Helical gears are one of the most common types of gears in mechanical transmissions, along with spur gears (spur gears). So what are the advantages and disadvantages of this type of gear? In what industrial applications is it used? Please refer to the article below from Nam Phuong Viet for a more general view of this type of gear.
What kind of gear is helical gear?
By definition, helical gears or spiral gears refer to gears with a cylindrical structure and grooves that are machined to the left or right depending on the design compared to the gear axis.
The characteristics of this type of gear are that the tooth grooves and gears have better meshing than spur gears. The noise is lower and the load capacity is also higher. Therefore, this type of helical gear is extremely suitable for applications requiring high transmission speeds.
Types of helical gears
Left helical gear
Left helical gears are the most common one-way helical gears, with teeth inclined to the left. This design allows the gear to handle heavy loads and operate smoothly, especially in systems requiring high speeds and high-power transmission.
Right helical gear
Similar to left helical gears, right helical gears are also common helical gears in transmission systems. These two types of gears are often used together to create meshing between the gears.
Double helical gear
Double helical gears are gears that have two sets of teeth that are inclined in opposite directions on the same gear.
The advantage of this design is to maintain the balance of the axial force generated during the transmission process, minimizing the axial thrust on the rotating shaft and bearings. Therefore, the transmission system using two-way helical gears often has high stability.
How to determine gear tilt direction
Determining the correct gear tilt direction will help the transmission system to be installed and operated correctly.
Currently, there are two basic tilt directions: left and right, according to the types that Nam Phuong Viet mentioned in the section on tilt gear classification. You can determine the tilt direction of the gear according to the following steps:
Step 1: Place the gear upright, perpendicular to your eyes
Step 2: Observe the tooth grooves on the surface of the gear:
- If you see the direction from the tooth root to the tooth tip-tilted to the left, then the gear has a left tilt direction.
- If you see the direction from the tooth root to the tooth tip-tilted to the right, then the gear has a right tilt direction.
In helical gear drive systems, the gear pair must be tilted in opposite directions to mesh properly. Otherwise, it can cause tooth slippage or unwanted axial forces.
Advantages and disadvantages of helical gears
Advantages of helical gears
Helical gears operate smoothly and quietly, thanks to the sequential contact between the teeth, which creates low play. This is a major advantage when compared to spur gears, especially in systems that require high quietness such as automotive gearboxes and precision equipment.
The high load capacity of helical gears, thanks to the helical tooth design increases the contact area when transmitting power by at least 33%. Ensures long service life even under continuous working conditions and high loads.
The helical gear drive system has high stability because the helical tooth design helps to distribute the impact force evenly throughout the drive process.
Helical gears have flexible transmission capabilities, they can transmit between parallel or non-parallel shafts (usually between crossed shafts at a 90° angle).
Disadvantages of helical gears
It is easy to generate axial thrust force pushing on the rotating shaft. If this force is not well controlled, it will cause wear and damage to the bearing, bend or deform the shaft, thereby reducing the transmission efficiency of the system.
Helical gears require precise machining and careful installation to ensure perfect fit and efficient operation.
High manufacturing costs, when it is necessary to use axial load bearing and high machining requirements.
Applications of helical gears in industry
Due to their good load capacity, high transmission efficiency and smooth operation, helical gears are used in many different industrial applications. The most common are:
- Gearboxes for automobiles, tractors, agricultural harvesters, etc.
- Main shaft systems of milling machines, lathes, CNC drilling machines and other mechanical processing machines.
- Wind turbines, industrial generators, and transmission systems for conveyor belts in power plants.
- Conveyors, robotic arms, lifting systems and machinery in factories manufacturing and assembling automobiles, electronics and consumer goods.
- Control gearboxes, actuators in aircraft and orientation control systems of satellites and spacecraft.
- Industrial reduction gearboxes
Guide to selecting, purchasing and maintaining helical gears
To ensure efficient and durable operation of helical gears, careful selection is required according to actual operating conditions and applications. At the same time, maintenance should also be performed periodically to extend the life of the equipment.
Guide to choosing to buy helical gear:
- Before purchasing or ordering helical gears, it is necessary to determine the application load to select the type of material to manufacture the gears:
- Steel materials are suitable for high-power and heavy-load applications
- Cast iron materials are used for moderate-load applications
- Engineering plastic materials should only be used in lightly loaded drive systems
- Determine the transmission ratio of the system, thereby determining the number of teeth and the required size of the gear.
- Determine the tilt direction of the gear
Helical gear maintenance instructions:
- Use a soft brush or compressed air to periodically clean the tooth surface to remove dirt and debris formed by long-term friction.
- During the cleaning process, do not forget to check the wear level of the teeth. If the wear is excessive, replace the new helical gear.
- After cleaning, apply lubricant to lubricate and reduce friction in the system.
- Finally, do not forget to check and tighten the bolts and nuts to avoid slipping or misalignment.
Some popular helical gear reducers
Nowadays, helical gears are widely used in speed reducers because of their high transmission capacity and high transmission efficiency. The most prominent are the planetary speed reducers of Apex Dynamics such as:
- Apex gearbox PAII Series
- Apex gearbox PAIIR Series
- Apex gearbox AB Series
- Apex gearbox ABR Series
- Apex gearbox AF Series
Helical gears are used in planetary gear mechanisms of gearboxes. Therefore, Apex gearboxes often have a 33% higher tooth contact ratio than other brands. At the same time, the noise level is also quite low, mostly below 70 dB, some even below 56 dB.
Above is the general information about helical gears. Hopefully, this information will be useful for your work. If you need to buy an Apex gearbox, please contact Nam Phuong Viet immediately to buy genuine products at the original price of a level 1 dealer.
