Planetary Gear Reduction

Many “gears” are utilized for automobiles, but they are also utilized for many additional machines. The most frequent one may be the “tranny” that conveys the energy of engine to tires. There are broadly two roles the transmission of an automobile plays : one is definitely to decelerate the high rotation acceleration emitted by the engine to transmit to tires; the various other is to change the reduction ratio in accordance with the acceleration / deceleration or generating speed of a car.
The rotation speed of an automobile’s engine in the general state of traveling amounts to at least one 1,000 – 4,000 rotations per minute (17 – 67 per second). Because it is not possible to rotate tires with the same rotation velocity to run, it is necessary to lower the rotation speed utilizing the ratio of the number of gear teeth. Such a role is named deceleration; the ratio of the rotation velocity of engine and that of tires is named the reduction ratio.
Then, why is it necessary to modify the reduction ratio in accordance with the acceleration / deceleration or driving speed ? The reason being substances need a large force to begin moving however they usually do not require such a large force to excersice once they have started to move. Automobile can be cited as an example. An engine, nevertheless, by its nature can’t so finely modify 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 amount of the teeth of gears meshing with one another can be deemed as the ratio of the space of levers’ arms. That’s, if the reduction ratio is large and the rotation velocity as output is lower in comparison compared to that as insight, the energy output by transmitting (torque) will be huge; if the rotation quickness as output is not so low in comparison to that as insight, however, the power output by tranny (torque) will be small. Thus, to improve the reduction ratio utilizing transmitting is much comparable to the principle of moving things.
Then, how does a transmission alter the reduction ratio ? The answer is based on the system called a planetary equipment mechanism.
A planetary gear system is a gear mechanism consisting of 4 components, namely, sun gear A, several planet gears B, internal equipment C and carrier D that connects planet gears as observed in the graph below. It includes a very complex framework rendering its style or production most challenging; it can understand the high reduction ratio through gears, nevertheless, it really is a mechanism suitable for a reduction system that requires both little size and powerful such as for example transmission for automobiles.
In a planetary gearbox, many teeth are engaged at once, that allows high speed decrease to be achieved with relatively small gears and lower inertia reflected back again to the motor. Having multiple teeth discuss the load also enables planetary gears to transmit high levels of torque. The mixture of compact size, large speed reduction and high Planetary Gear Reduction torque transmitting makes planetary gearboxes a favorite choice for space-constrained applications.
But planetary gearboxes perform involve some disadvantages. Their complexity in style and manufacturing can make them a more expensive option than other gearbox types. And precision manufacturing is extremely important for these gearboxes. If one planetary gear is put closer to sunlight gear than the others, imbalances in the planetary gears can occur, leading to premature wear and failing. Also, the compact footprint of planetary gears makes heat dissipation more difficult, so applications that operate at very high speed or experience continuous operation may require cooling.
When using a “standard” (i.electronic. inline) planetary gearbox, the motor and the powered equipment should be inline with one another, although manufacturers offer right-angle designs that integrate other gear sets (frequently 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 linked to ratio and max result speed
3 Max radial load positioned at optimum load position
4 Weight varies with configuration and ratio selected
5 Requires tapered roller planet bearings (unavailable 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 perfect for use in applications that demand high performance, precise positioning and repeatability. These were specifically developed for make use of with state-of-the-art servo motor technology, providing restricted integration of the electric motor to the unit. Design features include mounting any servo motors, regular low backlash, high torsional stiffness, 95 to 97% efficiency and quiet 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 installation 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 are available. Right-angle and insight shaft versions of the reducers are also offered.
Common applications for these reducers include precision rotary axis drives, traveling gantries & columns, material handling axis drives and digital line shafting. Industries served 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 noise, making them the many accurate and efficient planetaries available. Standard planetary style has three planet gears, with a higher torque edition using four planets also offered, please see the Reducers with Output Flange chart on the Unit Ratings tab under the “+” unit sizes.
Bearings: Optional result bearing configurations for program specific radial load, axial load and tilting moment reinforcement. Oversized tapered roller bearings are standard for the ISO Flanged Reducers.
Housing: Single piece steel housing with integral ring gear provides higher concentricity and remove speed fluctuations. The casing can be fitted with a ventilation module to improve insight speeds and lower operational temperature ranges.
Output: Available in a solid shaft with optional keyway or an ISO 9409-1 flanged interface. We offer an array of standard pinions to attach right to the output design of your choice.
Unit Selection
These reducers are typically selected based on the peak cycle forces, which usually happen during accelerations and decelerations. These routine forces depend on the driven load, the rate vs. time profile for the cycle, and any other external forces functioning 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 in 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, ideal for motors which range from NEMA 17 to NEMA 42 and larger. The Spur Gearbox range provides 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 gear ratios, with torque rankings up to 10,488 in-pounds (167,808 oz-in), and so 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 movement control applications requiring a NEMA size input/output interface. It includes 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
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 gear, 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 type of gear – simple to manufacture and suitable for an array of applications.
One’s tooth of a spur gear have got an involute profile and mesh 1 tooth at the same time. The involute type means that spur gears just generate radial forces (no axial forces), nevertheless the method of tooth meshing causes high pressure on the gear the teeth and high sound creation. For this reason, spur gears are usually utilized for lower swiftness applications, although they could be utilized at nearly 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 an individual point where the involutes satisfy. This aspect motions along the tooth areas as the gears rotate, and the type of force ( referred to as the line of activities ) is definitely tangent to both foundation circles. Hence, the gears adhere to the essential regulation of gearing, which promises 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 steel or brass, or from plastics such as for example nylon or polycarbonate. Gears manufactured from plastic produce less audio, but at the difficulty of power and loading capacity. Unlike other tools types, spur gears don’t encounter high losses because of slippage, therefore they often have high transmission efficiency. Multiple spur gears can be employed in series ( known as a gear teach ) to attain large reduction ratios.
There are two primary types of spur gears: external and internal. Exterior gears have got one’s teeth that are cut externally surface of the cylinder. Two exterior gears mesh with one another and rotate in reverse directions. Internal gears, in contrast, have tooth that are cut on the inside surface area of the cylinder. An external gear sits within the internal equipment, and the gears rotate in the same path. Because the shafts sit closer together, internal equipment assemblies are smaller sized than external gear assemblies. Internal gears are mainly used for planetary equipment drives.
Spur gears are usually viewed as best for applications that want speed decrease and torque multiplication, such as for example ball mills and crushing gear. Types of high- velocity applications that make use of spur gears – despite their high noise levels – include consumer appliances such as washers 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.