbing Machine
Ø12m Gear Cutting Machine (Switzerland)
Ø10m Hobbing Machine (Germany)
Ø4m CNC High Speed Hobbing Machine (Germany)
Ø1.6m Horizontal CHC Hobbing Machine (Germany)
Ø5m CNC Profile Gear Grinding Machine (Germany)
Ø2.8m CNC Profile Gear Grinding Machine (Germany)
Ø1.25m CNC Profile Gear Grinding Machine (Germany)
Ø1m CNC Profile Gear Grinding Machine (Germany)
Ø0.8m CNC Profile Gear Grinding Machine (Germany)

With more than 1000 girth gears sold over the world CHINAMFG Gear is a leading supplier in the cement and mineral industry. And as member of AGMA (American Gear Manufacturers Association), we do actively take part in defining the standard for gear rating calculations and service factors. 
We provide girth gears in 3 different designs
Fabricated steel- forged ring- rolled plate  Cast steel 

Ductile (Nodular) cast iron  
Fabricated gears became more common in the past and are constructed with forged steel gear rim materials and electro welded body structure. The rings are manufactured from a whole block of high resistance alloy steel. After the rough machining of the ring, we carry out hardening and tempering heat treatment in order to improve the mechanical characteristic and therefore its relevant performance.  
Avantages of fabricated girth gears
The forged material structure excludes the risk of inclusions
Structure defects like gas holes, micro shrinkage, pin holes, hot tears, sand and slag inclusions are avoided
Hence, repair welding of the body structure and e.g. grinding of toothed areas is not required.
The fabricated manufacturing procedure excludes the need for patterns and risers
Rim material has higher hardness and higher strength than the material used for the underlying structure (i.e. web, gussets)
These features will reduce the lead time and costs. Fabricated manufacturing ensures a fast delivery.
This is especially beneficial in an emergency situation, where the existing gear rim is suffering from damage   


External teeth 
Maximum diameter: 16000 mm 
Toothed face width: 1700 mm 
Maximum module: 45 by hob 
Maximum module: 65 gear finishing cutter
Internal teeth 
Maximum Diameter: 6500 mm 
Maximum module: 25.4 
Toothed face width: 400 mm

CHINAMFG Gear invested in significant resources and achieved many innovations with pinions. The right combination of material, hardness and finishing between pinion and gear is crucial for a long lifetime of the installed equipment. We design and manufacture pinions to match every customers need, no matter how unique the situation might be. 

Quality assurance documents
The following reports are to be submitted to Quality Assurance:
a. Chemistry report
b. Physical report
c. Heat treatment documents
CITIC HMC  Q/HM 973.2-2007 Specification for Steel Castings for Grinding Mills
d. Ultrasonic inspection report (before and after repairs)
e. Magnetic particle inspection report (before and after repairs)
f. Dimensional report
g. Weld repair maps
h. Weld procedures and Procedure qualification record
i. Welder qualification
j. Nondestructive testing inspector qualification

Item Structural features Processing measure Test content
Girth Gear (1)GS42CrMo4Alloy Steel (corporate proprietary standards)
HB 220~240
(2)semi-structured, Y-Spoke 
(4) reasonable sealing and alignment structure of alloy steel (corporate proprietary standards)
(1) outer steel refining (R-H argon and vacuum treatment) 
(2) proprietary cold mold hanging sand technology to ensure the casting, the teeth dense 
(3) normalizing (proprietary technology) to ensure that the tooth surface hardness 
(4)rough hobbing, release time, repair the joint surface, then fine roll 
(5) proprietary homemade hob fine hobbing
(1)castings mechanical properties and chemical composition (internal standard) 
(2) roughing after sonic testing 
(3)semi-finishing, finishing after ultrasonic testing and magnetic particle inspection 
(4) tooth surface magnetic particle inspection, hardness test 
(5)tooth tolerance check 
(6) the factory assembly load test to check the accuracy of the size of gear

