Silence Your Linear Actuator: Common Causes of Excessive Noise and How to Fix Them
Electric linear actuators are a crucial part of many automated processes in our daily lives. They can be integrated into various applications where noise sensitivity is critical, such as modern medical beds. When considering the types of actuators that provide noise containment, electric linear actuators are the best option. Compared to pneumatic systems, electric linear actuators emit less noise, making them the preferred choice in many areas, including medical facilities.
However, apart from their superiority over pneumatic systems, what can make a linear actuator sound different or operate louder than usual? Excessive noise is a complicated issue to address, as it can have multiple sources of the problem. This article will present some of the most common causes of excessive noise in linear actuators.
The main source of noise coming from an Actuator is the drive gears inside the actuator. There are several types of gear drive mechanisms commonly used inside them, and each of them can relate to the potential noise they create in different ways. Here are some examples:
- Spur Gears: These are the most common type of gears and are also the simplest. Spur gears have straight teeth and can create a lot of noise due to the teeth engaging abruptly.
- Helical Gears: These gears have angled teeth, which makes them quieter than spur gears because the engagement between the teeth is gradual.
- Bevel Gears: These gears are cone-shaped, and the teeth are cut along the sloping surface. They are quieter than spur gears but can create noise due to their complex geometry.
- Worm Gears: These gears have a helical gear wrapped around a cylindrical gear. They are very quiet and can transmit power at right angles, making them ideal for use in tight spaces.
- Planetary Gears: These gears have a central gear (the sun gear) that is surrounded by multiple smaller gears (the planet gears). They are often used in situations where high torque and efficiency are required but can create noise due to the complexity of their design.
|Gear Type||Expected Noise Level|
|Helical Gears||Low to Medium|
|Bevel Gears||Medium to High|
|Planetary Gears||Medium to High|
In general, gears with angled or helical teeth are quieter than gears with straight teeth, and the complexity of the gear design can also contribute to the amount of noise created. It is essential to choose the right gear drive mechanism based on your specific application to minimize noise and maximize efficiency.
One issue that can cause periodic mechanical noise when the actuator is moving is the imperfections of the lead screw and drive nut tolerance. This issue is more noticeable under heavy loads and can cause vibrations if the lead screw and nut do not mate well. If the lead screw and nut are too loose, it can cause extra noise and vibrations, while if they are too tight, it can cause friction and a drop in speed. This is a manufacturing issue and may be resolved by replacing the drive nut.
Another issue that can cause excessive noise is motor stator issues. The motor is held between two bearings, and if they are loose in their sockets, they can cause vibrations that lead to more noise in the gearbox or whining within the motor. Loose bearings can even lead to excessive current problems. This issue may be resolved by putting the bearings back inside their sockets and ensuring that they are entirely flat. It is best to replace the bearings completely, and sometimes replacing the whole actuator may be necessary.
Gearbox noise is also a common cause of excessive metal gear noise. If the gears inside the gearbox are not making proper contact, they can cause excessive noise. The gear spacing requirements could be violated due to manufacturing tolerances of the gears, or the rotor may be slightly tilted, affecting the gear gap. This issue may be resolved by purchasing a new set of replacement gears or checking the bearings on the rotor.
Insufficient grease in the gearbox can also cause excessive noise, and this is a manufacturing issue that should be resolved by the manufacturer. Adding grease to the gears can fix the problem or distributing the grease already inside the gearbox more evenly and efficiently.
In conclusion, electric linear actuators are usually chosen as a lower noise alternative to hydraulic and pneumatic actuators, but they can still be quite loud for several reasons. It is important to pay attention to the noise coming out of the actuators during operation, as this could indicate a serious manufacturing issue. If your linear actuator sound is irregular and making excessive noise, it is a good idea to investigate and repair/replace the damaged components.
What are all the different components in a linear actuator that can create noise
- Lead Screw and Drive Nut Tolerance: If the lead screw and nut do not mate well, it can cause periodic mechanical noise when the actuator is moving. If they are too loose, it can cause extra noise and vibrations, while if they are too tight, it can cause friction and a drop in speed.
- Motor Stator: If the bearings holding the motor in place are loose in their sockets, they can cause vibrations that lead to more noise in the gearbox or whining within the motor. Loose bearings can even lead to excessive current problems.
- Gearbox: If the gears inside the gearbox are not making proper contact, they can cause excessive noise. If the gear spacing requirements are violated due to manufacturing tolerances of the gears, or the rotor is slightly tilted, it can affect the gear gap.
- Insufficient Grease in the Gearbox: If there is not enough grease on the gears, the mechanical friction will be too high, and the gears will produce more noise, wear out faster, and vibrate.
It is essential to pay attention to the noise coming out of the actuators during operation, as this could indicate a serious manufacturing issue. If your linear actuator sound is irregular and making excessive noise, it is a good idea to investigate and repair/replace the damaged components.
Lead-screws also create some noise. There are several different types of lead screws, and each of them has different noise characteristics.
- Acme Thread Lead Screws: These lead screws have a trapezoidal thread profile that provides good accuracy and efficiency. They are commonly used in machine tools, robotics, and automation equipment.
- Square Thread Lead Screws: These lead screws have a square thread profile that provides excellent accuracy and is often used in high-precision applications such as optical instruments.
- Buttress Thread Lead Screws: These lead screws have a triangular thread profile with one side at a 45-degree angle, providing high load-carrying capacity and efficiency. They are commonly used in heavy-duty applications such as presses, jacks, and hoists.
- Worm Gear Lead Screws: These lead screws are used in applications where high gear reduction ratios are required. The thread profile is often trapezoidal, and the lead screw is paired with a worm gear.
- Ball Screw Lead Screws: These lead screws use a ball bearing system to reduce friction and improve efficiency. They are commonly used in high-precision applications such as CNC machines and aerospace equipment.
The choice of lead screw depends on the specific application and the desired characteristics such as load-carrying capacity, accuracy, and efficiency.
Here is a table to show the differences between them:
|Lead Screw Type||Thread Profile||Characteristics|
|Acme Thread Lead Screws||Trapezoidal||Good accuracy and efficiency. Commonly used in machine tools, robotics, and automation equipment.|
|Square Thread Lead Screws||Square||Excellent accuracy. Often used in high-precision applications such as optical instruments.|
|Buttress Thread Lead Screws||Triangular||High load-carrying capacity and efficiency. Commonly used in heavy-duty applications such as presses, jacks, and hoists.|
|Worm Gear Lead Screws||Trapezoidal||Used in applications where high gear reduction ratios are required. Often paired with a worm gear.|
|Ball Screw Lead Screws||Ball bearing system||High precision and efficiency. Commonly used in high-precision applications such as CNC machines and aerospace equipment.|
The motor stator in a DC motor can create noise depending on various factors such as speed and load.
At low speeds, the noise produced by the stator is usually minimal. However, as the speed increases, the noise can become more noticeable. This is because the magnetic field in the stator generates a force that interacts with the rotor, producing vibration and noise. The higher the speed, the greater the force and the more noise that is produced.
The noise level can also be affected by the load on the motor. As the load increases, the stator has to work harder to maintain the rotation of the rotor, which can lead to more noise being generated.
In addition to the stator, other components in the DC motor can also contribute to the overall noise level. For example, the brushes and commutator can produce noise due to their mechanical movement and contact. The gearbox can also create noise due to the meshing of gears and friction.
Overall, the noise level in a DC motor can be affected by various factors, including the speed, load, and other components in the motor.
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