China Standard CZPT Slewing Gear for Container Cranes (21′′) with Good quality

Product Description


.; Introduction of CHINAMFG heavy load slewing drive
Slewing Drive is also called slewing gear,; worm gear,; worm drive,; rotary drive,; slew drive,; worm gear reducer and rotary drive unit.; At present the majority of such devices are caller Slewing Drive.;
LYHY heavy load slewing drive is usually composed of a slewing ring,; worm,; casting housing,; and standard components likebearing and bolts,; etc.; While used in photovoltaic power generation system,; the slewing drive is usually used in combination with DC planetary speed reducer motor and AC speed reducer motor.; While used in engineering equipment,; it is regularly used in combination with hydraulic motor to function as power driving system.;

2.; Structure
According to the raceway diameter of the slewing ring,; a heavy load slewing drive include M3 ich,; M5 inch,; M7 inch,; M9 inch,; M12 inch,; M14 inch,; M17 inch,; M21 inch,; M25inch,; H14 inch,; H17 inch,; H21 inch and H25 inch.;

3.; Features:;
Heavy load slewing drive is a special bearing.; And a slewing drive is usually composed of a slewing ring,; worm,; casting housing,; and standard components like bearing and bolts,; etc.;
Slewing drive is able to sustain more axial load,; radial load and tilting moment.; Turntable or frame rotates at azimuth and elevation driven by slewing drive.;

4.; Application:;
Slewing drives are widely used in solar power generation tracking system,; timber grab,; special vehicle,; heavy-duty flat-panel truck,; container cranes,; overhead working truck,; truck mounted crane,; automobile crane and aerial vehicles,; cranes,; gantry cranes,; small wind power stations,; space communications,; satellite receiver,; etc.;

LYHY can also design and make other standard and non-standard Slewing Drives as per customer’s different technical requirements.; For more information about the slewing drive,; please contact CHINAMFG Bearing sales department.; We will give you the best technical support.;

Model Rated output torque /KN-m Tilting Moment torque /KN-m Load /KN Gear ratio Self-locking gears Weight (KG);
Static load rating,; axial Static load rating,;radial Dynamic load rating,; axial Dynamic load rating,;radial
3″ 0.;25 0.;5 30 16.;6 9.;6 8.;4 62:;01:;00 yes 12
5″ 0.;37 0.;8 76 22.;6 13.;8 11.;8 62:;01:;00 yes 18
7″ 1.;3 13.;5 133 53 32 28 73:;01:;00 yes 23
9″ 9.;2 33.;9 338 135 81 71 61:;01:;00 yes 50
12″ 11.;7 54.;3 475 190 114 100 78:;01:;00 yes 60
14″ 12.;7 67.;8 555 222 133 117 85:;01:;00 yes 73
17″ 18.;5 135.;6 975 390 235 205 102:;01:;00 yes 110
21″ 29 203 1598 640 385 335 125:;01:;00 yes 158
25″ 34 271 2360 945 590 470 150:;01:;00 yes 230

Application: Industry
Hardness: Hardened
Manufacturing Method: Rolling Gear
Toothed Portion Shape: Curved Gear
Material: Bearing Steel
Type: Worm And Wormwheel


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worm gear

How does a worm gear impact the overall efficiency of a system?

A worm gear has a significant impact on the overall efficiency of a system due to its unique design and mechanical characteristics. Here’s a detailed explanation of how a worm gear affects system efficiency:

A worm gear consists of a worm (a screw-like gear) and a worm wheel (a cylindrical gear with teeth). When the worm rotates, it engages with the teeth of the worm wheel, causing the wheel to rotate. The main factors influencing the efficiency of a worm gear system are:

  • Gear Reduction Ratio: Worm gears are known for their high gear reduction ratios, which are the ratio of the number of teeth on the worm wheel to the number of threads on the worm. This high reduction ratio allows for significant speed reduction and torque multiplication. However, the larger the reduction ratio, the more frictional losses occur, resulting in lower efficiency.
  • Mechanical Efficiency: The mechanical efficiency of a worm gear system refers to the ratio of the output power to the input power, accounting for losses due to friction and inefficiencies in power transmission. Worm gears typically have lower mechanical efficiency compared to other gear types, primarily due to the sliding action between the worm and the worm wheel teeth. This sliding contact generates higher frictional losses, resulting in reduced efficiency.
  • Self-Locking: One advantageous characteristic of worm gears is their self-locking property. Due to the angle of the worm thread, the worm gear system can prevent the reverse rotation of the output shaft without the need for additional braking mechanisms. While self-locking is beneficial for maintaining position and preventing backdriving, it also increases the frictional losses and reduces the efficiency when the gear system needs to be driven in the opposite direction.
  • Lubrication: Proper lubrication is crucial for minimizing friction and maintaining efficient operation of a worm gear system. Inadequate or improper lubrication can lead to increased friction and wear, resulting in lower efficiency. Regular lubrication maintenance, including monitoring viscosity, cleanliness, and lubricant condition, is essential for optimizing efficiency and reducing power losses.
  • Design and Manufacturing Quality: The design and manufacturing quality of the worm gear components play a significant role in determining the system’s efficiency. Precise machining, accurate tooth profiles, proper gear meshing, and appropriate surface finishes contribute to reducing friction and enhancing efficiency. High-quality materials with suitable hardness and smoothness also impact the overall efficiency of the system.
  • Operating Conditions: The operating conditions, such as the load applied, rotational speed, and temperature, can affect the efficiency of a worm gear system. Higher loads, faster speeds, and extreme temperatures can increase frictional losses and reduce overall efficiency. Proper selection of the worm gear system based on the expected operating conditions is critical for optimizing efficiency.