1. The technical requirements of a large CHINAMFG Gear ring:
1) is pretreated before normalizing surface hardening treatment, the hardness should HB210 ~ 250; mechanical performance are the ultimate strength Rb \ 690MPa, yield stress Rs \ 490MPa, elongation D5 \ 11%, reduction of area W \ 25% , impact toughness Ak \ 30J; teeth induction hardened, hardness HRC50 ~ 55; effective hardened layer depth \ 3 ~ 5mm.
2) overall ultrasonic flaw detection, internal quality should meet 2 requirements GB7233-87 standard requirements; tooth and fillet magnetic particle inspection, quality should meet 2 requirements GB/T9444-88 standards.
3) Note the casting is not rounded R5 ~ R10.
4) Tooth chamfer at both ends and 1 45b.5) by 2 and a half ring gear tooth width of each ring coupling along the edge of a whole ring made with high strength bolts, combined with the tooth surface must be at the bottom center.
2 large ring gear manufacturing process

2.1  of rough
Steel casting blank is provided by CITIC Heavy Machinery Co., Ltd. Heavy Forging plant, run by GB11352-89 standard specifies requirements for modeling according to the casting process, smelting, casting, hit boxes, cleaning, dressing castings;. During inspection and acceptance by the drawings and Technical requirements for steel blank
Checks, according JB/T6402-92 standards issued after acceptance
Down procedure.
2.2  roughing
Crossed by drawing and stay out allowance, alignment, connection, processing both inside and outside the circle, combining face milling, drilling and other processes.
2.3  Exploration injury
Overall ultrasonic flaw detection, internal quality should meet the 2 requirements of GB7233-87 standards.
2.4  normalizing pretreatment
Semi-ring pairs normalizing and tempering treatment, provide a good organization for subsequent surface hardening; press drawings deformation of the half ring gear inspection after heat treatment.
2.5  Machining
First 2 and a half ring is made with high strength bolts connecting the ring as a whole, the overall process by drawing a circle Quannei Wai teeth and upper and lower end, and then drawing and machining milling process requirements.
2.6  Elimination of processing stress
The overall ring annealed to eliminate stress.
2.7  overall ring surface hardening
IF along the alveolar tooth surface induction hardening, hardness HRC50 ~ 55, effective hardened layer depth \ 3 ~ 5mm.
2.8  Final inspection
First, the detection frequency quenching, the hardness after tempering ring gear cogging meets the requirements of the drawings; secondly, to detect whether the maximum outer diameter larger size D6944 as the deformation \ 3mm, the mechanical correction required until qualified; Thirdly, tooth and fillet magnetic particle inspection, quality should meet 2 requirements GB/T9444-88 standard requirements; Finally, according to the drawings and technical requirements for final inspection.

Company Profile

Our mode of transport is taken according to each country’s situation is different transportation, while our packaging, according to the latest customs situation, constantly updated, improved our packaging, we guarantee that you receive it within 3-7 working days to your product.
High quality service :
Best Service with after-sales service and consultation,we have an excellent customer service driven approach to our
business, unlike most sites we are consistently available via sales hotline, email, or MSN and always respond to
emails within 30 mins
Pre-Sales Service
• Provide details about the production procedure
• Assign engineers for installation and testing
Sales Service
• Customized solution designs
• Product rendering and steel structure drawing
•successful project examples and visits to our production and R&D base
After-Sales Service
• Two-year quality warranty with lifelong maintenance.
•Free guarantee repair (including labor and material): free repair service during the quality warranty period and reasonable charge for spare parts and maintaining service after the quality warranty period.  We will never exempt our responsibilities on product owned defects.  
•Responding time: CHINAMFG receiving user’s notification, we ensure 24-hour after-sales technical support.

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After-sales Service: Twenty Four Hour Online
Warranty: a Year
Weight: Max 120 Mt Single Piece
Module Range: 10 Module to 70 Module
Certificate: ISO 9001:2008
Gear Cutting Machines: 16m CNC Hobbing Machine


Customized Request

spur gear

How do you ensure proper alignment when connecting spur gears?

