Planetary Gear Reduction

Many “gears” are utilized for automobiles, but they are also used for many additional machines. The most typical one may be the “transmission” that conveys the power of engine to tires. There are broadly two functions the transmission of a car plays : one can be to decelerate the high rotation acceleration emitted by the engine to transmit to tires; the various other is to improve the reduction ratio in accordance with the acceleration / deceleration or traveling speed of an automobile.
The rotation speed of an automobile’s engine in the general state of driving amounts to 1 1,000 – 4,000 rotations per minute (17 – 67 per second). Because it is impossible to rotate tires with the same rotation velocity to run, it is required to lower the rotation speed utilizing the ratio of the number of gear teeth. This kind of a role is called deceleration; the ratio of the rotation rate of engine and that of tires is called the reduction ratio.
Then, exactly why is it necessary to alter the reduction ratio relative to the acceleration / deceleration or driving speed ? The reason being substances require a large force to begin moving however they usually do not require this kind of a big force to excersice once they have began to move. Automobile could be cited as an example. An engine, nevertheless, by its character can’t so finely change its output. As a result, one adjusts its output by changing the reduction ratio employing a transmission.
The transmission of motive power through gears quite definitely resembles the principle of leverage (a lever). The ratio of the number of the teeth of gears meshing with one another can be deemed as the ratio of the length of levers’ arms. That’s, if the decrease ratio is huge and the rotation rate as output is lower in comparison to that as input, the energy output by tranny (torque) will be huge; if the rotation acceleration as output isn’t so low in comparison compared to that as insight, however, the power output by transmission (torque) will be little. Thus, to improve the reduction ratio utilizing transmission is much akin to the theory of moving things.
After that, how does a transmission modify the reduction ratio ? The Planetary Gear Reduction answer lies in the mechanism called a planetary equipment mechanism.
A planetary gear system is a gear mechanism consisting of 4 components, namely, sunlight gear A, several planet gears B, internal gear C and carrier D that connects world gears as seen in the graph below. It has a very complex structure rendering its design or production most difficult; it can realize the high decrease ratio through gears, nevertheless, it is a mechanism suitable for a reduction system that requires both little size and high performance such as transmission for automobiles.
In a planetary gearbox, many teeth are engaged at once, which allows high speed decrease to be performed with fairly small gears and lower inertia reflected back to the motor. Having multiple teeth share the load also enables planetary gears to transmit high levels of torque. The combination of compact size, large speed reduction and high torque transmission makes planetary gearboxes a popular choice for space-constrained applications.
But planetary gearboxes perform involve some disadvantages. Their complexity in design and manufacturing tends to make them a far more expensive answer than additional gearbox types. And precision manufacturing is really important for these gearboxes. If one planetary gear is put closer to the sun gear than the others, imbalances in the planetary gears can occur, leading to premature wear and failure. Also, the small footprint of planetary gears makes warmth dissipation more difficult, so applications that operate at high speed or encounter continuous operation may require cooling.
When using a “standard” (i.electronic. inline) planetary gearbox, the motor and the powered equipment should be inline with each other, although manufacturers offer right-angle designs that include other gear sets (frequently bevel gears with helical teeth) to provide an offset between your input and output.
Input power (max)27 kW (36 hp)
Input speed (max)2800 rpm2
Output torque (intermittent)12,880 Nm(9,500 lb-ft)
Output torque (continuous)8,135 Nm (6,000 lb-ft)
1 Actual ratio would depend on the drive configuration.
2 Max input speed linked to ratio and max output speed
3 Max radial load placed at optimum load position
4 Weight varies with configuration and ratio selected
5 Requires tapered roller planet bearings (not available with all ratios)
Approximate dry weight100 -181 kg (220 – 400 lb)4
Radial load (max)14,287kg (31,500 lb)3
Drive typeSpeed reducer
Hydraulic motor input SAE C or D hydraulic
Precision Planetary Reducers
This standard range of Precision Planetary Reducers are perfect for use in applications that demand high performance, precise positioning and repeatability. They were specifically developed for make use of with state-of-the-art servo motor technology, providing tight integration of the engine to the unit. Design features include mounting any servo motors, standard low backlash, high torsional stiffness, 95 to 97% efficiency and calm running.
They are available in nine sizes with decrease ratios from 3:1 to 600:1 and result torque capacities up to 16,227 lb.ft. The output can be provided with a solid shaft or ISO 9409-1 flange, for installation to rotary or indexing tables, pinion gears, pulleys or other drive elements without the need for a coupling. For high precision applications, backlash levels right down to 1 arc-minute are available. Right-angle and input shaft versions of these reducers are also available.
Normal applications for these reducers include precision rotary axis drives, traveling gantries & columns, materials handling axis drives and electronic line shafting. Industries offered include Material Managing, Automation, Aerospace, Machine Tool and Robotics.
