planetary gear reduction

Many “gears” are utilized for automobiles, however they are also used for many various other machines. The most typical one is the “transmitting” that conveys the energy of engine to tires. There are broadly two roles the transmission of a car plays : one can be to decelerate the high rotation rate emitted by the engine to transmit to tires; the various other is to improve the reduction ratio relative to the acceleration / deceleration or traveling speed of an automobile.
The rotation speed of an automobile’s engine in the general state of traveling 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 acceleration to run, it is necessary to lessen the rotation speed using the ratio of the amount of gear teeth. Such a role is named deceleration; the ratio of the rotation swiftness of engine and that of tires is named the reduction ratio.
Then, why is it necessary to change the reduction ratio in accordance with the acceleration / deceleration or driving speed ? This is because substances need a large force to begin moving however they do not require such a big force to keep moving once they have started to move. Automobile could be cited as a good example. An engine, nevertheless, by its character can’t so finely modify its output. Consequently, one adjusts its output by changing the decrease ratio employing a transmission.
The transmission of motive power through gears quite definitely resembles the principle of leverage (a lever). The ratio of the amount of the teeth of gears meshing with one another can be deemed as the ratio of the space of levers’ arms. That is, if the reduction ratio is large and the rotation swiftness as output is lower in comparison compared to that as insight, the power output by tranny (torque) will be large; if the rotation speed as output isn’t so lower in comparison to that as insight, however, the power output by transmission (torque) will be little. Thus, to improve the decrease ratio utilizing tranny is much comparable to the theory of moving things.
Then, how does a transmitting modify the reduction ratio ? The answer is based on the system called a planetary equipment mechanism.
A planetary gear mechanism is a gear system comprising 4 components, namely, sunlight gear A, several planet gears B, internal gear C and carrier D that connects planet gears as observed in the graph below. It has a very complex structure rendering its design or production most difficult; it can recognize the high decrease ratio through gears, however, it is a mechanism suited to a reduction system that requires both little size and high performance such as transmission for automobiles.
In a planetary gearbox, many teeth are involved at once, which allows high speed reduction to be performed with relatively small gears and lower inertia reflected back again to the motor. Having multiple teeth share the load also allows planetary gears to transmit high levels of torque. The mixture of compact size, huge speed decrease and high torque tranny makes planetary gearboxes a favorite choice for space-constrained applications.
But planetary gearboxes perform have some disadvantages. Their complexity in design and manufacturing tends to make them a more expensive remedy than various other gearbox types. And precision production is extremely important for these gearboxes. If one planetary gear is positioned closer to the sun gear compared to the others, imbalances in the planetary gears can occur, leading to premature wear and failure. Also, the small footprint of planetary gears makes heat dissipation more difficult, therefore applications that operate at very high speed or experience continuous procedure may require cooling.
When using a “standard” (i.electronic. inline) planetary gearbox, the motor and the driven equipment should be inline with one another, although manufacturers offer right-angle designs that integrate other gear sets (often bevel gears with helical teeth) to provide an offset between the 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 related to ratio and max output speed
3 Max radial load positioned 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 electric 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. Style features include mounting any servo motors, standard low backlash, high torsional stiffness, 95 to 97% efficiency and noiseless running.
They can be purchased in nine sizes with decrease ratios from 3:1 to 600:1 and output torque capacities up to 16,227 lb.ft. The output can be provided with a solid shaft or ISO 9409-1 flange, for mounting to rotary or indexing tables, pinion gears, pulleys or other drive elements with no need for a coupling. For high precision applications, backlash levels down to 1 arc-minute can be found. Right-angle and input shaft versions of these reducers are also obtainable.
Common applications for these reducers include precision rotary axis drives, traveling gantries & columns, material handling axis drives and electronic line shafting. Industries offered include Material Handling, Automation, Aerospace, Machine Tool and Robotics.
