Planetary Gear Reduction

Many “gears” are utilized for automobiles, but they are also used for many various other machines. The most frequent one is the “transmitting” that conveys the energy 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 additional is to improve the reduction ratio relative to the acceleration / deceleration or driving speed of an automobile.
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 not possible to rotate tires with the same rotation acceleration to run, it is required to lower the rotation speed utilizing the ratio of the amount of gear teeth. Such a role is named deceleration; the ratio of the rotation quickness of engine and that of tires is named the reduction ratio.
Then, exactly why is it necessary to alter the reduction ratio in accordance with the acceleration / deceleration or driving speed ? It is because substances need a large force to start moving however they usually do not require this kind of a large force to excersice once they have started to move. Automobile could be cited as a good example. An engine, however, by its character can’t so finely modify its output. As a result, one adjusts its result 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 considered as the ratio of the length of levers’ arms. That is, if the decrease ratio is huge and the rotation quickness as output is low in comparison compared to that as input, the power output by transmission (torque) will be huge; if the rotation swiftness as output is not so low in comparison to that as insight, however, the energy output by tranny (torque) will be little. Thus, to change the decrease ratio utilizing transmitting is much akin to the theory of moving things.
After that, how does a transmitting modify the reduction ratio ? The answer is based on the system called a planetary gear mechanism.
A planetary gear system is a gear mechanism consisting of 4 components, namely, sunlight 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 style or production most challenging; it can understand the high reduction ratio through gears, nevertheless, it is a mechanism suited to 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 decrease to be performed with fairly small gears and lower inertia reflected back again to the electric motor. Having multiple teeth discuss the load also enables 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 do have some disadvantages. Their complexity in design and manufacturing can make them a far more expensive solution than additional gearbox types. And precision manufacturing is extremely important for these gearboxes. If one planetary gear 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 high temperature dissipation more difficult, therefore applications that operate at very high speed or encounter continuous procedure may require cooling.
When utilizing a “standard” (i.electronic. inline) planetary gearbox, the motor and the driven equipment should be inline with each other, although manufacturers provide right-angle designs that include other gear sets (often bevel gears with helical teeth) 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 placed 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 make use of with state-of-the-art servo electric motor technology, providing limited integration of the electric motor to the unit. Style features include installation any servo motors, standard 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 good 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 input shaft versions of the reducers are also obtainable.
Regular applications for these reducers include precision rotary axis drives, traveling gantries & columns, materials handling axis drives and digital line shafting. Industries served include Material Managing, Automation, Aerospace, Machine Tool and Robotics.
Unit Design &
Planetary Gear Reduction Construction
Gearing: Featuring case-hardened & ground gearing with minimal put on, low backlash and low sound, making them the many accurate and efficient planetaries obtainable. Standard planetary design has three planet gears, with a higher torque version using four planets also obtainable, please see the Reducers with Result 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 instant reinforcement. Oversized tapered roller bearings are standard for the ISO Flanged Reducers.
Housing: Single piece steel housing with integral band gear provides better concentricity and remove speed fluctuations. The housing can be fitted with a ventilation module to increase insight speeds and lower operational temperatures.
Output: Available in a solid shaft with optional keyway or an ISO 9409-1 flanged interface. You can expect a wide range of standard pinions to attach directly to the output design of your choice.
Unit Selection
These reducers are typically selected predicated on the peak cycle forces, which often happen during accelerations and decelerations. These cycle forces rely on the driven load, the speed vs. time profile for the routine, and any other external forces acting on the axis.
For application & selection assistance, please call, fax or email us. Your application info will be reviewed by our engineers, who’ll recommend the 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 look goal of supplying a cost-effective gearbox, without sacrificing quality. These Planetary Gearboxes can be found in sizes from 40mm to 180mm, ideal for motors ranging from NEMA 17 to NEMA 42 and bigger. The Spur Gearbox range 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 ratings 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 great gearbox value for servo, stepper, and other motion 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
Additional 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 easiest and most common type of gear – simple to manufacture and ideal for an array of applications.
One’s tooth of a spur gear ‘ve got an involute profile and mesh a single tooth at the same time. The involute type means that spur gears just generate radial forces (no axial forces), however the method of tooth meshing causes ruthless on the gear the teeth and high sound creation. For this reason, spur gears are often used for lower swiftness applications, although they can be utilized at almost every speed.
An involute products tooth carries a profile this is actually 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 actions along the tooth areas as the gears rotate, and the kind of force ( referred to as the line of actions ) can be 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 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 audio, but at the difficulty of power and loading capability. Unlike other tools types, spur gears don’t encounter high losses due to slippage, so they often times have high transmission efficiency. Multiple spur gears can be utilized in series ( referred to as a equipment 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 external gears mesh with one another and rotate in opposite directions. Internal gears, in contrast, have the teeth that are cut inside surface area of the cylinder. An exterior gear sits within the internal equipment, and the gears rotate in the same direction. Because the shafts sit closer together, internal equipment assemblies are more compact than external gear assemblies. Internal gears are mainly used for planetary gear drives.
Spur gears are generally 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 make use of spur gears – despite their high noise amounts – include consumer home appliances such as washers 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.