planetary gear reduction

Many “gears” are used for automobiles, but they are also used for many other machines. The most typical one is the “transmitting” that conveys the power of engine to tires. There are broadly two functions the transmission of an automobile plays : one is certainly to decelerate the high rotation speed emitted by the engine to transmit to tires; the other is to change 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 overall state of traveling amounts to 1 1,000 – 4,000 rotations per minute (17 – 67 per second). Because it is difficult 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 swiftness of engine and that of wheels is called the reduction ratio.
Then, exactly why is it necessary to change the reduction ratio relative to the acceleration / deceleration or driving speed ? This is because substances require a large force to start moving however they do not require such a huge force to keep moving once they have began to move. Automobile can be cited as an example. An engine, nevertheless, by its character can’t so finely change its output. Therefore, one adjusts its output by changing the decrease ratio employing a transmission.
The transmission of motive power through gears very much resembles the principle of leverage (a lever). The ratio of the number of teeth of gears meshing with one another can be considered as the ratio of the space of levers’ arms. That’s, if the reduction ratio is huge and the rotation swiftness as output is low in comparison compared to that as insight, the energy output by tranny (torque) will be large; if the rotation velocity as output is not so lower in comparison to that as input, on the other hand, the energy output by tranny (torque) will be small. Thus, to improve the reduction ratio utilizing transmission is much comparable to the theory of moving things.
Then, how does a transmitting modify the reduction ratio ? The answer lies in the system called a planetary equipment mechanism.
A planetary gear mechanism is a gear system consisting of 4 components, namely, sun gear A, several world gears B, internal gear C and carrier D that connects planet gears as observed in the graph below. It has a very complex framework rendering its design or production most difficult; it can recognize the high reduction ratio through gears, nevertheless, it is a mechanism suitable for a reduction system that requires both small size and powerful such as transmission for automobiles.
In a planetary gearbox, many teeth are involved at once, that allows high speed reduction to be achieved with fairly small gears and lower inertia reflected back to the electric motor. Having multiple teeth share the load also enables planetary gears to transmit high levels of torque. The mixture of compact size, large speed decrease and high torque transmission makes planetary gearboxes a popular choice for space-constrained applications.
But planetary gearboxes do have some disadvantages. Their complexity in style and manufacturing can make them a far more expensive alternative than various other gearbox types. And precision manufacturing is really important for these gearboxes. If one planetary equipment is positioned closer to sunlight gear than the others, imbalances in the planetary gears may appear, resulting in premature wear and failing. Also, the small footprint of planetary gears makes heat dissipation more difficult, therefore applications that run at very high speed or encounter continuous procedure may require cooling.
When using a “standard” (i.electronic. inline) planetary gearbox, the motor and the powered equipment must be inline with each other, although manufacturers provide right-angle designs that integrate other gear sets (often bevel gears with helical tooth) to supply 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 is dependent on the drive configuration.
2 Max input speed linked 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 ideal for use in applications that demand powerful, precise positioning and repeatability. These were specifically developed for use with state-of-the-art servo electric motor technology, providing tight integration of the electric motor to the unit. Design features include mounting any servo motors, standard low backlash, high torsional stiffness, 95 to 97% efficiency and peaceful running.
They can be purchased in nine sizes with reduction 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 installation to rotary or indexing tables, pinion gears, pulleys or other drive components 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 the reducers are also obtainable.
Typical applications for these reducers include precision rotary axis drives, traveling gantries & columns, materials handling axis drives and digital line shafting. Industries offered include Material Handling, Automation, Aerospace, Machine Tool and Robotics.
Unit Design &
Construction
Gearing: Featuring case-hardened & surface planetary gear reduction gearing with minimal use, low backlash and low sound, making them the most accurate and efficient planetaries offered. Standard planetary style has three planet gears, with an increased torque edition using four planets also offered, please see the Reducers with Result Flange chart on the Unit Ratings tab under the “+” unit sizes.
Bearings: Optional output bearing configurations for app specific radial load, axial load and tilting moment 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 increase input speeds and lower operational temperature ranges.
Output: Available in a good shaft with optional keyway or an ISO 9409-1 flanged interface. We offer 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 usually happen during accelerations and decelerations. These cycle forces rely on the driven load, the rate vs. period profile for the routine, and any other exterior forces acting on the axis.
For application & selection assistance, please call, fax or email us. Your 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 in affordable prices! The Planetary Gearbox product offering includes both In-Line and Right-Position configurations, built with the look goal of supplying a cost-effective gearbox, without sacrificing quality. These Planetary Gearboxes are available in sizes from 40mm to 180mm, ideal for motors ranging from NEMA 17 to NEMA 42 and larger. The Spur Gearbox collection offers an efficient, cost-effective choice compatible with Ever-Power Automation’s AC Induction Gear Motors. Ever-Power Automation’s Gearboxes can be found in up to 30 different gear ratios, with torque rankings up to 10,488 in-lbs (167,808 oz-in), and are compatible with 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 provides 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 teeth that are straight and oriented parallel to the shafts. They’re arguably the simplest and most common kind of gear – easy to manufacture and ideal for a range of applications.
One’s teeth of a spur gear ‘ve got an involute profile and mesh one tooth simultaneously. The involute type implies that spur gears simply generate radial forces (no axial forces), however the approach to tooth meshing causes high pressure on the gear one’s teeth and high noise creation. Because of this, spur gears are usually utilized for lower swiftness applications, although they could be utilized at almost every speed.
An involute equipment tooth includes a profile this is the involute of a circle, which means that since two gears mesh, they speak to at an individual point where in fact the involutes meet. This aspect actions along the tooth areas as the gears rotate, and the kind of force ( referred to as the line of activities ) is tangent to both bottom circles. Therefore, the gears stick to the essential 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 for example metal or brass, or from plastics such as for example nylon or polycarbonate. Gears produced from plastic produce less sound, but at the trouble of power and loading capability. Unlike other tools types, spur gears don’t encounter high losses because of slippage, therefore they often have high transmission 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 the teeth that are cut externally surface of the cylinder. Two exterior gears mesh with each other and rotate in reverse directions. Internal gears, in contrast, have teeth that are cut inside surface of the cylinder. An external gear sits within the internal gear, and the gears rotate in the same path. Because the shafts are positioned closer together, internal gear assemblies are smaller sized than external gear assemblies. Internal gears are mainly used for planetary gear drives.
Spur gears are usually viewed as best for applications that require speed decrease and torque multiplication, such as ball mills and crushing equipment. Types of high- velocity applications that use spur gears – despite their high noise levels – include consumer devices such as washing machines and blenders. Even though noise limits the use of spur gears in passenger automobiles, they are generally used in aircraft engines, trains, and even bicycles.

TAGs:

Recent Posts