Proper alignment is crucial when connecting spur gears to ensure smooth and efficient gear operation. Here’s a detailed explanation of how to ensure proper alignment when connecting spur gears:

  • Visual Inspection: Start by visually inspecting the gears, gear shafts, and associated components for any visible misalignment or damage. Look for signs of wear, uneven tooth engagement, or any abnormalities that may affect alignment.
  • Shaft Alignment: Align the gear shafts accurately before connecting the gears. Proper shaft alignment ensures that the gears are positioned correctly relative to each other. This can be achieved through various alignment techniques, such as using alignment tools, laser alignment systems, or measuring devices. The goal is to ensure parallel or coaxial alignment between the gear shafts.
  • Backlash Adjustment: Adjust the backlash between the gear teeth to achieve proper alignment. Backlash refers to the slight gap between the mating teeth of gears. It is important to maintain an appropriate amount of backlash to allow for smooth gear engagement and minimize the risk of binding or jamming. Follow the manufacturer’s recommendations or industry standards for the recommended backlash range and adjust as necessary during gear installation.
  • Check Gear Mesh: Verify the gear meshing pattern to ensure proper alignment. The gear teeth should mesh smoothly and evenly without any signs of excessive or uneven contact. If there are indications of improper meshing, such as concentrated contact on a specific area of the tooth, it may imply misalignment or other issues that need to be addressed.
  • Shim Adjustment: If misalignment is detected, shimming can be employed to correct it. Shimming involves placing thin metal shims between the gear and the shaft to adjust the positioning and alignment. Shims are available in various thicknesses, allowing for precise alignment adjustments. Careful measurement and selection of the appropriate shim thickness can help achieve the desired alignment.
  • Tightening Bolts: When connecting the gears to the shafts, ensure that the bolts or fasteners are tightened evenly and to the recommended torque specifications. Uneven tightening can introduce misalignment or uneven load distribution, leading to gear misalignment and potential issues.
  • Post-Installation Verification: After connecting the gears, perform a final verification of the alignment. Rotate the gears manually or through the gear system’s intended operation and observe the gear meshing behavior. Look for any signs of abnormal noise, vibration, or irregular tooth engagement. If any issues are detected, further adjustments or inspections may be necessary.
  • Regular Maintenance: Implement a proactive maintenance program that includes periodic inspections and alignment verification. Gears can experience wear or misalignment over time due to factors such as load variations, temperature changes, or prolonged operation. Regular maintenance allows for early detection and correction of alignment issues, ensuring optimal gear performance and longevity.

Proper alignment is essential for maximizing the efficiency, durability, and reliability of spur gear systems. By following these alignment practices and considering the manufacturer’s recommendations, industry standards, and expert advice, you can ensure proper alignment when connecting spur gears.

It’s important to note that the specific alignment techniques and procedures may vary depending on the gear system’s design, size, application, and other factors. Consulting with gear manufacturers, engineers, or alignment specialists can provide further guidance on the recommended alignment practices for your specific gear system.

spur gear

How do you install a spur gear system?

Installing a spur gear system involves several steps to ensure proper alignment, engagement, and operation. Here’s a detailed explanation of how to install a spur gear system:

  1. Preparation: Before installation, gather all the necessary components, including the spur gears, shafts, bearings, and any additional mounting hardware. Ensure that the gear system components are clean and free from debris or damage.
  2. Shaft Alignment: Proper shaft alignment is crucial for the smooth operation of a spur gear system. Ensure that the shafts on which the gears will be mounted are aligned accurately and parallel to each other. This can be achieved using alignment tools such as dial indicators or laser alignment systems. Adjust the shaft positions as needed to achieve the desired alignment.
  3. Positioning the Gears: Place the spur gears on the respective shafts in the desired configuration. Ensure that the gears are positioned securely and centered on the shafts. For shafts with keyways, align the gears with the key and ensure a proper fit. Use any necessary mounting hardware, such as set screws or retaining rings, to secure the gears in place.
  4. Checking Gear Engagement: Verify that the teeth of the gears mesh properly with each other. The gear teeth should align accurately and smoothly without any excessive gaps or interference. Rotate the gears by hand to ensure smooth and consistent meshing throughout their rotation. If any misalignment or interference is observed, adjust the gear positions or shaft alignment accordingly.
  5. Bearing Installation: If the spur gear system requires bearings to support the shafts, install the bearings onto the shafts. Ensure that the bearings are the correct size and type for the application. Press or slide the bearings onto the shafts until they are seated securely against any shoulder or bearing housing. Use appropriate methods and tools to prevent damage to the bearings during installation.
  6. Lubrication: Apply a suitable lubricant to the gear teeth and bearings to ensure smooth operation and reduce friction. Refer to the gear manufacturer’s recommendations for the appropriate lubrication type and amount. Proper lubrication helps minimize wear, noise, and heat generation in the gear system.
  7. Final Inspection: Once the gears, shafts, and bearings are installed, perform a final inspection of the entire spur gear system. Check for any unusual noises, misalignment, or binding during manual rotation. Verify that the gears are securely mounted, shafts are properly aligned, and all fasteners are tightened to the specified torque values.

