Tag Archives: worm reducer gearboxes

China supplier Light Weight Aluminum Case Worm Gear Nrv Reducer Input Shaft Gearboxes with Good quality

Product Description

 
       

   

Technical data list: 

Type: Worm Gear Speed Reducer
Model: NMRV571–150
Ratio: 1:7.5,10,15,20,25,30,40,50,60,80,100
Color: Blue/Silver Or On Customer Request
Material Housing: Blue-Coloured Cast-Iron
Worm Gear-Copper-10-3#
Worm-20CrMn Ti with carburizing and quenching, surface harness is 56-62HRC
Shaft-chromium steel-45#
Lubricant: Synthetic&Mineral
Bearing: C&U Bearing
Seal: NAK SKF
Warranty: -30-40°C
ICE FLANGE 80B5,90B5,100B5,112B5,132B5,160B5 
Rated power: 0.06KW,0.12KW,0.25KW,0.75KW,1.5KW,3KW,5.5KW,7.5KW
Application Metallurgical machinery, food machinery, stage machinery,
welding machinery, road machinery, amusement machines,
packaging machinery, Rubber and plastic machinery,
environmental protection machinery ,engineering machinery,
construction machinery, machine tool industry,
 automotive industry, logistics and transportation and so on

 
 

NMRV PAM N M P D
  ICE       5 7.5 10 15 20 25 30 40 50 60 80 100
25 56B14 50 65 80 9 9 9 9 9   9 9 9 9    
30 63B5 95 115 140 11 11 11 11 11 11 11 11 11      
63B14 60 75 90                        
56B5 80 100 120 9 9 9 9 9 9 9 9 9 9 9  
56B14 50 65 80                        
40 71B5 110 130 160 14 14 14 14 14 14 14 14        
71B14 70 85 105                        
63B5 95 115 140 11 11 11 11 11 11 11 11 11 11 11 11
63B14 60 75 90                        
56B5 80 100 120                 9 9 9 9
50 80B5 130 165 200 19 19 19 19 19 19 19          
80B14 80 100 120                        
71B5 110 130 160 14 14 14 14 14 14 14 14 14 14 14  
71B14 70 85 105                        
63B5 95 115 140               11 11 11 11 11
63 90B5 130 165 200   24 24 24 24 24 24          
90B14 95 115 140                        
80B5 130 165 200   19 19 19 19 19 19 19 19 19    
80B14 80 100 120                        
71B5 110 130 160               14 14 14 14  14
71B14 70 85 105                        
75 100/112B5 180 215 250   28 28 28                
100/112B14 110 130 150                        
90B5 130 165 200   24 24 24 24 24 24 24        
90B14 95 115 140                        
80B5 130 165 200         19 19 19 19 19 19 19 19
80B14 80 100 120                        
71B5 110 130 160                 14 14 14 14
90 100/112B5 190 215 250   28 28 28 28 28 28          
100/112B14 110 130 160                        
90B5 130 165 200   24 24 24 24 24 24 24 24 24    
90B14 95 115 140                        
80B5 130 165 200               19 19 19 19 19
80B14 80 100 120                        
110 132B5 230 265 300   38 38 38 38              
100/112B5 180 215 250   28 28 28 28 28 28 28 28 28    
90B5 130 165 200           24 24 24 24 24 24 24
80B5 130 165 200                     19 19
130 132B5 230 265 300   38 38 38 38 38 38 38        
100/112B5 180 215 250           28 28 28 28 28 28 28
90B5 130 165 200                     24 24
150 160B5 250 300 350   42 42 42 42 42            
132B5 230 265 250         38 38 38 38 38 38    
100/112B5 180 215 200                 28 28 28 28

Workshop show

  

 FAQ

Q: Are you trading company or manufacturer ?

A: We are factory.

Q: How long is your delivery time?

A: Generally it is 5-10 days if the goods are in stock. or it is 15-20 days if the goods are not in stock, it is according to quantity.

Q: Do you provide samples ? is it free or extra ?

A: Yes, we could offer the sample for free charge but do not pay the cost of freight.

Q: What is your terms of payment ?