Unit Design &
Construction
Gearing: Featuring case-hardened & surface gearing with minimal use, low backlash and low noise, making them the most accurate and efficient planetaries obtainable. Standard planetary design has three planet gears, with a higher torque edition using four planets also available, please see the Reducers with Output Flange chart on the Unit Ratings tab beneath the “+” unit sizes.
Bearings: Optional result bearing configurations for app specific radial load, axial load and tilting minute reinforcement. Oversized tapered roller bearings are standard for the ISO Flanged Reducers.
Housing: Single piece metal housing with integral ring gear provides higher concentricity and eliminate speed fluctuations. The housing can be fitted with a ventilation module to increase input speeds and lower operational temperature ranges.
Result: Available in a good shaft with optional keyway or an ISO 9409-1 flanged interface. You can expect an array of standard pinions to mount directly to the output style of your choice.
Unit Selection
These reducers are usually selected predicated on the peak cycle forces, which often happen during accelerations and decelerations. These cycle forces depend on the powered load, the quickness vs. period profile for the routine, and any other external forces acting on the axis.
For application & selection assistance, please call, fax or email us. The application info will be examined by our engineers, who’ll recommend the best solution for the application.
Ever-Power Automation’s Gearbox product lines offer high precision at affordable prices! The Planetary Gearbox product offering contains both In-Line and Right-Angle 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, perfect for motors ranging from NEMA 17 to NEMA 42 and bigger. The Spur Gearbox collection offers an efficient, cost-effective choice appropriate for Ever-Power Automation’s AC Induction Gear Motors. Ever-Power Automation’s Gearboxes are offered in up to 30 different equipment ratios, with torque rankings up to 10,488 in-lbs (167,808 oz-in), and so are appropriate for most Servo,
SureGear Planetary Gearboxes for Little 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 designed 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
Additional motion control applications requiring a Ever-Power input/output
Spur gears are a type of cylindrical gear, with shafts that are parallel and coplanar, and the teeth that are directly and oriented parallel to the shafts. They’re arguably the easiest and most common type of gear – simple to manufacture and ideal for an array of applications.
One’s tooth of a spur gear have got an involute profile and mesh one tooth at the same time. The involute type implies that spur gears just generate radial forces (no axial forces), nevertheless the approach to tooth meshing causes high pressure on the gear the teeth and high noise creation. For this reason, spur gears are often used for lower swiftness applications, although they could be utilized at almost every speed.
An involute products tooth includes a profile this is the involute of a circle, which means that since two gears mesh, they speak to at a person point where the involutes satisfy. This aspect motions along the tooth areas as the gears rotate, and the type of force ( known as the line of actions ) is definitely planetary gear reduction tangent to both foundation circles. Therefore, the gears adhere to the essential regulation of gearing, which promises that the ratio of the gears’ angular velocities must stay continuous throughout the mesh.
Spur gears could be produced from metals such as for example metal or brass, or from plastics such as nylon or polycarbonate. Gears produced from plastic produce less audio, but at the difficulty of power and loading capacity. Unlike other gear types, spur gears don’t encounter high losses due to slippage, therefore they often times have high transmission overall performance. Multiple spur gears can be employed in series ( known as a gear teach ) to achieve large reduction ratios.
There are two primary types of spur gears: external and internal. Exterior gears possess one’s teeth that are cut externally surface of the cylinder. Two exterior gears mesh with each other and rotate in reverse directions. Internal gears, on the other hand, have the teeth that are cut on the inside surface of the cylinder. An external gear sits in the internal gear, and the gears rotate in the same direction. Because the shafts are positioned closer together, internal gear assemblies are smaller sized than external equipment assemblies. Internal gears are primarily used for planetary gear drives.
Spur gears are generally viewed as best for applications that want speed reduction and torque multiplication, such as ball mills and crushing equipment. Examples of high- velocity applications that use spur gears – despite their high noise amounts – include consumer home appliances such as washers and blenders. And while noise limits the usage of spur gears in passenger automobiles, they are often used in aircraft engines, trains, and even bicycles.

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