How to Choose Planetary Gearbox for a Concrete Mixer?
What is a Planetary Gearbox?
The planetary gearbox is a system that revolves a number of planetary gears around the sun gear. It’s also a way to lower the gearbox ratio while increasing the motor torque proportionally.It boasts a reliable transmission, a big bearing capacity, a large transmission ratio, a long service life, a small volume, and a beautiful look, among other things.Planetary gears are frequently used in manufacturing, automobiles, and other sectors.
The acceleration hub of a bicycle is an outstanding example of a planet-wheel mechanism: Have you ever wondered how such a small hub can pack so much power and capability? A one-stage planetary gear system is utilised in a three-speed hub, whereas a two-stage is used in a five-speed hub. A reduction state, direct coupling, and acceleration mode are all present in each planet’s gear system.
Where Are Planetary Gears Used?
Because planetary gears are often smaller than other types of gearboxes, they are employed in applications where space is limited.
They also serve as the foundation for the hydraulic planetary automatic gearbox, which is the most prevalent type of automatic transmission. Planetary gears are used in the majority of current automatic transmissions in the automotive industry.
Planetary gears are also utilised in augers and wind turbines, as well as in helicopter and aircraft engine in-vehicle drive systems.
Industrial machinery, such as guided robots, laser cutting machines, and even hospital operating tables, use planetary gear systems. There’s also a good probability that the sandwich meat in your fridge was chopped with a planetary gear cutter.
Planetary gears are used in passenger automobiles with automatic gearboxes.
What Is a Gearbox for Concrete Mixer?
The planetary concrete mixer is a relatively new type of mixing equipment. The product features an unusual mixing method. In the kettle, there are 2 or 3 multi-layer paddle agitators and 1 or 2 automatic scrapers.
While the agitator rotates around the axis of the kettle body, it also rotates at varying speeds around its own axis. such that the materials in the kettle body make complicated movements and are severely sheared and kneaded. Its efficiency is usually many times higher than that of a typical mixer.
Why does the Gearbox Use for a Concrete Mixer?
The main engine of the planetary concrete mixer is a planetary gear reducer. The planetary gearbox is the most significant core component of the planetary concrete mixer.
1.Gearbox transmission structure
A gearbox, sometimes known as a transmission, is a device that converts speed and torque from a rotating power source to another device using gears and gear trains. Gearboxes are used to transform input from high-speed power sources to low-speed (for example, lifts, cranes, and crushing machines) or multiple speeds (Lathe, Milling Machine and Automobiles).
A single stage gearbox is a gearbox that turns a high-speed input into a single output. It normally has two shafts and two gears.
A multi-speed gearbox is a gearbox that converts a high-speed input into a variety of different speed outputs. There are more than two gears and shafts in a multi-speed gearbox. A multi-speed gearbox slows down the vehicle in stages.
Assuming that ‘n’ speed must be obtained from a single input, meshing ‘n’ pairs of gears in two shafts is not viable to achieve the requisite speed. The greatest number of speeds that two shafts can produce is three. As a result, intermediate shafts must be used between the input and output shafts. The structural formula aids in determining the number of stages and gears required to achieve the specified speeds.
2.Gearbox reduction ratio
To reduce the output speed of the motor, reduction gearboxes, also known as torque multipliers or speed reducers, are used. Reduction gearboxes, such as the gear train between a motor and machinery, are quite simple to make.
The output gear’s ratio to the input gear allows the output shaft to rotate more slowly, resulting in increased torque and reduced speed.
The smallest reduction ratio is 3: 1 and the greatest is 10: 1. The sun gear gets too huge versus the planet gears when the ratio is less than 3. The sun wheel becomes too small at a ratio larger than 10, and the torque drops. The ratios are normally exact, that is, they are integers.
3.Rated working ratio of reducer
The reducer’s maximum rated input speed is 18000rpm (depending on the size of the reduction). The lower the rated input speed, the greater the reducer. An industrial planetary reducer’s output torque is usually less than 2000 Nm.
The Super torque planetary reducer, in particular, can reach more than 10000nm. Working temperatures range from – 25 to 100 degrees Celsius. Changing the oil might alter the working temperature.
4.Planetary gearbox stage
The number of sets refers to the number of stages in planetary gears. Because planetary gears are incapable of meeting the demands of a large transmission ratio.
To achieve the requirements of sustaining a large transmission ratio, two or three sets are sometimes required. The length of a 2-stage or 3-stage reducer will increase as the number of planetary gears increases, and the efficiency will decrease.
Low speed shaft designs include cylindrical with key, splined, hollow with shrink disc, and splined hollow shaft in 3 stage planetary gearboxes.
A high capacity output bearing is in a three-stage planetary gearbox. As a result, all three-stage planetary gearboxes have a large axial and radial capacity. They are also resistant to tilting moments, boosting the gearbox’s durability and efficiency.
As a quality-conscious planetary gearbox manufacturer, we meticulously machine the tooth profiles of all three-stage planetary gearboxes to ensure quiet operation.
We can machine any flange, foot, or shaft mounting solution to your exact specifications.Before being shipped, each gearbox item is subjected to a thorough quality inspection.You can select from a wide range of speed and torque outputs with your planetary gear calculator. The modular nature of our three-stage planetary gearboxes allows for easy customization.
A strong and stable support is also included with every three-stage planetary gearbox. As a result, each gear box has a high torsion rigidity.
