Planetary Gear Reduction

Many “gears” are used for automobiles, however they are also utilized for many various other machines. The most frequent one is the “tranny” that conveys the energy of engine to tires. There are broadly two functions the transmission of a car plays : one can be to decelerate the high rotation rate emitted by the engine to transmit to tires; the additional 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 driving amounts to 1 1,000 – 4,000 rotations per minute (17 – 67 per second). Since it is difficult to rotate tires with the same rotation speed to perform, it is necessary to lessen the rotation speed using the ratio of the amount of gear teeth. Such a role is called deceleration; the ratio of the rotation velocity 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 ? This is because substances need a large force to begin moving however they do not require such a big force to excersice once they have started to move. Automobile can be cited as a good example. An engine, nevertheless, by its nature can’t so finely alter its output. As a result, one adjusts its output by changing the decrease ratio utilizing a transmission.
The transmission of motive power through gears quite definitely resembles the principle of leverage (a lever). The ratio of the number of tooth of gears meshing with each other can be deemed as the ratio of the length of levers’ arms. That’s, if the reduction ratio is huge and the rotation velocity as output is lower in comparison compared to that as insight, the energy output by transmission (torque) will be large; if the rotation swiftness as output isn’t so lower in comparison to that as input, however, the energy output by tranny (torque) will be little. Thus, to improve the decrease ratio utilizing transmitting is much akin to the theory of moving things.
After that, how does a tranny modify the reduction ratio ? The answer lies in the mechanism called a planetary gear mechanism.
A planetary gear system is a gear mechanism consisting of 4 components, namely, sun gear A, several world gears B, internal equipment C and carrier D that connects planet gears as observed in the graph below. It has a very complex structure rendering its style or production most difficult; it can understand the high decrease ratio through gears, however, it is a mechanism suitable for a reduction system that Planetary Gear Reduction requires both small size and powerful such as transmission for automobiles.
In a planetary gearbox, many teeth are engaged at once, that allows high speed decrease to be achieved with fairly small gears and lower inertia reflected back again to the engine. Having multiple teeth share the load also allows planetary gears to transmit high degrees of torque. The combination of compact size, huge speed reduction and high 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 far more expensive solution than additional gearbox types. And precision production 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, leading to premature wear and failing. Also, the small footprint of planetary gears makes heat dissipation more difficult, so applications that run at 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 one another, although manufacturers provide right-angle designs that include other gear sets (often bevel gears with helical the teeth) to supply 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 is dependent on the drive configuration.
2 Max input speed linked to ratio and max result 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 electric 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 powerful, 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 are available in nine sizes with decrease ratios from 3:1 to 600:1 and output torque capacities up to 16,227 lb.ft. The output could 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 can be found. Right-angle and insight shaft versions of these reducers are also offered.
Typical applications for these reducers include precision rotary axis drives, traveling gantries & columns, material handling axis drives and electronic line shafting. Industries served include Material Managing, Automation, Aerospace, Machine Tool and Robotics.
Unit Design &
Construction
Gearing: Featuring case-hardened & surface gearing with minimal wear, low backlash and low noise, making them the the majority of accurate and efficient planetaries offered. Standard planetary design has three planet gears, with a higher torque edition using four planets also available, please see the Reducers with Result Flange chart on the Unit Ratings tab under the “+” unit sizes.
Bearings: Optional result bearing configurations for app particular radial load, axial load and tilting moment reinforcement. Oversized tapered roller bearings are regular for the ISO Flanged Reducers.
Housing: Single piece metal housing with integral band gear provides greater concentricity and remove speed fluctuations. The casing can be installed with a ventilation module to improve insight speeds and lower operational temperature ranges.
Output: Available in a good shaft with optional keyway or an ISO 9409-1 flanged interface. We offer a wide range of standard pinions to mount right to the output style of your choice.
Unit Selection
These reducers are typically selected predicated on the peak cycle forces, which usually happen during accelerations and decelerations. These cycle forces depend on the powered load, the swiftness 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 very best solution for your application.
Ever-Power Automation’s Gearbox product lines 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 are available in sizes from 40mm to 180mm, perfect for motors which range from NEMA 17 to NEMA 42 and bigger. The Spur Gearbox series offers an efficient, cost-effective option appropriate for Ever-Power Automation’s AC Induction Gear Motors. Ever-Power Automation’s Gearboxes can be found in up to 30 different equipment ratios, with torque rankings up to 10,488 in-lbs (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 superb 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 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 mounting 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 certainly are a type of cylindrical gear, with shafts that are parallel and coplanar, and tooth that are directly and oriented parallel to the shafts. They’re arguably the easiest and most common type of gear – easy to manufacture and suitable for an array of applications.
One’s tooth of a spur gear ‘ve got an involute profile and mesh one particular tooth at the same time. The involute type implies that spur gears just generate radial forces (no axial forces), nevertheless the approach to tooth meshing causes high pressure on the gear the teeth and high sound creation. For this reason, spur gears are usually used for lower swiftness applications, although they could be utilized at nearly every speed.
An involute devices tooth carries a profile this is the involute of a circle, which means that since two gears mesh, they get in touch with at a person point where in fact the involutes fulfill. This aspect movements 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 bottom circles. Hence, the gears adhere 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 be produced from metals such as for example steel or brass, or from plastics such as nylon or polycarbonate. Gears produced 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 due to slippage, therefore they often times have high transmission functionality. Multiple spur gears can be utilized in series ( referred to as a equipment teach ) to realize large reduction ratios.
There are two primary types of spur gears: external and internal. Exterior gears possess the teeth that are cut externally surface area of the cylinder. Two external gears mesh with one another and rotate in opposite directions. Internal gears, in contrast, have tooth that are cut inside surface area of the cylinder. An external gear sits in the internal gear, and the gears rotate in the same direction. Because the shafts sit closer together, internal gear assemblies are more compact than external equipment 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 ball mills and crushing gear. Types of high- velocity applications that make use of spur gears – despite their high noise levels – include consumer home appliances such as washers and blenders. Even though noise limits the usage of spur gears in passenger automobiles, they are often found in aircraft engines, trains, and even bicycles.