It’s important to follow the specific installation instructions provided by the gear manufacturer to ensure proper installation and operation. Additionally, consult any applicable industry standards and guidelines for gear system installation.

By carefully following these installation steps, you can ensure a well-aligned and properly functioning spur gear system in your machinery or equipment.

spur gear

How do you choose the right size spur gear for your application?

Choosing the right size spur gear for your application requires careful consideration of various factors. Here’s a detailed explanation of the steps involved in selecting the appropriate size spur gear:

  1. Determine the Required Torque: Start by determining the torque requirements of your application. Calculate or estimate the maximum torque that the gear will need to transmit. Consider factors such as the power input, speed, and load conditions to determine the required torque.
  2. Identify the Speed Requirements: Determine the desired rotational speed or RPM (revolutions per minute) for your application. This will help in selecting a gear with the appropriate pitch diameter and tooth configuration to achieve the desired speed.
  3. Consider the Load Conditions: Evaluate the expected load conditions, including the magnitude and direction of the load. Determine if the load is constant or variable, and if it involves shock loads or cyclic loading. This will impact the gear’s durability and load-carrying capacity.
  4. Calculate the Pitch Diameter: Based on the torque and speed requirements, calculate the pitch diameter of the spur gear. The pitch diameter is determined by the formula: Pitch Diameter = (2 x Torque) / (Pressure Angle x Allowable Tooth Shear Stress).
  5. Select the Module Size: Choose an appropriate module size based on the gear size and application requirements. The module size determines the tooth size and spacing. Smaller module sizes are used for fine tooth profiles and higher precision, while larger module sizes are suitable for heavier loads and higher torque applications.
  6. Determine the Number of Teeth: Based on the pitch diameter and module size, calculate the number of teeth required for the gear. Ensure that the gear has an adequate number of teeth for smooth operation, load distribution, and sufficient contact ratio.
  7. Consider Space Constraints: Evaluate the available space and mounting requirements in your application. Ensure that the selected gear size can fit within the available space and can be properly mounted on the shaft or gearbox.
  8. Choose the Material: Consider the operating conditions, such as temperature, humidity, and presence of corrosive substances, to select the appropriate material for the spur gear. Common materials include steel, cast iron, brass, and plastic. Choose a material that offers the necessary strength, wear resistance, and durability for your specific application.
  9. Consider Additional Design Features: Depending on your application requirements, you may need to consider additional design features such as profile shift, hub configuration, and surface treatments. Profile shift can optimize gear performance, while specific hub configurations and surface treatments may be necessary for proper mounting and enhanced durability.

It’s important to note that gear selection is a complex process, and it may require consultation with gear manufacturers or experts in the field. They can provide guidance based on their expertise and assist in selecting the most suitable spur gear for your specific application.

By thoroughly considering factors such as torque requirements, speed, load conditions, pitch diameter, module size, number of teeth, space constraints, material selection, and additional design features, you can choose the right size spur gear that meets the demands of your application in terms of performance, durability, and efficiency.

China supplier Rotary Kiln Spur Girth Gear Used in Construction Industry Machinery supplier China supplier Rotary Kiln Spur Girth Gear Used in Construction Industry Machinery supplier
editor by Dream 2024-04-26


Plastic Spur Gears

As one of the plastic spur gears manufacturers, suppliers, and exporters of mechanical products, We offer plastic spur gears and many other products.

Please get in touch with us for details.

Manufacturer supplier exporter of plastic spur gears.

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