Advantages of Concrete Mixer Planetary Gearbox
A concrete mixer’s vertical planetary gearbox offers a reliable transmission and excellent efficiency. A transmission hard tooth surface reducer is sturdy and long-lasting. It provides the advantages of minimal noise, high torque, and low maintenance cost at the same time.
- Input and output shafts are arranged coaxially.
- distributing loads to many planetary gears
- Low rolling power results in high efficiency.
- Due to the combination of numerous planet phases, there are nearly infinite transmission ratio options.
- Because this or that component of the gearbox is fixed, it is suitable as planetary switching gear.
- Use as an overriding gearbox is possible.
- Optimal volume output
- Applicability in a wide range of situations
How to Choose a Planetary Gearbox for a Concrete Mixer？
The main bearing, in particular, has a strong capability of supporting vertical and horizontal loads conveyed by the drum due to its oblique contact with a high sweep angle. Furthermore, the gear’s proportions ensure optimal function reliability throughout the mixer’s life, even under difficult operating conditions.
Based on the size, rated power, and output capacity of the concrete mixer, select the right planetary gearbox model. The gearbox for a concrete mixer is typically 250L-3000L in output capacity, with specific sizes available for particular output capacities.
The following are the stages involved in selecting a planetary gearbox. The following parameters should be understood before beginning the selection of a Planetary Gearbox.
- Torque to be transmitted (output torque)
- Motor Power (kW)
- Input speed (RPM)
- Output speed (RPM)
- Operating condition (i.e. Number of start-ups per hour and its impact)
- Ambient temperature (°C)
- Radial load on output shaft and, if needed, input shaft thrust load.
The Steps of Choosing Planetary Gearbox for a Concrete Mixer
STEP 1: Select the reduction ratio
Input Speed/Output Speed can be used to compute the reduction ratio.
If the output torque is unknown, the torque can be determined using the formula:
STEP 2: Calculate the output Torque(Nm)
Output torque = (P x 9546)/N
Where P is Power in kW (multiply P with 0.746 if power is in HP)
N is output speed (RPM)
STEP 3: Find the service Factor
Assume the service factor depending on the type of application and working hours. The Top Gear catalogue mentions it.
STEP 4: Calculate the Rated Torque
Rated torque = Calculated output torque * service factor
STEP 5: From the Catalogue, choose a Model.
- Determine the Gearbox’s life based on operating hours and output speed (n2h)
- Select the most appropriate model based on rated torque and lifespan.
STEP 6: Check the thermal rating of the model you’ve chosen.
The continuous power transmitted by a gear unit with splash lubrication and a maximum oil temperature of 90° C at an ambient temperature of 25° and an input speed of 1440 RPM is referred to as the thermal rating.
Following the model selection, the thermal capacity of the reducer thermal rating must be checked (Kw)
STEP 7: Verification of hollow frame
If the selected planetary gearbox is required in a hollow input arrangement, the frame size must be confirmed. Check to see if the frame size for a certain model is appropriate for the motor’s rated power.
STEP 8: Check for Overhang Load
When the output is coupled to a sprocket, pulley, timing belt, gear, or friction wheel, radial load is generated on the shaft. Which must be examined for overhang load capability at high and low speeds.
What are the Problems Easily Caused by Planetary Gearboxes?
Depending on the number of speeds, planetary gearboxes employ one or two epicyclic gear trains (for automobile gearboxes). The main disadvantages of using a planetary gearbox stem from its nature as a mechanism.
1.Two degree of freedom transmission system
It’s a two-degree-of-freedom transmission system that requires two inputs to achieve the required gear ratio; for example, solar input and locked ring gear, locked solar and input by planetary carrier, and so on.
2.Clutches, brakes, hydraulic system
As a result, extra components, such as clutches, brakes, and hydraulic systems, are designed and implemented to assist in engaging the target speed. As a result, the complexity of the gearbox system grows, as does the quantity of stock parts.
3.Operating perspective
Unless the power fluid and transmission oil have separate systems. The lubricating oil must be a compromise between the requirements of power transmission fluid for the hydraulic system and the necessity to keep asperities in the localised rolling contacts of the gear faces and bearings apart. Not to add that, despite good filtering meshes, the clutch and brake lining material accelerates the rate of oil contamination.
4.Gear design
Incorrect parameter selection, insufficient coincidence, tooth profile alteration that is insufficient or non-existent, and so on.
Because the pitch and tooth profile defects are so large, gear processing should be avoided. The tooth side clearance, as well as the surface roughness, are both high.
5.Gear train and transmission
Insufficient shaft, bearing, and support stiffness, low rotation accuracy, and inappropriate bearing clearance, among other things. The assembly eccentricity, poor contact precision, and shaft parallelism
6.Input torque in other aspects
Due to detent torque and other losses, stepper motor torque falls fast as speed increases. Because of the inverse relationship between speed and torque, increasing speed only goes so far until the motor can’t deliver the required torque (even when multiplied by the gear ratio).
Conclusion
The outcome should determine the type of planetary gearbox to use, as well as its size and gearing ratio. It’s a delicate balancing act of size, efficiency, performance, and price. We use a consultative approach to design . We begin each job by gaining a thorough grasp of the application, as well as the machine’s speeds, torque, and function.
We apply our knowledge and experience to find and deliver a cost-effective and dependable planetary gear solution. Each gearbox we provide will provide years of trouble-free service. Lancereal remains at the forefront of gearbox technology because to a mix of engineering excellence and continuous innovation.
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