Planetary Gear Reduction

Many “gears” are used for automobiles, however they are also used for many other machines. The most typical one may be the “tranny” that conveys the power of engine to tires. There are broadly two roles the transmission of a car plays : one is to decelerate the high rotation rate emitted by the engine to transmit to tires; the additional is to change the reduction ratio relative to the acceleration / deceleration or generating speed of a car.
The rotation speed of an automobile’s engine in the overall state of driving amounts to at least one 1,000 – 4,000 rotations each and every minute (17 – 67 per second). Because it is difficult to rotate tires with the same rotation acceleration to perform, it is required 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 rate of engine and that of tires is named the reduction ratio.
Then, exactly why is it necessary to change the reduction ratio relative to the acceleration / deceleration or driving speed ? The reason being substances need a large force to start moving however they usually do not require such a sizable force to excersice once they have started to move. Automobile can be cited as a good example. An engine, nevertheless, by its character can’t so finely alter its output. As a result, one adjusts its result 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 amount of teeth of gears meshing with each other can be considered as the ratio of the length of levers’ arms. That is, if the reduction ratio is large and the rotation rate as output is lower in comparison to that as insight, the power output by tranny (torque) will be huge; if the rotation swiftness as output is not so low in comparison to that as input, however, the energy output by tranny (torque) will be small. Thus, to change the reduction ratio utilizing transmission is much akin to the basic principle of moving things.
After that, how does a transmission modify the reduction ratio ? The answer is based on the system called a planetary gear mechanism.
A planetary gear mechanism is a gear mechanism consisting of 4 components, namely, sunlight gear A, several world gears B, internal equipment C and carrier D that connects planet gears as seen in the graph below. It has a very complex framework rendering its design or production most difficult; it can understand the high reduction ratio through gears, however, it is a mechanism suitable for a reduction system that requires both small size and powerful such as for Planetary Gear Reduction example transmission for automobiles.
In a planetary gearbox, many teeth are engaged at once, that allows high speed reduction to be performed with relatively small gears and lower inertia reflected back again to the motor. Having multiple teeth discuss the load also allows planetary gears to transmit high degrees of torque. The combination of compact size, huge speed reduction and high torque tranny makes planetary gearboxes a favorite 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 remedy than various other gearbox types. And precision manufacturing is extremely important for these gearboxes. If one planetary equipment is put closer to the sun gear than the others, imbalances in the planetary gears may appear, resulting in premature wear and failing. Also, the compact footprint of planetary gears makes warmth dissipation more difficult, so applications that run at very high speed or experience continuous operation may require cooling.
When using a “standard” (i.electronic. inline) planetary gearbox, the motor and the driven equipment must be inline with each other, although manufacturers offer right-angle designs that include other gear sets (often bevel gears with helical the 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 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 motor input SAE C or D hydraulic
Precision Planetary Reducers
This standard selection of Precision Planetary Reducers are ideal for use in applications that demand high performance, precise positioning and repeatability. They were specifically developed for use with state-of-the-art servo motor technology, providing limited integration of the electric motor to the unit. Design features include installation any servo motors, regular low backlash, high torsional stiffness, 95 to 97% efficiency and calm running.
They are available in nine sizes with reduction 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 mounting to rotary or indexing tables, pinion gears, pulleys or other drive components with no need for a coupling. For high precision applications, backlash amounts right down to 1 arc-minute can be found. Right-angle and insight shaft versions of the reducers are also available.
Standard applications for these reducers include precision rotary axis drives, traveling gantries & columns, material 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 & floor gearing with minimal wear, low backlash and low sound, making them the most accurate and efficient planetaries offered. Standard planetary style has three planet gears, with a higher 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 moment reinforcement. Oversized tapered roller bearings are regular for the ISO Flanged Reducers.
Housing: Single piece steel housing with integral band gear provides higher concentricity and remove speed fluctuations. The casing can be installed with a ventilation module to improve 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 a wide selection of standard pinions to attach right 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 cycle, and any other exterior forces acting on the axis.
For application & selection assistance, please call, fax or email us. Your application details will be examined by our engineers, who’ll recommend the very best solution for the application.
Ever-Power Automation’s Gearbox products offer high precision at affordable prices! The Planetary Gearbox item offering includes both In-Line and Right-Angle configurations, built with the design goal of offering a cost-effective gearbox, without sacrificing quality. These Planetary Gearboxes are available in sizes from 40mm to 180mm, well suited for motors ranging from NEMA 17 to NEMA 42 and larger. 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 are offered in up to 30 different equipment ratios, with torque ratings up to 10,488 in-lbs (167,808 oz-in), and are compatible with most Servo,
SureGear Planetary Gearboxes for Little Ever-Power Motors
The SureGear PGCN series is a superb gearbox value for servo, stepper, and other movement control applications requiring a NEMA size input/output interface. It provides the best quality available for the price point.
Features
Wide variety of ratios (5, 10, 25, 50, and 100:1)
Low backlash of 30 arc-min or less
20,000 hour service life
Free of maintenance; 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 certainly are a type of cylindrical equipment, 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 suitable for an array of applications.
One’s the teeth of a spur gear ‘ve got an involute profile and mesh one tooth simultaneously. The involute type means that spur gears just generate radial forces (no axial forces), however the method of tooth meshing causes high pressure on the gear one’s teeth and high sound creation. For this reason, spur gears are usually used for lower swiftness applications, although they could be utilized at almost every speed.
An involute apparatus tooth carries a profile this is actually the involute of a circle, which implies that since two gears mesh, they speak to at a person point where the involutes meet. This aspect movements along the tooth areas as the gears rotate, and the kind of force ( referred to as the line of actions ) is usually tangent to both base circles. Hence, the gears adhere to the fundamental regulation of gearing, which statements that the ratio of the gears’ angular velocities must stay continuous throughout the mesh.
Spur gears could be produced from metals such as steel or brass, or from plastics such as for example nylon or polycarbonate. Gears manufactured from plastic produce less sound, but at the difficulty of power and loading capability. Unlike other products types, spur gears don’t encounter high losses because of slippage, so they often have high transmission performance. Multiple spur gears can be utilized in series ( referred to as a equipment teach ) to attain 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 external gears mesh with each other and rotate in opposite directions. Internal gears, in contrast, have tooth that are cut inside surface area of the cylinder. An external gear sits inside the internal gear, and the gears rotate in the same path. Because the shafts are positioned closer together, internal gear assemblies are more compact than external gear assemblies. Internal gears are primarily used for planetary gear drives.
Spur gears are usually viewed as best for applications that require speed decrease and torque multiplication, such as for example ball mills and crushing gear. Types of high- velocity applications that use spur gears – despite their high noise amounts – include consumer appliances such as washers and blenders. And while noise limits the usage of spur gears in passenger automobiles, they are often found in aircraft engines, trains, and even bicycles.