Gear Reducer
Gear reducers are also called speed reducers. Either of these two mechanical attachments is designed to reduce the rotational speed transmitted between the motor and the machinery it drives. In the world of mechanical power transmission, there are many moving parts, and things will quickly become complicated. Gear reducers are an essential part of these compound machines that transfer power from the prime mover to the load. This article will focus on some basic knowledge about gear reducers. We will discuss their different types and some significant applications.
What is a Gear Reducer
A gear reducer slows down the speed produced by the motor to control the speed at which the machine operates and, at the same time, boosts the torque produced by the motor. Multiplying the torque the motor generates will increase the machine’s available power, which is said to make a “mechanical advantage.”
On a larger scale, gear reducers are tools for improving the efficiency of facility operations. Gear reducers often use rollers and screw shafts to work more efficiently by gaining mechanical advantage. Electric motors are usually designed to run at a specific RPM. Although this speed can be adjusted by using a variable frequency drive, in many cases, it is more advantageous to use a particular set of gears to adjust the speed. Output speed, thereby increasing torque.
What are Gear Reducers used for
A gear reducer, also known as a gearbox or transmission, is a gear system that reduces the input rotational speed and redirects it to another component at a lower speed and higher torque. It reduces the speed to avoid losing control in rotating systems, such as from the car’s engine to the wheels. The gear reducer changes the energy input by changing the rotation ratio of two mechanical parts.
There are different types of gear reducers for various industries and applications. Gear reducers operate all kinds of industrial and household machines, automotive, bicycle, and conveyor systems that require a safe and effective reduction in motor speed. As a gearbox system, the reducer gearbox is noticeable due to its complexity. Various reducer system designs can be provided according to the needs and specifications of different applications.
How to choose the right Gear Reducer
In a given application, many factors affect the choice of gearbox. The required ratio, speed, power, and torque must be considered not only continuous torque but also repetitive peak torque, acceleration torque, and braking torque.
However, many factors affect the selection of the most suitable gearbox, including shaft alignment, duty cycle, backlash, efficiency, installation arrangement, size, weight, noise, transmission stability, service life, and maintenance requirements. So, let’s look at various standard gearbox arrangements and check their characteristics, advantages, and disadvantages.
Spur gear reducer
The spur gear reducer represents the most straightforward type of gearbox. It can handle high transmission ratios with efficiencies close to 100 percent. However, this type of gear reducer is very loud and can only be used when the noise is acceptable. A reducer is a housing that contains two or more sets of gears (depending on the desired ratio), supporting bearings, shafts, and seals. The housing also includes gear and bearing lubricants. The reducer comes in many materials, styles, and configurations. The reducer utilizes various gears, including worm, spiral, bevel, and planet gears.
These gears can only mesh correctly if they are mounted on parallel shafts. They can handle high gear ratios and provide over ninety percent efficiency. The disadvantage of spur gears is that the teeth suddenly meet in straight line contact over the entire width, causing stress and noise. This noise is particularly troublesome when driving at high speeds. Therefore, spur gears are often used in low-speed applications where noise control is not a problem.
Worm gear reducer
The worm gear reducer is a right angle reducer that generates less noise and vibration as most contact created is a sliding motion. Worm gear reducers have been used for driving sources in the past, but due to poor transmission efficiency, they have mostly been replaced with orthogonal axes gear reducers by now.
The worm gear includes the worm itself and meshes with an ordinary gear appearance. They provide a simple, compact way to achieve high torque and low-speed gear ratios. However, the disadvantage is that the efficiency is much lower, and the efficiency may be as low as 50%.
Helical gear reducer
Here, the leading edge of the tooth is not parallel to the axis of rotation but at a certain angle. The gear is curved, and its tooth profile is described as a spiral. Helical gears can mesh in parallel or cross, but the load capacity of helical gears is significantly reduced. In helical gear reducers, the gears are usually locked at 90 degrees. They are generally in a parallel or crossing position. Parallel gear reducers have a higher load capacity than cross-gear reducers. A helical gear reducer is much quieter than a spur gear reducer during operation due to its helical gear design.
The following helical gear reducers have different variations. Helical gear reducers are more efficient and can withstand higher suspended loads. Online gearboxes are cheaper than parallel shaft gearboxes, but parallel shafts have more flexibility and options. Spiral reducers are used in higher-power applications where long-term operating efficiency is more important than the initial cost. This gear reducer is ideal for heavy loads because of its rigidity and robustness.
Planetary gear reducer
This gear reducer is characterized by a gear orbiting around the sun gear. It is compact and can handle high ratios, thus transmitting a lot of torque. It is effective even at low speeds. One of the advantages is its unique combination of compactness and excellent power transmission efficiency. The typical efficiency loss in a planetary gear reducer device is only 3% per stage. This efficiency ensures that most of the energy input to the reducer is multiplied and transferred to torque rather than wasted on mechanical losses inside the gearbox.
Another advantage of the planetary gear unit is load distribution. The transmitted load is shared among multiple gears, leading to significantly increased torque capacity. Planetary gearboxes are very efficient, even at low speeds. They provide a high transmission ratio per stage. They are highly compact and capable of transmitting three times the torque of a conventional spur gearbox of similar size because the transmitted load is shared on multiple planets. The multi-stage planetary gearbox can provide a very high transmission ratio, and the efficiency loss per stage is only around two percent.
Bevel Gear Reducer
Bevel gears provide another option: a gear in which two shafts intersect, and the tooth surface of the gear itself is shaped like a cone. This design offers maximum flexibility in the angle between the shafts, although the most common one is ninety degrees. The considerations for specifying bevel gears are that the gears must be installed accurately and the shaft can withstand large forces.
Noise at higher speeds is also a problem. The efficiency is lower than the gear design discussed, usually around 95 percent. However, they can handle lower gear ratios with higher efficiency, better than helical gear designs. These gears are generally only used at lower speeds.