It’s important to note that while worm gears may have lower mechanical efficiency compared to some other gear types, they offer unique advantages such as high gear reduction ratios, compact design, and self-locking capabilities. The suitability of a worm gear system depends on the specific application requirements and the trade-offs between efficiency, torque transmission, and other factors.

When designing or selecting a worm gear system, it is essential to consider the desired balance between efficiency, torque requirements, positional stability, and other performance factors to ensure optimal overall system efficiency.

worm gear

What are the potential challenges in designing and manufacturing worm gears?

Designing and manufacturing worm gears can present several challenges due to their unique characteristics and operating conditions. Here’s a detailed explanation of the potential challenges involved:

  1. Complex geometry: Worm gears have complex geometry with helical threads on the worm shaft and corresponding teeth on the worm wheel. Designing the precise geometry of the gear teeth, including the helix angle, lead angle, and tooth profile, requires careful analysis and calculation to ensure proper meshing and efficient power transmission.
  2. Gear materials and heat treatment: Selecting suitable materials for worm gears is critical to ensure strength, wear resistance, and durability. The materials must have good friction and wear properties, as well as the ability to withstand the sliding and rolling contact between the worm and the worm wheel. Additionally, heat treatment processes such as carburizing or induction hardening may be necessary to enhance the gear’s surface hardness and improve its load-carrying capacity.
  3. Lubrication and cooling: Worm gears operate under high contact pressures and sliding velocities, resulting in significant heat generation and lubrication challenges. Proper lubrication is crucial to reduce friction, wear, and heat buildup. Ensuring effective lubricant distribution to all contact surfaces, managing lubricant temperature, and providing adequate cooling mechanisms are important considerations in worm gear design and manufacturing.
  4. Backlash control: Controlling backlash, which is the clearance between the worm and the worm wheel, is crucial for precise motion control and positional accuracy. Designing the gear teeth and adjusting the clearances to minimize backlash while maintaining proper tooth engagement is a challenge that requires careful consideration of factors such as gear geometry, tolerances, and manufacturing processes.
  5. Manufacturing accuracy: Achieving the required manufacturing accuracy in worm gears can be challenging due to their complex geometry and tight tolerances. The accurate machining of gear teeth, maintaining proper tooth profiles, and achieving the desired surface finish require advanced machining techniques, specialized tools, and skilled operators.
  6. Noise and vibration: Worm gears can generate noise and vibration due to the sliding contact between the gear teeth. Designing the gear geometry, tooth profiles, and surface finishes to minimize noise and vibration is a challenge. Additionally, the selection of appropriate materials, lubrication methods, and gear housing design can help reduce noise and vibration levels.
  7. Efficiency and power loss: Worm gears inherently have lower efficiency compared to other types of gear systems due to the sliding contact and high gear ratios. Minimizing power loss and improving efficiency through optimized gear design, material selection, lubrication, and manufacturing accuracy is a challenge that requires careful balancing of various factors.
  8. Wear and fatigue: Worm gears are subjected to high contact stresses and cyclic loading, which can lead to wear, pitting, and fatigue failure. Designing the gear teeth for proper load distribution, selecting appropriate materials, and applying suitable surface treatments or coatings are essential to mitigate wear and fatigue issues.
  9. Cost considerations: Designing and manufacturing worm gears can be cost-intensive due to the complexity of the gear geometry, material requirements, and precision manufacturing processes. Balancing performance requirements with cost considerations is a challenge that requires careful evaluation of the gear’s intended application, performance expectations, and budget constraints.

Addressing these challenges requires a comprehensive understanding of gear design principles, manufacturing processes, material science, and lubrication technologies. Collaboration between design engineers, manufacturing experts, and material specialists is often necessary to overcome these challenges and ensure the successful design and production of high-quality worm gears.

worm gear

How do you calculate the gear ratio of a worm gear?

Calculating the gear ratio of a worm gear involves determining the number of teeth on the worm wheel and the pitch diameter of both the worm and worm wheel. Here’s the step-by-step process:

  1. Determine the number of teeth on the worm wheel (Zworm wheel). This information can usually be obtained from the gear specifications or by physically counting the teeth.
  2. Measure or determine the pitch diameter of the worm (Dworm) and the worm wheel (Dworm wheel). The pitch diameter is the diameter of the reference circle that corresponds to the pitch of the gear. It can be measured directly or calculated using the formula: Dpitch = (Z / P), where Z is the number of teeth and P is the circular pitch (the distance between corresponding points on adjacent teeth).
  3. Calculate the gear ratio (GR) using the following formula: GR = (Zworm wheel / Zworm) * (Dworm wheel / Dworm).

The gear ratio represents the speed reduction and torque multiplication provided by the worm gear system. A higher gear ratio indicates a greater reduction in speed and higher torque output, while a lower gear ratio results in less speed reduction and lower torque output.

It’s worth noting that in worm gear systems, the gear ratio is also influenced by the helix angle and lead angle of the worm. These angles determine the rate of rotation and axial movement per revolution of the worm. Therefore, when selecting a worm gear, it’s important to consider not only the gear ratio but also the specific design parameters and performance characteristics of the worm and worm wheel.

China Standard CZPT Slewing Gear for Container Cranes (21′′) with Good qualityChina Standard CZPT Slewing Gear for Container Cranes (21′′) with Good quality
editor by CX 2023-11-16