A: Payment 30%TT in advance. 70% T/T before shippment

 

Application: Motor, Electric Cars, Motorcycle, Machinery, Marine, Toy, Agricultural Machinery, Car
Hardness: Hardened Tooth Surface
Gear Position: Internal Gear
Manufacturing Method: Cut Gear
Toothed Portion Shape: Double Helical Gear
Material: Cast Steel
Samples:
US$ 20/Piece
1 Piece(Min.Order)

|
Request Sample

Customization:
Available

|

Customized Request

worm gearbox

Is it Possible to Reverse the Direction of a Worm Gearbox?

Yes, it is possible to reverse the direction of a worm gearbox by changing the orientation of either the input or output shaft. However, reversing the direction of a worm gearbox can have some implications that need to be considered:

  • Efficiency: Reversing the direction of a worm gearbox can potentially affect its efficiency. Worm gearboxes are typically more efficient in one direction of rotation due to the design of the worm and worm wheel.
  • Backlash: Reversing the direction of rotation might lead to increased backlash or play in the gearbox, which can impact precision and smooth operation.
  • Lubrication: Depending on the gearbox’s design, reversing the direction could affect lubrication distribution and lead to uneven wear on the gear teeth.
  • Load: Reversing the direction might also impact the gearbox’s load-carrying capacity, especially if it’s designed for predominantly one-way operation.
  • Noise and Vibration: Direction reversal can sometimes result in increased noise and vibration due to changes in gear engagement and meshing behavior.

If you need to reverse the direction of a worm gearbox, it’s advisable to consult the gearbox manufacturer’s guidelines and recommendations. They can provide insights into whether the specific gearbox model is suitable for reversible operation and any precautions or adjustments needed to ensure proper functioning.

worm gearbox

Worm Gearbox vs. Helical Gearbox: A Comparison

Worm gearboxes and helical gearboxes are two popular types of gear systems, each with its own set of advantages and disadvantages. Let’s compare them:

Aspect Worm Gearbox Helical Gearbox
Efficiency Lower efficiency due to sliding friction between the worm and worm wheel. Higher efficiency due to rolling contact between helical gear teeth.
Torque Transmission Excellent torque transmission and high reduction ratios achievable in a single stage. Good torque transmission, but may require multiple stages for high reduction ratios.
Noise and Vibration Generally higher noise and vibration levels due to sliding action. Lower noise and vibration levels due to smoother rolling contact.
Backlash Higher inherent backlash due to the design. Lower backlash due to meshing of helical teeth.
Efficiency at Higher Speeds Less suitable for high-speed applications due to efficiency loss. More suitable for high-speed applications due to higher efficiency.
Overload Protection Natural self-locking feature provides some overload protection. May not have the same level of inherent overload protection.
Applications Commonly used for applications requiring high reduction ratios, such as conveyor systems and heavy-duty machinery. Widely used in various applications including automotive transmissions, industrial machinery, and more.

Both worm and helical gearboxes have their place in engineering, and the choice between them depends on the specific requirements of the application. Worm gearboxes are preferred for applications with high reduction ratios, while helical gearboxes are chosen for their higher efficiency and smoother operation.

worm gearbox

How Does a Worm Gearbox Compare to Other Types of Gearboxes?

Worm gearboxes offer unique advantages and characteristics that set them apart from other types of gearboxes. Here’s a comparison between worm gearboxes and some other common types:

  • Helical Gearbox: Worm gearboxes have higher torque multiplication, making them suitable for heavy-load applications, while helical gearboxes are more efficient and offer smoother operation.
  • Bevel Gearbox: Worm gearboxes are compact and can transmit motion at right angles, similar to bevel gearboxes, but worm gearboxes have self-locking capabilities.
  • Planetary Gearbox: Worm gearboxes provide high torque output and are cost-effective for applications with high reduction ratios, whereas planetary gearboxes offer higher efficiency and can handle higher input speeds.
  • Spur Gearbox: Worm gearboxes have better shock load resistance due to their sliding motion, while spur gearboxes are more efficient and suitable for lower torque applications.
  • Cycloidal Gearbox: Cycloidal gearboxes have high shock load capacity and compact design, but worm gearboxes are more cost-effective and can handle higher reduction ratios.

While worm gearboxes have advantages such as high torque output, compact design, and self-locking capability, the choice between gearbox types depends on the specific requirements of the application, including torque, efficiency, speed, and space limitations.

