planetary gear reduction

Many “gears” are used for automobiles, but they are also utilized for many additional machines. The most frequent one may be the “transmission” that conveys the power of engine to tires. There are broadly two roles the transmission of a car plays : one is definitely to decelerate the high rotation acceleration emitted by the engine to transmit to tires; the various other is to improve the reduction ratio relative to the acceleration / deceleration or generating speed of a car.
The rotation speed of an automobile’s engine in the general state of generating amounts to 1 1,000 – 4,000 rotations per minute (17 – 67 per second). Because it is unattainable to rotate tires with the same rotation speed to perform, it is necessary to lessen 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 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 begin moving however they do not require this kind of a sizable 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 change its output. For that reason, one adjusts its result by changing the reduction ratio utilizing 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 considered as the ratio of the distance of planetary gear reduction levers’ arms. That’s, if the decrease ratio is huge and the rotation speed as output is lower in comparison compared to that as insight, the energy output by transmitting (torque) will be huge; if the rotation speed as output isn’t so low in comparison to that as insight, however, the power output by transmitting (torque) will be little. Thus, to improve the reduction ratio utilizing transmitting is much comparable to the theory of moving things.
After that, how does a transmission change the reduction ratio ? The answer lies in the mechanism called a planetary gear mechanism.
A planetary gear system is a gear mechanism comprising 4 components, namely, sun gear A, several world gears B, internal equipment C and carrier D that connects world gears as observed in the graph below. It includes a very complex structure rendering its design or production most difficult; it can understand the high reduction ratio through gears, nevertheless, it really is a mechanism suitable for a reduction mechanism that requires both small size and high performance such as for example transmission for automobiles.
In a planetary gearbox, many teeth are involved at once, which allows high speed reduction to be achieved with relatively small gears and lower inertia reflected back again to the electric motor. Having multiple teeth reveal the load also allows planetary gears to transmit high levels of torque. The combination of compact size, large speed reduction and high torque transmitting makes planetary gearboxes a favorite choice for space-constrained applications.
But planetary gearboxes perform have some disadvantages. Their complexity in style and manufacturing can make them a far more expensive solution than other gearbox types. And precision production 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, leading to premature wear and failure. Also, the small footprint of planetary gears makes heat dissipation more difficult, so 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 one another, although manufacturers offer right-angle designs that integrate other gear sets (frequently bevel gears with helical tooth) 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 engine input SAE C or D hydraulic
Precision Planetary Reducers
This standard selection 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 engine technology, providing limited integration of the electric motor to the unit. Design features include installation any servo motors, standard low backlash, high torsional stiffness, 95 to 97% efficiency and noiseless 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 could be provided with a good shaft or ISO 9409-1 flange, for mounting to rotary or indexing tables, pinion gears, pulleys or other drive elements without the need for a coupling. For high precision applications, backlash levels down to 1 arc-minute are available. Right-angle and input shaft versions of these reducers are also offered.
Usual applications for these reducers include precision rotary axis drives, traveling gantries & columns, materials handling axis drives and electronic line shafting. Industries served include Material Handling, Automation, Aerospace, Machine Tool and Robotics.
Unit Design &
Construction
Gearing: Featuring case-hardened & ground gearing with minimal use, low backlash and low noise, making them the many accurate and efficient planetaries obtainable. Standard planetary design has three planet gears, with an increased torque version using four planets also available, please start to 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 minute reinforcement. Oversized tapered roller bearings are regular for the ISO Flanged Reducers.
Housing: Single piece steel housing with integral ring gear provides higher concentricity and eliminate speed fluctuations. The housing can be installed with a ventilation module to increase input speeds and lower operational temperatures.
Result: Available in a good shaft with optional keyway or an ISO 9409-1 flanged interface. We offer a wide variety of standard pinions to install right to the output design of your choice.
Unit Selection
These reducers are usually selected based on the peak cycle forces, which often happen during accelerations and decelerations. These routine forces rely on the powered load, the velocity vs. time profile for the routine, and any other exterior forces acting on the axis.
For application & selection assistance, please call, fax or email us. The application details will be reviewed by our engineers, who’ll 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 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, ideal for motors which range from NEMA 17 to NEMA 42 and bigger. The Spur Gearbox range 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 rankings up to 10,488 in-pounds (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 superb gearbox value for servo, stepper, and other movement control applications requiring a NEMA size input/output interface. It includes 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 designed 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 certainly are a type of cylindrical gear, with shafts that are parallel and coplanar, and the 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 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), nevertheless the approach to tooth meshing causes ruthless on the gear one’s 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 equipment tooth carries a profile this is actually the involute of a circle, which implies that since two gears mesh, they get in touch with at an individual point where the involutes satisfy. This aspect actions along the tooth areas as the gears rotate, and the kind of force ( known as the line of activities ) can be tangent to both bottom 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 metal or brass, or from plastics such as nylon or polycarbonate. Gears manufactured from plastic produce less audio, but at the difficulty of power and loading capacity. Unlike other apparatus types, spur gears don’t encounter high losses due to slippage, therefore they often have high transmission functionality. Multiple spur gears can be employed 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 have the teeth that are cut externally surface area of the cylinder. Two external gears mesh with one another and rotate in reverse directions. Internal gears, on the other hand, have teeth that are cut inside surface area of the cylinder. An exterior gear sits in the internal equipment, and the gears rotate in the same direction. Because the shafts are positioned closer together, internal gear assemblies are more compact than external gear assemblies. Internal gears are mainly used for planetary equipment drives.
Spur gears are usually seen as best for applications that require speed reduction and torque multiplication, such as for example ball mills and crushing equipment. Examples of high- velocity applications that use spur gears – despite their high noise levels – include consumer appliances such as washers and blenders. Even though noise limits the use of spur gears in passenger automobiles, they are often used in aircraft engines, trains, and even bicycles.