Unit Design &
Construction
Gearing: Featuring case-hardened & floor gearing with minimal wear, low backlash and low noise, making them the the majority of accurate and efficient planetaries obtainable. Standard planetary design has three planet gears, with an increased torque version using four planets also offered, please start to see the Reducers with Result Flange chart on the machine Ratings tab beneath the “+” unit sizes.
Bearings: Optional output bearing configurations for software specific radial load, axial load and tilting minute reinforcement. Oversized tapered roller bearings are regular for the ISO Flanged Reducers.
Housing: Single piece steel housing with integral ring gear provides greater concentricity and remove speed fluctuations. The casing can be installed with a ventilation module to improve input speeds and lower operational temperatures.
Output: Available in a good shaft with optional keyway or an ISO 9409-1 flanged interface. You can expect a wide variety of standard pinions to attach right to the output style of your choice.
Unit Selection
These reducers are typically selected based on the peak cycle forces, which often happen during accelerations and decelerations. These cycle forces depend on the powered load, the acceleration vs. period profile for the cycle, and any other exterior forces functioning on the axis.
For application & selection assistance, please call, fax or email us. Your application details will be examined by our engineers, who will recommend the very best solution for the application.
Ever-Power Automation’s Gearbox products offer high precision in affordable prices! The Planetary Gearbox item offering contains both In-Line and Right-Position configurations, built with the design goal of offering a cost-effective gearbox, without sacrificing quality. These Planetary Gearboxes can be found in sizes from 40mm to 180mm, ideal for motors ranging from NEMA 17 to NEMA 42 and bigger. The Spur Gearbox collection provides an efficient, cost-effective option compatible with Ever-Power Automation’s AC Induction Gear Motors. Ever-Power Automation’s Gearboxes can be found in up to 30 different equipment ratios, with torque rankings up to 10,488 in-pounds (167,808 oz-in), and so are appropriate for most Servo,
SureGear Planetary Gearboxes for Small Ever-Power Motors
The SureGear PGCN series is a good gearbox value for servo, stepper, and other motion control applications requiring a NEMA size input/output interface. It offers the best quality available for the price point.
Features
Wide range of ratios (5, 10, 25, 50, and 100:1)
Low backlash of 30 arc-min or less
20,000 hour service life
Maintenance free; requires no additional lubrication
NEMA sizes 17, 23, and 34
Includes hardware for installation to SureStep stepper motors
Optional shaft bushings available for mounting to other motors
1-year warranty
Applications
Material handling
Pick and place
Automation
Packaging
Other motion control applications requiring a Ever-Power input/output
Spur gears are a type of cylindrical equipment, with shafts that are parallel and coplanar, and tooth that are straight and oriented parallel to the shafts. They’re arguably the simplest and most common kind of gear – easy to manufacture and suitable for an array of applications.
One’s teeth of a spur gear ‘ve got an involute profile and mesh one particular tooth simultaneously. The involute type means that spur gears simply generate radial forces (no axial forces), nevertheless the method of tooth meshing causes ruthless on the gear the teeth and high sound creation. Because of this, spur gears are often utilized for lower swiftness applications, although they could be utilized at almost every speed.
An involute gear tooth carries a profile this is the involute of a circle, which implies that since two gears mesh, they speak to at a person point where in fact the involutes satisfy. This aspect actions along the tooth areas as the gears rotate, and the type of force ( referred to as the line of activities ) is certainly tangent to both bottom circles. Hence, the gears adhere to the fundamental regulation of gearing, which statements that the ratio of the gears’ angular velocities must stay continuous through the entire mesh.
Spur gears could possibly be produced from metals such as metallic or brass, or from plastics such as nylon or polycarbonate. Gears manufactured from plastic produce much less audio, but at the difficulty of power and loading capacity. Unlike other equipment types, spur gears don’t encounter high losses due to slippage, therefore they often have high transmission overall performance. Multiple spur gears can be utilized in series ( known as a equipment teach ) to attain large reduction ratios.
There are two primary types of spur gears: external and internal. Exterior gears possess the teeth that are cut externally surface area of the cylinder. Two exterior gears mesh with one another and rotate in opposite directions. Internal gears, in contrast, have the teeth that are cut on the inside surface of the cylinder. An exterior gear sits within the internal gear, and the gears rotate in the same direction. Because the shafts are positioned closer together, internal gear assemblies are more compact than external equipment assemblies. Internal gears are mainly used for planetary gear drives.
Spur gears are usually viewed as best for applications that want speed reduction and torque multiplication, such as ball mills and crushing gear. Examples of high- velocity applications that make use of spur gears – despite their high noise amounts – include consumer devices such as washing machines and blenders. And while noise limits the use of spur gears in passenger automobiles, they are generally used in aircraft engines, trains, and even bicycles.