China supplier Light Weight Aluminum Case Worm Gear Nrv Reducer Input Shaft Gearboxes   with Good quality China supplier Light Weight Aluminum Case Worm Gear Nrv Reducer Input Shaft Gearboxes   with Good quality
editor by CX 2023-09-28

China OEM Nmrv Worm Gearboxes Speed Reducer Gear Motor gearbox adjustment

Product Description

Parameters:

Models Rated Power Rated Ratio Input Hole Dia. Input Shaft Dia. Output Hole Dia. Output Shaft Dia. Center Distance
RV571 0.06KW~0.12KW 5~60 Φ9 Φ9 Φ11 Φ11 25mm
RV030 0.06KW~0.25KW 5~80 Φ9(Φ11) Φ9 Φ14 Φ14 30mm
RV040 0.09KW~0.55KW 5~100 Φ9(Φ11,Φ14) Φ11 Φ18(Φ19) Φ18 40mm
RV050 0.12KW~1.5KW 5~100 Φ11(Φ14,Φ19) Φ14 Φ25(Φ24) Φ25 50mm
RV063 0.18KW~2.2KW 7.5~100 Φ14(Φ19,Φ24) Φ19 Φ25(Φ28) Φ25 63mm
RV075 0.25KW~4.0KW 7.5~100 Φ14(Φ19,Φ24,Φ28) Φ24 Φ28(Φ35) Φ28 75mm
RV090 0.37KW~4.0KW 7.5~100 Φ19(Φ24,Φ28) Φ24 Φ35(Φ38) Φ35 90mm
RV110 0.55KW~7.5KW 7.5~100 Φ19(Φ24,Φ28,Φ38) Φ28 Φ42 Φ42 110mm
RV130 0.75KW~7.5KW 7.5~100 Φ24(Φ28,Φ38) Φ30 Φ45 Φ45 130mm
RV150 2.2KW~15KW 7.5~100 Φ28(Φ38,Φ42) Φ35 Φ50 Φ50 150mm

Product Description
Components:
1. Housing: Die-cast Aluminium Alloy Gearbox (RV571~RV090)Cast Iron Gearbox (RV110~RV150)
2. Worm Wheel: Wearable Tin Bronze Alloy, Aluminum Bronze Alloy
3. Worm Shaft: 20Cr Steel, carburizing, quenching, grinding, surface hardness 56-62HRC, 0.3-0.5mm remaining carburized layer after precise grinding
4. Input Configurations:
Equipped with Electric Motors (AC Motor, Brake Motor, DC Motor, Servo Motor)
IEC-normalized Motor Flange
Solid Shaft Input
Worm Shaft Tail Extension Input
5. Output Configurations:
Keyed Hollow Shaft Output
Hollow Shaft with Output Flange
Plug-in CZPT Shaft Output
6. Spare Parts: Worm Shaft Tail Extension, Single Output Shaft, Double Output Shaft, Output Flange, Torque Arm, Dust Cover
7. Gearbox Painting:
Aluminium Alloy Gearbox:
After Shot Blasting, Anticorrosion Treatment and Phosphating, Paint with the Color of RAL 5571 Gentian Blue or RAL 7035 Light Grey
Cast Iron Gearbox:
After Painting with Red Antirust Paint, Paint with the Color of RAL 5571 Gentian Blue
Models:
Hollow Shaft Input with IEC-normalized Motor Flange
RV571~RV150
Solid Shaft Input
RV571~RV150
Features:
1. Quality aluminum alloy gear box, light weight and not rust
2. 2 optional worm wheel materials: Tin bronze or aluminum bronze alloy
3. Standard parts and very flexible for shaft configurations and motor flange interface
4. Several optional mounting options
5. Low noise, High efficiency in heat dissipation

Worm Gearboxes in Conveyor Systems: Benefits and Considerations

Worm gearboxes play a crucial role in conveyor systems, offering several benefits and considerations for their effective integration:

  • Space Efficiency: Worm gearboxes have a compact design, making them suitable for applications with limited space, such as conveyor systems.
  • High Reduction Ratios: Worm gearboxes can achieve high reduction ratios in a single stage, allowing for slower conveyor speeds without sacrificing torque.
  • Self-Locking: Worm gearboxes have inherent self-locking properties, preventing the conveyor from moving when the motor is not actively driving it.
  • Directional Control: Worm gearboxes facilitate directional control, enabling the conveyor to move forward or reverse as needed.
  • Low Noise: Worm gearboxes often produce lower noise levels compared to other gearbox types, contributing to quieter conveyor operation.

