planetary gear reduction

Many “gears” are utilized for automobiles, but they are also utilized for many other machines. The most typical one is the “transmission” 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 velocity emitted by the engine to transmit to tires; the other is to change the reduction ratio in accordance with the acceleration / deceleration or driving speed of an automobile.
The rotation speed of an automobile’s engine in the overall state of driving amounts to 1 1,000 – 4,000 rotations per minute (17 – 67 per second). Because it is difficult to rotate tires with the same rotation swiftness to perform, it is necessary to lessen the rotation speed utilizing the ratio of the amount of gear teeth. Such a role is named deceleration; the ratio of the rotation velocity of engine and that of tires is called the reduction ratio.
Then, why is it necessary to modify the reduction ratio relative to the acceleration / deceleration or driving speed ? This is because substances require a large force to begin moving however they usually do not require such a large force to keep moving once they have began to move. Automobile could be cited as an example. An engine, however, by its nature can’t so finely modify its output. For that reason, 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 amount of tooth of gears meshing with one another can be considered 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 to that as input, the power output by tranny (torque) will be huge; if the rotation rate as output isn’t so low in comparison to that as insight, on the other hand, the power output by transmitting (torque) will be small. Thus, to change the decrease ratio utilizing transmitting is much akin to the theory of moving things.
Then, how does a transmission modify the reduction ratio ? The answer lies in the mechanism called a planetary equipment mechanism.
A planetary gear mechanism is a gear system consisting of 4 components, namely, sun gear A, several world gears B, internal gear C and carrier D that connects world gears as seen in the graph below. It includes a very complex framework rendering its design or production most challenging; it can realize the high decrease 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 engaged at once, which allows high speed decrease to be performed with fairly 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 mixture of compact size, huge speed decrease and high torque transmitting makes planetary gearboxes a popular choice for space-constrained applications.
But planetary gearboxes do involve some disadvantages. Their complexity in design and manufacturing tends to make them a more expensive option than various other gearbox types. And precision production is really important for these gearboxes. If one planetary gear is positioned closer to the sun gear than the others, imbalances in the planetary gears may appear, resulting in premature wear and failure. Also, the small footprint of planetary gears makes high temperature dissipation more difficult, so applications that operate at high speed or encounter continuous operation may require cooling.
When using a “standard” (i.electronic. inline) planetary gearbox, the motor and the driven equipment must be inline with one another, although manufacturers offer right-angle designs that integrate other gear sets (often bevel gears with helical tooth) 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 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 electric motor input SAE C or D hydraulic
Precision Planetary Reducers
This standard range of Precision Planetary Reducers are perfect 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 tight integration of the motor to the unit. Design features include installation any servo motors, regular low backlash, high torsional stiffness, 95 to 97% efficiency and silent 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 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 insight shaft versions of the reducers are also offered.
Common 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, planetary gear reduction Automation, Aerospace, Machine Tool and Robotics.
Unit Design &
Construction
Gearing: Featuring case-hardened & surface 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 offered, please start to see the Reducers with Output Flange chart on the Unit Ratings tab beneath the “+” unit sizes.
Bearings: Optional result bearing configurations for program particular radial load, axial load and tilting moment reinforcement. Oversized tapered roller bearings are standard for the ISO Flanged Reducers.
Housing: Single piece metal housing with integral ring gear provides higher concentricity and eliminate speed fluctuations. The casing can be installed with a ventilation module to increase insight speeds and lower operational temperature ranges.
Result: Available in a solid shaft with optional keyway or an ISO 9409-1 flanged interface. We offer an array of standard pinions to mount directly to the output design 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 driven load, the acceleration vs. time profile for the routine, and any other external forces functioning on the axis.
For application & selection assistance, please call, fax or email us. Your 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 at affordable prices! The Planetary Gearbox product offering includes both In-Line and Right-Position 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 which range from NEMA 17 to NEMA 42 and larger. The Spur Gearbox line offers an efficient, cost-effective option 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-lbs (167,808 oz-in), and are compatible with most Servo,
SureGear Planetary Gearboxes for Small 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 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 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
Various 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 easiest and most common type of gear – simple to manufacture and suitable for an array of applications.
One’s teeth of a spur gear have got an involute profile and mesh 1 tooth simultaneously. The involute type implies that spur gears simply generate radial forces (no axial forces), nevertheless the method of tooth meshing causes high pressure on the gear the teeth and high noise creation. Because of this, spur gears are often utilized for lower swiftness applications, although they can be utilized at nearly every speed.
An involute tools 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 the involutes fulfill. This aspect motions along the tooth areas as the gears rotate, and the kind of force ( referred to as the line of activities ) is usually tangent to both base circles. Hence, the gears adhere to the fundamental regulation of gearing, which claims that the ratio of the gears’ angular velocities must stay continuous throughout the mesh.
Spur gears could possibly be produced from metals such as metallic or brass, or from plastics such as nylon or polycarbonate. Gears manufactured from plastic produce less audio, but at the trouble of power and loading capacity. Unlike other devices types, spur gears don’t encounter high losses because of slippage, so they often times have high transmission functionality. Multiple spur gears can be utilized in series ( referred to as a gear teach ) to attain 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 exterior gears mesh with each other and rotate in reverse directions. Internal gears, in contrast, have teeth that are cut inside surface of the cylinder. An exterior gear sits within the internal equipment, and the gears rotate in the same path. Because the shafts are positioned closer together, internal equipment assemblies are more compact than external equipment 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 gear. Examples of high- velocity applications that make use of spur gears – despite their high noise amounts – include consumer home 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.