However, there are also considerations to keep in mind when using worm gearboxes in conveyor systems:

  • Efficiency: Worm gearboxes may have lower mechanical efficiency compared to some other gearbox types, leading to energy losses.
  • Heat Generation: Worm gearboxes can generate more heat due to sliding contact between the worm and gear, necessitating proper cooling mechanisms.
  • Lubrication: Proper lubrication is critical to prevent wear and ensure efficient operation. Regular maintenance is required to monitor lubrication levels.
  • Load and Speed: Worm gearboxes are well-suited for applications with high torque and low to moderate speed requirements. They may not be optimal for high-speed conveyors.

Before integrating a worm gearbox into a conveyor system, it’s important to carefully consider the specific requirements of the application, including load, speed, space constraints, and efficiency needs. Consulting with gearbox experts and manufacturers can help ensure the right choice for the conveyor’s performance and longevity.

Application: Motor, Machinery
Hardness: Hardened Tooth Surface
Installation: 90 Degree
Layout: Coaxial
Gear Shape: Conical – Cylindrical Gear
Step: Stepless
Samples:
US$ 200/Piece
1 Piece(Min.Order)

|
Request Sample

Customization:
Available

|

Customized Request

How Does a Worm Gearbox Compare to Other Types of Gearboxes?

Worm gearboxes offer unique advantages and characteristics that set them apart from other types of gearboxes. Here’s a comparison between worm gearboxes and some other common types:

  • Helical Gearbox: Worm gearboxes have higher torque multiplication, making them suitable for heavy-load applications, while helical gearboxes are more efficient and offer smoother operation.
  • Bevel Gearbox: Worm gearboxes are compact and can transmit motion at right angles, similar to bevel gearboxes, but worm gearboxes have self-locking capabilities.
  • Planetary Gearbox: Worm gearboxes provide high torque output and are cost-effective for applications with high

    Maintenance Tips for Prolonging the Life of a Worm Gearbox

    Proper maintenance is essential to ensure the longevity and reliable performance of a worm gearbox. Here are some maintenance tips to consider:

    • Lubrication: Regularly check and replenish the lubricant in the gearbox. Use the recommended lubricant type and quantity specified by the manufacturer.
    • Lubrication Schedule: Follow a lubrication schedule based on the operating conditions and manufacturer recommendations. Regular lubrication prevents friction, reduces wear, and dissipates heat.
    • Temperature Monitoring: Keep an eye on the operating temperature of the gearbox. Excessive heat can degrade the lubricant and damage components.
    • Cleanliness: Keep the gearbox and surrounding area clean from debris and contaminants. Regularly inspect and clean the gearbox exterior.
    • Seal Inspection: Check for any leaks or damage to seals and gaskets. Replace them promptly to prevent lubricant leaks and contamination.
    • Alignment: Ensure proper alignment between the worm and worm wheel. Misalignment can lead to increased wear and reduced efficiency.
    • Torque Monitoring: Monitor the torque levels during operation. Excessive torque can cause overloading and premature wear.
    • Regular Inspections: Periodically inspect all components for signs of wear, damage, or unusual noise. Replace worn or damaged parts promptly.
    • Proper Usage: Operate the gearbox within its specified limits, including load, speed, and temperature. Avoid overloading or sudden changes in operating conditions.
    • Expert Maintenance: If major maintenance or repairs are needed, consult the manufacturer’s guidelines or seek the assistance of qualified technicians.

    By following these maintenance tips and adhering to the manufacturer’s recommendations, you can extend the lifespan of your worm gearbox and ensure its optimal performance over time.

    reduction ratios, whereas planetary gearboxes offer higher efficiency and can handle higher input speeds.

  • Spur Gearbox: Worm gearboxes have better shock load resistance due to their sliding motion, while spur gearboxes are more efficient and suitable for lower torque applications.
  • Cycloidal Gearbox: Cycloidal gearboxes have high shock load capacity and compact design, but worm gearboxes are more cost-effective and can handle higher reduction ratios.

While worm gearboxes have advantages such as high torque output, compact design, and self-locking capability, the choice between gearbox types depends on the specific requirements of the application, including torque, efficiency, speed, and space limitations.

China OEM Nmrv Worm Gearboxes Speed Reducer Gear Motor   gearbox adjustment	China OEM Nmrv Worm Gearboxes Speed Reducer Gear Motor   gearbox adjustment
editor by CX 2023-09-01

China Gearboxes Nmrv Worm Gearing Small Speed Reducer Helical Bevel Agricultural Planetary Gearbox double worm gearbox

Product Description

Gearboxes Nmrv Worm Gearing Little Pace Reducer Helical Bevel Agricultural Planetary Gearbox

US $10-999
/ Piece
|
100 Pieces

(Min. Order)

###

Application: Motor, Electric Cars, Motorcycle, Machinery, Marine, Agricultural Machinery, Car
Function: Distribution Power, Clutch, Change Drive Torque, Change Drive Direction, Speed Changing, Speed Reduction, Speed Increase
Layout: Coaxial
Hardness: Hardened Tooth Surface
Installation: Horizontal Type
Step: Three-Step

###

Samples:
US$ 9999/Piece
1 Piece(Min.Order)

|
Request Sample

US $10-999
/ Piece
|
100 Pieces

(Min. Order)

###

Application: Motor, Electric Cars, Motorcycle, Machinery, Marine, Agricultural Machinery, Car
Function: Distribution Power, Clutch, Change Drive Torque, Change Drive Direction, Speed Changing, Speed Reduction, Speed Increase
Layout: Coaxial
Hardness: Hardened Tooth Surface
Installation: Horizontal Type
Step: Three-Step

###

Samples:
US$ 9999/Piece
1 Piece(Min.Order)

|
Request Sample

Advantages and disadvantages of worm gear reducer gearbox

If you are looking for a worm gear reducer gearbox, you have come to the right place. This article will cover the pros and cons of worm gear reducer gearboxes and discuss the different types available. You will learn about multi-head worm gear reducer gearboxes, hollow shaft worm gear reducer gearboxes as well as hypoid gear sets and motors.
worm reducer

Hollow shaft worm gear reducer gearbox

Hollow shaft worm gear reducer gearboxes are used to connect two or more rotating parts. They are available in single-axis and dual-axis versions and can be connected to various motor types. They can also have different ratios. The ratios of these gear reducer gearboxes depend on the quality of the bearings and assembly process.
Hollow shaft worm gear reducer gearboxes are made of bronze worm gears and cast iron hubs. The gears are lubricated with synthetic oil. They are lightweight and durable. They can be installed in various engine housings. Additionally, these gear reducer gearboxes are available in a variety of sizes. The range includes 31.5, 40, 50, 63, and 75mm models. Other sizes are available upon request.
In addition to worm gear reducer gearboxes, there are also helical gear reducer gearboxes. These reducer gearboxes can achieve very low output speeds. They are also suitable for all-around installations. In addition, the advantage of a multi-stage reducer gearbox is that it is more efficient than a single-stage gear reducer gearbox. They also feature low noise, low vibration, and low energy consumption.
Hollow shaft worm gear reducer gearboxes are generally less expensive and last longer. They are also a suitable replacement for solid shaft gearboxes for machines that require high torque without compromising strength. Typical gear arrangements include worm, spur, helical and bevel gears. Gear ratio is the ratio of input torque to output torque.

Multi-head worm gear reducer gearbox

The multi-head worm gear reducer gearbox is used to reduce the speed of the machine. It uses friction to hold the worm in place while transmitting power. These gears can also be called ground worms and hardened worm gears. They are useful in conveying systems and most engineering applications.
Multiple worm reducer gearboxes have a large number of gear ratios. These gear designs have a central cross-section that forms the front and rear boundaries of the worm gear. This design is a better choice than other worm gears because it is less prone to wear and can be used with a variety of motors and other electronics.
Adjustable multi-head worm gear reducer gearbox to reduce axial play. Usually, the backlash on the left and right sides of the worm is the same. However, if you need less backlash, you can buy a double lead worm gear. This design is ideal for precision applications requiring small clearances. The lead of the opposing teeth of the double worm gear is different from the right side, so the backlash can be adjusted without adjusting the center distance between the worm gears.
Worm gear reducer gearboxes are available from a variety of manufacturers. Many gear manufacturers stock these gears. Since the gear ratios are standardized, there is no need to adjust the height, diameter, or length of the shaft. Worm gears have fewer moving parts, which means they require less maintenance.
worm reducer

Hypoid Gear Set

Worm gears are the most common type of gear. While these gears are great for high-to-low ratios, hypoid gear sets are much more efficient in all ratios. This difference is due to higher torque density, better geometry and materials, and the way hypoid gears transmit force differently than worm gears.
Hypoid gear sets have curved helical teeth. This results in smooth gear meshing and little noise. This is because the hypoid gears start to slowly contact each other, but the contact progresses smoothly from tooth to tooth. This reduces friction and wears, thereby increasing the efficiency of the machine.
The main advantages of hypoid gears over worm gears are higher torque capacity and lower noise levels. Although their upfront cost may be higher, hypoid gears are more efficient than worm gears. They are able to handle higher initial inertia loads and can deliver more torque with a smaller motor. This saves money in the long run.
Another advantage of hypoid gears is the lower operating temperature. They also do not require oil lubrication or ventilation holes, reducing maintenance requirements. The hypoid gear set is maintenance-free, and the grease on the hypoid gear set lasts for decades.

Hypoid gear motor

A hypoid gear motor is a good choice for a worm gear reducer gearbox as it allows for a smaller motor and more efficient energy transfer. In fact, a 1 hp motor driving a hypoid reducer gearbox can provide the same output as a 1/2 hp motor driving a worm reducer gearbox. A study by Agknx compared two gear reduction methods and determined that a hypoid gear motor produces more torque and power than a worm reducer gearbox when using a fixed reduction ratio of 60:1. The study also showed that the 1/2 HP hypoid gear motor is more energy efficient and reduces electricity bills.
Worm reducer gearboxes run hotter than hypoid gears, and the added heat can shorten their lifespan. This can cause components to wear out faster, and the motor may require more frequent oil changes. In addition, hypoid gear motors are more expensive to manufacture.
Compared to worm gears, hypoid gears offer higher efficiency and lower operating noise. However, they require additional processing techniques. They are made of bronze, a softer metal capable of absorbing heavy shock loads. Worm drives require work hardening and are less durable. Operating noise is reduced by up to 30%, and hypoid gears are less prone to breakage than bevel gears.
Hypoid gear motors are prized for their efficiency and are used in applications requiring lower torque. A unique hypoid tooth profile reduces friction. In addition, hypoid gear motors are ideal for applications where space is limited. These geared motors are often used with pulleys and levers.

R series worm gear reducer gearbox

R series worm gear reducer gearboxes have a variety of characteristics that make them ideal for different applications. Its high rigidity cast iron housing and rigid side gears are designed for smooth drive and low noise. It also features high load capacity and long service life. Additionally, it can be assembled into many different configurations as required.
High efficiency, large output torque and good use efficiency. It comes in four basic models ranging from 0.12KW to 200KW. It can be matched with right angle bevel gearbox to provide large speed ratio and high torque. This combination is also suitable for low output and high torque.
worm reducer

AGKNX Electric Worm Gear reducer gearbox

AGKNX Electric worm gear reducer gearboxes are available with NEMA C-face mounting flanges for a variety of motors. These reducer gearboxes feature double lip oil seals, an aluminum alloy housing, and two bearings on the input and output shafts. These reducer gearboxes are rust-proof and have epoxy paint on the inside. They are available in a variety of ratios, from 7.5:1 to 100:1.
Worm reducer gearboxes are one of the most cost-effective and compact gears. These reducer gearboxes increase output torque while reducing input speed. AGKNX Electric’s worm gear reducer gearboxes are pre-installed with Mobil SHC634 Synthetic Gear Oil. These reducer gearboxes have an internal oil gallery guide to protect the shaft. They also have a one-piece cast iron housing.
AGKNX Electric Corporation is the leading independent distributor of electric motors in the United States. They have eight strategically located warehouses, enabling them to ship most orders on the same day. They offer motors of various sizes up to 20,000 hp. They also offer a variety of motor controls and variable speed drives.
China Gearboxes Nmrv Worm Gearing Small Speed Reducer Helical Bevel Agricultural Planetary Gearbox     double worm gearboxChina Gearboxes Nmrv Worm Gearing Small Speed Reducer Helical Bevel Agricultural Planetary Gearbox     double worm gearbox
editor by czh 2023-02-05